全文获取类型
收费全文 | 1290篇 |
免费 | 44篇 |
国内免费 | 5篇 |
专业分类
化学 | 995篇 |
晶体学 | 5篇 |
力学 | 16篇 |
数学 | 163篇 |
物理学 | 160篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 49篇 |
2021年 | 56篇 |
2020年 | 34篇 |
2019年 | 29篇 |
2018年 | 22篇 |
2017年 | 16篇 |
2016年 | 42篇 |
2015年 | 35篇 |
2014年 | 46篇 |
2013年 | 60篇 |
2012年 | 67篇 |
2011年 | 97篇 |
2010年 | 69篇 |
2009年 | 54篇 |
2008年 | 70篇 |
2007年 | 86篇 |
2006年 | 65篇 |
2005年 | 59篇 |
2004年 | 48篇 |
2003年 | 53篇 |
2002年 | 61篇 |
2001年 | 18篇 |
2000年 | 11篇 |
1999年 | 11篇 |
1998年 | 15篇 |
1997年 | 8篇 |
1996年 | 14篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 17篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1978年 | 5篇 |
1976年 | 3篇 |
1974年 | 4篇 |
1939年 | 2篇 |
1938年 | 2篇 |
1937年 | 2篇 |
1921年 | 2篇 |
排序方式: 共有1339条查询结果,搜索用时 0 毫秒
911.
Lucia Pusillo 《Journal of Global Optimization》2008,40(1-3):339-352
The aim of this contribution is an overview on Potential Games. This class of games is special, in fact we can investigate
their properties by a unique function: the potential function. We consider several types of potential games: exact, ordinal,
bayesian and hierarchical. Some results are generalized to multicriteria decisions.
相似文献
912.
Rong‐Chang Chen Diego Dreossi Lucia Mancini Ralf Menk Luigi Rigon Ti‐Qiao Xiao Renata Longo 《Journal of synchrotron radiation》2012,19(5):836-845
Synchrotron‐radiation computed tomography has been applied in many research fields. Here, PITRE (Phase‐sensitive X‐ray Image processing and Tomography REconstruction) and PITRE_BM (PITRE Batch Manager) are presented. PITRE supports phase retrieval for propagation‐based phase‐contrast imaging/tomography (PPCI/PPCT), extracts apparent absorption, refractive and scattering information of diffraction enhanced imaging (DEI), and allows parallel‐beam tomography reconstruction for conventional absorption CT data and for PPCT phase retrieved and DEI‐CT extracted information. PITRE_BM is a batch processing manager for PITRE: it executes a series of tasks, created viaPITRE, without manual intervention. Both PITRE and PITRE_BM are coded in Interactive Data Language (IDL), and have a user‐friendly graphical user interface. They are freeware and can run on Microsoft Windows systems via IDL Virtual Machine, which can be downloaded for free and does not require a license. The data‐processing principle and some examples of application will be presented. 相似文献
913.
Lucia D’Ulivo 《Analytical and bioanalytical chemistry》2014,406(7):1815-1816
914.
Francesco Tadini Buoninsegni Lucia Becucci Maria Rosa Moncelli Rolando Guidelli 《Journal of Electroanalytical Chemistry》2001,500(1-2)
The thermodynamic ‘total’ charge density is the charge to be supplied to the electrode to keep the applied potential constant when the electrode surface is increased by unity, while the extrathermodynamic ‘free’ charge density is the charge actually experienced by the diffuse layer ions. The total charge density at dioleoylphosphatidylcholine (DOPC) and octadecanethiol (ODT) monolayers and mixed ODT/DOPC bilayers self-assembled on mercury from aqueous solutions was determined from chronocoulometric single potential steps to a final potential negative enough to cause complete desorption of the film. The effect of different alkali metal ions and of tetramethylammonium on DOPC desorption was examined. The total charge for ODT monolayers and ODT/DOPC bilayers, +56±3 μC cm−2, agrees with the value obtained by integration of the current under the reductive desorption voltammetric peaks, only provided the scan rate is higher than 100 mV s−1. An approximate model of the interface of the ODT-coated electrode, which accounts for partial charge transfer from sulfur to mercury and for the degree of dissociation of the sulfhydryl group upon self-assembly, was employed to estimate the free charge density. 相似文献
915.
Markus Hegland Conrad Burden Lucia Santoso Shev MacNamara Hilary Booth 《Journal of Computational and Applied Mathematics》2007
An important driver of gene regulatory networks is noise arising from the stochastic nature of interactions of genes, their products and regulators. Thus, such systems are stochastic and can be modelled by the chemical master equations. A major challenge is the curse of dimensionality which occurs when one attempts to integrate these equations. While stochastic simulation techniques effectively address the curse, many repeated simulations are required to provide precise information about stationary points, bifurcation phenomena and other properties of the stochastic processes. An alternative way to address the curse of dimensionality is provided by sparse grid approximations. The sparse grid methodology is applied and the application demonstrated to work efficiently for up to 10 proteins. As sparse grid methods have been developed for the approximation of smooth functions, a variant for infinite sequences had to be developed together with a multiresolution analysis similar to Haar wavelets. Error bounds are provided which confirm the effectiveness of sparse grid approximations for smooth high-dimensional probability distributions. 相似文献
916.
Claudia Chinosi Lucia Della Croce 《Journal of Computational and Applied Mathematics》2007,210(1-2):106-115
In this paper rectangular plates made of functionally graded materials (FGMs) are studied. A two-constituent material distribution through the thickness is considered, varying with a simple power rule of mixture. The equations governing the FGM plates are determined using a variational formulation arising from the Reissner–Mindlin theory. To approximate the problem a simple locking-free Discontinuous Galerkin finite element of non-conforming type is used, choosing a piecewise linear non-conforming approximation for both rotations and transversal displacement. Several numerical simulations are carried out in order to show the capability of the proposed element to capture the properties of plates of various gradings, subjected to thermo-mechanical loads. 相似文献
917.
Using V. Ficker’s and P. Capek’s algebraic approach by ideals a Lebesgue decomposition theorem for a wide class of non-additive set functions called null-additive set functions is obtained. In special cases decompositions theorems for ⊕-decomposable measures andk-triangular set functions are obtained. 相似文献
918.
Monolayers of 3,3′-dithiodipropionic acid (DTDPA) were prepared on a polycrystalline gold electrode through a self-assembly procedure to produce a gold 3,3′-dithiodipropionic acid self-assembled monolayer (AuDTDPA) modified electrode. The characterization of the AuDTDPA electrode was investigated by cyclic voltammetry and ac impedance using the [Fe(CN)6]3−/4− redox couple. The electrochemical behavior of DA on the modified electrode AuDTDPA was studied by cyclic and square-wave voltammetries, using phosphate buffer as supporting electrolyte. The oxidation peak current for DA increases linearly with concentration in the range of 0.35 × 10−5 to 3.4 × 10−5 mol L−1. The performance of the AuDTDPA modified electrode was evaluated for the electroanalytical determination of dopamine (DA) in a pharmaceutical formulation. The AuDTDPA modified electrode showed a stable behavior and the presence of surface-COOH groups avoided the passivation of the electrode surface during the dopamine oxidation. 相似文献
919.
Intermediate free radicals in the oxidation of wastewaters 总被引:1,自引:0,他引:1
Roberto Bianchini Lucia Calucci Claudio Lubello Calogero Pinzino 《Research on Chemical Intermediates》2002,28(2-3):247-256
The cleaning action on wastewater as obtained through oxidation methods has been investigated by means of EPR spectroscopy to achieve qualitative and quantitative information on the radicals produced upon utilising peracetic acid and hydrogen peroxide with and without UV irradiation. The DEPMPO spin trap was employed to detect hydroxyl and carbon-centred short living radicals during water disinfection, either in the absence or in the presence of UV-C irradiation. Moreover, three different kinds of water (wastewater, demineralized water, distilled water) were analysed in order to assess the contribution of Fenton reactions to the radical production. The spectroscopic results are discussed in relation to the efficiency of the different oxidising agents and UV irradiation in wastewater disinfection evaluated as Escherichia coli, faecal and total coliforms inactivation. 相似文献
920.
The title compound 2 was prepared in excellent yield by diazotation of the parent amino derivative. Compound 2 was found to react with a variety of acyclic and cyclic active methylene compounds to yield the corresponding pyrazolo-4-ylhydrazones. 相似文献