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991.
It is in general challenging to characterize planar mechanical properties of extremely soft tissues such as cell-seeded collagen gels. One of the difficulties is related to premature failure of specimens. This issue may be resolved by employing fillets on stress-concentrated spots of the specimen. The existence of fillets, however, complicates the estimation of stress at the center of the specimen where stiffness data are collected. In this study, cruciform rubber specimens with two types of fillets (general vs. cut-in fillets) at the intersections of perpendicular arms were prepared and subjected to planar biaxial mechanical testing, aiming at investigating how the fillets affect the estimation of mechanical properties of cruciform specimens. Digital image correlation was used to analyze full-field deformation in the central region of the specimens. Finite element analysis with a Neo-Hookean model was performed to simulate the full-field deformation under the same experimental boundary conditions. The strain distribution for each specimen geometry obtained by finite element analysis was found to be in good agreement with that analyzed by digital image correlation, validating the finite element models. Finite element simulation showed that the greatest value of the maximum principal strain decreased with increasing the fillet radius regardless of the fillet type. Increasing the fillet radius, in general, also reduced the strain field uniformity in the central region. Compared with general fillets, however, the use of cut-in fillets provided greater strain field uniformity given the same fillet radius. Finite element analysis was also used to estimate effective transverse length required to convert tensile force at the boundary to local stress at the center. It was found that the effective transverse length for each specimen geometry remained relatively constant if the specimen was not excessively deformed (i.e., global equibiaxial stretch ≤ 1.2). We suggest using cut-in fillets at the intersections of perpendicular arms when preparing cruciform specimens for testing extremely soft tissues. 相似文献
992.
In this paper the problem of wave propagation over an adjoining-type of composite submerged poroelastic breakwater with different materials is investigated theoretically. A new analytical solution for describing the dynamic response of wave interaction with poroelastic structures is presented. A set of simultaneous equations is developed and numerically solved in order to produce a general solution for each region subject to matching boundary conditions. The present paper focuses on the changes of influence parameters such as different component widths of the composite breakwater, permeability coefficients, composite materials and configurations of breakwater on wave variations. 相似文献
993.
Shu-Yu Hsu 《Geometriae Dedicata》2013,162(1):375-388
We give a simple proof for the rotational symmetry of ancient solutions of Ricci flow on surfaces. As a consequence we obtain a simple proof of some results of Daskalopoulos, Hamilton and Sesum on the a priori estimates for the ancient solutions of Ricci flow on surfaces. We also give a simple proof for the solution to be a Rosenau solution under some mild conditions on the solutions of Ricci flow on surfaces. 相似文献
994.
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996.
The purpose of this study is to explore the single-machine scheduling with the effects of exponential learning and general deterioration. By the effects of exponential learning and general deterioration, we meant that job processing time is decided by the functions of their starting time and positions in the sequence. Results showed that with the introduction of learning effect and deteriorating jobs to job processing time, single-machine makespan, and sum of completion time (square) minimization problems remained polynomially solvable, respectively. But for the following objective functions: the weighted sum of completion time and the maximum lateness, this paper proved that the weighted smallest basic processing time first (WSPT) rule and the earliest due date first (EDD) rule constructed the optimal sequence under some special cases, respectively. 相似文献
997.
As a theoretical completion or a substantial supplement to a recent joint paper by He et al. [Discrete Math. 308 (2008), pp. 3427–3440] containing a pair of series transformation formulas with a variety of illustrative examples, we provide some convergence theorems for the transformation formulas under certain general conditions. We also show that these two transformation formulas subject to the convergence conditions can be further utilized to produce more than 30 special power series sums and combinatorial identities (in a wider sense) mostly not given previously. 相似文献
998.
Chunqiu Li Cheng Hsiung Hsu Jian Jhong Lin 《Journal of Difference Equations and Applications》2013,19(10):1404-1426
The purpose of this work is to investigate the asymptotic behaviours of solutions for the discrete Klein–Gordon–Schrödinger type equations in one-dimensional lattice. We first establish the global existence and uniqueness of solutions for the corresponding Cauchy problem. According to the solution's estimate, it is shown that the semi-group generated by the solution is continuous and possesses an absorbing set. Using truncation technique, we show that there exists a global attractor for the semi-group. Finally, we extend the criteria of Zhou et al. [S. Zhou, C. Zhao, and Y. Wang, Finite dimensionality and upper semicontinuity of compact kernel sections of non-autonomous lattice systems, Discrete Contin. Dyn. Syst. A 21 (2008), pp. 1259–1277.] for finite fractal dimension of a family of compact subsets in a Hilbert space to obtain an upper bound of fractal dimension for the global attractor. 相似文献
999.
Zuhl AM Mohr JT Bachovchin DA Niessen S Hsu KL Berlin JM Dochnahl M López-Alberca MP Fu GC Cravatt BF 《Journal of the American Chemical Society》2012,134(11):5068-5071
Serine hydrolases are one of the largest and most diverse enzyme classes in Nature. Most serine hydrolases lack selective inhibitors, which are valuable probes for assigning functions to these enzymes. We recently discovered a set of aza-β-lactams (ABLs) that act as potent and selective inhibitors of the mammalian serine hydrolase protein-phosphatase methylesterase-1 (PME-1). The ABLs inactivate PME-1 by covalent acylation of the enzyme's serine nucleophile, suggesting that they could offer a general scaffold for serine hydrolase inhibitor discovery. Here, we have tested this hypothesis by screening ABLs more broadly against cell and tissue proteomes by competitive activity-based protein profiling (ABPP), leading to the discovery of lead inhibitors for several serine hydrolases, including the uncharacterized enzyme α,β-hydrolase domain-containing 10 (ABHD10). ABPP-guided medicinal chemistry yielded a compound ABL303 that potently (IC(50) ≈ 30 nM) and selectively inactivated ABHD10 in vitro and in living cells. A comparison of optimized inhibitors for PME-1 and ABHD10 indicates that modest structural changes that alter steric bulk can tailor the ABL to selectively react with distinct, distantly related serine hydrolases. Our findings, taken together, designate the ABL as a versatile reactive group for creating first-in-class serine hydrolase inhibitors. 相似文献
1000.
As shown in the literature, gold nanoparticles (NPs) were popularly used in the fields of catalyst and surface-enhanced Raman scattering (SERS). In this work, size-controllable Au NPs coated on TiO(2) are synthesized by adjusting the pH of solutions based on sonoelectrochemical methods. The size-controlled Au NPs on TiO(2), ranging from 2 to 80 nm in diameter, can be obtained by varying the pH of solutions from 3 to 7 and placing the sample for 3 h before sonoelectrochemical reductions. The optimal particle sizes of Au NPs on TiO(2) to obtain the strongest SERS effects under an irradiation of 785 nm for probe molecules of adsorbed Rhodamine 6G (R6G) and deposited polypyrrole (PPy) are all ca. 60 nm. 相似文献