Safety Assessment of Circular Arches Tunnel Evacuation on Surrounding Geotechnical Environment

Based on the stochastic medium theory, influence on the surrounding rock and soil by tunnel excavation was studied. formula for predicting movement and deformation of rock and soil mass caused by tunnelling were deduced. And especially for the tunnel with circular arch section, half analytic solution for this problem was put forward. Furthermore, a program was developed to compute the movement and deformation of the rock and soil mass resulted from excavation. The deformation failure criterion of stochastic medium for estimating the surroundings safety was provided and was applied in an engineering example, which proved that the results of the research were reasonable and significant for the tunnel safety construction.     

Performance analysis on improved PDA AI for moving target tracking

Aim at the problem that the EO imaging tracking system is inconsistent with the model of probabilistic data association with amplitude information (PDA AI), which supposes that the greater the amplitude value is, the greater the probability of being the tracked target will be, a modified PDA AI (MPDA AI) is presented . Based on the fact that the amplitude and the motion of the interested target are consistent in a short period, the MPDA AI models the amplitude information and the motion information of the target as well as their consistency with Markov stationary signal to analyze the association procedure of motion and amplitude. The lower bounds of Cramer Rao estimation error for PDA AI and MPDA AI are calculated and discussed in detail. The theoretical analysis and experimental results show that estimating the target motion with the MPDA AI will be more accurate and more reliable than estimating with the original PDA AI.     

静松灵在驴与牛体内药化动力学及其差异性的研究

静松灵在驴与牛体内药化动力学及其差异性的研究万宝，赵明彬（北京农业大学动物医学院，１０００９４）静松灵具有镇静、镇痛、肌肉松弛作用，化学名称为２，４－二甲苯胺噻唑。是一种α＿２－肾上腺素能受体激动剂，它通过激动动物体内的α－肾上腺素能受体而发挥药理作...     

Technique of Classification of Coal and Gas Outburst Mines

managing the coal mines according their dangerous grade determined. can decrease the engineering quanity and lessen the sightless characteristic. It has marked benefit for community and great economic benefit. The dangerous grade of outburst mines are determined Outburst coal mines are classified into mines with serious outburst hazard, mines with middle outburst hazard and mines with ordinary outburst hazard. Twelve classification indicators are used in comprehensively evaluating the dangerous grade of outburst mines. The dangerous grade of outburst mines are determined according to the principle of the most subjection with fuzzy comprehensive evaluation method, on the basis of the classification indicators and its quantification. By the model founded, some coal mines are studied and the research results are accordant with the fact.     

锌一邻硝基苯基荧光酮一阳离子表面活性剂体系显色的反应

研究了在阳离子表面活性剂（ＣＴＭＡＢ）作用下的锌（Ⅱ）与邻硝基苯基荧光酮（０－ＮＰＦ）的显色反应。实验证明,在ｐＨ为（８．８０～９．５６）的硼砂缓冲体系中,锌（Ⅱ）与邻硝基苯基荧光酮,在阳离子表面活性剂（ＣＴＭＡＢ）存在下,生成红色配合物,其最大吸收波长为５７０ｎｍ,摩尔吸收系数为６．２９×１０４,锌含量在０～１２．０μｇ／２５ｍｌ范围内符合比耳定律,配合物中锌与邻硝基苯基荧光酮的比值为１：２,用此方法测定了食品中的锌（Ⅱ）,结果满意。     

Technological Measures for Reducing Two-Stroke Motorcycle Exhaust Emissions

The main technological measures for reducing two stroke motorcycle exhaust emission in China and foreign country are introduced. The characteristics of the measures in structure, effect, cost, etc., are analysed. The results show that the enleanment of conventional carburetor mixture and the improvement of the carburetor intake passage shape is a simple and effective measure, the adoption of the electronically controlled in cylinder direct fuel injection technique is a unique measure to completely improve emissions from two stroke motorcycles. The structure and cost of a stratified scavenging system is lower than that of in cylinder direct fuel injection, but its effect is better than that of the enleanment of carburetor mixture, so, it is worth investigating further. The factories of two stroke motorcycles may select the reduction measures of the exhaust emission by referring to the analyses and comparisons.     

复方噻胺酮对小型猪血清中多种元素的影响

试验采用动物给药前报自身对照的方法，观察了我国新研制的兽用复合全麻药－－复方噻胺酮对10头小型猪血清中的常量元素（K，Na,Ca,Mg）和微量元素（Cu,Fe,Zn）含量的影响。结果表明，小型猪肌肉注射临床麻醉剂量（15mg/kg）的复方噻胺酮后，血清中Na,K,Cu,Fe可在一定时间内呈显著升高（P＜0.05）；Ca显著下降（P＜0.05）；Mg和Zn未发生显著变化，但上述诸元素的变化均未超出正常范围。尽管如此，若对已患上述诸元素缺乏或过高的动物进行麻醉时，或是需在麻醉状态下进行有关元素方面的研究时，对这种影响也应给予足够重视。