5ESS交换机接入TIMS话务终端的实现方法

将5ESS交换机接入TIMS本地网管系统，从而达到集中维护的目的。本文详细介绍了接入过程中的一部分－－网管话务终端的定义步骤。     

DRILLING CHARACTERISTICS OF COMBINATIONS OF DIFFERENT HIGH PRESSURE JET NOZZLES

The high speed fluid jet for directly or indirectly breaking rock is one of the most effective ways to improve the deep penetration rate.In order to maximize the efficiency of energy use,the flow characteristics of different combinations of high pressure jet nozzles are analyzed through numerical simulations.According to the velocity vectors at the bottom and the bottom hole pressure diagram,the effects of the high pressure nozzle combinations on the flow structure and the penetration rate are analyzed.It is shown that the combination of three vertical edge nozzles is very efficient,but inefficient in cleaning the bottom hole and eroding the wall.The jet velocity is 400 m/s and the radius is 5 mm,with a center nozzle added,the problem can be solved,but the high-pressure fluid displacement would increase.The center nozzle’s jet velocity is 200 m/s and the radius is 8 mm,the combination of two vertical edge nozzles and a center tilt nozzle or that of a vertical edge nozzle and a center tilt nozzle would provide a flow structure favorable for drilling.The angle of inclination is 10o.To take advantage of high pressure jet energy to improve the efficiency of drilling,it is important to select a suitable nozzle combination according real conditions.     

基于Return-Oriented Programming的程序攻击与防护

随着w⊕x等技术的引入,传统的代码注入攻击几乎被消除,return-to-lib攻击受到很大程度的抑制。在此 背景下,Hovav Shacham提出了Return-Oriented Programming(ROP)的思想,该思想基于栈溢出的原理,通过使用程 序库中有效的以ret指令结尾的短指令序列构建gadget集合,使之具有图灵完备特性,来完成计算和攻击。讲述ROP 思想自提出以来的一些研究成果和其实际的攻击能力,阐述ROP自动化的当前成果与未来可能的发展方向,进而分 析和预测ROP自动化的下一步的研究方向。同时,也将从ROP的几个特征分析消除这种攻击的策略和方法,并介绍 目前已有的防护思想和成果,论述这些方法的优缺点和改进方向。综合阐述ROP攻击与ROP防护这一矛与盾的问 题,力争使读者理解ROP的思想,知悉当前的发展状态,并在此基础上能够进一步推进ROP攻击及其防范的研究。     

Effect of Coordinating Solvents on Solution Speciation and the Crystallisation via ROP of a Triphos-Silver Coordination Cage

There is a general lack of understanding of how coordination polymers (metal-organic frameworks) form. Some insight can be gained from observations of formal ROP (ring-opening polymerisation) relationships between coordination polymers and their discrete soluble precursors. Most ROP examples reported previously have involved bidentate bridging ligands. Here we present an unusual example of a ROP relationship based on a tripodal ligand. In particular, 1,3,5-tris(diphenylphosphino)benzene (L1) is found to form a symmetrical coordination cage of stoichiometry Ag₃(L1)₂ in solution in acetonitrile. This contrasts with previous observations in less-coordinating solvents in which higher nuclearity cages are also formed, and shows that the coordinating acetonitrile solvent reduces anion-templating effects. On crystallization from acetonitrile a one-dimensional polymeric structure [Ag₃(L1)₂(NCCH₃)(OTf)₃] _n is obtained. The structure is noteworthy in being a ROP isomer of the trinuclear cage observed in solution. The structure also exhibits solvent-filled channels (maximum diameter 6.1 Å) but the material is not stable to desolvation. The structure of the polymer contrasts with that obtained from less-coordinating solvents, the latter being a stable hexagonal 2-dimensional structure with nanoporosity.     

Performance prediction of hard rock Tunnel Boring Machines (TBMs) in difficult ground

Performance prediction of TBMs is an essential part of project scheduling and cost estimation. This process involves a good understanding of the complexities in the site geology, machine specification, and site management. Various approaches have been used over the years to estimate TBM performance in a given ground condition, many of them were successful and within an acceptable range, while some missing the actual machine performance by a notable margin. Experience shows that the best approach for TBM performance prediction is to use various models to examine the range of estimated machine penetration and advance rates and choose a rate that best represents the working conditions that is closest to the setting of the model used for the estimation. This allows the engineers to avoid surprises and to identify the parameters that could dominate machine performance in each case. This paper reviews the existing models for performance prediction of TBMs and some of the ongoing research on developing better models for improved accuracy of performance estimate and increasing TBM utilization.     

Orthogonal ligation to spherical polymeric microparticles: Modular approaches for surface tailoring

Modular ligation strategies for the functionalization of polymeric microspheres provide new perspectives for their applications in material science. In the current trend article we highlight variable synthetic procedures for generating functional microspheres via orthogonal modular conjugation chemistries. An overview of the different surface chemistries available is provided, followed by surface-sensitive characterization techniques relevant for the microparticles. Finally, we explore future trends in modular orthogonal modification approaches on microparticles and provide an outlook on the perspectives that the field of surface-modification of polymeric microparticles holds.     

Interpolymer radical coupling: A toolbox complementary to controlled radical polymerization

The current review focuses on the relevance and practical benefit of interpolymer radical coupling methods. The latter are developing rapidly and constitute a perfectly complementary macromolecular engineering toolbox to the controlled radical polymerization techniques (CRP). Indeed, all structures formed by CRP are likely to be prone to radical coupling reactions, which multiply the available synthetic possibilities. Basically, the coupling systems can be divided in two main categories. The first one, including the atom transfer radical coupling (ATRC), silane radical atom abstraction (SRAA) and cobalt-mediated radical coupling (CMRC), relies on the recombination of macroradicals produced from a dormant species. The second one, including atom transfer nitroxide radical coupling (ATNRC), single electron transfer nitroxide radical coupling (SETNRC), enhanced spin capturing polymerization (ESCP) and nitrone/nitroso mediated radical coupling (NMRC), makes use of a radical scavenger in order to promote the conjugation of the polymer chains. More than a compilation of macromolecular engineering achievements, the present review additionally aims to emphasize the particularities, synthetic potential and present limitations of each system.     

XC—82型液力旋冲钻具和配套钻头研制及应用

大庆油田山地的岩性一般是青石板、砾石，在泥土和细沙中所用的三翼刮刀钻头在山地钻炮眼时很容易损坏，且机械钻速大大降低了。针对这一问题，大庆物探公司研制出XC-82型液力旋冲钻具及配套钻头。这是一种将钻井液能量转化成对钻头的高频机械冲击能量，来实现破岩的一种钻井工具，具有冲击力大、频率较高、机械钻速比牙轮钻头高的特点，且结构简单，组装方便，操作简单，经室内及现场试验效果良好。     

负压脉冲钻井技术理论及方法

国内油气勘探开发逐渐向深部地层发展,钻井施工中遇到的地层更加复杂、坚硬,岩石可钻性级别不断上升,机械钻速大幅度下降。井底负压脉冲技术既可实现井底负压又可提高射流能量,因此在提高深部地层机械钻速上具有独到的优势。分析了负压脉冲钻井提高机械钻速的原理及特点,介绍了国内外具有代表性的几种负压脉冲工具的工作原理及特点,着重介绍了胜利油田MCP-178型机械阻断式脉冲钻井工具的研制与应用,对提高深部地层钻井速度,降低钻井成本具有重要意义。     

钻井液提速剂性能研究

影响机械钻速因素比较多而且复杂,钻井液因素只是其中之一.实践证明,钻井液的密度、固相含量、失水量及滤液性质、粘附性、润滑性和亚微米颗粒含量明显影响机械钻速.通过添加钻井液提速剂来增强钻井液某些功能以提高机械钻速是简单有效的措施之一,提速剂主要通过快速吸附作用以增强钻井液的防粘附聚结能力、钻井液滤液渗透能力、润滑能力以及...