煤与瓦斯突出预测技术研究现状及发展趋势

对矿井煤与瓦斯突出预测方法的研究现状及发展趋势进行了论述及分析。目前我国大量使用的是钻屑量S、钻孔瓦斯涌出初速度q、瓦斯解吸指标Δh2 、瓦斯放散指数ΔP等钻孔静态预测方法 ,这些方法花费大量的人力、物力和财力 ,而且准确性较低。而声发射和电磁辐射等方法是很有前途的预测方法。未来煤与瓦斯突出预测的发展趋势是 ,利用声发射监测技术对变形破裂剧烈区域进行定位 ,利用电磁辐射监测技术工作面非接触连续预测 ,再结合现有的环境监测系统监测的瓦斯动态涌出对煤与瓦斯突出现象进行准确预测     

池火特性参数计算及其热辐射危害评价

可燃性油品池火的火焰及其产生的热辐射 ,可能导致周围人员伤亡或设备设施损坏。笔者介绍了油品池火的质量燃烧速率、火焰长度、火焰倾角及火焰后拖量等特性参数的计算方法 ,提出了池火热辐射强度的预测模型 ,给出了热辐射伤害 /破坏准则 ,并进行了模拟计算和评价。     

The effect of environmental conditions on the ability of a constructed wetland to disinfect municipal wastewaters

Constructed wetlands are widely used all over the world for the treatment of municipal wastewaters, which are characterized by high concentrations of pathogens. The objectives of this study were (1) to study the effect of solar radiation and temperature on the ability of a constructed wetland to reduce the concentration of total coliforms (TC), and (2) to evaluate the relationship between the presence of Salmonella spp. in the outflow and the concentration of TC. The results of this study showed that under Mediterranean environmental conditions, the percentage reduction in coliforms was lower during winter compared to all other seasons. Maximum removal of coliforms was achieved under conditions of high solar radiation and temperature. In addition, solar radiation was found to play a greater role in coliform die-off at low temperatures than at high temperatures. Finally, it was found that the probability of Salmonella spp. appearance in the outflow of the wetland was related to the concentration of TC. The increase in coliform bacteria in the effluents also increased the chances of Salmonella appearance. The risk of Salmonella spp. appearance in the outflow is minimized when the concentration of TC is below 10²/100 mL.     

The risks of radiation

Summary The risks of radioactivity are a really complicated matter, yet they are much better known than are the risks relating to thousands of chemical poisons that occur in our environment. The greatest mistakes are probably made in the definition of safety margins. Except for the bombs dropped in Japan and one other case in the Marshall Islands, there has always—luckily—been a wide safety margin between fallout radiation and doses dangerous to health; the margin has actually been about 1000-fold. The Chernobyl dose of 0.5 mGy/year that we received is only 1/1000 of the acute dose of 0.5 Gy which would cause a slight and nonpermanent change in the blood picture.There is no such safety margin with respect to many air pollutants. The safety standards for sulfuric or nitric oxides, ozone and so on, have been set only just below the level that already causes a health hazard, and these standards are exceeded once in a while. Otherwise, traffic would have to be forbidden and many industrial plants, especially power stations using coal, would have to stop working whenever a low-temperature inversion occurred. Environmental radioactivity does not represent a likely health risk in Finland unless a nuclear war breaks out. Air pollutants, on the contrary, are a real and almost daily health risk that should be carefully considered when decisions about our energy production are being made.In spite of what happened at Chernobyl, global consumption of nuclear power will double by the year 2000, since there are about 140 nuclear power plants presently under construction. It is not likely that another catastrophe like Chernobyl will happen, yet nuclear plant accidents are of course possible, even if their likelihood is diminished by improving reactor safety and even if any eventual damage could be expected to be smaller. If a reactor is hooded by a containment structure, no significant release of radioactive materials should be possible even in case of an accident. However, we must be prepared to protect the population with carefully planned civil defense and radiation protection measures.I would like to sum up all of this as follows: The risks of radiation are a fact, but the fear they arouse is often disproportionate. There are risks related to all other methods of energy production as well; nuclear power is no exception in that respect. It is good that we aim at greater safety, but I hope that false presumptions will not lead us to mistaking a less safe alternative for a safer one.     

Radioactivity Monitored From Moored Oceanographic Buoys

The principles and operation of a gamma radiation sensor mounted on oceanographic buoys are described. the sensor has proved rugged in severe weather conditions and has satisfactory detection limits and accuracy. Continuous monitoring of artificially produced γ-emitters such as ¹³⁷Cs, ¹³⁴Cs, ¹³¹I, ¹³³I, ¹³²Te, naturally occuring emitters such as ⁴⁰k and ²¹⁴Bi in open sea conditions can provide important information in critical situations.     

放射性表面污染测定应注意的几个问题

对放射性表面污染如何准确测量的细节问题进行了较详尽的阐述。     

The effect of elevated UV-B (280–320 nm) radiation levels on Silene vulgaris: A comparison between a highland and a lowland population

Highland (altitude 1600 m above sea level) and lowland (altitude −2 m below sea level) populations of the perennial herb Silene vulgaris (Moench) Garcke, were tested on their response to elevated levels of UV-B radiation. Highland populations typically receive high natural UV-B fluxes, whereas lowland populations receive a lower natural UV-B dose. Adaptation to high UV-B levels of the highland population is to be expected. Experimental comparison of growth rates, gas exchange rates, transpiration and biochemical parameters using adult plants as well as seedlings did not show a difference in the response to elevated UV-B levels between the two populations. Individuals of both populations were relatively insensitive to elevated UV-B radiation. The response of alpine and lowland populations of Silene vulgaris is discussed in relation to the dispersal of this species after the last ice age.     

Effect of Additives on the Improvement of Mechanical and Degradable Properties of Photografted Jute Yarn with Acrylamide

The jute yarn was grafted with acrylamide monomer (AA) under ultraviolet (UV) radiation to modify its mechanical and degradable properties. A number of AA solutions of different concentrations in methanol (MeOH) along with photoinitiator Irgacure 907 [2-methyl-1-(4-methylthiophenyl)-2-morpholinopropanone-1] were prepared. The monomer concentration and irradiation time were optimized. Jute yarn grafted with 30% AA under UV radiation for 60 min showed of the highest polymer loading (PL) value of 22% with a enhanced tensile strength (TS) value of 195% and elongation at break (Eb) value of 256% compared to untreated jute yarn. To further improve the properties of jute yarn, a number of additives (1%) such as urea, polyvinylpyrrolidone, urethane acrylate, and urethane diacrylate were used in the AA (30%) solution. Among all the additives used, urea significantly influenced the PL (27%), TS (230%), and Eb (264%) values of the treated jute yarns. Water uptake and the degradation properties of treated and untreated jute yarn caused by simulated weathering and in soil (25% water) were also studied. The rate of degradation of grafted sample is lower then that of untreated sample. DSC studies showed the thermal stability of the AA plus urea grafted sample.     

电磁辐射危害现状及对策的研究

本文着重讨论了工厂射频设备对操作人员的危害和防治对策。具体研究内容包括射频设备电磁辐射对操作人员危害的调查;射频设备场强分布规律的研究;采用系统工程方法,建立数学模型对全国射频设备和从事作业人员进行测算;提出防治电磁辐射危害的对策。调查和测试了全国150多个单位,运用模糊数学理论,将测得的3.5万个数据用计算机进行处理,得出全国现有射频设备总台数和从事射频作业人员数。通过研究找出了今后防治重点和解决电磁辐射危害的宏观对策。     

吉东山区总辐射资源的地理空间分布特征

本文以地理纬度、经度和海拔高度为因子,采用二次趋势面函数,建立了描述吉林省东部长白山区年总辐射、5～9月总辐射和日平气温稳定通过10℃期间的总辐射资源的地理空间分布特征的数学模式。采用地理细网格场的分析方法,揭示了该山区总辐射资源的空间分布情况。