全文获取类型
收费全文 | 969篇 |
免费 | 4篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 15篇 |
金属工艺 | 2篇 |
机械仪表 | 1篇 |
建筑科学 | 5篇 |
能源动力 | 2篇 |
轻工业 | 8篇 |
水利工程 | 1篇 |
无线电 | 4篇 |
一般工业技术 | 13篇 |
冶金工业 | 866篇 |
自动化技术 | 53篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2017年 | 4篇 |
2015年 | 1篇 |
2014年 | 23篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 11篇 |
2010年 | 11篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 31篇 |
1998年 | 266篇 |
1997年 | 142篇 |
1996年 | 79篇 |
1995年 | 51篇 |
1994年 | 38篇 |
1993年 | 44篇 |
1992年 | 5篇 |
1991年 | 15篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 11篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 33篇 |
1976年 | 89篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1955年 | 2篇 |
1954年 | 1篇 |
排序方式: 共有973条查询结果,搜索用时 0 毫秒
971.
Emilie R. Baker Khoi Ly Nikola Bosnjak Maura R. O’Neill Rachel Miller Sandra Li Robert F. Shepherd Meredith N. Silberstein 《Advanced Engineering Materials》2023,25(19):2300629
Triply periodic minimal surface lattices have mechanical properties that derive from the unit cell geometry and the base material. Through computation software like nTopology and Abaqus, these geometries are used to tune nonlinear stress–strain curves not readily achievable with solid materials alone and to change the compliance by two orders of magnitude compared to the constituent material. In this study, four elastomeric TPMS gyroids undergo large deformation compression and tension testing to investigate the impact of the structure's geometry on the mechanical properties. Among all the samples, the modulus at strain ε varies by over one order of magnitude (7.7–293.4 kPa from FEA under compression). These lattices are promising candidates for designing multifunctional systems that can perform multiple tasks simultaneously by leveraging the geometry's large surface area to volume ratio. For example, the architectural functionality of the lattice to bear loads and store mechanical energy along with the larger surface area for energy storage is combined. A compliant double-gyroid capacitor that can simultaneously achieve three functions is demonstrated: load bearing, energy storage, and sensing. 相似文献
972.
Ilze Kumpina Vladislavs Baskevics Khoi D. Nguyen Dr. Martins Katkevics Prof. Eriks Rozners 《Chembiochem : a European journal of chemical biology》2023,24(15):e202300291
Triple-helical recognition of any sequence of double-stranded RNA requires high affinity Hoogsteen hydrogen binding to pyrimidine interruptions of polypurine tracts. Because pyrimidines have only one hydrogen bond donor/acceptor on Hoogsteen face, their triple-helical recognition is a formidable problem. The present study explored various five-membered heterocycles and linkers that connect nucleobases to backbone of peptide nucleic acid (PNA) to optimize formation of X•C-G and Y•U-A triplets. Molecular modeling and biophysical (UV melting and isothermal titration calorimetry) results revealed a complex interplay between the heterocyclic nucleobase and linker to PNA backbone. While the five-membered heterocycles did not improve pyrimidine recognition, increasing the linker length by four atoms provided promising gains in binding affinity and selectivity. The results suggest that further optimization of heterocyclic bases with extended linkers to PNA backbone may be a promising approach to triple-helical recognition of RNA. 相似文献
973.
Hoang Thien Khoi Nguyen Trang An Duong Chang Won Ahn Byeong Woo Kim Hyoung-Su Han Jae-Shin Lee 《Journal of the American Ceramic Society》2023,106(6):3622-3632
The stabilization of ergodicity plays an important role in realizing large strain in a Bi1/2Na1/2TiO3 (BNT)-based relaxor, which is strongly related to the degree of random fields with respect to the randomly distributed different cations. To clarify the effects of different ionic radii, this study investigated and compared the microstructures, crystal structures, phase transition behaviors, and electrical properties of BNT–ST-based ternary ceramics by modifying BiMeO3 (where Me = Al and Fe). It was observed that the stabilized relaxor states are different between BiFeO3-/and BiAlO3-modified BNT–ST ternary ceramics. As a result, it is suggested that phase transition (more precisely, the stabilization of ergodicity) can be influenced by the different internal strain in BNT–ST-based ternary ceramics. 相似文献