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151.
Novel continuous flow carboxylation system was constructed using pressurized CO2 at 6.5 MPa and immobilized enzyme, Bacillus megaterium PYR 2910 decarboxylase. The decarboxylase catalyzed the backward reaction, carboxylation, to convert pyrrole to pyrrole-2-carboxylate at the improved space-time yield by 25 times compared to the corresponding batch reaction. 相似文献
152.
3,4-cis-4-Acetoxy-3-O-acetyl-4-dehydro-5,7,3′,4′-tetra-O-benzyl-(+)-catechin (1a) or (−)-epicatechin (1b) reacted high regio- and stereo-selectively with 1.5 equiv of the 5,7,3′,4′-tetra-O-benzyloxyflavan-3-ol (4a or 4b) in the presence of 1 equiv of TMSOTf to give the corresponding procyanidins. On the other hand, the self-condensation of 1a in the presence of a catalytic amount of B(C6F5)3 afforded wide-range procyanidins from dimer to 15-mer like a biomass. 相似文献
153.
Nozawa D Okubo T Ishii T Chaki S Okuyama S Nakazato A 《Chemical & pharmaceutical bulletin》2007,55(7):1044-1050
While examining antagonists of the melanocortin-4 receptor (MC4 receptor), we found that compound 12b, containing a diphenylmethyl moiety, had a relatively high affinity for the MC4 receptor. When diphenylmethyl analogues were further examined, compounds 12c and 18 were also found to exhibit a high affinity for the MC4 receptor (IC(50)=46.7 nM and 33.2 nM, respectively). Furthermore, compound 12c was also found to show a high affinity for the serotonin transporter (IC(50)=10.7 nM). Here, we describe the synthesis and biological evaluation of various diphenylmethyl analogues in relation to their actions on the MC4 receptor and the serotonin transporter. 相似文献
154.
An improved and widely applicable chemo-enzymatic method for the synthesis of a series of 1-beta-O-acyl glucuronides 5a-f has been developed from the corresponding methyl acetyl derivatives 3a-f, which were stereospecifically synthesized from cesium salts of carboxylic acids 1a-f and methyl 2,3,4-tri-O-acetyl-1-bromo-1-deoxy-alpha-D-glucopyranuronate (2). Chemoselectivity of lipase AS Amano (LAS) in the hydrolytic removal of O-acetyl groups of 3a-f to provide methyl esters 4a-f was influenced by the nature of their 1-beta-O-acyl groups; high selectivity was evident only for 3b and 3f. Carboxylesterase from Streptomyces rochei (CSR), newly screened as an alternative to LAS, showed much greater chemoselectivity toward the O-acetyl groups than LAS; 3a, 3d, and 3e were chemoselectively hydrolyzed only by CSR. The combination of CSR with LAS yielded better results in the hydrolysis of 3c and 3f than did single usage of CSR. Final deprotection of the methyl ester groups of 4a-f to provide 5a-f was chemoselectively achieved by using lipase from Candida antarctica type B (CAL-B) as well as esterase from porcine liver (PLE), although CAL-B possessed higher chemoselectivity and catalytic efficiency than did PLE. CSR also exhibited high chemoselectivity in the synthesis of (S)-naproxen 1-beta-O-acyl glucopyranoside (7) from its 2,3,4,6-tetra-O-acetyl derivative 6. 相似文献
155.
156.
Synthesis of 6‐Aminoindolo[2,1‐a]isoquinoline‐5‐carbonitriles by the Cu‐Catalyzed Reaction of 2‐(2‐Bromophenyl)‐1H‐indoles with CH2(CN)2
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Kazuhiro Kobayashi Kosuke Ezaki Daisuke Hanioka Ippei Nozawa 《Helvetica chimica acta》2015,98(2):179-183
A series of 6‐aminoindolo[2,1‐a]isoquinoline‐5‐carbonitriles 4 have been prepared by treatment of 2‐(2‐bromophenyl)‐1H‐indoles 1 , available from 1‐(2‐bromophenyl)ethanones or 1‐(2‐bromophenyl)propan‐1‐ones by using Fischer indole synthesis, with propanedinitrile in the presence of a catalytic amount of CuBr and an excess of K2CO3 in DMSO at 100°. 相似文献
157.
Y. Ichikawa H. C. Bhang S. Bufalino H. Ekawa P. Evtoukhovitch A. Feliciello H. Fujioka S. Hasegawa S. Hayakawa R. Honda K. Hosomi K. Imai S. Ishimoto C. W. Joo S. Kanatsuki R. Kiuchi T. Koike H. Kumawat Y. Matsumoto K. Miwa M. Moritsu T. Nagae M. Naruki M. Niiyama Y. Nozawa R. Ota A. Sakaguchi H. Sako V. Samoilov S. Sato K. Shirotori H. Sugimura S. Suzuki T. Takahashi T. N. Takahashi H. Tamura T. Tanaka K. Tanida A. O. Tokiyasu Z. Tsamalaidze B. J. Roy M. Ukai T. O. Yamamoto S. B. Yang 《Few-Body Systems》2013,54(7-10):1191-1194
In the J-PARC E27 experiment, we search for a K ? pp bound state via the d(π +, K +) reaction at 1.7 GeV/c at the K1.8 beam line. The binding energy and decay width of the K ? pp bound state can be obtained in the missing mass measurement with a good energy resolution of 2 MeV/c 2. A range counter array (RCA) was constructed to detect the two high-momentum protons from the K ? pp decay and to reduce the background such as quasi-free hyperon production. Recently, we have carried out a pilot run in June, 2012. The d(π +, K +) missing-mass spectrum has been obtained for the first time. In this report, an overview of the E27 experiment and a preliminary result on this pilot run are presented. 相似文献
158.
The line strengths, N2? and O2-broadened half-widths in the ν3, ν1+2ν2 and 2ν1 bands of 14N2 16O were determined from spectra obtained by a high-resolution Fourier transform spectrometer at room temperature. The squared vibrational transition dipole moments and the coefficients of the Herman–Wallis factor were also determined for these bands. The squared vibrational transition dipole moments for these bands agreed with the values of HITRAN and high-resolution experiments within 6%. The N2? and O2-broadened half-widths were in agreement with the results of recent high-resolution experiments. The air-broadened half-widths were calculated using the smoothed N2? and O2-broadened half-widths and compared with the compiled values in the HITRAN database. 相似文献
159.
Tadao Ishii 《Solid State Ionics》2009,180(6-8):441-445
A first-principles derivation of the master equation is systematically given based on Kikuchi's ansatz, which is then applied to non-interacting (ideal) and interacting lattice–gas systems. The former application to an anomalous diffusion, observed by MD simulation of β-AgI, makes its mechanism clear in terms of relaxation modes such that the anomalous diffusion is due to non-diffusive (collective) modes. It is also shown in random systems that anomalous frequency-dependent conductivities, made up of Jonscher and nearly constant loss regimes, are reduced to a single master curve. The case of interacting lattice–gas system is discussed on the ab-plane of Rb3H(SeO4)2 by a pair approximation of the path probability method, where a spontaneous strain involved in the ferroelastic phase turns out to be a proton-trapped state originated in an attractive strain energy mediated by a proton–displacement interaction, and the transition to superprotonic phase is due to an off-trapping of protons. This mechanism is confirmed by no phase transition without the attractive strain energy. 相似文献
160.
Shigeru Ohba Kumi Yoshida Tadao Kondo 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o893-o896
The title compound, 6‐C‐glucopyranosyl‐7‐O‐methylapigenin dihydrate, C22H22O10·2H2O, is a natural C‐glucosylflavone. The flavone skeleton is almost planar, the dihedral angle between the pyran moiety and the 4‐hydroxyphenyl ring being 9.8 (3)°. The basal plane of the pyranosyl ring of the glucose moiety is almost perpendicular to the benzopyran ring system. The flavone skeletons are stacked along the a axis, forming layers parallel to (001). Between these hydrophobic layers, the glucose groups and water molecules of crystallization are connected via O—H⋯O hydrogen bonds, forming hydrophilic layers. 相似文献