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101.
Don Coppersmith Nick Howgrave-Graham S. V. Nagaraj. 《Mathematics of Computation》2008,77(261):531-545
Let be integers satisfying , , , and let . Lenstra showed that the number of integer divisors of equivalent to is upper bounded by . We re-examine this problem, showing how to explicitly construct all such divisors, and incidentally improve this bound to .
102.
Di Censo D Fantacci S De Angelis F Klein C Evans N Kalyanasundaram K Bolink HJ Grätzel M Nazeeruddin MK 《Inorganic chemistry》2008,47(3):980-989
Highly phosphorescent blue-light-emitting anionic iridium complexes (C4H9)4N[Ir(2-phenylpyridine)2(CN)2] (1), (C4H9)4N[Ir(2-phenyl-4-dimethylaminopyridine)2(CN)2] (2), (C4H9)4N[Ir(2-(2,4-difluorophenyl)-pyridine)2(CN)2] (3), (C4H9)4N[Ir(2-(2,4-difluorophenyl)-4-dimethylaminopyridine)2(CN)2] (4), and (C4H9)4N[Ir(2-(3,5-difluorophenyl)-4-dimethylaminopyridine)2(CN)2] (5) were synthesized and characterized using NMR, UV-vis absorption, and emission spectroscopy and electrochemical methods. In these complexes color and quantum yield tuning aspects are demonstrated by modulating the ligands with substituting donor and acceptor groups on both the pyridine and phenyl moieties of 2-phenylpyridine. Complexes 1-5 display intense photoluminescence maxima in the blue region of the visible spectrum and exhibit very high phosphorescence quantum yields, in the range of 50-80%, with excited-state lifetimes of 1-4 micros in acetonitrile solution at 298 K. DFT and time dependent-DFT calculations were performed on the ground and excited states of the investigated complexes to provide insight into the structural, electronic, and optical properties of these systems. 相似文献
103.
Efficient Blue‐Colored Solid‐State Dye‐Sensitized Solar Cells: Enhanced Charge Collection by Using an in Situ Photoelectrochemically Generated Conducting Polymer Hole Conductor 下载免费PDF全文
Jinbao Zhang Dr. Nick Vlachopoulos Dr. Yan Hao Dr. Thomas W. Holcombe Prof. Gerrit Boschloo Dr. Erik M. J. Johansson Prof. Michael Grätzel Prof. Anders Hagfeldt 《Chemphyschem》2016,17(10):1441-1445
A high power conversion efficiency (PCE) of 5.5 % was achieved by efficiently incorporating a diketopyrrolopyrrole‐based dye with a conducting polymer poly(3,4‐ethylenediothiophene) (PEDOT) hole‐transporting material (HTM) that was formed in situ, compared with a PCE of 2.9 % for small molecular spiro‐OMeTAD‐based solid‐state dye solar cells (sDSCs). The high PCE for PEDOT‐based sDSCs is mainly attributed to the significantly enhanced charge‐collection efficiency, as a result of the three‐order‐of‐magnitude higher hole conductivity (0.53 S cm?1) compared with that of the widely used low molecular weight HTM spiro‐OMeTAD (3.5×10?4 S cm?1). 相似文献
104.
Nitrosylation of Nitric‐Oxide‐Sensing Regulatory Proteins Containing [4Fe‐4S] Clusters Gives Rise to Multiple Iron–Nitrosyl Complexes 下载免费PDF全文
Pauline N. Serrano Dr. Hongxin Wang Dr. Jason C. Crack Christopher Prior Prof. Matthew I. Hutchings Prof. Andrew J. Thomson Dr. Saeed Kamali Dr. Yoshitaka Yoda Dr. Jiyong Zhao Dr. Michael Y. Hu Dr. Ercan E. Alp Dr. Vasily S. Oganesyan Prof. Nick E. Le Brun Prof. Stephen P. Cramer 《Angewandte Chemie (International ed. in English)》2016,55(47):14575-14579
The reaction of protein‐bound iron–sulfur (Fe‐S) clusters with nitric oxide (NO) plays key roles in NO‐mediated toxicity and signaling. Elucidation of the mechanism of the reaction of NO with DNA regulatory proteins that contain Fe‐S clusters has been hampered by a lack of information about the nature of the iron‐nitrosyl products formed. Herein, we report nuclear resonance vibrational spectroscopy (NRVS) and density functional theory (DFT) calculations that identify NO reaction products in WhiD and NsrR, regulatory proteins that use a [4Fe‐4S] cluster to sense NO. This work reveals that nitrosylation yields multiple products structurally related to Roussin's Red Ester (RRE, [Fe2(NO)4(Cys)2]) and Roussin's Black Salt (RBS, [Fe4(NO)7S3]. In the latter case, the absence of 32S/34S shifts in the Fe?S region of the NRVS spectra suggest that a new species, Roussin's Black Ester (RBE), may be formed, in which one or more of the sulfide ligands is replaced by Cys thiolates. 相似文献
105.
Rodgers SL Davis AM Tomkinson NP van de Waterbeemd H 《Journal of chemical information and modeling》2007,47(6):2401-2407
It is assumed that compounds occupying the same region of model space will be subject to similar errors in prediction, and hence, where these errors are known, they can be applied to predictions. Thus, any available measured data can be used to refine predictions of query compounds. This study describes the application of a correction library to a human plasma protein binding model. Compounds that have been measured since the model was built are entered into the library to improve predictions of current compounds. Time-series simulations were conducted to measure the time dependence of the correction library. This study demonstrates significant improvements in predictions where a library is applied, compared with both a static model and an updating model that includes recently measured data. 相似文献
106.
Nick Dungey 《Probability Theory and Related Fields》2007,137(3-4):429-442
Let G be a compactly generated, locally compact group, and let T be the operator of convolution with a probability measure μ on G. Our main results give sufficient conditions on μ for the operator T to be analytic in L
p
(G), 1 < p < ∞, where analyticity means that one has an estimate of form for all n = 1, 2, ... in L
p
operator norm. Counterexamples show that analyticity may not hold if some of the conditions are not satisfied. 相似文献
107.
Ozturk II Hadjikakou SK Hadjiliadis N Kourkoumelis N Kubicki M Baril M Butler IS Balzarini J 《Inorganic chemistry》2007,46(21):8652-8661
Five new antimony(III) complexes with the heterocyclic thiones 2-mercapto-benzimidazole (MBZIM), 5-ethoxy-2-mercapto-benzimidazole (EtMBZIM), and 2-mercapto-thiazolidine (MTZD) of formulas {[SbCl(2)(MBZIM)4]+.Cl-.2H(2)O. (CH(3)OH)} (1), {[SbCl(2)(MBZIM)4]+.Cl-.3H(2)O.(CH3CN)} (2), [SbCl(3)(MBZIM)2] (3), [SbCl(3)(EtMBZIM)(2)] (4), and [SbCl(3)(MTZD)2] (5) have been synthesized and characterized by elemental analysis, FT-IR, far-FT-IR, differential thermal analysis-thermogravimetry, X-ray diffraction, and conductivity measurements. Complex {[SbCl2(tHPMT)(2)]+Cl-}, (tHPMT = 2-mercapto-3,4,5,6-tetrahydro-pyrimidine), already known, was also prepared, and its X-ray crystal structure was solved. It is shown that the complex is better described as {[SbCl3(tHPMT)(2)]} (6). Crystal structures of all other complexes (1-5) have also been determined by X-ray diffraction at ambient conditions. The crystal structure of the hydrated ligand, EtMBZIM.H2O is also reported. Compound [C(28)H(24)Cl(2)N(8)S(4)Sb.2H(2)O.Cl.(CH(3)OH)] (1) crystallizes in space group P2(1), with a = 7.7398(8) A, b = 16.724(3) A, c = 13.717(2) A, beta = 98.632(11) degrees, and Z = 2. Complex [C(28)H(24)Cl(2)N(8)S(4)S(b).Cl.3H(2)O.(CH(3)CN)] (2) corresponds to space group P2(1), with a = 7.8216(8) A, b = 16.7426(17) A, c = 13.9375(16) A, beta = 99.218(10) degrees , and Z = 2. In both 1 and 2 complexes, four sulfur atoms from thione ligands and two chloride ions form an octahedral (Oh) cationic [SbS(4)Cl(2)]+ complex ion, where chlorides lie at axial positions. A third chloride counteranion neutralizes it. Complexes 1 and 2 are the first examples of antimony(III) compounds with positively charged Oh geometries. Compound [C(14)H(12)Cl(3)N(4)S(2)S(b)] (3) crystallizes in space group P, with a = 7.3034(5) A, b = 11.2277(7) A, c = 12.0172(8) A, alpha = 76.772(5) degrees, beta = 77.101(6) degrees, gamma = 87.450(5) degrees, and Z = 2. Complex [C(18)H(20)Cl(3)N(4)O(2)S(2)S(b)] (4) crystallizes in space group P1, with a = 8.6682(6) A, b = 10.6005(7) A, c = 13.0177(9) A, alpha = 84.181(6) degrees, beta = 79.358(6) degrees, gamma = 84.882(6) degrees, and Z = 2, while complex [C(6)H(10)Cl(3)N(2)S(4)S(b)] (5) in space group P2(1)/c shows a = 8.3659(10) A, b = 14.8323(19) A, c = 12.0218(13) A, beta = 99.660(12) degrees, and Z = 4 and complex [C(8)H(16)Cl(3)N(4)S(2)S(b)] (6) in space group P1 shows a = 7.4975(6) A, b = 10.3220(7) A, c = 12.1094(11) A, alpha = 71.411(7) degrees, beta = 84.244(7) degrees, gamma = 73.588(6) degrees, and Z = 2. Crystals of complexes 3-6 grown from acetonitrile solutions adopt a square-pyramidal (SP) geometry, with two sulfur atoms from thione ligands and three chloride anions around Sb(III). The equatorial plane is formed by two sulfur and two chloride atoms in complexes 3-5, in a cis-S, cis-Cl arrangement in 3 and 5 and a trans-S, trans-Cl arrangement in 4. Finally, in the case of 6, the equatorial plane is formed by three chloride ions and one sulfur from the thione ligand while the second sulfur atom takes an axial position leading to a unique SP conformation. The complexes showed a moderate cytostatic activity against tumor cell lines. 相似文献
108.
109.
Chi Ching Mak Nick Bampos Jeremy K. M. Sanders 《Angewandte Chemie (International ed. in English)》1998,37(21):3020-3023
Rigid and flexible linkers are combined in the new dendrimer shown schematically in the picture, which contains nine metalloporphyrin units (Porph). The construction is such that the four “arms” of the dendrimer can fold in a cooperative and predetermined manner in response to added 1,4-diazabicyclo[2.2.2]octane (DABCO). 相似文献
110.