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901.
Akikazu Matsumoto Sachiyo Umehara Hiroyuki Watanabe Takayuki Otsu 《Journal of Polymer Science.Polymer Physics》1993,31(5):527-535
Poly(N-n-butylitaconimide) was prepared by radical polymerization in benzene and in bulk at 60°C and was subsequently fractionated at 30°C with benzene and methanol as solvent and nonsolvent, respectively. Relationships between molecular weight and intrinsic viscosity (Mark-Houwink-Sakurada equations) in tetrahydrofuran, benzene, and toluene at 30°C are established. From the Burchard-Stockmayer-Fixman plot, the characteristic ratio of this polymer is determined, and local chain conformation is discussed in relation to the termination process in radical polymerization. © 1993 John Wiley & Sons, Inc. 相似文献
902.
903.
Y.M. LeeO. Song C.S. YoonC.K. Kim Y. AndoH. Kubota T. Miyazaki 《Microelectronics Journal》2003,34(9):805-808
Magnetic tunnel junctions (MTJ), with the tunnel barrier plasma oxidized in two steps, were fabricated in order to obtain structurally uniform AlOx insulator. The doubly oxidized junctions exhibited the magnetoresistance (MR) ratio of 27-31% without showing any noticeable drop in the MR ratio even after oxidation time was extended well beyond the optimal oxidation time for the normal junctions. Transmission electron microscopy of the junctions confirmed that the AlOx thickness was thinner for the doubly oxidized junctions compared to the singly oxidized MTJ. X-ray photoelectron spectroscopy of the doubly oxidized junction also strongly suggested that the initial oxide layer prevents the over-oxidation of the bottom electrode. The AlOx tunnel barrier oxidized in two steps improved the junction performance and widened the processing window. 相似文献
904.
Teik-Cheng Lim 《Journal of mathematical chemistry》2007,42(1):93-101
This paper tests the validity of a Lennard–Jones-type and Morse-type potential functions, consisting a combination of pi and
golden ratio constants, for describing intermolecular and interatomic interaction energy. The adjustable parameter, n, can be obtained based on experimental data near the minimum well-depth or by parametric conversion from other established
potential functions. The remarkably good correlation of the proposed potential functions with experimental data and other
potential functions reveal an intriguing property of the relationship between pi and golden ratio within the context of chemistry. 相似文献
905.
Hélène Pellissier Author Vitae 《Tetrahedron》2007,63(16):3235-3285
906.
Haijun Tao Jun Zhang Xiaolin Wang Jiali Gao 《Journal of Polymer Science.Polymer Physics》2007,45(2):153-161
The effects of the polymer concentration and quenching temperature on the phase separation, the membrane morphology and polymer crystallization behavior in a poly(4‐methyl‐1‐pentene) (TPX)‐dioctylsebacate (DOS)‐dimethylphthalate (DMP) system via thermally induced phase separation were studied with a pseudobinary phase diagram, with the weight ratio of DOS:DMP = 1:1. SEM was used to observe the membrane morphology and structure, whereas the TPX crystallization behavior was studied with DSC and WAXD. Liquid‐liquid phase separation occurred, although quenching under the crystallization temperature. As the quenching temperature decreased, the pore size decreased, with better connected pore structure formed. The membranes quenched at 333 and 363 K showed good cellular structures, with an average pore size of about 2.3μm, whereas the pores of the membranes quenched at 393 and 423 K were not well formed, with some lamellar crystals on the inner side. The diluent assisted the mobility of the polymer chain, which improved the polymer crystallization. Dual‐melting‐peak behavior occurred for all the samples studied here. As the quenching temperature increased, the first peak of the melting trace moved to a higher temperature, whereas the second one stayed almost the same. The flexibility of the TPX main chain was restricted by the side groups, which allowed liquid‐liquid phase separation to occur first when quenched below the equilibrium crystallization temperature. This allowed primary and secondary crystallization, which was responsible for the dual‐melting‐peak behavior. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 153–161, 2007 相似文献
907.
Jens S. Frederiksen Kim S. Larsen John Noga Patchrawat Uthaisombut 《Journal of Algorithms in Cognition, Informatics and Logic》2003,48(2):407
When messages, which are to be sent point-to-point in a network, become available at irregular intervals, a decision must be made each time a new message becomes available as to whether it should be sent immediately or if it is better to wait for more messages and send them all together. Because of physical properties of the networks, a certain minimum amount of time must elapse in between the transmission of two packets. Thus, whereas waiting delays the transmission of the current data, sending immediately may delay the transmission of the next data to become available even more. We propose a new quality measure and derive optimal deterministic and randomized algorithms for this on-line problem. 相似文献
908.
噪声系数自动测量仪的研制 总被引:2,自引:0,他引:2
分析了噪声系数Y因子测量法的工作原理。介绍了噪声系数自动测量仪的组成和工作流程,给出了实验结果,并指出了其应用前景。 相似文献
909.
910.
M. L. Avramov Ivić S. D. Petrović F. Vonmoos D. Z. Mijin P. M. Zivković K. M. Drljević 《Russian Journal of Electrochemistry》2008,44(8):931-936
The aim of the present study was to examine the behavior of commercial clarithromycin, Clathrocyn®, comparing to the results previously obtained using pure clarithromycin under the same experimental conditions. The study was performed by cyclic linear sweep voltammetry and the bulk of electrolyte was analyzed by FTIR spectroscopy and HPLC. At gold electrode, in the range of ?1.2 V to 1.0 V vs. SCE in 0.05 M NaHCO3, the electrochemical determination of pure clarithromycin was previously defined by four anodic and one cathodic reproductive peaks, and commercial clarithromycin is defined by reproductive one anodic peak which appears from 0.60 to 0.80 V vs. SCE. Previously, FTIR analysis of the bulk electrolyte showed the apparent changes in pure clarithromycin molecule structure: in the ester bond of the lactone and in ethers and acetal bonds. FTIR analysis of the bulk electrolyte also showed changes in the molecule structure in commercial-tablets form of clarithromycin: indicating disappearance of lactone structure and changes of carbonyl group at position 9. 相似文献