爆炸分离冲击信号修正及结构状态分析

为了对爆炸分离冲击信号进行有效性分析及校正,进而对关键结构的状态变化进行分析,基于离散小波分解方法,对实测分离冲击信号及其速度积分进行校正,去除零漂趋势项.选取冲击结束后剩余自由响应阶段,对结构状态进行分析,基于冲击信号初始谱及剩余谱相关性分析,提出确定剩余自由响应阶段起始分析时间的确定方法.对该剩余响应信号结合频域窗...     

DETECTING BASE FLOW IMPACTS IN COASTAL PLAIN STREAMS1

ABSTRACT: An established trend analysis methodology was applied to the problem of identifying and quantifying stream base flow impacts from water withdrawals and water loss through interbasin transfers. Impacts were simulated using base flow values selected from two U.S. Geological Survey (USGS) continuous record streamflow sites located within the Pinelands of southern New Jersey. Study site base flows were regressed against index site base flows with monotonic and step trend tests applied to the residuals from the regression model. The smallest, significantly detectable (α= 0.10) percentage reduction within a given simulation was used as an estimate of the sensitivity of a trend test. Evaluation of the trend analysis methodology led to the following practical considerations regarding trend test sensitivity. The proportion of study site base flow variability explained by index site base flows should be maximized, while at the same time minimizing positive, first-order autocorrelation in the regression residuals. Given the importance of detecting autocorrelation, missing values should be avoided or minimized. The quarterly (three-month) interval reduced the magnitude of autocorrelation relative to a shorter two-month sampling interval. Sensitivity appeared to improve when equalizing the number of values before and after a base flow impact(s) while seasonally biased sampling appeared to reduce sensitivity. Based primarily on past trend detection studies, nonparametric tests were deemed a better choice over their parametric counterparts, due to the lack of stringent data distributional requirements coupled with little or no loss of power even when applied to normally distributed data.     

深圳市排污收费系统的开发与研究

排污收费是环境保护工作中的重要内容,它直接体现了监管的力度和执法的效果。由于这项工作与其他业务部门,如建设项目审批、环境监督、环境监测、环境执法等部门联系密切,因而信息结构复杂。目前在我国投入使用的排污收费管理系统软件大多是FOXPRO数据库,难于实现收费信息共享。基于城市级环境信息管理系统的需求以及目前进行的污染物总量排污收费制度的试点,开发出一套WINDOWS环境采用SYBASE数据库的排污收费管理系统PWSF是十分必要的。      

Ontogenetic changes in alarm-call production and usage in meerkats (<Emphasis Type="Italic">Suricata suricatta</Emphasis>): adaptations or constraints?

In many species, individuals suffer major mortality in their first year because of predation. Behaviours that facilitate successful escape are therefore under strong selection, but anti-predator skills often emerge gradually during an individual’s early development. Using long-term data and acoustic recordings of alarm calls collected during natural predator encounters, we aimed to elucidate two largely unsolved issues in anti-predator ontogeny: (1) whether incorrect predator assignment is adaptively age-appropriate, given that vulnerability often changes during development, or whether age-related differences reflect true mistakes made by immature individuals; and (2) the extent to which the development of adult-like competence in alarm-call production and usage is simply a function of maturational processes or dependent upon experience. We found that young meerkats (Suricata suricatta) were less likely to give alarm calls than adults, but alarmed more in response to non-threatening species compared to adults. However, stimuli that pose a greater threat to young than adults did not elicit more calling from young; this argues against age-related changes in vulnerability as the sole explanation for developmental changes in calling. Young in small groups, who were more likely to watch out for predators, alarmed more than less vigilant young in larger groups. Moreover, despite similarities in acoustic structure between alarm call types, calls appeared in the repertoire at different rates, and those that were associated with frequently encountered predators were produced relatively early on. These results indicate that experience is a more plausible explanation for such developmental trajectories than maturation.     

特种设备安全法规标准体系现状与发展

通过回顾特种设备安全法规标准体系的历史过程,对由五个层次构成的特种设备安全法规标准体系的现状逐一进行了说明,从特种设备法规标准的法律地位、作用及特性等方面分析了特种设备安全法规标准的关系,归纳总结特种设备法规标准的体系化、技术性及内容综合化等特点。最终提出了特种设备法规标准体系的发展重点,如重点协调特种设备法所提出的特种设备经营管理、召回及应急响应制度相应的法规标准,确定不同特种设备的基本安全要求,形成特种设备法规标准实施效果评估等。     

基于可公度方法的陕西及邻近地区重大自然灾害发生趋势探讨

针对重大自然灾害预测预报的世界难题,在可公度方法的基础上,提出时间对称性观点;进而对陕西及可能影响到陕西的部分全国重大自然灾害进行了趋势研究。研究认为,2010年、2012年、2013年及2019年,陕西及邻近地区有发生重大灾害的可能性。并认为,适应全球变化首先要适应频繁的自然灾害。     

哈尔滨市高空气候变暖变化分析

依据哈尔滨市1970-2005年的探空资料,采用线性模拟、相关和回归等分析方法,对哈尔滨市35年来地面及高空气候的变化进行分析和预测。研究结果认为:①哈尔滨市对流层中下层、平流层下层气候变化明显,对流层中下层气候变暖变湿,且对流层下层经向风速变小,年平均风速也变小,其中值得关注的是温度升高可延伸到400hPa,比湿增加也从地面延伸到400hPa;②建立了二氧化碳与水汽之间的关系方程,二氧化碳增加,水汽含量也随之增加,二氧化碳每增加一个单位,水汽就增加0.011g/kg;③各层次温度与比湿存在线性关系,水汽对各层次温度所起到的增加作用,随高度的增加增温效果越明显。     

青海省旅游客源市场分析研究

青海省旅游资源独特,资源的垄断性高,但旅游业起步晚且发展水平较低,在国际和国内旅游客源市场上占有的份额小。作者运用1990年～1997年旅游统计资料,研究了青海省国内、国际旅游客源市场的数量和地域构成现状,并针对其客源市场发展目标,提出了相应的开发措施。     

环境影响评价与西部大开发的可持续发展

环境影响评价作为协调经济发展与环境保护关系的重要手段,将在西部大开发中发挥重要作用。本文从可持续发展的高度,提出进一步完善环境影响评价的具体对策,以确保实现西部大开发的可持续发展。     

广州市城市垃圾终处理的现状及发展策略

结合广州市自然地理,社会经济条件,概括总结了广州市垃圾产出特点及垃圾终处理的发展阶段,重点分析了现有垃圾填埋场存在的问题及产生原因。在此基础上,提出了广州市垃圾终处理要“四个坚持”的发展策略。