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Tracing the impact of stack configuration on interface resistances in reverse electrodialysis by in situ electrochemical impedance spectroscopy

《环境科学与工程前沿（英文）》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1480-9

摘要：

• RED performance and stack resistance were studied by EIS and LSV.

关键词： Reverse electrodialysis     Electrochemical impedance spectroscopy     Concentration polarization     Spacer shadow effect    

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Removal of Ni(II) ions from wastewater by micellar enhanced ultrafiltration using mixed surfactants

Amar D. Vibhandik, Kumudini V. Marathe

《化学科学与工程前沿（英文）》 2014年 第8卷 第1期   页码 79-86 doi: 10.1007/s11705-014-1407-0

摘要： Ni(II) ions were removed from aqueous waste using micellar enhanced ultrafiltration (MEUF) with a mixture of surfactants. The surfactant mixture was the nonionic surfactant Tween 80 (TW80) mixed with the anionic surfactant sodium dodecyl sulfate (SDS) in different molar ratios ranging from 0.1–1.5. The operational variables of the MEUF process such as pH, applied pressure, surfactant to metal ion ratio and nonionic to ionic surfactant molar ratio (α) were evaluated. Rejection of Ni and TW80 was 99% and 98% respectively whereas that for SDS was 65%. The flux and all resistances (fouling resistance, resistance due to concentration polarization) were measured and calculated for entire range of α respectively. A calculated flux was found to be declined with time, which was mainly attributed to concentration polarization rather than resistance from membrane fouling.

关键词： MEUF     Ni (II) ions     membrane resistance     concentration polarization     mixed surfactants    

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Computational fluid dynamics applied to high temperature hydrogen separation membranes

Guozhao JI, Guoxiong WANG, Kamel HOOMAN, Suresh BHATIA, Jo?o C. DINIZ da COSTA

《化学科学与工程前沿（英文）》 2012年 第6卷 第1期   页码 3-12 doi: 10.1007/s11705-011-1161-5

摘要： This work reviews the development of computational fluid dynamics (CFD) modeling for hydrogen separation, with a focus on high temperature membranes to address industrial requirements in terms of membrane systems as contactors, or in membrane reactor arrangements. CFD modeling of membranes attracts interesting challenges as the membrane provides a discontinuity of flow, and therefore cannot be solved by the Navier-Stokes equations. To address this problem, the concept of source has been introduced to understand gas flows on both sides or domains (feed and permeate) of the membrane. This is an important solution, as the gas flow and concentrations in the permeate domain are intrinsically affected by the gas flow and concentrations in the feed domain and vice-versa. In turn, the source term will depend on the membrane used, as different membrane materials comply with different transport mechanisms, in addition to varying gas selectivity and fluxes. This work also addresses concentration polarization, a common effect in membrane systems, though its significance is dependent upon the performance of the membrane coupled with the operating conditions. Finally, CFD modeling is shifting from simplified single gas simulation to industrial gas mixtures, when the mathematical treatment becomes more complex.

关键词： membrane     gas separation     computational fluid dynamics     concentration polarization     hydrogen    

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Spin polarization strategy to deploy proton resource over atomic-level metal sites for highly selective

《化学科学与工程前沿（英文）》 2022年 第16卷 第12期   页码 1772-1781 doi: 10.1007/s11705-022-2197-4

摘要： Unlocking of the extremely inert C=O bond during electrochemical CO2 reduction demands subtle regulation on a key “resource”, protons, necessary for intermediate conversion but also readily trapped in water splitting, which is still challenging for developing efficient single-atom catalysts limited by their structural simplicity usually incompetent to handle this task. Incorporation of extra functional units should be viable. Herein, a proton deployment strategy is demonstrated via “atomic and nanostructured iron (A/N-Fe) pairs”, comprising atomically dispersed iron active centers spin-polarized by nanostructured iron carbide ferromagnets, to boost the critical protonation steps. The as-designed catalyst displays a broad window (300 mV) for CO selectivity > 90% (98% maximum), even outperforming numerous cutting-edge M–N–C systems. The well-placed control of proton dynamics by A/N-Fe can promote *COOH/*CO formation and simultaneously suppress H2 evolution, benefiting from the magnetic-proximity-induced exchange splitting (spin polarization) that properly adjusts energy levels of the Fe sites’ d-shells, and further those of the adsorbed intermediates’ antibonding molecular orbitals.

关键词： CO2 electrolysis     single-atom catalysts     spin polarization     proton dynamics     in situ IR spectroscopy     kinetic isotope effect    

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Stress induced polarization switching and coupled hysteretic dynamics in ferroelectric materials

Linxiang WANG, Roderick MELNIK, Fuzai LV

《机械工程前沿（英文）》 2011年 第6卷 第3期   页码 287-291 doi: 10.1007/s11465-011-0230-2

摘要：

The dynamic responses of ferroelectric materials upon external mechanical and electrical stimulations are inherently nonlinear and coupled. In the current paper, a macroscopic differential model is constructed for the coupled hysteretic dynamics via modeling the orientation switching induced in the materials. A non-convex potential energy is constructed with both mechanic and electric field contributions. The governing equations are formulated as nonlinear ordinary differential equations by employing the Euler-Lagrange equation, and can be easily recast into a state space form. Hysteresis loops associated with stress induced polarization switching and butterfly-shaped behavior in ferroelectric materials are also successfully captured. The effects of mechanical loadings on the electrically induced switching are numerically investigated, as well as the mechanically-induced switching with various bias electric fields.

关键词： differential model     state space     electromechanical switching     butterfly effects     hysteresis    

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Localized high-concentration electrolytes for lithium metal batteries: progress and prospect

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1354-1371 doi: 10.1007/s11705-022-2286-4

摘要： With the increasing development of digital devices and electric vehicles, high energy-density rechargeable batteries are strongly required. As one of the most promising anode materials with an ultrahigh specific capacity and extremely low electrode potential, lithium metal is greatly considered an ideal candidate for next-generation battery systems. Nevertheless, limited Coulombic efficiency and potential safety risks severely hinder the practical applications of lithium metal batteries due to the inevitable growth of lithium dendrites and poor interface stability. Tremendous efforts have been explored to address these challenges, mainly focusing on the design of novel electrolytes. Here, we provide an overview of the recent developments of localized high-concentration electrolytes in lithium metal batteries. Firstly, the solvation structures and physicochemical properties of localized high-concentration electrolytes are analyzed. Then, the developments of localized high-concentration electrolytes to suppress the formation of dendritic lithium, broaden the voltage window of electrolytes, enhance safety, and render low-temperature operation for robust lithium metal batteries are discussed. Lastly, the remaining challenges and further possible research directions for localized high-concentration electrolytes are outlined, which can promisingly render the practical applications of lithium metal batteries.

关键词： high-concentration electrolyte     localized high-concentration electrolyte     lithium metal battery     solid electrolyte interphase     dendrite    

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PM concentration declining saves health expenditure in China

《环境科学与工程前沿（英文）》 2023年 第17卷 第7期 doi: 10.1007/s11783-023-1690-4

摘要：

● Monthly hospitalization expenses are sensitive to increases in PM2.5 exposure.

关键词： Air pollution     Health expenditure     PM2.5 concentration     Economic impact     Heterogeneous effect    

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Kinetics of enhanced adsorption by polarization for organic pollutants on activated carbon fiber

HAN Yanhe, QUAN Xie, ZHAO Huimin, CHEN Shuo, ZHAO Yazhi

《环境科学与工程前沿（英文）》 2007年 第1卷 第1期   页码 83-88 doi: 10.1007/s11783-007-0016-2

摘要： The adsorption kinetics for model pollutants on activated carbon fiber (ACF) by polarization was investigated in this work. Kinetics data obtained for the adsorption of these model pollutants at open-circuit, 400 mV, and -400 mV polarization were applied to the Lagergren equation, and adsorption rate constants () were determined. With the anodic polarization of 400 mV, the capacity of sodium phenoxide was increased from 0.0083 mmol/g at open-circuit to 0.18 mmol/g, and a 17-fold enhancement was achieved; however, the capacity of -nitrophenol was decreased from 2.93 mmol/g at open-circuit to 2.65 mmol/g. With the cathodal polarization of -400 mV, the capacity of aniline was improved from 3.60 mmol/g at open-circuit to 3.88 mmol/g; however, the capacity of sodium dodecylbenzene sulfonate was reduced from 2.20 mmol/g at open-circuit to 1.59 mmol/g. The enhancement for electrosorption changed with dif ferent groups substituting. Anodic polarization enhances the adsorption of benzene with the electron-donating group. But whether anodic or not, cathodal polarization had less effect on the adsorption of electron-accepting aromatic compounds, and decreased the adsorption capacity of benzene-bearing donor-conjugate bridge-acceptor, while increasing its adsorption rate. Electrostatic interaction played a very important role in the electrosorption of ion-pollutants.

关键词： ACF     activated     17-fold enhancement     donor-conjugate bridge-acceptor     Electrostatic interaction    

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Dynamic modulation performance of ferroelectric liquid crystal polarization rotators and Mueller matrix

Song ZHANG, Lelun WANG, Anze YI, Honggang GU, Xiuguo CHEN, Hao JIANG, Shiyuan LIU

《机械工程前沿（英文）》 2020年 第15卷 第2期   页码 256-264 doi: 10.1007/s11465-019-0573-7

摘要： A ferroelectric liquid crystal polarization rotator (FLCPR) has been widely used in polarization measurement due to its fast and stable modulation characteristics. The accurate characterization of the modulation performance of FLCPR directly affects the measurement accuracy of the instrument based on liquid crystal modulation. In this study, FLCPR is accurately characterized using a self-developed high-speed Stokes polarimeter. Strong linear and weak circular birefringence are observed during modulation processes, and all the optical parameters of FLCPR are dependent on driving voltage. A dual FLCPR-based Mueller matrix polarimeter is designed on the basis of the Stokes polarimeter. The designed polarimeter combines the advantages of the high modulation frequency of FLCPR and the ultrahigh temporal resolution of the fast polarization measurement system in the Stokes polarimeter. The optimal configuration of the designed polarizer is predicted in accordance with singular value decomposition. A simulated thickness measurement of a 24 nm standard SiO thin film is performed using the optimal configuration. Results show that the relative error in thickness measurement caused by using the unsatisfactory modulation characteristics of FLCPR reaches up to −4.34%. This finding demonstrates the importance of the accurate characterization of FLCPR in developing a Mueller matrix polarizer.

关键词： ferroelectric liquid crystal polarization rotator (FLCPR)     dual liquid crystal Mueller matrix polarizer     design and optimization    

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Spontaneous polarization enhanced bismuth ferrate photoelectrode: fabrication and boosted photoelectrochemical

《能源前沿（英文）》 2021年 第15卷 第3期   页码 781-790 doi: 10.1007/s11708-021-0782-8

摘要： In this paper, the fabrication of a highly orientated Bi2Fe4O9 (BFO) photoelectrode in the presence of two-dimensional (2D) graphene oxide (GO) was reported. It was found that the GO can be used as a template for controlling the growth of BFO, and the nanoplate composites of BFO/reduced graphene oxide (RGO) with a high orientation can be fabricated. The thickness of the nanoplates became thinner as the ratio of GO increased. As a result, the ferroelectric spontaneous polarization unit arranges itself in the space in a periodic manner, leading to the formation of a polarization field along a special direction. Therefore, the created built-in electric field of the nanoplate composites of BFO/RGO is improved upon the increase of the amount of RGO. As expected, carrier separation is enhanced by the built-in electric field, therefore substantially enhancing the photoelectrochemical (PEC) activity of water splitting compared to pure BFO under the irradiation of visible-light.

关键词： bismuth ferrate     ferroelectric polarisation     photoelectrochemical (PEC) water splitting     graphene oxide (GO)     high orientation    

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极限工程——产品开发和制造中的极化

Andrew Kusiak

《工程（英文）》 2021年 第7卷 第3期   页码 282-284 doi: 10.1016/j.eng.2020.01.012

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Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 595-608 doi: 10.1007/s11709-021-0720-1

摘要： The effective notch stress approach for evaluating the fatigue strength of rib–deck welds requires notch stress concentration factors obtained from complex finite element analysis. To improve the efficiency of the approach, the notch stress concentration factors for three typical fatigue-cracking modes (i.e., root–toe, root–deck, and toe–deck cracking modes) were thoroughly investigated in this study. First, we developed a model for investigating the effective notch stress in rib–deck welds. Then, we performed a parametric analysis to investigate the effects of multiple geometric parameters of a rib–deck weld on the notch stress concentration factors. On this basis, the multiple linear stepwise regression analysis was performed to obtain the optimal regression functions for predicting the notch stress concentration factors. Finally, we employed the proposed formulas in a case study. The notch stress concentration factors estimated from the developed formulas show agree well with the finite element analysis results. The results of the case study demonstrate the feasibility and reliability of the proposed formulas. It also shows that the fatigue design curve of FAT225 seems to be conservative for evaluating the fatigue strength of rib–deck welds.

关键词： notch stress concentration factor     rib–deck weld     parametric analysis     regression analysis     parametric equation    

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Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

《化学科学与工程前沿（英文）》 2020年 第14卷 第6期   页码 1065-1071 doi: 10.1007/s11705-019-1909-x

摘要： Micro-arc oxidation (MAO) is an efficient approach to improve the hardness, wear resistance, and other properties of aluminum alloys. In order to investigate the effect of the electrolyte concentration on the properties of MAO coatings for LY12 alloy, the voltage variation during the MAO process was recorded. The surface morphologies and phase compositions of the coatings produced with different electrolytes were investigated using scanning electron microscopy and X-ray diffraction, respectively. The roughness and thickness of the coatings were measured using a pocket roughness meter and an eddy-current thickness meter, respectively. The tribological performances of the coatings were investigated against GCr15 bearing steel on a ball-on-disc wear tester in open air. The results showed that with an increase in the Na SiO content, the working voltage of the MAO process decreased, the roughness and thickness of the coatings increased significantly, and the relative content of the -Al O phase decreased. With an increase in the KOH content, the working voltage decreased slightly, the roughness and thickness of the coatings increased slightly, and the α- and -Al O phase contents remained unchanged. The friction coefficient and wear rate of the coatings increased with an increase in the Na SiO and KOH concentrations. A decrease in the porosity and roughness and an increase in the α-Al O content of the coatings reduced their wear mass loss.

关键词： aluminum alloy     micro-arc oxidation     coating     electrolyte concentration     tribological performance    

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Self-supported copper-based gas diffusion electrodes improve the local CO concentration for efficient

《化学科学与工程前沿（英文）》 2024年 第18卷 第3期 doi: 10.1007/s11705-024-2392-6

摘要： Electrochemical CO2 reduction is a sustainable approach in green chemistry that enables the production of valuable chemicals and fuels while mitigating the environmental impact associated with CO2 emissions. Despite its several advantages, this technology suffers from an intrinsically low CO2 solubility in aqueous solutions, resulting in a lower local CO2 concentration near the electrode, which yields lower current densities and restricts product selectivity. Gas diffusion electrodes (GDEs), particularly those with tubular architectures, can solve these issues by increasing the local CO2 concentration and triple-phase interface, providing abundant electroactive sites to achieve superior reaction rates. In this study, robust and self-supported Cu flow-through gas diffusion electrodes (FTGDEs) were synthesized for efficient formate production via electrochemical CO2 reduction. They were further compared with traditional Cu electrodes, and it was found that higher local CO2 concentration due to improved mass transfer, the abundant surface area available for the generation of the triple-phase interface, and the porous structure of Cu FTGDEs enabled high formate Faradaic efficiency (76%) and current density (265 mA·cm–2) at –0.9 V vs. reversible hydrogen electrode (RHE) in 0.5 mol·L–1 KHCO3. The combined phase inversion and calcination process of the Cu FTGDEs helped maintain a stable operation for several hours. The catalytic performance of the Cu FTGDEs was further investigated in a non-gas diffusion configuration to demonstrate the impact of local gas concentration on the activity and performance of electrochemical CO2 reduction. This study demonstrates the potential of flow-through gas-diffusion electrodes to enhance reaction kinetics for the highly efficient and selective reduction of CO2, offering promising applications in sustainable electrochemical processes.

关键词： CO2 electroreduction     flow-through delivery     hollow fiber structure     local concentration     formate    

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Diagnostic evaluation of plasma aldosterone concentration to plasma renin activity ratio in primary aldosteronism

ZHANG Huilan, WANG Daowen

《医学前沿（英文）》 2008年 第2卷 第1期   页码 11-14 doi: 10.1007/s11684-008-0003-4

摘要： Using the plasma aldosterone concentration to plasma renin activity ratio (PAC/PRA ratio) as the screening test of choice for primary aldosteronism in hypertensive patients, we studied the clinical characteristics and the diagnostic value of PAC/PRA ratio in primary aldosteronism. The plasma aldosterone concentration (PAC) and plasma renin activity (PRA) levels were measured by radioimmunoassay in 902 hypertensive patients from out-patient clinics or hospitals. One hundred and twenty-six suspected primary aldosteronism patients whose PAC/PRA ratio was > 25 ng/dL/ng/mL/hr had a lamellar computed tomography (CT) scan in the adrenal gland and follow-up visits. The proportion of primary aldosteronism in hypertensive patients was 14% (126/902). There were 54 patients with unilateral or bilateral hyperplasia and 25 patients with adenoma according to the CT scan. 39% (49/126) of the patients with primary aldosteronism had hypokalemia. Twenty-five patients received surgical treatment. The efficacy and cure rates were 100% (25/25) and 48% (12/25), respectively. The effective rate of aldactone and the single-drug cure rate were 89% (48/54) and 24% (13/54), respectively. Primary aldosteronism affects over 10% of hypertensive patients in China. The PAC/PRA ratio can be considered as a routine screening test in hypertensives, especially resistant hypertensive patients and a high PAC/PRA ratio is an invaluable index in primary aldosteronism diagnosis.
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标题 作者 时间 类型 操作

Tracing the impact of stack configuration on interface resistances in reverse electrodialysis by in situ electrochemical impedance spectroscopy

期刊论文

Removal of Ni(II) ions from wastewater by micellar enhanced ultrafiltration using mixed surfactants

Amar D. Vibhandik, Kumudini V. Marathe

期刊论文

Computational fluid dynamics applied to high temperature hydrogen separation membranes

Guozhao JI, Guoxiong WANG, Kamel HOOMAN, Suresh BHATIA, Jo?o C. DINIZ da COSTA

期刊论文

Spin polarization strategy to deploy proton resource over atomic-level metal sites for highly selective

期刊论文

Stress induced polarization switching and coupled hysteretic dynamics in ferroelectric materials

Linxiang WANG, Roderick MELNIK, Fuzai LV

期刊论文

Localized high-concentration electrolytes for lithium metal batteries: progress and prospect

期刊论文

PM concentration declining saves health expenditure in China

期刊论文

Kinetics of enhanced adsorption by polarization for organic pollutants on activated carbon fiber

HAN Yanhe, QUAN Xie, ZHAO Huimin, CHEN Shuo, ZHAO Yazhi

期刊论文

Dynamic modulation performance of ferroelectric liquid crystal polarization rotators and Mueller matrix

Song ZHANG, Lelun WANG, Anze YI, Honggang GU, Xiuguo CHEN, Hao JIANG, Shiyuan LIU

期刊论文

Spontaneous polarization enhanced bismuth ferrate photoelectrode: fabrication and boosted photoelectrochemical

期刊论文

极限工程——产品开发和制造中的极化

Andrew Kusiak

期刊论文

Parametric equations for notch stress concentration factors of rib–deck welds under bending loading

期刊论文

Effect of electrolyte concentration on the tribological performance of MAO coatings on aluminum alloys

Chao Wang, Jun Chen, Jihua He, Jing Jiang, Qinyong Zhang

期刊论文

Self-supported copper-based gas diffusion electrodes improve the local CO concentration for efficient

期刊论文

Diagnostic evaluation of plasma aldosterone concentration to plasma renin activity ratio in primary aldosteronism

ZHANG Huilan, WANG Daowen

期刊论文