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101.
This paper presents possible approaches to the design of a novel low-voltage, low-power, and high-precision current conveyor of the second generation (CCII±) based on the bulk-driven folded cascode operational transconductance amplifier (OTA) with extended input common-mode voltage range. This CCII± utilizes bulk-driven differential pairs to obtain a nearly rail-to-rail input stage at a low supply voltage. The proposed conveyor operates at a low supply voltage of ±400 mV with a reduced power consumption of only 64 μW. A current-mode multifunction filter is presented as an application of the CCII±. This filter provides five transfer functions simultaneously, namely low-pass, band-pass, high-pass, notch, and all-pass. The filter has the following properties and advantages: it employs three bulk-driven current conveyors BD-CCII±, three grounded resistors, and two grounded capacitors, which is suitable for integrated circuit implementation. Furthermore, the input signal is connected to the low-impedance X terminal of the BD-CCII± whereas the output signals are taken from the high-impedance output terminals Z+ and Z−. Finally, the pole frequency and quality factor of the designed filter are tunable independent of each other. PSpice simulation results using the 0.18 μm CMOS technology are included to prove the results. 相似文献
102.
Improve on/off ratio of organic heterojunction transistors by adopting single-sandwich configuration
Jianwu Shi Hua Wang Haibo Wang Hongkun Tian Yanhou Geng Donghang Yan 《Solid-state electronics》2011,61(1):65-68
Organic heterojunction transistors (OHJTs) based on 5,5′″-bis(naphtha-2-yl)-2,2′:5″,2′″-quaterthiophene (NaT4)/copper-hexadecafluoro-phthalocyanine (F16CuPc) heterojunction were fabricated in single-sandwich and sandwich configurations, respectively. All the devices operated in depletion-accumulation (normally-on) mode. High field-effect mobility of 0.35 cm2/Vs was obtained for all devices, which was higher than that, 0.20 cm2/Vs of the devices with NaT4 as active layer. The on/off ratio of 1 × 105 was obtained for OHJTs with single-sandwich configuration, which is three orders of magnitude higher than that of OHJTs with sandwich configuration. Compared with OHJTs with sandwich configuration, the higher on/off ratio was mainly determined by the lower off state current in OHJTs with single-sandwich configuration. In OHJTs with single-sandwich configuration, the well-type shield effect of the source and drain electrodes caused a very narrow empty region in F16CuPc film, which is responsible for the lower off state current. 相似文献
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Yaru Fu Xiaoyu Jiang Zhaolin Jiang Seong Tae Jhang 《Journal of Applied Analysis & Computation》2020,10(4):1599-1613
In this paper, tridiagonal Toeplitz matrix (type I, type II) with opposite-bordered rows are introduced. Main attention is paid to calculate the determinants, the inverses and the eigenpairs of these matrices. Specifically, the determinants of an $n\times n$ tridiagonal Toeplitz matrix with opposite-bordered rows can be explicitly expressed by using the $(n-1)$th Fibonacci number, the inversion of the tridiagonal Toeplitz matrix with opposite-bordered rows can also be explicitly expressed by using the Fibonacci numbers and unknown entries from the new matrix. Besides, we give the expression of eigenvalues and eigenvectors of the tridiagonal Toeplitz matrix with opposite-bordered rows. In addition, some algorithms are presented based on these
theoretical results. Numerical results show that the new algorithms have much better computing efficiency than some existing algorithms studied recently. 相似文献
106.
《Physics and Chemistry of Liquids》2012,50(6):819-821
The recent study of He and You [P.-S. He and W.-L. You, Int. J. Mod. Phys. B26, 1250107 (2012)] on the relation between superfluid and condensate densities in a two-dimensional weakly interacting Boson system assumed a δ(x???x′) interaction between two particles at sites x and x′. The main purpose of this article is to point out the sensitivity of the conclusions of He and You to the choice of interaction. Thus, it is known for logarithmic interactions that one can have superfluidity without a condensate. Finally, some related ideas are mentioned in relation to superfluidity in liquid 4 He at exceedingly low temperatures. 相似文献
107.
《Analytical letters》2012,45(13):1367-1384
Abstract Interferences from small amounts of sea salt in the determination of cadmium and lead were investigated. Test samples were made to mimic solutions obtained after extraction of sea water for trace metal analysis. Sea salt concentrations in the range 0–400 mg/l were investigated. Background absorption from this salt was high but easily minimised through the addition of nitric acid (2 % v/v). Sensitivity reductions due to the salt were considerable and varied from one graphite tube to the other. This problem was overcome by the addition of 1000 mg lanthanum per litre of sample. The positive effect of the lanthanum matrix modification is thought to be due to a change of the graphite tube surface. 相似文献
108.
Anna‐Marie Zorn Christopher Barner‐Kowollik 《Journal of polymer science. Part A, Polymer chemistry》2012,50(12):2366-2377
In the present study, n‐butyl acrylate macromonomer (BAMM) (Mn = 1900 g mol?1; PDI = 1.96) has been synthesized via a high‐temperature polymerization process. Subsequently, the olefinic termini of the BAMM have been transformed into a diol via a dihydroxylation process using KMnO4 as an oxidizing agent. The OH‐terminated macroinitiator pBA(OH)2 has subsequently been employed for the ring‐opening polymerization (ROP) of ε‐caprolactone via various catalytic systems, that is, organo‐(1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene), metal (tin(II) 2‐ethylhexanoate), and enzymatic catalysis (Novozym® 435). The obtained pBA‐b‐pCL block copolymers and the initiation efficiency of the BAMM macroinitiator have been investigated via size exclusion chromatography (SEC), electrospray ionization–mass spectrometry (ESI‐MS) hyphenated with SEC and liquid chromatography at the critical conditions of both poly(ε‐caprolactone) (pCL) and pBA. The in vitro enzyme catalysis (eROP) approach proved to be the most efficient catalysis system due to minor transesterification side reactions during the polymerization process. However, side reactions such as transesterifications occur in each catalytic system and—while they cannot be suppressed—they can be minimized. The species generated during the eROP process include the desired block copolymer pBA‐b‐pCL as main species as well as pCL homopolymer and residual macroinitiator pBA(OH)2. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
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