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51.
To study the interaction between liposomes and proteins, intact liposomes were immobilized on a metal planar support by chemical binding and/or bioaffinity using a quartz crystal microbalance (QCM). A large decrease in the resonance frequency of quartz crystal was observed when the QCM, modified by a self-assembled monolayer (SAM) of carboxythiol, was added to liposome solutions. The stable chemical immobilization of intact liposomes onto SAM was judged according to the degree with which adsorbed mass depended on the prepared size of liposomes, as well as on the activation time of SAMs when amino-coupling was introduced, where the liposome coverage of electrodes was 69+/-8% in optimal conditions. When avidin-biotin binding was used on amino-coupling liposome layers, liposome immobilization finally reached 168% coverage of the electrode surface. Denatured protein was also successfully detected according to the change in the frequency of the liposome-immobilized QCM. The adsorbed mass of denatured carbonic anhydrase from bovine onto immobilized liposomes showed a characteristic peak at a concentration of guanidine hydrochloride that corresponded to a molten globule-like state of the protein, although the mass adsorbed onto deactivated SAM increased monotonously. 相似文献
52.
H Kobayashi H Morita M Yamauchi R Ikeda H Kitagawa Y Kubota K Kato M Takata S Toh S Matsumura 《Journal of the American Chemical Society》2012,134(30):12390-12393
We have synthesized and characterized homogeneous solid-solution alloy nanoparticles of Pd and Rh, which are immiscible with each other in the equilibrium bulk state at around room temperature. The Pd-Rh alloy nanoparticles can absorb hydrogen at ambient pressure and the hydrogen pressure of Pd-Rh alloys for hydrogen storage is dramatically decreased by more than 4 orders of magnitude from the corresponding pressure in the metastable bulk state. The solid-solution state is still maintained in the nanoparticles even after hydrogen absorption/desorption, in contrast to the metastable bulks which are separated into Pd and Rh during the process. 相似文献
53.
We report nanosize-induced hydrogen storage in Ir, which does not absorb hydrogen in its bulk form. The mean diameter of the obtained Ir nanoparticles was estimated as 1.5 ± 0.5 nm by transmission electron microscopy. Hydrogen storage was confirmed by solid-state (2)H NMR and hydrogen pressure-composition isotherm measurements. 相似文献
54.
Diguet A Yanagisawa M Liu YJ Brun E Abadie S Rudiuk S Baigl D 《Journal of the American Chemical Society》2012,134(10):4898-4904
We study the behavior of multicomponent giant unilamellar vesicles (GUVs) in the presence of AzoTAB, a photosensitive surfactant. GUVs are made of an equimolar ratio of dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC) and various amounts of cholesterol (Chol), where the lipid membrane shows a phase separation into a DPPC-rich liquid-ordered (L(o)) phase and a DOPC-rich liquid-disordered (L(d)) phase. We find that UV illumination at 365 nm for 1 s induces the bursting of a significant fraction of the GUV population. The percentage of UV-induced disrupted vesicles, called bursting rate (Y(burst)), increases with an increase in [AzoTAB] and depends on [Chol] in a non-monotonous manner. Y(burst) decreases when [Chol] increases from 0 to 10 mol % and then increases with a further increase in [Chol], which can be correlated with the phase composition of the membrane. We show that Y(burst) increases with the appearance of solid domains ([Chol] = 0) or with an increase in area fraction of L(o) phase (with increasing [Chol] ≥ 10 mol %). Under our conditions (UV illumination at 365 nm for 1 s), maximal bursting efficiency (Y(burst) = 53%) is obtained for [AzoTAB] = 1 mM and [Chol] = 40 mol %. Finally, by restricting the illumination area, we demonstrate the first selective UV-induced bursting of individual target GUVs. These results show a new method to probe biomembrane mechanical properties using light as well as pave the way for novel strategies of light-induced drug delivery. 相似文献
55.
Maity P Wakabayashi T Ichikuni N Tsunoyama H Xie S Yamauchi M Tsukuda T 《Chemical communications (Cambridge, England)》2012,48(49):6085-6087
Organogold clusters Au(54)(C(2)Ph)(26) were selectively synthesized by reacting polymer-stabilized Au clusters (1.2 ± 0.2 nm) with excess phenylacetylene in chloroform. 相似文献
56.
In the past, we have questioned the accuracy of the stereochemistry of elisabethatriene, a putative biosynthetic intermediate of pseudopterosins, in light of the configuration of elisabethatrienol isolated from Pseudopterogorgia elisabethae, which was represented as 1S,4R,9S,11S. We have reinvestigated the stereochemistry of elisabethatriene. Elisabethatriene with the reported 1S,4R,9R,11S configuration was synthesized starting from (-)-isopulegol in its enantiomeric form. The (1)H- and (13)C-NMR data of the synthesized compound differed from those reported for elisabethatriene. In addition to the fact that elisabethatriene is converted into pseudopterosins, this finding has allowed us to propose that elisabethatriene should have the 1S,4R,9S,11S stereochemistry, which is identical to that of elisabethatrienol. 相似文献
57.
Artem Plyusnin Jingwei He Cindy Elschner Miho Nakamura Julia Kulkova Axel Spickenheuer Christina Scheffler Lippo V. J. Lassila Niko Moritz 《Molecules (Basel, Switzerland)》2021,26(5)
The use of bioresorbable fracture fixation plates made of aliphatic polyesters have good potential due to good biocompatibility, reduced risk of stress-shielding, and eliminated need for plate removal. However, polyesters are ductile, and their handling properties are limited. We suggested an alternative, PLAMA (PolyLActide functionalized with diMethAcrylate), for the use as the matrix phase for the novel concept of the in situ curable bioresorbable load-bearing composite plate to reduce the limitations of conventional polyesters. The purpose was to obtain a preliminary understanding of the chemical and physical properties and the biological safety of PLAMA from the prospective of the novel concept. Modifications with different molecular masses (PLAMA-500 and PLAMA-1000) were synthesized. The efficiency of curing was assessed by the degree of convergence (DC). The mechanical properties were obtained by tensile test and thermomechanical analysis. The bioresorbability was investigated by immersion in simulated body fluid. The biocompatibility was studied in cell morphology and viability tests. PLAMA-500 showed better DC and mechanical properties, and slower bioresorbability than PLAMA-1000. Both did not prevent proliferation and normal morphological development of cells. We concluded that PLAMA-500 has potential for the use as the matrix material for bioresorbable load-bearing composite fracture fixation plates. 相似文献
58.
Katsuhiko Tahara Eiji Nagahara Yasushi Itoi Satoru Nishiyama Shigeru Tsuruya Mitsuo Masai 《Reaction Kinetics and Catalysis Letters》1996,59(1):15-18
The conversion of a carboxylic acid was increased to 90% with 100% selectivity to the corresponding alcohol by calcination of the catalyst precursor, Sn/alumina, of Ru–Sn/alumina in the hydrogenation of the carboxylic acid. 相似文献
59.
Miho Saito 《Tetrahedron》2007,63(23):4865-4873
Treatment of N-(2-arylcyclohex-1-en-1-yl)-α-(methylthio)acetamides with N-chlorosuccinimide (NCS) gave 3a-aryl-2,3,3a,4,5,6-hexahydro-3-(methylthio)indol-2-ones. Desulfurization of the cyclization products followed by a catalytic hydrogenation of the resulting hexahydroindol-2-ones gave predominantly or exclusively trans-fused octahydroindol-2-ones. On the other hand, reduction of the desulfurization products with Et3SiH in CF3CO2H exclusively provided cis-fused octahydroindol-2-ones. A chiral induction of N-[2-(3,4-dimethoxy)phenylcyclohex-1-en-1-yl]-α-(methylthio)acetamide having an (R)-1-(1-naphthyl)ethyl group on the nitrogen atom led to the synthesis of (−)-mesembrane and (−)-trans-mesembrane. 相似文献
60.
The mechanisms of nitrosation of acetone through sodium enolate [CH3COCH2]- Na+ (1) or naked enolate [CH3COCH2]- (2) with tert-butyl nitrite (CH3)3CONO (3) were studied using ab initio molecular orbital (MO) methods. When the modified complex model was used in the elimination process, our results demonstrated the predominant formation of E-1-hydroxy-imino-2-oxo-propane CH3COCH=NOH (4E), in which a counter-cation of the base catalyst did not participate during the reaction. On the other hand, participation of the counter-cation during the reaction contributed to the formation of the Z-isomer of 4 (4Z). 相似文献