A survey of some metallographic etching reagents for restoration of obliterated engraved marks on aluminium-silicon alloy surfaces

A brief survey to assess the sensitivity and efficacy of some common etching reagents for revealing obliterated engraved marks on Al-Si alloy surfaces is presented. Experimental observations have recommended use of alternate swabbing of 10% NaOH and 10% HNO(3) on the obliterated surfaces for obtaining the desired results. The NaOH etchant responsible for bringing back the original marks resulted in the deposition of some dark coating that has masked the recovered marks. The coating had been well removed by dissolving it in HNO(3) containing 10-20% acid. However, the above etching procedure was not effective on aluminium (99% purity) and Al-Zn-Mg-Cu alloy surfaces. Also the two reagents (i) immersion in 10% aq. phosphoric acid and (ii) alternate swabbing of 60% HCl and 40% NaOH suggested earlier for high strength Al-Zn-Mg-Cu alloys [23] were quite ineffective on Al-Si alloys. Thus different aluminium alloys needed different etching treatments for successfully restoring the obliterated marks. Al-Si alloys used in casting find wide applications especially in the manufacture of engine blocks of motor vehicles. Hence, the results presented in this paper are of much relevance in serial number restoration problems involving this alloy.     

红外光谱相似的汽车中涂漆的鉴别分析

目的 应用裂解气相色谱-质谱法结合聚类分析,鉴别9个红外光谱相似的汽车中涂漆样品.方法 从漆片中分离、提取出中涂漆样品,用裂解气相色谱-质谱检测并结合红外光谱检测,结果采用SPSS 19统计软件（美国IBM公司）对裂解数据进行聚类分析.结果 裂解气相色谱质谱的检测结果经聚类分析处理,9个中涂漆样品按其裂解图谱的差异可分为4类;而结合红外光谱的检验结果,最终可将5类中涂漆样品一一区分.结论 在汽车中涂漆的鉴别中,裂解气相色谱-质谱检测是对红外光谱检测的重要补充,能够有效地提高对中涂漆的鉴别能力.     

书写材料的无损检验系统研究

本研究运用显微分光光度仪、文件检验仪和傅立叶变换拉曼光谱仪三种方法,分别对在中国市场上收集的不同厂家、牌号、型号的35种黑墨水、20种蓝黑墨水、22种蓝墨水、49种黑色墨水笔、30种蓝色墨水笔、45种黑色圆珠笔、和50种蓝色圆珠笔等七组样品进行非破坏检验。结果表明:(1三种非破坏检验方法都能单独对七组样品进行不同程度的鉴别,区分率在50%—94.4%之间;(2)三种方法联用后对黑墨水、蓝黑墨水、蓝墨水、黑色墨水笔、蓝色墨水笔、黑色圆珠笔和蓝色圆珠笔的区分率可分别提高到93.4%、97.3%、99.1%97.2%、97.2%、95.6%和91.8%。通过三种非破坏检验方法的联用,证明它们之间有较强的互补性,最大限度地提高了检验效应,可建立系统的非破坏检验方法。     

东道国对跨国公司活动的法律规制

跨国公司在东道国的活动一直就好比是一把双刃剑 ,既有好的影响 ,也有相当大的负面作用。那么 ,如何对跨国公司活动实施有效而适度的法律规制 ,消除其不利影响 ,充分发挥其对本国经济与社会发展的正面作用呢 ?本文首先分析东道国为什么要对跨国公司进行法律规制 ,然后抓住当前规制跨国公司活动的两个最有代表性的焦点问题 ,即反垄断、反倾销展开论述。由于垄断与倾销并非同一范畴的概念 ,因此本文侧重于从宏观层面谈反垄断的立法问题 ,而谈反倾销则侧重于从微观层面谈细节操作性问题。最后将结合我国在这方面的立法现状提出建议。     

论我国高等教育学学位点布局的不均衡性

我国高等教育学学位点布局结构的不均衡是相对的.这种不均衡是多种因素影响的结果,尤其深受各地高等教育发展水平的制约.换言之,高等教育自身发展水平直接影响高等教育学学位点的布局,而高等教育学位点布局结构反过来又对高等教育的发展起促进作用.从逻辑上看,前者是因,后者是果.因此,我们不能简单地认为是高等教育学学位点布局的不均衡影响了高等教育发展的不均衡,而是应该承认高等教育发展的不均衡影响着高等教育学学位点的布局结构.     

How Much Can a Forensic Laboratory Do to Discriminate Questioned Ink Entries?

Questioned document examiners are frequently required to determine whether the questioned ink entries on a document are written with the same ink, either for forged document identification or relative ink dating. How many methods are sufficient to discriminate potentially different inks? In this paper, 18 blue ballpoint inks were first nondestructively examined with a video spectral comparator. The ink entries were subsequently extracted with organic solvents for analysis of the volatile solvents and dyes by GC/MS, TLC, and LC‐MS/MS. The 18 ink samples were divided into 10, 9, 12, and 14 categories by these four methods, respectively. With the combined results, there were only two inks that remained indistinguishable, but they were further differentiated by microscopy. Therefore, to achieve effective discrimination of ballpoint ink entries, the authors suggest that a complete examination should include an analysis of their optical features, volatile solvents, and dyes as well as the ink quality.     

面对WTO完善我国消费者权益保护法的思考

WTO是全球的“经济联合国” ,中国加入WTO不可阻挡。市场经济是消费需要拉动型经济 ,消费的开放和保护两者不可或缺 ,而保护消费者权益及完善与此相关的法律体系是我们面临“入世”所亟待解决的问题。就现行的消费者权益保护法进行比较 ,WTO主要成员与我国既有共同的基本精神和内容 ,又有着不同的优劣和特色。面对WTO ,本文着重探讨了我国应建立和完善消费者权益法律保护制度 ,并提出了一些粗浅的看法。     

埃及北部三角洲城市走廊探析

城市走廊是在经济全球化迅猛发展的背景下,城市化速度加快、城市空间大型化过程中形成的一种城市空间形态。埃及城市化进程深入以及区域经济的发展,导致北部三角洲城市走廊形成,并在发展过程中呈现出较强的通达性、土地利用复杂化和节点城市间引力差异明显等特征。三角洲城市走廊已成为该区域重要的基础设施带、区域发展的核心以及国家区域规划的主要目标。从世界范围看,三角洲城市走廊发展尚处于初级阶段,面临着城市沿走廊无序蔓延、协调机制不完善和地价飞涨等问题。尽管如此,三角洲城市走廊跨国化发展已成趋势。