上海典型燃烧源铅和汞大气排放趋势分析

上海百年来快速的城市化进程导致资源能源的大量消耗,并向城市环境中排放了大量有毒有害污染物.为探寻上海典型燃烧源重金属大气排放历史及趋势,基于上海化石燃料(煤炭和汽油)的历史消耗量及其大气铅(Pb)和汞(Hg)的排放因子,估算了上海主要燃煤部门(燃煤电厂、工业部门和居民生活)和机动车燃油大气Pb和Hg的历史排放量.结果表明,1949~2015年间大气Pb和Hg的燃煤排放量随时间推进均呈现先增长后下降趋势,即1949年解放后快速增长的煤炭消耗和较少的烟尘控制措施使其排放量出现急剧地波动式增长,至20世纪80~90年达到高峰,此后上海采取了各种减排和控制措施,使得目前三大燃煤源的大气Pb和Hg排放量出现大幅度下降.1980~2015年间上海大气Hg的燃煤排放比例一直占据主导地位(87.5%~99.7%).含铅汽油自1997年完全退出上海市场之后,燃煤排放替代其成为大气Pb的主要贡献源(78.2%~83.5%),然而自2005年起随着汽油消耗的急速增长,汽油燃烧排放又成为其主要贡献源(55.5%~79.1%).     

Difference in dummy responses in matched side impact tests of vehicles with and without side airbags

Objective: Insurance Institute for Highway Safety (IIHS) high-hooded side impacts were analyzed for matched vehicle tests with and without side airbags. The comparison provides a measure of the effectiveness of side airbags in reducing biomechanical responses for near-side occupants struck by trucks, SUVs, and vans at 50 km/h.

Method: The IIHS moving deformable barrier (MDB) uses a high-hooded barrier face. It weighs 1,500 kg and impacts the driver side perpendicular to the vehicle at 50 km/h. SID IIs dummies are placed in the driver and left second-row seats. They represent fifth percentile female occupants.

IIHS tests were reviewed for matches with one test with a side airbag and another without it in 2003–2007 model year (MY) vehicles. Four side airbag systems were evaluated: (1) curtain and torso side airbags, (2) head and torso side airbag, (3) curtain side airbag, and (4) torso side airbag.

There were 24 matched IIHS vehicle tests: 13 with and without a curtain and torso side airbags, 4 with and without a head and torso side airbag, 5 with and without a side curtain airbag, and 2 with and without a torso airbag. The head, chest, and pelvis responses were compared for each match and the average difference was determined across all matches for a type of side airbag.

Results: The average reduction in head injury criterion (HIC) was 68 ± 16% (P < .001) with curtain and torso side airbags compared to the HIC without side airbags. The average HIC was 296 with curtain and torso side airbags and 1,199 without them. The viscous response (VC) was reduced 54 ± 19% (P < .005) with curtain and torso side airbags. The combined acetabulum and ilium force (7 ± 15%) and pelvic acceleration (?2 ± 17%) were essentially similar in the matched tests.

The head and torso side airbag reduced HIC by 42 ± 30% (P < .1) and VC by 32 ± 26% compared to vehicles without a side airbag. The average HIC was 397 with the side head and torso airbag compared to 729 without it. The curtain airbag and torso airbag only showed lower head responses but essentially no difference in the chest and pelvis responses.

Conclusion: The curtain and torso side airbags effectively reduced biomechanical responses for the head and chest in 50 km/h side impacts with a high-hooded deformable barrier. The reductions in the IIHS tests are directionally the same as estimated fatality reductions in field crashes reported by NHTSA for side airbags.     

Effect of initial temperature on the explosion pressure of various liquid fuels and their blends

In this work, the effect of initial temperature on the explosion pressure, P_ex, of various liquid fuels (isooctane, toluene and methanol) and their blends (isooctane-toluene and methanol-toluene, with three different fuel-fuel ratios) was investigated by performing experiments in a 20-l sphere at different concentrations of vaporized fuel in air. The initial temperature was varied from 333 K to 413 K.Results show that, as the fuel-air equivalence ratio, Φ, is increased, a transition occurs from a “thermodynamics-driven” explosion regime to a “radiant heat losses-driven” explosion regime. The maximum pressure, P_max, is found in the former regime (Φ < 3), which is characterized by a trend of decreasing P_ex with increasing initial temperature. This trend has been explained by thermodynamics. In the latter regime (Φ > 3), P_ex increases with increasing initial temperature. This trend has been addressed to the decrease in emissivity (and, thus, radiant heat losses) with the increase in temperature.     

The Impending Peak and Decline of Petroleum Production: an Underestimated Challenge for Conservation of Ecological Integrity

Abstract: In the last few decades petroleum has been consumed at a much faster pace than new reserves have been discovered. The point at which global oil extraction will attain a peak (“peak oil”) and begin a period of unavoidable decline is approaching. This eventuality will drive fundamental changes in the quantity and nature of energy flows through the human economic system, which probably will be accompanied by economic turmoil, political conflicts, and a high level of social tension. Besides being a geological and economic issue, peak oil is also a fundamental concern as it pertains to ecological systems and conservation because economics is a subsystem of the global ecosystem and changes in human energy‐related behaviors can lead to a broad range of effects on natural ecosystems, ranging from overuse to abandonment. As it becomes more difficult to meet energy demands, environmental considerations may be easily superseded. Given the vital importance of ecosystems and ecosystem services in a postpetroleum era, it is crucially important to wisely manage our ecosystems during the transition period to an economy based on little or no use of fossil fuels. Good policies can be formulated through awareness and understanding gained from scenario‐based assessments. Presently, most widely used global scenarios of environmental change do not incorporate resource limitation, including those of the Millennium Ecosystem Assessment and the Intergovernmental Panel on Climate Change. Considering the potential magnitude of the effects of peak oil on society and nature, the development of resource‐constrained scenarios should be addressed immediately. Ecologists and conservation biologists are in an important position to analyze the situation and provide guidance, yet the topic is noticeably absent from ecological discussions. We urge politicians, corporate chief executives, thought leaders, and citizens to consider this problem seriously because it is likely to develop into one of the key environmental issues of the 21st century.     

Use of Surrogates to Predict the Stressor Response of Imperiled Species

Abstract: Rare or narrowly distributed species may be threatened by stressors to which they have never been exposed or for which data are very limited. In such cases the species response cannot be predicted on the basis of directly measured data, but may be inferred from the response of one or more appropriate surrogate species. Here, I propose a practical way to use the stressor response of one or more surrogate species to develop a working hypothesis or model of the stressor response of the target species. The process has 4 steps: (1) identify one or more candidate surrogate species, (2) model the relationship between the stressor and the response variable of interest for the surrogate species, (3) adapt the stressor–response relationship from the surrogate species to a model for the target species, possibly using Bayesian methods, and (4) incorporate additional data as they become available and adjust the response model of the target species appropriately. I applied the approach to an endangered fish species, the amber darter (Percina antesella), which is potentially threatened by urbanization. I used a Bayesian approach to combine data from a surrogate species (the bronze darter[Percina palmaris]) with available data for the amber darter to produce a model of expected amber darter response. Although this approach requires difficult decisions on the part of the manager, especially in the selection of surrogate species, its value lies in the fact that all assumptions are clearly stated in the form of hypotheses, which may be scrutinized and tested. It therefore provides a rational basis for instituting management policy even in the face of considerable uncertainty.     

汽车电子电磁场抗扰度测试方法及系统研究

分析了当前汽车电子零部件电磁场抗扰度主流标准及测试方法,针对目前单台设备适用特定标准的局限性,提出了一种基于Lab VIEW虚拟仪器远程系统的自动测试方法。该系统利用GPIB总线、USB总线、TCP/IP总线实现了计算机与各台仪器的通讯,通过自主研发的软件实现了测试频段的扩充,同时兼顾到了软件后期的维护和扩展。     

控制温室效应的战略选择

尽管人类对温室效应和全球变化的认识还是很不充分的，但是继续拖延不采取措施是危险的，采取对抗温室效应和全球变化的措施是行不通的。只有在继续进行全球性科学研究的同时，积极寻求适应一定程度全球变化的措施，并立即着手减少温室气体的排放才是唯一明智的态度。化石能源是人类社会生存和发展的基础，既使用化石能源，又不排放二氧化碳是不可能是。首要的任务是减少化石能源的使用。     

HACH公司COD测定仪替代试剂的开发

美国HACH公司制造的COD测定仪，使用方便，但试剂依赖进口且价格昂贵，我们经过反复试验，开发出仍适用于该仪器的替代试剂。     

默克公司COD测试剂的替代品开发

德国默克（MERCK）公司制造的COD测定仪在我国环保行业、科研院所的水质监测工作中应用广泛，但配套测试剂价格昂贵，限制了该仪器的使用。设计了高量程（100～1500mg／L）和低量程（25～100mg／L）下COD测试剂替代品的开发方案。通过实验，确定了两个量程下COD测试剂替代品中K2Cr2O2，H2SO4-Ag2SO4，HgSO4的浓度和加入量以及测试方法。实验结果表明，在高量程和低量程范围内，使用COD测试剂替代品的测试结果与MERCK公司配套测试剂的测试结果比较相符，反应时间也可缩短至0．5h。     

汽车环境风洞地面区域流场数值仿真

目的 探究汽车环境风洞地面区域流场规律,获取风洞边界层抽吸装置的最佳抽吸率和底盘测功机对风洞地面区域边界层厚度、风速、总压和静压的影响规律,并比较MRF法和旋转壁面法对底盘测功机转毂转动模拟的精度。方法 运用计算流体动力学方法对汽车环境风洞流场进行数值仿真计算。结果 边界层抽吸装置对应于喷口风速120 km/h时的最佳抽吸率为0.048。底盘测功机区域总压呈现下降趋势。相比于存在底盘测功机,汽车环境风洞无底盘测功机时,底盘测功机区域内相同位置的边界层厚度会增加1.28～12.22 mm。在前转毂的前侧、上侧、后侧和后转毂的上侧和后侧会有一个高风速区域,区域内风速比设定风速高1%～4%,与无底盘测功机相比,区域内静压值低0.32～46.02 Pa。在前后转毂前侧和后侧与地面相连接的凹部会有一个低风速区域,区域内风速比设定风速低1%～5%,与无底盘测功机相比,区域内静压值高0.08～49.34 Pa。底盘测功机转毂的转动会使附近区域的地面边界层厚度变大。在前转毂前侧,采用旋转壁面法进行模拟比MRF法地面边界层厚度增加近8 mm,而在其他位置,2种模拟方法对边界层厚度的模拟差别在1.5 mm...