规模化养殖畜禽粪便量估算及环境影响研究

利用规模化养殖的空间信息,结合面积比例法,获取畜禽养殖统计数据.在此基础上,进行了畜禽粪便量和纯养分估算及对土壤环境影响研究,辅以土壤耕层和亚耕层中有效磷含量及变化来阐释畜禽粪便对土壤环境污染的影响.以北京市大兴区为例,对该区规模养殖畜禽粪便量进行估算,评估了其对环境的影响,验证了该方法的准确性、合理性.结果表明,大兴区2005年耕地畜禽粪便磷养分负荷为93.72kg/hm2,其中规模化养殖耕地畜禽粪便磷养分负荷为57.56kg/hm2.耕层及亚耕层的有效磷含量远高于背景值,且变异系数分别为72.66%和79.12%,富集系数(耕层/亚耕层)为2.31,变异系数和富集系数进一步说明了规模化养殖畜禽粪便对土壤环境污染影响程度.     

供水管壁的磷释放对管网水质生物稳定性的影响

为了研究供水系统金属管壁磷释放及其对管网水质生物稳定性的影响,采用新旧有水泥涂衬球墨铸铁管,考察了管壁和水泥涂衬中磷的含量,管网水中可同化有机碳(AOC)、异养菌平板计数(HPC)及生物可利用磷(MAP)的变化规律.结果表明,在铸铁管金属管壁和水泥涂衬中均有磷元素及其他微生物生长所需微量元素存在.旧管和新管均可向悬浮水中释放磷元素并可被微生物吸收利用,旧管释放水平高于新管;同时旧管释放产生的AOC和旧管水中的HPC也明显高于新管;新管对水中pH值有明显影响,但随时间推移逐渐减弱.     

A novel extraction method for analysing available sulfamethoxazole in soil

A novel extraction method was established to determine the water-extractable (available) content of sulfamethoxazole (SMX) in soil. The SMX imprinted polymers (MIPs) were synthesised and the performance was evaluated by Fourier transform infrared spectroscopy, scanning electron microscopy and binding experiments. Results showed that the MIPs exhibited good selectivity for SMX, so the MIPs were applied as a sorbent. SMX in soil was extracted by water, sorbed from the extract to MIPs and analysed with a high performance liquid chromatography (HPLC) after its desorption from MIPs. Meanwhile, the classic organic solvent extraction was employed to measure the total SMX content in soil. Results showed that when SMX level in spiked soils varying from 1.0–500?μg?kg^?1, the observed recoveries of available SMX contents ranged from 63.27?±?3.11% to 82.11?±?2.77% (n?=?3), while the total SMX varied between 89.59?±?1.65% and 97.64?±?3.92% (n?=?3). The detection limit of the developed method for SMX in soils was 0.05?μg?kg^?1. Available SMX contents in five field soil samples ranged from 0.13 to 4.14?μg?kg^?1, which were only 0.35–25.40% of the respective total SMX contents. Results from this study manifest the importance of the extents of SMX immobilisation with different soils for assessing SMX's ecological and human health risks.     

塔里木河下游第五次应急输水后地下水恢复量的计算

依据塔里木河下游应急输水前与第五次第一阶段输水后地下水的监测资料,分析了输水前后地下水位的响应特征:地下水位在应急输水前持续下降,呈近似水平状态;输水后则由于接受了河道渗漏的补给,地下水位表现出逐次回升的趋势且受输水的影响,宽度(距离河道)也随之加大。在此基础上,逐断面拟合了第五(I)次输水后地下水位与离河距离的二次多项式方程,同时运用地下水水均衡的原理,推导了计算地下水净恢复量的数学公式,并以此为工具对第五(I)次输水后地下水的净恢复量进行了计算。     

COLIWAVE a simulation model for survival of E. coli O157:H7 in dairy manure and manure-amended soil

A simulation model was developed to investigate the relative effects of temperature, oxygen concentration, substrate content and competition by autochthonous microbial community on the oscillatory behaviour and survival of Escherichia coli O157:H7 in manure and manure-amended soil. The overall decline in E. coli O157:H7 was primarily determined by competition with autochthonous copiotrophic bacteria simulated by an inter-specific competition term according to Lotka-Volterra. Oscillations of bacterial populations were attained by the relationships between relative growth and death rates with readily available substrate content. The model contains a logistic and exponential relation of relative growth and death rates, respectively, of E. coli O157:H7 and copiotrophic bacteria with temperature, resulting in optimum curves for net growth rates similar to the curves reported in the literature. The model has been both calibrated and validated on experimental data. The model was used to perform sensitivity analysis and to evaluate different manure and soil management scenarios in terms of survival of E. coli O157:H7. The relative effects of changes in temperature on simulated survival time of E. coli O157:H7 were more pronounced than changes in oxygen condition. Testing manure storage scenarios with realistic data revealed that manure stored in a heap that was turned every week resulted in almost 70% reduction of E. coli O157:H7 survival compared to unturned manure. At the surface of a heap with unturned manure, simulated survival time was the longest (2.4 times longer than inside the same heap). The simulation model provides a new approach to investigating dynamic changes of invasive microorganisms in natural substrates such as manure or manure-amended soil.     

银杏叶中有效成分的提取

通过使用不同溶剂比较了两种装置提取银杏叶中有效成分的优缺点。结果表明，简易装置所用时间较短、收率较高且操作简单方便；利用95％乙醇作为提取剂在使用简易装置时，银杏叶粗提物得率最高。     

Vent Sizing Criteria for Partial Volume Deflagration

The accidental spill of volatile solvents or the release of flammable gases within equipment and buildings is likely to form fuel concentration gradients unless efficient mixing is provided. As a consequence, even small amounts of fuel can form flammable clouds, and partial volume deflagrations may occur. Nevertheless, few indications are given in international guidelines for vent sizing and only over-conservative well-mixed stoichiometric assumptions are used. In this paper, we propose a predictive methodology for the evaluation of the dynamics of partial volume deflagration, aiming at defining useful correlations for the design of vent devices, starting from the fundamental equation for the rate of pressure rise and flame propagation in closed vessel. We define a ‘stratified gas deflagration index’ K_G(m), where m is the filling ratio, and use it with the most common design equations for vent sizing. The approach has been validated by means of a CFD code for the simulation of stratified laminar methane–air explosion by varying both filling ratio and volume.     

液化石油气钢瓶长径比研究

分析钢瓶的长度和直径之比(长径比)对容积变形率的影响,在材料相同的条件下,长径比大的气瓶的容积变形率的要求也相应提高。笔者分别从钢瓶的边界效应、冲压工艺、制造经济性3个方面探讨了液化石油气钢瓶的合适长径比,并综合提出了液化石油气钢瓶的长径比的适宜范围为0.8～1.6。     

含炭织物材料的吸附性能比较研究

本文以三类典型含炭织物材料为研究对象,对它们的孔结构、吸苯量和吸二正丙基硫醚（DPS）量进行测试。结果表明：三种含炭织物材料的吸附性能有较大差异,且其微孔容积与静态吸苯量和吸DPS量之间的关系呈线性关系。     

建筑物最佳机械排烟量的研究

基于工程性能的防排烟设计,最佳机械排烟量的确定是个关键性的问题。在分析火灾中烟流性状的基础上,给出了火灾安全疏散判别依据,从烟控系统性能化设计的角度提出了最佳机械排烟量的基本思想,并利用实例进行了验证。计算结果表明:综合了安全性和经济性的最佳排烟量定义是正确的,该建筑物的最佳机械排烟量为72m3/(h.m2)。研究成果对建筑物防排烟系统的性能化设计具有重要参考价值。