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81.
Hongfeng Li Peng Wu Yawen Xiao Meng Shao Yu Shen Yun Fan Huanhuan Chen Ruijie Xie Wenlei Zhang Sheng Li Jiansheng Wu Yu Fu Bing Zheng Weina Zhang Fengwei Huo 《Angewandte Chemie (International ed. in English)》2020,59(12):4763-4769
Metal–organic frameworks (MOFs) are promising materials with fascinating properties. Their widespread applications are sometimes hindered by the intrinsic instability of frameworks. However, this instability of MOFs can also be exploited for useful purposes. Herein, we report the use of MOFs as metal ion precursors for constructing functional nanocomposites by utilizing the instability of MOFs. The heterogeneous growth process of nanostructures on substrates involves the release of metal ions, nucleation on substrates, and formation of a covering structure. Specifically, the synthesized CoS with carbon nanotubes as substrates display enhanced performance in a lithium‐ion battery. Such strategy not only presents a new way for exploiting the instability of MOFs but also supplies a prospect for designing versatile functional nanocomposites. 相似文献
82.
Dou Ma Ping Li Xiangyu Duan Jiazhen Li Pengpeng Shao Zhongling Lang Lixia Bao Yuanyuan Zhang Zhengguo Lin Bo Wang 《Angewandte Chemie (International ed. in English)》2020,59(10):3905-3909
Metal–organic frameworks (MOFs) with long‐term stability and reversible high water uptake properties can be ideal candidates for water harvesting and indoor humidity control. Now, a mesoporous and highly stable MOF, BIT‐66 is presented that has indoor humidity control capability and a photocatalytic bacteriostatic effect. BIT‐66 (V3(O)3(H2O)(BTB)2), possesses prominent moisture tunability in the range of 45–60 % RH and a water uptake and working capacity of 71 and 55 wt %, respectively, showing good recyclability and excellent performance in water adsorption–desorption cycles. Importantly, this MOF demonstrates a unique photocatalytic bacteriostatic behavior under visible light, which can effectively ameliorate the bacteria and/or mold breeding problem in water adsorbing materials. 相似文献
83.
AbstractTwo new alkaloids, fluevirines E (1) and F (2), along with six known Securinega alkaloids, were isolated from the methanol extract of the twigs and leaves of Flueggea virosa. The structures and absolute configurations of the new compounds were elucidated by means of MS, NMR, and ECD analyses. Compound 1 is a new dimeric indole alkaloid while 2 is a new securinega-type alkaloid. The in vitro cytotoxic activities of the isolated alkaloids against several human cancer cell lines and their acetylcholinesterase inhibitory activity were also evaluated. 相似文献
84.
Hui Sun Yun-Feng Zhang Hui-Xia Huo Peng-Wei Guan Chao-Chao Wang Hui-Na Yao 《Natural product research》2020,34(14):2030-2036
AbstractTwo new benzophenone glycosides, aquilarisides A (1) and B (2), together with six known analogues (3-8) were isolated from the pericarps of Aquilaria yunnanensis S. C. Huang. Their structures were elucidated on the basis of 1D and 2D NMR and mass spectroscopic analyses, and the absolute configuration of compound 1 was determined by experimental and calculated electronic circular dichroism (ECD) spectra. Anti-inflammatory activities of all compounds 1–8 were evaluated for their inhibitory activities against lipopolysaccharide (LPS)-stimulated induced nitric oxide (NO) production in RAW 264.7 cells using the Griess assay. Compound 2 indicated a weak inhibition of NO production. 相似文献
85.
Shuxin Zhang Chang Chen Chang Xue Dingran Chang Huo Xu Bruno J. Salena Yingfu Li Zai‐Sheng Wu 《Angewandte Chemie (International ed. in English)》2020,59(34):14584-14592
Herein, we report on the design of a programmable DNA ribbon using long‐chain DNA molecules with a user‐defined repetitive padlock sequence. The DNA ribbon can be further combined with gold nanoparticles (AuNPs) to create a composite nanomaterial that contains an AuNP core and a high‐density DNA crown carrying a cancer‐cell‐targeting DNA aptamer, a fluorescent tag for location tracking, and a cell‐killing drug. This composite material can be efficiently internalized by cancer cells and its cellular location can be tracked by fluorescence imaging. The system offers several attractive characteristics, including simple design, tunable DNA crown, high drug‐loading capacity, selective cell targeting, and pH‐sensitive drug release. These features make such a material a promising therapeutic agent. 相似文献
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介绍了3 cm低噪声接收前端的设计方法及为使其小型化应用使用了芯片GaAS MMIC混频器,并使用MWO软件对低噪声放大器电路进行了仿真。仿真数据和实测结果都表明,所设计的放大器具有较低的噪声和带内起伏,接收前端具有较高的镜像抑制度及良好的带外抑制。 相似文献
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绝缘子表面粗糙处理是提升其沿面闪络性能的重要途径,表面粗糙化处理方式不当,极易带来表面结构不均匀,难以获得稳定耐压性能的绝缘材料。为提升绝缘子表面粗糙处理的均匀性,本文利用表面喷砂技术对圆柱形有机玻璃(PMMA)绝缘子进行了粗糙化处理研究,以球形二氧化硅(SiO2)颗粒为工作介质,研究了不同喷砂粒径、氢氟酸后处理等因素对绝缘材料表面形貌和组分的影响,并利用短脉冲高压测试平台对喷砂处理前后有机玻璃绝缘子样品进行了真空沿面闪络性能测试。研究结果表明,喷砂处理在有机玻璃表面形成了较为均匀的凹坑,HF酸能够有效去除表面残留的SiO2颗粒,具有表面喷砂粗糙结构的绝缘子沿面闪络电压得到了稳定提升,相较于未处理的绝缘子闪络电压提升了约80%。 相似文献