检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2016年第11期24卷 1533-1540页

作者： Zhuan Yi Fa-dong Wu Yong Zhou cong-jie gao Department of Ocean Zhejiang University of Technology Hangzhou 310014 China Water Treatment Technology Development Center Hangzhou 310012 China

Microstructure in selective layer has played a decisive role in permselectivity of nanofiltration(NF) membranes,and nanomaterials were well-known additives that had been applied to mediate the microstructure and permeability of polyamide NF membranes. However, nanoadditives generally displayed a poor dispersion in membranes or in fabrication process. To solve this problem, we showed an interesting concept that novel NF membranes with hybrid selective layer consisting of flexible polyisobutylene(PIB) and rigid polyamide could be fabricated from well-defined interfacial polymerization. The hydrophobic polymer mediated phase separation and microdomains formation in polyamide layer were found. The immiscibility between the rigid polyamide and flexible PIB as well as the resultant interface effect was interpreted as the reason for the polymer enhanced permselectivity, which was similar with the well-known thin film nanocomposite(TFN) membranes that nanoparticles incorporated contributed significantly to membrane permeability and rejection *** results have demonstrated that novel NF membranes with enhanced performance can be prepared from immiscible polymers, which is a new area that has not been extensively studied before.

关键词： Nanofiltration membranes Interfacial polymerization Polymer additive Hydrophobicity Fabrication

Synthesis and Characterization of the Polyacrylonitrile-block- poly(methyl acrylate) by RAFT Technique

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第3期17卷 365-368页

作者： Quan Fu AN Jin Wen QIAN cong jie gao Department of Polymer Science and Engineering Zhejiang University Hangzhou 310027 The Development Center of Water Treatment Technology State Oceanic Administration Hangzhou 310012

Polyacrylonitrile-block-poly（methyl acrylate）（P（AN-b-MA）） was synthesized by reversible addition-fragmentation chain transfer （RAFT） polymerization employing macro-RAFT agent （PAN-RAFT） as the chain transfer agent and azobis（isobutyronitrile）（AIBN） as the initiator. A linear relationship between ln（[M]0/[M]1） and reaction time was observed. The molecular structure of P（AN-b-MA） was characterized by ^1H-NMR, element analysis, FTIR and SEC. The molecular weight distribution （MWD） was less than 1.40, the Mn could be controled from 0.733 to 4.834×10^4, and the molar content of MA in P（AN-b-MA） were from 15.6 to 75.0 percentage, respectively.

关键词： RAFT acrylonitrile methyl acrylate block polymer.

Recent advances in nanofiltration,reverse osmosis membranes and their applications in biomedical separation field

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2022年第9期35卷 76-99页

作者： Kai Zhang Huan-Huan Wu Hui-Qian Huo Yan-Li Ji Yong Zhou cong-jie gao Center for Membrane and Water Science&Technology Zhejiang University of TechnologyHangzhou 310014China

In the face of human society's great requirements for health industry,and the much stricter safety and quality standards in the biomedical industry,the demand for advanced membrane separation technologies continues to rapidly grow in the ***(NF)and reverse osmosis(RO)as the highefficient,low energy consumption,and environmental friendly membrane separation techniques,show great promise in the application of biomedical separation *** chemical compositions,microstructures and surface properties of NF/RO membranes determine the separation accuracy,efficiency and operation cost in their ***,recent studies have focused on tuning the structures and tailoring the performance of NF/RO membranes via the design and synthesis of various advanced membrane materials,and exploring universal and convenient membrane preparation strategies,with the objective of promoting the better and faster development of NF/RO membrane separation technology in the biomedical separation *** paper reviews the recent studies on the NF/RO membranes constructed with various materials,including the polymeric materials,different dimensional inorganic/organic nanomaterials,porous polymeric materials and metal coordination polymers,***,the influence of membrane chemical compositions,interior microstructures,and surface characteristics on the separation performance of NF/RO membranes,are comprehensively ***,the applications of NF/RO membranes in biomedical separation field are systematically ***,the perspective for future challenges of NF/RO membrane separation techniques in this field is discussed.

关键词： Nanofiltration Reverse osmosis Membrane Separation Biomedical

Recent developments in polymeric nano-based separation membranes

在线全文

学校读者我要写书评

暂无评论

Fundamental Research 2022年第2期2卷 254-267页

作者： Yan-Li Ji Ming-jie Yin Quan-Fu An cong-jie gao Center for Membrane and Water Science&Technology Zhejiang University of TechnologyHangzhou 310014China Bejing Key Laboratory for Green Catalysis and Separation Department of Envronmental and Chemical Engineering Bejing University of TechnologyBeijing 100124China

Polymeric nanomaterials,which have tuneable chemical structures,versatile functionalities,and good compatibility with polymeric matrices,have attracted increasing interest from researchers for the construction of polymeric nano-based separation *** their distinctive nanofeatures,polymeric nano-based membranes show great promise in overcoming bottlenecks in polymer membranes,namely,the trade-off between permeability and selectivity,low stability,and fouling ***,recent studies have focused on tuning the structures and tailoring the surface properties of polymeric nano-based membranes via exploitation of membrane fabrication techniques and surface modification strategies,with the objective of pushing the performance of polymeric nano-based membranes to a new *** this review,first,the approaches for fabricating polymeric nano-based mixed matrix membranes and homogeneous membranes are summarized,such as surface coating,phase inversion,interfacial polymerization,and self-assembly ***,the manipulation strategies of membrane surface properties,namely,the hydrophilicity/hydrophobicity,charge characteristics,and surface roughness,and interior microstructural properties,namely,the pore size and content,channel construction and regulation,are comprehensively ***,the separation performances of liquid ions/molecules and gas molecules through polymeric nano-based membranes are systematically ***,we conclude this review with an overview of various unsolved scientific and technical challenges that are associated with new opportunities in the development of advanced polymeric nano-based membranes.

关键词： Polymeric nanomaterial Polymeric nano-based membrane Mixed matrix membrane Homogeneous membrane Separation application

Precursor solution prepared by evaporation deamination complex method for solvent separation of Mo and W by H_2O_2-complexation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2013年第4期23卷 1139-1146页

作者：关文娟张贵清高从堦中南大学冶金科学与工程学院长沙410083 中南大学稀有金属冶金与材料制备湖南省重点试验室长沙410083

An novel method on preparation of precursor solution for solvent separation of molybdenum （Mo） and tungsten （W） by hydrogen peroxide （H2O2）-complexation from the ammonium tungstate solution containing high Mo was studied. The precursor solution was obtained via evaporation deamination and H202-complex transformation processes. Then it was extracted with a mixture extractant of tri-alkyl phosphine oxide （TRPO） and tributyl phosphate （TBP） to separate Mo and W. The results indicated that the evaporation deamination complex method reduced the acid consumption by more than 90% in comparison with the traditional directly acid regulation complex method. The transformation rates of W and Mo were higher than 95% and the decomposition rate of H202 was less than 15% at a 1.8-1.9 times H202 dosage, 45-50 ℃, initial pH of 1.80-1.90, and transformation volume ratio of 100% for 60 min in the H2O2-complexation transformation process. The minimum extraction rate of W was 2%, the maximum extraction rate of Mo was 82.6% and the highest separation coefficient was 76.7 in a single-stage extraction.

关键词： tungsten molybdenum solvent extraction separation precursor solution H202

Iron-Catalyzed Reductive C(aryl)—Si Cross-Coupling of Diaryl Ethers with Chlorosilanes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第6期42卷 578-584页

作者： Pei Liu Baowei Wu Xuefeng cong jie Kong School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi'anShaanxi710072 China Institute of Molecular Plus Department of Chemistry and Haihe Laboratory of Sustainable Chemical TransformationsTianjin University92 Weijin RoadTianjin300072 China

The reductive cross-coupling between C(aryl)—O and Si—Cl bonds is of much importance as a valuable strategy for the construction of C(aryl)—Si bonds but has remained a great ***,we report a reductive cross-coupling of diaryl ethers and chlorosilanes via strong electrophilic C(aryl)—O and Si—Cl bonds cleavage by iron catalysis,which constitutes an efficient protocol for the synthesis of a range of functionalized *** combination of low cost FeCl2 as the precatalyst and iPrMgCl as the reductant shows high activity in the successive cleavage of unactivated C(aryl)—O bonds of diaryl ethers and strong electrophilic Si—Cl bonds of chlorosilanes,allowing their cross-coupling in a reductive *** low-valent iron species generated in situ by reduction of FeCl2 with iPrMgCl was proposed,which prefers to initially cleavage the C(aryl)—O bond of diaryl ethers with the chelation help of an o-amide auxiliary.

关键词： Cross-coupling Diaryl ethers Chlorosilanes C—O bond cleavage Iron catalyst 3d transition metals Selectivity Regioselectivity

Numerical Analysis on the Static Performance of Gas Journal Bearing by Using Finite Element Method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nanomanufacturing and Metrology 2024年第1期7卷 28-47页

作者： Pengfeng Wang Yuntang Li Xiang gao Yueliang Ye Ruirui Li Xiaolu Li Yuan Chen jie Jin cong Zhang College of Modern Science and Technology China Jiliang UniversityJinhua 322002China College of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou 310018China

In this paper,finite element method is used to calculate the static performance of gas journal bearing,in which rotation speed term is introduced into the stiffness matrix of linear triangular element to realize the performance calculation of the bearing with rotation *** results indicate that the average gas film thicknesses corresponding to the maximum load capac-ity and stiffness,and the minimum attitude angle increase with the growth of orifice *** capacity and stiffness significantly improved with the increase of rotation speed,eccentricity ratio and supply pressure when the bearing has thin average gas film *** angle increases with the growth of rotation speed,while the growth rate slows down or even decreases at high *** most effective way of reducing attitude angle is to increase supply *** can be found that rotation speed affects attitude angle through changing gas pressure difference between two orifices,while other parameters have the same effect by changing gas pressure at orifice outlet.

关键词： Finite element method(FEM) Gas journal bearing Stiffness matrix Attitude angle

Coordinated Capacitor Voltage Balancing Method for Cascaded H-bridge Inverter with Supercapacitor and DC-DC Stage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CES Transactions on Electrical Machines and Systems 2024年第2期8卷 191-201页

作者： Ye Zhang Zixin Li Fanqiang gao cong Zhao Yaohua Li IEEE Key Laboratory of High Density Electromagnetic Power and Systems(Chinese Academy of Sciences) Institute of Electrical EngineeringChinese Academy of SciencesHaidian District University of Chinese Academy of Sciences Shijingshan District

Cascaded H-bridge inverter(CHBI) with supercapacitors(SCs) and dc-dc stage shows significant promise for medium to high voltage energy storage applications. This paper investigates the voltage balance of capacitors within the CHBI, including both the dc-link capacitors and SCs. Balance control over the dc-link capacitor voltages is realized by the dcdc stage in each submodule(SM), while a hybrid modulation strategy(HMS) is implemented in the H-bridge to balance the SC voltages among the SMs. Meanwhile, the dc-link voltage fluctuations are analyzed under the HMS. A virtual voltage variable is introduced to coordinate the balancing of dc-link capacitor voltages and SC voltages. Compared to the balancing method that solely considers the SC voltages, the presented method reduces the dc-link voltage fluctuations without affecting the voltage balance of SCs. Finally, both simulation and experimental results verify the effectiveness of the presented method.

关键词： Cascaded H-bridge inverter(CHBI) Hybrid modulation strategy(HMS) Capacitor voltage balancing DClink voltage fluctuation Supercapacitor(SC)

Real-time Operation Optimization in Active Distribution Networks Based on Multi-agent Deep Reinforcement Learning

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 886-899页

作者： jie Xu Hongjun gao Renjun Wang Junyong Liu the College of Electrical Engineering Sichuan UniversityChengduChina

The increasing integration of intermittent renewable energy sources(RESs)poses great challenges to active distribution networks(ADNs),such as frequent voltage *** paper proposes a novel ADN strategy based on multiagent deep reinforcement learning(MADRL),which harnesses the regulating function of switch state transitions for the realtime voltage regulation and loss *** deploying the calculated optimal switch topologies,the distribution network operator will dynamically adjust the distributed energy resources(DERs)to enhance the operation performance of ADNs based on the policies trained by the MADRL *** to the model-free characteristics and the generalization of deep reinforcement learning,the proposed strategy can still achieve optimization objectives even when applied to similar but unseen ***,integrating parameter sharing(PS)and prioritized experience replay(PER)mechanisms substantially improves the strategic performance and *** framework has been tested on modified IEEE 33-bus,IEEE 118-bus,and three-phase unbalanced 123-bus *** results demonstrate the significant real-time regulation capabilities of the proposed strategy.

关键词： Reconfiguration active distribution network distributed energy resource real-time control deep reinforcement learning parameter sharing scalability

Projected changes in Köppen-Trewartha climate zones under 1.5-4℃global warming targets over mid-high latitudes of Northern Asia using an ensemble of RegCM4 simulations

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第2期15卷 185-196页

作者： jie WU Xue-jie gao Xian-Bing TANG Filippo GIORGI School of Geography and Environmental Engineering Gannan Normal UniversityGanzhou 341000China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China The Abdus Salam International Centre for Theoretical Physics Trieste 34100Italy

Mid-high latitude Northern Asia is one of the most vulnerable and sensitive areas to global warming,but relatively less studied *** used an ensemble of a regional climate model(RegCM4)projections to assess future changes in surface air temperature,precipitation and Köppen-Trewartha(K-T)climate types in Northern Asia under the 1.5-4℃global warming ***4 is driven by five CMIP5 global models over an East Asia domain at a grid spacing of 25 *** of the present day(1986-2005)simulations shows that the ensembles of RegCM4(ensR)and driving GCMs(ensG)reproduce the major characters of the observed temperature,precipitation and K-T climate zones reasonably *** and more realistic spatial detail is found in RegCM4 compared to the driving GCMs.A general warming and overall increases in precipitation are projected over the region,with these changes being more pronounced at higher warming *** projected warming by ensR shows different spatial patterns,and is in general lower,compared to ensG in most months of the year,while the percentage increases of precipitation are maximum during the cold *** future changes in K-T climate zones are characterized by a substantial expansion of Dc(temperature oceanic)and retreat of Ec(sub-arctic continental)over the region,reaching∼20%under the 4℃warming *** most notable change in climate types in ensR is found over Japan(∼60%),followed by Southern Siberia,Mongolia,and the Korean Peninsula(∼40%).The largest change in the K-T climate types is found when increasing from 2 to 3℃.The results will help to better assess the impacts of climate change and in implementation of appropriate adaptation measures over the region.

关键词： Mid-high latitudes of Northern Asia Köppen climate zones Global warming targets Regional climate model