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101.
K. K. Makhija Arabinda Ray R. M. Patel U. B. Trivedi H. N. Kapse 《Bulletin of Materials Science》2005,28(1):9-17
A sensor for ammonia gas and ethanol vapour has been fabricated using indium oxide thin film as sensing layer and indium tin
oxide thin film encapsulated in poly(methyl methacrylate) (PMMA) as a miniature heater. For the fabrication of miniature heater
indium tin oxide thin film was grown on special high temperature corning glass substrate by flash evaporation method. Gold
was deposited on the film using thermal evaporation technique under high vacuum. The film was then annealed at 700 K for an
hour. The thermocouple attached on sensing surface measures the appropriate operating temperature.
The thin film gas sensor for ammonia was operated at different concentrations in the temperature range 323–493 K. At 473 K
the sensitivity of the sensor was found to be saturate. The detrimental effect of humidity on ammonia sensing is removed by
intermittent periodic heating of the sensor at the two temperatures 323K and 448 K, respectively. The indium oxide ethanol
vapour sensor operated at fixed concentration of 400 ppm in the temperature range 293–393 K. Above 373 K, the sensor conductance
was found to be saturate. With various thicknesses from 150–300 nm of indium oxide sensor there was no variation in the sensitivity
measurements of ethanol vapour. The block diagram of circuits for detecting the ammonia gas and ethanol vapour has been included
in this paper. 相似文献
102.
A general formulation for modeling frictional contact interactions in a constrained multi-flexible body system is outlined in this paper. The governing differential-algebraic equations (DAE) for the constrained motion contains not only a frictional term but also, the unknown contact conditions. These contact conditions are characterized by a set of nonlinear complementarity equations. To demonstrate the model, a falling-spinning beam impacting a rough elastic ground with damping is solved and comparison with Stewart-Trinkles' results provided. 相似文献
103.
The effect of melting temperature, time, and the type of raw material, NaNO3 or Na2CO3, as a source for Na2O on the glass formation for a Na2O·4TeO2(NT4) melt was investigated. Melting with NaNO3 at 750°C for a short time (15 min) produced a glass that is slightly more chemically durable and more resistant to crystallization than glasses melted at a higher temperature (800°C), or for a longer time (60 min), or using Na2CO3. A thin surface layer (<1.5 nm) that contains some nitrogen and a higher concentration of bridging oxygen is suspected to be the reason for the higher chemical durability and higher resistance to crystallization for this glass. However, melting at 800°C for 60 min produced a glass, whose properties were independent of the type of raw material, NaNO3 or Na2CO3, used. 相似文献
104.
This paper reports the presence of Al- O- Al linkages in an aluminosilicate glass where Si/Al = 1 by using 2D17O triple quantum MAS NMR technique (3Q MASNMR). The experiments were performed at external magnetic fields of 8.4 and 14.4T.
Despite17OMAS NMR spectra of the sample in both fields do not give much information about the different kinds of linkages in the sample,
3Q MAS NMR spectrum shows clear evidence that there are some amounts of Al-O-Al linkages in the sample giving two completely
resolved peaks. These two peaks were attributed to the Si-O-Al and Al-O-Al linkages on the basis of their chemical shifts
and, quadrupolar coupling constants which are quite sensitive to the local structure. 相似文献
105.
Lake RE Dean A Maheswaranathan N Lange AP Ray MP Sosolik CE 《The Review of scientific instruments》2008,79(1):013703
We demonstrate that scanning tunneling microscope tip-surface crash events can be utilized as an efficient means for the creation of predefined island configurations for diffusion studies. Using this method, islands of varying size can be created and placed in close proximity, increasing the probability of initiating and observing coalescence events. Data obtained from crash initiated events on a Ag(111) surface are presented. Relaxation time exponents extracted from these data confirm that our method gives results consistent with previous, sputter-obtained island coalescence studies. We also describe an instrument-control routine developed for these measurements that utilizes commercial imaging and off-the-shelf automation software to automate the tracking of islands or other features by the microscope. 相似文献
106.
Conley R Liu C Qian J Kewish CM Macrander AT Yan H Kang HC Maser J Stephenson GB 《The Review of scientific instruments》2008,79(5):053104
A multilayer Laue lens (MLL) is an x-ray focusing optic fabricated from a multilayer structure consisting of thousands of layers of two different materials produced by thin-film deposition. The sequence of layer thicknesses is controlled to satisfy the Fresnel zone plate law and the multilayer is sectioned to form the optic. An improved MLL geometry can be created by growing each layer with an in-plane thickness gradient to form a wedge, so that every interface makes the correct angle with the incident beam for symmetric Bragg diffraction. The ultimate hard x-ray focusing performance of a wedged MLL has been predicted to be significantly better than that of a nonwedged MLL, giving subnanometer resolution with high efficiency. Here, we describe a method to deposit the multilayer structure needed for an ideal wedged MLL and report our initial deposition results to produce these structures. 相似文献
107.
Virtual environments (VE) are becoming an important tool for simulating manufacturing systems. A problem in their adoption is the lack of an easy and effective approach to building large and complex virtual environments that are required by many manufacturing simulation tasks. This paper reports on research into this problem and presents a novel approach - domain-analysis-based top-down construction - to constructing complex virtual manufacturing environments. Based on this approach, a software system is designed and implemented to provide easy-to-use and flexible tools that enable users to construct virtual environments rapidly and with minimum modelling effort. 相似文献
108.
109.
Evaluation of fire performance of organic fire retardant free acrylic based coatings applied on various building materials by cone calorimetric method 下载免费PDF全文
Fire performance of water‐based plaster systems containing acrylic copolymer binder and non‐flammable mineral and ceramic fillers intended for decorative coating application was determined by cone calorimetric method. The coatings were applied on common building substrate materials used in construction sector, namely, Medium Density Fibre (MDF) boards, Gypsum Boards (GIB) and Stainless Steel (SS), and the different plaster finishes attempted on these substrates were Tierrafino, Suave and Bone China respectively. Group numbers of the different test samples were also evaluated following the Kokkala method. Based on various measurements, especially heat release, smoke evolution, mass loss data and the Group number estimates, it is evident that these organic fire retardant free coatings can offer good fire safety if applied on appropriate substrates like GIB or SS. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
110.
Abstract In this study the hydraulic characteristics and the start‐up of anaerobic rotating biological contactor (AnRBC) were investigated experimentally and theoretically. Results of tracer study showed that the AnRBC reactor is a well‐mixed reactor in the first and second stages. Start‐up of the AnRBC reactor was successfully carried out using high strength synthetic wastewaters at hydraulic retention time of 21.6 hours, organic surface loading of 111.4 g‐COD/m2?d, organic volumetric loading of 13.33 Kg‐COD/m3?d, disk rotational speed of 12 rpm and 100% disk submergence. In the steady‐state operating condition, the removal efficiencies of soluble COD and BOD could be up to 71% and 76% for the inlet COD and BOD concentrations of 12,000 and 7,267 mgL‐1, respectively. The microscopic observations after start‐up of the AnRBC reactor showed that the acetogenic bacteria are significant in the first two stages while the methanogenic bacteria predominate in the last two stages. 相似文献