Preparation and electrochemical performance of SnO2 and its composites as anode material for lithium-ion battery

能源危机与环境问题促使人们不断寻找可替代化石能源的新能源结构和设备。锂离子电池作为有效的储能设备已经广泛应用于各种小型便携式电子产品以及电动自行车等，新一代电动汽车(EV)、混合动力汽车(HEV)的商业化开发，对锂离子电池的能量密度及性能提出了更高的要求。传统的碳系负极材料在比容量、安全性等方面都己经不能很好地满足新领域应用的需要，因此研发新型非碳负极材料具有极为重要的意义。 二氧化锡（SnO2）作为可替代石墨负极的锂离子电池负极材料，具有质量比容量和体积比容量上的优势，但同时也存在材料在嵌脱锂过程中体积膨胀严重、循环寿命短以及首圈容量损失严重等问题。本课题从SnO2材料的纳米化和如何均匀分...Lithium ion batteries have been widely used in all kinds of portable electronics and communicational devices. However, the application of lithium ion batteries into the automobile industry to develop electronic vehicles (EV) and hybrid electronic vehicles (HEV) requires higher energy density and power density, which is a great challenge for the traditional cathode and anode materials of lithium io...学位：理学硕士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：2052008115171

The Effective of Macroeconomic Management on Housing Price in China: Theoretical and Empirical Analysis

房地产业是国民经济的支柱产业，一方面，通过对上下游相关产业的带动，其发展从供给面推动整个国民经济的增长。另一方面，房地产业所提供的住宅商品同时是一国居民财富的一个重要组成部分，其价格的波动从需求面对整个国民经济的运行以及国民福利产生重要影响。 受美国次贷危机影响，出口增长的快速下滑导致我国经济增长减速，当前宏观政策全面转向扩大内需。尽管出台了一系列保持房地产市场发展的相关政策，但是，高房价依然是抑制居民购买房屋的主要因素。不仅如此，高房价导致居民为购买住房而进行强制储蓄，因而极大地抑制了居民消费需求的扩张。我国宏观调控政策能否以及在多大程度上能影响我国房地产市场的价格，必然关系到当前扩大内需...The real estate industry is the pillar industry in the national economy. On one side, due to its impacts on related industries, the operation and development of real estate sector influence the whole national economic from the supply side. On another side, as the major commodity provided by real estate sector, residential property is an important part of residents' wealth. Thus the fluctuation of ...学位：经济学硕士院系专业：经济学院经济系_西方经济学学号：1532006115079

基于差分进化算法的光纤布拉格光栅横向局部应力与温度分离技术

鉴于横向应力和温度对光纤布拉格光栅的交感耦合呈现非线性关系,将横向局部应力与温度的交感问题转化为非线性系统参数辨识问题:首先根据光纤布拉格光栅横向应力与温度的传感原理构造一个理论意义上的反射光谱,然后利用理论光谱和采样光谱之间的差异度建立系统参数辨识模型,通过差分进化算法对该优化辨识模型进行求解,最终实现横向局部应力与温度的同时测量。实验和仿真结果表明,本文提出的方法具有较高的辨识精度,得到的横向应力误差绝对值一般小于4.0×10-3N,温度误差绝对值一般小于3.0×10-3℃,传感器对温度的灵敏度为11.7 pm/℃。该方法能够解决光纤布拉格光栅横向局部应力和温度的交叉敏感问题,提升光纤布拉格光栅传感网络在实际工程中的传感精度。国家自然科学基金(11201391)资

Tannin dynamics of Kandelia candel roots in different salinity culture

对不同盐度(0‰-40‰)栽培下秋茄根的总酚、可溶性缩合单宁、结合缩合单宁、总缩合单宁的含量进行测定,探讨盐度对单宁生产的效应.结果表明:(1)不同盐度下栽培60-135d,总酚含量在相同盐度条件下随栽培时间的延长呈现出先波动而后升高的趋势,其中总酚最高含量出现在高盐度,说明一定的高盐度胁迫可以促进总酚的合成;总缩合单宁与可溶性缩合单宁含量变化趋势相似,其中可溶性缩合单宁含量显著高于结合缩合单宁.(2)在15‰盐度下栽培75-135d,秋茄根不同部位的总酚、可溶性缩合单宁、结合缩合单宁和总缩合单宁含量有相似的变化趋势,即由根尖往远离根尖的部位呈下降趋势.Total phenolics(TP),extractable condensed tannins(ECT),bound condensed tannins(BCT),and total condensed tannins(TCT) contents of Kandelia candel roots in different salinity culture were determined.In addition,the effect of salinity on tannin production was studied.The results showed as follows:(1) During the period of different salinity culture(from 60 d to 135 d),TP content fluctuated with increasing salinity,with the highest occurring in high salinity.ECT and TCT contents fluctuated under different salinity conditions with a consistent pattern.ECT contents were significantly higher than BCT contents.(2) At culture salinity of 15‰,the distribution of tannins in different parts of roots in the same period from 75 d to 135 d followed the identical pattern: the closer the root tip was,the higher the TP,ECT,BCT,and TCT contents were.福建省自然科学基金资助项目(B0410006);; 国家自然科学基金资助项目(40376026

厦门市某医院体检人群中有机氯农药暴露与胆石症发病的关联性研究

目的探讨厦门市第二医院体检人群中有机氯农药暴露与胆结石发生的关联及其发病危险因素。方法收集2015年2月-8月在医院健康体检人群中经B超确诊的新发胆囊结石患者100例,以同期参加体检的非胆囊结石者为对照,进行1∶2配比的病例对照研究。进行流行病学调查,采用气相色谱联用电子捕获器检测研究对象外周血中有机氯农药水平。应用多因素条件Logistic回归模型分析有机氯农药与胆囊结石发病的关系。结果病例组血清中α-HCH残留水平高于对照组,差异有统计学意义;Logistic回归分析非酒精性脂肪肝、2型糖尿病、血清α-HCH含量增高可能增加胆结石的患病危险,OR值及95%CI分别为5.134(1.952~13.502)、4.754(1.849~12.220)和1.357(1.094~1.854)。结论环境有机氯农药暴露可能是胆囊结石病发生的危险因素。厦门市科技计划项目(3502Z20163006)；厦门市集美区科技计划项目(20142C01)；厦门大学校长基金(20720152012)

专题:环境力学

20世纪80年代以来,随着经济的迅速发展,人们愈来愈认识到环境对社会和经济可持续发展的重要作用.对环境问题的研究逐步走向精细化和定量化,大量数据的积累要求模型化和数学化,推动着环境科学由宏观向细观深入,并且宏观与细观相结合.力学在其发展过程中形成的分析、计算、实验相结合的学术风格,十分有利于深化对环境问题中基本规律的认识

Spatial-temporal features and potential pressure of marine vessel activities based on AIS and multi-scales spatial model

Based on the ship automatic identification system (AIS) data,the spatial-temporal feature of fishing vessels and commercial ships activities were identified,and the potential pressure caused by marine ships on ecological red line sea area and marine functional zone in Laizhou Bay were assessed by using GIS spatial analysis and geospatial simulation methods. Results show that maritime vessel activities in Laizhou Bay are concentrated in the southwest sea area and marine functional areas,such as port shipping area,agricultural fishery area and so on; the daily and seasonal variations of fishing vessels are more obvious; the potential pressure of the marine vessel activities in the southwestern sea area of the Laizhou Bay and the northwest of Longkou port area is greater. It is recommended to strengthen the supervision of fishing activities and fishing operations in Laizhou Bay in the 9-11 months of the year. Ecological environment quality monitoring of marine ecological red line areas such as Yellow River Estuary and Laizhou shoal should be carried out,and prevent the harmful effect resulted from commercial vessel activities on the marine environment of culture zone and oceanic pasture surrounding the port and shipping zone

a hop-by-hop transport protocol for satellite networks

卫星网络大时延、高误码等特点,使得TCP协议无法在卫星上提供高效的传输控制服务。不同于TCP端到端的传输方式,采用跳到跳确认思想提出了一种适合卫星网络的传输协议。协议在跳到跳的基础上采用了ACK与SNACK结合的确认机制,保证了端到端传输的可靠性。同时采用了基于负载因子的拥塞控制算法,有效地提高了链路利用率,特别适合于卫星网络长延迟的环境,吞吐量接近最优

SaclTCP:基于跨层设计的卫星网络传输协议

卫星网络大时延、高误码率及链路不对称等特点,使得TCP/IP协议无法提供令人满意的服务。针对卫星网络的特点,设计了SaclTCP协议,采用跨层设计思想减少层次网络的冗余性,实时获取网络状态信息。协议根据链路层反馈的有效带宽信息准确地设定拥塞窗口门限阈值;在网络层对路由器缓冲队列进行管理,计算网络发生拥塞的概率并发送显示拥塞通知反馈给发送方传输层;还可区分丢包原因,避免由于传输错误造成的发送窗口减小。实验结果表明与传统协议相比,极大提高了传输性能。Satellite network has some special characteristics, such as the big propagation delay, high bit-error rate and asymmetric channels, and these characteristics make TCP/IP protocols incapable of providing satisfying service for satellite network. The idea of cross-layer design can reduce the redundancy of multi-layer, and capture network status information at any moment. The protocol can set a window congestion gate-limit threshold more effectively by getting the available bandwidth information from the link layer. And in the link layer a router buffer queue managing mechanism is set to compute the network congestion probability and then feedback it to the sender. It can also differentiate the packet losses between congestion and link error to avoid reducing the send window unnecessarily. The protocol will use this information to regulate the size of window dynamically. The experiment shows the protocol greatly improved the transport performance of satellite networks