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541.
为研究不同类型表面活性剂对煤润湿性的调控机理,首先将所选煤样的润湿性与煤样成分进行关联分析,然后采用透过高度法实验及量子化学计算相结合的方法研究表面活性剂对煤样润湿性的影响效果及机理。结果表明:煤的润湿性与煤中固有水分、灰分呈正相关关系,与煤中固定碳呈负相关关系;所选取的4种表面活性剂的加入会降低褐煤的亲水性,而对长焰煤、焦煤和无烟煤亲水性有提升作用,并且十二烷基硫酸钠对于这3种煤样亲水性的提升作用最为明显;表面活性剂分子、水分子及煤分子的表面静电势分布共同决定了表面活性剂对煤浸润性的影响。 相似文献
542.
Polybrominated diphenyl ethers in chicken tissues and eggs from an electronic
waste recycling area in southeast China 总被引:3,自引:0,他引:3
Xiaofei Qin Zhanfen Qin Yan Li Yaxian Zhao Xijuan Xi Shishuai Yan Mi Tian Xingru Zhao Xiaobai Xu Yongjian Yang 《环境科学学报(英文版)》2011,23(1):133-138
The levels and distributions of polybrominated diphenyl ethers (PBDEs) in chicken tissues from an electronic waste (e-waste)
recycling area in southeast China were investigated. Human dietary intake by local residents via chicken muscle and eggs was estimated.
The mean PBDEs concentrations in tissues ranged from 15.2 to 3138.1 ng/g lipid weight (lw) and in egg the concentration was 563.5
ng/g lw. The results showed that the level of total PBDEs (PPBDEs) in the chicken tissue was 2–3 orders of magnitude higher than
those reported in the literature. The large di erence of PPBDEs concentrations between tissues confirmed that the distribution of
PBDEs in tissues depend on tissue-specificity rather than the “lipid-compartment”. BDE-209 was the predominant congener (82.5%–
94.7% of PPBDEs) in all chicken tissues except in brain (34.7% of PPBDEs), which indicated that deca-BDE (the major commercial
PBDE formulation comprising 65%–70% of total production) was major pollution source in this area and could be bioaccumulated in
terrestrial animals. The dietary PBDEs intake of the local residents from chicken muscle and egg, assuming only local bred chickens
and eggs were consumed, ranged from 2.2 to 22.5 ng/(day kg body weight (bw)) with a mean value of 13.5 ng/(day kg bw), which was
one order of magnitude higher than the value reported in previous studies for consumption of all foodstu s. 相似文献
543.
The experimental study on ozonation of ethylenethiourea(ETU) is conducted.The reaction of gas-phase ETU with 0.63 × 10-6 mol/L ozone is carried out in a 200-L reaction chamber.The secondary organic aerosol(SOA) resulted from the ozonation of gas-phase ETU is observed with a scanning mobility particle size(SMPS).The rapid exponential growth of SOA reveals that the atmospheric lifetime of ETU vapor towards ozone reaction is less than four days.The ozonation of dry ETU particles,ETU-contained water droplets an... 相似文献
544.
Phosphorus is the restrictive factor of water eutrophication and phosphorus removal is the key point to control this phenomenon. It's also important to recover phosphorus resource from wastewater. Crystallization method was used to treat and recycle high concentration phosphorus wastewater, the selection of organic solvent, influence of volume ratio of organic solvent and wastewater, precipitation time and stirring speed on the production of crystal and its structure was investigated. Experimental results indicate that, with ethanol as extractant, under the condition of volume ratio of ethanol to wastewater being 1.5:1 and stirring speed about 200 r/min, crystal precipitated fast with fine crystal shape and purity, phosphorus removal efficiency more than 85% was obtained. 相似文献
545.
546.
Robert K. Dixon Xi Wang Michael Q. Wang Ju Wang Zhihong Zhang 《Mitigation and Adaptation Strategies for Global Change》2011,16(7):775-789
The demand for urban transportation in China, including cars, motorbikes, buses, and trains, is growing substantially. China’s
transportation fleet is projected to expand from 16 to 94 million vehicles between 2000 and 2020, with liquid and electricity
transport fuel demand growing from about 5 Quadrillion British Thermal Units (Quads) to over 20 Quads in 2035. In response
to energy security, economic growth and environmental protection needs, Chinese government agencies, academia and the private
sector have organized their programs and investments to advance development and demonstration of sustainable alternative transportation
systems. This analysis surveys historic development of fuel cell vehicle (FCV) including fuel cell buses (FCB) technology
in China, summarizes recent efforts to scale-up FCV development and associated infrastructure in major Chinese cities, and
briefly addresses future directions in Chinese fuel cell and hydrogen energy technology development. Since the late 1990’s,
Chinese universities, government institutions and the private sector have implemented research, development, demonstration
and deployment programs for electric (EV), fuel cell (FCV), and hybrid electric vehicles (HEV). These efforts have advanced
the feasibility of FCVs to be a part of sustainable urban transportation system, including technical performance, infrastructure,
and customer acceptance. Three generations of FCVs, START I, START II and START III have been developed, demonstrated and
deployed. Similarly, several generations of FCBs have been developed and demonstrated. Collectively, these efforts have demonstrated
and deployed over 1,000 FCBs and FCVs in several Chinese cities. Large-scale, intensive-use FCV and FCB demonstration trials,
including those during the 2008 Beijing Olympics and the 2010 Shanghai World Exposition (EXPO), have been successfully built
and operated. Infrastructure, such as hydrogen production facilities, fuelling stations, and maintenance stations have been
constructed and operated to support the fleets of FCBs and FCVs. Experiences learned from these FCV research, development,
and demonstration activities are the foundation for scaling up infrastructure and fleet trials in a growing number of cities
in eastern and western China. An aggressive research and development vision and 2020 technology performance targets provide
a foundation for the next generation of EVs, FCVs and HEVs, and, options for China’s efforts to develop a portfolio of sustainable
transportation systems. 相似文献
547.
无机添加剂对PVDF/PMMA/TPU中空纤维共混膜结构与性能的影响 总被引:2,自引:0,他引:2
采用相转化法制备纳米氧化物PVDF/PMMA/TPU共混中空纤维膜。测定共混膜的纯水接触角和黏度、并经扫描电子显微镜、共混膜的超滤实验和拉伸实验分别对不同添加剂膜的亲水性能、微观结构、超滤性能和机械性能进行了分析。结果表明,纳米氧化物的加入使膜的性能有明显的改善,其中无氧化物、添加SiO2、TiO2、Al2O3的PVDF/PMMA/TPU复合膜对牛血清白蛋白的截留率分别为28.7%、65.8%7、1.4%和79.6%,同时添加无机氧化物的膜水通量也较未添加无机氧化物的膜有所提高;而且无机氧化物的加入还能改善膜的亲水性能和机械性能。 相似文献
548.
为有效提高雾化降尘效率,以长焰煤为例,从接触角、表面张力静态试验和粒径测定、喷雾降尘动态试验角度切入,探究不同类型表面活性剂与无机盐的协同关系,进而优选出降尘效果最佳的配比方案。研究结果表明:阴与阴、阴与非、非与非离子复配型表面活性剂与无机盐之间均存在显著协同效应,且通过正交试验可确定协同效果最优的3组配方及其最佳浓度;对比清水,3组配方的平均粒径均有所减小,降尘效率均有大幅提升。综合优选出的最佳配比为质量分数0.08%的仲烷基磺酸钠、0.04%的曲拉通X-100和0.04%的氯化钙复合配制的溶液,该方案的全尘降尘效率为92.55%,比清水提升79.95%;呼尘降尘效率为91.27%,比清水提升82.36%。 相似文献
549.
MBR污水处理工艺中活性污泥动力学参数测定 总被引:5,自引:1,他引:4
缺乏可靠的污泥动力学设计参数是膜-生物反应器(membrane bioreactor,MBR)工艺在实际应用中遇到的主要问题之一.以某座处理城市污水的实际规模MBR工程的好氧活性污泥为对象,采用耗氧速率表征方法,测定计算得到以下动力学参数值:异养菌产率系数YH=0.693、自养菌产率系数YA=0.263、异养菌衰减系数KdH=0.108 d-1、自养菌衰减系数KdA=0.089 d-1、COD最大比去除速率vmS=1.94 mg·(mg·d)-1、COD去除半饱和常数KS=34.6 mg·L-1、氨氮最大比去除速率vmN=0.18 mg·(mg·d)-1、氨氮去除半饱和常数KN=1.06 mg·L-1.以上结果与传统活性污泥法工艺(CAS)中污泥的文献报道值相比,YH和KdH较高,而vmS和vmN较低.MBR的高污泥浓度条件可能是导致上述差异出现的主要原因. 相似文献
550.