Electron beam welding of Re and BT5-1 titanium alloy

Based on the binary alloy phase diagram of Re-Ti, the weldability of Re and BT5-1 titanium alloy was analyzed. Using two methods of direct electron beam welding （EBW-D） and intergradafion electron beam welding （EBW-I）, Re and BT5-1 was welded. Experimental results show that the joint figuration of EBW-D between Re and BT5-1 is not fine, and the joint is inclined to brittleness rupture. The joint figuration of EBW-I between Re and BT5-1 is fine. No cracking and other disfigures occur in the intergradation joint. The element distribution of Re, Me, and Ti in the weld metal is progressional diversification.     

Advances in the research of nitrogen containing stainless steels

The current status of nitrogen containing stainless steels at home and aboard has been introduced. The function and existing forms of nitrogen in the stainless steels, influence of nitrogen on mechanical properties and anti-corrosion properties as well as the application of nitrogen containing cast stainless steels were discussed in this paper. It is clear that nitrogen will be a potential and important alloying element in stainless steels. And Argon Oxygen Decarbonization (AOD) refining can provide an advanced manufacture process for nitrogen containing stainless steels with ultra-low- carbon and high cleanliness.     

STUDIES ON FLOODING POINT AND HOLD-UP IN A SOLVENT EXTRACTION COLUMN WITH RECIPROCATING SIEVE PLATES

The flooding point and hold-up of the dispersed phase in an extraction column with reciprocating-sieve plates of 32 mm inside diameter and 1960 mm effective column height have been investigated under thefollowing conditions:Percent perforation of the plates 40%,53.5% and 63.7%,diameters of perforatedholes 7.8,9.0 and 9.8 mm,and distances between plates 20 and 40 mm respectively.Experiments werecarried out with three different liquid-liquid systems covering a rather wide range of physical properties.The relative velocity of the two phases passing through the perforations of the plates is consideredin the present work to be related to the work done by the oscillating plates in the column on unit massof liquid in unit time.Therefore the flooding velocity and hold-up in extraction column with reci-procating sieve plates should be related to A~2F~3 instead of AF as reported before.Equations weredeveloped to correlate the experimental data of flooding point and hold-up respectively.     

混杂系统的一致输入输出对状态稳定性

混杂系统的输入输出对状态稳定性是混杂控制系统领域极富挑战性的课题之一. 为了观测混杂系统的状态,本文提出了一类混杂系统的一致输入输出对状态稳定的充分条件,分析了混杂系统的一致输入输出对状态稳定性、光滑Lyapunov函数存在性和状态模估计器存在性三者之间的关系. 借助状态模估计器将混杂系统化为受扰动系统,获得了受扰动系统一致输入输出对状态稳定性的结果,并进一步证明了混杂系统的一致输入输出对状态稳定性.     

1，4-环己烷二甲酸

介绍了1,4-环己烷二甲酸的物化性质、性能特点及应用,并综述了其专利制备技术的研究进展。     

基于Hg~(2+)诱导DNA双链形成的汞离子检测试纸条研制

Hg2+能特异性地与2个胸腺嘧啶碱基(T)共价结合,介导T-T错配形成稳定的T-Hg2+-T结构。基于DNA修饰的纳米金探针研制了一种可检测水溶液中Hg2+浓度的层析试纸条。试纸条包含1条控制线和2条测试线,检测结果在5 min内可见,裸眼可见检测灵敏度为100 nmol/L。金标条阅读仪分析结果在10 nmol/L~10μmol/L范围内具有良好的线性关系,且对常见二价重金属离子Cu2+,Ni2+,Mg2+,Zn2+,Pb2+具有很好的选择性。该试纸条灵敏特异、快捷简单、操作方便、成本低廉,在环境监测和食品安全的现场快速检测中具有很好的应用前景。     

基于不完全转移率的连续Markov 跳变奇异系统的H∞ 控制

研究一类不完全转移率信息的Markov跳变奇异系统的H∞控制问题,提出连续Markov跳变奇异系统的新型有界实引理,并将其推广到不完全转移率条件.进一步设计H∞状态反馈控制器,使得闭环系统在转移率部分未知的条件下随机可容许,且满足H∞性能H.所得结论涵盖了奇异矩阵模态依赖情形,且表示为严格线性矩阵不等式形式,利于工程实现.最后,通过仿真算例表明了所提出方法的有效性和优越性.     

一种适用于物联网设备的自适应跳频方法

由于2.4 GHz频段的免授权性和开放性,新的无线系统在该频段内的自由接入必定会受到同频系统的干扰。针对上述问题,采用自适应跳频技术保证通信双方在通信中自动适应信道变化,实时避开频率集中被干扰的频点,提高通信的可靠性和抗干扰能力。首先介绍自适应跳频技术的2种相关算法,时间同步及信道评估算法,接着介绍基于CC2500的物联网设备的具体实现流程,并采用公共信道实现跳频信令的传输,在基于CC2500的物联网设备上做了具体实践,最后通过实验分析表明,该跳频算法具有一定的实用性和先进性。     

离子液介质中生物催化与生物转化的研究进展

Ionic liquids have negligibly low vapor pressure, high stability and polarity. They are regarded as green solvents. Enzymes, especially lipases, as well as whole-cell of microbe, are catalytically active in ionic liquids or aqueous-ionic liquid biphasic systems. Up to date, there have been many reports on enzyme-exhibited features and enzyme-mediated reactions in ionic liquids. In many cases, remarkable results with respect to yield, catalytic activity, stability and (enantio-, regio-) selectivity were obtained in ionic liquids in comparison with those observed in conventional media. Accordingly, ionic liquids provide new possibilities for the application of new type of solvent in biocatalytic reactions.     

高效广谱微生物复合破乳剂的制备及其应用

为解决破乳剂的选择性强、破乳效率低的问题,采用化学破乳剂和微生物破乳剂复合的方法,研制出了广谱、高效、低成本的破乳剂,并用大庆三次采油采出液、塔河原油、南阳原油、蓬莱原油、俄罗斯混合原油进行了脱水、脱盐评价。结果表明:对于大庆油田采出液,微生物复合与化学破乳剂比较,脱水效率提高5%以上,脱出水含油可降低40%以上;对于易乳化的南阳原油、蓬莱原油,脱后含盐可达3 mg/L以下,脱出水含油可降低50%以上。工业应用表明:对于俄罗斯混合原油脱后含盐可达2 mg/L以下,脱出水含油可降低70%以上,脱后排水含油小于15 mg/L。所研制的微生物复合破乳剂适应性强,成本可降低20%~50%。