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41.
青海玉树Ms7.1级地震地质灾害主要特征 总被引:2,自引:0,他引:2
2010年4月14日7时49分,青海省玉树县发生Ms7.1级地震。玉树地震产生较连续的地表破裂和大量房屋破坏,并诱发了滑坡、崩塌和震裂山体。此外,地震诱发的砂土液化、水渠溃决等加剧了局部山体地质灾害。通过现场调查和地震前后玉树县地质灾害发育状况,简要阐述了地震地质灾害的主要发育特征,包括震后地质灾害数量明显增加、地震地质灾害分布受活动断裂控制、低位滑坡为主、地质灾害链生效应显著等,并对灾后重建过程中的地质灾害防治提出了建议。 相似文献
42.
孙芳强〓苏生瑞〓彭建兵 《力学学报》2010,18(2):183
应用计算流体动力学方法对人体在循环呼吸模式下口喉模型内的气流运动特性进行数值模
拟,分析了循环呼吸模式下口喉模型内的气流组织形式以及气流运动对呼吸道壁面以及气溶
胶运动沉积的影响. 吸气阶段,在咽部外壁和声门下游气管上部外壁气流发生分离,形成分
离区. 呼气阶段,分别在咽部外壁和喉部外壁形成高速区. 循环呼吸模式下,咽部、喉部与
气管内的高轴向速度区和二次涡流运动均是在呼吸过程中间歇性的产生,形成的高剪应力区
也是间歇性的. 壁面受到的剪应力周期性地改变方向,引起壁面劳损和组织损伤的可能性增
大,同时在这些部位容易造成气溶胶的沉积. 相似文献
43.
Analyses of 41 elements reveal that Holocene sediments in the Changjiang Estuary bear regular elemental compositions in different sedimentary environments, and Holocene sediments came mainly from the Changjiang River based on compositions of REEs and most trace elements. Some heavy metals are more enriched in the surface sediment than in the deltaic sediments, reflecting human impact. Elemental compositions of the river channel sediment are related to the influence of proximal sediments. Sedimentary environments exert some influences on elemental compositions. Some chemical indices can be used to record chemical weathering undergone by the Changjiang sediment and environmental change. 相似文献
44.
《Comptes Rendus de l'Académie des Sciences》2000,328(10):709-712
In this paper, we establish compatibility equations satisfied by the right Cauchy–Green stress tensor by annihiling the associated curvature and torsion. The cancelation of torsion, using variables introduced by the polar decomposition, is not trivial as is usually the case. This point is the key to the decomposition of compatibility conditions in two first-order EDPs. 相似文献
45.
46.
通过固定光谱校准曲线,压缩光谱谱带间隙,可降低测试成本,工作效率提高1.5倍,分析质量准确可靠. 相似文献
47.
《中国化学快报》2020,31(10):2779-2783
The removal efficiency of pollutants in Fe(0) electrocoagulation (EC) has been associated closely with the speciation of generated Fe(II)/Fe(III) oxides during this process, which is very complicated and can be affected by various factors. In this work, in-situ Raman, X-ray diffraction and some other techniques have been used to study the speciation of Fe under different conditions and to establish a relationship between Fe speciation and Sb(V) removal efficiency. Results indicated that concentration of dissolved oxygen (DO) is a key factor influencing Fe(0) EC. It was found that green rusts (GRs) were formed and were then transformed into magnetite at lower DO concentration, and Sb(V) removal efficiency reached 99.9% after 30 min of EC. In contrast, γ-FeOOH was formed at high DO concentration, and the removal efficiency of Sb(V) after 30 min of EC was only 72.8%. In the presence of sulfite and phosphate with low concentrations, GRs can be stabilized and benefit the removal of Sb(V). We believe this work will provide some new insights on the mechanism of Fe(0) EC and the effective removal of other pollutants during Fe(0) EC process. 相似文献
48.
《European Journal of Operational Research》2007,181(1):338-349
Multicriteria analysis methods have been used over the past decade for resolving environmental issues. This paper deals with the application of a multicriteria analysis (MCA) approach to urban stormwater drainage management. Stormwater source control has become a popular alternative solution for managing stormwater in urban areas. Source control constitutes one variant of best management practices (BMPs) that can be evaluated with respect to various criteria, including: hydraulic efficiency, pollution retention, environmental impact, operation and maintenance, economic investment, and social and sustainable urban living. A French survey was undertaken to assess the performance of different BMPs at the national scale; results highlight the main reasons justifying the use of BMPs. These reasons are primarily related to flood prevention, which far outweighs the economic incentives. Moreover, hydraulic and technical aspects are most frequently noted by users, whereas operation and maintenance aspects are often seen as obstacles to application of these techniques. The survey results, completed by a literature review and expert statements, have been used to establish a matrix of alternatives for multicriteria analysis. The MCA results obtained allow ranking the various alternatives from best to worst, taking into account the different strategies adopted by the decision-makers involved. The development of a multicriteria approach could, in the future, serve as a supporting decision-aid tool, whose purpose would be to guide users in their choice of stormwater source solution. 相似文献
49.
中国陆架沉积物标准物质研制 总被引:2,自引:0,他引:2
报道了我国研制的2个大陆架沉积物标准物质MS-E1,MS-S1。MS-E1和MS-S1的原样分别取自东海和南海。样品经风干、破碎,球磨制备成均匀的粉体样品。均匀性采用高精度的X射线荧光光谱法检验。样品的化学组分采用国内外多实验室协同分析方式定值,有7个国内实验室和9个国外实验室参加了合作分析。测试组分均为67个,分别有43和42个组分定为保证值,8和9个组分作为参考值。全组分百分总和分别为99.8%和99.6%。经2年多的试用,2个标准物质已于2005年被国家计量部门批准为国家一级标准物质,其编号分别为:GBW07335和GBW07336。 相似文献
50.
《Journal of Analytical and Applied Pyrolysis》2009,86(1-2):497-501
This work deals with thermochemical conversion of peat into solvent-soluble oil and volatile gaseous products by using pyrolysis and catalytical hydrocracking methods. Distribution of liquid compounds between solubilized in water, benzene, and in acetone was determined and as a result the oil yield as total solubles was calculated. Chromatographic and FTIR-spectroscopic methods were used to characterize the composition of conversion products. Investigation of peat pyrolysis regularities in comparison with those of oil shale by using Rock-Eval analysis demonstrated essential differences between peat and oil shale as pyrolysis feedstock. As a result of hydrocracking the total oil yield was increased more than twice compared with that of semicoking, 29.8 and 13%, respectively. Hydrocracking and semicoking led to significant deoxygenation of oil and solid residual conversion products via oxygen removal as carbon dioxide and water. Hydroxyl-, carboxyl-, carbonyl- and other oxygen functionalities in peat initial matter being hydrocracked and modified, the oil was characterized by elevated hydrocarbon content and decreased that of polar oxygen compounds. As the oxygen content of the product decreases, the energy content significantly increases and peat oil, particularly its hydrophobic fractions, can be used for synthetic liquid fuel. 相似文献