全文获取类型
收费全文 | 2486篇 |
免费 | 93篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 19篇 |
综合类 | 2篇 |
化学工业 | 718篇 |
金属工艺 | 81篇 |
机械仪表 | 49篇 |
建筑科学 | 100篇 |
矿业工程 | 5篇 |
能源动力 | 72篇 |
轻工业 | 218篇 |
水利工程 | 13篇 |
石油天然气 | 1篇 |
无线电 | 221篇 |
一般工业技术 | 531篇 |
冶金工业 | 141篇 |
原子能技术 | 46篇 |
自动化技术 | 368篇 |
出版年
2023年 | 14篇 |
2022年 | 30篇 |
2021年 | 48篇 |
2020年 | 26篇 |
2019年 | 29篇 |
2018年 | 45篇 |
2017年 | 52篇 |
2016年 | 52篇 |
2015年 | 37篇 |
2014年 | 83篇 |
2013年 | 149篇 |
2012年 | 137篇 |
2011年 | 178篇 |
2010年 | 127篇 |
2009年 | 138篇 |
2008年 | 141篇 |
2007年 | 124篇 |
2006年 | 125篇 |
2005年 | 87篇 |
2004年 | 75篇 |
2003年 | 69篇 |
2002年 | 90篇 |
2001年 | 48篇 |
2000年 | 46篇 |
1999年 | 42篇 |
1998年 | 54篇 |
1997年 | 51篇 |
1996年 | 42篇 |
1995年 | 40篇 |
1994年 | 29篇 |
1993年 | 37篇 |
1992年 | 22篇 |
1991年 | 22篇 |
1990年 | 25篇 |
1989年 | 21篇 |
1988年 | 19篇 |
1987年 | 13篇 |
1986年 | 16篇 |
1985年 | 14篇 |
1984年 | 22篇 |
1983年 | 16篇 |
1982年 | 16篇 |
1981年 | 19篇 |
1980年 | 11篇 |
1979年 | 17篇 |
1978年 | 14篇 |
1976年 | 18篇 |
1975年 | 12篇 |
1974年 | 9篇 |
1972年 | 7篇 |
排序方式: 共有2585条查询结果,搜索用时 31 毫秒
1.
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
2.
Load testing of applications is an important and costly activity for software provider companies. Classical solutions are very difficult to set up statically, and their cost is prohibitive in terms of both human and hardware resources. Virtualized cloud computing platforms provide new opportunities for stressing an application's scalability, by providing a large range of flexible and less expensive (pay‐per‐use model) computation units. On the basis of these advantages, load testing solutions could be provided on demand in the cloud. This paper describes a Benchmark‐as‐a‐Service solution that automatically scales the load injection platform and facilitates its setup according to load profiles. Our approach is based on: (i) virtualization of the benchmarking platform to create self‐scaling injectors; (ii) online calibration to characterize the injector's capacity and impact on the benched application; and (iii) a provisioning solution to appropriately scale the load injection platform ahead of time. We also report experiments on a benchmark illustrating the benefits of this system in terms of cost and resource reductions. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
3.
Lai-Ying Leong Teck-Soon Hew Keng-Boon Ooi Alain Yee Loong Chong Voon-Hsien Lee 《Information & Management》2021,58(2):103416
This paper examines what influences trust in mobile social commerce environment. Drawing on trust-based acceptance model (i.e. cognitive and emotional trust) and online review features (i.e. profile photo, linguistic style, and reported experience), we examine how these factors affect trust in mobile social commerce. Hypotheses were tested using survey data. The results of our model showed that there are significant influences of profile photo, reported experience, cognitive, and emotional trust towards trust in ms-commerce. This work contributes to existing literature by examining the roles of previous trust in mobile payments and online reviews on trust in mobile social commerce. 相似文献
4.
Igboamalu Frank Nonso Ndjiongue Alain Richard Ferreira Hendrik Christoffel 《Telecommunication Systems》2020,73(4):521-530
Telecommunication Systems - Signals from indoor access points in a wireless fidelity suffer from high attenuation as a result of the thick walls and metal structures in the multilevel-storey... 相似文献
5.
Désiré Lara; Veissier Isabelle; Després Gérard; Boissy Alain 《Canadian Metallurgical Quarterly》2004,118(4):363
Appraisal theories provide a framework that gives insight into emotions and could allow comparisons across species. According to these theories, events are first evaluated on their suddenness, novelty, and unpredictability. The authors examined the ability of lambs (Ovis aries) to evaluate an event according to these 3 criteria through 3 tests. The lambs responded to suddenness with a startle response coupled with an increase in heart rate and to novelty with an orientation response coupled with an increase of vagal activity. There was no clear evidence that lambs can detect the predictability of an event. Those results support the usefulness of appraisal theories to assess emotion in animals. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
T Garnier 《Canadian Metallurgical Quarterly》1996,56(3):297-302
According to some ultrastructural studies, the pericapillary axon terminals in the central nervous system (CNS) are functionally connected with the capillary vessel wall. Thus, it may be expected that the population of pericapillary axon terminals will be morphologically distinct from the terminals at a further distance from the capillary walls. To test this hypothesis, morphometrical analysis of 3,048 axon terminals was performed, comparing terminals situated in the close vicinity of the capillary vessel with those at a distance from the vessels in the lateral, basal, medial, central and cortical nuclei of the amygdaloid body of eight cats. The cross-sectional area and circumference of each identified axon terminal profile were measured, and the shape of synaptic vesicles and the presence of synaptic contacts and granular vesicles were recorded. The statistical evaluation of results was performed by means of the Newman-Keuls' test, Wilcoxon's test, Fisher's contingency-table test and the test for two coefficients of structure. The morphometric examination revealed two ultrastructurally distinct groups of axon terminals, pericapillary and distant terminals, in all the nuclei of the amygdaloid body. The differentiating features were the shape of the synaptic vesicles, the number of synaptic contacts, and the size of the axon terminals. These results further support the hypothesis of a functional connection between axon terminals and the capillary vessel wall in the CNS. 相似文献
7.
8.
Jean-Louis Havet Myriam Billiau-Loreau Catherine Porte Alain Delacroix 《Journal of Automated Methods and Management in Chemistry》2002,24(4):111-119
Chemometric tools were used to generate the modelling of solvent e inverted exclamation markects on the N-alkylation of an isocyanuric acid salt. The method proceeded from a central composite design applied on the Carlson solvent classification using principal components analysis. The selectivity of the reaction was studied from the production of different substituted isocyanuric derivatives. Response graphs were obtained for each compound and used to devise a strategy for solvent selection. The prediction models were validated and used to search for the best selectivity for the reaction system. The solvent most often selected as the best for the reaction is the N,N-dimethylformamide. 相似文献
9.
10.