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601.
Jian-jun Jiang Li Zhang Yi-qun Wang Yu-yuan Peng Kun Zhang Wen He 《Safety Science》2011,49(6):843-851
Monitoring process is an important part in a high safety digital main control room of nuclear power plant (NPP), it is the source extracted information and found abnormal information in time. As the human factors events arisen from monitoring process recently take place more and more frequent, the authors propose a reliability Markov model to effectively decrease these abnormal events. The model mainly analyzes next monitoring object probability in terms of current information and plant state. The authors divide digital human–machine interface into two parts that are referred as logical homogeneous Markov and logical heterogeneous Markov. For the former, a series of methods of probability evaluation are proposed, such as, Markov transition probability with condition, probability distributed function with human factors, system state and alarm; for the latter, the authors propose the calculation of probability of correlation degree between last time and next time and probability calculation methods with multi-father nodes. The methods can effectively estimate the transition probability from a monitoring component to next monitoring component at time t, can effectively analyze which information is more important in next monitoring process and effectively find more useful information in time t + 1, so that the human factors events in monitoring process can greatly be decreased. 相似文献
602.
本文简迷了皮肤防护器材--化学防护服(衣)化学防护性能试验与评价用标准物质的重要性,系统地概述了外军化学防护服(衣)化学防护性能试验与评价用标准物质的研究现状,并提出了我国化学防护服(衣)防护性能试验与评价用标准物质研制过程中应注意的一些问题. 相似文献
603.
臭氧已成为影响我国环境空气质量的重要污染物之一,准确解析环境臭氧及其前体物VOCs的关键源类及其贡献对于有效防控臭氧污染具有重要作用.因此,利用光化学年龄参数方法估算了青岛胶州市2021年1月1日至2月28日在线VOCs监测数据的初始浓度,矫正环境VOCs物种的光化学损耗;并利用正定矩阵因子分解(PMF)和臭氧生成潜势(OFP)模型进行了环境VOCs及其OFP来源解析研究,以期为青岛市环境臭氧污染的防控提供数据支撑.结果表明,研究期间青岛市环境ρ(TVOCs)和OFP的平均值分别为65.9μg·m-3和176.7μg·m-3;其中丙烷浓度(12.4μg·m-3)和占比(18.9%)最高,而间/对-二甲苯的OFP(24.6μg·m-3)及占比(13.9%)最高.研究期间TVOCs的初始浓度为153.1μg·m-3,其光化学损耗率达到63.8%.烯烃是光化学损耗率(92.1%)最高的VOCs物种,其中异戊二烯的光化学损耗率达到98.6%,明显高于其它VOCs物种.基于初始浓度的来源... 相似文献
604.
Yuanhang Zhang Yuesi Wang Xin Jin Zirui Liu Gehui Wang Guiqian Tang Keding Lu Bo Hu Shanshan Wang Guohui Li Xinqin An Chao Wang Qihou Hu Lingyan He Fenfen Zhang 《环境科学学报(英文版)》2023,123(1):350-366
Atmospheric oxidizing capacity (AOC) is an essential driving force of troposphere chemistry and self-cleaning, but the definition of AOC and its quantitative representation remain uncertain. Driven by national demand for air pollution control in recent years, Chinese scholars have carried out studies on theories of atmospheric chemistry and have made considerable progress in AOC research. This paper will give a brief review of these developments. First, AOC indexes were established that represent apparent atmospheric oxidizing ability (AOIe) and potential atmospheric oxidizing ability (AOIp) based on aspects of macrothermodynamics and microdynamics, respectively. A closed study refined the quantitative contributions of heterogeneous chemistry to AOC in Beijing, and these AOC methods were further applied in Beijing-Tianjin-Hebei and key areas across the country. In addition, the detection of ground or vertical profiles for atmospheric OH·, HO2·, NO3· radicals and reservoir molecules can now be obtained with domestic instruments in diverse environments. Moreover, laboratory smoke chamber simulations revealed heterogeneous processes involving reactions of O3 and NO2, which are typical oxidants in the surface/interface atmosphere, and the evolutionary and budgetary implications of atmospheric oxidants reacting under multispecies, multiphase and multi-interface conditions were obtained. Finally, based on the GRAPES-CUACE adjoint model improved by Chinese scholars, simulations of key substances affecting atmospheric oxidation and secondary organic and inorganic aerosol formation have been optimized. Normalized numerical simulations of AOIe and AOIp were performed, and regional coordination of AOC was adjusted. An optimized plan for controlling O3 and PM2.5 was analyzed by scenario simulation. 相似文献
605.
红色旅游资源是革命精神的核心载体,其保护和旅游利用面临着破碎化、片段化、静态化等问题,亟需开展整合开发研究。以中央苏区核心区为例,基于文化生态学理论,采用GIS空间分析方法和修正的引力模型,研究红色旅游资源空间格局和文化生态变迁,在此基础上提出整合开发的策略,结论如下:(1)红色旅游资源点空间上呈现局部聚集特征,赣南苏区形成章贡区、瑞金市、于都县“金三角”分布格局,闽西苏区则形成新罗区、永定区、上杭县、连城县“银菱形”分布格局;(2)闽西和赣南苏区各重大事件红色旅游资源点在空间上8.9~106.6 km的范围内,形成带状或面状的文化生态基底,并呈现一致向服务业主导型转变的发展态势;(3)红色旅游资源网络联系方向与服务业主导型文化生态方向错位发展,这是赣南和闽西红色旅游资源内部网络联系度较强,跨区域网络联系度较弱的重要原因。在此基础上,遵循红色旅游资源文化生态空间一体化、文化生态演变全域化、文化生态发展动态化的原则,提出空间集聚区优先整合开发、高发展指数红色旅游资源跨省域优先整合开发、跨主导类型关键节点优先整合开发三个整合开发对策,以期促进中央苏区红色旅游高质量发展。 相似文献
606.
Jin Xie Xiao-Dong Niu Jiao-Jiao Xie Kai-Qiang He Meng-Dan Shi Su-Juan Yu Chun-Gang Yuan Jing-Fu Liu 《环境科学学报(英文版)》2021,33(10):1-7
The distribution and chemical speciation of arsenic (As) in different sized atmospheric particulate matters (PMs), including total suspended particles (TSP), PM10, and PM2.5, collected from Baoding, China were analyzed. The average total mass concentrations of As in TSP, PM10, and PM2.5 were 31.5, 35.3, and 54.1 µg/g, respectively, with an order of PM2.5 >PM 10 > TSP, revealing that As is prone to accumulate on fine particles. Due to the divergent toxicities of different As species, speciation analysis of As in PMs is further conducted. Most of previous studies mainly focused on inorganic arsenite (iAsIII), inorganic arsenate (iAsV), monomethylarsonate (MMA), and dimethylarsinate (DMA) in PMs, while the identification and sensitive quantification of trimethylarsine oxide (TMAO) were rarely reported. In this study, a high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry system was optimized for As speciation including TMAO in PMs. An anion exchange column was used to separate MMA, DMA and iAsV, while a cation exchange column to separate TMAO and iAsIII. Results showed that iAsV was the dominate component in all the samples, corresponding to a portion of 79.2% ± 9.3% of the total extractable species, while iAsIII, TMAO and DMA made up the remaining 21%. Our study demonstrated that iAsIII accounted for about 14.4% ± 11.4% of the total extracted species, with an average concentration of 1.7 ± 1.6 ng/m3. It is worth noting that TMAO was widely present in the samples (84 out of 97 samples), which supported the assumption that TMAO was ubiquitous in atmospheric particles. 相似文献
607.
608.
Modified clay (MC), an effective material used for the emergency elimination of algal blooms, can rapidly reduce the biomass of harmful algal blooms (HABs) via flocculation. After that, MC can still control bloom population through indirect effects such as oxidative stress, which was initially proposed to be related to programmed cell death (PCD) at molecular level. To further study the MC induced cell death in residual bloom organisms, especially identifying PCD process, we studied the physiological state of the residual Prorocentrum donghaiense. The experimental results showed that flocculation changed the physiological state of the residual cells, as evidenced by growth inhibition and increased reactive oxygen species production. Moreover, this research provides biochemical and ultrastructural evidence showing that MC induces PCD in P. donghaiense. Nuclear changes were observed, and increased caspase-like activity, externalization of phosphatidylserine and DNA fragmentation were detected in MC-treated groups and quantified. And the mitochondrial apoptosis pathway was activated in both MC-treated groups. Besides, the features of MC-induced PCD in a unicellular organism were summarized and its concentration dependent manner was proved. All our preliminary results elucidate the mechanism through which MC can further control HABs by inducing PCD and suggest a promising application of PCD in bloom control. 相似文献
609.
In this work, Bi2XO6 (X = W, Mo) are synthesized at different temperatures. The results of tests find the optimal temperatures of Bi2WO6 and Bi2MoO6 are 180 and 160°C (BW-180, BM-160). Then, BW-180 and BM-160 are further compounded with different contents of CuS. The results of photoelectrochemical (PEC) tests show that CuS can improve the PEC performance of semiconductor materials, and it has better performance when CuS mass fraction is 5%. These maybe the photoelectron potentials generated by CuS/Bi2XO6 (X = Mo, W) heterojunction reduce the combination of photogenerated electrons and holes. When the PEC sensor based on 5%-CuS/BW-180 detects Cr(VI), it has a linear range of 1–80 μmol/L with detection limit of 0.95 μmol/L, while the PEC sensor based on 5%-CuS/BM-160 detects Cr(VI) has a linear range of 0.5–230 μmol/L and a detection limit of 0.12 μmol/L. Thus, 5%-CuS/Bi2XO6 has potential application in hexavalent chromium detection. 相似文献
610.
Contents and sources of polycyclic aromatic hydrocarbons and organochlorine pesticides in vegetable soils of Guangzhou, China 总被引:36,自引:0,他引:36
We investigated contents, distribution and possible sources of PAHs and organochlorine pesticides (Ops) in 43 surface and subsurface soils around the urban Guangzhou where variable kinds of vegetables are grown. The results indicate that the contents of PAHs (16 US EPA priority PAHs) range from 42 to 3077 microg/kg and the pollution extent is classified as a moderate level in comparison with other investigations and soil quality standards. The ratios of methylphenanthrenes to phenanthrene(MP/P), anthracene to anthracene plus phenanthrene (An/178), benz[a]anthracene to benz[a]anthracene plus chrysene (BaA/228), indeno[1,2,3-cd]pyrene to indeno[1,2,3-cd]pyrene plus benzo[ghi]perylene (In/In+BP) suggest that the sources of PAHs in the soil samples are mixed with a dominant contribution from petroleum and combustion of fossil fuel. The correlation analysis shows that the PAHs contents are significantly related to total organic carbon contents (TOC) (R2=0.75) and black carbon contents (BC) (R2=0.62) in the soil samples. Dichlorodiphenyltrichloroethane and metabolites (DDTs) and hexachlorocyclohexanes and metabolites (HCHs) account largely for the contaminants of OPs. The concentrations of DDTs range from 3.58 to 831 microg/kg and the ratios for DDT/(DDD+DDE) are higher than 2 in some soil samples, suggesting that DDT contamination still exists and may be caused by its persistence in soils and/or impurity in the pesticide dicofol. The concentrations of HCHs are 0.19-42.3 microg/kg. 相似文献