微型血液低温操作台的研制

阐述了微型血液低温操作台的研制背景、结构组成和性能特点;介绍了该机的设计研制情况。     

STXS135型旋塞阀本体的有限元分析

钻柱内防喷系统,就是预防及处理钻柱内井喷的配套系列产品。目前,针对内防喷系统中重要工具之一的旋塞阀的研究还很薄弱,因此,展开对旋塞阀的全面研究具有重要的理论意义和工程意义。旋塞阀本体的断裂问题,一直困扰着生产商和用户。针对这一问题,运用ANSYS软件,建立阀本体的有限元模型,分别对本体在拉、扭、内压等多种载荷下的本体强度详细分析,找出阀本体应力集中的主要原因,提出改进建议,这些研究工作将为旋塞阀的改进研制提供具有参考价值的理论依据。     

汽轮机负荷波动的原因分析及处理

通过对安泰发电厂7#汽轮机负荷摆动的分析和研究,总结了负荷波动对电网运行的弊端,提出了在负荷控制方式下,由于PID调节的作用,放大了汽轮机本身原因引起的负荷波动,并将将负荷控制的PID调节参数的积分时间适当调整后,负荷波动的幅度和频率大大减小。     

Seal-Inlet Disturbance Boundary Condition Correlations for Rotordynamics Models,Part 2: Assessment

Nearly all seal rotordynamics models were forced to assume that the seal-inlet swirl velocity disturbance boundary condition components (W _1C and W _1S ) are zero. The companion (Part 1) paper employs an extensive parametric study to develop a complete set of widely applicable seal-inlet disturbance boundary condition correlations that will alleviate this shortcoming. The benefits of using the new seal-inlet boundary condition correlations were assessed by implementing them into a CFD-perturbation model. Two widely different test cases were employed. Case 1 is a test of the correlations for large upstream chambers using a simple liquid smooth-plain seal, and Case 2 is a test for small, as well as radial injection, upstream chambers using a complicated gas labyrinth seal. For both cases, consistently improved agreement with measurements was obtained for the options with non-zero W _1C and W _1S compared to the option with W _1C = W _1S = 0. Specifically, the correlation set using the W _1C -profile option gave a clearly better prediction of the effective damping and the cross-coupled stiffness than did the set using the W _1C -bulk option for the higher spin speed case of the challenging gas labyrinth. For the smooth-plain liquid seal case, the correlations with the W _1C -profile and W _1C -bulk options gave nearly the same level of agreement with measurements.     

孔口坝段高温季节施工温控防裂研究

针对高温季节施工的孔口坝段孔口部位的牛腿混凝土最高温度超标以及牛腿与坝体主体混凝土温差过大的问题，以某拱坝孔口坝段为例，用三维有限元仿真分析方法对其进行了研究。结果表明：虽然牛腿部位最高温度严重超标，但应力并未超标，其最大应力发生在牛腿与坝体交界处；孔口顶板混凝土较底板和侧墙有较大开裂风险，其应力主要为横河向应力。因此，牛腿相对于大坝主体混凝土而言，温度控制标准可适当放宽；可通过加大顶板第一层混凝土的厚度、减小顶板上层混凝土厚度的方法，达到减小顶板横河向超标应力的目的。     

Synthesis of K6Ta10.8O30 nanowires by molten salt technique

The synthesis of single crystalline K₆Ta_10.8O₃₀ nanowires by molten salt method was reported for the first time. X-ray diffraction results indicated that the as-prepared products were pure phase K₆Ta_10.8O₃₀. Scanning electron microscopy and transmission electron microscopy results showed that the products consisted of wire-like nanostructures with 100-300 nm in diameter and several micrometers in length. High resolution electron microscopy and selected area electron diffraction results indicated that the K₆Ta_10.8O₃₀ nanowires were single crystalline with a growth direction of [0 0 1]. The ultraviolet-visible diffuse reflectance measurement showed that the band gap of the nanowires was about 4.1 eV. The effects of reaction temperature, time, and weight ratio of the precursor (mixture of K₂CO₃ and Ta₂O₅) to KCl salt on the morphology of the products were investigated.     

国内外绿色混凝土的发展动态及趋势

混凝土作为目前最大宗的土木建筑材料，在给社会带来良好的经济和社会效益，同时，也造成了严重的环境污染和生态破坏。本文分析探讨了国内外绿色混凝土发展状况及趋势。目前，开展绿色材料其相关理论的研究，从而实现材料科学与技术的持续发展，是历史发展的必然，也是材料科学的进步。在这种的背景条件下，具有环境协调和自然相适应的特性绿色混凝土应运而生。     

变向平面挤压对Al2O3／TiC双颗粒增强铝合金的影响

由原位反应得到的Al203/TiC双颗粒增强铝合金的性能与纯铝相比,其性能有所提高,但是,Al2O3/TiC双颗粒增强铝合金中所存在的长条状、硬而脆的Al3Ti,严重影响了铝合金的综合力学性能.利用变向平面挤压工艺对Al2O3/TiC双颗粒增强铝合金进行挤压,实现大变形,由此打碎了长条状Al3Ti,并且细化晶粒,从而提高了铝合金的综合机力学能.     

芯片级原子钟的气密性能分析

基于相干布居囚禁(CPT)原理芯片级原子钟(CSAC)原子腔体积小、采用微电子机械系统硅-玻璃键合工艺制造,其气密性是决定CSAC寿命的关键因素。本文提出了"多层缓冲原子腔"方案大幅度提高原子腔的气密性能,从而提高CPT CSAC的稳定性和寿命。建立了一个"毛细管等效气流模型"模拟多层缓冲原子腔的泄漏以分析原子腔的气密性能,应用Matlab仿真对比了单层密封、多层密封、添加保护腔等不同方式下气密性能的改善幅度。仿真结果验证了"多层缓冲原子腔"在提高CPT CSAC物理系统气密性能方面的可行性和有效性,为原子腔的设计提供指导。