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121.
Kotera N Delacour L Traoré T Tassali N Berthault P Buisson DA Dognon JP Rousseau B 《Organic letters》2011,13(9):2153-2155
The development of molecular imaging using hyperpolarized xenon MRI needs highly optimized biosensors. Cryptophane-111 and cryptophane-222 are promising candidates that show complementary encapsulation properties although they only differ by the length of the three alkane linkers joining two cyclotriphenolene units. Cryptophanes containing both methoxy and ethoxy linkers have never been synthesized. Here we synthesize two new cages with intermediate internal volumes, in two steps from cyclotriphenolene. 相似文献
122.
A diastereoselective synthesis of the Leu-Pro type phosphinyl dipeptide isostere in its protected form was achieved from stereodefined α-amino-H-phosphinate. The methodology involved a cross-coupling reaction with alkenyl triflate and subsequent diastereoselective hydrogenation of the alkene moiety, which capitalized on the phosphorus chirality. 相似文献
123.
124.
Nakashima Y Abe H Abe N Aikawa K Ito Y 《Chemical communications (Cambridge, England)》2011,47(29):8367-8369
Branched RNAs with three- or four-way junctions were designed by assembling single-stranded RNA for RNA interference. Human Dicer transformed branched RNAs into about 20 base pairs of double-stranded RNA, which is a standard siRNA species. Our tetramer design provides a potent silencing effect over a period of 5 days. 相似文献
125.
Traoré T Clavé G Delacour L Kotera N Renard PY Romieu A Berthault P Boutin C Tassali N Rousseau B 《Chemical communications (Cambridge, England)》2011,47(34):9702-9704
Cryptophane-111 is one of the best candidates for (129)Xe MRI-based applications. Herein, we report the first metal-free and water-soluble cryptophane-111 core which involves an efficient and unusual post-synthetic sulfonation procedure. 相似文献
126.
Hiroshi Ikeda Naoko Ikuta Daisuke Nakata Hiroshi Fukumi Keiji Terao 《Journal of inclusion phenomena and macrocyclic chemistry》2012,73(1-4):443-447
A 1H NMR study that explored the ability of α-cyclodextrin (α-CD) to preferentially bind (R)-α-lipoic acid is presented. The interaction between α-CD and (R)-α-lipoic acid was found to be stronger than that between α-CD and (S)-α-lipoic acid. Structures for the (R)-α-lipoic acid/α-CD and (S)-α-lipoic acid/α-CD inclusion complexes were constructed using restraints derived from ROESY spectra and MM2 molecular mechanics calculations. The models built for both complexes have the 1,2-dithiolane ring and the carboxyl moiety of α-lipoic acid oriented toward the secondary and primary hydroxy sides of α-CD, respectively. 相似文献
127.
128.
Kohno K Morimoto K Manabe N Yajima T Yamagishi A Sato H 《Chemical communications (Cambridge, England)》2012,48(32):3860-3862
A chiral gelator, RR- or SS-N,N'-diperfluorooctanoyl-1,2-diaminocyclohexane, gelated racemic 2-butanol. The gel was most stable at the racemic mixture, its stability lowered with the increase in the optical purity of the gelator. Notably, characteristic helically coiled fibrils were formed in the narrow region of enantiomer excess (ee = 0.2-0.4). Promotion effects of the antipodal enantiomers are proposed. 相似文献
129.
Kenji Okuyama Naoko Kawano Souichi Uehori Keiichi Noguchi Nobuhiro Okabe Yoshiichi Suzuki 《Molecular Crystals and Liquid Crystals》2013,570(1-2):193-201
Abstract Crystal structures of two antiferroelectric mesogens, TFMHPBC and MHPBC-10, were analysed by an X-ray diffraction method. In both crystals, mesogen molecules formed a herringbone structure which was essentially the same as that proposed for the antiferroelectric liquid crystal phase. Because of the crystallographic 21-symmetry along the b-axis, only the b-axis component of the dipole moment remains in a smectic layer. Since the dipole moment in the next layer has the same magnitude but the opposite direction, both crystals show no dipole moment as a whole. These structural features observed in their crystal states seem to be conserved in their antiferroelectric liquid crystal phases which are just above their crystal phases. 相似文献
130.