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Estimation of Cellobiohydrolase I Activity by Numerical Differentiation of Dynamic Ultraviolet spectroscopy

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Acta Biochimica et Biophysica sinica 2006年第6期38卷 372-378页

作者： Bin WU Yue ZHAO Pei-Ji GAO The state key laboratory of Microbial Technology,shandong University,Jinan 250100,china The state key laboratory of Microbial Technology Shandong UniversityJinan 250100 China

1,4-β-D-glucan cellobiohydrolase I （CBH I）,p-nitrophenyl β-D-cellobioside,p-nitrophenol andcellobiose show distinct ultraviolet spectra,allowing the design of an assay to track the dynamic process ofp-nitrophenyl β-D-cellobioside hydrolysis by CBH *** on the linear relationship between p-nitrophenolformation in the hydrolysate and its first derivative absorption Curve of AUC340400nm（area under the curve）,a new sensitive assay for the determination of CBH I activity was *** dynamic parameters ofcatalysis reaction,such as Vm and kcat,can all be derived from this *** influence of β-glucosidase andendoglucanase in crude enzyme sample on the assay was discussed in *** approach is useful foraccurate determination of the activity of CBHs.

关键词： cellobiohydrolase dynamic spectrum area under the curve(AUC)

sediment pollution and its effect on fish through food chain in the Yangtze River

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International Journal of sediment Research 2008年第4期23卷 338-347页

作者： Yujun YI 1,Zhaoyin WANG 2,Kang ZHANG 3,Guoan YU 4,and Xuehua DUAN 51 Dr.,Lecturer,state key laboratory of Hydroscience,school of Environment,Beijing Normal University,Beijing 100875,china2 Prof.,state key laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,china 3 Ph.D.,state key laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,china 4 Ph.D.,state key laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,china 5 Ph.D.,state key laboratory of Hydroscience and Engineering,Tsinghua University,Beijing,100084,china Dr. Lecturer State Key Laboratory of Hydroscience School of Environment Beijing Normal University Beijing 100875 China Prof. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Ph. D. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Ph. D. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

suspended sediment adsorbs pollutants from flowing water in rivers and deposits onto the bed. However, the pollutants accumulated in the river bed sediment may affect the bio-community through food chain for a long period of time. To study the problem the concentration of heavy metals (Cr, Cd, Hg, Cu, Fe, Zn, Pb and As) in water, sediment, and fish/invertebrate were investigated in the middle and lower reaches of the Yangtze River during 2006-2007. The concentrations of heavy metals were 100-10,000 times higher in the sediment than in the water. Benthic invertebrates had relatively high concentrations of heavy metals in their tissues due to their proximity to contaminated sediments. Benthic invertivore fish had moderately high concentrations of heavy metals whereas phytoplanktivore fish, such as the silver carp, accumulated the lowest concentration of heavy metals. The concentrations of Cu, Zn, and Fe were higher than Hg, Pb, Cd, Cr, and As in the tissue samples. The concentration of heavy metals was lower in the river sediments than in the lake sediments. Conversely, the concentration of heavy metals was higher in river water than in lake water. While a pollution event into a water body is often transitory, the effects of the pollutants may be long-lived due to their tendency to be absorbed in the sediments and then released into the food chain. The heavy metals were concentrated in the following order: bottom material > demersal fish and benthic fauna > middle-lower layer fish > upper-middle layer fish > water.

关键词： sediment pollution Heavy metal Fish Invertebrate Yangtze River

surface pollen and modern vegetation in southern xinjiang,china

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science china Earth sciences 2024年第2期67卷 510-530页

作者： Yun ZHANG Lixin CHEN Yaoyao xi Zhaochen KONG xianguo QIAO state key laboratory of Black soils Conservation and Utilization Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun130102China Institute of Botany Chinese Academy of SciencesBeijing100093China key laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China University of Chinese Academy of sciences Beijing100049China school of Geosciences and Resources China University of Geosciences(Beijing)Beijing100083China

The study of modern pollen,and vegetation can improve the accuracy of paleoenvironmental reconstruction based on fossil pollen data.A total of 188 pollen surface samples were collected from southern xinjiang(34°00’–43°00’N,74°00’–94°00’E)in china,with an elevation range of 888–4530 *** pollen and vegetation were studied in the northern region of the Kunlun Mountains and the southern region of the Tianshan *** results showed that the surface pollen assemblages on the southern slope of the Tianshan Mountains(3530–1124 m)were divided into three pollen zones,namely,montane steppe,montane desert steppe,and montane *** zones were dominated by Artemisia,Chenopodiaceae,and Ephedra *** surface pollen assemblages in the eastern Pamir Plateau(4530–1287 m)could be divided into alpine meadow,montane desert steppe,and montane desert zones,which were predominantly characterized by Artemisia,Chenopodiaceae,and Asteraceae ***,the southern Tarim Basin(3548–888 m)comprised montane desert steppe and montane desert zones,which was dominated by Artemisia and Chenopodiaceae *** geographic distribution of the surface pollen sites obtained using ArcGIs,the R-value,and Pearson correlation analyses indicated that the over-represented Picea and Pinus pollen were of external origin and were transported by wind,water(rivers),and ice(glacier movement).Over-representation of Ephedra and Nitraria pollen was mainly distributed in the montane desert and desert steppe zones,*** from Chenopodiaceae and Artemisia were over-represented and broadly distributed across southern *** pollen was concentrated in areas with walnut trees,strongly indicating the presence of local parent *** to the Hybrid singleparticle Lagrangian Integrated Trajectory model,more Pinus pollen was transported to the Pamir region by external airflows during spring and summer,resulting in its higher surface pollen *** elucidating t

关键词： surface pollen Vegetation Distribution Picea southern xinjiang

NONCONFORMING FINITE ELEMENT APPROxiMATIONs TO THE UNILATERAL PROBLEM

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Journal of Computational Mathematics 1999年第1期17卷 15-24页

作者： Lie-heng Wang(state key laboratory of scientific and Engeneering Computing, ICMsEC,Chinese Academy of sciences, Beijing 100080, china) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京

The nonconforming finite element (two Crouzeix-Raviart linear elements and Wilson element) approximations to the unilateral problem are considered. The error bounds for these elements are obtained in the appropriate a... 详细信息

关键词： unilateral problem nonconforming finite element

Wind-resistant studies on tall buildings and structures

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science china(Technological sciences) 2010年第10期53卷 2630-2646页

作者： GU Ming state key laboratory of Disaster Reduction in Civil Engineering, Tongji University, shanghai 200092, china state key laboratory of Disaster Reduction in Civil Engineering Tongji University Shanghai China

This paper introduces some aspects of wind-resistant studies of our research team on tall buildings and structures. Wind tunnel tests were carried out on 27 typical tall building models by using wind pressure scanning and HFFB techniques. The characteristics of wind pressures and forces acting on these buildings were analyzed. some results have been adopted in a shanghai code for structural design of steel tall buildings. Interference effects on wind forces and wind pressures among two and three tall buildings were experimentally investigated with about 10000 testing conditions. Regression analyses of the interference factors under different parameter conditions were made and the main regression formulas are presented. Theoretical study on equivalent static wind loads of tall buildings and structures are then introduced. Especially,a new concept of "mode coupling factor" and a modified sRss method for wind response and equivalent static wind load of complicated tall buildings and structures with consideration of multi mode contributions and their coupling effects are presented. Finally,practical applications of wind-resistant studies on tall building and structures,taking the Guangzhou New TV Tower as an example,are presented.

关键词： tall building and structure wind pressure and force interference effect equivalent static wind load application

Theoretical observation of hexaatomic molecules containing pentacoordinate planar carbon

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science china Chemistry 2008年第11期51卷 1030-1035页

作者： LUO Qiong state key laboratory of Explosion science and Technology, Beijing Institute of Technology, Beijing 100081, china state key laboratory of Explosion science and Technology Beijing Institute of Technology Beijing China

The smallest molecules up to date containing a D5h pentacoordinate planar carbon (PPC) atom, CBe5 and CBe54-, are presented by means of ab initio calculations. To gain a better understanding about which electronic factors contribute to their stabilization, natural bond orbital (NBO) analysis and the nucleus independent chemical shifts (NICs) were calculated. The data reported here suggest that D5h CBe5 is σ aromaticity in nature, while in D5h CBe54- π aromaticity is dominating. The classical octet rule is well satisfied in both molecules, and is one of the fundamental reasons to understand the stability of the pentagon structures. The Be5 ring serves as σ donor in D5h CBe5, and π-acceptor in D5h CBe54-. The D5h CBe54- possessing 18 valence electrons with a closed-shell electron configuration is the most plau-sible candidate for experimental detection.

关键词： pentacoordinate planar carbon Be5 ring ab initio

Cardiac nonrigid motion analysis from image sequences

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Progress in Natural science:Materials International 2006年第10期16卷 1115-1118页

作者： LIU Huafeng (state key laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, china) state key laboratory of Modern Optical Instrumentation Zhejiang University Hangzhou 310027 China

Noninvasive estimation of the soft tissue kinematics properties from medical image sequences has many important clinical and physiological implications, such as the diagnosis of heart diseases and the understanding of cardiac mechanics. In this paper, we present a biomechanics based strategy, framed as a priori constraints for the ill-posed motion recovery problems, to realize estimation of the cardiac motion and deformation parameters. By constructing the heart dynamics system equations from biomechanics principles, we use the finite element method to generate smooth estimates of heart kinematics throughout the cardiac cycle. We present the application of the strategy to the estimation of displacements and strains from in vivo left ventricular magnetic resonance image sequence.

关键词： cardiac motion and deformation continnum mechanics model finite element method.

THERMOMECHANICAL REsPONsE OF sMA FIBER COMPOsITEs WITH NON-UNIFORM TEMPERATURE DIsTRIBUTION

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Acta Mechanica solida sinica 2003年第4期16卷 334-344页

作者： Zhang Zhen Wang Jian shen Yapeng (The state key laboratory of Mechanical structural and Vibration,xi’an Jiaotong University,xi’an 710049,china) stt. key Lab. of Mech. struct./Vibr. Xi'an Jiaotong University Xi'an 710049 China

A micromechanics method based on the High-Order-Theory developed by Aboudi et *** used to predict the thermomechanical response of composites reinforced by shape memory alloy (sMA) fibers,and the non-uniform thermal distribution in composite arising from the process of heating or cooling is *** numerical development based on this model was coded to predict the thermomechanical response of shape memory alloy fiber/elastomer matrix composite subjected to thermal cycle *** the composite is heated,two heating ways,thermal gradients and heat source by passing an electric current through the sMA fibers are imposed on the composite *** cooling,the first thermal boundary condition and the second thermal boundary condition are subjected to the composite respectively.A series of stress distributions and temperature distributions for different instants are calculated to reveal the interaction between the sMA material and *** is useful to analyze and design the sMA actuator driven by heat source or the surface temperature.

关键词： shape memory alloy composites fiber

Eu^(3+)-doped LaPO_4 and LaAlO_3 nanosystems and their luminescence properties

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science china Chemistry 2009年第8期52卷 1104-1112页

作者： WAN Qiang,HE YuPing,DAI Ning & ZOU Bingsuo state key laboratory of state key laboratory of Chemo/Biosensing and Chemometrics and key laboratory for Micro-Nano Opto-Electronic Devices of Ministry of Education,Hunan University,Changsha 410082,china state key laboratory of state key laboratory of Chemo/Biosensing and Chemometrics and key laboratory for Micro-Nano Opto-Electronic Devices of Ministry of Education Hunan University Changsha China

Eu3+ ion-doped LaPO4 nanowires or nanorods have been successfully synthesized by a simple hydrothermal *** influence of varying the hydrothermal and subsequent sintering conditions on the morphology and structure of the LaPO4 host has been investigated by scanning electron microscopy(sEM) and X-ray diffraction(XRD).For comparison,the Eu3+ ions were also doped into monoclinic monazite LaPO4 nanoparticles and perovskite LaAlO3 *** relative intensities of the emission lines of the LaPO4:Eu3+ nanosystems were essentially independent of their *** optimal doping concentrations in the monoclinic LaPO4 and perovskite LaAlO3 nanosystems were determined to be about 5.0 and 3.5 mol%,*** appropriate UV-radiation,the red light emitted from LaAlO3:Eu3+(3.5 mol%) was brighter than that from LaPO4:Eu3+(5.0 mol%) nanomaterial,resulting from differences in their spin-orbit couplings and covalence,which indicates that the nanoscale LaAlO3 is a promising host material for rare earth ions.

关键词： doping synthesis luminescence nanosystem