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41.
Hybrid Petri net (HPN) is an extension of the Petri net formalism, which enables us to handle continuous information in addition
to discrete information. Firstly, this paper demonstrates how biological pathways can be modeled by the integration of discrete
and continuous elements, with an example of the λ phage genetic switch system including induction and retroregulation mechanisms.
Although HPN allows intuitive modeling of biological pathways, some fundamental biological processes such as complex formation
cannot be represented with HPN. Thus, this paper next provides the formal definition of hybrid functional Petri net with extension
(HFPNe), which has high potential for modeling various kinds of biological processes. Cell Illustrator is a software tool
developed on the basis of the definition of HFPNe. Hypothesis creation by Cell Illustrator is demonstrated with the example
of the cyanobacterial circadian gene clock system. Finally, our ongoing tasks, which include the development of a computational
platform for systems biology, are presented. 相似文献
42.
Tabu search for attribute reduction in rough set theory 总被引:2,自引:0,他引:2
Abdel-Rahman Hedar Jue Wang Masao Fukushima 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2008,12(9):909-918
In this paper, we consider a memory-based heuristic of tabu search to solve the attribute reduction problem in rough set theory.
The proposed method, called tabu search attribute reduction (TSAR), is a high-level TS with long-term memory. Therefore, TSAR
invokes diversification and intensification search schemes besides the TS neighborhood search methodology. TSAR shows promising
and competitive performance compared with some other CI tools in terms of solution qualities. Moreover, TSAR shows a superior
performance in saving the computational costs. 相似文献
43.
Topological design considering flexibility under periodic loads 总被引:1,自引:1,他引:0
S. Nishiwaki K. Saitou S. Min N. Kikuchi 《Structural and Multidisciplinary Optimization》2000,19(1):4-16
Topology optimization has been extensively considered to design the structural configuration for the stiffness maximization
and the eigenfrequency maximization. In this paper, we construct a topology optimization method implementing flexibility with
the time-periodic loading condition. First, the flexibility in the dynamic periodic loading is formulated using the mutual
energy concept. Second, the multi-optimization problem is formulated using a new multi-objective function in order to obtain
an optimal solution incorporating both flexibility and stiffness. Next, the topology optimization procedure is developed using
the homogenization design method. Finally, some examples are provided to confirm the optimal design method presented here.
Received January 18, 1999 相似文献
44.
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46.
Bubble wake visualization by using photochromic dye 总被引:1,自引:0,他引:1
Wake structure of a single “clean bubble”, rising in rectilinear, zigzagging or spiraling path, is experimentally investigated. A single nitrogen gas bubble was produced in a silicone oil pool and the wake structure development in the rear of the rising bubble was visualized by using photochromic dye. The flexibility of this visualization method enabled us to distinguish wake from drift easily. Both bubble motion and wake structure were recorded by using stereo high-speed video camera simultaneously. We present the first experimental support for the existence of the standing eddy at the rear of the clean bubble, as predicted by a previous numerical study by Ryskin and Leal [1984. Journal of Fluid Mechanics 148, 19-35], Dandy and Leal [1986. Physics of Fluids 29(5), 1360-1366] and Blanco and Magnaudet [1995. Physics of Fluids 7(6), 1265-1274]. We study motion of a pair of vortex filaments, which is called double-threaded type wake, in the case of bubble rising in an axi-asymmetric path. Visualization results of multiple formations of horse-shoe type vortices in one period of zigzag motion of rising bubble with shape oscillations, which has not been observed in previous studies are also presented. 相似文献
47.
48.
K. Ohtani D. Numata T. Kikuchi M. Sun K. Takayama K. Togami 《International Journal of Impact Engineering》2006,33(1-12):555-565
This paper reports a result of hypervelocity impact experiments on cryogenically cooled aluminum alloys and a composite material. Experiments are carried out on a target palate at 122 K. Aluminum spheres at 1.95 km/s in 50 kPa air were impinged against the target plate at cryogenic temperature and the result was compared with room temperature target plates. Hypervelocity impact (HVI) processes were visualized with shadowgraph arrangement and recorded with high-speed video camera and to ensure the temperature dependence we compared HVI tests with metal target plates with AUTODYN 2D and SPH numerical simulations. We found that cryogenic impacts created slight differences of impact damage from room temperature ones, i.e., the shape and averaged diameters of HVI crater holes were less at cryogenic impacts. 相似文献
49.
Atsushi Ikeda Tatsuya Suzuki Masao Aida Yasuhiko Fujii Toshiaki Mitsugashira Mitsuo Hara Masaki Ozawa 《Progress in Nuclear Energy》2005,47(1-4):454-461
A novel chromatographic separation technique using a tertiary pyridine type resin has been applied to the partitioning of the trivalent actinides (An) and lanthanides (Ln) and several successful results have been shown. In an alcoholic hydrochloric acid system, the trivalent An were clearly separated from the Ln, while no such group separation was achieved in an alcoholic nitric acid system. On the other hand, the nitric acid system was more effective for the intragroup (i.e. individual) separation of the trivalent An and the Ln than the hydrochloric acid system. On the basis of these results, a novel concept for the partitioning of the trivalent An and Ln using the present separation technique and its flowchart have been proposed with its advantages and disadvantages. 相似文献
50.