全文获取类型
收费全文 | 902篇 |
免费 | 41篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 27篇 |
化学工业 | 231篇 |
金属工艺 | 9篇 |
机械仪表 | 24篇 |
建筑科学 | 22篇 |
能源动力 | 23篇 |
轻工业 | 58篇 |
水利工程 | 9篇 |
石油天然气 | 1篇 |
无线电 | 66篇 |
一般工业技术 | 135篇 |
冶金工业 | 207篇 |
原子能技术 | 10篇 |
自动化技术 | 126篇 |
出版年
2023年 | 16篇 |
2022年 | 23篇 |
2021年 | 40篇 |
2020年 | 18篇 |
2019年 | 25篇 |
2018年 | 27篇 |
2017年 | 26篇 |
2016年 | 28篇 |
2015年 | 16篇 |
2014年 | 38篇 |
2013年 | 47篇 |
2012年 | 40篇 |
2011年 | 29篇 |
2010年 | 35篇 |
2009年 | 37篇 |
2008年 | 36篇 |
2007年 | 25篇 |
2006年 | 29篇 |
2005年 | 31篇 |
2004年 | 16篇 |
2003年 | 26篇 |
2002年 | 16篇 |
2001年 | 16篇 |
2000年 | 13篇 |
1999年 | 16篇 |
1998年 | 57篇 |
1997年 | 53篇 |
1996年 | 33篇 |
1995年 | 26篇 |
1994年 | 16篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 8篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1956年 | 1篇 |
1955年 | 2篇 |
1954年 | 1篇 |
排序方式: 共有948条查询结果,搜索用时 15 毫秒
1.
Ottavia Colombo Simona Villani Giovanna Pinelli Claudia Trentani Maurizia Baldi Orazio Tomarchio Anna Tagliabue 《Nutrition journal》2008,7(1):5
Background
Excess body fat is a major risk factor for disease primarily due to its endocrine activity. In recent years several criteria have been introduced to evaluate this factor. Nevertheless, treatment need is currently assessed only on the basis of an individual's Body Mass Index (BMI), calculated as body weight (in kg) divided by height in m2. The aim of our study was to determine whether application of the BMI, compared to adiposity-based criteria, results in underestimation of the number of subjects needing lifestyle intervention. 相似文献2.
3.
MC Bueno Jayme Gallani RC Rodrigues Colombo E de Araújo Cintra S Brunelli Rigacci 《Canadian Metallurgical Quarterly》1996,4(2):179-199
The overall purpose of this study was to explore nurses' feelings about the applicability and adequacy of a pilot model of nursing assessment (PMNA) developed for coronary care units (CCU) in order to obtain data that could help in establishing a definitive model. The evaluation, performed by 11 CCU nurses, showed that they considered the development and implementation of PMNA as valuable, and that its design was adequate for interviewing cardiac patients. These results will be employed in the elaboration of a definitive model of nursing assessment. 相似文献
4.
5.
Identification of the cytoskeletal elements and their role in the formation as well as the maintenance of head membrane compartmentalization is a much debated issue in mammalian spermatozoa. Data which have emerged during the last ten years are summarized. Those which have converged in a common opinion, such as the distribution of actin in mammalian spermiogenesis, are distinguished from those which have to be confirmed, such as the role of actin related proteins and actin in mature spermatozoa. 相似文献
6.
The aim of this study was to assess whether P-glycoprotein (Pgp) inhibitors altered the blood-brain barrier and enhanced vinblastine (VBL) distribution in brain, testis and other Pgp-expressing tissues. Trifluoperazine, cyclosporin A, amiodarone, quinidine, the nifedipine analog Bay K8644 and verapamil were selected among Pgp inhibitors and were administered intraperitoneally 1 hr before an intravenous dose of 10 mg/kg VBL. Trifluoperazine and cyclosporin A were also administered intraperitoneally for 7 days before VBL. VBL and its metabolite O4-deacetylvinblastine were measured in tissues by high-performance liquid chromatography assay. None of the reversing agents (RA) appreciably raised VBL concentrations in brain and testis, whereas all except quinidine significantly enhanced VBL distribution in liver and kidney; the most effective were trifluoroperazine and cyclosporin A. In mice treated with RA and VBL combined, O4-deacetylvinblastine levels in liver and kidney reached either the same or higher levels than in mice treated with VBL alone, indicating that the increase in VBL levels is not due to inhibition of its metabolism. The main conclusions are that (1) inhibitors of Pgp, even at high doses, do not increase the permeability of the blood-brain barrier in mice, suggesting caution in the clinical use of RA combined with antitumor agents for brain tumors; and (2) several RA achieve high enough concentrations to enhance the distribution of VBL in other normal tissues expressing Pgp, thus potentially increasing VBL toxicity. 相似文献
7.
8.
E Austoni F Colombo F Mantovani E Patelli O Fenice 《Canadian Metallurgical Quarterly》1995,67(5):359-364
The radical surgical option we propose for Peyronie's disease consists in removing the sclero-hyanolitic focus (plaque) and replacing it by an autologous dermal graft taken from the upper outer thigh area. Between 1981 and 1994, we operated 564 patients with Induration penis plastica (IPP), 418 of whom underwent plaque excision and dermal grafting. All could be assessed at two-year follow-up. Two main complications were observed: penile flexure relapse (71 Pts, 17% of cases), and erectile dysfunction with decreased corporal rigidity (84 Pts, 20% of cases). A mild deviation of the penis can occur some months after surgery and it is not due to disease progression (as it should have evolutive characteristics) but is mere scar retraction (44 Pts, 76% of examined relapsed flexures). The degree of this graft retraction is linked to the individual's histologic response and can be due to an idioptic tissular response or to an insufficient size of the patch. In some cases, the post-op penile flexure can result from a progression of disease (14 Pts, 24% of examined relapses flexures) and can be due either to a new "focus" or to an incomplete removal of the previous plaque. As the patient will date the onset of a possible postoperative erectile deficit from the time of the operation, it is advisable to assess preoperatively the real erectile ability of all patients. Furthermore, a post-op impaired erectile response (84 Pts, 20%) could result from a subalbuginear fibrosis of the erectile tissue that leads to a caverno-occlusive dysfunction (60%). In more than 35% of patients we found a psychogenic component, due to post-surgical stress, that involves an adrenergic hypertone with peripherical vasoconstriction. In few cases (4%) the post-op erectile dysfunction is the consequence of peroperative arterial damages that results in hypoaesthesia of the glans (injury of dorsal arteries) or in failure to obtaining corporal rigidity (damage of cavernosal arteries). A review of our experience involving plaque excision and dermal grafting led us to propose this option in case of mechanical disturbance during coitus and when the association of erectile dysfunction can be excluded. 相似文献
9.
S. Colombo M. C. Forde I. G. Main J. Halliday M. Shigeishi 《Materials and Structures》2005,38(9):851-856
Concrete bridges were built originally to have a cost-effective maintenance free life of 120 years, however both in Europe and the USA this has proved to the totally optimistic. Concrete bridges require major maintenance after twenty to thirty years in order to extend their life The Acoustic Emission technique has been successfully applied to monitor and provide information on the safety of concrete bridges, but the processing of the AE data is often not trivial. This paper proposes a method of AE analysis to assess concrete bridges based on the fact that the AE energy is one of the effective parameters to evaluate the damage of a concrete structure. Results from experiments on concrete beams with different design and loading configurations are presented. It is argued that in some cases the state of damage of bridge beams can be estimated from the AE energy analysis when approximately 45% of the ultimate load has been applied. 相似文献
10.
Ian Stoppa Casimiro Luca Gigliotti Nausicaa Clemente Deepika Pantham Chiara Dianzani Chiara Monge Chiara Puricelli Roberta Rolla Salvatore Sutti Filippo Ren Renzo Boldorini Elena Boggio Umberto Dianzani 《International journal of molecular sciences》2022,23(13)
Background: ICOS and its ligand ICOSL are immune receptors whose interaction triggers bidirectional signals that modulate the immune response and tissue repair. Aim: The aim of this study was to assess the in vivo effects of ICOSL triggering by ICOS-Fc, a recombinant soluble form of ICOS, on skin wound healing. Methods: The effect of human ICOS-Fc on wound healing was assessed, in vitro, and, in vivo, by skin wound healing assay using ICOS−/− and ICOSL−/− knockout (KO) mice and NOD-SCID-IL2R null (NSG) mice. Results: We show that, in wild type mice, treatment with ICOS-Fc improves wound healing, promotes angiogenesis, preceded by upregulation of IL-6 and VEGF expression; increases the number of fibroblasts and T cells, whereas it reduces that of neutrophils; and increases the number of M2 vs. M1 macrophages. Fittingly, ICOS-Fc enhanced M2 macrophage migration, while it hampered that of M1 macrophages. ICOS−/− and ICOSL−/− KO, and NSG mice showed delayed wound healing, and treatment with ICOS-Fc improved wound closure in ICOS−/− and NSG mice. Conclusion: These data show that the ICOS/ICOSL network cooperates in tissue repair, and that triggering of ICOSL by ICOS-Fc improves cutaneous wound healing by increasing angiogenesis and recruitment of reparative macrophages. 相似文献