高Nb X80管线钢析出物及析出行为研究

以高Nb X80管线钢为研究对象,分析了析出粒子的大小、形貌、成分及其析出行为。研究结果表明,高Nb X80管线钢中除了圆形的NbC和方形的TiN析出粒子外,还存在形貌不规则且尺寸较大的Nb的析出物,后者降低了钢的性能和Nb的利用。降低N含量并进行Ti/N比值的调整,可以提高钢中固溶Nb的含量,充分发挥高Nb的作用,才能生产出综合性能最优、成本控制较低的高Nb X80管线钢。     

Multivariate Sampling Plans in Quality Control: A Numerical Example

This paper presents an attributes acceptance sampling procedure where several measurements are available on each item in the sample set. It is thus especially relevant when these measurements on each item are correlated; usual procedures cannot account for correlations. Correlations are considered by using a classification rule to assign the attribute good or bad to each item in the sample set; this rule uses the non-parametric k-nearest neighbor estimator. The test by which the lot is accepted or rejected, based on the outcomes of the rule for all items in the sample set, is the same as in acceptance sampling by attributes. The estimator has only to be compensated for errors at the level of the classification rule. This procedure has been used since 1978 in industry, thanks to a software package which implements it. Applications have mostly been to process quality control and mechanical parts. The procedure has the interesting feature of applying under relaxed assumptions on the distributions of the measurements on the bad items. The numerical example covers such a case. Because the classification rule operates individually on each sample item, nothing is changed in the definitions of the acceptable quality level and the limiting quality level. They apply to the whole lot. This is true because the multivariate measurements on each item are aggregated into a binary attribute on each item, as in classical sampling by attributes.     

Optimization for microbial degradation of petroleum hydrocarbon (TPH) by Enterobacter sp. S-1 using response surface methodology

In this research, the response surface method designed by Box-Behnken was used to study the effect of temperature, pH value and TPH concentration on the biodegradation of Enterobacter sp. S-1contaminated soil. The value of determination coefficient (R²=0.9565) by analysis of variance (ANOVA) indicated a satisfactory agreement between the quadratic model and the experimental data. It was found that TPH degradation rate was more significantly affected (P?<?0.0006) by temperature compared with other two parameters. In the temperature of 30?°C, pH value of 7.14 and TPH concentration was 4.83?g/L, the best degradation rate was 81.63%.     

欠压实地层条件下高压油气层控制方法探讨

欠压实地层、异常地层压力和高压油气层在成因上存在伴生关系,正是这种伴生关系使得三者在空间组合上具有一定的复杂性。这种复杂性导致钻井出现异常工况,同时绐与欠压襄地层有关的高压油气层的控制带来了很大困难。基于三者戒因上的关联性与空间组合上的研究．通过多年现场钻探实例积累分析,在卡好欠压实地层的基础上,总结出“重预测、抓打开、跟上返、抢返出、盯后效”的高压油气层控制方法,遵循这一方法在实际应用中收到了理想效果。     

一种基于LSH的时间子序列匹配查询算法

提出了一种基于LSH（locality sensitive hashing,局部敏感散列）算法处理时间子序列匹配问题的方法LSHSM。不同于FRM和DualMatch方法,该方法不需要对时间序列做DFT、DWT等特征变换,而是直接把序列看成高维数据点,利用LSH能处理高维数据的特性来查找相似时间子序列。实验采用3种不同的时间序列数据集,通过与线性扫描算法比较,验证了算法的有效性,性能有很大的提高。     

五极彩色荧光象素管及其电视图像显示

本文给出了五极彩色荧光象素管的基本结构及工作原理，基于发光亮度和工作电压之间的关系，讨论了它的周边电路的配置方法及彩色电视图像显示的驱动方案。最后介绍了１．６ｍ２彩色图像显示系统样机，其垂直扫描采用双栅组合译码方式，因而扫描驱动器由Ｎ个减少到Ｎ／１６＋１６个。     

应用于大功率MMIC开关的AlGaN背势垒GaN HEMT

报道了应用于大功率开关的AlGaN背势垒0.25μm GaN HEMT。通过引入AlGaN背势垒,MOCVD淀积在3英寸SiC衬底上的AlGaN/GaN异质结材料缓冲层的击穿电压获得了大幅度的提升,相比于普通GaN缓冲层和掺Fe GaN缓冲层击穿电压提升幅度分别为4倍和2倍。采用具有AlGaN背势垒AlGaN/GaN 外延材料研制的GaN HEMT开关管在源漏间距为2μm、2.5μm、3μm、3.5μm和4μm时,估算得到的关态功率承受能力分别为25.0W、46.2W、64.0W、79.2W和88.4W。基于源漏间距为2.5μm的GaN HEMT开关管设计了DC-12GHz的单刀双掷MMIC开关。该开关采用了反射式串-并-并结构,整个带内插入损耗最大1.0dB、隔离度最小30dB,10GHz下连续波测试得到其功率承受能力达44.1dBm。     

Urchin‐Like CoSe2 as a High‐Performance Anode Material for Sodium‐Ion Batteries

Urchin‐like CoSe₂ assembled by nanorods has been synthesized via simple solvothermal route and has been first applied as an anode material for sodium‐ion batteries (SIBs) with ether‐based electrolytes. The CoSe₂ delivers excellent sodiation and desodiation properties when using 1 m NaCF₃SO₃ in diethyleneglycol dimethylether as an electrolyte and cycling between 0.5 and 3.0 V. A high discharge capacity of 0.410 Ah g^?1 is obtained at 1 A g^?1 after 1800 cycles, corresponding to a capacity retention of 98.6% calculated from the 30th cycle. Even at an ultrahigh rate of 50 A g^?1, the capacity still maintains 0.097 Ah g^?1. The reaction mechanism of the as‐prepared CoSe₂ is also investigated. The results demonstrate that at discharged 1.56 V, insertion reaction occurs, while two conversion reactions take place at the second and third plateaus around 0.98 and 0.65 V. During the charge process, Co first reacts with Na₂Se to form Na_xCoSe₂ and then turns back to CoSe₂. In addition to Na/CoSe₂ half cells, Na₃V₂(PO₄)₃/CoSe₂ full cell with excessive amount of Na₃V₂(PO₄)₃ has been studied. The full cell exhibits a reversible capacity of 0.380 Ah g^?1. This work definitely enriches the possibilities for anode materials for SIBs with high performance.     

A multistrip moment method technique and its application to thepost problem in a circular waveguide

A moment method technique for solving obstacle problems in a waveguide is presented. Instead of using a multifilament current representation, which leads to a slowly converging series, a multistrip representation of the current is proposed. In the procedure, the matrix elements are determined by a series involving integrals of mode functions over the strips and the convergence is improved. The true currents on obstacle surfaces are replaced by equivalent planar currents in a number of waveguide cross sections inside the obstacle. The technique is applied to a pair of metallic posts in the TE₁₁-mode circular waveguide. Numerical results are compared with experimental data