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排序方式: 共有163条查询结果,搜索用时 781 毫秒
131.
Masahiro Kiyama Satoshi Iwano Satoshi Otsuka Shijia W. Lu Rika Obata Atsushi Miyawaki Takashi Hirano Shojiro A. Maki 《Tetrahedron》2018,74(6):652-660
The dimethylamino group of AkaLumine ((4S)-2-[(1E,3E)-4-[4-(dimethylamino)phenyl]-1,3-butadien-1-yl]-4,5-dihydro-4-thiazolecarboxylic acid), a red-light-emitting firefly luciferin analogue, was replaced by cyclic amino groups (1-pyrrolidinyl, 1-piperidino, 1-azepanyl, and 4-morpholino) to give AkaLumine analogues exhibiting desirable bioluminescence with emission maxima in the red region (656–667 nm). In particular, a bioluminescence reaction of 1-pyrrolidinyl analogue with a recombinant Photinus pyralis luciferase showed a higher quantum yield than that with AkaLumine, giving an improved bioluminescence intensity. The 1-pyrrolidinyl analogue also showed the strongest luminescence in whole-body luciferase-expressing mice among the analogues, indicating that a quantum yield improvement of a luciferin analogue is effective to increase bioluminescence imaging intensity. 相似文献
132.
Shigeo Suzuki Rika Tanaka Keiko Takada Nozomi Inoue Yuka Yashima Akiko Honda Susumu Honda 《Journal of chromatography. A》2001,910(2):115
A method for the analysis of the sialo-N-glycans in glycoproteins was established by the electrokinetic chromatography mode of capillary electrophoresis (CE) in sodium dodecyl sulfate (SDS) micelles as 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatives, using sialo-N-glycans in fetuin as a model. Six major and some minor peaks were observed for the N-glycans in fetuin, which were well separated from each other using 50 mM phosphate buffer, pH 6.0, containing SDS to a concentration of 30 mM in an uncoated fused-silica capillary, and these peaks were assigned to sialo-N-glycans having either of the biantennary or β1-3/β1-4 linked galactose-containing complex type triantennary N-glycans as the basic structures, by an indirect method based on the assignment of the peaks in high-performance liquid chromatography separated in parallel with CE and peak collation between these two separation methods. The attaching position of the sialic acid residue was determined using the linkage preference of neuraminidase isozymes. The established system is considered to be useful for routine analysis of microheterogeneity of the carbohydrate moiety of this model glycoprotein from the following reasons: (1) the derivatization with PMP proceeds quantitatively under mild conditions without causing release of the sialic acid residue, (2) the derivatives can be sensitively detected by UV absorption, (3) the procedure is simple, rapid and reproducible. Preliminary results of N-glycan analysis for several other glycoproteins under these conditions are also presented. 相似文献
133.
Surudee Treetepvijit Suchada Chuanuwatanakul Yasuaki Einaga Rika Sato Orawon Chailapakult 《Analytical sciences》2005,21(5):531-535
The electrochemical analysis of tetracycline was investigated using nickel-implanted boron-doped diamond thin film electrode by cyclic voltammetry and amperometry with a flow injection system. Cyclic voltammetry was used to study the electrochemical oxidation of tetracycline. Comparison experiments were carried out using as-deposited boron-doped diamond thin film electrode (BDD). Nickel-implanted boron-doped diamond thin film electrode (Ni-DIA) provided well-resolved oxidation irreversible cyclic voltammograms. The current signals were higher than those obtained using the as-deposited BDD electrode. Results using nickel-implanted boron-doped diamond thin film electrode in flow injection system coupled with amperometric detection are presented. The optimum potential for tetracycline was 1.55 V versus Ag/AgCl. The linear range of 1.0 to 100 microM and the detection limit of 10 nM were obtained. In addition, the application for drug formulation was also investigated. 相似文献
134.
Masahiro Mikuriya Mayu Hamagawa Natsuki Tomioka Rika Fujimori Daisuke Yoshioka Shoichi Hori Taro Kuriyama Hiroshi Sakiyama Makoto Handa Ryoji Mitsuhashi 《Chemical Papers》2016,70(1):69-74
A nickel(II) complex, [Ni(taetacn)](ClO4)2 ? H2O, where taetacn = 1,4,7-tris(2-aminoethyl)-1,4,7-triazacyclononane was synthesized. The crystal structure was determined by the single-crystal X-ray diffraction method at 293 K. The complex crystallizes in the orthorhombic space group Pna21 with a = 16.004(2) Å, b = 10.186(1) Å, c = 13.937(2) Å, V = 2271.9(5) Å3, Dx = 1.56 g cm?3, Dm = 1.59 g cm?3 (floatation method), and Z = 4. The R1 [I > 2σ(I)] and wR2 (all data) values are 0.0636 and 0.1672, respectively, for all 4845 independent reflections. The compound is composed of octahedral nickel(II) cation with three 2-aminoethyl pendant groups of taetacn, tetrahedral ClO 4 ? anion, and a water molecule of crystallization. Electronic spectra are consistent with the octahedral geometry. Temperature dependence of the magnetic susceptibility (4.5–300 K) can be interpreted considering the zero-field splitting of the nickel(II) ion (g = 2.14, D = 3.72 cm?1, and Nα = 300 × 10?6 cm3 mol?1). Cyclic voltammetry in DMF showed quasi-reversible and irreversible oxidation waves (Epa = 0.54 V, Epc = 0.45 V; Epa = 1.16 V, Epc = 0.71 V vs. Ag/Ag+). 相似文献
135.
A Step‐by‐Step Assembly of a 3D Coordination Polymer in the Solid‐State by Desolvation and [2+2] Cycloaddition Reactions
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Dr. Raghavender Medishetty Rika Tandiana Dr. Jien Wu Zhaozhi Bai Dr. Yonghua Du Prof. Jagadese J. Vittal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(34):11948-11953
Two solid‐state structural transformations that occur in a stepwise and a controlled manner are described. A combination of desolvation and cycloaddition reactions has been employed to synthesise a 3D coordination polymer (CP) from 1D CP [Cd(bdc)(4‐spy)2(H2O)]?2 H2O?2 DMF (bdc=1,4‐benzenedicarboxylate, 4‐spy=4‐styrylpyridine) presumably via a 2D layered structure, [Cd2(bdc)2(4‐spy)4]. In the absence of single crystals to follow the course of the photocycloaddition reaction, thermogravimetry, XAFS and NOESY NMR experiments were used to propose the formation of layered and pillared layered structures. Further, the present strategy enables us to synthesise new multidimensional architectures that are otherwise inaccessible by the self‐assembly process. 相似文献
136.
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138.
Application of partial least square on quantitative analysis of L-, D-, and DL-tartaric acid by terahertz absorption spectra 总被引:1,自引:0,他引:1
Nishikiori R Yamaguchi M Takano K Enatsu T Tani M de Silva UC Kawashita N Takagi T Morimoto S Hangyo M Kawase M 《Chemical & pharmaceutical bulletin》2008,56(3):305-307
Absorption spectra of polycrystalline L-, D-, and DL-tartaric acid have been measured by terahertz time domain spectroscopy (THz-TDS). Different absorption bands are observed for DL-tartaric acid and its enantiomers (L- and D-tartaric acid). This result shows that the THz-TDS can be used for distinguishing between DL-tartaric acid and enantiomers (L- and D-tartaric acid). Moreover, partial least square (PLS) can be found to improve the quantitation of L-tartaric acid in L- and DL-tartaric acid mixture by THz-TDS. 相似文献
139.
Henrik Koch Rika Kobayashi Poul Jrgensen 《International journal of quantum chemistry》1994,49(6):835-848
A derivation of the linear response function for the Brueckner coupled cluster method is presented that enables the calculation of second-order molecular properties such as frequency-dependent polarizabilities. By using the Brueckner orbital variant of coupled cluster theory, the spurious pole structure inherent in the standard coupled cluster approach with orbital relaxation is avoided. © 1994 John Wiley & Sons, Inc. 相似文献
140.
[reaction: see text] Starting from (S)-glycidol, the asymmetric total synthesis of novel D-seco Corynanthe-type oxindoles Us-7 and Us-8 was accomplished. The structure of Us-7 was revised from the reported structure 1 with the (3R,7S) form to structure 22 with (3S,7R), and the absolute stereochemistry at C15 of both alkaloids was established. 相似文献