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On the fouling mechanism of polysulfone ultrafiltration membrane in the treatment of coal gasification wastewater

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Frontiers of Chemical Science and Engineering 2016年第4期10卷 490-498页

作者： Xue zou Jin Li School of Civil Engineering Beijing Jiaotong University Beijing 100044 China College of Architectural Engineering North China University of Technology Beijing 100144 China

Membrane fouling has been investigated by using a polysulfone ultrafiltration membrane with the molecular weight cutoff of 20 kDa to treat crushed coal pressurized gasification wastewater. Under the conditions of different feed pressures, the permeate flux declines and rejection coefficients of pollutants referring to three parameters （total organic carbon （TOC）, chroma and turbidity） were studied. The membrane fouling mechanism was simulated with three classical membrane fouling models. The membrane image and pollutants were analyzed by scanning electron microscopy and gas chromatography-mass spectrography （GC-MS）. The results indicate that the permeate flux decreases with volume reduction factor before reaching a constant value. The rejection coefficients were also measured： fTOC = 70.5%,fc = 84.9% andfa- = 91%. Further analysis shows that the higher the feed pressure is, the sooner the permeate flux reaches constant value and the more sharply the permeate flux declines. Constant flux indicates a nonlinear growth with feed pressure （PF）： when Pr equals 1.2 bar, the mark for the critical flux, slight membrane fouling occurs; when PF exceeds 1.2 bar, cake layer pollution aggravates. Also the rejection coefficients of global pollutant increases slightly with PF, suggesting the possibility of cake compression when PF exceeds 1.2 bar. Through regression analysis, the fouling of polysulfone ultrafiltration membrane could be fitted very well by cake filtration model. The membrane pollutants were identified as phthalate esters and long-chain alkenes by GC-MS, and a certain amount of inorganic pollutants by X-ray photoelectron spectroscopy.

关键词： membrane fouling ultrafiltration membrane,coal gasification wastewater rejection coefficient

The “twinkling star” materials: highly superior molecular switches for bioimaging

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Science China Chemistry 2019年第6期62卷 657-658页

作者： Qi zou Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power Shanghai University of Electric Power

Artificial molecular switches have been the robust tools for diverse fields of modern science and technology, including molecular machines, smart materials, and bioimaging [1]. The development of new concepts to enable the creation of efficient molecular switches has been a longstanding activity in these fields. Up to date, various kinds of molecular switches have been developed, most of which work between two or more stable states, and the rest of them requires at least an additional energy or chemical stimuli.

关键词： molecular development states

Discussion on the geometric factor in the detection of high energy electrons in geospace

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Science China(Technological Sciences) 2008年第1期51卷 1-9页

作者： CHEN HongFei SHI WeiHong zou Hong zou JiQing Institute of Space Physics and Applied Technology School of Earth and Space SciencesPeking UniversityBeijing 100871China

High energy electron is a kind of sources to be detected in the geospace environ- ment. Generally, the particle telescope with much thick semiconductor detector is used as the sensor for energetic electrons because they can penetrate deeply into the detector. The more energy of the electrons is, the deeper they can penetrate into, so that the geometric factor varies with energy of the incident electrons. We discuss the geometric factor of particle radiation detector (PRD), which is a payload on ZY-1 (CBERS-1 and CBERS-2) satellites to monitor the high energy particle ra- diation inside the satellites. According to the NASA’s AE8 model, the geometric factors of electrons for the low energy bin (0.5―1.0 MeV) and the high energy bin (> 2.0 MeV) are 2.468 and 1.736 cm2·sr, respectively. These results are much differ- ent from the traditional calculation of the geometric factor that is 1.18 cm2·sr. The angle-response function of the telescope is also derived, which can be useful for design of the telescope and analysis of the directional distribution.

关键词： geometric factor high energy electrons particle radiation space exploration

Solidification segregation behavior of Nb-containing 310S steel

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Journal of Iron and Steel Research International 2023年第1期30卷 82-87页

作者： Yu-tuo Zhang Hao zou School of Materials Science and Engineering Shenyang Ligong UniversityShenyang 110159LiaoningChina Institute of Metal Research Chinese Academy of SciencesShenyang 110016LiaoningChina

The solidification characteristics and segregation behavior of solute elements Nb,Ni,Mn,Si,Cr and C in 0.3 wt.%Nb-310S steel were investigated using the isothermal solidification quenching experiment and Thermo-Calc *** phase transformation for 0.3%Nb-310S steel under equilibrium condition can be summarized as follows:liquid(L)→L+γ(1406℃)→γ(1334℃)→γ+NbC(1322℃)→γ+NbC+M_(23)C_(6)(1006℃)→γ+NbC+M_(23)C_(6)→σ(755℃).The results showed that the solidification began with the formation of primary austenite *** volume fraction of the liquid phase decreased rapidly as the temperature decreased in the initial solidification stage,and then,the liquid phase fraction decreased *** austenite formed,Mn and Ni were enriched in the solid phase,while Nb and C were rejected into the *** was present the highest segregation coefficient in 0.3%Nb-310S austenitic stainless *** segregation of Nb was the most serious,followed by Mn,Ni and *** and Si exhibited slight segregation during the *** solidification was terminated by the formation of NbC phase.

关键词： 310S steel Nb Solidification Segregation Thermo-Calc calculation

Research on polarization of oil spill and detection

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Acta Oceanologica Sinica 2016年第3期35卷 84-89页

作者： CAI Yang zou Yarong LIANG Chao zou Bin South China Sea Forecast Center State Oceanic Administration Guangzhou 510310 China National Satellite Ocean Application Services Beijing 100081 China Key Laboratory of Space Ocean Remote Sensing and Application State Oceamic Administration Beijing 100081 China

The SAR（Synthetic Aperture Radar） has the capabilities for all-weather day and night use. In the case of determining the effects of oil spill dumping, the oil spills areas are shown as dark spots in the SAR ***, using SAR data to detect oil spills is becoming progressively popular in operational monitoring, which is useful for oceanic environmental protection and hazard reduction. Research has been conducted on the polarization decomposition and scattering characteristics of oil spills from a scattering matrix using allpolarization of the SAR data, calculation of the polarization parameters, and utilization of the CPD（Co-polarized Phase Difference） of the oil and the sea, in order to extract the oil spill information. This method proves to be effective by combining polarization parameters with the characteristics of oil spill. The results show that when using Bragg, the oil spill backscattering machine with Enopy and a mean scatter α parameter. The oil spill can be successfully identified. However, the parameter mechanism of the oil spill remains unclear. The use of CPD can easily extract oil spill information from the ocean, and the polarization research provides a base for oil spill remote sensing detection.

关键词： oil spill polarization detection SAR

Hydrogel-based optically and mechanically manipulable broadband microwave absorber

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Nano Research 2023年第7期16卷 10175-10182页

作者： Xiqiao Chen Lin Du Guobao Jiang Zhuang Wu Yingchang zou Yanhong zou School of Electronic Information and Electrical Engineering Changsha UniversityChangsha 410022China School of Physics and Electronics Hunan UniversityChangsha 410082China

Microwave absorbers with unique optical and mechanical performance are urgent for complex electromagnetic ***,we demonstrate the mechanically flexible,optically transparent,and microwave-absorbing polyacrylamide(PAM)hydrogel,in which the polar water molecules with high polarization contribute to the efficient microwave attenuation,but the binding between water molecules and PAM will slow down the orientation polarization of polar ***,the dominated dielectric property of water molecules in PAM hydrogel determines that the molecules displacement in polymer mixture is feasible for manipulating ***,by decreasing temperature,the flexible and transparent hydrogel will switch to rigid and opaque state as the phase conversion between amorphous and polycrystal *** constructing structures with such hydrogel,the obtained absorber also exhibits the optical and mechanical switchable properties,covering the effective absorption within 5.7-18 *** work provides an effective method to fabricate optically and mechanically manipulable microwave absorbers for intelligent electromagnetic stealth systems.

关键词： microwave absorption polyacrylamide hydrogel optical properties mechanical properties

Investigation of the application of a magnetic abrasive finishing process using an alternating magnetic field for finishing micro-grooves

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Nanotechnology and Precision Engineering 2021年第3期4卷 12-19页

作者： Huijun Xie Yanhua zou Graduate School of Engineering Utsunomiya University7-1-2YotoUtsunomiyaTochigi 321-8585Japan

A magnetic abrasive finishing process using an alternating magnetic field is proposed for the finishing of complex *** an alternating field,the periodic changes in current will cause the magnetic cluster used as a magnetic brush to fluctuate,which will not only continuously replace the abrasive particles in contact with the workpiece,but also periodically adjust the shape of the magnetic cluster to better fit the surface of the *** this paper,the influence of a combination of alternating and static magnetic fields on the magnetic field in the finishing area is *** feasibility of this process for finishing micro-grooves is *** and experimental measurements show that the combination of alternating and static magnetic fields can retain the advantages of the alternating field while increasing the magnetic flux density in the finishing *** experimental results show that the process is feasible for finishing micro-grooves,with an excellent deburring effect on the groove edges.

关键词： Alternating magnetic field Complex surface Deburring Magnetic abrasive finishing Micro-groove

A Note on Supersaturated Design

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Acta Mathematicae Applicatae Sinica 2022年第3期38卷 729-739页

作者： Na zou Hong QIN School of Statistics and Mathematics Zhongnan University of Economics and LawWuhan 430073China Faculty of Mathematics and Statistics Central China Normal UniversityWuhan 430079China

Supersaturated designs are common choice for screening *** paper studies the properties of supersaturated *** give new lower bounds of E(s^(2))-criterion and E(f_(NOD))-*** linkages between the combined/double design and its original design are firstly provided,and the lower bounds of E(s^(2)) and E(f_(NOD)) for the combined/double design are also ***,the close relationship between the minimum Lee-moment aberration criterion and the criteria for optimal supersaturated designs is *** theoretical results can be used to construct or search for optimal supersaturated designs in *** results are also provided,which lend further support to our theoretical findings.

关键词： supersaturated design E(s^(2))-criterion E(f_(NOD))-criterion minimum Lee-moment aberration criterion foldover double

GOES-16 ABI Brightness Temperature Observations Capturing Vortex Rossby Wave Signals during Rapid Intensification of Hurricane Irma(2017)

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Journal of Meteorological Research 2024年第4期38卷 768-783页

作者： Yanyang HU Xiaolei zou Joint Center of Data Assimilation for Research and Application Nanjing University of Information Science&TechnologyNanjing 210044

Geostationary Operational Environmental Satellite-16(GOES-16) Advanced Baseline Imager(ABI) observations of brightness temperature(TB) are used to examine the temporal evolutions of convection-affected structures of Hurricane Irma(2017) during its rapid intensification(RI) period from 0600 to 1800 UTC 4 September *** ABI observations reveal that both an elliptical eye and a spiral rainband that originated from Irma's eyewall obviously exhibit wavenumber-2 TB *** elliptical eye underwent a counterclockwise rotation at a mean speed of a wavenumber-2 vortex Rossby edge wave from 0815 to 1005 UTC 4 *** the following about 2 hours(1025–1255 UTC 4 September),an inner spiral rainband originated from the eyewall and propagated at a phase speed that approximates the vortex Rossby wave(VRW) phase speed calculated from the aircraft reconnaissance *** the RI period of Irma,ABI TB observations show an on–off occurrence of low TB intrusions into the eye,accompanying a phase lock of eyewall TB asymmetries of wavenumbers 1 and 2 and an outward propagation of VRW-like inner spiral rainbands from the *** phase lock leads to an energy growth of Irma's eyewall *** the eye remained clear from 1415 to 1725 UTC 4 September,an inner spiral rainband that originated from a large convective area also had a VRW-like outward propagation,which is probably due to a vertical tilt of *** study suggests a potential link between convection sensitive GOES imager observations and hurricane dynamics.

关键词： Geostationary Operational Environmental Satellite(GOES)imager brightness temperature(TB) hurricane vortex Rossby wave(VRW)