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Ting-Ting Zhang Cheng-Ye Yang Prof. Jin Qu Dr. Wei Chang Yu-Hao Liu Xian-Zhi Zhai Hong-Jun Liu Prof. Zhi-Guo Jiang Prof. Zhong-Zhen Yu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(31):e202200363
As competitive next-generation rechargeable batteries, lithium-sulfur batteries (LSBs) suffer from the shuttle effect and the sluggish kinetics of intermediate polysulfides during charge and discharge processes, adversely affecting their electrochemical performances and actual applications. Herein, we demonstrate a polymer encapsulation strategy to synthesize atomic Fe and N co-doped hollow carbon nanospheres (Fe−NHC) with Fe−Nx sites for modifying commercial PP separator of LSBs to suppress the shuttle effect and promote the kinetics of intermediate polysulfides. Benefiting from the excellent structural design, the doped-N with positive charges could effectively adsorb negatively charged soluble polysulfides, help attract the soluble polysulfides to the Fe atoms and boost the catalytic transformation of the soluble polysulfides. Additionally, such a thin carbon shell could provide a short mass diffusion pathway and hence promote the adsorption and the catalytic conversion. Therefore, the battery with the Fe−NHC/PP separator delivers outstanding cycling and rate performances. At the large current density of 1 C, the specific capacity is 1079 mA h g−1 and maintains a low loss of 0.076 % per cycle within 500 cycles. Even at a harsh current density of 4 C, a high capacity of 824 mA h g−1 is still achieved, indicating the advantage of the Fe−NHC/PP separator in LSBs. 相似文献
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Structural effect of substituents directly bonded to carbanions bearing a phosphorate moiety is examined. Nucleophihc addition of phosphonate carbanion to 1-nitroalkene followed by subsequent reaction with chlorotrimethylsilane leads to a series of 2-isoxazoline based on the formation of an alkene and silyl nitronate as a 1,3-dipole. On the other hand, addition of carbanion derived from isocyanomethylphosphonate to nitroalkene with the formation of nitronate followed by intromolecular cyclization provides substituted phosphoryl pyrroles. 相似文献
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Chiral 1 or 2 hydroxyalkanephosphonatesshowintrigu ingpropertiesinbiologyandorganicchemistry .1Thetradi tionalsyntheticrouteleadingtosuchcompoundssometimeshasdrawbackssuchasharshreactionconditions ,expensivereagentsandlowchemicalyields .2 Toexplorenewandconv… 相似文献
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A visual detection of protein content based on titration of moving reaction boundary electrophoresis
Hou-Yu Wang Cheng-Ye Guo Chen-Gang Guo Liu-Yin Fan Lei Zhang Cheng-Xi Cao 《Analytica chimica acta》2013
A visual electrophoretic titration method was firstly developed from the concept of moving reaction boundary (MRB) for protein content analysis. In the developed method, when the voltage was applied, the hydroxide ions in the cathodic vessel moved towards the anode, and neutralized the carboxyl groups of protein immobilized via highly cross-linked polyacrylamide gel (PAG), generating a MRB between the alkali and the immobilized protein. The boundary moving velocity (VMRB) was as a function of protein content, and an acid–base indicator was used to denote the boundary displacement. As a proof of concept, standard model proteins and biological samples were chosen for the experiments to study the feasibility of the developed method. The experiments revealed that good linear calibration functions between VMRB and protein content (correlation coefficients R > 0.98). The experiments further demonstrated the following merits of developed method: (1) weak influence of non-protein nitrogen additives (e.g., melamine) adulterated in protein samples, (2) good agreement with the classic Kjeldahl method (R = 0.9945), (3) fast measuring speed in total protein analysis of large samples from the same source, and (4) low limit of detection (0.02–0.15 mg mL−1 for protein content), good precision (R.S.D. of intra-day less than 1.7% and inter-day less than 2.7%), and high recoveries (105–107%). 相似文献
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Reaction of diethyl 2,2-difluoro-3-(a-methylbenzyl)imino-4,4,4-trifluoropropanephosphonate (3) with triethylamine afforded a mixture of normal [1,3]-proton shift reaction product 5 and its HF-eliminated compound 6Z in 1 : 1 ratio. Upon hydrolysis, this reaction mixture gave solely 1,3,3,3-tetrafluoro-2-dioxypropanephosphonate (9). Reaction of 3 with DBU provided only 6, in which the ratio of E/Z forms was dependent on the reaction conditions. Aqueous hydrolysis of 6 led to 9. Catalytic hydrogenation and hydrogenolysis of 6 gave geometric isomers of 11 as expected. The reaction mechanism involved was discussed. 相似文献
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Introduction Baker’syeast (Saccharomycescerevisiae)iswellrecognizedasavaluablestereoselectivereagentinbio transformationsoforganicmolecules .Theasymmetricre ductionofcarbonylgroupswiththismicrobehasbeenstudiedextensively .Moreover,inthecourseofreductiono… 相似文献
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通过水热法,在黑磷(BP)纳米片表面生长FeOOH纳米材料,制备出FeOOH/BP纳米复合材料。作为电化学析氧反应(OER)催化剂,该复合材料在20 mA·cm-2时的过电位仅为191 mV,Tafel斜率为49.9 mV·dec-1;在循环1 000圈后,过电位仅仅增加了3 mV,且循环过程中元素价态不变,表现出优秀的稳定性。纳米FeOOH负载于BP表面,客观上能隔断氧气对BP的氧化,保护BP的载流子传导性能。同时,生长的FeOOH颗粒尺度小,结晶性弱,这有利于丰富其活性位点,增大活性面积。 相似文献