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841.
利用2017-2019年中卫市环保局提供的环境监测资料,统计分析中卫市主要污染物的变化及污染物平均浓度与气象要素的关系.结果表明,中卫市空气污染主要出现在冬、春两季,主要污染物为PM10和PM2.5,4月开始一直到夏季,中卫市典型的大气污染源为,中卫市中度以上污染主要为PM10污染,大多由扬沙、浮尘天气引起.PM2.5...  相似文献   
842.
A systematic modeling approach to describing, prescribing, and predicting usability of a product has been presented. Given the evaluation results of the usability dimension (UD) and the measurement of the product’s design variables, referred to as the human interface elements (HIEs), the approach enables one to systematically assess the relationship between the UD and HIEs. The assessed relationship is called a usability model. Once built, such a usability model can relate, in a quantitative manner, the HIEs directly to the UDs, and thus can serve as an effective aid to designers by evaluating and predicting the usability of an existing or hypothetical product. A usability model for elegance of audiovisual consumer electronic products has been demonstrated.  相似文献   
843.
利用1957—2010年新疆巴州地区焉耆和若羌气象站太阳总辐射,建立适用于计算巴州地区太阳总辐射的经验公式,其焉耆和若羌的相对误差分别在3.9%—6%、3.45%—9.3%之间。据此分析了巴州地区太阳总辐射的月际、年际分布状况,并对太阳能资源按行业标准进行了评估。结果表明,巴州地区年太阳总辐射等级为II级,资源丰富;年日照时数>6h的天数在259—294d之间,利用价值高;若羌和且末K<2,资源稳定度高,是光伏产业的首选之地。  相似文献   
844.
以协商的方式确定水污染物间接排放标准的规定打破了人们对标准确定性、强制性的传统认识。协定标准的优势在于充分利用污水处理厂的污水处理能力,减轻企业的污水处理负担,使企业可以集中力量搞生产。协定标准具有灵活性和优越性,应充分利用。通过对协定标准概念和重要性的分析,指出协定标准存在效力不确定、缺少对协定范围的限制等问题,造成协定标准在实践中通常被忽视或者滥用。并从明确协定标准的范围、加强排污企业的管理和协定标准的监督等方面,进一步提出了限制和完善水污染物间接排放标准的建议。  相似文献   
845.
• The Chinese population exposure habits were surveyed. • The risks of three scenarios of reclaimed water utilization were evaluated by QMRA. • The risks were markedly higher than the threshold (10−4 pppy) recommended by WHO. • The risks were age-, educational background-, region- and gender-specific. Reclaimed water utilization provides an effective way to alleviate water shortage. However, the residual pathogens in the recycled water like Legionella, could be spread into the air as aerosols through water-to-air transmission process. Inhaling the aerosols by the people nearby increases their susceptibility to diseases. For estimating the health risks associated with the potential exposure of airborne Legionella emitted from the urban use of reclaimed water in China, nationwide questionnaire was designed to investigate the exposure habits of Chinese population in different scenarios. Quantitative microbial risk assessment (QMRA) served as the suitable explanatory tool to estimate the risk. The results indicated that annual infection probability of populations exposed to Legionella for three scenarios, 0.0764 (95% CI: 0.0032–0.6880) for road cleaning, 1.0000 (95% CI: 0.1883–1.0000) for greenfield irrigation, 0.9981 (95% CI: 0.0784–1.0000) for landscape fountain, were markedly higher than the threshold recommended by WHO (10−4 per person per year (pppy)) according to the concentration distribution of Legionella in the reclaimed water. An age-, educational background-, region- and gender-specific data in annual infection probability also showed different tendencies for some subpopulations. This study provides some detailed information on the health risks from the water reuse in China and will be useful to promote the safe application of reclaimed water in water-deficient areas.  相似文献   
846.
长江口最大浑浊带潮滩沉积物间隙水营养盐剖面研究   总被引:5,自引:2,他引:3  
2005-03~2006-02对长江口崇明东滩高、中、低潮滩3个典型站点沉积物间隙水中各营养盐成分含量及其随深度的变化做了为期1a的逐月观测.结果显示,研究区域间隙水中NH4+和SiO32-的浓度一般在200~500μmol/L之间,高、中、低潮滩间显示出了不同的分布态势;与高潮滩和中潮滩相比,没有植被覆盖、粒径较粗的低潮滩往往具有较高的NH+4浓度和较低的SiO32-浓度;  相似文献   
847.
Sorption of Cr(VI) was carried out from dilute solutions using live and pretreated biomass in a batch mode. Effects of agitation time, adsorbent dosage and pH were examined. The autoclaved biomass that showed maximum adsorption capacity (Q(0)=0.335 mg g(-1)) was used as an adsorbent in column studies. The optimized flow rate of 2.5 ml min(-1) and bed height 10 cm were used to determine the effect of metal ion concentration on removal of Cr(VI). Applying the BDST model to calculate the adsorption capacity (N(0)) of column, which showed 4.56 x 10(-5), 7.28 x 10(-5), 6.89 x 10(-5), 3.07 x 10(-5), 2.80 x 10(-5)mg g(-1) for 4, 8, 12, 16 and 20 mg dm(-3) of Cr(VI), respectively. Batch sorption proved to be more efficient than the column sorption and hence batch sorption was used to remove Cr(VI) from a textile dyeing industry wastewater. The phytotoxic effect of treated and untreated wastewater was studied against Zea mays. Toxicity was reduced by 50% in the treated effluent.  相似文献   
848.
A study was conducted to determine the adsorption/desorption of butachlor, myclobutanil and chlorpyrifos on five soils using a batch equilibration technique and to study the relationship between bioavailability to Allolobophora caliginosa and the adsorption/desorption of these three pesticides. The results showed that the adsorption/desorption processes of the tested compounds were mainly controlled by soil organic matter content (OM) and octanol/water-partitioning coefficient (K(ow)), and that the bioavailability of the pesticides was dependent on characteristics of pesticides, properties of soils, and uptake routes of earthworms. Bioconcentration of butachlor and myclobutanil was negatively correlated with Freundlich adsorption constant K(af) and K(df). However, only a slightly positive correlation between bioconcentration and K(af) and K(df) was observed for chlorpyrifos due to its high affinity onto soil.  相似文献   
849.
Imidacloprid, the major component of many widely used insecticide formulations, is highly persistent in soils. In this study, the sorption of imidacloprid by six soils as well as its photodegradation and hydrolysis in water were studied. The soils differed significantly in organic matter content and other physical and chemical properties. Sorption increased with increasing soil organic matter content but was not significantly correlated with other soil properties. Removal of organic matter via H2O2 oxidation decreased the sorption. By normalizing the Freundlich coefficients (Kf) to organic matter contents, the variability in obtained sorption coefficient (Kom) was substantially reduced. These results indicate that soil organic matter was the primary sorptive medium for imidacloprid. The low heat of sorption calculated from Kom suggests that partition into soil organic matter was most likely the mechanism. The photodegradation and hydrolysis of imidacloprid in water followed pseudo-first-order kinetics; however, the latter process needed a six-time-higher activation energy. While both processes produced the same main intermediate, they occurred via different pathways. The hydrolysis of imidacloprid was not catalyzed by the high interlayer pH in the presence of metal-saturated clays, which appeared to result from the lack of the pesticide adsorption in the interlayers of clays.  相似文献   
850.
近年来,作为现代服务业的象征,楼宇经济已成为区域经济发展的支柱,其产业聚能和辐射效应日益凸显,但与此同时,它也给业主单位的安全管理带来了新的挑战。本文针对商务楼宇的主要类型以及安全管理工作中存在的主要问题,从业主单位必须创新商务楼宇安全管理工作理念,完善商务楼宇安全管理工作机制,提升商务楼宇安全管理的专业化、信息化和社会化三个方面探索了顺应时代发展需要、符合商务楼宇自身特色的安全管理模式,以期为我国商务楼宇的安全管理提供新的思路。  相似文献   
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