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181.
陈述彭 《云南地理环境研究》1989,1(1):4-9
对应于人口、资源、环境与经济这些复杂系统的信息系统,其结构是多层次的。分别应用于国家宏观决策、地区开发与城市建设。对于空间型与统计型各有侧重。我国资源信息系统起步较晚,进展参差不齐,还不配套。人口数据库缺乏空间型结构:经济数据库属于统计型结构;而海洋环境与资源信息系统则系文献检索的性质。资源信息系统的功能,不应局限于检索、查询,而应走向高层次的分析、模拟与预测。目前已经具备回答决策过程中的一些主要命题,诸如:数据可靠性、资源容量、环境适应性、交通的接近度、工程的可行性和生产的稳定性。正在进一步为建立系统动力模型和专家系统而努力。 相似文献
182.
文章从辽东半岛南部石英岩板岩区地下水富水不均的特点出发,论述了基岩地下水富集规律:贮存在蓄水构造中,汇集在集水网络里,运移富集在充水脉络交接、结点处。进一步对水文物探各类富水曲线进行了分类,概括富水异常特征。结合多年实际勘测成果,论证了依据“结点异常”确定富水点位。 相似文献
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Pattern recognition techniques(PCA,Bayesian analysis,LDA and KNN)are applied to a set of datacomposed of cancer patients and controls.A rather good separation between different populations isobtained using four tumor markers determined for each patient. 相似文献
185.
A non-parametric method for supervised pattern recognition is presented. The method is of the classmodelling type, meaning that a classification rule is developed for each class, using the dissimilaritiesbetween the objects of the class. The dissimilarities between the objects within a class are related to thedistances between all pairs of training objects. As distance metric, a measure is proposed that takes thecorrelation between the interval-scale variables into account, and that moreover can be used for mixedtypes of variables. The classification rule is based on the construction of a boundary in the measurementspace. For the determination of the class boundary, several strategies are proposed and compared. The performance of the technique is evaluated on the basis of several data sets. Comparison with theclass modelling technique UNEQ shows its usefulness for practical applications. 相似文献
186.
本文用一种叫作两组判别分析的模式识别方法,对无机氧化物的溶解性进行归类判别。其中用了密度、电负性、荷徑比、原子半徑、电离势、电子构型和主副族等7个指标,45个样本。除2个样本外,其余43个正确归类。 相似文献
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In previous work, a significant relationship was identified between the meridional displacement of the Asian westerly jet(JMD) and the Silk Road Pattern(SRP) in summer. The present study reveals that this relationship is robust in northward JMD years but absent in southward JMD years. In other words, the amplitude of the SRP increases with northward displacement of the jet but shows little change with southward displacement. Further analysis indicates that, in northward JMD years, the Rossby wave source(RWS) anomalies, which are primarily contributed by the planetary vortex stretching, are significantly stronger around the entrance of the Asian jet, i.e., the Mediterranean Sea–Caspian Sea area, with the spatial distribution being consistent with that related to the SRP. By contrast, in southward JMD years, the RWS anomalies are much weaker.Therefore, this study suggests that the RWS plays a crucial role in inducing the asymmetry of the JMD–SRP relationship.The results imply that climate anomalies may be stronger in strongly northward-displaced JMD years due to the concurrence of the JMD and SRP, and thus more attention should be paid to these years. 相似文献
190.
Xiang Sun Jun Deng Qingjie Gong Qingfei Wang Liqiang Yang Zhongying Zhao 《Journal of Geochemical Exploration》2009
Kohonen neural network (KNN) and factor analysis are applied to regional geochemical pattern recognition for a Pb–Zn–Mo–Ag mining area around Sheduolong in Qinghai Province, China. Prior to factor analysis, the geochemical data are classified by KNN. The results demonstrate that the 4-factor model accounted for 67% of the variation in the data. Factor F1, a Pb–Zn–Mo factor and Factor F4, an Au–Ag factor, correlates with monzonitic granite intrusions and particularly with Pb–Zn–Mo–Ag mineralization within those rocks. Factor F2, an As–Co factor, correlates with metamorphic rocks of paleoproterozoic Baishahe formation. Factor F3, a Bi–Cu factor, correlates with granodiorite intrusions. The factor score maps suggest a revised location of faults and their mineralization significance in coarse geological map. The approach not only effectively interprets the geological significance of the factors, but also reduces the area of exploration targets. 相似文献