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101.
利用世界银行1970—2007年的112个国家(地区)的人均碳排放量和城市化率数据,基于SPSS与Eviews软件,分析城市化水平与人均碳排放量的关联机理。结果表明,随着城市化水平的上升,人均碳排放量逐步增加;40%的城市化率是人均碳排放变化的转折点;在相近城市化水平下,经济发展水平较高地区和化石能源主产区的人均碳排放高于其他地区。格兰杰因果检验表明,人均碳排放与城市化之间基本存在着格兰杰因果关系;地区之间的格兰杰因果检验结果既有共性,也有差异。 相似文献
102.
Subrata K. Chakrabarti 《Ocean Engineering》1999,26(10):446
Breakwaters are often built in coastal waters to facilitate navigation and recreation, both inside and outside regions of the breakwater. This requires that the reflection and transmission characteristics of the structure be both minimized at the same time. This is achieved by a design that will allow dissipation of wave energy by multiple reflection. Such structures will need the knowledge of these characteristics in their design. Model tests were performed on a shallow water breakwater concept of this type to determine the reflection and transmission coefficients. The concept of the breakwater was to reduce both the reflection and transmission of waves. It was found that the breakwater design was effective at certain wave characteristics. Nondimensional loads and local pressures on the breakwater panels are also reported which will facilitate the structural design of such breakwaters. 相似文献
103.
Locating regional seismic events with global optimization based on interval arithmetic 总被引:4,自引:0,他引:4
Matti Tarvainen Timo Tiira & Eystein S. Husebye 《Geophysical Journal International》1999,138(3):879-885
More than 1000 seismic events in northern Europe at distances of up to 400 km from the detecting network are located using an optimization method in which the global minimum of the traveltime function residuals is searched for using an Interval Arithmetic (IA) method. Epicentres are determined using P waves detected by the Finnish national seismic network: up to 15 stations were used in the analysis. The IA results coincide with locations provided by the University of Helsinki bulletins with a median location bias of 7.6 km.
A second data set of 59 explosions in the Siilinjärvi mine in central Finland was examined in detail, because the locations of the explosions were known exactly. In this case, the median difference of IA locations was 3.8 km from the average location of mine explosions, while all 59 events were located within 9 km of the 'true' epicentres. The corresponding median error of the University of Helsinki locations was smaller (3.2 km), but some Helsinki locations were well over 10 km from the mine. The convergence towards the global optimum using interval arithmetic was fast when compared with the conventional least-squares approaches for epicentre determinations. 相似文献
A second data set of 59 explosions in the Siilinjärvi mine in central Finland was examined in detail, because the locations of the explosions were known exactly. In this case, the median difference of IA locations was 3.8 km from the average location of mine explosions, while all 59 events were located within 9 km of the 'true' epicentres. The corresponding median error of the University of Helsinki locations was smaller (3.2 km), but some Helsinki locations were well over 10 km from the mine. The convergence towards the global optimum using interval arithmetic was fast when compared with the conventional least-squares approaches for epicentre determinations. 相似文献
104.
静力触探(CPT)是一种速度快,数据连续、再现性好、操作省力等优点的原位测试方法。随着海洋开发的迅速发展,CPT测试技术在国内外海洋工程领域的使用越来越普遍。因此,了解国外海上CPT设备和应用情况,探讨应用中的问题,对CPT测试技术在我国海上工程领域的应用具有重要意义。文章描述了国外海上静力触探(CPT)测试技术的发展现状,阐明了主要的海床CPT(Seabed CPT)设备和井下CPT(Downhole CPT)设备的特点,并对不同CPT设备在海洋工程领域的应用作了分析,这对海上CPT测试技术在我国的应用和发展具有一定的参考价值和指导作用。 相似文献
105.
The alkaline filter elution assay using the gills of the freshwater clam species Corbicula fluminea detects breaks in single‐stranded DNA and is thus a good method for determining the genotoxic potential of surface waters. In attempting to standardize the procedure, a wide range of factors which could have an influence on the uptake of genotoxic substances by the exposed clams were studied. The most important parameters of the static exposure in relation to the rate of filtration by the animals turned out to be the temperature, the volume of the water, and the exposure time. Differences in body size and in the amount of suspended particles in surface waters did not play a significant role. The results demonstrate that the in vivo test system can be quite sensitive and its results reproducible when the relevant species‐specific characteristics of the test organisms are brought into consideration, even if the test organism belongs to a biologically more advanced group. A clear dose‐response relationship to the reference substances 4‐nitroquinoline‐1‐oxide (NQO) and N‐methyl‐N‐nitro‐N‐nitrosoguanidine (MNNG) can be observed even after a short exposure time of between four and twenty hours. No genotoxic effects were observed when using this method on surface waters from the area of Cologne (including water from the Rhine River and within the protection zone 2 of the Cologne waterworks). 相似文献
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108.
通过就业结构演变驱动旅游需求的简单反馈模型假设,利用单位根检验(unit root test)、协整检验(cointegra-tion test)和格兰杰因果检验(Granger causality test)计量方法,以我国1984-2006年三大产业的就业人数和国内旅游人次变动数据为依据,探讨国内就业结构演变与旅游需求变化的关系。实证结果表明,三大产业就业结构演变与国内旅游人次的变化具有很强的相关性,其间存在长期稳定的均衡关系且具有正负增长递减的规律;第一产业就业人数的减少是国内旅游需求增长的重要驱动因素。 相似文献
109.
1995年7月12日,在云南省西南部的孟连县以西中缅边境发生了一次Ms7.3强烈地震。震前,距震中280km以远的滇西实验场重力网红河断裂以西出现了重力异常,平均变化幅值达70×10^-8ms^-1,最大变化幅值达114×10^-8ms^-2,云南省地震工程研究所测量队重力组根据上述重力异常变化,对此次地震作了较好的中短期预测预报。 相似文献
110.
对含砷金矿石中的金的回收以往所采用的选(冶)矿工艺流程一般是浮选-氰化浸出和浮选-焙烧-氰化浸出工艺流程。为了简化含砷金矿石选(冶)矿工艺流程,根据该矿矿石性质试验研究了单一混汞工艺流程、混汞-汞尾氰化浸出工艺流程、混汞-汞尾预处理-氰化浸出工艺流程和全泥硫脲浸出工艺流程方案,结果表明:混汞-汞尾氰化浸出工艺流程获得的指标较高,总回收率可达83%,因此,该矿适采用联合的选(冶)矿工艺流程,试验数据可以作为该矿开发和评价的依据。 相似文献