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71.
Maiti B. Tobin P.J. Okada Y. Reid K.G. Ajuria S.A. Hegde R.I. Kaushik V. 《Electron Device Letters, IEEE》1996,17(6):279-281
Reoxidation of an oxynitride gate dielectric grown by NO anneal of thermal oxide has been studied. This process has demonstrated ~3-5X improvement of QBD of active edge intensive capacitors in comparison to thermal oxide, N2O and NO oxynitride. This improvement is believed to be due to the reduction of local thinning of the gate dielectric at the field oxide edge which also reduces local build-up of positive charge near the gate electrode at the isolation edges 相似文献
72.
M. Maiti 《International Journal of Fracture》1979,15(4):389-393
Dislocation layers have been utilized to study the effect of rigid inclusion on the crack extension in an infinite body and thereby to derive the crack extension condition from Irwin's criterion. Some particular cases have also been considered.
Résumé On a eu recours aux couches de dislocation pour étudier l'effet d'une inclusion rigide sur l'extension d'une fissure dans un corps infini et déterminer en conséquence les conditions d'extension d'une fissure en utilisant le critère d'Irwin. Certains cas particuliers ont également été considérés.相似文献
73.
The problem of opening two coplanar Griffith cracks in an infinite elastic medium has been considered in this note. The application of Somigliana's method to this mixed boundary value problem leads to a Föppl integral equation, whose solution has been derived in closed form with the help of a convolution theorem connected with finite Hilbert transforms.
Résumé On a considéré, dans ce mémoire, le problème de l'ouverture de 2 fissures coplanaires de Griffith dans un milieu élastique infini. L'application de la méthode de Somigliana au problème de la valeur de la frontière indéfinie conduit à une équation intégrale de Föppl dont la solution a été dérivée sous une forme fermée en utilisant un théorème de convolution connecté à une transformée finie de Hilbert.相似文献
74.
For the last few years fast ion conducting lithium glasses are being studied due to their potential use in advanced electrochemical
devices. A number of glass systems containing oxides, sulphides and other lithium compounds prepared by both conventional
cooling and rapid quenching techniques have been reported. In this paper we review the transport properties of lithium ion
conducting glasses. The special features of the ionic conduction process have been highlighted and some experimental techniques
to study transport properties have been described. Some of the common observations of the properties have been discussed and
finally some important problems for future development have been pointed out. 相似文献
75.
Xylanase effects on softwood pulp delignification were investigated experimentally and using mathematical models. The effect of xylanase molecular size on pulp delignification was investigated. As xylanase molecular weight decreased from 67 kDaltons to 20 kDaltons, lignin removal from pulp increased from 30 wt% to 48 wt%, respectively. The rate of xylanase-aided pulp delignification was studied using a batch system. The rate-data was fitted to a mathematical model of the batch system that enabled estimation of process parameters including xylanase and lignin effective diffusivities, lignin mass transport coefficient, and effective particle diameter for mass transport. Parameter values thus obtained were used to simulate the semi-batch delignification process, which predicted 84.6% of lignin available to UGA xylanase (MW=39,000 Daltons) would be removed in 2.5 h. 相似文献
76.
A problem of stress analysis for a long circular cylinder has been dealt with in this paper by analytical methods. The cylinder is assumed to be made of an elastic material which is not isotropic but the elastic properties are considered to be similar in directions perpendicular to the axis of the cylinder. The body under consideration is supposed to contain an infinite row of penny-shaped cracks which are parallel to each other and located periodically along the cylinder-axis. All the cracks are assumed to be opened by the same distribution of internal pressure on their surfaces. By choosing appropriate potential functions the problem is treated mathematically through the use of integral equation approach. Numerical results for the stress-intensity factor, the strain energy and the critical pressure, obtained on the basis of the analysis are also given. 相似文献
77.
A.-H. I. Mourad S. K. Maiti 《Fatigue & Fracture of Engineering Materials & Structures》1996,19(1):75-84
Abstract Mode II stable crack extension has been examined for an aircraft grade aluminium alloy D16AT. Both theoretical and experimental results are presented. The experimental observations include load displacement diagrams, plastic wake, crack front tunnelling and scanning electron micrographs of the fracture surfaces. The crack shows a tendency for in-plane extension, and the fracture surface is very flat, smooth and free of any dimples. The crack front advances with neghgible tunnelling at all stages of extension. The span of mode II stable crack growth (SCG) is longer than in the case of mode I SCG reported earlier for the same material and there is also more extensive plastic deformation. In the presence of a slight mode I load, the crack grows out-of-plane and the fractured surface facets resemble that of a mode I or mixed-mode dimpled fracture. The theoretical study is based on a finite element analysis using small deformation theory and incremental plasticity. Some of the experimental results have been theoretically predicted using the COA criterion as the governing criterion. The theoretical results include load-displacement diagrams, crack edge displacement curves, plastic zones and the J resistance curves. There is good agreement between the load-displacement diagrams. The initiation and maximum loads differ by less than 15%. The J resistance curve has a constant slope over the whole span of stable crack growth. 相似文献
78.
Tapas Kumar Maiti Satya Sopan Mahato Pinaki Chakraborty Chinmay Kumar Maiti Subir Kumar Sarkar 《Journal of Computational Electronics》2010,9(1):1-7
Negative Bias Temperature Instability (NBTI) in p-MOSFETs is a serious reliability concern for digital and analog CMOS circuit
applications. Strain in the channel region affects negative bias temperature instabilities, low frequency noise, radiation
hardness, gate oxide quality and hot carrier performance. The understanding of these phenomena in strain-engineered p-MOSFETs
from fundamental physics is essential. In this paper, technology CAD (TCAD) has been used to study the effects of strain on
the negative bias temperature instabilities in p-MOSFETs. A quasi two dimensional (quasi-2D) physics-based Coulomb scattering
mobility model for strained-Si has been developed and implemented in Synopsys Sentaurus Device tool for device simulation
to understand NBTI in strain-engineered p-MOSFETs. 相似文献
79.
Pijush Kanti Mandal Rabindranath Majumdar Kalyan Kumar Mukherjee Omprakash Chakrabarti Himadri Sekhar Maiti 《Journal of Porous Materials》2009,16(2):157-163
Stems of Jute (Corchorus capsularis L.) and sticks of Cane (Calamus rotang L.), plants of immense economic importance in the Indian subcontinent, were converted into carbonaceous perform (C-preform)
maintaining the circular cylindrical shapes in lengths of 0.02–0.05 m by controlled thermal processing. Plant material precursors
were characterized by analysis of elemental (C, H, N) and molecular (cellulose, hemicellulose, lignin) compositions, by determination
of Bulk Density (BD) and ash content and by optical microscopy and X-ray diffractometry (XRD). C-preforms were also characterized
by measurement of BD and by Scanning Electron Microscopy (SEM) and XRD. The C-preforms were further subjected to infiltration
with Si-melt (1823–1923 K) under vacuum. Spontaneous infiltration and reaction yielded composite ceramics preserving the morphology
of native Jute Stem (JS) and Cane Stick (CS) precursors on macro and micro scale. The materials were found to be duplex composites
with Si and β-SiC as crystalline phases. The end ceramics were characterized by measurement of BD, and also by SEM and by
XRD. Measured mean BD of the Si/SiC composites derived from JS and CS were 2190 Kg m−3 and 2250 Kg m−3. The respective volume fractions of large diameter (>100 μm) bulk pores were 0.134 and 0.204, in the composites derived from
JS and CS. Taking into account the measured volume fraction internal pores of 0.11 and 0.149, the volume fractions of SiC
were calculated to be 0.136 and 0.307 in the composites derived from JS and CS respectively, closely tallying with those calculated
from the C-preform bulk densities. The cellular Si/SiC ceramics derived from JS and CS having special morphologies with long
and large porous channels and oriented growth of constituent phases are likely to be suitable for devices such as high temperature
insulators, catalyst support structures for gas phase reactions at elevated temperatures, molten metal filters and others. 相似文献
80.
In this article, morphological modification of Saccharum spontaneum L, a natural fiber through graft copolymerization with methylmethacrylate using ferrous ammonium sulfate—potassium per sulfate redox initiator has been reported. Different reaction parameters such as reaction temperature, time, initiator molar ratio, monomer concentration, pH and solvent were optimized to get maximum graft yield (144%). The graft copolymers thus formed were characterized by Fourier transform infrared, scanning electron microscopy, X‐ray diffraction and thermogravimetric, differential thermal analysis, and differential thermogravimetric techniques. Graft copolymer has been found to be more moisture resistant and also showed higher chemical and thermal resistance. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献