闭值域算子和框架的扰动

研究了B(H)上的闭值域算子的扰动问题,并把结果推广到框架理论.证明了当{fi}∞i＝1分别是H上的Bessel序列、框架或Riesz基,{gi}∞i＝1是一个序列,且{fi}∞i＝1和{gi}∞i＝1满足一定条件时,{gi}∞i＝1也分别是H上的Bessel序列、框架或Riesz基.     

无领导小组讨论在教学中的应用

无领导小组讨论自20世纪80年代传入我国至今,在各领域得到了广泛的应用。无领导小组讨论本身是一种培训工具,应用于教学具有可行性,具体实施办法有教师讲解、模拟演练、学生和教师分别点评,丰富了教学手段和方法。     

船舶系统研制知识工程信息化平台建设

 船舶系统研制是一项典型的知识密集型的复杂工作，结合知识工程的具体实践，分析了知识工程体系的理论模型、建设内容和原则，探讨了知识工程信息化平台的构建，并展望了未来知识工程信息化的建设。应用本方法开展知识工程体系建设，可实现企业知识的有效获取和管理，促进知识与研发流程的关联应用，使得知识真正成为支撑企业发展的智力资产。     

Theoretical and experimental design of Pt-Co(OH)_2 electrocatalyst for efficient HER performance in alkaline solution

Design efficient electrocatalysts become significant for the hydrogen evolution reaction (HER) in alkaline solution.Here,the HER performance on Pt-Co(OH)2 has been investigated by using DFT calculations.Compared with pure Pt,the Pt-Co(OH)2 shows excellent hydrogen binding energy (-0.29 eV) and hydrogen adsorption free energy (0.02 eV).More strikingly,the water dissociation process on Pt-Co(OH)2 is an exothermic reaction while that of Pt is an endothermic reaction,demonstrating that the Pt-Co(OH)_2 is an excellent catalyst for HER in alkaline medium.Then the two-step electrodepositions was used to fabricate Pt-Co(OH)2 on the carbon paper (CP).The Pt-Co(OH)_2/CP shows the lowest overpotential of only 37.6 mV at a current density of 10 mA cm~(-2) in 0.1M KOH,the smallest Tafel slope of58 mV dec~(-1) and the good stability for 20000s without obvious degradation.     

开放式虚拟制造开发工具框架

相对集中式制造,提出开放式虚拟制造开发工具模型．给出虚拟制造开发工具的对象描述与应用系统的组成模式．说明微机上可实现的开发环境．制定虚拟制造开发工具中类定义格式,并举出两个对象的接口定义模型．在此基础上成功实现虚拟制造开发工具的理论原型．     

海藻酸微球的制备及结构与性能间相互关系

采用高压静电液滴法制备海藻酸钙微球(AGS)。首先通过改进高压装置中电场环境,形成均匀电场,制备单分散AGS;在此基础上,以牛血清白蛋白、血红蛋白为药物模型,系统地研究载药微球的表面形貌、内部结构、溶胀比以及载药释药性能。实验结果表明:在电场中加入直径为17cm的圆形铁环,可有效减少子液滴的形成,制得粒径为(219±6)μm的单分散AGS;另外,海藻酸钠包载不同的药物将形成不同的AGS内部结构,进而影响AGS强度及载药释药性能。释放液中牛血清白蛋白的聚丙烯酰胺凝胶电泳显示,该制备方法并未对被包埋蛋白的相对分子质量产生影响,为AGS在蛋白类药物缓控释载体领域中的应用奠定了基础。     

基于AHP和灰色评价法的武汉市水环境风险评价及管理战略思考

通过构建武汉市城市水环境风险指标体系,综合运用AHP和灰色评价法对当前武汉市水环境总体风险、及其形成原因和结果表现进行评价.结果显示：1）武汉市水环境风险总体处于＂风险较高＂水平;2）成因方面,社会发展对水环境有一定负面影响;3）表现结果方面看,水污染负荷程度较高.最后,基于评价结果和武汉市未来社会经济发展的＂基准情景＂、＂优化情景＂和＂绿色低碳情景＂进行假设,并对科学制定武汉水环境管理战略提出了建议.     

基于激光扫描共焦显微技术的刀具刃口精密测量

为表征刀具刃口结构,提出了一种刃口精密测量和数据处理方法.采用激光扫描共焦显微镜对刀具刃口进行精密测量,通过数据后处理拟合刃口圆弧半径.研究结果表明:测量采用的角度块倾角会对刃口测量范围及刃口不对称度判定产生影响,应根据刀具结构参数合理选择,对于TPMT16T304刀具选择倾角为50.5°的角度块时测量效果较好;数据平滑可以有效去除测量噪声,提高数据处理效率和测量精度;刀具刃口最小二乘拟合结果与扫描电镜法测量值及标称值较吻合,标准不确定度优于0.084μm.以上结果说明,基于激光扫描共焦显微技术的刀具刃口测量方法简便、测量精度高且不破坏刀具.     

Isolation and characterization of rl（t）, a gene that controls leaf rolling in rice

Moderate leaf rolling is one of the most important morphological traits in rice breeding for plant ideotype. Previous studies have shown that the rl（t） gene has a high breeding potential for developing hybrid-rice varieties with an ideal ideotype, because it leads to an appropriate leaf rolling index （LRI） of about 30 % in the heterozygous state, and had a positive effect on grain yield. In this study, we isolated rl（t） and performed a preliminary investigation of its function in regulating leaf rolling in rice. DNA sequencing identified a single base change （G to T） in the finely mapped region （11 kb） containing rl（t）, and this is located in 3′-untranslated region （3′-UTR） of the only predicted gene, Roc5 （Rice outermost cell-specific）. The expression level of Roc5 is significantly higher in the rl（t） mutant than in the wild-type. Using RNAi and overexpression analysis, we found that the expression level of Roc5 correlated with LRI and leaf bulliform area, and wasalso associated with leaf abaxial or adaxial rolling. These results confirmed that Roc5 controls leaf rolling in a dosagedependent manner. Bioinformatics analysis revealed a conserved 17-nt sequence （called the GU-rich element） in the 3′-UTR of HD-GL2 （Homeodomain-Glabra2） family genes including Roc5. Based on the model of this element in regulating mRNA stability in mammals, we speculate that the single nucleotide change in this element accounts for the higher expression level of Roc5 in the rl（t） mutant compared to the wild-type, which ultimately leads to adaxial rolling of the leaf. This discovery further enhances our knowledge of the molecular mechanisms underlying leaf rolling in rice.     

On nonsingularity and group inverse of linear combinations of generalized and hypergeneralized projectors

In this paper, some conditions for the nonsingularity and group inverses of linear combinations of generalized and hypergeneralized projectors are established. Moreover, some formulae for the inverses and group inverses of them are derived. The work of this paper extends some previous results.