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31.
Fluoroalkanoyl peroxides were reacted with adamantane in the presence of radical polymerizable monomers such as acrylic acid, acryloylmorpholine, and N,N‐dimethylacrylamide to afford fluoroalkyl end‐capped oligomers having adamantane units in the main chains via a radical process under very mild conditions. Thermal stability of these new fluorinated adamantane co‐oligomers thus obtained became higher than that of the corresponding fluorinated homo‐oligomers having no adamantane units. Interestingly, these fluorinated adamantane co‐oligomers exhibited good solubility in traditional organic solvents such as methanol, ethanol, tetrahydrofuran, chloroform, benzene, dimethylsulfoxide and N,N‐dimethylformamide including water, although the parent adamantane exhibited no solubility in water, methanol and dimethylsulfoxide. Furthermore, these adamantane co‐oligomers were able to reduce the surface tension effectively to form the nanometer size‐controlled self‐assembled fluorinated molecular aggregates. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
32.
Katsuya Matsui 《Tetrahedron letters》2005,46(11):1943-1946
A new double-activation catalysis is presented for the Morita-Baylis-Hillman (MBH) reaction of an α,β-unsaturated ketone and an aldehyde by the combined use of a heterobimetallic asymmetric complex and tributylphosphine ((n-Bu)3P) to afford the α-methylene-β-hydroxy ketone with up to 99% ee. 相似文献
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34.
Michito Shiotsuka Naoki Nishiko Yasushi Tsuji Noboru Kitamura Satoru Onaka Katsuya Sako 《Transition Metal Chemistry》2010,35(2):129-135
A novel asymmetric dinuclear gold(I) complex with 3,6-diethynylphenanthroline, 3,6-bis{(PPh3)–Au–C≡C}2-phen, has been synthesized from Au(PPh3)Cl (PPh3 = triphenylphosphine) and 3,6-diethynyl-1,10-phenanthroline. The asymmetrical dinuclear gold(I) complex, 3,6-bis{(PPh3)–Au–C≡C}2-phen, demonstrated a weak phosphorescence assignable to the metal-perturbed 3
π–π* transition in the long wavelength region compared to an intense emission of the symmetrical dinuclear complex with 3,8-diethynylphenanthroline,
3,8-bis{(PPh3)–Au–C≡C}2-phen. A similar tendency of phosphorescent bands for the mononuclear gold(I) complexes with 5-ethynylphenanthroline, 5-{(PPh3)–Au–C≡C}-phen, and 3-ethynylphenanthroline, 3-{(PPh3)–Au–C≡C}-phen was observed. The absorption bands assignable to the π–π*(C≡Cphen) transition and phosphorescent emission assignable to the metal-perturbed 3
π–π* transition for these four gold(I) complexes were reasonably consistent with the results calculated by DFT and TD-DFT. 相似文献
35.
Low-velocity pneumatic conveying in horizontal pipe for coarse particles and fine powders 总被引:3,自引:0,他引:3
First,the characteristics of low-velocity conveying of particles having different hardness are experimentally investigated in a horizontal pipeline in terms of flow pattern and pressure drop to show that the slug flow can be classified into two types depending on the settling of particles along the pipeline,and the period is small for slug flow without the settled layer,which is called solitary slug flow.The pressure drop for soft particles is shown to be larger than that for hard particles.Then,experimental results are presented on horizontal fluidized-bed conveying of fine powders to show that air release from the top surface of the conveying channel is an important factor for high mass flow rate of particles. 相似文献
36.
Ken Naitoh Yasuo Takagi Kunio Kuwahara Egon Krause Katsuya Ishii 《Fluid Dynamics Research》1990,6(5-6):277-294
The transition to turbulent flow in the compression stage of a reciprocating engine is studied by obtaining the finite-difference numerical solutions to the governing Navier-Stokes equations without using explicit turbulence models. A computational method is developed under the assumption that the flow is in a low-subsonic regime with strong compression. The numerical method is a simple extension of the well known MAC method. Computations were performed for three different chamber geometries at the engine speed of 1400 rpm. The results of the computations clearly demonstrate the transient process in which large tumbling vortices break down into smaller ones near the end of the compression process. The transition process is also caught experimentally by using Mach-Zehnder interferometry. 相似文献
37.
Naoki Fujita Takayuki Makino Yasuhiro Sakoishi Katsuya Asano Masanobu Kusunoki 《Crystal Research and Technology》2016,51(3):215-219
The relation between O2 pressure and composition in the pulsed‐laser deposition of fluoroapatite was investigated using both on‐axis and off‐axis methods to determine the optimal conditions for obtaining a pure fluoroapatite film without OH groups. Through this, it was found that an O2 pressure of 10 Pa, combined with an off‐axis method, results in P/Ca and F/Ca values (0.6 and 0.2, respectively) that match closely with a stoichiometric composition of Ca10(PO4)6F2. Fourier transform infrared spectroscopy analysis confirmed that this optimized film was almost pure fluoroapatite, with no evidence of any OH groups originating from hydroxyapatite. X‐ray diffraction also revealed that this fluoroapatite film crystallizes with a c‐axis orientation perpendicular to its surface. 相似文献
38.
39.
Katsunori Watabe Hisashi Kanda Katsuya Sato Toshiyuki Hobo 《Journal of chromatography. A》1992,590(2):289-296
In continuous counter-current gas-liquid chromatography, which has a high resolving power and is suitable for the large-scale purification of organic solvents, it is very important that the samples that can be applied extend from easily separable to more difficult to separate, such as azeotropes, low-volatility compounds and stereoisomers. A system was designed and constructed for high-temperature operation up to 200°C, and was applied to the separation of dimethyl and diethyl phthalate, trans- and cis-decahydronaphthalene and cis-decahydronaphthalene and tetrahydronaphthalene. It was confirmed that over 99% of purity could be achieved for dimethyl and diethyl phthalate, trans-decahydronaphthalene, and tetrahydronaphthalene. 相似文献
40.
Reconstitution of Biosynthetic Machinery for the Synthesis of the Highly Elaborated Indole Diterpene Penitrem 下载免费PDF全文
Dr. Chengwei Liu Koichi Tagami Dr. Atsushi Minami Tomoyuki Matsumoto Jens Christian Frisvad Hideyuki Suzuki Jun Ishikawa Katsuya Gomi Prof. Dr. Hideaki Oikawa 《Angewandte Chemie (International ed. in English)》2015,54(19):5748-5752
Penitrem A is one of the most elaborated members of the fungal indole diterpenes. Two separate penitrem gene clusters were identified using genomic and RNA sequencing data, and 13 out of 17 transformations in the penitrem biosynthesis were elucidated by heterologous reconstitution of the relevant genes. These reactions involve 1) a prenylation‐initiated cationic cyclization to install the bicyclo[3.2.0]heptane skeleton (PtmE), 2) a two‐step P450‐catalyzed oxidative processes forming the unique tricyclic penitrem skeleton (PtmK and PtmU), and 3) five sequential oxidative transformations (PtmKULNJ). Importantly, without conventional gene disruption, reconstitution of the biosynthetic machinery provided sufficient data to determine the pathway. It was thus demonstrated that the Aspergillus oryzae reconstitution system is a powerful method for studying the biosynthesis of complex natural products. 相似文献