资源类型

期刊论文 107

年份

2023 19

2022 12

2021 10

2020 12

2019 4

2018 5

2017 11

2016 1

2015 8

2014 3

2013 6

2012 4

2009 5

2008 2

2007 3

展开 ︾

关键词

增材制造 5

激光选区熔化 2

电子束 2

选区激光熔化 2

选择性激光熔化 2

CCS 1

CO2分离 1

HEMTs);栅槽;数字湿法腐蚀;选择性湿法腐蚀 1

五模材料 1

介观尺度模型 1

介观模型 1

偶氮苯 1

分子开关 1

动力学 1

原料不均一性 1

可降解镁合金 1

吸收率 1

多尺度建模 1

多目标跟踪;广义标签多伯努利;辐射源信号特征;模糊C-均值;动态聚类 1

展开 ︾

检索范围:

排序: 展示方式:

Spectral emittance measurements of micro/nanostructures in energy conversion: a review

Shiquan SHAN, Chuyang CHEN, Peter G. LOUTZENHISER, Devesh RANJAN, Zhijun ZHOU, Zhuomin M. ZHANG

《能源前沿(英文)》 2020年 第14卷 第3期   页码 482-509 doi: 10.1007/s11708-020-0693-0

摘要: Micro/nanostructures play a key role in tuning the radiative properties of materials and have been applied to high-temperature energy conversion systems for improved performance. Among the various radiative properties, spectral emittance is of integral importance for the design and analysis of materials that function as radiative absorbers or emitters. This paper presents an overview of the spectral emittance measurement techniques using both the direct and indirect methods. Besides, several micro/nanostructures are also introduced, and a special emphasis is placed on the emissometers developed for characterizing engineered micro/nanostructures in high-temperature applications (e.g., solar energy conversion and thermophotovoltaic devices). In addition, both experimental facilities and measured results for different materials are summarized. Furthermore, future prospects in developing instrumentation and micro/nanostructured surfaces for practical applications are also outlined. This paper provides a comprehensive source of information for the application of micro/nanostructures in high-temperature energy conversion engineering.

关键词: concentrating solar power (CSP)     emittance measurements     high temperature     micro/nanostructure     selective absorber     selective emitter     thermophotovoltaics (TPV)    

Analysis of the double-layer α-Si:H emitter with different doping concentrations for α-Si:H/c-Si heterojunction

Haibin HUANG,Gangyu TIAN,Tao WANG,Chao GAO,Jiren YUAN,Zhihao YUE,Lang ZHOU

《能源前沿(英文)》 2017年 第11卷 第1期   页码 92-95 doi: 10.1007/s11708-016-0432-8

摘要: Double-layer emitters with different doping concentrations (DLE) have been designed and prepared for amorphous silicon/crystalline silicon (α-Si:H/c-Si) heterojunction solar cells. Compared with the traditional single layer emitter, both the experiment and the simulation (AFORS-HET, http://www.paper.edu.cn/html/releasepaper/2014/04/282/) prove that the double-layer emitter increases the short circuit current of the cells significantly. Based on the quantum efficiency (QE) results and the current-voltage-temperature analysis, the mechanism for the experimental results above has been investigated. The possible reasons for the increased current include the enhancement of the QE in the short wavelength range, the increase of the tunneling probability of the current transport and the decrease of the activation energy of the emitter layers.

关键词: double-layer emitter     α-Si:H/c-Si heterojunction solar cell     short circuit current     quantum efficiency     current-voltage-temperature    

POCl3 diffusion for industrial Si solar cell emitter formation

Hongzhao LI,Kyung KIM,Brett HALLAM,Bram HOEX,Stuart WENHAM,Malcolm ABBOTT

《能源前沿(英文)》 2017年 第11卷 第1期   页码 42-51 doi: 10.1007/s11708-016-0433-7

摘要: POCl diffusion is currently the standard method for industrial n-type emitter fabrication. In this study, we present the impact of the following processing parameters on emitter formation and electrical performance: deposition gas flow ratio, drive-in temperature and duration, drive-in O flow rate, and thermal oxidation temperature. By showing their influence on the emitter doping profile and recombination activity, we provide an overall strategy for improving industrial POCl tube diffused emitters.

关键词: POCl3 diffusion     emitter recombination     oxidation     silicon    

基于时序优化长短期记忆和自适应阈值的高排放重型柴油车识别 Research Article

许镇义1,王仁军1,2,曹洋1,3,4,康宇1,3,4

《信息与电子工程前沿(英文)》 2023年 第24卷 第11期   页码 1633-1646 doi: 10.1631/FITEE.2300005

摘要: 在实际场景中,重型柴油车是城市氮氧化物的重要来源,其排放的氮氧化物(NOx)占车辆总排放量的80%以上,颗粒物(PM)占90%以上。检测和控制重型柴油车的排放对保护公众健康至关重要。目前,道路上的车辆必须每6个月或每年定期检测一次,在车辆检查站过滤出高排放的移动源。然而,由于年检间隔时间较长,很难及时有效地筛选出高排放车辆,而且固定的阈值不能适应车辆驾驶工况的动态变化。车载诊断设备(OBD)安装在车辆内部,可以连续跟踪和实时记录排放数据。本文提出一种时间优化长短期记忆(LSTM)和自适应动态阈值方法,使用OBD数据识别重型高排放车辆。首先,建立一个时间优化LSTM排放预测模型,以解决实际中大量OBD数据流造成的时间步注意力偏重问题。然后,利用灵活的阈值标准检测浓度预测误差序列,以区分异常排放情况,该阈值随驾驶条件变化自适应计算得到。最后,引入时间序列的相似性度量策略,以纠正一些假的异常结果。在3个真实OBD时间序列排放数据集上的实验表明,该方法得到优异的高排放源识别结果。

关键词: 高排放识别;时序优化;车载诊断设备(OBD);动态阈值    

Recent advances in selective acetylene hydrogenation using palladium containing catalysts

Alan J. McCue, James A. Anderson

《化学科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 142-153 doi: 10.1007/s11705-015-1516-4

摘要: Recent advances with Pd containing catalysts for the selective hydrogenation of acetylene are described. The overview classifies enhancement of catalytic properties for monometallic and bimetallic Pd catalysts. Activity/selectivity of Pd catalysts can be modified by controlling particle shape/morphology or immobilisation on a support which interacts strongly with Pd particles. In both cases enhanced ethylene selectivity is generally associated with modifying ethylene adsorption strength and/or changes to hydride formation. Inorganic and organic selectivity modifiers (i.e., species adsorbed onto Pd particle surface) have also been shown to enhance ethylene selectivity. Inorganic modifiers such as TiO change Pd ensemble size and modify ethylene adsorption strength whereas organic modifiers such as diphenylsulfide are thought to create a surface template effect which favours acetylene adsorption with respect to ethylene. A number of metals and synthetic approaches have been explored to prepare Pd bimetallic catalysts. Examples where enhanced selectivity is observed are generally associated with decreased Pd ensemble size and/or hindering of the ease with which an unselective hydride phase is formed for Pd. A final class of bimetallic catalysts are discussed where Pd is not thought to be the primary reaction site but merely acts as a site where hydrogen dissociation and spillover occurs onto a second metal (Cu or Au) where the reaction takes place more selectively.

关键词: acetylene     ethylene     selective hydrogenation     palladium     bimetallic    

Preparation of polysulfone-based block copolymer ultrafiltration membranes by selective swelling and

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 745-754 doi: 10.1007/s11705-021-2038-x

摘要: Selective swelling of block copolymers of polysulfone-b-poly(ethylene glycol) is an emerging strategy to prepare new types of polysulfone ultrafiltration membranes. Herein, we prepared nanoporous polysulfone-b-poly(ethylene glycol) ultrafiltration membranes by selective swelling and further promoted their porosity and ultrafiltration performances by using CaCO3 nanoparticles as the sacrificial nanofillers. Different contents of CaCO3 nanoparticles were doped into the solution of polysulfone-b-poly(ethylene glycol), and thus obtained suspensions were used to prepare both self-supported and bi-layered composite structures. Selective swelling was performed on the obtained block copolymer structures in the solvent pair of ethanol/acetone, producing nanoporous membranes with poly(ethylene glycol) lined along pore walls. The CaCO3 nanoparticles dispersed in polysulfone-b-poly(ethylene glycol) were subsequently etched away by hydrochloric acid and the spaces initially occupied by CaCO3 provided extra pores to the block copolymer layers. The porosity of the membranes was increased with increasing CaCO3 content up to 41%, but further increase in the CaCO3 content led to partial collapse of the membrane. The sacrificial CaCO3 particles provided extra pores and enhanced the connectivity between adjacent pores. Consequently, the membranes prepared under optimized conditions exhibited up to 80% increase in water permeance with slight decrease in rejection compared to neat membranes without the use of sacrificial CaCO3 particles.

关键词: block copolymers     selective swelling     ultrafiltration     CaCO3 nanoparticles     sacrificial nanofillers    

Highly efficient and selective removal of vanadium from tungstate solutions by microbubble floating-extraction

《化学科学与工程前沿(英文)》 2023年 第17卷 第5期   页码 581-593 doi: 10.1007/s11705-022-2235-2

摘要: Selective separation of dissolved tungsten and vanadium is of great significance for the utilization of the secondary resources of these elements. In this work, selective removal of vanadium from tungstate solutions via microbubble floating-extraction was systematically investigated. The results indicated that vanadium can be more easily mineralized over tungsten from tungstate solutions using methyl trioctyl ammonium chloride as mineralization reagent under weak alkaline conditions. Owing to the higher bubble and interface mass transfer rates, high-efficiency enrichment and deep separation of vanadium could be achieved easily. Additionally, the deep recovery of tungsten and vanadium from the floated organic phase could be easily realized using a mixed solution of sodium hydroxide and sodium chloride as stripping agents. The separation mechanism mainly included the formation of hydrophobic complexes, their attachment on the surface of rising bubbles, and their mass transfer at the oil–water interface. Under the optimal conditions, the removal efficiency of vanadium reached 98.5% with tungsten loss below 8% after two-stage microbubble floating-extraction. Therefore, the microbubble floating-extraction could be an efficient approach for separating selectively vanadium from tungstate solutions, exhibiting outstanding advantages of high separation efficiency and low consumption of organic solvents.

关键词: tungsten     vanadium     selective separation     reagent mineralization     microbubble floating-extraction    

Mechanistic insights into the selective photocatalytic degradation of dyes over TiO/ZSM-11

《环境科学与工程前沿(英文)》 2023年 第17卷 第8期 doi: 10.1007/s11783-023-1701-5

摘要:

● TiO2/ZSM-11 was prepared by a facile solid state dispersion method.

关键词: Selective dye degradation     Photocatalysis     TiO2     ZSM-11     Chemisorption    

Porous ultrathin-shell microcapsules designed by microfluidics for selective permeation and stimuli-triggered

《化学科学与工程前沿(英文)》   页码 1643-1650 doi: 10.1007/s11705-022-2201-z

摘要: Microcapsules are versatile delivery vehicles and widely used in various areas. Generally, microcapsules with solid shells lack selective permeation and only exhibit a simple release mode. Here, we use ultrathin-shell water-in-oil-in-water double emulsions as templates and design porous ultrathin-shell microcapsules for selective permeation and multiple stimuli-triggered release. After preparation of double emulsions by microfluidic devices, negatively charged shellac nanoparticles dispersed in the inner water core electrostatically complex with positively charged telechelic α,ω-diamino functionalized polydimethylsiloxane polymers dissolved in the middle oil shell at the water/oil interface, thus forming a porous shell of shellac nanoparticles cross-linked by telechelic polymers. Subsequently, the double emulsions become porous microcapsules upon evaporation of the middle oil phase. The porous ultrathin-shell microcapsules exhibit excellent properties, including tunable size, selective permeation and stimuli-triggered release. Small molecules or particles can diffuse across the shell, while large molecules or particles are encapsulated in the core, and release of the encapsulated cargos can be triggered by osmotic shock or a pH change. Due to their unique performance, porous ultrathin-shell microcapsules present promising platforms for various applications, such as drug delivery.

关键词: microcapsule     emulsion     microfluidics     selective permeation     stimuli-triggered release    

Highly selective and green recovery of lithium ions from lithium iron phosphate powders with ozone

《化学科学与工程前沿(英文)》 2023年 第17卷 第6期   页码 749-758 doi: 10.1007/s11705-022-2261-0

摘要: Since lithium iron phosphate cathode material does not contain high-value metals other than lithium, it is therefore necessary to strike a balance between recovery efficiency and economic benefits in the recycling of waste lithium iron phosphate cathode materials. Here, we describe a selective recovery process that can achieve economically efficient recovery and an acceptable lithium leaching yield. Adjusting the acid concentration and amount of oxidant enables selective recovery of lithium ions. Iron is retained in the leaching residue as iron phosphate, which is easy to recycle. The effects of factors such as acid concentration, acid dosage, amount of oxidant, and reaction temperature on the leaching of lithium and iron are comprehensively explored, and the mechanism of selective leaching is clarified. This process greatly reduces the cost of processing equipment and chemicals. This increases the potential industrial use of this process and enables the green and efficient recycling of waste lithium iron phosphate cathode materials in the future.

关键词: lithium iron phosphate powder     stoichiometric number     selective leaching     lithium recovery    

Shape selective catalysis in methylation of toluene: Development, challenges and perspectives

Jian Zhou, Zhicheng Liu, Yangdong Wang, Dejin Kong, Zaiku Xie

《化学科学与工程前沿(英文)》 2018年 第12卷 第1期   页码 103-112 doi: 10.1007/s11705-017-1671-x

摘要: Toluene methylation with methanol offers an alternative method to produce -xylene by gathering methyl group directly from C1 chemical sources. It supplies a “molecular engineering” process to realize directional conversion of toluene/methanol molecules by selective catalysis in complicated methylation system. In this review, we introduce the synthesis method of -xylene, the development history of methylation catalysts and reaction mechanism, and the effect of reaction condition in -selective technical process. If constructing -xylene as the single target product, the major challenge to develop -selective toluene methylation is to improve the -xylene selectivity without, or as little as possible, losing the fraction of methanol for methylation. To reach higher yield of -xylene and more methanol usage in methylation, zeolite catalyst design should consider improving mass transfer and afterwards covering external acid sites by surface modification to get short “micro-tunnels” with shape selectivity. A solid understanding of mass transfer will benefit realizing the aim of converting more methanol feedstock into -methyl group.

关键词: shape selective catalysis     methylation of toluene    

Design and operational considerations for selective catalytic reduction technologies at coal-fired boilers

Jeremy J. SCHREIFELS, Shuxiao WANG, Jiming HAO

《能源前沿(英文)》 2012年 第6卷 第1期   页码 98-105 doi: 10.1007/s11708-012-0171-4

摘要: By the end of 2010, China had approximately 650 GW of coal-fired electric generating capacity producing almost 75% of the country’s total electricity generation. As a result of the heavy reliance on coal for electricity generation, emissions of air pollutants, such as nitrogen oxides (NO ), are increasing. To address these growing emissions, the Ministry of Environmental Protection (MEP) has introduced new NO emission control policies to encourage the installation of selective catalytic reduction (SCR) technologies on a large number of coal-fired electric power plants. There is, however, limited experience with SCR in China. It is therefore useful to explore the lessons from the use of SCR technologies in other countries. This paper provides an overview of SCR technology performance at coal-fired electric power plants demonstrating emission removal rates between 65% and 92%. It also reviews the design and operational challenges that, if not addressed, can reduce the reliability, performance, and cost-effectiveness of SCR technologies. These challenges include heterogeneous flue gas conditions, catalyst degradation, ammonia slip, sulfur trioxide (SO ) formation, and fouling and corrosion of plant equipment. As China and the rest of the world work to reduce greenhouse gas emissions, carbon dioxide (CO ) emissions from parasitic load and urea-to-ammonia conversion may also become more important. If these challenges are properly addressed, SCR can reliably and effectively remove up to 90% of NO emissions at coal-fired power plants.

关键词: nitrogen oxides (NOx)     coal     selective catalytic reduction (SCR)     air pollution control    

Low-temperature selective catalytic reduction of NO with NH based on MnO-CeO/ACFN

SHEN Boxiong, LIU Ting, SHI Zhanliang, SHI Jianwei, YANG Tingting, ZHAO Ning

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 325-329 doi: 10.1007/s11705-008-0053-9

摘要: MnO-CeO/ACFN were prepared by the impregnation method and used as catalyst for selective catalytic reduction of NO with NH at 80°C–150°C. The catalyst was characterized by N-BET, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The fraction of the mesopore and the oxygen functional groups on the surface of activated carbon fiber (ACF) increased after the treatment with nitric acid, which was favorable to improve the catalytic activities of MnO-CeO/ACFN. The experimental results show that the conversion of NO is nearly 100% in the range 100°C–150°C under the optimal preparation conditions of MnO-CeO/ACFN. In addition, the effects of a series of performance parameters, including initial NH concentration, NO concentration and O concentration, on the conversion of NO were studied.

关键词: preparation     conversion     favorable     selective catalytic     MnO-CeO/ACFN    

Multi-stage ammonia production for sorption selective catalytic reduction of NO

Chen ZHANG, Guoliang AN, Liwei WANG, Shaofei WU

《能源前沿(英文)》 2022年 第16卷 第5期   页码 840-851 doi: 10.1007/s11708-021-0797-1

摘要: Sorption selective catalytic reduction of nitrogen oxides (NOx) (sorption-SCR) has ever been proposed for replacing commercial urea selective catalytic reduction of NOx (urea-SCR), while only the single-stage sorption cycle is hitherto adopted for sorption-SCR. Herein, various multi-stage ammonia production cycles is built to solve the problem of relative high starting temperature with ammonia transfer (AT) unit and help detect the remaining ammonia in ammonia storage and delivery system (ASDS) with ammonia warning (AW) unit. Except for the single-stage ammonia production cycle with MnCl2, other sorption-SCR strategies all present overwhelming advantages over urea-SCR considering the much higher NOx conversion driven by the heat source lower than 100°C and better matching characteristics with low-temperature catalysts. Furthermore, the required mass of sorbent for each type of sorption-SCR is less than half of the mass of AdBlue for urea-SCR. Therefore, the multifunctional multi-stage sorption-SCR can realize compact and renewable ammonia storage and delivery with low thermal energy consumption and high NOx conversion, which brings a bright potential for efficient commercial de-NOx technology.

关键词: selective catalytic reduction (SCR)     nitrogen oxides (NOx)     ammonia     composite sorbent     chemisorption    

Insight into the promotion mechanism of activated carbon on the monolithic honeycomb red mud catalyst for selective

《环境科学与工程前沿(英文)》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1337-7

摘要:

• Activated carbon was proposed to be an efficient accelerant for molded red mud catalyst.

关键词: NOx     Selective catalytic reduction     Iron-based catalyst     Red mud     Monolithic catalyst     Activated carbon    

标题 作者 时间 类型 操作

Spectral emittance measurements of micro/nanostructures in energy conversion: a review

Shiquan SHAN, Chuyang CHEN, Peter G. LOUTZENHISER, Devesh RANJAN, Zhijun ZHOU, Zhuomin M. ZHANG

期刊论文

Analysis of the double-layer α-Si:H emitter with different doping concentrations for α-Si:H/c-Si heterojunction

Haibin HUANG,Gangyu TIAN,Tao WANG,Chao GAO,Jiren YUAN,Zhihao YUE,Lang ZHOU

期刊论文

POCl3 diffusion for industrial Si solar cell emitter formation

Hongzhao LI,Kyung KIM,Brett HALLAM,Bram HOEX,Stuart WENHAM,Malcolm ABBOTT

期刊论文

基于时序优化长短期记忆和自适应阈值的高排放重型柴油车识别

许镇义1,王仁军1,2,曹洋1,3,4,康宇1,3,4

期刊论文

Recent advances in selective acetylene hydrogenation using palladium containing catalysts

Alan J. McCue, James A. Anderson

期刊论文

Preparation of polysulfone-based block copolymer ultrafiltration membranes by selective swelling and

期刊论文

Highly efficient and selective removal of vanadium from tungstate solutions by microbubble floating-extraction

期刊论文

Mechanistic insights into the selective photocatalytic degradation of dyes over TiO/ZSM-11

期刊论文

Porous ultrathin-shell microcapsules designed by microfluidics for selective permeation and stimuli-triggered

期刊论文

Highly selective and green recovery of lithium ions from lithium iron phosphate powders with ozone

期刊论文

Shape selective catalysis in methylation of toluene: Development, challenges and perspectives

Jian Zhou, Zhicheng Liu, Yangdong Wang, Dejin Kong, Zaiku Xie

期刊论文

Design and operational considerations for selective catalytic reduction technologies at coal-fired boilers

Jeremy J. SCHREIFELS, Shuxiao WANG, Jiming HAO

期刊论文

Low-temperature selective catalytic reduction of NO with NH based on MnO-CeO/ACFN

SHEN Boxiong, LIU Ting, SHI Zhanliang, SHI Jianwei, YANG Tingting, ZHAO Ning

期刊论文

Multi-stage ammonia production for sorption selective catalytic reduction of NO

Chen ZHANG, Guoliang AN, Liwei WANG, Shaofei WU

期刊论文

Insight into the promotion mechanism of activated carbon on the monolithic honeycomb red mud catalyst for selective

期刊论文