诱发IAF夹杂物与原晶粒的尺寸匹配关系

 对于氧化物冶金船板钢而言,细小弥散分布的夹杂物会对其原始晶粒产生钉扎和诱发晶内铁素体的双重作用,且研究发现诱发晶内铁素体的夹杂物尺寸与原始奥氏体晶粒尺寸存在一定的匹配关系。围绕上述问题进行了系统的分析研究和数据统计,结果表明,不同晶粒尺寸下,诱发晶内铁素体的夹杂物尺寸与原奥氏体晶粒度间存在近似线性关系,且随着奥氏体晶粒度的增大,诱发晶内铁素体的夹杂物尺寸则相应减小。     

Computational study on influence of RF shielding box on inductance of coil

Despite the fact that a radio frequency (RF) shielding box affects a coil inductance used in matching network, RF engineers have used a coil inductance measured in open space on designing matching networks since it is difficult to precisely measure the coil inductance within the RF shielding box. In this work, we investigate the influences of the RF shielding box on the coil inductance via a 3D full electromagnetic wave simulation. Simulation results shows that the coil inductance decreases from -6.0% to -11.9% compared with its ideal inductance depending on coil positions within the RF shielding box. Both inductive and capacitive coupling between the coil and surfaces of the RF shielding box contribute to the reduction of the coil inductance. We expect that these results would be useful for those who design RF matching networks.     

基于“炉机对应”原则的连浇优化方案

国内某炼钢厂为保证浇注周期较短的2号连铸机连浇,多座转炉需同时向该连铸机供应钢水,导致炉 机对应关系不明确,生产组织难度较大。通过对该厂炼钢 连铸过程的工序作业周期与生产运行模式进行解析,在保证连铸机连浇的基础上,探究合理的炉 机对应关系,改善该厂的生产顺行。结果表明,在“一一对应”运行模式下,2号连铸机最大连浇炉数仅为6炉;而在“定炉对定机”运行模式下,若适时接受3号转炉冶炼的钢水,2号连铸机最大连浇炉数可延长至19炉。在此基础上,通过对连铸机“柔性”的优化和钢水供应的合理调配,2号连铸机可满足实际生产的连浇要求。此外,运用“炉→机”匹配度进行评价,计算结果表明优化后的炉 机对应关系得到显著改善。     

从引进610ERW机组透视东西方技术价值观念的差异

我国引进的610ERW机组大多来自欧美和日本等国,其工艺参数和设备结构有所不同,例如成型机、高频焊机、中频正火装置、连续与非连续生产方式、全线设备(入口段、成形段和精整段)组成的匹配模式以及设备国产化的程度等.通过对东西方有关高频电阻焊技术价值观念差异的分析,总结我国引进610ERW机组的经验,为今后企业引进、消化引进和技术创新提供参考.     

聚合物抗氧剂结构与抗氧性能关系

介绍了胺类、酚类、亚磷酸酯类、硫类及天然抗氧剂的结构与抗氧性能的关系,及各个官能团在抗氧剂中的作用,并展望了国内外抗氧剂的发展。     

一种左、右手材料结构吸波体吸波特性研究

提出了一种空气／左手介质／右手介质／金属的双层吸波体结构,引入左手材料做匹配层,利用传输线模型与计算机仿真方法考察了左手材料各个参数变化对吸波性能的影响．仿真结果表明：左手材料各个参数适当的选择对提高吸收率起着重要作用;在给定参量条件下,左手材料层厚度最佳值为1mm;随着左手材料层厚度的变化,吸波体的吸收峰值将降低且峰值对应的频率也将分别向低频或高频移动．     

Using recursion to compute the inverse of the genomic relationship matrix

Computing the inverse of the genomic relationship matrix using recursion was investigated. A traditional algorithm to invert the numerator relationship matrix is based on the observation that the conditional expectation for an additive effect of 1 animal given the effects of all other animals depends on the effects of its sire and dam only, each with a coefficient of 0.5. With genomic relationships, such an expectation depends on all other genotyped animals, and the coefficients do not have any set value. For each animal, the coefficients plus the conditional variance can be called a genomic recursion. If such recursions are known, the mixed model equations can be solved without explicitly creating the inverse of the genomic relationship matrix. Several algorithms were developed to create genomic recursions. In an algorithm with sequential updates, genomic recursions are created animal by animal. That algorithm can also be used to update a known inverse of a genomic relationship matrix for additional genotypes. In an algorithm with forward updates, a newly computed recursion is immediately applied to update recursions for remaining animals. The computing costs for both algorithms depend on the sparsity pattern of the genomic recursions, but are lower or equal than for regular inversion. An algorithm for proven and young animals assumes that the genomic recursions for young animals contain coefficients only for proven animals. Such an algorithm generates exact genomic EBV in genomic BLUP and is an approximation in single-step genomic BLUP. That algorithm has a cubic cost for the number of proven animals and a linear cost for the number of young animals. The genomic recursions can provide new insight into genomic evaluation and possibly reduce costs of genetic predictions with extremely large numbers of genotypes.     

中美新型大国关系的提出与构建

奥巴马执政后,中美关系一度出现利好局势,但始终处于起伏不定的状态,紧张态势更是频频出现,严重影响了两国关系的正常发展。为了改善并发展中美关系,共建新时期的国际秩序,中国领导人高瞻远瞩,提出了建立中美新型大国关系的宏大构想。当前,中美新型大国关系的构建之路面临着巨大的挑战,如何从战略角度出发推动和发展两国新型大国关系,成为至关重要的问题。     

Carotenoids are Effective Inhibitors of in vitro Hemolysis of Human Erythrocytes,as Determined by a Practical and Optimized Cellular Antioxidant Assay

β‐Carotene, zeaxanthin, lutein, β‐cryptoxanthin, and lycopene are liposoluble pigments widely distributed in vegetables and fruits and, after ingestion, these compounds are usually detected in human blood plasma. In this study, we evaluated their potential to inhibit hemolysis of human erythrocytes, as mediated by the toxicity of peroxyl radicals (ROO?). Thus, 2,2′‐azobis (2‐methylpropionamidine) dihydrochloride (AAPH) was used as ROO? generator and the hemolysis assay was carried out in experimental conditions optimized by response surface methodology, and successfully adapted to microplate assay. The optimized conditions were verified at 30 × 10⁶ cells/mL, 17 mM of AAPH for 3 h, at which 48 ± 5% of hemolysis was achieved in freshly isolated erythrocytes. Among the tested carotenoids, lycopene (IC₅₀ = 0.24 ± 0.05 μM) was the most efficient to prevent the hemolysis, followed by β‐carotene (0.32 ± 0.02 μM), lutein (0.38 ± 0.02 μM), and zeaxanthin (0.43 ± 0.02 μM). These carotenoids were at least 5 times more effective than quercetin, trolox, and ascorbic acid (positive controls). β‐Cryptoxanthin did not present any erythroprotective effect, but rather induced a hemolytic effect at the highest tested concentration (3 μM). These results suggest that selected carotenoids may have potential to act as important erythroprotective agents by preventing ROO?‐induced toxicity in human erythrocytes.     

基于CO2激光的AgGaS2差频产生太赫兹波的数值分析

采用中红外CO₂激光差频产生太赫兹波是提高转换效率和输出功率的一种有效方法。根据差频过程中的三波互作用对AgGaS₂晶体进行了理论分析,数值模拟了oeo类和oee类两种匹配条件下差频产生太赫兹波的角度调谐曲线,并计算了光波在晶体中的走离角和允许参量。另外,还考虑了晶体的有效非线性系数和理论功率转换效率。研究结果表明,AgGaS₂晶体适用于中红外CO₂激光差频产生可广泛调谐的太赫兹波。