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111.
Kentaro Noda Nguyen Binh-Khiem Yusuke Takei Tomoyuki Takahata Kiyoshi Matsumoto Isao Shimoyama 《Applied physics. B, Lasers and optics》2014,115(1):69-76
This paper reports on a detailed deformation model of varifocal liquid lenses fabricated by Parylene-on-liquid-deposition (POLD), which can be applied to measure and adjust the focal length of such lenses without using extra sensors or sensing mechanisms. The lens was fabricated by encapsulating a liquid between a transparent electrode and a polymer film that was covered with a metal electrode. When voltage is applied to the two electrodes, the lens deforms due to the electrostatic force, and its focal length and the capacitance between the two electrodes change simultaneously. This characteristic enables the focal length of the lens to be adjusted and detected by measuring the capacitance change. The focal length of the fabricated varifocal liquid lens changed from 153.6 to 82.6 mm by applying 150-V. The focal length change of the liquid lens was calculated from the change in its capacitance. Finally, to confirm the efficiency of this varifocal liquid lens, we fabricated a confocal distance sensor using the lens for laser scanning and demonstrated that this system can be used to measure distances of 94–140 mm with an average error of 0.83 mm and a standard deviation of 0.77 mm. 相似文献
112.
X Wang A Pakdel C Zhi K Watanabe T Sekiguchi D Golberg Y Bando 《J Phys Condens Matter》2012,24(31):314205
An improved 'chemical blowing' route presuming atmospheric-pressure pre-treatment and moderate heating rate of designated precursors was developed to synthesize ultra-thin boron nitride (BN) nanosheets with high yield and large lateral dimensions. The yield reached as high as 40 wt% with respect to raw materials (ammonia borane). The strong oxygen-related ultraviolet luminescence together with a blue emission of these BN nanosheets was then documented and analyzed. This implies potential applications in solid-state lighting, ultraviolet lasing and full-color luminescence. Mechanical strength of different polymeric composites with a small fraction of BN nanosheet fillers was dramatically increased by tens of per cent, while high transparency of composite materials was still maintained in the visible optical range. The increased yield and reduced cost of BN nanosheets should promote their wide practical applications in various composites. 相似文献
113.
Enthalpies of fusion have been measured by differential scanning calorimetry for a Na2O-SiO2 system at 50, 66.6, and 74.4 mol% SiO2. Enthalpies of mixing of liquids obtained from different calorimetry techniques are critically evaluated. The data on calorimetric enthalpy, activity of Na2O, cristobalite liquidus, and immiscibility gap are used to determine the enthalpy and entropy of mixing of sodium-silicate liquids are determined as a function of composition by the least squares method. The derived mixing properties are based only on the experimental data and are independent of any assumption about the structure and chemical species in liquids. The enthalpy of mixing has a minimum value of −120 kJ/mol at 35-40 mol% SiO2 and is convex upward around 80-90 mol% SiO2. The entropy of mixing have a maximum value of + 6 J/K-mol at 75 mol% SiO2, and it decreases with the SiO2 content to −5 J/K-mol at 40 mol% SiO2. This decrease in entropy can be accounted for by ideal mixing of Q4, Q3, and Q0 + 1 + 2 (= Q0 + Q1 + Q2) species in the liquids and is responsible for the negative temperature dependence of the partial molar Gibbs energy of mixing of Na2O, observed in activity measurements. Comparison of the present results with previous values suggests that a quasi-chemical model and the Adam-Gibbs model overestimate the configurational entropy of mixing of liquids. 相似文献
114.
Mamoru Kobayashi Kentaro Uchino Takashi Ishizone 《Journal of polymer science. Part A, Polymer chemistry》2005,43(18):4126-4135
Well‐defined end‐functionalized polystyrene, poly(α‐methylstyrene), and polyisoprene with polymerizable aziridine groups were synthesized by the termination reactions of the anionic living polymers of styrene, α‐methylstyrene, and isoprene with 1‐[2‐(4‐chlorobutoxy)ethyl]aziridine in tetrahydrofuran at ?78 °C. The resulting polymers possessed the predicted molecular weights and narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight < 1.1) as well as aziridine terminal moieties. The cationic ring‐opening polymerization of the ω‐monofunctionalized polystyrene having an aziridinyl group with Et3OBF4 gave the polymacromonomer, whereas the α,ω‐difunctional polystyrene underwent crosslinking reactions to afford an insoluble gel. Crosslinking products were similarly obtained by the reaction of the α,ω‐diaziridinyl polystyrene with poly(acrylic acid)‐co‐poly(butyl acrylate). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4126–4135, 2005 相似文献
115.
Miyuki Harada Kentaro Aoyama Mitsukazu Ochi 《Journal of Polymer Science.Polymer Physics》2005,43(11):1296-1302
The fracture toughness of liquid‐crystalline epoxy systems, which had a nematic polydomain structure (domain size about 40 μm), with an increasing loading rate was evaluated. In this system, the fracture toughness dramatically decreased from 1.96 to 0.22 MN/m3/2 with an increasing loading rate (0.1–5 mm/min). The network orientation near the fracture surface of different loading rate systems was investigated with polarized optical microscopy and polarized infrared spectroscopy. As a result, a large oriented region of mesogenic groups was observed near the fracture surface in the relatively low loading rate (0.1 and 0.5 mm/min) systems, but such a phenomenon was not observed in the high loading rate (2 and 5 mm/min) systems. These results showed that the high fracture toughness of the system at the low loading rate was due to the magnitude and region of the reorientation of the mesogenic groups in the fracture process and that high toughness could not be achieved at a high loading rate because the loading rate was too fast to allow orientation of the networks containing the mesogenic groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1296–1302, 2005 相似文献
116.
The previously reported distillation method for the separation of fluoride as trimethyl- fluorosilane is much improved. When hexamethyldisilazane serves as the silylating agent, interference of silica can be avoided and distillation is rapid at room temperature. Aluminum is effectively masked by pyrophosphoric acid. Almost all ions tested can be tolerated in 1000-fold molar amounts to fluoride. Over 98% recovery is obtained for 49 μg of fluoride in the presence of 80 mg of aluminum plus 200 mg of silica. Concentration of fluoride from very dilute (μg l-1) solutions is easily achieved. Satisfactory results were obtained for standard rocks. 相似文献
117.
We analyze the effects of inelastic scattering on the tunneling time theoretically, using generalized Nelson’s quantum mechanics.
This generalization enables us to describe quantum system with channel couplings and optical potential in a real time stochastic
approach, which seems to give us a new insight into quantum mechanics beyond Copenhagen interpretation 相似文献
118.
Kentaro Hirata 《Proceedings of the American Mathematical Society》2005,133(8):2309-2317
We prove a Littlewood-type theorem which shows the sharpness of the Korányi approach region for the boundary behavior of Poisson-Szegö integrals on the unit ball of . Our result is stronger than Hakim and Sibony (1983).
119.
Summary We give the fibre structure to the two complementary distributions, one being holomonic and the other being in general non-holomonic,
by assigning the structure preserving transformations of the coordinates and of the frames. By the conversion from such fibred
spaces we derive the spaces of non-linear connections as their image, in which we point out that the usual conditions imposed
on Ckji and the covariant differentiation of gji in the metric spaces of non-linear connections can be interpreted respectively as the parallel and isometric conditions imposed
on the fibre of the corresponding fibred Riemannian spaces.
To Enrico Bompiani on his scientific Jubilee. 相似文献
120.
Summary We start from a tensor field Q of type (1, 1) defined in a2n-dimensional manifold M which satisfies Q
2=0 and has rank n. The tensor field Q defines an almost tangent structure in M. We then introduce another tensor field P of
the same type and having properties similar to those of Q. We then define and study the tensors H=PQ, V=QP, J=P−Q, K=P+Q,
L=PQ−QP, (J, K, L) defining an almost quaternion structure of the second kind on M. We study the differential geometry on
almost tangent manifolds in terms of these tensors.
To ProfessorBeniamino Segre on his seventieth birthday
Entrata in Redazione il 7 giugno 1973. 相似文献