187 research outputs found

    戴维营和平进程的结局分析

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    里根就任总统后,美国中东战略的重声、在于建立抗苏“战略一致”以对付苏联的攻势,而没有致力于推进戴维营和平进程;埃以关于巴勒斯坦自治问题谈判的失败,是戴维营和平进程终结的标志。此后,中东和平进程虽然还在发展,但已不再是戴维营和平进程的继续

    高分散度铜基甲醇合成催化剂的研究

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    高分散度铜基甲醇合成催化剂的研究李基涛高利珍张伟德陈明树(厦门大学化学系物理化学研究所361005)70年来甲醇合成催化剂被广泛关注,特别是60年代后期英国ICI公司发明低温低压铜基甲醇合成催化剂以来,人们对铜基甲醇合成催化剂的制备与表征进行了深入地...国家自然科学基金;固体表面物理化学国家重点实验室资

    The Acetylation of Thymosin α1 is Independent on RimL in Escherichia coli

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    目的:考察大肠杆菌乙酰转移酶rIMl对胸腺素α1(Tα1)乙酰化修饰的影响。方法:构建含500bP同源臂的卡那抗性基因打靶片段,利用rEd同源重组系统,使大肠杆菌bl21(dE3)的rIMl基因插入失活,随后导入质粒PCP20去除抗性基因,构建突变菌株rIMl-bl21(dE3);将重组质粒PET-Tα1-l12分别转入出发菌株和突变菌株中进行表达,经固定金属离子亲和层析和反向高效液相层析后,将所得纯品进行质谱分析,精确测定相对分子质量。结果:PCr鉴定结果证明成功敲除rIMl基因;质谱结果表明,rIMl基因敲除菌中所表达的Tα1-l12融合蛋白与出发菌株一样,均有部分乙酰化修饰。结论:Tα1的乙酰化修饰并不依赖于rIMl。Objective:To investigate the effect of RimL,a N-terminal acetyltransferase of E.coli,on thymosin α1(Tα1) acetylation.Methods:A kanamycin cassette with two 500 bp long arms homologous to the regions around rimL as the replacement fragment was electroporated into cells,in which the Red recombinant functions was induced.Subsequently,the plasmid pCP20 was transformed to eliminate the kanamycin resistant gene.The plasmid pET-Tα1-L12 was transformed into the original and mutant strains respectively.The expressed fusion protein Tα1-L12 was purified by IMAC and RP-HPLC.The accurate molecular weight of the fusion protein was measured by Q-Tof-MS.Results:The gene rimL was inactivated by insertion of the replacement fragment successfully.According to the MS results,the fusion protein Tα1-L12 was still partly acetylated when it was expressed in the mutant strains as in the original strains.Conclusion:Tα1 acetylation was independent on RimL

    Purification and part characterization of a novel antibacterial protein Scygonadin, isolated from the seminal plasma of mud crab, Scylla serrata (Forskål, 1775)

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    【英文摘要】A novel protein was isolated from the seminal plasma of the mud crab, Scylla serrata (Forskål, 1775). It exhibited an antibacterial activity against the Gram-positive bacterium Micrococcus leteus with IC90 of 0.125 mg/ml. The extraction procedure for the protein included techniques of acid extraction, ion-exchange chromatography on SP-Sepharose Fast Flow and reverse-phase liquid chromatography on Source 5R RPC. It showed a molecular mass of 10.8 kDa by SDS-PAGE. A partial 20 residue NH2-terminal sequence was determined by Edman degradation and MS-fingerprint of the protein was conducted. Similarity search in protein databases (BLAST) revealed that the protein exhibited no significant homology to any other reported antimicrobial peptides. We propose the name Scygonadin (from the gonad of S. serrata) for this antibacterial protein

    A male-specific expression gene, encodes a novel anionic antimicrobial peptide, scygonadin, in Scylla serrata

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    【英文摘要】Scygonadin is a novel antimicrobial peptide, which was originally isolated from the seminal plasma of the mud crab, Scylla serrata. Based on the partial 20-residue NH2-terminal sequence of the peptide, H-Gly-Gln-Ala-Leu-Asn-Lys-Leu-Met-Pro-Lys-Ile-Val-Ser-Ala-Ile-Ile-Tyr-Met-Val-Gly-OH, scygonadin was cloned from the gonads of S. serrata using a degenerated reverse transcriptase (RT)-PCR and rapid amplification of cDNA ends (RACE). The full-length cDNA sequence contains an open reading frame of 539 bases (excluding polyA) with a coding capacity of 126 amino acids, which constitutes a putative NH2-terminal signal sequence (1–24) and a mature peptide (25–126). Analysis of the genomic DNA sequence revealed that scygonadin consists of 2300 bp containing two introns (1569 and 120 bp) and three exons (187, 131 and 218 bp) and this sequence is different from any other reported antimicrobial peptide. The theoretical pI of the mature peptide is 6.09, which suggests that it is an anionic molecule. The sex and tissue-specific expression of the scygonadin gene was revealed using RT-PCR and Northern-blot analysis of multiple tissues of S. serrata males and females and this demonstrated that the scygonadin gene was predominantly expressed in the male reproductive tract of S. serrata and was restricted to the ejaculatory duct. This suggests that scygonadin might be one of the antibacterial peptides responsible for protection of the male crab reproductive tract from invading pathogenic microorganisms, so as to maintain a sterile environment leading to successful fertilization

    Interfacial Effects in Iron-Nickel Hydroxide–Platinum Nanoparticles Enhance Catalytic Oxidation

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    该研究工作是在郑南峰教授的领导下,由校内外、国内外多个课题组共同努力,历时三年完成。郑南峰、傅钢、陈明树等三个课题组紧密协作负责催化剂的合成、表征、性能测试以及催化机理研究;中国科学院物理研究所谷林研究员主要负责纳米颗粒的亚埃级球差校正高分辨透射电子显微研究;加拿大达尔豪斯大学化学系的张鹏教授课题组和台湾同步辐射研究中心李志甫研究员等参与催化剂的同步辐射X-射线吸收光谱研究。 该工作受到了国家自然科学基金委、科技部、厦门大学、固体表面物理化学国家重点实验室、能源材料化学协同创新中心以及醇醚酯化工清洁生产国家工程实验室的资助与支持。Hybrid metal nanoparticles can allow separate reaction steps to occur in close proximity at different metal sites and accelerate catalysis. We synthesized iron-nickel hydroxide–platinum (transition metal-OH-Pt) nanoparticles with diameters below 5 nanometers and showed that they are highly efficient for carbon monoxide (CO) oxidation catalysis at room temperature. We characterized the composition and structure of the transition metal–OH-Pt interface and showed that Ni2+ plays a key role in stabilizing the interface against dehydration. Density functional theory and isotope-labeling experiments revealed that the OH groups at the Fe3+-OH-Pt interfaces readily react with CO adsorbed nearby to directly yield carbon dioxide (CO2) and simultaneously produce coordinatively unsaturated Fe sites for O2 activation. The oxide-supported PtFeNi nanocatalyst rapidly and fully removed CO from humid air without decay in activity for 1 month

    中国物理海洋学研究70年:发展历程、学术成就概览

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    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

    a new methodology for user driven domain specific application software development

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    提出一种应用软件开发的新方法 ,称为“用户工程”.这是一种基于构件化软件系统结构的用户主导的面向领域的应用软件开发方法 ,强调用户在应用软件开发中的主导作用 ,试图将应用软件的开发过程变成用户详细定义过程 ,而不仅仅是传统的编程过程 .它为越来越多的应用软件开发需求提供了可能有效的一个途

    An Integrated Solution for Software Process Improvement

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    Since 1990s, the software industry in China has been developed very rapidly and the total revenue in recent three years of 2005, 2006 and 2007 were 390.0, 480.0, and 583.4 billions RMB respectively, increased by 28.3% annually on an average basis [1]. By the end of 2007, there were about 18,000 software enterprises in China, and the population of software professionals was 1.48 millions roughly. In the global software market, China, with annual revenue about 82.2 billions USD (8.74% of the total: 940 billions USD), currently ranks on the fourth after USA, EU and Japan. However, the software industry in China is still comparatively weak. Most software enterprises have only tens of employees and millions RBM of revenue. And the software development productivity in China varies highly across the software industry in terms of organization, development type, business area, region, language, project size and team size [2]. Co-operative efforts from the government, the industry and the academy are needed [3]. Continuous software process improvement is an effective way to change the challenging situation of the software industry in China
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