全文获取类型
收费全文 | 3255篇 |
免费 | 148篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 87篇 |
综合类 | 25篇 |
化学工业 | 747篇 |
金属工艺 | 111篇 |
机械仪表 | 42篇 |
建筑科学 | 135篇 |
矿业工程 | 25篇 |
能源动力 | 49篇 |
轻工业 | 792篇 |
水利工程 | 15篇 |
石油天然气 | 2篇 |
无线电 | 153篇 |
一般工业技术 | 552篇 |
冶金工业 | 162篇 |
原子能技术 | 15篇 |
自动化技术 | 501篇 |
出版年
2023年 | 51篇 |
2022年 | 31篇 |
2021年 | 85篇 |
2020年 | 60篇 |
2019年 | 60篇 |
2018年 | 108篇 |
2017年 | 76篇 |
2016年 | 122篇 |
2015年 | 82篇 |
2014年 | 121篇 |
2013年 | 166篇 |
2012年 | 132篇 |
2011年 | 129篇 |
2010年 | 129篇 |
2009年 | 139篇 |
2008年 | 132篇 |
2007年 | 132篇 |
2006年 | 87篇 |
2005年 | 70篇 |
2004年 | 62篇 |
2003年 | 50篇 |
2002年 | 66篇 |
2001年 | 35篇 |
2000年 | 47篇 |
1999年 | 45篇 |
1998年 | 49篇 |
1997年 | 46篇 |
1996年 | 25篇 |
1995年 | 28篇 |
1994年 | 35篇 |
1993年 | 24篇 |
1992年 | 22篇 |
1991年 | 30篇 |
1990年 | 26篇 |
1989年 | 21篇 |
1987年 | 18篇 |
1985年 | 22篇 |
1984年 | 22篇 |
1983年 | 19篇 |
1979年 | 18篇 |
1976年 | 18篇 |
1974年 | 21篇 |
1936年 | 18篇 |
1925年 | 19篇 |
1924年 | 26篇 |
1923年 | 19篇 |
1918年 | 28篇 |
1917年 | 30篇 |
1916年 | 26篇 |
1915年 | 34篇 |
排序方式: 共有3413条查询结果,搜索用时 187 毫秒
1.
Karina Polak Beata Bergler-Czop Micha Szczepanek Kamila Wojciechowska Aleksandra Frtczak Norbert Kiss 《International journal of molecular sciences》2021,22(9)
Psoriasis is a chronic, immune-mediated inflammatory disease that affects around 125 million people worldwide. Several studies concerning the gut microbiota composition and its role in disease pathogenesis recently demonstrated significant alterations among psoriatic patients. Certain parameters such as Firmicutes/Bacteroidetes ratio or Psoriasis Microbiome Index were developed in order to distinguish between psoriatic and healthy individuals. The “leaky gut syndrome” and bacterial translocation is considered by some authors as a triggering factor for the onset of the disease, as it promotes chronic systemic inflammation. The alterations were also found to resemble those in inflammatory bowel diseases, obesity and certain cardiovascular diseases. Microbiota dysbiosis, depletion in SCFAs production, increased amount of produced TMAO, dysregulation of the pathways affecting the balance between lymphocytes populations seem to be the most significant findings concerning gut physiology in psoriatic patients. The gut microbiota may serve as a potential response-to-treatment biomarker in certain cases of biological treatment. Oral probiotics administration as well as fecal microbial transplantation were most reported in bringing health benefits to psoriatic patients. However, the issue of psoriatic bacterial gut composition, its role and healing potential needs further investigation. Here we reviewed the literature on the current state of the relationship between psoriasis and gut microbiome. 相似文献
2.
3.
A contact layer element for large deformations 总被引:1,自引:0,他引:1
4.
5.
Marcus Heinze Sandra Starke Marcel Händler Hartmut Komber Marco Drache Norbert Moszner Brigitte Voit Doris Pospiech 《应用聚合物科学杂志》2019,136(48):48256
We demonstrate in this study that the combination of modern inline monitoring methods [here: inline nuclear magnetic resonance (NMR)] with simulations gains more exact and profound kinetic results than previously used methods like linearization without that combination. The 1H-NMR spectroscopic data (more than 100 data points) are used to construct the copolymerization diagram. The reactivity ratios are obtained applying the van Herks nonlinear least square method. The examination of the radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) with (2-{[2-(ethoxycarbonyl)prop-2-en-1-yl]oxy}ethyl) phosphonic acid (ECPPA) as important adhesive monomer used in dentistry yields reactivity ratios of rHEMA = 1.83; rECPPA = 0.42. The copolymerization diagram reflects nonideal, non-azeotropic copolymerization. The sequence distribution of the obtained by Monte Carlo simulation indicates the generation of statistical copolymers. As an important finding, it is demonstrated that the repeating units responsible for etching and adhesion are arranged over the whole polymer chain, which is necessary to achieve proper functionality. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48256. 相似文献
6.
7.
Semi‐Markovian processes (SMP) serve as a versatile means to model various traffic types generated by sources or superposed
from links in ATM networks. An efficient discrete time analysis method is proposed for SMP/G/1 queueing systems to evaluate
ATM switches with non‐renewal input. Some basic results are derived for the autocorrelation function of semi‐Markovian processes
and for the effect of state space reduction on autocorrelation, which show how to represent correlated traffic with given
characteristic by an adequate SMP model of limited size.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
8.
9.
10.