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931.
本溪市环境质量“十五”与“九五”相比有了明显好转,本文就环境质量现状分布规律及变化因素进行了综合分析,并提出了进一步改善环境质量的对策。  相似文献   
932.
在颗粒状黏土素瓷载体上 ,经灼烧制备具有共价结合的铝胶薄膜 ,并以此为载体 ,在聚合氯化铝形成过程中与氯化铝悬浊液共熟化 ,在铝胶薄膜表面生成聚合氯化铝 ,经灼烧进一步固化而制得表面包覆聚合氯化铝吸附材料。该吸附材料作为絮凝剂可循环使用约 17次。用于处理造纸污水 ,COD、BOD、悬浮物、硫化物、色度等指标可分别降低约 93%、77%、96 %、94 %和 80 %。  相似文献   
933.
Objective: The State of Connecticut has a partial motorcycle helmet law, which has been linked to one of the lowest helmet compliance rates in the Northeast. We examine the clinical and financial impact of low motorcycle helmet use in the State of Connecticut.

Methods: A retrospective cohort study comparing the outcomes between helmeted and nonhelmeted motorcycle crash victims over a 12.5-year period, from July 2, 2002, to December 31, 2013. All patients who were admitted to the hospital after a motorcycle crash were included in the study. Patients were stratified into helmeted and nonhelmeted cohorts. Group differences were compared using t-test or Wilcoxon rank test for continuous variables and chi-square test for dichotomous outcomes. Regression models were created to evaluate predictors of helmet use, alcohol and drugs as confounding variables, and factors that influenced hospital costs.

Results: The registry included 986 eligible patients. Of this group, 335 (34%) were helmeted and 651 (66%) were nonhelmeted. Overall, nonhelmeted patients had a worse clinical presentation, with lower Glasgow Coma Scale (GCS; P <.01), higher Injury Severity Score (ISS; P <.01), higher incidence of loss of consciousness (LOC; P <.01), longer intensive care unit (ICU; P <.01) admissions, and higher incidence of head (P <.01) or face injuries (P <.01). Nonhelmeted patients were also twice as more likely to die from their injuries (P =.04, odds ratio [OR] = 1.89, 95% confidence interval [CI], 1.02–3.45). Financially, nonhelmeted patients incurred mean hospital costs of $18,458, whereas helmeted patients incurred $14,970 (P =.18). ISS, GCS, and ICU length of stay were significantly correlated with increased hospital costs (P <.01). Not using a helmet was a significant predictor of mortality (P =.04) after adjusting for alcohol/drug use and age.

Conclusions: Helmet use is associated with lower injury severity and increased survival after a motorcycle crash. These outcomes remained consistent even after controlling for age and alcohol and drug use. The medical and financial impact of Connecticut's partial helmet law should be carefully evaluated to petition for increased education and enforcement of helmet use.  相似文献   

934.
确保主要行业主要污染物排放总量数据的准确性对制定总量减排和区域环境质量改善规划尤为重要.以济南某石化企业为例,对石油加工业常减压、催化裂化、延迟焦化、柴油加氢、硫磺回收等工艺二氧化硫产排污系数开展验证研究.将产排污系数与监测结果对比分析,发现该企业通过产排污系数计算的二氧化硫排放量远大于实际排放量.在此基础上,提出石油加工业二氧化硫产排污系数修订建议.  相似文献   
935.
This research analyses urban expansion patterns and their eco-risks in the Poyang Lake region in China. A hybrid model consisting of auto-logistic regression, Markov chain and cellular automata (CA) is designed to improve the performance of the standard logistic regression model. An eco-risk assessment (ERA) index by integrating landscape fragmentation index and area weighted eco-service value index is established to promote the effectiveness for dynamically evaluating the environment and eco-security in watersheds. Scenario predictions are introduced to better understand the relationship between urban dynamics and their eco-risks. Three urban development scenarios such as historical development trend (HDT), environment protection priority (EPP) and goal-oriented restriction (GOR) are designed and transplanted into the CA model through the parameter self-modification method. The quantitative analysis results showed that in the period of the past five years, the urban growth primarily concentrated in the metropolitans. The simulations show that under the HDT scenario the urban growth will mainly emerge in the metropolitans, while under the EPP and GOR scenarios the urban growth will expand along with the metropolitans or the road networks and highways, respectively. Moreover, the ERA demonstrated that the GOR scenario was more effective in meeting the goal of environment protection and urban sustainable development for the study area.  相似文献   
936.
2012年9月1日至30日利用大气气溶胶OC/EC在线分析仪在线分析了西安PM2.5中的OC、EC,并结合O3和紫外辐射数据(UV)进行了分析。结果表明:PM2.5、OC、EC、及O3的日均值分别为85.22,19.50,7.18,56.69μg/m3。PM2.5及其中OC、EC的日变化规律呈现"双峰"分布,OC、EC的日波动范围较PM2.5小,且OC的波动范围较EC大,OC、EC的相关性较高(R2=0.73)。PM2.5中TCA的平均比重为47.85%,是PM2.5的主要成分之一,TCA以OM为主,OM中SOC的平均比重高达54.76%,PM2.5中SOC的平均比重为21.25%,SOC和O3的相关性较高,表明研究期间西安市有机物光化学反应较重。1 d中10:00至19:00是PM2.5中SOC比重最高的时段且呈上升趋势,而PM2.5中TCA的变化规律则呈"W"型双峰分布。  相似文献   
937.
Flower-, wire-, and sheet-like MnO2-deposited diatomites have been prepared using a hydrothermal method with Mn(Ac)2, KMnO4and/or MnSO4 as Mn source and diatomite as support. Physical properties of the materials were characterized by means of numerous analytical techniques, and their behaviors in the adsorption of chromium(VI) were evaluated.It is shown that the MnO2-deposited diatomite samples with different morphologies possessed high surface areas and abundant surface hydroxyl groups(especially the wire-like MnO2/diatomite sample). The wire-like MnO2/diatomite sample showed the best performance in the removal of Cr(VI), giving the maximum Cr(VI) adsorption capacity of 101 mg/g.  相似文献   
938.
酚类物质作为一类主要的污染物,已引起国内外高度重视,但目前其对陆生生物的毒性研究较少。本试验探究了4-叔丁基苯酚、间甲酚、2-氯苯酚、2-甲酚、2,4-二氯苯酚这5种酚类物质对中国本土物种中国白羽鹌鹑和中华蜜蜂的急性毒性。在中国白羽鹌鹑的急性经口试验中,2-氯苯酚、2-甲酚的7 d的半致死浓度(7 d-LC50)分别为331 mg·kg~(-1)和413 mg·kg~(-1),其他3种酚类物质的7 d-LC50均大于限度值1 000 mg·kg~(-1);在中国白羽鹌鹑的急性饲喂试验中,5种酚类物质的8 d-LC50均大于限度值2 000 mg·kg~(-1);在中华蜜蜂的急性经口试验中,2-氯苯酚、2-甲酚和2,4-二氯苯酚的48 h-LC50分别为306 mg·L~(-1)、358 mg·L~(-1)和364 mg·L~(-1);在中华蜜蜂的急性接触试验中,2,4-二氯苯酚的48 h的半致死量(48 h-LD50)为2.6μg·蜂~(-1),其他4种酚类物质的48h-LD50均大于限度值100μg·蜂~(-1)。研究结果表明不同的酚类物质由于其结构不同亦表现出不同的毒性,甲酚的邻位取代比间位取代对中国白羽鹌鹑和中华蜜蜂的毒性更高,不同物种表现出了相似的规律性。5种酚类物质对我国本土物种中国白羽鹌鹑和中华蜜蜂毒性比对其他水生生物更敏感,存在良好的剂量效应关系。  相似文献   
939.
采用滴定吸附法将过氧乙酸组装于中孔硅胶中,通过红外光谱分析和N2吸附法对组装体进行了表征,研究了常温常压下,该组装体氧化、吸附、脱除柴油硫化物的活性.结果表明,该组装体具有优良的脱硫性能.柴油中硫化物与过氧乙酸在硅胶孔中发生氧化反应,氧化产物被吸附在硅胶上,使柴油的含硫量从1697μg/g降到14μg/g,符合美国环境保护署标准.  相似文献   
940.
氨基苯甲酸稀溶液的络合萃取研究   总被引:8,自引:0,他引:8  
本文利用三辛胺或磷酸三丁酯为络合剂,正辛醇或煤油为稀释剂,在不同的P则定了氨基本甲酸稀溶液的萃取相平衡分配系数,讨论了影响因素,提出了同时考虑络合萃取作用和物理萃取作用的平衡分配系数的表达式。  相似文献   
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