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101.
S. Krishnamoorthy J. Feng A. C. Henry L. E. Locascio J. J. Hickman S. Sundaram 《Microfluidics and nanofluidics》2006,2(4):345-355
Covalent surface modification techniques, in particular surface oxidation procedures, have been employed as a mean to modify polymer microfluidic channels for the purpose of modulating microflow. The focus of this work is to experimentally and computationally characterize electroosmotic flow (EOF) to understand the impact of surface modifications and buffer pH on sample mixing and dispersion. The experimental results are used to calibrate and validate the simulation model that solves the Navier–Stokes equation for fluid flow and Poisson equation to resolve external electric field. Experimental and simulated results are presented for hybrid microfluidic systems, consisting of both pristine polymer surfaces and chemically modified polymer surfaces. The results show that the selective surface modification induces hydrodynamic pressure gradient, leading to enhanced sample dispersion. The mass flow rate increases linearly with the level of oxidation. All channels (pristine, oxidized, and hybrid) showed an increasing EOF with increasing pH until the near neutral regime (7<pH<9), where the EOF leveled off at a maximum value—behavior that is typical of a microchannel with negative surface moieties populating its surface. 相似文献
102.
Multiphysics Modeling of Microwave Heating of a Frozen Heterogeneous Meal Rotating on a Turntable 下载免费PDF全文
Krishnamoorthy Pitchai Jiajia Chen Sohan Birla David Jones Ric Gonzalez Jeyamkondan Subbiah 《Journal of food science》2015,80(12):E2803-E2814
A 3‐dimensional (3‐D) multiphysics model was developed to understand the microwave heating process of a real heterogeneous food, multilayered frozen lasagna. Near‐perfect 3‐D geometries of food package and microwave oven were used. A multiphase porous media model combining the electromagnetic heat source with heat and mass transfer, and incorporating phase change of melting and evaporation was included in finite element model. Discrete rotation of food on the turntable was incorporated. The model simulated for 6 min of microwave cooking of a 450 g frozen lasagna kept at the center of the rotating turntable in a 1200 W domestic oven. Temperature‐dependent dielectric and thermal properties of lasagna ingredients were measured and provided as inputs to the model. Simulated temperature profiles were compared with experimental temperature profiles obtained using a thermal imaging camera and fiber‐optic sensors. The total moisture loss in lasagna was predicted and compared with the experimental moisture loss during cooking. The simulated spatial temperature patterns predicted at the top layer was in good agreement with the corresponding patterns observed in thermal images. Predicted point temperature profiles at 6 different locations within the meal were compared with experimental temperature profiles and root mean square error (RMSE) values ranged from 6.6 to 20.0 °C. The predicted total moisture loss matched well with an RMSE value of 0.54 g. Different layers of food components showed considerably different heating performance. Food product developers can use this model for designing food products by understanding the effect of thickness and order of each layer, and material properties of each layer, and packaging shape on cooking performance. 相似文献
103.
Adrian Lara Byrav Ramamurthy Kiran Nagaraja Aravind Krishnamoorthy Dipankar Raychaudhuri 《Photonic Network Communications》2014,28(2):165-177
Mobile devices are expected to become the Internet’s predominant technology. Current protocols such as TCP/IP were not originally designed with mobility as a key consideration, and therefore underperform under challenging mobile and wireless conditions. MobilityFirst, a clean slate architecture proposal, embraces several key concepts centered around secure identifiers that inherently support mobility and trustworthiness as key requirements of the network architecture. This includes a hop-by-hop segmented data transport based on a globally unique identifier. This allows late and dynamic rebinding of end-point addresses to support mobility. While this provides critical gains in wireless segments, some overheads are incurred even in stable segments such as in the core. Bypassing routing-layer decisions in these cases, with lower layer cut-through forwarding, can improve said gains. In this work, we introduce a general bypass capability within the MobilityFirst architecture that provides better performance and enables both individual and aggregate flow-level traffic control. Furthermore, we present an OpenFlow-based proof-of-concept implementation of the bypass function using layer 2 VLAN tagging. We run experiments on the ORBIT and Global Environment for Network Innovations (GENI) testbeds to evaluate the performance and scalability of the solution. By implementing the bypass functionality, we are able to significantly reduce the number of messages processed by the controller as well as the number of flow rules that need to be pushed into the switches. 相似文献
104.
Krishnamoorthy M. Nagy G. Seth S. Viswanathan M. 《IEEE transactions on pattern analysis and machine intelligence》1993,15(7):737-747
A method for extracting alternating horizontal and vertical projection profiles are from nested sub-blocks of scanned page images of technical documents is discussed. The thresholded profile strings are parsed using the compiler utilities Lex and Yacc. The significant document components are demarcated and identified by the recursive application of block grammars. Backtracking for error recovery and branch and bound for maximum-area labeling are implemented with Unix Shell programs. Results of the segmentation and labeling process are stored in a labeled x -y tree. It is shown that families of technical documents that share the same layout conventions can be readily analyzed. Results from experiments in which more than 20 types of document entities were identified in sample pages from two journals are presented 相似文献
105.
M. Abdul Majeed L. Vijayaraghavan S.K. Malhotra R. Krishnamoorthy 《Journal of Materials Processing Technology》2009,209(5):2499-2507
Increasing demand for materials for severe working environment necessitates the use of ceramics. Fiber/whisker reinforcement in the structure can lead to certain defects such as debonding/delamination. Hence one can resort to particulate reinforcements. Of late attempts have been made to introduce dispersion strengthened/particulate reinforced ceramic composites. Addition of lanthanum phosphate (LaPO4) and cerium phosphate (CePO4) to alumina (Al2O3) matrix has been attempted. In this study Al2O3/LaPO4 composites containing different LaPO4 content have been assessed for the significance of LaPO4 content on structure-property and consequent machinability. Ultrasonic drilling trials have been carried out. The response of the material to the machining environment has been assessed by monitoring the acoustic emission (AE) from the composites and defects induced during machining. 相似文献
106.
M. J. Antonell C. R. Abernathy V. Krishnamoorthy R. W. Gedridge Jr. T. E. Haynes 《Journal of Electronic Materials》1997,26(11):1283-1286
The thermal stability of tellurium in InP has been examined in samples doped with Te up to an electron concentration of 1.4
× 1020 cm−3. Annealing was conducted using rapid thermal annealing for a period of one minute at temperatures over the range 650–800°C.
Secondary ion mass spectroscopy analysis showed virtually no change in the Te profile before and after annealing, even at
the highest annealing temperatures. High resolution x-ray diffraction and Hall measurements revealed a general decrease in
the lattice strain and carrier concentration for annealing temperatures above 650°C. No evidence of strain relief was found
in the form of cross-hatching or through the formation of a dislocation network as examined by scanning electron microscopy
or transmission electron microscopy (TEM). These results are most likely due to the formation of Te clusters, though such
clusters could not be seen by crosssectional TEM. 相似文献
107.
108.
C. S. Krishnamoorthy P. Prasanna Venkatesh R. Sudarshan 《Canadian Metallurgical Quarterly》2002,16(1):66-75
Genetic algorithms have been shown to be very effective optimization tools for a number of engineering problems. Since the genetic processes typically operate independent of the actual problem, a core genetic algorithm library consisting of all the genetic operators having an interface to a generic objective function can serve as a very useful tool for learning as well as for solving a number of practical optimization problems. This paper discusses the object-oriented design and implementation of such a core library. Object-oriented design, apart from giving a more natural representation of information, also facilitates better memory management and code reusability. Next, it is shown how classes derived from the implemented libraries can be used for the practical size optimization of large space trusses, where several constructibility aspects have been incorporated to simulate real-world design constraints. Strategies are discussed to model the chromosome and to code genetic operators to handle such constraints. Strategies are also suggested for member grouping for reducing the problem size and implementing move-limit concepts for reducing the search space adaptively in a phased manner. The implemented libraries are tested on a number of large previously fabricated space trusses, and the results are compared with previously reported values. It is concluded that genetic algorithms implemented using efficient and flexible data structures can serve as a very useful tool in engineering design and optimization. 相似文献
109.
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