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101.
It is very common to find meta-analyses in which some of the studies compare 2 groups on continuous dependent variables and others compare groups on dichotomized variables. Integrating all of them in a meta-analysis requires an effect-size index in the same metric that can be applied to both types of outcomes. In this article, the performance in terms of bias and sampling variance of 7 different effect-size indices for estimating the population standardized mean difference from a 2 × 2 table is examined by Monte Carlo simulation, assuming normal and nonnormal distributions. The results show good performance for 2 indices, one based on the probit transformation and the other based on the logistic distribution. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
102.
This paper proposes an information model for tracing CNC manufacturing operations. The objective of the model is to assure that traceability data is comprehensive and available for every CNC machined product, independent of the relationship between the subcontractor and the contractor. The prominent feature of the model is a link between CNC report data for a product instance, the CAD design and the CAM data. This link enables users to browse the traceability data and understand the relationships between the manufacturing process, the CAD design and the CAM data. The link is independent of the systems used to build the CAD and CAM data, and allows the users to be sure the manufactured product contains the required characteristics. Then if a product instance fails, this linkage will make possible to analyze the trace data and identify any exceptions or unusual conditions in the manufacturing process.  相似文献   
103.
104.
The Capacitated Vehicle Routing Problem with Time Windows is an important combinatorial optimization problem consisting in the determination of the set of routes of minimum distance to deliver goods, using a fleet of identical vehicles with restricted capacity, so that vehicles must visit customers within a time frame. A large number of algorithms have been proposed to solve single-objective formulations of this problem, including meta-heuristic approaches, which provide high quality solutions in reasonable runtimes. Nevertheless, in recent years some authors have analyzed multi-objective variants that consider additional objectives to the distance travelled. This paper considers not only the minimum distance required to deliver goods, but also the workload imbalance in terms of the distances travelled by the used vehicles and their loads. Thus, MMOEASA, a Pareto-based hybrid algorithm that combines evolutionary computation and simulated annealing, is here proposed and analyzed for solving these multi-objective formulations of the VRPTW. The results obtained when solving a subset of Solomon’s benchmark problems show the good performance of this hybrid approach.  相似文献   
105.
This work describes a model of the biodegradation of phenol carried out by aerobic granules. These granules were obtained by culturing an activated sludge supernatant in a sequencing batch reactor fed with a synthetic waste water and subsequently, by acclimation to phenol (100 mg/L). The kinetics of phenol biodegradation by the aerobic granules was investigated over a wide range of initial phenol concentrations (40–1112 mg/L) in shake‐flask cultures. A Haldane‐type model was adjusted to the experimental results, which depicts successfully the phenol biodegradation profiles in the entire range of initial concentrations studied by using only one set of parameters. It is our view that the proposed model could contribute to the knowledge about the ability of aerobic granular systems to biodegrade toxic, inhibitory compounds such as phenol.  相似文献   
106.
Regenerating the load‐bearing tissues requires 3D scaffolds that balance the temporary mechanical function with the biological requirements. In functional tissue engineering, designing scaffolds with biomimetic mechanical properties could promote tissue ingrowth since the cells are sensitive to their local mechanical environment. This work aims to design scaffolds that mimic the mechanical response of the biological tissues under physiological loading conditions. Poly(L ‐lactide) (PLLA) scaffolds with varying porosities and pore sizes were made by the 3D‐plotting technique. The scaffolds were tested under unconfined ramp compression to compare their stress profile under load with that of bovine cartilage. A comparison between the material parameters estimated for the scaffolds and for the bovine cartilage based on the biphasic theory enabled the definition of an optimum window for the porosity and pore size of these constructs. Moreover, the finite element prediction for the stress distribution inside the scaffolds, surrounded by the host cartilaginous tissue, demonstrated a negligible perturbation of the stress field at the site of implantation. The finite element modeling tools in combination with the developed methodology for optimal porosity/pore size determination can be used to improve the design of biomimetic scaffolds. POLYM. ENG. SCI., 47:608–618, 2007. © 2007 Society of Plastics Engineers.  相似文献   
107.
Liquid chromatography coupled with mass spectrometry is an outstanding methodology for fast analysis of phenolic compounds in biological samples. Twenty two compounds were quickly and accurately identified in the methanolic extract of the Antarctic lichen Ramalina terebrata for the first time using ultra high pressure liquid chromatography coupled with photodiode array detector and high resolution mass spectrometry (UHPLC-PDA-Q/Orbitrap/MS/MS). In addition, the extract and the four compounds isolated from this species were tested for the inhibitory activity of tau protein aggregation, which is a protein involved in Alzheimer’s disease (AD). All compounds showed null activity with the exception of parietin, which it was able to inhibit aggregation process of tau in a concentration range between 3 µg/mL (10 µM) to 28 µg/mL (100 µM). In addition, we show how parietin interact with tau 306VQIVYK311 hexapeptide inside of the microtubule binding domain (4R) with the help of molecular docking experiments. Finally, the constituents present in the methanolic extract could possibly contribute to the established anti-aggregation activity for this extract and this in-depth analysis of the chemical composition of R. terebrata could guide further research into its medicinal properties and potential uses.  相似文献   
108.
RFID is a relatively heterogenous radio technology, where it is necessary to put an extra effort on security and privacy-related issues. As early as 2004, some authors suggested the use of a PRNG for increasing security. This was later questioned because many thought a PRNG implementation may go well beyond the very limited computational capabilities of low-cost RFID tags. However, its use has been ratified by EPCGlobal (EPC Class-1 Generation-2) and ISO (ISO/IEC 18000-6C). This motivates our proposal of a new PRNG, named LAMED, which is compliant with the standards and successfully passes several batteries of very demanding randomness tests (ENT, DIEHARD, NIST, and SEXTON). A study of its hardware complexity shows that LAMED can be implemented with slightly less than 1.6 K gates, and that pseudo-random numbers can be generated each 1.8 ms. So we can affirm this is a realist proposal both conforming with the EPC-G1C2 standard, and suitable for low-cost RFID tags.  相似文献   
109.
Timely run‐time software replacement techniques are a corner stone for reconciling real‐time systems development and dynamic behavior. Typical real‐time systems do not consider dynamic behavior because it deeply challenges predictability and timeliness. Current efforts are starting to merge the safe and predictable execution with a controllable level of dynamicity by imposing a set of bounds and limitations to the system dynamic behavior. One of the obstacles for this is how to time‐bound the different operations required to effectively implement component replacement. In this paper, the main challenges for this problem are identified, and a model to ensure that components can be replaced at run time preserving the temporal properties of the system is provided that also avoids failures in replacements. A real example and simulations of our replacement model are provided that validate the presented ideas. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
110.
This paper describes a new approach for sensing electrochemically active substrates in microfluidic systems. This two-electrode sensor relies on electrochemical detection at one electrode and electrogenerated chemiluminescent (ECL) reporting at the other. Each microfabricated indium tin oxide electrode is located in a separate microfluidic channel, but the channels are connected downstream of the electrodes to maintain a complete electrical circuit. Because of laminar flow, there is no bulk mixing of the fluids in the detecting and reporting channels. This approach allows the ECL reaction to be physically and chemically decoupled from the sensing channel of the device, which greatly expands the number of analytes that can be detected. However, because the cathode and anode are connected, electron-transfer processes occurring at the sensing electrode are electrically coupled to the ECL reaction. Charge balance permits the ECL light output to be quantitatively correlated to electrochemical reductions at the cathode. The system is used to detect Fe(CN)6(3-), Ru(NH3)6(3+), and benzyl viologen and report their presence via Ru(bpy)3(2+) (bpy = bipyridine) luminescence. Each different redox target initiates ECL at a unique potential bias related to its standard redox potential. The influence of the concentrations of Ru(bpy)3(2+) and the target analytes is discussed.  相似文献   
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