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101.
Da Quan Zhang Xing Jin Bin Xie Hyung Goun Joo Li Xin Gao Kang Yong Lee 《Surface and interface analysis : SIA》2012,44(1):78-83
The corrosion inhibition of ammonium heltamolybdate (AH) and calcium gluconate (CG) for AA6061 alloy in 3% NaCl solution was investigated by the electrochemical measurements. It indicates that AH inhibits the corrosion of AA6061 alloy and acts as an anodic inhibitor. Maximum inhibition efficiency reaches 74.3% at the concentration of 1 × 10?4 mol.l?1 AH. The results of the electrochemical studies reveal AH is physically adsorbed on the AA6061 alloy surface and the adsorption follows Langmuir isotherm. The combination of AH and CG enhances the inhibition efficiency to 95.9%. The enhanced inhibition is attributed to the promotion of AH adsorption by CG. The mixture of AH and CG is a mixed‐type inhibitor and renders the corrosion potential to more positive values. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
102.
This paper deals with ultrasound medical image processing, particularly to filter the noise while preserving the edges and
structures of information. The mathematical processing consists in solving by a numerical way a nonlinear evolutive boundary
value problem. Several numerical semi-implicit time marching schemes are considered and analyzed. At each time step, parallel
synchronous or asynchronous Schwarz alternating methods are used to solve the linear system and its convergence is studied.
Lastly, the results of sequential and parallel simulations are presented.
相似文献
103.
A new family of univariate exponential slash distribution is introduced, which is based on elliptical distributions and defined by means of a stochastic representation as the scale mixture of an elliptically distributed random variable with respect to the power of an exponential random variable. The same idea is extended to the multivariate case. General properties of the resulting families, including their moments and kurtosis coefficient, are studied. And inferences based on methods of moment and maximum likelihood are discussed. A real data is presented to show this family is flexible and fits much better than other related families. 相似文献
104.
Jin Luo Shu Li Qiongwen Kang Yi Sun 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):1180-1186
AbstractSixteen novel 3-methylthio-5-substituted benzamido-6-arylamino-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H)-one derivatives (4a–p) were successfully synthesized from iminophosphoranes, aryl isocyanate, and substituted benzoylhydrazine. The structures of the title compounds were elucidated by FT-IR, 1H NMR, 13C NMR, and HRMS. Herbicidal activity of the compounds 4a–p against Brassica napus (rape), Echinochloa crusgalli (barnyard grass), Cucumis sativus (cucumber), and Triticum aestivum (wheat) were determined. The results showed that 5-(2-chlorobenzamido)-6-phenylamino-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H)-one (4c) displayed remarkable inhibition activity against the stalk and root of rape with 100% inhibition rate at the dosages of 10?mg/L and 100?mg/L, and 5-(4-nitrobenzamido)-6-phenylamino-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H) -one (4d) exhibited excellent activity against the stalk and root of barnyard grass with 100% inhibition rate at the same dosages. 相似文献
105.
106.
A simple but robust droplet-based microfluidic system was developed for dose–response enzyme inhibition assay by combining concentration gradient generation method with electrochemical detection method. A slotted-vials array and a tapered tip capillary were used for reagents introduction and concentration gradient generation, and a polydimethylsiloxane (PDMS) microfluidic chip integrated with microelectrodes was used for droplet generation and electrochemical detection. Effects of oil flow rate and surfactant on electrochemical sensing were investigated. This system was validated by measuring dose–response curves of three types of acetylcholinesterase (AChE) inhibitors, including carbamate pesticide, organophosphorus pesticide, and therapeutic drugs regulating Alzheimer's disease. Carbaryl, chlorpyrifos, and tacrine were used as model analytes, respectively, and their IC50 (half maximal inhibitory concentration) values were determined. A whole enzyme inhibition assay was completed in 6 min, and the total consumption of reagents was less than 5 μL. This microfluidic system is applicable to many biochemical reactions, such as drug screening and kinetic studies, as long as one of the reactants or products is electrochemically active. 相似文献
107.
Treatment of 2-methoxyisoindoline-1,3-dione with resonance-stabilized alkylidenephosphoranes afforded the corresponding monoalkenes as the sole reaction product, in ~58–63% yields, whereas more than 80% yields of the same monoolefin products were obtained when the reactions were carried out under microwave conditions. Similarly, 2-(phenylamino)isoindoline-1,3-dione reacted under either thermal or microwave conditions to give only the corresponding monoalkene derivatives. The alkene products from both substrates were further reduced to the corresponding isoindoles using Zn-dust in EtOH. Prediction of the designed compounds and the in vivo anti-inflammation activity of the products in the rat adjuvant model were also studied. The work is the first demonstration of the anti-inflammatory activity of phthalimide derivatives. 相似文献
108.
Salah Abd El Wanees Sabry Hamed Seda 《Journal of Dispersion Science and Technology》2013,34(12):1813-1826
AbstractThe kinetics of H2 production during Zn corrosion in 0.5?M HCl without and with various additives of N,N'-bis-(1-hydroxyphenylimine)-2,5-thiophenedicarboxaldehyde (HPTD) was studied using gasometry and electrochemical techniques. The surface of the corroded Zn samples was investigated using SEM and Optical Profilometry. The rate of H2 production (RHP) increased with the immersion time and temperature. Presence of HPTD mitigated RHP due to an adsorption process. The electrochemical impedance spectroscopy showed that HPTD had a good inhibitive effect. Polarization data proved that HPTD acted as a surface-active mixed-type inhibitor. Some thermodynamic parameters were deduced and discussed. Theoretical calculations were also conducted to corroborate the capability of HPTD to protect Zn surface from corrosion process. 相似文献
109.
Xiaogang Yang Bin Li Haizeng Wang Baorong Hou 《Journal of Dispersion Science and Technology》2013,34(5):672-676
The inhibition effect of cetyl trimethyl ammonium bromide (CTAB) on the corrosion of mild steel in 1.0 mol L?1 hydrochloric acid (HCl) has been studied at different temperatures (25–60°C) by weight loss and potentiodynamic polarization methods. The results reveal that CTAB behaves as an effective inhibitor in 1.0 mol L?1 HCl, and the inhibition efficiency increases with the inhibitor concentration. Polarization curves show that CTAB is a mixed-type inhibitor in hydrochloric acid. The results obtained from weight loss and polarizations are in good agreement. The effect of immersion time on corrosion inhibition has also been examined and is discussed. The adsorption of inhibitor on mild steel surface obeys the Langmuir adsorption isotherm equation. Thermodynamic parameters have been obtained by adsorption theory. The inhibition effect is satisfactorily explained by the parameters. 相似文献
110.
Silver nanoparticles enhanced glucose oxidase electrodes were prepared on the basis of chitosan matrix. The enzyme electrodes exhibited high sensitivity and excellent response performance to glucose with a linear range from 1×10?6 to 8×10?3 mol · L?1. And the time reaching the steady‐state amperometric response was less than 5 seconds. The inhibition percentage of this enzyme electrode against copper ions concentration was linear ranging from 1.2×10?6 to 5×10?5 mol · L?1. These properties of enzyme electrodes are probably due to the excellent electron transfer of silver nanoparticles and the orientation of glucose oxidase molecule. 相似文献