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21.
As service-oriented computing increases, so does the role of e-contracts in helping business partners automate contractual agreements and relationships. The key challenge is to translate traditional contracts into executable e-contracts in a way that facilitates runtime monitoring and management. As research in this area progresses, organizations will have different approaches for modeling, implementing, and managing e-contracts. For now, developers must contend with several key research issues and challenges. 相似文献
22.
We have built a database that provides term vector information for large numbers of pages (hundreds of millions). The basic operation of the database is to take URLs and return term vectors. Compared to computing vectors by downloading pages via HTTP, the Term Vector Database is several orders of magnitude faster, enabling a large class of applications that would be impractical without such a database. This paper describes the Term Vector Database in detail. It also reports on two applications built on top of the database. The first application is an optimization of connectivity-based topic distillation. The second application is a Web page classifier used to annotate results returned by a Web search engine. 相似文献
23.
24.
Sudip Misra P. Venkata Krishna Akhil Bhiwal Amardeep Singh Chawla Bernd E. Wolfinger Changhoon Lee 《The Journal of supercomputing》2012,62(1):4-23
Reliable routing of packets in a Mobile Ad Hoc Network (MANET) has always been a major concern. The open medium and the susceptibility of the nodes of being fault-prone make the design of protocols for these networks a challenging task. The faults in these networks, which occur either due to the failure of nodes or due to reorganization, can eventuate to packet loss. Such losses degrade the performance of the routing protocols running on them. In this paper, we propose a routing algorithm, named as learning automata based fault-tolerant routing algorithm (LAFTRA), which is capable of routing in the presence of faulty nodes in MANETs using multipath routing. We have used the theory of Learning Automata (LA) for optimizing the selection of paths, reducing the overhead in the network, and for learning about the faulty nodes present in the network. The proposed algorithm can be juxtaposed to any existing routing protocol in a MANET. The results of simulation of our protocol using network simulator 2 (ns-2) shows the increase in packet delivery ratio and decrease in overhead compared to the existing protocols. The proposed protocol gains an edge over FTAR, E2FT by nearly 2% and by more than 10% when compared with AODV in terms of packet delivery ratio with nearly 30% faulty nodes in the network. The overhead generated by our protocol is lesser by 1% as compared to FTAR and by nearly 17% as compared to E2FT when there are nearly 30% faulty nodes. 相似文献
25.
N. D. V. N. S. Murali Krishna Ligy Philip 《Clean Technologies and Environmental Policy》2005,7(4):285-293
Nitrogen dioxide (NO2) removal efficiency of a biotrikling filter was evaluated under different operating conditions. Activated alumina (AA) was
used as the immobilization matrix for Thiobacillus denitrificans (T. denitrificans) in the biotrickling filter. Batch studies were conducted to find out the degradation kinetics of nitrate and nitrite for
a concentration range of 600–10,000 mg/L expressed as nitrogen. Nitrite exhibited maximum degradation rate followed by nitrate.
Electron acceptor in the form of NO2 gas showed least removal efficiency. Bio-kinetic parameters for T. denitrificans, by utilizing nitrate and nitrite as electron acceptors, were also evaluated. The μmax (Maximum specific growth rate) and YT (Yield coefficient) values for T. denitrificans in the presence of nitrate and nitrite were 1.03 h−1, 0.275 and 0.63 h−1, 0.1316 respectively. Column study was conducted to find the adsorption and desorption potential of activated alumina. The
adsorbed NO2 from AA could easily be desorbed using distilled water with an efficiency of 76±0.8%. Once fed batch studies were conducted
to evaluate the NO2 removal efficiency by a biotrickling filter. With an influent NO2 gas concentration of 2,735 ppm, the reactor could achieve a removal efficiency of 99% within 2 min from gas phase and within
96 h from the liquid phase, with an average biomass concentration of 200 mg/g of AA. The mechanism of NO2 gas removal in the biotrickling filter seems to be the dissolution of NO2 in water to form NO3−, conversion of NO3− to NO2
−, and finally to N2 gas. 相似文献
26.
Power and energy constraints are becoming increasingly prevalent in real-time embedded systems. Voltage-scaling is a promising technique to reduce energy and power consumption: clock speed tends to decrease linearly with supply voltage while power consumption goes down quadratically. We therefore have a tradeoff between the energy consumption of a task and the speed with which it can be completed. The timing constraints associated with real-time tasks can be used to resolve this tradeoff. In this paper, we present two algorithms for voltage-scaling. Assuming that a processor can operate in one of two modes: high voltage and low voltage, we show how to schedule the voltage settings so that deadlines are met while reducing the total energy consumed. We show that significant reductions can be made in energy consumption. 相似文献
27.
Ch. R. V. S. Nagesh Ch. Sridhar Rao N. B. Ballal P. Krishna Rao 《Metallurgical and Materials Transactions B》2004,35(1):65-74
The Kroll process of magnesium reduction of titanium tetrachloride is used the world over the production of titanium metal
in the form of sponge. Although the process has been in practice for the last five decades, there is no clear understanding
of the reaction mechanism and sponge formation. The present study involved reduction experiments in a 2000 kg titanium sponge-capacity
prototype reactor to develop a better understanding of TiCl4 reduction of magnesium with respect to the process parameters. Experiments were also conducted in two smaller experimental
reactors to study the temperature evolution during the process as a function of the TiCl4 feed rate. Based on the results of all these experiments, a model has been proposed for the mechanism of sponge formation
in the Kroll process. 相似文献
28.
Pushpapraj SinghAuthor Vitae Jianmin MiaoAuthor Vitae Lichun ShaoAuthor VitaeRama Krishna KotlankaAuthor Vitae Woo-Tae ParkAuthor Vitae Dim-Lee KwongAuthor Vitae 《Sensors and actuators. A, Physical》2011,171(2):178-185
Microcantilevers are very effective tools in detecting of small amount of bio-species and chemicals. Recent advances in metal-oxide-semiconductor field effect transistor (MOSFET) as a transducer to detect the molecule binding-induced cantilever deflection has gained extensive attention due to its high sensitivity and direct compatibility with micro-electro-mechanical system (MEMS) sensors. In this paper, six different piezoresistive nMOSFET-embedded microcantilevers are designed and characterized to systematically study the impacts of different cantilever and transistor channel geometries on the device sensitivity. It is found that the amount of change in the drain current is the same range as reported in the literature. For point-loading applications, transistors with lower channel width are optimal for relative drain current change even though their absolute current output is less. In particular, the embedded nMOSFET Exhibits 63.6% higher sensitivity by decreasing transistor channel width from 300 to 60 μm. Furthermore, theoretical results are compared with experimental data to optimize cantilever and transistor geometrical factors to achieve higher stress or force sensitivity. The low frequency noise characteristics of the devices show better resolution for higher aspect-ratio transistors, with drain current noise in the nanoampere range. Results reveal useful design guidelines to enhance the MOSFET-embedded microcantilever sensitivity for various applications. 相似文献
29.
In this paper we examine the suitability of higher order shear deformation theory based on cubic inplane displacements and parabolic normal displacements, for stress analysis of laminated composite plates including the interlaminar stresses. An exact solution of a symmetrical four layered infinite strip under static loading has been worked out and the results obtained by the present theory are compared with the exact solution. The present theory provides very good estimates of the deflections, and the inplane stresses and strains. Nevertheless, direct estimates of strains and stresses do not display the required interlaminar stress continuity and strain discontinuity across the interlaminar surface. On the other hand, ‘statically equivalent stresses and strains’ do display the required interlaminar stress continuity and strain discontinuity and agree very closely with the exact solution. 相似文献
30.
V. K. Manupati Tobias Schoenherr M. Ramkumar Sai Krishna Pabba R. Inder Raj Singh 《国际生产研究杂志》2020,58(7):2222-2241
Blockchain technology is destined to revolutionise supply chain processes. At the same time, governmental and regulatory policies are forcing firms to adjust their supply chains in response to environmental concerns. The objective of this study is therefore to develop a distributed ledger-based blockchain approach for monitoring supply chain performance and optimising both emission levels and operational costs in a synchronised fashion, producing a better outcome for the supply chain. We propose the blockchain approach for different production allocation problems within a multi-echelon supply chain (MESC) under a carbon taxation policy. As such, we couple recent advances in digitalisation of operations with increasingly stringent regulatory environmental policies. Specifically, with lead time considerations under emission rate constraints (imposed by a carbon taxation policy), we simultaneously consider the production, distribution and inventory control decisions in a production allocation-based MESC problem. The problem is then formulated as a Mixed Integer Non-Linear Programming (MINLP) model. We show that the distributed ledger-based blockchain approach minimises both total cost and carbon emissions. We then validate the feasibility of the proposed approach by comparing the results with a non-dominated sorting genetic algorithm (NSGA-II). The findings provide support for policymakers and supply chain executives alike. 相似文献