上海科技管理标准体系构建研究

为全面落实中央关于上海要加快向具有全球影响力的科技创新中心进军的新要求,进一步梳理和整合科技管理部门的工作思路和方法,提升标准化这一战略工具运用在科技管理和服务领域的效能,本文立足科技管理实务操作基础,结合标准化工作理念,构建科技管理和服务标准体系框架,为科技管理标准化建设提供可操作、可复制、可推广的技术支撑.     

Mn对22%Cr双相不锈钢700℃时效σ相及韧性的影响

利用光学显微镜(OM)、X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)结合析出动力学和冲击实验,研究了不同Mn含量(4.3%,6.9%,9.7%,质量分数,下同)对22%Cr节镍型双相不锈钢700℃时效析出相形成和韧性的影响。结果表明:随Mn含量由4.3%增加至9.7%,时效76h,析出形貌分别为铁素体/奥氏体(δ/γ)界面细小σ相颗粒析出和铁素体晶内σ相/二次奥氏体(γ_2)共析组织。Mn含量增加使Avrami指数n减小,反应常数B增大,Mn元素参与并促进σ相析出,σ相开始析出和完全析出时间均提前,开始析出与完全析出的时间间隔增大,析出速率降低。时效过程中δ相分解量低于1%(体积分数,下同)对冲击韧度影响不大,δ相分解量由1%增至5%会显著降低冲击韧度。Mn含量增加在时效前期对冲击韧度有利,时效中期则会促使δ相分解量更早超过1%,导致冲击韧度快速下降。     

密闭空间煤粉爆炸特性的实验研究

为了探明煤粉在密闭空间中的爆炸特性参数,利用20 L球形爆炸装置进行实验测试,实验研究了不同点火能量对煤粉爆炸行为的影响,对比CaCO_3和Al(OH)_3两种惰性介质的抑爆效果及惰性介质的抑爆效力随点火能量的变化规律进行了重点探讨。结果表明:随着点火能量的增加,爆炸压力随着煤粉浓度的增加呈现先上升后下降的趋势,在同一浓度下,粉尘最大爆炸压力和最大升压速率呈线性上升,在高浓度下,粉尘爆炸压力受点火能量的影响更显著;添加CaCO_3和Al(OH)_3能够降低煤粉的爆炸压力,相对于CaCO_3的物理抑爆而言,Al(OH)_3的物理-化学抑爆效果更佳;惰性介质抑爆效力随点火能量增加而下降,建议采用5~10 k J点火能量考察惰性介质对煤粉爆炸的抑制效力。     

自适应聚类Hough变换及地震断层检测

针对现有基于Hough变换的地震断层检测方法只能检测单个断层,不能准确检测多个断层的不足,提出了一种基于自适应聚类Hough变换的地震断层检测方法。该方法首先对预处理后的地震相干图像进行边缘检测并对边缘图像进行Hough变换以检测出边缘图像中的线段,然后根据倾斜角和位置信息对线段进行自适应聚类以获得更完整的线段,最后根据初始地震图像对完整线段中的各点进行调整以获得准确、平滑的断层。为验证该方法的有效性,在实际地震图像上进行了对比实验。实验结果表明,该方法可正确检测地震图像中的多个断层,正确率达到90%以上,与现有方法相比,峰值信噪比提高了约10%。     

液氢电容式密度传感器结构系数的不确定度评定

本文通过全面分析电容式密度传感器在液氢环境下结构系数的不确定度来源,并依据测量不确定度评定方法,得到了密度传感器结构系数的不确定度,为液氢密度测量结果的准确性提供了重要的评判依据。     

自制地温转接板引起测量误差偏移量的测定

本文通过实验方式,建立了测定自制地温转接板引起测量误差偏移量的测量模型,通过实验数据,计算出了自制地温转接板引起的被校传感器测量误差偏移量。     

激光与碳纤维相互作用的研究现状及发展趋势

由于高比强度、比模量等优良特性,碳纤维成为轻量化制造业的关键原材料之一,拥有广阔的发展潜力,然而高成本、低产率及工艺缺陷等弊端限制了其发展。激光技术的引入给碳纤维的加工制备提供了新的方向。概述了激光与碳纤维相互作用的最新研究进展,详细介绍了激光在加工、制备碳纤维各工艺过程中的作用机制,总结了激光技术在碳纤维复合材料生产加工领域的研究进展,最后分析和展望了激光辅助加工制备碳纤维过程目前仍存在的一些问题及可能的发展方向、应用前景。     

电容式电压互感器电磁单元异常发热故障分析

通过红外测温技术发现了一起110kV电容式电压互感器电磁单元异常发热的故障,在分析电容式电压互感器结构特点的基础上,结合高压试验、绝缘油色谱分析和解体检查获知了缺陷产生的原因,并提出了处理对策.     

A thermovisco-hyperelastic constitutive model of HTPB propellant with damage at intermediate strain rates

The uniaxial compressive tests at different temperatures (223–298 K) and strain rates (\(0.40\mbox{--}63~\mbox{s}^{-1}\)) are reported to study the properties of hydroxyl-terminated polybutadiene (HTPB) propellant at intermediate strain rates, using a new INSTRON testing machine. The experimental results indicate that the compressive properties (mechanical properties and damage) of HTPB propellant are remarkably affected by temperature and strain rate and display significant nonlinear material behaviors at large strains under all the test conditions. Continuously decreasing temperature and increasing strain rate, the characteristics of stress-strain curves and damage for HTPB propellant are more complex and are significantly different from that at room temperature or at lower strain rates. A new constitutive model was developed to describe the compressive behaviors of HTPB propellant at room temperature and intermediate strain rates by simply coupling the effect of strain rate into the conventional hyperelastic model. Based on the compressive behaviors of HTPB propellant and the nonlinear viscoelastic constitutive theories, a new thermovisco-hyperelastic constitutive model with damage was proposed to predict the stress responses of the propellant at low temperatures and intermediate strain rates. In this new model, the damage is related to the viscoelastic properties of the propellant. Meanwhile, the effect of temperature on the hyperelastic properties, viscoelastic properties and damage are all considered by the macroscopical method. The constitutive parameters in the proposed constitutive models were identified by the genetic algorithm (GA)-based optimization method. By comparing the predicted and experimental results, it can be found that the developed constitutive models can correctly describe the uniaxial compressive behaviors of HTPB propellant at intermediate strain rates and different temperatures.     

Nanoscale Lacing by Electrons

The ability to harness the optical or electrical properties of nanoscale particles depends on their assembly in terms of size and spatial characteristics which remains challenging due to lack of size focusing. Electrons provide a clean and focusing agent to initiate the assembly of nanoclusters or nanoparticles. Here an intriguing route is demonstrated to lace gold nanoclusters and nanoparticles in string assembly through electron‐initiated nucleation and aggregative growth of Au(I)‐thiolate motifs on a thin film substrate. This size‐focused assembly is demonstrated by controlling the electron dose under transmission electron microscopic imaging conditions. The Au(I)‐thiolate motifs, in combination with the molecularly mediated alignment, facilitate the interstring electrostatic and intrastring aurophilic interactions, which functions as a molecular template to aid electron‐initiated 1D lacing. The findings demonstrate a hierarchical route for the 1D assemblies with size and spatial tunable catalytic, optical, sensing, and diagnostic properties.