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161.
3个月平均气温距平的CCA预测方法 总被引:2,自引:1,他引:2
用根据CCA方法设计的一个统计预报模式对我国3个月平均气温距平进行预报试验,并用交叉检验方法进行估计,结果表明:预报技巧随提前时时间增长而减小得较少,用全球表面温度作预报因子有较高的预报技巧,7,8,9月3个月较易预报,而10,11,12月3个月较难预报。 相似文献
162.
应用天气学和统计学方法对1993年LAFS数值降水预报产品进行检验。结果表明:多数主要降水过程预报较好;全年降水10mm级和25mm级降水预报准确率高于50mm级降水的准确率;南方降水预报水平比其它地区高,高原地区最差;降水预报范围过大是LAFS的一大弱点。 相似文献
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本文利用一适合复杂地形区的有限区域预报模式系统,分别采用欧洲中期天气预报中心的格点资料和我国国家气象中心的DCD电码资料,对1981年7月1-30日和1988年8月10-14日两时段共35天作了48小时预报。形势场和降水预报的主客观评分表明,该模型系统已具备了在业务环境下作预报的可能,该模型预报性能良好,具有较好的强降水预报的能力。 相似文献
166.
《国际泥沙研究》2020,35(6):621-635
The objective of the proposed method is to utilize a site investigation of a debris flow disaster and verify a real scale analysis to evaluate the impulsive load on an open sabo dam. The Nagiso debris flow disaster which occurred in Nagano in 2014, where damage caused by Typhoon Neogri was studied. The verification result of the site investigation demonstrated the weak components of the open Sabo dam experienced damage owing to the debris flow. A discrete element method is normally applied to a solid body to calculate an interaction function force with respect to the contact point between boulders and the dam. The numerical method initially concatenates elements that model the open Sabo dam. Moreover, the stiffness coefficient of flanges and coupling joints between pipes was expressed to utilize the sectional partition method to determine the structural characteristics. The method was improved to separate from the connecting elements beyond the boundary conditions. The debris flow model uses a water flow distribution model, and the debris flow flowed from 200 m upstream of the open sabo dam. Accordingly, the proposed method was examined to verify the primary cause of damage to the open sabo dam and used to reproduce the circumstances that evaluated the impulsive load occurrence mechanism in the case of a real disaster. In addition, the coupling joints between the hollow steel pipes utilized a ‘reproduction analysis’ for a real sabo dam and a ‘reinforced analysis’ for a reinforced sabo dam were applied to assess the weak point of the dam. 相似文献
167.
A. Plewka T. Gnauk E. Brüggemann C. Neusüss H. Herrmann 《Journal of Atmospheric Chemistry》2004,48(2):131-156
Inorganic ions, organic carbon (OC), elemental carbon (EC) and a variety of organic single species in airborne particles have been determined at the research station of the Leibniz – Institut für Troposphärenforschung (IfT) in Melpitz (Germany) in autumn 1997.Samples of eight selected measurement events were divided in two groups in order to investigate differences in the chemical composition of particles originating from southwesterly (SW – developed EU countries) or from easterly directions (E – less developed eastern countries). Differences between these two groups were tested statistically by Student's t-test.Five stage cascade impactor samples show nitrate as most abundant in the accumulation mode in the SW group. EC and sulphate show the most abundant mass fractions in the E group. That can be considered as a consequence of domestic coal heating and coal-fired power plant emissions in the region of westerly Poland, northern Czech Republic and easterly Germany. Higher nitrate concentrations in the SW group can be explained by stronger NO
x
emissions caused by the leeward plume of the conurbation of Leipzig, as well as by the still higher traffic density in western Germany.The methane sulphonic acid (MSA) mass fraction was higher for SW air masses in accumulation mode particles, probably indicating marine origin. Succinic acid also showed higher mass fractions for the SW group. This could be caused by primary emission in automobile exhaust gases and photochemical formation during transport from SW. Indeed, during SW sampling, solar radiation intensity was higher than during E sampling.The observed differences in the particle composition are an expression of the still existing technology gradient in Europe. Future campaigns could show the development to a joint economy with smaller differences in anthropogenic emissions. 相似文献
168.
对目前在煤田地勘单位贯彻ISO 9001:2000标准7.5.2条款中对需确认的过程的不同观点进行了分析,从“过程确认”的概念入手,并结合煤田地质勘查组织生产和服务提供过程及其特点,提出了煤田地质勘查单位需确认的过程的识别和控制方法。 相似文献
169.
介绍了一种以本地天气知识库和业务资料数据库为基础,建立集预报培训和工作考核于一体的WEB型预报业务平台的思路和方法。 相似文献
170.
张学庄 《武汉大学学报(信息科学版)》2002,27(6):611-615
讨论了光电测距仪的乘常数问题,并举出了按光电测距仪检定规程(试行)JJG703-90检测得到的乘常数(R)不正确的例子,分析了R误差大的原因。 相似文献