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排序方式: 共有167条查询结果,搜索用时 15 毫秒
11.
T. Watanabe P. Bydžovský K. Dobashi S. Endo Y. Fujii O. Hashimoto T. Ishikawa K. Itoh H. Kanda M. Katoh T. Kinoshita O. Konno K. Maeda A. Matsumura F. Miyahara H. Miyase T. Miyoshi K. Mizunuma Y. Miura S.N. Nakamura H. Nomura Y. Okayasu T. Osaka M. Oyamada A. Sasaki T. Satoh H. Shimizu M. Sotona T. Takahashi T. Tamae H. Tamura T. Terasawa H. Tsubota K. Tsukada M. Ukai M. Wakamatsu H. Yamauchi H. Yamazaki 《Physics letters. [Part B]》2007
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Jing-Kun Fang De-Lie An Kan Wakamatsu Tetsuo Iwanaga Daisuke Matsuo Junzo Otera 《Tetrahedron letters》2010,51(6):917-6811
A series of diphenylamino-substituted phenylene-(poly)ethynylenes were successfully synthesized by a combination of Sonogashira coupling and double elimination protocol of β-substituted sulfones. When UV-light was irradiated, the amino-substituted phenylene-(poly)ethynylene emitted strong luminescence. The emission underwent a large bathochromic shift in polar solvent because of stabilization of their charge-separated excited states. Analyses of fluorescence life times of aminoacetylenes revealed that radiationless process was suppressed in the polar solvent CH2Cl2, resulting in high quantum yields. 相似文献
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The Critical Effect of Niobium Doping on the Formation of Mesostructured TiO2: Single‐Crystalline Ordered Mesoporous Nb‐TiO2 and Plate‐like Nb‐TiO2 with Ordered Mesoscale Dimples 下载免费PDF全文
Takamichi Matsuno Dr. Yoshiyuki Kuroda Prof.Dr. Atsushi Shimojima Prof.Dr. Hiroaki Wada Prof.Dr. Kazuyuki Kuroda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):13073-13079
Highly ordered mesoporous niobium‐doped TiO2 with a single‐crystalline framework was prepared by using silica colloidal crystals with ca. 30 nm in diameter as templates. The preparation of colloidal crystals composed of uniform silica nanoparticles is a key to obtain highly ordered mesoporous Nb‐doped TiO2. The XPS measurements of Nb‐doped TiO2 showed the presence of Nb5+ and correspondingly Ti3+. With the increase in the amount of doped Nb, the crystalline phase of the product was converted from rutile into anatase, and the lattice spacings of both rutile and anatase phases increased. Surprisingly, the increase in the amount of Nb led to the formation of plate‐like TiO2 with dimpled surfaces on one side, which was directly replicated from the surfaces of the colloidal silica crystals. 相似文献
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Takahashi H Wakamatsu S Tabata H Oshitari T Harada A Inoue K Natsugari H 《Organic letters》2011,13(4):760-763
To elucidate the active conformation of indometacin that differentiates between cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), the stereochemistry around the N-benzoylated indole moiety of indometacin was studied. Resolution of stable atropisomers as representative conformations was found to be possible by restricting rotation about the N-C7' and/or C7'-C1' bond. Only the aR-isomer showed specific inhibition of COX-1, and COX-2 was not inhibited by either atropisomer. 相似文献
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Photoswitching of the transformation between seconds and hours time-scales is demonstrated using the threading of per-hydroxylated pillar[5]arene onto the azobenzene-end of a viologen derivative. When the azobenzene moiety was in the trans form, the threading of per-hydroxylated pillar[5]arene quickly took place at 25 °C and could not be monitored directly. The exchange rate (k) and half-life time (t(1/2)) examined by 2D EXSY NMR spectroscopy were found to be 0.209 ± 0.013 s(-1) and 3.33 ± 0.21 s, respectively. In contrast, the cis form of the azobenzene moiety required very long time (k = 2.14 ± 0.27 × 10(-5) s(-1), t(1/2) = 9.13 ± 1.2 h) to thread per-hydroxylated pillar[5]arene at 25 °C. Photoisomerization from the trans to the cis form generated the following increment of free energy of activation at 25 °C: ΔG(in)(?) (cis form) - ΔG(in)(?) (trans form) = 22.8 ± 0.24 kJ mol(-1), which led to the time-scale transformation. The tuning of the threading was also accomplished by heating/cooling: the rate constants increased on heating and decreased on cooling. 相似文献
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Masashi Wakamatsu 《Nuclear Physics A》1979,329(3):381-406
The effects of the Δ(3-3) resonance components on the binding energy of 4He are studied within the framework of reaction matrix theory. In this approach, the Δ -configurations in 4He are introduced in terms of the NΔ transition potential by solving the reaction matrix equation and thus it goes beyond perturbation theory with the NΔ transition potential. Not only the two-body cluster energy but also the three-body cluster energy containing Δ-configurations are calculated. 相似文献
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With a particular view to gaining a real understanding of the quark degrees of freedom in nuclei, we propose a simple model for nucleon-nucleon interactions within the framework of the quark cluster theory, which simultaneously incorporates the quark- and gluon-exchange mechanism at short distance and the meson-exchange mechanism at long and intermediate distances. It is shown to reproduce the experimental NN phase shifts and the deuteron properties fairly well. The model is then applied to a study of the electromagnetic properties of the two-baryon system, by putting particular emphasis upon the relation with conventional nuclear theory. The present study shows how the quark degrees of freedom, which should manifest themselves at high momentum transfer, are concealed in the conventional treatment of the two-nucleon problem as long as we observe low momentum transfer phenomena only. 相似文献