Time distance diagram of the jet initation of covered high explosive charges

The bulging behaviour of a steel barrier in front and in contact with a high explosive charge desensitises the charge sensitivity for a shaped charge jet impact. The reasons are rampwave behaviour and pre-compression of the charge, which is explained in detail with a time distance diagram.     

Structural integrity assessment of weldments at high temperature: A proposed new approach for R5

The R5 procedures provide a comprehensive methodology for the assessment of structures operating within the high temperature creep regime. This includes advice on the modifications required to the basic procedure to account for weldments in creep–fatigue crack initiation assessments. The current approach is based on the use of a Fatigue Strength Reduction Factor (FSRF) which has a value according to the particular class of welded joint. The FSRF affects the calculation of creep and fatigue damage. However, the current approach can be excessively conservative for as-welded weldments which are the main type of weldments in plant.     

Monitoring of steel corrosion in concrete by electrode arrays and electrical resistance probes

In the present work two relatively new methods were implemented, in order to follow exactly the time and spatial evolution of steel corrosion in concrete. Measuring with a coupled electrode array is by some means the advancement of electrochemical noise (EN) with electrically connected micro-electrodes, which are spatially arranged, the assessment of anodic and cathodic currents distribution in time is possible. An electrical resistance (ER) probe can provide general corrosion rate, which is calculated from the thickness reduction; however, its response to localize corrosion is limited. The measurements were performed in concrete specimens, which were exposed to periodic wetting and drying cycles. The results of both used methods were compared and related to the conditions of the micro-electrodes and the ER probes after the test was finished. It was found that micro-electrode arrays can monitor the time and spatial evolution of steel corrosion in concrete. The measured currents reliable indicate the temporal anodic and cathodic activities of individual electrodes, and the assessment of general corrosion rates is also possible. Two characteristic fluctuations of the measured currents from the micro-electrode arrays were defined: slower fluctuations and shorter transients. It is believed that the slower fluctuations were generated by rather general corrosion of the electrodes, whereas the shorter transients were very probably generated by the initiation of pits. In accordance with the results of our previous study, it was confirmed that electrical resistance probes (ER) are able to measure reliably the cumulative corrosion damage, as well as the average general corrosion rate. The general corrosion rates obtained by using ER probes were generally slightly higher than those estimated from the measured currents. It should be mentioned that due to the relatively short duration of the experiments, the reliability of the methods for long-term practical applications still needs to be assessed.     

Comparing narratives of personal and preferred partner characteristics in online dating advertisements

This study explored online personal ads of 294 heterosexual and homosexual men and women in the United States through a qualitative analysis and comparison of participant-generated “personal” and “preferred partner” narratives. Nine characteristics were identified and combined into three overarching categories: physical, lifestyle, and personality characteristics. These three personal and preferred partner characteristics were examined for difference by gender, sexual orientation, age and desired relationship type of the advertisers. Main effects emerged for all four predictors, most notably for age and desired relationship type. Additionally, this study explored the possibility that personal and preferred partner narratives contained similar constellations of characteristics, finding significant correlations on all three variables, lending support for the matching hypothesis in dating partner characteristics.     

基于AR1688的IP电话机的解决方案

网络宽带化发展迅速,语音、数据和视频的"三网合一"将逐渐实现,然而作为与我们日常生活最密切的电话,也将由传统电路交换转变为分组交换,对直接用于因特网通话良好的IP电话机的需求是十分的迫切。提出了一种采用AR1688的简洁的IP电话机解决方案,此方法既直接接入到因特网,通话质量又能满足IP电话机的规范要求;阐述了采用AR1688的IP电话机的硬件原理与硬件电路的设计方法;介绍了采用AR1688的IP电话机的软件设计方案;通过对设计的IP电话机进行相关的测试,表明所提出的方案能在因特网运行良好。     

Effect of Habit Modifiers on Morphology and Properties of Nano‐HNS Explosive in Prefilming Twin‐Fluid Nozzle‐Assisted Precipitation

This article was published in Early View with DOI 10.1002/prep.200800071 – what is wrong. It has appeared with the correct DOI 10.1002/prep.200900071 – in Propellants, Explosives, Pyrotechnics 2009 (34) issue 1/2009 on pp 72‐77.     

开挖爆破对邻近隧洞的震动影响研究

爆破震动对邻近隧洞的影响及其控制是水利、铁道、交通等工程建设过程中的关键技术问题。运用动力有限元数值模拟 ,研究了爆破震动对邻近隧洞的影响问题。比较了掌子面上的崩落、缓冲、光面等不同炮孔爆破、不同分段方式和起爆顺序对邻近隧洞的震动影响。在确定邻近隧洞周边峰值振速和峰值拉应力分布的基础上 ,分析了开挖爆破对邻近隧洞震动影响的关键因素 ,并提出了合理的起爆顺序和爆破震动控制措施。     

Numerical research of rotating detonation initiation processes with different injection patterns

Three-dimensional numerical simulations are performed to study the initiation process of the rotating detonation combustor initiated by a pre-detonator. Navier-Stokes equations are solved with a 7-species and 8-steps H₂/Air chemical reaction mechanism. Three different injection patterns are considered, including the inner-slit injection, outer-slit injection and mid-slit injection. A single stable rotating detonation wave is established finally for all three injection patterns. Firstly, the initiator dynamics of the pre-detonator is discussed. The initial detonation wave spreads into the combustor from the pre-detonator and two oppositely propagating detonation waves are formed in the combustor in all cases, causing wave collisions. Similar fresh gas injection disturbance is seen, suggesting the little effect of different injection patterns at the beginning. After the recovery of the injection, ‘L-form’ fresh mixture layers are formed in the inner-slit/outer-slit injection patterns, leading to a rapid establishment of stable propagation mode. While in the mid-injection pattern, transition of fresh mixture layer structure is seen from ‘I-form’ to ‘L-form’. Severe lateral expansion exists during this period, resulting in a long-term wave initiation.     

NGN网络合法侦听技术的研究与分析

从国家信息安全的角度考虑,通信网合法侦听技术的应用与发展势在必行。本文在研究分析了传统电信网合法侦听实现方法的基础上,结合NGN自身特点,介绍了NGN网络实现合法侦听的两种方法,并对这两种实现方法中的关键技术进行了研究与说明。     

IMS基本探讨TP3-0

IMS，IP多媒体子系统，为下一代网络用户服务提供强大的会话和服务体系结构平台。简要回顾了IMS的发展历程；详细介绍了IMS的体系结构，阐述了IMS机构的三层：应用层、会话控制层、传输与端点层的基本技术与功能；从兼容性、管理、安全三个方面分析了IMS的特点；展望未来IMS的应用前景。