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Comparison Study of Constitutive Models for Overconsolidated Clays

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Acta Mechanica Solida Sinica 2020年第1期33卷 98-120页

作者： z.Wan y.p.yao z.W.Gao Research institute of Base and Foundation China Academy of Building ResearchBeijing 100013China School of Transportation Science and Engineering Beihang UniversityBeijing 100091China School of Engineering University of GlasgowGlasgow G128QQUK

Widely distributed in natural deposits,the overconsolidated(OC)clays have attracted extensive experimental investigations on their mechanical behaviors,especially in the 1960s and *** on these results,numerous constitutive models have also been *** models generally fall into two categories:one based on the classical plasticity theory and the other the bounding surface(BS)plasticity theory,with the latter being more popular and *** BS concept and the subloading surface(SS)concept are the two major BS plasticity *** features of these two concepts and the representative models based on them are introduced,*** unified hardening(UH)model for OC clays is also based on the BS plasticity theory but distinguishes itself from other models by the integration of the reference yield surface,unified hardening parameter,potential failure stress ratio,arid transformed stress *** is made to the Hvorslev envelop employed in the UH model to improve its capability of describing the behaviors of clays with extremely high overconsolidation ratio in this *** comparison among the BS model,SS model,and UH model is *** shows that all these three models can characterize the fundamental behaviors of OC clays,such as the stress dilatancy,strain softening and attainment of the critical *** UH model with the revised Hvorslev envelop has the fewest parameters which are identical to those of the modified Cam-Clay model.

关键词： Clay Overconsolidation Critical state Bounding surface Subloading surface Unified hardening model

Optimization of performance of the KM2A full array using the Crab Nebula

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Chinese physics C 2024年第6期48卷 169-178页

作者：曹臻 F.Aharonian 安琪阿西克古白云翔包逸炜 D.Bastieri 毕效军毕玉江蔡金庭曹晴曹文羽曹喆常进常劲帆陈尚明陈恩生陈亮陈林陈龙陈明君陈玛丽陈起辉陈素弘陈天禄陈阳程宁程耀东崔明阳崔树旺崔晓红崔昱东戴本忠代洪亮戴子高单增罗布 D.della Volpe 董绪强段凯凯樊军辉范一中方军方堃冯存峰封莉冯少辉丰晓婷冯有亮 S.Gabici 高博高川东高林青高启高卫高伟康葛茂茂耿利斯 G.Giacinti 龚光华苟全补顾旻皓郭福来郭晓磊郭义庆郭莹莹韩毅昂何会海贺昊宁何佳银何新波何钰 M.Heller 贺远强侯博文侯超侯贤胡红波胡铨胡世聪黄代绘黄天奇黄文俊黄性涛黄晓渊黄勇黄志成季筱璐贾焕玉贾康江琨姜晓巍姜泽军金敏康明铭柯通 D.Kuleshov.K.Kurinov 李兵兵李澄李骢李丹李飞李海波李会财李华阳李军李剑李捷李凯李文龙李文莲李秀荣李昕李一卓李哲黎卓梁恩维梁云峰林苏杰刘冰刘成刘栋刘虎刘海东刘佳刘江来刘金艳刘茂元柳若愚刘四明刘伟刘怡刘以农鲁睿罗晴吕洪魁马伯强马玲玲马欣华毛基荣闵振 W.Mitthumsiri 穆慧君南云程 A.Neronov 区子维庞彬宇 p.pattarakijwanich 裴致远齐孟尧祁业情乔冰强秦家军 D.Ruffolo A.Sáiz D.Semikoz 邵澄宇邵琅 O.Shchegolev 盛祥东舒富文宋慧超 yu.V.Stenkin V.Stepanov 苏扬孙秦宁孙晓娜孙志斌谭柏轩唐庆文唐泽波田文武王超王昌贝王广威王洪光王惠惠王建成汪凯王利苹王玲玉王培汉王冉王为王祥高王祥玉王阳王玉东王岩谨王忠海王仲翔王振王铮韦大明魏俊杰魏永健文韬吴超勇吴含荣武莎吴雪峰吴雨生席邵强夏捷夏君集项光漫肖迪泫肖刚辛广广辛玉良邢祎熊峥徐东莲徐仁峰徐仁新徐伟立薛良闫大海颜景志颜田杨朝文杨帆杨冯帆杨何文杨佳盈杨莉莉杨明洁杨睿智杨深邦姚玉华姚志国叶一锰尹丽巧尹娜游晓浩游智勇于艳红袁强岳华曾厚敦曾婷轩曾玮查敏张彬彬张丰张海明张恒英张建立张丽霞张力张鹏飞张佩佩张瑞张少博张少如张寿山张潇张笑鹏张云峰张毅张勇赵兵赵静赵雷赵立志赵世平郑福周斌周浩周佳能周猛周平周荣周勋秀祝成光祝凤荣朱辉朱科军左雄 LHAASO Collaboration Key Laboratory of particle Astrophyics&Experimental physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China Tianfu Cosmic Ray Research Center Chengdu 610000China Dublin institute for Advanced Studies 31 Fitzwilliam Place2 DublinIreland Max-planck-institut for Nuclear physics P.O.Box 10398069029 HeidelbergGermany State Key Laboratory of particle Detection and Electronics China University of Science and Technology of China Hefei 230026China School of physical Science and Technology&School of information Science and Technology Southwest Jiaotong UniversityChengdu 610031China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Center for Astrophysics Guangzhou UniversityGuangzhou 510006China Hebei Normal University Shijiazhuang 050024China Key Laboratory of Dark Matter and Space Astronomy&Key Laboratory of Radio Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China Tsung-Dao Lee institute&School of physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory for Research in Galaxies and Cosmology Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030China Key Laboratory of Cosmic Rays(Tibet University) Ministry of EducationLhasa 850000TibetChina National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China School of physics and Astronomy(zhuhai)&School of physics(Guangzhou)&Sino-French institute of Nuclear Engineering and Technology(zhuhai) Sun Yat-sen UniversityZhuhai 519000&Guangzhou 510275China School of physics and Astronomy Yunnan UniversityKunming 650091China Département de physique Nucléaire et Corpusculaire Facultéde SciencesUniversitéde Genève24 Quai Ernest Ansermet1211 GenevaSwitzerland institute of Frontier and interdisciplinary Science Shandong UniversityQingdao 266237China ApC Universit'e Paris Cit'eCNRS/IN2P3CEA/IRFUObservat

The full array of the Large High Altitude Air Shower Observatory(LHAASO)has been in operation since July *** its kilometer-square array(KM2A),we optimized the selection criteria for very high and ultrahigh energyγ-rays using data collected from August 2021 to August 2022,resulting in an improvement in significance of the detection in the Crab Nebula of approximately 15%,compared with that of previous *** the implementation of these new selection criteria,the angular resolution was also significantly improved by approximately 10%at tens of *** aspects of the full KM2A array performance,such as the pointing error,were also calibrated using the Crab *** resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV are well fitted by a log-parabola model,which is consistent with the previous results from LHAASO and other experiments.

关键词： γ-ray Crab Nebula significance

Magnetocaloric properties of the Gd_5Si_(2.05-x)Ge_(1.95-x)Mn_(2x) compounds

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Journal of Rare Earths 2010年第3期28卷 477-480页

作者： E.yüzüak i.Dincer y.Elerman Ankara University Faculty of EngineeringDepartment of Engineering Physics

The influence of the manganese-alloying on the structure and magnetocaloric properties of the Gd5Si2.05Ge1.95 compound was studied by X-ray powder diffraction and magnetization *** Gd5Si2.05-xGe1.95-xMn2x(2x=0,0.03 and 0.08) compounds crystallized in the Gd5Si2Ge2-type monoclinic *** all X-ray powder diffraction patterns,a minor hexagonal Gd5Si3 phase was observed as a second *** increasing Mn content,the unit cell volume *** the compounds with x=0,0.03 and 0.08,the fi...

关键词： magnetic materials heat treatments intermetallics rare earths

Effects of manganese doping on magnetocaloric effect in Ge-rich Gd_5Ge_(2.05)Si_(1.95) alloy

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Journal of Rare Earths 2012年第3期30卷 217-221页

作者： E.yüzüak i.Dincer y.Elerman Department of Engineering physics Faculty of EngineeringAnkara University

The structure, magnetic and magnetocaloric properties of the Ge-rich Gd5Ge2.05-xSi1.95-xMn2x （x=0.01 and 0.03） alloys were investigated by scanning electron microscopy, X-ray powder diffraction, differential scanning calorimeter （DSC） and magnetization measurements. The results of energy dispersive X-ray analysis （EDX） and X-ray diffraction analyses showed that the composition and crystal structure of the alloys were desired. DSC measurements were performed to determine the transformation temperatures for each alloy. Both alloys exhibited the first order phase transition around room temperature. The alloys showed an anti-ferromagnetic transition around 60 K. The isothermal magnetic entropy changes of the alloys were determined from the isothermal magnetization measurements by using the Maxwell relation. The maximum values of isothermal magnetic entropy change of the Gd5Ge2.05-xSi1.95-xMn2x alloy with x=0.01 was found to be -12.1 and -19.8 J/（kg·K） using Maxwell equation around 268 K in applied fields of 2 and 5 T, respectively.

关键词： magnetocaloric effect entropy change magnetic materials rare earths

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全球变暖与城市

气候变化研究进展 2024年第4期20卷 504-508页

作者：赵宗慈罗勇黄建斌清华大学地球系统科学系北京100084 中国气象局国家气候中心北京100081 中国科学院大学资源环境学院北京100049

城市(city)、城镇(town)和都市(urban)都是城市的考虑范围。城市的界定是一个复杂的问题,直到目前为止,没有一个确定城市边界的国际标准。一般以大量人居住与生活和工作的地方,政府、商业与运输的枢纽为城市,考虑“城市本身”“城市聚... 详细信息

城市(city)、城镇(town)和都市(urban)都是城市的考虑范围。城市的界定是一个复杂的问题,直到目前为止,没有一个确定城市边界的国际标准。一般以大量人居住与生活和工作的地方,政府、商业与运输的枢纽为城市,考虑“城市本身”“城市聚集”“大城市区”等作为界定。世界上超过一半人口生活在城市,处在气候变化的前沿。据联合国统计,2022年城市人口占54.5%,预计到2030年将可能达到60%,2050年将可能达到68%。城市的分级也很复杂,一般城市分级从万人极小城市,到千万人特大城市,城镇人口则可能小到仅有百十人。据联合国统计,人口至少101万的城市,在2022年全球有512个,预计2030年全球将达到662个。观测到的不利影响特别集中在经济和社会边缘化(低收入或无收入)的城市居民中(高信度)。人口1000万或以上的特大城市群(megacity)是人为造成的,更值得注意[1-2]。

关键词：社会边缘化城镇人口城市边界城市聚集特大城市全球变暖城市居民气候变化

production of porous silica by the combustion of rice husk ash for tundish lining

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Journal of University of Science and Technology Beijing 2008年第3期15卷 307-313页

作者： y.M.z.Ahmed E.M.Ewais z.i.zaki Central Metallurgical Research and Development institute(CMRDi)

in order to study the production of porous silica compacts by the combustion of rice husk ash （RHA） for tundish lining, the experimental design technique was used to evaluate the effect of firing temperature, soaking time and compaction pressure on controlling both the porosity degree and compressive strength of rice husk ash compacts. The results revealed that while the porosity degree of the compacts decreased with the increase in the entire studied parameters, the compressive strength exhibited another trend especially at a lower soaking time. At a lower soaking time, the increase in firing temperature led to a slight decrease in compressive strength and then increasing thereafter. The porous silica compacts having 30% porosity and 〉 2.5 Mpa compressive strength suitable for tundish lining could be obtained from the combustion of rice husk ash compacts.

关键词： porous silica rice husk ash tundish lining compressive strength porosity

OpTiCAL SpECTRA OF LOW-DiMENSiONAL SEMiCONDUCTORS

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红外与毫米波学报 2003年第6期22卷 401-405页

作者： Fu y Chiragwandi z Gthberg p Willander M Laboratory for physical Electronics and photonics Department of Physics and Engineering PhysicsChalmers University of TechnologyLaboratory for Physical Electronics and PhotonicsDepartment of Physics and Engineering PhysicsChalmers University of TechnologyLaboratory for Physical Electronics and PhotonicsDepartment of Physics and Engineering PhysicsChalmers University of TechnologyLaboratory for Physical Electronics and PhotonicsDepartment of Physics and Engineering PhysicsChalmers University of Technology S-412 96 GteborgSwedenS-412 96 GteborgSwedenS-412 96 GteborgSwedenS-412 96 GteborgSweden

We have studied the optical spectra of low-dimensional semiconductor systems by calculating all possible optical transitions between electronic states. Optical absorption and emission have been obtained under different carrier population conditions and in different photon wavelengths. The line-shapes of the peaks in the optical spectrum are determined by the density of electronic states of the system, and the symmetries and intensities of these peaks can be improved by reducing the dimensionality of the system. Optical gain requires in general a population inversion, whereas for a quantum-dot system, there exists a threshold value of the population inversion.

关键词：光谱低维半导体光学增益总体反转数值分析

风化过程中铼和硒的活动性及其对化石有机碳风化的指示

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中国科学：地球科学 2024年第3期54卷 760-770页

作者：张玉红汪进曲远馨朱超金章东中国科学院地球环境研究所黄土与第四纪地质国家重点实验室西安710061 中国科学院大学北京100049 西安地球环境创新研究院西安710061 西安交通大学全球环境变化研究院西安710049

化石有机碳风化是地质时间尺度上重要的碳源,对全球碳循环和气候变化具有重要影响,但如何量化一直是个挑战.河水铼(Re)含量的变化被认为具有示踪流域化石有机碳风化强度的潜力,然而Re的来源及其与化石有机碳风化之间的关系还知之甚少.... 详细信息

化石有机碳风化是地质时间尺度上重要的碳源,对全球碳循环和气候变化具有重要影响,但如何量化一直是个挑战.河水铼(Re)含量的变化被认为具有示踪流域化石有机碳风化强度的潜力,然而Re的来源及其与化石有机碳风化之间的关系还知之甚少.为了更好地认识这一指标的有效性,本文选择重庆市城口县下寒武统水井沱组页岩风化剖面为研究对象,通过元素含量、逐级提取实验等分析,探讨页岩风化序列中Re和硒(Se)的活动性及其与化石有机碳风化的关系.结果表明,化学蚀变指数(CiA)从基岩到风化层逐步升高,指示增强的风化强度.根据逐级提取实验和质量迁移系数(τ)的变化发现,页岩中的Re和Se主要赋存于有机质相,风化过程中与化石有机碳同步流失,而与页岩中的硫化物矿物氧化无明显相关;风化过程中Re和Se不同的地球化学行为导致其与化石有机碳非等量流失.本研究支持Re作为示踪化石有机碳风化的指标,而Se是示踪化石有机碳风化的潜在指标.未来需要不同类型沉积岩剖面与流域相结合的研究,明确河水Re和Se的来源及其与流域化石有机碳风化之间的关系.

关键词： Re和Se 页岩活动性化石有机碳化学风化

Mycorrhizal fungi mitigate nitrogen losses of an experimental grassland by facilitating plant uptake and soil microbial immobilization

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pedosphere 2024年第2期34卷 399-410页

作者： yangyang JiA Marcel G.A.VAN DER HEiJDEN Alain y.VALzANO-HELD Markus JOCHER Florian WALDER postdoctoral Mobile Station of Ecology College of Ecology and EnvironmentXinjiang UniversityÜrümqi 830046China Research Group plant-Soil interactions AgroscopeZürich 8046Switzerland Research Group Climate and Agriculture AgroscopeZürich 8046Switzerland Department of plant and Microbial Biology University of ZürichZürich 8008Switzerland Research Group Soil Quality and Soil Use AgroscopeZürich 8046Switzerland

Nitrogen(N)is one of the most limited nutrients of terrestrial ecosystems,whose losses are prevented in tightly coupled cycles in finely tuned *** change-induced N enrichment through atmospheric deposition and application of vast amounts of fertilizer are now challenging the terrestrial N *** mycorrhizal fungi(AMF)are known drivers of plant-soil nutrient fluxes,but a comprehensive assessment of AMF involvement in N cycling under global change is still ***,we simulated N enrichment by fertilization(low/high)in experimental grassland microcosms under greenhouse conditions in the presence or absence of AMF and continuously monitored different N pathways over nine *** found that high N enrichment by fertilization decreased the relative abundance of legumes and the plant species dominating the plant community changed from grasses to forbs in the presence of AMF,based on aboveground *** presence of AMF always maintained plant N:phosphorus(p)ratios between 14 and 16,no matter how the soil N availability *** in plant N:p ratios due to the increased plant N and p uptake might thus be a primary pathway of AMF altering plant community ***,we constructed a comprehensive picture of AMF’s role in N cycling,highlighting that AMF reduced N losses primarily by mitigating N leaching,while N_(2)O emissions played a marginal *** mycorrhizal fungi reduced N_(2)O emissions directly through the promotion of N_(2)O-consuming *** underlying mechanism for reducing N leaching is mainly the AMF-mediated improved nutrient uptake and AMF-associated microbial *** results indicate that synergies between AMF and other soil microorganisms cannot be ignored in N cycling and that the integral role of AMF in N cycling terrestrial ecosystems can buffer the upcoming global changes.

关键词： N cycling N enrichment N uptake N:p ratio plant community structure symbiotic soil fungi