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101.
102.
Studies on metabolism of total glucosides of paeony from Paeoniae Radix Alba in rats by UPLC‐Q‐TOF‐MS/MS 下载免费PDF全文
Wenli Cao Xinguo Wang Haojie Li Xuliang Shi Wencheng Fan Shaohua Zhao Minyan Liu Liying Niu 《Biomedical chromatography : BMC》2015,29(11):1769-1779
Total glucosides of paeony are the active constituents of Paeoniae Radix Alba. In this study, a novel strategy was proposed to find more metabolites and the differences between paeoniflorin, albiflorin and total glucosides of paeony (TGP). This strategy was characterized as follows: firstly, the animals were divided into three groups (paeoniflorin, albiflorin and TGP) to identify the source of TGP metabolites from paeoniflorin or albiflorin; secondly, a generic information‐dependent acquisition scan for the low‐level metabolites was triggered by the multiple mass defect filter and dynamic background subtraction; thirdly, the metabolites were identified with a combination of data‐processing methods including mass defect filtering, neutral loss filtering and product ion filtering; finally, a comparative study was used in the metabolism of paeoniflorin, albiflorin and TGP. Based on the strategy, 18 metabolites of TGP, 10 metabolites of paeoniflorin and 13 metabolites of albiflorin were identified respectively. The results indicated that the hydrolysis, conjugation reaction and oxidization were the major metabolic pathways, and the metabolic sites were the glycosidic linkage, the ester bond and the benzene ring. This study is first to explore the metabolism of TGP, and these findings enhance our understanding of the metabolism and the interactions of paeoniflrin and albiflorin in TGP. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
103.
In this paper, we propose a parareal algorithm for stochastic differential equations
(SDEs), which proceeds as a two-level temporal parallelizable integrator with the Milstein
scheme as the coarse propagator and the exact solution as the fine propagator. The convergence order of the proposed algorithm is analyzed under some regular assumptions.
Finally, numerical experiments are dedicated to illustrating the convergence and the convergence order with respect to the iteration number $k$, which show the efficiency of the
proposed method. 相似文献
104.
In this paper, we couple the parareal algorithm with projection methods of the trajectory
on a specific manifold, defined by the preservation of some conserved quantities of
stochastic differential equations. First, projection methods are introduced as the coarse
and fine propagators. Second, we apply the projection methods for systems with conserved
quantities in the correction step of original parareal algorithm. Finally, three numerical
experiments are performed by different kinds of algorithms to show the property of convergence
in iteration, and preservation in conserved quantities of model systems. 相似文献
105.
106.
Li Feng Chen Liying Zhang Hongyun Wu Qingan Li Yanhong Cui Zhanhua Niu Yunyin Jiang Haigang 《Transition Metal Chemistry》1995,20(5):511-513
Summary Formylferrocenyl-3-hydroxyl-2-naphthoylhydrazone and its transition metal coordination compounds have been synthesized and characterized by elemental analyses, i.r., 1H-n.m.r., u.v.-vis., t.g.-d.t.a. and molar conductivities. The results show that the ligand coordinates to transition metal ions in the enolic form, accompanied by the release of acetate or nitrate. 相似文献
107.
108.
An experiment of laser propagation was carried out at the urban terrain range of 3.5 km during the period of March to May of 2006. The received intensity scintillations and atmosphere turbulence strength in complex urban atmosphere circumstance were simultaneously measured concentratively. The results show the statistical characteristics of irradiance scintillation and atmosphere turbulence strength and link fade margin for urban free-space optical links. 相似文献
109.
Liying Xu Wenyan Zhao Ruimiao Chang Guangbin Zhang Hongfen Zhang Anjia Chen 《Journal of the Iranian Chemical Society》2018,15(7):1477-1483
The purpose of this study was to develop a novel, simple and precise ligand-exchange capillary electrophoresis method to separate the diastereomer pairs of four major cinchona alkaloids (quinine/quinidine and cinchonine/cinchonidine). The l-lysine and copper(II) were chosen as the ligand and the central ion, respectively. Optimal separation conditions of four alkaloids were 4.0 mM l-lys, 2.0 mM copper(II) and 30 mM NH4Ac at pH 8.9 and a applied voltage of 15 kV . Meanwhile, the first-order derivative electropherogram was used for resolving the overlapping peaks of cinchonidine and quinidine. Under the optimum condition, good linearities were obtained with correlation coefficients from 0.9908 to 0.9935. The limits of detection (LOD, S/N?=?3) and the limits of quantitation (LOQ, S/N?=?10) ranged from 0.24 to 0.41 μg/mL and from 0.73 to 1.35 μg/mL, respectively. The recoveries ranged between 95.38 and 106.03%. The proposed ligand-exchange capillary electrophoresis method was suitable for the quantitative determination of four cinchona alkaloids in some preparations such as Compound Quinine Injection, Tonic Water and Klorane quinine and Vitamin B complex Shampoo. 相似文献
110.
Hou?Guangjin Wang?Liying Lu?Xiaoming Zheng?Anmin Deng?Feng Ye?ChaohuiEmail author 《中国科学B辑(英文版)》2004,47(3):214-221
13C 2D-PASS spectra of two new cis-dioxo catecholatomolybdenum complexes (NH2CH2NH2CHCH2)2(H+)3[MovO
2(C6H4O2)2] and (NH2CH2CH2CH2NH2)2(H+)3[Mo(v)O2 (C2H2O2)2] have been obtained by solid-state nuclear magnetic resonance (NMR), in which the spinning sidebands were well-separated.
The principal components of the 13C shielding tensors were extracted by theoretically fitting the intensities of 13C spinning sidebands. The effects of counter cations on 13C chemical shift isotropy and shielding tensor of cis-dioxo catecholatomolybdenum complex anion [Mo (v)O2(C6H4O2)2]3− were studied, comparing the 13C CSA of those carbon sites in complex anions with that of the counter cations. Based on the known structure of the molybdenum
complex crystal, theoretical values of 13C shielding tensors were calculated by the ainitio GIAO method, in comparison with the experimental results. 相似文献