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981.
Pure green emitters are essential for realizing an ultrawide color gamut in next‐generation displays. Herein, by fusing the difficult‐to‐access aza‐aromatics onto B (boron)–N (nitrogen) skeleton, a hybridized multi‐resonance and charge transfer (HMCT) molecule AZA‐BN was successfully synthesized through an effective one‐shot multiple cyclization method. AZA‐BN shows pure green fluorescence with photoluminance quantum yield of 99.7 %. The corresponding green device exhibits a maximum external quantum efficiency and power efficiency of 28.2 % and 121.7 lm W?1, respectively, with a full width half maximum (FWHM) of merely 30 nm and Commission Internationale de l'Eclairage (CIE) coordinate y of 0.69, representing the purest green bottom‐emitting organic light‐emitting diode.  相似文献   
982.
To separate small molecules from the solvent with high permeability and selectivity, the membrane process is thought to be highly effective with much lower energy consumption when compared to the traditional thermal‐based separation process. To achieve high solvent permeance, a sub‐10 nm thick polyamide nanofiltration membrane was synthesized through interfacial polymerization of ethidium bromide (EtBr) and trimesoyl chloride (TMC). Thanks to the extremely low solubility of the EtBr monomer in the organic phase, the polymerization process was strictly limited at the interface of the water and hexane, leading to an ultrathin polyamide membrane with a thickness down to sub‐10 nm. When used in nanofiltration, these ultrathin membranes display ultrafast water permeation of 40 liter per square meter per hour per bar (L m?2 h?1 bar?1), and a high Congo red rejection rate of 93 %. This work demonstrates a new route to synthesize ultrathin polyamide membranes by the traditional interfacial polymerization.  相似文献   
983.
Chitosan nanoparticles with magnetic properties can be potentially used as separation materials in adsorption of oil for enhanced oil recovery. Different from the traditional surfactants, the novel magnetic Co0.5Zn0.5Fe2O4-chitosan nanoparticles are of excellent biodegradation and a high level of controllability. The Co0.5Zn0.5Fe2O4-chitosan nanoparticles with core-shell structure were prepared successfully. The image of transmission electron microscope and the scanning electron microscopy showed that the cubic-shape magnetic Co0.5Zn0.5Fe2O4-particles were encapsulated by the spherical chitosan nanoparticles. The size of the Co0.5Zn0.5Fe2O4-chitosan nanoparticles was below 100 nm. The saturated magnetization of the Co0.5Zn0.5Fe2O4-chitosan nanoparticles could reach 80 emu g?1 and showed the characteristics of superparamagnetism at the same time. The evaluation on the interfacial properties of the product demonstrated that the interfacial tension between crude oil and water could be reduce to ultra-low values (to about 10?3 mN m?1) when the magnetic Co0.5Zn0.5Fe2O4-chitosan nanoparticle was used in several blocks in Shengli Oilfield without other additives. Meanwhile, the magnetic Co0.5Zn0.5Fe2O4-chitosan nanoparticles possessed good salt-resisting capacity.  相似文献   
984.
An efficient enantioselective reduction of α‐amino ketones with potassium borohydride solution catalyzed by chiral N,N′‐dioxide–metal complex catalysts was accomplished under mild reaction conditions for the first time. It provided a simple, convenient, and practical approaches for obtaining synthetically important chiral β‐amino alcohols in good to excellent yields (up to 98 %) and enantioselectivities (up to 97 % ee).  相似文献   
985.
Numerous strategies have been developed to mitigate the intrinsic low detection sensitivity that is a limitation of capillary electrophoresis. Among them, in-line stacking is an effective strategy to address the sensitivity challenge, and among the different stacking techniques, stacking based on field amplification is the most effective and simplest method of achieving high sensitivity without special complicated mechanisms or operations. This review introduces several stacking techniques based on field amplification. Field-amplified sample stacking, large-volume sample stacking, matrix field-amplified stacking injection (FASI), head-column FASI, matrix FASI combined with head-column FASI, FASI coupled with extraction and clean-up methods, electrokinetic supercharging, cation–anion selective exhaustive injection-sweeping-micellar electrokinetic chromatography, and newly developed techniques based on field amplification combined with other methods are included, and examples of straightforward methods for solving the sensitivity problem are provided. We also present a brief overview of the advantages, limitations, and future developments of these techniques. Graphical Abstract
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986.
A device was designed and assembled to analyze the outgassing of molecular glass(MG)photoresists under extreme ultraviolet(EUV)exposure.The outgassing of the photoresists with different components and different concentrations of tert-butoxycarbonyl(t-Boc),photo-generated acid(PAG),and acid quencher was systematically investigated.Based on experiments,some solutions for reducing the outgassing of MG photoresists were proposed.  相似文献   
987.
1,3‐Dipolar cycloaddition reaction between nitrile oxide and alkyne was used to capture 3‐amino‐4‐oxycyanofurazan (AOCF), which was considered as the key intermediate during the synthesis of 3,4‐bis(4‐aminofurazano‐3‐yl)furoxan (DATF) from 3‐amino‐4‐chloroximinofurazan. The isolated isoxazoles from the reaction afforded evidences for the existence of AOCF. The structures of the isoxazoles were characterized by IR, 1H NMR, 13C NMR, MS, and elemental analysis. In addition, single crystal X‐ray diffraction of one isoxazole was obtained.  相似文献   
988.
文章以射频芯片CC2540为核心,构建一个低功耗、低时延的无线数据通信网络,将实验室负载工作电流、温度、湿度等物理量实时传送到上位机。文中给出了系统硬件电路及上、下位机软件设计。测试表明系统数据传输稳定、准确,设计方案有效、可行。  相似文献   
989.
NGB-W系统综述   总被引:2,自引:2,他引:0  
NGB-W作为新一代的智能融合媒体网络及全新的双向开放技术平台,可承载多种三网融合业务,为用户提供精细化的服务,从而实现对现有无线广播电视网络体系的全面升级换代。在分析NGB-W系统架构及重要组成部分的基础上,详细介绍了NGB-W系统的9大特点,三大业务覆盖范围及基础广播电视、交互广播电视、移动互联网接入、物联网业务、紧急广播、跨行业应用等主要应用场景,对中国地面电视行业的发展具有重要的指导意义。  相似文献   
990.
孙琴  曲连强 《数学学报》2019,62(1):87-102
本文对带相依终止事件的复发事件数据提出了一个联合建模分析方法,用一个带脆弱变量的可加可乘比率模型来刻画复发事件过程,还用带脆弱变量的Cox风险率模型来刻画终止事件过程,而且这两个过程的相依性由脆弱变量来刻画.我们利用估计方程的方法,对模型参数进行了估计,给出了所得估计的渐近性质.同时,通过数值模拟分析验证了估计的渐近性质.最后,利用该方法分析了弗吉尼亚大学慢性心脏病病人医疗诊费数据.  相似文献   
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