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181.
Benchmarking quantum control methods on a 12-qubit system 总被引:1,自引:0,他引:1
Negrevergne C Mahesh TS Ryan CA Ditty M Cyr-Racine F Power W Boulant N Havel T Cory DG Laflamme R 《Physical review letters》2006,96(17):170501
In this Letter, we present an experimental benchmark of operational control methods in quantum information processors extended up to 12 qubits. We implement universal control of this large Hilbert space using two complementary approaches and discuss their accuracy and scalability. Despite decoherence, we were able to reach a 12-coherence state (or a 12-qubit pseudopure cat state) and decode it into an 11 qubit plus one qutrit pseudopure state using liquid state nuclear magnetic resonance quantum information processors. 相似文献
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183.
A series of geometry, frequency, and energy calculations of bromoaquazinc(II) complexes were carried out at up to the MP2/6-31+G*
level. A thorough examination of all species up to and including hexacoordinate species, and with up to four bromides, was
carried out. The structures of the complexes are compared with experimental data where available. The solution chemistry of
zinc(II) in the presence of bromide is discussed. 相似文献
184.
Dr. Anna F. Oliveri Christopher A. Colla Dr. Cory K. Perkins Noushin Akhavantabib Joseph R. Callahan Corey D. Pilgrim Scott E. Smart Prof. Dr. Paul H.‐Y. Cheong Dr. Long Pan Prof. Dr. William H. Casey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(52):18682-18685
The solution chemistry of aluminum has long interested scientists due to its relevance to materials chemistry and geochemistry. The dynamic behavior of large aluminum–oxo‐hydroxo clusters, specifically [Al13O4(OH)24(H2O)12]7+ ( Al13 ), is the focus of this paper. 27Al NMR, 1H NMR, and 1H DOSY techniques were used to follow the isomerization of the ?‐Al13 in the presence of glycine and Ca2+ at 90 °C. Although the conversion of ?‐Al13 to new clusters and/or Baker–Figgis–Keggin isomers has been studied previously, new 1H NMR and 1H DOSY analyses provided information about the role of glycine, the ligated intermediates, and the mechanism of isomerization. New 1H NMR data suggest that glycine plays a critical role in the isomerization. Surprisingly, glycine does not bind to Al30 clusters, which were previously proposed as an intermediate in the isomerization. Additionally, a highly symmetric tetrahedral signal (δ=72 ppm) appeared during the isomerization process, which evidence suggests corresponds to the long‐sought α‐Al13 isomer in solution. 相似文献
185.
Tanay Kesharwani Krystal A. Giraudy Jordan L. Morgan Cory Kornman Abayomi D. Olaitan 《Tetrahedron letters》2017,58(7):638-641
Herein, we report the first synthesis of chlorinated benzo[b]selenophenes via environmentally friendly electrophilic chlorocyclization reaction using “table salt” as a source of “electrophilic chlorine” and ethanol as a solvent. In addition, the synthesis of diverse halogenated heterocycles, including 3-chloro, 3-bromo and 3-iodo thiophenes, selenophenes, and benzo[b]selenophenes was successfully accomplished under the same environmentally benign reaction conditions. This methodology has several advantages over other previously reported reactions as it employs simple starting compounds, an environmentally friendly solvent, ethanol, and non-toxic inorganic reagents under mild reaction conditions, resulting in the high product yields. 相似文献
186.
Single crystal silicon is an excellent system to explore dynamic nuclear polarization (DNP), as it exhibits a continuum of properties from metallic to insulating as a function of doping concentration and temperature. At low doping concentrations DNP has been observed to occur via the solid effect, while at very high-doping concentrations an Overhauser mechanism is responsible. Here we report the hyperpolarization of (29)Si in n-doped silicon crystals, with doping concentrations in the range of (1-3)?× 10(17) cm(-3). In this regime exchange interactions between donors become extremely important. The sign of the enhancement in our experiments and its frequency dependence suggest that the (29)Si spins are directly polarized by donor electrons via an Overhauser mechanism within exchange-coupled donor clusters. The exchange interaction between donors only needs to be larger than the silicon hyperfine interaction (typically much smaller than the donor hyperfine coupling) to enable this Overhauser mechanism. Nuclear polarization enhancement is observed for a range of donor clusters in which the exchange energy is comparable to the donor hyperfine interaction. The DNP dynamics are characterized by a single exponential time constant that depends on the microwave power, indicating that the Overhauser mechanism is a rate-limiting step. Since only about 2% of the silicon nuclei are located within 1 Bohr radius of the donor electron, nuclear spin diffusion is important in transferring the polarization to all the spins. However, the spin-diffusion time is much shorter than the Overhauser time due to the relatively weak silicon hyperfine coupling strength. In a 2.35 T magnetic field at 1.1 K, we observed a DNP enhancement of 244 ± 84 resulting in a silicon polarization of 10.4 ± 3.4% following 2 h of microwave irradiation. 相似文献
187.
Rillahan CD Brown SJ Register AC Rosen H Paulson JC 《Angewandte Chemie (International ed. in English)》2011,50(52):12534-12537
Sweet screens: A high-throughput screening platform for identification of inhibitors of sialyl- and fucosyltransferases based on fluorescence polarization (FP) has been developed. An analogue of the natural donor substrate carrying a fluorescent label (green star) is transferred to a glycoprotein acceptor, which results in robust FP. The screening of 16,000 compounds against different glycosyltransferases has identified various interesting inhibitors. 相似文献
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190.
The geometries, energies, and vibrational frequencies of various isomers of XO(4)(m-)(H2O)n, x = Cl, Br, Se, As, V; n = 0-6, m = 1-3 are calculated at various levels up to MP2/6-31+G*. These properties are studied as a function of increasing cluster size. The experimental and theoretical vibrational spectra are compared where available. 相似文献