Computation of Three-Dimensional Temperature Distribution and Thermal Analysis to Integrated Circuit Substrates

The exact three di me nsional temperatu re distribution and thermal analysiS to inte-grated circuit substrates have been presen ted by means of numerical method of a fin ite difference.Thismethed.which will overcome the di fficuItv of mathematical deduction mav be consltieredas an analytical way aided by com puters for thermal design of electron ic compon ents.     

A METHOD FOR MEASUREING LARGE OPTICAL PATH DIFFERENCE WITH THE HOLOGRAPHIC THREE WAVEFRONT INTERFEROMETER

The holographic three wavefront interferometer is used to measure large optical path difference. This method is proved to be practical through the measurement of the deformation -Voltage Curve of piezocrystal.     

Energy Assessement for Procedure Rationality of Recycling Materials from Wastes

The mathematical relationship for assessing total energy consumption within a material life cycle is presented in this paper. According to the relationship,the procedure rationality of recycling waste may be assessed quantitatively.     

Pricise Processing on 3D Surface with Laser

Studyin g the processin g tech n ology of mak in g holee by laser com plicated sur-face,and developing a CAD/CAM flexible manufacture system.     

Dark Interfere Fringes on Copying Hologram with White Light

The dark interfere fringes appearing on a copying hologram with white light are discussed. Which are caused by the minute distance between the original hologram and the coping holographic plate during the coping process. Two wave fronts of the virtue image and the real image are reconstructed from the original hologram and recorded on the coping holographic plate during the coping process. If the two holographic plates have a minute distance, there are two virtue images wave fronts are reconstructed from the coping hologram. These two virtual images wave front are the same but have a little spatial shift. The two shifted wave front will interfere and produce dark fringes on the hologram even with white light to illuminate the hologram. The methods to eliminate the dark interfere fringes also discussed.     

对三农问题和农村城市化问题的若干思考

中国是一个农业大国，农业经济状况在很大程度上决定了整体经济的发展态势。对中国当前农业发展现状中的主要问题进行分析，认为只有积极进行城市化建设才能解决中国农业发展的根本问题，同时，就中国城市化的路径选择与城市化发展的中短期目标提出自己的看法。     

旋耕刀正切刃设计方法的研究

论述了旋耕刀正切刃的设计，推导了正切丸弯折方程，讨论了正切刃滑切角的计算，应用偏心圆方法设计了正切刃，并对有关参数进行了分析。     

土壤机械阻力的连续测定及空间变异结构分析

设计了一个土壤机械阻力连续测定系统。利用试验所得数据,初步探讨了土壤机械阻力的空间变异性和分形特征。结果表明,土壤机械阻力表现出空间变异结构,在一定范围内存在空间相关现象,用半方差法和功率谱密度法计算出土壤机械阻力的分维值分别为1.79~1.91和2.12~2.30。     

机组段运转特性曲线的绘制及其应用

机组段是水电站运行的基本单元。从运行的需要出发,采用机组段运转特性曲线来指导运行,比用水轮机运转特性曲线方便。本文介绍机组段运转特性曲线的绘制方法及其在水电站运行中的作用。     

深松耕作对土壤水分物理特性及作物生长的影响

通过对两种土壤深松耕作及传统耕作的对比试验研究，表明深松耕作可有效打破犁底层，使土壤容重降低0．1t／m3，孔隙度增大3．6％～4．0％，110cm上体内可多蓄纳雨水15．2～17．5mm。对粘壤上深松耕作可提高土壤的入渗能力，而对粉砂壤土则没有提高。同传统耕作相比，深松耕作可明显提高夏玉米的根长、根深及根量，为有效利用土壤水分及养分创造了条件．可使夏玉米产量提高5．7％～11．3％。