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91.
Hierarchical and probabilistic quantum state sharing via a non-maximally entangled stateHierarchical and probabilistic quantum state sharing via a non-maximally entangled stateHierarchical and probabilistic quantum state sharing via a non-maximally entangled state
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A scheme that probabilistically realizes hierarchical quantum state sharing of an arbitrary unknown qubit state with a four-qubit non-maximally entangled 丨X) state is presented in this paper. In the scheme, the sender Alice distributes a quantum secret with a Bell-state measurement and publishes her measurement outcomes via a classical channel to three agents who are divided into two grades. One agent is in the upper grade, while the other two agents are in the lower grade. Then by introducing an ancillary qubit, the agent of the upper grade only needs the assistance of any one of the other two agents for probabilistically obtaining the secret, while an agent of the lower grade needs the help of both the other two agents by using a controlled-NOT operation and a proper positive operator-valued measurement instead of the usual projective measurement. In other words, the agents of two different grades have different authorities to reconstruct Alice's secret in a probabilistic manner. The scheme can also be modified to implement the threshold-controlled teleportation. 相似文献
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94.
The intent of this study is to examine nonequilibrium heat transfer in a copper-argon nanofluid by molecular dynamics simulation. Two different methods, the physical definition method and the curve fitting method, are introduced to calculate the coupling factor between nanoparticles and base fluid. The results show that the coupling factors obtained by these two methods are consistent. The coupling factor is proportional to the volume fraction of the nanoparticle and inversely proportional to nanoparticle diameter. In the temperature range of 90-200 K, the coupling factor is not affected by temperature. The nanoparticle aggregation results in a decrease of the coupling factor. 相似文献
95.
Xiaoji Cao Jingfang Qiao Liping Wang Xuemin Ye Lebin Zheng Nan Jiang Weimin Mo 《Rapid communications in mass spectrometry : RCM》2012,26(7):740-748
A powerful ionic liquid‐based ultrasonic‐assisted extraction (ILUAE) method combined with ultra‐performance liquid chromatography coupled to electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (UPLC/ESI‐QTOFMSn) was employed in the rapid simultaneous screening of iridoid glycosides, phenylethanoid glycosides, and cucurbitacin glycosides from P. scrophulariiflora. The ILUAE procedure was optimized over several ultrasonic parameters, including the ultrasonic power, concentration of the ionic liquid, and solid–liquid ratio. A comparison with conventional heat‐reflux extraction and regular UAE demonstrated that the optimized approach yielded a high extraction efficiency (Picroside I, 2.84%; Picroside II, 3.57%; 6‐O‐E‐feruloyl catalpol, 2.20%) within a short extraction time of 30 min. Negative ion mode ESI‐QTOFMS2 analysis of the fragmentation reactions of the [M–H]– ions was conducted to characterize the diagnostic ions related to the glycosyl moieties, aglycone units, and the type and substituted position of the ester groups. Interestingly, the positional isomers of the iridoid glycosides could be easily discriminated based on the characteristic ions. A total of 15 glycosides, including three groups of iridoid glycoside isomers and two groups of phenylethanoid glycoside isomers, were conveniently identified within 13.5 min. Moreover, 6'‐O‐vanilloyl catalpol was identified in P. scrophulariiflora for the first time. The method developed here was further validated by measuring the recovery, correlation coefficient (R2), and reproducibility (RSD, n = 5) of three iridoid glycosides: 89.60%–109.02%, 0.9991–0.9998, and 0.93%–1.44%, respectively. This study demonstrated the capabilities of ILUAE combined with UPLC/ESI‐QTOFMSn for the rapid screening of glycosides in P. scrophulariiflora. This method offers an approach to similar studies on other natural plants. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
96.
Hui Mei Wenjia Han Jianglin Hu Se Xiao Yizhu Lei Rui Zhang Wanlin Mo Guangxing Li 《应用有机金属化学》2013,27(3):177-183
This work describes a highly efficient unstrained C(sp3)―N bond activation approach for synthesis of N,N‐dimethylacetamide (DMAc) via catalytic carbonylation of trimethylamine using a PdCl2/bipy (bipy = 2,2′‐bipyridine)/Me4NI catalyst system. A low Pd catalyst dosage (1.0 mol%) is sufficient for high selectivity (98.1%) and yield (90.8%), with a turnover number (TON) of 90.0 mmol of DMAc obtained per mmol of PdCl2 employed under mild reaction conditions. The influence of reaction parameters such as catalyst precursor dosage, ligand type and promoter on activity is investigated. This work also discusses in detail the halide promoter's role in the reaction, and provides a plausible mechanism based on the intermediates methyl iodide and acetyl iodide. Analyses indicate that the carbonylation of trimethylamine may proceed through an active intermediate acetyl iodide formed by carbonylation of methyl iodide generated from the decomposition of the promoter Me4NI under reaction conditions. The formation of acetyl iodide favors the cleaving efficiency of the inert unstrained C(sp3)―N bond of trimethylamine. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
97.
Alejandro Ortega Moñux Steve Greedy Ginés Lifante 《Optical and Quantum Electronics》2013,45(4):307-307
98.
Dr. Dai Wu Xiu-Fang Mo Prof. Piao He Dr. Hai-Ru Li Prof. Xiao-Yi Yi Prof. Chao Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(40):10313-10322
Seven three dimensional (3D) uranyl organic frameworks (UOFs), formulated as [NH4][(UO2)3(HTTDS)(H2O)] ( 1 ), [(UO2)4(HTTDS)2](HIM)6 ( 2 , IM=imidazole), [(UO2)4(TTDS)(H2O)2(Phen)2] ( 3 , Phen=1,10-phenanthroline), [Zn(H2O)4]0.5[(UO2)3(HTTDS)(H2O)4] ( 4 ), and {(UO2)2[Zn(H2O)3]2(TTDS)} ( 5 ), {Zn(UO2)2(H2O)(Dib)0.5(HDib)(HTTDS)} ( 6 , Dib=1,4-di(1H-imidazol-1-yl)benzene) and [Na]{(UO2)4[Cu3(u3-OH)(H2O)7](TTDS)2} ( 7 ) have been hydrothermally prepared using a rigid octadentate carboxylate ligand, tetrakis(3,5-dicarboxyphenyl)silicon(H8TTDS). These UOFs have different 3D self-assembled structures as a function of co-ligands, structure-directing agents and transition metals. The structure of 1 has an infinite ribbon formed by the UO7 pentagonal bipyramid bridged by carboxylate groups. With further introduction of auxiliary N-donor ligands, different structure of 2 and 3 are formed, in 2 the imidazole serves as space filler, while in 3 the Phen are bound to [UO2]2+ units as co-ligands. The second metal centers were introduced in the syntheses of 4–7 , and in all cases, they are part of the final structures, either as a counterion ( 4 ) or as a component of framework ( 5 − 7 ). Interesting, in 7 , a rare polyoxometalate [Cu3(μ3-OH)O7(O2CR)4] cluster was found in the structure. It acts as an inorganic building unit together with the dimer [(UO2)2(O2CR)4] unit. Those uranyl carboxylates were sufficiently determined by single crystal X-ray diffraction, and their topological structures and luminescence properties were analyzed in detail. 相似文献
99.
Solvent‐Controlled Bifurcated Cascade Process for the Selective Preparation of Dihydrocarbazoles or Dihydropyridoindoles
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Dr. Dong‐Liang Mo Dr. Donald J. Wink Dr. Laura L. Anderson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(41):13217-13225
A solvent‐controlled cascade process has been identified for the dual purpose of the preparation of either dihydrocarbazoles or dihydropyridoindoles from identical N‐aryl‐α,β‐unsaturated nitrones and electron‐deficient allene starting materials. These reactions proceed smoothly under mild metal‐free conditions affording a range of two types of skeletally distinct indole‐based heterocycles in high yield and diastereoselectivity. These transformations demonstrate the use of a bifurcated cascade process that hinges on the ring‐opening event of a benzazepine intermediate for the synthesis of skeletally diverse heterocyclic products and rapid access to biologically‐significant, indole‐based structures. 相似文献
100.
In social network services, such as Facebook, Google+, Twitter, and certain postings attract more people than others. In this paper, we propose a novel method for predicting the lifespan and retweet times of tweets, the latter being a proxy for measuring the popularity of a tweet. We extract information from retweet graphs, such as posting times; and social, local, and content features, so as to construct prediction knowledge bases. Tweets with a similar topic, retweet pattern, and properties are sequentially extracted from the knowledge base and then used to make a prediction. To evaluate the performance of our model, we collected tweets on Twitter from June 2012 to October 2012. We compared our model with conventional models according to the prediction goal. For the lifespan prediction of a tweet, our model can reduce the time tolerance of a tweet lifespan by about four hours, compared with conventional models. In terms of prediction of the retweet times, our model achieved a significantly outstanding precision of about 50%, which is much higher than two of the conventional models showing a precision of around 30% and 20%, respectively. 相似文献