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Visible-light-driven heterostructured g-CN/Bi-TiO floating photocatalyst with enhanced charge carrierseparation for photocatalytic inactivation of

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1417-3

摘要：

• Bi doping in TiO2 enhanced the separation of photo-generated electron-hole.

关键词： Bi doping     Visible light     Algal removal     Charge carrier separation    

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Charge-carrier photogeneration and extraction dynamics of polymer solar cells probed by a transient photocurrentnearby the regime of the space charge-limited current

Boa Jin, Hyunmin Park, Yang Liu, Leijing Liu, Jongdeok An, Wenjing Tian, Chan Im

《化学科学与工程前沿（英文）》 2021年 第15卷 第1期   页码 164-179 doi: 10.1007/s11705-020-1976-z

摘要： To understand the complex behaviors of photogenerated charge carriers within polymer-based bulk-heterojunction-type solar cells, the charge-carrier photogeneration and extraction dynamics are simultaneously estimated using a transient photocurrent technique under various external-bias voltages, and a wide range of excitation intensities are analyzed. For this purpose, conventional devices with 80 nm thick active layers consisting of a blend of representative P3HT and PTB7 electron-donating polymers and proper electron-accepting fullerene derivatives were used. After the correction for the saturation behavior at a high excitation-intensity range nearby the regime of the space charge-limited current, the incident-photon-density-dependent maximum photocurrent densities at the initial peaks are discussed as the proportional measures of the charge-carrier-photogeneration facility. By comparing the total number of the extracted charge carriers to the total number of the incident photons and the number of the initially photogenerated charge carriers, the external quantum efficiencies as well as the extraction quantum efficiencies of the charge-carrier collection during a laser-pulse-induced transient photocurrent process were obtained. Subsequently, the charge-carrier concentration-dependent mobility values were obtained, and they are discussed in consideration of the additional influences of the charge-carrier losses from the device during the charge-carrier extraction that also affects the photocurrent-trace shape.

关键词： charge-carrier photogeneration     transient photocurrent     polymer solar cells     charge-carrier extraction     space charge-limited current    

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Effects of BTA2 as the third component on the charge carrier generation and recombination behavior of

Leijing Liu, Hao Zhang, Bo Xiao, Yang Liu, Bin Xu, Chen Wang, Shanpeng Wen, Erjun Zhou, Gang Chen, Chan Im, Wenjing Tian

《化学科学与工程前沿（英文）》 2021年 第15卷 第1期   页码 127-137 doi: 10.1007/s11705-020-1936-7

摘要： Effects of a benzotriazole (BTA)-based small molecule, BTA2, as the third component on the charge carrier generation and recombination behavior of poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7):[6,6]-phenyl-C -butyric acid methyl ester (PC BM) organic solar cells (OSCs) were investigated by optical simulation of a transfer matrix model (TMM), photo-induced charge extraction by linearly increasing voltage (photo-CELIV) technique, atomic force microscope (AFM), and the Onsager–Braun model analysis. BTA2 is an A A D A A -type non-fullerene small molecule with thiazolidine-2,4-dione, BTA, and indacenodithiophene as the terminal acceptor (A ), bridge acceptor (A ), and central donor (D), respectively. The short-circuit current density of the OSCs with BTA2 can be enhanced significantly owing to a complementary absorption spectrum. The optical simulation of TMM shows that the ternary OSCs exhibit higher internal absorption than the traditional binary OSCs without BTA2, resulting in more photogenerated excitons in the ternary OSCs. The photo-CELIV investigation indicates that the ternary OSCs suffer higher charge trap-limited bimolecular recombination than the binary OSCs. AFM images show that BTA2 aggravates the phase separation between the donor and the acceptor, which is disadvantageous to charge carrier transport. The Onsager-Braun model analysis confirms that despite the charge collection efficiency of the ternary OSCs being lower than that of the binary OSCs, the optimized photon absorption and exciton generation processes of the ternary OSCs achieve an increase in photogenerated current and thus improve power conversion efficiency.

关键词： third component     organic solar cells     charge carrier generation     charge carrier recombination     bimolecular recombination    

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Charge and separation characteristics of nanofiltration membrane embracing dissociated functional groups

Zhun MA,Meng WANG,Xueli GAO,Congjie GAO

《环境科学与工程前沿（英文）》 2014年 第8卷 第5期   页码 650-658 doi: 10.1007/s11783-013-0605-1

摘要： The current work focused on the investigation of charge and separation characteristics of nanofiltration (NF) membrane embracing dissociated functional groups under different electrolyte solutions. The electro-kinetic method was carried out to assess the membrane volume charge density ( ) with different salt concentrations ranging from 0.1 to 10 mol·m and different electrolyte species, such as type 1–1, type 2–1 and type 3–1. The Donnan steric pore model-dielectric exclusion (DSPM-DE) model was employed to evaluate the separation characteristics of the NF membrane for wide range of electrolyte concentration (from 25.7 to 598.9 mol·m ). The results indicated that the dissociation of the hydrophilic functional groups and the specific adsorption contributed to charge formation on membrane surface. The former played a dominant role in type 1–1 and type 2–1 electrolytes at dilute aqueous solutions (0.1–0.5 mol·m ). However, for type 3–1 electrolyte, specific adsorption should contribute to the charge effect to a large extent. Moreover, the correlation between the volume charge density and feed concentration was in accordance with Freundlich isotherm. Furthermore, it was found that the separation characteristic of NF membrane could be evaluated well by DSPM-DE model coupling with electro-kinetic method in a whole concentration range.

关键词： Sulfonated polyethersulfone nanofiltration membrane     charge characteristics     electro-kinetic method     volume charge density     separation behavior    

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Effects of pressure and temperature on fixed-site carrier membrane for CO 2 separation from natural gas

Meng WANG, Dongxiao YANG, Zhi WANG, Jixiao WANG, Shichang WANG,

《化学科学与工程前沿（英文）》 2010年 第4卷 第2期   页码 127-132 doi: 10.1007/s11705-009-0231-4

摘要： In this paper, the effect of testing temperature on the performance of fixed carrier membrane for CO separation were studied. The blend composite membranes were developed respectively with a blend of PEI-PVA (polyetheleneimine-polyvinyl alcohol) as separation layer and PS (polysulfone) ultrafiltration membranes as the substrates. The permselectivity of the membranes was measured with CO/CH mixed gas. The effect of testing temperature on membrane separation performance was investigated. The results showed that both the permeances of CO and CH decreased with the increase of temperature, and the permeances decreased more quickly under low pressure than those under high pressure. At the feed pressure of 0.11MPa, the CO/ CH selectivity of PEI-PVA/PS blend composite membrane reduced along with temperature increment. Under the feed pressure of 0.21MPa, as well as 1.11MPa, the selectivity decreased with the increase of temperature.

关键词： temperature increment     high pressure     permselectivity     separation performance     temperature    

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membranes using SPES as a hydrophilic polymer for the effective removal of dyes via steric hindrance and charge

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1555-1567 doi: 10.1007/s11705-023-2338-4

摘要： Herein, polyethersulfone (PES) and sulfonated polysulfone (SPSf) blend membranes were prepared with addition of sulfonated polyethersulfone (SPES) as a hydrophilic polymer and adipic acid as a porogen via non-solvent induced phase separation method for effective fractionation of dyes based on the influence of steric hindrance and charge effect. Raman spectroscopy and molecular dynamic simulation modeling confirmed that hydrogen bonds between PES, SPSf, SPES, and adipic acid were crucial to membrane formation and spatial arrangement. Further addition of hydrophilic SPES resulted in a membrane with reduced pore size and molecular weight cut-off as well as amplified negative charge and pure water permeance. During separation, the blend membranes exhibited higher rejection rates for nine types of small molecular weight (269.3–800 Da) dyes than for neutral polyethylene glycol molecules (200–1000 Da). This was attributed to the size effect and the synergistic effect between steric hindrance and charge repulsion. Notably, the synergistic impact decreased with dye molecular weight, while greater membrane negative charge enhanced small molecular dye rejection. Ideal operational stability and anti-fouling performance were best observed in M2 (PES/SPSf/SPES, 3.1 wt %). Summarily, this study demonstrates that SPES with –SO3‒ functional groups can be applied to control the microstructure and separation of membranes.

关键词： adipic acid     loose nanofiltration membrane     dye/salt selective separation     steric hindrance     charge effect    

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Review on design and evaluation of environmental photocatalysts

Xin Li, Jun Xie, Chuanjia Jiang, Jiaguo Yu, Pengyi Zhang

《环境科学与工程前沿（英文）》 2018年 第12卷 第5期 doi: 10.1007/s11783-018-1076-1

摘要：

Fundamentals on the photocatalytic degradation were systematically summarized.

Charge carrier dynamics for the photocatalytic degradation were reviewed.

Adsorption and photodegradation kinetics of reactants were highlighted.

The mechanism aspects, including O2 reduction, reactive oxidation species and key intermediates were also addressed.

Selectivity and stability of semiconductors for photodegradation were clarified.

关键词： Photocatalytic degradation     Environmental remediation     Charge carrier dynamics     Reactive oxygen species     O2 reduction    

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Covering α-Fe

Jing Gu, Hongtao Yu, Xie Quan, Shuo Chen

《环境科学与工程前沿（英文）》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0957-z

摘要： The spontaneous oxidation process of pristine silicon (Si) limits its application as photocatalyst or electrode in aqueous solution or moist air. Covering a protection layer on Si surface is an effective approach to overcome this disadvantage. In this paper, α-Fe O is demonstrated to be an excellent alternative as a protection material. α-Fe O layer was deposited around each p-type Si micropillar (SiMP) in well-ordered array by chemical bath deposition method. The diameter of SiMP was 5 mm and the thickness of α-Fe O layer was about 20 nm. The photoeletrochemical stability of SiMP/α-Fe O was proved by 10 circles cyclic voltammetry testing. Compared with SiMP, its optical absorption and photocurrent density improved 2 times and 4 times, respectively, and its onset potential for hydrogen evolution moved positively about 0.4 V. These improved performances could be ascribed to the enhanced photogenerated-charge-separation efficiency deriving from built-in electric field at the interface between Si and α-Fe O . The above results show an effective strategy to utilize Si material as photocatalyst or electrode in aqueous solution or moist air.

关键词： Si     α-Fe2O3     Photoelectrochemistry     Photogenerated charge separation    

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Rational design on photoelectrodes and devices to boost photoelectrochemical performance of solar-driven water splitting: a mini review

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 777-798 doi: 10.1007/s11705-022-2148-0

摘要： As an eco-friendly, efficient, and low-cost technique, photoelectrochemical water splitting has attracted growing interest in the production of clean and sustainable hydrogen by the conversion of abundant solar energy. In the photoelectrochemical system, the photoelectrode plays a vital role in absorbing the energy of sunlight to trigger the water splitting process and the overall efficiency depends largely on the integration and design of photoelectrochemical devices. In recent years, the optimization of photoelectrodes and photoelectrochemical devices to achieve highly efficient hydrogen production has been extensively investigated. In this paper, a concise review of recent advances in the modification of nanostructured photoelectrodes and the design of photoelectrochemical devices is presented. Meanwhile, the general principles of structural and morphological factors in altering the photoelectrochemical performance of photoelectrodes are discussed. Furthermore, the performance indicators and first principles to describe the behaviors of charge carriers are analyzed, which will be of profound guiding significance to increasing the overall efficiency of the photoelectrochemical water splitting system. Finally, current challenges and prospects for an in-depth understanding of reaction mechanisms using advanced characterization technologies and potential strategies for developing novel photoelectrodes and advanced photoelectrochemical water splitting devices are demonstrated.

关键词： photoelectrochemical water splitting     photoelectrodes     hydrogen production     charge separation     catalytic mechanism    

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growth of a-few-layered MoS on CdS nanorod for high efficient photocatalytic H production

《能源前沿（英文）》 2021年 第15卷 第3期   页码 752-759 doi: 10.1007/s11708-021-0779-3

摘要： An ultrathin MoS2 was grown on CdS nanorod by a solid state method using sulfur powder as sulfur source for photocatalytic H2 production. The characterization result reveals that the ultrathin MoS2 nanosheets loaded on CdS has a good contact state. The photoelectrochemical result shows that MoS2 not only are beneficial for charge separation, but also works as active sites, thus enhancing photocatalytic activity. Compared with pure CdS, the photocatalytic activity of MoS2 loaded CdS was significantly improved. The hydrogen evolution rate on m(MoS2): m(CdS) = 1: 50 (m is mass) reaches 542 μmol/h, which is 6 times of that on pure CdS (92 μmol/h). This work provides a new design for photocatalysts with high photocatalytic activities and provides a deeper understanding of the effect of MoS2 on enhancing photocatalytic activity.

关键词： photocatalytic H2 production     CdS     MoS2 cocatalyst     charge separation    

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Cu-doped Bi/Bi2WO6 catalysts for efficient N2 fixation by photocatalysis

《化学科学与工程前沿（英文）》 2023年 第17卷 第10期   页码 1412-1422 doi: 10.1007/s11705-023-2312-1

摘要： In this paper, Cu-doped Bi2WO6 was synthesized via a solvothermal method and applied it in photocatalytic N2 immobilization. Characterization results showed the presence of a small amount of metallic Bi in the photocatalyst, indicating that the synthesized photocatalyst is actually Bi/Cu-Bi2WO6 composite. The doped Cu had a valence state of +2 and most likely substituted the position of Bi3+. The introduced Cu did not affect the metallic Bi content, but mainly influenced the energy band structure of Bi2WO6. The band gap was slightly narrowed, the conduction band was elevated, and the work function was reduced. The reduced work function improved the transfer and separation of charge carriers, which mainly caused the increased photoactivity. The optimized NH3 generation rates of Bi/Cu-Bi2WO6 reached 624 and 243 μmol·L–1·g–1·h–1 under simulated solar and visible light, and these values were approximately 2.8 and 5.9 times higher those of Bi/Bi2WO6, respectively. This research provides a method for improving the photocatalytic N2 fixation and may provide more information on the design and preparation of heteroatom-doped semiconductor photocatalysts for N2-to-NH3 conversion.

关键词： Bi2WO6     Cu doping     work function     photocatalytic N2 fixation     charge separation    

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Multi-objective genetic algorithms based structural optimization and experimental investigation of the planet carrier

Pengxing YI,Lijian DONG,Tielin SHI

《机械工程前沿（英文）》 2014年 第9卷 第4期   页码 354-367 doi: 10.1007/s11465-014-0319-5

摘要：

To improve the dynamic performance and reduce the weight of the planet carrier in wind turbine gearbox, a multi-objective optimization method, which is driven by the maximum deformation, the maximum stress and the minimum mass of the studied part, is proposed by combining the response surface method and genetic algorithms in this paper. Firstly, the design points’ distribution for the design variables of the planet carrier is established with the central composite design (CCD) method. Then, based on the computing results of finite element analysis (FEA), the response surface analysis is conducted to find out the proper sets of design variable values. And a multi-objective genetic algorithm (MOGA) is applied to determine the direction of optimization. As well, this method is applied to design and optimize the planet carrier in a 1.5 MW wind turbine gearbox, the results of which are validated by an experimental modal test. Compared with the original design, the mass and the stress of the optimized planet carrier are respectively reduced by 9.3% and 40%. Consequently, the cost of planet carrier is greatly reduced and its stability is also improved.

关键词： planet carrier     multi-objective optimization     genetic algorithms     wind turbine gearbox     modal experiment    

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Numerical simulation of charge stratifications to improve combustion and NO formation of lean-burn SI

Zhijun PENG ,

《能源前沿（英文）》 2009年 第3卷 第3期   页码 353-358 doi: 10.1007/s11708-009-0035-8

摘要： The influences of charge stratification on spark ignition (SI) engine combustion and NO emission were analyzed using a phenomenological model. The mixture in the cylinder was divided spherically into three parts: a central core with a stoichiometric air-fuel charge, a dilution region without any combustible charge, and a mixing region lying between the core and the dilution region. Three mixture stratification parameters such as the extent of dilution in the mixing region, the extent of combustible charge in the mixing region, and the gradient of stratification in the mixing region were investigated. The results indicate that the extent of combustible charge in the mixing region could reduce in-cylinder NO formation significantly, compared with the extent of dilution in the mixing region. As long as the degree of dilution in the mixing region is within the dilution limit of the combustible charge, the gradient of dilution has little effect on combustion and NO formation.

关键词： charge stratification     SI engine     lean-burn combustion     NO emission    

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Effects of carrier-attached biofilm on oxygen transfer efficiency in a moving bed biofilm reactor

Yanling WEI,Xunfei YIN,Lu QI,Hongchen WANG,Yiwei GONG,Yaqian LUO

《环境科学与工程前沿（英文）》 2016年 第10卷 第3期   页码 569-577 doi: 10.1007/s11783-015-0822-x

摘要： Three laboratory-scale moving bed biofilm reactors (MBBR) with different carrier filling ratios ranging from 40% to 60% were used to study the effects of carrier-attached biofilm on oxygen transfer efficiency. In this study, we evaluated the performance of three MBBRs in degrading chemical oxygen demand and ammonia. The three reactors removed more than 95% of -N at an air flow-rate of 60 L·h . The standard oxygen transfer efficiency (αSOTE) of the three reactors was also investigated at air flow-rates ranging from 60 to 100 L·h . These results were compared to αSOTE of wastewater with a clean carrier (no biofilm attached). Results showed that under these process conditions, αSOTE decreased by approximately 70% as compared to αSOTE of wastewater at a different carrier-filling ratio. This indicated that the biofilm attached to the carrier had a negative effect on αSOTE. Mechanism analysis showed that the main inhibiting effects were related to biofilm flocculants and soluble microbial product (SMP). Biofilm flocs could decrease αSOTE by about 20%, and SMP could decrease αSOTE by 30%–50%.

关键词： carrier     biofilm     oxygen transfer efficiency     moving bed biofilm reactor    

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真实空气中TNT装药爆炸近区冲击波传播特性研究

周丰峻,郑磊,孙云厚,张鏖,夏明

《中国工程科学》 2017年 第19卷 第6期   页码 18-26 doi: 10.15302/J-SSCAE-2017.06.004

摘要：

本文基于点源爆炸理论，建立了面源、线源和点源TNT装药强爆炸解，填补了面源与线源强爆炸解的空白；采用真实空气状态方程进行分析计算，研究了真实空气条件下球形TNT装药爆炸近区冲击波的传播特性。通过算例分析，计算结果与已有文献资料数据吻合较好。本文的研究成果对爆炸力学和防护工程研究起到了重要的参考作用。

关键词： TNT装药爆炸     真实空气状态方程     面源装药     线源装药     点源装药     抗爆防护    

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标题 作者 时间 类型 操作

Visible-light-driven heterostructured g-CN/Bi-TiO floating photocatalyst with enhanced charge carrierseparation for photocatalytic inactivation of

期刊论文

Charge-carrier photogeneration and extraction dynamics of polymer solar cells probed by a transient photocurrentnearby the regime of the space charge-limited current

Boa Jin, Hyunmin Park, Yang Liu, Leijing Liu, Jongdeok An, Wenjing Tian, Chan Im

期刊论文

Effects of BTA2 as the third component on the charge carrier generation and recombination behavior of

Leijing Liu, Hao Zhang, Bo Xiao, Yang Liu, Bin Xu, Chen Wang, Shanpeng Wen, Erjun Zhou, Gang Chen, Chan Im, Wenjing Tian

期刊论文

Charge and separation characteristics of nanofiltration membrane embracing dissociated functional groups

Zhun MA,Meng WANG,Xueli GAO,Congjie GAO

期刊论文

Effects of pressure and temperature on fixed-site carrier membrane for CO 2 separation from natural gas

Meng WANG, Dongxiao YANG, Zhi WANG, Jixiao WANG, Shichang WANG,

期刊论文

membranes using SPES as a hydrophilic polymer for the effective removal of dyes via steric hindrance and charge

期刊论文

Review on design and evaluation of environmental photocatalysts

Xin Li, Jun Xie, Chuanjia Jiang, Jiaguo Yu, Pengyi Zhang

期刊论文

Covering α-Fe

Jing Gu, Hongtao Yu, Xie Quan, Shuo Chen

期刊论文

Rational design on photoelectrodes and devices to boost photoelectrochemical performance of solar-driven water splitting: a mini review

期刊论文

growth of a-few-layered MoS on CdS nanorod for high efficient photocatalytic H production

期刊论文

Cu-doped Bi/Bi2WO6 catalysts for efficient N2 fixation by photocatalysis

期刊论文

Multi-objective genetic algorithms based structural optimization and experimental investigation of the planet carrier

Pengxing YI,Lijian DONG,Tielin SHI

期刊论文

Numerical simulation of charge stratifications to improve combustion and NO formation of lean-burn SI

Zhijun PENG ,

期刊论文

Effects of carrier-attached biofilm on oxygen transfer efficiency in a moving bed biofilm reactor

Yanling WEI,Xunfei YIN,Lu QI,Hongchen WANG,Yiwei GONG,Yaqian LUO

期刊论文

真实空气中TNT装药爆炸近区冲击波传播特性研究

周丰峻,郑磊,孙云厚,张鏖,夏明

期刊论文