应用数字PWM器件SA4828的大功率直流电源

本文介绍一种智能型、高精度PWR控制器SA4828，其控制实行全数字化产生三相脉宽调制波形．本文采用此器件设计大功率直流电源应用于22KW直流电机测试，对感性负载表现出具有纹波小，响应迅速、硬件电路简洁、控制简单易于编写的优点。     

SO2转化温度异常情况分析

结合凤山实业总公司硫酸车间 SO2 转化系统的具体工艺流程 ,分析近几年转化系统出现温度不正常的原因 ,提出解决方法     

论GPS星座组成及若干抗AS方案

本文首先讨论GPS星座组成及美国的用政策，阐述了AS措施及其对GPS测量的影响。然后，对抗AS的若干方案进行介绍，分别对平方法、互相关法、码相关干法及P－W技术（Ashtech法）进行叙述和评论，指出它们的优缺点，评述它们在GPS技术发展过程所起的作用。最后，对GPS星座建成后的形势作了小结，并对当前我国GPS事业的有关问题提出四点建议。     

SA299钢冷脆行为的研究

某锅炉厂生产的锅炉汽包,在冬季制造过程中发生破裂,汽包材料为 SA299钢,对断口的初步分析发现为脆性解理断口,据此认为是冷脆破坏。本文依据冷脆特征温度 Tc 的概念对 SA299钢的冷脆行为进行了细致的分析。     

A decrease in the density of trapping centers in silicon oxide as a result of radiation-thermal treatment

The results of processing the experimental drain-gate characteristics of test MOS transistors after irradiation with fast electrons and subsequent heat treatment are reported. It is shown that the concentration of trapping centers in the oxide is lowered as a result of radiation-thermal treatment.     

P，Zr，B对定向凝固IN738合金组织和偏析的影响SCIEI

用不同凝固速度下定向凝固和定向凝固加快淬的方法研究了Ｐ，Ｚｒ，Ｂ对定向凝固ＩＮ７３８合金组织和偏析的影响发现随磷含量的增加，合金固液两相区宽度及温度区间显著增加；凝固前沿低熔点液相区增大；树枝晶组织发达，二次晶变细、变多；固液界面表面积增加。发现只加Ｐ与同时加Ｐ，Ｚｒ合金的溶质原子偏析规律有差异。Ｐ，Ｚｒ，Ｂ促进合金中（γ＋γ′）共晶形成，在其前沿有（γ＋硼化物）共晶析出。     

一种基于混合决策树的调度知识获取算法*

提出了一种基于混合决策树的调度知识获取算法。将模拟退火算法融入遗传算法中,作为一种具有自适应变概率的变异操作,构成一种混合优化方法。利用这种混合方法求解在不同调度目标下制造系统的最优特征子集,同时确定控制决策树规模的最优参数;使用决策树评价混合方法中染色体编码的适应度,在得到不同调度目标下的最优特征子集和最优决策树参数后,生成调度知识。仿真实验结果表明,该算法在性能上优于其他算法。     

Hormonal Responses to Susceptible,Intermediate, and Resistant Interactions in the Brassica napus–Leptosphaeria maculans Pathosystem

Hormone signaling plays a pivotal role in plant–microbe interactions. There are three major phytohormones in plant defense: salicylic acid (SA), jasmonic acid (JA), and ethylene (ET). The activation and trade-off of signaling between these three hormones likely determines the strength of plant defense in response to pathogens. Here, we describe the allocation of hormonal signaling in Brassica napus against the fungal pathogen Leptosphaeria maculans. Three B. napus genotypes (Westar, Surpass400, and 01-23-2-1) were inoculated with two L. maculans isolates (H75 8-1 and H77 7-2), subsequently exhibiting three levels of resistance: susceptible, intermediate, and resistant. Quantitative analyses suggest that the early activation of some SA-responsive genes, including WRKY70 and NPR1, contribute to an effective defense against L. maculans. The co-expression among factors responding to SA/ET/JA was also observed in the late stage of infection. The results of conjugated SA measurement also support that early SA activation plays a crucial role in durable resistance. Our results demonstrate the relationship between the onset patterns of certain hormone regulators and the effectiveness of the defense of B. napus against L. maculans.     

Gr（C）纤维增强镁基复合材料的界面结构

采用真空—压力浸渗工艺制备Ｇｒ（Ｃ）／Ｍｇ复合材料，Ｇｒ／Ｍｇ材料界面上无化学反应迹象，有析出物γ相（Ｍｇ１７Ａｌ１２），该析出物形状、大小与制备工艺条件，主要是纤维预制件温度有关。Ｃ／Ｍｇ复合材料界面Ａｌ含量较基体高出２倍多，文中分析了可能的原因