印尼巨大地震引起的云南水位异常记录及其意义   总被引：3，自引：0，他引：3       下载免费PDF全文

付虹  邬成栋  刘强  王世芹  陈燕 《地震地质》2007,29(4):873-882

2004年12月26日和2005年3月29日印度尼西亚苏门答腊西北海域相继发生了2次巨大地震,云南地区的地下水位观测记录到了这2次地震的大量信息。文中给出了云南水位数字和模拟记录到的印尼2次巨大地震的响应情况,并对其进行了初步分析。认为:目前的水位模拟记录较数字化记录能更清晰地看到巨大地震引起的水位异常变化过程;大震引起的水位上升和下降可能是地震波的作用改变了构造单元的应力所致,并与井点的地质构造部位有关;同一井孔对同一断层上破裂方式一致的大地震的响应方式是一致的,只是对震级大的地震响应幅度大,震级减小,响应幅度亦减小  相似文献   

混凝土强度与其波速度关系之探讨     

张莉萍 《浙江国土资源》1996,(2)

本文从实际工程引出混凝土强度（q）与波速度（v）关系问题，并对检测资料进行解释，统计回归得q－v定量关系；并指出q－v关系的诸多影响因素及进一步讨论q－v定量关系的几点认识。q－v关系的定量研究必将更好地发挥工程物探在国民经济中的作用。  相似文献   

齐齐哈尔市地下水资源潜力分析及开发利用对策研究   总被引：2，自引：0，他引：2  

孙化江  王永顺  倪锡举  栾晓燕  崔惠娟  付国平 《水文地质工程地质》1997,(5)

本文系统地论述了齐齐哈尔市地下水资源分布特征、变化规律和地表水资源状况。采用最近统计资料，对齐齐哈尔市水资源的开发利用现状及潜力进行了分析论述。针对水资源开发利用中存在的问题提出了一系列对策。  相似文献   

Measuring molecular variation in zooplankton populations: DNA extraction from smallDaphnia species     

Mona A. Mort  Bruno Streit 《Aquatic Sciences - Research Across Boundaries》1992,54(1):77-84

We present methods developed for the small-sizedDaphnia species,D. galeata, D. hyalina, D. cucullata, and their hybrids, which facilitate the use of DNA variation in population studies. Described are large-scale production of material from single genotypes ofDaphnia and subsequent extraction of total DNA. The average DNA yields ranged between 6 µg per gram wet weight (D. cucullata) and 12 µg per gram wet weight (D. galeata). For comparison, the large-sized speciesD. pulex was tested and yielded an average of 28 µg DNA per gram wet weight. The DNA isolated in this manner lends itself well to molecular genetic techniques suited for population studies.Reprint requests to B. Streit.  相似文献   

省界断面水资源监测站网建设实施与探讨          下载免费PDF全文

蒋蓉  孙世雷  李夏 《水文》2016,36(5):54-57

省界断面水资源监测是实行最严格水资源管理制度的重要基础工作,介绍了省界断面水资源监测站网建设的建设目标、主要任务、建设内容和投资,阐述了项目的实施和安排,并针对当前项目实施情况和特点,探讨了项目实施和运行管理需要注意的问题。  相似文献   

Toward a mechanistic understanding of larval dispersal: insights from genomic fingerprinting of the deep-sea hydrothermal vent tubeworm Riftia pachyptila     

Timothy M. Shank  & Kenneth M. Halanych 《Marine Ecology》2007,28(1):25-35

Larval dispersal is critical for the maintenance of species populations in patchy and ephemeral hydrothermal vent habitats. On fast‐spreading ridges, such as the East Pacific Rise, rates of habitat turnover are comparable to estimated lifespans of many of the inhabiting species. Traditionally, dispersal questions have been addressed with two very different approaches, larval studies and population genetics. Population genetic studies of vent‐endemic species have been informative for determining whether patterns of dispersal are suggestive of stepping stone or island models and estimating rates of gene flow (effective migrants per generation) over broad geographic ranges. However, these studies leave fundamental questions unanswered about the specific mechanisms by which larvae disperse and species maintain their populations and biogeographic ranges. With the goal of examining genetic structure and elucidating alternative larval dispersal mechanisms, we employed a genomic DNA fingerprinting technique, amplified fragment length polymorphisms (AFLPs). To assess the potential utility of AFLPs, and genetic structure of the hydrothermal vent tubeworm Riftia pachyptila, genomic ‘fingerprints’ were recovered from 29 individuals from five vent fields spanning a distance of up to c. 5000 km along the East Pacific Rise. In contrast to previous population genetic studies that found little to no genetic structure using allozymes and mitochondrial DNA, genetic analyses of 630 polymorphic AFLP loci identified distinct subclades within R. pachyptila populations. Significant levels of differentiation were observed among populations from all vent regions as well as within each region. Discrete assemblages of tubeworms separated by as little as c. 400 m within a given vent region were genetically distinguishable and cohorts (based on size‐frequency distribution) within an aggregation were found to be most closely related. These results suggest that mechanisms of larval dispersal act to retain cohort fidelity in R. pachyptila.  相似文献   

Conservation of genetic variation in harvested salmon populations     

Hindar  Kjetil; Tufto  Jarle; Saettem  Leif Magnus; Balstad  Torveig 《ICES Journal of Marine Science》2004,61(8):1389-1397

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大菱鲆体重和形态性状的遗传动态分析     

王新安  马爱军  马得友 《海洋学报(英文版)》2015,34(2):55-62

In order to elucidate the genetic mechanism of growth traits in turbot during ontogeny, developmental genetic analysis of the body weights, total lengths, standard lengths and body heights of turbots was conducted by mixed genetic models with additive-dominance effects, based on complete diallel crosses with four different strains of Scophthalmus maximus from Denmark, Norway, Britain, and France. Unconditional genetic analysis revealed that the unconditional additive effects for the four traits were more significant than unconditional dominance effects, meanwhile, the alternative expressions were also observed between the additive and dominant effects for body weights, total lengths and standard lengths. Conditional analysis showed that the developmental periods with active gene expression for body weights, total lengths, standard lengths and body heights were 15–18, 15 and 21–24, 15 and 24, and 21 and 27 months of age, respectively. The proportions of unconditional/conditional variances indicated that the narrow-sense heritabilities of body weights, total lengths and standard lengths were all increased systematically. The accumulative effects of genes controlling the four quantitative traits were mainly additive effects, suggesting that the selection is more efficient for the genetic improvement of turbots. The conditional genetic procedure is a useful tool to understand the expression of genes controlling developmental quantitative traits at a specific developmental period(t-1→t) during ontogeny. It is also important to determine the appropriate developmental period(t-1→t) for trait measurement in developmental quantitative genetic analysis in fish.  相似文献   

Lessons Learned from Reviewing Research in GIS Education   总被引：4，自引：4，他引：0  

《The Journal of geography》2012,111(6):231-233

Abstract

Traditional lectures generally force students to play a passive role in the classroom. In an effort to promote active learning, we added discussion sections to a large lecture hall course. Field trips, student journals, and group-based assignments, in particular, enhanced the learning experience. To ensure the success of the new format, course planners must enlist the sustained cooperation of key faculty and administrators on campus, as well as teaching assistants assigned to the new sections. The new discussion sections allowed students to acknowledge the environmental impact their actions have on campus and to recognize that environmental problems occur at multiple scales.  相似文献   

公安系统防雷设计方案探讨   总被引：7，自引：7，他引：0  

韦传波  王信辉 《气象研究与应用》2008,29(2):68-69,71

针对海南省琼中县公安系统频遭雷击而提出,从查找问题、分析原因入手,以《建筑物防雷设计规范》GB50057-94为依据,参照有关防雷规范标准进行防雷方案探讨。  相似文献