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排序方式: 共有1417条查询结果,搜索用时 656 毫秒
711.
介绍了大气清洁度指数法、地衣微核检测法等地衣监测大气污染的几种常用方法,并针对地衣对各种污染物的监测研究进行讨论.在总结国内外相关研究的基础上,探讨了目前我国地衣研究中存在的问题和未来研究方向.  相似文献   
712.
通过分析2006~2010年空气自动监测的数据,结果表明:沈阳市这5年空气污染日数占全年总天数的9.9%-12.1%,其中,冬季污染日最多,春季次之,秋季和夏季污染日较少.  相似文献   
713.
贾祥焱 《环境保护科学》2011,37(5):56-58,66
探讨了通过气相色谱仪双通道检测室内空气中总挥发性有机化合物的可行性.建立了前、后双通道的苯、甲苯、乙酸丁酯、乙苯、苯乙烯、对(间)二甲苯、邻二甲苯、正十一烷等9种典型有机污染物的外标曲线,各组分相关系数R2为0.9995~1,并通过各自的标准曲线来计算其标样考核结果,对比标样真实浓度值,验证前、后双通道的准确性以及相互...  相似文献   
714.
党的十七大提出"加强能源资源节约和生态环境保护,增强可持续发展能力",这是我们党科学发展、和谐发展理念的一次升华。开发低碳能源是建设低碳城市的基本保证,清洁生产是建设低碳城市的关键。传统燃煤加热炉能耗高、污染重。P-HTAC是在蓄热式加热炉的基础上研制的先进技术,采用脉冲方式控制燃烧系统,使燃烧更充分、炉温控制更精确,为企业走上一条经济效益好、资源消耗低、环境污染少的可持续发展道路铺垫了坚实的技术基础。  相似文献   
715.
建立了以亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸[Bmim]BF4和Na H2PO4形成的二元双水相作为气浮溶剂分离/富集水样中盐酸多西环素的新方法,并采用紫外分光光度法对盐酸多西环素进行测定。考察了离子液体的初始加入量、盐的种类及浓度、p H值、浮选时间及N2流速等因素对体系浮选分离盐酸多西环素的影响。结果表明,改变离子液体和无机盐的加入量,会使体系的富集倍数发生变化,从而使体系的浮选效率和浓集系数发生变化;随浮选时间增加,体系的浮选效率先增加后略微下降;过大或过小的N2流速都会使体系对盐酸多西环素的浮选效率降低;而p H值对体系浮选盐酸多西环素影响不大。当[Bmim]BF4溶液加入量为3 m L、Na H2PO4加入量为25 g(质量分数为33.3%)、气浮时间为40 min、气浮速率为50 m L/min时,体系的浮选效率最高,可达95.8%,浓集系数可达23.95,此时体系的p H值为4.38。与离子液体双水相萃取(ILATPE)相比,该方法的优点在于不仅有较高的浮选率、浓集系数,还有效减少了离子液体的用量,同时操作更简单、环境友好。  相似文献   
716.
通过对鞍山市典型区域(6个污染源、4个居住区、一个对照点)土壤及大气中有机氯农药(organochlorine pesicides,OCPs)的监测,利用逸度及逸度模型的相关概念计算鞍山市有机氯农药类污染物土-气交换的迁移方向及交换通量。OCPs土-气交换现状表明,土壤仍是OCPs主要储存地。各点位检出有机氯农药组分数据为83个,土-气交换通量范围在-28.4~1518 g/(km2·月)之间,其中污染物由空气相向土壤相迁移占比9.6%,其余均呈现由土壤相向空气相迁移;对照点千山只检出两种污染物,通量值只有3.37 g/(km2·月);各点位污染物中,3种六六六(HCHs)交换通量占比最大,占总交换量的43%~95%。  相似文献   
717.
Foam is used as part of an effective dust suppression method in underground coal mines, but conventional foaming devices severely restrict its popularization and application due to the high cost of foam preparation, poor applicability and high pressure loss. Therefore, a new spiral mesh foam generator is designed, and its performance is investigated and evaluated experimentally. The results show that the pressure gradient of the spiral mesh foam generator increases with the increase of foam concentration in water. There is a large pressure gradient gap between the top and bottom at both ends of the foam generator. However, the gap disappears and uniform foam is generated in the middle section of the foam generator. When the pressure gradient is higher than minimum pressure gradient, the foam production quantity will increase sharply. Based on the length of spiral mesh and operating conditions determined, the new foam generator is applied to produce foam for dust suppression in the heading face of coal mines. A good foaming effect, less pressure loss and high dust suppression efficiency suggest that the new foam generator will greatly promote the large-scale application of foam technology used to suppress dust in underground coal mines.  相似文献   
718.
选取典型的室内公共场所,按照室内空气检测标准进行布点采样,检测这些场所的C02浓度及采样时的温度、湿度及空气流速结果发现,商场内C02浓度基本都在标准限值内,超市内C02浓度超标严重,且C02分布与超市内采样层区之间无明显的相关性。其它类型场所C02分布各有差异,但浓度值基本在标准限度值上下浮动统计结果:公共场所内影响C02浓度的主要原因是空气流速与人群密度的大小空气流速越快,C02浓度越低;人群密度越大,C02浓度越高此外,根据,James L Repace理论进行分析发现,各类公共场所空气交换状况均较差,存在威胁人们健康的风险。  相似文献   
719.
● Haze formation in China is highly correlated with iron and steel industry. ● VOCs generated in sinter process were neglected under current emission standard. ● Co-elimination removal of sinter flue gas complex pollutants are timely needed. Recent years have witnessed significant improvement in China’s air quality. Strict environmental protection measures have led to significant decreases in sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter (PM) emissions since 2013. But there is no denying that the air quality in 135 cities is inferior to reaching the Ambient Air Quality Standards (GB 30952012) in 2020. In terms of temporal, geographic, and historical aspects, we have analyzed the potential connections between China’s air quality and the iron and steel industry. The non-target volatile organic compounds (VOCs) emissions from iron and steel industry, especially from the iron ore sinter process, may be an underappreciated index imposing a negative effect on the surrounding areas of China. Therefore, we appeal the authorities to pay more attention on VOCs emission from the iron and steel industry and establish new environmental standards. And different iron steel flue gas pollutants will be eliminated concurrently with the promotion and application of new technology.  相似文献   
720.
● This study explored the long-term association by double robust additive models. ● Individual exposure concentrations were assessed by integrating GAM, LUR and BPNN. ● PM2.5, SO2 and NO2 are positively associated with cerebrovascular disease. ● CO could reduce the risk of cerebrovascular disease with the highest robustness. ● The elderly, women and people with normal BMI are at higher risk for air pollution. The relationship between air pollution and cerebrovascular disease has become a popular topic, yet research findings are highly heterogeneous. This study aims to investigate this association based on detailed individual health data and a precise evaluation of their exposure levels. The integrated models of generalized additive model, land use regression model and back propagation neural network were used to evaluate the exposure concentrations. And doubly robust additive model was conducted to explore the association between cerebrovascular disease and air pollution after adjusted for demographic characteristics, physical examination, disease information, geographic and socioeconomic status. A total of 25097 subjects were included in the Beijing Health Management Cohort from 2013 to 2018. With a 1 μg/m3 increase in the concentrations of PM2.5, SO2 and NO2, the incidence risk of cerebrovascular disease increased by 1.02 (95% CI: 1.008–1.034), 1.06 (95% CI: 1.034–1.095) and 1.02 (95% CI: 1.010–1.029) respectively. Whereas CO exposure could decrease the risk, with an odds ratio of 0.38 (95% CI: 0.212–0.626). In the subgroup analysis, individuals under the age of 50 with normal BMI were at higher risk caused by PM2.5, and SO2 was considered more hazardous to women. Meanwhile, the protective effect of CO on women and those with normal BMI was stronger. Successful reduction of long-term exposure to PM2.5, SO2 and NO2 would lead to substantial benefits for decrease the risk of cerebrovascular disease especially for the health of the susceptible individuals.  相似文献   
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