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51.
A VERY SIMPLE SET OF PROCESS CONTROL RULES 总被引:2,自引:0,他引:2
52.
Using methods of dynamical systems, we construct examples of smooth, almost universally observable vector fields on the projective 1-space. These vector fields are non-linear, non-autonomous and their time dependence is almost periodic. 相似文献
53.
G. S. Gopalakrshna M. J. Mahesh S. P. Madhu K. G. Ashamanjari M. A. Shridhara S. Prasad 《Journal of Materials Science》2006,41(5):1423-1427
CsNiP and 2(LiZnHP2O7) crystals were synthesized by hydrothermal technique at moderate P-T conditions. Solubility results of both the compound
shown positive thermal coefficient and single crystal X-ray studies revealed, CsNiP crystallized in hexagonal system with
cell parameters; a = 7.173(2), c = 5.944(9) Å, V = 264.87(7) Å3 and space group P63/mmc and 2(LiZnHP2O7) crystallized in orthorhombic system with cell parameters; a = 12.3636 Å, b = 27.5330 Å, c = 6.8647 Å and space group, Pca21 exhibiting ring type of cavities with open aperture in the structure. CsNiP is a frequency
dependent paramagnetic and 2(LiZnHP2O7) is a diamagnetic. 相似文献
54.
We present the surface modification of Si(111) into silicon nitride by exposure to energetic N2+ ions. In-situ UHV experiments have been performed to optimize the energy and fluence of the N2+ ions to form silicon nitride at room temperature (RT) and characterized in-situ by X-ray photoelectron spectroscopy. We have used N2+ ion beams in the energy range of 0.2–5.0 keV of different fluence to induce surface reactions, which lead to the formation of SixNy on the Si(111) surface. The XPS core level spectra of Si(2p) and N(1s) have been deconvoluted into different oxidation states to extract qualitative information, while survey scans have been used for quantifying of the silicon nitride formation, valence band spectra show that as the N2+ ion fluence increases, there is an increase in the band gap. The secondary electron emission spectra region of photoemission is used to evaluate the change in the work function during the nitridation process. The results show that surface nitridation initially increases rapidly with ion fluence and then saturates. 相似文献
55.
Mahesh Kumar G. Janardhana Reddy G. Ravi Kiran M. A. Mohammed Aslam O. Anwar Beg 《亚洲传热研究》2019,48(3):1067-1092
Entropy generation is an important aspect of modern thermal polymer processing optimization. Many polymers exhibit strongly non‐Newtonian effects and dissipation effects in thermal processing. Motivated by these aspects in this study, a numerical analysis of the entropy generation with viscous dissipation effect in an unsteady flow of viscoelastic fluid from a vertical cylinder is presented. The Reiner‐Rivlin physical model of grade 2 (second‐grade fluid) is used, which can envisage normal stress variations in polymeric flow‐fields. Viscosity variation is included. The obtained governing equations are resolved using implicit finite difference method of Crank‐Nicolson type with well imposed initial and boundary conditions. Key control parameters are the second‐grade viscoelastic fluid parameter (), viscosity variation parameter (), and viscous dissipation parameter (). Also, group parameter (), Grashof number (Gr), and Prandtl number (Pr) are examined. Numerical solutions are presented for steady‐state flow variables, temperature, time histories of friction, wall heat transfer rate, entropy, and Bejan curves for distinct values of control parameters. The results specify that entropy generation decreases with augmenting values of , , and Gr. The converse trend is noticed with increasing Pr and . Furthermore, the computations reveal that entropy and Bejan lines only occur close to the hot cylinder wall. 相似文献
56.
Mahesh Kumar Mohana K. RajpalkeThirumaleshwara N. Bhat Basanta Roul Neeraj SinhaA.T. Kalghatgi S.B. Krupanidhi 《Materials Letters》2011,65(9):1396-1399
Indium nitride (InN) epilayers have been successfully grown by nitrogen-plasma-assisted molecular beam epitaxy (NPA-MBE) on Si (111) substrates using different buffer layers. Growth of a (0001)-oriented single crystalline wurtzite-InN layer was confirmed by high resolution X-ray diffraction (HRXRD). The Raman studies show the high crystalline quality and the wurtzite lattice structure of InN films on the Si substrate using different buffer layers and the InN/β-Si3N4 double buffer layer achieves minimum FWHM of E2 (high) mode. The energy gap of InN films was determined by optical absorption measurement and found to be in the range of ~ 0.73-0.78 eV with a direct band nature. It is found that a double-buffer technique (InN/β-Si3N4) insures improved crystallinity, smooth surface and good optical properties. 相似文献
57.
Mahesh Kumar Gudala Janardhana Reddy Nedunuri Naresh Kumar Osman Anwar Bg 《亚洲传热研究》2019,48(2):582-600
In the present article, the transient rheological boundary layer flow over a stretching sheet with heat transfer is investigated, a topic of relevance to non‐Newtonian thermal materials processing. Stokes couple stress model is deployed to simulate non‐Newtonian characteristics. Similarity transformations are utilized to convert the governing partial differential equations into nonlinear ordinary differential equations with appropriate wall and free stream boundary conditions. The nondimensional boundary value problem emerging is shown to be controlled by a number of key thermophysical and rheological parameters, namely the rheological couple stress parameter (), unsteadiness parameter (), Prandtl number (Pr), buoyancy parameter . The semi‐analytical differential transform method (DTM) is used to solve the reduced nonlinear coupled ordinary differential boundary value problem. A numerical solution is also obtained via the MATLAB built‐in solver “bvp4c” to validate the results. Further validation with published results from the literature is included. Fluid velocity is enhanced with increasing couple stress parameter, whereas it is decreased with unsteadiness parameter. Temperature is elevated with couple stress parameter, whereas it is initially reduced with unsteadiness parameter. The flow is accelerated with increasing positive buoyancy parameter (for heating of the fluid), whereas it is decelerated with increasing negative buoyancy parameter (cooling of the fluid). Temperature and thermal boundary layer thickness are boosted with increasing positive values of buoyancy parameter. Increasing Prandtl number decelerates the flow, reduces temperatures, increases momentum boundary layer thickness, and decreases thermal boundary layer thickness. Excellent accuracy is achieved with the DTM approach. 相似文献
58.
R. Mahesh A. P. Vinod Edmund M-K. Lai Amos Omondi 《Journal of Signal Processing Systems》2011,62(2):157-171
The ability to support multiple channels of different communication standards, in the available bandwidth, is of importance
in modern software defined radio (SDR) receivers. An SDR receiver typically employs a channelizer to extract multiple narrowband
channels from the received wideband signal using digital filter banks. Since the filter bank channelizer is placed immediately
after the analog-to-digital converter (ADC), it must operate at the highest sampling rate in the digital front-end of the
receiver. Therefore, computationally efficient low complexity architectures are required for the implementation of the channelizer.
The compatibility of the filter bank with different communication standards requires dynamic reconfigurability. The design
and realization of dynamically reconfigurable, low complexity filter banks for SDR receivers is a challenging task. This paper
reviews some of the existing digital filter bank designs and investigates the potential of these filter banks for channelization
in multi-standard SDR receivers. We also review two low complexity, reconfigurable filter bank architectures for SDR channelizers
based respectively on the frequency response masking technique and a novel coefficient decimation technique, proposed by us
recently. These filter bank architectures outperform existing ones in terms of both dynamic reconfigurability and complexity. 相似文献
59.
Glutamate is an important excitatory signal in the hypothalamus for the steroid-mediated preovulatory gonadotropin surge. Steroids may exert this action by regulating glutamate receptor levels or glutamate release, or both. Work in our laboratory found no changes in NMDA and kainate receptor binding in the hypothalamus of castrated or castrated plus steroid-replaced male and female rats. Likewise, we found that NMDA and kainate binding did not change over the onset of puberty in the female rat. A competitive quantitative RT-PCR assay using exogenous internal standards was used to measure NMDAR1, GluR1, and beta-actin mRNAs levels. NMDAR1 and GluR1 expression was examined in the preoptic hypothalamic area and in the medial basal hypothalamus at Postnatal Days 10, 15, 20, 25, 30, 32, 34, 36, 40, and 63. A transient increase in GluR1 mRNA levels in the preoptic hypothalamic area was observed on Day 20, with all other time points showing comparable levels. NMDAR1 levels in the POA and medial basal hypothalamus did not change significantly at any of the time points; in contrast, however, AMPA receptor binding levels were increased in the hypothalamus at the time of puberty in the female rat. Thus, in addition to the previously reported elevation of glutamate release rates in the hypothalamus at the time of puberty, AMPA receptors may also be elevated and play a role in mediating glutamate regulatory effects on the timing of puberty in the female rat. 相似文献
60.
In this study, automation of the circuit board assembly process is considered using artificial neural networks with knowledge-based systems. Basic issues in achieving intelligent control that can adapt to changing conditions in the assembly process are discussed. The feasibility of using neural networks for pattern recognition and optimum component insertion sequence generation is examined. The study provides a basic foundation for designing a conceptual architecture for adaptive intelligent control of circuit board assembly. Real-time testing of component recognition is conducted using adaptive resonance theory (ART 1) as a neural network paradigm. 相似文献