检索结果-南通市图书馆

Free cupric ions in contaminated agricultural soils around a copper mine in eastern Nanjing City, China

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2006年第5期18卷 927-931页

作者： LUO Xiao-san ZHOU Dong-mei wang yu-jun State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

To determine the environmental free metal ion activity was a recent hot issue. A method to measure low-level free cupric ion activity in soil solution extracted with 0.01 mol/L KNO3 was developed by using cupric ion-selective electrode （ISE） and calibrating with Cu-buffer solution. Three copper buffers including iminodiacetic acid （IDA）, ethylenediamine （EN）, and glycine （Gly） were compared for calibrating the Cu-ISE curves in the range of free cupric ions （pCu^2＋） 7-13. The Cu-EN buffer showed the best electrode response and thus was applied as the calibration buffer. The pCu^2＋ of 39 contaminated agricultural soils around a copper mine was measured, ranging from 5.03 to 9.20. Most Cu in the soil solutions was found to be complexed with dissolved soil organic matters, averaging 98.1%. The proportion of free Cu^2＋ ions in the soil solutions decreased with the increasing of solution pH. Soluble Cu and free Cu^2＋ ions concentrations were analyzed by multiple linear regressions to evaluate the effects of soil properties on metal levels and speciation. The results showed that soil solution pH was the most significant factor influencing pCu^2＋（with R^2 value of 0.76）, while not important for the soluble Cu concentration.

关键词： copper ion selective electrode (Cu-ISE) free metal ion activity soil solution metal speciation bioavailability

Effects of phosphate on the adsorption of glyphosate on three different types of Chinese soils

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2005年第5期17卷 711-715页

作者： wang yu-jun ZHOU Dong-mei SUN Rui-juan State Key Laboraton of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

Glyphosate （GPS） is a non-selective, post-mergence herbicide that is widely used throughout the world. Due to the similar molecular structures of glyphosate and phosphate, adsorption of glyphosate on soil is easily affected by coexisting phosphate, especially when phosphate is applied at a significant rate in farmland. This paper studied the effects of phosphate on the adsorption of glyphosate on three different types of Chinese soils including two variable charge soils and one permanent charge soil. The results indicated that Freundlich equations used to simulate glyphosate adsorption isotherms gave high correlation coefficients（0.990-0.998） with K values of 2751, 2451 and 166 for the zhuanhong soil（ZH soil, Laterite）, red soil（ RS, Udic Ferrisol） and Wushan paddy soil（WS soil, Anthrosol）, respectively. The more the soil iron and aluminum oxides and clay contained, the more glyphosate adsorbed. The presence of phosphate significantly decreased the adsorption of glyphosate to the soils by competing with glyphosate for adsorption sites of soils. Meanwhile, the effects of phosphate on adsorption of glyphosate on the two variable charge soils were more significant than that on the permanent charge soil. When phosphate and glyphosate were added in the soils in different orders, the adsorption quantities of glyphosate on the soils were different, which followed GPS-soil 〉 GPS-P-soil = GPS-Soil-P 〉 P-soil-GPS, meaning a complex interaction occurred among glyphosate, phosphate and the soils.

关键词： soil glyphosate phosphate competitive adsorption

Binding and Adsorption Energies of Heavy Metal Ions with Hapli-Udic Argosol and Ferri-Udic Argosol Particles

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2007年第6期17卷 688-696页

作者： wang yu-jun LI Cheng-Bao wang Wei ZHOU Dong-Mei XU Ren-Kou Institute of Soil Science the Chinese Academy of Sciences P.O. Box 821 Nanjing 210008 （China） College of Resource and Environment Nanjing Agricultural University Nanjing 210095 （China）

Gibbs free binding energy and adsorption energy between cations and charged soil particles were used to evaluate the interactions between ions and soil particles. The distribution of Gibbs free adsorption energies could not be determined experimentally before the development of Wien effect measurements in dilute soil suspensions. In the current study, energy relationships between heavy metal ions and particles of Hapli-Udic Argosol （Alfisol） and Ferri-Udic Argosol were inferred from Wien effect measurements in dilute suspensions of homoionic soil particles （〈 2 μm） of the two soils, which were saturated with ions of five heavy metals, in deionized water. The mean Gibbs free binding energies of the heavy metal ions with Hapli-Udic Argosol and Ferri-Udic Argosol particles diminished in the order of Pb^2＋〉 Cd^2＋〉 Cu^2＋〉 Zn^2＋〉 Cr^3＋, where the range of binding energies for Hapli-Udic Argosol （7.25-9.32 kJ mol^-1） was similar to that for Ferri-Udic Argosol （7.43-9.35 kJ mol^-1）. The electrical field-dependent mean Gibbs free adsorption energies of these heavy metal ions for Hapli-Udic Argosol and for Ferri-Udic Argosol descended in the order： Cu^2＋〉 Cd2^＋〉 Pb^2＋〉 Zn^2＋〉 Cr^3＋, and Cd^2＋〉 Cu^2＋〉 Pb^2＋〉 Zn^2＋〉 Cr^3＋, respectively. The mean Gibbs free adsorption energies of Cu^2＋, Zn^2＋, Cd^2＋, Pb^2＋, and Cr^3＋ at a field strength of 200 kV cm^-1, for example, were in the range of 0.8-3.2 kJ mo1^-1 for the two soils.

关键词： adsorption energy Argosol binding energy heavy metal ion Wien effect

A PARTIALLY-AVERAGED NAVIER-STOKES MODEL FOR HILL AND CURVED DUCT FLOW

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2011年第4期23卷 466-475页

作者： MA Jia-mei wang Fu-jun yu Xin LIU Zhu-qing College of Water Conservancy and Civil Engineering China Agricultural University Beijing 100083 China

Turbulent flows past hill and curved ducts exist in many engineering applications. Simulations of the turbulent flow arc carried out based on a newly developed technique, the Partially-Averaged Navier-Stokes （PANS） model, including separation, recirculation, reattachment, turbulent vortex mechanism. The focus is on how to accurately predict typical separating, reattaching and secondary motion at a reasonable computational expense. The effect of the parameter, the unresolved-to-total ratio of kinetic energy （ fk ）, is examined with a given unresolved-to-total ratio of dissipation （ fE ） for the hill flow with a much coarser grid system than required by the LES. An optimal value of fk can be obtained to predict the separation and reattachment locations and for more accurate simulation of the resolved turbulence. In addition, the turbulent secondary motions are captured by a smaller fi as compared with the RANS method with the same grid.

关键词： Partially-Averaged Navier-Stokes (PANS) flow separation recirculation reattachment resolved turbulence

Biases in hydrostatic mass profiles introduced by hot gas substructures:Chandra study of four galaxy clusters

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2010年第10期10卷 1005-1012页

作者： Li-Yi Gu yu wang jun-Hua Gu Jing-Ying wang Zhen-Zhen Qin Meng-yu Yao Jian-Long Yang Hai-Guang Xu Department of Physics Shanghai Jiao Tong University Shanghai 200240 China

By analyzing the azimuthal variations of total gravitating mass profiles in the central 300 h^-1 71 kpc regions of four galaxy clusters with Chandra data, we find that the azimuthally-averaged mass profiles may have been systematically underestimated by 16^＋9 -8% at lσ significance in the 50-100 h^-1 71 kpc regions, probably due to the prevailing existence of 2-D hot gas substructures in 100-300h^-1 71 kpc. The mass biases become negligible（-7＋11 _9＋ %） at 〉 150 h^-1 71 kpc. We confirm the results that the gas temperature maps can be used to probe the departure from hydrostatic equilibrium and help quantify the systematic biases in X-ray mass measurements in the central regions of clusters.

关键词： cosmology dark matter -- galaxies clusters general -- galaxies inter-galactic medium -- X-rays galaxies clusters

Effect of BCP ultrathin layer on the performance of organic light-emitting devices

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2008年第5期4卷 317-320页

作者： wang Hong yu jun-sheng LI Lu TANG Xiao-qing JIANG Ya-dong School of Optoelectronic Information State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China Chengdu 610054 China

Based on conventional double layer device, triple layer organic light-emitting diodes (OLEDs) with two heterostructures of indium-tin oxide (ITO)/N,N'-diphenyl-N,N'-bis(1-naphthyl)(1,1'-biphenyl)-4,4'-diamine(NPB)/2,9-dimethyl-4,7-diphenyl- 1,10-phenanthroline (BCP)/ 8-Hydroxyquinoline aluminum (Alq3)/Mg:Ag using vacuum deposition method have been fabricated. The influence of different film thickness of BCP layer on the performance of OLEDs has been investigated. The results showed that when the thickness of the BCP layer film gradually varied from 0.1 nm to 4.0 nm, the electrolumines- cence (EL) spectra of the OLEDs shifted from green to greenish-blue to blue, and the BCP layer acted as the recombination region of charge carriers related to EL spectrum, enhancing the brightness and power efficiency. The power efficiency of OLEDs reached as high as 7.3 lm/W.

关键词：电致发光器件超薄层 OLEDs 异质结构

Interactions of Heavy Metal Ions with Paddy Soils as Inferred from Wien Effect Measurements in Dilute Suspensions

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2006年第6期16卷 718-725页

作者： JIANG jun LI Cheng-Bao ZHAO An-Zhen XU Ren-Kou wang yu-jun S. P. FRIEDMAN Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China Institute of Soil Water and Environmental Sciences Agricultural Research Organization Voleani Center Bet Dagan 50250 Israel

Interactions of three heavy metal ions, Cu^2＋, Cd^2＋, and Pb^2＋, and, for comparison, Na^＋ with electrodialytic clay fractions （less than 2μm in diameter） of four paddy soils as well as a yellow-brown soil as a control soil were evaluated based on measurements of the Wien effect in dilute suspensions with a clay concentration of 10 g kg^-1 in four nitrate solutions of 2 × 10^-4/z mol L^-1, where z is the cation valence, and a nitric acid solution of 3 × 10^-5 mol L^-1, Field strengths ranging from 15 to 230 kV cm^-1 were applied for measuring the electrical conductivities （ECs） of the suspensions. The mean free binding energies between the various cations and all of the soils determined from exchange equilibrium increased in the order： Na^＋〈 Cd^2＋〈 Cu^2＋〈 Pb^2＋. In general, the ECs of the suspensions in the sodium nitrate solution were smaller than those of the suspensions in the heavy metal solutions because of the lower electrophoretic mobility of sodium compared to the divalent cations. In terms of relative electrical conductivity-field strength relationships, relative electrical conductivity （REC） of suspensions containing various cations at field strengths larger than about 50 kV cm^-1 were in the descending order： Na^＋〉 Cu^2＋〉 Cd^2＋〉 Pb^2＋ for all tested soils. A characteristic parameter of the REC-field strength curves, AREC200, REC at a field strength of 200 kV cm^-1 minus that at the local minimum of the concave segment of the REC-field strength curves, characterized the strength of adsorption of the cations stripped off by the applied strong electrical field, and for all soils the values of AREC200 were generally in the order： Na^＋〈 Cu^2＋ ≤ Cd^2＋〈 Pb^2＋.

关键词： binding energy electrical conductivity field strength heavy metal ions paddy soils

Application of modified two-cuff technique and multiglycosides tripterygium wilfordii in hamster-to-rat liver xenotransplant model

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2003年第7期9卷 1550-1553页

作者： Hua Guo Yi-jun Wu Shu-Sen Zheng Wei-Lin wang jun yu, Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College Zhejiang University, Hangzhou 310003, Zhejiang Province, China Department of Hepatobiliary Surgery First Affiliated Hospital Medical College of Zhejiang University 79 Qingchun Lu Hangzhou 310003 Zhejiang Province China. ggghua@***

AIM: To modify the hamster-to-rat liver xenotransplant technique to prevent postoperative complications, and to study the inhibiting effect of multiglycosides tripterygium wilfordii (TⅡ) on immune ***: Female golden hamsters and inbred male Wistar rats were used as donors and recipients, respectively. One hundred and twelve orthotopic liver xenotransplants were performed by Kamada′s cuff technique with *** 72 hour survival of the animal after operation was considered as a successful operation. When the established surgical model became stable, 30 of the latest 42 cases were divided into untreated control group (n=15) and TⅡgroup (n=15) at random. Survival of recipients was observed. Liver specimens were collected at 2 and 72 h from the operated animals and postmortem, respectively, for histological ***: The successfully operative rate of the 30operations was 80 %, and the survival of the control and TⅡ group was 7.1±0.35 was days and 7.2±0.52 days, respectively (t=0.087, P=0.931). The rate of conjunctival hyperemia in control group (100 %) differed significantly from that (31%)in TⅡ group (P=0.001). Rejection did not occur in both groups within 2 h postoperatively, but became obvious in control group at 72 h after surgery and mild in TⅡ group. Although rejections were obvious in both groups at death of recipients,it was less severe in TⅡ group than in control ***: This modified Kamada′s technique can be used to establish a stable hamster-to-rat liver xenotransplant model. Monotherapy with multiglycosides tripteryguiumwilfordii prolong survival of recipients.

关键词：多糖苷雷公藤异种肝移植免疫排斥反应动物实验

Preparation and Identification of Monoclonal Antibodies against Chicken Immunoglobulin G

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Animal Husbandry and Feed Science 2010年第10期2卷 26-27页

作者： wang jun-jun yu Wei-yi Key Laboratory of Zoonoses of Anhui Province Anhui Agricultural University Hefei 230036 China

[ Objective] To prepare monoclonal antibodies against chicken immunoglobulin G （IgG） and improve the diagnostic level of specific antibodies in chickens. [ Method] Chicken IgG was isolated by saturated ammonium sulfate and purified by Sephadex G-200 column chromatography. Then the BALB/c mice were immunized by the chicken IgG, and the spleen cells were fused with mouse myeloma cells SP2/0. Finally, the positive hybridoma cells were screened and detected by indirect enzyme-linked immunosorbent assay （ELISA）. [ Result] Four hybridoma cell strains secre- ting monoclonal antibodies against chicken IgG were obtained and named as C44, C45, C67 and C68, and their ascites titers in indirect ELISA were 1 ： 640 000, 1 ： 320 000, 1 ： 640 000 and 1 ： 80 000, respectively. The monoclonal antibodies secreted by C44 and C45 could recognize light chains of chicken IgG and those secreted by C,67 and C68 could recognize heavy chains of chicken IgG. They all could not recognize IgG from duck, rabbit and swine. Additionally, the Ig type identification results showed that they all belonged to IgGl. [ Conclusion] Four cell strains of obtained hybridoma can stably produce the monoclonal antibodies against chicken IgG.

关键词： Chicken IgG Monoclonal antibody. SPecificity. Identification