全文获取类型
收费全文 | 1856篇 |
免费 | 74篇 |
国内免费 | 22篇 |
专业分类
电工技术 | 81篇 |
综合类 | 1篇 |
化学工业 | 409篇 |
金属工艺 | 61篇 |
机械仪表 | 66篇 |
建筑科学 | 39篇 |
能源动力 | 79篇 |
轻工业 | 106篇 |
水利工程 | 4篇 |
石油天然气 | 1篇 |
无线电 | 200篇 |
一般工业技术 | 368篇 |
冶金工业 | 335篇 |
原子能技术 | 55篇 |
自动化技术 | 147篇 |
出版年
2023年 | 11篇 |
2022年 | 32篇 |
2021年 | 64篇 |
2020年 | 33篇 |
2019年 | 36篇 |
2018年 | 44篇 |
2017年 | 34篇 |
2016年 | 51篇 |
2015年 | 39篇 |
2014年 | 60篇 |
2013年 | 120篇 |
2012年 | 76篇 |
2011年 | 124篇 |
2010年 | 88篇 |
2009年 | 77篇 |
2008年 | 84篇 |
2007年 | 56篇 |
2006年 | 59篇 |
2005年 | 62篇 |
2004年 | 46篇 |
2003年 | 48篇 |
2002年 | 48篇 |
2001年 | 31篇 |
2000年 | 24篇 |
1999年 | 40篇 |
1998年 | 120篇 |
1997年 | 82篇 |
1996年 | 54篇 |
1995年 | 36篇 |
1994年 | 34篇 |
1993年 | 37篇 |
1992年 | 15篇 |
1991年 | 24篇 |
1990年 | 13篇 |
1989年 | 26篇 |
1988年 | 18篇 |
1987年 | 12篇 |
1986年 | 10篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1973年 | 2篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有1952条查询结果,搜索用时 31 毫秒
1.
The World robot summit disaster robotics category – achievements of the 2018 preliminary competition
Satoshi Tadokoro Tetsuya Kimura Masayuki Okugawa Katsuji Oogane Hiroki Igarashi Yoshikazu Ohtsubo 《Advanced Robotics》2019,33(17):854-875
The World Robot Summit is a robot Olympics and aims to be held in a different country every four years from 2020. The concept of the Plant Disaster Prevention challenge is daily inspections, checks, and emergency response in industrial plants, and in this competition, robots must carry out these types of missions in a mock-up plant. The concept of the Tunnel Disaster Response and Recovery challenge is emergency response to tunnel disasters, and is a simulation competition whereby teams compete to show their ability to deal with disasters, by collecting information and removing debris. The Standard Disaster Robotics challenge assesses, in the form of a contest, the standard performance levels of a robot that are necessary for disaster prevention and emergency response. The World Robot Summit Preliminary Competition was held at Tokyo Big Sight in October 2018, and 36 teams participated in the Disaster Robotics Category. UGVs and UAVs contended the merits of new technology for solving complex problems, using core technologies such as mobility, sensing, recognition, performing operations, human interface, autonomous intelligence etc., as well as system integration and implementation of strategies for completing missions, gaining high-level results. 相似文献
2.
N Manabe Y Imai H Ohno Y Takahagi M Sugimoto H Miyamoto 《Canadian Metallurgical Quarterly》1996,52(7):647-651
The porcine antral follicles, 3-6 mm in diameter, were dissected from the ovaries of mature pigs, and then granulosa and cumulus cells were isolated from each follicle. In atretic follicles, high activity of neutral Ca2+/Mg2+-dependent endonuclease and DNA ladder formation, estimated by electrophoresis, were noted in granulosa cells but not in cumulus cells. Extremely low activity of the endonuclease and no DNA ladder formation were observed in both types of cells obtained from healthy follicles. Moreover, apoptotic cells were observed histochemically among granulosa cells only. A good correlation (r = 0.987) between the endonuclease activity of granulosa cells and the progesterone/estradiol ratio of follicular fluid in each follicle was found. These results suggest that apoptosis occurs in granulosa cells but not cumulus cells in the atretic antral follicles in pigs. 相似文献
3.
There are several damping phenomena in quantum optics. Such phenomena have been usually explained by open systems. In statistical physics, open system dynamics have been used to study the irreversibility and the approach to equilibrium. In this paper, the dynamical change of the mutual entropy for an open system, frequently studied in the quantum optics literature, is rigorously computed through a model of quantum Markov chain. In particular, the concrete formula of Stinespring expression for such a model is obtained and applied to the derivation of the mutual entropy, and some computational results are presented. 相似文献
4.
Tatsuo Inoue Nobutada Ohno Akihiko Suzuki Toshihide Igari 《Nuclear Engineering and Design》1989,114(3)
Uniaxial tests to identify plasticity-creep interaction in
steel at 600°C were carried out as the Benchmark Project by the Subcommittee on Inelastic Analysis and Life Prediction, JSMS. The purpose of this paper is to present recent experimental data and predictions of constitutive models obtained in the project. Ten types of constitutive models were utilized to compare analytical predictions to sixteen benchmark experiments which are grouped into four categories: (I) tensile and creep tests under monotonic loading, (II) mixed mode tests under plastic and creep loading, (III) ratcheting deformation tests under program loads, and (IV) cyclic deformation tests under the combination of different strain rates. The benchmark tests in Group IV are used to estimate the creep-fatigue life of
steel; the results will be published in a separate paper. 相似文献
5.
Hideki Taguchi Yuzuru Takahashi Hiroki Miyamoto 《Journal of the American Ceramic Society》1985,68(10):264-C
Specimens of partially stabilized zirconia were slip cast from aqueous suspensions and sintered at 1500°C for 3 h. The relative density of the cast specimens and the firing shrinkage of the sintered specimens depend on the milling time for the suspension. Vickers hardness and KIC values of 11.46±s0.07 GN/m2 and 6.10 ±0.04 MN.m3/2 , respectively, were obtained for all sintered specimens. The dispersion of the suspension is important in increasing the relative density of the cast specimens. 相似文献
6.
7.
K Hashimoto M Noshiro S Ohno T Kawamoto H Satakeda Y Akagawa K Nakashima A Okimura H Ishida T Okamoto H Pan M Shen W Yan Y Kato 《Canadian Metallurgical Quarterly》1997,1355(3):303-314
Malignant human gliomas are the most common forms of primary tumors in the central nerve system. Due to their location and invasive nature, treatment so far has been mainly palliative. Thus, understanding the molecular detail of tumor transformation and progression is crucial for developing effective therapeutic strategy for this fetal tumor. Among the genetic alternations found in these tumors, p53 inactivation and PDGF/PDGFR activation represent the early events, and the loss of chromosome 10 and gene amplification and rearrangement of EGFR represent the late events. Studies with both glioma cell lines and primary tumor tissues have strongly suggested that TGF-alpha and EGFR function as an important autocrine loop in supporting proliferation of human glioma, especially in high grade glioma, since elevated TGF-alpha expression is also found in these high grade tumors. Furthermore, down regulation of the expression of TGF-alpha by antisense constructs has been shown to inhibit several types of human tumor cell growth including glioma. Other means of therapeutic approaches using this autocrine loop as a target also include the use of monoclonal antibodies and their cytotoxic conjugated. Considerable understanding of the EGFR-mediated signal transduction pathways has become available recently, which including GRB2/mSOS1 mediated MAP kinase activation; JAK/STATs pathway; PLC-gamma pathway. However, much work still needs to be done before a specific component of these pathways can be applied for effective control of tumor growth in the clinic. 相似文献
8.
9.
Persistence of the hypoglossal artery is an unusual congenital abnormality of the carotid arterial system, and the simultaneous occurrence of atheromatous disease in the internal carotid artery and persistent hypoglossal artery is even more uncommon. Carotid surgery in this situation is challenging, and the surgeon must be aware of potential inherent pitfalls. A 74-year-old woman with asymptomatic stenosis of both internal carotid and hypoglossal arteries associated with occlusion of the contralateral internal carotid artery underwent successful revascularization. The anatomy of this unusual lesion and the surgical strategies, which included cranial nerve dissection and mandibular subluxation, are reviewed. 相似文献
10.
Tetsuya Suemitsu Yoshino K. Fukai Hiroki Sugiyama Kazuo Watanabe Haruki Yokoyama 《Microelectronics Reliability》2002,42(1):47-52
The reliability of InP-based HEMTs is studied, focussing on how it is affected by the doped layer material and gate recess structure. Bias-and-temperature stress tests reveal that fluorine-induced donor passivation in the recess region, formed adjacent to the gate electrode, causes the source resistance (Rs) to increase at large drain bias voltages. The increase in Rs can be prevented by using InP or InAlP as the carrier supply layer material instead of InAlAs. On the other hand, the increase in the drain resistance (Rd) does not depend on the material of the carrier supply layer, which suggests that a mechanism different from that in the case of Rs should be considered. It is also found that a deep gate recess suppresses the increase in Rd after long-term stressing. 相似文献