全文获取类型
收费全文 | 890篇 |
免费 | 22篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 50篇 |
综合类 | 4篇 |
化学工业 | 260篇 |
金属工艺 | 34篇 |
机械仪表 | 28篇 |
建筑科学 | 20篇 |
矿业工程 | 1篇 |
能源动力 | 47篇 |
轻工业 | 77篇 |
无线电 | 52篇 |
一般工业技术 | 160篇 |
冶金工业 | 31篇 |
原子能技术 | 55篇 |
自动化技术 | 102篇 |
出版年
2022年 | 5篇 |
2021年 | 9篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 10篇 |
2016年 | 14篇 |
2015年 | 15篇 |
2014年 | 13篇 |
2013年 | 50篇 |
2012年 | 40篇 |
2011年 | 64篇 |
2010年 | 29篇 |
2009年 | 33篇 |
2008年 | 42篇 |
2007年 | 35篇 |
2006年 | 44篇 |
2005年 | 40篇 |
2004年 | 28篇 |
2003年 | 29篇 |
2002年 | 25篇 |
2001年 | 19篇 |
2000年 | 18篇 |
1999年 | 29篇 |
1998年 | 14篇 |
1997年 | 19篇 |
1996年 | 17篇 |
1995年 | 13篇 |
1994年 | 17篇 |
1993年 | 12篇 |
1992年 | 7篇 |
1991年 | 19篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 12篇 |
1986年 | 18篇 |
1985年 | 13篇 |
1984年 | 20篇 |
1983年 | 11篇 |
1982年 | 12篇 |
1981年 | 11篇 |
1980年 | 6篇 |
1979年 | 16篇 |
1978年 | 13篇 |
1977年 | 9篇 |
1976年 | 7篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有921条查询结果,搜索用时 15 毫秒
21.
Emad Shihab Akinori Ihara Yasutaka Kamei Walid M. Ibrahim Masao Ohira Bram Adams Ahmed E. Hassan Ken-ichi Matsumoto 《Empirical Software Engineering》2013,18(5):1005-1042
Bug fixing accounts for a large amount of the software maintenance resources. Generally, bugs are reported, fixed, verified and closed. However, in some cases bugs have to be re-opened. Re-opened bugs increase maintenance costs, degrade the overall user-perceived quality of the software and lead to unnecessary rework by busy practitioners. In this paper, we study and predict re-opened bugs through a case study on three large open source projects—namely Eclipse, Apache and OpenOffice. We structure our study along four dimensions: (1) the work habits dimension (e.g., the weekday on which the bug was initially closed), (2) the bug report dimension (e.g., the component in which the bug was found) (3) the bug fix dimension (e.g., the amount of time it took to perform the initial fix) and (4) the team dimension (e.g., the experience of the bug fixer). We build decision trees using the aforementioned factors that aim to predict re-opened bugs. We perform top node analysis to determine which factors are the most important indicators of whether or not a bug will be re-opened. Our study shows that the comment text and last status of the bug when it is initially closed are the most important factors related to whether or not a bug will be re-opened. Using a combination of these dimensions, we can build explainable prediction models that can achieve a precision between 52.1–78.6 % and a recall in the range of 70.5–94.1 % when predicting whether a bug will be re-opened. We find that the factors that best indicate which bugs might be re-opened vary based on the project. The comment text is the most important factor for the Eclipse and OpenOffice projects, while the last status is the most important one for Apache. These factors should be closely examined in order to reduce maintenance cost due to re-opened bugs. 相似文献
22.
Tetsushi Oka Toyokazu Abe Kaoru Sugita Masao Yokota 《Artificial Life and Robotics》2009,13(2):455-459
This article describes a multimodal command language for home robot users, and a robot system which interprets users’ messages
in the language through microphones, visual and tactile sensors, and control buttons. The command language comprises a set
of grammar rules, a lexicon, and nonverbal events detected in hand gestures, readings of tactile sensors attached to the robots,
and buttons on the controllers in the users’ hands. Prototype humanoid systems which immediately execute commands in the language
are also presented, along with preliminary experiments of faceto-face interactions and teleoperations. Subjects unfamiliar
with the language were able to command humanoids and complete their tasks with brief documents at hand, given a short demonstration
beforehand. The command understanding system operating on PCs responded to multimodal commands without significant delay.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
23.
Tetsushi Oka Toyokazu Abe Kaoru Sugita Masao Yokota 《Artificial Life and Robotics》2009,14(2):219-223
This article considers the success rates in a multimodal command language for home robot users. In the command language, the
user specifies action types and action parameter values to direct robots in multiple modes such as speech, touch, and gesture.
The success rates of commands in the language can be estimated by user evaluations in several ways. This article presents
some user evaluation methods, as well as results from recent studies on command success rates. The results show that the language
enables users without much training to command home robots at success rates as high as 88%–100%. It is also shown that multimodal
commands combining speech and button-press actions included fewer words and were significantly more successful than single-modal
spoken commands. 相似文献
24.
25.
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
26.
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
27.
28.
Toshiyuki Abe Junji KubotaTamotsu Tanaka Kuniaki ShojiAkio Tajiri Masao Kaneko 《Electrochimica acta》2002,47(24):3901-3907
Electrocatalytic O2 reduction was studied using a modified electrode coated with a Nafion membrane (Nf) dispersing a trinuclear ruthenium ammine complex ([(NH3)5RuIIIORuIV(NH3)4ORuIII(NH3)5]Cl6, Ru-red). When measuring cyclic voltammogram under O2 atmosphere (at 0.5 mV s−1), catalytic currents due to O2 reduction were found to develop below −0.2 V (vs. Ag/AgCl). Since Ru-red undergoes irreversible decomposition into the mononuclear complexes via the reduced state (RuIII-RuIII-RuIII) (∼−0.1 V), it is suggested that the electrocatalysis originates from the decomposed species (initial active species: RuII(NH3)5(OH2) and RuII(NH3)4(OH2)2) rather than from the Ru-red. Although the present electrocatalyst was also applied to H2O2 reduction system, the catalytic activity was found to be poor from the voltammetric behavior. It appeared that the kinetics of the electrocatalysis is much faster in the O2 reduction than in the H2O2 one. A selective and direct catalysis for O2 reduction into H2O was suggested from a ring-disk voltammogram to take place by an aggregate of the mononuclear ruthenium complexes in the polymer matrix. In addition, it was found that electrocatalytic O2 reduction involves a slow kinetic process, so that factors affecting the overall kinetics were discussed in terms of the catalysis mechanism. 相似文献
29.
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
30.
Koichiro Hirano Masafumi Fukuda Mikio Takano Yoshio Yamazaki Toshiya Muto Sakae Araki Nobuhiro Terunuma Masao Kuriki Mitsuo Akemoto Hitoshi Hayano Junji Urakawa 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2006,560(2):233-239
A multi-bunch photo-cathode RF gun system has been developed as an electron source for the production of intense quasi-monochromatic X-rays based on inverse Compton scattering. The desired multi-bunch beam is 100 bunches/pulse with a total charge of 500 nC and a bunch spacing of 2.8 ns. We modified the gun cavity of a ‘BNL-type IV’ RF gun to allow a CsTe cathode plug in the end plate. The system uses a four-dipole chicane beam line to allow the injection of laser light normal to the cathode surface. We compensate the gun cavity beam loading caused by the high-intensity multi-bunch electron beam by injecting the laser pulse before RF power has filled the cavity. We have achieved a total intensity of 220 nC in 100 bunches with a bunch-to-bunch energy spread under 1.3% (peak-to-peak). This paper concentrates on experiments to generate the high-intensity multi-bunch beam with compensation of the bunch-to-bunch energy spread due to heavy beam loading. 相似文献