全文获取类型
收费全文 | 2222篇 |
免费 | 110篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 40篇 |
综合类 | 1篇 |
化学工业 | 215篇 |
金属工艺 | 28篇 |
机械仪表 | 35篇 |
建筑科学 | 82篇 |
矿业工程 | 62篇 |
能源动力 | 39篇 |
轻工业 | 332篇 |
水利工程 | 6篇 |
石油天然气 | 11篇 |
武器工业 | 1篇 |
无线电 | 231篇 |
一般工业技术 | 332篇 |
冶金工业 | 609篇 |
原子能技术 | 17篇 |
自动化技术 | 296篇 |
出版年
2022年 | 18篇 |
2021年 | 17篇 |
2020年 | 21篇 |
2019年 | 24篇 |
2018年 | 29篇 |
2017年 | 18篇 |
2016年 | 37篇 |
2015年 | 24篇 |
2014年 | 36篇 |
2013年 | 124篇 |
2012年 | 78篇 |
2011年 | 83篇 |
2010年 | 71篇 |
2009年 | 78篇 |
2008年 | 103篇 |
2007年 | 87篇 |
2006年 | 97篇 |
2005年 | 95篇 |
2004年 | 85篇 |
2003年 | 73篇 |
2002年 | 82篇 |
2001年 | 47篇 |
2000年 | 40篇 |
1999年 | 48篇 |
1998年 | 165篇 |
1997年 | 92篇 |
1996年 | 76篇 |
1995年 | 41篇 |
1994年 | 55篇 |
1993年 | 65篇 |
1992年 | 21篇 |
1991年 | 30篇 |
1990年 | 25篇 |
1989年 | 27篇 |
1988年 | 18篇 |
1987年 | 19篇 |
1986年 | 20篇 |
1985年 | 19篇 |
1984年 | 20篇 |
1983年 | 22篇 |
1982年 | 11篇 |
1981年 | 17篇 |
1980年 | 18篇 |
1979年 | 15篇 |
1978年 | 11篇 |
1977年 | 20篇 |
1976年 | 31篇 |
1974年 | 13篇 |
1971年 | 9篇 |
1970年 | 10篇 |
排序方式: 共有2337条查询结果,搜索用时 15 毫秒
1.
2.
Joshua C. Price Simon J. Levett Valentin Radu David A. Simpson Aina Mogas Barcons Christopher F. Adams Melissa L. Mather 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(22)
Fluorescent nanodiamonds (fNDs) containing nitrogen vacancy (NV) centers are promising candidates for quantum sensing in biological environments. This work describes the fabrication and implementation of electrospun poly lactic‐co‐glycolic acid (PLGA) nanofibers embedded with fNDs for optical quantum sensing in an environment, which recapitulates the nanoscale architecture and topography of the cell niche. A protocol that produces uniformly dispersed fNDs within electrospun nanofibers is demonstrated and the resulting fibers are characterized using fluorescent microscopy and scanning electron microscopy (SEM). Optically detected magnetic resonance (ODMR) and longitudinal spin relaxometry results for fNDs and embedded fNDs are compared. A new approach for fast detection of time varying magnetic fields external to the fND embedded nanofibers is demonstrated. ODMR spectra are successfully acquired from a culture of live differentiated neural stem cells functioning as a connected neural network grown on fND embedded nanofibers. This work advances the current state of the art in quantum sensing by providing a versatile sensing platform that can be tailored to produce physiological‐like cell niches to replicate biologically relevant growth environments and fast measurement protocols for the detection of co‐ordinated endogenous signals from clinically relevant populations of electrically active neuronal circuits. 相似文献
3.
Pakteera Sripokar Yi Zhang Benjamin K. Simpson Egon Bech Hansen Suppasil Maneerat Sappasith Klomklao 《International Journal of Food Science & Technology》2021,56(12):6368-6375
Beardless barb is a common fish species used in fermentation of fish paste Ka-pi-plaa. Autolytic profile of beardless barb muscle showed the maximum autolysis was at 50 °C, at both acidic and alkaline pH values. With augmentation concentration of NaCl, autolytic activity slightly decreased. Endogenous proteinases isolated from fish muscle in crude extract forms were also characterised. The acidic proteinases had optimum activity at pH 3.0 and 50°C, and they showed higher proteolytic activity than the alkaline proteinases which were optimally active at pH 9.0 and 50 °C. Proteinases in peak at pH 3.0 were inhibited by pepstatin A, but those in peak at pH 9.0 were highly inhibited by PMSF, TLCK and soybean trypsin inhibitor, suggesting that both aspartic and serine proteinases were existed in beardless barb muscle. The proteinases were stable in pH range of 2.0-5.0 but unstable at the temperatures higher than 40 °C. NaCl suppressed the proteolytic activity, ATP activated the proteinase activity, while CaCl2, MgCl2 and CoCl2 exhibited no influence on the activity. The results implied that cathepsin D is the predominant proteinase responsible for autolysis in beardless barb. The findings were useful to improve the processing and qualities of Ka-pi-plaa product using beardless barb as raw material. 相似文献
4.
5.
6.
S Moss B Ibbotson H Prosser D Goldberg P Patel N Simpson 《Canadian Metallurgical Quarterly》1997,32(6):344-354
The Psychiatric Assessment Schedule for Adults with Developmental Disability (PAS-ADD) is a semi-structured interview for use with respondents who have learning disability and for key informants. This report investigates the ability of the instrument to detect symptoms that had been found to exist during routine clinical assessment of the patients. Field trials involved 95 referred patients with learning disability and a key informant for each sample member. Clinical opinions of the referring psychiatrists were sought using a symptom checklist. Referrer checklist symptoms and PAS-ADD data were both factor analysed. Validity testing involved (a) computation of correlations between PAS-ADD factors and checklist data and (b) comparison of PAS-ADD and referrers' diagnoses. Results indicated good validity for the PAS-ADD in relation to psychotic symptoms and depressive symptoms. Anxiety symptom identification was not well validated, probably due to small numbers. Expansive mood identified by the referrers was not detected by the PAS-ADD because there is currently no corresponding section in the interview. Where the PAS-ADD produced a diagnosis (in 58 members of the sample), 44 were in agreement with the referrer. Probability of diagnosis by PAS-ADD increased with the number of relevant active symptoms identified by the referrer. The PAS-ADD has been shown in a previous report to have the sensitivity to detect mental disorders not known to psychiatric services. For psychotic and depressive conditions, our results showed that symptom detection was in good agreement with the information provided by the referring psychiatrists on their patients. The PAS-ADD needs a section on hypomania and further investigation of its detection of anxiety disorders. 相似文献
7.
Renal cell carcinoma may metastasize to the head and neck region at different stages of its evolution. We present a case of an undiagnosed renal cell carcinoma presenting as an ear polyp, and discuss the difficulties of the diagnosis and the management of these tumours. 相似文献
8.
10.