辽宁省白石水库主要地质问题综述

本文着重就区域构造稳定性、水库渗漏、坝线比选、坝基地层岩性、坝基地质构造、坝基缓倾角结构面、坝基渗漏与渗透稳定、大坝下游冲刷坑、天然建筑材料等主要地质问题进行了综合评述。     

A noncompetitive peptide inhibitor of the nicotinic acetylcholine receptor from Conus purpurascens venom

A paralytic peptide, psi-conotoxin Piiie has been purified and characterized from Conus purpurascens venom. Electrophysiological studies indicate that the peptide inhibits the nicotinic acetylcholine receptor (nAChR). However, the peptide does not block the binding of alpha-bungarotoxin, a competitive nAChR antagonist. Thus, psi-conotoxin Piiie appears to inhibit the receptor at a site other than the acetylcholine-binding site. As ascertained by sequence analysis, mass spectrometry, and chemical synthesis, the peptide has the following covalent structure: HOOCCLYGKCRRYOGCSSASCCQR* (O = 4-trans hydroxyproline; * indicates an amidated C-terminus). The disulfide connectivity of the toxin is unrelated to the alpha- or the alphaA-conotoxins, the Conus peptide families that are competitive inhibitors of the nAChR, but shows homology to the mu-conotoxins (which are Na+ channel blockers).     

矿业可持续发展理论及应用

在简要回顾我国矿业发展现状及其在环境破坏污染和资源浪费损失的基础上，提出矿业可持纽发展的概念与内涵，论述矿业可持续发展的动态２特征，并就如何实施矿业可持结发展战略进行了思考。     

Role of embB in natural and acquired resistance to ethambutol in mycobacteria

The mycobacterial embCAB operon encodes arabinosyl transferases, putative targets of the antimycobacterial agent ethambutol (EMB). Mutations in embB lead to resistance to EMB in Mycobacterium tuberculosis. The basis for natural, intrinsic resistance to EMB in nontuberculous mycobacteria (NTM) is not known; neither is the practical implication of resistance to EMB in the absence of embB mutations in M. tuberculosis well understood. The conserved embB resistance-determining region (ERDR) of a collection of 13 strains of NTM and 12 EMB-resistant strains of M. tuberculosis was investigated. Genotypes were correlated with drug susceptibility phenotypes. High-level natural resistance to EMB (MIC, . or =64 microg/ml) was associated with a variant amino acid motif in the ERDR of M. abscessus, M. chelonae, and M. leprae. Transfer of the M. abscessus emb allele to M. smegmatis resulted in a 500-fold increase in the MICs. In M. tuberculosis, embB mutations were associated with MICs of > or =20 microg/ml while resistance not associated with an ERDR mutation generally resulted in MICs of < or =10 microg/ml. These data further support the notion that the emb region determines intrinsic and acquired resistance to EMB and might help in the reassessment of the current recommendations for the screening and treatment of infections with EMB-resistant M. tuberculosis and NTM.     

深亚微米MOSFET衬底电流的模拟与分析

利用器件模拟手段对深亚微米ＭＯＳＦＥＴ的衬底电流进行了研究和分析，给出了有效的道长度，栅氧厚度，源漏结深，衬底掺杂浓度以及电源电压对深亚微米ＭＯＳＦＥＴ衬底电流的影响，发现电源电压对深亚微米ＭＯＳＦＥＴ的衬底电流有着强烈的影响，热载流子效应随电源电压的降低而迅速减小，当电源电压降低到一定程度时，热载流子效应不再成为影响深亚微米ＭＯＳ电路可靠性的主要问题。     

光纤0_2/CO_2复合传感器的研制

本文报导一种新型的光纤氧、二氧化碳复合传感器.通过在同一敏感膜载体上固定两种不同的荧光试剂——芘丁酸及羟基芘三磺酸,制作了一种对氧和二氧化碳敏感的复合敏感膜.该传感器在医学临床检验范围内具有良好的线性,其测氧的分辩率是0.1％,测二氧化碳的分辩率是0.5％,响应时间短于1min.文中还讨论了三种敏感膜载体的比较及复合传感器测量进程中氧和二氧化碳的相互干扰问题.     

NK-EH500调质钢爆炸硬化的冲击动力学研究

通过试验并运用爆炸冲击动力学理论NK－EH500调质钢爆炸硬化进行了深入的研究，结果表明，金属材料存在硬化极限，调整炸药组成改变爆炸硬化可以满足不同金属材料的硬化要求，隔离式爆炸硬化有利于保护硬化工件外观的完整性，本研究对拓展爆炸硬化在实践中的应用领域具有重要的理论指导意义。     

Direct observation of the crystal-growth transition in undercooled silicon

Using an electromagnetic levitation facility with a laser heating unit, silicon droplets were highly undercooled in the containerless state. The crystal morphologies on the surface of the undercooled droplets during the solidification process and after solidification were recorded live by using a high-speed camera and were observed by scanning electron microscopy. The growth behavior of silicon was found to vary not only with the nucleation undercooling, but also with the time after nucleation. In the earlier stage of solidification, the silicon grew in lateral, intermediary, and continuous modes at low, medium, and high undercoolings, respectively. In the later stage of solidification, the growth of highly undercooled silicon can transform to the lateral mode from the nonlateral one. The transition time of the sample with 320 K of undercooling was about 535 ms after recalescence, which was much later than the time where recalescence was completed.     

铜铅锌银多金属矿湿法分离新工艺

依据不同金属硫化物氧化分解电位的差异 ,针对某含铜、铅、锌、银复杂多金属硫化矿的难选冶特性 ,对浮选获得的混合精矿采取在线控制浸出过程氧化还原电位的方法 ,分步选择性氯化浸出各有价元素 ,并辅之以沉淀、置换、萃取等工艺 ,使有价金属以较高的回收率得到了有效的分离提取 ,在各工序最佳条件下 ,Cu、Pb、Zn、Ag各金属的浸出率均大于 99 0 % ,元素硫的回收率大于 76%