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Syntheses and Crystal Structures of Two Coordination Polymers with Aromatic Dioxide as Bridge Ligands

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Chinese Journal of Structural Chemistry 2007年第2期26卷 214-218页

作者： SHI Jing-Min XU Hai-yan zhang Feng-xia WU Chang-Ju LIU Lian-Dong Department of Chemistry Shandong Normal University Jinan 250014 China

Two coordination polymers, namely, two-dimensional complex 1 {[Cu（μ- L）1.5（ClO4）2（H2O）].（H2O）0.5]n （L = pyrazine-1,4-dioxide） and one-dimensional complex 2 [Co（μ-L）Br2（H2O）2]n, have been synthesized with pyrazine-1,4-dioxide as bridging ligands, and their crystal structures were determined by X-ray crystallography. Crystal data for complex 1： monoclinic system, space group C2/c, with a = 23.310（3）, b = 12.2338（17）, c = 10.6075（15） A, β= 110.487（2）°, V = 2833.6（7） A3, Z = 8, C6H9C12CuN3O12.5, Mr = 457.60, Dc = 2.145 g/cm^3, F（000） = 1832 and μ = 1.998 mm^-1; and those for 2： monoclinic system, space group C2/c, with a = 11.012（3）, b = 7.483（2）, c = 11.451（3） A, β = 101.654（4）°, V = 924.2（4） A3, Z = 4, C4HsBr2CoN2O4, Mr = 366.87, Dc = 2.637 g/cm^3, F（000） = 700 and μ = 10.487 mm^-1. 1 shows a two-dimensional sheet structure on the ac plane through the coordination of μ-L bridging ligands with Cu（Ⅱ） ions, while 2 displays a zigzag one-dimensional chain along the c axis via the coordination of μ-L bridging ligand with Co（Ⅱ） ions. Hydrogen bonds in 1 and 2 make the sheets （or chains） connect each other to form a three-dimensional structure.

关键词： Aromatic Dioxide coordination polymers Hydrogen bonds

Changes of Cu, Zn, and Cd speciation in sewage sludge during composting

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Journal of Environmental Sciences 2005年第6期17卷 957-961页

作者： GAO Ding ZHENG Guo-di CHEN Tong-bin LUO Wei GAO Wei zhang Yi-an LI yan-xia Center for Environmental Remediation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

The potential toxicity risks from heavy metals depend on their chemical speciation. The four stages of the Tessier sequential extraction method were employed to investigate changes in heavy metal speciation （Cu, Zn, and Cd） of sewage sludge during forced aeration composting, and then to identify whether the composting process would reduce or enhance their toxicities. Throughout the composting process, the exchangeable, carbonate-bound, Fe-Mn oxide-bound, and organic matter-bound fractions of Cu were converted to the residual Cu fraction. The organic matter-bound Cu fraction greatly contributed to this transformation. Residual Zn fraction was transformed to the Fe-Mn oxide-bound and organic matter-bound fractions after composting. The residual Zn fraction was a major contributor to the organic matter-bound Zn fraction. The availability of Cu and Zn was reduced by composting such that the risk of heavy metal toxicity decreased with prolonged treatment times. Additionally, attention should be paid to the increased availability of Cd in sewage sludge after composting treatment.

关键词： composting distribution heavy metal sewage sludge speciation

Approaches to biosynthesis of salidroside and its key metabolic enzymes

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Forestry Studies in China 2007年第4期9卷 295-299页

作者： Shi Ling-ling Wang Li zhang yan-xia Liu Yu-jun College of Biological Sciences and Biotechnology Beijing Forestry University Beijing 100083 P. R. China Department of Medicine Tibet College for Nationalities Xianyang 712082 P. R. China

As a main component of efficiency in Rhodiola plants, salidroside is a promising environmental acclamation medicine and possesses specific medical properties against symptoms of fatigue, old age, microwave radiation, viral infections and tumors. Salidroside plays important roles, especially in military, aerospace, sport and healthcare medicine and has, therefore, recently, drawn more and closer attention. This article probes mainly into the probable biosynthetic pathway of salidroside following a brief introduction of the exploitation and utilization values of Rhodiola plants and the current condition of its natural resources. We have come to the conclusion that tyrosol, the aglycon of salidroside, is biosynthesized through the well-characterized shikimic acid pathway. A molecule of glucose is transferred by the UDP-glucosyltransferase （or possibly by the β-D-glucosidase too） to the tyrosol to form salidroside. On the other hand, salidroside may be degraded into tyrosol and glucose by β-D-glucosidase. Progress in research of these two key-enzymes, involved in the metabolism of salidroside, is finally elaborated.

关键词： Rhodiola salidroside tyrosol UDP-glucosyltransferase β-D-glucosidase

Mycophenolate mofetil affects monocyte Toll-like receptor 4 signaling during mouse renal ischemia/reperfusion injury

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Chinese Medical Journal 2013年第7期126卷 1224-1229页

作者： zhang yan-xia zhang Jian-rong WANG Zhi-gang Department of Nephropathy Affiliated Beijing Friendship Hospital Capital Medical University Beijing 100050 China Department of Nephropathy General Hospital of Armed Police Force Beijing 100039 China

Background Mycophenolate mofetil （MMF） has been used to prevent transplant rejection for many years and has been shown to have protective effects against renal failure. The objective was to investigate the effect of MMF on monocyte Toll-like receptor 4 （TLR4） signaling in the early stages of renal ischemia/reperfusion injury （IRI） of mice. Methods Sixty BALB/C mice were randomly divided into two groups： an IRI group, in which renal IRI was induced by clamping the renal pedicles for 45 minutes, and an MMF group, in which MMF was given （40 ***-l.d-1, intraperitoneally） from 2 days before renal IRI. The plasma creatinine level and renal tissue damage of each group mice were observed 6, 12, 24, and 48 hours after reperfusion. The concentration of plasma high-mobility group box 1 （HMGB-1）（TLR4 ligand）, interleukin 6 （IL-6）, monocyte chemoattractant protein-1 （MCP-1）, and tumor necrosis factor a （TNF-cc） and the expression of TLR-4 on monocytes were determined. Results The plasma creatinine concentration in the MMF group was lower compared to the IRI group （after reperfusion of 6, 12, 24, or 48 hours, P 〈0.05）. Pathological analysis showed that the renal damage was slighter, TLR-4 expression was reduced （after reperfusion of 6, 12, 24, or 48 hours, P 〈0.05）, and the concentration of cytokines in the plasma was lower （P 〈0.05） in the MMF group. No differences in the concentrations of HMGB-1 were observed （P 〉0.05）. Conclusion Monocyte TLR4 signaling is important in the early stage of kidney IRI, but MMF can inhibit it and improve renal function.

关键词： mycophenolate mofetil Toll-like receptor 4 ischemia/reperfusion injury monocyte innate immunity

Applicability of Temperature Discrete Equation to NMRF Boundary Layer Scheme in GRAPES Model

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Journal of Tropical Meteorology 2022年第1期28卷 12-28页

作者： zhang yan-xia CHEN Zi-tong MENG Wei-guang XU Dao-shen Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction CMAGuangzhou 510641 China

By deriving the discrete equation of the parameterized equation for the New Medium-Range Forecast(NMRF)boundary layer scheme in the GRAPES model,the adjusted discrete equation for temperature is obviously different from the original equation under the background of hydrostatic equilibrium and adiabatic *** the present research,three discrete equations for temperature in the NMRF boundary layer scheme are applied,namely the original(hereafter NMRF),the adjustment(hereafter NMRF-gocp),and the one in the YSU boundary-layer scheme(hereafter NMRF-TZ).The results show that the deviations of height,temperature,U and V wind in the boundary layer in the NMRF-gocp and NMRF-TZ experiments are smaller than those in the NMRF experiment and the deviations in the NMRF-gocp experiment are the *** deviations of humidity are complex for the different forecasting lead time in the three ***,there are obvious diurnal variations of deviations from these variables,where the diurnal variations of deviations from height and temperature are similar and those from U and V wind are also ***,the diurnal variation of humidity is relatively *** root means square errors of 2m temperature(T2m)and 10m speed(V10m)from the three experiments show that the error of NMRF-gocp is the smallest and that of NMRF is the *** is also a diurnal variation of T2m and V10m,where T2m has double peaks and V10m has only one *** of the discrete equations between NMRF and NMRF-gocp experiments shows that the deviation of temperature is likely to be caused by the calculation of vertical eddy diffusive coefficients of heating,which also leads to the deviations of other elements.

关键词： NMRF boundary layer scheme turbulent equation temperature discrete equation CMA-GD model

INSTANTANEOUS AVAILABILITY ASSESSMENT OF RENEWABLE COMPONENT IN EXPONENTIAL DISTRIBUTIONS

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Applied Mathematics(A Journal of Chinese Universities) 2006年第4期21卷 397-404页

作者： zhang Guofen xia yan Xu Ganggang Department of Mathematics Zhejiang University Zhejiang 310027 China.

A renewable component with exponential failure and repair times is considered, and its instantaneous availability at time t is denoted by A（t）. This paper proposes two methods for constructing lower confidence limit... 详细信息

关键词： instantaneous availability lower confidence limit generalized p-value approach.

Characteristics of the HIV/AIDS Epidemic in Women Aged 15-49 Years from 2005 to 2012 in China

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Biomedical and Environmental Sciences 2015年第10期28卷 701-708页

作者： zhang xia yan HUANG Tao FENG Yi Bing LI Meng CHEN Fang Fang LI Yin Ge JIN Shan Shan BU Kai WANG Lu National Center for AIDS/STD Control and Prevention Chinese Center for Disease Control and Prevention Shandong Provincial Center for Disease Control and Prevention College of Public Health University of South Florida

Objective To describe the characteristics of the HIV/AIDS epidemic in women aged 15-49 years in China. Methods HIV/AIDS cases from 2005 to 2012 that fulfilled the inclusion and exclusion criteria were identified on the Chinese HIV/AIDS case reporting system. Descriptive and spatial analyses were performed. Results A total of 103,559 female HIV/AIDS cases were included in our study. Based on the descriptive analysis, between 2005 and 2012, the proportion of heterosexually acquired HIV infection among women （15-49 years） increased rapidly from 35.8% to 87.4%. Approximately 60% of these cases were infected through non-marital heterosexual contact. Among older women （40-49 years）, a slightly increasing trend was identified. The spatial analysis detected ＇hot spots＇ in the Xinjiang, Yunnan, Sichuan, Guangxi, and Chongqing provinces. The epidemic trends in these areas were predominately driven by heterosexual transmission. Conclusion Non-marital heterosexual contact is a very important factor in the HIV/AIDS epidemic in women aged 15-49 years, and the HIV infection rate in older women is increasing. Several epidemic hot spots were detected in northwestern and southwestern China. Efficient interventions are needed to control the spread of HIV/AIDS among women living in these areas.

关键词： AIDS Women Epidemiology China

Improved Tropical Cyclone Forecasts with Increased Vertical Resolution in the TRAMS Model

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Journal of Tropical Meteorology 2022年第4期28卷 377-387页

作者： XU Dao-sheng LIANG Jia-hao LU Ze-bin zhang yan-xia HUANG Fei FENG Ye-rong zhang Bang-lin Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction CMAGuangzhou 510641 China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081 China College of Ocean and Meteorology Guangdong Ocean UniversityZhanjiangGuangdong 524088 China Zhuhai Meteorological Bureau ZhuhaiGuangdong 519099 China

The numerical simulation of typhoons has been found to be very sensitive to the vertical resolution of the *** the updating of the TRAMS model from version 1.0 to 3.0,the horizontal resolution has been increased from 36 km to 9 km,while the vertical layer number only increased from 55 to 65 *** lack of high vertical resolution limits the performance of the TRAMS model in typhoon forecasting to a certain *** order to study the potential improvement of typhoon forecasting by increasing the vertical resolution,this paper increases the vertical resolution of the TRAMS model from 65 to 125 layers for the first time for a comparative simulation *** results of the case study with Typhoon Hato(2017)show that the model with high vertical resolution can significantly enhance the warm structure caused by water vapor flux convergence and vertical transport,thus accurately simulating the rapid strengthening process of the ***,the model with 125-layer vertical resolution can simulate the asymmetric structural characteristics of the wind field,which are closer to the observations and can help to reduce the bias in typhoon track *** improvement of vertical resolution is also trialed by using the batch test results of several landfalling typhoons in *** experimental results show that the typhoon forecast of the model becomes consistent with the observations only when the number of vertical layers of the model increases to about 125 layers,which in turn causes a large computational *** the next step,we will try to solve the computational burden problem caused by ultra-high vertical resolution with the top boundary nesting technique,and realize the application of high vertical resolution in the actual operation of the TRAMS model.

关键词： typhoon model vertical resolution verification

Inequalities Among Eigenvalues of Left-definite Sturm-Liouville Problems

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Chinese Quarterly Journal of Mathematics 2010年第2期25卷 300-307页

作者： zhang yan-xia zhang Xue-feng Faculty of Mathematics and Physics Anhui University of Technology Maanshan 243002 China Department of Computer Science Anhui University of Technology Maanshan 243002 China

There are well-known inequalities among eigenvalues of right-definite Sturm- Liouville problems. In this paper, we study left-definite regular self-adjoint Sturm-Liouville problems with separated and coupled boundary conditions. For any fixed equation, we establish a sequence of inequalities among the eigenvalues for different boundary conditions, which is both theoretical and computational importance.

关键词： Sturm-Liouville problems right-definiteness left-definiteness eigenvalue ineaualities