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排序方式: 共有289条查询结果,搜索用时 31 毫秒
1.
《中国化学快报》2020,31(7):1919-1922
A novel BODIPY (boradiazaindacene) dye denoted as BODIPY-DT containing terpyridine unit has been designed and characterized. The dye is found to be selective and visual solvatochromic sensor toward DMF among test organic solvents. The sensing process displays time-controllable, dynamic signal outputs in the emission colors including red, purple, yellow and even white emission colors. It is presented that selective free radical oxidation reaction happens during the recognition process. 相似文献
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Nonlinear Dynamics - Two kinds of controllable evolutions of optical solitons are predicted in nonlocal nonlinear media by gradually tuning the characteristic length of response function. On the... 相似文献
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We study the electron tunneling through a single level quantum dot in the presence of electron–phonon interaction. By using the Green’s function and canonical transformation methods, we calculated exactly the current. It is found that the current vs dot level exhibits satellite peaks even without occurring of phonon-assisted tunneling processes, and properties of the current are affected heavily by the strength of electron–phonon interaction and phonon temperature. 相似文献
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We consider four classes of polynomials over the fields , , , , , , , where . We find sufficient conditions on the pairs for which these polynomials permute and we give lower bounds on the number of such pairs. 相似文献
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Lifeng Wang Naiqing Ren Dr. Yu Yao Dr. Hai Yang Dr. Wei Jiang Zixu He Dr. Yang Jiang Prof. Shuhong Jiao Prof. Li Song Prof. Xiaojun Wu Prof. Zhong-Shuai Wu Prof. Yan Yu 《Angewandte Chemie (International ed. in English)》2023,62(6):e202214372
Metallic Na is a promising metal anode for large-scale energy storage. Nevertheless, unstable solid electrolyte interphase (SEI) and uncontrollable Na dendrite growth lead to disastrous short circuit and poor cycle life. Through phase field and ab initio molecular dynamics simulation, we first predict that the sodium bromide (NaBr) with the lowest Na ion diffusion energy barrier among sodium halogen compounds (NaX, X=F, Cl, Br, I) is the ideal SEI composition to induce the spherical Na deposition for suppressing dendrite growth. Then, 1,2-dibromobenzene (1,2-DBB) additive is introduced into the common fluoroethylene carbonate-based carbonate electrolyte (the corresponding SEI has high mechanical stability) to construct a desirable NaBr-rich stable SEI layer. When the Na||Na3V2(PO4)3 cell utilizes the electrolyte with 1,2-DBB additive, an extraordinary capacity retention of 94 % is achieved after 2000 cycles at a high rate of 10 C. This study provides a design philosophy for dendrite-free Na metal anode and can be expanded to other metal anodes. 相似文献
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Surfactant-mediated wetting and spreading are ubiquitous. Understanding of these phenomena in-depth allows precise tailoring of wetting performance which can contribute to global challenges in the food supply chain, healthcare, ecology and industrial processes. The first part of this review shows how surfactants can be used to improve the efficacy of fertilisers and pesticides in agriculture, enhanced oil recovery, treatment of lung diseases and extinguishing fires involving flammable liquids. The second part provides analysis of recent studies on wetting and spreading over solid substrates. It includes discussion on the effect of surfactants on the outcome of the impact of liquid drops, the wetting state after impact, autophobic effect and spreading kinetics for both partial and complete wetting, including superspreading. Perspectives of future development in the area of surfactant-assisted wetting and spreading on solid substrates are outlined. 相似文献
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降雨冲刷对黄土公路边坡植物防护影响的试验研究 总被引:1,自引:0,他引:1
通过对裸露黄土公路边坡、厚层基材植草公路边坡、三维网植草公路边坡以及平台植树公路边坡的现场降雨冲刷试验,阐述了不同防护型式的公路黄土边坡在降雨条件下的坡面径流、含泥量以及坡面冲刷情况,得出了"降雨对边坡坡面的侵蚀过程,首先是从雨滴直接打击土体开始,进而引起溅蚀,分散土粒,紧接着发生超渗径流造成坡面冲刷。"以及"对坡面破坏最大的是坡顶上方来水"等重要结论。验证了坡面植物防护以及平台植树等防护方法可以有效降低降雨冲刷对坡面的侵蚀破坏,为黄土地区公路边坡植物防护的设计施工以提供了可靠的依据。 相似文献
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Wen-Hui Ma Ce-Ming Tan Jian-Cheng He Peng-Shan Duan Lu-Ping Qin 《Chemistry of Natural Compounds》2011,47(5):713-715
Chemical investigation on the stems of Schisandra sphenanthera has afforded a novel eudesmene-type sesquiterpenoid, schisansphene
A (1), and a known compound, alismol (2). Their structures and configurations were elucidated by spectroscopic methods, including 2D NMR techniques. 相似文献