掺锑钨酸铅晶体性能的测量

钨酸铅晶体是新一代对撞机谱仪ＣＭＳ的电磁量能器的主体。为达到所要求的测量精度,对晶体的各项性能提出了很高的要求。本文主要介绍了对几块全尺寸（２３ｃｍ长）掺锑钨酸铅晶体荧光性能和抗辐照能力的评估和测量方法,并给出了测量结果。     

Effect of wall wettability condition on drift-flux parameters in lead–bismuth two-phase flow in circular and annular bubble columns

Lead–bismuth two-phase flow in a cylindrical vessel and annulus was experimentally investigated by varying the surface wettability of the vessel wall. The test section used in this study was a cylindrical stainless vessel with/without inner sleeve to change the hydraulic diameter. Volume-averaged void fraction was measured by varying the surface wettability of the test section, which was enhanced by using a soldering flux. Measured void fraction was compared with existing two-phase flow correlations and with one-dimensional theoretical simulations assuming one-dimensional drift-flux model. From experimental results, measured distribution parameters of the lead–bismuth two-phase flow are much larger than that of ordinary two-phase flow regardless of the surface wettability. In the present work, the one-dimensional analysis was carried out for the cylindrical vessel to reproduce the distribution parameter. From the simulation results, predicted value for the cylindrical vessel showed good agreement with experimental results. However, in annulus, the distribution parameters in annulus were underestimated by the present model. It was suggested that, in case of annulus, steeper void fraction profile might be formed near the inner surface for poor wettability condition.     

Research and development of advanced structured packing in a rotating packed bed

As the core component of the rotating packing bed, packing is a place for efficient gas–liquid mixing and mass transfer. In this paper, a 3D structured packing composed of a mesh structure and a support structure was designed. The mesh structure is a ring-shaped mesh surrounded by triangular meshes, which is stable in structure and can achieve a high degree of dispersion and aggregation of the liquid phase. The support structure is composed of ring-shaped structural units arranged at a certain a...     

毛细滴管-吸量管数滴微型滴定法现场快速测定水的总硬度

毛细滴管-吸量管数滴微型滴定法以自制的液滴体积为0.01～0.02 mL的聚乙烯毛细滴管和5～10 mL吸量管为量器进行滴定,具有仪器简单,滴定快速、准确,试剂消耗量少的特点.不确定度理论证明,用该法测定水的总硬度,相对扩展不确定度Urel(C)约为0.86%;试验结果表明,当滴定剂用量为80～110滴时,回收率为98.8%～101%,RSD为0.36%～0.79%.该法克服了常量法中滴定管、移液管、铁架台和蝴蝶夹等仪器携带不方便的不足,适用于工业用水现场和野外水质的快速分析.     

水质硬度自动监控系统在油田注汽锅炉水处理设备上的应用

水质硬度自动在线监控系统是在生产实践中逐步发展和完善的自动化控制系统.它由上位机系统、硬度检测、控制系统三大部分组成,具有实时监控、在线检测等功能,精度高、功能强大,用户界面友好.本文阐述了该系统的硬件组成结构和系统功能,分析了系统的工作原理.在实际应用中,系统运行稳定、减少了值班人员的工作量,降低了水处理的单耗,经济效益明显.     

Genome-Wide Analysis of the Peroxidase Gene Family and Verification of Lignin Synthesis-Related Genes in Watermelon

Watermelon (Citrullus lanatus) is an important horticultural crop worldwide, but peel cracking caused by peel hardness severely decreases its quality. Lignification is one of the important functions of class III peroxidase (PRX), and its accumulation in the plant cell wall leads to cell thickening and wood hardening. For in-depth physiological and genetical understanding, we studied the relationship between peel hardness and lignin accumulation and the role of PRXs affecting peel lignin biosynthesis using genome-wide bioinformatics analysis. The obtained results showed that lignin accumulation gradually increased to form the peel stone cell structure, and tissue lignification led to peel hardness. A total of 79 ClPRXs (class III) were identified using bioinformatics analysis, which were widely distributed on 11 chromosomes. The constructed phylogenetics indicated that ClPRXs were divided into seven groups and eleven subclasses, and gene members of each group had highly conserved intron structures. Repeated pattern analysis showed that deletion and replication events occurred during the process of ClPRX amplification. However, in the whole-protein sequence alignment analysis, high homology was not observed, although all contained four conserved functional sites. Repeated pattern analysis showed that deletion and replication events occurred during ClPRXs’ amplification process. The prediction of the promoter cis-acting element and qRT-PCR analysis in four tissues (leaf, petiole, stem, and peel) showed different expression patterns for tissue specificity, abiotic stress, and hormone response by providing a genetic basis of the ClPRX gene family involved in a variety of physiological processes in plants. To our knowledge, we for the first time report the key roles of two ClPRXs in watermelon peel lignin synthesis. In conclusion, the extensive data collected in this study can be used for additional functional analysis of ClPRXs in watermelon growth and development and hormone and abiotic stress response.     

焊接接头微型剪切试验与机械性能试验之间的关系

在对工程应用中强度级别在450-750MPa之间的数十种焊接接头进行大量微型剪切试验、硬度试验和冲击试验的基础上,运用概率论与数理统计相关知识,通过最小二乘曲线拟合,回归得出了焊缝、熔合线和热影响区各狭窄区域内剪切强度氏与硬度试验HV10之间,剪切韧性形。与冲击韧性‰之间关系的经验公式。这些经验公式的相关系数都能满足显著性水平达到0．01的回归精度。     

工件作超声振动时的磨削特性研究

磨削是加工硬脆性材料并获得高加工精度的常用工艺,加工过程中表面质量与材料的去除率是一对矛盾,超声振动的引入在很大程度上缓解了这一矛盾。对工件作超声振动的磨削加工特性进行了试验及理论分析,从工件振动的等效硬度特性角度分析了磨削力比降低的原因,并对其进行了量化计算。该结果对超声辅助磨削加工硬脆材料具有现实的指导意义。     

用HIFN 5NP4GS3网络处理器设计8Gbit/s线速路由器

介绍了使用5NP4GS3网络处理器设计的准交换结构8Gb／8线速路由器。HIFN公司的5NP4G3是OC-48级别网络处理器中综合性能最佳的一个芯片产品,准交换结构设计充分挖掘了这颗处理器能力,使设计具有很高的性价比。文章给出了路由器各个部分的设计,经过实际测试,证明了系统设计的正确性和可靠性。     

基于Lexra网络处理器的家庭网关QoS研究

家庭网络多媒体正成为网络主要推动力,而家庭网关成为家庭网络的核心设备。该文完成了基于Lexra网络处理器家庭网关设计,并讨论了网关QoS设计原则,在路由和队列调度层面上实现了QoS保证,并在实际项目中验证了QoS性能。