二次侧非能动余热排出系统流动不稳定性研究

二次侧非能动余热排出（ASP）系统是压水堆核电厂应对全厂断电事故的重要措施之一。为研究ASP系统的运行特性,设计建造了ASP系统试验装置（ASPTF）。在ASPTF上开展了ASP系统运行稳定性影响试验,并对试验结果进行了理论分析。试验研究与理论分析结果表明：低压低功率下ASP系统中出现流动不稳定性;增加蒸汽管线或回水管线阻力系数可抑制ASP系统出现流动不稳定性;降低加热功率时ASP系统更易出现流动不稳定性;主泵运行状态影响ASP系统的输入功率进而影响系统的流动不稳定性。     

IR—UT钢水升温工艺实验

以苏州钢铁厂钢包为原型，通过水模和中频感应炉实验，确定了ＩＲ－ＵＴ－１６型精炼装置的设备参数和工艺参数，证实了采用Ａｌ或Ｓｉ－Ｃａ－Ｂａ－Ａｌ作发热剂进行钢水吹氧升温的可行性，钢水成分可满足小方坯连铸的要求。     

压水堆核电厂堆外源量程探测器计数率分析

压水堆核电厂启动过程中,次级中子源为堆外源量程探测器提供本底计数率,避免测量盲区,确保反应堆安全启动。但次级中子源的引入会为核电厂带来较大的经济和环境负担,同时也需承受次级中子源破损等带来的风险。为此,可使用受辐照燃料组件的自发裂变中子源进行替代,即无源启动方式。通过研究堆外源量程探测器计数率的理论计算方法,并基于运行电厂测量数据进行分析验证,为源量程探测器计数率的理论预估提供了较为完善的理论方法流程。本文结果可为无源启动源量程探测器计数率分析提供支持,同时也可用于次级中子源装载量或布置位置的优化分析等。     

Molecular and Physiological Responses of Citrus sinensis Leaves to Long-Term Low pH Revealed by RNA-Seq Integrated with Targeted Metabolomics

Low pH-induced alterations in gene expression profiles and organic acids (OA) and free amino acid (FAA) abundances were investigated in sweet orange [Citrus sinensis (L.) Osbeck cv. Xuegan] leaves. We identified 503 downregulated and 349 upregulated genes in low pH-treated leaves. Further analysis indicated that low pH impaired light reaction and carbon fixation in photosynthetic organisms, thereby lowering photosynthesis in leaves. Low pH reduced carbon and carbohydrate metabolisms, OA biosynthesis and ATP production in leaves. Low pH downregulated the biosynthesis of nitrogen compounds, proteins, and FAAs in leaves, which might be conducive to maintaining energy homeostasis during ATP deprivation. Low pH-treated leaves displayed some adaptive responses to phosphate starvation, including phosphate recycling, lipid remodeling, and phosphate transport, thus enhancing leaf acid-tolerance. Low pH upregulated the expression of some reactive oxygen species (ROS) and aldehyde detoxifying enzyme (peroxidase and superoxidase) genes and the concentrations of some antioxidants (L-tryptophan, L-proline, nicotinic acid, pantothenic acid, and pyroglutamic acid), but it impaired the pentose phosphate pathway and V_E and secondary metabolite biosynthesis and downregulated the expression of some ROS and aldehyde detoxifying enzyme (ascorbate peroxidase, aldo-keto reductase, and 2-alkenal reductase) genes and the concentrations of some antioxidants (pyridoxine and γ-aminobutyric acid), thus disturbing the balance between production and detoxification of ROS and aldehydes and causing oxidative damage to leaves.     

炮孔计算机辅助设计系统研究

对爆破设计中的需求进行了系统分析,确定了炮孔参数和炮孔设计图的形成思想,介绍了炮孔计算机辅助设计中的数据库技术,以及如何利用Arx2000对AutoCAD进行二次开发实现设计功能。     

VBA技术在企业中的应用

计算机常规技术在企业中的应用一直是研究的热点,通过构建快速高效的VBA程序,可以解决实际工作中的问题,有力提升效率。VBA技术可以广泛应用于企业的财务核算、生产管理、技术研发领域,借助其易于二次开发、开发周期短、容易维护、运行效率高的优点,可以协同解决很多实际技术难题。     

Plant Responses to Herbivory,Wounding, and Infection

Plants have various self-defense mechanisms against biotic attacks, involving both physical and chemical barriers. Physical barriers include spines, trichomes, and cuticle layers, whereas chemical barriers include secondary metabolites (SMs) and volatile organic compounds (VOCs). Complex interactions between plants and herbivores occur. Plant responses to insect herbivory begin with the perception of physical stimuli, chemical compounds (orally secreted by insects and herbivore-induced VOCs) during feeding. Plant cell membranes then generate ion fluxes that create differences in plasma membrane potential (Vm), which provokes the initiation of signal transduction, the activation of various hormones (e.g., jasmonic acid, salicylic acid, and ethylene), and the release of VOCs and SMs. This review of recent studies of plant–herbivore–infection interactions focuses on early and late plant responses, including physical barriers, signal transduction, SM production as well as epigenetic regulation, and phytohormone responses.     

协同环境下基于角色任务的个性化服务模型

针对多人协作的动态任务分配、动态资源推送等问题,建立了一种基于角色任务的个性化服务模型以支持网络大规模应用。将工作流中涉及到的用户、角色、任务、资源等要素抽象出来,构建统一的元模型作为整体应用基础;根据每个用户的角色特征、任务负载量等因素建立了针对用户的任务和资源匹配算法,并实时根据协同环境中任务的状态迁移将相关任务和资源推送给用户;通过一个实例来验证该模型的可行性和有效性。结果表明该模型为大规模网络服务应用中的资源推送机制提供了参考实现途径。     

超高压可控电抗器抑制潜供电流研究

笔者阐述了抑制潜供电流的意义和国内外的研究现状。针对潜供电流产生的机理及抑制措施进行了详细分析,介绍了可控电抗器的结构和基本工作原理,列出了四射线补偿方法下并联电抗器中性点小电抗器的计算公式,并建立了三峡右岸-江陵500 kV输电线路和可控电抗器模型,仿真研究了用可控电抗器取代常规并联电抗器后抑制潜供电流的效果。仿真结果表明,超高压可控电抗器能有效地抑制潜供电流。     

光栅衍射缝间干涉因子次极大强度对称性的菲涅耳半波带法证明

本文用菲涅耳半波带法推导出了一个非常有用的次极大位置公式,将该位置公式和振幅矢量法求出的次极大位置结合起来,方便地求出了缝间干涉因子的次极大的强度,证明了缝向干涉因子的次极大强度具有对称性。避免了对振幅矢量法求次极大位置这个方程的直接求解,因为用该方法求出的次极大强度与理论值完全符合,说明菲涅耳半波带法不但可以用来分析单缝衍射,同时还完全能够用来分析光栅衍射。