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971.
Co(30)Fe(70) nanoparticles with mean particle size of about 8 nm were successfully synthesized by the chemical reduction of cobalt chloride and iron chloride with borohydride as a reducing agent in aqueous solution. The composition and size of the Co(30)Fe(70) nanoparticles were optimized by controlling the molar ratio of starting materials, reaction time, and dropping rate of aqueous reducing agent. As alloy powders prepared by chemical reduction tend to be amorphous in the as-synthesized state, the as-precipitated Co(30)Fe(70) nanoparticles were heat-treated to achieve crystallinity at the different temperatures for 1 h. The Co(30)Fe(70) nanocrystallite by chemical reduction shows excellent soft magnetic behavior, such as high permeability, negligible coercivity, and high saturation magnetization like that of Co(30)Fe(70) bulk.  相似文献   
972.
We have synthesized heterostructured zinc oxide-aluminosilicate nanohybrids through a hydrothermal reaction between the colloidal suspension of exfoliated montmorillonite nanosheets and the sol solution of zinc acetate. According to X-ray diffraction, N2 adsorption-desorption isotherm, and field emission-scanning electron microscopic analyses, it was found that the intercalation of zinc oxide nanoparticles expands the basal spacing of the host montmorillonite clay, and the crystallites of the nanohybrids are assembled to form a house-of-cards structure. From UV-vis spectroscopic investigation, it becomes certain that calcined nanohybrid contains two kinds of the zinc oxide species in the interlayer space of host lattice and in mesopores formed by the house-of-cards type stacking of the crystallites. Zn K-edge X-ray absorption near-edge structure/extended X-ray absorption fine structure analyses clearly demonstrate that guest species in the nanohybrids exist as nanocrystalline zinc oxides with wurzite-type structure.  相似文献   
973.
We study deformations of functions on isolated singularities.A unified proof of the equality of Milnor and Tjurina numbersfor functions on isolated complete intersections singularitiesand space curves is given. As a consequence, the base spaceof their miniversal deformations is endowed with the structureof an F-manifold, and we can prove a conjecture of V. Goryunov,stating that the critical values of the miniversal unfoldingof a function on a space curve are generically local coordinateson the base space of the deformation. 2000 Mathematics SubjectClassification 32S05.  相似文献   
974.
UNEXPECTED SUBSPACES OF TENSOR PRODUCTS   总被引:1,自引:0,他引:1  
We describe complemented copies of 2 both in C(K1) C(K2) when at least one of the compact spaces Kiis not scattered and in L11)L12) when at least one of the measures is not atomic.The corresponding local construction gives uniformly complementedcopies of the in c0 c0. We continue the study of c0 c0 showing that it contains a complementedcopy of Stegall's space and proving that (c0 c0)' is isomorphicto , together with other results. In the last section we use Hardy spaces to find an isomorphiccopy of Lp in the space of compact operators from Lq to Lr,where 1 < p, q, r < and 1/r = 1/p + 1/q.  相似文献   
975.
[structure: see text]. The synthesis of two tamandarin B analogues in which the N,O-Me2Tyr5 unit was replaced by N-Me-phenylalanine (N-MePhe5) and (S)-2-(methylamino)-3-(naphthalen-2-yl)propanoic acid (N-MeNaphth5) is described. The choice of the macrocyclization site was crucial to achieve satisfactory macrolactamization. Coupling between norstatine (Nst1) and threonine (Thr6) afforded only a 15% yield, while lactamization between proline (Pro4) and the aromatic moiety could be achieved in 65% yield.  相似文献   
976.
Concise syntheses of orlistat (Xenical), a two-carbon transposed orlistat derivative, and valilactone are described that employ the tandem Mukaiyama aldol-lactonization (TMAL) process as a key step. This process allows facile modification of the alpha-side chain. Versatile strategies for modifying the delta-side chain are described, involving cuprate addition and olefin metathesis. Comparative antagonistic activity of these derivatives toward a recombinant form of the thioesterase domain of fatty acid synthase is reported along with comparative activity-based profiling.  相似文献   
977.
We investigate the creation of squeezing via operations subject to noise and losses and ask for the optimal use of such devices when supplemented by noiseless passive operations. Both single and repeated uses of the device are optimized analytically and it is proven that in the latter case the squeezing converges exponentially fast to its asymptotic optimum, which we determine explicitly. For the case of multiple iterations we show that the optimum can be achieved with fixed intermediate passive operations. Finally, we relate the results to the generation of entanglement and derive the maximal two-mode entanglement achievable within the considered scenario.  相似文献   
978.
FinFET domino logic with independent gate keepers   总被引:1,自引:0,他引:1  
Scaling of single-gate MOSFET faces great challenges in the nanometer regime due to the severe short-channel effects that cause an exponential increase in the sub-threshold and gate-oxide leakage currents. Double-gate FinFET technology mitigates these limitations by the excellent control over a thin silicon body by two electrically coupled gates. In this paper a variable threshold voltage keeper circuit technique using independent-gate FinFET technology is proposed for simultaneous power reduction and speed enhancement in domino logic circuits. The threshold voltage of a keeper transistor is dynamically modified during circuit operation to reduce contention current without sacrificing noise immunity. The optimum independent-gate keeper gate bias conditions are identified for achieving maximum savings in delay and power while maintaining identical noise immunity as compared to the standard tied-gate FinFET domino circuits. With the variable threshold voltage double-gate keeper circuit technique the evaluation speed is enhanced by up to 49% and the power consumption is reduced by up to 46% as compared to the standard domino logic circuits designed for similar noise margin in a 32 nm FinFET technology.  相似文献   
979.
Conventional scheduling algorithms usually adjust the clock cycle duration to the execution time of the longest operations. This results in large slack times wasted in those cycles with faster operations. To reduce the wasted times multi-cycle and chaining techniques have been employed. Chaining contributes to reduce the circuit latency if it is applied to the critical path operations, and multi-cycle operators usually result in smaller clock cycles. Both techniques are applied at the operation level, and thus their impact on the circuit performance is bounded by the selected latency. Additionally, they have limited reusability. The design methodology presented in this paper overcomes the limitations of previous techniques to obtain substantially faster circuits. It fragments some of the specification operations into several smaller ones that are handled independently. This way, some operations can begin before their predecessors have finished and can also be executed in several unconsecutive cycles. Furthermore, the fragmentation of operations favours the reusability of hardware resources, leading also to smaller designs.  相似文献   
980.
A new scan approach is described, named ‘Virtual Chain Partition’ (VCP) architecture, capable of substantially reducing the test application time, test data volume and test power. The VCP architecture maintains the original scan cell order. A simple procedure is proposed, which uses the scan test set generated for the original circuit to determine the maximum reduction in test cycles obtainable with the architecture and to select the most suitable configuration for each circuit. The experiments carried out with the ISCAS 89 benchmarks show that the VCP architecture allows considerable reductions to be achieved both for single and multiple scan chain circuits.  相似文献   
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