全文获取类型
收费全文 | 6893篇 |
免费 | 75篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 36篇 |
综合类 | 6篇 |
化学工业 | 679篇 |
金属工艺 | 90篇 |
机械仪表 | 57篇 |
建筑科学 | 191篇 |
矿业工程 | 11篇 |
能源动力 | 143篇 |
轻工业 | 355篇 |
水利工程 | 26篇 |
石油天然气 | 12篇 |
无线电 | 313篇 |
一般工业技术 | 503篇 |
冶金工业 | 4111篇 |
原子能技术 | 37篇 |
自动化技术 | 402篇 |
出版年
2022年 | 25篇 |
2019年 | 36篇 |
2018年 | 29篇 |
2017年 | 42篇 |
2016年 | 51篇 |
2015年 | 38篇 |
2014年 | 48篇 |
2013年 | 181篇 |
2012年 | 99篇 |
2011年 | 135篇 |
2010年 | 109篇 |
2009年 | 113篇 |
2008年 | 120篇 |
2007年 | 119篇 |
2006年 | 106篇 |
2005年 | 121篇 |
2004年 | 94篇 |
2003年 | 92篇 |
2002年 | 107篇 |
2001年 | 68篇 |
2000年 | 71篇 |
1999年 | 165篇 |
1998年 | 1030篇 |
1997年 | 619篇 |
1996年 | 396篇 |
1995年 | 276篇 |
1994年 | 228篇 |
1993年 | 284篇 |
1992年 | 91篇 |
1991年 | 93篇 |
1990年 | 96篇 |
1989年 | 104篇 |
1988年 | 99篇 |
1987年 | 87篇 |
1986年 | 101篇 |
1985年 | 112篇 |
1984年 | 71篇 |
1983年 | 52篇 |
1982年 | 67篇 |
1981年 | 99篇 |
1980年 | 79篇 |
1979年 | 45篇 |
1978年 | 42篇 |
1977年 | 172篇 |
1976年 | 327篇 |
1975年 | 75篇 |
1974年 | 33篇 |
1973年 | 42篇 |
1972年 | 42篇 |
1970年 | 32篇 |
排序方式: 共有6972条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Removal of gold from basic solutions containing [Au(CN)2]? has been demonstrated using the inherently conducting polymer polypyrrole. Polymers containing sulfonated aromatic dopants have been found to display a significant ability to remove gold from such solutions. Experiments performed in solutions containing both gold and copper cyanide complexes indicate that the recovery process is not highly selective. However, the polypyrroles used display significantly faster rates of gold recovery than activated carbon. © 2003 Society of Chemical Industry 相似文献
5.
A semiconductor laser rate equation theory is presented that describes sideband injection locking under both weak optical injection and current modulation. By simultaneous optical injection and current modulation, control of both the phase and the frequency of a semiconductor laser is demonstrated. The phase-locked semiconductor laser operates at a different frequency to the optical injection source, with a frequency-difference given by the current modulation frequency. This method can be used to produce broadband sources, such as those producing ultrashort pulses and those required for coherent control, or to create high-frequency electronic oscillator sources with phase control by interference beating 相似文献
6.
RE Vlietstra 《Canadian Metallurgical Quarterly》1993,16(10):2073-2074
7.
BF Habbick JL Nanson RE Snyder RE Casey AL Schulman 《Canadian Metallurgical Quarterly》1996,87(3):204-207
Ethers and thioethers of monosaccharides have been synthesised which show potent toxicity to mouse (LD50 > or = 4 g.kg-1 O.W. and 0.2 to 1.5 g.kg-1 I.P.W.). A study of calcium antagonist activity for the full series of compounds indicated that the activity was similar for both O- and S- ethers and maximum activities were observed for monoacetoneglucose ethers possessing carbon chain close to 8 carbons. 相似文献
8.
BACKGROUND: IgE-mediated hypersensitivity to latex proteins has become a significant clinical problem over the last decade. Nursing and medical staff are at risk because of their occupational exposure to latex. AIMS: To determine the prevalence of type I hypersensitivity to latex allergens in the nursing staff of an Australian hospital. METHODS: A questionnaire which asked about symptoms associated with the use of latex gloves was completed by 140 nurses working in the Alfred Hospital (72 in general medical wards, 68 in intensive care units). Skin prick tests with eluates of five different types of latex glove as well as common aeroallergens (rye pollen and house dust mite) and banana extract were performed. RESULTS: Thirty-one nurses (22%) were skin prick test positive to at least one of the five latex glove eluates. All of these nurses were atopic, having positive skin prick tests to rye pollen or house dust mite. Symptoms of local dryness, itch and erythema associated with glove use were reported by more than half the study group, but not more frequently by those who were skin prick test positive to latex. Urticaria associated with glove use was reported more frequently by those with positive latex skin prick tests (13% vs 4%, p = 0.05). Eighty-seven per cent of the nurses who were latex skin test positive were also positive to banana extract. CONCLUSIONS: IgE-mediated hypersensitivity to latex is common in nurses working in an Australian hospital. Glove associated symptoms were frequently reported, but in most cases the symptoms were more typical of irritant or contact dermatitis rather than type I hypersensitivity reactions. However, the extent of subclinical sensitisation to latex found in this study suggests that symptomatic latex allergy is likely to emerge as an increasing problem for nursing staff in this country. 相似文献
9.
10.
John C. Hart Gordon W. Lescinsky Daniel J. Sandin Thomas A. DeFanti Louis H. Kauffman 《The Visual computer》1993,9(7):346-355
The pipelined architecture and parallel organization of the AT&T Pixel Machine image computer are described and demonstrated with applications for the visualization of multidimensional fractals, particularly linear fractals and quaternion/ stacked Julia sets. Techniques for pushing the Pixel Machine to its peak abilities are described and apply to more recent parallel image computers as well. 相似文献