声光调Q全固态绿激光器中的双控驱动电路

研制出新型双控声光驱动器,能够同步控制声光Q开关和LD抽运源的工作时间,并具有10W以上的输出功率及15ns(1个声光驱动射频周期)内的调Q开关时间.应用该驱动器的全固态调Q绿光激光器的能耗减少50%以上,温升减少10℃以上,热稳定时间减少到22%,用1W的LD抽运,得到了脉宽14.5ns、峰值功率lkW的无寄生脉冲绿激光输出.     

四川盆地天然气录井特点与识别方法

四川盆地天然气录井具有隐蔽性强的特点，使过平衡钻井中不易识别、发现气层，易发生井漏与井喷，对产层的解释评价也有一定难度。为此，总结和归纳了四川盆地天然气录井特点与识别方法：在常规钻井条件下的天然气识别方法主要靠气测，辅之以钻时、岩屑录井技术，并及时进行小层对比，以确保发现储层。欠平衡钻井的天然气识别方法主要有4种：①气测录井仍是判断油气显示的主要依据；②精细分析钻时，从微弱变化中明查储层；③正确录取和鉴别岩屑是及时发现储层的关键；④及时观察出口工程参数及火焰的变化，是发现气层的佐证。天然气录井中的井控工作包括：搞好地质预报预告，及时发现油气水漏显示与预警，加强坐岗记录以保证钻井安全。     

A method for fast simulation of multiple catastrophic faults in analogue circuits

The paper offers an efficient method for simulation of multiple catastrophic faults in linear AC circuits. The faulty elements are either open circuits or short circuits. The method exploits the well‐known Householder formula in matrix theory to find the node voltages deviations due to the perturbations of some circuit elements. The main achievement of the paper is a systematic method for performing the simulation of all combinations of the multiple catastrophic faults. The method includes two new procedures enabling us to find very efficiently the node impedance matrix of the nominal circuit and inverses of some matrices corresponding to different fault combinations. The procedures are the crucial point of this approach and make it very efficient. Consequently, the amount of the computing power needed to carry out all the simulations is significantly reduced. Numerical examples illustrating the proposed approach are provided. Copyright © 2008 John Wiley & Sons, Ltd.     

川西地区钻井管理模式与监督办法

提出了适合川西地区天然气勘探开发钻井特点的生产管理模式和监督办法。探讨了该地区优化钻井设计与施工方面的问题。实践证明，川西地区科学钻井的尝试是成功的，对进一步提高钻井水平和经济效益将产生积极作用。     

发展中的越南石油工业

2009年10月18日,CCOP第46届年会在越南头顿(VUNG TAU)召开。会议期间,主办国越南向CCOP成员国展示了前所未有的热情和活力,也使各国参会代表充分了解了不一样的越南和发展中的越南石油工业。近年来,越南的石油工业发展迅速,国际合作项目也接踵而至,在东南亚的发展速度中名列前茅。伴随着越南与我国双方领海争议,越南正日益成为我国在东南亚市场的潜在竞争对手。     

谈谈重庆天然气干管隧道穿越长江工程――介绍一种大型管道穿越大江(河)的新工艺

在江底建隧道安装大型天然气管道工艺具有工程质量优、建设投资低、管理维护方便、用途可予扩充等诸多优点.文章以重庆市新建成投运的天然气主干管(Φ426×10mm)穿越长江的江底隧道工程与以往的各类天然气干管穿、跨越大江(河)工程相比进行介绍.诚望能在国家和各地城市建设中推广应用,必将获得巨大的经济和社会效益.     

Assessment of DNA damage in coal open-cast mining workers using the cytokinesis-blocked micronucleus test and the comet assay

Coal mining is one of the most important causes of environmental pollution, as large quantities of coal dust particles are emitted. Colombia-South America has large natural coal reserves and “El Cerrejón” is the world's largest open-cast mine located in the northern department of Guajira. The aim of the present study was to evaluate genotoxic effects in a population exposed to coal residues from the open-cast mine “El Cerrejón”. 100 exposed workers and 100 non-exposed control individuals were included in this study. The exposed group was divided according to different mining area activities: (i). Transport of extracted coal, (ii). Equipment field maintenance, (iii). Coal stripping and, (iv). Coal embarking. Blood samples were taken to investigate biomarkers of genotoxicity, specifically, primary DNA damage as damage index (DI), tail length and% of tail DNA using the Comet assay (alkaline version) and chromosome damage as micronucleus (MN) frequency in lymphocytes. Both biomarkers showed statistically significantly higher values in the exposed group compared to the non-exposed control group. No difference was observed between the exposed groups executing different mining activities. These results indicate that exposure to coal mining residues may result in an increased genotoxic exposure in coal mining workers. We did not find a correlation between age, alcohol consumption and service time with the biomarkers of genotoxicity. Our results are the first data of genotoxic effects induced by coal mining exposure in Colombia, and thus, contribute to the exploration of test batteries use for monitoring of exposed populations and may stimulate designing control, hygiene and prevention strategies for occupational health risk assessment in developing countries.     

关于试验中“发动机转速提升困难”的故障检查

在新车试验开发阶段,车辆的很多硬件和软件都是新状态的,其可靠性都需要在试验中来验证,所以难免在试验中出现各种疑难杂症。当这些问题出现的时候,往往相应的诊断软件还未开发出来而无法用诊断仪读取故障码,很多时候只能靠试验人员的经验来进行排查。本文以五菱宏光/五菱宏光S/五菱荣光S系列车型为基础,通过对车辆在试验开发过程中遇到的关于引起“发动机转速无法提升”的常见的几种原因进行分析排查,希望对大家在以后的工作和生活中处理类似问题时能够提供参考。