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451.
Sustainable Heterogeneous Platinum Catalyst for Direct Methylation of Secondary Amines by Carbon Dioxide and Hydrogen
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Dr. Kenichi Kon Dr. S. M. A. Hakim Siddiki Wataru Onodera Dr. Ken‐ichi Shimizu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(21):6264-6267
Pt and MoOx co‐loaded TiO2 is found to be highly effective for direct methylation of aliphatic and aromatic secondary amines by CO2 and H2 under solvent‐free conditions. This is the first additive‐free and reusable heterogeneous catalytic system with acceptable turnover number. 相似文献
452.
Fujita W Awaga K Kondo R Kagoshima S 《Journal of the American Chemical Society》2006,128(18):6016-6017
We have studied the crystal structure and magnetic properties of the organic radical cation salt, BBDTA.InCl4. This material formed a one-dimensional coordination polymer. Magnetic measurements indicated the spin-Peierls transition-like behavior at 108 K, which was higher than those typically observed for the other organic spin-Peierls materials. The structural aspects of the lattice distortion from X-ray diffraction measurements at 50 K have been discussed. 相似文献
453.
A novel polyicosahedral nanowire is spontaneously formed in a series of annealing molecular dynamics simulations of liquid Si inside a nanopore of 1.36 nm in diameter. The polyicosahedral Si nanowire is stable even in a vacuum up to about 77% of the melting temperature of bulk Si. Our structural energy calculations reveal that the polyicosahedral nanowire is energetically advantageous over the pentagonal one for a wire whose diameter is less than 6.02 nm, though the latter has been recently proposed as the lowest energy wire. These results suggest the possibility of the formation of a new stable polyicosahedral Si nanowire. 相似文献
454.
Alkylimidazolium type ionic liquids have been prepared with acidic anions derived from multivalent anions with the expectation of excellent thermal properties and ionic conductivity, including proton conduction. 相似文献
455.
456.
Tetsu Ito Wataru Shichi Yoshie Nishioka Masao Ichida Hideki Gotoh Hidehiko Kamada Hiroaki Ando 《Journal of luminescence》2008,128(5-6):865-867
The dependence of electron spin g-factor on magnetic field has been investigated in GaAs/AlGaAs quantum wells. We have estimated the electron g-factor from spin precession frequency in time-resolved photoluminescence measurements under a magnetic field in different configurations; the magnetic field perpendicular (g⊥) and parallel (g∥) to the quantum confinement direction. When the angle between the magnetic field and the confinement direction is 45°, we have found that g-factor varies depending on the direction of magnetic field and the circular polarization type of excitation light (σ+ or σ?). These dependences of g-factor exhibit main features of Overhauser effect that nuclear spins react back on electron spin precession. The value of g⊥ and g∥ corrected for the nuclear effects agree well with the results of four-band k·p perturbation calculations. 相似文献
457.
Toshie Fujishima Takuro Komatsu Yuri Takao Wataru Yonamine Tsutomu Suenaga Hiroaki Isono Masayuki Morikawa Keisuke Takaguchi 《Tetrahedron》2019,75(8):1098-1106
Five novel vitamin D analogues (2a, 2b, 3a, 3b and 4) bearing an aromatic side chain have been designed and synthesized in a convergent manner. The requisite CD-ring synthons (10a–c) were prepared from C22 aldehyde (5) using four- or five-step procedures. Using turbo-Grignard reagents allowed aromatic side chains with a polar functional moiety to be installed in a single step with excellent yields. A preliminary biological evaluation using bovine thymus vitamin D receptor (VDR) suggested that incorporating a carboxylic acid instead of the C25-hydroxy group had a positive effect on the VDR affinity compared with the corresponding esters. 相似文献
458.
Kazushi Fujimoto Rajadeep Singh Payal Tomonori Hattori Wataru Shinoda Masayuki Nakagaki Shigeyoshi Sakaki Susumu Okazaki 《Journal of computational chemistry》2019,40(29):2571-2576
A dissociative force field for all-atomistic molecular dynamics calculations has been developed to investigate impact fracture of polymers accompanying dissociation of chemical bonds of polymer main chain. Energy of dimer molecules was evaluated as a function of both bond-length b and bond-angle θ by CASPT2 calculations, whose quality is enough to describe dissociation of chemical bonds. Because we found that the bond dissociation energy D decreases with increasing bond-angle, we employed the Morse-type function VBond(b, θ) = {D − VAngle(θ)}[1 − exp{−α(b − b0) − β(b − b0)2}] where a quartic function VAngle(θ) = k1(θ − θ0) + k2(θ − θ0)2 + k3(θ − θ0)3 + k4(θ − θ0)4 . This function reproduced well the CASPT2 potential energy surface in a wide range of b and θ. The parameters have been obtained for four popular glassy polymers, polyethylene, poly(methyl methacrylate), poly(styrene), and polycarbonate. © 2019 Wiley Periodicals, Inc. 相似文献
459.
Jaewoon Jung Wataru Nishima Marcus Daniels Gavin Bascom Chigusa Kobayashi Adetokunbo Adedoyin Michael Wall Anna Lappala Dominic Phillips William Fischer Chang-Shung Tung Tamar Schlick Yuji Sugita Karissa Y. Sanbonmatsu 《Journal of computational chemistry》2019,40(21):1919-1930
The growing interest in the complexity of biological interactions is continuously driving the need to increase system size in biophysical simulations, requiring not only powerful and advanced hardware but adaptable software that can accommodate a large number of atoms interacting through complex forcefields. To address this, we developed and implemented strategies in the GENESIS molecular dynamics package designed for large numbers of processors. Long-range electrostatic interactions were parallelized by minimizing the number of processes involved in communication. A novel algorithm was implemented for nonbonded interactions to increase single instruction multiple data (SIMD) performance, reducing memory usage for ultra large systems. Memory usage for neighbor searches in real-space nonbonded interactions was reduced by approximately 80%, leading to significant speedup. Using experimental data describing physical 3D chromatin interactions, we constructed the first atomistic model of an entire gene locus (GATA4). Taken together, these developments enabled the first billion-atom simulation of an intact biomolecular complex, achieving scaling to 65,000 processes (130,000 processor cores) with 1 ns/day performance. Published 2019. This article is a U.S. Government work and is in the public domain in the USA. 相似文献
460.
Wataru Takahashi 《Journal of Mathematical Analysis and Applications》1985,109(1):130-139
Various first-order sufficient optimality criteria for continuous-time nonlinear programming problems with nonlinear equality and inequality constraints are established under generalized convexity assumptions, and applications of these criteria to optimal control and continuous-time fractional programming problems are briefly discussed. 相似文献