重点企业清洁生产推进的驱动因素分析

构建了清洁生产驱动力模型,提出重点企业清洁生产推进的定量化分析指标,采用回归方法分析了经济发展水平、污染压力和外部条件对重点企业清洁生产推进的影响.结果表明:以重点企业审核率为指标反映重点企业清洁生产的推进情况更合适和准确.我国重点企业清洁生产在经济发展水平、污染压力和外部条件等方面共同作用下逐步推进,现阶段则更多地依靠经济发展和污染压力外部驱动力推进,这种驱动模式的速度较慢.要快速推进重点企业清洁生产,需加强和激发企业内部条件的推动作用.      

The Illinois .08 law. An evaluation

Lowering state blood alcohol concentration (BAC) limits to 0.08, though controversial, has been supported by most evaluation studies to date. The Illinois .08 BAC law implemented in 1997 provided a unique opportunity to evaluate the effect of the law without the simultaneous passage of an administrative license revocation (ALR) law, which has clouded some previous evaluations of the .08 laws. The proportion of all drinking drivers in fatal crashes was compared before versus after implementing the .08 law using time-series analysis to evaluate 12 years of fatal crash data for Illinois and five bordering states. The results showed that the proportion of drinking drivers in fatal crashes decreased by 14% in Illinois and increased by 3% in bordering states. The proportion of drinking drivers in fatal crashes in Illinois, though increasing since 1995, was sharply reduced after passage of the .08 law in 1997, saving more than 100 lives in 1998 and 1999 than it would have without the .08 law.     

Forfeiture programs in California: why so few?

PROBLEM: It is estimated that at least 75% of suspended or revoked drivers continue to drive illegally. In states like California, there are also a substantial and growing number of people who drive without ever having been licensed. Some states, such as Ohio and California, have enacted vehicle impoundment and forfeiture programs as sanctions to reduce these offenses. Published evaluations indicate that vehicle impoundment laws reduce recidivism and crash rates. However, vehicle forfeiture programs have been less successful, mostly because of low levels of enforcement. METHOD: Police officers and district attorneys from 17 jurisdictions were interviewed by phone or in person to determine current enforcement levels and impediments to more aggressive application of statutory authority. RESULTS AND DISCUSSION: The survey found that most California jurisdictions are enforcing vehicle impoundments for first-time offenders. However, very few jurisdictions were enforcing the vehicle forfeiture law for repeat offenders. Among the reasons for not enforcing the vehicle forfeiture law was a perception that it was too time-consuming and/or not a priority among prosecutors. However, a number of authorities indicated that the simple vehicle impoundment procedure is often functionally equivalent to forfeiture because many drivers fail to retrieve the vehicle at the end of the impoundment period. IMPACT ON INDUSTRY: Vehicle impoundment programs are effective mechanisms in deterring illicit driving, and states should be encouraged to initiate vehicle impoundment laws. States could achieve even greater safety benefits if vehicle forfeiture sanctions were extensively used for repeat offenders. However, based on California's experience, the incremental benefits of vehicle forfeiture (over vehicle impoundment) may not be very great.     

Using a driving simulator to identify older drivers at inflated risk of motor vehicle crashes

PROBLEM: To develop appropriate assessment criteria to measure the performance of older drivers using an interactive PC-based driving simulator, and to determine which measures were associated with the occurrence of motor-vehicle crash. METHOD: One hundred and twenty-nine older drivers residing in a metropolitan city volunteered to participate in this retrospective cohort study. Using the driving simulator, appropriate driving tasks were devised to test the older drivers, whose performances were assessed by 10 reliable assessment criteria. Logistic regression analysis was then undertaken to determine those criteria that influence the self-reported crash outcome. RESULTS: As expected, driving skill of older drivers was found to decline with age. Over 60% of the sample participants reported having at least one motor-vehicle crash during the past year. Adjusting for age in a logistic regression analysis, the cognitive abilities associated with the crash occurrence were working memory, decision making under pressure of time, and confidence in driving at high speed. SUMMARY: The findings of this retrospective study indicated those individuals at inflated risk of vehicle crashes could be identified using the PC-based interactive driving simulator. Prospective studies need to be undertaken to determine whether the driving simulator can predict future crash events. IMPACT ON INDUSTRY: This study demonstrated an economical driving simulator approach to screen out problematic or unsafe older drivers before a more detailed but expensive road test is considered.     

山岳型旅游地旅游城镇化动力机制研究——以九华山为例

旅游城镇化是指发展旅游业的地区为了给旅游者提供交通、游览、食宿、娱乐、购物等一系列服务，使生产、提供这些商品和服务的行业与居民大量在此聚集，逐渐形成具有明显职能特色的城镇的过程。分析旅游城镇化现象产生的动力机制是旅游城镇化研究的重要内容。在实地调研的基础上，以九华山为例，分析了山岳型旅游地旅游城镇化现象产生和发展的内外多维动力系统，并结合九华山独特的佛教旅游地特征，有针对性地分析了九华山旅游城镇化发展的特点。     

不同城市化速度地区建设用地演变驱动力比较研究

以深圳和武汉为例,选择与建设用地相关性大的10项社会经济指标,采用简单的逐步回归方法对城市化速度存在较大差异的2个城市建设用地演变驱动力进行了比较分析,对2个城市驱动力的共性和差异给出了合理解释,可增强对城市化过程中建设用地演变机理的动态理解,为抑制建设用地的过快增长提供参考。     

浮游微型真核生物群落对电厂温排水增温的响应

浮游微型真核生物作为初级生产者,细菌捕食者和较大型生物寄生者,在维持生态系统稳定中起核心作用.因此,研究浮游微型真核生物对温排水增温的响应对评价近年来大量电厂兴建的环境效应具有重要意义.沿象山港乌沙山电厂温排水水流采集表层水样,利用Illumina技术测定18S r DNA基因研究浮游微型真核生物群落组成.真核浮游生物的主要组成为囊泡虫门(Protalveolata)、纤毛亚门(Ciliophora)、甲藻门(Dinoflagellata)和丝足虫类(Cercozoa).多元回归树分析发现浮游微型真核生物多样性主要受溶解氧、硝态氮和温度的控制.温排水造成的增温梯度显著地改变了浮游微型真核生物的群落组成(Global RANOSIM=0.422,P0.001);反向选择筛选到空间距离、溶解氧、叶绿素a和温度是造成群落变异的主要因子.浮游微型真核生物的空间分布遵循空间距离-群落相似性衰减模型(R=-0.192,P=0.039),周转速率为0.002.此外,筛选到15个敏感的真核生物科,其相对丰度与增温幅度显著相关.重要的是对某一特定的科,其相对丰度随温度的变化与其已知的生态功能相吻合,可以作为评价温排水增温的指示种群.本研究阐明了温排水增温梯度下真核浮游生物群落的空间分布规律,并为评价温排水对微生态效应提供了灵敏的生物学指标.     

QCM-D与AFM联用解析EfOM在SiO2改性PVDF超滤膜表面的吸附机制

为了进一步从微观角度上研究不同过滤阶段出水有机物(Ef OM)在纳米Si O2改性超滤膜表面的具体吸附机制,通过调节Si O2添加比例从而获得不同改性程度的实际膜.借用耗散型石英晶体微天平(QCM-D)与原子力显微镜(AFM)联用技术分别测定Ef OM在膜表面的吸附情况和Ef OM与膜之间的相互作用力.QCM-D实验结果与分析表明,膜表面的亲水性越好,膜表面Ef OM吸附量就越少,以及Ef OM在膜表面的吸附速率明显减缓.实验结果还发现,Ef OM的吸附经历了两个阶段:在初始阶段(15 min内),有机物快速吸附到膜表面并堆积;当Ef OM的吸附频率达到平衡时,耗散却处于非平衡状态,该现象说明虽然Ef OM在膜表面的吸附量达到稳定,但其吸附层的构象却仍在发生变化.AFM测定结果证明,随着亲水性的不断改善,Ef OM-膜、Ef OM-Ef OM之间的作用力均有所减小,该结果揭露了膜面Ef OM吸附量减少吸附速率下降的本质原因.QCM-D与AFM的联用有效地解释了膜改性对Ef OM吸附机制的影响.     

微米Fe3O4磁粉调理-压力电场污泥脱水工艺过程研究

研究了微米Fe_3O_4磁粉调理污泥的投加量的优化以及微米磁粉调理-压力电场污泥脱水工艺(MPEOD)的操作参数(电场作用时间、机械压力、电压)对脱水效果和能耗的影响,分析了磁化调理后污泥上清液、污泥絮体理化性质及接触能变化特征.结果表明,微米Fe_3O_4磁粉最佳调理投加量为0.15 g·g~(-1);结合能耗与脱水效果,电场作用时间、电压和机械压力分别确定为2 h、30~50 V和400~600 k Pa.当MPEOD工艺的机械压力、电场作用时间和电压分别为400 k Pa、2 h和50 V时,污泥含水率由初始的99.18%降低至44.46%,水分脱除率和污泥减量化分别可达99.34%和98.30%,相应的能耗仅为0.013 3k W·h·kg~(-1).微米磁粉调理污泥时,絮凝作用机制的影响很小,污泥脱水性能得到提高的主要原因是微米磁粉大大降低了污泥颗粒间的路易斯酸碱作用,致使污泥絮体聚集,絮体间孔径增大,利于脱水.较之经典的DLVO理论,扩展后的EDLVO理论能准确描述污泥颗粒的凝聚及分散行为.     

长江上游植被覆盖的时空分异季节变化及其驱动因子研究

以GIMMS/NDVl为基础,结合气候与人类活动数据,研究了1982～2003年间长江上游植被覆盖季节变化的空间分布.结果表明,近22年来,长江上游春季、夏季植被覆盖呈增加趋势,以春季最显著;秋季、冬季植被覆盖呈降低趋势,以秋季降低最显著.春季、夏季降雨与气温的同步增加,致使植被覆盖增加;秋季降雨减少,以及气温的增加导致植被覆盖降低;另外,作物播种面积的增加是春季、夏季植被覆盖增加,秋季、冬季植被覆盖减少的重要原因.春季→夏季→秋季→冬季NDVI增加的区域在窄问上大致呈现低纬度向高纬度转移的趋势.春季、夏季所有植被类型的NDVI均有增加趋势;而秋季所有植被类型的NDVI均降低;冬季植被除针叶林的NDVI略有增长外,其余植被类型的NDVI均降低.