印制板阻焊塞孔加工技术实验研究

结合电路板阻焊塞孔工艺技术产品批产化,根据生产线现有设备的实际情况,解决阻焊塞孔印制板加工过程所遇到由于过孔阻焊塞孔不良（空洞及露铜等）而导致锡珠入孔,造成的短路异常风险隐患等各种工艺难题。采用此种工艺制作技术方法均可实现阻焊塞孔印制板产品的批量在线的加工。     

浅谈防焊显影不净

针对防焊出现的显影不净问题,通过实际的生产跟进分析验证,找出造成显影不净的主要因素：无尘房的温湿度、油墨本身的性能、油墨在产线（开油到显影的停放时间）。为解决此类问题提供思路。     

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目前的钻井基本上处于地面开环控制状态，它的频繁起下钻使钻井效率降低、成本提高，甚至难以实现设计的井眼轨迹。随着钻井的位移和井深不断增加，能够解决上述问题的井眼轨迹闭环控制已成为钻井行业的前沿课题。可控偏心器是结合了微电子、信息、液压、控制等技术开发的一种智能导向工具。通过它构成的井眼轨迹闭环控制系统能够实现井眼轨迹的自动控制，从而提高井眼轨迹控制精度，降低钻井成本。为此，文章根据可控偏心器的导向机理，提出了带可控偏心器的井眼轨迹闭环控制系统及控制策略；探讨了可控偏心器冀片缸压合矢量的闭环控制方法，通过仿其实验验证了其可行性，对可控偏心器的现场应用具有重要的指导意义。     

Effect of a magnetic field on the conduction mechanism in Silicon PN junctions

The influence of a weak magnetic field on the electric current across silicon P⁺N junctions has been studied. The theoretical analysis considers two types of diodes: diodes with short base and diodes with long base and the magnetic field is assumed to be perpendicular to the direction of the electric current across the junction. The results show that the variation of the current is directly related to the variation of the hole diffusion coefficient, which is then calculated in the approximation of a P-type silicon material. The relative variation of the diffusion coefficient was found B² dependent. Experimental investigations have then been carried out in order to validate the theoretical calculations. The experimental results were in good agreement with the theoretical development when taking into account the two types of holes in the diffusion mechanism in silicon.     

调整井钻井过程中的出水问题与处理

为了解决断块油田开发中、后期由于地质情况复杂、注采不平衡引起的新井钻井井涌、漏失问题，在选定的平衡井下液柱压力、相邻注水井停注泄压的适当压井工艺条件下，对老区调整井钻井过程中的出水外溢、井漏等复杂问题进行了调查分析，并结合实例加以佐证，探讨了油田注水开发中由于各种干扰引起的压力异常，对处理技术措施和效果进行了评价。压力异常是调整井钻井井源、井漏的主要原因。     

汾河二库枢纽大坝帷幕灌浆及其效果分析

汾河二库大坝坝基节理发育,断层、破碎带多,岩溶较为发育。大坝帷幕灌浆主要采用小口径钻孔,孔口封闭,自上而下分段施工,孔内循环的灌浆方案,钻孔保证孔向准确,偏差不超过规范规定的值,在灌浆之前进行钻孔冲洗和压水试验,灌浆自上而下分段进行,每段5m ,浆液由稀至浓。检查钻孔压水试验及单位耗灰量分析,灌浆达到设计要求。该灌浆方案在汾河二库工程中是成功的     

Comparison of Electronic Transport Measurements on Organic Molecules

We compile, compare, and discuss experimental results on low‐bias, room‐temperature currents through organic molecules obtained in different electrode–molecule–electrode test‐beds. Currents are normalized to single‐molecule values for comparison and are quoted at 0.2 and 0.5 V junction bias. Emphasis is on currents through saturated alkane chains where many comparable measurements have been reported, but comparison to conjugated molecules is also made. We discuss factors that affect the magnitude of the measured current, such as tunneling attenuation factor, molecular energy gap and conformation, molecule/electrode contacts, and electrode material.     

新型抗盐膏钻井液体系在堂古5井的应用

堂古5井是在山东聊城境内渤海湾台坳临清块坳堂邑构造带南堂邑背斜上的一口重点区域探井,设计井深4300m。该井主要目的层奥陶系峰峰-冶里组是724m长的石膏层和石膏夹层,所以井壁稳定问题是南堂邑构造安全快速钻井的关键。针对堂古5井的地质情况,研制出了以抗盐膏聚合物KC-8,抗钙磺化处理剂SMP、SMC、护胶剂CMC为主的新型抗盐膏钻井液体系。经现场应用表明,该体系舱有效地解决堂古5井四开井段盐膏层易溶解、易垮塌造成的井壁不稳定问题,满足了堂古5井的钻井施工要求。     

有孤立热节的小铸件缩孔解决方法

对有孤立热节的小铸件产生缩孔的原因进行了分析，通过提高型壳温度和浇注温度可减少和消除缩孔的产生，针对不同铸件采用不用的组树方案，以及增设铸造圆角均可有效地减少缩孔。