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Synthesis and Crystal Structure of an Acetate Radical Bridged Dinuclear Copper(Ⅱ) Complex

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Chinese Journal of Structural Chemistry 2007年第3期26卷 347-351页

作者： DU Qiao-yun MA Liang qin Jian-Hua Department of Chemistry Luoyang Normal University Luoyang 471022 China

A new acetate radical bridged dinuclear copper（ Ⅱ ） complex [（C8H9NO2）2- Cu2（CH3COO）4] has been synthesized by the reaction of Cu（OAc）2 with pyridine-3-ethyl formate and further characterized by X-ray single-crystal diffraction. Crystal data for the title compound： triclinic system, space group Pí, with a = 8.1654（14）, b = 9.7010（16）, c = 9.9005（17） A, α = 83.266（2）, β = 78.887（2）, γ = 72.881（2）°, V= 733.9（2） A^3, Mr = 665.58, Z = 1, Dc = 1.506 g/cm^3, F（000） = 342,μ = 1.510 mm^-1, the final R = 0.0392 and wR = 0.1005. According to the structural determination, each unit of the title compound is composed of two Cu（ Ⅱ ） atoms, two pyridine-3-ethyl formate molecules and four acetate ions. Each Cu（Ⅱ） coordinates to oxygen atoms of acetate and nitrogen atoms of pyridine- 3-ethyl formate ligand to give a six-coordinate distorted octahedral geometry. It is worth mentioning that strong Cu-Cu bond can be observed in the title compound.

关键词： pyridine-3-carboxylic acetate radical bridge Cu( Ⅱ ) crystal structure

Resource allocation using time division multiple access over wireless relay networks

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The Journal of China Universities of Posts and Telecommunications 2008年第3期15卷 69-74页

作者： DAI qin-yun RONG Lu HU Hong-lin SU Gang Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200052 China The Department of Electronics and Information Engineering Huazhong University of Science and Technology Wuhan 430074 China

This article considers a wireless network consisting of multiple sources that communicate with the corresponding destination utilizing a single half-duplex relay, whereas, the sources use the relay opportunistically. By integrating the information theory with the concept of effective capacity, this article proposes a dynamic time allocation strategy over the wireless relay network that aims at maximizing the relay network throughput, subject to a given delay quality of service （QoS） constraint, where time division multiple access （TDMA） is applied in the relay network. The simulation results show that the proposed allocation strategy can significantly improve the effective capacity as compared to the traditional equal time allocation strategy.

关键词： resource allocation wireless relay networks effective capacity opportunistic transmission cooperative diversity

Intrinsically asymmetric atomic character regulates piezoelectricity in two-dimensional materials

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Frontiers of physics 2024年第3期19卷 153-162页

作者： yun-qin Li Qi-Wen He Dai-Song Tang Xiao Shang Xiao-Chun Wang School of Physics Science and Information Technology Liaocheng UniversityLiaocheng 252000China Key Laboratory of Polar Materials and Devices Ministry of EducationDepartment of ElectronicsEast China Normal UniversityShanghai 200241China Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012China

Decreasing of layer thickness causes the decrease of polarization until it disappears due to the existence of depolarization ***,the search for strong piezoelectric materials is highly desirable for multifunctional ultra-thin piezoelectric ***,we propose a common strategy for achieving strong piezoelectric materials through the electronic asymmetry induced by the intrinsically asymmetric atomic character of different chalcogen ***,in the tetrahedral lattice structures,for example,M4X3Y3(M=Pd/Ni,X/Y=S,Se or Te,X≠Y)monolayers are proved to display excellent out-of-plane ***4Se3Te3 possesses the largest piezoelectric coefficient d33 of 61.57 pm/V,which is much larger than that of most 2D *** the electronic asymmetry further increases the out-of-plane piezoelectricity of Janus M4X3Y3 ***,the out-of-plane piezoelectricity is positively correlated with the ratio of electronegativity difference(Red)and the electric dipole moment(P).This work provides alternative materials for energy harvesting nano-devices or self-energized wearable devices,and supplies a valuable guideline for predicting 2D materials with strong out-of-plane piezoelectricity.

关键词： piezoelectricity intrinsically asymmetric atomic character ratio of electronegativity difference electric dipole moment first-principles calculations

Dynamic microstructure evolution and mechanical properties of dilute Mg-Al-Ca-Mn alloy during hot rolling

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Journal of Materials Science & Technology 2022年第34期129卷 1-14页

作者： Shiwei Xu Congcong Zhu Zhanhong Lin Chen Jin S.Kamado K.Oh-ishi yun qin College of Materials Science and Engineering Hunan UniversityChangsha 410082China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China qinghai Salt Lake Teli Magnesium Co.Ltd. Xining 810000China Department of Mechanical Engineering Nagaoka University of TechnologyNagaoka 940-2188Japan Toyota Central R&D Labs. Inc.41-1 YokomichiNagakuteAichi 480-1192Japan Research Institute(R&D Centre) Baowu Steel Group CorporationShanghai 201900China

The dynamic microstructure and texture of dilute Mg-0.50Al-0.71Ca-0.33Mn(wt.%) during hot rolling at two slab temperatures were investigated by electron backscattered diffraction(EBSD) and high resolution transmission electron microscopy(HRTEM). The results show that the development of the rolling microstructures is to first form {10–12} extension twins in the original grains, thereby forming the extension-twinned regions, and then to further form {10–11}-{10–12} double twins and kinks in the extension-twinned regions, and finally to form continuous dynamic recrystallized(continuous DRXed)grains in the double twins and the cross parts of the shear-deformed coarse extension-twinned *** extension twins, double twins and kinks show a decisive effect on the formation of rolling *** number of {10–11}-{10–12} double twins and resultant the continuous DRX process are strongly affected by the rolling slab temperature and the reduction thickness per pass. By optimizing the rolling conditions, texture and microstructures of the multi-pass rolled Mg-Al-Ca-Mn alloy sheets are successfully modified. Although the total alloy content is only 1.5 wt.%, these Mg-Al-Ca-Mn alloy sheets show much higher strength than the commercial Mg-3Al-1 Zn(wt.%)(AZ31B) sheet.

关键词： Mg-Al-Ca-Mn alloy Hot rolling Dynamic recrystallization Texture control Mechanical properties

Assessment of clinical outcomes of advanced hilar cholangiocarcinoma

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Hepatobiliary & Pancreatic Diseases International 2018年第2期17卷 155-162页

作者： Kang-Jie Chen Fu-Chun Yang yun-Sheng qin Jing Jin Shu-Sen Zheng Division of Hepatobiliary Pancreatic Surgery First Affiliated Hospital Zhejiang University School of Medicine

Background: Low resectability and poor survival outcome are common for hilar cholangiocarcinoma(HCCA), especially in advanced stages. The present study was to assess the clinical outcome of advanced HCCA, focusing on therapeutic modalities, survival analysis and prognostic ***: Clinical data of 176 advanced HCCA patients who had been treated in our hospital between January 2013 and December 2015 were analyzed retrospectively. Prognostic effects of clinicopathological factors were explored by univariate and multivariate analysis. Survival predictors were evaluated by the receiver operating characteristic(ROC) ***: The 3-year overall survival rate was 13% for patients with advanced HCCA. Preoperative total bilirubin(P = 0.009), hepatic artery invasion(P = 0.014) and treatment modalities(P = 0.020) were independent prognostic factors on overall survival. A model combining these independent prognostic factors(area under ROC curve: 0.748; 95% CI: 0.678–0.811; sensitivity: 82.3%, specificity: 53.5%) was highly predictive of tumor death. After R0 resection, the 3-year overall survival was up to 38%. Preoperative total bilirubin was still an independent negative factor, but not for hepatic artery ***: Surgery is still the best treatment for advanced HCCA. Preoperative biliary drainage should be performed in highly-jaundiced patients to improve survival. Prediction of survival is improved significantly by a model that incorporates preoperative total bilirubin, hepatic artery invasion and treatment modalities.

关键词： Hilar cholangiocarcinoma Hepatic artery resection Preoperative biliary drainage Prognostic factors

Self-management and self-efficacy status in liver recipients

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Hepatobiliary & Pancreatic Diseases International 2015年第3期14卷 253-262页

作者： Lei Xing qin-yun Chen Jia-Ning Li Zhi-Qiu Hu Ye Zhang Ran Tao Center for Organ Transplantation and Department of Surgery Ruijin Hospital Shanghai Jiaotong University School of Medicine Nursing School Shanghai Jiaotong University School of Medicine Department of General Surgery Central Hospital of Minhang District

BACKGROUND： Liver transplantation （LT） is a viable treatment for patients with end-stage chronic liver diseases. The main aim of LT is to prolong life and improve life quality. However, although survival after LT continues to improve, some aspects of recipient＇s health-related quality of life such as self-man- agement and self-efficacy have been largely ignored.

关键词： liver transplantation self-management self-efficacy quality of life questionnaires

Experimental Dissection of the Column Efficiency in Gradient Column

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Chemical Research in Chinese Universities 1994年第1期10卷 49-53页

作者： yun, Xi-qin Kou, Deng-min Lu, Xuang-yu Liu, Shang-yuan

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关键词： GC column Gradient loaded column Column efficiency

Nitrogen in soils beneath 18 65 year old stands of subtropical evergreen broad-leaved forests in Laoshan Mountains in Eastern China

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Journal of Forestry Research 2011年第4期22卷 583-590页

作者： GU Feng ZHANG Kai ZHANG yun-qi WANG qin XU Xiao-niu Department of Forest Science Anhui Agricultural University Hefei 230036 China

Monitoring of soil nitrogen （N） cycling is useful to assess soil quality and to gauge the sustainability of management practices. We studied net N mineralization, nitrification, and soil N availability in the 0-10 cm and 11-30 cm soil horizons in east China during 2006-2007 using an in situ incubation method in four subtropical evergreen broad-leaved forest stands aged 18-, 36-, 48-, and 65-years. The properties of surface soil and forest floor varied between stand age classes. C：N ratios of surface soil and forest floor decreased, whereas soil total N and total organic C, available P, and soil microbial biomass N increased with stand age. The mineral N pool was small for the young stand and large for the older stands. NO3^--N was less than 30% in all stands. Net rates of N mineralization and nitrification were higher in old stands than jn younger stands, and higher in the 0-10 cm than in the 11-30 cm horizon. The differences were significant between old and young stands （p 〈 0.031） and between soil horizons （p 〈 0.005）. Relative nitrification was somewhat low in all forest stands and declined with stand age. N trans- formation seemed to be controlled by soil moisture, soil mierobial biomass N, and forest floor C：N ratio. Our results demonstrate that analyses of N cycling can provide insight into the effects of management disturbances on forest ecosystems.

关键词： microbial biomass nitrogen nitrogen availability nitrogenmineralization soil horizon subtropical forest

Application of geographically weighted regression model in the estimation of surface air temperature lapse rate

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Journal of Geographical Sciences 2021年第3期31卷 389-402页

作者： qin yun REN Guoyu HUANG yunxin ZHANG Panfeng WEN Kangmin Department of Atmospheric Science School of Environmental StudiesChina University of GeosciencesWuhan 430074China Laboratory for Climate Studies National Climate CenterChina Meteorological AdministrationBeijing 100081China School of Resource and Environmental Science Hubei UniversityWuhan 430062China

The surface air temperature lapse rate(SATLR)plays a key role in the hydrological,glacial and ecological modeling,the regional downscaling,and the reconstruction of high-resolution surface air ***,how to accurately estimate the SATLR in the regions with complex terrain and climatic condition has been a great challenge for *** geographically weighted regression(GWR)model was applied in this paper to estimate the SATLR in China’s mainland,and then the assessment and validation for the GWR model were *** spatial pattern of regression residuals which was identified by Moran’s Index indicated that the GWR model was broadly reasonable for the estimation of *** small mean absolute error(MAE)in all months indicated that the GWR model had a strong predictive ability for the surface air *** comparison with previous studies for the seasonal mean SATLR further evidenced the accuracy of the ***,the GWR method has potential application for estimating the SATLR in a large region with complex terrain and climatic condition.

关键词： temperature lapse rate geographically weighted regression surface air temperature estimation regression residual