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991.
Can Liao Wei Wang Junling Wang Longfei Han Shuilai Qiu Lei Song Zhou Gui Yongchun Kan Yuan Hu 《Journal of Energy Chemistry》2021,(5):1-10
To date,lithium-ion batteries are becoming increasingly significant in the application of portable devices and electrical vehicles,and revolutionary progress in theoretical research and industrial application has been achieved.However,the commercial polyolefin separators with unsatisfying electrolytes affinity and poor thermal stability have extremely restricted the further application of lithium-ion batteries,especially in the high-temperature fields.In this work,magnetron sputtering deposition technique is employed to modify the commercial polyimide separator by coating silicon nitride on both sides.Magnetron sputtering deposition modified polyimide(MSD-PI)composite separator shows high thermal stability and ionic conductivity.More importantly,compared with the cells using Celgard separator,the cells with MSD-PI separator exhibit superior electrochemical performance,especially long-term cycle performance under high temperature environment,owing to the high thermal conductivity of surface Si3 N4 particles.Hence,lithium-ion batteries with MSD-PI separator are capable of improving thermal safety and capacity retention,which demonstrates that magnetron sputtering deposition technique could be regarded as a promising strategy to develop advanced organic/inorganic composite separators for high-temperature lithium-ion batteries. 相似文献
992.
993.
环形光纤声发射传感器的相位调制特性研究 总被引:4,自引:0,他引:4
提出了一种基于光纤Sagnac干涉仪的环形传感器,用于固体表面传播的超声波的检测.这种传感器的特点是能够精确地检测由固体表面传播的超声波产生的微弱振动.当超声波信号通过光纤传感器的两个臂到达探测器时,干涉仪的输出光强度受到了超声信号的调制.通过检测干涉仪的输出光强度并利用Fourier变换,测得了超声信号的振幅和频率.而且对传感系统的位相调制特性进行了仿真,并对实验结果进行了分析,结果表明该系统可用于固体表面传播的超声波频率特征的识别. 相似文献
994.
Developing an ideal and cheap adsorbent for adsorbing heavy metals from aqueous solution has been urgently need. In this study, a novel, effective and low-cost method was developed to prepare the biochar from lettuce waste with H3PO4 as an acidic activation agent at a low-temperature (circa 200 °C) hydrothermal carbonization process. A batch adsorption experiment demonstrated that the biochar reaches the adsorption equilibrium within 30 min, and the optimal adsorption capacity of Cd(II) is 195.8 mg∙g−1 at solution pH 6.0, which is significantly improved from circa 20.5 mg∙g−1 of the original biochar without activator. The fitting results of the prepared biochar adsorption data conform to the pseudo-second-order kinetic model (PSO) and the Sips isotherm model, and the Cd(II) adsorption is a spontaneous and exothermic process. The hypothetical adsorption mechanism is mainly composed of ion exchange, electrostatic attraction, and surface complexation. This work offers a novel and low-temperature strategy to produce cheap and promising carbon-based adsorbents from organic vegetation wastes for removing heavy metals in aquatic environment efficiently. 相似文献
995.
The most effective methodologies for the construction of polynuclear complexes usually take advantage of preorganized building blocks.Herein,we successfully developed a new versatile heterometallic{BiNb4}moiety,which can be applied for the assembly of less explored organic-inorganic hybrid polyoxoniobates.Through controlled condensation reactions,three{BiNb4}moieties can be assembled into a pair of isomeric Bi3Nb18clusters at different temperatures;whilst four{BiNb4}moieties can be combined into two unique Bi4Nb16and Bi4Nb18tetramers in different solvents.Interestingly,we have used mass spectrometry to probe the above condensation reactions,which clearly confirmed a stepwise bottom-up assembly process by capturing the presence of bismuth subsalicylate precursors,salicylate coordinated intermediates,Nb incorporated{BiNb4}moieties and the final BixNby-oxo clusters,respectively.Moreover,the packing modes of the{BiNb4}units induce different solution behaviors,and the{BiNb4}units in Bi4Nb16can be recombined by post-synthetic recrystallization in acetonitrile to produce a new tetramer Bi4Nb18-R.Therefore,this work provides not only a useful{BiNb4}building unit but also the mechanism for their condensation,both of which will promote the future development of metal-oxo clusters. 相似文献
996.
997.
999.
The equation of state of MgSiO3 perovskite under high pressure and high temperature is simulated using the molecular dynamics method. It was found that the molecular dynamics simulation is very successful in accurately reproducing the measured molar volumes of MgSiO3 perovskite over a wide range of temperatures and pressures. The simulated equation of state of MgSiO3 perovskite matched experimental data at up to 140GPa at 300 K, as well as the fitting data of others and results from the first-principles simulation based on the local density approximation. The simulated equations of state of MgSiO3 perovskite at higher temperatures and higher pressures also correspond to the other calculations. In addition, the volume compression data of MgSiO3 perovskite is simulated up to 120 GPa at 300, 900, 2000 and 3000 K, respectively. 相似文献
1000.
Micrometer-sized MoO2 hollow spheres were synthesized hydrothermally with ammonium heptamolybdate tetrahydrate as molybdenum source, Cetyltrimethylammonium bromide as structure-directing agent and C2H5OH as reducing agent, respectively. The products were investigated by X-ray diffraction, thermo- gravimetry and differential thermal analysis, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. A morphology transition of "blocks-solid spheres-hollow spheres" during the growth process was observed and the possible mechanism for the formation of MoO2 samples was proposed to be through a microscale Kirkendall effect. 相似文献