全文获取类型
收费全文 | 2131篇 |
免费 | 68篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 157篇 |
综合类 | 3篇 |
化学工业 | 537篇 |
金属工艺 | 74篇 |
机械仪表 | 33篇 |
建筑科学 | 31篇 |
矿业工程 | 1篇 |
能源动力 | 94篇 |
轻工业 | 148篇 |
水利工程 | 4篇 |
石油天然气 | 3篇 |
无线电 | 176篇 |
一般工业技术 | 439篇 |
冶金工业 | 265篇 |
原子能技术 | 53篇 |
自动化技术 | 189篇 |
出版年
2024年 | 3篇 |
2023年 | 10篇 |
2022年 | 26篇 |
2021年 | 46篇 |
2020年 | 18篇 |
2019年 | 44篇 |
2018年 | 46篇 |
2017年 | 38篇 |
2016年 | 60篇 |
2015年 | 47篇 |
2014年 | 47篇 |
2013年 | 92篇 |
2012年 | 101篇 |
2011年 | 130篇 |
2010年 | 83篇 |
2009年 | 109篇 |
2008年 | 111篇 |
2007年 | 99篇 |
2006年 | 64篇 |
2005年 | 76篇 |
2004年 | 77篇 |
2003年 | 61篇 |
2002年 | 43篇 |
2001年 | 54篇 |
2000年 | 35篇 |
1999年 | 52篇 |
1998年 | 126篇 |
1997年 | 85篇 |
1996年 | 68篇 |
1995年 | 37篇 |
1994年 | 38篇 |
1993年 | 40篇 |
1992年 | 32篇 |
1991年 | 36篇 |
1990年 | 17篇 |
1989年 | 21篇 |
1988年 | 10篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 12篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1980年 | 11篇 |
1979年 | 5篇 |
1978年 | 4篇 |
1976年 | 15篇 |
1975年 | 6篇 |
1968年 | 2篇 |
排序方式: 共有2207条查询结果,搜索用时 15 毫秒
991.
Satoshi Shiba Masafumi Uchida Akio Nozawa Hirotoshi Asano Hitoshi Onogaki Tota Mizuno Hideto Ide Syuichi Yokoyama 《Artificial Life and Robotics》2009,14(2):213-218
A modular robot can be built with a shape and function that matches the working environment. We developed a four-arm modular
robot system which can be configured in a planar structure. A learning mechanism is incorporated in each module constituting
the robot. We aim to control the overall shape of the robot by an accumulation of the autonomous actions resulting from the
individual learning functions. Considering that the overall shape of a modular robot depends on the learning conditions in
each module, this control method can be treated as a dispersion control learning method. The learning object is cooperative
motion between adjacent modules. The learning process proceeds based on Q-learning by trial and error. We confirmed the effectiveness
of the proposed technique by computer simulation. 相似文献
992.
Rujie Yuehong Wang Takayuki Baba Daiki Masumoto Shigemi Nagata 《Pattern recognition》2008,41(8):2645-2655
In content-based image retrieval, relevance feedback is studied extensively to narrow the gap between low-level image feature and high-level semantic concept. However, most methods are challenged by small sample size problem since users are usually not so patient to label a large number of training instances in the relevance feedback round. In this paper, this problem is solved by two strategies: (1) designing a new active selection criterion to select images for user's feedback. It takes both the informative and the representative measures into consideration, thus the diversities between these images are increased while their informative powers are kept. With this new criterion, more information gain can be obtained from the feedback images; and (2) incorporating unlabeled images within the co-training framework. Unlabeled data partially alleviates the training data scarcity problem, thus improves the efficiency of support vector machine (SVM) active learning. Systematic experimental results verify the superiority of our method over existing active learning methods. 相似文献
993.
Asato Mizuno Helen Benjamin Yasuhiro Shimizu Yoshiaki Shuku Michio M. Matsushita Neil Robertson Kunio Awaga 《Advanced functional materials》2019,29(42)
A new anionic gold dithiolene complex NBu4·[1] is synthesized from the (1‐((1,1‐biphenyl)‐4‐yl‐)‐ethylene‐1,2‐dithiolene ligand 1, and the cis and trans isomers are separated by recrystallization. The trans isomer is oxidized via electrocrystallisation to the neutral gold dithiolene complex 2. Complex 2 crystalizes in 1D chains, held together by short (3.30–3.37 Å) S–S contacts, which are packed in a herringbone arrangement in the ab‐plane. The complex exhibits semiconductor behavior (σRT = 1.5 × 10?4 S cm?1) at room temperature with a small activation energy (Ea = 0.11 eV), with greater conductivity along the stacking direction. The charge transport behavior of complex 2 is further investigated in single‐crystal field‐effect transistor (FET) measurements, the first such measurements reported for gold dithiolene complexes. Complex 2 shows incredibly balanced ambipolar behavior in the single‐crystal field‐effect transistor (SC‐FET), with high charge‐carrier mobilities of 0.078 cm2 V?1 s?1, the highest ambipolar mobilities reported for metal dithiolene complexes. This well‐balanced behavior, along with the activated conductivity and band structure calculations, suggests that 2 behaves as a Mott insulator. The magnetic properties are also studied by superconducting quantum interference device (SQUID) magnetometry and solid state 1H NMR, with evidence of a nonmagnetic ground state at low temperature. 相似文献
994.
High‐resolution OLED display with remarkably low power consumption using blue/yellow tandem structure and RGBY subpixels 下载免费PDF全文
Ryohei Yamaoka Toshiki Sasaki Riho Kataishi Noriko Miyairi Koji Kusunoki Makoto Kaneyasu Hiroyuki Miyake Nobuharu Ohsawa Satoshi Seo Yoshiharu Hirakata Shunpei Yamazaki Koji Ono Takayuki Cho Hidenori Mori 《Journal of the Society for Information Display》2015,23(10):451-456
A top‐emission organic light‐emitting diode (OLED) with a microcavity structure combined with a blue/yellow tandem structure was developed. A high‐resolution active‐matrix OLED display with the world's lowest level of power consumption using the tandem OLED with red, green, blue, and yellow subpixels was fabricated. 相似文献
995.
Sachio Tsuchida Mamoru Satoh Kazuyuki Sogawa Yusuke Kawashima Sayaka Kado Takayuki Ishige Minako Beppu Setsu Sawai Motoi Nishimura Yoshio Kodera Kazuyuki Matsushita Fumio Nomura 《Proteomics. Clinical applications》2014,8(3-4):232-240
Periodontal disease is a bacterial infection that destroys the gingiva and surrounding tissues of the oral cavity. In recent years, studies have shown a definite association between periodontal disease and other inflammatory conditions of the body. High-throughput analysis of proteins has become possible with the development of MS technology. This breakthrough in proteome technology enables comparative studies of comprehensive protein expression and identification of protein. In case of periodontal disease, proteome analysis using 2DE, as well as gel-free methods, has been reported. As a fluid lying in close proximity to periodontal tissue, the gingival crevicular fluid (GCF) is the principal target in the search for biomarkers of periodontal disease, because its protein composition may reflect the disease pathophysiology. Biochemical marker analysis of GCF is effective for objective diagnosis in the early and advanced stages of periodontal disease. Increasing numbers of recent reports have provided evidence that the proteomic approach is a promising tool for the discovery and identification of biochemical markers of periodontal disease. This search is of continuing interest in the field of experimental and clinical periodontal disease research. In this article, we summarize recent comprehensive proteomic studies aimed at discovering and identifying biomarkers of periodontal disease in GCF. 相似文献
996.
In vitro characterization of the relationship between the Q-angle and the lateral component of the quadriceps force 总被引:4,自引:0,他引:4
Elias JJ Mattessich SM Kumagai M Mizuno Y Cosgarea AJ Chao EY 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》2004,218(1):63-67
Although the Q-angle is routinely measured, the relationship between the Q-angle and the lateral component of the quadriceps force acting on the patella is unknown. Five cadaver knees were flexed on a knee simulator with a normal Q-angle, and flexed after increasing and decreasing the Q-angle by shifting the quadriceps origin laterally and medially, respectively. The motion of the femur, tibia and patella was tracked from 20 to 90 degrees of flexion using electromagnetic sensors. The motion of landmarks used to quantify the Q-angle was tracked to determine the 'dynamic Q-angle' during flexion. The lateral component of the force applied by the actuator secured to the quadriceps tendon was also quantified throughout flexion. Increasing the initial Q-angle significantly (p < 0.05) increased the dynamic Q-angle and the lateral force exerted through the quadriceps tendon throughout flexion. Decreasing the initial Q-angle significantly decreased the dynamic Q-angle at 90 degrees of flexion and significantly decreased the lateral force exerted through the quadriceps tendon from 20 to 40 degrees of flexion. Even though the dynamic Q-angle changes during flexion, an abnormally large initial Q-angle can be an indicator of an abnormally large lateral force acting on the patella during flexion. 相似文献
997.
Applied Intelligence - With the rapid development of Internet, the online discussion system or social democratic system has become an important and effective vehicle for group decision-making... 相似文献
998.
Miguel A. Lopez-Carmona Ivan Marsa-Maestre Mark Klein Takayuki Ito 《Autonomous Agents and Multi-Agent Systems》2012,24(3):485-535
Negotiating contracts with multiple interdependent issues may yield non- monotonic, highly uncorrelated preference spaces
for the participating agents. These scenarios are specially challenging because the complexity of the agents’ utility functions
makes traditional negotiation mechanisms not applicable. There is a number of recent research lines addressing complex negotiations
in uncorrelated utility spaces. However, most of them focus on overcoming the problems imposed by the complexity of the scenario,
without analyzing the potential consequences of the strategic behavior of the negotiating agents in the models they propose.
Analyzing the dynamics of the negotiation process when agents with different strategies interact is necessary to apply these
models to real, competitive environments. Specially problematic are high price of anarchy situations, which imply that individual rationality drives the agents towards strategies which yield low individual and social
welfares. In scenarios involving highly uncorrelated utility spaces, “low social welfare” usually means that the negotiations
fail, and therefore high price of anarchy situations should be avoided in the negotiation mechanisms. In our previous work,
we proposed an auction-based negotiation model designed for negotiations about complex contracts when highly uncorrelated,
constraint-based utility spaces are involved. This paper performs a strategy analysis of this model, revealing that the approach
raises stability concerns, leading to situations with a high (or even infinite) price of anarchy. In addition, a set of techniques
to solve this problem are proposed, and an experimental evaluation is performed to validate the adequacy of the proposed approaches
to improve the strategic stability of the negotiation process. Finally, incentive-compatibility of the model is studied. 相似文献
999.
Takayuki Sasaki Yuu Takeno Taishi Kobayashi Akira Kirishima Nobuaki Sato 《Journal of Nuclear Science and Technology》2016,53(3):303-311
The gamma ray radionuclides Cs-137, Ba-140, I-131, Ce-141, Ru-103, Zr-95, and Np-239 were produced by neutron irradiation of UO2–ZrO2 solid solutions that were synthesized as simulated fuel debris under reducing and oxidizing conditions. The leaching ratio of radionuclides was investigated under atmospheric conditions at 25 °C for non-filtered natural surface seawater, as well as deionized water after filtration with a membrane of 0.45-µm pore size or that of nominal molecular weight limit of 3 kDa. The uranium molar concentration was affected by the oxidation state in the solid solution samples. The congruent dissolution of Cs, I, and Ba with the hexavalent uranium of U3O8 was facilitated in the seawater samples, whereas a lower leaching ratio of nuclides was observed in the deionized water samples. Neptunium-239, originally produced from uranium-238 in U3O8, showed behavior that was similar to that of Cs, I, and Ba. However, the dissolution of Np (as a parent nuclide of Pu-239) in the debris of UO2 and UO2–ZrO2 was suppressed in the same manner as Zr(IV) and Ce(IV). The concentration exhibited no filtration dependence after 15 d, which shows that most of the leached nuclides can exist in their ionic form in seawater. 相似文献
1000.
Taishi Kobayashi Takayuki Sasaki Ikuji Takagi Hirotake Moriyama 《Journal of Nuclear Science and Technology》2016,53(11):1787-1793
The solid phases and solubilities of thorium(IV) hydroxide after aging at 363 K were investigated in the pHc range of 2–8 in NaClO4 or NaCl solutions having a 0.1–3.0 mol/dm3 (M) ionic strength. Sample solutions containing solid amorphous thorium hydroxide (Th(OH)4(am)) were prepared by the oversaturation method, and stored in a temperature chamber kept at an aging temperature (Ta) of 363 K for specified periods. The sample solutions were then cooled to 298 K for measurement of the apparent solubilities. The apparent solubilities, after aging at Ta = 363 K, decreased about 3 orders of magnitude from the solubility of Th(OH)4(am) at Ta = 298 K. The solid phases were investigated by X-ray diffraction (XRD) in order to determine the particle sizes in the thorium hydroxide solid phases. A slight growth of the particle size of the solid phases after aging at Ta = 363 K was suggested from the obtained XRD spectrum and was correlated to the decrease of the apparent solubility at Ta = 363 K based on the particle size effect of the solubility product. 相似文献