软质防弹材料的发展

近年来,软质防弹材料发展非常迅猛,本文系统地分析了软质防弹材料的防弹机理及其影响因素,提出了防弹装备设计的关注点。     

驾驶员脑电模糊熵与酒后驾车交通事故倾向相关性研究

少数驾驶员适度饮酒后安全驾驶能力不降反升和不同人对酒精作用存在个体差异的事实表明:利用血液酒精浓度(BAC)判定酒后驾车行为的技术方案存在不足。为探索新型量化参数,结合酒后状态诱发试验和模拟驾驶测试,测取12位驾驶员不同程度饮酒后的脑电(EEG)和规范化交通事故倾向指标。结果发现:随着饮酒量的增加,驾驶员左额叶区EEG的瞬时复杂度和长时周期度都增加。结合模糊熵算法构造并计算EEG特征参数。相关性分析表明:在驾驶员从未饮酒到重度饮酒的过程中,其左额叶区EEG模糊熵和规范化事故倾向指标间的平均相关系数为0.76,二者正相关。因此,根据该模糊熵变化能判断其酒后安全驾驶能力的变化。     

典型进口废物循环利用技术园区投资建设模式研究

随着社会经济的快速发展、资源及原材料需求量的不断增加,以进口废物为原料进行加工利用的循环经济园区也随之蓬勃发展。循环经济产业园区建设过程中有投资巨大、资本回收周期长、投资主体众多的特点。在考虑经济效益的同时,也要统筹考虑社会效益和环境效益,因此选择何种投资建设模式来指导园区建设具有十分重大的意义。本文通过对国内三省的四个园区投资建设模式的调查研究,分析对比了不同投资建设模式的典型特征,总结概括了不同模式之间的优缺点,为同类园区的开发建设提供了有益参考。     

绥棱县城镇环境噪声变化趋势的研究

绥棱县环境监测站自1987年以来,每年对城镇环境噪声进行一次监测。经过多年监测,获得监测数据30多万个,通过对比得出：工业噪声源的影响在逐年变小,工业声源影响构成百分比由20年前的38%降至现在的20%,但局部地区对附近居民的影响依旧存在;随着城镇建设速度的加快,建筑施工噪声源的影响在逐年加大,施工声源构成百分比由20年前的2%增加到12%;随着交通运输业的发展,车流量的逐年增多,道路交通噪声污染在逐年加重,超标路段由20年前的13.7%上升到现在的32.3%;目前处于超标环境中的面积率和人口率分别为51.9%和69.2%,白天居民生活居住区和混合区噪声污染较重,夜间有三分之一居住混合区污染还很严重。     

苏北农房易损性分析研究

分析研究农村房屋易损性是防震减灾工作中必不可少的一部分.本文通过对苏北地区自然村民房的随机调查,分析其存在的问题,对其做出易损性的分析研究.苏北地区农房抗震性能总体水平较低.随着农村经济的发展和提高,应加强农村民居防震减灾工作指导,提高农村民居抗震能力.     

扎龙保护区野生丹顶鹤种群现状及保护对策

对多年扎龙湿地野生丹顶鹤的种群数量及繁殖情况的调查数据作了详细统计,阐述了种群数量和繁殖巢数变化的原因,分析了丹顶鹤生存环境面临的威胁因素,并提出了相应的保护措施.     

梯级拦河堰对典型山地城市河流重金属元素的滞留效应:以重庆市梁滩河为例

梯级拦河堰通过改变水力条件的方式将大量重金属元素滞留到河底沉积物中,滞留在沉积物中的重金属会长期影响地表水质和水生态.在2020年5月采集位于重庆市主城区、布设有梯级拦河堰的典型山地城市河流——梁滩河干流河底沉积物,并监测各河段内沉积物累积量和样品中重金属元素含量以及其它基本理化指标.结果表明,梁滩河干流沉积物ω（As）、ω（Cd）、ω（Cu）、ω（Hg）、ω（Ni）和ω（Pb）均值分别为（4.66±4.78）、（0.361±0.256）、（32.30±14.38）、（0.069±0.039）、（33.47±15.37）和（26.34±11.52） mg·kg^-1,由于污染源空间分布不均和梯级拦河堰对河流连通性的破坏,各点位沉积物重金属含量有着较大的空间变异系数.改进的地累积指数（I_m）显示,Cd是沉积物中污染水平最高的重金属元素;有12.50%的监测点位处于偏中度或中度污染水平,污染主要分布于建设用地集中的上下游区域.潜在生态风险评价指数法（RI）和沉积物质量基准法（SQGs）显示,除污染水平较高、毒性强的Cd和Hg外,流域内背景值含量较高的Ni也对地表水生态风险形成威胁.在梯级拦河堰的影响下,干流沉积物中滞留As、Cd、Cu、Hg、Ni和Pb总量分别为446.10、47.28、4997.80、10.81、5135.68和4048.16 kg,其中Cd、Ni和Pb会长期威胁地表水生态安全.由于较高的重金属滞留总量和更易形成厌氧环境,各级拦河堰上游附近河段也是重金属内源释放所需关注的重点区域.利用主成分分析和聚类分析解析沉积物中重金属元素来源：Cd、Cu和Pb主要源于居民/工业点源污染;Hg主要源于农业面源污染;As和Ni主要源于自然土壤侵蚀.     

Biofuel development, food security and the use of marginal land in China

With concerns of energy shortages, China, like the United States, European Union, and other countries, is promoting the development of biofuels. However, China also faces high future demand for food and feed, and so its bioenergy program must try to strike a balance between food and fuel. The goals of this paper are to provide an overview of China's current bioethanol program, identify the potential for using marginal lands for feedstock production, and measure the likely impacts of China's bioethanol development on the nation's future food self-sufficiency. Our results indicate that the potential to use marginal land for bioethanol feedstock production is limited. Applying a modeling approach based on highly disaggregated data by region, our analysis shows that the target of 10 million t of bioethanol by 2020 seems to be a prudent target, causing no major disturbances in China's food security. But the expansion of bioethanol may increase environmental pressures due to the higher levels of fertilizer use. This study shows also that if China were able to cultivate 45% of its required bioethanol feedstock on new marginal land, it would further limit negative effects of the bioethanol program on the domestic and international economy, but at the expense of having to apply another 750 thousand t of fertilizer.     

Effects of the "Conversion of Cropland to Forest and Grassland Program" on the water budget of the Jinghe River catchment in China

In 1999 China adopted the "Conversion of Cropland to Forest and Grassland Program" (CCFGP), a nationwide ecological recovery program, to minimize wide-scale soil erosion and vegetation degradation in China, as well as to improve water budgeting results. In the 10 yr since implementation, the CCFGP has resulted in the recovery and reforestation of >100,000 km of cropland and bare land, though the quantitative effect of this program on catchment water budget is not entirely clear. Therefore, we used the Soil and Water Assessment Tool to evaluate and quantify the effects of the CCFGP on the water budget of the Jinghe River catchment, a tributary of the Yellow River covering the central region of the Loess Plateau. Our results indicated that precipitation had dropped by 12.0% from the 1970s (611.6 mm) to the 2000s (538 mm) and that there was a corresponding 25.2% decrease in humidity index from 0.48 to 0.36. Before the CCFGP's implementation, forest and grassland had been decreasing, while bare land, cropland, and shrub land had been increasing. After the implementation of the CCFGP, the opposite trend was observed. Moreover, streamflow increased by about 15 and 20% for the upstream and middle stream subbasins, respectively, while soil water content also showed an obvious increase. Over the same period, evapotranspiration decreased by 5.2 and 13.5 mm and runoff decreased by 37.5 and 38.6% in the two subbasins. The same trends were obtained in the downstream subbasin, where changes were even greater. As a result of the reduced runoff and evapotranspiration, utilization of water resources was more efficient and ecological environment was improved under the CCFGP policy. Our results indicate the CCFGP resulted in a favorable ecological impact and should therefore be maintained.     

环境中多环芳烃(PAHs)的生物标志物的功效分析

污染物的生物监测一直是环境风险评估研究的重要内容.肝脏中谷胱甘肽硫转移酶(glutathione-S -transferase,GST)、7-乙氧基-3-异吩恶唑酮-脱乙基酶(ethoxyresorufin-O-deethylase,EROD)、DNA-加合物(DNA-adducts)和胆汁中多环芳烃代谢物(PAH m...