黄石市废旧弹药的销毁

黄石地区近年来在收购废旧钢材时,部分未爆废旧弹药随同一起进入了黄石钢铁厂和一些回收站,必须销毁。本次销毁弹药种类多、数量大,决定采用硐室爆破法将其销毁。文中阐述了爆破硐室的设计,实施销毁的炸药选择及药量的计算,炸药的现场装填,起爆网路的设计与安全措施,为类似废旧弹药的销毁工作提供了有益的经验。     

Lithium Implantation into Fullerite

Abstract

The depth profiles of lithium, implanted into fullerene at different fluences and temperatures are reported. They deviate considerably from the simple ballistic predictions. They can be understood in terms of depth dependent Li mobility immediately after the ion implantation. This mobility depends considerably on the temperature and on the degree of fullerene damage. It appears that the fullerene destruction products which act as traps for the mobile lithium are somewhat mobile themselves, essentially at high temperatures, and at low damage levels.     

抗毁式多跳无线网路由协议的研究

在对多跳无线网路由协议的研究现状进行分析的基础上，选择了专用按需距离向量路由（AODV）协议作为抗毁式多跳无线网络由协议，协议的实现充分考虑了无线信道的有限带宽和移动性，提高了网络性能和抗毁性。此无线路由协议适用于特殊环境下多跳无线网的抗毁性要求，通过对专用按需距离向量跳由（AODV）协议的分析，得出了有指导意义的结论。     

Rock roadway complementary support technology in Fengfeng mining district

This paper takes No. 52 return uphill roadway of Yangquhe coal mine as a research project. Based on the research, especially its geological condition, indoor experiments, numerical simulation and theor...     

Oxidative Destruction of Chitosan During Ozonization

Abstract

Ozonization of water suspension of chitosan leads to oxidation of amino groups which accompanied by deamination and crosslinkihg of macromolecules. The clearing of 1,4-β-v-glucoside bonds in macromolecule is a basic process in the protection of amino groups by protonation with acid. The polymerization degree of ozonolysis products in acidic medium can be varied in wide ranges depending on reaction conditions. The rate of the interaction of ozone with chitosan depends on the conformation of polysaccharide macromolecules.     

废旧弹药销毁方法探讨

废旧弹药销毁是事关人民生命财产安全和社会治安的一件大事。以安全销毁废旧弹药为出发点,探讨了销毁废旧弹药的方法、过程和注意事项;对废旧弹药销毁工作有一定的指导作用。     

Experimental investigation on the thermal stability of some new zero ODP refrigerants

Five zero ODP (ozone depletion potential) hydro-fluorocarbon refrigerants (HFC-23, HFC-143a, HFC-227ea, HFC-236fa, HFC-245fa) were tested to define their maximum usable temperature and their thermal degradation threshold. Pyrolysis is detected (a) as a pressure change at constant temperature and volume; (b) as a departure of the vapour pressure curve of the heated fluid from that of the original substance. Visual inspection of the vessel walls and fluid chemical analysis complement the method. The minimum detectable degradation rate is believed to be less than 1% in 50 h. All the fluids exhibit a variable, but excellent thermal stability up to the following temperatures at which no decomposition was observable in 50–100 h: 425 °C for HFC-227ea, 400 °C for HFC-23 and HFC-236fa, 350 °C for HFC-143a and 300 °C for HFC-245fa. Clear degradation signs were observed at temperatures 25–50 °C higher. Most of the fluids heated up to their thermal stability threshold exhibited an induction period of 5–50 h in which no decomposition was detectable but after which an observable degradation started. For a given fluid such period decreases at increasing temperatures. The use of fluids in a cyclic process in which the working medium permanence at the top temperature is very brief could take advantage of this behaviour with a reduction in degradation rates or with an increase in the limiting temperature. The influence of the decomposition products on the functionality of a thermodynamic power cycle was investigated by means of an appropriate computer code. The working fluid was assumed to be a binary mixture with 1 to 3% concentration of a light decomposition product of the methane series. Chemical species such as CH₄ and CF4 with a critical temperature much lower than that of the base fluid strongly affect the cycle configuration. On the contrary species with critical temperatures closer to that of the base fluid such as CH₃F, CH₂F₂ or CHF₃ influence only marginally the cycle performance. In general a small concentration of decomposition products in the working medium is likely to be acceptable without noticeable drawbacks.

Résumé

Five zero ODP (ozone depletion potential) hydro-fluorocarbon refrigerants (HFC-23, HFC-143a, HFC-227ea, HFC-236fa, HFC-245fa) were tested to define their maximum usable temperature and their thermal degradation threshold. Pyrolysis is detected (a) as a pressure change at constant temperature and volume; (b) as a departure of the vapour pressure curve of the heated fluid from that of the original substance. Visual inspection of the vessel walls and fluid chemical analysis complement the method. The minimum detectable degradation rate is believed to be less than 1% in 50 h. All the fluids exhibit a variable, but excellent thermal stability up to the following temperatures at which no decomposition was observable in 50–100 h: 425 °C for HFC-227ea, 400 °C for HFC-23 and HFC-236fa, 350 °C for HFC-143a and 300 °C for HFC-245fa. Clear degradation signs were observed at temperatures 25–50 °C higher. Most of the fluids heated up to their thermal stability threshold exhibited an induction period of 5–50 h in which no decomposition was detectable but after which an observable degradation started. For a given fluid such period decreases at increasing temperatures. The use of fluids in a cyclic process in which the working medium permanence at the top temperature is very brief could take advantage of this behaviour with a reduction in degradation rates or with an increase in the limiting temperature. The influence of the decomposition products on the functionality of a thermodynamic power cycle was investigated by means of an appropriate computer code. The working fluid was assumed to be a binary mixture with 1 to 3% concentration of a light decomposition product of the methane series. Chemical species such as CH₄ and CF4 with a critical temperature much lower than that of the base fluid strongly affect the cycle configuration. On the contrary species with critical temperatures closer to that of the base fluid such as CH₃F, CH₂F₂ or CHF₃ influence only marginally the cycle performance. In general a small concentration of decomposition products in the working medium is likely to be acceptable without noticeable drawbacks.     

The effects of strength models in numerical study of metal plate destruction by contact explosive charge

Based on a complete mathematical model, the authors set up a problem of metal plate destruction by contacting explosive charge in highly nonlinear dynamic software AUTODYN and solved in two cases using the Johnson–Cook and von Mises strength models. The numerical simulation results were compared with the experimental results and showed a good fit of numerical calculations versus experiments by using the von Mises strength model. The study also shows that the Johnson–Cook strength model, if applied unreasonably, will lead to large errors, which would help to avoid mistakes in the future high speed impact study.     

Studies in Radiation Chemistry: Application to Ozonation and Other Advanced Oxidation Processes

Advanced oxidation/reduction processes (AORPs) are an alternative water treatment that is becoming more widely utilized. Our radiation-chemistry based studies are being used to develop a fundamental understanding of AOP treatment options, and are divided into three complementary types of contaminants; disinfection by-products (DBPs), emerging pollutants of concern (EPoCs), and natural organic matter (NOM). More than 600 DBPs have been identified, and one class that appears to have severe potential adverse health effects is the halonitromethanes (HNMs). Of the nine HNMs, trichloronitromethane (chloropicrin) is the most common, with levels up to 180 nM in US drinking waters. EPoCs are of interest because of their biological activity at low concentrations in water and while the initial focus was on endocrine disruptor chemicals (EDCs) this class has now been expanded to include many other recalcitrant chemicals such as hormones, antibiotics, industrial contaminants, and health care products. Natural organic matter is one of the most common radical scavengers in natural waters and therefore may adversely affect AOPs. Our approach is to study NOM both directly and using model compounds thought to be representative of structural components of this complex material.     

马兰庄铁矿开采最终边坡角稳定性分析

在马兰庄铁矿工程地质调查的基础上,完成了矿山边坡工程地质岩组的划分及各岩组的工程地质性质的调查,并借助岩石力学性质试验分析、楔型体等传统方法、极限平衡分析法优化确定马兰庄铁矿露天境界最终边坡角,力求能够准确合理的评价边坡稳定情况.分析结果表明马兰庄铁矿白马山和沙河山两采场最终边坡角都有提高的潜力.