电弧作用下 AgMeO 触头材料的物理冶金过程分析

本文分析了ＡｇＭｅＯ触头材料电弧侵蚀机理,对电弧的热力作用下触头材料的各种响应从物理冶金本质角度进行全面研究,在此基础上对ＡｇＭｅＯ触头材料组元和组织的优化设计作了完整的分析讨论,提出优化设计判据,最后提出能充分表征触头材料电气使用性能的材料物理性能参数。     

GB/T9945《热轧球扁钢》国家标准修订综述

简要介绍了热轧球扁钢的发展和技术要求,并研究了新标准的修订情况.     

出钢顺立案模型在宝钢炼钢厂的应用

从基本概念和程序的具体实现两方面,阐述了出钢顺立案模型的功能、特点以及在生产实践中所取得的效果。     

基于函数插值的柯氏质量流量计信号处理方法

对基于离散傅里叶变换(DFT)信号处理方式的柯氏质量流量计来说,影响其精度的关键问题是如何实现信号的整周期采样。提出了一种全新的方法,用采样率固定不变的采样数据,通过软件实时地确定信号的频率并且实现信号整周期重新采样。实验结果表明该方法在求取相位差时具有极高的精度。     

Antireflection and band gap extension effects of ZnO nanocrystalline films grown on ITO-coated glasses by low temperature process

Zinc oxide (ZnO) nanocrystalline films coated on indium tin oxides (ITO, 90:10 wt%) glasses were prepared by low temperature process. The thin films were composed of uniform nanoparticles with average diameter around 8.4 nm. All samples exhibited excellent optical antireflective phenomena, and the maximum transmission reached 92.8% for the sample spin coated at 1500 rpm at 453 nm, improved by 21.5%. The antireflective results were explained by the coherence theory. And the antireflective effects were induced by the ITO and ZnO films. The calculated thicknesses of the ZnO films agreed well with the experimental results. The theoretical calculated band gap from the average diameter of ZnO nanoparticles was also well consistent with the experimental ones obtained from the optical transmission spectra. This result was promising for applications in organic solar cells.     

Effect of doping cobalt on the micro-morphology and electrochemical properties of birnessite MnO2

Birnessite-type MnO₂ nanoparticles are synthesized by mixing KMnO₄ solution directly with ethylene glycol under ambient conditions. When cobalt exists in the solution, the micro-morphology of the products transforms from conglomeration to dispersive state. The result of transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) shows that the product is constructed with nanosphere in sizes of ca. 40 nm. These nanospheres are twisted by nanorods clusters. X-ray diffraction (XRD) pattern shows that the products are birnessite-type. The electrochemical properties of the prepared materials are studied using cyclic voltammetry (CV) and galvanostatic charge–discharge test in aqueous electrolyte. The product shows a very high specific capacity of 326.4 F g⁻¹. These results indicate that cobalt has great effects on the micro-morphology and electrochemical properties of manganese dioxide.     

Orbitrap高分辨质谱法快速筛查上海市流通环节蔬菜的农药残留

摘 要：目的 建立蔬菜农药多残留的筛查方法。方法 使用国家标准方法规定的QuEChERS法净化蔬菜样品,结合静电场轨道阱高分辨质谱法(orbitrap high resolution mass spectrometry)开展809种农药的快速非靶向筛查。结果 62种阳性农药的筛查限(screening detection limit, SDL)为0.005~0.010 mg/kg,定量限(limits of quantitation, LOQ)为0.01 mg/kg,线性范围为0.01~0.20 mg/kg,线性相关系数(r2)为0.9917~0.9997,日内精密度为2.77%~6.98% (n=5),日间精密度为4.82%~10.8% (n=5)。200批次样品共检出62种农药,不合格样品28批次,不合格率为14.0%。豇豆的不合格情况比较突出,不合格样品22批次,主要的不合格项是灭蝇胺和噻虫胺。结论 方法快速、准确、分析通量高,在无标准品的情况下实现了蔬菜中809种农药的非靶向快速筛查,可为蔬菜农药残留风险监测和质量控制提供支撑。     

Secreted HSP90α-LRP1 Signaling Promotes Tumor Metastasis and Chemoresistance in Pancreatic Cancer

The extracellular heat shock protein 90α (eHSP90α) has been reported to promote cancer cell motility. However, whether pancreatic cancer (PC) cells expressed membrane-bound or secreted HSP90α, as well as its underlying mechanism for PC progression, were still unclear. Our study demonstrated that the amounts of secreted HSP90α proteins were discrepant in multiple PC cells. In addition, highly invasive Capan-2 cells have a higher level of secreted HSP90α compared with those of less invasive PL45 cells. The conditioned medium of Capan-2 cells or recombinant HSP90α treatment stimulated the migration and invasion of PC cells, which could be prevented with a neutralizing anti-HSP90α antibody. Furthermore, secreted HSP90α promoted elements of epithelial–mesenchymal transition in PL45 cells, including increases in vimentin and Snail expressions, decreases in E-cadherin expression, and changes in cell shape towards a mesenchymal phenotype, but these phenomena were reversed by the anti-HSP90α antibody in Capan-2 cells. In addition, high levels of low-density lipoprotein receptor-related protein 1 (LRP1) were associated with worsened patient survival in pancreatic adenocarcinoma. We demonstrated LRP1 as a receptor of eHSP90α for its stimulatory role in metastasis, by activating the AKT pathway. In addition, silencing LRP1 enhanced the chemosensitivity to gemcitabine and doxorubicin in Capan-2 cells. Therefore, our study indicated that blocking secreted HSP90α underlies an aspect of metastasis and chemoresistance in PC.