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101.
Nobuhiro Honda 《Inventiones Mathematicae》2008,174(3):463-504
In a recent paper ([9]) we constructed a series of new Moishezon twistor spaces which are a kind of variant of the famous LeBrun twistor spaces. In this paper we explicitly give projective models of another series of Moishezon twistor spaces on n CP 2 for arbitrary n≥3, which can be regarded as a generalization of the twistor spaces of ‘double solid type’ on 3CP 2 studied by Kreußler, Kurke, Poon and the author. Similarly to the twistor spaces of ‘double solid type’ on 3CP 2, projective models of the present twistor spaces have a natural structure of double covering of a CP 2-bundle over CP 1. We explicitly give a defining polynomial of the branch divisor of the double covering, whose restriction to fibers is degree four. If n≥4 these are new twistor spaces, to the best of the author’s knowledge. We also compute the dimension of the moduli space of these twistor spaces. Differently from [9], the present investigation is based on analysis of pluri-(half-)anticanonical systems of the twistor spaces. 相似文献
102.
Kentaro Okuma Jun-ichi Sakata Yuji Tachibana Takumi Honda Hiroshi Ohta 《Tetrahedron letters》1987,28(52):6649-6652
Wittig reagents were successfully changed to symmetrical olefins when treated with elemental selenium. The reaction proceeds through a selenocarbonyl intermediate, which existence was confirmed by Diels-Alder reaction. 相似文献
103.
Mibu N Yokomizo K Kashige N Miake F Miyata T Uyeda M Sumoto K 《Chemical & pharmaceutical bulletin》2007,55(1):111-114
N-Monoacyl-2,6-diaminopyridines (2a-c) and N,N'-diacyl-2,6-diaminopyridines (3a-c) were synthesized from 2,6-diaminopyridine by acylation with the corresponding acyl halide or by dehydration with the corresponding carboxylic acid using 1,3-dicyclohexylcarbodiimide (DCC). The antiviral activities of N-monoacyl- and N,N'-diacyl-2,6-diaminopyridines (2a-c and 3a-c) were estimated using plaque reduction assay with HSV-1. All N-monoacyl derivatives (2a-c) showed significant anti-herpes simplex virus (HSV)-1 activity (EC(50) = 15.3-18.5 microg/ml). The CC(50) values of 2a-c measured using Vero cells ranged at 37.5-50.0 microg/ml. These compounds showed no significant antibacterial activities with Escherichia coli or Staphylococcus aureus even at a concentration of 1 mg/ml. The N,N'-diacyl derivatives (3a-c) showed no significant anti-HSV-1 activity. 相似文献
104.
105.
T. Honda T. Oi T. Ossaka T. Nozaki H. Kakihana 《Journal of Radioanalytical and Nuclear Chemistry》1989,130(1):81-97
Hot spring water and crater lake water samples were analyzed for their rare earth elements: (REE's) by neutron activation method, which, in the irradiation, sample preparation, incorporated a coprecipitation process in which aluminium was used as a collector. Ten REE's, La, Ce, Sm, Eu, Gd, Tb, Dy, Tm, Yb and Lu, were consequently detected and determined at the ppb level with satisfactory precision. It was shown that the aluminium coprecipitation is effective in enhancing concentrations of the REE's and reducing the amounts of interfering nuclides before neutron irradiation. 相似文献
106.
Masakazu Kobayashi Takuya Honda Atsushi Kanzawa 《Plasma Chemistry and Plasma Processing》1985,5(1):39-54
The effect of gas injection on an atmospheric thermal argon plasma flow in a water-cooled tube was investigated experimentally and numerically. The injection gas is argon, helium, or nitrogen. The static pressure with helium injection increases greatly because of its high thermal conductivity, while little increase occurs for nitrogen injection because of the dissociation. The increasing rate of the static pressure depends on the ratio of the momentum term to the viscosity term. The heat flux to the tube wall with gas injection changes less than that without injection. The numerical results showed variations similar to the experimental ones. 相似文献
107.
Nahoko Uchiyama Fumiyuki Kiuchi Gisho Honda Yoshio Takeda Ozodbek A. Ashurmetov 《Tetrahedron》2006,62(18):4355-4359
Trypanocidal constituents of Dracocephalum komarovi were investigated. Under guidance of the in vitro trypanocidal activity against epimastigotes of Trypanosoma cruzi, the causative agent of Chagas' disease, two new diterpenes, dracocequinones A (1) and B (2), and two known triterpene acids, ursonic acid and ursolic acid, were isolated as trypanocidal constituents, in addition to previously reported diterpenes, cyclocoulterone (4), komaroviquinone (5), dracocephalone A (6) and komarovispirone (7). Furthermore a new diterpene, komarovinone A (3), was isolated, together with four known terpenes. Among these compounds, komaroviquinone (5) showed the most potent activity with minimum lethal concentration of 0.4 μM. Structure elucidation of the new diterpenes 1-3 was described. 相似文献
108.
Tanaka H Zaima N Yamamoto N Suzuki M Mano Y Konno H Unno N Setou M 《Analytical and bioanalytical chemistry》2011,400(7):1873-1880
Arteriovenous fistulae (AVF) using vein grafts are frequently used for vascular access in hemodialysis. When superficial veins
are used as autogenous access grafts for hemodialysis, atherosclerotic-like tissue degeneration often causes stenosis and
obstruction. Although the differences between the pathology of degeneration in AVF and atherosclerosis (i.e., peripheral artery
occlusive disease (PAD)) are known, their underlying molecular mechanisms are not. We determined the characteristic abnormal
lipid metabolism of AVF. Oil red O staining clearly showed the accumulation of lipid molecules in AVF and PAD tissues. We
found that the staining pattern was different between AVF and PAD tissues. The media and adventitia of AVF and the intima
and media of PAD were intensely stained. Quantitative lipid analysis revealed that the amount of PL was significantly increased
in AVF and PAD. Next, we performed matrix-assisted laser desorption/ionization imaging mass spectroscopy and determined the
characteristic distribution of lysophosphatidylcholine (LPC) and phosphatidylcholine (PC) in AVF. The distribution patterns
of LPC (1-acyl 16:0) and PC (diacyl 16:0/20:4) were consistent with the Oil red O staining images, suggesting that metabolisms
related to LPC (1-acyl 16:0) and PC (diacyl 16:0/20:4) are altered in AVF. 相似文献
109.
The environmental radioactivity caused by the reactor accident at Chernobyl' was investigated from May 7 to May 31 of 1986 in Toyama. Measurement of radioactivities in airborne particles, rain water, drinking water, milk, and mugwort are carried out by gamma-ray spectrometry (pure Ge detector; ORTEC GMX-23195). Ten different nuclides (103Ru, 106Ru, 131I, 132Te-I, 134Cs, 136Cs, 137Cs, 140Ba-La) are identified from samples of airborne particles. In the air samples, a maximum radioactivity concentration of each nuclide is observed on 13th May 1986. The time of the reactor shut-down and the flux of thermal neutron at the reactor were calculated from 131I/132I and 137Cs/134Cs ratio. The exposure dose in Toyama by this accident is given as follows: internal exposure; [thyroid] adult-59 microSv, child-140 microSv, baby-130 microSv, [total body] adult-0.2 microSv, child, baby-0.4 microSv, external exposure; 7 microSv, effective dose equivalent; adult-9 microSv, child-12 Sv, baby-11 microSv. 相似文献
110.
Zhi C Bando Y Tang C Honda S Sato K Kuwahara H Golberg D 《The journal of physical chemistry. B》2006,110(4):1525-1528
An effective method was proposed to remove obstinate boron nitride phase impurities in boron nitride nanotubes (BNNTs). The method is based on strong interactions between BNNTs and a conjugated polymer wrapping them and significant weight and size difference between BNNTs and impurities. The as-grown samples and purified samples were compared through detailed characterization, using scanning electron microscopy, transmission electron microscopy, and Raman and Fourier transformed infrared spectroscopy. The results reveal that impurities are effectively removed and resultant BNNTs possess perfect crystallization. 相似文献