全文获取类型
收费全文 | 312227篇 |
免费 | 5396篇 |
国内免费 | 839篇 |
专业分类
电工技术 | 5192篇 |
综合类 | 170篇 |
化学工业 | 50903篇 |
金属工艺 | 12286篇 |
机械仪表 | 9126篇 |
建筑科学 | 7667篇 |
矿业工程 | 1885篇 |
能源动力 | 7339篇 |
轻工业 | 31068篇 |
水利工程 | 3472篇 |
石油天然气 | 7196篇 |
武器工业 | 17篇 |
无线电 | 32429篇 |
一般工业技术 | 60940篇 |
冶金工业 | 56153篇 |
原子能技术 | 7601篇 |
自动化技术 | 25018篇 |
出版年
2021年 | 2835篇 |
2019年 | 2629篇 |
2018年 | 4775篇 |
2017年 | 4713篇 |
2016年 | 5062篇 |
2015年 | 3354篇 |
2014年 | 5286篇 |
2013年 | 14130篇 |
2012年 | 8475篇 |
2011年 | 10753篇 |
2010年 | 8813篇 |
2009年 | 9754篇 |
2008年 | 10052篇 |
2007年 | 9838篇 |
2006年 | 8486篇 |
2005年 | 7887篇 |
2004年 | 7339篇 |
2003年 | 7058篇 |
2002年 | 7058篇 |
2001年 | 6826篇 |
2000年 | 6432篇 |
1999年 | 6510篇 |
1998年 | 16433篇 |
1997年 | 12082篇 |
1996年 | 9218篇 |
1995年 | 6890篇 |
1994年 | 6205篇 |
1993年 | 6070篇 |
1992年 | 4569篇 |
1991年 | 4516篇 |
1990年 | 4340篇 |
1989年 | 4355篇 |
1988年 | 4327篇 |
1987年 | 3670篇 |
1986年 | 3658篇 |
1985年 | 4223篇 |
1984年 | 4020篇 |
1983年 | 3652篇 |
1982年 | 3460篇 |
1981年 | 3616篇 |
1980年 | 3480篇 |
1979年 | 3390篇 |
1978年 | 3474篇 |
1977年 | 4017篇 |
1976年 | 5231篇 |
1975年 | 3184篇 |
1974年 | 3028篇 |
1973年 | 3057篇 |
1972年 | 2654篇 |
1971年 | 2484篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Alawiya Reslan Juliano G. Haddad Liadrine Moukendza Koundi Philippe Desprs Jean-Loup Bascands Gilles Gadea 《International journal of molecular sciences》2021,22(5)
Mosquito-borne Zika virus (ZIKV) became a real threat to human health due to the lack of vaccine and effective antiviral treatment. The virus has recently been responsible for a global outbreak leading to millions of infected cases. ZIKV complications were highlighted in adults with Guillain–Barré syndrome and in newborns with increasing numbers of congenital disorders ranging from mild developmental delays to fatal conditions. The ability of ZIKV to establish a long-term infection in diverse organs including the kidneys has been recently documented but the consequences of such a viral infection are still debated. Our study aimed to determine whether the efficiency of ZIKV growth in kidney cells relates to glucose concentration. Human kidney HK-2 cells were infected with different ZIKV strains in presence of normal and high glucose concentrations. Virological assays showed a decrease in viral replication without modifying entry steps (viral binding, internalization, fusion) under high glucose conditions. This decrease replication was associated with a lower virus progeny and increased cell viability when compared to ZIKV-infected HK-2 cells in normal glucose concentration. In conclusion, we showed for the first time that an elevated glucose level influences ZIKV replication level with an effect on kidney cell survival. 相似文献
22.
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
23.
Andrade R. G. S. A. de Oliveira A. E. Guerra V. G. 《Theoretical Foundations of Chemical Engineering》2022,56(4):504-512
Theoretical Foundations of Chemical Engineering - The corona onset voltage is an important operating parameter in the electrostatic precipitation of nanoparticulate, however, its experimental... 相似文献
24.
Silicon - The products of solid-phase mechanochemical interaction between pyrocatechol and silicon dioxide yielding a powdered composite were studied using a number of physicochemical methods. This... 相似文献
25.
Young Been Kim Sung Hyeon Jung Dong Su Kim Nishad G. Deshpande Hee Won Suh Hak Hyeon Lee Ji Hoon Choi Ho Seong Lee Hyung Koun Cho 《Advanced functional materials》2021,31(38):2102439
Antimony triselenide (Sb2Se3) nanoflake-based nitrogen dioxide (NO2) sensors exhibit a progressive bifunctional gas-sensing performance, with a rapid alarm for hazardous highly concentrated gases, and an advanced memory-type function for low-concentration (<1 ppm) monitoring repeated under potentially fatal exposure. Rectangular and cuboid shaped Sb2Se3 nanoflakes, comprising van der Waals planes with large surface areas and covalent bond planes with small areas, can rapidly detect a wide range of NO2 gas concentrations from 0.1 to 100 ppm. These Sb2Se3 nanoflakes are found to be suitable for physisorption-based gas sensing owing to their anisotropic quasi-2D crystal structure with extremely enlarged van der Waals planes, where they are humidity-insensitive and consequently exhibit an extremely stable baseline current. The Sb2Se3 nanoflake sensor exhibits a room-temperature/low-voltage operation, which is noticeable owing to its low energy consumption and rapid response even under a NO2 gas flow of only 1 ppm. As a result, the Sb2Se3 nanoflake sensor is suitable for the development of a rapid alarm system. Furthermore, the persistent gas-sensing conductivity of the sensor with a slow decaying current can enable the development of a progressive memory-type sensor that retains the previous signal under irregular gas injection at low concentrations. 相似文献
26.
Chemical and Petroleum Engineering - The processes of separation of impurities of particles of different sizes are analyzed under conditions of irregularity of structural and kinematic parameters... 相似文献
27.
Ana Clara Sabbione Santiago Suárez María Cristina Añón Adriana Scilingo 《International Journal of Food Science & Technology》2019,54(5):1506-1513
In this study, amaranth flour was used as an ingredient to prepare gluten-free cookies. The production process and attributes of amaranth cookies were characterised, and the potential use of amaranth flour as a functional ingredient was analysed. Cookies exhibited a non-uniform reddish brown colour and a cookie factor ratio of 4.5 ± 0.6. Storage studies indicated that after 3 weeks at room temperature cookies presented slight variations in the texture. Simulated gastrointestinal digestion of this product was able to release peptides capable of exerting potential antithrombotic and antihypertensive activities, IC50 values of 0.22 ± 0.04 and 0.23 ± 0.03 mg mL−1 protein, respectively. This work demonstrates for the first time that food made with amaranth flour exerts potential antithrombotic and antihypertensive activity. In conclusion, these amaranth cookies could be an alternative way of incorporating potentially health beneficial products for people who choose a conscious diet, including coeliac or vegan consumers. 相似文献
28.
29.
30.
Fermanelli Carla S. Galarza Emilce D. Pierella Liliana B. Renzini María S. Saux Clara 《Topics in Catalysis》2019,62(12-16):918-930
Topics in Catalysis - In this work, a simple thermal-catalytic system was used to valorize peanut shells (Arachis hypogaea), the residual biomass from the peanut industry. To accomplish this... 相似文献