全文获取类型
收费全文 | 2468篇 |
免费 | 213篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 12篇 |
综合类 | 4篇 |
化学工业 | 1009篇 |
金属工艺 | 24篇 |
机械仪表 | 46篇 |
建筑科学 | 58篇 |
矿业工程 | 5篇 |
能源动力 | 54篇 |
轻工业 | 400篇 |
水利工程 | 27篇 |
石油天然气 | 9篇 |
无线电 | 150篇 |
一般工业技术 | 370篇 |
冶金工业 | 190篇 |
原子能技术 | 13篇 |
自动化技术 | 311篇 |
出版年
2024年 | 8篇 |
2023年 | 19篇 |
2022年 | 193篇 |
2021年 | 226篇 |
2020年 | 74篇 |
2019年 | 102篇 |
2018年 | 89篇 |
2017年 | 90篇 |
2016年 | 116篇 |
2015年 | 100篇 |
2014年 | 120篇 |
2013年 | 168篇 |
2012年 | 165篇 |
2011年 | 160篇 |
2010年 | 111篇 |
2009年 | 122篇 |
2008年 | 124篇 |
2007年 | 92篇 |
2006年 | 76篇 |
2005年 | 70篇 |
2004年 | 51篇 |
2003年 | 43篇 |
2002年 | 28篇 |
2001年 | 25篇 |
2000年 | 19篇 |
1999年 | 15篇 |
1998年 | 45篇 |
1997年 | 29篇 |
1996年 | 30篇 |
1995年 | 22篇 |
1994年 | 13篇 |
1993年 | 17篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 9篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1973年 | 4篇 |
1967年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有2682条查询结果,搜索用时 31 毫秒
1.
2.
3.
Daniela Fogli Antonio Piccinno Stefan Carmien Gerhard Fischer 《Behaviour & Information Technology》2020,39(1):27-46
ABSTRACTThe digital age of the future is ‘not out there to be discovered’, but it needs to be ‘designed’. The design challenge has to address questions about how we want to live, work, and learn (as individuals and as communities) and what we value and appreciate, e.g.: reflecting on quality of life and creating inclusive societies. An overriding design trade-off for the digital age is whether new developments will increase the digital divide or will create more inclusive societies. Sustaining inclusive societies means allowing people of all ages and all abilities to exploit information technologies for personally meaningful activities. Meta-design fosters the design of socio-technical environments that end-user developers can modify and evolve at use time to improve their quality of life and favour their inclusion in the society. This paper describes three case studies in the domain of assistive technologies in which end users themselves cannot act as end-user developers, but someone else (e.g.: a caregiver or a clinician) must accept this role requiring multi-tiered architectures. The design trade-offs and requirements for meta-design identified in the context of the case studies and other researchers’ projects are described to inform the development of future socio-technical environments focused on social inclusion. 相似文献
4.
5.
6.
7.
Daniela Frasca Maria Romero Alain Diaz Denisse Garcia Seth Thaller Bonnie B. Blomberg 《International journal of molecular sciences》2021,22(4)
Senescent cells accumulate in the adipose tissue (AT) of individuals with obesity and secrete multiple factors that constitute the senescence-associated secretory phenotype (SASP). This paper aimed at the identification of B cells with a SASP phenotype in the AT, as compared to the peripheral blood, of individuals with obesity. Our results show increased expression of SASP markers in AT versus blood B cells, a phenotype associated with a hyper-metabolic profile necessary to support the increased immune activation of AT-derived B cells as compared to blood-derived B cells. This hyper-metabolic profile is needed for the secretion of the pro-inflammatory mediators (cytokines, chemokines, micro-RNAs) that fuel local and systemic inflammation. 相似文献
8.
9.
Daniela M. Nevskaia Maria Luisa Rojas Cervantes Antonio Guerrero Ruíz Juan de Dios Lpez Gonzlez 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1995,63(3):249-256
Adsorption of Triton X-100 on various silica substrates has been investigated. A number of solids, including a natural quartz, this quartz washed with HCl acid and subsequently heated at 1273 K; two aerosils and one Kieselgel silicas were studied. These solids exhibit surface areas in the range of 5 to 430 m2 g?1. All the Triton adsorption isotherms display an S-shape at the adsorption temperatures studied (298 and 308 K). It has been found that the pretreatments of natural quartz (by water washing, impurities removed by acid and/or high temperature calcination) affect considerably the amounts of TX-100 adsorbed. Measurements of surface composition have been made by X-ray photoelectron spectroscopy (XPS) with particular emphasis on the presence of impurities and on the number of OH groups at the surface of the samples. The nature of the surface hydroxyl has also been studied by infrared spectroscopy. Furthermore, the specific number of hydroxyl groups on the surface of the silica samples has been determined by thermogravimetric analysis. Finally an attempt to correlate solid surface characteristics with adsorption isotherms has been developed. 相似文献
10.
E Arvat R Giordano J Ramunni G Arnaldi A Colao R Deghenghi G Lombardi F Mantero F Camanni E Ghigo 《Canadian Metallurgical Quarterly》1998,83(12):4207-4211
We previously reported that in Cushing's disease (CD) the ACTH- and cortisol (F)-releasing activity of Hexarelin (HEX), a GH secretagogue, is exaggerated with respect to that in normal subjects and is higher than that of human CRH (hCRH), but it is absent in Cushing's syndrome. Our aim was to extend the study about the effects of HEX (2.0 microg/kg, iv) on ACTH and F secretion in 21 patients with CD (3 men and 18 women, 16-68 yr old). Based on magnetic resonance imaging, 15 CD patients had pituitary microadenoma, and 6 had macroadenoma. The results in CD patients were compared with those in 27 normal age-matched controls (NS; 10 men and 17 women, 24-69 yr old). Basal ACTH and F levels in CD were similar in patients with microadenom (mean+/-SEM, 78.3+/-7.2 pg/mL and 237.1+/-23.6 microg/L, respectively) and macroadenoma (57.4+/-9.0 pg/mL and 196.9+/-20.1 microg/L, respectively) and were higher (P < 0.001) than those in NS (17.7+/-2.0 pg/mL and 115.3+/-6.7 microg/L, respectively). In microadenoma CD patients, HEX induced marked ACTH and F increases (delta peak, mean+/-SEM: 261.2+/-77.6 pg/mL and 226.1+/-87.2 microg/L, respectively), which were higher (P < 0.04) than those induced by hCRH (45.6+/-16.9 pg/mL and 84.6+/-25.7 microg/L, respectively). Moreover, in microadenoma CD patients, the ACTH and F responses to HEX were higher (P < 0.001) than those in NS (18.5+/-4.0 pg/mL and 36.1+/-6.8 microg/L, respectively). In macroadenoma CD patients, HEX induced a slight, but significant increase (P < 0.02) in ACTH and F levels (33.9+/-18.0 pg/mL and 89.6+/-34.3 microg/L, respectively), which was not significantly different from that elicited by hCRH (20.0+/-7.0 pg/mL and 54.8+/-21.3 microg/L, respectively). In macroadenoma CD patients, the ACTH and F responses to HEX and hCRH were, in turn, similar to those in NS. In conclusion, our findings demonstrate that the ACTH and F hyperresponsiveness to HEX is present in Cushing's disease with micro-, but not macro- ACTH-secreting pituitary adenoma. This finding agrees with other evidence pointing toward differences in the hormonal behavior between micro- and ACTH-secreting pituitary macroadenomas. 相似文献