变压吸附制氮技术的发展和应用

综述了变压吸附技术的原理、发展及碳分子筛和沸石分子筛两种吸附剂变压吸附技术制氮的国内外研究进展,提出了变压吸附技术制氮的发展方向。     

阀口动压反馈低压溢流阀的研究

针对系统中的普通低压直动式溢流阀的静特性,提出了阀口动压反馈低压直动式溢流阀的新结构,改善了溢流压力随流量变化的特性;且当通过流量在大范围变化时,减小了溢流阀溢流压力的变化比率。     

电站锅炉压力容器检验单位资质问题的现状及思考

文章回顾了电力行业锅监工作的历史及检验体系的建立,针对目前电站锅炉压力容器检验单位资质问题的现状,为了保证对电力安全生产及锅炉压力容器设备的安全稳定运行,对检验单位的资质问题进行了分析,并对目前以及将来的检验工作、检验单位的发展、检验市场的建立等提出了建设性的意见。     

土钉墙分步开挖中挡土机理分析

土钉墙和由它派生出的复合支护方式在实际工程中广泛应用,但在理论上对它的挡土机理研究还不够。本文对均质土中的土钉墙,采用数值分析方法,探讨开挖过程中土钉、面层、土体三者的受力变化及土钉墙的稳定机理,得到了面层受到的总土压力是主动土压力的0．05倍等一些结论。     

A Novel Mouse Model of TGFβ2-Induced Ocular Hypertension Using Lentiviral Gene Delivery

Glaucoma is a multifactorial disease leading to irreversible blindness. Primary open-angle glaucoma (POAG) is the most common form and is associated with the elevation of intraocular pressure (IOP). Reduced aqueous humor (AH) outflow due to trabecular meshwork (TM) dysfunction is responsible for IOP elevation in POAG. Extracellular matrix (ECM) accumulation, actin cytoskeletal reorganization, and stiffening of the TM are associated with increased outflow resistance. Transforming growth factor (TGF) β2, a profibrotic cytokine, is known to play an important role in the development of ocular hypertension (OHT) in POAG. An appropriate mouse model is critical in understanding the underlying molecular mechanism of TGFβ2-induced OHT. To achieve this, TM can be targeted with recombinant viral vectors to express a gene of interest. Lentiviruses (LV) are known for their tropism towards TM with stable transgene expression and low immunogenicity. We, therefore, developed a novel mouse model of IOP elevation using LV gene transfer of active human TGFβ2 in the TM. We developed an LV vector-encoding active hTGFβ2^C226,228S under the control of a cytomegalovirus (CMV) promoter. Adult C57BL/6J mice were injected intravitreally with LV expressing null or hTGFβ2^C226,228S. We observed a significant increase in IOP 3 weeks post-injection compared to control eyes with an average delta change of 3.3 mmHg. IOP stayed elevated up to 7 weeks post-injection, which correlated with a significant drop in the AH outflow facility (40.36%). Increased expression of active TGFβ2 was observed in both AH and anterior segment samples of injected mice. The morphological assessment of the mouse TM region via hematoxylin and eosin (H&E) staining and direct ophthalmoscopy examination revealed no visible signs of inflammation or other ocular abnormalities in the injected eyes. Furthermore, transduction of primary human TM cells with LV_hTGFβ2^C226,228S exhibited alterations in actin cytoskeleton structures, including the formation of F-actin stress fibers and crossed-linked actin networks (CLANs), which are signature arrangements of actin cytoskeleton observed in the stiffer fibrotic-like TM. Our study demonstrated a mouse model of sustained IOP elevation via lentiviral gene delivery of active hTGFβ2^C226,228S that induces TM dysfunction and outflow resistance.     

高压差越孔密封技术

油田井下滑套类工具普遍存在高压差下越孔密封的技术难题.为了保证滑套能够反复越孔后仍能可靠密封,分析了压力平衡式、双密封圈组合式和异形密封圈3种越孔密封技术的结构和特点,并进行了试验研究.结果表明,这3种技术满足从一次性越孔密封到长期频繁越孔密封的不同要求,基本满足当前油田井下工具对高压差越孔密封的需要.其中压力平衡式越孔密封技术满足长期频繁越孔密封的要求,双密封圈组合式越孔密封技术满足密封次数少于5次的密封要求,而异形密封圈越孔密封技术适用于要求一次性高压差越孔密封的场合.     

减压阀静态密封的故障研究

本文概述了减压阀存在的静密封问题,分析了渗漏的机理,并提出了改进方案.通过提高密封表面的质量、增加O型圈的直径等措施,解决了渗漏问题.     

The effect of nitrogen and sulphur compounds on extreme pressure lubrication

This paper reports the synthesis of hydroxyheptadecyl-substituted-1,3,4-thiadiazoles and mercapto-1,2,4-triazoles and the evaluation of extreme pressure activity of their admixtures (0.5% and 1% w/ v) with a paraffinic oil in a four-ball test. Alloy steel bearing balls of 12.7 mm diameter were used as test specimens. All the additives exhibited good activity in reducing wear and increasing the values of mean Hertz load (MHL) and flash temperature parameter (FTP) as compared to the base fluid. The presence of p-methoxy- and p-chloro- groups in the thiadiazole and mercapto triazole rings has been found to enhance the activity of these additives. Scanning Auger Electron Spectroscopy surface studies were conducted to analyse the additive-metal interaction.     

三峡船闸阀门流激振动问题

三峡多级船闸中间级水头达４９．５ｍ。阀门的振动问题是需研究的难题之一。试验在１：２５的局部模型中按恒定与非恒定流进行试验研究，主要研究了作用于廊道边壁及阀门的压力脉动与流激阀门振动，阀门采用结构动态优化方案及其修正方案。采用自适应最小二乘格型算法估计了非恒定流脉动与振动的谱密度，探讨了阀门开启速度对脉动与振动的影响。给出了相应的统计特征．讨论了阀门与启闭杆的振动特征及高阻尼材料的抑振效果．分析了两个方案的振动情况及进一步改善的措施．     

溢流阀常见压力故障的原因及处理办法

分析了溢流阀常见压力故障的原因,并指出了各种故障的一些消除措施。