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91.
Shunji H Yoshikatsu T Akihiro F Hiroyasu I Kiyoshi T Yasuyuki S Masa-aki U Akihiko K Kazuo T Hideyuki O Katsunori A 《Journal of chromatography. A》2008,1178(1-2):187-198
Polychlorinated dibenzo-p-dioxins and dibenzofurans in crude extracts of fly ash and flue gas from municipal waste incinerators were quantified using a comprehensive multidimensional gas chromatograph (GC x GC) coupled to a high-resolution time-of-flight mass spectrometer (HR-TOFMS). For identification and quantification, we developed our own program to prepare 3D chromatograms of selected mass numbers from the data of the GC x GC/HR-TOFMS. Isolation of all congeners with a TCDD toxic equivalency factor from the other isomers by only one injection was confirmed. The instrumental detection limit of TCDD on the GC x GC/HR-TOFMS was 0.9 pg by the relative calibration method. Quantification of these substances in the crude extracts was achieved by direct injection to the GC x GC/HR-TOFMS. The results agree with the values obtained using a generic gas chromatography/high-resolution mass spectrometry (GC/HRMS) system. It was confirmed that measurement by high-resolution TOFMS and GC x GC effectively reduces interference from other chemicals. 相似文献
92.
Irwin Stone Emil Fischer Lawson V. Peakes jun Joseph B. Niederl Bradley Whitman M. Boëtius Fr. Vetter M. Chaix Ivan Marek F. Pregl M. Nicloux Firmin Govaert Sh. Ogawa Wm. J. Saschek A. Friedrich E. Küs R. Schnürch S. P. L. Sorensen V. Pedersen H. Willard J. J. Thompson U. O. Oakdale Adalbert Elek Douglas W. Hill Fred E. Beamish S. W. Parr W. Münster Joseph L. Goldberg J. O. Ralls A. Soltys Shunji Tsurumi Yasaburo Sasaki Phyllis May Marrian Guy Frederic Marrian Arthur S. Williams R. H. Müller H. M. Partridge Herbert Schiedewitz J. F. Hyde H. W. Scherp Roger Adams R. L. Shriner 《Analytical and bioanalytical chemistry》1935,102(11-12):456-464
93.
Ito S Inabe H Morita N Ohta K Kitamura T Imafuku K 《Journal of the American Chemical Society》2003,125(6):1669-1680
A series of poly(6-azulenylethynyl)benzenes substituted with n-hexyloxycarbonyl chains at 1,3-positions in azulene rings, i.e., hexakis-, 1,2,4,5-tetrakis-, 1,3,5-tris-, and 1,4-bis(6-azulenylethynyl)benzene derivatives 1, 2, 3, and 4b, have been prepared by a simple one-pot reaction involving repeated Pd-catalyzed alkynylation of halogenated arenes with substituted 6-ethynylazulene and/or ethynylated arenes with substituted 6-bromoazulene under Sonogashira-Hagihara conditions. The redox behavior of these novel poly(6-azulenylethynyl)benzene derivatives was examined by cyclic voltammetry (CV), which revealed the presumed multielectron redox properties. Compound 4b exhibited a one-step, two-electron reduction wave upon CV, which revealed the formation of the dianion stabilized by two 6-azulenylethynyl substituents under electrochemical reduction conditions. Four 6-azulenylethynyl substituents on a benzene ring in a 1,2,4,5 relationship increased the electron-accepting properties because of the formation of a stabilized closed-shell dianionic structure, whereas 3 was reduced at more negative reduction potentials. In contrast to the multistep redox behavior of 2, compound 1 was reduced in one step at -1.28 V upon CV. Compound 1 showed a wide temperature range of columnar mesophases (Col(ho) and Col(ro)) from 77.3 degrees C to the decomposition temperature at ca. 270 degrees C. Compounds 2, 3, and 4b exhibited columnar mesomorphism (Col(ro)) with crystalline polymorphs for 2, unusual triple-melting behavior for 3, and both double-melting behavior and columnar mesomorphism (Col(ho)) for 4b. Therefore, the investigated systems exemplify a new principle for multielectron redox behavior with liquid crystalline properties. 相似文献
94.
95.
Koshi Okazaki Shunji Nagase Hajime Baba Kazuo Kodaira 《Journal of fluorine chemistry》1974,4(4):387-397
The electrochemical fluorination of chlorine-containing ethers has been studied. In general, it was found that a chlorine bonded to an a-carbon atom in the ethers was readily removed during electrochemical reaction in anhydrous hydrogen fluoride, whilst a chlorine bonded to the β-carbon atom was retained to yield β-chlorinated polyfluoroethers.Through the use of this method, several new chloropolyfluoroethers, e.g. 2-chloro-1,1,2,2-tetrafluoroethyl difluoromethyl ether, 2,2-dichloro-1,1,2-trifluoroethyl trifluoromethyl ether 2,2-dichloro-1,1,2-trifluoroethyl difluoromethyl ether, 2,2-dichloro-1,1,2-trifluoroethyl chlorodifluoromethyl ether, 2-chloro-1,1,2,2-tetrafluoroethyl chlorodifluoromethyl ether and 2,2-trichloro-1,1-difluoroethyl trifluoromethyl ether, have isolated and characterized. 相似文献
96.
Microfabrication of FeMnPt films involving magnetic phase change due to structural transformation caused by ion irradiation 下载免费PDF全文
Correlations between crystal structures and magnetic properties of Fe1–xMnx Pt films were studied. The disordered films with x ≥ 0.44 had paramagnetic properties and the ordered films with x ≥ 0.46 had antiferromagnetic properties, viz. a difference of 0.02 in the x ‐value (i.e., 1.0 at%) was found. At x = 0.44 with the ordered structure, the uniaxial magnetocrystalline anisotropy was about 2.1 × 107 erg cm–3. A microfabrication process involving the slight composition difference of 0.02, which results in ferromagnetic–paramagnetic phase change due to the structural transformation caused by ion irradiation, was investigated. Only the area irradiated by Mn ions changed from ferromagnetic to paramagnetic phase. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
97.
Takashi Shibahara Noriko Kurimoto Shunji Kiyoda Yoshimasa Kobayashi Genta Sakane 《Journal of Cluster Science》2000,11(2):333-341
Oxygen/sulfur-bridged incomplete cubane-type molybdenum aqua clusters [Mo3(
3-S)(-X)(-S)2(H2O)9]4+ (X=O, S) in hydrochloric acid react with dien (diethylenetriamine) to give [Mo3(
3-S)(-X)(-S)2(dien–)(dien)2]Cl3·nH2O [1, X=O, n=3; 2, X=S, n=4; dien–=NH2(CH2)2NH(CH2)2NH–], respectively, where each cluster has a deprotonated dien. The X-ray structural analysis of 1 revealed proton dissociation from an amino group of one of the three dien ligands: one Mo–N distance [1.987(4) Å] is clearly shorter than the other eight Mo–N distances [2.229(3)–2.276(3) Å]. The 1H NMR spectra of the Mo–dien clusters 1 and 2 in D2O show two well-resolved methylene proton signals in the 2.8- to 3.0-ppm region, which indicates that both deprotonated amines in 1 and 2 receive D+ ions from solvent D2O. The factors for the proton dissociation are discussed. 相似文献
98.
This paper proposes two types of alternative criteria of optimality for the continuous time portfolio selection problem. The optimality criteria, the so–called Laplace–Stieltjes transform (LST) criteria, are based on the assumption that the financial agent has a target level for the wealth accumulation process. These criteria are closely related to the so–called threshold stopping investment rule. We analytically derive the LST criteria and numerically compare them with the well–known Kelly criterion. It is shown that the portfolio strategies suggested may overcome the problem that the growth portfolio is often overestimated in several investment situations. 相似文献
99.
Yusei Maruyama Satoru Motohashi Masayuki Tanaka Hironori Ogata Biao Zhou Akiko Kobayashi Masayuki Shoda Shunji Bandow Sumio Iijima 《Solid State Communications》2010,150(33-34):1584-1586
Thin films of hybrid material (ssDNA–SWCNT) prepared by ultrasonic mixing of both materials in water have been examined from the viewpoint of electrical, magnetic and optical properties, and morphological features to probe the possibly induced novel functions due to mutual interactions. Enclosing of DNA molecules inside a SWCNT is confirmed by the image and its motion. The temperature dependence of electrical resistivities is best-fitted to the two-dimensional variable-range-hopping regime. The radial breathing mode of the Raman spectra of the SWCNT exhibits significant modification due to interaction with DNA. The expected change in magnetic susceptibilities is not found in this case. 相似文献
100.
Huizhen Zhang Wanfu Zhong Qiaobin Gong Pengfei Sun Xiaozhen Fei Dr. Xuejiao Wu Sha Xu Prof. Qinghong Zhang Prof. Gang Fu Prof. Shunji Xie Prof. Ye Wang 《Angewandte Chemie (International ed. in English)》2023,62(25):e202303405
Photo-driven CH4 conversion to multi-carbon products and H2 is attractive but challenging, and the development of efficient catalytic systems is critical. Herein, we construct a solar-energy-driven redox cycle for combining CH4 conversion and H2 production using iron ions. A photo-driven iron-induced reaction system was developed, which is efficient at selective coupling of CH4 as well as conversion of benzene and cyclohexane under mild conditions. For CH4 conversion, 94 % C2 selectivity and a C2H6 formation rate of 8.4 μmol h−1 is achieved. Mechanistic studies reveal that CH4 coupling is induced by hydroxyl radical, which is generated by photo-driven intermolecular charge migration of an Fe3+ complex. The delicate coordination structure of the [Fe(H2O)5OH]2+ complex ensures selective C−H bond activation and C−C coupling of CH4. The produced Fe2+ can be used to reduce the potential for electrolytic H2 production, and then turns back into Fe3+, forming an energy-saving and sustainable recyclable system. 相似文献