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从BRDF到BPDF:遥感反演基础模型的演进初探

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中国科学:信息科学 2024年第8期54卷 2001-2020页

作者：尚可晏磊张飞舟褚君浩杨彬刘思远 Kevin TANsEY 贾秀萍 oleg DUBOVIK 张子晗李飞北京大学地球与空间科学学院遥感与地理信息系统研究所北京大学空间信息集成与3S工程应用北京市重点实验室中国科学院上海技术物理研究所红外物理国家重点实验室湖南大学电气与信息工程学院中国兵器工业导航与控制技术研究所 school of Geography Geology and the Environment University of Leicester school of Engineering and Technology The University of New South Wales Laboratoire d'Optique Atmosphérique CNRS/Université Lille

光的本质是横波电磁波矢量,以双向反射分布函数BRDF (bidirectional reflectance distribution function)为基础模型的标量遥感体系只利用植被反射光的整体强度信息,无法进一步区分反射辐射蕴含的叶表、叶内和冠层结构信息;在标量遥感... 详细信息

光的本质是横波电磁波矢量,以双向反射分布函数BRDF (bidirectional reflectance distribution function)为基础模型的标量遥感体系只利用植被反射光的整体强度信息,无法进一步区分反射辐射蕴含的叶表、叶内和冠层结构信息;在标量遥感基础上考虑垂直于电磁波传播方向的二维偏振矢量特性(强度+方向)就能深化为矢量遥感体系,从而有望精确刻画反射光中蕴含的多种信息,提升植被参数反演精度.刻画偏振反射空间分布的双向偏振分布函数BPDF目前存在精度低、泛化性差等问题,因此进一步探索矢量遥感基础理论,构建通用性强的植被矢量遥感基础模型具有迫切的现实需求.本文旨在利用光子与植被元素的相互作用构建通用性较强的植被BPDF物理模型.首先基于光子–植被元素相互作用的光谱不变原理,提出基于方向逃逸概率的植被BPDF物理模型基础形式,并基于植被单次反射的辐射传输理论推导模型解析表达;随后通过考虑叶片散射随干物质含量的变化,提出光谱不变原理优化表达并推导模型通用表达式;最后分别利用三维矢量辐射传输模型和多尺度实测数据实现模型的正演直接验证和间接验证.结果表明,本文构建的BPDF物理模型的解析表达和通用表达在不同植被场景下,对偏振反射率的正演均方根误差可达0.001以内,与矢量辐射传输模型正演结果在半球空间内具有很强一致性,在多尺度实测数据也简洁验证了模型关系的稳定性,模型R2普遍高于0.9.相比于现存植被偏振反射模型,本文构建的模型兼具物理机理、简洁形式、可接受的参数化方案、较高精度和较强泛化能力,对浓密植被具备通用性,为在BRDF一维标量遥感的基础上进一步考虑BPDF二维偏振特性从而形成矢量遥感体系这一转变过程提供了理论基础和探索性方案.

关键词：植被 BPDF 矢量遥感物理模型偏振

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Presepsin as a biomarker of bacterial translocation and an indicator for the prescription of probiotics in cirrhosis

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World Journal of Hepatology 2024年第5期16卷 822-831页

作者： Irina Efremova Roman Maslennikov Elena Poluektova oleg Medvedev Anna Kudryavtseva George Krasnov Maria Fedorova Filipp Romanikhin Maria Zharkova Oxana Zolnikova Gyunay Bagieva Vladimir Ivashkin Department of Internal Medicine Gastroenterology and HepatologySechenov UniversityMoscow 119435Russia Department of scientific Scientific Community for the Promotion of the Clinical Study of the Human MicrobiomeMoscow 119435Russia Department of Pharmacology Lomonosov Moscow State UniversityMoscow 119192Russia Department of Post-Genomic Research Laboratory Engelhardt Institute of Molecular BiologyRussian Academy of SciencesMoscow 119991Russia

BACKGROUND The gut–liver axis and bacterial translocation are important in cirrhosis,but there is no available universal biomarker of cellular bacterial translocation,for which presepsin may be a *** To evaluate the relationship of the blood presepsin levels with the state of the gut microbiota in cirrhosis in the absence of obvious *** This study included 48 patients with Child–Pugh cirrhosis classes B and C and 15 healthy *** fecal microbiome was assessed using 16s rRNA gene *** levels of presepsin were measured.A total of 22 patients received a probiotic(saccharomyces boulardii)for 3 *** Presepsin levels were higher in patients with cirrhosis than in healthy individuals[342(91-2875)vs 120(102-141)pg/mL;P=0.048].Patients with elevated presepsin levels accounted for 56.3%of all included *** had lower levels of serum albumin and higher levels of serum total bilirubin and overall severity of cirrhosis as assessed using the Child–Pugh *** with elevated presepsin levels had an increased abundance of the main taxa responsible for bacterial translocation,namely Bacilli and Proteobacteria(including the main class Gammaproteobacteria and the minor taxa Xanthobacteraceae and stenotrophomonas),and a low abundance of bacteria from the family Lachnospiraceae(including the minor genus Fusicatenibacter),which produce short-chain fatty acids that have a positive effect on intestinal barrier *** presepsin level directly correlated with the relative abundance of Bacilli,Proteobacteria,and inversely correlated with the abundance of Lachnospiraceae and *** 3 months of taking the probiotic,the severity of cirrhosis on the Child–Pugh scale decreased significantly only in the group with elevated presepsin levels[from 9(8-11)to 7(6-9);P=0.004],while there were no significant changes in the group with normal presepsin levels[from 8(7-8)to 7(6-8);P=0.123].A high level of presepsin

关键词： Dysbiosis Gut Intestinal permeability Leaky gut Gut-liver axis Liver Microbiota

CCD/EMCCD光电参数测试系统的设计与应用

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中国光学（中英文） 2024年第3期17卷 693-703页

作者：沈吉 VIACHEsLAV V.Zabudsky 常维静那启跃简云飞 oleg V.Rikhalsky OLEKsANDR G.Golenkov VOLODYMYR P.Reva 华东光电集成器件研究所江苏苏州215263 乌克兰科学院V.E.Lashkaryov半导体物理研究所乌克兰基辅01001 乌克兰科学院Bogomoletz生理学研究所乌克兰基辅01001

本文开发了一种用于测量CCD和EMCCD(电子倍增CCD)芯片光电参数的测试系统。该测试系统通过自动模式或手动模式间的切换,测量器件的暗电流、读出放大器的响应度、电荷转移效率、电荷容量和其他参数。该测试系统可以针对不同规格和结构的C... 详细信息

本文开发了一种用于测量CCD和EMCCD(电子倍增CCD)芯片光电参数的测试系统。该测试系统通过自动模式或手动模式间的切换,测量器件的暗电流、读出放大器的响应度、电荷转移效率、电荷容量和其他参数。该测试系统可以针对不同规格和结构的CCD/EMCCD器件,实现CCD晶圆或封装好的成品的参数测试,实现576×288、640×512、768×576、1024×1024、1280×1024 CCD/EMCCD的测试和筛选。

关键词： CCD EMCCD 测试系统光电参数

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The concept of sUAs/DL-based system for detecting and classifying abandoned small firearms

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Defence Technology（防务技术） 2023年第12期30卷 23-31页

作者： Jungmok Ma oleg A.Yakimenko Department of Defense science Korea National Defense University(KNDU)Republic of Korea Department of systems Engineering Naval Postgraduate School(NPS)USA

Military object detection and identification is a key capability in surveillance and *** is a major factor in warfare effectiveness and warfighter ***,portable,and rapidly deployable small unmanned aerial systems(s UAs)in conjunction with powerful deep learning(DL)based object detection models are expected to play an important role for this *** prove overall feasibility of this approach,this paper discusses some aspects of designing and testing of an automated detection system to locate and identify small firearms left at the training range or at the *** a system is envisioned to involve an s UAs equipped with a modern electro-optical(EO)sensor and relying on a trained convolutional neural network(CNN).Previous study by the authors devoted to finding projectiles on the ground revealed certain challenges such as small object size,changes in aspect ratio and image scale,motion blur,occlusion,and *** study attempts to deal with these challenges in a realistic operational scenario and go further by not only detecting different types of firearms but also classifying them into different *** study used a YOLOv2CNN(Res Net-50 backbone network)to train the model with ground truth data and demonstrated a high mean average precision(m AP)of 0.97 to detect and identify not only small pistols but also partially occluded rifles.

关键词： small firearms Object detection Deep learning small unmanned aerial systems

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Efficient passivation of DY center in CH_(3)NH_(3)PbBr_(3) by chlorine:Quantum molecular dynamics

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Nano Research 2022年第3期15卷 2112-2122页

作者： Ran shi Wei-Hai Fang Andrey s.Vasenko Run Long oleg V.Prezhdo College of Chemistry Key Laboratory of Theoretical&Computational Photochemistry of Ministry of EducationBeijing Normal UniversityBeijing 100875China National Research University Higher school of Economics(HsE)University 101000 MoscowRussia Donostia International Physics Center(DIPC) Paseo Manuel de Lardizabal 4San Sebastián/Donostia20018 Basque CountrySpain Department of Chemistry University of Southern CaliforniaLos AngelesCA 90089USA

MAPbBr_(3)(MA=CH_(3)NH_(3)^(+))doping with bismuth increases electric conductivity,charge carrier density and photostability,reduces toxicity,and expands light ***,Bi doping shortens excited-state lifetimes due to formation of DY−charge recombination *** nonadiabatic molecular dynamics and time-domain density functional theory,we demonstrate that the DY−center forms a deep,highly localized hole trap,which accelerates nonradiative relaxation ten-fold and is responsible for 90%of carrier *** trapping occurs by coupling between the valence band and the trap state,facilitated by the Br atoms surrounding the Bi *** of the DY−center with chlorines heals the local geometry distortion,eliminates the trap state,and makes the carrier lifetimes longer than even in pristine MAPbBr_(3).The decreased charge recombination arises from reduced nonadiabatic coupling and shortened coherence time,due to diminished electron–hole overlap around the passivated *** study demonstrates accelerated nonradiative recombination in Bi-doped MAPbBr_(3),suggests a strategy for defect passivation and reduction of nonradiative energy losses,and provides atomistic insights into unusual defect properties of metal halide perovskites needed for rational design of high-performance perovskite solar cells and optoelectronic devices.

关键词： Hybrid organic-inorganic perovskite DY−center and Cl passivation charge trapping and recombination nonadiabatic molecular dynamics time-domain density functional theory.

A class of high-mobility layered nanomaterials by design

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Journal of Materials science & Technology 2023年第33期164卷 179-187页

作者： Dmitry V.Averyanov Ivan s.sokolov oleg E.Parfenov Alexander N.Taldenkov oleg A.Kondratev Andrey M.Tokmachev Vyacheslav G.storchak National Research Center “Kurchatov Institute” Kurchatov Sq.1Moscow 123182Russia

Design of materials with particular functional properties is indispensable albeit very *** and structural analogies can be helpful in this endeavor,especially when a particular combination of properties is sought *** aim is to bundle together 3 characteristics:high carrier mobility,magnetism,and scalability to nanomaterials in the form of a film–such a combination is particularly advantageous for ***,inspired by recent studies of MAl_(2)si_(2)and related compounds,we develop magnetic EuAl_(2)Ge_(2)and non-magnetic srAl_(2)Ge_(2)nanomaterials with high carrier *** syntheses employing sacrificial 2D templates result in epitaxial films of MAl_(2)Ge_(2)seamlessly integrated with *** syntheses are followed by a study of the atomic structure,magnetic and electron transport *** particular,the films demonstrate high carrier mobility,exceeding 10,000 cm^(2)V^(-1)s^(-1)in the case of EuAl_(2)Ge_(2),making the materials appealing for *** together,MAl_(2)Ge_(2)and MAl_(2)si_(2)form a class of high-mobility layered nanomaterials.

关键词： High carrier mobility Magnetism srAl_(2)Ge_(2) EuAl_(2)Ge_(2) Germanium

Operating limits and features of direct air capture on K_(2)CO_(3)/ZrO_(2) composite sorbent

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Chinese Journal of Chemical Engineering 2022年第6期35卷 11-20页

作者： Vladimir s.Derevschikov Janna V.Veselovskaya Anton s.shalygin Dmitry A.Yatsenko Andrey Z.sheshkovas oleg N.Martyanov Boreskov Institute of Catalysis sB RAs Akademika Lavrentieva Av.5630090 NovosibirskRussia Novosibirsk state University Pirogova Str.1630090 NovosibirskRussia

Potassium carbonate-based sorbents are prospective materials for direct air capture(DAC).In the present study,we examined and revealed the influence of the temperature swing adsorption(TsA)cycle conditions on the CO_(2) sorption properties of a novel aerogel-based K_(2)CO_(3)/ZrO_(2) sorbent in a DAC *** was shown that the humidity and temperature drastically affect the sorption dynamic and sorption capacity of the *** a temperature at the sorption stage was 29℃ and a water vapor pressure P_(H2O) in the feed air was 5.2 mbar(1 bar=105 Pa),the composite material demonstrated a stable CO_(2) sorption capacity of 3.4%(mass).An increase in sorption temperature leads to a continuous decrease in the CO_(2) absorption capacity reaching a value of 0.7%(mass)at T=80℃.The material showed the retention of a stable CO_(2) sorption capacity for many cycles at each temperature in the *** PH2O in the inlet air from 5.2 to 6.8 mbar leads to instability of CO_(2) sorption capacity which decreases in the course of 3 consecutive TsA cycles from 1.7%to 0.8%(mass)at T=29℃.A further increase in air humidity only facilitates the deterioration of the CO_(2) sorption capacity of the material.A possible explanation for this phenomenon could be the filling of the porous system of the sorbent with solid reaction products and an aqueous solution of potassium salts,which leads to a significant slowdown in the CO_(2) diffusion in the composite sorbent *** investigate the regeneration step of the TsA cycle in situ,the macro ATRFTIR(attenuated total reflection Fourier-transform infrared)spectroscopic imaging was applied for the first *** was shown that the migration of carbonate-containing species over the surface of sorbent occurs during the thermal regeneration stage of the TsA *** movement of the active component in the porous matrix of the sorbent can affect the sorption characteristics of the composite *** revealed features make it possible

关键词： Zirconia aerogel Potassium carbonate Carbon dioxide Direct air capture Fourier-transform infrared spectroscopic imaging

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Understanding Lithium-ion Transport in sulfolane- and Tetraglyme-Based Electrolytes Using Very Low-Frequency Impedance spectroscopy

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Energy & Environmental Materials 2023年第1期6卷 368-376页

作者： Janet sHo oleg A.Borodin Michael sDing Lin Ma Marshall A.schroeder Glenn R.Pastel Kang Xu Energy sciences Division Sensors and Electron Devices DirectorateUS Army Research LaboratoryAdelphi MD 20783USA

With the increasing interest in highly concentrated electrolyte systems,correct determination of the cation transference number is ***-field gradient NMR technique,which measures self-diffusion coefficients,is often applied on liquid electrolytes because of the wide accessibility and simple sample ***,since the assumptions of this technique,that is,complete salt dissociation,all ions participating in motion,and all of them moving independently,no longer hold true in concentrated solutions,the transference numbers,thus obtained are often *** the present work,impedance spectroscopy at a frequency range of 1 MHz to 0.1 mHz was used to examine the concentration effect on lithium-ion transference number under anion-blocking conditions T abc Liþfor two electrolytes:lithium bis(fluorosulfonyl)imide(LiFsI)in sulfolane(sL)and lithium bis(trifluorosulfonyl)imide(LiTFsI)in tetraglyme(G4).The T abc Liþof the former was almost an order of magnitude higher than that of the *** also appeared to increase with increasing concentration while the latter followed an opposite *** faster Li^(+)transport in the sL system is attributed to the formation of a liquid structure consisting of extended chains/bridges of sL molecules and the anions,which facilitate a cation-hopping/ligand-exchanged-typed diffusion mechanism by partially decoupling the cations from the anions and solvent *** G4 system,in contrast,is dominated by the formation of long-lived,stable[Li(G4)]+solvation cages that results in a sluggish Li+*** difference between the two transport mechanisms is discussed via comparison of the bulk ionic conductivity,viscosity,ion self-diffusion coefficients,and the Onsager transport coefficients.

关键词： anion-blocking conditions ion correlations low-frequency impedance spectroscopy transference number

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Time and energy minimization strategy codetermine the loop migration of demoiselle cranes around the Himalayas

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Integrative Zoology 2022年第5期17卷 715-730页

作者： Chunrong MI Xinhai LI Falk HUETTMANN oleg GOROsHKO Yumin GUO school of Ecology and Nature Conservation Beijing Forestry UniversityChina Institute of Zoology Chinese Academy of SciencesBeijingChina University of Chinese Academy of sciences BeijingChina EWHALE Lab Department of Biology and WildlifeInstitute of Arctic BiologyUniversity of Alaska-FairbanksFairbanksUSA Daursky state Nature Biosphere Reserve Institute of Nature ResourcesEcology and Cryology RASRussia

Tens of thousands of demoiselle cranes’crossing the Himalayas to the Indian subcontinent have been reported for decades,but their exact spring migration route remained a mystery until our previous study found they made a detour in spring along the western edge of the Himalayas and crossed the Mongolian Plateau to their breeding areas based on satellite telemetry of 3 *** corroborate the loop migration pattern and explore whether demoiselle crane’s loop migration route is shaped by time-and energy-minimization strategies in spring and autumn and how the temporal and spatial variation of environmental conditions contribute to crane’s selection of migration routes,we tracked 11 satellite-tagged demoiselle cranes from their breeding area in China and Russia,simulated 2 pseudo migration routes,and then compared the environmental conditions,time,and energy cost between true and pseudo routes in the same *** show that demoiselles’spring migration obeyed time-minimization hypothesis,avoiding the colder Qinghai-Tibet Plateau,beneﬁted by abundant food and higher thermal and orographic uplift along the route;autumn migration follows energy-minimization hypothesis with the shorter *** research will contribute to uncover the mechanical reasons why demoiselle crane avoids crossing the giant barrier of the Himalayas in spring,and shapes a loop migration route.

关键词： Anthropoides virgo barrier cross loop migration strategy satellite tracking the Himalayas