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971.
This paper presents a continuous finite element solution for fluid flows with interfaces. The method is founded on the sign-preserving flux correction transport methodology and extends nonoscillatory finite element algorithm capabilities to predict interface motion efficiently. The procedure is composed of three main stages, along the lines of the conservative level set method: transport of phase function, reconstruction of phase function, and solution of equations of motion of two incompressible fluids. The flux correction technique takes action on the three steps. Limiting process incorporates a straightforward refinement to remove global mass residuals present in the earliest version of the algorithm. This is of particular importance in the transport step. Moreover, new method retains the efficacy of the original. To reconstruct the phase function after transport, a novel nonlinear (and conservative) streamlined diffusion equation is proposed, with an anisotropic diffusivity comprising artificial compression and diffusive fluxes along interface displacements direction. A substantial reduction of unphysical overshoots along the interface is reached by an improved bound estimation that includes interface information. Complete operation of the correction algorithm for two incompressible fluids flows requires two pressure solutions. We explore a reduced form to circumvent this extra burden. Numerical experiments verify the formulation by reproducing stringent benchmarks both for transport/reinitialization and for two-fluid interface propagation. 相似文献
972.
Dr. Luis Martínez-Crespo Jia Liang Sun-Wang Pedro Ferreira Chiara F. M. Mirabella Dr. Gemma Aragay Prof. Pablo Ballester 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(18):4775-4781
We disclose the results of our investigations on the influence that the insertion method of aryl-extended calix[4]pyrrole into liposomal membranes exerts on their properties as anion carriers. We use the standard HPTS assay to assess the transport properties of the carriers. We show that the post-insertion of the carrier, as DMSO solution, assigns better transport activities to the “two-wall” α,α-aryl-extended calix[4]pyrrole 1 compared to the “four-wall” α,α,α,α-counterpart 2 . Notably, opposite results were obtained when the carriers were pre-inserted into the liposomal membranes. We assign this difference to an improved incorporation of carrier 2 into the membrane when delivered by the pre-insertion method. On the other hand, carrier 1 shows comparable levels of transport independently of the method used for its incorporation. Thus, an accurate comparison of the chloride transport activities featured by these two carriers demands their pre-incorporation in the liposomal membranes. In contrast, using the lucigenin assay with the pre-insertion method both carriers displayed similar transport efficiencies. 相似文献
973.
Lucía Álvarez-Rodríguez Prof. Dr. Javier A. Cabeza Dr. Pablo García-Álvarez Prof. Dr. Mar Gómez-Gallego Laura González-Álvarez Alba D. Merinero Prof. Dr. Miguel A. Sierra 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(6):1588-1594
The formation of the five-membered-ring germylene complexes [M(CO)5{Ge(tBu2bzamC(OEt)Me)tBu}] ( 3M ; M=Cr, W), which occurs readily at room temperature from the germylene Ge(tBu2bzam)tBu ( 1 t Bu ) and Fischer carbenes [M(CO)5{C(OEt)Me}] ( 2M ; M=Cr, W), has been found to be reversible. Upon heating at 60 °C, complexes 3M undergo epimerization to an equilibrium mixture of 3M and 3′M . At that temperature, the chromium epimers (but not the tungsten ones) release CO to end in the mixed germylene–Fischer carbene complexes [Cr(CO)4{C(OEt)Me}{Ge(tBu2bzam)tBu}] (cis- 4Cr and trans- 4Cr ). The latter decompose at 120 °C to [Cr(CO)5{Ge(tBu2bzam)tBu}] ( 6Cr ). Because the formation of cis- 4Cr and trans- 4Cr from 3Cr or 3′Cr requires the presence of free 1 t Bu and 2Cr in the reaction solutions, the reactions of 1 t Bu with 2M to give 3M (and 3′M at 60 °C) should be reversible. This proposal has been proven by germylene-exchange crossover reactions in which free 1 t Bu and [M(CO)5{Ge(tBu2bzamC(OEt)Me)CH2SiMe3}] ( 5′M ; M=Cr, W) were formed when complexes 3M were treated at room temperature with the germylene Ge(tBu2bzam)CH2SiMe3 ( 1tmsm ). A clear differential behavior between N-heterocyclic carbenes (NHCs) and amidinatogermylenes ( 1 t Bu and 1tmsm ) in their reactivity against group 6 metal Fischer carbene complexes is demonstrated. The higher electron-donor capacity of amidinatogermylenes with respect to NHCs and the bias of the former to get involved in ring expansion processes are responsible for this differential behavior. 相似文献
974.
Saif Ullah Pablo A. Denis Fernando Sato 《International journal of quantum chemistry》2019,119(11):e25900
We employ first-principles DFT calculations to explore the potential use of BeN dual doped graphene (DDG) as an anode material for alkali-based batteries. The introduction of BeN in graphene raise the adsorption of Li, Na, and K by 1.37 eV (2.23 times), 1.23 eV (2.83 times), and 1.14 eV (2.14 times), respectively. Furthermore, BeN DDG offers a modest energy barrier for alkali atoms studied. Moreover, the alkali atoms have good chemistry with Be and the interaction strength decreases during the migration toward N. Most importantly, the exceptional storage capacity of BeN DDG for Li (~2255 mAh/g), Na (~996 mAh/g), and K (~747 mAh/g) makes it a highly desirable anode material. Additionally, the average open circuit voltage offered for Li (0.66 V), Na (0.33 V), and (K = 1.10 V) is found to be in excellent range. All these outstanding properties provide the possibility of using BeN DDG in future alkali-based batteries. 相似文献
975.
976.
The urban sound environment of New York City (NYC) can be, amongst other things: loud, intrusive, exciting and dynamic. As indicated by the large majority of noise complaints registered with the NYC 311 information/complaints line, the urban sound environment has a profound effect on the quality of life of the city’s inhabitants. To monitor and ultimately understand these sonic environments, a process of long-term acoustic measurement and analysis is required. The traditional method of environmental acoustic monitoring utilizes short term measurement periods using expensive equipment, setup and operated by experienced and costly personnel. In this paper a different approach is proposed to this application which implements a smart, low-cost, static, acoustic sensing device based around consumer hardware. These devices can be deployed in numerous and varied urban locations for long periods of time, allowing for the collection of longitudinal urban acoustic data. The varied environmental conditions of urban settings make for a challenge in gathering calibrated sound pressure level data for prospective stakeholders. This paper details the sensors’ design, development and potential future applications, with a focus on the calibration of the devices’ Microelectromechanical systems (MEMS) microphone in order to generate reliable decibel levels at the type/class 2 level. 相似文献
977.
Gomes Pablo A. Sanchis Rémy Silva Roger W. C. 《Letters in Mathematical Physics》2020,110(12):3427-3434
Letters in Mathematical Physics - We consider independent anisotropic bond percolation on $${mathbb {Z}}^dtimes {mathbb {Z}}^s$$ where edges parallel to $${mathbb {Z}}^d$$ are open with... 相似文献
978.
Monatshefte für Mathematik - The normal covering number $$gamma (G)$$ of a finite, non-cyclic group G is the minimum number of proper subgroups such that each element of G lies in some... 相似文献
979.
Andrea Madabeni Marco Dalla Tiezza Folorunsho Bright Omage Pablo Andrei Nogara Marco Bortoli João Batista Teixeira Rocha Laura Orian 《Journal of computational chemistry》2020,41(23):2045-2054
Methylmercury is a highly toxic compound and human exposure is mainly related to consumption of polluted fish and seafood. The inactivation of thiol-based enzymes, promoted by the strong affinity binding of electrophilic mercuric ions to thiol and selenol groups of proteins, is likely an important factor explaining its toxicity. A key role is played by the chemistry and reactivity of the mercury–chalcogens bond, particularly Hg S and Hg Se, which is the focus of this computational work (level of theory: (COSMO)-ZORA-BLYP-D3(BJ)/TZ2P). We analyze nine ligand-exchange model reactions (the so-called Rabenstein's reactions) involving an entering ligand (methylchalcogenolate) and a substrate (methylchalcogenolatemethylmercury). Trends in reaction and activation energies are discussed and a change in mechanism is reported for all cases when going from gas phase to water, that is, from a single-well potential energy surface (PES) to a canonical SN2-like mechanism. The reasons accounting for the biochemically challenging and desired displacement of methylmercury from a seleno/thiol protein can be found already in these model reactions, as can be seen from the similarities of the ligand exchange reactions in solution in thermodynamics and kinetics. 相似文献
980.
Plasma Chemistry and Plasma Processing - Thermal plasmas are utilized in diverse applications that require high power densities or throughputs, such as metal cutting, welding, spraying, metallurgy,... 相似文献