software reliability growth model considering defect correlation

非齐次泊松过程类软件可靠性增长模型(NHPP-SRGMs)是评价软件产品可靠性指标的有效工具,但大多数该类模型都未考虑软件缺陷关联这一测试过程中普遍存在的现象.该文在考虑软件缺陷关联关系的基础上对缺陷进行分类,提出一个改进的NHPP类软件可靠性增长模型.在一组失效数据上的实验分析表明,改进的模型具有较好的拟合效果和预测能力

Effects of Salinity and Temperature on Introduction and Cultivation of the Euhalophyte Salicornia bigelovii Torr. in the Xiamen Ambient Sea

研究了厦门海区盐度和温度对北美海蓬子(Salicornia bigelovii)种子萌发和幼苗生长的影响。结果显示,海蓬子种子对温度变化反应非常敏感,在15°C时发芽率最高(94%),但萌发指数最低,而在20°C时萌发指数最大;在盐度5g.L-1时种子具有最高的发芽率和萌发指数,在盐度50g.L-1时仍有13.3%的发芽率,并且各种盐度处理下逐日萌发指数均能在2天内达到最大。盐度10-20g.L-1最适宜幼苗生长,高盐(>30g.L-1)具有一定的抑制作用,主要表现为生长缓慢,含水量和根系活力下降,并且根的盐敏感程度大于茎。在不同盐度处理下,北美海蓬子适应一种新的耐盐机制,在无盐(0g.L-1)和高盐(40g.L-1)胁迫下,过氧化氢酶(catalase,CAT)和过氧化物酶(peroxide,POD)这2种酶蛋白对盐离子效应敏感,起主要的抗氧化作用;相反,生长在适宜盐度范围(10-30g.L-1)内,超氧化物歧化酶(superoxide dismutase,SOD)维持较高活性。研究结果表明,北美海蓬子适宜在沿海滩涂环境条件下生长,有望作为一种抗盐耐海水蔬菜加以开发和利用,并进一步在污染海水净化修复中发挥可能的生态功能。To introduce and cultivate euhalophyte Salicornia bigelovii T. in the Xiamen ambient sea,we studied the effects of salinity and temperature on seed germination and seedling growth. The fastest rate of germination occurred with fewer than 15°C seeds germinated with a minimal germination index,which was maximal under 20°C. The germination of seeds was sensitive to salinity,and decreases in salinity resulted in progressive increments of the germination rate,which reached the peak level(94.0%) at salinity of 5 g.L-1 and was still 13.3% at 50 g.L-1 salinity;as well,the maximal daily germination index was reached within 2 days under all treatments. Also,high salinity(>30 g.L-1) reduced the growth of seedlings,tissue water content and root vigor,although adequate salinity(10-20 g.L-1) promoted these features. The salt tolerance ability of the plant is associated with the original function of internal antioxidant enzymes,including superoxide dismutase(SOD) ,catalase(CAT) and peroxidase(POD) ,with SOD showing high activity at optimal salinity,10-30 g.L-1,and POD and CAT showing high activity at polar salinity of 0 and 40 g.L-1,with the activity of POD 5-10 times higher than that of CAT. On the basis of its adaptation to salinity and temperature,S. bigelovii is suitable for cultivation in the Xiamen ambient sea and can be applied for phytoremediation in the sea.863计划(No.2007AA091704

用于放射性束流实验的低气压二维位置灵敏多丝正比室

为在放射性束流线上进行核反应研究而研制了灵敏面积为50mm×50mm的二维位置灵敏的低气压多丝正比室。低气压多丝正比室为穿透式,在真空中使用,工作气压为800Pa,透射性好,不干扰束流。放射性束流在束测试结果表明:它的x、y方向的位置双径迹分辨为1mm;对30～40MeV的低Z放射性束的探测效率大于80%,适用于中能次级束实验中入射束的定位和反应中产生的带电粒子出射角度的测量

Synthesis of ZnO nanostructures by spontaneous oxidation of Zn films on p-type silicon substrates

ZnO nanostructures have been synthesized on p-type silicon substrates using a two-step, spontaneous oxidation of Zn films method at room temperature. The samples both with and without a thin layer of gold in different positions have been spontaneously oxidized in a humid atmosphere for seven days to form nanosheets and ball-cactus like nanostructures. Diverse morphologies of hierarchical ZnO nanostructures have been obtained by annealing the samples at 700 C in a nitrogen atmosphere for 1 h. A growth mechanism has been proposed for the formation of different ZnO nanostructures. It was found that the band-gap emission can be greatly improved and that the defect emission is suppressed to a noise level when a thin layer of Au was deposited between the Zn and the Si substrate. Moreover, our results show that the ZnO/p-Si heterojunction exhibits good performance for visible spectrum detection

新疆、青海、内蒙古盐湖卤虫资源调查及开发利用

共调查盐湖４３处，水域面积约３５００平方米公里，发现有卤虫的盐湖３１处，水域１６２０平方公里，占４６．３％，对２８处盐湖进行普查，对９处重点盐进行盐湖生态学和卤虫生物学调查，收集了盐湖湖盆，形态、水文、气象等资料，采休水化样品３７６瓶，生物样品６３０瓶；卤虫样品１０８５瓶，进行室内实验、分析、共获得４００００多个数据，通过卤虫的分布密度和生物量，评估了卤虫，卵资源量，提出了开发方案，撰写了３０万字的调查报告，全面完成了合同中规定的任务和各项指标。主要成果如下：对２８处湖泊的水质进行理化分析，掌握了盐湖盐度的同年变化。对２３处盐湖的浮游生物，进行采样镜检定分性、定量分析。经镜检有浮游植物共９２个种属，浮游动物共４２种属。卤虫生物滂的研究

Electroactivities of Pd/Fe3O4-C catalysts for electro-oxidation of methanol, ethanol and propanol

制备对醇氧化反应具有优异电活性的钯催化剂是醇燃料电池研究的重要内容。本文用硼氢化钠还原法制备了钯纳米颗粒, 然后沉积在Fe3O4/C复合物表面, 得到了不同Fe3O4负载量的Pd/Fe3O4-C催化剂. 透射电镜（TEM）图显示钯纳米颗粒均匀地分散在Fe3O4/C表面. 对制备好的Pd/Fe3O4-C催化剂进行了循环伏安法（CV）、计时电流（CA）和电化学阻抗谱（EIS）的测试, 研究了其在碱性介质中对C1-C3醇类（甲醇、乙醇和丙醇）氧化的电催化活性. 结果表明, 所制备的不同Fe3O4负载量的Pd/Fe3O4(2%)-C,Pd/Fe3O4(5%)-C, Pd/Fe3O4(10%)-C和Pd/C催化剂中, Pd/Fe3O4(5%)-C催化剂表现出最高的醇氧化电流密度. 依据循环伏安（CV）数据，Pd/Fe3O4(5%)-C催化剂对甲醇、乙醇、正丙醇和异丙醇氧化的阳极峰电流密度分别是Pd/C催化剂的1.7、1.4、1.7和1.3倍. Pd/Fe3O4(5%)-C催化剂对乙醇氧化的电荷传递电阻也远低于Pd/C催化剂. 制备的所有催化剂对C1-C3醇类电氧化的电流密度大小排序如下: 正丙醇﹥乙醇﹥甲醇﹥异丙醇. 此外, 碳粉中Fe3O4纳米颗粒的存在提高了钯纳米颗粒的电化学稳定性.Development of palladium (Pd) catalysts with high electroactivity for alcohol oxidation is significant for alcohol fuel cells. In this work, Pd nanoparticles were formed by sodium borohydride (NaBH4) reduction method and subsequently deposited on the surface of carbon supported ferriferrous oxide (Fe3O4/C) composites to obtain the Pd/Fe3O4-C catalysts with different Fe3O4 loadings. Their transmission electron microscopic (TEM) images show that the Pd nanoparticles were uniformly dispersed on the Fe3O4/C. Electroactivities of the prepared Pd/Fe3O4-C catalysts toward oxidations of C1-C3 alcohols (methanol, ethanol, n-propanol and iso-propanol) in alkaline media were investigated by cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy. Among the prepared catalysts (Pd/Fe3O4(2%)-C, Pd/Fe3O4(5%)-C, Pd/Fe3O4(10%)-C and Pd/C), the Pd/Fe3O4(5%)-C catalyst presented the highest electro-oxidation current density for oxidations of C1-C3 alcohols. According to the CV data, the anodic peak current densities for oxidations of methanol, ethanol, n-propanol and iso-propanol on the Pd/Fe3O4(5%)-C catalyst were over 1.7, 1.4, 1.7 and 1.3 times larger than that on the Pd/C catalyst, respectively. Furthermore, the charge transfer resistance of ethanol oxidation on the Pd/Fe3O4(5%)-C catalyst was much lower than that on the Pd/C catalyst. For all of the prepared catalysts, the decreases in electro-oxidation current density of the tested C1-C3 alcohols followed the order of n-propanol >ethanol > methanol >iso-propanol. In addition, the presence of Fe3O4 nanoparticles in the carbon powder improved the electrochemical stability of the Pd nanoparticles.国家自然科学基金项目(21376070)，湖南省研究生科研创新项目(CX2016B567)资助作者联系地址：1.湖南科技大学，化学化工学院，中国,湘潭，411201；2.理论有机化学与功能分子教育部重点实验室，中国湖南，湘潭，411201Author's Address: 1.School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China; 2.Key Laboratory of Theoretical Organic Chemistry and Functional Molecule, Ministry of Education, Xiangtan 411201, Hunan, China通讯作者E-mail：[email protected]

农业资源高效利用与管理技术

该课题建立了区域农业资源利用效率评价指标体系与评价模型,首次编制了中国农业生态区划方案,建立了农业资源高效利用决策支持系统,在农业资源高效利用研究的理论与方法方面取得了重要进展。系统分析了中国的农业资源态势和发展前景,提出了以县为单元的商品粮基地建设构想,综合评估了中国不同时期、不同生态区的农业资源综合生产能力和人口承载能力,总结提出了适宜不同类型区的14种农业资源高效利用优化模式与技术体系集成方案和21项节水、节地、节肥、节粮、节本的高效利用农业资源的技术创新组合方案,具有一定的推广应用价值;研究提出的藏粮于土、提高农业资源综合生产能力的相关结论和建议,对国家和地区农业资源高效利用与区域可持..