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81.
Improved rejection of multiply scattered photons in confocal microscopy using dual-axes architecture
We perform Monte Carlo simulations to show that the dual-axes (DA) confocal architecture has superior rejection of multiply scattered photons in tissue to that of single axis. As a result, the DA configuration provides improved signal-to-noise ratio and dynamic range, and thus is sensitive to ballistic photons from deeper within tissue, features that are particularly useful for performing vertical cross-sectional reflectance images in tissue. 相似文献
82.
Daniel Joven-Sancho Dr. Miguel Baya Prof. Dr. Larry R. Falvello Dr. Antonio Martín Dr. Jesús Orduna Dr. Babil Menjón 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(50):12796-12806
The involvement of silver in two-electron AgI/AgIII processes is currently emerging. However, the range of stability of the required and uncommon AgIII species is virtually unknown. Here, the stability of AgIII towards the whole set of halide ligands in the organosilver(III) complex frame [(CF3)3AgX]− (X=F, Cl, Br, I, At) is theoretically analyzed. The results obtained depend on a single factor: the nature of X. Even the softest and least electronegative halides (I and At) are found to form reasonably stable AgIII−X bonds. Our estimates were confirmed by experiment. The whole series of nonradiative halide complexes [PPh4][(CF3)3AgX] (X=F, Cl, Br, I) has been experimentally prepared and all its constituents have been isolated in pure form. The pseudohalides [PPh4][(CF3)3AgCN] and [PPh4][(CF3)3Ag(N3)] have also been isolated, the latter being the first silver(III) azido complex. Except for the iodo compound, all the crystal and molecular structures have been established by single-crystal X-ray diffraction methods. The decomposition paths of the [(CF3)3AgX]− entities at the unimolecular level have been examined in the gas phase by multistage mass spectrometry (MSn). The experimental detection of the two series of mixed complexes [CF3AgX]− and [FAgX]− arising from the corresponding parent species [(CF3)3AgX]− demonstrate that the Ag−X bond is particularly robust. Our experimental observations are rationalized with the aid of theoretical methods. Smooth variation with the electronegativity of X is also observed in the thermolyses of bulk samples. The thermal stability in the solid state gradually decreases from X=F (145 °C, dec.) to X=I (78 °C, dec.) The experimentally established compatibility of AgIII with the heaviest halides is of particular relevance to silver-mediated or silver-catalyzed processes. 相似文献
83.
Dr. Xinghai Ning Dr. Wonewoo Seo Dr. Seungjun Lee Dr. Kiyoko Takemiya Dr. Mohammad Rafi Dr. Xuli Feng Dr. Daiana Weiss Dr. Xiaojian Wang Larry Williams Vernon M. Camp Malveaux Eugene Prof. W. Robert Taylor Prof. Mark Goodman Prof. Niren Murthy 《Angewandte Chemie (International ed. in English)》2014,53(51):14096-14101
A positron emission tomography (PET) tracer composed of 18F‐labeled maltohexaose (MH18F) can image bacteria in vivo with a sensitivity and specificity that are orders of magnitude higher than those of fluorodeoxyglucose (18FDG). MH18F can detect early‐stage infections composed of as few as 105 E. coli colony‐forming units (CFUs), and can identify drug resistance in bacteria in vivo. MH18F has the potential to improve the diagnosis of bacterial infections given its unique combination of high specificity and sensitivity for bacteria. 相似文献
84.
Xiaonan Duan Dr. Stéphane C. Corgié Prof. Daniel J. Aneshansley Prof. Peng Wang Prof. Larry P. Walker Prof. Emmanuel P. Giannelis 《Chemphyschem》2014,15(5):974-980
We report a new family of hierarchical hybrid catalysts comprised of horseradish peroxidase (HRP)–magnetic nanoparticles for advanced oxidation processes and demonstrate their utility in the removal of phenol from water. The immobilized HRP catalyzes the oxidation of phenols in the presence of H2O2, producing free radicals. The phenoxy radicals react with each other in a non‐enzymatic process to form polymers, which can be removed by precipitation with salts or condensation. The hybrid peroxidase catalysts exhibit three times higher activity than free HRP and are able to remove three times more phenol from water compared to free HRP under similar conditions. In addition, the hybrid catalysts reduce substrate inhibition and limit inactivation from reaction products, which are common problems with free or conventionally immobilized enzymes. Reusability is improved when the HRP–magnetic nanoparticle hybrids are supported on micron‐scale magnetic particles, and can be retained with a specially designed magnetically driven reactor. The performance of the hybrid catalysts makes them attractive for several industrial and environmental applications and their development might pave the way for practical applications by eliminating most of the limitations that have prevented the use of free or conventionally immobilized enzymes. 相似文献
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89.
Dr. Rebeca Arevalo Dr. Ramón López Prof. Larry R. Falvello Dr. Lucía Riera Dr. Julio Perez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(1):379-389
The reactions of [Re(N-N)(CO)3(PMe3)]OTf (N-N=2,2′-bipyridine, bipy; 1,10-phenanthroline, phen) compounds with tBuLi and with LiHBEt3 have been explored. Addition to the N-N chelate took place with different site-selectivity depending on both chelate and nucleophile. Thus, with tBuLi, an unprecedented addition to C5 of bipy, a regiochemistry not accessible for free bipy, was obtained, whereas coordinated phen underwent tBuLi addition to C2 and C4. Remarkably, when LiHBEt3 reacted with [Re(bipy)(CO)3(PMe3)]OTf, hydride addition to the 4 and 6 positions of bipy triggered an intermolecular cyclodimerization of two dearomatized pyridyl rings. In contrast, hydride addition to the phen analog resulted in partial reduction of one pyridine ring. The resulting neutral ReI products showed a varied reactivity with HOTf and with MeOTf to yield cationic complexes. These strategies rendered access to ReI complexes containing bipy- and phen-derived chelates with several C(sp3) centers. 相似文献
90.
Peter Alfeld Larry L. Schumaker Tatyana Sorokina 《Advances in Computational Mathematics》2010,32(4):381-391
A variant of the classical C
1 Powell-Sabin-12 macro-element is defined that has the same approximation power, but has fewer degrees of freedom and only
requires vertex data. The same idea is then applied to a related C
1 trivariate macro-element. 相似文献