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An approach for determination of lateral limit angle in kinematic planar sliding analysis for rock slopes

Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1305-1314页

作者： Xiaojuan Yang Jie Hu Honglei Sun jun zheng College of Civil Engineering Zhejiang University of TechnologyHangzhou310023China Department of Civil Engineering Zhejiang UniversityHangzhou310058China Center for Balance Architecture Zhejiang UniversityHangzhou310007China The Architectural Design & Research Institute of Zhejiang University Co. Ltd.Hangzhou310063China

Planar sliding is one of the frequently observed types of failure in rock *** analysis is a classic and widely used method to examine the potential failure modes in rock *** accuracy of planar sliding kinematic analysis is significantly influenced by the value assigned to the lateral limit angleγ***,the assignment ofγlim is currently used generally based on an empirical *** study aims to propose an approach for determining the value ofγlim in deterministic and probabilistic kinematic planar sliding analysis.A new perspective is presented to reveal thatγlim essentially influences the probability of forming a potential planar sliding *** procedure to calculate this probability is introduced using the block theory *** is found that the probability is correlated with the number of discontinuity sets presented in rock ***,different values ofγlim for rock masses with different sets of discontinuities are recommended in both probabilistic and deterministic planar sliding kinematic analyses;whereas a fixed value ofγlim is commonly assigned to different types of rock masses in traditional ***,an engineering case was used to compare the proposed and traditional kinematic analysis *** error rates of the traditional method vary from 45%to 119%,while that of the proposed method ranges between 1%and 17%.Therefore,it is likely that the proposed method is superior to the traditional one.

关键词： Kinematic analysis Block theory Planar sliding Lateral limit angle Rock slope

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Phylogenetically clustering of rhizobia by genome structure:application to unclassified Rhizobium

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Journal of Environmental Sciences 2006年第3期18卷 530-536页

作者： zheng jun-fang LIU Gui-rong LIU Shu-lin Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Department of Microbiology Peking University Health Science Center Beijing 100083 China

Previous research reveals that the genome structures of rhizobial type strains and reference strains can reflect their phylogenetic relationships. In order to further explore the potential application of genome structure as a phylogenetic marker in rhizobial natural taxonomy, this study analyzed the genome structures of 29 unclassified nodule bacteria isolated from the root nodules of leguminous trees, Robinia sp., Dalbergia spp., and A lbizia spp. and 7 rhizobial reference strains by I-CeuI cleavage, then clustered these bacteria phylogenetically based on their genome structures and compared these clusters with those based on numerical taxonomy and 16S rDNA PCR-RFLP. Eleven phylogenetic clusters were obtained, The clusters were in large part consistent with those based on numerical taxonomy and 16S rDNA PCR-RFLP. Also there are inconsistent clusters based on the above three methods. But results are completely consistent with 16S rRNA clusters. This suggested that the genome structure clustering method can be used to lastly identify root nodule isolates and detect their phylogenetic relationships. The credibility and repeatability of the results, together with the simplicity and possibility to analyze a large number of strains in a short time of the method, indicates the broad potential application of genome structure as phylogenetic marker to categorize rhizobial isolates and should in the future facilitate biodiversity studies.

关键词： rhizobia genome structure phylogenetic analysis pulsed field gel electrophoresis I-CeuI

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Evolution in physiochemical and cloud condensation nuclei activation properties of crop residue burning particles during photochemical aging

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Journal of Environmental Sciences 2019年第3期31卷 43-53页

作者： Yan Ma Chao Chen junfeng Wang Youling Jiang Zewen zheng Hui Chen jun zheng Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science and Technology Harvard-NUIST Joint Laboratory for Air Quality and Climate (JLAQC) Nanjing University of Information Science and Technology NUIST Reading Academy Nanjing University of Information Science and Technology

As a main form of biomass burning in agricultural countries, crop residue burning is a significant source of atmospheric fine particles. In this study, the aging of particles emitted from the burning of four major crop residues in China was investigated in a smog *** particle size distribution, chemical composition and cloud condensation nuclei(CCN)activity were simultaneously measured. The properties of crop residue burning particles varied substantially among different fuel types. During aging, the particle size and mass concentration increased substantially, suggesting condensational growth by formation of secondary aerosols. The particle composition was dominated by organics. Aging resulted in considerable enhancement of organics and inorganics, with enhancement ratios of 1.24–1.44 and 1.33–1.76 respectively, as well as a continuous increase in the oxidation level of organics. Elevated CCN activity was observed during aging, with the hygroscopicity parameter κ varying from 0.16 to 0.34 for fresh particles and 0.19 to 0.40 for aged *** on the volume mixing rule, the hygroscopicity parameter of organic components(κorg) was derived. κorgexhibited an increasing tendency with aging, which was generally consistent with the tendency of the O:C ratio, indicating that the oxidation level was related to the hygroscopicity and CCN activity of organic aerosols from crop residue burning. Our results indicated that photochemical aging could significantly impact the CCN activation of crop burning aerosols, not only by the production of secondary aerosols, but also by enhancing the hygroscopicity of organic components, thereby contributing to the aerosol indirect climate forcing.

关键词： Crop residue burning Aging Cloud condensation nuclei activity Hygroscopicity Organic aerosol

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Unified proof to oscillation property of discrete beam

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Applied Mathematics and Mechanics(English Edition) 2014年第5期35卷 621-636页

作者：郑子君陈璞王大钧 Department of Mechanics and Engineering Science State Key Laboratory for Turbulence and Complex SystemsCollege of EngineeringPeking University

The oscillation property （OP） is a fundamental and important qualitative property for the vibrations of single span one-dimensional continuums such as strings, bars, torsion bars, and Euler beams. Any properly discretized continuum model should keep the OP. In literatures, the OP of discrete beam models is discussed essentially by means of matrix factorization. The discussion is model-specific and boundary-condition- specific. Besides, matrix factorization is difficult in handling finite element （FE） models of beams. In this paper, according to a sufficient condition for the OP, a new approach to discuss the property is proposed. The local criteria on discrete displacements rather than global matrix factorizations are given to verify the OP. Based on the proposed approach, known results such as the OP for the 2-node FE beams via the Heilinger- Reissener principle （HR-FE beams） as well as the 5-point finite difference （FD） beams are verified. New results on the OP for the 2-node PE-FE beams and the FE Timoshenko beams with small slenderness are given. Through a simple manipulation, the qualitative property of discrete multibearing beams can also be discussed by the proposed approach.

关键词： oscillation property (OP) finite element method (FEM) finite differencemethod (FDM) Euler beam Timoshenko beam

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Chaotic Dynamics of Triatomic Normal Mode Molecules

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Chinese Physics Letters 2012年第6期29卷 118-121页

作者： ZHAI Liang-jun zheng Yu-jun DING Shi-Liang School of Physics Shandong UniversityJinan 250100

We investigate the chaotic dynamics of normal mode molecules from the classical point of view using the coupling Morse *** interesting phenomena of the fractured tori and the cross of tori on the poincaré section,which go against our traditional understanding,are found and ***,we find that the phenomenon of tori cross is a siggature of the single bond's energy beyond the total vibrational ***,a method to improve this scarcity is proposed.

关键词： energy vibrational Morse

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Probabilistic assessment of tunnel convergence considering spatial variability in rock mass properties using interpolated autocorrelation and response surface method

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Geoscience Frontiers 2018年第6期9卷 1619-1629页

作者： Qing Lü Zhipeng Xiao jun zheng Yuequan Shang College of Civil Engineering and Architecture Zhejiang University

This study aims at the probabilistic assessment of tunnel convergence considering the spatial variability in rock mass properties. The method of interpolated autocorrelation combined with finite difference analysis is adopted to model the spatial variability of rock mass properties. An iterative procedure using the first-order reliability method(FORM) and response surface method(RSM) is employed to compute the reliability index and its corresponding design point. The results indicate that the spatial variability considerably affects the computed reliability index. The probability of failure could be noticeably overestimated in the case where the spatial variability is neglected. The vertical scale of fluctuation has a much higher effect on the probabilistic result with respect to the tunnel convergence than the horizontal scale of fluctuation. And the influence of different spacing of control points on the computational accuracy is investigated.

关键词： Spatial variability Rock mass Tunnel convergence FORM Random field

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Microwave-prompted Rapid and Efficient Synthesis of Diacyl Thiosemicarbazides and Semicarbazides in Solvent and Catalyst Free Condition

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Chinese Chemical Letters 2005年第8期16卷 1027-1030页

作者： Xi Cun WANG zheng jun QUAN Man Gang WANG zheng LI Gansu Key Laboratory of Polymer Materials College of Chemistry and Chemical Engineering Northwest Normal University Lanzhou 730070

Eighteen 1-aroyl-4-（2-iodobenzoyl）thiosemicarbazides and corresponding semicarbazides were synthesized in excellent yield under microwave irradiation in solvent and catalyst free condition.

关键词： Microwave irradiation 1,4-diaroyl thiosemicarbazides 1,4-diaroyl semicarbazides,solvent-free synthesis.

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Natural orifice transluminal endoscopic surgery:New minimally invasive surgery come of age

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World Journal of Gastroenterology 2011年第39期17卷 4382-4388页

作者： Chen Huang Ren-Xiang Huang zheng-jun Qiu Department of General Surgery Affiliated First People＇s Hospital Shanghai Jiao Tong University Shanghai 200080 China Digestive Endoscopy Center Affiliated Huadong Hospital Fudan University Shanghai 200040 China

Although in the past two decades,laparoscopic surgery,considered as a great revolution in the minimally inva-sive surgery field,has undergone major development worldwide,another dramatic surgical revolution has quietly appeared in recent *** since Kalloo's first report on transgastric peritoneoscopy in a porcine model in 2004,interest in a new surgical procedure named natural orifice transluminal endoscopic surgery(NOTES)has blossomed *** that a NOTES procedure could theoretically avoid any abdomi-nal incision,operation-related pain and scarring,many surgeons and endoscopists have been enthusiastic in their study of this new *** recent years,sev-eral NOTES studies have been carried out on porcine models and even on humans,including transvaginal cholecystectomy,transgastric appendectomy,transvagi-nal appendectomy,and transvesical *** what is the current situation of NOTES and how many challenges do we still face?This review discusses the current research progress in NOTES.

关键词： Laparoscopic surgery Natural orifice trans-luminal endoscopic surgery Endoscopy

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Spin-Selective Transport of Electron in a Quantum Dot under Magnetic Field

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Chinese Physics Letters 2012年第10期29卷 182-185页

作者： LI Bo-Xin zheng jun CHI Feng College of New Energy Bohai UniversityJinzhou 121013 SKLSM Institute of SemiconductorsChinese Academy of SciencesBeijing 100083 College of Engineering Bohai UniversityJinzhou 121013

We study electronic spin-polarised transport in a system composed of a quantum dot(QD)connected to one normal metal electrode and one ferromagnetic *** electrical current of each spin component and the spin accumulation on the QD are calculated by using the nonequilibrium Green's function *** find that in the Coulomb blockade regime,the current spin polarisation can reach 100%under a strong magnetic ***,the spin accumulation on the QD approaches to unit,and thus the dot is occupied by electrons of one certain spin *** system can operate as a spin injector from a normal metal reservoir to a semiconductor material,and may find real usage in solid state quantum information processes.

关键词： method field quantum

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Transformation Sequence Rule of Martensite Plates and Temperature Memory Effect in Shape Memory Alloys

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Acta Metallurgica Sinica(English Letters) 2015年第10期28卷 1286-1290页

作者： Tian-Wei Liu Yan-jun zheng Li-Shan Cui Department of Materials Science and Engineering China University of Petroleum

In thermoelastic martensitic transformation, it is well established that the first martensite plate appearing upon cooling becomes the final one during reverse transformation to austenite upon heating. The results obtained from this work show that the transformation sequence of the martensite appears to be random. Newly formed martensite plates can modify the elastic strain energy level stored in the already existing martensite. Additionally, the elastic strain energy stored in newly formed martensite is not necessarily to be higher than the remaining martensite. The obtained results may assist in understanding phenomena related to partial transformation of shape memory alloys, such as temperature memory effect.

关键词： Phase transformation Shape memory alloys TEM Transformation sequence

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