全文获取类型
收费全文 | 567篇 |
免费 | 56篇 |
专业分类
综合类 | 2篇 |
化学工业 | 188篇 |
金属工艺 | 14篇 |
机械仪表 | 7篇 |
建筑科学 | 23篇 |
矿业工程 | 2篇 |
能源动力 | 27篇 |
轻工业 | 89篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 36篇 |
一般工业技术 | 78篇 |
冶金工业 | 78篇 |
原子能技术 | 4篇 |
自动化技术 | 72篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 23篇 |
2021年 | 57篇 |
2020年 | 22篇 |
2019年 | 27篇 |
2018年 | 23篇 |
2017年 | 16篇 |
2016年 | 24篇 |
2015年 | 21篇 |
2014年 | 24篇 |
2013年 | 31篇 |
2012年 | 38篇 |
2011年 | 42篇 |
2010年 | 48篇 |
2009年 | 21篇 |
2008年 | 31篇 |
2007年 | 34篇 |
2006年 | 18篇 |
2005年 | 25篇 |
2004年 | 16篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 9篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1992年 | 2篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有623条查询结果,搜索用时 0 毫秒
621.
Danis I. Badrtdinov Carlos Rodriguez-Fernandez Magdalena Grzeszczyk Zhizhan Qiu Kristina Vaklinova Pengru Huang Alexander Hampel Kenji Watanabe Takashi Taniguchi Lu Jiong Marek Potemski Cyrus E. Dreyer Maciej Koperski Malte Rösner 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(41):2300144
A key advantage of utilizing van-der-Waals (vdW) materials as defect-hosting platforms for quantum applications is the controllable proximity of the defect to the surface or the substrate allowing for improved light extraction, enhanced coupling with photonic elements, or more sensitive metrology. However, this aspect results in a significant challenge for defect identification and characterization, as the defect's properties depend on the the atomic environment. This study explores how the environment can influence the properties of carbon impurity centers in hexagonal boron nitride (hBN). It compares the optical and electronic properties of such defects between bulk-like and few-layer films, showing alteration of the zero-phonon line energies and their phonon sidebands, and enhancements of inhomogeneous broadenings. To disentangle the mechanisms responsible for these changes, including the atomic structure, electronic wavefunctions, and dielectric screening, it combines ab initio calculations with a quantum-embedding approach. By studying various carbon-based defects embedded in monolayer and bulk hBN, it demonstrates that the dominant effect of the change in the environment is the screening of density–density Coulomb interactions between the defect orbitals. The comparative analysis of experimental and theoretical findings paves the way for improved identification of defects in low-dimensional materials and the development of atomic scale sensors for dielectric environments. 相似文献
622.
Nika Sokolova Lili Zhang Sadaf Deravi Rick Oerlemans Prof. Dr. Matthew R. Groves Prof. Dr. Kristina Haslinger 《Chembiochem : a European journal of chemical biology》2023,24(9):e202300076
Oxygen-directed methylation is a ubiquitous tailoring reaction in natural product pathways catalysed by O-methyltransferases (OMTs). Promiscuous OMT biocatalysts are thus a valuable asset in the toolkit for sustainable synthesis and optimization of known bioactive scaffolds for drug development. Here, we characterized the enzymatic properties and substrate scope of two bacterial OMTs from Desulforomonas acetoxidans and Streptomyces avermitilis and determined their crystal structures. Both OMTs methylated a wide range of catechol-like substrates, including flavonoids, coumarins, hydroxybenzoic acids, and their respective aldehydes, an anthraquinone and an indole. One enzyme also accepted a steroid. The product range included pharmaceutically relevant compounds such as (iso)fraxidin, iso(scopoletin), chrysoeriol, alizarin 1-methyl ether, and 2-methoxyestradiol. Interestingly, certain non-catechol flavonoids and hydroxybenzoic acids were also methylated. This study expands the knowledge on substrate preference and structural diversity of bacterial catechol OMTs and paves the way for their use in (combinatorial) pathway engineering. 相似文献
623.
Dr. Chiara Borsari Brieuc Matagne Dr. Kristina Goncharenko Prof. Rui Moreira Dr. Yves P. Auberson 《ChemMedChem》2023,18(1):e202200245
Diversity in science refers to cultivating talent, while promoting full inclusion across the community. In medicinal chemistry and chemical biology, it enhances creativity and encourages contributions from multiple perspectives, leading to better decision making and broader scientific impact. The European Federation for Medicinal chemistry and Chemical biology (EFMC) embraces and promotes diversity, to ensure representation of all talents, and enable equality of opportunity through fairness and transparency. EFMC has historically paid continuous attention to diversity in terms of culture, geography and equilibrium between academia and industry, with over the last few years a focus on increasing gender balance, aiming at a fair representation of the scientific community and equal opportunities independently of gender. EFMC promotes cultural diversity as it reinforces openness and mutual respect. All scientific organizations of a scope compatible with its remit are welcome within EFMC, where their members benefit from a welcoming, psychologically safe, and stimulating environment. Herein, we describe the state of diversity within the EFMC, how the situation has evolved over the years and where diversity should be further encouraged. 相似文献