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nitrobenzene by the nano-structured Cu catalyst prepared by an electrodeposited method via tuning applied voltage

Yali CHEN,Lu XIONG,Weikang WANG,Xing ZHANG,Hanqing YU

《环境科学与工程前沿(英文)》 2015年 第9卷 第5期   页码 897-904 doi: 10.1007/s11783-015-0782-1

摘要: Pollution caused by toxic nitrobenzene has been a widespread environmental concern. Selective reduction of nitrobenzene to aniline is beneficial to further efficient and cost-effective biologic treatment. Electrochemical reduction is a promising method and Cu-based catalysts have been found to be an efficient cathode material for this purpose. In this work, Cu catalysts with different morphologies were fabricated on Ti plate using a facile electrodepositon method via tuning the applied voltage. The dendritic nano-structured Cu catalysts obtained at high applied voltages exhibited an excellent efficiency and selectivity toward the reduction of nitrobenzene to aniline. Effects of the working potential and initial nitrobenzene concentration on the selective reduction of nitrobenzene to aniline using the Cu/Ti electrode were investigated. A high rate constant of 0.0251 min and 97.1% aniline selectivity were achieved. The fabricated nano-structured Cu catalysts also exhibited good stability. This work provides a facile way to prepare highly efficient, cost-effective, and stable nano-structured electrocatalysts for pollutant reduction.

关键词: nitrobenzene     nano-structured Cu     electro-reduction     voltage-dependent electrodeposition     high selectivity     high stability    

A novel algorithm for frequency dependent modeling of ferrite ring and its optimum design to study VFTO

Mehrdad MAJIDI, Hamid JAVADI, Moein MANBACHI

《能源前沿(英文)》 2014年 第8卷 第1期   页码 90-100 doi: 10.1007/s11708-013-0286-2

摘要: One of the fundamental issues in gas insulated substations (GIS) which has destructive effects on GIS equipment is the very fast transient over-voltages (VFTOs). This paper models a 400/230 kV substation in order to study the effects of VFTO extensively implemented on EMTP-RV. In addition, the application of ferrite rings for suppressing VFTOs is assessed thoroughly. The main advantage of this paper is its new proposed algorithm according to the ferrite ring frequency dependent modeling that is validated with experimental results. This paper examines the effects of three compositions of the ferrite ring on VFTO suppression. Moreover, it estimates the dimension of the ferrite ring based on the SF6 gas insulation withstand and the maximum effect of ferrite rings on VFTO suppression constraint with the COMSOL multiphysics software. Furthermore, it gains VFTO attenuated percentages due to the installation of the ferrite ring in different GIS nodes. Finally, it analyzes the offered VFTO amendment technique in various GIS switching scenarios.

关键词: comsol multiphysics     EMTP-RV     ferrite ring     gas insulated substations (GIS)     transient over-voltage     insulation coordination    

Effects of additive NaI on electrodeposition of Al coatings in AlCl

Tianyu Yao, Haiyan Yang, Kui Wang, Haiyan Jiang, Xiao-Bo Chen, Hezhou Liu, Qudong Wang, Wenjiang Ding

《化学科学与工程前沿(英文)》 2021年 第15卷 第1期   页码 138-147 doi: 10.1007/s11705-020-1935-8

摘要: Effects of NaI as an additive on electrodeposition of Al coatings in AlCl -NaCl-KCl (80-10-10 wt-%) molten salts electrolyte at 150°C were investigated by means of cyclic voltammetry, chronopotentiometry, scanning electron microscopy and X-ray diffraction (XRD). Results reveal that addition of NaI in the electrolyte intensifies cathodic polarization, inhibits growth of Al deposits and increases number density of charged particles. The electrodeposition of Al coatings in the AlCl -NaCl-KCl molten salts electrolyte proceeds via three-dimensional instantaneous nucleation which however exhibits irrelevance with NaI. Galvanostatic deposition results indicate that NaI could facilitate the formation of uniform Al deposits. A compact coating consisting of Al deposits with an average particle size of 3 μm was obtained at a current density of 50 mA∙cm in AlCl -NaCl-KCl molten salts electrolyte with 10 wt-% NaI. XRD analysis confirmed that NaI could contribute to the formation of Al coating with a preferred crystallographic orientation along (220) plane.

关键词: NaI     additive     electrodeposition     molten salts     Al coating    

Data-driven approach to solve vertical drain under time-dependent loading

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 696-711 doi: 10.1007/s11709-021-0727-7

摘要: Currently, the vertical drain consolidation problem is solved by numerous analytical solutions, such as time-dependent solutions and linear or parabolic radial drainage in the smear zone, and no artificial intelligence (AI) approach has been applied. Thus, in this study, a new hybrid model based on deep neural networks (DNNs), particle swarm optimization (PSO), and genetic algorithms (GAs) is proposed to solve this problem. The DNN can effectively simulate any sophisticated equation, and the PSO and GA can optimize the selected DNN and improve the performance of the prediction model. In the present study, analytical solutions to vertical drains in the literature are incorporated into the DNN–PSO and DNN–GA prediction models with three different radial drainage patterns in the smear zone under time-dependent loading. The verification performed with analytical solutions and measurements from three full-scale embankment tests revealed promising applications of the proposed approach.

关键词: vertical drain     artificial neural network     time-dependent loading     deep learning network     genetic algorithm     particle swarm optimization    

Parameter identification of interconnected power system frequency after trip-out of high voltage transmission

Xuzhan ZHOU,Shanshan LIU,Mingkun WANG,Yiping DAI,Yaohua TANG

《能源前沿(英文)》 2014年 第8卷 第3期   页码 386-393 doi: 10.1007/s11708-014-0323-9

摘要: Accurate modeling and parameters of high voltage (HV) grid are critical for stability research of system frequency. In this paper, simulation modeling of the system frequency was conducted of an interconnected power system with HV transmission lines in China. Based on recorded tripping data of the HV transmission lines, system parameters were identified by using genetic algorithm (GA). The favorable agreement between simulation results and recorded data verifies the validity of gird models and the accuracy of system parameters. The results of this paper can provide reference for the stability research of HV power grid.

关键词: high voltage (HV) grid     frequency stability parameter identification     primary frequency regulation (PFR)    

Recent advances toward high voltage, EC-free electrolytes for graphite-based Li-ion battery

Tong Zhang, Elie Paillard

《化学科学与工程前沿(英文)》 2018年 第12卷 第3期   页码 577-591 doi: 10.1007/s11705-018-1758-z

摘要:

Lithium-ion batteries are a key technology in today’s world and improving their performances requires, in many cases, the use of cathodes operating above the anodic stability of state-of-the-art electrolytes based on ethylene carbonate (EC) mixtures. EC, however, is a crucial component of electrolytes, due to its excellent ability to allow graphite anode operation–also required for high energy density batteries–by stabilizing the electrode/electrolyte interface. In the last years, many alternative electrolytes, aiming at allowing high voltage battery operation, have been proposed. However, often, graphite electrode operation is not well demonstrated in these electrolytes. Thus, we review here the high voltage, EC-free alternative electrolytes, focusing on those allowing the steady operation of graphite anodes. This review covers electrolyte compositions, with the widespread use of additives, the change in main lithium salt, the effect of anion (or Li salt) concentration, but also reports on graphite protection strategies, by coatings or artificial solid electrolyte interphase (SEI) or by use of water-soluble binder for electrode processing as these can also enable the use of graphite in electrolytes with suboptimal intrinsic SEI formation ability.

关键词: lithium-ion     electrolyte     solid electrolyte interphase     additives     high voltage     graphite    

Analysis and stabilization control of a voltage source controlled wind farm under weak grid conditions

《能源前沿(英文)》 2022年 第16卷 第6期   页码 943-955 doi: 10.1007/s11708-021-0793-5

摘要: This paper investigates and discusses the interaction stability issues of a wind farm with weak grid connections, where the wind turbines (WTs) are controlled by a new type of converter control strategy referred to as the voltage source (VS) control. The primary intention of the VS control method is to achieve the high-quality inertial response capability of a single WT. However, when it is applied to multiple WTs within a wind farm, its weak-grid performance regarding the stability remains concealed and needs to be clarified. To this end, a frequency domain model of the wind farm under the VS control is first developed. Based on this model and the application of a stability margin quantification index, not only the interactions between the wind farm and the weak grid but also those among WTs will be systematically assessed in this paper. A crucial finding is that the inertial response of VS control has negative impacts on the stability margin of the system, and the dominant instability mode is more related to the interactions among the WTs rather than the typical grid-wind farm interaction. Based on this knowledge, a stabilization control strategy is then proposed, aiming for stability improvements of VS control while fulfilling the demand of inertial responses. Finally, all the results are verified by time-domain simulations in power systems computer aided design/electromagnetic transients including DC(PSCAD/EMTDC).

关键词: weak grids     voltage source (VS) control     wind turbine (WT)     stabilization control     wind farm     inertial response    

Development and advances in modular multilevel converter based HVDC projects in China

《工程管理前沿(英文)》   页码 183-189 doi: 10.1007/s42524-022-0248-7

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关键词: high voltage direct current     power converter     power systems     renewable energy     ultra-high voltage    

Chloride binding and time-dependent surface chloride content models for fly ash concrete

S. MUTHULINGAM,B. N. RAO

《结构与土木工程前沿(英文)》 2016年 第10卷 第1期   页码 112-120 doi: 10.1007/s11709-015-0322-x

摘要: Corrosion of embedded rebars is a classical deterioration mechanism of reinforced concrete structures exposed to chloride environments. Such environments can be attributed to the presence of seawater, deicing or sea-salts, which have high concentrations of chloride ion. Chloride ingress into concrete, essential for inducing rebar corrosion, is a complex interaction between many physical and chemical processes. The current study proposes two chloride ingress parameter models for fly ash concrete, namely: 1) surface chloride content under tidal exposure condition; and 2) chloride binding. First, inconsistencies in surface chloride content and chloride binding models reported in literature, due to them not being in line with past research studies, are pointed out. Secondly, to avoid such inconsistencies, surface chloride content and chloride binding models for fly ash concrete are proposed based upon the experimental work done by other researchers. It is observed that, proposed models are simple, consistent and in line with past research studies reported in literature.

关键词: binding isotherms     chloride ingress     concrete     fly ash     surface chloride content    

GDF15 negatively regulates chemosensitivity via TGFBR2-AKT pathway-dependent metabolism in esophageal

《医学前沿(英文)》 2023年 第17卷 第1期   页码 119-131 doi: 10.1007/s11684-022-0949-7

摘要: Treating patients with esophageal squamous cell carcinoma (ESCC) is challenging due to the high chemoresistance. Growth differentiation factor 15 (GDF15) is crucial in the development of various types of tumors and negatively related to the prognosis of ESCC patients according to our previous research. In this study, the link between GDF15 and chemotherapy resistance in ESCC was further explored. The relationship between GDF15 and the chemotherapy response was investigated through in vitro and in vivo studies. ESCC patients with high levels of GDF15 expression showed an inferior chemotherapeutic response. GDF15 improved the tolerance of ESCC cell lines to low-dose cisplatin by regulating AKT phosphorylation via TGFBR2. Through an in vivo study, we further validated that the anti-GDF15 antibody improved the tumor inhibition effect of cisplatin. Metabolomics showed that GDF15 could alter cellular metabolism and enhance the expression of UGT1A. AKT and TGFBR2 inhibition resulted in the reversal of the GDF15-induced expression of UGT1A, indicating that TGFBR2-AKT pathway-dependent metabolic pathways were involved in the resistance of ESCC cells to cisplatin. The present investigation suggests that a high level of GDF15 expression leads to ESCC chemoresistance and that GDF15 can be targeted during chemotherapy, resulting in beneficial therapeutic outcomes.

关键词: GDF15     esophageal squamous cell carcinoma     chemoresistance     cellular metabolism     TGFBR2     AKT    

Cluster voltage control method for “Whole County” distributed photovoltaics based on improved differential

《能源前沿(英文)》   页码 782-795 doi: 10.1007/s11708-023-0905-8

摘要: China is vigorously promoting the “whole county promotion” of distributed photovoltaics (DPVs). However, the high penetration rate of DPVs has brought problems such as voltage violation and power quality degradation to the distribution network, seriously affecting the safety and reliability of the power system. The traditional centralized control method of the distribution network has the problem of low efficiency, which is not practical enough in engineering practice. To address the problems, this paper proposes a cluster voltage control method for distributed photovoltaic grid-connected distribution network. First, it partitions the distribution network into clusters, and different clusters exchange terminal voltage information through a “virtual slack bus.” Then, in each cluster, based on the control strategy of “reactive power compensation first, active power curtailment later,” it employs an improved differential evolution (IDE) algorithm based on Cauchy disturbance to control the voltage. Simulation results in two different distribution systems show that the proposed method not only greatly improves the operational efficiency of the algorithm but also effectively controls the voltage of the distribution network, and maximizes the consumption capacity of DPVs based on qualified voltage.

关键词: distributed photovoltaics (DPVs)     cluster partitioning     improved differential evolution algorithm     voltage control     consumption capacity of distributed photovoltaics    

Analysis of dispatching rules in a stochastic dynamic job shop manufacturing system with sequence-dependent

Pankaj SHARMA,Ajai JAIN

《机械工程前沿(英文)》 2014年 第9卷 第4期   页码 380-389 doi: 10.1007/s11465-014-0315-9

摘要:

Stochastic dynamic job shop scheduling problem with consideration of sequence-dependent setup times are among the most difficult classes of scheduling problems. This paper assesses the performance of nine dispatching rules in such shop from makespan, mean flow time, maximum flow time, mean tardiness, maximum tardiness, number of tardy jobs, total setups and mean setup time performance measures viewpoint. A discrete event simulation model of a stochastic dynamic job shop manufacturing system is developed for investigation purpose. Nine dispatching rules identified from literature are incorporated in the simulation model. The simulation experiments are conducted under due date tightness factor of 3, shop utilization percentage of 90 % and setup times less than processing times. Results indicate that shortest setup time (SIMSET) rule provides the best performance for mean flow time and number of tardy jobs measures. The job with similar setup and modified earliest due date (JMEDD) rule provides the best performance for makespan, maximum flow time, mean tardiness, maximum tardiness, total setups and mean setup time measures.

关键词: scheduling     stochastic dynamic job shop     sequence-dependent setup times     dispatching rule     simulation    

大中功率节能调速传动的合理电压等级

马小亮

《中国工程科学》 2001年 第3卷 第11期   页码 80-84

摘要:

大中功率风机和泵采用变频调速可节约大量电能,大部分功率在0.2~2 MW范围中。我国现在200 kW以上的电机多是中压,现行中压电网多为10 kV,选用10 kV直接变频从技术和经济角度看都不太合理。由于变频器输入侧都有变压器,因此电机和变频器没有必要和电网一致。文章讨论不同功率段的合理电压等级以及在电机电压和电网电压不同情况下当变频器出现故障时如何实现旁路工作。

关键词: 大中功率     节能调速     合理电压等级     低压变频     中压变频     旁路    

power quality conditioner based on a three-level NPC inverter using fuzzy control techniques for all voltage

Salim CHENNAI,M-T BENCHOUIA

《能源前沿(英文)》 2014年 第8卷 第2期   页码 221-239 doi: 10.1007/s11708-014-0317-7

摘要: This paper presents a novel and efficient control scheme for unified power quality conditioner (UPQC) based on three-level neutral point clamped (NPC) inverter using fuzzy logic techniques. The proposed UPQC is capable of mitigating source current harmonics and compensate all voltage disturbances such as voltage sags, swells, unbalances and harmonics. It is designed by the integration of series and shunt active filters (AFs) sharing a common DC bus capacitor. The DC voltage is maintained constant using proportional integral voltage controller. The synchronous reference frame (SRF) theory is used to get the reference signals for shunt active power filters (APFs) and the power reactive theory (p-q theory) for series APFs. The shunt and series APF reference signals derived from the control algorithm and sensed signals are injected in two controllers to generate switching signals. To improve the UPQC capability, fuzzy logic techniques are introduced to control the series APF. The performances of the proposed UPQC system are evaluated in terms of power factor correction, mitigation of voltage or current harmonics and all other voltage disturbances compensation using Matlab-Simulink software and SimPowerSystem toolbox. The simulation results illustrate the performance of the proposed UPQC at the common connection point of the nonlinear load to improve the power energy quality.

关键词: three-level neutral point clamped (NPC) inverter     unified power quality conditioner (UPQC)     current harmonics mitigation     fuzzy logic controller     voltage disturbance compensation     shunt active filter     series active filter     power quality energy improvement    

Experimental study of pollution effect on the behavior of high voltage insulators under alternative current

Hani BENGUESMIA, Nassima M’ZIOU, Ahmed BOUBAKEUR

《能源前沿(英文)》 2021年 第15卷 第1期   页码 213-221 doi: 10.1007/s11708-017-0479-1

摘要: In this paper, the impact of the conductivity and the distribution of pollution on the behavior of the high voltage insulator cap and pin 1512L, artificially polluted is described. An experimental model in form of a disc is proposed. This experimental model reproduces the real model which is the 1512L insulator. Besides, a comparative study is presented. For this comparative study, different solutions are adopted to s`imulate the pollution (containing NaCl+ distilled water) that has different conductivities for a discontinuous distribution of the pollution on the insulator under an AC voltage. Furthermore, the influence of the pollution on the flashover voltage and the leakage current is studied. Finally, the behavior of real and experimental model of the insulator is investigated.

关键词: 1512L insulator     circular model     artificial pollution     flashover     leakage current     discontinuous pollution     high voltage    

标题 作者 时间 类型 操作

nitrobenzene by the nano-structured Cu catalyst prepared by an electrodeposited method via tuning applied voltage

Yali CHEN,Lu XIONG,Weikang WANG,Xing ZHANG,Hanqing YU

期刊论文

A novel algorithm for frequency dependent modeling of ferrite ring and its optimum design to study VFTO

Mehrdad MAJIDI, Hamid JAVADI, Moein MANBACHI

期刊论文

Effects of additive NaI on electrodeposition of Al coatings in AlCl

Tianyu Yao, Haiyan Yang, Kui Wang, Haiyan Jiang, Xiao-Bo Chen, Hezhou Liu, Qudong Wang, Wenjiang Ding

期刊论文

Data-driven approach to solve vertical drain under time-dependent loading

期刊论文

Parameter identification of interconnected power system frequency after trip-out of high voltage transmission

Xuzhan ZHOU,Shanshan LIU,Mingkun WANG,Yiping DAI,Yaohua TANG

期刊论文

Recent advances toward high voltage, EC-free electrolytes for graphite-based Li-ion battery

Tong Zhang, Elie Paillard

期刊论文

Analysis and stabilization control of a voltage source controlled wind farm under weak grid conditions

期刊论文

Development and advances in modular multilevel converter based HVDC projects in China

期刊论文

Chloride binding and time-dependent surface chloride content models for fly ash concrete

S. MUTHULINGAM,B. N. RAO

期刊论文

GDF15 negatively regulates chemosensitivity via TGFBR2-AKT pathway-dependent metabolism in esophageal

期刊论文

Cluster voltage control method for “Whole County” distributed photovoltaics based on improved differential

期刊论文

Analysis of dispatching rules in a stochastic dynamic job shop manufacturing system with sequence-dependent

Pankaj SHARMA,Ajai JAIN

期刊论文

大中功率节能调速传动的合理电压等级

马小亮

期刊论文

power quality conditioner based on a three-level NPC inverter using fuzzy control techniques for all voltage

Salim CHENNAI,M-T BENCHOUIA

期刊论文

Experimental study of pollution effect on the behavior of high voltage insulators under alternative current

Hani BENGUESMIA, Nassima M’ZIOU, Ahmed BOUBAKEUR

期刊论文