An online test microstructure for thermal conductivity of surface-micromachined polysilicon thin films

An online test structure for measuring the thermal conductivity of surface micromachined polysilicon thin films is presented. In the structure, a pair of microstructures, i.e., a reference structure and a test structure, are used. The surface micromachined structures are heated electrically. Heat dissipation by convection, radiation, and heat transfer through the air gap and into the substrate is considered in an electrothermal model. The model is confirmed by ANSYS Software. In experiments, current-voltage measurements are only required, and all measurements can be carried out in free air. The surface-micromachined and p-doped polysilicon thin films with a sheet resistance 116.25 /spl Omega//sq. are measured to have a thermal conductivity 28.7 W/mK at 300 K.     

空气钻井条件下录井工艺方法与技术配套探讨

针对玉门青西油田深部高陡易斜地层存在可钻性差、自然造斜能力强，致使钻井周期长、成本高等特点，中油集团公司在吐哈油田设立钻探“工程探索井（L14井）”重大科研项目，试验研究空气钻井技术。根据L14井录井的实际情况，首先分析了空气钻井条件对录井带来的影响和常规的录井工艺方法和技术设备存在的不足；从5个方面介绍了录井工艺、技术方法的改进，探讨了空气钻井下的岩屑上返理论；介绍了配置装备的改进，分析了该井录井配套技术的应用效果。从该试验井的录井效果看，经改进的录井工艺、方法及装备基本上能满足空气钻井的需要，取全取准了地质及工程资料，为地质解释和评价提供了可靠依据；在工程监测、保障施工安全方面，工程录井也发挥了作用。但综合录井仪软件及后台评价程序还不适应空气钻井的需要，相关的理论研究及工艺完善还有许多课题尚需深入。     

K—调和映射的稳定性

本广继[8]后讨论了K—调和映射的稳定性。作为其应用最后得出了当N具常数截面曲率时,稳定2、3—调和映射的几个不存在定理。     

Experimental treatment of brain tumor cells using CD suicide gene

Pro-opiomelanocortin (POMC) is a polyhormone precursor produced predominantly in the pars distalis and pars intermedia of the pituitary gland where it undergoes tissue specific processing to produce a whole array of peptides. We have shown previously that peptides derived from the N-terminal region of POMC are involved in adrenal growth in rats. Using specific two site immunoradiometric assays we have found that the plasma of 17 week old fetal sheep contain a 50 fold excess of pro-gamma-MSH over ACTH. As term approached, the levels of pro-gamma-MSH fell and ACTH rose with evidence of fragmentation of pro-gamma-MSH, suggesting that these peptides act in concert in the development of the fetal adrenal cortex and also provide the necessary drive to bring about parturition. In an attempt to explore the pathophysiology of adrenal function we have cloned human POMC cDNA which led to the discovery of a 9bp addition/deletion mutation in the C-terminus of gamma 3-MSH between positions 67-73. Chinese hamster ovary cells (CHO) cells stably transfected with constructs containing the variant POMC cDNAs have shown a degree of partial processing. Work is currently underway to further investigate the effects of these mutations on the processing by the prohormone converting enzymes PC1 and PC2.     

An approximate expression of KImax for sphere/nozzle corner cracks

Based on the flat-nozzle model loaded by uniform biaxial tension, using the O-integral of the weight function method and introducing suitable free-surface correcting factors M₁, M₂, and a curvature correcting factor M_c, an approximate expression of K_Imax of sphere/nozzle circular corner cracks has been presented in this paper. The results so calculated are compared with those reported in the literatures and they show good agreement, the discrepancies being less than 10%. This shows that the approximate expression is effective and can be used in practice.     

南桐矿区龙潭煤系热演化及煤变质研究

川东地区二叠系龙潭煤系煤变质分带与褶皱关系密切，背斜部位变质浅，向斜部位变质深，且变化急剧．在对南桐矿区重点研究的基础上，用沉积速率比值法和沉积趋势法恢复了川东地区各时期的沉积厚度以及褶皱运动前后龙潭煤系的热演化史，并用Ｈｏｏｄ法确定了煤变质阶段，对川东的煤变质规律作出了合理的解释。     

三参量速度分析的迭代算法

采用预求倾角法进行三参量速度分析时，首先要确定地下界面的倾向和倾角。若没有准确速度，就求不准倾向和倾角，因此无法一次求得准确的结果。若采用迭代算法，则可以使三参量逐渐向精确值逼近。在地层倾角小于４５＾０的情况下，迭代是收敛的。在有噪音的情况下，噪音会使叠加道集上同相轴的时间发生变化，从而影响倾向的确定，因此在迭代的每一步，都必须估算倾向。理论实际资料的试算表明，采用迭代方法求取地下界面参数是切实可     

相干光纤通信系统中的偏振分集接收机的实验研究

本文讨论了相干光纤通信系统中的偏振分集接收机的基本原理,并在实验中首次实现了基于偏振分集的偏振不敏感接收。在调制信号为137.2MHz和146.0MHz正弦波的情况下,得到了很好的与信号偏振面无关的解调信号。这一结果正在应用于1.5μm波段140Mb/s FSK相干光纤通信系统之中。