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41.
Dongfeng Du Shuo Zhao Zhuo Zhu Fujun Li Jun Chen 《Angewandte Chemie (International ed. in English)》2020,59(41):18140-18144
The storage of solar energy in battery systems is pivotal for a sustainable society, which faces many challenges. Herein, a Zn–air battery is constructed with two cathodes of poly(1,4‐di(2‐thienyl))benzene (PDTB) and TiO2 grown on carbon papers to sandwich a Zn anode. The PDTB cathode is illuminated in a discharging process, in which photoelectrons are excited into the conduction band of PDTB to promote oxygen reduction reaction (ORR) and raise the output voltage. In a reverse process, holes in the valence band of the illuminated TiO2 cathode are driven for the oxygen evolution reaction (OER) by an applied voltage. A record‐high discharge voltage of 1.90 V and an unprecedented low charge voltage of 0.59 V are achieved in the photo‐involved Zn–air battery, regardless of the equilibrium voltage. This work offers an innovative pathway for photo‐energy utilization in rechargeable batteries. 相似文献
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A new class of paramagnetic macromolecular magnetic resonance imaging contrast agents has been developed. Eight new polyamide ligands were synthesized by copolymerization of ethylenediaminetetraacetic acid dianhydride or diethylenetriaminepentaacetic acid dianhydride and diamine monomers. Their gadolinium(III), manganese(II) and iron(III) complexes were also synthesized. All polyamide ligands and metal complexes were characterized by 1H nuclear magnetic resonance, infrared spectra and elemental analyses. Relaxivity studies showed that the polyamide paramagnetic metal complexes had obviously higher relaxation effectiveness as compared to corresponding simple monomeric paramagnetic metal complexes. 相似文献
44.
Xin Xiangjun Wang Zhuo Yang Qinglan Li Fagen 《International Journal of Theoretical Physics》2020,59(3):918-929
International Journal of Theoretical Physics - Designated verifier signatures are very useful in the applications such as e-voting and auction. In this paper, an identity-based quantum designated... 相似文献
45.
本文结合可见-近红外-中红外瞬态吸收光谱技术对离子交换法制备的少层MoS2中缺陷介导的载流子动力学进行了详细的解析. 在近红外瞬态吸收光谱中观察到的宽带漂白信号表明少层MoS2纳米片带隙中分布着大量的缺陷态. 实验结果明确揭示了载流子被缺陷态的快速捕获以及进一步的复合过程,证明带隙中的缺陷态对MoS2光生载流子动力学过程起着至关重要的作用. 在中红外瞬态吸收光谱中观察到的正信号到负信号的转变进一步证实了在导带下小于0.24 eV处存在被载流子占据的缺陷态. 这些在少层MoS2纳米片中存在的缺陷态可以作为有效的载流子捕获中心来辅助光生载流子在皮秒时间尺度内完成非辐射复合过程. 相似文献
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本文报导了双酚A聚砜(B)与对苯二酚聚砜(H)两组份含量不同的嵌段共聚物的X射线衍射结果,B链的加入,使共聚物的结晶性能被破坏,B/H为0.48(摩尔比)时,所得共聚物已呈现出完全非晶相结构的特征.由IGC及DSC实验测定,表明这两种聚砜链是相容的. 相似文献
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Deng J Hu XP Huang JD Yu SB Wang DY Duan ZC Zheng Z 《The Journal of organic chemistry》2008,73(15):6022-6024
A series of chiral beta-aryl-substituted gamma-amino butyric acid derivatives were synthesized in good enantioselectivities via the Cu-catalyzed asymmetric conjugate reduction of gamma-phthalimido-alpha,beta-unsaturated carboxylic acid esters using Cu(OAc)2 x H2O as a catalyst precursor, (S)-BINAP as a ligand, PMHS as a hydride source, and t-BuOH as an additive. The methodology has been applied successfully to the enantioselective synthesis of a chiral pharmaceutical, (R)-baclofen. 相似文献
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Chloroacetate‐Promoted Selective Oxidation of Heterobenzylic Methylenes under Copper Catalysis 下载免费PDF全文
Dr. Jianming Liu Xin Zhang Hong Yi Dr. Chao Liu Ren Liu Dr. Heng Zhang Prof. Dr. Kelei Zhuo Prof. Dr. Aiwen Lei 《Angewandte Chemie (International ed. in English)》2015,54(4):1261-1265
The efficient selective oxidation and functionalization of C? H bonds with molecular oxygen and a copper catalyst to prepare the corresponding ketones was achieved with ethyl chloroacetate as a promoter. In this transformation, various substituted N‐heterocyclic compounds were well tolerated. Preliminary mechanistic investigations indicated that organic radical species were involved in the overall process. The N‐heterocyclic compounds and ethyl chloroacetate work synergistically to activate C? H bonds in the methylene group, which results in the easy generation of free radical intermediates, thus leading to the corresponding ketones in good yields. 相似文献