河床演变影响下桥区水域通航安全研究

为了科学地设定滩槽易变河段处的桥梁跨径布置方案,针对荆州长江大桥桥区水域河床演变影响通航安全的问题,采用实例调研及历史资料分析的方法,指出滩槽易变河段选址建设的桥梁,其最大风险是滩槽移位导致船舶从通航孔位置移动到非通航孔位置,提出新建桥梁通航孔布置应覆盖深泓和可能成为航道的深槽的摆动范围;根据提出的原则研究拟建的李埠桥...     

Highly efficient conversion of sugarcane bagasse pretreated with liquid hot water into ethanol at high solid loading

Liquid hot water (LHW), an environmental-friendly physico-chemical treatment, was applied to pretreat the sugarcane bagasse (SCB). Tween80, a non-ionic surfactant, was used to enhance the enzymatic hydrolysis of the pretreated SCB. It found that 0.125 mL Tween80 /g dry matter could make the maximum increase (33.2%) of the glycan conversion of the LHW-pretreated SCB. A self-designed laboratory facility with a plate-and-frame impeller was applied to conduct batch hydrolysis, fed-batch hydrolysis, and the process of high-temperature (50°C) fed-batch hydrolysis following low-temperature (30°C) simultaneous saccharification and fermentation (SSF) which was adopted to overcome the incompatible optimum temperature of saccharification and fermentation in the SSF process. After hydrolyzing LHW-pretreated SCB for 120 h with commercial cellulase, the total sugar concentration and glycan conversion obtained from fed-batch hydrolysis were 91.6 g/L and 68.3%, respectively, which were 9.7 g/L and 7.3% higher than those obtained from batch hydrolysis. With Saccharomyces cerevisiae Y2034 fermenting under the non-sterile condition, the ethanol production and theoretical yield obtained from the process of SSF after fed-batch hydrolysis were 55.4 g/L and 88.3% for 72h, respectively, which were 15.5 g/L and 24.7% higher than those from separate fed-batch hydrolysis and fermentation. The result of this work was superior to the reported results obtained from the LHW-pretreated SCB.     

虹膜识别在肉类食品安全追溯系统中的应用及关键技术研究

为了提高大型动物肉类食品的安全性,在研究肉类食品供应链的安全管理的基础上,将大型动物的虹膜识别技术引入食品供应链管理中,构建基于虹膜识别的大型动物肉类食品安全可追溯系统,达到肉类食品安全信息查询及出现安全问题后的个体溯源的目的。借鉴人眼虹膜识别的相关技术,以牛眼为例对大型动物虹膜识别的相关算法和虹膜定位等关键技术进行研究,运用改进的Sobel算子对图像进行边缘检测;引入二次B样条曲线算法实现了牛眼虹膜的精确定位;分析牛虹膜纹理特征的分布特点,实现了虹膜特征区域的提取及归一化处理。研究成果对大型动物的虹膜识别研究和肉类食品供应链安全管理具有一定的参考意义。     

青藏公路路堤边坡水土保持措施及效益分析

公路建设加速了区域的原有侵蚀,为了摸清公路边坡的侵蚀特征,寻找有效的防治措施,在青藏公路边坡布设不同水土保持措施的径流观测小区,进行了两年的观测（2003年和2004年）,结果表明：（1）工程措施具有较好的水土保持效益,其减流（减沙）效益在第一年和第二年分别达到3883％（8189％）和48.72％（9581％）,其中截排水措施的水土保持效益一方面说明公路路面来水也是边坡侵蚀的重要动力,有效拦截路面来水将会极大地减少径流和泥沙,另一方面也说明要提高公路边坡土壤侵蚀的预测能力,应该将路面来水作为重要的驱动力之一;（2）植被措施可以起到一定的减流减沙效果,其中人工植被措施有很大的潜力,其减蚀效益都在50％以上;（3）综合措施表现出了极好的水土保持效益（减流在40％以上,减沙在97％以上）,尤其土工格室+植被措施,兼具水土保持与景观双重效益。该研究可以为青藏高原地区的水土保持设计和生态环境保护规划提供数据支持。〖     

固相微萃取-气相色谱法测定生活污水中壬基酚

采用固相微萃取-气相色谱法测定生活污水中的壬基酚,优化了萃取纤维涂层材料、萃取时间与温度、解析时间与温度、盐度、pH值、搅拌速度等试验参数。方法在0.001mg／L-1.00mg／L范围内线性良好,检出限为0.0006mg／L,标准溶液平行测定的RSD为7.6％,生活污水加标回收率为42.7％-74.0％。     

江苏省危险化学品生产状况调查分析及监管对策

根据《危险化学品名录》,分析江苏省取得危险化学品安全生产许可证的1774家企业的化学品种类、数量、生产企业类型分布情况.结果表明,江苏省危险化学品生产企业在地域分布上苏南多于苏北;化工、建材行业的危险化学品生产企业所占比例较高;危险化学品涉及除爆炸品外的6大类,达3 790种,以生产易燃液体的企业数目为最多;有31家企业生产10种以上危险化学品.笔者建议,通过评估摸清企业安全生产状况,严格控制危险化学品企业安全生产许可证发放,实现危险化学品运输企业的动态管理,建立安全监测预警技术平台.     

环境监测市场化管理工作思考

阐述了我国及其他国家环境监测市场管理的经验,以及我国在推进环境监测市场化管理方面的探索;指出了目前环境监测市场化管理中存在的问题,提出,应加快建立适合国情的监测总体格局;建立完善环境监测社会化监管制度体系;充分发挥行业协会在监管中的作用;强化对社会监测机构监管力度;提高社会环境监测机构能力。     

Diurnal concentrations variations,size distributions for ambient air particles and metallic pollutants (Cr,Mn, Ni,Cd, Pb) during summer season at a traffic area

This study characterized and discussed particulate ambient air particulate concentrations and seasonal variations for PM₁₈, PM₁₀, PM_2.5, and PM₁ during June 2013–July 2013 at this traffic sampling site. In addition, this study also characterized the ambient air particulates size distributions by using MOUDI-100S4 sampler to collect 1-day the ambient suspended particles (PM₁₈, PM₁₀, PM_2.5, and PM₁) at this sampling site. In addition, the study also showed that the main pollutants contributions were from traffic and residual areas. As for the pollutants seasonal concentrations variations, the results indicated that the average particle concentrations orders were all displayed as daytime?>?nighttime for PM₁₈, PM₁₀, PM_2.5 and PM₁ at this characteristic sampling site. The results further indicated that the mean highest of metal concentrations in this study indicated that the average metal concentration were all displayed as Mn?>?Cr?>?Ni?>?Pb?>?Cd for PM₁₈, PM₁₀, PM_2.5 and PM₁ on daytime and nighttime at this characteristic sampling site.     

Distribution and source analysis of aluminum in rivers near Xi’an City, China

To study the status and source of aluminum (Al) contamination, a total of 21 sampling sites along six rivers near Xi’an City (Shaanxi province, China) were investigated during 2008–2010. The results indicated that the average concentration of total Al (Al_t) in the six rivers increased by 1.6 times from 2008 to 2010. The spatial distribution of Al_t concentrations in the rivers near Xi’an City was significantly different, ranged from 367 μg/L (Bahe River) to 1,978 μg/L (Taiping River). The Al_t concentration was highest near an industrial area for pulp and paper-making (2,773 μg/L), where the Al level greatly exceeded the water quality criteria of both the USA (Criterion Continuous Concentration, 87 μg/L) and Canada (100 μg/L). The average concentration of inorganic monometric aluminum (Al_im) was 72 μg/L which would pose threats to fishes and other aquatic lives in the rivers. The concentrations of exchangeable Al (Al_ex) in the sediment of the Taiping River sampled were relatively high, making it to be an alternative explanation of increasing Al concentrations in the rivers near Xi’an City. Furthermore, an increasing Al level has been detected in the upstream watershed near Xi’an City in recent years, which might indicate another notable pollution source of Al.