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Seepage laws in aquifer near a partially penetrating river with an intensive extraction of ground water

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Science China(Technological Sciences) 1997年第5期40卷 489-496页

作者：刘国东李俊亭 Department of Hydraulic Engineering Sichuan Union University Chengdu 610065 China Department of Hydrogeology and Engineering-Geology Xi'an Geology College Xi'an 710054 China

The intensive extraction of ground water from aquifers near a river is an efficient way to exploit ground water resources. A lot of problems, however, have arisen because the mechanism of ground water flow in this way has not been clear. A sand-box model and a numerical model are respectively used to simulate the extraction of ground water near a partially penetrating river physically and theoretically. The results show that the ground water will lose saturated hydraulic connection with the river water as the pumping intensity increases. The broken point of hydraulic connection is located in the interior of aquifers rather than on the riverbed. After hydraulic disconnection occurs, two saturated zones, a suspended saturated zone linked with river and an unconfined aquifer, are formed.

关键词： the extraction of ground water ground water-well field near a river water table saturated-unsat-urated flow.

Corrigendum to “Advances in In Vitro and In Vivo Bioreactor-Based Bone Generation for Craniofacial Tissue Engineering”

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Biomedical Engineering Frontiers 2023年第1期4卷 197-198页

作者： Emma Watson Antonios G.Mikos Department of Bioengineering Rice UniversityHoustonTX 77030USA

In the review article“Advances in In Vitro and In Vivo Bioreactor-Based Bone Generation for Craniofacial Tissue Engineering,”the authors made an error in table.In table,10 cells in the Results column contain the word“enter,”which was erroneously added instead of starting a new line of text during proofing.This error did not affect the results,discussion,or conclusion of this paper.table 1 has now been corrected in the PDF and HTML(full text).

关键词： HTML table starting

Centrifuge model test on earthquake-induced differential settlement of foundation on cohesive ground

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Science China(Technological Sciences) 2009年第7期52卷 2138-2146页

作者： SHAMOTO Yasuhiro HOTTA Hiroyuki MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang University Hangzhou 310058 China Insititute of Technology Shimizu Corporation Tokyo 135-8530 Japan

Dynamic centrifuge model test was conducted to study the earthquake-induced differential settlement of foundation on cohesive ground, and the influence of asymmetry of building was investigated. During the experiment, the overconsolidated kaolin clay ground with a three-dimensional asymmetrical structure model was shaken by a basically balanced input motion, and bender elements were used to measure shear wave velocities of model ground to reveal the soil fabric evolution during and after shaking. The test results show that, the total seismic settlement of foundation is composed of instantaneous and long-term post-earthquake settlements, and most of the differential settlement occurs immediately after the earthquake while the post-earthquake settlement is relatively uniform despite its large amplitude. The asymmetry of building affects the settlement behavior considerably. Compared with 1-or 2-dimensional structures, more evident differential settlement occurs under threedimensional asymmetrical building during shaking, which accounts for one-half of the total seismic settlements and results in complex spatial tilting effects of foundation.

关键词： soft clay centrifuge model test shaking table earthquake-induced differential settlement bender elements

Determination of Pyrethroids in Human Urine by Gas Chromatography

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Biomedical and Environmental Sciences 1994年第3期7卷 216-221页

作者： WUYI－QUN GAOXIAO－YEN 等 InstituteofOccupationalMedicine ChineseAcademyofPreventiveMedicine29NanWeiRoadBeijing100050China I

A gas chromatographic method for the determination of deltamethrin and fenvalerate in human urine is described. Both deltamethrin and fenvalerate have been analysed by gas chromatography with a electron capture detector. The least detectable concentration of both pyrethroids in urine is 0.2 g per litre. The precision and accuracy of the method were within acceptable limits. The method has been used to determine the pyrethroids in urine samples obtained from packers, spraymen and acute pyrethroids poisoning patients

关键词： Chromatography Walden table Clean Canada Rec emulsion

Changes in regeneration and leaf traits of Rhododendron campanulatum along a treeline ecotone in central Nepal

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Journal of Mountain Science 2020年第3期17卷 602-613页

作者： SHARMA Prasad Krishna TIWARI Achyut SHRESTHA Babu Bharat Central Department of Botany Tribhuvan UniversityKathmandu44613Nepal Budhanilkantha School Kathmandu44622Nepal

Changes in population structure and plant functional traits across environmental gradient in the near natural treeline is a critical determinant of environmental changes in treelines. In this study we analyzed population characteristics and leaf traits of Rhododendron campanulatum across treeline ecotone in a trans-Himalayan region of Mustang district in central Nepal. Along 4 vertical transects, a total of 72 quadrats(5 m × 5 m)-34 above Betula utilis treeline and 38 below treeline-were sampled to analyze the population structure, regeneration,specific leaf area(SLA) and leaf-stem relationship of R. campanulatum. Our results showed that the regeneration of R. campanulatum was fairly good in both habitats, as evident from density-diameter curve.The species showed type Ⅲ survivorship curve in both habitats with the highest mortality during early stage of life. However, the seedling density and mortality was higher below treeline than above treeline. Canopy cover and basal cover were found to be the major factors affecting regeneration, as indicated by higher number of juveniles in relatively open areas above treeline. The total leaf area increased(p <0.001) with stem cross-section area in both habitats. However, the SLA was higher below treeline(55 cm^2/g) than above(47 cm^2/g)(p < 0.001);it also increased with the canopy cover of trees(R^2 =0.59, p <0.001) below the treeline. In conclusion,high density of juvenile, low mortality of seedlings,and low SLA above treeline indicated that the species has successfully adapted in climatically stressful alpine habitat with potential to expand upward.

关键词： Rhododendron Climate change Life table Mortality Specific leaf area Mustang district

Influence factors on the seismic behavior and deformation modes of gravity retaining walls

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Journal of Mountain Science 2019年第1期16卷 168-178页

作者： ZHU Hong-wei YAO Ling-kan LI Jing School of Environment and Resource Southwest University of Science and Technology MOE Key Laboratory of High-speed Railway Engineering Southwest Jiaotong University School of Civil Engineering Southwest Jiaotong University

This study investigated the influence factors on the seismic response and deformation modes of retaining walls using large-scale model shaking table tests. Experimental results showed that the distribution of peak seismic earth pressures along the height of a wall was a single peak value curve. The seismic earth pressures on a gravel soil retaining wall were larger than the pressures on the weathered granite and quartz retaining walls. Also, the peak seismic earth pressure increased with increases in the peak ground acceleration and the wall height. The measured seismic active earth pressures on a rock foundation retaining wall were larger than the calculated values, and the action position of resultant seismic pressure was higher than 0.33 H. In the soil foundation retaining wall, the measured seismic earth pressures were much smaller than the calculated values, while the action position was slightly higher than 0.33 H. The soil foundation retaining wall suffered base sliding and overturning under earthquake conditions, while overturning was the main failure mode for the rock foundation retaining walls.

关键词： Gravity retaining wall Earthquake action Seismic behavior Deformation mode Shaking table test

Research and application of multi-angle polarization characteristics of water body mirror reflection

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Science China Earth Sciences 2007年第6期50卷 946-952页

作者： LUO YangJie ZHAO YunSheng LI XiaoWen WU TaiXia ZHAO LiLi Department of Management and Resources Environment Neijiang Teachers CollegeNeijiang 641112China College of Urban and Environment Sciences Northeast Normal UniversityChangchun 130024China Institute of Remote Sensing Applications Chinese Academy of SciencesBeijing 100101China Institute of Remote Sensing&Geographic Information System Peking UniversityBeijing 100871China

On the basis of the multi-angle polarized reflection spectrum of the water samples,the water body mirror reflection polarization characteristics and mechanism are described systematically. By altering such influential factors as the angle of incidence,detecting angle,detecting azimuth angle and polari-zation angle,ubiquitous laws for the multi-angle polarized reflection spectrum of the water samples are obtained. Combining multi-angle remote sensing with polarized light,the multi-angle polarized reflec-tion method about eliminating the water body mirror reflection and the suitable time of the polarized remote sensing of the water body are proposed. This study provides technical references for the ap-plication of multi-angle polarization technology on water body remote sensing.

关键词： water body remote sensing mirror reflection multi-angle polarization Brewster angle reference time table

Coulomb explosion of nanodroplets drives the conversion of laser energy to nuclear energy

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High Power Laser Science and Engineering 2013年第2期1卷 69-73页

作者： Isidore Last Shlomo Ron Andreas Heidenreich Joshua Jortner School of Chemistry Tel Aviv University Kimika Fakultatea Euskal Herriko Unibertsitatea (UPV/EHU) and Donastia International Physics Center (DICP) IKERBASQUE Basque Foundation for Science

Theoretical–computational studies of table-top laser-driven nuclear fusion of high-energy(up to 15 MeV)deuterons with7Li,6Li,and D nuclei demonstrate the attainment of high fusion yields within a source–target reaction design.This constitutes a source of Coulomb-exploding deuterium nanodroplets driven by an ultraintense femtosecond near-infrared laser and a solid hollow cylindrical target containing the second element.The source–target reaction design attains the highest table-top fusion efficiencies(up to 4×109J 1per laser pulse)obtained to date.The highest conversion efficiency of laser energy to nuclear energy(10 2–10 3)for table-top DD fusion attained in the source–target design is comparable to that for DT fusion currently accomplished for‘big science’inertial fusion setups.

关键词： Coulomb explosion nanodroplets and clusters source-target design table top nuclear fusion ultraintense lasers

CALCULATIONS AND ANALYSIS OF THE SPINNING ROTOR BEARING SYSTEM BY USING FEM

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Journal of China Textile University(English Edition) 1991年第2期9卷 21-26页

作者：陈瑞琪李谦 Department of Mechanical Engineering

In this paper the formulation of finite element analysis for frame casing problems of theharmonic type is described. Attention is paid to the OE spinning rotor bearing assembly (RBA)’ sdynamic model, whose harmonic parameters, such as natural frequencies and modal shapes, aresolved by means of structural analysis program using personal computer, i.e. SAP84 software. Ac-cording to orthogonal factorial design table (OFDT), the predominant sensitive influential factors(PSIF) of RBA are determined.

关键词： rotor spinning frame finite element methods orthogonal design rotor bearing assembly orthogonal factorial design table predominant sensitive influential factors