Trust evaluation mechanism for distributed Hash table network nodes in cloud data secure self-destruction system

在云环境下的数据自毁机制中,针对分布式哈希表(DHT)网络的恶意节点和不诚信节点容易造成密钥分量丢失或泄露等问题,提出面向云数据安全自毁的DHT网络节点信任评估机制。该机制首先为节点建立二维信任评估模型,对节点可信程度进行定性和定量的考察;接着改进节点直接信任值和推荐信任值的计算方法,充分考虑节点内外因素,从节点运行环境和交互经验两个维度出发并细化到不同层级计算节点信任值,得到信任评价子云;然后将各个信任评价子云加权合成得到综合信任云,采用云发生器描绘出综合信任云一维高斯云图形;最后结合信任决策算法选出最优可信节点。实验结果表明该机制能够帮助原有的数据自毁机制找到更适合存储密钥分量的DHT网络节点,提高了系统的容灾能力并降低了系统计算负载。Distributed Hash Table( DHT) network is widely used in secure self-destruction schemes of privacy data in cloud computing environment,but malicious nodes and dishonest nodes in the DHT network easily lead to key shares loss or leakage. To tackle those problems,a trust evaluation mechanism was proposed for the DHT network used in cloud-data secure self-destruction system. In this mechanism,a trust cloud model was established for DHT nodes to describe their trust information qualitatively and quantitatively. By introducing an improved calculation method of direct trust value together with recommended trust value and fully considering the internal and external factors of DHT nodes,the trust value of nodes were first calculated on two dimensions consisted of operating experiment and interactive experience. The result data were used to build trust evaluation sub-cloud for each index. After that,all these trust evaluation sub-clouds were summed up to generate the comprehensive trust cloud according to the weights of different evaluation indexes. Then,the comprehensive trust cloud,by means of cloud generator algorithm,could be described as one-dimensional normal cloud. Finally,the reliable and efficient nodes could be selected using trust decision algorithm. Experimental results show that the proposed mechanism can help original data self-destruction system making comprehensive trust decision and finding reliable DHT network nodes,further enhancing disaster-tolerant capability and reducing computational cost of the system.国家自然科学基金资助项目(61402109,61370078);; 福建省自然科学基金资助项目(2015J05120);; 福建省高校杰出青年科研人才培育计划项目(2015)~

中非产能合作推动非洲“三网一化建设”

发展缓慢的工业化和落后的基础设施建设成为非洲各国经济和社会发展的两大瓶颈,非洲经济发展对"三网一化"建设需求强烈。开展中非产能对接合作将从多方面推进非洲"三网一化"建设:改善非洲基础设施建设落后状况;加快非洲工业化进程并改善其贸易结构,促进国际收支平衡;促进非洲人口就业;加速非洲国家产业资本积累;提升非洲各国技术水平。为推进中非产能合作顺利进行,中国及非洲政府层面及企业层面均应审时度势采取相应策略。非洲经济发展对"三网一化"建设的强烈需

Discussion about Some Problems of Environment On-line Monitoring System

相对于传统的环境监测方式,环境在线自动监控作为一种先进技术,在环境应急反应、提高办事效率及管理水平等方面具有突出优势,但在实际应用过程中面临着在企业的推广有难度、监管方式尚需完善以及监测方法不统一等方面的问题。本文针对这些问题从管理模式、运营机制、管理方式以及监测方法等四个方面提出了相应的解决方案,以求通过这些措施的应用,确保环境自动监测系统在未来的环境管理中发挥更加重要的作用。Compared with traditional methods of environmental monitoring,environment on-line monitoring system has outstanding advantages in environmental emergency response,improve efficiency and management level.But there are some problems exist in the process of application,such as the promotion in enterprises,inadequate supervision and non-uniform monitoring methods.This article raised the corresponding measures to resolve these problems from management mode,operation mechanism,management and monitoring method and ensure environment on-line monitoring system will play a more important role in the future

胆甾醇疏水改性的羧乙基普鲁兰多糖合成及自组装性质

背景:将羧基引入疏水改性的多糖,使其自组装的纳米粒子带上表面电荷,有利于提高其稳定性,更好的发挥作为药物载体的优良性质。目的:观察合成胆甾醇疏水改性的羧乙基普鲁兰多糖在水溶液中的自组装行为及其纳米粒子的性质。方法:利用丙烯酸与普鲁兰多糖反应生成羧乙基普鲁兰多糖(CEP),然后按前期方法合成胆甾醇琥珀酰基N-羟基琥珀酰亚胺(CSN),最后CSN和CEP在催化剂下生成目标物。应用核磁共振仪对产物进行表征。结果与结论:通过1H-NMR分析,表明成功合成了胆甾醇疏水改性的羧乙基普鲁兰多糖,该材料在水溶液中能自组装为具有乳光的球型纳米粒子。CHS-CEP纳米粒子平均粒径为148.6nm,平均Zeta电位约为-19.9mV,在水溶液中分散度好,分布均匀,具有长期稳定性,可作为良好的药物载体

Plant Regeneration in vitro of Cuscuta chinensis Lam.

选取萌发3～5d、长度3～5cm的中国菟丝子(Cuscuta chinensis Lam.)幼苗,将其分为上、中、下3部分并作为外植体进行离体培养与植株再生研究。结果表明,其上、中部片段更适宜愈伤组织诱导;诱导培养基以添加1mgL-1NAA和1mgL-1BA的MMS培养基效果最好,此培养基也可用于愈伤组织的继代培养,愈伤组织在上述培养基中已生长一年之久。分化培养基为添加1mgL-1BA的MMS培养基,平均每块愈伤组织可以产生2.8株植株。An efficient method of callus induction and plant regeneration of Cuscuta chinensis was established.The seedlings germinated for 3~5 d and about 3~5 cm length were selected as explants,and then divided into three parts,upper,middle and lower.Callus were inducted from upper or middle parts of seedlings on a modified Murashige and Skoog(MMS)medium supplemented with 1 mg L-1 NAA and 1 mg L-1 BA.The calli have been subcultured on such medium for over a year.Shoot regeneration from callus was achieved on MMS medium containing 1 mg L-1 BA and could obtain 2.8 shoots per callus

优化预测运动矢量的快速运动估计算法

提出了一种优化预测运动矢量的快速运动估计算法.在对预测运动矢量研究的基础上,根据序列图像中运动矢量的中心-中值偏置分布特性和矢量间的时空相关性,结合运动矢量的相似度分析,选用中心、中值和时间相关的三个矢量作为基本预测矢量.设置相似门限来减少由三个空间相邻块预测矢量带来的大量冗余信息,对算法中关键的门限技术进行了改进.实验结果证明,本文算法对各种类型的运动序列都有很强的自适应性,在保持搜索准确度的同时,可大幅度提高运动估计的速度,其平均搜索速度是FS的208倍,明显优于PMVFAST的146倍、MVFAST的77倍、DS的55倍,提高了视频压缩中现有的运动估计算法的性能. (A new Optimizing Predictive Motion Vector Fast Motion Estimation Algorithm (OPM-VFMEA) is proposed. Based on the center-median-biased distributed characteristic of the motion vector of real-world sequences and the high space-time correlation of adjacent block's motion vector, combined with similar analysis of the motion vectors, the center, median, forward vector are selected as the basic predictive motion vector to predict the current one, then the similar threshold is set to reduce the redundant information from the three space adjacent block motion vectors. In addition, the adaptive threshold to enable half-stop is also represented. Experiment results show that the algorithm is able to adapt to all types of video sequences and can offer a high performance of PSNR. The search speed of the algorithm is faster than that of the existing well-known algorithms. For case examined, it is about 208 times faster than that of FS in average, which is superior to that of 146 times for PMV-FAST, 77 times for MVFAST and 55 times for DS. Therefore, the algorithm improves the performance of existing motion estimation algorithms.)国家自然科学基金资助项目(No.60472081);航空科学基金资助项目(No.05F07001

Electric-field-induced selective catalysis of single-molecule reaction

随着单分子电学检测技术的迅速发展，分子电子学的研究不再局限于分子电子学器件的构筑及其电学性质的测量，而且扩展到单分子尺度化学反应过程的探索。然而目前相关的研究仍然局限于理论计算方面，在单分子尺度上实时监测和调控化学反应的活性和选择性是化学领域的长期目标和挑战。针对这一挑战，洪文晶教授课题组与程俊教授课题组合作，自主研发了精密科学仪器，将单个有机分子定向连接在两个末端尺寸为原子级的电极之间，解决了化学反应中分子取向控制的问题.理论计算结果证实了定向电场可以有效地稳定化学反应的过渡态，从而降低反应能垒。该研究工作在化学化工学院洪文晶教授、程俊教授、能源材料化学协同创新中心（iChEM）刘俊扬副研究员的共同指导下完成，由硕士研究生黄晓艳、iChEM博士研究生唐淳、博士研究生李洁琼以及兰州大学的陈力川博士作为共同第一作者，化学化工学院师佳副教授、陈招斌高级工程师、夏海平教授和田中群教授，萨本栋微纳研究院杨扬副教授、环境与生态学院白敏冬教授以及兰州大学张浩力教授参与了研究工作的讨论并给予指导，博士后乐家波、博士研究生郑珏婷、张佩（已毕业）、李瑞豪、李晓慧也参与了研究工作。Oriented external electric fields (OEEFs) offer a unique chance to tune catalytic selectivity by orienting the alignment of the electric field along the axis of the activated bond for a specific chemical reaction; however, they remain a key experimental challenge. Here, we experimentally and theoretically investigated the OEEF-induced selective catalysis in a two-step cascade reaction of the Diels-Alder addition followed by an aromatization process. Characterized by the mechanically controllable break junction (MCBJ) technique in the nanogap and confirmed by nuclear magnetic resonance (NMR) in bottles, OEEFs are found to selectively catalyze the aromatization reaction by one order of magnitude owing to the alignment of the electric field on the reaction axis. Meanwhile, the Diels-Alder reaction remained unchanged since its reaction axis is orthogonal to the electric fields. This orientation-selective catalytic effect of OEEFs reveals that chemical reactions can be selectively manipulated through the elegant alignment between the electric fields and the reaction axis.This work was supported by the National Key R&D Program of China (2017YFA0204902), the National Natural Science Foundation of China (21722305, 21703188, 21673195, 21621091, 51733004, 51525303, and 91745103), the China Postdoctoral Science Foundation (2017M622060), and the Young Thousand Talents Project of China. 该工作得到国家自然科学基金委（21722305、21703188、21673195、51733004、51525303、91745103），国家重点研发计划课题（2017YFA0204902），中国博士后面上基金（2017M622060）的资助，以及固体表面物理化学国家重点实验室、醇醚酯化工清洁生产国家工程实验室、能源材料化学协同创新中心的支持

中国物理海洋学研究70年：发展历程、学术成就概览

本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军

The Method of Event-based Integration Modeling And Its Application Analysis

本文以福建省重点科技项目“ACR树脂工艺生产过程的建模仿真、控制优化及软件开发”(项目编号：2001H020)为背景，针对典型的化工流程工业，提出了基于事件的集成建模方法（Event-basedIntegrationModeling，EIM），其主要思想是将不同类型事件的相互联系、相互作用作为贯穿建模过程的主线，然后研究了流程工业的信息化技术，最后给出了厦门电化厂生产管理集成系统的逻辑框架。 本文共分五章。 第一章以流程工业的行业特点为研究对象，通过与离散工业的对比，对流程工业的信息化问题进行了分析，指出流程工业信息化的重点内容是生产系统的过程监控、管理系统的经营决策，以及生产与管理集成的...This thesis is based upon the key science & technology project of Fujian Province, “Modeling, Simulation, Control, Optimization, as Well as Software Developing of the Technological Production Process of ACR Resin” (No. 2001H020). Aiming at typical chemical process industry, we put forward a method of Event-based Integration Modeling (EIM) and its main idea is to utilizing the interrelationship and...学位：工学博士院系专业：计算机与信息工程学院自动化系_系统工程学号：20003103