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Estimation of interfacial damage in composites with reinforced particles based on ultrasonic data

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Journal of University of Science and Technology Beijing 2007年第3期14卷 280-285页

作者： Xiqiang liu Peijun Wei li zhang Hang wang Applied Science School University of Science and Technology Beijing Beijing 100083 China

The scattering of elastic waves by a spherical particle with imperfect interface and the nondestructive detection of interfacial damage were studied. First, the scattering of elastic waves by a spherical particle with imperfect interface, i.e. spring interface model, was studied. Then, multiple scattering by random distributed particles was investigated and the equations to evaluate the velocity and attenuation of effective waves defined by statistic averaging were given. Furthermore, on the basis of the established relation between the velocity and interfacial constants, a method to evaluate the interfacial damage nondestructively from the ultrasonic data was pro- posed. Numerical simulation was performed for the SiC-Al composites. The velocities of the effective waves were computed to show the influence of the interface constants. Using the genetic algorithm, the interfacial damage was evaluated from the synthetic experi- mental data with various noise levels. The numerical results showed the feasibility of the method proposed.

关键词： spring model average waves scattering genetic algorithm inverse problem

A Modern Method for Analyzing Thermal Energy System with System State Equation and Analytical Formula of Performance Index

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Journal of Thermal Science 2007年第1期16卷 90-96页

作者： Chunfa zhang liping li Huijie wang Ning ZHAO School of Energy and Power North China Electric Power University Baoding 071003

This paper addresses overall performance analysis of coal-fired power unit. From the point of view of system engineering, a general steam-water distribution equation of the thermal plant system is presented. This system state equation is an exact expression combining system topological structure and system properties. Through proper mathematic transform, the inner relationship and interaction between the main system and auxiliary system are revealed and its general form is given. An analytical formula for the heat consumption rote of thermal power plant is one direct fruit of the equation, which greatly facilitate the online analyzing and optimizing of complex thermal system. The new approach, with the aid of modem data acquiring technology, is a perfect extension of the traditional analysis method based on the First Law of Thermodynamics.

关键词： steam-water distribution equation heat consumption rate thermal system thermodynamic analysis.

An IBM2 Description of the E(5) Symmetry in 134Ba and 108pd

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Communications in Theoretical Physics 2002年第7期38卷 71-74页

作者： zhang Da-li wang Hong-ling Department of Physics Huzhou Teacher''s College Huzhou 313000 Zhejiang Province China Department of Physics Xuchang Teacher''s College Xuchang 461000 Henan Province China

With the low-lying energy levels, E2 transition branching ratios and absolute transition rates of the 134Ba and 108Pd, are investigated in the neutron-proton interacting boson model (IBM2) which includes the quadrupole quadrupole interaction between like bosons and the E(5) symmetry, it shows that the IBM2 can describe the nuclei at critical point of a phase transition well.

关键词： E(5) symmetry, 134Ba, 108pd, neutron-proton interaction boson model

A Compact System of Capacitively Coupled Contactless Conductivity Detection Based on the Square Wave Excitation Signal for Capillary Electrophoresis

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维普期刊数据库

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Chinese Chemical Letters 2006年第9期17卷 1229-1232页

作者： Shui Feng zhang li Shi wang Zhi DANG College of Environmental Science and Engineering South China University of Technology Guangzhou 510640

This paper reported a compact system of capacitively coupled contactless conductivity detection （C4D） based on the square wave excitation voltage for capillary electrophoresis, and it exhibited excellent sensitivity at the optimal frequency of 198 kHz. The feasibility and sensitivity of this detector was demonstrated by simultaneous detection of thirteen ions including alkali, alkaline earth and heavy metal ions. And the detection limits （S/N 3） were in the range of 0.2-1μmol/L for Mn^2＋, K^＋, Na^＋, Mg^2＋, Ca^2＋, li^＋, Ba^2＋, and 7-25 μmol/L for Ni^2＋, Cu^2＋, Cd^2＋, Pb^2＋, Co^2＋, Zn^2＋.

关键词： Capillary electrophoresis square wave excitation signal contactless conductivitydetector metal ions.

Sensing Escherichia coli O157:H7 via frequency shift through a self-assembled monolayer based QCM immunosensor

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第2期9卷 121-131页

作者： li-jiang wang Chun-sheng WU Zhao-ying HU Yuan-fan zhang Rong li Ping wang Biosensor National Special Laboratory Key Laboratory of Biomedical Engineering of Ministry of Education Department of Biomedical Engineering Zhejiang University Hangzhou 310027 China

By means of the specific immuno-recognition and ultra-sensitive mass detection, a quartz crystal microbalance (QCM) biosensor for Escherichia coli O157:H7 detection was developed in this work. As a suitable surfactant, 16-mercaptohexadecanoic acid (MHDA) was introduced onto the Au surface of QCM, and then self-assembled with N-hydroxysuccinimide (NHS) raster as a reactive intermediate to provide an active interface for the specific antibody immobilization. The binding of target bacteria with the immobilized antibodies decreased the sensor’s resonant frequency, and the frequency shift was correlated to the bacterial concentration. The stepwise assembly of the immunosensor was characterized by means of the electrochemical techniques. Using the immersion-dry-immersion procedure, this QCM biosensor could detect 2.0×102 colony forming units (CFU)/ml E. coli O157:H7. In order to reduce the fabrication time, a polyelectrolyte layer-by-layer self-assembly (LBL-SA) method was adopted for fast construction. Finally, the reproducibility of this biosensor was discussed.

关键词： Biosensor Escherichia coli O157:H7 Immunosensor Layer-by-layer self-assembly (LBL-SA) Quartz crystalmicrobalance (QCM)

A NOTE ON MERRIS'CONJECTURES

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Applied Mathematics(A Journal of Chinese Universities) 1999年第2期14卷 197-202页

作者： zhang Xiaodong\ li Jiongsheng\ wang Ping Dept. of Math. University of Science and Technology of China Hefei

The Merris conjectures for threshold graphs and d regular graphs are *** the one of the conjectures of Merris holds for trees is also proved.

关键词： Merris推测极限图 d-规则图图论

EFFECTS OF RAPAMYCIN ON INTRACELLULAR CHOLESTEROL HOMEOSTASIS OF GLOMERULAR MESANGIAL CELL IN THE PRESENCE OF INTERLEUKIN-1β

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Chinese Medical Sciences Journal 2008年第4期23卷 205-211页

作者： Guo-iuan zhang Hang li Xue-wang li Department of Nephrology Peking Union Medical College Hospital Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100730

Objective To investigate the effects of rapamycin on cholesterol homeostasis of glomerular mesangial cells and the underlying mechanisms. Methods Intracellular cholesterol accumulation was measured by Oil Red O staining and high performance liquid chromatography. The effects of rapamycin on interleukin-1β（1L-1β）-induced mRNA and protein changes of low-density lipoprotein receptor （LDLR） and ATP-binding cassette transporter Al （ABCAl） were assayed by quantitative real-time PCR and Western blot. Transient expressions of 3 types of mammalian target of rapamycin （mTOR）, including mTOR-WT （wild type）, mTOR-RR （rapamycin resistant, with kinase activity）, and mTOR-RR-KD （rapamycin resistant, without kinase activity）, were obtained by plasmid transfection. Results Rapamycin had no significant influence on intracellular cholesterol concentration trader normal condition, but it significantly decreased the intracellular cholesterol concentration in the presence of IL-1β. Rapamycin dose-dependently suppressed the increased expression of LDLR induced by IL-1β and up-regulated the suppressed expression of ABCAl caused by IL-1β Transient expression of 3 types of mTOR all reduced ABCAl mRNA expression significantly, which all could be overroded by rapamycin. Conclusions Rapamycin may contribute to the maintaining of glomerular mesangial cell intracellular cholesterol homeostasis under inflammatory state by both reducing cholesterol uptake and increasing cholesterol effiux. And the effect may be not completely mediiated by mTOR.

关键词： rapamycin glomerular mesangial cell cholesterol low-density lipoprotein receptor ATP-binding ca, sette transporter A1

Spatial flow influence factor: A novel concept for indoor air pollutant control

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Science China(Technological Sciences) 2006年第1期49卷 115-128页

作者： zhang Yinping li Xiaofeng wang Xinke DENG Wei QIAN Ke Department of Building Science Tsinghua University Beijing 100084 China Department of Building Science Tsinghua University Beijing 100084 China Department of Building Science Tsinghua University Beijing 100084 China Department of Building Science Tsinghua University Beijing 100084 China Department of Building Science Tsinghua University Beijing 100084 China

This paper puts forward a novel concept, the spatial flow influence factor (SFIF), which provides a new insight into the airflow structure. This concept is very helpful in the control of indoor air pollutants since: (1) for a given indoor airflow; given sources of volatile organic compounds (VOCs), the optimal arrangement of the VOC sources can easily be obtained; (2) for given positions of VOC sources; occupied regions (or target regions), the optimal indoor airflow pattern or organization can be determined; (3) the SFIF for an indoor space can also be regarded as the indoor air safety index of that space. To illustrate this concept, we present several examples of applying a SFIF to indoor air VOC control.

关键词： volatile organic compounds, indoor air quality, indoor air pollutant control, spatial flow influence factor.

Synthesis of highly concentrated,carrier free ^(188)Re-mercaptoacetyltriglycine

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Nuclear Science and Techniques 2002年第4期13卷 237-243页

作者： zhang Xiu-li, wang Yong-Xian, li Jun-ling, zhang Chun-Fu, wang li-Hua,YIN Duan-Zhi(Shanghai Institute of Nuclear Research, the Chinese Academy of Sciences, Shanghai 201800) Shanghai Institute of Nuclear Research the Chinese Academy of Sciences 201800

Chelation of 188Re to compounds such as MAG3 will further reduce the radiation dose to the patient in case of balloon rupture through the rapid excretion from the body. In order to prepare highly concentrated, carrier free 188Re-MAG3, Sbenzoyl mercaptoacetyltriglycine (S-Bz-MAG3) was synthesized, labeled with carrier free 188Re. The overall yield of S-Bz-MAG3 is higher than those published in theliterature. Dependence of the labeling yield of 1ssRe-MAG3 upon concentrations of reducing agent, pH, reaction time, etc. was examined and optimum conditions were confirmed. The concentration procedure was succeeded with Sep-Pak C18 cartridge to obtain highly concentrated 1s8Re-MAG3. In the case of optimun conditions, the labeling yield of 188Re-MAG3 was more than 98%. Radiochemical purity of 188ReMAG3 was more than 92% after 24 hour storage at room temperature.

关键词：放射同位素 ^188Re 放射免疫疗法