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111.
利用衡水市环境监测站2005—2007年度大气例行检测的数据,对衡水市大气中主要污染物SO^2、NO^2、PM10体积质量值的逐日数据进行统计分析,得出了衡水市空气污染的现状和时间变化规律:(1)污染物体积质量值的月变化曲线呈槽型分布,非取暖期的空气状况明显好于取暖期,取暖期SO^2平均体积质量是非取暖期的2.45倍;(2)污染物体积质量值的日变化曲线基本为两高两低型,其中取暖期污染指数早晨出现极高值的时间比非取暖期明显偏晚;(3)污染物体积质量值的年变化表明了SO^2的体积质量在降低,而NO^2的体积质量却有了小幅增长。  相似文献   
112.
利用室内动三轴实验研究了振动频率与龄期对河道淤泥气泡混合轻质土(FMLSS)动力特性的影响。结果表明,振动频率和龄期对FMLSS的动力特性有明显影响。振动频率越小,轴向动应变和阻尼比越大,动模量越小。随着养护龄期的增长,动模量增大而阻尼比减小。动模量曲线在振动频率大、养护龄期长和水泥含量高时更加陡峭。当动应变较小时,不同龄期的FMLSS阻尼比很接近,随着动应变不断发展,阻尼比差异增大。FMLSS的动模量曲线都呈平缓衰减型,阻尼比在0.01~0.03之间,体现出FMLSS是良好的弹性材料。最后,探讨了振动频率和龄期对FMLSS动力特性的影响机理。  相似文献   
113.
Summary. Larvae of Chrysomela leaf beetles release for defence volatile compounds belonging to various chemical families. This study focuses on the defensive strategy based on the esterification of isobutyric acid and 2-methylbutyric acid with a wide variety of alcohols taken up from the host plant. To date, only two species are known to produce these repellents C. interrupta, which is associated with Betulaceae and C. lapponica which occurs either on Betulaceae or Salicaceae.? In order to know if other species have developed this chemical defence and how the food plant influences the secretion of these toxins, we targeted by mass spectrometry the presence of iso- and 2-methylbutyric acids and esters of them in the defensive secretions of Chrysomela larvae exclusively associated with Betulaceae or Salicaceae. ?Screening analyses reveal that the synthesis of these compounds is a common character restricted to all the members belonging to the C. interrupta group sensu Brown (1956) regardless of the host-plant family. These results suggest that the biochemical mechanism leading to the synthesis of these compounds could be considered as a synapomorphy meaning that the group is probably monophyletic. ?Defensive secretions of the members of the interrupta group are quantitatively assayed for iso- and 2-methylbutyric acids and their (Z)-3-hexenyl esters. Results reveal a chemical plasticity developed by Chrysomela species associated with Salicaceae. The amounts of iso- and 2-methylbutyric acids derivatives and of salicylaldehyde in their larval secretions depend on the food plant and on its content in phenolglucosides. Received 5 October 1998; accepted 25 November 1998.  相似文献   
114.
塔里木河流域综合治理的环境影响趋势分析   总被引:2,自引:0,他引:2  
塔里木河流域综合治理已被列入国家和自治区的重点工程,本文分析了目前塔河流域的环境现状和的问题,着重讨论了综合治理规划实施对塔河流域环境的影响趋势。  相似文献   
115.
为解决转载点粉尘污染问题,采用量纲分析法将影响转载点诱导风量的因素进行分类推演,建立转载系统诱导风量计算模型,并搭建转载点诱导气流实验装置,系统分析物料在转载过程中给料量、落料高差、下料管倾角和皮带运行速度等因素对产生诱导气流的影响,拟合得出转载点诱导风量计算模型的数学表达式。结果表明:转载点物料的给料量和落料高差是影响诱导风量的主要因素;对量纲分析所得模型利用实验数据进行拟合所得各参数系数的标准误差优于0.032 1,实验结果与数学模型计算结果误差小于9.48%。该计算模型可用于估算转载点诱导风量大小,为现场的粉尘治理及生产实践提供参考依据。  相似文献   
116.
本文旨在用统计的方法 ,分析影响北京市居民为改善大气环境质量而付费的支付意愿的主要社会经济因素。分析结果表明 ,对被调查者支付意愿影响最显著的因素是家庭收入 ,其次是年龄、家庭人口数和教育水平。其中 ,收入和教育水平对支付意愿的影响为正 ,年龄和家庭人口数的影响为负。对调查范围内八个行政区被调查者的支付意愿均值比较显示 ,这八个区居民的支付意愿没有显著性差异。本文的结论是 ,提高收入水平和环境意识水平 ,是提高公众为改善环境质量而付费的支付意愿的有效途径  相似文献   
117.
Objectives: The Alcohol Use Disorders Identification Test (AUDIT) is used to assess the level of alcohol use/misuse and to inform the intensity of intervention delivered within screening, brief intervention, and referral to treatment (SBIRT) programs. Policy initiatives are recommending delivery of SBIRT within health care settings to reduce alcohol misuse and prevent alcohol-impaired driving. Recent reports are considering extending delivery of SBIRT to criminal justice settings. One consideration in implementing SBIRT delivery is the question of resource utilization; the amount of effort required in delivering the 4 different intensities of intervention in SBIRT: Alcohol education, simple advice, brief counseling and continued monitoring, and brief counseling and referral to specialist (from least to most intense in terms of delivery time, the skill level of the provider, and personnel resources).

Methods: In order to inform expectations about intervention intensity, this article describes the AUDIT scores from 982 adults recently arrested for alcohol-impaired driving. The distribution of scores is extrapolated to state rates for individuals arrested for alcohol-impaired driving by intervention level.

Results: Though alcohol education was the most common intervention category, about one quarter of the sample scored in a range corresponding with the more intensive interventions using the brief counseling, continued monitoring for ongoing alcohol use, and/or referral to specialist for diagnostic evaluation and treatment.

Conclusions: This article provides local distribution of AUDIT scores and state estimates for the number of individuals scoring in each level of risk (AUDIT risk zone) and corresponding intervention type. Routine criminal justice practice is well positioned to deliver alcohol screening, education, simple advice, and continued alcohol monitoring, making delivery of SBIRT feasible for the majority of alcohol-impaired drivers. Challenges to implementing the full range of SBIRT services include resource demands of brief counseling, identifying the appropriate providers within a criminal justice context, and availability of community providers for referral to diagnostic and specialty care. Solutions may vary by state due to differences in population density and incidence rates of alcohol-impaired driving.  相似文献   

118.
In this paper the data of a forest health inventory are analyzed. Since 1983 the degree of defoliation, together with various explanatory variables (covariates) concerning stand, site, soil and weather, are recorded by the second of the two authors, in the forest district of Rothenbuch (Spessart, Bavaria). The focus is on the space and time dependencies of the data. The mutual relationship of space-time functions and the set of covariates is evaluated. For this we use generalized linear models (GLMs) for ordinal response variables and semiparametric estimation approaches. By using goodness-of-fit measures it turns out that (i) the contribution of space-time functions is quantitatively comparable with that of the set of covariates, (ii) the contribution of space-time functions is small compared with the contribution of a set of variables describing the last-year and neighboring response values. By applying appropriate residual methods a detailed analysis of the individual sites in the area can be carried out. This analysis reveals where the predictive power of the covariates fail to explain the observed defoliation.  相似文献   
119.
In young-of-the-year perch (Perca fluviatilis), individuals within groups differed in the degree of boldness, estimated by habitat utilisation and feeding activity in visual contact with a potential predator. We looked at changes in individual behaviour in connection with change of group composition. During the first period, perch were randomly assigned to groups, and time spent in open habitat versus in vegetation and number of prey attacks were registered. The perch were then categorised into personality types (shy, bold, intermediate) according to their behaviour. During the second period, fish were observed when sorted into new groups, each containing only one personality type. Shy individuals showed the largest changes in behaviour, and increased both the time spent in the open and the number of prey attacks when placed into the new groups. Feeding activity in shy fish during the second period was affected by group composition during the first period. After regrouping, bold individuals decreased their time in the open, whereas intermediate individuals did not change behaviour. Time in the open habitat was, to some extent, influenced by the behaviour of the other members of the group, but number of prey attacks was not. The behaviour of fish of the different personality types we have defined in this study seemed to be based on innate traits, but also modified by the influence of other group members and by habituation to the environment.Communicated by J.Krause  相似文献   
120.
韶山灌溉工程是湖南省最大的水利灌溉工程,到目前已安全运行了30多年,该工程的兴建,使该地区摆脱了旱魔的长期威胁,促进了区内农业经济持续,稳定,快速发展,从而带动了区域经济的全面提高。从纵向与横向和定性与定量的计算,对比分析研究中,总结了该工程对区域社会经济的深远影响。  相似文献   
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