全文获取类型
收费全文 | 4345篇 |
免费 | 316篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 40篇 |
综合类 | 11篇 |
化学工业 | 981篇 |
金属工艺 | 65篇 |
机械仪表 | 86篇 |
建筑科学 | 184篇 |
矿业工程 | 30篇 |
能源动力 | 161篇 |
轻工业 | 623篇 |
水利工程 | 49篇 |
石油天然气 | 13篇 |
无线电 | 337篇 |
一般工业技术 | 621篇 |
冶金工业 | 567篇 |
原子能技术 | 13篇 |
自动化技术 | 891篇 |
出版年
2024年 | 9篇 |
2023年 | 42篇 |
2022年 | 86篇 |
2021年 | 152篇 |
2020年 | 122篇 |
2019年 | 125篇 |
2018年 | 159篇 |
2017年 | 168篇 |
2016年 | 190篇 |
2015年 | 133篇 |
2014年 | 174篇 |
2013年 | 343篇 |
2012年 | 236篇 |
2011年 | 305篇 |
2010年 | 228篇 |
2009年 | 226篇 |
2008年 | 242篇 |
2007年 | 227篇 |
2006年 | 178篇 |
2005年 | 122篇 |
2004年 | 117篇 |
2003年 | 122篇 |
2002年 | 104篇 |
2001年 | 44篇 |
2000年 | 58篇 |
1999年 | 59篇 |
1998年 | 178篇 |
1997年 | 102篇 |
1996年 | 76篇 |
1995年 | 47篇 |
1994年 | 40篇 |
1993年 | 43篇 |
1992年 | 23篇 |
1991年 | 19篇 |
1990年 | 15篇 |
1989年 | 20篇 |
1988年 | 16篇 |
1987年 | 17篇 |
1986年 | 12篇 |
1985年 | 17篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 4篇 |
1981年 | 14篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1971年 | 3篇 |
排序方式: 共有4672条查询结果,搜索用时 31 毫秒
1.
Vanessa Modelski Schatkoski Thaís Larissa do Amaral Montanheiro Beatriz Rossi Canuto de Menezes Raissa Monteiro Pereira Karla Faquine Rodrigues Renata Guimarães Ribas Diego Morais da Silva Gilmar Patrocínio Thim 《Ceramics International》2021,47(3):2999-3012
Studies related to biomaterials that stimulate the repair of living tissue have increased considerably, improving the quality of many people's lives that require surgery due to traumatic accidents, bone diseases, bone defects, and reconstructions. Among these biomaterials, bioceramics and bioactive glasses (BGs) have proved to be suitable for coating materials, cement, scaffolds, and nanoparticles, once they present good biocompatibility and degradability, able to generate osteoconduction on the surrounding tissue. However, the role of biomaterials in hard tissue engineering is not restricted to a structural replacement or for guiding tissue regeneration. Nowadays, it is expected that biomaterials develop a multifunctional role when implanted, orchestrating the process of tissue regeneration and providing to the body the capacity to heal itself. In this way, the incorporation of specific metal ions in bioceramics and BGs structure, including magnesium, silver, strontium, lithium, copper, iron, zinc, cobalt, and manganese are currently receiving enhanced interest as biomaterials for biomedical applications. When an ion is incorporated into the bioceramic structure, a new category of material is created, which has several unique properties that overcome the disadvantages of primitive material and favors its use in different biomedical applications. The doping can enhance handling properties, angiogenic and osteogenic performance, and antimicrobial activity. Therefore, this review aims to summarize the effect of selected metal ion dopants into bioceramics and silicate-based BGs in bone tissue engineering. Furthermore, new applications for doped bioceramics and BGs are highlighted, including cancer treatment and drug delivery. 相似文献
2.
3.
Martinez-Yelmo Isaias Alvarez-Horcajo Joaquin Briso-Montiano Miguel Lopez-Pajares Diego Rojas Elisa 《Telecommunication Systems》2019,72(4):555-565
Telecommunication Systems - The Software-Defined Networking (SDN) architecture decouples the control plane from the data plane, but it does not explicitly state where the control should be located.... 相似文献
4.
5.
Precil Diego M. M. Neves Fernanda M. Freitas Christiane A. Kojima Beatriz L. Carmello Rodrigo Bazan Pasqual Barretti Luis C. Martin 《Hemodialysis international. International Symposium on Home Hemodialysis》2015,19(1):143-145
Antibiotics are potentially a cause of neurotoxicity in dialysis patients, the most common are the beta‐lactams as ceftazidime and cefepime, and few cases have been reported after piperacillin/tazobactam use. This report presents a case of a hypertensive and diabetic 67‐year‐old woman in regular hemodialysis, which previously had a stroke. She was hospitalized presenting pneumonia, which was initially treated with cefepime. Two days after treatment, she presented dysarthria, left hemiparesis, ataxia, and IX and X cranial nerves paresis. Computed tomography showed no acute lesions and cefepime neurotoxicity was hypothesized, and the antibiotic was replaced by piperacillin/tazobactam. The neurologic signs disappeared; however, 4 days after with piperacillin/tazobactam treatment, the neurological manifestations returned. A new computed tomography showed no new lesions, and the second antibiotic regimen withdrawn. After two hemodialysis sessions, the patient completely recovered from neurological manifestations. The patient presented sequentially neurotoxicity caused by two beta‐lactams antibiotics. This report meant to alert clinicians that these antibiotics have dangerous neurological effects in chronic kidney disease patients. 相似文献
6.
7.
8.
欧盟的电信管制陷入了与国家政体冲突的泥潭中,尽管高层有一些关于改革的勇敢论调,但事实胜于雄辩。欧盟所规定的电信规则设想在这个有25个国家、超过4.5亿人口的市场,以远远超出这个范围的影响创造一个公平的竞争环境,它能奏效吗?于布鲁塞尔制定的电信政策在许多方面呈现多极化趋向,这反映了对泛欧“超级国家”实体更大的争议。根据每天问题的不同,随着观点的转移,欧洲电信规则被同等程度地喜爱和痛恨着。对一方来说很协调的东西,对另一方则成了毫无根据 相似文献
9.
Ana M. García José M. Villora Diego A. Moreno Carlos Ranninger Pío Callejas M. Flora Barba 《Journal of the American Ceramic Society》2003,86(12):2200-2202
The objective of this research was to study the removal of cadmium and lead from an aqueous solution through a biological treatment. For this purpose a glass-ceramic material was manufactured from industrial and urban wastes. Biofilms of microorganisms found in wastewater were developed on its surface, and continuous tests were conducted in the presence and absence of the biofilm to analyze the glass-ceramic's ability to remove the heavy metals from an aqueous environment. The results suggest that this bioremediation process, developed on an industrial scale, could represent an alternative to the chemical processes currently used. 相似文献
10.
JJ Jiménez-Nácher N de Alonso B Vega A del Río JL Moya V Barrios A Hurtado 《Canadian Metallurgical Quarterly》1993,193(6):290-292
Pericardial effusion (PE) as a hypothyroidism associated sign, is something that can be found with relative frequency; nevertheless, cardiac tamponade (CT) as the first sign of this disease may be considered exceptional especially in young patients. We report a 31 years old woman with clinical symptoms and signs of CT that in the forward workshop was diagnosed of primary hypothyroidism as cause of the CT. We shortly describe the case and review the literature, emphasizing the importance of the knowledge of CT trigger factors in myxedematous PE, as well as its usual benign evolution with hormonal treatment, without recurrences of the CT after pericardiocentesis is performed. This justify a conservative approach, in spite of the slow resolution of the PE what can take as long as 1.5 years. 相似文献