Effect of Strain Rate on Discontinuous Flow and Mechanical Characteristics of High-Nitrogenous Steel

Experimental study on the effect of strain rate on discontinuous flow and mechanical characteristics of the high-nitrogenous steel Kh23AG19F has been performed. Within the range of strain rates from 4.62 · 10^-5 to 1.85 · 10 ^-4 s^-1, discontinuous flow, reflected by serration on the tensile diagram, is chiefly determined by intergranular deformation mechanisms. Under strain rates over 1.85 · 10^-2 s^-1, combined deformation modes prevail, which cause a change in the character of discontinuous flow and transform a serrated tensile diagram into a wavy graph, with the yield stress of steel increased significantly.     

能源实时监控与信息管理系统出现的问题及解决的方法

中国石化北京燕化石油化工股份有限公司动力事业部二供水车间电气改造完成后，能源实时监控与信息管理系统出现线路名称不统一、电流互感系数变比不起作用、数据查询功能及统计报表数据的准确性等问题，严重地影响系统的使用。通过对比分析，找到了出现问题的实质，对源代码进行修改，问题得到了解决。同时也成功地解决了其他部门遇到相类似的问题。     

七里北地区钻井工程地质特征及提高钻速的技术途径

七里北潜伏构造南邻渡口河、北邻铁山坡,这些构造均在飞仙关鲕滩钻获良好的天然气,具有很好的勘探前景。七里北1井钻探表明,该井在飞仙关地层获天然气80×104m3,但储层埋藏深度达5600m,且侏罗系地层的钻井工程地质条件与相邻构造有显著差异,钻井速度低和钻具事故多这两大问题突出,严重制约了探井钻井速度。认真分析了七里北1井的钻井工程地质特征,有针对性地提出提高飞仙关探井钻井速度的技术途径,有利于解决钻井工程面临的突出问题,对加快该地区飞仙关鲕滩气藏的勘探速度有着重要意义。     

变表皮系数在气井试井解释中的应用

在气井试井解释中,使用固定的表皮系数来进行压力全历史拟合,很难将压力历史曲线拟合好,而且不尽合理。气体的高速流动,导致气井附加的压力降。流量越大,表皮系数越大。基于叠加原理,以及变表皮系数的理论,通过实例分析,对气井不稳定试井进行压力全历史拟合,获得了很好的拟合效果。通过拟合获得的各流动段表皮系数,由线性回归得到真表皮系数。     

滨北地区T5和T4不整合面剥蚀量恢复

根据不同剥蚀量恢复方法的特点和松辽盆地滨北地区实际地质情况,采用不同的方法对滨北地区T5和T4不整合面进行剥蚀量恢复。利用镜质体反射率法和体积平衡-沉积速率法相结合对T5不整合面进行剥蚀量恢复;应用镜质体反射率法、地层趋势分析法和沉积速率法相结合对T4不整合面进行剥蚀量恢复。研究结果表明T5不整合面因经历较长时间的剥蚀,剥蚀量较大,剥蚀量在700~2800m之间;T4不整合面剥蚀量多在200~1000m,在经历剥蚀时间较长的地区和靠近断陷盆地边缘的地区剥蚀量大。     

弱碱三元复合驱与强碱三元复合驱的对比

三元复合驱即将成为大庆油田的主导开发技术,为了推荐出合适的三元复合驱类型,对比研究了弱碱三元复合驱与强碱三元复合驱。研究表明,弱碱三元复合驱可以比水驱提高采收率20%以上,与强碱三元复合驱相当;弱碱三元复合驱与强碱三元复合驱乳化液粘度都超过100 mPa.s,两种类型三元复合乳化能力相差不多,甚至弱碱三元复合驱乳化能力还略强一些;在注采能力、采油速度方面,弱碱三元复合驱甚至高于强碱三元复合驱;特别是在结垢程度上,弱碱三元复合驱比强碱三元复合驱弱,对生产井的影响较小。因此,在三元复合驱推广应用时应当选用弱碱三元复合驱。     

国产风机盘管空调系统常见问题分析

分析了国产风机盘管使用中常见的问题,指出机组因风量不足、冷量风量匹配不合理以及风机盘管某些设备故障,导致了风机盘管精度低、舒适性差、能耗高等一系列问题。指出应引起空调设计和运行维护人员的注意。     

Wireless video streaming with TCP and simultaneous MAC packet transmission (SMPT)

Video streaming is expected to account for a large portion of the traffic in future networks, including wireless networks. It is widely accepted that the user datagram protocol (UDP) is the preferred transport protocol for video streaming and that the transmission control protocol (TCP) is unsuitable for streaming. The widespread use of UDP, however, has a number of drawbacks, such as unfairness and possible congestion collapse, which are avoided by TCP. In this paper we investigate the use of TCP as the transport layer protocol for streaming video in a multi‐code CDMA cellular wireless system. Our approach is to stabilize the TCP throughput over the wireless links by employing a recently developed simultaneous MAC packet transmission (SMPT) approach at the link layer. We study the capacity, i.e. the number of customers per cell, and the quality of service for streaming video in the uplink direction. Our extensive simulations indicate that streaming over TCP in conjunction with SMPT gives good performance for video encoded in a closed loop, i.e. with rate control. We have also found that TCP is unsuitable (even in conjunction with SMPT) for streaming the more variable open‐loop encoded video. Copyright © 2004 John Wiley & Sons, Ltd.     

Determining the Instantaneous Effective Energy of x-Ray Tube Bremsstrahlung

A method is described for determining the instantaneous effective energy of x-ray tube brehmsstrahlung by means of two semiconductor detectors employing epitaxial GaAs structures and a measurement circuit, which together determine the effective energy with an error of 5% in the range 20–80 keV in the presence of nonlinearity in the detector response.     

提高深井硬地层钻井速度技术难点及对策

乌龙1井地层为南方海相沉积,地层古老、岩石硬度大、研磨性强、可钻性差、地层倾角大(最大为80°)井斜难以控制、蹩跳钻严重,制约了该地区深井钻井速度。文章介绍了解决提高钻井速度这一瓶颈问题,从深井优快钻井及其配套技术、硬地层钻进的钻头优选、优化钻井参数、引用新技术、新工艺、新工具等方面进行了探索,钻井速度有了大幅度地提高,对类似井具有一定的借鉴作用。