检索结果-南通市图书馆

Controlling reversible complexation-mediated polymerization(RCMP)via deep eutectic solvents:fast kinetics,narrow molecular weight distribution and mechanistic insights

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2728-2736页

作者： Xin Fu Zhen lu Shen Li zheng-Hong luo Lin-Xi Hou Department of Materials-Oriented Chemical Engineering College of Chemical EngineeringFuzhou UniversityFuzhou 350116China Department of Chemical Engineering School of Chemistry and Chemical EngineeringState Key Laboratory of Metal Matrix CompositesShanghai Jiao Tong UniversityShanghai 200030China Chemical Engineering Zhicheng College of Fuzhou UniversityFuzhou 350116China qingyuan Innovation Laboratory Quanzhou 362801China

The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric *** this work,serials of deep eutectic solvents(DES)with intermolecular-hydrogen-bonding interaction were constructed as catalysts and medium for actuating reversible complexation-mediated polymerization(RCMP)for the first time,yielding methacrylate polymers with high monomer conversion and narrow dispersion molecular weight in both water and oil *** mechanism and elementary reaction of RCMP were explored deeply,revealing that the complexation of initiator with DES to generate radicals was a ratecontrolling step and intermolecular-hydrogen-bond was primary factor to influence polymerization ***,the insights of density functional theory calculations revealed that negative electrostatic potential ensured nucleophilic *** investigation demonstrated the considerable potential of DES for RCMP,which is anticipated for other polymerization applications as a novel medium mode.

关键词： deep eutectic solvent reversible complexation-mediated polymerization intermolecular hydrogen bonding density functional theory elementary reaction steps

Dynamic lithium-compensation mechanism for densification of garnet-type Li_(7)La_(3)Zr_(2)O_(12)electrolyte by Li_(2)O atmosphere buffer pair

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 6184-6191页

作者： Chujun zheng Ya Chen Haoxin Dong Yan lu Jun Jin Zhaoyin Wen CAS Key Laboratory of Materials for Energy Conversion Shanghai Institute of CeramicsChinese Academy of ScienceShanghai 200050China State Key Lab High Performance Ceram and Superfine Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Solid-state lithium metal batteries are one of the most promising options for next-generation batteries pursuing high-energy density and ***,the inevitable volatilization of lithium compounds during sintering leads to low relative density and low ionic conductivity of solid-state ***,the dynamic lithium-compensation mechanism is proposed to facilitate the densification of Ta-substituted garnet-type electrolyte(Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZT))through the reversible manipulating of Li_(2)O ***_(2)ZrO_(3)is used as mother powder additive,which reacts with Li_(2)O in sintering atmosphere and forms Li_(6)Zr_(2)O_(7).Li_(2)ZrO_(3)/Li_(6)Zr_(2)O_(7)buffer pair manipulates the sintering Li_(2)O atmosphere,which is vital for LLZT,within the Li_(2)O partial pressure range corresponding to Li_(2)ZrO_(3)and Li_(6)Zr_(2)O_(7).Furthermore,the reversibility mechanism of buffer pair for Li_(2)O absorption and release is *** obtained LLZT exhibits a relative density of over 96%and an ionic conductivity exceeding 7×10^(−4)S·cm^(−1)with no abnormal grain *** symmetric cell demonstrates an excellent lithium dendrite suppressing ability(stable cycling at a current density of 0.3 mA·cm^(−2)for over 1000 h).Such dynamic lithium-compensation strategy has been successfully applied in atmosphere manipulation of LLZT sintering process,which reduces the dependence of LLZT on the Li_(2)O atmosphere,making it conducive to large-scale preparation of electrolyte ceramics.

关键词： solid-state batteries garnet-type electrolyte high-density electrolyte dynamic lithium-compensation buffer pair

In-situ formation of nitrogen doped microporous carbon nanospheres derived from polystyrene as lubricant additives for anti-wear and friction reduction

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第3期12卷 439-451页

作者： Yixin WANG qi lu Huijie XIE Shujuan LIU qian YE Feng ZHOU Weimin LIU State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Solid lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

This study presents a nitrogen-doped microporous carbon nanospheres(N@MCNs)prepared by a facile polymerization–carbonization process using low-cost *** N element in situ introduces polystyrene(PS)nanospheres via emulsion polymerization of styrene with cyanuric chloride as crosslinking agent,and then carbonization obtains N@*** as-prepared carbon nanospheres possess the complete spherical structure and adjustable nitrogen amount by controlling the relative proportion of tetrachloromethane and cyanuric *** friction performance of N@MCNs as lubricating oil additives was surveyed utilizing the friction experiment of ball-disc *** results showed that N@MCNs exhibit superb reduction performance of friction and *** the addition of N@MCNs was 0.06 wt%,the friction coefficient of PAO-10 decreased from 0.188 to 0.105,and the wear volume reduced by 94.4%.The width and depth of wear marks of N@MCNs decreased by 49.2% and 94.5%,*** carrying capacity of load was rocketed from 100 to 400 N *** the analysis of the lubrication mechanism,the result manifested that the prepared N@MCNs enter clearance of the friction pair,transform the sliding friction into the mixed friction of sliding and rolling,and repair the contact surface through the repair ***,the tribochemical reaction between nanoparticles and friction pairs forms a protective film containing nitride and metal oxides,which can avert direct contact with the matrix and improve the tribological *** experiment showed that nitrogen-doped polystyrene-based carbon nanospheres prepared by in-situ doping are the promising materials for wear resistance and reducing *** preparing method can be ulteriorly expanded to multi-element co-permeable *** and boron co-doped carbon nanospheres(B,N@MCNs)were prepared by mixed carbonization of N-enriched PS and boric acid,and exhibited high load carrying capacity and good tribolog

关键词： lubricant additives hypercrosslinked polystyrene carbon nanospheres friction reduction anti-wear

In-situ analysis of laser-induced breakdown spectra for online monitoring of femtosecond laser machining of sapphire

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第1期67卷 73-82页

作者： SHANGGUAN ShiYong ZHANG JianGuo LI ZhanZhu SHI Wei WANG WenKe qi DongFeng zheng HongYu Center for Advanced Laser Manufacturing(CALM) Shandong University of TechnologyZibo 255000China

Laser-induced breakdown spectroscopy(LIBS)is widely used for elemental ***,its application for monitoring and analyzing a laser machining process by examining the changes in spectral information warrants further *** this study,we investigate the effect of laser parameters on the spectra,variations in the time-resolved plasma emission spectra,and the relationship between the morphology of craters and plasma plume evolution during the femtosecond(fs)laser ablation of *** Boltzmann plot method and Stark’s broadening model are employed to estimate the temporal temperature and electron density of the plasma plume,revealing the process of plasma *** study aims to demonstrate the feasibility of LIBS for online monitoring of laser processing through experimental data and theoretical explanations.

关键词： laser-induced breakdown spectroscopy plasma plume online monitoring sapphire

Numerical Study on Heat Transfer and Frictional Resistance of Two Types of Molten Salts in Straight Channels and Supercritical Carbon Dioxide in Airfoil Channels

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第4期33卷 1443-1457页

作者： WANG Yanquan lu Yuanwei GAO qi LI Feng MA Yancheng WANG Yuanyuan WU Yuting MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation Beijing Key Laboratory of Heat Transfer and Energy ConversionBeijing University of TechnologyBeijing100124China

Molten salt and supercritical carbon dioxide(sCO_(2))are considered to be one of the most promising combined heat transfer refrigerants for third-generation solar thermal power *** evaluate the potential of chloride salts and carbonates in third-generation solar thermal power generation,this paper uses molten salts and sCO_(2)as the working media of printed circuit board heat exchangers(PCHE),and uses numerical simulation to study the heat transfer and friction of PCHE channels with different molten salts and sCO_(2),and establishes predictive correlations respectively.A local heat transfer and friction study was conducted on the sCO_(2)side of the airfoil channel,and it was found that the inlet mass flow rate has a significant impact on it,while the inlet temperature has a relatively small impact.A comprehensive comparison was made between the heat transfer and friction of two molten salts,and the comprehensive performance of chloride salts was 70%-80%higher than that of *** results indicate that the potential of chloride salts in third-generation solar thermal power generation is much greater than that of carbonates.

关键词： third generation solar thermal power generation sCO_(2) PCHE molten salt

Electrochemical synthesis of trimetallic nickel-iron-copper nanoparticles via potential-cycling for high current density anion exchange membrane water-splitting applications

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第2期89卷 535-542,I0012页

作者： Ziqi Zhang Sheng Wan Hanbo Wang Jinghan He Ruige Zhang Yuhang qi Haiyan lu State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012JilinChina

Hydrogen is known for its elevated energy density and environmental compatibility and is a promising alternative to fossil *** water electrolysis utilizing renewable energy sources has emerged as a means to obtain high-purity ***,electrocatalysts used in the process are fabricated using conventional wet chemical synthesis methods,such as sol-gel,hydrothermal,or surfactantassisted approaches,which often necessitate intricate pretreatment procedures and are vulnerable to post-treatment ***,this study introduces a streamlined and environmentally conscious one-step potential-cycling approach to generate a highly efficient trimetallic nickel-iron-copper electrocatalyst in situ on nickel *** synthesized material exhibited remarkable performance,requiring a mere 476 mV to drive electrochemical water splitting at 100 mA cm^(-2)current density in alkaline ***,this material was integrated into an anion exchange membrane watersplitting device and achieved an exceptionally high current density of 1 A cm^(-2)at a low cell voltage of2.13 V,outperforming the noble-metal benchmark(2.51 V).Additionally,ex situ characterizations were employed to detect transformations in the active sites during the catalytic process,revealing the structural transformations and providing inspiration for further design of electrocatalysts.

关键词： Electrocatalytic water splitting Hydrogen evolution reaction Oxygen evolution reaction Electrochemical synthesis Anion exchange membrane

Numerical and experimental study on the falling film flow characteristics with the effect of co-current gas flow in hydrogen liquefaction process

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1369-1384页

作者： Chong-zheng Sun Yu-Xing Li Hui Han Xiao-Yi Geng Xiao lu College of Energy Storage Technology Shandong University of Science and TechnologyQingdao 266590ShandongChina College of Pipeline and Civil Engineering/Shandong Provincial Key Laboratory of Oil&Gas Storage and Transportation Safety China University of PetroleumQingdao 266580ShandongChina

Liquid hydrogen storage and transportation is an effective method for large-scale transportation and utilization of hydrogen energy. Revealing the flow mechanism of cryogenic working fluid is the key to optimize heat exchanger structure and hydrogen liquefaction process(LH2). The methods of cryogenic visualization experiment, theoretical analysis and numerical simulation are conducted to study the falling film flow characteristics with the effect of co-current gas flow in LH2spiral wound heat *** results show that the flow rate of mixed refrigerant has a great influence on liquid film spreading process, falling film flow pattern and heat transfer performance. The liquid film of LH2mixed refrigerant with column flow pattern can not uniformly and completely cover the tube wall surface. As liquid flow rate increases, the falling film flow pattern evolves into sheet-column flow and sheet flow, and liquid film completely covers the surface of tube wall. With the increase of shear effect of gas-phase mixed refrigerant in the same direction, the liquid film gradually becomes unstable, and the flow pattern eventually evolves into a mist flow.

关键词： Hydrogen liquefaction Spiral wound heat exchanger Flow pattern transition Falling film flow

Efficacy and safety of Yiqi Peiyuan granules for improving the short-term prognosis of patients with acute kidney injury:A multicenter,double-blind,placebo-controlled,randomized trial

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2024年第3期22卷 279-285页

作者： Jia-jia Wu Tian-yi Zhang Ying-hui qi Min-yan Zhu Yan Fang Chao-jun qi Li-ou Cao Ji-fang lu Bo-han lu lu-min Tang Jian-xiao Shen Shan Mou Department of Nephrology Molecular Cell Lab for Kidney DiseaseShanghai Peritoneal Dialysis Research CenterUremia Diagnosis and Treatment CenterRenji Hospital Affiliated to Shanghai Jiaotong University School of MedicineShanghai 200127China Department of Nephrology Shanghai Pudong New Area Punan HospitalShanghai 200125China Department of Nephrology Ningbo Hangzhou Bay HospitalNingbo 315336Zhejiang ProvinceChina

Background:Yiqi Peiyuan(YQPY)prescription,a composite prescription of traditional Chinese medicine,has been used to prevent or delay the continued deterioration of renal function after acute kidney injury(AKI)in some institutions and has shown considerable ***:This is the first randomized controlled trial to assess efficacy and safety of YQPY for improving short-term prognosis in adult patients with ***,setting,participants and interventions:This is a prospective,double-blind,multicenter,randomized,and placebo-controlled clinical trial.A total of 144 enrolled participants were randomly allocated to two groups according to a randomization ***,caregivers and investigators assessing the outcomes were blinded to group *** in the YQPY group received 36 g YQPY granules twice a day for 28 *** in the placebo group received a placebo in the same dose as the YQPY *** outcome measures:The primary outcome was the change in the estimated glomerular filtration rate(eGFR)between baseline and after 4 and 24 weeks of *** secondary outcomes were the change of serum creatinine(Scr)level between baseline and after treatment,and the incidence of endpoint events,defined as eGFR increasing by more than 25%above baseline,eGFR>75 mL/min per1.73 m2or the composite endpoint,which was defined as the sum of patients meeting either of the above ***:Data from a total of 114 patients(59 in the YQPY group and 55 in the control group)were *** mean changes in eGFR and Scr in weeks 4 and 24 had no difference between the two *** further subgroup analysis(22 in the YQPY group and 31 in the control group),the mean change in eGFR after treatment for 4 weeks was 27.39 mL/min per 1.73 m2in the YQPY group and 5.78 mL/min per1.73 m2in the placebo group,and the mean difference between groups was 21.61 mL/min per 1.73 m2(P<0.001).Thirteen(59.1%)patients in the YQPY group and 5(16.1%)in the placebo g

关键词： Chinese herbal medicine Randomized controlled trial Acute kidney injury Renal function

Physically modulated phytoplankton production and export at submesoscales in the oligotrophic South China Sea Basin

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第8期67卷 2681-2698页

作者： Zhonghua ZHAO Mengdi XU Bangqin HUANG Wenfang lu Hongshuai qi Feng CAI Yuwu JIANG State Key Laboratory of Marine Environmental Science Xiamen UniversityXiamen 361102China College of Ocean and Earth Sciences Xiamen UniversityXiamen 361102China Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies Xiamen UniversityXiamen 361102China National Observation and Research Station for the Taiwan Strait Marine Ecosystem Xiamen UniversityXiamen 361102China School of Marine Sciences Sun Yat-Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519000China Laboratory of Ocean and Coast Geology Third Institute of OceanographyMinistry of Natural ResourcesXiamen 361005China

Oceanic submesoscales can significantly influence phytoplankton production and export owing to their similar timescales of *** on two-year Biogeochemical Argo(BGC-Argo) observations,this study investigated the development of submesoscale instabilities,particularly symmetric and mixed-layer baroclinic instabilities,and their impacts on biological production and export in the oligotrophic South China Sea *** the northern basin,near-surface winter blooms consistently cooccurred with seasonally deepened mixed ***,significantly stronger and weaker winter blooms were observed over two consecutive winters within the BGC-Argo observation *** the first winter,symmetric-instability-induced upward nutrient entrainment played a crucial role in initiating the strong winter bloom in early December,when the mixed layer was approximately 20–30 m shallower than the *** bloom occurred approximately 20–30 days earlier than that anticipated owing to the contact between the seasonally deepened mixed layer and mesoscale-cyclone-induced uplifted *** symmetric instability also facilitated the export of fixed phytoplankton carbon from the surface to deeper ***,during the second winter,remarkably intense mixed-layer baroclinic instability associated with an intense mesoscale anticyclone led to more significant shoaling of the mixed layer compared to the nutricline,thus increasing the vertical distance between the two *** this condition,upward nutrient injection,phytoplankton bloom,and carbon export were *** contrast,the BGC-Argo float in the central basin revealed significantly inhibited seasonality of phytoplankton biomass and submesoscale instabilities compared to those in the northern basin,primarily owing to the significantly shallower winter mixed layer.

关键词： Submesoscale instability Phytoplankton Nutrient transport BGC-Argo South China Sea