煤矿工人个体安全防护装备的创新与改进

本文从井下工作人员所需穿戴的安全防护装备入手,结合矿井环境特点．探讨如何在现有装备的基础上进行改进,以提高工作时的安全系数,更好保护井下工作人员的身体健康．以及在事故发生时起到更好的救护作用。     

绿色合成膨胀石墨负载纳米零价铁去除水中Cd(Ⅱ)

工业生产中Cd(Ⅱ)对水体的危害,本文合成了两种新型吸附剂,纳米零价铁(nZVI)和膨胀石墨负载纳米零价铁(EG-nZVI).利用FESEM、EDS、TEM、XRD、FTIR及BET比表面积测定对nZVI和EG-nZVI进行表征,探讨了二者对溶液中Cd(Ⅱ)的去除效果.结果 表明,含有100 mg·L-1Cd(Ⅱ)溶液,nZVI和EG-nZVI的投加量分别达到0.4 mg·L-1和2 mg·L-1,在超声波辅助的条件下,常温、pH 8、反应30 min时,Cd(Ⅱ)去除率分别为56.3％和78.4％.EG-nZVI和nZVI去除Cd (Ⅱ)过程均符合伪二级动力学模型和Langmuir吸附等温模型;将吸附剂置于空气中不同时间,测定结果显示EG-nZVI对Cd(Ⅱ)的去除活性明显高于nZVI,说明EG-nZVI较nZVI有更高的去除效能和稳定性.     

Spatial and temporal patterns of soil erosion in the Tibetan Plateau from 1984 to 2013北大核心CSCD

Soil erosion has a critical effect on ecological security and socioeconomics, which may deteriorate ecosystem services and common human well-being. The revised universal soil loss equation (RUSLE) was applied to assess soil erosion from 1984 to 2013 in the Tibetan Plateau and analyzed the temporal and spatial variation of soil erosion intensity. Furthermore, the temporal and spatial variation rates of soil erosion were explored across different ecosystems. The results indicated that the annual soil erosion fuctuated in the Tibetan Plateau, the soil erosion intensity decreased from south to north, and the most serious soil erosion was mainly distributed in the southern Tibetan Plateau (Xigaze and Changdu regions, Lhasa, and north of the Shannan region). The soil erosion intensity was higher in shrub, alpine meadow, and sparse vegetation ecosystems. The highest soil erosion was found in alpine meadow (2.17 × 1010 t), followed by alpine grassland (1.59 × 1010 t) and sparse vegetation (1.30 × 1010 t) ecosystems. Meanwhile, although the most serious soil erosion intensity was found in the regions of 3 000-4 000 m altitude, the soil erosion was mainly observed in the regions of 4 000-5 000 m altitude. In the three most recent decades, annual soil erosion decreased at a rate of-1.78 × 108 t/a. Additionally, soil erosion mainly increased in south of the Qiangtang Plateau and in the periphery of the Qaidam basin. Decreased soil erosion was mainly found along the Hengduan Mountains, central Himalayas. Although the increased annual normalized difference vegetation index (NDVI) had positive effects for soil protection, changes in soil erosion was mainly controlled by the change of annual precipitation. Thus, the fragility of ecological systems and increased rainfall erosivity accounted for the obviously increased soil erosion in the alpine grassland ecosystem (1.19 × 10 t/a). However, increased ecosystem stability and decreased rainfall erosivity contributed to the decreased soil erosion in forest and shrub ecosystems, by-0.77 × 10 t/a and-1.65 × 10 t/a, respectively. The slightly decreased rainfall erosivity accounted for a decrease of soil erosion in the sparse vegetation ecosystem (-0.44 × 10 t/a). Meanwhile, soil erosion has decreased in the alpine meadow ecosystem over the past 30 years, which may owing to the relatively higher NDVI that neutralized the increase of rainfall erosivity to some extent. This study revealed serious soil erosion regions and ecosystems in the Tibetan Plateau and explored possible reasons for variations in soil erosion in different ecosystems, which may provide a scientific reference for soil erosion conservation and control in the near future. © 2018 Science Press. All rights reserved.     

Measurement and Modelling of Ammonia Emissions at Waste Treatment Lagoon-Atmospheric Interface

Global emissions of ammonia are approximately 75 Tg N/yr (1 Tg =10¹²g). The major global source is excreta from domestic animals ( 32 Tg N ^-1yr^-1). Waste storage and treatment lagoonsare used to treat the excreta of hogs in North Carolina (NC). Proteins and nitrogen rich compounds in the lagoon are convertedto ammonia, through a series of biological and chemical transformations. The process of ammonia emission has been investigated using two different model approaches: (1) CoupledMass Transfer with Chemical Reaction Model (Model I), and (2)Mass Transport without Chemical Reaction Model (Model II). Asensitivity analysis is performed with the models, and the modelresults are compared with ammonia emission experiments at a swinewaste storage and treatment lagoon in NC using a dynamic emissionflux chamber.Results of model predictions of emission flux indicate an exponential increase in ammonia flux with increasing lagoontemperature and pH, a linear increase with increasing lagoontotal ammoniacal nitrogen (TAN), and a secondary degree increasewith the increasing wind speed. In addition, the fluxes predictedby Model I are consistently larger than fluxes predicted by Model II. Experimental values of flux agreed well with model predictions, with the experimental values lying in different positions between the two model predictions under different physical and chemical conditions. Further, when compared to diurnal and seasonal experimental flux values, Model I corroborates the results in calm meteorological conditions (windspeed U10 = 1.5 m s^-1). However, the observed results are better predicted by Model II during unstable conditions, when wind speeds are higher than 2.0 m s^-1 and physical transfer process functions dominate.     

Occurrence and fate of pharmaceuticals and personal care products (PPCPs) in biosolids

Each year, large quantities of pharmaceuticals and personal care products (PPCPs) are used worldwide. Once conveyed to wastewater treatment plants, PPCPs can remain unchanged or undergo partial or complete transformation during wastewater treatment processes before discharge into the environment via effluent and biosolids for land application. Biosolids can be a major sink for some PPCPs. Previous investigations have indicated that land application of biosolids may be a potential important route through which PPCPs enter the environment. However, no information is available on exactly how closely the concentrations of PPCPs in the environmental media are related to the land application of PPCP-containing biosolids. This paper reviews currently available information on the occurrence of PPCPs in biosolids, methods of analysis, the potential fate of PPCPs in biosolids-applied soils, and composting as a potential means for removal of PPCPs from biosolids.     

特大型双曲线自然通风冷却塔噪声治理设计及效果

火力发电厂闭式循环冷却水系统多数是采用钢筋混凝土结构自然通风冷却塔,其噪声污染治理是一个难题.本文以上海吴泾电厂八期1#、2#机组所用特大型双曲线自然通风冷却塔为例,介绍其噪声特性、控制措施及治理效果,可供同类冷却塔噪声控制参考.     

Estimation of 222Rn release from the phosphogypsum board used in housing panels

Phosphogypsum board is a popular construction material used for housing panels in Korea. Phosphogypsum often contains (226)Ra which decays into (222)Rn through an alpha transformation. (222)Rn emanated from the (226)Ra-bearing phosphogypsum board has drawn the public concern due to its potential radiological impacts to indoor occupants. The emanation rate of (222)Rn from the board is estimated in this paper. A mathematical model of the emanation rate of (222)Rn from the board is presented and validated through a series of experiments. The back diffusion effect due to accumulation of (222)Rn-laden air was incorporated in the model and found to have a strong impact on the (222)Rn emanation characteristics.     

Emergy evaluation perspectives of a multipurpose dam proposal in Korea

The 'emergy' concept was used to evaluate the economy of Korea and the contributions of a multipurpose dam proposal to the real wealth of the Korean economy. Emergy is defined as the available energy of one kind previously used up directly and indirectly to make a product or service. The indices for Korea calculated from the emergy evaluation were close to those of developed countries. Even though its monetary balance of payments was negative in 1997, the economy of Korea showed positive balance in trade when exports and imports were expressed in emergy. The emergy evaluation showed that the Korean economy places a large stress on its environment. Water supply and generation of electricity were the most important contributions of the proposed dam in terms of emergy; 46.5 and 45.1% of the total benefit, respectively. Flood control contributed 8.4% of the total benefit. Major costs associated with the proposed dam were from sediments (33.2% of the total cost), construction services (22.8%), and social disruption of the region (21.6%). In terms of emergy, the ratio of benefits to costs of the proposed dam was 2.78 if sediments are not included, and 1.86 if sediments are included, which result in more benefits than costs in both cases. The benefit to cost ratio of the dam was larger than that of the current system (1.42) without the dam whether sediments are included in the total cost or not. The environmental stress of the proposed dam was considerably lower than that of the Korean economy, but the dam might increase stress on local environment.     

Effect of 17beta-estradiol on the reproduction of Japanese medaka (Oryzias latipes)

Estrogenic compounds such as 17beta-estradiol (E2) and its analogs are present in the aquatic environment and can adversely affect the reproductive systems of aquatic organisms. Although E2 has been detected at a maximum concentration of 64 ng/l in effluents of sewage treatment works (STWs), few reports address the associated effects on reproduction in fish. Therefore, we exposed adult medaka (Oryzias latipes) to mean measured E2 concentrations of 29.3, 55.7, 116, 227, and 463 ng/l for 21 d and assessed the effects on the egg number and fertility of paired medaka during the exposure period. In addition, we determined the hepatic vitellogenin (Vtg) concentration and histologically assessed the gonads of these fish. The number of egg produced and fertility of the paired medaka exposed to 463 ng/l E2 were significantly less compared with those of the control fish. Males in all treatment groups had developed testis-ova. Males treated with E2 concentrations = 55.7 ng/l contained relating great concentrations of hepatic Vtg. Therefore, although only the greatest E2 concentration tested in our study affected fecundity and fertility, effects of E2 were observed on induction of Vtg and testis-ova in male medaka exposed to environmentally relevant concentrations of E2.     

经济植物复层栽培对三峡库区水土保持和移民经济的作用

三峡库区森林覆盖率低，水土流失严重。三峡工程兴建后，由于大量耕地被淹，移民后靠，库区的生态环境与移民经济之间的矛盾将会更加突出。本文提出了经济植物复层栽培方法，对其在减少库区水土流失、改善库区生态环境和解决库区移民经济方面的作用作了全面的论述。经济植物复层栽培是解决三峡库区生态环境和移民经济的基本途径，采用扩大种植农作物的方法来解决三峡库区移民经济问题将会加剧水土流失，使生态环境更加恶化。