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Template Syntheses and Crystal Structures of Hexaaza Macrocyclic Complexes with C-Methyl Substituents

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Chinese Journal of Structural Chemistry 2005年第11期24卷 1259-1263页

作者： ZHANG bing KOU Hui-Zhong CUI Ai-Li wang ru-Ji Department of Chemistry Tsinghua University Beijing 100084 China

Two new macrocyclic complexes with C-methyl substituents on the framework, namely, [CuL]（ClO4）2 （L = 5,12-dimethyl-1,8-dihydroxyethyl-1,3,6,8,10,13-hexaazacyclotetradecane） 1 and [NiL]（ClO4）2 2, have been synthesized and structurally characterized through X-ray diffraction analysis. Also, crystal structure of [CuL^1]（ClO4）2 （L^1 = 1,8-dimethyl- 1,3,6,8, [ 0,13- hexaazacyclotetradecane） 3 has been determined. Crystal data for 1： C14H32C12CuN6O10, Mr = 578.90, monoclinic, P2 1/n, α = 8.3529（11）, b = 10.8105（17）, c = 13.3709（17） ,A, β = 105.189（10）°, V= 1165.2（3） A3, Z = 2, Dc = 1.650 g/cm^3, F（000） = 602, λ（MoKct） = 0.71073 A,μ = 1.229 mm ^-1, R = 0.0474 and wR = 0.0895 for 2771 observed reflections （I 〉 2σ（Ⅰ））. Crystal data for 2： C14H32C12N6NiO10, Mr = 574.07, monoclinic, P2 1/c, a = 8.3636（12）, b = 12.997（2）, c = 10.764（2） A, β = 99.31（2）°, V = 1154.7（3） A^3, Z = 2, DC = 1.651 g/cm^3, F（000） = 600, λ（MoKa） = 0.71073 A,μ = 1. 134 mm^-1, R = 0.0380 and wR = 0.0796 for 2670 observed reflections （i 〉 2σ（Ⅰ））. Crystal data for 3： C 10H26Cl2CuN6O8, Mr = 492.81, monoclinic, P2 1/n, a = 8.4860（17）, b = 8.6320（17）, c = 12.662（3） ,A,β = 103.40（3）°, V = 902.2（3）A^3, Z = 2, Dc = 1.814 g/cm^3, F（000） = 510, λ（MoKa） = 0.71073A, μ = 1.562 mm^-1, R = 0.0505 and wR = 0.1061 for 1967 observed reflections （I〉 2σ（Ⅰ））. Complexes 1 and 2 are isostructural with the metal ions situated at the inversion center/Hydrogen bonds between O atoms of pendant and perchlorate anion give rise to a two-dimensional supramolecular layer. The Cu（Ⅱ） ions of compounds 1 and 3 adopt distorted axially-elongated octahedral coordinate geometry, and the nickel（Ⅱ） ion in complex 2 is four-coordinated with a square-planar configuration.

关键词： synthesis crystal structure macrocycle C-methyl substituent copper nickel synthesis crystal structure macrocycle C-methyl substituent copper nickel

A Review of Methods for Studying Microbial Diversity in Soils

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Pedosphere 2006年第1期16卷 18-24页

作者： LIU bing-ru JIA Guo-Mei CHEN Jian wang Gang Key Laboratory of Arid and Grassland Agroecology at Lanzhou University Ministry of Education Lanzhou 730000（China）. School of Life Science Lanzhou University Lanzhou 730000 （China）

Soil microorganisms play a central role in decomposing organic matter, in determining the release of mineral nutrients, and in nutrient cycling. Recently, extensive studies have focused on soil microbial diversity. However, understanding the diversity of this complex microbial community in the soil environment is a challenging task. Thus, it is important to master and comprehend appropriate methods for studying soil microbial diversity. Concepts of soil microbial diversity and major methods of study are briefly introduced in this paper. Then, the application of biochemical-based and molecular-based techniques in this area, and their advantages and disadvantages are evaluated. Based on recent related research, perspectives for studying microbial diversity in soils are presented.

关键词： bacteria diversity fungi molecular soil

Answering queries using cooperative semantic cache in mobile computing environments

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The Journal of China Universities of Posts and Telecommunications 2012年第3期19卷 54-59页

作者： LIANG ru-bing LIU Qiong College of Science South China Agricultural University Guangzhou 510642 China School of Computer Science and Engineering South China University of Technology Guangzhou 510006 China

In cooperative cache research domain, most of previous work engage in peer-to-peer systems and distributed systems, but do not involve applying cooperative semantic cache in mobile computing environments, which wireless communications disconnect at times and clients move frequently. In this paper, we extend the general semantic cache mechanism by enabling mobile clients to share their local semantic caches in a cooperative matter, and the process way and flow chart of the algorithm are described in detail. In addition, we discuss the methods used in cache consistence maintenance, which focus on confirm receiver of the periodic cache invalidation report and the process of validate client＇s local cache. The experiment results indicate cooperative semantic cache mechanism could reduce query response time and increase cache hit ratio effectively.

关键词： cooperative semantic cache cache consistence mobile computing

采样位置与时间选择对土壤重金属风险评估工作的影响

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食品安全质量检测学报 2016年第11期7卷 4447-4451页

作者：何昭颖哈雪姣刘静李冰茹王北洪北京农业质量标准与检测技术研究中心北京100097 农业部农产品质量安全风险评估实验室(北京) 北京100097 北京市大兴区土肥工作站北京102600

目的：建立一种具有代表性且能够综合、准确反映多种重金属元素在土壤中污染状况的样品采集方法,为土壤重金属风险评估工作的顺利展开提供有力的保障。方法模拟铜、铅2种元素在土壤中的迁移条件,结合试验田铜元素、铅元素的背景值,分别... 详细信息

目的：建立一种具有代表性且能够综合、准确反映多种重金属元素在土壤中污染状况的样品采集方法,为土壤重金属风险评估工作的顺利展开提供有力的保障。方法模拟铜、铅2种元素在土壤中的迁移条件,结合试验田铜元素、铅元素的背景值,分别添加Cu（NO3）2、Pb（NO3）2,使试验田中心污染源铜元素和铅元素的分别达到2.6×103 mg/kg和4.0×103 mg/kg。设置3组不同的灌溉量,每组设2个平行试验,分别于d 7、14、31、49进行采样,之后利用电感耦合等离子体发射光谱仪（ICP-OES）、原子吸收分光光度计检测这2种重金属元素含量,研究铜、铅在土壤中的迁移规律。结果检测结果显示铜、铅2种元素在土壤中的横向迁移速度差异较大。铜元素横向扩散速度较快,在d 49时监测位点的铜元素浓度趋于稳定,接近最大值；而铅元素较慢,监测位点的铅元素浓度基本没有发生变化。结论单一的取样点难以同时满足铜、铅2种重金属元素的风险评估工作需要,建议对这2种重金属元素的取样检测工作应尽量区别开展。

关键词：风险评估铜铅土壤横向迁移

The B→D^(*)lv_l decays in the pQCD approach with the Lattice QCD input

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Science Bulletin 2015年第23期60卷 2009-2015页

作者： Ying-Ying Fan Zhen-Jun Xiao ru-Min wang bing-Zhong Li College of Physics and Electronic Engineering Xinyang Normal University Department of Physics and Institute of Theoretical Physics Nanjing Normal University

In this decays B → D^（＊）l^-vl paper, we studied by using the the semileptonic ＂pQCD ＋ Lattice QCD＂ method. We made the extrapolation for the six relevant form factors by using the input values obtained from the pQCD factorization approach in the low q2 region of 0 ≤ q^2≤≤mt^2 and the lattice QCD input at the endpoint q^2 = q^2max· We then calculated the ratios R（D） and R（D^＊） of the branching ratios B（B→ D^（＊）l^-vl） and found numeri- cally that （1） the ＂pQCD ＋ Lattice QCD＂ predictions for the branching ratios B（B → D^（＊）l^-vl） agree well with the measured values within one standard deviation; and （2） the ＂pQCD ＋ Lattice QCD＂ predictions for the ratios R（D^（＊）） are R（D） =0.037-0.037^＋0.038 and R（D^＊） = 20269-03020^＋03021;they agree with the data within 2σ deviation, in other words, one can explain the ＂R（D（^＊）-puzzle＂ in the framework of the Standard Model.

关键词： "R(D^(*))-puzzle" · → D^(*)lvl decays ·The pQCD approach · Lattice QCD

Friction and wear properties of PM cam materials with different boron contents

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Rare Metals 2023年第12期42卷 4255-4263页

作者： rui wang Lin-Shan wang Xue-bing Liang wang Zhang Yan-ru Mu Jing-Jie Xu Li-Min wang Shao-Ming Zhang General Research Institute for Nonferrous Metals Beijing 100088China GRIPM Advanced Materials Co.Ltd Beijing 101407China Beijing Hengyuantianqiao Powder Metallurgy Co.Ltd Beijing 101407China Beijing Engineering Research Center for Metal Powder Beijing 101407China

In this study,effects of B addition on the sintering densification,microstructure,hardness,friction and wear properties of sintered Fe-2.4C-4Cr-1Mo-0.5P-0.7Si-2.5Cu(in wt%)were *** spite of the decreased sintered density,the addition of B changes the phase composition of the materials and their ***,hardness of either the matrix or the liquid solidification structure dramatically *** changes in micro structure result in higher friction coefficient and lower wear *** is observed that the addition of0.1 wt%B offers the optimum friction and wear properties with a running-in period of only 30 s and wear volume loss of 0.006 mm^(3) under the testing *** friction and wear properties are superior to those of the other two widely used cam materials,cast iron and 45 steel.

关键词： Boron addition Friction and wear property Cam material Microstructure Wear mechanism

An ＂In Vivo Self-assembly＂ Strategy for Constructing Superstructures for Biomedical Applications

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Chinese Journal of Polymer Science 2018年第10期36卷 1103-1113页

作者： Man-Zhu Zhao Dong-bing Cheng Zhao-ru Shang Lei wang Zeng-Ying Qiao Jing-Ping' Zhang Hao wang School of Chemistry Northeast Normal University Changchun 130024 China Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety National Center for Nanoscience and Technology (NCNST) Beijing 100190 China

The interfacing study of biopolymer and supramolecular chemistry enables a better understanding of fundamental biochemical processes and the creating of new high-performance biomaterials. In this review, we introduced an ＂in vivo self-assembly＂ strategy which means in situ construction of functional self-assembled superstructures in specific physiological or pathological conditions in cell, tissue or animal levels that exhibit diverse biomedical effects. By using this strategy, unexpected phenomena and insights, e.g, assembly/aggregation induced retention （AIR） effect have been demonstrated where the self-assembled nanostructures showed extraordinary enhanced accumulation and retention of therapeutics in targeted sites.

关键词： In vivo self-assembly Supramolecular polymer Therapy Imaging

Isoselective Ring-opening Polymerization of Racemic Lactide Catalyzed by N-heterocyclic Olefin/(Thio)urea Organocatalysts

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Chinese Journal of Polymer Science 2021年第6期39卷 709-715,I0006页

作者： Zhen-Yu wang Guang-Qiang Xu Li Zhou Cheng-Dong Lv ru-Lin Yang bing-Zhe Dong Qing-Gang wang Key Laboratory of Biobased Materials Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The isoselective ring-opening polymerization of racemic lactide was achieved by combining N-heterocyclic olefin(NHO)with mono(thio)ureas or bis(thio)ureas as catalytic *** polymerization process shows high stereoselectivity,controllability and reactivity,delivering multi-block isotactic polylactides with high chain-end fidelity and narrow molecular weight *** enhancement of catalytic performance was observed in the following order:bisthiourea(DTU)

关键词： mechanism. heterocyclic polymerization

ON INSTABILITY OF DILUTE FIBER SUSPENSIONS IN AN AXISYMMETRIC TAYLOR-COUETTE FLOW

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Journal of Hydrodynamics 2005年第4期17卷 398-403页

作者： WAN Zhan-hong LIN Jian-zhong LI bing-ru Department of Mechanics State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

A stability analysis of flow between two coaxial rotating cylinders in the presence of fibers was performed. Based on the axisymmetric normal mode for the disturbances, a modified stability equation was derived. Then the numerical solution of the eigenvalue problem about the equation was obrained using the fourth order finite difference scheme. The marginal curves that determine the instability property were drawn. The results show that the flow instability of the dilute fiber suspensions is governed by the aspect ratio of fiber H, the inerement of H causes an increase of critical inner Reynohts number. The fiber additives effectively attenuate the instability of the flow. which is in agreement with those of related experiments.

关键词： linear stability fiber suspensions Taylor-Couette flow numerical simulation