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A convenient synthesis of 2-aryl substituted benzo[f][1,2,4]triazolo[1,5-a]azepine derivatives

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Chinese Chemical Letters 2007年第7期18卷 785-787页

作者： Qing Qing Meng He Xiang Bai feng li Quan rui Wang feng Gang Tao Department of Chemistry Fudan University Shanghai 200433 China

A convenient synthetic pathway to 2-aryl-5,6-dihydro-4H-benzo[f][1,2,4]triazolo[1,5-a]azepine derivatives 7 was *** synthesis was based on the cycloaddition of the 1,2,3,4-tetrahydronaphthalene α-acetoxy azo compound... 详细信息

关键词： Benzotriazoloazepine Nitriles 1,3-Dipolar cycloaddition Ring expansion

Unexpected Carrier Mobility Anisotropy in the Two-dimensional Ca2Si Monolayer from First-principles Calculations

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Chinese Journal of Structural Chemistry 2020年第7期39卷 1243-1251页

作者： li rui-feng YU Xin-Jiang WEN Cui-lian ZHANG Ying-Gan liN Hui-ling SA Bai-Sheng Multiscale Computational Materials Facility and Key Laboratory of Eco-materials Advanced TechnologyCollege of Materials Science and EngineeringFuzhou UniversityFuzhou 350100China College of Materials Xiamen UniversityXiamen 361005China College of Mathematics and Informatics Fujian Normal UniversityFuzhou 350100China

Development of the nano-electronics requires materials with both high carrier mobility and a sufficiently large electronic band *** this work,by means of ab initio calculations,we have predicted a new 2D Ca2Si monolayer with a quasi-planar hexa-coordinate *** geometrical structure,stability and electronic properties of Ca2Si monolayer have been systemically *** Ca2Si monolayer is an indirect semiconductor with band gap of about 0.77 eV,which exhibits stable chemical bonding interactions as well as thermal and dynamic ***,the carrier mobility in Ca2Si monolayer is electron dominated with a high electron mobility about 4590.47 cm2×V-1×*** is excited that the 2D Ca2Si monolayer exhibits strong directionally anisotropic carrier mobility,which could effectively facilitate the migration and separation of the generated electron-hole *** calculations demonstrate that the 2D Ca2Si monolayer is potential for high efficiency solar cells and other nano-electronic applications.

关键词： two-dimensional materials Ca2Si monolayer first-principles calculations carrier mobility

li,Na,and Cs-based metal-organic frameworks for room temperature phosphorescence applications

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Science China Chemistry 2025年

作者： Jiaqi Ma rui feng Yanyuan Jia Mingshi Zhang Shuo Guo College of Chemistry and Chemical Engineering Inner Mongolia University School of Materials Science and Engineering Smart Sensing Interdisciplinary Science Center Nankai University & TKL of Metal and Molecule Based Material Chemistry Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Nankai University Department of Chemistry and Biochemistry University of California San Diego

The conventional design of metal-organic frameworks (MOFs) with room-temperature phosphorescence (RTP) mostly relies on using heavy metals,as the heavy atom effect can effectively increase the efficiency of intersystem crossing (ISC) to get a better phosphorescence *** the first time,we reported the highly efficient RTP of a lithium-based MOF IMU-101 with a lifetime (τ) of 299 ms and a quantum yield (QY) of 4.91%.In addition,MOFs IMU-102 and IMU-103,with sodium and cesium as metal nodes,were successfully *** phosphorescence properties of this series of alkali metal MOFs were systematically studied and *** crystallography and computational calculation show that the mechanism for achieving RTP for this material lies in the ultrashort coordination bond of li,which enables the reduction of non-radiative ***-101,as a cheap and environmentally friendly room-temperature phosphorescent material,has been further developed into composite polymer inks and bulk *** makes them promising for applications in anti-counterfeiting and information encryption.

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Discovery of ideal training to strengthen the ability of medical students： theory and practice

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中国病理生理杂志 2013年第10期29卷 1890-1890页

作者： li rui-feng Shandong University Jinan 250000 China

It is known that pathophysiology is a bridging curriculum that connects basic and clinical *** aims at not only learning medical knowledge,but also making good use of this knowledge to deal with clinical ***,we pay more attention to memorization than *** to change this teaching mode still remains to be ***-based teaching mode is a valuable tool to help medical students strengthen their ability to solve practical problems,from which students can use the knowledge they have learned to figure out the questions derived from each individual medical *** is known to all,the dominant role of medical education is to train professional doctors for *** achieve this,experimental education is required as a consolidated *** the current condition of medicine,it is impossible for medical students to improve operation skills directly in patients,thus performing surgeries in animals plays a critical role in medical training *** showing and practicing enable students to set up a series of good habits in these mimic operations of ***,formal equipment of operation room should be ***,we have already equipped shadowless lamp lighting and established demonstrational system of functional medicine,which pave the way for standard training of medicine.

关键词：医学生培训能力病理生理学理想医学知识临床医学基础医学

Microbial Community Changes Along a Land-Use Gradient of Desert Soil Origin

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Pedosphere 2012年第5期22卷 593-603页

作者： WANG Bao-Zhan ZHANG Cai-Xia liU Ji-liang ZENG Xiao-Wei li feng-rui WU Yu-Cheng liN Xian-Gui XIONG Zheng-Qin XU Jian JIA Zhong-Jun Institute of Soil Science Chinese Academy of SciencesNanjing 210008(China) Nanjing Agricultural University Nanjing 210095(China) Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of SciencesLanzhou 730000(China) Qingdao Institute of BioEnergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101(China)

Soil harbors remarkably stabilize bacterial communities at the phylum level. However, no two soils have exactly the same structure of bacterial phyla. The structure of microbial community is strongly influenced by the type of land-use through changes in soil attributes. Using high-throughput pyrosequencing and quantitative polymerase chain reaction techniques, soil microbial community structures were investigated along a land-use gradient of 100- and 27-year farmlands, a 33-year Pinus forest, a 28-year poplar forest, and a 21-year shrubland, as well as a native desert from which all cultivated systems were converted. The results revealed that the dominant phylotypes in the native soil comprised primarily of Alphaproteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes, accounting for 〉 71.4% of the total bacterial 16S rRNA sequence reads. Changes in land-use led to a significant decrease in these dominant phylotypes down to 33.4%. In contrast, the phylotypes with low abundance, such as Acidobaeteria, Chloroflexi, Nitrospira, and Gammaproteobaeteria, increased sharply from 4.5%-5.9% in the native soil to 20.9% 30.2% of the total 16S rRNA gene sequences in the cultivated soils except for the soil from the shrubland. These contrasting changes in the major taxa appear to be correlated with the changes in soil attributes. For instance, bacterial and archaeal amoA genes were found to be 960- and 3 800-fold more abundant in the soil from the 100-year farmland than the native soil. The changes in numerically less dominant nitrifying phylotypes are consistent with soil inorganic nitrogen dynamics. Quantification of the 16S rRNA genes demonstrated that bacteria and archaea were about two to three orders of magnitude more abundant in the cultivated soil than in the native soil. Hence, land-use type affects the soil bacterial community structure, which has profound consequences on ecosystem function.

关键词： amoA ecosystem functions land-use type polymerase chain reaction pyrosequencing

EFFECT OF CATIONS ON PROPERTIES OF ZEOliTE MATERIAL PREPARED IN A NONAQUEOUS SYSTEM

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Journal of Energy Chemistry 1994年第4期 417-426页

作者： li rui-feng Ma Jing-Hong TIAN Zheng XU Wen-YangInstitute of Special Chemicals Taiyuan University of Technology Taiyuan, Shanxi 030024

The influence of the type of alkali metal cations on the properties ofzeolite synthesized in a nonaqueous system was *** results indicatedthat different cations induced different topological structure of zeolite with thesame composition,and influenced the physicochemical and catalytic propertiesof zeolite in CO hydrogenation to light ***-48 and CsNaZSM-48supported iron catalysts had special activity for CO conversion and selectivity toC—Colefins（64% and 61% respectively）.

关键词： EFFECT OF CATIONS ON PROPERTIES OF ZEOliTE MATERIAL PREPARED IN A NONAQUEOUS SYSTEM

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机器人双目视觉系统的标定与定位算法

哈尔滨工业大学学报 2007年第11期39卷 1719-1722页

作者：李瑞峰李庆喜哈尔滨工业大学机器人研究所哈尔滨150001

介绍了双目视觉系统的构成,选用简单实用的张正友标定法对系统使用的两个CCD摄像机进行了标定.基于双目视觉系统,提出一种计算物体位置信息的解析解方法——投影法,利用标定结果对不同位置进行深度信息测量,通过计算结果分析,基于视觉... 详细信息

介绍了双目视觉系统的构成,选用简单实用的张正友标定法对系统使用的两个CCD摄像机进行了标定.基于双目视觉系统,提出一种计算物体位置信息的解析解方法——投影法,利用标定结果对不同位置进行深度信息测量,通过计算结果分析,基于视觉信息探测到的位置信息在1500mm范围内,3个方向的误差分别为0.72mm,0.69mm,20.96mm,验证了方法的正确性.

关键词：视觉系统移动机器人定位算法

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西北干旱区流域水资源管理研究

冰川冻土 2008年第1期30卷 12-19页

作者：李锋瑞中国科学院寒区旱区环境与工程研究所临泽内陆河流域综合研究站甘肃兰州730000

水是人类生存和繁衍之本,也是维持自然生态系统功能和生物多样性、保障区域经济和社会可持续发展的基础性资源.随着人口急剧增长和经济快速发展,水资源短缺对我国生态环境建设及社会经济发展的瓶颈制约效应越来越明显,特别是对水资源十... 详细信息

水是人类生存和繁衍之本,也是维持自然生态系统功能和生物多样性、保障区域经济和社会可持续发展的基础性资源.随着人口急剧增长和经济快速发展,水资源短缺对我国生态环境建设及社会经济发展的瓶颈制约效应越来越明显,特别是对水资源十分稀缺的西北内陆干旱区来说,这种瓶颈制约效应更加显著.我国用水效率低下及水危机问题的产生,并不完全在于缺少各种节水技术(包括工程、生物和农艺节水措施)和水污染治理技术,更重要的是缺少一个能有效促进全社会水资源高效配置和节约用水的水资源管理制度及运行机制.从表面上看,我国的水危机属于资源性危机,但从深层次看,更多地是由于管理制度不完善所致.因此,对现行的水资源管理制度及运行机制进行变革和创新,是根本上解决我国用水效率低下和水危机问题的关键所在.重点围绕我国干旱缺水地区水资源管理的重要性、流域水资源管理制度改革与创新的若干基础理论问题及如何建立流域水资源科学管理体系等问题进行了系统的探讨,并初步提出了流域水资源管理制度创新的基本思路.

关键词：水资源管理制度创新流域尺度缺水地区

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我国农村教育发展与农村经济增长的实证研究

财经问题研究 2007年第4期 92-96,F0003页

作者：李瑞锋中国农业大学经济管理学院北京100094

通过对20年来我国农村教育发展与农村经济增长的实证研究发现:(1)我国农村教育发展对农村经济就增长具有显著的正向促进作用,平均受教育年限每增加一年,农村经济就增长0.28%。(2)我国农村教育对农村经济增长的贡献率高达24%。(3)农村义... 详细信息

通过对20年来我国农村教育发展与农村经济增长的实证研究发现:(1)我国农村教育发展对农村经济就增长具有显著的正向促进作用,平均受教育年限每增加一年,农村经济就增长0.28%。(2)我国农村教育对农村经济增长的贡献率高达24%。(3)农村义务教育对农村经济增长的作用最为明显,但我国低重心的农村义务教育财政体制导致投入不足,农村基础教育发展异常艰难。

关键词：农村教育农村经济人力资本