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951.
结合物联网技术,介绍一种智能化安全仿真实训技术,通过对培训关键控制指标的筛选以及感知元件的应用,研发了安全仿真实训项目的感知层设计方案,以及多项目间的培训状态数据匹配技术,形成了系统的智能化安全仿真实训技术方案。通过与当前普遍应用的安全仿真实训技术进行对比,该技术方案能够有效提升培训考核的客观性,提高安全仿真实训实施效率,更好满足企业需求。 相似文献
952.
953.
构建空气质量治理前后与人呼吸系统疾病患者例数的定量分析关系模型,获取呼吸系统疾病例数与空气质量的关系,通过人呼吸道疾病实证分析,明确空气质量治理前后的人呼吸系统影响变化状况。以荆州地区某中心医院收治的患有呼吸道疾病的患者为研究对象,通过为期两年的观测,结合四季空气质量治理程度的监测数据,建立呼吸系统疾病感染例数与空气质量治理程度的定量回归分析模型,结合稳健性检验分析方法,在显著度水平大于10%的条件下进行空气质量与呼吸系统疾病患者例数的统计分析,并测试人们的身体指参数,实现两者关系的定量分析。 相似文献
954.
Nini Pang Jian Gao Fei Che Tong M Su Liu Yan Yang Pusheng Zhao Jie Yuan Jiayuan Liu Zhongjun Xu Fahe Chai 《环境科学学报(英文版)》2020,32(9):201-209
To investigate the cause of fine particulate matter (particles with an aerodynamic diameter less than 2.5 µm, PM2.5) pollution in the heating season in the North China Plain (specifically Beijing, Tianjin, and Langfang), water-soluble ions and carbonaceous components in PM2.5 were simultaneously measured by online instruments with 1-hr resolution, from November 15, 2016 to March 15, 2017. The results showed extreme severity of PM2.5 pollution on a regional scale. Secondary inorganic ions (SNA, i.e., NO3?+SO42+ NH4+) dominated the water-soluble ions, accounting for 30%-40% of PM2.5, while the total carbon (TC, i.e., OC + EC) contributed to 26.5%-30.1% of PM2.5 in the three cities. SNA were mainly responsible for the increasing PM2.5 pollution compared with organic matter (OM). NO3? was the most abundant species among water-soluble ions, but SO42- played a much more important role in driving the elevated PM2.5 concentrations. The relative humidity (RH) and its precursor SO2 were the key factors affecting the formation of sulfate. Homogeneous reactions dominated the formation of nitrate which was mainly limited by HNO3 in ammonia-rich conditions. Secondary formation and regional transport from the heavily polluted region promoted the growth of PM2.5 concentrations in the formation stage of PM2.5 pollution in Beijing and Langfang. Regional transport or local emissions, along with secondary formation, made great contributions to the PM2.5 pollution in the evolution stage of PM2.5 pollution in Beijing and Langfang. The favourable meteorological conditions and regional transport from a relatively clean region both favored the diffusion of pollutants in all three cities. 相似文献
955.
Penghui Li Min Su Xiaodan Wang Xiaoyan Zou Xia Sun Junpeng Shi Hongwu Zhang 《环境科学学报(英文版)》2020,32(2):248-259
Silver nanoparticles (AgNPs) are widely used in many consumer products, whereas their environmental behaviors in natural aquatic systems remain unknown, especially in natural brackish media. Therefore, it is urgent to investigate the environmental fate of AgNPs in natural brackish waters. Here, we investigated the stability of citrate-coated AgNPs in natural brackish water collected from 6 different sites with distinct salinities in the Xinglinwan Reservoir, located in Xiamen City, southeast China. The obtained results showed that AgNP colloids remained stable in low-salinity waters, which was mainly determined by the effects of dissolved organic matter (DOM) promoting the stability of the nanoparticles. However, the environmental fate of AgNPs in high-salinity waters was dominated by the salinity or ionic strength, especially the free ion concentrations of Cl?, SO42?, or S2?, resulting in rapid sedimentation and dissolution. In addition, both DOM and salinity contributed to the environmental behavior of AgNPs in moderate-salinity waters, ultimately resulting in either colloidal stability or sedimentation. Overall, these results may reveal that AgNPs remain relatively stable for a long period in low-salinity natural waters, and that the stability might gradually decrease as AgNPs are transferred from freshwaters through brackish waters and eventually end up in seawater along the bay. Our findings also further indicate that the toxicity and potential risks of AgNPs may present more serious threats to the environment and organisms in natural freshwaters than in natural estuarine systems or seawater. 相似文献
956.
The leaching concentrations of different metals in stainless steel pickling residue(SSPR)were determined and the toxic metals were treated using Na_2 S·xH_2 O,FeSO_4·6 H_2 O,and phosphoric acid.A modified European Community Bureau of Reference(BCR) sequential extraction was used to identify the speciation of the concerned metals.Results showed that SSPR contains a large amount of Ca(58.41%),Fe(29.44%),Cr(3.83%),Ni(2.94%),Mn(2.82%) and some of Al,Cu,Mg,Zn.Among them,Cr and Ni were the most toxic metals in SSPR,thus the raw SSPR falls into hazardous waste category due to the leaching amount of Cr.In addition,the leached Cr was identified as Cr6+(MgCr04) in the waste.BCR test revealed that risk assessment code(RAC) of Cr and Ni were 33.29% and 61.7%,indicating they posed "high" and "very high" risk to the environment,respectively.After fixing by Na_2 S·xH_2 O and FeSO_4·6 H_2 O,the leaching concentrations of Cr and Ni were less than 1.5 and 0.5 mg/L,respectively.After fixing by Na_2 S·xH_2 O and FeSO_4·6 H_2 O the tre ated SSPR can be safely reused as roadbed materials,concrete and cement aggregates.This study provides a useful implication in treatment and beneficial reuse of heavy metal-containing hazardous wastes. 相似文献
958.
铜仁汞矿区土壤汞污染现状调查研究 总被引:1,自引:0,他引:1
为了进一步对废弃汞矿污染区的生态环境进行跟踪调查及科学的评价,2015年通过对铜仁市废弃汞矿区周围的稻田、旱田及菜地土壤汞污染现状调查分析。采用S型随机抽样方式,并使用原子荧光光度法对研究对象进行分析。结果表明:万山镇、云场萍及路腊村汞矿区稻田土壤总汞(THg)含量平均值分别为123.75、79.33、21.89 mg/kg;其旱田土壤THg含量平均值分别为:117.20、73.34、19.90 mg/kg;其菜地土壤THg含量平均值分别为129.40、81.78、26.50 mg/kg;且,万山汞矿区甲基汞(Me Hg)含量平均值分别为6.48(稻田)、4.80(旱田)、6.40μg/kg(菜地);云场萍汞矿区Me Hg含量平均值分别为3.73(稻田)、2.47(旱田)、6.40μg/kg(菜地);路腊村汞矿区Me Hg含量平均值分别为1.92(稻田)、0.87(旱田)、2.47μg/kg(菜地)。以上结果说明万山废弃汞矿区的污染程度高于云场萍废弃汞矿区及路腊村废弃汞矿区。 相似文献
959.
Basic-oxygen furnace slag(BOF-slag) contains 35%CaO,a potential component for CO_2sequestration.In this study,slag-water-CO_2 reaction experiments were conducted with the longest reaction duration extending to 96 hr under high CO_2 pressures of 100-300 kg/cm2 to optimize BOF-slag carbonation conditions,to address carbonation mechanisms,and to evaluate the extents of V and Cr release from slag carbonation.The slag carbonation degree generally reached the maximum values after 24 hr slag-water-CO_2 reaction and was controlled by slag particle size and reaction temperature.The maximum carbonation degree of 71%was produced from the experiment using fine slag of0.5 mm under 100℃and a CO_2 pressure of 250 kg/cm~2 with a water/slag ratio of 5.Vanadium release from the slag to water was significantly enhanced(generally 2 orders) by slag carbonation.In contrast,slag carbonation did not promote chromium release until the reaction duration exceeded 24 hr.However,the water chromium content was generally at least an order lower than the vanadium concentration,which decreased when the reaction duration exceeded 24 hr.Therefore,long reaction durations of 48-96 hr are proposed to reduce environmental impacts while keeping high carbonation degrees.Mineral textures and water compositions indicated that Mg-wustite,in addition to CaO-containing minerals,can also be carbonated.Consequently,the conventional expression that only considered carbonation of the CaO-containing minerals undervalued the CO_2 sequestration capability of the BOF-slag by~20%.Therefore,the BOF-slag is a better CO_2 storage medium than that previously recognized. 相似文献
960.
Bin Wang Ning Li Furong Deng Nicholas Buglak George Park Shu Su Aiguo Ren Guofeng Shen Shu Tao Xinbiao Guo 《环境科学学报(英文版)》2016,28(9):201-210
Epidemiological studies have demonstrated the exacerbation of respiratory diseases following sandstorm-derived particulate matter(PM) exposure.The presence of anthropogenic and biological agents on the sandstorm PM and the escalation of PM 2.5 μm(PM2.5)pollution in China have led to serious concerns regarding the health effects of PM2.5during Asian sandstorms.We investigated how changes in PM2.5composition,as the weather transitioned towards a sandstorm,affected human airway epithelial cells.Six PM2.5samples covering two sandstorm events and their respective background and transition periods were collected in Baotou,an industrial city near the Gobi Desert in China.PM samples from all three periods had mild cytotoxicity in human bronchial epithelial cell line BEAS-2B,which was positively correlated with the contents of polycyclic aromatic hydrocarbons and several metals.All PM samples potently increased the release of interleukin-6(IL-6) and interleukin-8(IL-8).Endotoxin in all samples contributed significantly to the IL-6 response,with only a minor effect on IL-8.Cr was positively correlated with both IL-6 and IL-8 release,while Si was only associated with the increase of IL-6.Our study suggests that local agricultural and industrial surroundings in addition to the sandstorm play important roles in the respiratory effects of sandstorm-derived PM. 相似文献