节能减排的环保型新工艺—化学镀镍-磷合金

本文介绍了化学镀镍技术的特点、分类、原理和镀液,也论述了发展前景.     

一种新型VHF/UHF双频宽带车载全向天线

提出了一种工作在VHF/UHF频段的双频段宽带垂直极化车载鞭状天线。天线在VHF中馈车载鞭状天线的下辐射体顶端加一个UHF频段8λ40 MHz/4同轴扼流套,将上辐射体分为三段并在段间串接两个λ840 MHz/2倒相线圈,在天线底部加同轴扼流圈,完成了一种VHF中馈鞭状天线与一副UHF三元串联馈电直线阵天线复合的新型VHF/UHF双频段超宽频带垂直极化车载全向天线。该天线在VHF频段(30 MHz~225 MHz),UHF频段(800 MHz~880 MHz)内均具有良好的辐射特性。增益在VHF频段为1.5~4.5 dB i,在UHF频段大于6 dB i。     

基于多特征提取和粒子群算法的图像分类

现有图像分类大都采用单一特征,不能利用多个特征之间性能互补优势,且将特征选择与分类器构造分割开来,影响图像分类的精度和分类器的泛化能力。针对以上问题提出一种基于混沌二进制粒子群算法(CBPSO)的特征选择和SVM参数同步优化方法,利用图像的综合特征,将特征选择和SVM分类器构造结合同步优化,仿真实验结果表明,该算法能同步找出最优的特征子集和合适的SVM参数,提高了图像分类精度和分类器泛化能力。     

任意层高密度互连板对位系统优化

随着电子产品的发展,电路板的设计朝着高密度化和薄型化的方向发展,任意层HDI板更多的应用于高端智能产品中。对于任意层HDI板,其对准度直接影响到任意层HDI板的良率及公司的市场竞争力。文章概述了现有的任意层HDI板对位系统,并对其对位系统进行了优化。     

贵州薏米致霉菌的分离鉴定

从贵州霉变薏米中分离纯化霉菌菌株,通过反接种验证其致霉性并进行生物学分类鉴定。采用点植法观察霉菌在PDA培养基上的生长性状、菌落特征,在形态学鉴定基础上,辅以ITS序列扩增等分子生物学方法将菌株拟鉴定到属种。最终筛出15株霉菌,并将其中8株致霉菌鉴定到种,分别为:C1米曲霉菌(Aspergillus oryzae)、C2黑曲霉菌(Aspergillus niger)、C3构巢曲霉菌(Aspergillus nidulans)、C4烟曲霉菌(Aspergillus fumigatus)、C5冠突曲霉菌(Aspergillus cristatus)、C6层生镰刀霉菌(Fusarium proliferatum)、C7木贼镰刀菌(Fusarium equiseti)和C8青霉菌(Penicillium aethiopicum)。从薏米中分离的霉菌对薏米有明显的致霉作用,推测其为薏米中主要致霉菌类型。本文为今后薏米储藏及防霉抑腐控制提供参考依据。      

烯啶虫胺等13种杀虫剂对褐飞虱的室内毒力测定与评价

采用稻苗浸渍法测定了烯啶虫胺等13种药剂对褐飞虱的室内毒力。结果表明,属于超高效的杀虫剂有烯啶虫胺、氟虫腈、噻嗪酮,对3龄若虫5d的LC50分别为0.13、0.19、0.29mg/L;属于高效的药剂有吡虫啉、氯噻啉、阿维菌素、甲维盐、高效氯氰菊酯、高效氯氟氰菊酯、二嗪磷,对3龄若虫的LC50介于1～10mg/L之间;属于有效的药剂有毒死蜱、异丙威、吡蚜酮,对3龄若虫5d的LC50分别为14.68、22.13、28.07mg/L。根据药剂类型、作用方式、作用机制等,建议防治稻飞虱时首选烯啶虫胺、噻嗪酮、吡蚜酮等药剂。     

A CAD-suitable approach for the analysis of nonuniform MMIC andMHMIC transmission lines

A new method of moment-based formulation for the solution of the telegraphist's equations in nonuniform transmission lines is presented. Entire domain basis functions that build in a frequency variation are used to cover wider frequency and physical dimension ranges. The results obtained using the proposed formulation are validated by comparison to those obtained by a CAD package and to measured data. Different nonuniform lines in microstrip and coplanar technologies on monolithic microwave/millimeter wave integrated circuit (MMIC) and miniaturized hybrid microwave integrated circuit (MHMIC) substrates are investigated with an application to the design a matched taper transition in a MMIC coplanar line     

韶冶铅锌烧结添加有机粘结剂工业试验研究

介绍了韶关冶炼厂烧结分厂在铅锌烧结混合料中添加WC有机粘结剂的工业试验情况，试验表明该粘结剂有利于强化烧结混合料的制粒，改善烧结状况，提高有效块率。     

Induction of platelet-activating factor in mice by intravenous administration of a neutral fraction of bakers' yeast mannan

A neutral subfraction of mannan of bakers' yeast (WNM) was found to show a lethal effect in mice when administered intravenously. Symptoms caused by intravenous (i.v.) administration of WNM resembled those resulting from the administration of platelet-activating factor (PAF). CV-3988 and ONO-6240, selective PAF antagonists, prevented hypotension and death caused by the administration of WNM or PAF. A β-adrenoceptor agonist was shown to prevent death caused by WNM, whereas propranolol increased the lethal activity of WNM. Intravenous administration of WNM into mice produced PAF in gall bladder fluid which was determined by platelet aggregation assay. The findings indicate that WNM is able to induce PAF in mice and that the resultant PAF may participate in the WNM-induced lethal activity observed in mice.