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991.
The present study uses modern time series methodology to understand long‐run equilibrium in markets and provides additional evidence of the frequent existence of stationary market shares for frequently purchased consumer products. Dekimpe and Hanssens, Marketing Science 1995; 14(2):G109–121 using a database of over 400 prior studies, found that 78 per cent of the market share series they studied were stationary, but that 68 per cent of the sales series were evolving. Our findings reconcile these results. A major contribution of this paper is its demonstration that the prior empirical evidence that a majority of sales series is in evolution is consistent with stationary market shares, if brand sales and category sales are cointegrated. To the extent that competitive activities have an effect on market share, an implication of our findings is that these activities may, in general, only have a temporary effect on market share. Finally, we distinguish, from a strategic perspective, between sales and share response at the primary‐demand level (category sales), selective‐demand level (brand sales) and relative‐position level (market share) and identify strategic scenarios depending upon their stable/evolving nature. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
992.
Jayabal Kaliappan Andreas Menzel Arockiarajan Arunachalakasi Sivakumar M Srinivasan 《PAMM》2010,10(1):299-300
Piezoelectric materials are one of the most prominent smart materials due to their strong electromechanical coupling behaviour. Ferroelectric ceramics behave like piezoelectric materials under low electrical and mechanical loads, but exhibit pronounced nonlinear response at higher loads due to microscopic domain switching. Modern smart devices consist of complex geometries that may force the ferroelectrics employed within them to experience higher fields than they were originally designed for, so that the material responds within its nonlinear region. Hence, models predicting the nonlinear effects of ferroelectrics under complex loading cases are important from the design point of view. Within standard finite element models dealing with electromechanical problems, each grain may be subdiscretized by several finite elements. This problem can be approximated or rather overcome by a polygonal finite element method, where each grain is modelled by solely one single finite element. In this contribution, a micromechanically motivated switching model for ferroelectric ceramics, as based on volume fraction concepts, is combined with polygonal finite element approach. Related representative numerical examples allow to further study and understand the nonlinear response of this material under complex loading cases. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
993.
Dmitry Gavinsky Shachar Lovett Michael Saks Srikanth Srinivasan 《Random Structures and Algorithms》2015,47(1):99-108
We prove a Chernoff‐like large deviation bound on the sum of non‐independent random variables that have the following dependence structure. The variables are arbitrary [0,1]‐valued functions of independent random variables , modulo a restriction that every Xi influences at most k of the variables . © 2014 Wiley Periodicals, Inc. Random Struct. Alg., 47, 99–108, 2015 相似文献
994.
995.
G. Srinivasan R. T. Rajendra Kumar J. Kumar 《Journal of Sol-Gel Science and Technology》2007,43(2):171-177
Thin films of ZnO were grown by the sol–gel method using spin-coating technique on (0001) sapphire substrates. The effect
of doping after annealing on the structural and optical properties has been investigated by means of X-ray diffraction (XRD),
cathodoluminescence (CL) spectrum, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The films that were
dried at 623 K and then post annealed at 873 K showed (0002) as the predominant orientation. Two emission bands have been
observed from CL spectrum. Lithium doped film shows shift in the near band edge UltraViolet emission peak and suppressed defect
level emission peak in the visible range. SEM analysis of the films exhibits many spherical shaped nanoparticles. Roughness
of the films determined using atomic force microscopy.
相似文献
996.
Bikshandarkoil R. Srinivasan Ashish R. Naik Christian Nther Wolfgang Bensch 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(3):m81-m84
The structure of the title compound, (C2H10N2)[WOS3], consists of ethylenediammonium dications and tetrahedral [WOS3]2− dianions, which are linked with the aid of four varieties of hydrogen bond, namely N—H⋯O, N—H⋯S, C—H⋯O and C—H⋯S. The strength and number of these hydrogen bonds affect the W—O and W—S bond distances. 相似文献
997.
Champaka Gurudevaru Mohan Gopalakrishnan Kabali Senthilkumar Hridya Hemachandran Ramamoorthy Siva Thothadri Srinivasan Devadasan Velmurugan Swaminathan Shanmugan Nallasamy Palanisami 《应用有机金属化学》2018,32(2)
Mononuclear and dinuclear copper(II) complexes with thiophenecarboxylic acid, [Cu(3‐TCA)2(2,2′‐bpy)] ( 1 ), [Cu(3‐Me‐2‐TCA)2(H2O)(2,2′‐bpy)] ( 2 ), [Cu(5‐Me‐2‐TCA)2(H2O)(2,2′‐bpy)] ( 3 ) and [Cu2(2,5‐TDCA)(DMF)2(H2O)2(2,2′‐bpy)2](ClO4)2 ( 4 ) (where 3‐TCA = 3‐thiophenecarboxylic acid; 3‐Me‐2‐TCA = 3‐methyl‐2‐thiophenecarboxylic acid; 5‐Me‐2‐TCA = 5‐methyl‐2‐thiophenecarboxylic acid; 2,5‐TDCA = thiophene‐2,5‐dicarboxylic acid; 2,2′‐bpy = 2,2′‐bipyridyl; DMF = N,N‐dimethylformamide), were synthesized. Compounds 1 – 4 were extensively characterized using both analytical and spectroscopic methods. Additionally, the solid‐state structures of 1 and 4 were unambiguously established from single‐crystal X‐ray diffraction studies. The hexacoordinated Cu(II) centre in 1 (CuO4N2) is a distorted octahedral geometry whereas the pentacoodinated 4 (CuO3N2) has distorted square pyramidal geometry. Compounds 1 and 4 exhibit intermolecular hydrogen bonding which leads to the formation of two‐ and three‐dimensional supramolecular architectures, respectively. Spectrophotometric and computational investigations suggest that these compounds bind with DNA in minor groove binding such that Kb = 4.9 × 105 M?1 and Ksv = 3.4 × 105 M?1, and binding score of ?5.26 kcal mol?1. The binding affinity of these complexes to calf thymus DNA is in the order 2 > 3 > 4 > 1 . Methyl‐substituted thiophene ring increases the DNA binding affinity whereas unsubstituted thiophene ring DNA binding rate is reduced. The methyl group on the thiophene ring would sterically hinder π–π stacking of the ring with DNA base pairs, and subsequently they are involved in hydrophobic interaction with the DNA surface rather than partial intercalative interaction. Compounds 1 – 4 show pronounced activity against B16 mouse melanoma skin cancer cell lines as measured by MTT assay yielding IC50 values in the micromolar concentration range. The compounds could prove to be efficient anti‐cancer agents, since at a concentration as low as 2.1 μg ml?1 they exerted a significant cytotoxic effect in cancer cells whereas cell viability was not affected in normal cells. 相似文献
998.
999.
Dr. Shikha Sharma Dr. Suman Rathod Satya Prakash Yadav Arunavo Chakraborty Prof. Ashok K. Shukla Dr. Nagaphani Aetukuri Prof. Satish Patil 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(47):12172-12180
Redox flow batteries (RFBs) employing nonaqueous electrolytes could potentially operate at much higher cell voltages, and therefore afford higher energy and power densities, than RFBs employing aqueous electrolytes. The development of such high-voltage nonaqueous RFBs requires anolytes that are electrochemically stable, especially in the presence of traces of oxygen and/or moisture. The inherent atmospheric reactivity of anolytes mandates judicious molecular design with high electron affinity and electrochemical stability. In this study, diketopyrrolopyrrole (DPP)-based TDPP-Hex-CN4 is proposed as a stable redox-active molecule for anolytes in nonaqueous organic RFBs. We demonstrate organic RFBs using TDPP-Hex-CN4 as anolyte with unisol blue (UB) 1,4-bis(isopropylamino)anthraquinone and 1,4-di-tert-butyl-2,5-bis(2-methoxyethoxy)benzene (DBBB) as catholytes. Cyclic voltammetry measurements with scans repeated over 200 cycles were performed to establish the electrochemical stability of the redox pairs. Symmetric flow-cell studies show that TDPP-Hex-CN4 exhibits stable capacity up to 700 cycles. Redox flow cells employing TDPP-Hex-CN4 /UB and TDPP-Hex-CN4/DBBB as redox pairs demonstrate that DPP derivatives are propitious materials for anolytes in all organic nonaqueous RFBs. 相似文献
1000.
This work presents the fabrication of Nafion (Nf) or Nafion/Multiwalled Carbon Nanotubes (Nf/MWCNTs) modified gold microarray (Au‐µA) and macro‐(Au‐M)electrode biosensors. The surface morphologies of the above electrodes were examined using SEM. The catalytic properties of the above electrodes towards dopamine were tested using square wave voltammetric technique. The Nf/MWCNT/Au‐µA electrode exhibited a wide range (0.1–1000 nM) of linearity among the other electrodes. The LOD of Nf/MWCNT/Au‐µA electrode was 50 pM for dopamine in the presence of 5000 µM ascorbic acid. Therefore, the Nf/MWCNT/Au‐µA biosensor was applied for the determination of dopamine in human serum. 相似文献