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Formation and ecological response of sand patches in the protection system of Shapotou section of the Baotou-Lanzhou railway,China

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Journal of Arid Land 2024年第2期16卷 298-313页

作者： DUN Yaoquan QU Jianjun KANG Wenyan LI Minlan LIU Bin WANG Tao SHAO Mei Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of chinese academy of sciences Beijing 100049China College of Urban and Environmental sciences Northwest UniversityXi'an 710100China Zhongwei Works Section of China Railway Lanzhou Bureau Group Company Limited Zhongwei 755000China

The development of bare patches typically signifies a process of ecosystem *** the protection system of Shapotou section of the Baotou-Lanzhou railway,the extensive emergence of bare sand patches poses a threat to both stability and ***,there is limited knowledge regarding the morphology,dynamic changes,and ecological responses associated with these sand ***,we analyzed the formation and development process of sand patches within the protection system and its effects on herbaceous vegetation growth and soil nutrients through field observation,survey,and indoor analysis *** results showed that sand patch development can be divided into three stages,i.e.,formation,expansion,and stabilization,which correspond to the initial,actively developing,and semi-fixed sand patches,*** average dimensions of all sand patch erosional areas were found to be 7.72 m in length,3.91 m in width,and 0.32 m in *** actively developing sand patches were the largest,and the initial sand patches were the *** the stage of formation and expansion,the herbaceous community composition changed,and the plant density decreased by more than 50.95%.Moreover,the coverage and height of herbaceous plants decreased in the erosional area and slightly increased in the depositional lobe;and the fine particles and nutrients of soils in the erosional area and depositional lobe showed a decreasing *** the stabilization phases of sand patches,the area from the inlet to the bottom of sand patches becomes initially covered with *** and 0-2 cm surface soil condition improved in the erosional area,but this improvement was not yet evident in the depositional *** such as disturbance,climate change,and surface resistance to erosion exert notable influences on the formation and dynamics of sand *** results can provide evidence for the future treatment of sand patches and the management of the pro

关键词： railway protection system sand patch morphology vegetation characteristic soil property

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Specifications and control of spatial frequency errors of components in two-beam laser static holographic exposure for pulse compression grating fabrication

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High Power Laser Science and Engineering 2024年第1期12卷 1-12页

作者： Chen Hu Songlin Wan Guochang Jiang Haojin Gu Yibin Zhang Yunxia Jin Shijie Liu Chengqiang Zhao Hongchao Cao Chaoyang Wei Jianda Shao Precision Optical Manufacturing and Testing Center Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences(CAS)ShanghaiChina Key Laboratory for High Power Laser Material of chinese academy of sciences Shanghai Institute of Optics and Fine MechanicsCASShanghaiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijingChina Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhouChina China-Russian Belt and Road Joint Laboratory on Laser Science ShanghaiChina

The large-aperture pulse compression grating(PCG) is a critical component in generating an ultra-high-intensity, ultra-short-pulse laser;however, the size of the PCG manufactured by transmission holographic exposure is limited to large-scale high-quality materials. The reflective method is a potential way for solving the size limitation, but there is still no successful precedent due to the lack of scientific specifications and advanced processing technology of exposure mirrors. In this paper, an analytical model is developed to clarify the specifications of components, and advanced processing technology is adopted to control the spatial frequency errors. Hereafter, we have successfully fabricated a multilayer dielectric grating of 200 mm × 150 mm by using an off-axis reflective exposure system with Φ300 mm. This demonstration proves that PCGs can be manufactured by using the reflection holographic exposure method and shows the potential for manufacturing the meter-level gratings used in 100 petawatt class high-power lasers.

关键词： high-power laser off-axis reflective exposure system pulse compression grating spatial frequency errors specifications

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Intraseasonal variability of the Kuroshio observed via mooring at 18°N

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Journal of Oceanology and Limnology 2024年第2期42卷 468-483页

作者： Xin YUAN Qingye WANG Jie MA Shijian HU Dunxin HU Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of chinese academy of sciences Beijing 100049China Laoshan Laboratory Qingdao 266237China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Insufficient observations near the origin of the Kuroshio have led to incomplete understanding of the intraseasonal variability(ISV)of the *** measurements of the Kuroshio velocity were performed with an array of three profiler moorings(122.7°E,123°E,and 123.3°E)along 18°N from January 2018 to February *** ISV of the Kuroshio at 18°N was investigated based on a combination of mooring observations and global high-resolution HYbrid Coordinate Ocean Model reanalysis *** estimated time-averaged transport in the upper 350 m across the observation transect was 6.5±2.6 Sv(1.0 Sv=10^(6)m^(3)/s).Two significant ISV peaks at 50-60 and~100 d were recognized in the power spectra of the meridional velocity and *** analysis indicated that the ISV at 50-60 d was caused by westward-propagating eddies at average propagation speed of~13 cm/s and wavelength of~635 *** ISV peak at~100 d was mainly caused by northward-propagating eddies generated in the North Equatorial Current *** investigation indicated that the ISV of the Kuroshio at 18°N is dominated by meridional transport,rather than by the zonal migration of the Kuroshio main *** findings provide a better understanding of the ISV of the Kuroshio east of Luzon Island.

关键词： intraseasonal variability(ISV) Kuroshio mooring observation eddy

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Multiple Uplift and Exhumation of the Southeastern Tibetan Plateau:Evidence from Low-Temperature Thermochronology

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 569-584页

作者： WU Limin PENG Touping FAN Weiming ZHAO Guochun GAO Jianfeng DONG Xiaohan PENG Shili MIN Kang Tin Aung MYINT State Key Laboratory of Isotope Geochemistry Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China chinese academy of sciences Center for Excellence in Deep Earth Science Guangzhou 510640China University of chinese academy of sciences Beijing 100049China chinese academy of sciences Center for Excellence in Tibetan Plateau Earth sciences Beijing 100101China Department of Earth sciences The University of Hong KongHong Kong 999077China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) ZhuhaiGuangdong 519085China Department of Geology University of MandalayMandalay 05011Myanmar

Since the Cenozoic,the Tibetan Plateau has experienced large-scale uplift and outgrowth due to the India-Asia ***,the mechanism and timing of these tectonic processes still remain ***,using apatite fission track dating and inverse thermal modeling,we explore the mechanism of different phases of rapid cooling for different batholiths and intrusions in the southeastern Tibetan *** contrast to previous views,we find that the coeval granitic batholith exposed in the same tectonic zone experienced differential fast uplift in different sites,indicating that the present Tibetan Plateau was the result of differential uplift rather than the entire lithosphere uplift related to lithospheric collapse during Cenozoic *** addition,we also suggest that the 5-2 Ma mantle-related magmatism should be regarded as the critical trigger for the widely coeval cooling event in the southeastern Tibetan Plateau,because it led to the increase in atmospheric CO_(2)level and a hotter upper crust than before,which are efficient for suddenly fast rock weathering and ***,we propose that the current landform of the southeastern Tibetan Plateau was the combined influences of tectonic and climate.

关键词： apatite fission track rapid cooling differential uplift magmatism southeastern Tibetan Plateau

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Light People:*** May Lau,newly elected US NAE member in Hong Kong,talks about future of photonics and women in science

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Light(Science & Applications) 2024年第4期13卷 602-608页

作者： Yating Wan Chenzi Guo Electrical and Computer Engineering the ComputerElectrical and Mathematical Sciences and Engineering DivisionKing Abdullah University of Science and Technology23955-6900 ThuwalSaudi Arabia Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchunChina

Editorial Photonics technology remains a driving force in today’s scientific landscape,marked by continuous innovation and crossdisciplinary *** an enlighting conversation with Light:Science&Applications,*** May Lau,a pioneer in photonics research,shares her deep insights on the evolution of technologies of LEDs,lasers,challenges of hetero-epitaxy,and the future of micro-LEDs and quantum dot *** honored as a member of the US National academy of Engineering(NAE)for her significant contributions to photonics and electronics using III-V semiconductors on silicon,*** stands out as the sole Hong Kong scholar inducted into the NAE this year,joining 114 new and 21 international *** this exclusive Light People interview,*** shares her journey as a pioneering woman in engineering,her commitment to mentorship and academia,and her perspective on advancing female representation in *** summary provided is distilled from ***’s thoughtful responses during the *** a deeper exploration of ***’s experiences and advice,the full interview is available in the Supplementary material.

关键词： interview lighting driving

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Synthesis and Crystal Structure of 2-Nitrophenyl N,N-Bis(2-chloroethyl)-N'-(4-methylbenzene- sulfonamino)ethyl-phosphorodiamidate

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chinese Journal of Structural Chemistry 2006年第7期25卷 797-800页

作者： ZHANG Gai-Hong CHEN Ru-Yu HUANG You MIAO Zhi-Wei Institute and State Key Laboratory of Elemento-organic Chemistry Nankai University Tianjin 300071 China

The crystal structure of 2-nitrophenyl N,N-bis（2-chloroethyl）-N＇-（4-methylbenzene-sulfonamino）ethyl-phosphorodiamidate （C19H25Cl2N4O6PS） was determined by single-crystal X-ray diffraction analysis. The compound crystallizes in the triclinic system, space group PI^- with a = 9.3664（13）, b = 9.9560（14）, c = 13.1803（18） ,A, α = 87.338（2）, β= 87.632（2）, γ = 79.536（2）°, Dc = 1.484 g/cm^3, Z = 2, λ = 0.71073 A, μ（MoKα） = 0.465, Mr = 539.36, V = 1206.7（3） A^3, F（000） = 560, the final R = 0.0426 and wR = 0.1097 for 3463 observed reflections with I 〉 2σ（I）.

关键词： sulfonamide crystal structure phosphorodiamidate

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Post-exascale supercomputing:research opportunities abound

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Frontiers of Information Technology & Electronic Engineering 2018年第10期19卷 1203-1208页

作者： Zuo-ning CHEN Jack DONGARRA Zhi-wei XU chinese academy of Engineering Electrical Engineering and Computer Science Department University of Tennessee Institute of Computing Technology Chinese Academy of Sciences

Exascale supercomputing refers to the scientific research efforts and activities to build and use supercomputers that can perform scientific computing at the speed of exaflops,or 10^(18) floating-point(64-bit)operatio... 详细信息

关键词：计算研究机科学研究浮点操作

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Evidence for diurnal periodicity of earthquakes from midnight to daybreak

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National Science Review 2019年第5期6卷 1016-1023页

作者： Jinlai Hao Jinhai Zhang Zhenxing Yao Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences

Previously, inadequate earthquake catalogs and the lack of method made it challenging, if not impossible, to determine the dominant period of earthquake *** the advent of densely distributed seismic stations in Japan since 2002, 410 642 M1.0+ earthquakes have been cataloged under the mainland within30-km depth, which provide a superb dataset to identify the periodicity of *** processed this catalog using time-frequency analyses and daily stacking, which are powerful in extracting weak periodical signal from strong random *** concentrated on the time sector from 0:00 to 6:00(*** midnight to daybreak), which is a reliable time window for much higher detectability of weak earthquakes,since it has the lowest affects from cultural *** successfully observed two apparent periodicities of12-and 24-hour, which are much smaller than the fortnightly periodicity presented previously in the *** earth tides, after intentionally ignoring the contribution from the Moon, present similar dominant periods as the *** may indicate that the dominant period of earthquakes is statistically associated with the Sun rather than the *** daily stacking number of earthquakes using a15-minute or 1-hour interval shows a peak around 1:30, rather than usually expected 3:00 to 4:*** addition, bigger earthquakes show more evident variations in the stacking results, and the trend is very consistent for various lower limits of earthquake magnitude from M1.0 to *** discoveries settled the disputes on the existence of the periodicity of earthquakes since 1886 and may open a window to unravel the mystery of earthquakes.

关键词： periodicity of earthquakes time-frequency analyses ocean tide earth tide Local Mean Time

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The Nonlinear Wave Force on a Circular Cylinder in Shallow Water

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China Ocean Engineering 1992年第2期7卷 117-136页

作者： Qiu Dahong

Based on the 1st order cnoidal wave theory, the nonlinear wave diffraction around a circular cylinder in shallow water is studied in this paper. The equation of the wave surface around the cylinder is formulated and by using this formula the wave surface elevation on the cylinder surface can be obtained. In this paper, the formula for calculating the cnoidal wave force on a circular cylinder is also derived. For the wave conditions which are often encountered in practical engineering designs, the ratios of the nonlinear wave forces to the linear wave forces are calculated, and the results are plotted in this paper for design purposes. In order to verify the theoretical results, model tests are conducted. After comparing the test results with the theoretical ones, it is concluded that, in shallow water, for the case of T g / d^(1/2) > 8-10 and H / d > 0.3, the cnoidal wave theory should be used to calculate the wave action on a cylindrical pier.

关键词： cnoidal wave force cylinder shallow water

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BARN:Behavior-Aware Relation Network for multi-label behavior detection in socially housed macaques

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Zoological Research 2023年第6期44卷 1026-1038页

作者： Sen Yang Zhi-Yuan Chen Ke-Wei Liang Cai-Jie Qin Yang Yang Wen-Xuan Fan Chen-Lu Jie Xi-Bo Ma College of Medicine and Biological Information Engineering Northeastern UniversityShenyangLiaoning 110169China MAIS State Key Laboratory of Multimodal Artificial Intelligence SystemsInstitute of AutomationChinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing100049China School of Automation Harbin University of Science and TechnologyHarbinHeilongjiang 150080China

Quantification of behaviors in macaques provides crucial support for various scientific disciplines,including pharmacology,neuroscience,and *** recent advancements in the analysis of macaque behavior,research on multi-label behavior detection in socially housed macaques,including consideration of interactions among them,remains *** the lack of relevant approaches and datasets,we developed the Behavior-Aware Relation Network(BARN)for multi-label behavior detection of socially housed *** approach models the relationship of behavioral similarity between macaques,guided by a behavior-aware module and novel behavior classifier,which is suitable for multi-label *** also constructed a behavior dataset of rhesus macaques using ordinary RGB cameras mounted outside their *** dataset included 65?913 labels for19 behaviors and 60?367 proposals,including identities and locations of the *** results showed that BARN significantly improved the baseline SlowFast network and outperformed existing relation *** conclusion,we successfully achieved multilabel behavior detection of socially housed macaques with both economic efficiency and high accuracy.

关键词： Macaque behavior Drug safety assessment Multi-label behavior detection Behavioral similarity Relation network

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