Статті в журналах: "High-vacuum environment"

1

Shiina, Takahiro, Takashi Nakamura, and Hiroyuki Oguma. "OS11W0355 Effects of high vacuum environment on high cycle fatigue properties of Ti-6Al-4V alloy." Abstracts of ATEM : International Conference on Advanced Technology in Experimental Mechanics : Asian Conference on Experimental Mechanics 2003.2 (2003): _OS11W0355. http://dx.doi.org/10.1299/jsmeatem.2003.2._os11w0355.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Sabulsky, D. O., X. Zou, J. Junca, A. Bertoldi, M. Prevedelli, Q. Beaufils, R. Geiger, et al. "Reaching ultra-high vacuum for a large vacuum vessel in an underground environment." E3S Web of Conferences 357 (2022): 05001. http://dx.doi.org/10.1051/e3sconf/202235705001.

Повний текст джерела

Анотація:

Located far from anthropical disturbances and with low seismic and magnetic background noise profiles, the LSBB facility is the ideal location for a new hybrid detector for the study of space-time strain. The MIGA infrastructure [1], utilizes an array of atom interferometers manipulated by the same beam, the resonant optical field of a 150 m long optical cavity. The infrastructure constitutes a new method for geophysics, for the characterization of spatial and temporal variations of the local gravity, and is a demonstrator for future decihertz gravitational wave observation. Such an infrastructure requires ultra-high vacuum (10−9 mbar) on a size (150 m) and scale (36 m3) not typically seen in underground laboratories other than CERN [2], and especially in underground environments with high humidity (up to 100%) and significant dust contamination (milimetric to micrometric porous rock particles). Here, we detail the status of the MIGA infrastructure and describe the ongoing generation and analysis of the vacuum works - this comes from tests of the prototype vacuum vessel, focusing on heating cycles, residual gas and heating analysis.

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Xie, Ke, Chang Jiang Song, Ke Feng Li, Liang Zhu, and Qi Jie Zhai. "The Magnetic Properties of Fe-6.5wt.%Si Alloy Powders Produced by High Pressure Gas Atomization." Advanced Materials Research 800 (September 2013): 302–7. http://dx.doi.org/10.4028/www.scientific.net/amr.800.302.

Повний текст джерела

Анотація:

The soft magnetic properties of Fe-6.5wt.%Si alloy powders produced via high pressure gas atomization under different powder sizes, environments (atmospheric and vacuum) and heat-treatment were presented by vibrating sample magnetometer (VSM), respectively. It is found that the soft magnetic properties of powder gradually grow up as the increasing of the powder size under atmospheric and vacuum environments. However, the using of vacuum environment has an optimal capacity to strengthening the properties rather than atmospheric environment. The heat-treatment of 1000°C for 2 hours offers considerable potential for improving the soft magnetic properties of the powders.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Bai, Yizhou, Jibin Pu, Haixin Wang, Liping Wang, Qunji Xue, and Shuan Liu. "High humidity and high vacuum environment performance of MoS2/Sn composite film." Journal of Alloys and Compounds 800 (September 2019): 107–15. http://dx.doi.org/10.1016/j.jallcom.2019.06.038.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Engel, Thomas, and Donald Braid. "High‐speed motor for use in an ultrahigh‐vacuum environment." Review of Scientific Instruments 56, no. 8 (August 1985): 1668–69. http://dx.doi.org/10.1063/1.1138123.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Tenholte, D., S. Kurth, T. Geßner, and W. Dötzel. "A MEMS friction vacuum gauge suitable for high temperature environment." Sensors and Actuators A: Physical 142, no. 1 (March 2008): 166–72. http://dx.doi.org/10.1016/j.sna.2007.05.031.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Totolin, Vladimir, Marcello Conte, Edurne Berriozábal, Francesco Pagano, Ichiro Minami, Nicole Dörr, Josef Brenner, and Amaya Igartua. "Tribological investigations of ionic liquids in ultra-high vacuum environment." Lubrication Science 26, no. 7-8 (February 15, 2013): 514–24. http://dx.doi.org/10.1002/ls.1224.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Kim, Wan-Soo, Dong-Jin Lee, and Sun-Kyu Lee. "Nano-Positioning of High-Power Ultrasonic Linear Motor Stage in High-Vacuum Environment." Transactions of the Korean Society of Mechanical Engineers A 34, no. 11 (November 1, 2010): 1613–22. http://dx.doi.org/10.3795/ksme-a.2010.34.11.1613.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Mishra, Rajat, Himashu Sharma, and Harshit Mishra. "High-speed vacuum air vehicle." Transportation Systems and Technology 4, no. 3 suppl. 1 (November 19, 2018): 328–39. http://dx.doi.org/10.17816/transsyst201843s1328-339.

Повний текст джерела

Анотація:

Background: There are a number of problems in the prior art, those are topics of research inputs likes ranges of the drag force generated by the vehicle, lift force at high vehicle motion velocities for compensation of the vehicle weight, Aerodynamic aspects of operation of the vehicle, Aim: Stream wise stability of vehicle motion and levitation and breaking of the vehicles and supersonic speed is not achieved in any mode of transportation. But this present invention related to high speed magnetic levitating transportation. More particularly, present invention is related to high speed magnetic levitating transportation using compressed air chamber in the transportation vehicle. Methods: The present invention is more particularly related to high speed vehicle levitated on a vacuum tunnel by using electromagnetic levitation. As this vehicle will move from one place to another in a vacuum environment and this vehicle will levitate above track with the help of electromagnets. Results: The important thing is its motion, which is possible due to reaction force of high pressure air, coming out from compressed air chamber present in vehicle. Conclusion: It can give us the acceleration as per load requirement and it can achieve supersonic speed in few seconds.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Jin, Chenggang, Yongqi Zhang, Wenbin Ling, Manxing Liu, Peng E, Chunxi Chen, Yunxuan Li, Zhiyong Peng, Yaowen Lu, and Liyi Li. "Vacuum control system for the Space Plasma Environment Research Facility." Journal of Vacuum Science & Technology B 40, no. 3 (May 2022): 034201. http://dx.doi.org/10.1116/6.0001785.

Повний текст джерела

Анотація:

The Space Plasma Environment Research Facility (SPERF) is a ground simulation user facility for studying the space plasma physical processes. This study presents the design and construction of a vacuum control system for the SPERF to set up an appropriate vacuum environment for plasma experiments, including the terrestrial space and near space vacuum control systems. Based on the requirements of remote automation, distributed control, centralized management, high reliability, expansibility, and safety, the architecture of the vacuum control system has been divided into three levels. Among these, the local level is the most essential part of the control system, which adopts the programmable logical controller (PLC) with Siemens S7-1500 CPU as the core. The PLC supports multiple communication protocols and can accurately control and monitor the actuators in the process of establishing a vacuum environment. Furthermore, it has the ability to communicate and interact with remote upper computers and the central control system through the supervisory control and data acquisition (scada) software developed based on iFix. Based on the architecture of the vacuum control system, the control process for establishing the vacuum environment, including the ultimate vacuum and experimental vacuum, was designed. It is noteworthy that in experimental vacuum acquisition, the injection of working fluid gas is controlled directly by the central control system, considering the different requirements of the terrestrial space and near space systems for the experimental working pressure and flexibility of the experimental vacuum control. The vacuum control system designed in this study provides technical support for the SPERF to perform the plasma experiments successfully. In addition, it offers reference and insights for the design of vacuum control systems in similar large-scale plasma simulation facilities.

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Okubo, Hitoshi. "Technical Trend of Environment-friendly High Voltage Vacuum Circuit Breaker (VCB)." IEEJ Transactions on Power and Energy 123, no. 2 (2003): 129–32. http://dx.doi.org/10.1541/ieejpes.123.129.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Takahashi, H., K. Agari, E. Hirose, M. Ieiri, Y. Katoh, M. Minakawa, H. Noumi, et al. "Magnet Operation in Vacuum for High Radiation Environment Near Production Target." IEEE Transactions on Applied Superconductivity 16, no. 2 (June 2006): 1346–49. http://dx.doi.org/10.1109/tasc.2005.864315.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Barnes, Paul W. "MEMS Device Sealing in a High Vacuum Atmosphere Achieving Long Term Reliable Vacuum Levels." International Symposium on Microelectronics 2010, no. 1 (January 1, 2010): 000715–19. http://dx.doi.org/10.4071/isom-2010-wp5-paper5.

Повний текст джерела

Анотація:

Microeletromechanical Systems (MEMS) require encapsulation of delicate microelements in a controlled atmosphere or vacuum environment. In order to achieve proper device operation and protection from harsh environments, these packages must be hermetically sealed and the internal atmosphere must be maintained to prevent degradation of the device over it's lifetime. Controlled atmospheres and vacuum levels can change over time due to improper consideration of material and their outgassing characteristics. Packaging of MEMS has been and continues to be a major challenge unless all of the materials comprising of a sealed package are evaluated at the initial design phase. This paper will address the issues related to a ceramic package with a gold metallization seal ring, the importance of using low outgassing sensor attach materials, incorporating a getter material to be sealed in the package cavity, and the proper handling of the hermetic lid. In order to achieve the best and highest entrapped vacuum in the package, materials must be prepared before processing. This will involve proper vacuum baking and activating the getter film prior to sealing the MEMS device. By controlling the vacuum levels with aggressive bake outs, fully activating the getter, addressing all material out gassing rates, and optimizing the high vacuum sealing process profile a MEMS device with a controlled vacuum level can be obtained.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Li, Xiang, Qinghua Peng, Qian Xie, Min Zhao, Libing Cai, and Lijun Tong. "Research on High-power Transmission Technology of Satellite Borne RF Connector." Journal of Physics: Conference Series 2085, no. 1 (November 1, 2021): 012001. http://dx.doi.org/10.1088/1742-6596/2085/1/012001.

Повний текст джерела

Анотація:

Abstract The reliability of the communication link shall be affected severely due to failure modes such as multipactor, low pressure discharge, and thermal damage that are commonly found in the RF connector when it performs high-power microwave signal transmission in the vacuum environment of outer space. This paper proposes supporting measures in respect of design against multipactor, low pressure discharge and thermal damage after analyzing mechanisms of failure modes of the RF connectors when it transmits high-power microwave signals in a vacuum environment. Upon tests, these proposed measures can effectively guarantee the reliability of the RF coaxial connector transmitting high-power signals in vacuum.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Lian, Xue, Nan Hua, Liu Jiaqi, Liu Xin, and Meng Gang. "The Design of Large Arc-shape High-precision Walking Device in TV (thermal-vacuum) Conditions." MATEC Web of Conferences 237 (2018): 03014. http://dx.doi.org/10.1051/matecconf/201823703014.

Повний текст джерела

Анотація:

The large-sized space environmental simulation test facility is mainly used for providing thermal radiation environment in high-vacuum, cold and dark space for satellites, spacecraft, lunar spacecraft to carry out whole satellite thermal vacuum test and for large equipment like antenna to carry out tests in TV conditions. Monitoring the spacecraft’s surface optical image or temperature is a main task in space environment simulation test. In previous tests, optical image test mainly took place in a fixed position, so the measuring location and angle are limited. This paper focuses on large spherical space environmental simulation test facility, and designs a large arc-shape high-precision walking device in a space environment simulation test device. It introduces key technology in detail like structure design, thermal design, processes and manufacturing, etc. The test results show that this device can work steadily and reliably under simulation space environments, and the precision exceeds 0.5°.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Jiang, Runkun, Lei Mei, and Q. M. Zhang. "An Epoxy Bonding Apparatus for Applications under Extreme Environment." MRS Advances 1, no. 21 (2016): 1525–30. http://dx.doi.org/10.1557/adv.2016.147.

Повний текст джерела

Анотація:

ABSTRACTA number of electrical components and devices work in extreme environment such as high temperature, high pressure, strong vibration, corrosive chemicals, etc. A common practice to protect them is to shield them in materials that are mechanically and chemically resistant to these harsh conditions. In this scenario, epoxy bonding is preferred and it is crucial to have high bonding strength. One example is the acoustic transducers used in oil drilling. The temperature can reach 200 °C and the pressure can reach 140 MPa. The piezoelectric ceramic parts cannot withstand these conditions so different packaging materials are used such as polyether ether ketone (PEEK).Here an epoxy bonding apparatus is presented that has demonstrated ultrahigh bonding strength. Though epoxy resin is degassed before applying, which gets rid of air bubbles generated in the mixing process, there is trapped air when two surfaces are closed together. This trapped air has minuscule effect for applications in ambient environment, but under extreme environment, it compromises the bonding strength majorly. We devised a vacuum system that contains a motorized stage with the bonding parts attached. After the epoxy is applied and the system is pumped to 1% vacuum, a computer controls the motor to move the bonding parts into contact. Since the entire operation is in vacuum, it leaves no trapped air and results in increased bonding strength. This apparatus confirmed the importance of surface preparation, including removal of air by starting the cure in vacuum (5 mm Hg) and subsequently releasing the vacuum [1].Another technique to improve the bonding strength utilizes the finding that a uniform epoxy resin layer between 50 µm and 150 µm [2] results in the optimal bonding strength. Here we applied spacers such as optic fiber (125 µm in diameter) or glass fiber fabric (150 µm in thickness) in between the bonding surfaces. These spacers ensure that the epoxy resin layer is of uniform thickness. It also utilizes the principle of glass-epoxy compositing to increase mechanical strength by fiber reinforcement and load distribution [3, 4].The above bonding apparatus has been proven to increase the bonding strength by experiments. Acoustic transducers bonded with this technique passed the high pressure, high temperature tests resembling the oil drilling conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Wu, Hou Ya, Tie Niu Yang, and Xiao Jun Wang. "Researches of Pressure Measurement Method in Vacuum Environment." Applied Mechanics and Materials 347-350 (August 2013): 19–23. http://dx.doi.org/10.4028/www.scientific.net/amm.347-350.19.

Повний текст джерела

Анотація:

wafer processing is one process of the IC industry which is a booming area nowadays, the quality of the production of this course depends on the performance of the film which is formed by deposition. And one of the most important factors influencing the performance is working pressure. Variable structure chamber for flowing experiment and testing which is a multifunction testing platform with changeable structure and sufficient measurement points all-covered the chamber, a device has been designed and manufactured to measure and research vacuum flow filed. By using this equipment, the pressure in vacuum chamber could be measured precisely and promptly, thus relationships among the size and shape of the chamber, the pressure, and the gauges would be clear, there would be helpful for vacuum measurement. Background The course of manufacturing a chip of IC production including 400~500 processes which could be divide into two categories: wafer processing which is FEOL (front-end-of-line) and chip packaging which is BEOL (back end of line), as it illustrated in Fig. 1. Wafer manufacturing is a process of exacting and refining high purity silicon (usually 99.999%) from silica; Wafer processing is depositing a thin film (among 100um to 22nm, according to the requirement and depending on technology) which contains required elements on the face of the original wafer; Dicing is chipping out wafer into little blockages to face different requirement; Assemble and packaging is fabricating chip into IC component. During the course of Wafer processing, the working condition is usually under low velocity, high vacuum and high temperature condition (depends on the characteristics of sediment), take the project Deposition of Hydrogenated Amorphous Silicon as an example---- 5.0 sccm, 11.0~16.0 mtor, and 250°C[1]. The performance of wafer is decided by the nature of reactors and the processing condition of which a little change would lead a different property of the production. Thus it is necessary and imperative to figure out the relationship among the factors influencing depositing process. And the most important among these factors are pressure, velocity, and temperature. In this paper, a method of pressure measurement based on a device of variable structure chamber for flowing experiment and testing will be introduced. Fig. 1, Semiconductor manufacturing process

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Rice, Trisha, and Ralph Knowles. "Ultra High Resolution SEM on Insulators and Contaminating Samples." Microscopy Today 13, no. 3 (May 2005): 40–43. http://dx.doi.org/10.1017/s1551929500051634.

Повний текст джерела

Анотація:

Historically, SEM developed as a high vacuum technique requiring sample chamber vacuum of 10-5 Torr or better. Energetic electrons scatter from any molecules they encounter, so their creation and transport from source to sample, through the focusing lenses of the electron column, requires high vacuum. This imposes a number of limitations on the kinds of samples that can be examined. Samples must tolerate the vacuum environment and the vacuum system must tolerate the sample. Generally, samples have to be solid, clean, dry, and not contain volatile components. Furthermore, since the vacuum insulates the sample from everything except the stub that supports it, non-conductive samples require a conductive pathway between the scanned region and ground to prevent the accumulation of charge deposited by the beam electrons.

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Tsao, Chia-Wen, Yuan-Jing Lin, Pi-Yu Chen, Yu-Liang Yang, and Say Hwa Tan. "Nanoscale silicon surface-assisted laser desorption/ionization mass spectrometry: environment stability and activation by simple vacuum oven desiccation." Analyst 141, no. 16 (2016): 4973–81. http://dx.doi.org/10.1039/c6an00659k.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Liu, Hai Tao, Zhi Yu Wen, Li Chen, and Zhong Quan Wen. "System Simulation and Test of a Field Emission Accelerometer." Key Engineering Materials 562-565 (July 2013): 306–10. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.306.

Повний текст джерела

Анотація:

Field emission accelerometer work in vacuum environment, the negative exponential relationship between the current and the distance of the cathode and anode electrode make the accelerometer has high sensitivity and serious non-linearity. A system simulation method by using SIMULINK tools was put forward, and the system simulation model was proposed. The system simulation was carried out under low vacuum and high vacuum environment. On the guidance of the simulation result, the circuit was designed and the performance of accelerometer was tested. The result indicated that the accelerometer have good linearity and sensitivity.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Boyes, Ed. "Controlled Environment (ECELL) HREM." Microscopy and Microanalysis 3, S2 (August 1997): 589–90. http://dx.doi.org/10.1017/s1431927600009831.

Повний текст джерела

Анотація:

The ability to control the environment inside the electron microscope is a very desirable general capability and one long pursued for higher vacuum or chemical reactions (1,2) Here we are primarily concerned with providing the essential facilities for realistic in-situ dynamic studies of chemical reactions between gases or vapors and solids. The compromises with microscope performance have been reduced substantially compared with previous gas experiments (2,3).The primary applications for the present instrument are to reaction catalysts and the products of reactions where they are solid state materials of commercial value. Firstly, the catalyst may have to be (re)processed after transfer through the air or other hostile (i.e. non-reactor) environment. Secondly, the high vacuum atmosphere in a typical TEM may not be a compatible environment for the catalyst or other material (e.g. if it is solvated). Thirdly, the sequence of events in changes in the microstructure of a chemically active species will likely depend on the atmosphere in which those changes take place or are promoted (e.g. by heating).

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Podzorov, V., E. Menard, S. Pereversev, B. Yakshinsky, T. Madey, J. A. Rogers, and M. E. Gershenson. "Interaction of organic surfaces with active species in the high-vacuum environment." Applied Physics Letters 87, no. 9 (August 29, 2005): 093505. http://dx.doi.org/10.1063/1.2035323.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Song, Hui, Jie Chen, Nan Jiang, Li Ji, Hongxuan Li, and Jianmin Chen. "Low friction and wear properties of carbon nanomaterials in high vacuum environment." Tribology International 143 (March 2020): 106058. http://dx.doi.org/10.1016/j.triboint.2019.106058.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Michaud, J., L. Bechou, D. Veyrie, F. Laruelle, S. Dilhaire, and S. Grauby. "Thermal Behavior of High Power GaAs-Based Laser Diodes in Vacuum Environment." IEEE Photonics Technology Letters 28, no. 6 (March 15, 2016): 665–68. http://dx.doi.org/10.1109/lpt.2015.2504394.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

25

YOSHINAKA, Fumiyoshi, and Takashi NAKAMURA. "Effect of vacuum environment on fatigue fracture surfaces of high strength steel." Mechanical Engineering Letters 2 (2016): 15–00730. http://dx.doi.org/10.1299/mel.15-00730.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Takeda, S., K. Koto, Masako Hirata, T. Kuno, S. Iijima, and T. Ichihashi. "Electron Irradiation Effects in Silicon Thin Foils Under Ultra-High Vacuum Environment." Materials Science Forum 258-263 (December 1997): 553–58. http://dx.doi.org/10.4028/www.scientific.net/msf.258-263.553.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Shangguan, Minghui, Youjun Xie, Shengqiao Xu, Ce Gao, Guangcheng Long, Fan Wang, and Mengjing Liu. "Mechanical properties characteristics of high strength concrete exposed to low vacuum environment." Journal of Building Engineering 63 (January 2023): 105438. http://dx.doi.org/10.1016/j.jobe.2022.105438.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

28

KOBAYASHI, Yusuke, Takashi NAKAMURA, and Takeshi OOKA. "G0310702 Effects of High Vacuum Environment on Fatigue Crack Growth Properties of High Strength Steel." Proceedings of Mechanical Engineering Congress, Japan 2014 (2014): _G0310702——_G0310702—. http://dx.doi.org/10.1299/jsmemecj.2014._g0310702-.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

29

Iino, Y., M. Itoh, M. Omote, Y. Yamaguchi, and T. Ban. "Effects of High Temperature Gas Environments(H₂, Pure Air, Ar, Vacuum) on Slow Strain Rate Tensile Properties at 700°C of TiAl Alloy." Key Engineering Materials 345-346 (August 2007): 1007–10. http://dx.doi.org/10.4028/www.scientific.net/kem.345-346.1007.

Повний текст джерела

Анотація:

Tensile test of TiAl alloy was carried out in 700oC gas environment(H2, pure air, Ar, vacuum) at three strain rates, 2.8x10-4, 2.8x10-5, and 2.8x10-6s-1. With decreasing strain rate, the ultimate tensile strength decreased in all environments similarly. However, elongation to fracture differed from each environment. With decreasing strain rate, the elongation to fracture in vacuum and Ar increased slightly, that in H2 increased much and that in pure air significantly. The reasons of such behaviour are not known. One of the reasons for high elongation to fracture would be formation of multiple microcracks in H2 and pure air on the gauge surface of the specimen during tensile deformation.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Ponce, F. A., S. Suzuki, H. Kobayashi, Y. Ishibashi, Y. Ishida, and T. Eto. "Ultra-high-vacuum, high-resolution Transmission Electron Microscopy at 400 kV." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 606–9. http://dx.doi.org/10.1017/s0424820100144498.

Повний текст джерела

Анотація:

Electron microscopy in an ultra high vacuum (UHV) environment is a very desirable capability for the study of surfaces and for near-atomic-resolution imaging. The existence of amorphous layers on the surface of the sample generally prevents the direct observation of the free surface structure and limits the degree of resolution in the transmission electron microscope (TEM). In conventional TEM, these amorphous layers are often of organic nature originating from the electron bombardment of hydrocarbons in the vicinity of the sample. They can in part also be contaminants which develop during the specimen preparation and transport stages. In the specimen preparation stage, contamination can occur due to backsputtering during the ion milling process. In addition, oxide layers develop from contact to air during transport to the TEM. In order to avoid these amorphous overlayers it is necessary: i) to improve the vacuum of the instrument, thus the need for ultra high vacuum; and ii) to be able to clean the sample and transfer it to the column of the instrument without breaking the vacuum around the sample.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Moldarev, Dmitrii, Kristina Komander, Radek Holeňák, Max Wolff, and Daniel Primetzhofer. "A new setup for optical measurements under controlled environment." Review of Scientific Instruments 94, no. 3 (March 1, 2023): 035104. http://dx.doi.org/10.1063/5.0142068.

Повний текст джерела

Анотація:

We present a new analytical instrument for studying the optical properties of materials in different gaseous environments at room and controlled elevated temperatures. The system consists of a vacuum chamber, which is equipped with temperature and pressure controllers, a heating band, and a residual gas analyzer and is connected to a gas feeding line via a leak valve. Two transparent view ports located around a sample holder allow for optical transmission and pump-probe spectroscopy using an external optical setup. The capabilities of the setup are demonstrated by conducting two experiments. In the first experiment, we study the photodarkening and bleaching kinetics of photochromic oxygen-containing yttrium hydride thin films illuminated in ultra high-vacuum and correlate it with changes in partial pressures inside the vacuum chamber. In the second study, we investigate changes in the optical properties of a 50 nm V film upon hydrogen absorption.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Gnauck, Peter, Volker Drexel, and J. Greiser. "A New High Resolution Field Emission SEM with Variable Pressure Capabilities." Microscopy and Microanalysis 7, S2 (August 2001): 880–81. http://dx.doi.org/10.1017/s1431927600030476.

Повний текст джерела

Анотація:

To examine non conductive samples in their natural state (i.e. without significant sample preparation) at high resolution in the SEM the technique of low voltage field emission scanning electron microscopy (LVFESEM) is used. Due to the limitation in accelerating voltage (U<1kV) this technique is limited in respect of chemical analysis. Furthermore it is not possible to examine humid and outgassing samples in high vacuum. in recent years the application of variable pressure scanning electron microscopes (VPSEM) became an important technique in materials science as well as in life science. Due to the capability of maintaining a high chamber pressure humid, outgassing and non-conductive samples, can be examined in their natural state without significant sample modification or preparation. Especially compound materials with different electron yields can be imaged without any charging effects (Fig. 2), [2]. This paper describes a high resolution field emission electron microscope, that combines low voltage and variable pressure capabilities.The high pressure capabilities of the instrument are realized by eliminating the high vacuum requirements of SEM in the microscope chamber. This is done by separating the vacuum environment in the chamber from the ultra high vacuum environment in the gun area.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Tang, Yuqing, Hanyu Deng, Tenghui Liao, and Yingjian Qi. "Research on the vacuum aging performance of HTPB propellant based on the DSC method." Journal of Physics: Conference Series 2403, no. 1 (December 1, 2022): 012013. http://dx.doi.org/10.1088/1742-6596/2403/1/012013.

Повний текст джерела

Анотація:

Abstract The space environment has extreme conditions such as high vacuum and rapid temperature changes, which will lead to problems such as energy drop, irregular burning rate, and abnormal ignition of solid propellants. To obtain the space aging law of HTPB propellant, the aging performance of HTPB (hydroxyl-terminated polybutadiene) propellant in a vacuum environment was studied and compared with that under the atmosphere. According to the DSC test results of the propellant before and after aging, the behaviors of oxidative crosslinking, chain-scission degradation, and oxidant decomposition during the aging process of solid propellant were investigated. The research showed that the low-temperature endothermic peak and “V-type” high-temperature exothermic peak temperature of HTPB propellant increased after aging, and the high-temperature peak bifurcated into “W-type” double peaks. The right peak caused by the “decarboxylation” reaction was more obvious after atmospheric aging while the left peak caused by AP decomposition was remarkable after vacuum aging. In addition, the oxidative crosslinking reaction occurred after aging, and the activation energy characterized by low-temperature peaks continued to increase. In the later stage of atmospheric aging, chain-scission degradation occurred due to OA moisture absorption, and the activation energy decreased. It firstly increased by 126% within 93 days, and then decreased by 23.4%. No degradation and chain-scission reaction occurred in a vacuum environment, the crosslinking reaction rate was high, and the activation energy increased by 40.4% within 49 days. After the aging of the HTPB propellant, the internal AP decomposed, and the activation energy characterized by the high-temperature exothermic right peak continued to increase. The activation energy increased by 40.5% within 49 days after vacuum aging, and increased by 29.9% within 93 days after atmospheric aging, indicating that the decomposition of AP in the HTPB propellant was more obvious under a vacuum environment.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Fagnoni, Francesco, and Piotr Konarski. "Hydrogen Degassing of Zirconium under High-Vacuum Conditions." Metals 12, no. 5 (May 19, 2022): 868. http://dx.doi.org/10.3390/met12050868.

Повний текст джерела

Анотація:

Micromechanics techniques, such as nano-indentation and micro-pillar compression, can be applied to study hydrogen-charged zirconium alloys at elevated temperatures, which is highly relevant for the nuclear industry. Such experiments are often conducted inside a scanning electron microscope (SEM) under high-vacuum conditions (10−5 mbar). The combination of a high-temperature and high-vacuum environment causes some hydrogen to escape from the sample into the chamber. Although this effect is evident at temperatures above 600 °C, the extent of hydrogen desorption at lower temperatures is still unclear. In the presented study, the desorption of hydrogen was assessed in zirconium cladding tube material under temperature and hydrogen content conditions comparable to those faced by used nuclear fuel during dry storage. The measured hydrogen loss due to the high vacuum was compared to the simulations obtained using an extended version of a hydrogen behavior tool developed at PSI.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Even, U. "Pulsed Supersonic Beams from High Pressure Source: Simulation Results and Experimental Measurements." Advances in Chemistry 2014 (August 3, 2014): 1–11. http://dx.doi.org/10.1155/2014/636042.

Повний текст джерела

Анотація:

Pulsed beams, originating from a high pressure, fast acting valve equipped with a shaped nozzle, can now be generated at high repetition rates and with moderate vacuum pumping speeds. The high intensity beams are discussed, together with the skimmer requirements that must be met in order to propagate the skimmed beams in a high-vacuum environment without significant disruption of the beam or substantial increases in beam temperature.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Wang Xiaodong, 王晓东, 汪盛烈 Wang Shenglie, and 刘劲松 Liu Jinsong. "Effect of Quasi-Vacuum Environment in Ablation with High Repetition Rate Pulsed Laser." Chinese Journal of Lasers 36, no. 1 (2009): 238–43. http://dx.doi.org/10.3788/cjl20093601.0238.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

37

JIANG Shao-dong, 姜劭栋, 苏岩 SU Yan, 裘安萍 QIU An-ping, and 施芹 SHI Qin. "Temperature characteristics of quality factor of silicon micromachined gyroscope under high-vacuum environment." Optics and Precision Engineering 23, no. 7 (2015): 1990–95. http://dx.doi.org/10.3788/ope.20152307.1990.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

38

McDonald, M. L., J. M. Gibson, and F. C. Unterwald. "Design of an ultrahigh‐vacuum specimen environment for high‐resolution transmission electron microscopy." Review of Scientific Instruments 60, no. 4 (April 1989): 700–707. http://dx.doi.org/10.1063/1.1141004.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Yue, Wu, Guo Qingliang, Fang Mingyuan, Sun Juan, Guo Ziyin, and Wei Xi. "Research on detection method of leakage rate of rough pumping valve in space environment simulator." E3S Web of Conferences 198 (2020): 03015. http://dx.doi.org/10.1051/e3sconf/202019803015.

Повний текст джерела

Анотація:

As an important part of the vacuum system in the space environment simulator, the rough pumping system reduces the vacuum degree of the container from atmospheric pressure to the pressure of the high vacuum system when the space environment simulator starts up. As the key equipment of the rough pumping system, the rough pumping valve plays the role of isolating the rough pumping system from the environmental simulator, and its leakage rate has a direct impact on the vacuum degree that the space environment simulator can reach. Therefore, it is very important to detect the leakage rate of the rough pumping valve. In this paper, the leakage rate detection method of the rough pumping valve is introduced, including the valve delivery stage and valve installation stage to the simulator stage, in order to provide some basis for the follow-up valve leakage rate detection work

Стилі APA, Harvard, Vancouver, ISO та ін.

40

Kubic, Thomas A., and JoAnn Buscaglia. "Application of high-pressure scanning electron microscopy (ECO-SEM) in forensic sample analysis." Proceedings, annual meeting, Electron Microscopy Society of America 54 (August 11, 1996): 848–49. http://dx.doi.org/10.1017/s0424820100166701.

Повний текст джерела

Анотація:

Traditionally to obtain satisfactory images and reasonable resolution with a Scanning Electron Microscope (SEM), it has been necessary to employ a high vacuum within the sample chamber.High vacuum can result in the dehydration of materials with an alteration of sample morphology and in some cases the introduction of artifacts. In such an environment, samples that are nonconductive experience extensive charging with image degradation. Samples of forensic concern, such as textile bundles or swatches, exhibit this problem even after the application of metal coating. The problem is even more pronounced when carbon coating is used, as is often the preference of forensic microscopists in order to simplify interpretation of the EDX spectra.The commercial availability of "high pressure" or controlled environment SEMs that operate with sample chamber pressures from 50 to 4000 millitorr, while the electron guns and columns are kept at high vacuum conditions have solved these problems. The presence of this "higher" pressure retards dehydration while charging effects are nearly eliminated.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

Gardos, M. N., and B. L. Soriano. "The effect of environment on the tribological properties of polycrystalline diamond films." Journal of Materials Research 5, no. 11 (November 1990): 2599–609. http://dx.doi.org/10.1557/jmr.1990.2599.

Повний текст джерела

Анотація:

Essentially pure, ∼1.5 μm thick, polycrystalline diamond films DC–PACVD deposited on polycrystalline α-SiC flats were friction and wear tested against similarly coated α-SiC pins. The oscillatory sliding tests were performed with a Knudsen cell-type, wide temperature range tribometer built into a scanning electron microscope. Experiments were completed in 1.33 × 10−3 Pa (1 × 10−5 Torr) and 13.3 Pa (1 × 10−1 Torr) Pair, at test flat temperatures cycled to 850°C and back to room temperature. The results are compared with similar tests previously completed with diamond versus bare α–SiC and diamond versus Si(100) sliding combinations. In the absence of in situ surface analytical capability in the SEM tribometer, the findings are interpreted based on relevant information collected from the literature. The data indicate that the friction of the respective, tangentially sheared interfaces depends on the generation and annihilation of dangling bonds. Desorption of hydrogen during heating and sliding under the electron beam, in vacuum, create unoccupied orbitals on the rubbing surfaces. These dangling bonds spin-pair with others donated from the counterface, leading to high friction. Resorption of adsorbates such as hydrogen (e.g., by cooling the tribosystem) lowers the interfacial adhesion and friction. At high temperatures, in vacuum, the interaction energy may also be reduced by surface reconstruction and graphitization. At high temperatures, in Pair, the coefficient of friction of diamond versus itself is substantially lower than that in vacuum. This reduction is most probably caused by the generation of oxidation products combined with the temperature-shear-oxygen-induced phase transformation of diamond to graphite. The wide temperature wear rates of pure, polycrystalline diamond, characteristic of our test procedure, varied from ∼4 × 1016 m3/N · m in 1.33 × 10−3 Pa vacuum to ∼1 × 10−15 m3/N · m in 13.3 Pair.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Wight, S. A. "Electron behavior in the gaseous environment of the ESEM chamber." Proceedings, annual meeting, Electron Microscopy Society of America 54 (August 11, 1996): 838–39. http://dx.doi.org/10.1017/s0424820100166658.

Повний текст джерела

Анотація:

Measurements of electrons striking the sample in the Environmental Scanning Electron Microscope (ESEM) are needed to begin to understand the effect of the presence of the gas on analytical measurements. Accurate beam current is important to x-ray microanalysis and it is typically measured with a faraday cup. A faraday cup (Figure 1) was constructed from a carbon block embedded in non-conductive epoxy with a 45 micrometer bore platinum aperture over the hole. Currents were measured with an electrometer and recorded as instrument parameters were varied.Instrument parameters investigated included working distance, chamber pressure, condenser percentage, and accelerating voltage. The conditions studied were low vacuum with gaseous secondary electron detector (GSED) voltage on; low vacuum with GSED voltage off; and high vacuum (GSED off). The base conditions were 30 kV, 667 Pa (5 Torr) water vapor, 100,000x magnification with the beam centered inside aperture, GSED voltage at 370 VDC, condenser at 50%, and working distance at 19.5 mm. All modifications of instrument parameters were made from these conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

Oguma, Hiroyuki, and Takashi Nakamura. "Formation Mechanism of Specific Fracture Surface Region in the Sub-Surface Fracture of Titanium Alloy." Advanced Materials Research 891-892 (March 2014): 1436–41. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1436.

Повний текст джерела

Анотація:

In Ti–6Al–4V alloy, fatigue properties have been widely investigated, and the origin of fatigue fracture is usually at the surface in the high stress and lower fatigue life region, whereas in low stress and longer fatigue lifetimes origins are generally sub-surface in nature. Very high cycle fatigue tests were conducted, and observation of fracture surfaces revealed that a unique fine concave and convex agglutinate (hereinafter called Granular Region) formed on the fracture surface of sub-surface fractures. The granular region was not observed on the fracture surface of surface fractures. To clarify the formation mechanism and process of forming the granular region, which is a unique phenomenon in the very high cycle fatigue, fatigue tests using specimens with an artificial surface defect were conducted in air and vacuum. The fatigue tests were based on the idea that the environment around a sub-surface fatigue crack is a vacuum-like environment. During the tests, fracture surfaces were intentionally contacted in air and vacuum under different loading conditions. Fracture surface observations revealed that repeated contact of the fracture surfaces and a vacuum environment are necessary for the formation of the granular region. A mechanism for the formation of the granular region will be proposed.

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Seangsri, Soontaree, Thanasak Wanglomklang, Nopparut Khaewnak, Nattawat Yachum, and Jiraphon Srisertpol. "Optimizing Ultra-High Vacuum Control in Electron Storage Rings Using Fuzzy Control and Estimation of Pumping Speed by Neural Networks with Molflow+." Systems 11, no. 3 (February 23, 2023): 116. http://dx.doi.org/10.3390/systems11030116.

Повний текст джерела

Анотація:

This paper presents the design of a fuzzy-controller-based ultra-high vacuum pressure control system and its performance evaluation for a sputter-ion vacuum pump used in the electron storage ring at the Synchrotron Light Research Institute (Public Organization) in Thailand. The production of synchrotron light requires advanced vacuum technology to maintain stability and prevent interference of electrons in an ultra-high vacuum pressure environment of about 10−9 Torr. The presence of heat and gas rupture from the pipe wall can affect the quality of the light in that area. The institute currently uses a sputter-ion vacuum pump which is costly and requires significant effort to quickly reduce pressure increases in the area. Maintaining stable vacuum pressure throughout electron motion is essential in order to ensure the quality of the light. This research demonstrates a procedure for evaluating the performance of a sputter-ion vacuum pump using a mathematical model generated by a neural network and Molflow+ software. The model is used to estimate the pumping speed of the vacuum pump and to design a fuzzy control system for the ultra-high vacuum system. The study also includes a leakage rate check for the vacuum system.

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Ghosh, Jyotirmoy, Rabin Rajan J. Methikkalam, Radha Gobinda Bhuin, Gopi Ragupathy, Nilesh Choudhary, Rajnish Kumar, and Thalappil Pradeep. "Clathrate hydrates in interstellar environment." Proceedings of the National Academy of Sciences 116, no. 5 (January 10, 2019): 1526–31. http://dx.doi.org/10.1073/pnas.1814293116.

Повний текст джерела

Анотація:

Clathrate hydrates (CHs) are ubiquitous in earth under high-pressure conditions, but their existence in the interstellar medium (ISM) remains unknown. Here, we report experimental observations of the formation of methane and carbon dioxide hydrates in an environment analogous to ISM. Thermal treatment of solid methane and carbon dioxide–water mixture in ultrahigh vacuum of the order of 10−10 mbar for extended periods led to the formation of CHs at 30 and 10 K, respectively. High molecular mobility and H bonding play important roles in the entrapment of gases in the in situ formed 512 CH cages. This finding implies that CHs can exist in extreme low-pressure environments present in the ISM. These hydrates in ISM, subjected to various chemical processes, may act as sources for relevant prebiotic molecules.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Shi, Shanshuang, Huapeng Wu, Yuntao Song, and Heikki Handroos. "Mechanical design and error prediction of a flexible manipulator system applied in nuclear fusion environment." Industrial Robot: An International Journal 44, no. 6 (October 16, 2017): 711–19. http://dx.doi.org/10.1108/ir-04-2017-0066.

Повний текст джерела

Анотація:

Purpose The purpose of this paper is to introduce a development and error modeling of a serial redundant manipulator system applied in nuclear fusion environment. Detailed mechanical design of vacuum-compatible arms and actuators are presented, and manipulator flexibility is studied through experiments and model identification algorithm to evaluate the deformation. Design/methodology/approach First, the manipulator is designed to be several modular segments to obtain enough and flexible workspace inside the fusion device with narrow and complex geometries. Joint actuators with “rotation-linear-rotation” chains are developed to provide both huge reduction ratios and vacuum sealing. The redundant manipulator system has 11 degree of freedoms in total with a storage cask system to dock with the device vacuum vessel. In addition, to improve the position accuracy, an error prediction model is built based on the experimental study and back-propagation neural network (BPNN) algorithm. Findings Currently, the implementation of the manipulator system has been successfully carried out in both atmosphere and vacuum condition. Excellent performance indicates that the mechanical design is suitable. The validation of BPNN model shows an acceptable prediction accuracy (94∼98 per cent) compared with the real measurement. Originality/value This is a special robot system which is practically used in a nuclear fusion device in China. It will allow remote inspection and maintenance of plasma facing components in the vacuum vessel of fusion device without breaking the ultra-high vacuum condition during physical experiments. Its design, mechanism and error prediction strategy have great reference values to the similar robots in vacuum and temperature applications.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Cantillo, David, Hassan Sheibani, and C. Oliver Kappe. "Flash Flow Pyrolysis: Mimicking Flash Vacuum Pyrolysis in a High-Temperature/High-Pressure Liquid-Phase Microreactor Environment." Journal of Organic Chemistry 77, no. 5 (February 22, 2012): 2463–73. http://dx.doi.org/10.1021/jo3001645.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Straub, Axel, Nils-Peter Harder, Yidan Huang, and Armin G. Aberle. "High-quality homo-epitaxial silicon growth in a non-ultra-high vacuum environment by ion-assisted deposition." Journal of Crystal Growth 268, no. 1-2 (July 2004): 41–51. http://dx.doi.org/10.1016/j.jcrysgro.2004.05.003.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Takao Katsura, Haruhiko Ito, Kirina Komuro, Katsunori Nagano, and Saim Memon. "Analysis of indoor environment and performance of net-zero energy building with vacuum glazed windows." International Journal of Solar Thermal Vacuum Engineering 3, no. 1 (August 25, 2021): 1–14. http://dx.doi.org/10.37934/stve.3.1.114.

Повний текст джерела

Анотація:

The total energy and indoor thermal environment of an office building, which aims at the net-zero energy building, were measured and analysed. The annual total primary energy consumption of ‘Measurement’ was smaller than the value of ‘Calculation’ at design phase and achieved net-zero. The result of analysis of the thermal environment shows that the comfortable thermal environment was maintained. Also, the insulation performance and heat balance of the vacuum glazed windows in winter was evaluated. The overall heat transfer coefficients calculated by using the monitoring data were almost equal to the rated overall heat transfer coefficient and the high insulation performance of vacuum glazed windows was maintained even in the second year’s operation. In addition, the amount of heat gain due to solar radiation on the window surface was much larger than the amount of heat loss due to transmission. The vacuum glazed windows with high thermal insulation performance on the south side can reduce the heating load and contribute to the achievement of net-zero in the buildings.

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Feng, Jiangshan, Yuxiao Jiao, Hui Wang, Xuejie Zhu, Youming Sun, Minyong Du, Yuexian Cao, Dong Yang, and Shengzhong (Frank) Liu. "High-throughput large-area vacuum deposition for high-performance formamidine-based perovskite solar cells." Energy & Environmental Science 14, no. 5 (2021): 3035–43. http://dx.doi.org/10.1039/d1ee00634g.

Повний текст джерела

Анотація:

An in-vacuum low-temperature annealing process is developed to make high-density formamidine-based perovskite films. When the temperature is optimized, the efficiency increases to 21.32%, the highest value for a PSC fabricated with vacuum deposition.

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "High-vacuum environment"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями