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排序方式: 共有252条查询结果,搜索用时 46 毫秒
41.
K. Jinno S. Shimura N. Tanaka K. Kimata J. C. Fetzer W. R. Biggs 《Chromatographia》1989,27(7-8):285-291
Summary Planarity recognition of polycyclic aromatic hydrocarbons has been investigated using bonded octadecyl stationary phases synthesized
in different ways. Retention results indicate apparent differences among the functionalities of the stationary phases, a fact
found useful for identifying the functionality of commercially available octadecylsilica (ODS) phases. Retention behevior
can be explained by the slit-like structures of polymeric oDS phases, as evidenced by suspension13C NMR measurements. 相似文献
42.
43.
Thermal reaction of 2-[N-(alk-2-enyl)benzylamino]-3-(2-substituted and 2,2-disubstituted)vinylpyrido[1,2-a]pyrimidin-4(4H)-ones gave azepine, the desired ene products, and/or pyran derivatives. The formation of the latter was responsible for the [4+2] cycloaddition reaction between the α,β-unsaturated ester carbonyl moiety as a diene part and the alkenylamino moiety as an ene one. The reaction features depended upon the kinds of substituents both on the vinyl and alkenyl counterparts; strongly electron-withdrawing substituents on the vinyl moiety or an electron-donating substituent on the alkenyl one changed the reaction feature from the ene reaction to the hetero Diels-Alder reaction. 相似文献
44.
Two cyclophanes, [2.2](2,6)biphenylenophane and [2](2,6)biphenyleno[2](2,6)naphthalenophane, were prepared. 相似文献
45.
A method has been developed for photometric detection of cyclodextrins (CD) in liquid chromatography using iodine (I2) generated electrochemically in-situ. Iodide ion in the mobile phase was electrochemically oxidized to I2 which was subsequently reacted with I–, in an electrochemical flow cell, forming I3–. The absorbance of I3– was found to be greatly enhanced when CD were present in the mobile phase. The absorbance enhancement was caused by the change in the mole fraction of I3–, because of the inclusion reaction of I3– with CD. On the basis of this phenomenon, CD were detected by means of a photodiode-array UV–visible detector positioned downstream of the electrochemical flow cell. The signals were found to be linearly dependent on CD concentration. Because the formation constants of I3– with CD decrease in the order -CD>-CD>-CD, -CD was most detectable by the method. Detection limits were 1.0 mol L–1 for -CD, 65 mol L–1 for monoG1--CD, 100 mol L–1 for -CD, and 200 mol L–1 for -CD. 相似文献
46.
Toyonobu Yoshida Kunihiko Nakagawa Toshiya Harada Kazuo Akashi 《Plasma Chemistry and Plasma Processing》1981,1(1):113-129
A numerical model has been developed for predicting the two-dimensional flow and temperature fields in a radio-frequency (rf) plasma torch. The method employed here is based on Boulos' model with the exception of the boundary conditions for the electric and magnetic field equations. Calculations have been made for the confirmation of a new sample injection method, which is capable of completely evaporating refractory materials at high feeding rates without interfering with the stability of the plasma. In the newly designed torch, the reagent is radially injected into the hottest part of the plasma through quartz capillary tubes set symmetrically between an inductor coil. Experimental investigations have also been performed for verifying the proper function of the design. These results provide evidence that our radial injection method developed here is more effective in practical processing than the conventional axial injection methods. 相似文献
47.
Masao Onda Motoo Asai Toshiya Kohno Yasuhiro Kikuchi Ichiro Yamaguchi 《Journal of Molecular Structure》1987,162(3-4):183-189
The microwave spectrum of benzoyl chloride was observed in the frequency range 12–18.6 GHz. Rotational constants have been obtained for the ground vibrational state, the first three excited torsional states of the COCl group, and one of the out-of-plane bending states. The residual inertial defect obtained from the ground and the torsional excited states indicates that the equilibrium conformation is planar. Ab initio MO calculations (STO-3G) showed the potential energy curve as a function of the COCl torsional angle to be rather flat around zero degrees. 相似文献
48.
Keiichi Moriya Toshihiro Yamane Toshiya Suzuki Tsuyoshi Masuda Hiroshi Mizusaki Shinichi Yano 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6-7):1427-1432
Cyclotriphosphazene and cyclotetraphosphazene derivatives with mesogenic 4-N-(4-alkoxyphenyl)iminomethyl)phenoxy and 4-(4'-alkoxy)biphenoxy moieties were synthesized. Schiff base moiety has higher mesomorphic stability than that in biphenyl moiety both in cyclotriphosphazene and cyclotetraphosphazene. Cyclotriphosphazenes possess higher thermal stability in the mesomorphic phase than the cyclotetraphosphazenes, suggesting the difference in the molecular structure. 相似文献
49.
Takeshi Koishi Mai Sasaki Toshiya Nakaguchi Norimichi Tsumura Yoichi Miyake 《Optical Review》2010,17(2):54-60
We propose a practical and simple measurement function of three dimensional (3D) length for endoscopy based on triangulation
using manually pointed correspondences. This system is a novel combination of conventional methods. 3D length information
is useful for many medical purposes and the burden of manual procedures can be reduced by focusing on length. We employed
a novel combination for length measurement, that is, a monocular endoscope with an electromagnetic tracking sensor. The proposed
method can measure the length without any equipment for light projection and changing the current procedure of endoscopy.
Our method is made more robust and reliable than the automatic correspondence techniques through the best use of the expertise
of endoscopists. We developed a prototype system and evaluated its accuracy. From experimental results, we showed that the
proposed method can measure the 3D length of static objects accurately as long as the measurement geometry is suitable. 相似文献
50.
Takumi Inaba Takahiro Morimoto Toshiya Okazaki 《Surface and interface analysis : SIA》2022,54(5):501-509
A simulation method for correlating the resistivity and resistance of sparse carbon nanotube (CNT) networks via atomic force microscopy images was proposed. For the demonstration, resistance values simulated by this method were compared with values obtained by directory measuring the resistance of sparse CNT networks. Results were also compared with those obtained by a thin-film approximation in which CNT networks are approximated as thin rectangles. Simulated resistance values were closer to the experimental values of the same samples than those estimated on the basis of the thin-film approximation. The use of atomic force microscopy (AFM) images enabled the implementation of inhomogeneity to numerical models, as well as one-to-one comparison between real samples and numerical models. 相似文献