全文获取类型
收费全文 | 1935篇 |
免费 | 106篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 20篇 |
化学工业 | 616篇 |
金属工艺 | 28篇 |
机械仪表 | 56篇 |
建筑科学 | 92篇 |
矿业工程 | 2篇 |
能源动力 | 89篇 |
轻工业 | 207篇 |
水利工程 | 10篇 |
石油天然气 | 13篇 |
无线电 | 132篇 |
一般工业技术 | 308篇 |
冶金工业 | 89篇 |
原子能技术 | 14篇 |
自动化技术 | 369篇 |
出版年
2024年 | 3篇 |
2023年 | 18篇 |
2022年 | 78篇 |
2021年 | 102篇 |
2020年 | 53篇 |
2019年 | 59篇 |
2018年 | 63篇 |
2017年 | 72篇 |
2016年 | 79篇 |
2015年 | 63篇 |
2014年 | 87篇 |
2013年 | 131篇 |
2012年 | 96篇 |
2011年 | 167篇 |
2010年 | 92篇 |
2009年 | 105篇 |
2008年 | 108篇 |
2007年 | 92篇 |
2006年 | 75篇 |
2005年 | 53篇 |
2004年 | 67篇 |
2003年 | 62篇 |
2002年 | 49篇 |
2001年 | 25篇 |
2000年 | 30篇 |
1999年 | 27篇 |
1998年 | 24篇 |
1997年 | 18篇 |
1996年 | 20篇 |
1995年 | 17篇 |
1994年 | 5篇 |
1993年 | 9篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1965年 | 4篇 |
排序方式: 共有2045条查询结果,搜索用时 15 毫秒
51.
Giulia Poli Consuelo Fabi Chiara Sugoni Marina Maria Bellet Claudio Costantini Giovanni Luca Stefano Brancorsini 《International journal of molecular sciences》2022,23(9)
Varicocele (VC) is the most common abnormality identified in men evaluated for hypofertility. Increased levels of reactive oxygen species (ROS) and reduced antioxidants concentrations are key contributors in varicocele-mediated hypofertility. Moreover, inflammation and alterations in testicular immunity negatively impact male fertility. In particular, NLRP3 inflammasome activation was hypothesized to lead to seminal inflammation, in which the levels of specific cytokines, such as IL-1β and IL-18, are overexpressed. In this review, we described the role played by oxidative stress (OS), inflammation, and NLRP3 inflammasome activation in VC disease. The consequences of ROS overproduction in testis, including inflammation, lipid peroxidation, mitochondrial dysfunction, chromatin damage, and sperm DNA fragmentation, leading to abnormal testicular function and failed spermatogenesis, were highlighted. Finally, we described some therapeutic antioxidant strategies, with recognized beneficial effects in counteracting OS and inflammation in testes, as possible therapeutic drugs against varicocele-mediated hypofertility. 相似文献
52.
Claudio Bernardazzi Morgana Teixeira Lima Castelo-Branco Beatriz Pêgo Beatriz Elias Ribeiro Siane Lopes Bittencourt Rosas Patrícia Teixeira Santana Joo Carlos Machado Camille Leal Fabiano Thompson Robson Coutinho-Silva Heitor Siffert Pereira de Souza 《International journal of molecular sciences》2022,23(9)
53.
54.
Nicola Buratti Claudio Mazzotti Marco Savoia 《Construction and Building Materials》2011,25(5):2713-2722
The present paper describes the results of an experimental investigation on the performances of concrete specimens reinforced with either steel or macro-synthetic fibres under three-point bending. Steel fibres are often used to improve the flexural toughness of concrete and are used in various structural applications while synthetic fibres are more often used to reduce crack opening due to shrinkage. Macro-synthetic fibres have been proposed more recently with the aim of creating an alternative to steel fibres in structural applications but their use is still limited.In the tests performed, specimens cast with the same concrete mix, but containing different dosages of either steel or macro-synthetic fibres, were used and compared. In general steel fibres were more efficient in increasing the toughness of concrete than macro-synthetic fibres, even though their results were significantly more scattered.Test results were used to calculate the parameters of stress-crack opening relations via inverse analysis using a cracked hinge model. This numerical model provided results, in terms of force-Crack Mouth Opening Displacement (CMOD) curves, in very good agreement with the experimental data. 相似文献
55.
This paper presents the results of experimental tests on flexural behaviour of reinforced concrete beams repaired by polymer-modified mortar. Tests were repeated varying repair thickness, which included or did not include the steel reinforcement. Also the position of repair mortar was varied, as it was carried out either in the tension or compression region. Finally, the reinforcement ratios of beam sections were also varied. Results were compared with those from control beams, which were tested in non-damaged, non-repaired conditions. Thick repairs that include the longitudinal reinforcement can restore the load-bearing capacity and ductility of non-damaged control beams, whether they are applied in the tension or in the compression region. Thin repairs in tension, which substitute the concrete cover, but do not include the reinforcement, can even decrease the load bearing capacity and ductility of the beam, whereas thin repairs in compression are more effective than those in tension. 相似文献
56.
Claudio RONCO 《Hemodialysis international. International Symposium on Home Hemodialysis》2011,15(1):121-123
International Vicenza Courses represent important educational events held yearly in the city of Palladio. Claudio Ronco organizes since 1982 international courses on peritoneal dialysis, hemodialysis and critical care nephrology. The faculty is outstanding and the content very informative and useful for beginners and for experts in the various fields. Every year the entire course is recorded in a DVD and the proceedings are available at the beginning of the course. Information can be obtained at http://www.vicenzanephrocourses.com . 相似文献
57.
58.
59.
Valeska Ormazabal Estefanía Nova-Lampeti Daniela Rojas Felipe A. Zúiga Carlos Escudero Paola Lagos Alexa Moreno Yanara Pavez Camila Reyes Milly Yez Mabel Vidal Guillermo Cabrera-Vives Katherine Oporto Claudio Aguayo 《International journal of molecular sciences》2022,23(2)
Tissue regeneration is often impaired in patients with metabolic disorders such as diabetes mellitus and obesity, exhibiting reduced wound repair and limited regeneration capacity. We and others have demonstrated that wound healing under normal metabolic conditions is potentiated by the secretome of human endothelial cell-differentiated mesenchymal stem cells (hMSC-EC). However, it is unknown whether this effect is sustained under hyperglycemic conditions. In this study, the wound healing effect of secretomes from undifferentiated human mesenchymal stem cells (hMSC) and hMSC-EC in a type-2 diabetes mouse model was analyzed. hMSC were isolated from human Wharton’s jelly and differentiated into hMSC-EC. hMSC and hMSC-EC secretomes were analyzed and their wound healing capacity in C57Bl/6J mice fed with control (CD) or high fat diet (HFD) was evaluated. Our results showed that hMSC-EC secretome enhanced endothelial cell proliferation and wound healing in vivo when compared with hMSC secretome. Five soluble proteins (angiopoietin-1, angiopoietin-2, Factor de crecimiento fibroblástico, Matrix metallopeptidase 9, and Vascular Endothelial Growth Factor) were enriched in hMSC-EC secretome in comparison to hMSC secretome. Thus, the five recombinant proteins were mixed, and their pro-healing property was evaluated in vitro and in vivo. Functional analysis demonstrated that a cocktail of these proteins enhanced the wound healing process similar to hMSC-EC secretome in HFD mice. Overall, our results show that hMSC-EC secretome or a combination of specific proteins enriched in the hMSC-EC secretome enhanced wound healing process under hyperglycemic conditions. 相似文献
60.
Federico Bolognesi Nicola Fazio Filippo Boriani Viscardo Paolo Fabbri Davide Gravina Francesca Alice Pedrini Nicoletta Zini Michelina Greco Michela Paolucci Maria Carla Re Sofia Asioli Maria Pia Foschini Antonietta DErrico Nicola Baldini Claudio Marchetti 《International journal of molecular sciences》2022,23(3)
Defects of the peripheral nervous system are extremely frequent in trauma and surgeries and have high socioeconomic costs. If the direct suture of a lesion is not possible, i.e., nerve gap > 2 cm, it is necessary to use grafts. While the gold standard is the autograft, it has disadvantages related to its harvesting, with an inevitable functional deficit and further morbidity. An alternative to autografting is represented by the acellular nerve allograft (ANA), which avoids disadvantages of autograft harvesting and fresh allograft rejection. In this research, the authors intend to transfer to human nerves a novel technique, previously implemented in animal models, to decellularize nerves. The new method is based on soaking the nerve tissues in decellularizing solutions while associating ultrasounds and freeze–thaw cycles. It is performed without interrupting the sterility chain, so that the new graft may not require post-production γ-ray irradiation, which is suspected to affect the structural and functional quality of tissues. The new method is rapid, safe, and inexpensive if compared with available commercial ANAs. Histology and immunohistochemistry have been adopted to evaluate the new decellularized nerves. The study shows that the new method can be applied to human nerve samples, obtaining similar, and, sometimes better, results compared with the chosen control method, the Hudson technique. 相似文献