全文获取类型
收费全文 | 2158篇 |
免费 | 77篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 146篇 |
综合类 | 3篇 |
化学工业 | 662篇 |
金属工艺 | 71篇 |
机械仪表 | 62篇 |
建筑科学 | 65篇 |
能源动力 | 103篇 |
轻工业 | 228篇 |
水利工程 | 3篇 |
石油天然气 | 6篇 |
武器工业 | 2篇 |
无线电 | 110篇 |
一般工业技术 | 408篇 |
冶金工业 | 82篇 |
原子能技术 | 64篇 |
自动化技术 | 227篇 |
出版年
2023年 | 9篇 |
2022年 | 29篇 |
2021年 | 60篇 |
2020年 | 27篇 |
2019年 | 30篇 |
2018年 | 36篇 |
2017年 | 38篇 |
2016年 | 58篇 |
2015年 | 35篇 |
2014年 | 77篇 |
2013年 | 149篇 |
2012年 | 121篇 |
2011年 | 136篇 |
2010年 | 116篇 |
2009年 | 137篇 |
2008年 | 125篇 |
2007年 | 106篇 |
2006年 | 94篇 |
2005年 | 80篇 |
2004年 | 61篇 |
2003年 | 46篇 |
2002年 | 65篇 |
2001年 | 37篇 |
2000年 | 44篇 |
1999年 | 34篇 |
1998年 | 62篇 |
1997年 | 40篇 |
1996年 | 43篇 |
1995年 | 31篇 |
1994年 | 32篇 |
1993年 | 33篇 |
1992年 | 23篇 |
1991年 | 22篇 |
1990年 | 19篇 |
1989年 | 20篇 |
1988年 | 16篇 |
1987年 | 11篇 |
1986年 | 19篇 |
1985年 | 19篇 |
1984年 | 16篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1981年 | 12篇 |
1980年 | 9篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 12篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1972年 | 3篇 |
排序方式: 共有2242条查询结果,搜索用时 31 毫秒
61.
Makoto Kobayashi Masashi Shimada Yuji Hatano Takuji Oda Brad Merrill Yasuhisa Oya Kenji Okuno 《Fusion Engineering and Design》2013,88(9-10):1749-1752
The deuterium trapping behaviors in tungsten damaged by light ions with lower energy (10 keV C+ and 3 keV He+) or a heavy ion with higher energy (2.8 MeV Fe2+) were compared by means of TDS to understand the effects of cascade collisions on deuterium retention in tungsten. By light ion irradiation, most of deuterium was trapped by vacancies, whose retention was almost saturated at the damage level of 0.2 dpa. For the heavy ion irradiation, the deuterium trapping by voids was found, indicating that cascade collisions by the heavy ion irradiation would create the voids in tungsten. Most of deuterium trapped by the voids was desorbed in higher temperature region compared to that trapped by vacancies. It was also found that deuterium could accumulate in the voids, resulting in the formation of blisters in tungsten. 相似文献
62.
New pyrochlore-type solid solutions Y2−xLaxRu2O7 have been synthesized for x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 as single-phase materials. The lattice parameters for these solid solutions are linear with x and range from 1.0140 nm (x=0.0) to 1.0257 nm (x=0.6). All the samples show semiconducting behavior with an activation energy of about 0.1 eV. They show the spin-glass-like magnetic transition at low temperatures. Its transition temperature TG decreases from 77 K for Y2Ru2O7 with increasing the La3+ content. 相似文献
63.
Carbon nanotubes (CNTs) were produced by laser ablation of a graphite composite target in argon and nitrogen ambient gas. To investigate the effect of nitrogen gas on CNTs formation, the plasma plume was examined using optical emission spectroscopy. The vibrational temperature of C2 molecules was estimated by fitting of a Swan band spectrum. The temperature in N2 ambient gas is lower than that in Ar ambient gas. In a nitrogen atmosphere, the spectrum intensity of C2 Swan band was enhanced and CN violet system was also observed. Soot collected in the reaction tube was observed using FE-SEM and TEM. The soot deposited in the nitrogen gas contained more bundled CNTs than those in Ar ambience. 相似文献
64.
Makoto KUWABARA 《材料科学技术学报》2005,21(6):887-890
1. IntroductionZinc oxide films have been attracting more and moreattention because of their high diffractive index, low resis-tance, and photoluminescence properties, and are beingused as transparent electrodes, basis material for opti-cal wave guide devices, gas sensors and so on. Manymethods have been developed to prepare ZnO films, suchas chemical vapor deposition[1], reactive evaporation[2],pulsed laser ablation[3], sputtering[4], spray pyrolysis[5]and hydrothermal method[6]. There are a… 相似文献
65.
Manipulation of micro solid particles and induced flows in water by laser irradiation 总被引:1,自引:0,他引:1
Q-switch for pulsing laser beam and Galvano scanner for rapid scanning laser beam were adapted to manipulatemicro solid particles in a water droplet.The trapping of fine particles at micron-sized diameters by a YAG lasersystem,induced flows,and the induced motion of the particles by laser beam irradiations are discussed.Particlerotations are observed by using anisotropic micro objects,and moreover the rotational rate with clockwise direc-tion is 22 r/min.The fragments of a cover glass were mixed in a water droplet,and their size and shape are un-even.The rotation of that non-spheres without scanning by the Galvano scanner is also observed in water. 相似文献
66.
Akihiro Honda Shotaro Kamata Makoto Akahane Yui Machida Kie Uchii Yui Shiiyama Yuki Habu Saeka Miyawaki Chihiro Kaneko Takuji Oyama Isao Ishii 《International journal of molecular sciences》2022,23(9)
Among the agonists against three peroxisome proliferator-activated receptor (PPAR) subtypes, those against PPARα (fibrates) and PPARγ (glitazones) are currently used to treat dyslipidemia and type 2 diabetes, respectively, whereas PPARδ agonists are expected to be the next-generation metabolic disease drug. In addition, some dual/pan PPAR agonists are currently being investigated via clinical trials as one of the first curative drugs against nonalcoholic fatty liver disease (NAFLD). Because PPARα/δ/γ share considerable amino acid identity and three-dimensional structures, especially in ligand-binding domains (LBDs), clinically approved fibrates, such as bezafibrate, fenofibric acid, and pemafibrate, could also act on PPARδ/γ when used as anti-NAFLD drugs. Therefore, this study examined their PPARα/δ/γ selectivity using three independent assays—a dual luciferase-based GAL4 transactivation assay for COS-7 cells, time-resolved fluorescence resonance energy transfer-based coactivator recruitment assay, and circular dichroism spectroscopy-based thermostability assay. Although the efficacy and efficiency highly varied between agonists, assay types, and PPAR subtypes, the three fibrates, except fenofibric acid that did not affect PPARδ-mediated transactivation and coactivator recruitment, activated all PPAR subtypes in those assays. Furthermore, we aimed to obtain cocrystal structures of PPARδ/γ-LBD and the three fibrates via X-ray diffraction and versatile crystallization methods, which we recently used to obtain 34 structures of PPARα-LBD cocrystallized with 17 ligands, including the fibrates. We herein reveal five novel high-resolution structures of PPARδ/γ–bezafibrate, PPARγ–fenofibric acid, and PPARδ/γ–pemafibrate, thereby providing the molecular basis for their application beyond dyslipidemia treatment. 相似文献
67.
In vivo measurement of swallowing by monitoring thyroid cartilage movement in healthy subjects using thickened liquid samples and its comparison with sensory evaluation
下载免费PDF全文
![点击此处可从《Journal of texture studies》网站下载免费的PDF全文](/ch/ext_images/free.gif)
68.
The routines of information work are commonplace yet difficult to characterize. Although cognitive models have successfully characterized routine tasks within which there is little variation, a large body of ethnomethodological research has identified the inherent nonroutineness of routines in information work. We argue that work does not fall into discrete classes of routine versus nonroutine; rather, task performance lies on a continuum of routineness, and routineness metrics are important to the understanding of workplace multitasking. In a study of 10 information workers shadowed for 3 whole working days each, we utilize the construct of working sphere to model projects/tasks as a network of humans and artifacts. Employing a statistical technique called T-pattern analysis, we derive measures of routineness from these real-world data. In terms of routineness, we show that information workers experience archetypes of working spheres. The results indicate that T-patterns of interactions with information and computational media are important indicators of facets of routineness and that these measures are correlated with workers' affective states. Our results are some of the first to demonstrate how regular temporal patterns of media interaction in tasks are related to stress. These results suggest that designs of systems to facilitate so-called routine work should consider the degrees to which a person's working spheres fall along varying facets of routineness. 相似文献
69.
70.
This paper presents the silicon based on-chip antenna using a LC resonator. The proposed antenna consists of a stacked capacitor and a spiral inductor on silicon substrate. The spiral inductor structure without underpass was proposed for improvement the performance of the silicon based-antenna. The resonant frequency of the fabricated antenna was measured as 465 MHz. Its return loss was 23.4 dB at resonant frequency. The antenna has a gain of ?35.75 dBi due to small size and silicon substrate. However, the fabricated antenna has good performance in the near-field. 相似文献