全文获取类型
收费全文 | 674篇 |
免费 | 39篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 144篇 |
金属工艺 | 12篇 |
机械仪表 | 33篇 |
建筑科学 | 23篇 |
矿业工程 | 3篇 |
能源动力 | 59篇 |
轻工业 | 38篇 |
水利工程 | 8篇 |
石油天然气 | 3篇 |
无线电 | 55篇 |
一般工业技术 | 121篇 |
冶金工业 | 119篇 |
原子能技术 | 1篇 |
自动化技术 | 93篇 |
出版年
2023年 | 14篇 |
2022年 | 13篇 |
2021年 | 23篇 |
2020年 | 19篇 |
2019年 | 18篇 |
2018年 | 27篇 |
2017年 | 16篇 |
2016年 | 24篇 |
2015年 | 20篇 |
2014年 | 33篇 |
2013年 | 48篇 |
2012年 | 35篇 |
2011年 | 66篇 |
2010年 | 40篇 |
2009年 | 36篇 |
2008年 | 40篇 |
2007年 | 36篇 |
2006年 | 23篇 |
2005年 | 18篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 4篇 |
1998年 | 10篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 7篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 10篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1982年 | 4篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有718条查询结果,搜索用时 15 毫秒
711.
Walter Sebastian Scheld Kwangnam Kim Christian Schwab Alexandra C. Moy Shi-Kai Jiang Markus Mann Christian Dellen Yoo Jung Sohn Sandra Lobe Martin Ihrig Michael Gregory Danner Chia-Yu Chang Sven Uhlenbruck Eric D. Wachsman Bing Joe Hwang Jeff Sakamoto Liwen F. Wan Brandon C. Wood Martin Finsterbusch Dina Fattakhova-Rohlfing 《Advanced functional materials》2023,33(43):2302939
Solid-state batteries (SSBs) with a Li7La3Zr2O12 (LLZO) garnet electrolyte are attracting much attention as robust and safe alternative to conventional lithium-ion batteries. Technical challenges in the practical implementation of garnet SSBs are related to the need for high-temperature sintering, which often leads to undesirable chemical reactions with the cathode material. While these reactions are well understood for composite cathodes, very little is known about similar processes between cathode and separator during battery fabrication. This work focuses on understanding the processes between the composite LiCoO2-LLZO cathode and the LLZO separator and how they affect the battery performance. The extensive diffusion of Co-ions within LLZO, which leads to the often-observed LLZO darkening, is shown to have a significant impact on ionic conductivity, electronic conductivity, and dendrite stability of the separator. Experimental data coupled with large-scale molecular dynamics simulations uncover the diffusion mechanism for Co-ions and identify secondary phases that form during these interactions. In addition to extensive Co-ion diffusion within the grains, a non-uniform segregation of Co-ions at grain boundaries is found leading to the formation of three distinct Co-containing phases. This work offers a general approach to studying the fundamental ion diffusion processes that occur during the fabrication of oxide SSBs. 相似文献
712.
Geng Li Caroline M. Elliott Bruce C. Call Brandon J. Sansom Robert B. Jacobson Binbin Wang 《河流研究与利用》2023,39(9):1857-1874
River turbulence is spatially variable due to interactions between morphology of rivers and physical mechanics of flowing water. Understanding the variation of turbulence in rivers is important for characterizing transport processes of soluble and particulate materials in these systems. We present an exploratory effort to understand ecologically relevant flow patterns using measurements of mean flow and turbulence in a highly engineered river channel around an island in the lower Missouri River. Specifically, the profiles of mean river velocities were investigated to examine the logarithmic relation and associated parameters, including shear velocity and bed roughness. Turbulence intensity and Reynolds shear stress were compared with classic open-channel profiles and previously reported river data in the hydraulics literature. With the capability of pulse-to-pulse coherent Doppler velocity profiling in high spatial resolution, we estimated the profiles of turbulence dissipation rate using resolved one-dimensional velocity spectra. These measurement data allow us to examine the validity of turbulence production-dissipation balance and the classic open-channel profiles of turbulence statistics, including turbulence intensity, Reynolds shear stress, dissipation rate, and eddy viscosity. The field data show a strong variation of turbulence profiles in close vicinity of the river island. In shallow water depths close to the island, turbulence is substantially enhanced in comparison with classic open-channel profiles. Such turbulence enhancement is likely attributed to non-uniformity of the flow structures. 相似文献
713.
Simon Vecchioni Brandon Lu Jordan Janowski Karol Woloszyn Nataša Jonoska Nadrian C. Seeman Chengde Mao Yoel P. Ohayon Ruojie Sha 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(12):2206511
The successful self-assembly of tensegrity triangle DNA crystals heralded the ability to programmably construct macroscopic crystalline nanomaterials from rationally-designed, nanoscale components. This 3D DNA tile owes its “tensegrity” nature to its three rotationally stacked double helices locked together by the tensile winding of a center strand segmented into 7 base pair (bp) inter-junction regions, corresponding to two-thirds of a helical turn of DNA. All reported tensegrity triangles to date have employed turn inter-junction segments, yielding right-handed, antiparallel, “J1” junctions. Here a minimal DNA triangle motif consisting of 3-bp inter-junction segments, or one-third of a helical turn is reported. It is found that the minimal motif exhibits a reversed morphology with a left-handed tertiary structure mediated by a locally-parallel Holliday junction—the “L1” junction. This parallel junction yields a predicted helical groove matching pattern that breaks the pseudosymmetry between tile faces, and the junction morphology further suggests a folding mechanism. A Rule of Thirds by which supramolecular chirality can be programmed through inter-junction DNA segment length is identified. These results underscore the role that global topological forces play in determining local DNA architecture and ultimately point to an under-explored class of self-assembling, chiral nanomaterials for topological processes in biological systems. 相似文献
714.
Dr. Mohamed Ettaoussi Amélie Laversin Brandon Vreulz Dr. Marouane Rami Dr. Nicolas Lebegue Dr. Philippe Delagrange Dr. Daniel Henri Caignard Prof. Patricia Melnyk Dr. Maxime Liberelle Dr. Saïd Yous 《ChemMedChem》2022,17(3):e202100658
In our constant search for new successors of agomelatine, we report herein a new series of compounds resulting from bioisosteric modulation of the naphthalene ring. The isoquinoline and tetrahydroisoquinoline derivatives were synthesized and pharmacologically evaluated. This isosteric replacement of the naphthalene group of agomelatine has led to potent agonist and partial agonist compounds with nanomolar melatonergic binding affinities. Overall, the presence of a nitrogen atom was accompanied with a decrease in the binding affinity toward both MT1 and MT2 and the loss of 5HT2C response, especially for tetrahydroisoquinoline in comparison with the parent compound. Interestingly, due to the presence of this nitrogen atom, a notable improvement in the pharmacokinetic properties was observed for all compounds. 相似文献
715.
716.
Brandon Lu Simon Vecchioni Yoel P. Ohayon Karol Woloszyn Tiffany Markus Chengde Mao Nadrian C. Seeman James W. Canary Ruojie Sha 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(3):2205830
The rational design of nanoscopic DNA tiles has yielded highly ordered crystalline matter in 2D and 3D. The most well-studied 3D tile is the DNA tensegrity triangle, which is known to self-assemble into macroscopic crystals. However, contemporary rational design parameters for 3D DNA crystals nearly universally invoke integer numbers of DNA helical turns and Watson–Crick (WC) base pairs. In this study, 24-bp edges are substituted into a previously 21-bp (two helical turns of DNA) tensegrity triangle motif to explore whether such unconventional motif can self-assemble into 3D crystals. The use of noncanonical base pairs in the sticky ends results in a cubic arrangement of tensegrity triangles with exceedingly high symmetry, assembling a lattice from winding helical axes and diamond-like tessellation patterns. Reverting this motif to sticky ends with Watson–Crick pairs results in a trigonal hexagonal arrangement, replicating this diamond arrangement in a hexagonal context. These results showcase that the authors can generate unexpected, highly complex, pathways for materials design by testing modifications to 3D tiles without prior knowledge of the ensuing symmetry. This study expands the rational design toolbox for DNA nanotechnology; and it further illustrates the existence of yet-unexplored arrangements of crystalline soft matter. 相似文献
717.
Francisco J. Huizar Harrison M. Hill Emily P. Bacher Kaitlyn E. Eckert Eva M. Gulotty Kevin X. Rodriguez Zachary D. Tucker Monimoy Banerjee Haining Liu Dr. Olaf Wiest Dr. Jeremiah Zartman Dr. Brandon L. Ashfeld 《ChemMedChem》2022,17(4):e202100512
Deregulation of dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) plays a significant role in developmental brain defects, early-onset neurodegeneration, neuronal cell loss, dementia, and several types of cancer. Herein, we report the discovery of three new classes of N-heterocyclic DYRK1A inhibitors based on the potent, yet toxic kinase inhibitors, harmine and harmol. An initial in vitro evaluation of the small molecule library assembled revealed that the core heterocyclic motifs benzofuranones, oxindoles, and pyrrolones, showed statistically significant DYRK1A inhibition. Further, the utilization of a low cost, high-throughput functional genomic in vivo model system to identify small molecule inhibitors that normalize DYRK1A overexpression phenotypes is described. This in vivo assay substantiated the in vitro results, and the resulting correspondence validates generated classes as architectural motifs that serve as potential DYRK1A inhibitors. Further expansion and analysis of these core compound structures will allow discovery of safe, more effective chemical inhibitors of DYRK1A to ameliorate phenotypes caused by DYRK1A overexpression. 相似文献
718.
Bowen Brandon Chennamaneni Anitha Goulart Ana Lin Daisy 《International Journal of Information Security》2023,22(4):893-917
International Journal of Information Security - Intrusion detection systems (IDS) identify cyber attacks given a sample of network traffic collected from real-world computer networks. As a powerful... 相似文献