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Synthesis and Structure of a Novel Macrocyclic Complex [Cd_2(phen)_4(phth)_2]·4H_2O

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Chinese Journal of Structural Chemistry 2005年第11期24卷 1298-1301页

作者： SUN Ya-Guang GAO En-Jun WEI De-Zhou liu yi-nan Laboratory of Coordination Chemistry Shenyang Instituteof Chemical Technology Shenyang Liaoning 110142 China School of Resource ＆ Civil Engineering Northeastern University Shenyang Liaoning 110004 China

A novel complex [Cd2（phen）4（phth）2]·4H2O has been synthesized by the reaction of Hzphth（phthalic acid） and phen（1,10-phenanthroline） with Cd（Ⅱ） in ethanol-water solution. X-ray crystal structure analysis shows it crystallizes in triclinic, space group PI- with a = 10.619（3）, b = 12.560（4）, c = 12.651（4） A, a = 98.775（5）, β = 109.035（5）,γ = 113-576（5）°, C32H24CdN4O6, Mr= 672.95, V = 1381.7（7）A^3, Rint = 0.0358, Z = 2, Dc= 1.618 g/cm^3,μ = 0.845 mm^-1, -6 ≤h≤13, -15 ≤k ≤13, -15 ≤l≤14, F（000） = 680, S = 1.038, R = 0.0480 and wR = 0.0849 for 3992 observed reflections （1 〉 2σ（Ⅰ））. Phth bridges Cd（Ⅱ） to form a macrocyclic compound, and a 2D supramolecular motif is formed through hydrogen bonds and π-π interaction.

关键词： cadmium complex crystal structure hydrogen bonding π-π interaction

Identification and Promoter Activity Analysis of Porcine miR-181 and miR-1

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Journal of Integrative Agriculture 2012年第6期11卷 986-992页

作者： ZHANG Hai-xin ZHANG Rui liu yi-nan WANG Dao-lin ZHAO Yan-he REN Zhu-qing XIONGYuan-zhu Key Laboratory of Swine Genetics and Breeding Ministry of Agriculture/Key Laboratory of Agriculture Animal Genetics Breeding and Reproduction Ministry of Education/College of Animal Science Huazhong Agricultural University Wuhan 430070 P.R. China College of Life Science and Technology Huazhong Agricultural University Wuhan 430070 P.R.China

Since its discovery a decade ago, microRNA has been identified as one of the major regulatory gene families in eukaryotic cells. Many functions of microRNAs have been revealed both in flora and fauna in recent years, but the transcriptional regulation of microRNA genes is not well-understood. In the present study, a series of primers were designed in the 2 000 nt upstream regions of porcine miR-181 and miR-1 and then the sequences were cloned into pGL3-basic vector to test their transcriptional activity. Dual-luciferase reporter assays showed that, the activity of 5＂-flanking sequence of miR-181 started on construct -51, decreasing with the length of the fragment up to -444. The upstream 590 bp confer maximal transcriptional activity and the basal promoter activity is located within the -82 to ＋16 bp region. For miR-1, the activity starts on construct -50, decreasing with the length of the fragment up to -1 254 in despite of a bit of fluctuation, and the basal promoter activity is located within the -50 to ＋47 bp region. Furthermore, some putative regulation elements of both miR-181 and miR-1 were located. In addition, tissue distribution revealed that miR-181 is expressed at a relatively low level.

关键词： miR-181 miR-1 pigs promoter transcriptional activity

A GIS-based method for flooded area calculation and damage evaluation

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Journal of Geographical Sciences 2001年第2期11卷 187-192页

作者： liu Ren-yi, liu nan (The Zhejiang Provincial GIS Lab, Zhejiang University, Hangzhou 310028, China) Zhejiang University The Zhejiang Provincial GIS Lab Hangzhou China (GRID:grid.13402.34) (ISNI:***)

Using geographic information system to study flooded area and damage evaluation has been a hotspot in environmental disaster research for years. In this paper, a model for flooded area calculation and damage evaluation is presented. Flooding is divided into two types: ‘soruce flood’ and ‘non-source flood’. The source-flood area calculation is based on seed spread algorithm. The flood damage evaluation is calculated by overlaying the flooded ara range with thematic maps and relating the results to other social and economic data. To raise the operational efficiency of the model, a skipping approach is used to speed seed spread algorithm and all thematic maps are converted to raster format before overlay analysis. The accuracy of flooded area calculation and damage evaluation is mainly dependent upon the resolution and precision of the digital elevation model (DEM) data, upon the accuracy of registering all raster layers, and upon the quality of economic information. This model has been successfully used in the Zhejiang Province Comprehensive Water Management Information System developed by the authors. The applications show that this model is especially useful for most counties of China and other developing countries.

关键词： model flooded area calculation damage evaluation seed spread algorithm

Undrained anisotropy and non-coaxial behavior of clayey soil under principal stress rotation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2014年第4期15卷 241-254页

作者： Jian ZHOU Jia-jia YAN Zheng-yi liu Xiao-nan GONG Research Center of Coastal and Urban Geotechnical Engineering Zhejiang University Hangzhou 310058 China

In this study, a series of undrained tests were conducted on both intact and reconstituted clay using an automatic hollow cylinder apparatus. Monotonic shearing tests with fixed principal stress directions were carried out, pure and cyclic prin- cipal stress rotation tests were also performed. The non-coaxiality, defined as the non-coincidence of the principal plastic strain increment direction and the corresponding principal stress direction, of clayey soil was studied experimentally. The effects of the intermediate principal stress, shear stress level, and inherent anisotropy were highlighted. Clear non-coaxiality was observed during pure principal stress rotation, in both intact and reconstituted clay. The influence of the intermediate principal stress pa- rameter, shear stress level, and inherent anisotropy on the non-coaxial behavior of the clayey soil was found to be insignificant when compared with the sand. The non-coaxial behavior of the clayey soil depended more on the stress paths. Under undrained conditions, the contribution of elastic strain to the direction of the total principal strain increment cannot be ignored.

关键词： Non-coaxiality Clay Principal stress rotation Anisotropy

CH_4水合物分解过程的分子动力学模拟:扩散效应和气泡现象

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工程热物理学报 2018年第2期39卷 417-422页

作者：刘一楠邓帅赵力何俊南天津大学中低温热能高效利用教育部重点实验室天津300072

本文在三种系综(NVT、NpT和NVE)、不同温度下进行甲烷水合物分解模拟。NVE体系与外界绝热,传热阻碍较大;NVT和NpT中,分解产生的显热会很快移除,传质作用占主导地位。通过对比,对CH_4水合物分解过程的动力学特征、气泡现象和扩散效应分... 详细信息

本文在三种系综(NVT、NpT和NVE)、不同温度下进行甲烷水合物分解模拟。NVE体系与外界绝热,传热阻碍较大;NVT和NpT中,分解产生的显热会很快移除,传质作用占主导地位。通过对比,对CH_4水合物分解过程的动力学特征、气泡现象和扩散效应分别进行了解释,并提出了围绕气泡现象的三个分解阶段。考虑到气泡对局部扩散的影响,模拟中将体系划分为8个不同区域,研究局部均方位移和扩散系数,并提出了初步的扩散-气泡动力学模型。

关键词：水合物分子动力学模拟分解气泡

企业杠杆、企业投资与供给侧改革——基于面板双门限回归模型的微观证据

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上海经济研究 2016年第12期28卷 120-128,F0003页

作者：刘一楠复旦大学经济学院 200433

2015年底我国非金融企业债务总量达到112万亿元,相当于当年我国国内生产总值的163.6%,债务问题已成为制约我国微观企业发展的重要因素。该文以2003-2015年我国非金融上市公司为样本,构建面板双门限回归模型,研究企业杠杆与投资的非线性... 详细信息

2015年底我国非金融企业债务总量达到112万亿元,相当于当年我国国内生产总值的163.6%,债务问题已成为制约我国微观企业发展的重要因素。该文以2003-2015年我国非金融上市公司为样本,构建面板双门限回归模型,研究企业杠杆与投资的非线性关系,研究发现:第一,企业杠杆对投资水平的影响存在显著的双门限效应,即杠杆位于低位时增加杠杆将促进投资,而高杠杆则显著抑制企业投资,2012年后高杠杆对投资的抑制效应更为明显;第二,通过企业异质性分析证明国有企业、高增长企业、托宾q值更小的企业高杠杆对投资的抑制效应更强;第三,研究证明了目前我国非金融企业部门的高杠杆严重抑制了企业投资,故结构性去杠杆是经济增速回升的必由之路,为供给侧改革中的去杠杆提供了企业层面的微观证据。

关键词：杠杆企业投资 PTR模型

基于递归约简的在线自适应最小二乘支持向量回归机

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控制与决策 2014年第1期29卷 50-56页

作者：刘毅男张胜修张超第二炮兵工程大学自动控制工程系西安710025

鉴于传统在线最小二乘支持向量机在解决时变对象的回归问题时,模型跟踪精度不高,支持向量不够稀疏,结合迭代策略和约简技术,提出一种在线自适应迭代约简最小二乘支持向量机.该方法考虑新增样本与历史数据共同作用对现有模型产生的约束影... 详细信息

鉴于传统在线最小二乘支持向量机在解决时变对象的回归问题时,模型跟踪精度不高,支持向量不够稀疏,结合迭代策略和约简技术,提出一种在线自适应迭代约简最小二乘支持向量机.该方法考虑新增样本与历史数据共同作用对现有模型产生的约束影响,寻求对目标函数贡献最大的样本作为新增支持向量,实现了支持向量稀疏化,提高了在线预测精度与速度.仿真对比分析表明该方法可行有效,较传统方法回归精度高且所需支持向量数目最少.

关键词：最小二乘支持向量回归机在线自适应迭代策略约简技术

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遗迹化石三维重建研究新进展

地层学杂志 2016年第4期40卷 401-410页

作者：丁奕时敏敏刘祎楠中国科学院南京地质古生物研究所江苏南京210008 中国科学院大学北京100049 大庆油田有限责任公司第九采油厂黑龙江大庆163853 西北大学地质学系陕西西安710069

遗迹化石的鉴定与分类是遗迹学研究的基础,而形态特征则是鉴定遗迹化石的关键。表生遗迹和底生遗迹在岩层面上就可以清楚了解其形态;但内生遗迹往往很难直接观察到其三维空间展布形态,从而给鉴定及后续研究带来了困难。因此,内生遗迹化... 详细信息

遗迹化石的鉴定与分类是遗迹学研究的基础,而形态特征则是鉴定遗迹化石的关键。表生遗迹和底生遗迹在岩层面上就可以清楚了解其形态;但内生遗迹往往很难直接观察到其三维空间展布形态,从而给鉴定及后续研究带来了困难。因此,内生遗迹化石的三维形态研究历来是遗迹学研究的难点。以往的研究一般通过样品的连续切片获取内生遗迹的形态信息,完成对内生遗迹的三维重建。随着科技的日新月异,各种新方法陆续被应用到遗迹化石的研究中,使内生遗迹化石三维形态的高精度重建成为可能。X射线成像技术可以识别内生遗迹与围岩岩性的差异,其与连续切片相结合,可以更精确的重建内生遗迹的三维形态。核磁共振成像技术在遗迹化石研究中的应用,首次实现了内生遗迹化石三维空间形态的无损成像。笔者首次尝试利用X射线断层成像技术对内生遗迹化石进行了三维重建,也取得了良好的效果。另外,同步辐射X射线相衬显微断层成像技术近年来已成为实体化石无损三维显微成像研究的最佳方法,但还未应用于研究遗迹化石,该技术可望成为内生遗迹化石三维可视化研究的重要方法。

关键词：遗迹化石三维重建核磁共振成像 X射线成像 X射线断层成像

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一类非线性系统基于SVR的鲁棒自适应控制

控制工程 2013年第6期20卷 1055-1059页

作者：刘毅男张超第二炮兵工程大学自动控制工程系陕西西安710025

为解决逆控制方法较依赖系统精确模型及易受逆误差影响等问题,提出了一类非线性系统基于支持向量回归(Support Vector Regression,SVR)的鲁棒自适应控制方法,该方法通过支持向量回归辨识得到被控对象的逆模型,并构建自适应逆误差补偿环... 详细信息

为解决逆控制方法较依赖系统精确模型及易受逆误差影响等问题,提出了一类非线性系统基于支持向量回归(Support Vector Regression,SVR)的鲁棒自适应控制方法,该方法通过支持向量回归辨识得到被控对象的逆模型,并构建自适应逆误差补偿环节,在线修正由于逆模型误差、外界干扰等不确定因素对控制系统性能的不良影响,使得系统能够快速、准确的跟踪参考模型输出。导出了支持向量回归的权值自适应调整率,并利用Lyapunov稳定性理论证明了系统闭环渐近稳定。通过对典型非线性模型的仿真研究,证明了此控制方案在解决一类非线性问题上的可行性,且鲁棒性较好。

关键词：支持向量回归自适应控制反馈线性化非线性鲁棒性