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21.
22.
Farhan M. Khan Muhammad A. Abbasi Aziz-ur-Rehman Sabahat Z. Siddiqui Abdul R. Sadiq Butt Hussain Raza Ayesha Zafar Syed A. Ali Shah Muhammad Shahid Sung-Yum Seo 《Journal of heterocyclic chemistry》2021,58(5):1089-1103
By using a convergent methodology, a novel series of N-arylated 4-yl-benzamides containing a bi-heterocyclic thiazole–triazole core was synthesized, and the structures of these hybrid molecules, 9a–k , were corroborated through spectral analyses. The in vitro studies of these multifunctional molecules demonstrated their potent carbonic anhydrase inhibition relative to the standard used. The kinetics mechanism was exposed by Lineweaver–Burk plots, which revealed that 9j inhibited carbonic anhydrase non-competitively by forming an enzyme-inhibitor complex. The inhibition constants Ki calculated from Dixon plots for this compound was 1.2 μM. The computational study was also persuasive with the experimental results, and these molecules disclosed good results of all scoring functions and interactions, which suggested a good binding to carbonic anhydrase. So, it was predicted from the inferred results that these molecules might be considered as promising medicinal scaffolds for various diseases related to the uncontrolled production of this enzyme. 相似文献
23.
René Stangenberg Christos Grigoriadis Hans-Jürgen Butt Klaus Müllen George Floudas 《Colloid and polymer science》2014,292(8):1939-1948
The thermodynamic, optical, structural, and dynamic properties of the semifluorinated (E)-1-(4-octylphenyl)-2-(4-(perfluorooctyl)phenyl)diazene (4) and the corresponding (E)-1,2-bis(4-octylphenyl)diazene (5) have been studied with differential scanning calorimetry, polarizing optical microscopy, X-ray diffraction, and dielectric spectroscopy. 4 combines the azobenzene properties with the fluorophobic effect and gives rise to a responsive material with a temperature and dc-bias-driven switchable dielectric permittivity within the narrower nematic phase. This is caused by the nematic potential that inevitably brings some fluorocarbon chains in proximity to the hydrocarbon chains from adjacent molecules. Frustration is alleviated by reducing the nematic-to-isotropic transition temperature and by increasing the crystalline-to-nematic transition temperature, thus limiting the stability of the nematic phase. Unlike the normal isotropic phase of compound 5, the isotropic phase of compound 4 contains dipoles with short-range orientation correlations. Optimizing the type of interactions may result in materials with applications as molecular switches and electrooptic devices. 相似文献
24.
Daniel Leibig Margarita Messerle Tobias Johann Christian Moers Farzaneh Kaveh Hans-Jürgen Butt Doris Vollmer Axel H. E. Müller Holger Frey 《Journal of polymer science. Part A, Polymer chemistry》2020,58(1):181-192
Well-defined polystyrene homopolymers with surface-adhesive triethoxysilyl end group were synthesized via living carbanionic polymerization, epoxide end-functionalization and subsequent hydrosilylation with triethoxysilane. Grafting-to performance of polymers with various molecular weight (Mn = 3000–14,000 g mol−1) to a silicon surface was examined in dependence of reaction time, polymer concentration, solvent and number of alkoxysilyl end groups. Crosslinkable polymers for surface modification were synthesized by statistical carbanionic copolymerization of 4-vinylbenzocyclobutene (4-VBCB) and styrene, followed by epoxide end-functionalization and triethoxysilane modification (Mn = 4000–14,000 g mol−1). The copolymers were characterized by 1H-NMR, THF-SEC, and matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. In situ 1H-NMR kinetic studies in cyclohexane-d12 provided information regarding the monomer gradient in the polymer chains, with styrene being the more reactive monomer (rs = 2.75, r4-VBCB = 0.23). Thin polymer films on silicon wafers were prepared by grafting-to surface modification under conditions derived for the polystyrene homopolymer. The traceless, thermally induced crosslinking reaction of the benzocyclobutene units was studied by DSC in bulk as well as in 3–6 nm thick polymer films. Crosslinked films were analyzed by atomic force microscopy, ellipsometry, and nanoindentation, showing smooth polymer films with an increased modulus. © 2019 The Authors. Journal of Polymer Science published by Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 181–192 相似文献
25.
Butt AH Kariuki BM Percy JM Spencer NS 《Chemical communications (Cambridge, England)》2002,(7):682-683
Diels-Alder and conjugate addition reactions were used to prepare precursors to a range of fully functionalized and deoxy inositol phosphate analogues. 相似文献
26.
On the basis of a pyrrolidine tweezer 1, a library of peptidosulfonamide tweezers (15a-e, 16a-e) was synthesized on the solid phase. This library was screened in a simultaneous substrate screening procedure for the ability to enantioselectively catalyze the Ti(O-i-Pr)(4)-mediated addition of diethylzinc to aldehydes. One of the best solid-phase tweezer catalyst (i.e., 16d, giving an ee of 32% in solid-phase catalysis) was resynthesized in solution (compounds 20 and 21). The now homogeneous solution-phase catalysis showed even better enantioselectivity (i.e., up to 66%). 相似文献
27.
Graeme Butt N. Pirzada Ronald D. Topsom William Adcock Anil N. Abeywickrema 《Tetrahedron letters》1982,23(21):2161-2162
The carbon-13 substituent chemical shifts of 4-substituted bicyclo[2.2.2]oct-1-yl cyanides are a linear function of the substituent inductive parameters. 相似文献
28.
Adams GS Chasse M Cravey M Cummings JP Danko I Napolitano J Cronin-Hennessy D Park CS Park W Thayer JB Thorndike EH Coan TE Gao YS Liu F Stroynowski R Artuso M Boulahouache C Blusk S Butt J Dambasuren E Dorjkhaidav O Menaa N Mountain R Muramatsu H Nandakumar R Redjimi R Sia R Skwarnicki T Stone S Wang JC Zhang K Csorna SE Bonvicini G Cinabro D Dubrovin M Bornheim A Pappas SP Weinstein AJ Briere RA Chen GP Ferguson T Tatishvili G Vogel H Watkins ME Adam NE Alexander JP Berkelman K Cassel DG 《Physical review letters》2005,94(1):012001
The decay branching fractions of the three narrow Upsilon resonances to mu(+)mu(-) have been measured by analyzing about 4.3 fb(-1) e(+)e(-) data collected with the CLEO III detector. The branching fraction B(Upsilon(1S)-->mu(+)mu(-))=(2.49+/-0.02+/-0.07)% is consistent with the current world average, but B(Upsilon(2S)-->mu(+)mu(-))=(2.03+/-0.03+/-0.08)% and B(Upsilon(3S)-->mu(+)mu(-))=(2.39+/-0.07+/-0.10)% are significantly larger than prior results. These new muonic branching fractions imply a narrower total decay width for the Upsilon(2S) and Upsilon(3S) resonances and lower other branching fractions that rely on these decays in their determination. 相似文献
29.
Huang GS Miller DH Pavlunin V Sanghi B Shibata EI Shipsey IP Adams GS Chasse M Cummings JP Danko I Napolitano J Cronin-Hennessy D Park CS Park W Thayer JB Thorndike EH Coan TE Gao YS Liu F Stroynowski R Artuso M Boulahouache C Blusk S Butt J Dambasuren E Dorjkhaidav O Menaa N Mountain R Muramatsu H Nandakumar R Redjimi R Sia R Skwarnicki T Stone S Wang JC Zhang K Mahmood AH Csorna SE Bonvicini G Cinabro D Dubrovin M Bornheim A Lipeles E Pappas SP Weinstein AJ Briere RA Chen GP Ferguson T 《Physical review letters》2005,94(1):011802
We investigate the decays D(0)-->pi(-)l(+)nu and D(0)-->K(-)l(+)nu, where l is e or mu, using approximately 7 fb(-1) of data collected with the CLEO III detector. We find R(0) identical with B(D(0)-->pi(-)e(+)nu)/B(D(0)-->K(-)e(+)nu)=0.082+/-0.006+/-0.005. Fits to the kinematic distributions of the data provide parameters describing the form factor of each mode. Combining the form factor results and R(0) gives |f(pi)(+)(0)|(2)|V(cd)|(2)/|f(K)(+)(0)|(2)|V(cs)|(2)=0.038(+0.006+0.005)(-0.007-0.003). 相似文献
30.
He Q Muramatsu H Park CS Thorndike EH Coan TE Gao YS Liu F Artuso M Boulahouache C Blusk S Butt J Dorjkhaidav O Li J Menaa N Mountain R Nandakumar R Randrianarivony K Redjimi R Sia R Skwarnicki T Stone S Wang JC Zhang K Csorna SE Bonvicini G Cinabro D Dubrovin M Briere RA Chen GP Chen J Ferguson T Tatishvili G Vogel H Watkins ME Rosner JL Adam NE Alexander JP Berkelman K Cassel DG Crede V Duboscq JE Ecklund KM Ehrlich R Fields L Galik RS Gibbons L Gittelman B Gray R Gray SW Hartill DL 《Physical review letters》2005,95(22):221802
Using 0.8 x 10(6) D+ D- pairs collected with the CLEO-c detector at the psi(3770) resonance, we have searched for flavor-changing neutral current and lepton-number-violating decays of D+ mesons to final states with dielectrons. We find no indication of either, obtaining 90% confidence level upper limits of B(D+ --> pi+ e+ e-) < 7.4 x 10(-6), B(D+ --> pi- e+ d+) < 3.6 x 10(-6), B(D+ --> K+ e+ e-) < 6.2 x 10(-6), and B(D+ --> K- e+ e+) < 4.5 x 10(-6). 相似文献