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EXPERIMENTAL INVESTIGATIONS ON THE WALL IN NEMATICS

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Chinese Physics Letters 1988年第11期5卷 509-512页

作者： sun zhengmin Laboratory of Solid State Microstructure Nanjing UniversityNanjing

The static and dynamical characters of the wall in nematics at the magnetic field above the Fredericks transition have been investigated *** dependence of the width,the speed and the relaxation time of the wall on the reduced magnetic field were *** linear dependence of the speed of the wall on the tilt angle of the magnetic field was also revealed.

关键词： magnetic relaxation field

Low Frequency Raman Spectra in Ester Liquid Crystals Near Phase Transitions

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Chinese Physics Letters 1991年第2期8卷 90-93页

作者： ZHANG Mingsheng HU Gongjian CHEN Qiang sun zhengmin YIN Zhen Center for Materials Analysis Nanjing UniversityNanjing 210008 Department of Physics Nanjing UniversityNanjing 210008 also Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210008

Phase transitions of the ferroelectric liquid crystal were studied by recording low-frequency Raman spectra and three Raman lines at 15,49 and 93cm^(-1) were *** intensities of the 15 and 49 cm^(-1) modes reduce to zero at smectic C*transition temperature,and in the isotropic phase the 93cm^(-1) Raman line with partial frequency shift totally disappears.

关键词： Phase Transition totally

火电厂高盐废水烟道旁路蒸发系统设计和运行分析

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能源科技 2024年第1期22卷 47-50页

作者：孙正民胡大龙莫索克孙桦余耀宏天津国能盘山发电有限责任公司天津301900 西安西热水务环保有限公司陕西西安710054

针对高盐废水旁路烟气蒸发工艺应用缺乏长时间运行案例经验,实际工程应用系统设计、设备选型、运行维护方面存在的问题,提出了改进方法和应对措施。优化雾化水泵选型、烟道布置、蒸发器烟温测点位置,灰斗侧壁加装物料破拱装置,增加雾化... 详细信息

针对高盐废水旁路烟气蒸发工艺应用缺乏长时间运行案例经验,实际工程应用系统设计、设备选型、运行维护方面存在的问题,提出了改进方法和应对措施。优化雾化水泵选型、烟道布置、蒸发器烟温测点位置,灰斗侧壁加装物料破拱装置,增加雾化水管路大流量冲洗措施,蒸发器雾化水调节阀,采用V型调节球阀等。通过对火电厂高盐废水烟道旁路蒸发系统运行中出现的问题进行全面分析,并从工艺、设备及运行维护方面提出针对性措施,最终实现高盐废水烟道旁路蒸发系统安全稳定运行。

关键词：火电厂高盐废水烟道旁路蒸发零排放设计运行应对措施

Divergent responses of runoff to climate change in the upper basins of the Third Pole dominated by westerlies and monsoon

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Science China Earth Sciences 2024年第8期67卷 2592-2614页

作者： Qikai sun Fengge SU He sun State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China

The diverse climates,distribution of snow and glaciers,and geographic locations directly affect the runoff response to climate change in the upper basins of the Third *** present,a comprehensive analysis of runoff variations and their distinct responses to climate change in the westerlies-and monsoon-dominated upper basins is still *** study comprehensively analyzed annual runoff variations in westerlies-dominated basins(the upper basins of the Aksu(UAKS),Syr Darya(USRD),Yarkant(UYK),Hotan(UHT),Amu Darya(UAMD),and Indus(UI))and monsoon-dominated basins(the upper basins of the Yangtze(UYA),Yellow(UYE),Lancang(ULC),Nujiang(UNJ),and Yarlung Zangbo(UYZ))of the Third Pole from 1961 *** multi-source meteorological data and large-scale circulation factors,this study investigated the divergent responses of runoff in the upper basins to climate change,and explored the large-scale circulation mechanisms underlying runoff variations in these upper *** results showed that:(1)The annual runoff in the majority of upper basins(except for the UYE and UYZ)exhibited an increasing trend,and the annual runoff in the UAKS,UYK,and UI showed a significant increasing trend from1961 to *** annual runoff in the upper basins of the Third Pole changed abruptly from decreasing to increasing between the 1980s and 2000s,with the exception of the UYE.(2)The runoff in the monsoon-dominated upper basins has been controlled primarily by changes in precipitation over the past 55 *** contrast,the runoff in the westerlies-dominated upper basins exhibited three distinct long-term responses to climate change:temperature-dominated(UYK and UHT),precipitation-dominated(USRD and UAMD),and the combined influence of precipitation and temperature(UAKS and UI).Since the 1960s,the sensitivity of runoff to warm season temperature changes in the most westerlies-dominated upper basins has decreased,while the response of runoff to precipitation changes has intensified.(3)The stud

关键词： Upper basins of the Third Pole Climate change Westerlies and monsoon Runoff variations Large-scale circulation factors

New perspectives on deep carbon cycling

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Science China Earth Sciences 2024年第8期67卷 2411-2422页

作者： Weidong sun Center of Deep Sea Research Key Laboratory of Ocean Observation and ForecastingInstitute of OceanologyChinese Academy of SciencesQingdao 266071China Laoshan Laboratory Qingdao 266237China University of Chinese Academy of Sciences Beijing 100049China

The proto-atmosphere serves as a crucial starting point for the carbon *** based on atmospheric data from Mars and Venus suggest that Earth's proto-atmosphere contained>110 bar of CO_(2)and>2.6 bar of *** protoatmosphere had over 1000 bar of water vapor during the magma ocean stage,assuming the proto-ocean had a volume of two oceans of *** this stage both water and carbon dioxide were in a supercritical state at the magma-atmosphere *** serpentinization reactions occurred due to rock-water interaction,producing abundant ***,nitrogen is reduced to ammonia,and carbon dioxide to methane,forming carbonate *** proto-atmosphere dominated by methane,ammonia,and hydrogen formed a significant amount of amino acids through *** process is essential not only to the origin of life,but also to the early carbon-nitrogen cycle on *** the Hadean eon,a large amount of CO_(2)was sequestered as carbonate and organic ***,it mainly entered the deep mantle through mantle overturn or *** the mantle transition zone,carbonate undergoes“Redox freezing”,where carbonate is reduced to diamond through oxidation of ferrous iron in the *** the lower mantle,Fe^(2+)undergoes disproportionation reactions,forming Fe^(3+)and metallic *** these,Fe^(3+)mainly resides in bridgmanite,thereby increasing the oxygen fugacity of the lower mantle,while metallic iron falls to the Earth's *** distribution of carbon in the mantle is crucial for deep carbon *** density curves of diamond and mantle peridotite melt intersect at the bottom of the mantle transition zone(about 660 km).This density crossover leads to the accumulation of diamond during the magma ocean *** materials such as subducting slabs enter the lower mantle,compensatory upwelling of lower mantle material *** enters the upper mantle,decomposes,releasing Fe^(3+)ions and oxidizes diamond

关键词： Carbon cycling Proto-atmosphere Amino acids Subduction initiation Passive margin subduction Atmospheric carbon dioxide

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主战坦克目标易损性分析与毁伤评估仿真

弹箭与制导学报 2009年第6期29卷 274-277页

作者：王国辉李向荣孙正民装甲兵工程学院．北京100072

针对目标易损性分析仿真评估的关键问题,以"性能降低程度"为依据,构建了主战坦克各功能子系统的功能毁伤树图;在弹药对目标毁伤作用原理分析的基础上,建立了典型反坦克弹药对目标毁伤的数学模型,利用VC++平台开发了主战坦克目标易损性... 详细信息

针对目标易损性分析仿真评估的关键问题,以"性能降低程度"为依据,构建了主战坦克各功能子系统的功能毁伤树图;在弹药对目标毁伤作用原理分析的基础上,建立了典型反坦克弹药对目标毁伤的数学模型,利用VC++平台开发了主战坦克目标易损性分析与毁伤评估仿真系统。以穿甲弹为例进行了主战坦克毁伤评估,得到了主战坦克整体毁伤概率随打击速度、打击方位角等参数的变化规律。研究结果对主战坦克防护结构设计、反坦克弹药设计与威力提高等研究具有一定的指导意义。

关键词：目标易损性主战坦克毁伤评估功能毁伤树

Fossil Equidae in the Linxia Basin with Biostratigraphic and Paleozoogeographic Significance

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 1-9页

作者： sun Boyang Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China

The Linxia Basin is characterized by an abundance of Cenozoic sediments,that contain exceptionally rich fossil *** are abundant in the Linxia Basin,the fossil record of equids in this region including 16 species that represent 10 *** comparison to other classic late Cenozoic areas in China,the Linxia Basin stands out,because the fauna and chronological data accompanying Linxia equids render them remarkably useful for *** anchitheriines in the region,such as Anchitherium and Sinohippus,represent early equids that appeared in the late stages of the middle and late Miocene,*** the equines,most species of Chinese hipparions have been identified in the Linxia Basin and some species of the genera Hipparion and Hippotherium have FAD records for ***,Equus eisenmannae is one of the earliest known species of Equus in the Old World and is well-represented at the Longdan *** species with precise geohistorical distributions can serve as standards for high-resolution chronological units within this *** at the eastern margin of the Tibetan Plateau and subject to considerable uplift,the Linxia Basin has served as a biogeographic transition area for equids throughout the late Cenozoic.

关键词： Equidae Cenozoic biostratigraphy paleozoogeography Linxia Basin

Achieving simultaneously high conversion and high selectivity for light olefins directly producing from syngas

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Science China Chemistry 2024年第3期67卷 753-754页

作者： Yuhan sun Shanxi Research Institute Huairou Research LaboratoryTaiyuan 030032China Institute of Carbon Neutrality ShanghaiTech UniversityShanghai 201210China

The activity and selectivity are two primary indexes of a successful catalyst for chemical reactions. However,achieving a high activity and a high selectivity simultaneously is a long-standing challenge in catalysis, the socalled activity-selectivity trade-off. In the article recently published in Science, a research team led by Prof.

关键词： selectivity simultaneous catalysis

ONE-PARAMETER FINITE DIFFERENCE METHODS AND THEIR ACCELERATED SCHEMES FOR SPACE-FRACTIONAL SINE-GORDON EQUATIONS WITH DISTRIBUTED DELAY

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Journal of Computational Mathematics 2024年第3期42卷 705-734页

作者： Tao sun Chengjian Zhang Haiwei sun School of Mathematics and Statistics Huazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory of Engineering Modeling and Scientific Computing Huazhong University of Science and TechnologyWuhan 430074China Department of Mathematics University of MacaoMacaoChina

This paper deals with numerical methods for solving one-dimensional(1D)and twodimensional(2D)initial-boundary value problems(IBVPs)of space-fractional sine-Gordon equations(SGEs)with distributed *** 1D problems,we construct a kind of oneparameter finite difference(OPFD)*** is shown that,under a suitable condition,the proposed method is convergent with second order accuracy both in time and *** implementation,the preconditioned conjugate gradient(PCG)method with the Strang circulant preconditioner is carried out to improve the computational efficiency of the OPFD *** 2D problems,we develop another kind of OPFD *** such a method,two classes of accelerated schemes are suggested,one is alternative direction implicit(ADI)scheme and the other is ADI-PCG *** particular,we prove that ADI scheme can arrive at second-order accuracy in time and *** some numerical experiments,the computational effectiveness and accuracy of the methods are further ***,for the suggested methods,a numerical comparison in computational efficiency is presented.

关键词： Fractional sine-Gordon equation with distributed delay One-parameter finite difference methods Convergence analysis ADI scheme PCG method