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排序方式: 共有440条查询结果,搜索用时 8 毫秒
1.
We study deterministic finite automata (DFA) with recursive calls, that is, finite sequences of component DFAs that can call each other recursively. DFAs with recursive calls are akin to recursive state machines and unrestricted hierarchic state machines. We show that they are language equivalent to deterministic pushdown automata (DPDA). 相似文献
2.
Guha A. Pavan A. Liu J. Rastogi A. Steeves T. 《Selected Areas in Communications, IEEE Journal on》1995,13(4):749-763
This paper describes the distributed system, network and software architecture, the application development environment, the performance, and the early lessons learned on the ATM LAN testbed Mercuri established at the Honeywell Technology Center, to develop distributed multimedia technologies for real-time control applications. We have developed a client-server-based software architecture on Sun Sparcstation-2s connected by a Fore Systems' ASX-100 ATM switch, with video processing handled by Parallax's X Video cards. The architecture enables network-transparent applications and provides simple primitives for multimedia capture, display, transmission, storage, and retrieval. A real-time multimedia-in-the-loop control application was developed as the vehicle for testing the capabilities and performance of the network. Our test measurements focus on the end-user-level performance metrics such as message throughput and round-trip delay as well as video-frame jitter under no-load and load conditions. Our results show that the maximum burst throughput that can be supported at the user level is 48 Mb/s using AAL 5, while round-trip delays for 4-kbyte messages are about 3 ms. Our experience reveals a number of performance bottlenecks and open issues in using commercial ATM switches for practical applications. Our conclusions are outlined 相似文献
3.
A 10-year-old, previously healthy female presented to the emergency department via emergency medical service transport, with her tongue tightly entrapped inside a glass bottle (9 oz, Yoohoo brand of chocolate drink). The tongue was massively edematous and ecchymotic due to impaired venous return from constriction by the neck of the bottle. After repeated attempts at mechanically reducing the tongue out of the bottle, a professional glazier was contacted, who was able to remove the bottle in the operating room with a steel glass cutter. Needle evacuation of a small hematoma was then performed to decrease the pressure ischemia to the tongue, which began to improve quickly. 相似文献
4.
Obiora Valentine Saha Chitta Bazi Ammar Al Guha Koushik 《Microsystem Technologies》2021,27(8):3161-3169
Microsystem Technologies - This paper presents a critical analysis of the meta-heuristic techniques used in various researches on the optimisation of photovoltaic (PV) parameters, which involves... 相似文献
5.
Microsystem Technologies - This paper explained the dependency of collapse voltage on semiconductor device structural features (membrane diameter, membrane thickness and the vertical distance... 相似文献
6.
Sravani K. Girija Prathyusha D. Gopichand Ch. Maturi Surya Manoj Elsinawi Ameen Guha Koushik Rao K. Srinivasa 《Microsystem Technologies》2022,28(4):913-928
Microsystem Technologies - This paper presents the design a capacitive shunt type RF-MEMS switch with high isolation, high switching speed and low actuation voltage for Ka-band applications. The... 相似文献
7.
We proposed previously a cyclic code made of 22 triplets, which we now call the AB code. It is made up of the following chain: AUGGUGCCAUUCAAGACUAUGA. The letters A, U, C, G represent the classical symbols of the (purine and pyrimidine) bases of the genetic code. This chain presents the following features: (1) when it is in cyclic form, it begins with the initiation codon AUG, ends with the termination codon UGA, and it can be read triplet after triplet by choosing 1 and only 1 representative of each synonymy class in the classical degenerate genetic code made of 64 triplets. The chain, therefore, possesses 1 and only 1 codon for each amino-acid; (2) except for the doublet CG, triplets of the chain begin with the 15 other possible doublets of bases (satisfying the "wobble" hypothesis presented by Crick); (3) it corresponds (except for 1 base) to the "loop" part of the CEnothera mitochondrial Gly-tRNA; (4) it can be modified, without loss of the properties (1) and (2), in such a way as to have 15 bases in common with the loop part of other mitochondrial tRNA's considered as primitive, like Ala-, Pro- and Arg-tRNA; (5) it contains the most frequent triplets, but not the most rare ones, appearing in the genome of numerous species; (6) it exhibits a coherent internal structure with respect to the molecular weight of its triplets. This structure, also found in the loop part of mitochondrial tRNA's, contains an excess of AU bases with respect to GC bases. This fact has no explanation in the classical probabilistic model of the tRNA's. Therefore, we propose the cyclic AB code as a primitive genetic structure with the essential coding properties of the present genetic code. 相似文献
8.
Linear equalities, disequalities and inequalities on fixed-width bit-vectors, collectively called linear modular constraints, form an important fragment of the theory of fixed-width bit-vectors. We present a practically efficient and bit-precise algorithm for quantifier elimination from conjunctions of linear modular constraints. Our algorithm uses a layered approach, whereby sound but incomplete and cheaper layers are invoked first, and expensive but complete layers are called only when required. We then extend this algorithm to work with arbitrary Boolean combinations of linear modular constraints as well. Experiments on an extensive set of benchmarks demonstrate that our techniques significantly outperform alternative quantifier elimination techniques based on bit-blasting and linear integer arithmetic. 相似文献
9.
This paper investigates the sensitivity improvement of an air filled cavity based thermal accelerometer. The accelerometer does not contain any solid proof mass and it is realizable in CMOS technology. The sensitivity has been improved by a new square ring shaped heater structure. The sensitivity of accelerometer performance is compared with other different heater shapes. It is found that, heater design having higher heat dissipation in the suspended beam gives higher sensitivity. The simulation is carried out using commercial FEM simulator COMSOL Multiphysics. For the peak heater temperature of 609 K, the proposed square ring shaped heater provides a sensitivity of 0.335 K/g. Under same conditions, sensitivity of an accelerometer with a meander shaped heater structure is only 0.098 K/g and diamond shaped structure is 0.229 K/g. 相似文献
10.
Sudipto Guha 《The VLDB Journal The International Journal on Very Large Data Bases》2008,17(6):1509-1535
Synopses construction algorithms have been found to be of interest in query optimization, approximate query answering and
mining, and over the last few years several good synopsis construction algorithms have been proposed. These algorithms have
mostly focused on the running time of the synopsis construction vis-a-vis the synopsis quality. However the space complexity
of synopsis construction algorithms has not been investigated as thoroughly. Many of the optimum synopsis construction algorithms
are expensive in space. For some of these algorithms the space required to construct the synopsis is significantly larger
than the space required to store the input. These algorithms rely on the fact that they require a smaller “working space”
and most of the data can be resident on disc. The large space complexity of synopsis construction algorithms is a handicap
in several scenarios. In the case of streaming algorithms, space is a fundamental constraint. In case of offline optimal or
approximate algorithms, a better space complexity often makes these algorithms much more attractive by allowing them to run
in main memory and not use disc, or alternately allows us to scale to significantly larger problems without running out of
space. In this paper, we propose a simple and general technique that reduces space complexity of synopsis construction algorithms.
As a consequence we show that the notion of “working space” proposed in these contexts is redundant. This technique can be
easily applied to many existing algorithms for synopsis construction problems. We demonstrate the performance benefits of
our proposal through experiments on real-life and synthetic data. We believe that our algorithm also generalizes to a broader
range of dynamic programs beyond synopsis construction.
Sudipto Guha’s research supported in part by an Alfred P. Sloan Research Fellowship and by NSF Awards CCF-0430376, CCF-0644119.A
preliminary version of the paper appeared as “Space efficiency in synopsis construction algorithms”, VLDB Conference 2005,
Trondheim, [19]. 相似文献