Nitrile-Modified 2,5-Di-tert-butyl-hydroquinones as Redox Shuttle Overcharge Additives for Lithium-Ion Batteries

Nitrile-modifled 2,5-di-tert-butyl-hydroquinones were synthesized and investigated as redox shuttle overcharge additives for LiFePO4/Li cells. The cyanoethylation reaction was utilized to synthesize the target molecules 2,5-di-tert-butyl-l,4-di（β-cyanoet

Tracking nitrogen pollutants in Xiamen coastal river via multiple techniques and strategy of water quality management

全球变化背景下海岸带地区面临多种环境压力,快速城镇化和人类活动导致河流与海湾营养盐污染和富营养化问题加重,污染溯源是水体达标方案编制与实施的重要; 环节.兼顾科学性与操作性,本文基于综合溯源思路,以厦门湾河流为例,于水质较差的枯水期开展水系沿程梯度调查,进行氮的生物地球化学过程解析,结合硝酸; 盐氮氧双位素及土地利用统计分析,探明氮污染关键源区和氨氮超标成因.结果表明,研究区63%的站位水中氨氮占无机氮的50%以上,沿下游方向氨氮污染加; 重,且与城镇与农村宅基地、渔塘的面积占比均呈正相关.土壤氮、粪肥及污水和化肥贡献了硝酸盐89%~; 91%的来源.最后,提出了污染减排(控源)、生态修复(增容)、以海定陆(统筹)的水体达标策略,为我国水污染防治与管理提供方法示范.Global change has imposed multiple environment stresses on coastal; waters. Rapid urbanization and increasing human perturbation resulted in; severe nutrient loadings followed by eutrophication in coastal waters.; Therefore source identification and tracking become critical for water; quality management. Based on its feasibility,here we conducted a case; study for Xiamen coastal river,in order to track possible nitrogen; pollution sources. Water quality was measured in the whole river during; dry season,in order to explore the biogeochemical processes of nitrogen.; With dual isotopic techniques (delta15N and delta18 O) and statistical; information of land uses,we identified the key source of nitrogen; pollutants,and clarified the causes leading to ammonium levels of; exceeding standards. Current results show that ammonium was the dominant; form (>50%) of dissolved inorganic nitrogen at 63% sampling sites.; Ammonium concentration increased along river downward and significantly; correlated with the areal proportion of built /residence lands and; aquaculture ponds in associate catchment. Soil organic nitrogen,manure; and sewage,and synthetic fertilizer contribute 89% ~ 91% of nitrate; sources. Therefore,we proposed that nitrogen emission; abatement,ecological restoration and integrated sea-land management; should be considered together for improving water quality management.; This study provides an important reference for national water pollution; control and management.国家重点研发计划; 国家自然科学基

Kinetic analysis of moisture absorption and retention for HA and two new types of chitin moisturizers

[中文文摘]分别研究了透明质酸与两种甲壳素类新保湿剂在RH81%和RH43%时的吸湿动力学特性,以及在RH43%时的保湿动力学特征.结果表明它们的吸湿和保湿行为均符合二级吸附动力学方程,相关系数均达0.999以上.表明它们的吸湿过程主要受化学作用的控制.[英文文摘]Kinetic analysis of moisture absorption under RH81% and RH43%,and moisture retention under RH43% for Hyaluronic Acid(HA) and two new types of Chitin moisturizers were studied.The results showed that,the Second-Order Model of adsorption kinetic equation can characterize the adsorption process very well and the relation coefficients are all higher than 0.999.It means the adsorption processes of three moisturizers are controlled by chemistry effect.国家自然科学基金(20374041); 福建省自然科学基金(E0310002,E0510003); 厦门市科技计划项目(3502Z20055013)资助项目

有机光波导放大器最新进展

稀土掺杂平面光波导放大器是一类重要的光子学元件,它是光通信密集波分复用(DWDM)传输系统的重要组成部分,可以和调制器、光开关、隔离器、阵列波导光栅等任何有损耗的器件集成在一起,补偿光传输过程中的各类损耗。综述了应用于第二(1.33μm)、第三(1.53μm)标准通信窗口的有机光波导放大器的研究现状,阐述了不同类型材料制备的器件存在的优缺点、制备过程中存在的问题,并对其发展前景进行了展望

中国国际科学合作中的”华人现象“

将8 个国家的合作论文分成五种类型，重点考察了中国在与8 个国家的合作中所呈现的“华人现 象”。分析表明，海外华人（包括短期在外的科研人员）在现阶段正在发挥桥梁作用，在中国国际合作中表 现得非常活跃。分析了导致“华人现象”的社会基础和政策效应

基于Xen的可信计算环境构建关键技术研究

在以Xen为代表的虚拟平台上，引入可信计算技术可以为其构建可信计算环境，有效增强其安全。然而由于虚拟平台支持多个虚拟机系统运行的特点，致使可信计算技术无法直接为其可信计算环境构建提供支持。本文在引入TPM的Xen可信虚拟平台上研究其可信计算环境构建，首先分析了TCG信任链模型的不足，在其基础上提出了基于信任度的信任链模型，完善了原有模型的信任表述能力；紧接着将该模型扩展至可信虚拟平台，对其信任构建问题进行了探讨提出了一种信任树的信任构建方法；然后分析了可信虚拟平台数据封装存在的问题，并给出了可行的封装解决方案；最后实现了可信虚拟平台信任系统建立Xen平台可信计算环境。本文主要取得了以下几个方面的成果： 1、针对TCG信任链模型中完整性度量无法全面反映实体运行状况和无法表述信任传递损失的缺陷，提出了一种基于信任度的信任链模型，该模型丰富了可信计算的信任链理论知识，对信任链模型扩展研究具有一定的指导价值。 2、在基于信任度的信任链模型基础上，针对可信虚拟平台多系统运行的特点，提出了基于信任树的可信虚拟平台信任构建方法，该方法符合可信虚拟平台运行的安全需求，为可信虚拟平台可信计算环境构建奠定了基础。 3、提出了一种TPM支持的多级属性封装方案，该方案实现了TPM对所有虚拟机系统数据的属性封装，同时还对属性进行了分级扩展，基于属性的安全级别实施解封，增强了属性封装的灵活性，更有效的保证了可信虚拟平台上的数据安全。 4、针对可信虚拟平台上的数据使用需求，提出了一种按需属性封装方案，该方案不仅实现了数据与任意组件属性的封装，还保障了封装数据在不同虚拟机中的正常解封，增强了封装数据的可用性，充分满足了可信虚拟平台上敏感数据封装和共享的安全要求。 总的说来，本文的研究成果为虚拟技术的应用提供了安全支撑，并且为可信计算的相关研究提供了借鉴。For a virtual platform such as Xen, it can establish the trusted computing environment and enhance security by introducing the trusted computing technology. However, a virtual platform allows multiple virtual machines to run concurrently, so that it can't establish the trusted computing environment with the trusted computing technology directly. This thesis mainly studies the establishment of the trusted computing environment based on the trusted virtualization platform with Xen and TPM. First, we analyze the deficiencies of the TCG trust chain model, and propose a trustworthiness-based trust chain model on that basis, which improves the expressive ability on trust. Next, we extend the model to the trusted virtualization platform to discuss the trust establishment, and propose a trust establishment approach of trust tree. Then, we analyze the problems existing when sealing data on the trusted virtualization platform, and propose the feasible sealing solutions. Finally, we implement a trust system on the trusted virtualization platform to establish the trusted computing environment based on Xen. The main contributions of this thesis are listed as follows: (1)To avoid the deficiencies of the TCG trust chain model that the integrity measurements can’t reflect how entities run completely and it can’t express the loss of transitive trust, a trustworthiness-based trust chain model is advanced. The model enriches the trust chain theoretical knowledge of the trusted computing, and also has certain instructional value to research on the trust chain model extension. (2)According to the feature of the trusted virtualization platform that multiple systems may run, an approach to establishing trust for the trusted virtualization platform with the trust tree is presented based on the trustworthiness-based trust chain model. The approach meets the security requirements when the trusted virtualization platform runs, and lays a solid foundation for establishing the trusted computing environment for the trusted virtualization platform. (3)A multilevel property-based sealing scheme with the support of TPM is put forward. The scheme realizes property-based sealing for data in all virtual machines with TPM, expands properties with different security levels, and allows unsealing with the property’s security level. The scheme enhances flexibility of property-based sealing, and ensures data security on the trusted virtualization platform more efficiently. (4)According to the requirements of data usage on the trusted virtualization platform, an on-demand property-based sealing scheme is brought forward. The scheme realizes sealing data to any component’s property, and ensures that sealed data can be unsealed normally in different virtual machines. The scheme enhances availability of sealed data, and meets the security requirements of the sealing and share of sensitive data on the trusted virtualization platform well. In summary, the achievements of this thesis provide security support for the application of the virtualization technology, and give some suggestions for the research on the trusted computing

硫脲(IIL)法提金反应特性研究——工艺过程物理化学初探

本文研究了各操作因素对金浸取的影响;浸取速度的控制步骤;降低硫脲消耗的某些措施。酸性硅脲铁在矿浆浸出(IIL)法的作用原理在于铁置换金的同时,能减少硫脲的分解破坏损失,并能抑制矿石及其中所含炭质对金的吸附。 浸出速控因素为硫脲的扩散。为获得一定的金浸出率,所需浸出时间与硫脲浓度成反比,与浸取液固比无关

lois grub: a configurable trusted booting system

引导过程的安全是计算机系统安全的基点,安全的引导系统需要保证系统加电后引导执行链条中的实体未受篡改.当前,基于可信平台模块(TPM)开展的可信引导工作,仅能可信地记录并报告系统引导的证据链,无法进行验证以及进一步的处理.提出一种可配置的可信引导系统,可以配置认证引导和安全引导,支持细粒度的文件验证,以及操作系统内核的可信恢复.给出了系统的设计思想,并介绍了其原型工作,实验表明该系统能够有效实现其设计目标

an approach to data sealing based on trusted virtualization platform

可信计算平台的封装存储功能将数据的加密存储与平台配置结合起来,可提供更为强有力的数据安全服务.然而,平台配置的频繁变动如硬件更替、软件更新及系统补丁等又极大地限制了封装存储功能的使用.针对这个问题,提出了一种基于可信虚拟平台的数据封装存储方案.方案引入了虚拟PCR(vPCR)和安全属性的概念,利用可信平台模块(TPM)将数据与系统安全属性封装起来保护.该方案除能适应平台配置频繁变更的问题外,还能同时保护多个虚拟机系统中数据的安全,不受虚拟机系统配置变化的影响.该方案执行操作简单,实验结果表明与原有方案相比,TPM的负担较小,性能无显著差别