scholarly journals The Displacement of the Diffraction Pattern in the Motion of the Medium

2019 ◽  
Vol 5 (4) ◽  
pp. 12-23
Author(s):  
A. Glushchenko ◽  
E. Glushchenko
Keyword(s):  
Diffraction Pattern ◽  
Intensity Distribution ◽  
Physical Nature ◽  
Zero Order ◽  
Diffraction Intensity ◽  
Measuring Techniques ◽  
The One ◽  
Analytical Relations ◽  
Moving Media ◽  
Substrate Medium

Diffraction of waves of different physical nature is one of the most important and studied phenomena of nature in connection with its versatile use in devices and measuring techniques. The influence of media motion on the diffraction pattern attracted the attention of researchers in connection with the development of the theory of electrodynamics of moving media and continues to attract attention in connection with a number of unsolved problems of physics. In this paper we consider a model of the diffraction of waves on the slit and lattice, located on a movable substrate (medium). Analytical relations for the calculation of the diffraction pattern intensity distribution are obtained. The significant influence of the medium motion on the diffraction pattern is established. The position of the zero-order maximum does not depend on the motion of the medium, on the one hand, the distance between the diffraction maxima decreases, on the other hand increases, until they disappear. The conditions under which the motion of the medium leads to an asymmetrical appearance of the diffraction intensity distribution, which is not observed in a stationary medium, are established. Generalized conditions of diffraction minima are obtained taking into account the motion of the medium. Shows the effect of the direction of the velocity of motion of the medium on the intensity of the diffraction pattern.

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

Measurement and Reduction of Radiation Damage in Frozen Hydrated Crystalline Specimens

1978 ◽  
Vol 36 (3) ◽  
pp. 70-77 ◽  
Author(s):  
R.M. Glaeser ◽  
S.B. Hayward
Keyword(s):  
Diffraction Pattern ◽  
Structural Information ◽  
Structural Disorder ◽  
Structural Features ◽  
Biological Macromolecules ◽  
Diffraction Intensity ◽  
Object Structure ◽  
Specimen Material ◽  
Unit Cells ◽  
Identical Unit

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.

scholarly journals Peirce’s Classification of the Sciences

2020 ◽  
Vol 47 (3) ◽  
pp. 267-278
Author(s):  
Torjus Midtgarden
Keyword(s):  
Social Sciences ◽  
Life Experience ◽  
Physical Nature ◽  
Human Mind ◽  
Empirical Science ◽  
The Social ◽  
Methodological Principles ◽  
The One ◽  
Philosophical Pragmatism

Charles Peirce’s classification of the sciences was designed shortly after the turn of the twentieth century. The classification has two main sources of inspiration: Comte’s science classification and Kant’s theoretical philosophy. Peirce’s classification, like that of Comte, is hierarchically organised in that the more general and abstract sciences provide principles for the less general and more concrete sciences. However, Peirce includes and assigns a superordinate role to philosophical disciplines which analyse and provide logical, methodological and ontological principles for the specialised sciences, and which are based on everyday life experience. Moreover, Peirce recognises two main branches of specialised empirical science: the natural sciences, on the one hand, and the social sciences, the humanities and psychology on the other. While both branches share logical and methodological principles, they are based on different ontological principles in studying physical nature and the human mind and its products, respectively. Peirce’s most basic philosophical discipline, phenomenology, transforms his early engagement with Kant. Peirce’s classification of aesthetics, ethics and logic as normative sub-disciplines of philosophy relate to his philosophical pragmatism. Yet his more overarching division between theoretical (philosophical and specialised) sciences and practical sciences may be seen as problematic. Taking Peirce’s historical account of scientific developments into consideration, however, I argue that his science classification and its emphasis on the interdependencies between the sciences could be seen as sustaining and supporting interdisciplinarity and interaction across fields of research, even across the divide between theoretical and practical sciences.

REGARDING THE REGULATORY REGULATION OF TERMS AND PROCEDURE FOR ADMINISTRATIVE DETENTION OF OFFENSERS FOR DOMESTIC VIOLENCE

2021 ◽  
Vol 2 (2) ◽  
pp. 161-167
Author(s):  
Andrіy Shulha ◽  
◽  
Olha Peresada ◽  
Tetyana Khailova ◽  
◽  
...  
Keyword(s):  
Domestic Violence ◽  
Law Enforcement ◽  
Physical Nature ◽  
Law Enforcement Officers ◽  
The One ◽  
Administrative Proceedings ◽  
The Right ◽  
National Police ◽  
Current Code ◽  
Administrative Detention

The article deals with the issue of normative regulation of the terms and procedure of administrative detention of offenders committed domestic violence in order to justify increasing the detention period for domestic brawlers for more than three hours. It is proposed to supplement Article 263 of the Code of Ukraine on Administrative Offenses with the fourth part of the following content: “Persons who have committed domestic violence, i.e. the intentional commission of any act of a physical nature (use of violence that did not cause bodily harm; threats; insults or persecution; deprivation of housing, food, clothing, other property or funds that belongs to the victim, who has the right on it guaranteed by law, et.) must be detained for up to 72 hours for referral to trial if the physical or mental health of the victim was damaged or could be damaged. This applies to cases if the urgent injunction was not executed by the person in respect of whom the order was issued or if person did not notify the authorized units of the National Police of Ukraine of the place of his/her temporary stay”. It was proposed to detain domestic rowdies after administrative detention in special rooms for arrestees. The proposal of legal scholars and law enforcement officers regarding the possibility of administrative proceedings without the obligatory presence of a person who was brought to administrative responsibility for committing domestic violence has been also supported. This provision of the current Code of Ukraine on Administrative Offenses already in its content has certain precedents for increasing the term of compulsory detention of a detained person for committing certain administrative offenses. Thus, there is a certain procedural precedent, which makes it possible to increase the terms of administrative detention for other administrative offenses, which in their content have more significant harmful consequences for society, such as Article 10 of this Code. Thus, among the administrative offenses, such as those listed in paragraph 1 of part 2 of Article 262 of the Code of Administrative Offenses of Ukraine, for which administrative detention is provided for no more than three hours, domestic violence is the one that, on our opinion, has the most serious harmful consequences for society.

Atomic Layer and Unit-Cell Layer Growth of (Ca,Sr)CuO2 and Bi2Sr2Can-1CunO2n+4 Thin Films by Laser Molecular Bean Epitaxy

1991 ◽  
Vol 222 ◽  
Author(s):  
Masaki Kanai ◽  
Tomoji Kawai ◽  
Takuya Matsumoto ◽  
Shichio Kawai
Keyword(s):  
Thin Films ◽  
Diffraction Pattern ◽  
Cell Layer ◽  
Atomic Layer ◽  
High Energy ◽  
Layer Growth ◽  
Unit Cell ◽  
Layer By Layer ◽  
Diffraction Intensity

ABSTRACTThin films of (Ca,Sr)CuO2 and Bi2Sr2Can-1CunO2n+4 are formed by laser molecular beam epitaxy with in-situ reflection high energy electron diffraction observation. The diffraction pattern shows that these materials are formed with layer-by-layer growth. The change of the diffraction intensity as well as the analysis of the total diffraction pattern makes It possible to control the grown of the atomic layer or the unit-cell layer.

The splitting mechanism of zero order diffraction pattern by roof prisms

2013 ◽  
Vol 42 (4) ◽  
pp. 367-375
Author(s):  
Lu Jinjun ◽  
Sun Xueping ◽  
Zhu Weibing
Keyword(s):  
Diffraction Pattern ◽  
Zero Order ◽  
Order Diffraction

scholarly journals ENERGY-CONSERVING AND RECIPROCAL SOLUTIONS FOR HIGHER-ORDER PARABOLIC EQUATIONS

2001 ◽  
Vol 09 (01) ◽  
pp. 183-203 ◽  
Author(s):  
DMITRY MIKHIN
Keyword(s):  
Finite Difference ◽  
Energy Conservation ◽  
Difference Scheme ◽  
Numerical Solution ◽  
Finite Difference Scheme ◽  
Flow Reversal ◽  
Difference Operators ◽  
Energy Conserving ◽  
The One ◽  
Moving Media

The energy conservation law and the flow reversal theorem are valid for underwater acoustic fields. In media at rest the theorem transforms into well-known reciprocity principle. The presented parabolic equation (PE) model strictly preserves these important physical properties in the numerical solution. The new PE is obtained from the one-way wave equation by Godin12 via Padé approximation of the square root operator and generalized to the case of moving media. The PE is range-dependent and explicitly includes range derivatives of the medium parameters. Implicit finite difference scheme solves the PE written in terms of energy flux. Such formalism inherently provides simple and exact energy-conserving boundary condition at vertical interfaces. The finite-difference operators, the discreet boundary conditions, and the self-starter are derived by discretization of the differential PE. Discreet energy conservation and flow reversal theorem are rigorously proved as mathematical properties of the finite-difference scheme and confirmed by numerical modeling. Numerical solution is shown to be reciprocal with accuracy of 10–12 decimal digits, which is the accuracy of round-off errors. Energy conservation and wide-angle capabilities of the model are illustrated by comparison with two-way normal mode solutions including the ASA benchmark wedge.

scholarly journals X-ray laser–induced electron dynamics observed by femtosecond diffraction from nanocrystals of Buckminsterfullerene

2016 ◽  
Vol 2 (9) ◽  
pp. e1601186 ◽  
Author(s):  
Brian Abbey ◽  
Ruben A. Dilanian ◽  
Connie Darmanin ◽  
Rebecca A. Ryan ◽  
Corey T. Putkunz ◽  
...  
Keyword(s):  
Diffraction Pattern ◽  
Molecular Targets ◽  
Third Generation ◽  
Free Electron Lasers ◽  
Electron Dynamics ◽  
Incident Power ◽  
Synchrotron Source ◽  
High Brightness ◽  
X Ray ◽  
The One

X-ray free-electron lasers (XFELs) deliver x-ray pulses with a coherent flux that is approximately eight orders of magnitude greater than that available from a modern third-generation synchrotron source. The power density of an XFEL pulse may be so high that it can modify the electronic properties of a sample on a femtosecond time scale. Exploration of the interaction of intense coherent x-ray pulses and matter is both of intrinsic scientific interest and of critical importance to the interpretation of experiments that probe the structures of materials using high-brightness femtosecond XFEL pulses. We report observations of the diffraction of extremely intense 32-fs nanofocused x-ray pulses by a powder sample of crystalline C60. We find that the diffraction pattern at the highest available incident power significantly differs from the one obtained using either third-generation synchrotron sources or XFEL sources operating at low output power and does not correspond to the diffraction pattern expected from any known phase of crystalline C60. We interpret these data as evidence of a long-range, coherent dynamic electronic distortion that is driven by the interaction of the periodic array of C60 molecular targets with intense x-ray pulses of femtosecond duration.

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