全文获取类型
收费全文 | 1153篇 |
免费 | 36篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 22篇 |
化学工业 | 217篇 |
金属工艺 | 37篇 |
机械仪表 | 24篇 |
建筑科学 | 22篇 |
能源动力 | 28篇 |
轻工业 | 104篇 |
水利工程 | 3篇 |
石油天然气 | 5篇 |
无线电 | 76篇 |
一般工业技术 | 208篇 |
冶金工业 | 267篇 |
原子能技术 | 34篇 |
自动化技术 | 144篇 |
出版年
2022年 | 12篇 |
2021年 | 19篇 |
2020年 | 11篇 |
2019年 | 10篇 |
2018年 | 8篇 |
2017年 | 12篇 |
2016年 | 20篇 |
2015年 | 25篇 |
2014年 | 23篇 |
2013年 | 53篇 |
2012年 | 27篇 |
2011年 | 63篇 |
2010年 | 48篇 |
2009年 | 49篇 |
2008年 | 32篇 |
2007年 | 43篇 |
2006年 | 34篇 |
2005年 | 37篇 |
2004年 | 31篇 |
2003年 | 27篇 |
2002年 | 26篇 |
2001年 | 12篇 |
2000年 | 20篇 |
1999年 | 28篇 |
1998年 | 86篇 |
1997年 | 58篇 |
1996年 | 38篇 |
1995年 | 31篇 |
1994年 | 36篇 |
1993年 | 22篇 |
1992年 | 10篇 |
1991年 | 20篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 10篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 14篇 |
1981年 | 7篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 9篇 |
1973年 | 7篇 |
1971年 | 8篇 |
1970年 | 6篇 |
1969年 | 7篇 |
1968年 | 6篇 |
排序方式: 共有1191条查询结果,搜索用时 93 毫秒
1.
2.
The ENTOREL Database for radiation stressed electronic components and systems has been established to collate data on high doses (aiming at Mega Grays) which meet the requirements of advanced teleoperators working in hazardous or disordered nuclear environments within the frame of a European telerobotics programme for the nuclear industry. The ENTOREL Database holds data from 614 tests on total dose effects 相似文献
3.
This article presents a longitudinal study of employment, unemployment and health of migrant workers in Germany. The analyses were conducted with longitudinal samples of the waves 1-6 (1984-1989) and the waves 6-9 (1989-1992) of the German Socio-Economic Panel (GSOEP). German and migrant workers did not respect to their health satisfaction but unemployed foreign workers were quite less satisfied with their health than unemployed Germans. This corresponded with a high percentage of foreign unemployed (30-50%) who felt chronically ill. A further examination of two (dichotomously formulated) principal investigation hypotheses could not show that the data support the explanation that the poorer health of unemployed migrants was caused by the unemployment situation. The results are interpreted in the way that the unemployed migrants' poorer health can be explained with (health) selection processes in the labour market. 相似文献
4.
5.
6.
John Seifert Angela Frelich Linda Shecterle John St Cyr 《Journal of the International Society of Sports Nutrition》2008,5(1):1-5
D-ribose, a naturally occurring pentose carbohydrate, has been shown to replenish high- energy phosphates following myocardial ischemia and high intensity, repetitive exercise. Human studies have mainly involved short-term assessment, including potential toxicity. Reports describing adverse effects of D-ribose with prolonged ingestion have been lacking. Therefore, this study assessed the toxicity of extended consumption of D-ribose in healthy adults. Nineteen subjects ingested 20 grams/Day (10 grams, twice a Day) of ribose with serial measurements of biochemical and hematological parameters at Days 0, 7, and 14. No significant toxic changes over the 14-day assessment period occurred in complete blood count, albumin, alkaline phosphatase, gamma glutamyltransferase, alanine amiotransferase, and aspartate aminotransferase. However, D-ribose did produce an asymptomatic, mild hypoglycemia of short duration. Uric acid levels increased at Day 7, but decreased to baseline values by Day 14. D-ribose consumption for 14 days appears not to produce significant toxic changes in both hematological and biochemical parameters in healthy human volunteers. 相似文献
7.
All boiling water reactor (BWR) degraded core experiments performed prior to CORA-33 were conducted under ‘wet’ core degradation conditions, in which water remains within the core and continuous steaming feeds metal-steam oxidation reactions on the in-core metallic surfaces. However, one dominant set of accident scenarios would occur with reduced metal oxidation under ‘dry’ core degradation conditions and, prior to CORA-33, this set had been neglected experimentally. The CORA-33 experiment was designed specifically to address this dominant set of BWR ‘dry’ core severe accident scenarios and to resolve partially phenomenological uncertainties concerning the behavior of relocating metallic melts that drain into the lower regions of a ‘dry’ BWR core (the ex-reactor experiments at Sandia National Laboratories will further address these uncertainties). CORA-33 was conducted on 1 October 1992, in the CORA test facility at Karlsruhe. A review of the CORA-33 data indicates that the objectives were achieved; i.e. core degradation occurred at a core heat-up rate (characterized by the absence of any temperature escalation caused by oxidation) and a test section axial temperature profile (at incipient structural melting) that are prototypic of full-core nuclear power plant simulations under ‘dry’ core conditions. Simulations of the CORA-33 test at Oak Ridge National Laboratory (ORNL) have required the modification of existing control blade-canister materials interaction models to include the eutectic melting of the stainless steel-zircaloy interaction products and the heat of mixing of stainless steel and zircaloy. The timing and location of canister failure and melt intrusion into the fuel assembly appear to be adequately simulated by the ORNL models. This paper will present the results of the post-test analyses carried out at ORNL based on the experimental data and the post-test examination of the test bundle at Karlsruhe. The implications of these results with respect to degraded core modelling and the associated safety issues are also discussed. 相似文献
8.
The common way to construct Voronoi tessellations is to compare the distances between given reference points using a given
distance function. To generalize this distance-function concept we expand an existing approach which defines distance functions
by their ``unit circles'. Our new approach allows modeling the ``unit circles' by a closed Spline curve. Changing the control
polygon directly affects the tessellation's appearance. Typically generalized Voronoi diagrams are represented by Voronoi
vertices and curves separating the individual tiles. To obtain interactive modeling we extended an existing hardware accelerated
rendering approach computing a bitmap-representation using different colors for individual tiles. With our extension, we are
able to use our Spline distance representations as input for a growing process. This growing process easily takes into account
weighting approaches like multiplicative, additive, and even free functional weighting. 相似文献
9.
10.
A Blume K Seifert CJ Lebrun E M?llenhoff P Gass T Unger T Herdegen 《Canadian Metallurgical Quarterly》1998,241(2-3):87-90
Binding to olfactory receptors is the first step in odorant and pheromonal recognition and discrimination. These receptors constitute one of the most important, although poorly known, families of neuronal receptors. In this study we used degenerated oligonucleotides and a RT-PCR approach to selectively amplify olfactory receptors in the nasal epithelium of the domestic pig Sus scrofa. Several combinations of oligonucleotide were tested and allowed the isolation of eleven different partial sequences belonging to the seven transmembrane olfactory receptor family. These receptors formed a separate family within the seven transmembrane receptor superfamily in pigs. Using the criteria of Ben Arie et al. [Ben-Arie N., Lancet D., Taylor C., Khen M., Walker N., Ledbetter DH., Carrozzo R., Patel K., Sheer D., Lehrah H. and North M., Hum. Mol. Genet., 3 (1994) 229-235], the 11 receptors described here can be classified into three known families and seven subfamilies (one known and six new). 相似文献