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201.
FormationofCalcareousDepositduringCathodicProtectionandItsProperties¥WenGuo-Mou;ZhengFu-Yang;FangBing-Fu;MaTing-Chun;ChenAi-C... 相似文献
202.
L. Orsini A. Bermond 《International journal of environmental analytical chemistry》2013,93(1-4):97-108
Abstract The localization of trace metals in soils is usually performed by sequential extraction procedures. Our purpose was to study the fractioning of copper in calcareous soils, in order to predict its mobility, using the extraction procedure proposed by Tessier et al. This preliminary study is devoted to the improvements of this method applied to calcareous soil samples. First, it was necessary to assess the experimental conditions allowing the complete solubilisation of the different compartments involved in the extraction procedure with their appropriate reagent (acetic acid-sodium acetate and carbonates, iron hydroxide and hydroxylamine, organic matter and hydrogen peroxide, fluorhydric-perchloric acid and residual fraction). The complete solubilisation of each compartment was tested by measuring the residual phase. Secondly, it was necessary to study the analytical protocol for the determination of copper with electrothermal atomic absorption; an improvement of this determination was particularly necessary for the reagent used for the exchangeable fraction (sodium acetate at pH = 8.5). According to the experimental results, the quality (repeatability, concordance of the sum of fractions with the total content of copper determined with independent measurement) of the proposed protocol seems to be quite good. Some results of the fractioning of copper in calcareous soil samples are given; these samples are characterised by a high value of copper in the residual fraction corresponding to a poor availability of this element. 相似文献
203.
Michal Fisher Chanan Sluszny Batya Horowitz Valery Bulatov Vladimir V. Gridin Salah Hassoon 《International journal of environmental analytical chemistry》2013,93(1-4):9-24
Abstract Chemical imaging is a new analytical science, related to a combination of spatial and chemical resolutions. Several new chemical imaging tools have been developed and applied to environmental analysis. The advantages of such methods, which provide simultaneous morphological/geometrical and chemical speciation, are pointed out and exemplified in several environmental analytical applications. These include fast analysis of PAH contaminated aerosols at low concentrations, analysis of contaminated quartz sand particles, as well as improvement of laser induced fluorescence detection of PAH compounds in natural water, in the presence of various microparticles. It is shown that chemical imaging has a considerable potential in environmental applications and can provide detailed and unique information when particulate materials are concerned. 相似文献
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206.
Immersion of automotive parts in a fluidized bed of foundry sand is used to both strip the castings free from moulding sand and to heat-treat the castings at 500℃. The fluid bed is heated by hot gases from a burner directed first into a serpentine heat exchanger located near one side-wall of the rectangular tank, and then into a distributor consisting of horizontal sparger pipes having maintenance standpipes fixed into their upper surfaces. 相似文献
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208.
冻融循环次数和含水率对尾细砂力学性质的影响研究 总被引:2,自引:0,他引:2
为研究冻融循环次数和含水率对尾细砂力学性质的影响,利用GDH-2005B型高低温试验箱对尾矿砂试样进行冻融循环,并通过FST-200型应变控制式三轴剪力仪开展五种冻融循环次数(1次、3次、5次、7次、9次)和五种含水率(11%、13%、15%、17%、19%)尾矿砂试样常规三轴试验。研究表明:(1)相同含水率时,随着冻融循环次数的增大,变形模量逐渐减小,内聚力和内摩擦角均呈现降低的趋势;经历9次冻融循环后,内聚力降低至17.4kPa,内摩擦角降为14.82°。(2)相同冻融循环次数条件下,随着含水率的增大,尾矿砂的峰值应力降低,对应峰值应变增大;围压100kPa时,含水率19%的尾矿砂在经历9次冻融循环后应变为18.21%,应力为139.37kPa;各冻融循环次数下的尾矿砂抗压强度均呈现下降的趋势,内聚力和内摩擦角均随着含水率的增大而减小。研究成果可为尾矿砂物理力学性质理论的丰富以及尾矿砂相关工程的安全运营提供参考。 相似文献
209.
饱和砂土动本构理论研究进展 总被引:14,自引:2,他引:12
饱和砂土由于它对动载荷作用的特殊敏感性在土动力学和土工抗震问题研究中占据了重要的地位,本文介绍了饱和砂土的基本动力学特性,并对当前饱和砂土动本构理论的研究进展作了较为系统的评述,以期对进一步的研究有所稗益. 相似文献
210.
根据某1 t/h燃煤工业锅炉空气预热器的热力参数,设计并搭建了一套颗粒帘空气预热器模拟实验系统,研究了不同进气温度Tg0(150~300℃)、进气速度Vg0(0.9~1.5m/s)、颗粒帘进口厚度b0 (60~180 mm)、颗粒粒径dp(150~212μm)以及不同颗粒质量流量ms (550~2150 g/s)工况条件下热空气与进口温度tp0=20℃的硅砂颗粒帘间的换热特性。结果表明:影响颗粒帘换热器中气粒两相换热特性因素的重要性次序为进气温度、进气速度、颗粒质量流量、颗粒粒径、颗粒帘进口厚度;换热端差最低可至4.5℃,最大可达87℃;颗粒帘及颗粒帘出口气流的温度沿颗粒下落方向在前期上升迅速(186~475℃/m)而后期上升比较缓慢(60~108℃/m),并且在0~0.5 m和0.5~1.0 m的高度范围可分别用线性和对数方程来描述。 相似文献