Chlorofullerenes featuring triple sequentially fused pentagons

通讯作者地址: Tan,YZ(通讯作者),Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 电子邮件地址: [email protected], [email protected] triple sequentially fused pentagons (TSFP) motif is one of the basic subunits that could be used for constructing fullerenes, but it violates the isolated pentagon rule (IPR) and has not been found in carbon cages to date. The properties of TSFP-incorporating fullerenes are thus poorly explored both theoretically and experimentally. Reported herein are four chlorinated derivatives of three different fullerene cages, all with the TSFP motif. X-ray crystallographic analyses indicate that the molecular strain inherent to the pentagon adjacency of a TSFP is significantly relieved upon exohedral chlorination, leaving one of the four pentagon fusion sites unsaturated and rendering the present derivatives chiral. This unique reactivity, in stark contrast to that of previously reported non-IPR fullerenes containing double fused pentagons or triple directly fused pentagons, can be rationalized by density functional theory calculations, and are expected to stimulate further studies of these new members of the fullerene family, both theoretically and experimentally.NNSF of China 20525103,20531050,20721001,20423002 20673088 973 Program 2007CB81530

Research on Multi-Mode High Precision Positioning Satellite Terminal Antenna

摘要： 卫星导航系统为人们提供全天候、高精度和实时的导航、定位和授时信息。天线性能关乎卫星导航系统的有效性、准确性和整体性。目前对于卫星导航天线的研究，主要集中在多频兼容、圆极化技术、宽频技术等领域，对于多模兼容高精度定位卫星天线的研究相对较少。导航系统越来越多元化，导航资源越来越丰富的基础上，进行多模兼容高精度定位卫星天线研究是非常必要的。 本文主要针对卫星导航系统发展的应用需求，进行多频多模兼容技术研究，设计了多款结构新颖、性能优越、适用于高精度定位卫星导航系统的终端天线。本文研究主要分以下三个方面： 第一部分设计了两款双箭头锚式结构加载的双频卫星天线。首先提出新颖的双箭头锚式结构，...Abstract： Satellite navigation system providing people with round-the-clock, high-accuracy, real-time, navigation positioning and timing information. The performance of the antenna will affect the effectiveness, accuracy and integrity of the satellite navigation system. At present, the research of the satellite navigation system antenna mainly concentrates in the field of multi-frequency...学位：工学硕士院系专业：信息科学与技术学院_电磁场与微波技术学号：2312013115311

Food security in Grain for Green Project area of North Shaanxi based on households

对陕北退耕区米脂县(人口高密度区)和吴起县(低密度区)农户尺度粮食生产能力进行分析,应用最小人均耕地面积和生产函数方法研究了该区粮食安全状况及影响因素.结果表明:人口低密度区的粮食生产能力可基本保障其粮食安全,而人口高密度区不能确保粮食安全;基本农田面积和农业科技投入是影响农户粮食安全的主要因素,劳动力投入、素质和粮食补贴也有正向影响,但目前的农业科技水平和劳动力素质未达到粮食生产能力的囤蓄要求.应加大基本农田和农业科学技术的囤蓄力度,达到最小人均基本农田0.14 hm2,重视农业劳动力的技术培训,并制定合理的退耕后续政策

A study on prevailing factors for the success of small-scale shopping centre in Hong Kong

According to unofficial statistics information (i.e. Wikipedia and Editorial … etc.), the proportionality for small-scale shopping centres in Hong Kong is around three times of the same for large-scale. This indicates the market of small-scale shopping centres is significant and cannot be ignored. In fact, many studies were done by scholars regarding the successful management of large-scale shopping centres, yet detailed study related to such kind of small-scale shopping centres is found absent or pretty rare. Under observation, the management of stand-alone large-scale shopping centres is too perfect to criticize, whereas the same of small-scale shopping centres is unsystematic or can be called messy. Obstruction, security loophole, poor management and cleaning problem found in these shopping centres not only produce great nuisance to the owners/ occupiers, but also transform to be a social problem. The major scope in this study will be around the facilities and management services provided in small-scale shopping centres underneath composite building (residential + retail) or commercial building (office + retail). Meanwhile, pros and cons of these shopping centres will be noted and referred. By consolidating the data of difficulties in managing overseas Mixed-use developments. 7Ps marketing mix, management theories and practical examples, a framework for analyzing the prevailing factors for small-scale shopping centre is explored. Empirical research will indicate practical solutions to the drawbacks of small-scale shopping centres in stratified ownerships as well as the prevailing measures for the improvement of shopping centre environment. The results of this study are meaningful for prospective retailers to find shopping centres with good business environments and for other centre managers or practitioners to improve the environment/ strengthen the user-friendliness and competiveness of this kind of shopping centres.published_or_final_versionHousing ManagementMasterMaster of Housing Managemen

Regiospecific synthesis of 4-pyridyl-ketones, -esters, and -nitriles, via pyridinium cations

published_or_final_versionChemistryMasterMaster of Philosoph

Ecological cost of grain production in gully area of Loess Plateau

以黄土高原沟壑区的陕西省长武县为研究对象,应用生态学和经济学方法,对粮食生产生态成本进行了初步研究.结果表明:2008年该区粮食生产生态损失总价值相当于当年种植业总产值的7.2%;小麦和玉米生态成本已分别达到2.42和2.12元·kg-1,而出售单价分别为1.70和1.28元·kg-1,高成本低收益的情况对该区域生态经济可持续发展产生不利影响;利用灰色关联对粮食生产生态成本中各因素进行分析,单位产量、播种面积和农业机械费用是影响生态成本的重要因素,化肥费用和有机肥费用对其影响不大;在当前生产力水平下,适当加大科学技术投入水平,提高粮食产量,扩大家庭种植规模,可以降低生产单位粮食的生态成本

Product Management and Grain Supply and Demand After the Grain for Green Project in Wuqi County

运用吴起县农户农业生产经营状况调查资料,对退耕还林(草)后不同收入类型农户的土地利用结构及其变化,产业结构及经济效益以及2007年农户的粮食供需及输入输出情况等方面进行了分析。结果表明,目前吴起县农户最主要的土地利用方式是林草地和耕地,收入的主要来源是工副业和退耕补贴,各类型农户的产业结构差异显著,高收入户工副业比重达81.8%,低收入户工副业和种植业比重相近,但其收入来源中退耕补贴比例占46%,存在一定依赖性。各类型农户农业效益差异与自然条件和劳动力素质有关。吴起县农户粮食基本能够自给,输入率和输出率相当,不存在粮食安全问题。提出吴起县应合理调整农业结构、加大对农业技术的推广和基本农田及相关配套措施建设等建议

the study of intelligent traffic simulation and decision-making strategy of vehicle agent

文章介绍了Agent技术及特点,根据Agent的原理及其仿真的优势,着重叙述了Agent技术在交通仿真中的应用,详细探讨了基于Agent的智能仿真系统中车辆Agent的决策特点及模糊决策方法,同时,还分析了驾驶员因素对驾驶行为的影响

Exploration of the Ecological Costs of Food Production in the Alluvial Region of the Huang-Huai-Hai Plain

【目的】粮食生产必然对生态环境造成影响。以黄淮海冲积平原区河北省曲周县为研究对象,对粮食生产生态成本进行研究。【方法】依据水土流失和水环境污染相关理论,运用生态学和经济学方法对生态成本进行估算;采用灰色关联法对粮食生产生态成本中的各个因素进行分析。【结果】2008年该区粮食生产生态损失总价值相当于当年农业总产值的2%;小麦和玉米生态成本已分别达到1.51元/kg、1.12元/kg,而出售单价分别为1.62元/kg、1.38元/kg,高成本低收益的情况对该区域生态经济可持续发展产生着不利影响;单位面积产量、播种面积、农业机械费用和劳动力支出费用是影响粮食生产生态成本的重要因素,化肥费用、有机肥费用、农药费用和灌溉费用对粮食生产生态成本的影响较小;生态成本随着家庭种植规模的变大呈现出下降趋势。【结论】在当前生产力水平条件下,适度加强科学技术的投入,扩大家庭种植规模,可降低生产单位粮食的生态成本,有利于实现该区域生态经济可持续发展。【Objective】 Food production are bound to affect the ecological environment.In this paper,the ecological costs of food production were investigated in the alluvial region of the Huang-Huai-Hai Plain.【Method】 Based on the theory of soil erosion and water pollution,using economic and ecological methods to estimate the ecological costs of food production.The grey relationship matrix analysis was used to analyze various factors affecting the ecological costs of food production.【Result】 Ecological damage due to g..