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Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu T.W.Huang k.Jiang C.N.Wu H.Peng P.C.hen R.Li H.B.Zhuo C.T.Zhou Shenzhen key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

Analysis of the Impact of the Blazhko Effect Both on the Van Hoof Effect and Radial Velocity Amplitude in the Star RR Lyr

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Research in Astronomy and Astrophysics 2024年第6期24卷 253-272页

作者： Y.El jariri F.L.Sefyani A.Benhida Z.Benkhaldoun k.kolenberg k.Chafouai A.Habib M.Sabil Observatoire de l'Oukaimeden LPHEAFSSMUniversitéCadi AyyadMarrakech2390Morocco Observatoire de l'Oukaimeden LPHEAFSTGUniversitéCadi AyyadMarrakech549Morocco Département de physique Universitéd'Anvers Avenue Groenenborger 171Anvers2020Belgium LICPM ENSA-BMUniversitéSultan Moulay SlimaneBeni-Mellal23020Morocco

The Van Hoof effect is a phase shift existing between the radial velocity curves of hydrogen and metallic lines within the atmosphere of pulsating *** this article,we present a study of this phenomenon through the spectra of the brightest pulsating star RR Lyr of RR Lyrae stars recorded for 22 *** based ourselves,on the one hand,on 1268 spectra(41 nights of observation)recorded between the years 1994 and 1997 at the Observatory of Haute Provence(OHP,France)previously observed by Chadid and Gillet,and on the other hand on 1569 spectra(46nights of observation)recorded at our Oukaimeden Observatory(Morocco)between 2015 and *** this study,we have detected information on atmospheric dynamics that had not previously been ***,the Van Hoof effect which results in a clear correlation between the radial velocities of hydrogen and those of the metallic lines has been observed and analyzed at different Blazhko phases.A correlation between the radial velocities of different metallic lines located in the lower atmosphere has been observed as *** the first time,we were able to show that the amplitude of the radial velocity curves deduced from the lines of hydrogen and that of FeⅡ(λ4923.921?)increases toward the minimum of the Blazhko cycle and decreases toward the maximum of the same Blazhko ***,we found that the Van Hoof effect is also modulated by the Blazhko ***,toward the minimum of the Blazhko cycle the Van Hoof effect is more visible and at the maximum of the Blazhko cycle,this effect is *** also observed the temporal evolution of the amplitudes of the radial velocities of the lower and upper *** observed over a long time,we can interpret it as a function of the Blazhko phases.

关键词： stars:atmospheres stars:variables:RR Lyrae shock waves techniques:spectroscopic techniques:radial velocities stars:individual(RR Lyr)

Modeling OH transport phenomena in cold plasma discharges using the level set method

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Plasma Science and Technology 2019年第5期21卷 121-131页

作者： Wei HAN k N YU Department of Physics City University of Hong KongTat Chee AvenueKowloon TongHong KongPeople's Republic of China Center of Medical Physics and Technology Hefei Institutes of Physical SciencesChinese Academy of SciencesHefei 230031People's Republic of China Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions and School for Radiological and Interdisciplinary Sciences(RAD-X) Soochow UniversitySuzhou 215006People's Republic of China

Cold atmospheric plasmas(CAPs)have attracted considerable interest in the field of plasma *** reactive species such as hydroxyl(OH)species play an important role in applications of *** of OH species towards the target and distribution of these OH species in the plasma plume play an important role in the applications of plasma *** the present work,a computational model was built to simulate the transportation and distribution of OH species in CAP discharges,which was based on the level set method to dynamically track the propagation of plasma carrier gas in air.A reaction term was incorporated for the OH *** OH species tended to diffuse around the main stream of the carrier gas,and thus covered larger radial and axial distances.A CAP discharge onto a skin layer led to the largest accumulation of OH species at the central part of the exposed *** distribution of OH species on the skin was asymmetric,which agreed with *** computational model itself and the obtained results would be useful for future development of plasma medicine.

关键词： cold atmospheric plasmas plasma medicine two-phase flow diffusion level set method

Methionine sources and genotype affect embryonic intestinal development, antioxidants, tight junctions, and growth-related gene expression in chickens

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Animal Nutrition 2024年第1期16卷 218-230页

作者： James k.Lugata Sawadi F.Ndunguru Gebrehaweria k.Reda Xénia E.Ozsváth Eszter Angyal Levente Czeglédi Gabriella Gulyás Renáta knop János Oláh Zoltán Mészár Rita Varga Brigitta Csernus Csaba Szabó Department of Animal Nutrition and Physiology Faculty of Agriculture and Food Sciences and Environmental Management University of Debrecen Faculty of Agriculture and Food Sciences and Environmental Management Doctoral School of Animal Science University of Debrecen Department of Animal Husbandry Faculty of Agriculture and Food Sciences and Environmental Management University of Debrecen Department of Evolutionary Zoology and Human Biology Faculty of Science and Technology University of Debrecen Institutes for Agricultural Research and Educational Farm University of Debrecen Department of Anatomy Histology and Embryology Faculty of Medicine University of Debrecen

Methionine(Met) is an essential and first limiting amino acid in the poultry diet that plays a significant role in chicken embryonic development and growth. The present study examined the effect of in ovo injection of DL-Met and L-Met sources and genotypes on chicken embryonic-intestinal development and health. Fertilized eggs of the two genotypes, TETRA-SL layer hybrid(TSL)—commercial layer hybrid and Hungarian Partridge colored hen breed(HPC)—a native genotype, were randomly distributed into four treatments for each genotype. The treatment groups include the following: 1) control non-injected eggs(NoIn); 2) saline-injected(SaIn); 3) DL-Met injected(DLM); and 4) L-Met injected(LM). The in ovo injection was carried out on 17.5 d of embryonic development; after hatching, eight chicks per group were sacrificed, and the jejunum was extracted for analysis. The results showed that both DLM and LM groups had enhanced intestinal development as evidenced by increased villus width, villus height, and villus area(P ke growth factor 1(IGF1) gene, tricellulin(MD2), occludin(OCLN),superoxide dismutase 1(SOD1), and GST3 genes than the TSL genotype(P < 0.05). In conclusion, these findings showed that in ovo injection of Met enhanced intestinal development, and function, with genotypes responding differently under normal conditions. Genotypes also influenced the expression of intestinal antioxidants, tight junction, and growth-related genes.

关键词： DL-Methionine L-Methionine In ovo injection Intestinal development Poultry

Studies on unfolding energy spectra of neutrons using maximumlikelihood expectation–maximization method

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Nuclear Science and Techniques 2019年第9期30卷 24-33页

作者： Mehrdad Shahmohammadi beni D.krstic D.Nikezic k.N.Yu Department of Physics City University of Hong Kong Tat Chee Avenue Kowloon Tong Hong Kong China Faculty of Science University of Kragujevac Kragujevac Serbia State key Laboratory of Marine Pollution City University of Hong Kong Tat Chee Avenue Kowloon Tong Hong Kong China

Energy spectra of neutrons are important for identification of unknown neutron sources and for determination of the equivalent dose. Although standard energy spectra of neutrons are available in some situations, e.g., for some radiotherapy treatment machines, they are unknown in other cases, e.g., for photoneutrons created in radiotherapy rooms and neutrons generated in nuclear reactors. In situations where neutron energy spectra need to be determined, unfolding the required neutron energy spectra using the Bonner sphere spectrometer (BSS) and nested neutron spectrometer (NNS) has been found promising. However, without any prior knowledge on the spectra, the unfolding process has remained a tedious task. In this work, a standalone numerical tool named ‘‘NRUunfold’’ was developed which could satisfactorily unfold neutron spectra for BSS or NNS, or any other systems using similar detection methodology. A generic and versatile algorithm based on maximum-likelihood expectation– maximization method was developed and benchmarked against the widely used STAY’SL algorithm which was based on the least squares method. The present method could output decent results in the absence of precisely calculated initial guess, although it was also remarked that employment of exceptionally bizarre initial spectra could lead to some unreasonable output spectra. The neutron count rates computed using the manufacturer’s response functions were used for sensitivity studies. The present NRUunfold code could be useful for neutron energy spectrum unfolding for BSS or NNS applications in the absence of a precisely calculated initial guess.

关键词： Neutron spectrometry Maximum-likelihood expectation–maximization Nested neutron spectrometer

Non-Enzymatic Glucose Sensor Based on the Novel Flower Like Morphology of Nickel Oxide

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Soft Nanoscience Letters 2013年第4期3卷 46-50页

作者： Z.H.Ibupoto k.khun V.beni M.Willander Division of Physical Electronics and Nanotechnology Department of Science and TechnologyLinköping UniversityCampus NorrkopingNorrkopingSweden Department of Physics Chemistryand Biology(IFM)Linkoping UniversityLinkopingSwe-den

In this study, novel nickel oxide (NiO) flowers like nanostructures were fabricated onto gold coated glass substrate by hydrothermal method using high alkaline pH medium. The structural study of nickel oxide nanostructures was performed by scanning electron microscopy (SEM) and X-ray differaction (XRD) techniques. Nickel oxide nanostructures are highly dense, uniform and possess good crystalline quality. The so prepared structures were investigated for their electrochemical properties by cyclic voltammetry and amperometric techniques. The nickel oxide flower like morphology has shown good electrochemical performances for the oxidation of glucose. The presented sensing material was able to detected glucose in a wide range of concentration of 0.001 mM to 8 mM with a high sensitivity (123 μmA/mM) and regression coefficient of 0.99. Moreover, the NiO nanostructures based sensor is highly reproducible, stable, exhibiting a fast response time and selective in the response. All the obtained results indicate the potential use of this material in the development of enzyme free sensors for the detection of glucose.

关键词： Nickel Oxide Non-Enzymatic Sensor Glucose Selective Stable

Nutrient Export with Logs, and Release from Residues, after Harvest of a <i>Pinus taeda</i>Plantation in Uruguay

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Open Journal of Forestry 2020年第3期10卷 360-376页

作者： Amabelia del Pino Jorge henández Gimena Arrarte Department of Soil Science Facultad de Agronomía UDELAR Montevideo Uruguay

In Uruguay, Pinus taeda is usually planted a few months after harvest of the former turn, therefore;decomposing residues represents a nutrient source for the new plantation. The aim of this study was to determine the biomass and nutrient extraction off site, following the harvest of a P. taeda plantation. Residue decomposition patterns, and nutrient release were also examined. The site will be referred as S1, corresponding to the clear cut of a 22-year-old P. taeda plantation. Before the clear cut 10 trees were harvested, and logs, branches, twigs, and needles separately weighed. Additionally, forest litter at harvest time was quantified in three different areas. To assess decomposition, mesh bags with residues were allocated in three areas over the forest litter, and samples were taken periodically for 26 months. The remaining biomass, N, P k, Ca, and Mg contents were determined in the different fractions, calculating decompositon rates. Most of the harvested biomass was removed in logs, but the proportion of nutrients exported was considerably lower. Needles showed the highest biomass loss and only 39.1% remained after 26 months, while branches presented high rates in the first two months after cut, but slower thereafter, and at the end of the study more than two thirds of the woody residues remained. Potassium was rapidly released from the residues, while Ca, and Mg, were slowly released, and there was evidence of N and P immobilization in the early stages of decomposition. It was concluded that, although a lower proportion of nutrients were exported, compared to biomass, in the long term, nutrient export with logs could be significant for the sustainability of this production system. While k release from residues did not depend on biomass decay, the slow decomposition, and release of the other nutrients, indicates that this process could have been delayed by nutrient scarcity.

关键词： Residue Decomposition Litter Bags Litter Quality Nutrient Cycling

黑龙江鹿鸣钼矿区花岗岩锆石年龄、地球化学特征及其地质意义

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中国地质 2012年第5期39卷 1162-1171页

作者：马顺清陈静中国地质大学(北京) 北京100083 青海省地质调查院青藏高原北部地质过程与矿产资源重点实验室青海西宁810012

鹿鸣钼矿床位于伊春—延寿多金属成矿带中南段,是近年新发现的斑岩型钼矿床。矿区内成矿主岩为二长花岗岩-花岗斑岩,本文采用LA-ICP-MS微区原位同位素分析技术,测得锆石U-Pb年龄分别为(195.4±1.4)Ma和(197.6±1.3)Ma,形成于印支晚期—... 详细信息

鹿鸣钼矿床位于伊春—延寿多金属成矿带中南段,是近年新发现的斑岩型钼矿床。矿区内成矿主岩为二长花岗岩-花岗斑岩,本文采用LA-ICP-MS微区原位同位素分析技术,测得锆石U-Pb年龄分别为(195.4±1.4)Ma和(197.6±1.3)Ma,形成于印支晚期—燕山早期。岩石地球化学数据表明花岗岩SiO2质量分数为70.74%-75.80%、k2O和Na2O质量分数分别为3.85%-7.02%和0.93%-2.95%,里特曼指数为0.9-3.1,分析显示属于高钾钙碱性-钾玄岩系列岩体;稀土总量(ΣREE)偏低、有较强烈的轻重稀土元素分馏(LaN/YbN=7.76-26.47),Eu负异常明显(Eu/Eu*=0.34-0.62);微量元素富集Rb、Th、U、k,亏损Nb、Ta、Ti、Y和Yb等元素,这或者暗示其岩浆源区相对富水,或者反映岩浆源区可能遭受过俯冲带流体的交代作用,结合前人研究成果认为该矿床的形成与早中生代太平洋板块俯冲作用有关。

关键词：鹿鸣钼矿锆石U-Pb年龄岩石地球化学太平洋板块俯冲

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马尾松人工幼林施肥肥效与增益持续性研究

林业科学研究 2000年第6期13卷 652-658页

作者：谌红辉温恒辉中国林业科学研究院热带林业实验中心，广西凭样 532600

经 13a的马尾松幼林施肥试验表明 ,红壤地区施P肥有利于马尾松幼林生长 ,但产生肥效迟(施肥 7a后产生显著效果 ) ,施N、k肥对促进马尾松幼林生长无显著影响 ,过量还会产生负效应。施N、k肥会促进林木分化 ,施P肥则能使林分结构均一 ,经... 详细信息

经 13a的马尾松幼林施肥试验表明 ,红壤地区施P肥有利于马尾松幼林生长 ,但产生肥效迟(施肥 7a后产生显著效果 ) ,施N、k肥对促进马尾松幼林生长无显著影响 ,过量还会产生负效应。施N、k肥会促进林木分化 ,施P肥则能使林分结构均一 ,经偏相关分析表明 ,P元素是影响马尾松生长的主要因子 ,肥效有一定的时效性和增益持续性。施肥最佳处理组合为N1P3k2 ,即每公顷施N、P、k分别为 0、30、30kg。

关键词：马尾松幼林施肥生长效应肥料时效性