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951.
Shuai Wang Shuo Huang Minjie Yao Yan Zhang Zhiqiang Niu 《Angewandte Chemie (International ed. in English)》2020,59(29):11800-11807
The reversible capacity of AlCl4? intercalation/de‐intercalation in conventional cathodes of aluminum‐ion batteries (AIBs) is difficult to improve due to the large size of AlCl4? anions. Therefore, it is highly desirable to realize the intercalation/de‐intercalation of smaller Al‐based ions. Here, we fabricated polyaniline/single‐walled carbon nanotubes (PANI/SWCNTs) composite films and protonated the PANI nanorods. The protonation endows PANI with more active sites and enhanced conductivity. Hyper self‐protonated PANI (PANI(H+)) exhibits reversible AlCl2+ intercalation/de‐intercalation during the discharge/charge process. As a result, the discharge capacity of the Al/PANI(H+) battery is twice as high as that of the initial composite films. PANI(H+)@SWCNT electrodes also have a stable cycling life with only 0.003 % capacity decay per cycle over 8000 cycles. Owing to the excellent mechanical properties, PANI(H+)@SWCNT composite films can act as the electrodes of flexible AIBs. 相似文献
952.
Jiacai Zhu Minjie Yao Shuo Huang Jinlei Tian Zhiqiang Niu 《Angewandte Chemie (International ed. in English)》2020,59(38):16480-16484
Smart self‐protection is essential for addressing safety issues of energy‐storage devices. However, conventional strategies based on sol‐gel transition electrolytes often suffer from unstable self‐recovery performance. Herein, smart separators based on thermal‐gated poly(N‐isopropylacrylamide) (PNIPAM) hydrogel electrolytes were developed for rechargeable zinc‐ion batteries (ZIBs). Such PNIPAM‐based separators not only display a pore structure evolution from opened to closed states, but also exhibit a surface wettability transition from hydrophilic to hydrophobic behaviors when the temperature rises. This behavior can suppress the migration of electrolyte ions across the separators, realizing the self‐protection of ZIBs at high temperatures. Furthermore, the thermal‐gated behavior is highly reversible, even after multiple heating/cooling cycles, because of the reversibility of temperature‐dependent structural evolution and hydrophilic/hydrophobic transition. This work will pave the way for designing thermal‐responsive energy‐storage devices with safe and controlled energy delivery. 相似文献
953.
Wen‐Tong Chen Xi‐Rui Zeng Xiao‐Niu Fang Xin‐Fa Li Han‐Mao Kuang 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(12):m571-m573
The title compound, (C10H10N2)[CdBr4], was synthesized via a hydrothermal reaction. Its structure features discrete 4,4′‐bipyridinium cations and tetrahedral [CdBr4]2− anions linked into ion pairs by single N—H⋯Br hydrogen bonds. Photoluminescent investigation reveals that the title compound displays a strong emission in the blue region, which may originate from π→π* charge‐transfer interactions of the 4,4′‐bipyridinium cations. 相似文献
954.
Jing Han Siwang Zhang Junxin Niu Chunli Zhang Weichen Dai Yuanyuan Wu Lihong Hu 《Molecules (Basel, Switzerland)》2020,25(23)
Background: Microtubule-targeted drugs are the most effective drugs for adult patients with certain solid tumors. Taccalonolide AJ (AJ) can stabilize tubulin polymerization by covalently binding to β-tubulin, which enables it to play a role in the treatment of tumors. However, its clinical applications are largely limited by low water solubility, chemical instability in water, and a narrow therapeutic window. Clear-cell renal-cell carcinoma (cc RCC) accounts for approximately 70% of RCC cases and is prone to resistance to particularly targeted therapy drugs. Methods: we prepared a water-soluble cyclodextrin-based carrier to serve as an effective treatment for cc RCC. Results: Compared with AJ, taccalonolide AJ-hydroxypropyl-β-cyclodextrin (AJ-HP-β-CD) exhibited superior selectivity and activity toward the cc RCC cell line 786-O vs. normal kidney cells by inducing apoptosis and cell cycle arrest and inhibiting migration and invasion of tumor cells in vitro. According to acute toxicity testing, the maximum tolerated dose (MTD) of AJ-HP-β-CD was 10.71 mg/kg, which was 20 times greater than that of AJ. Assessment of weight changes showed that mouse body weight recovered over 7–8 days, and the toxicity could be greatly reduced by adjusting the injections from once every three days to once per week. In addition, we inoculated 786-O cells to generate xenografted mice to evaluate the anti-tumor activity of AJ-HP-β-CD in vivo and found that AJ-HP-β-CD had a better tumor inhibitory effect than that of docetaxel and sunitinib in terms of tumor growth and endpoint tumor weight. These results indicated that cyclodextrin inclusion greatly increased the anti-tumor therapeutic window of AJ. Conclusions: the AJ-HP-β-CD complex developed in this study may prove to be a novel tubulin stabilizer for the treatment of cc RCC. In addition, this drug delivery system may broaden the horizon in the translational study of other chemotherapeutic drugs. 相似文献
955.
Shao-Bin Dou Xing-Liang Jia Zhi-Jun Liu Ya-Qi Meng Zheng-Rong Mo Gao-Nan Li Zhi-Gang Niu 《中国化学会会志》2020,67(9):1624-1630
Heteroleptic cyclometalated iridium(III) complexes ( Ir1 – Ir5 ) featuring piz-based ligands and acetylacetone ancillary ligand are synthesized and characterized. Their photophysical and electrochemical properties were studied, and DFT calculations were used to further support the experiment results. All the complexes emit yellow color with quantum yields of 12.2–56.5% in dichloromethane solution at room temperature, and the emission originates from a hybrid 3MLCT/3ILCT/3LLCT excited state. 相似文献
956.
Qingsong Hu Zhenzhou Deng Manchen Hu Anjiang Zhao Yaqi Zhang Zhifang Tan Guangda Niu Haodi Wu Jiang Tang 《中国科学:化学(英文版)》2018,61(12):1581-1586
Metal halide perovskites have shown great performance for various applications,including solar cells,light emitting diodes,and radiation detectors,but they still suffer from the toxicity of lead and instability.Here we report the use of lanthanide series as trivalent metals to obtain low toxicity and highly stable double perovskites(Cs_2NaLnCl_6,Ln=Tb or Eu)with high scintillation light yield.The crystals exhibit typical f-f transitions of lanthanide cations,while Cs_2NaTbCl_6exhibits strong green photoluminescence,and Cs_2NaEuCl_6exhibits red photoluminescence.Under X-ray radiations,the light yield of Cs_2NaTbCl_6reaches46600 photons MeV~(-1),much higher than that of the commercially used(Lu,Y)_2SiO_5:Ce~(3+)crystals(LYSO,28500 photons MeV~(-1)),and previously reported lead-based perovskites(14000 photons MeV~(-1)).As a new member of lead-free perovskites,lanthanide-based double perovskites open up a new route toward radiation detections and potential medical imaging. 相似文献
957.
Acid‐Induced Shift of Intramolecular Hydrogen Bonding Responsible for Excited‐State Intramolecular Proton Transfer 下载免费PDF全文
The significant progress recently achieved in designing smart acid‐responsive materials based on intramolecular charge transfer inspired us to utilize excited‐state intramolecular proton transfer (ESIPT) for developing a turn‐on acid‐responsive fluorescent system with an exceedingly large Stokes shift. Two ESIPT‐active fluorophores, 2‐(2‐hydroxyphenyl)pyridine (HPP) and 2‐(2‐hydroxyphenyl)benzothiazole (HBT), were fused into a novel dye (HBT‐HPP) fluorescent only in the protonated state. Moreover, we also synthesized three structurally relevant control compounds to compare their steady‐state fluorescence spectra and optimized geometric structures in neutral and acidic media. The results suggest that the fluorescence turn‐on was caused by the acid‐induced shift of the ESIPT‐responsible intramolecular hydrogen bond from the HPP to HBT moiety. This work presents a systematic comparison of the emission efficiencies and basicity of HBT and HPP for the first time, thereby utilizing their differences to construct an acid‐responsive smart organic fluorescent material. As a practical application, red fluorescent letters can be written using the acid as an ink on polymer film. 相似文献
958.
Qun Liu Yan-xiang Wang Fang-xu Niu Lian-ru Ma Ce Qu Shan-long Fu Mei-ling Chen 《Polymer Science Series A》2018,60(5):638-646
In this work, acrylonitrile copolymers were prepared via precipitation polymerization. The copolymer solutions prepared at various ratio of dimethyl sulfoxide and dimethylacetamide were tested to prepare the nascent fibers by one-step wet-spun method. The effect of temperature, solvent ratio, molecular weight and the solid content on the rheological properties of polyacrylonitrile gel solution in different mixed solvent were studied. It was shown that the viscosity decreased with the increase of the temperature and fluctuated with the different solvent ratio reaching the minimal value at the ratio of dimethyl sulfoxide to dimethylacetamide equal to 1.25. The crystallinity of copolymers and the structure of the nascent fiber surface also depended from the solvent ratio in polymerization. The optimum conditions for spinnability of copolymers were determined. The high-quality polyacrylonitrile precursor was achieved with the controllable range of 0.5–0.8 dtex and the toughness of polyacrylonitrile precursor was greater than 6.0 cN/dtex after the wet spinning process, while the tensile strength of carbon fiber is up to 6.25 GPa after their pre-oxidation and carbonization process. 相似文献
959.
Shuyi Yang Wensheng Zhang Guoliang Pan Jiaying Chen Jiayi Deng Ke Chen Xianglun Xie Dongxue Han Mengjiao Dai Li Niu 《Angewandte Chemie (International ed. in English)》2023,62(43):e202312076
The effective conversion of carbon dioxide (CO2) and nitrogen (N2) into urea by photocatalytic reaction under mild conditions is considered to be a more environmentally friendly and promising alternative strategies. However, the weak adsorption and activation ability of inert gas on photocatalysts has become the main challenge that hinder the advancement of this technique. Herein, we have successfully established mesoporous CeO2-x nanorods with adjustable oxygen vacancy concentration by heat treatment in Ar/H2 (90 % : 10 %) atmosphere, enhancing the targeted adsorption and activation of N2 and CO2 by introducing oxygen vacancies. Particularly, CeO2-500 (CeO2 nanorods heated treatment at 500 °C) revealed high photocatalytic activity toward the C−N coupling reaction for urea synthesis with a remarkable urea yield rate of 15.5 μg/h. Besides, both aberration corrected transmission electron microscopy (AC-TEM) and Fourier transform infrared (FT-IR) spectroscopy were used to research the atomic surface structure of CeO2-500 at high resolution and to monitor the key intermediate precursors generated. The reaction mechanism of photocatalytic C−N coupling was studied in detail by combining Density Functional Theory (DFT) with specific experiments. We hope this work provides important inspiration and guiding significance towards highly efficient photocatalytic synthesis of urea. 相似文献
960.
Prof. Qingsong Hu Chengkai Zhang Xian Wu Guijie Liang Lei Wang Xiaowei Niu Zhi Wang Wei-Dan Si Yibo Han Ruiqin Huang Prof. Jiawen Xiao Prof. Di Sun 《Angewandte Chemie (International ed. in English)》2023,62(11):e202217784
The low efficiency triplet emission of hybrid copper(I) iodide clusters is a critical obstacle to their further practical optoelectronic application. Herein, we present an efficient hybrid copper(I) iodide cluster emitter (DBA)4Cu4I4 , where the cooperation of excited state structure reorganization and the metallophilicity interaction enables ultra-bright triplet yellow-orange emission with a photoluminescence quantum yield over 94.9 %, and the phonon-assisted de-trapping process of exciton induces the negative thermal quenching effect at 80–300 K. We also investigate the potential of this emitter for X-ray imaging. The (DBA)4Cu4I4 wafer demonstrates a light yield higher than 104 photons MeV−1 and a high spatial resolution of ≈5.0 lp mm−1, showing great potential in practical X-ray imaging applications. Our new copper(I) iodide cluster emitter can serve as a model for investigating the thermodynamic mechanism of photoluminescence in hybrid copper(I) halide phosphorescence materials. 相似文献