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81.
Abubakr M. Idris 《Journal of Analytical Chemistry》2010,65(1):36-42
A new spectrophotometric sequential injection analysis (SIA) method for the assay of olanzapine in pharmaceutical formulations was optimized by the factorial design and the response
surface approaches. The method was based on the oxidation of olanzapine by an excess amount of permanganate in sulfuric acid
media. The reduction of permanganate was spectrophotometrically detected at 570 nm. The 23 full factorial design was adopted for the optimization of permanganate concentration, sulfuric acid concentration and flow
rate. The method was validated based on the IUPAC guidelines. Real pharmaceutical samples were subjected to the proposed SIA
method and the results were in satisfactory agreement with those obtained by a previous spectrophotometric method. The full-automation
of SIA empowered the proposed method with high repeatability (RSD 1.74%, n = 7) and intermediate-precision (RSD 2.53%, n = 5). Additionally, both automation and miniaturization offered high sampling frequency (26 samples/h). Furthermore, the
employment of chemometric optimization enhanced sensitivity of the method with limits of detection and quantification of 1.07
and 3.57 mg/L, respectively. Comparing with previous olanzapine assay methods, which employing conventional analytical techniques,
the new SIA method is inexpensive in terms of instrumentation, consumption of reagents and samples as well as effort and manpower.
The SIA method is also safer for handling solutions and for the environment. 相似文献
82.
Let (X, B, μ, T) be a measure preserving dynamical system on a finite measure space. Consider the maximal function
R*:(f,g) ? LP ×Lq ? R*(f,g)(x) = supn [(f(Tnx)g(T2nx))/(n)]{R^*}:(f,g) \in {L^P} \times {L^q} \to {R^*}(f,g)(x) = \mathop {\sup }\limits_n {{f({T^n}x)g({T^{2n}}x)} \over n} 相似文献
83.
The main aim of this article is to obtain certain Laurent type hypergeometric generating relations. Using a general double series identity, Laurent type generating functions(in terms of Kampéde Fériet double hypergeometric function) are derived. Some known results obtained by the method of Lie groups and Lie algebras, are also modified here as special cases. 相似文献
84.
We extend our result on the convergence of double recurrence Wiener-Wintner averages to the case of a polynomial exponent. We show that there exists a unique set of full measure for which the averages 相似文献
$$\frac{1}{N}\sum\limits_{n = 1}^N {{f_1}\left( {{T^{an}}x} \right){f_2}\left( {{T^{bn}}x} \right)\phi \left( {p\left( n \right)} \right)} $$ 85.
Zhang Xuan-Jun Wu Jie-Ying Zhang Ming-Liang Tian Yu-Peng Jiang Min-Hua Usman Anwar Chantrapromma Suchada Fun Hoong-Kun 《Transition Metal Chemistry》2003,28(6):707-711
Two coordination polymers [Zn(Cabo)2(EtOH)2(4,4-Bipy)]
n
(1), and [Zn2(Cabo)2(NO3)2(4,4-Bipy)2]
n
(2) (Cabo = carbazolylacetate, 4,4-Bipy = 4,4-bipyridine) with chain and ladder structures, respectively, were prepared and characterized by X-ray single-crystal structural analysis. The results showed that the different anions of metal salts have a large effect on the construction of coordination frameworks. Both complexes show strong emissions in the solid state as well as high thermal stability. 相似文献
86.
Anwar Usman Ibrahim Abdul Razak Hoong‐Kun Fun Suchada Chantrapromma Yan Zhang Jian‐Hua Xu 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):o543-o544
In the title compound, C24H17NO2S, the dioxine and thiazoline rings are distorted from planarity towards a half‐chair and an envelope conformation, respectively. The configurations of the dioxine ring, the thiazoline ring and the attached phenyl ring are conditioned by the sp3 state of the two bridgehead C atoms. The phenanthrene system is nearly coplanar with the dioxine ring, while the attached phenyl ring is orthogonal to the thiazoline ring. 相似文献
87.
A simple, accurate, precise, rapid and sensitive stability-indicating capillary electrophoresis (CE) method was optimized and validated for the simultaneous determination of norfloxacin and its inactive decarboxylated degradant in pharmaceuticals. The univariant method was used to optimize electrophoretic factors including injection time, separation voltage and column temperature. Electrolyte concentration and pH were optimized using the factorial design and response surface methods. The optimum conditions obtained were: 10 mmol l− 1 phosphate at pH 2.5, hydrodynamic injection time of 8 s at pressure 0.5 p.s.i., separation voltage 25 kV and column temperature 25 °C. The separation was carried out into a fused-silica capillary column (31.2 cm length × 50 μm i.d.) with detection at 301 and 285 nm for the intact drug and the degradant, respectively using a diode array detector. For both analytes, the method enjoys wide dynamic range (1-50 μg ml− 1) with good detectability (limits of detection 0.11 μg ml− 1). In addition, acceptable accuracy (recovery > 95%); and good repeatability and intermediate precision (RSD < 3.5%) were obtained. 相似文献
88.
Anwar Usman Suchada Chantrapromma Hoong‐Kun Fun Bo‐Long Poh Chatchanok Karalai 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o46-o47
In the title complex, the 1:1 ionic adduct of hexamethylenetetraminium and 2,4,6‐trinitrophenolate, C6H13N4+·C6H2N3O7?, the cation acts as a donor for bifurcated hydrogen bonds to the O atoms of the phenolate and one of the nitro groups of the 2,4,6‐trinitrophenolate anion. The crystal structure is built from sheets of cations and anions, and is stabilized by intermolecular C—H?O and C—H?π interactions. 相似文献
89.
Suchada Chantrapromma Anwar Usman Hoong‐Kun Fun Bo‐Long Poh Chatchanok Karalai 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):o589-o590
In the title ternary complex, C10H9N2+·C7H3N2O6?·C7H4N2O6, the pyridinium cation adopts the role of the donor in an intermolecular N—H?O hydrogen‐bonding interaction with the carboxylate group of the 3,5‐dinitrobenzoate anion. The molecules of the ternary complex form molecular ribbons perpendicular to the b direction, which are stabilized by one N—H?O, one O—H?O and five C—H?O intermolecular hydrogen bonds. The ribbons are further interconnected by three intermolecular C—H?O hydrogen bonds into a three‐dimensional network. 相似文献
90.
Jia‐Xiang Yang Ze Zhang Jie‐Ying Wu Yu‐Peng Tian Qing‐Liang Liu Hoong Kun Fun Anwar Usman Zbi‐Qiang Xu K. Thompson Laurence 《中国化学》2003,21(11):1461-1465
The synthesis and characterization of the copper (II) complex [Cu2(OOCCH = C(CH3)Fc)3(phen)2]CIO4 · 2H2O (1) are reported. The structure of the complex was determined by single‐crystal X‐ray analysis. The compound crystallizes in the monoclinic system, space group Pc, with Z =2, a = 1.2799(4) nm, b =0.9969 (4) nm, c = 2.5228 nm, and β = 91.576 (1) °. The cationic part of 1 indicates a penametallic core in which three 3‐ferrocenyl‐2‐crotonic acid salt (FCA) groups act as (O, O') bridging ligands between two copper (II) ions with a square‐pyramidal environment. Cyclic voltammetric experiments in acetonitrile have been performed mainly to examine the Fe(II) → Fe(III) one‐electron oxidation in FCA and its complex. The variable‐temperature magnetic susceptibility measurements revealed very weak intramolecular anti‐ferromagnetic coupling. Fitting parameters are 2J = ‐0.2 cm?1, g = 2.114, and θ = 0K. 相似文献
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