Academic literature on the topic 'Bradford's Law of Scattering'

This paper deals with the applicability of Bradford law of scattering of the publications of India and China. The data for the study collected from WOS database, 887 journals publishing 1924 economics subject publications from India and 1627 journals published 4427 Chinese economics publications. The ranked list of journals prepared for both the datasets and the applicability of Bradford’s law was tested. The journals distribution pattern of the economics literature fit Bradford’s distribution pattern. The applicability of Egghe’s model (modification of Leimkuhler’s model) was also tested and found valid for both the datasets.

Swine Flu, unlike the seasonal flu, which is typically most dangerous to the very young, elderly, and those with a weakened immune system, can also be threatening to the young and healthy. This study attempts to analyze swine flu research in terms of relative growth rate, authorship pattern, and the scattering of articles by source and country. The period of study was 2001 to 2012. A total of 50,627 records were obtained from MEDLINE databases. The degree of collaboration C = 0.884 represents 88 percent of the collaborative author articles published during the period studied. Bradford's law (1934) was found to fit the sample well.

<p>The present study is based on 9053 citations appended to 92 doctoral theses submitted to the Department of Economics, Punjabi University, Patiala, during 2000-2014. The main objective of the study is to investigate authorship pattern of the citations, format of literature cited, electronic/print form of citations, chronological distribution of citations, geographical distribution of book and core journal citations. A ranked list of journals in economics is also compiled in order to find out the most referred journal. It is found that journals are the most consulted resources with 49.39 per cent citations in the field of economics. Bradford’s law of scattering is applicable to the present study with Bradford multiplier as 11.327.</p>

This study develops a general procedure for forming a well-defined collection of documents on a research topic, which is suitable for bibliometric analysis. The procedure is applied to one research topic in Library and Information Science, Bradford's Law of Scattering. An analysis is made of the underlying concepts, viz. 'document', 'selection', 'collection comprehensiveness', 'topic', 'research topic', and 'on' and 'relevant to' a research topic. An important distinction is drawn between graphical and semantic attributes of documents, and between their modes of analysis. The central problem of the study is that, while 'topic' is a problematic semantic attribute of documents, a well-defined collection of documents requires a selection criterion formulated on unproblematic graphical attributes. The solution proposed is to let specialist A&I Services legitimate a research topic and to provide a sample of its documents; then to extract a diagnostic graphical pattern from the sample, and from this construct a criterion which can be mechanically applied to all documents. Modifications introduced into the general procedure include the iterative development of the criterion from the growing collection, and allowing a content analysis of documents to suggest diagnostic patterns in the text. The graphical selection criterion developed for the specific collection was composed of six alternative pairs of word-stems separated by at most two words in the body of the text of documents. It has an estimated precision of 96% against the background literature and retrieves 90% of all known documents which might be judged to be on the topic. The final collection consists of 1187 analytical-level and scholarly documents written in 19 languages; it is well-defined, accords with convention, and is judged to be near completion for documents more strongly on and influential in the topic. Inadequacies in the procedure and in the collection formed were examined and improvements have been suggested. For example, the mixing of semantic and graphical methods in the pattern extraction process is clarified, recall can be enhanced by the addition of several small sub-collections, and measures of topic aboutness and topic influence were installed in the collection.

Literature studies reveal that the concept of â subjectâ has never been explicitly addressed in relation to Bradfordâ s law. The results of two empirical tests (Bradford analyses) demonstrate that different operationalizations of the concept of â subjectâ produce quite different lists of core-journals. Further, an empirical test reveals that Bradford analyses function discriminatorily against minority views. The paper questions one of the old dogmas of the field. The implication is that Bradford analysis can no longer be regarded as an objective and neutral method. The received view on Bradfordâ s law needs to be revised.

Auf der Basis des Impact-Faktors, entsprechend der Definition Eugene Garfields, werden die Implikationen dieses IF für szientometrische Überlegungen und deren Folgen für das Zeitschriftenwesen untersucht. Die Ergebnisse der vorliegenden Arbeit zeigen: Der Impact-Faktor ist ein Wert, der einen Hinweis auf den durchschnittlichen Bekanntheitsgrad eines Beitrags in einer vom SCI erfassten Zeitschrift gibt. Der Impact-Faktor ist ein Wert, der in hohem Maße vom Umfang des SCI bestimmt ist. Über die dort erfassten Zitationen wird ermittelt, wie oft eine Zeitschrift zitiert worden ist. Der Impact-Faktor ist in hohem Maße davon bestimmt, in wieweit die Quellen zugänglich sind, die zitiert werden. Der lineare Zusammenhang, den R. Rousseau und G.V. Hooydonk (1996) zwischen dem Impact-Faktor von Zeitschriften und der Zahl der darin erschienenen Aufsätze (Produktion) hergestellt haben, gilt nur in dem von ihnen untersuchten Bereich des Impact-Faktors 0,5 – 3. Bei höheren Werten kommt es zu einer Abflachung, bei Werten über 7 sogar zu einer Umkehr der Steigung. Es gibt einen Zusammenhang zwischen der Höhe des Impact-Faktors und seinem jährlichen Zuwachs im SCI. Je höher der IF, desto höher ist auch sein jährlicher Anstieg. Bei genauerer Analyse zeigte sich, dass der Zuwachs, zum Zeitpunkt der vorliegenden Untersuchung, gegen einen Grenzwert von 0,42 ging. Die Impact-Faktoren von Zeitschriften und deren Preise für die Abonnements hängen statistisch nur schwach voneinander ab. Ob Zeitschriften erworben werden müssen ist weitaus stärker von den Zitationen abhängig, die diese Zeitschriften auf sich versammeln. Der IF steigt mit der Auflagenhöhe von Zeitschriften, wenn diese bereits einen höheren IF aufweisen. Für wissenschaftliche Autoren ist der Druck, in Zeitschriften mit einem hohen IF zu publizieren, beobachtsam. Je höher dieser allgemeine Druck ist, desto geringer ist die Wahrscheinlichkeit für einen einzelnen Autor wiederholt in derartigen Zeitschriften publizieren zu können.
The current thesis investigates the Impact Factor (IF) in scientific journals and its consequences for scientometric considerations. The results are: The Impact Factor is a value for Journals listed in the Science Citation Index, which show the average degree of acquaintance in the scientific community. It is much less a sign of quality than often believed. The IF is highly determined by the degree of the extent of the SCI. The Impact Factor is also, to a considerable degree determined by the availability of the cited sources. Methodological the IF depends strongly on the topical adjustment of the SCI. A linear correlation, found by R. Rousseau and G.V. Hooydonk (1996) between the Impact Factor and the number of papers per journal, is only valid in the analysed range of 0.5 - 3 examined by these authors. At higher IF values it comes to a flattening, and for values greater 7 even to a reversal of the curve. There is an annual increase of the Impact Factor in the SCI, in which the annual rate is rising as higher the IF is. More exact analyses have shown that the increase had an upper of 0.42, at the investigated time. Impact factors of Journals and prices for their relations depend only on a weak statistic from each other. Whether Journal is acquired, depends by far more strongly on the citations, which meets these magazines on itself. The IF rises with the number of copies of magazines if these already exhibit a higher IF. A clear separation between a cause and effect cannot be recognized here. It would be both possible that Journals with high IF experience increased demand, so that the copy number thereby rises and that the IF rises, because the Journal enjoys a high interest. Scientific authors are under pressure to publish in journals with Ifs as high as possible. The higher this general pressure is the smaller is the probability for an author to publish in such journals repeatedly. Exceptions are the publishers or editors of these Journals.

Cette thèse à pour objet l’étude des résonances du laplacien sur les variétés à pointes. Ce sont des variétés dont les bouts sont des pointes hyperboliques réelles. Ces objets ont été introduits par Selberg pour les surfaces à pointes de courbure constante dans les années 50. Leur définition a ensuite été étendue en courbure variable par Lax et Phillips. Les résonances sont les poles d’une famille méromorphe de fonctions propres généralisées du laplacien. Elles sont associées au spectre continu du laplacien. Pour analyser ce spectre continu, plusieurs directions de recherche sont explorées ici. D’une part, on obtient des résultats sur la localisation de ces résonances. En particulier, si la courbure est négative, on montre que pour un ensemble générique de métriques, les résonances se séparent en deux ensembles. Le premier est contenu dans une bande près du spectre continu. L’autre partie est composé de résonances qui s’éloignent du spectre. Ceci laisse une zone de taille log sans résonance.D’autre part, on étudie les mesures microlocales associées à certaines suites de paramètre spectraux. En particulier, on montre que pour des suites de paramètres spectraux qui s’approche du spectre, mais pas trop vite, la mesure microlocale associée est nécessairement la mesure de Liouville. Cette propriété est valable quand la courbure de la variété est négative
In this thesis, we study the resonances of the Laplace operator on cusp manifolds. They are manifolds whose ends are real hyperbolic cusps. The resonances were introduced by Selberg in the 50's for the constant curvature cusp surfaces. Their definition was later extended to the case of variable curvature by Lax and Phillips. The resonances are the poles of a meromorphic family of generalized eigenfunctions of the Laplace operator. They are associated to the continuous spectrum of the Laplace operator. To analyze this continuous spectrum, different directions of research are investigated.On the one hand, we obtain results on the localization of resonances. In particular, if the curvature is negative, for a generic set of metrics, they split into two sets. The first one is included in a band near the spectrum. The other is composed of resonances that are far from the spectrum. This leaves a log zone without resonances. On the other hand, we study the microlocal measures associated to certain sequences of spectral parameters. In particular we show that for some sequences of parameters that converge to the spectrum, but not too fast, the associated microlocal measure has to be the Liouville measure. This property holds when the curvature is negative

La presente tesis doctoral, titulada "Contribution to the modelling of the light field distribution within Synechocystis sp. PCC 6803 cultures and its influence on cellular photosynthesis processes", engloba diversos trabajos cuyo objetivo es avanzar en la compresión de la distribución lumínica en cultivos de cianobacterias y en los efectos de la luz sobre los mecanismos fotosintéticos de dichos microorganismos. Se trata, en definitiva, de otro paso hacia la integración de modelos matemáticos sobre la fotosíntesis a nivel celular y a escala de cultivo. En primer lugar, para comprender cómo se comporta un cultivo de bacterias fotosintéticas, es fundamental predecir la distribución del campo de luz a lo largo del perfil del biorreactor, tanto a nivel de intensidad total, como respecto a su distribución de flujo de fotones. La distribución de longitudes de onda presente en el medio es importante puesto que muchos procesos de la fotosíntesis están regulados por ciertas longitudes de onda y, por tanto, están modulados por la distribución espectral - el color - de la luz. Aprovechando las propiedades inherentes ópticas del cultivo, se desarrolló un modelo matemático basado en el concepto de campo auto-consistente. Este algoritmo, bautizado en la correspondiente publicación como Auto-consistent Field Approximation Algorithm (AFA), proporciona una predicción del campo lumínico, incluyendo la evolución espectral del mismo a lo largo del camino óptico, para cultivos aclimatados a distintos valores de radiación. Dicha investigación se publicó en la revista Algal Research mediante el artículo titulado "Light distribution and spectral composition within cultures of micro-algae: Quantitative modelling of the light field in photobioreactors", en el que se valida el algoritmo con datos experimentales de dos cepas de estudio de la cianobacteria Synechocystis. Si bien los resultados fueron satisfactorios, el empleo de la ley de Lambert-Beer con un valor constante de atenuación no permite modelizar la parte del campo de luz con menor intensidad, donde el coeficiente de atenuación deja de ser constante y el comportamiento se desvía del exponencial. Por ello, se decidió modelizar el campo de luz con una función que generaliza el caso exponencial mediante el uso de cálculo fraccionario. Se empleó una función de Mittag-Leffler que cumplía con los requisitos formales y ofrecía un ajuste de los datos mejor al obtenido mediante la ley de Lambert-Beer. Como un hallazgo notable, se determinó que el valor de dicho parámetro, que caracteriza la función de Mittag-Leffler, era el mismo para los datos empíricos de las dos cepas estudiadas. Este trabajo se publicó en la contribución llamada "Estimation of the light field inside photosynthetic microorganism cultures through Mittag-Leffler functions at depleted light conditions" en la revista Journal of Quantitative Spectroscopy & Radiative Transfer. Después se procedió a utilizar sendos trabajos de investigación para calcular el campo de luz en un cultivo de Synechocystis y relacionarlo con su productividad máxima. En concreto se ha estudiado, como indicador del rendimiento de la fotosíntesis, la producción de oxígeno y los mecanismos respiratorios asociados a distintas intensidades de luz. Esta investigación está en su fase final y se está ultimando la escritura del artículo para enviarlo a una revista científica próximamente. Dicho manuscrito se titula "Experimental characterisation of Synechocystis sp. PCC 6803 cultures productivity up on light conditions". Finalmente, se está desarrollando una cuarta contribución titulada "Individual pigment contribution to overall in vivo absorption in Synechocystis sp. PCC 6803 cells". Esta investigación estudia la cantidad de luz absorbida por los cromóforos de Synechocystis en función del tipo de iluminación utilizada y calcula la concentración de pigmentos presentes en la célula.
The present doctoral thesis, entitled "Contribution to the modelling of the light field distribution within Synechocystis sp PCC 6803 cultures and its influence on cellular photosynthesis processes", includes several works whose objective is to advance in the understanding of the light distribution in cyanobacterial cultures and in the effects of light on the photosynthetic mechanisms of these microorganisms. It is, ultimately, another step towards the integration of mathematical models on photosynthesis at the cellular level and at the scale of culture. First, to understand how a culture of photosynthetic bacteria behaves, it is essential to predict the distribution of the light field along the bioreactor profile, both at the level of total intensity and with respect to its photon flux distribution. The distribution of wavelengths present in the medium is important since many processes of photosynthesis are regulated by certain wavelengths and are therefore modulated by the spectral distribution - the colour - of the light. Taking advantage of the inherent optical properties of the culture, a mathematical model based on the self-consistent field concept was developed. This algorithm, named in the corresponding publication as Auto-consistent Field Approximation Algorithm (AFA), provides an estimation of the light field, including the spectral evolution thereof along the optical path-length, for acclimated cultures to different radiation values. This research was published in the journal Algal Research through the article entitled "Light distribution and spectral composition within cultures of micro-algae: Quantitative modelling of the light field in photobioreactors", in which the algorithm is validated with experimental data of two strains of study of the cyanobacterium Synechocystis. Although the results were satisfactory, the use of the Lambert-Beer Law with a constant attenuation value, cannot correctly model the part of the light field with less intensity, where the attenuation coefficient ceases to be constant and the behaviour deviates from the exponential. Therefore, it was decided to model the light field with a function that generalizes the exponential case through the use of fractional calculus. A Mittag-Leffler function was used that fulfilled the formal requirements and offered a better data fit than that obtained with the Lambert-Beer law. As a remarkable finding, it was determined that the value of this parameter, which characterises the Mittag-Leffler function, was the same for the empirical data of both studied strains. This work was published in the contribution called "Estimation of the light field in photosynthetic microorganism cultures through Mittag-Leffler functions at depleted light conditions" in the journal Journal of Quantitative Spectroscopy & Radiative Transfer. Thereafter we proceeded to use both research works to calculate the light field within Synechocystis cultures and relate it to its maximum productivity. Specifically, it has been studied, as an indicator of the performance of photosynthesis, the production of oxygen and the associated respiratory mechanisms under different light intensities. This research is in its final phase and the writing of the article is being finalised to submit it to a scientific journal soon. This manuscript is entitled "Experimental characterization of Synechocystis sp. PCC 6803 cultures productivity up on light conditions". Finally, a fourth contribution entitled "Individual pigment contribution to overall in vivo absorption in Synechocystis sp. PCC 6803 cells" is under development. This research studies the amount of light absorbed by Synechocystis chromophores according to the type of employed illumination and calculates the concentration of pigments present in the cell.
La present tesi doctoral, titulada "Contribution to the modelling of the light field distribution within Synechocystis sp. PCC 6803 cultures and its influence on cellular photosynthesis processes", engloba diversos treballs l'objectiu dels quals és avançar en la compressió de la distribució lumínica en cultius de cianobacteris i en els efectes de la llum sobre els mecanismes fotosintètics d'aquests microorganismes. Llavors, es tracta en definitiva d'un altre pas cap a la integració de models matemàtics sobre la fotosíntesi a nivell cel·lular i a escala de cultiu. En primer lloc, per a comprendre com es comporta un cultiu de bacteris fotosintètics, és fonamental predir la distribució del camp de llum al llarg del perfil del bioreactor, tant a nivell d'intensitat total, com pel que fa a la seua distribució de flux de fotons. La distribució de longituds d'ona present en el medi és important ja que molts processos de la fotosíntesi estan regulats per certes longituds d'ona i, per tant, estan modulats per la distribució espectral - el color - de la llum. Aprofitant les propietats inherents òptiques del cultiu, es va desenvolupar un model matemàtic basat en el concepte de camp auto-consistent. Aquest algoritme, batejat en la corresponent publicació com Auto-consistent Field Approximation Algorithm (AFA), proporciona una predicció del camp lumínic, incloent l'evolució espectral del mateix al llarg del camí òptic, per a cultius aclimatats a diferents valors de radiació. Aquesta investigació es va publicar a la revista Algal Research mitjançant l'article titulat "Light distribution and espectral composition within cultures of micro-algae: Quantitative modelling of the light field in photobioreactors", en què es valida l'algoritme amb dades experimentals de dues soques d'estudi de la cianobacteri Synechocystis. Si bé els resultats van ser satisfactoris, l'ús de la llei de Lambert-Beer amb un valor constant d'atenuació no permet modelitzar la part del camp de llum amb menys intensitat, on el coeficient d'atenuació deixa de ser constant i el comportament es desvia del exponencial. Per això, es va decidir modelitzar el camp de llum amb una funció que generalitza el cas exponencial mitjançant l'ús de càlcul fraccionari. Es va emprar una funció de Mittag-Leffler que complia amb els requisits formals i oferia un ajust de les dades millor a l'obtingut mitjançant la llei de Lambert-Beer. Com una troballa notable, es va determinar que el valor d'aquest paràmetre, que caracteritza la funció de Mittag-Leffler, era el mateix per a les dades empíriques de les dues soques estudiades. Aquest treball es va publicar en la contribució anomenada "Estimation of the light field inside Photosynthetic microorganisme cultures through Mittag-Leffler functions at depleted light conditions" a la revista Journal of Quantitative Spectroscopy & Radiative Transfer. Després, es va procedir a utilitzar sengles treballs d'investigació per calcular el camp de llum en un cultiu de Synechocystis i relacionar-lo amb la seua productivitat màxima. En concret s'ha estudiat, com a indicador del rendiment de la fotosíntesi, la producció d'oxigen i els mecanismes respiratoris associats a diferents intensitats de llum. Aquesta investigació està en la seua fase final i s'està ultimant l'escriptura de l'article per enviar-lo a una revista científica pròximament. Dit manuscrit es titula "Experimental characterisation of Synechocystis sp. PCC 6803 cultures productivity up on light conditions". Finalment, s'està desenvolupant una quarta contribució titulada "Individual pigment contribution to overall in vivo absorption in Synechocystis sp. PCC 6803 cells". Aquesta recerca estudia la quantitat de llum absorbida pels cromòfors de Synechocystis en funció del tipus d'il·luminació utilitzada i calcula la concentració de pigments presents en la cèl·lula.
Fuente Herraiz, D. (2018). Contribution to the modelling of the light field distribution within Synechocystis sp. PCC 6803 cultures and its influence on cellular photosynthesis processes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/106362
TESIS

Etude experimentale de plusieurs systemes ternaires, comportant deux polymeres differents en solution par diffusion de la lumiere. L'analyse de l'intensite diffusee a vecteur d'onde nul a permis de caracteriser les proprietes thermodynamiques et plus particulierement le parametre d'interaction entre les deux polymeres

Le transport à haut débit de données à travers des fibres optiques grâce au multiplexage spatial est en pratique limité par la diaphonie modale. Au lieu de considérer ce couplage modal comme une limitation, nous exploitons ici ce mélange de modes comme une ressource. Nous mettons en oeuvre un réseau optique linéaire programmable basé sur le concept de design photonique inverse, exploitant les techniques de mise en forme du front d’onde. Nous démontrons la manipulation d’interférences quantiques à deux photons sur divers réseaux linéaires, comprenant des degrés de liberté spatiaux et de polarisations. En particulier, nous vérifions expérimentalement la « zero transmission law » dans des interféromètres de Fourier et de Sylvester, permettant de quantifier le degré d’indiscernabilité d’un état d’entrée. De plus, grâce à la possibilité de mettre en oeuvre un réseau non unitaire, nous mettons en évidence l’anti-coalescence de photons dans toutes les configurations de sortie, et réalisons une expérience d’absorption cohérente. Nous démontrons ainsi l’aspect reconfigurable de l’implémentation de tels réseaux optiques linéaires dans des fibres multimodes. De plus, nous étudions les propriétés statistiques du speckle à un et à deux photons générés à partir de divers états d’entrée, après propagation dans une fibre multimode. Ces propriétés statistiques du speckle peuvent être utilisées pour extraire des informations sur la dimensionnalité, la pureté et l’indiscernabilité d’un état quantique inconnu, permettant ainsi leur classification. Ce travail met en évidence le potentiel du contrôle de front d’onde en milieux complexes pour le traitement quantique de l’information
Transport of information through a multimode optical fibre raises challenges when one wants to increase the data traffic using many spatial modes due to modal cross-talk and dispersion. Instead of considering those complex mixing of modes as a detrimental process, in this dissertation, we harness its mode mixing to process quantum optical information. We implement a reconfigurable linear optical network, a fundamental building block for scalable quantum technologies, based on an inverse photonic approach exploiting the technology of wavefront shaping. We experimentally demonstrate manipulation of two-photon quantum interference on various linear optical networks across both spatial and polarization degrees of freedom. In particular, we experimentally show the zero-transmission law in Fourier and Sylvester interferometers, which are used to certificate the degree of indistinguishability of an input state. Moreover, thanks to the ability to implement a non-unitary network, we observe the photon anti-coalescence effect in all output configurations, as well as the realization of a tunable coherent absorption experiment. Therefore, we demonstrate the reconfigurability, accuracy, scalability and robustness of the implemented linear optical networks for quantum information processing. Furthermore, we study the statistical properties of one-and two-photon speckles generated from various ground-truth states of light after propagating through a multimode fibre. These statistical properties of speckles can be used to extract information about the dimensionality, purity, and indistinguishability of an unknown input state of light, therefore allowing for state classification. Our results highlight the potential of complex media combined with wavefront shaping for quantum information processing

This chapter reviews the basic ideas of electrostatics (Coulomb’s law) and magnetostatics (the Biot–Savart law). It studies the motion of a charge in a Coulomb field in detail. The chapter shows how the motion of a charge q in the Coulomb field of a charge Q held fixed at the origin of an inertial frame is governed by the Lorentz equation. Moreover, it can be solved like the Kepler problem discussed in the previous Book. Next, the chapter discusses the Rutherford scattering formula which established the ‘planetary’ model of the atom, the Bohr–Sommerfeld quantization which displayed the limits of the theory, and finally the spin coupling explaining the atomic fine structure.

This chapter focuses on the mathematics of elastic waves. In the case of a continuous medium, the field equations of physics (yielding the dynamic and thermodynamic variables) arise from three conservation equations: conservation of mass, momentum and energy. For an elastic medium, these equations of motion are known as Navier equations, which give rise to a rich variety of stress waves. There are two dynamic variables in an elastic solid: stress and strain. Stress and strain are linearly related in small-amplitude deformations; this relation is expressed by Hooke's law. The chapter first introduces the basic notation for elastic waves before discussing the solutions for plane waves. It also considers surface waves and Love waves.

This chapter discusses the physics of rays. In optics, a ray is a mathematical idealization of an infinitesimally narrow beam of light. Rays therefore exist only in a mathematical world and not in the physical realm. They are geometrical objects as opposed to physical ones, and may (usually) be regarded as normals to wavefronts (or to surfaces of constant phase). As real physical entities, rays have positions, directions, and speeds. They “carry” energy, and their “density” is a measure of power per unit area. After providing a background on rays, the chapter considers some mathematical definitions, geometric wavefronts, Fermat's principle, the intensity law, and heuristic derivation of Snell's laws. It also examines geometric and other proofs of Snell's laws of reflection and refraction.

In chapter 4 we use the results for the Fourier components to compute the unpolarized and spin-polarized SANS cross sections. These expressions serve to highlight certain features of magnetic SANS such as the role of the magnetodipolar and Dzyaloshinskii-Moriya interaction, and are then applied to analyze experimental SANS data on various bulk magnetic materials such as soft and hard magnetic nanocomposites. Furthermore, this chapter contains discussions on the magnetic Guinier law and on the asymptotic power-law exponents found in magnetic SANS experiments, as well as two sections summarizing magnetic SANS results on nanocrystalline rare-earth metals in the paramagnetic temperature regime and on dislocations.

Study of light scattering by nanoscale structures is essential to evaluate the radiative heat transfer in silica aerogels. For the purpose of simplification and feasibility regular structures are proposed to substitute irregular structures in silica aerogels to obtain average results of light scattering. The differential scattering cross section increases with density and decrease dramatically with wavelength in the visible spectrum. An inverse power-law relation can be observed between the differential scattering cross section and the incident wavelength. Furthermore, a power-law relation can be obtained for dimensionless scattering cross section and density. These findings are very helpful to understand the influences of structural parameters on light scattering.