液晶显示器和液晶电视

本文介绍了液晶显示器的基本结构和寻址方式。详细讨论了有源矩阵液晶显示屏的基本原理和特点,并对由MOS管寻址的液晶显示屏以及由其组成的液晶电视进行了分析和研究。     

齿厚极限偏差与公法线极限偏差的图解法

《渐开线圆柱齿轮精度》(JB179-83)对齿轮副侧隙作了新规定,采用“基中心距”制,即固定中心距极限偏差,改变齿厚,以满足不同的侧隙要求,因此,中心距和齿厚极限偏差为其主要参数。 齿厚偏差△E,是在分度圆柱面上,齿厚的实际值S′与公称值S之差,即: △E=S′-S按照定义,齿厚是以分度圆弧长计值(弧齿厚),但在实际检测时,是以顶圆定位,测得分度圆弦齿厚,如图1所示,其合格性条件为: E_(SS)≥△E_S≥E_(Si)(△E_S=S′- S) 式中:E_(ss)-齿厚上极限偏差; E_(si)-齿厚下极限偏差; △E_s-齿厚偏差;S′-分度圆实际弦齿厚;     

超声波破碎运动发酵单胞菌方法初探

用国产CPs——1A超声波粉碎机破碎运动发酵单胞菌的菌体细胞,探讨了不同破碎条件对细胞破碎程度的影响。     

以种胚为外植体的西伯利亚杏器官分化的研究

本文研究了以种胚为外植体西伯利亚杏器官分化各阶段的培养条件以及影响因素,并在愈伤组织上诱导出幼苗。为山杏的进一步研究和利用提供了方法和材料。     

Mixed Model for Silt-Laden Solid-Liquid Two-Phase Flows

The kinetic theory of molecular gases was used to derive the governing equations for dense solid-liquid two-phase flows from a microscopic flow characteristics viewpoint by multiplying the Boltzmann equation for each phase by property parameters and integrating over the velocity space. The particle collision term was derived from microscopic terms by comparison with dilute two-phase flow but with consideration of the collisions between particles for dense two-phase flow conditions and by assuming that the particle-phase velocity distribution obeys the Maxwell equations. Appropriate terms from the dilute two-phase governing equations were combined with the dense particle collision term to develop the governing equations for dense solid-liquid turbulent flows. The SIMPLEC algorithm and a staggered grid system were used to solve the discretized two-phase governing equations with a Reynolds averaged turbulence model. Dense solid-liquid turbulent two-phase flows were simulated for flow in a duct. The simulation results agree well with experimental data.     

Microstructure of ultrahigh carbon martensite

Recent experimental investigations suggest that the martensite formed by quenching carbon steels(0.2–1.26 mass %C) are composed of twins and nanoscale ω particles in twin boundaries, rather than carbon supersaturated uniform solutions. In order to probe the microstructure of the martensite with ultrahigh carbon content, a novel strategy is employed in the present study to obtain ultrahigh carbon martensite(approximate2.1 mass %C) by quenching ductile cast iron. The microstructure of the martensite was intensively characterized by high resolution transmitting electron microscopy. It is indicated that the microstructure of the ultrahigh carbon martensites is composed of ultrafine {112} 111 -type twins and high-density nano-scaled ω particles embedded in twin boundaries. These ω nanoparticles in twin boundaries could remarkably impede the deformation of the movement of the nanotwins in martensites, leading to poor ductility and strength of the quenched ductile cast iron. These findings not only reveal the substructures of ultrahigh carbon martensite, but also enhance the understanding of the mechanical behavior of high carbon steels and ductile cast irons.     

公历纪年与北京建都纪念

1986年10月,苏州举行了建城2500周年纪念活动。据考证,这座文化名城始建于春秋时代吴王阖闾元年,即公元前514年。由此容易推断,苏州建城2500周年其实应为1987年,而非1986年。也就是说,当初举行建城2500周年纪念活动,实在是超前了1年。这一年之误,系未计及“公历纪年中不存在公元0年”这一事实所致。始建于公元前514年的苏州城,到公元前1年为建城513年;再下一年,即公元1年,则为建城514年。据此易知,1986年乃是苏州建城2499周年。现在再说北京建都问题。近年来史家考证,周武王伐纣后分封的燕国于公元前1045年在今北京房山县琉璃河畔建都。此说有出土青铜铭文为证。近悉北京市有关部门为此拟于1995年举行北京建都3040周年的纪念活动。笔者久居北京,闻之甚觉欣然。但与此同时,亦深感实有必要及时提请有关方面注意：倘若果真如此纪念的话,则势将重蹈苏州建城纪念超前1年之误。因为,1995年其实是北建都3039周年,纪念建都3040周年的活动应推至1996年举行。这样说的原因,还是由于“公历纪年中不存在公元0年”。若以“公元前1045年燕国始建其都于今北京房山县琉璃河畔”作为北京建都之始,则公元前1年为北京建都1044周年,公元1年为其建都1045周年,进而易知,公元1996年才是北京建都3040周年。这区区一年之差,常常为人们所忽视。但逢到像北京建都纪念这样的大事,却务必慎之又慎啊。     

武昌郊区蔬菜害虫(鳞翅目)寄生六索线虫Hexamermis spp.的种类及分布

据初步调查,武昌郊区被六索线虫Hexamermis spp.寄生的蔬菜害虫有:小地老彪Agrotis ypsilon、菜粉蝶Pieris rapae、甜菜夜蛾Laphygma exigua、斜纹夜蛾Prodenia Litura和烟夜蛾Heliotkis assulta;前四种的寄生率分别为41.4%,34.0%,10.8%,5.7%;经鉴定,六索线虫共有5种,即:白色六索线虫中华亚种H.albicans sinensis、菜粉蝶六索线虫H.pieris、地老虎六索线虫H.agrotis、太湖六索线虫H.taihuensis,另一种种名待定Hexamermis sp.,前者为优势种,依次两种为常见种,后者为稀见种,六索线虫与害虫幼虫间无寄生专一性,可交叉感染。     

杂多酸催化合成丙烯酸酯的研究

本文研究了杂多酸催化合成丙烯酸酯的工艺条件及其对丙烯酸酯的阻聚作用。