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661.
Response surface methodology (RSM) and artificial neural networks (ANNs) based on a multivariate central composite design (CCD) were applied to model and optimize the photocatalytic degradation of N,N‐diethyl‐m‐toluamide (DEET). The individual and interaction effects of three main operating factors (mass of TiO2, initial DEET concentration, and irradiation intensity) on process efficiency were estimated, proving their important effect on % DEET removal. Among the independent variables, TiO2 concentration displayed the highest effect on DEET degradation followed by initial DEET concentration and UV intensity. The optimization and prediction capabilities of ANNs and RSM were compared on the basis of root mean squared error, mean absolute error, absolute average deviation, and correlation coefficient values. Results proved the usefulness and capability of the experimental design strategy for successful investigation and modeling of the photocatalytic process. Moreover, the selected ANN gave better estimation capabilities throughout the range of variables than RSM. Based on the models and the related experimental conditions, the optimal values of each parameter were determined. Under optimum conditions, DEET and total organic carbon (TOC) followed pseudo‐first order kinetics. Nearly complete degradation of DEET took place within 15 min whereas high TOC removal percentages (>85%) was achieved after 90 min irradiation time. 相似文献
662.
663.
664.
在对不同掏槽形式进行对比分析的基础上,结合工程实例,试验分析了不同掏槽形式下的爆破效果,认为斜眼掏槽和直眼掏槽都存在各自的缺陷,提出采用和推广准直眼掏槽方式的建议。 相似文献
665.
ENVI遥感图像监督分类方法比较 总被引:2,自引:0,他引:2
鉴于遥感监督分类方法的普遍应用,本文介绍了五种常用的监督分类方法:平行六面体法、最小距离法、马氏距离法、最大似然法和人工神经网络分类法。就同一地区TM影像应用这五种方法进行了土地利用分类,对比分析了这五种方法的分类精度,发现人工神经网络对土地覆盖与利用的分类精度高于最大似然法,最大似然法分类精度优于平行六面体法、最小距离法和马氏距离法。所得结论对有关遥感图像分类工作具有指导和借鉴意义。 相似文献
666.
根据工程的地域特点和工程的施工要求,分析了爆破挤淤技术的原理、参数的选择和可能造成的影响,提出了减小影响的措施,论证了合理地选择爆破参数、采用爆破挤淤技术的可行性。施工实践证明用爆破挤淤技术建设防浪堤是成功的。 相似文献
667.
C. V. Chrysikopoulos 《Environmental Geology》1993,22(1):60-70
Safe disposal of thermally spent geothermal brines that contain environmentally hazardous constituents is commonly obtained by reinjection. The reinjection process also serves to maintain reservoir pressure, enhance thermal recovery, and eliminate possible compactional subsidence. To avoid premature thermal breakthrough of reinjected fluids, tracer tests are employed for detection and evaluation of preferential path networks. In this paper some promising tracers that have not received much attention in geothermal reservoir studies are discussed, and a comprehensive tabulation of field sites of artificial tracer utilization is presented. Chemical and transport processes responsible for tracer retention by the formation of reservoir solids, as well as available tracer detection techniques, are emphasized. 相似文献
668.
Integrating GIS and DSS for identification of suitable areas for artificial recharge,case study Meimeh Basin,Isfahan, Iran 总被引:12,自引:0,他引:12
Jafar?GhayoumianEmail author B.?Ghermezcheshme S.?Feiznia A.?A.?Noroozi 《Environmental Geology》2005,47(4):493-500
Flood spreading is an inexpensive method for flood mitigation and artificial recharge of aquifers that results in a large budget return for relatively small investment.It is necessary to study some regional characteristics in order to determine the appropriate areas for artificial groundwater recharge by flood spreading in Meimeh Basin, Isfahan Province, Iran. Necessary regional characteristics to be studied are: slope, infiltration rate, sediment thickness, transmissivity, and water quality. In this research to identify suitable areas for artificial recharge several thematic layers were prepared, assigning each layer to one of the mentioned characteristics. The thematic layers were classified to several classes based on the existing criteria. All of the classes of the thematic layers were integrated and analyzed using a decision support system (DSS) in a geographical information system (GIS) environment. Finally suitability of the integrated classes for artificial recharge was identified in which the following classes were separated:(i) Very suitable, (ii) suitable, (iii) moderate suitability, and (iv) unsuitable.The validity of the generated model was verified by applying the model to a number of successful floodwater spreading stations throughout Iran. The verified model showed satisfactory results for all of the stations. The results for Meimeh Basin showed that about 70% of the Quaternary sediments in the studied area are suitable and moderately suitable for artificial recharge by flood spreading. 相似文献
669.
V.S.ROSE R.M.HYDE Department of Physical Sciences Wellcome Research Laboratories South Eden Park Ro Beckenham Kent BR BS U.K.H.J.H.MACFIE AFRC Institute of Food Research Reading Laboratory Shinfiel Reading RG AT U.K. 《地理学报(英文版)》1990,(5)
A survey of members of the U.K.QSAR Discussion Group has been made to determine the extent ofuse and development of chemometric and artificial intelligence(AI)methods in the analysis ofmultivariate quantitative structure-activity relationship(QSAR)data in the U.K.Chemometric methodswere found to be well established in both industrial and educational establishments and there wassignificant method development occurring.AI methods were not employed to any great extent and thegeneral level of interest in these techniques was low compared to chemometric methods.A requirementfor more education in multivariate statistical methods and regression methods was indicated.A need fora user-friendly,comprehensive,commercially available multivariate statistical package containingmultivariate stability testing and regression diagnostic methods was identified. 相似文献
670.
Luis Floría 《Celestial Mechanics and Dynamical Astronomy》1993,57(1-2):203-223
Within the framework of the Canonical Formalism in the extended phase space,a general Hamiltonian is investigated that covers a wide class of radial intermediaries accounting for themajor secular effects due to a planet's oblateness perturbations.An analytical, closed-form solution for this generic Hamiltonian is developed in terms of elementary functions via the corresponding Hamilton-Jacobi equation. The analytical solution so obtained can be contemplated according to a simple geometrical and dynamical interpretation in Keplerian language by means of the usual relations characterizing elliptic elements along ahypothetic Keplerian motion.Appropriate choices for the terms appearing in the proposed Hamiltonian lead to recovering the analogues of some well-known, classical radial intermediaries (those introduced by Deprit and the one built by Alfriend and Coffey), but also certain new ones derived by Ferrándiz for the Main Problem in the Theory of Artificial Satellites of the Earth. In any case, the results are also applicable to problems dealing with orbital motion of other planetary satellites.The generality of this pattern leads to asystematic obtaining of solutions to the considered intermediaries: special choices of the Hamiltonian yield the correspondinganalytical solution to the respective intermediary problem. 相似文献