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391.
曹净  李豪 《工业安全与环保》2021,47(4):10-14,30
提出了一种基于ACE法和模拟退火算法的土层参数反演方法:一方面先用均匀试验构造出输入数据与输出数据,再利用ACE非参数回归方法构造两者之间的高效响应面,然后通过响应面关系进行插值运算来得出对应参数的响应值;另一方面根据响应面的关系构造出反演目标函数,利用模拟退火法对目标函数进行寻优计算,从而能避免寻优过程中的目标函数值陷入局部极值状态,最终提高反演精度。应用该方法对一工程算例的土层等效参数进行反演,反演结果表明该方法是可行的。  相似文献   
392.
A group of sympatric aquatic and semiaquatic spiders inhabiting Western Siberia (Argyroneta, Dolomedes, Pirata, and Pardosa) has been studied with respect to specific ethological features. The results provide a basis for the conclusion that these spiders differ in a number of behavioral adaptations related to prey catching and the use of common biotopic space. Experiments with the predator–prey system have shown that spiders have different effects on the abundance of bloodsucking mosquito larvae and on the age and genetic structure (at the chromosomal level) of their populations. The functional role of spiders in communities is discussed.  相似文献   
393.
热岛效应已成为城市化发展中影响局地气候变化的重要因素之一.作为城市必要基础设施的一部分,城市污水处理厂对全球性气候变化的影响受到了广泛关注和研究,而对局地气候变化的影响却鲜有研究.文章首次尝试利用Landsat卫星遥感图像对1995年-2013年间苏州市11座城市污水处理厂进行了热岛效应研究,并对影响因素进行了初步分析.结果发现,11座城市污水处理厂热岛强度在18年间整体上增加了48%;从时间维度上来看,在污水处理厂施工建设或升级改造阶段,热岛强度都偏高.而根据回归分析发现,城市地表平均温度、污水处理厂的施工建设状态和主体处理工艺与WHII具有显著正相关性.  相似文献   
394.
通过研究水环境管理中的数据库或数据平台的规范建设模式,提出了基于EAM的水环境数据平台建设方法,采取EAM方法设计了分层数据库,引入了数据集市对业务模板分类管理,构建了多数据库兼容技术和算法生成模块,综合建设出一套适合大数据管理要求的水环境数据平台。实践表明,这种方法构建的数据平台,能有效解决目前多系统、多数据、应用需求动态变化、以及数据安全的问题,有利于提升水环境大数据建设的基础。  相似文献   
395.
环境质量改善是我国"十三五"期间环保工作的核心,危险废物管理是影响环境质量的重要因素。近年来,我国危险废物污染防治工作在制度建设和能力建设等方面取得积极进展,但仍存在底数不清、减量不足、利用不畅等问题,频发的危险废物非法倾倒和掩埋已成为突发环境事件的重要诱因,严重威胁环境安全和人体健康。严峻的环境形势迫使我国改进传统的危险废物管理方式。文章从危险废物无害化管理现状分析入手,提出构建危险废物无害化管理大数据应用研究平台的建议,实现依靠数据管理、数据决策和预测性分析的构想。  相似文献   
396.
The analysis of consequential alarms is beneficial to avoiding alarm flooding and finding out root alarms in an industrial process. In this context, a novel similarity computation method taking into account of correlation delays between process alarms is introduced firstly. Subsequently, the Granger causality method is suggested to further clarify mutual impacts of similar alarm variables based on process data. Through the combination of alarm data similarity analysis and process data causality analysis, the consequential alarms can be effectively identified along with their evolution paths. An industrial case is employed to illustrate the benefits of the contribution.  相似文献   
397.
Number concentration and distribution of airborne particles in the size range 5.6 to 560 um diameter were measured in Beijing for a 15-d period in winter 2005.Daily average number concentrations of nucleation mode(5.6-20 nm),Aitken mode(20-100 nm), and accumulation mode(100-560 nm)particles,and total particles were 17500,32000,4000,and 53500 cm~(-3),respectively.Average particle size distribution was monomodal with a mode diameter of about 40 um at night and bimodal with mode diameters of about 10 and about 40 nm during the daytime.New particle formation events,which were connected to diurnal variation of nucleation mode particles,were observed in more than half of the observation days.The events often started around 10:00-11:00 Chinese Standard Time (CST)and ended up after 3-4 h.Concentrations of Aitken and accumulation mode particles increased from midnight and reached their maxima at about 10:00 CST,and then decreased and became the lowest in the afternoon.Analysis of diurnal cycles in traffic volume and meteorological parameters revealed that the accumulation of the particles in Aitken and accumulation modes in the morning was influenced by formation of an inversion and increase in vehicle emission,and dispersion of such particles in the afternoon was associated with more effective vertical mixing and higher wind speed.  相似文献   
398.
In environmental monitoring, variables with analytically non-detected values are commonly encountered. For the statistical evaluation of these data, most of the methods that produce a less biased performance require specific computer programs. In this paper, a statistical method based on the median semi-variance (SemiV) is proposed to estimate the position and spread statistics in a dataset with single left-censoring. The performances of the SemiV method and 12 other statistical methods are evaluated using real and complete datasets. The performances of all the methods are influenced by the percentage of censored data. In general, the simple substitution and deletion methods showed biased performance, with exceptions for L/2, Inter and L/√2 methods that can be used with caution under specific conditions. In general, the SemiV method and other parametric methods showed similar performances and were less biased than other methods. The SemiV method is a simple and accurate procedure that can be used in the analysis of datasets with less than 50% of left-censored data.  相似文献   
399.
基于Landsat 7的武汉市热岛效应研究   总被引:1,自引:0,他引:1  
城市化使得城市数量和规模不断增加,城市作为人类对自然环境改造最为剧烈的部分,具有独特的区域环境,其中城市内部温度显著高于周边郊区的热岛效应是一个突出的城市环境问题,受到了普遍关注和研究。武汉市是长江中游特大城市,城市热岛效应明显,但对其研究很少。利用Landsat TM6波段数据,生成武汉市城市亮温场,分析了武汉市热场的分布、大小,利用亮温场均值、方差和相对温度评价城市热岛强度,并对城市热场的范围及强度变化与城市发展规模及方向进行了分析,取得了较好的效果。  相似文献   
400.
Protected areas present a global heritage. Assessing conservation achievements in protected areas is of crucial importance with respect to the on-time delivery of international biodiversity conservation targets. However, monitoring data from publicly accessible databases for comparative studies of conservation achievements in the protected areas of the world are very scarce, if not non-existent. At first glance this is surprising because, with regards to protected areas, at least according to well established protected area management guidelines and widely accepted public mandates, a great deal of monitoring work and data gathering is to be conducted. This would imply that data on changes of biodiversity in protected areas could be expected to exist, and the constant progress in information technologies and Web tools engenders hope that some of it might even be available online for the global public. This review article presents the results of an extensive online search and review of existing monitoring data from freely accessible online databases for its use in an assessment of conservation achievements in a larger sample of protected areas. Results show two contrary sides to the status quo of accessible data from the World Wide Web for conservation science: data overkill and data scarcity with poor metadata provision. While ever more research is, in fact, based on open-access online data, such as extrapolations of species ranges used in conservation management and planning, it remains almost impossible to obtain a basic set of information for an assessment of conservation achievements within a larger number of protected areas. This awareness has triggered a detailed discussion about the discrepancies in sharing data at the level of protected areas; mismatching relationships between expected activities in protected areas and the capacity for delivering these requirements are certainly among the main challenges. In addition, the fear of data misuse potentially resulting in harm for nature, careers, and competencies still seems to be a critical barrier strictly controlling the willingness to share data. Various initiatives aimed at tackling technical and cultural obstacles are introduced and discussed to reach the goal of a modern resource management based on adaptive management using digital opportunities of the new millennium for a sustainable global village.  相似文献   
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