Study on coupling between mineral resources exploitation and the mining ecological environment in Shanxi Province

Environment, Development and Sustainability - Due to rapid socioeconomic development, seeking the coordination of resources exploitation and the ecological environment has become an objective...     

Regulated emission characteristics of in-use LNG and diesel semi-trailer towing vehicles under real driving conditions using PEMS

On-road driving emissions of six liquefied natural gas(LNG) and diesel semi-trailer towing vehicles(STTVs) which met China Emission Standard IV and V were tested using Portable Emission Measurement System(PEMS) in northern China.Emission characteristics of these vehicles under real driving conditions were analyzed and proved that on-road emissions of heavy-duty vehicles(HDVs) were underestimated in the past.There were large differences among LNG and diesel vehicles, which also existed between China V vehicles and China IV vehicles.Emission factors showed the highest level under real driving conditions, which probably be caused by frequent acceleration, deceleration, and start-stop.NOx emission factors ranged from 2.855 to 20.939 g/km based on distance-traveled and 6.719–90.557 g/kg based on fuel consumption during whole tests, which were much higher than previous researches on chassis dynamometer.It was inferred from tests that the fuel consumption rate of the test vehicles had a strong correlation with NOx emission, and the exhaust temperature also affected the efficiency of Selected Catalytic Reduction(SCR) aftertreatment system, thus changing the NOx emission greatly.THC emission factors of LNG vehicles were 2.012–10.636 g/km, which were much higher than that of diesel vehicles(0.029–0.185 g/km).Unburned CH_4 may be an important reason for this phenomenon.Further on-road emission tests, especially CH_4 emission test should be carried out in subsequent research.In addition, the Particulate Number(PN) emission factors of diesel vehicles were at a very high level during whole tests, and Diesel Particulate Filter(DPF)should be installed to reduce PN emission.     

四环素胁迫对Shigella flexneri细菌四环素抗性基因抗性表达的影响过程

四环素(TC)抗生素在不同环境介质中已被广泛检出,为研究其对四环素抗性基因(TC-ARGs)丰度变化及表达水平的影响过程,以从活性污泥中筛选和纯化分离获得的弗氏志贺氏菌(Shigella flexneri)为研究对象,考察了不同浓度TC对其生长过程的作用影响,采用荧光定量PCR和逆转录PCR方法定量检测了不同抗性机制TC-ARGs,包括tetC、tetO和tetX基因的丰度变化及表达水平,并探讨了TC浓度与TC-ARGs丰度及其表达水平之间的相关关系.结果表明,在培养周期内(24 h),TC胁迫对Shigella flexneri细菌的生长具有抑制作用,细菌细胞浓度增长速率随TC暴露浓度的升高而降低,但对TC-ARGs丰度变化影响较小.TC胁迫能够促进Shigella flexneri细菌TC-ARGs的转录表达,tetC、tetO和tetX基因表达水平在整个培养周期内均先升高后降低.由相关性分析可知,TC浓度与TC-ARGs丰度及其表达水平之间相关关系不显著,但tetC和tetO基因丰度与其转录表达水平之间存在显著的正相关关系,表明其基因丰度一定程度上可用来衡量和评价其抗性表达水平.     

Adjusting sowing date and cultivar shift improve maize adaption to climate change in China

Mitigation and Adaptation Strategies for Global Change - This study investigates the impact of climate change on spring and summer maize (Zea mays) yield and evaluates several adaptation measures...     

基层卫生医疗机构财务管理战略对环境污染的影响分析研究

基层卫生医疗机构财务的优化管理能降低环境污染,定量分析基层卫生医疗机构财务管理战略对环境污染的影响,优化基层医疗机构的财务管理水平,从而抑制环境污染,提出基于关联规则统计分析模型的基层卫生医疗机构财务管理模型。结合定量回归分析方法进行环境污染的影响因素分析,采用解释变量的相关性分析方法进行统计平均检验,构建检测统计量和判决统计量进行环境污染影响及医疗卫生结构财务管理的关联规则分析评估,提高基层医疗结构财务管理的智能化水平。     

应用氧化锌改性沸石的城市污水重金属离子去除技术研究

天然沸石具有离子交换能力,但其中含有很多杂质,离子结合性强弱不一,导致交换性能较低,可以通过化学改性来提升沸石的交换性能。对应用氧化锌改性沸石的城市污水重金属离子去除技术进行研究。测试过程中,使用自来水对沸石填料进行反向冲洗,废水经过水泵提升之后,分别进至3个交换柱中,流过沸石填料,流量通过水阀门进行控制,试验每隔0.5 h~1 h进行取样1次,并分别取进水与出水的水样,读取测压管,对水头损失进行计算。     

关于室内装修有害气体烘焙排风稀释技术数值研究

依据实测数据,应用数值计算手法,对烘焙排风稀释技术不同工况下总挥发性有机化合物的排除量、烘焙排风稀释阶段室内空气中总挥发性有机化合物的浓度变化进行计算并讨论烘焙温度、换气次数对去除效果的影响。     

餐饮废水处理技术探讨

介绍了我国餐饮业的发展趋势，指出餐饮废水已经成为城市的主要高浓度污染源之一，同时适当地讨论了目前餐饮废水处理技术研究的现状以及处理系统的技术要求，最后提出了对不同规模的餐饮废水处理的适当方法。     

旋流器在船舶舱底含油污水分离中的应用

分析了船舶舱底含油污水的特性，讨论了船舶油水分离器的现状及使用中存在的问题，提出了使用旋流器对船舶舱底含油污水进行预处理，以改善进入船舶油水分离器的水质及减轻管理人员负担。     

油田采出水处理技术与发展趋势研究

油田采出水具有水量大,水质复杂,处理难度高等一系列特点,因此寻求合适的处理技术一直是油田面临的主要问题.针对油田采出水的产生和特点,介绍了近年来研究较多的油田采出水处理技术,主要包括分离技术、过滤技术、膜技术、气浮技术、吸附技术等物理法;盐析技术、混凝沉淀技术、化学氧化技术、电化学处理技术等化学和物理化学法;活性污泥技术、生物滤池技术等生物法,并概述了油田采出水处理技术的最新研究成果.通过对现有技术分析,总结出当前油田采出水处理中存在的问题,并对存在的处理难点做出了分析,提出了油田采出水处理技术的发展趋势.