卫星元器件抗辐射指标优化分析

目的在航天器设计中对选用的电子元器件提出了抗辐射指标要求。随着航天器设计寿命增加,对元器件提出的抗辐射指标越来越高,因此需要优化对元器件的抗辐射指标要求,以降低因辐射指标不满足而限制元器件的选择范围。方法通过对国内外抗辐射指标体系的对比分析和典型轨道、典型器件的数据分析,探讨总剂量指标的优化方法。对在轨翻转概率的影响因素进行分析,并采用典型数据的单粒子翻转概率评估,明确采用单一LET阈值指标的局限。结果总剂量效应和单粒子效应指标均有优化的方法和空间。结论通过对辐射环境的细化分析,降低辐射设计裕度,可降低总剂量的辐射指标要求。结合单粒子效应的应用需求以及防护设计,降低对器件LET阈值要求。     

In-vehicle VOCs composition of unconditioned, newly produced cars

The in-vehicle volatile organic compounds （VOCs） concentrations gains the attention of both car producers and users. In the present study, an attempt was made to determine if analysis of air samples collected from an unconditioned car cabin can be used as a quality control measure. The VOCs composition of in-vehicle air was analyzed by means of active sampling on Carbograph 1TD and Tenax TA sorbents, followed by thermal desorption and simultaneous analysis on flame ionization and mass detector （TD-GC/FID-MS）. Nine newly produced cars of the same brand and model were chosen for this study. Within these, four of the vehicles were equipped with identical interior materials and five others differed in terms of upholstery and the presence of a sunroof; one car was convertible. The sampling event took place outside of the car assembly plant and the cars tested left the assembly line no later than 24 hr before the sampling took place. More than 250 compounds were present in the samples collected; the identification of more than 160 was confirmed by comparative mass spectra analysis and 80 were confirmed by both comparison with single/multiple compounds standards and mass spectra analysis. In general, aliphatic hydrocarbons represented more than 60% of the total VOCs （TVOC） determined. Depending on the vehicle, the concentration of aromatic hydrocarbons varied from 12% to 27% of total VOCs. The very short period between car production and sampling of the in-vehicle air permits the assumption that the entire TVOC originates from off-gassing of interior materials. The results of this study expand the knowledge of in-vehicle pollution by presenting information about car cabin air quality immediately after car production.     

Polychlorinated biphenyls in the atmosphere of Taizhou, a major e-waste dismantling area in China

PM2.5,total suspended particles(TSP) and gas phase samples were collected at two sites of Taizhou,a major e-waste dismantling area in China.Concentrations,seasonal variations,congener profiles,gas-particle partitioning and size distribution of the atmospheric polychlorinated biphenyls(PCBs) were studied to assess the current state of atmospheric PCBs after the phase out of massive historical dismantling of PCBs containing e-wastes.The average 38PCBs concentration in the ambient air(TSP plus gas phase) near the e-waste dismantling area was(12,407 ± 9592) pg/m3 in winter,which was substantially lower than that found one decade ago.However,the atmospheric PCBs level near the e-waste dismantling area was 54 times of the reference urban site,indicating that the impact of the historical dismantling of PCBs containing e-wastes was still significant.Tri-Penta-CBs were dominant homologues,consisting with their dominant global production.Size distribution of particle-bound PCBs showed that higher chlorinated CBs tended to partition more to the fine particles,facilitating its long range air transportation.     

燃煤锅炉烟气中CPM与水溶性离子监测方法及应用研究

建立燃煤锅炉烟气可凝聚颗粒物(CPM)与水溶性离子监测采样方法,并应用于北京市典型烟气净化工艺燃煤锅炉排放监测。结果表明,北京市燃煤锅炉烟气中总颗粒物(TPM)基准排放质量浓度最高达82.4 mg/m3,最低14.0 mg/m3,其中CPM占TPM的43.5%~92.2%,水溶性离子对TPM的贡献水平为31.4%~62.2%。烟温对水溶性离子的分布形态有显著影响,进而影响TPM中可过滤颗粒物(FPM)和CPM的分配比例。颗粒物和水溶性离子的排放与烟气含湿量之间无显著相关性,而与燃煤锅炉烟气脱硫除尘净化工艺和脱硫产物的溶解度及其脱除方式密切相关。     

基于半分析方法的内陆湖泊水体总悬浮物浓度遥感估算研究

根据生物光学原理,通过对总悬浮物吸收占水体总吸收比例光谱的分析,确定适宜总悬浮物浓度反演的波段范围;结合以往学者对太湖等水体固有光学特性的研究成果,运用最小二乘法,确定生物光学模型的相关参数,建立了浑浊湖泊水体总悬浮物浓度的单波段估算模型.结果表明,在短波波段,总悬浮物的吸收占水体总吸收的比例较高,出现光饱和现象,不适...     

Multi N/C2100S总有机碳分析仪校准方法的建立

以德国Analytikjena公司Multi N/C 2100S分析仪为例,研究建立了合理可行的总有机碳分析仪校准方法.在总有机碳分析仪检定规程JJG 821-2005的基础上,增加零点漂移、直线性、标准曲线线性和检出限4项特性指标,改变了准确性特性的判定方法.根据仪器的使用频率和稳定性,建议校准周期不超过2年.     

污染水体的总抗氧化能力生物标志物研究

以无污染饲养鲫鱼为监测生物,采取主动生物监测法(ABM)对太湖北部梅梁湖与贡湖污染区进行生物监测,并分析各监测点常规水质指标及表层沉积物中多环芳烃(PAHs)、多氯联苯(PCBs)、有机氯农药(OCPs)与重金属含量,同时定期(7,14,2,28d)采集生物样,分析鲫鱼大脑组织及肌肉组织中总抗氧化能力(TAOC)活性.结果表明,鲫鱼脑组织TAOC活性比肌肉组织TAOC活性值高出约4倍,并且对污染物协迫反应敏感.实验第14d开始,脑组织TAOC呈显著诱导效应(P<0.05),最大值出现在PCBs污染严重的梅梁湖4号站点,相比参照点活性增加62.19%.其次是重金属污染严重的梅梁湖3号监测点,而污染最小的贡湖1号监测点TAOC变化较小.肌肉组织中TAOC对污染物反应不敏感,不适合作微污染区生物标志物.     

水分管理和外源硒对水稻吸收累积铅的影响

通过盆栽试验,研究了不同水分管理和外源亚硒酸盐的添加对水稻根际铅的动态变化和水稻吸收累积铅的影响.结果表明,淹水显著增加了根表铁膜对铅的吸附和根系对铅的吸收,淹水下苗期和成熟期水稻根系铅含量分别是非淹水处理时的4.2~8.5和1.4~1.5倍;淹水降低了地上部的铅分配,在苗期和成熟期分别降低85.9%~86.7%和51.8%~74.0%.加硒降低了土壤溶液、苗期水稻根系和地上部的铅含量以及成熟期水稻根表铁膜、根系和茎中的铅含量.与对照相比,淹水和非淹水下加硒处理使苗期水稻根系铅含量分别降低了5.4%~24.3%和2.7%~61.7%,使成熟期水稻根系铅含量分别降低了56.1%~64.1%和53.8%~63.2%.水稻籽粒中的铅含量在不同处理间无显著差异.因此,水分管理和外源硒的添加显著影响了水稻根系对铅的吸收,而对水稻籽粒对铅的累积无显著影响.     

华能辽宁分公司

正实施污染减排履行社会责任华能辽宁分公司成立于2009年3月30日,是华能国际电力股份有限公司全资子公司。下辖大连电厂、丹东电厂、营口电厂、营口热电有限责任公司和清洁能源分公司,总装机容量4735MW,其中:火电4600 MW,水电37.5 MW,风电97.5 MW。为了更好履行社会责任,华能在辽企业近年来不断加大环保投入,2007—2013年间     

加强对大气污染防治的审计监督——访上海市审计局总审计师林忠华

正2013年9月,国务院发布了《大气污染防治行动计划》,提出了大气污染防治的总体要求、奋斗目标和政策举措。目前已有25个省(区、市)制定了本地的落实方案,一场大气污染防治攻坚战已在全国打响。环境审计是国家审计的重要组成部分,应当在大气污染防治中发挥作用,但是目前我国各级审计机构对水环境保护审计问题较为熟悉,而在空气污染等方面则关注不足。为此本刊专访了上海市审计局总审计师、高级经济师林忠华,详细介绍了我国大气污