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Improving retrieval precision of NO

Jinpeng YANG

《机械工程前沿(英文)》 2009年 第4卷 第1期   页码 92-96 doi: 10.1007/s11465-009-0001-5

摘要: The NO density error retrieved by the traditional method of differential optical absorption spectroscopy (DOAS) was analyzed. The technique for reducing the error is proposed and used to obtain the NO density of Chengdu through DOAS.

关键词: absorption structure     low-frequency structure     absorption cross-section     NO2 density    

natural magnetite and siderite: Evidence from sorption kinetics, sequential extraction and extended X-ray absorptionfine-structure spectroscopy analysis

《环境科学与工程前沿(英文)》 2022年 第16卷 第9期 doi: 10.1007/s11783-022-1547-2

摘要:

• DPAA sorption followed pseudo-secondary and intra-particle diffusion models.

关键词: Diphenylarsinic acid (DPAA)     Sorption     Magnetite     Siderite     Sequential extraction     EXAFS    

Compressive behavior and energy absorption of polymeric lattice structures made by additive manufacturing

Sheng WANG, Jun WANG, Yingjie XU, Weihong ZHANG, Jihong ZHU

《机械工程前沿(英文)》 2020年 第15卷 第2期   页码 319-327 doi: 10.1007/s11465-019-0549-7

摘要: Lattice structures have numerous outstanding characteristics, such as light weight, high strength, excellent shock resistance, and highly efficient heat dissipation. In this work, by combining experimental and numerical methods, we investigate the compressive behavior and energy absorption of lattices made through the stereolithography apparatus process. Four types of lattice structures are considered: (i) Uniform body-centered-cubic (U-BCC); (ii) graded body-centered-cubic (G-BCC); (iii) uniform body-centered-cubic with -axis reinforcement (U-BCCz); and (iv) graded body-centered-cubic with -axis reinforcement (G-BCCz). We conduct compressive tests on these four lattices and numerically simulate the compression process through the finite element method. Analysis results show that BCCz has higher modulus and strength than BCC. In addition, uniform lattices show better energy absorption capabilities at small compression distances, while graded lattices absorb more energy at large compression distances. The good correlation between the simulation results and the experimental phenomena demonstrates the validity and accuracy of the present investigation method.

关键词: lattice structure     polymer     compressive behavior     additive manufacturing     simulation    

Nanostructured gold films exhibiting almost complete absorption of light at visible wavelengths

Hanbin Zheng, Christine Picard, Serge Ravaine

《化学科学与工程前沿(英文)》 2018年 第12卷 第2期   页码 247-251 doi: 10.1007/s11705-018-1710-2

摘要: Nanostructured metal surfaces have been known to exhibit properties that deviate from that of the bulk material. By simply modifying the texture of a metal surface, various unique optical properties can be observed. In this paper, we present a simple two step electrochemical process combining electrodeposition and anodization to generate black gold surfaces. This process is simple, versatile and up-scalable for the production of large surfaces. The black gold films have remarkable optical behavior as they absorb more than 93% of incident light over the entire visible spectrum and also exhibit no specular reflectance. A careful analysis by scanning electron microscopy reveals that these unique optical properties are due to their randomly rough surface, as they consist in a forest of dendritic microstructures with a nanoscale roughness. This new type of black films can be fabricated to a large variety of substrates, turning them to super absorbers with potential applications in photovoltaic solar cells or highly sensitive detectors and so on.

关键词: nanostructuration     light absorption     coating     gold     electrodeposition     anodization    

Effect of light scattering on the performance of a direct absorption solar collector

Kwang Hyun WON, Bong Jae LEE

《能源前沿(英文)》 2018年 第12卷 第1期   页码 169-177 doi: 10.1007/s11708-018-0527-5

摘要: Recently, a solar thermal collector often employs nanoparticle suspension to absorb the solar radiation directly by a working fluid as well as to enhance its thermal performance. The collector efficiency of a direct absorption solar collector (DASC) is very sensitive to optical properties of the working fluid, such as absorption and scattering coefficients. Most of the existing studies have neglected particle scattering by assuming that the size of nanoparticle suspension is much smaller than the wavelength of solar radiation (i.e., Rayleigh scattering is applicable). If the nanoparticle suspension is made of metal, however, the scattering cross-section of metallic nanoparticles could be comparable to their absorption cross-section depending on the particle size, especially when the localized surface plasmon (LSP) is excited. Therefore, for the DASC utilizing a plasmonic nanofluid supporting the LSP, light scattering from metallic particle suspension must be taken into account in the thermal analysis. The present study investigates the scattering effect on the thermal performance of the DASC employing plasmonic nanofluid as a working fluid. In the analysis, the Monte Carlo method is employed to numerically solve the radiative transfer equation considering the volume scattering inside the nanofluid. It is found that the light scattering can improve the collector performance if the scattering coefficient of nanofluid is carefully engineered depending on its value of the absorption coefficient.

关键词: direct absorption solar collector     plasmonic nanofluid     light scattering    

Performance analysis of solar absorption-subcooled compression hybrid refrigeration system in subtropical

Xiangyang YE,Liming LIU,Zeyu LI

《能源前沿(英文)》 2019年 第13卷 第1期   页码 185-192 doi: 10.1007/s11708-017-0452-z

摘要: Solar absorption-subcooled compression hybrid refrigeration system is a new type of efficient and economical solar refrigeration device which always meets the demand of cooling load with the change of solar irradiance. The performance of the hybrid system is higher due to the improvement of evaporator temperature of absorption subsystem. But simultaneously, the variation of working process as well as performance is complicated since the absorption and compression subsystems are coupled strongly. Based on the measured meteorological data of Guangzhou, a subtropical city in south China, a corresponding parametric model has been developed for the hybrid refrigeration system, and a program written by Fortran has been used to analyze the performance of the hybrid system under different external conditions. As the condensation temperature ranges from 38°C to 50°C, the working time fraction of the absorption subsystem increases from 75% to 85%. Besides, the energy saving fraction also increases from 5.31% to 6.02%. The average COP of the absorption subsystem is improved from 0.366 to 0.407. However, when the temperature of the absorption increases from 36°C to 48°C, the average COP of hybrid system decreases from 2.703 to 2.312. Moreover, the working time fraction of the absorption subsystem decreases from 80% to 71.7%. The energy saving fraction falls from 5.67% to 5.08%. In addition, when the evaporate temperature increases from 4°C to 14°C, the average COP of the absorption subsystem decreases from 0.384 to 0.365. The work of the compressor decreases from 48.2 kW to 32.8 kW and the corresponding average COP of the absorption subsystem is improved from 2.591 to 3.082.

关键词: solar     absorption-subcooled     compression hybrid     dynamic simulation     performance analysis    

饲料的分子结构与动物营养物质利用率和有效性的关系——一种新方法

俞培强, Luciana L. Prates

《工程(英文)》 2017年 第3卷 第5期   页码 726-730 doi: 10.1016/J.ENG.2017.03.007

摘要:

新的研究思路、研究方法和生物分析技术的创造和发展对动物科学(包括饲料和营养科学)的进步是必不可少的。本文介绍了以同步加速器为基础的先进生物分析技术作为一项崭新的研究工具,在研究由多种处理(如基因修饰、基因沉默、饲料的热加工处理、生物燃料加工等)诱导的饲料分子结构变化与动物消化吸收饲料营养物质的关系方面的潜在应用。以同步辐射为基础的先进技术[如同步辐射红外显微光谱技术(synchrotron radiation infrared microspectroscopy,SR-IMS)和同步辐射X射线技术]作为一种快速、无损的生物分析技术被开发利用。与传统的湿化学法不同,同步辐射技术不会破坏饲料内在的分子结构。尖端和先进的同步加速器光源(是日光的上百万倍)能够以超高分辨率在细胞和分子水平上探测生物组织的内在结构。总的来说,最近开发的基于同步辐射的生物分析技术结合常用的研究技术将带来动物饲料和营养研究的巨大进步。

关键词: 内部分子结构     同步辐射应用     分子营养     饲料科学技术     分子成像     养分消化与吸收    

β-Nickel hydroxide cathode material for nano-suspension redox flow batteries

Yue LI, Cheng HE, Elena V. TIMOFEEVA, Yujia DING, Javier PARRONDO, Carlo SEGRE, Vijay RAMANI

《能源前沿(英文)》 2017年 第11卷 第3期   页码 401-409 doi: 10.1007/s11708-017-0496-0

摘要: As part of an effort to build a prototype flow battery system using a nano-suspension containing β-Ni(OH) nanoparticles as the cathode material, nano-sized β-Ni(OH) particles with well-controlled particle size and morphology were synthesized via the one-step precipitation of a NiCl precursor. The composition and morphology of the nanoparticles were characterized by scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The XRD patterns confirmed that β-Ni(OH) was successfully synthesized, while SEM results showed that the particle sizes range from 70 to 150 nm. To ensure that Ni(OH) could be employed in the nano-suspension flow battery, the electrochemical performance of the synthesized β-Ni(OH) was initially tested in pouch cells through charge/discharge cycling. The phase transformations occurring during charge/discharge were investigated using X-ray absorption spectroscopy to obtain the shift in the oxidation state of Ni (X-ray adsorption near edge structure, XANES) and the distances between Ni and surrounding atoms in charged and discharged states (extended X-ray absorption fine structure, EXAFS). XANES results indicated that the electrode in the discharged state was a mixture of phases because the edge position did not shift back completely. XAFS results further proved that the discharge capacity was provided by β-NiOOH and the ratio between β-Ni(OH) and g-NiOOH in the electrode in the discharged state was 71:29. Preliminary nano-suspension tests in a lab-scale cell were conducted to understand the behavior of the nano-suspension during charge/discharge cycling and to optimize the operating conditions.

关键词: nano-suspension flow battery     β-Ni(OH)2     scanning electronic microscopy (SEM)     X-ray diffraction (XRD)     X-ray adsorption near edge structure (XANES)     extended X-ray absorption fine structure (EXAFS)    

Effect of fine solid particles on absorption rate of gaseous CO

LU Sumin, MA Youguang, SHEN Shuhua, ZHU Chunying

《化学科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 368-372 doi: 10.1007/s11705-008-0067-3

摘要: The influence of the properties of solid particles in slurry on the absorption of CO in the slurry was investigated in a stirred thermostatic reactor. The absorption experiments were carried out in three different slurries consisting of water, cyclohexane and soybean oil, respectively, and three kinds of solid particles (active carbon, active alumina and silica gel) were incorporated into each of the above mentioned slurries separately. The experimental results show that the active carbon particles could enhance the absorption rate of gaseous CO in the aqueous slurry, while in the cyclohexane slurry, active carbon particles indicated no the absorption enhancement effect. However, it was observed that the active alumina and silica gel particles could enhance the absorption rate of CO in the cyclohexane slurry. These phenomena indicate that the solid particles, which could enhance the gaseous CO absorption rate, should possess two properties simultaneously, i.e. they rejected the solvent and had higher adsorption capacity for the solute. The experimental results also show that, as for those solid particles which could enhance the gas absorption rate, the enhancement increased quickly with the increase of solid concentration in slurry at first, and then reached a constant value gradually. It was also found that the enhancement factor was related to the coverage fraction of solid particles on the gas-liquid interface, and due to the reduction of surface fraction with increasing stirred speed, the enhancement factor decreased.

关键词: constant     influence     soybean     solvent     concentration    

optimization of 1,3-dimethylimidazolylium dimethylphosphate-water binary mixture for a single effect absorption

Gorakshnath TAKALKAR, Ahmad K. SLEITI

《能源前沿(英文)》 2022年 第16卷 第3期   页码 521-535 doi: 10.1007/s11708-021-0720-9

摘要: The energy and exergy analyses of the absorption refrigeration system (ARS) using H O-[mmim][DMP] mixture were investigated for a wide range of temperature. The equilibrium Dühring ( - - ) and enthalpy ( - - ) of mixture were assessed using the excess Gibbs free non-random two liquid (NRTL) model for a temperature range of 20°C to 140°C and from 0.1 to 0.9. The performance validation of the ARS cycle showed a better coefficient of performance (COP) of 0.834 for H O-[mmim][DMP] in comparison to NH -H O, H O-LiBr, H O-[emim][DMP], and H O-[emim][BF4]. Further, ARS performances with various operating temperatures of the absorber ( ), condenser ( ), generator ( ), and evaporator ( ) were simulated and optimized for a maximum COP and exergetic COP (ECOP). The effects of from 50°C to 150°C and and from 30°C to 50°C on COP and ECOP, the , , and circulation ratio (CR) of the ARS were evaluated and optimized for from 5°C to 15°C. The optimization revealed that needed to achieve a maximum COP which was more than that for a maximum ECOP. Therefore, this investigation provides criteria to select low grade heat source temperature. Most of the series flow of the cases of cooling water from the condenser to the absorber was found to be better than the absorber to the condenser.

关键词: ionic liquid driven absorption cycle     H2O-[mmim][DMP]     coefficient of performance (COP)     exergy analysis     thermodynamics mixture property    

A district heating system based on absorption heat exchange with CHP systems

Lin FU, Yan LI, Yi JIANG, Shigang ZHANG,

《能源前沿(英文)》 2010年 第4卷 第1期   页码 77-83 doi: 10.1007/s11708-010-0022-0

摘要: In order to decrease the energy consumption of large-scale district heating systems with cogeneration, a district heating system is presented in this paper based on absorption heat exchange in the cogeneration system named Co-ah cycle, which means that the cogeneration system is based on absorption heat exchange. In substations of the heating system, the temperature of return water of primary heat network is reduced to about 25°C through the absorption heat-exchange units. In the thermal station of the cogeneration plant, return water is heated orderly by the exhaust steam in the condenser, the absorption heat pumps, and the peak load heater. Compared with traditional heating systems, this system runs with a greater circuit temperature drop so that the delivery capacity of the heat network increases dramatically. Moreover, by recovering the exhausted heat from the condensers, the capacity of the district heating system and the energy efficiency of the combined heat and power system (CHP system) are highly developed. Therefore, high energy and economic efficiency can be obtained.

关键词: cogeneration     district heating     absorption heat exchange     Co-ah cycle    

Improved rate-based modeling of carbon dioxide absorption with aqueous monoethanolamine solution

Stefania MOIOLI, Laura A. PELLEGRINI, Simone GAMBA, Ben LI

《化学科学与工程前沿(英文)》 2014年 第8卷 第1期   页码 123-131 doi: 10.1007/s11705-014-1415-0

摘要: This paper focuses on modeling and simulation of a post-combustion carbon dioxide capture in a coal-fired power plant by chemical absorption using monoethanolamine. The aim is to obtain a reliable tool for process simulation: a customized rate-based model has been developed and implemented in the ASPEN Plus software, along with regressed parameters for the Electrolyte-NRTL model worked out in a previous research. The model is validated by comparison with experimental data of a pilot plant and can provide simulation results very close to experimental data.

关键词: Absorption     carbon dioxide capture     rate-based model     monoethanolamine scrubbing    

Design of efficient Pt-based electrocatalysts through characterization by X-ray absorption spectroscopy

Nebojsa S. MARINKOVIC, Kotaro SASAKI, Radoslav R. ADZIC

《能源前沿(英文)》 2017年 第11卷 第3期   页码 236-244 doi: 10.1007/s11708-017-0487-1

摘要: A method is described to determine the internal structure of electrocatalyst nanoparticles by X-ray absorption spectroscopy (XAS). The nondestructive spectroscopic technique typically utilizing synchrotron radiation as the source measures changes in the X-ray absorption coefficient as a function of energy. The bulk technique has found its use for materials characterization in all scientific areas, including nanomaterials. The analysis of the internal structure of nanoparticles reveals interatomic distances and coordination numbers for each element, and their values and mutual relations indicate whether the elements form a homogeneous or heterogeneous mixture. The core-shell heterogeneous structure in which certain elements are predominantly located in the core, and others form the encapsulating shell is of particular importance in catalysis and electrocatalysis because it may reduce the amount of precious metals in nanoparticles by replacing the atoms in the core of nanoparticles with more abundant and cheaper alternatives. The examples of nanoparticle structures designed in the laboratory and the approach to model efficient catalysts through systematic analysis of XAS data in electrochemical systems consisting of two and three metals are also demonstrated.

关键词: X-ray absorption spectroscopy     EXAFS     XANES     nanocatalysts     core shell    

Effect of fiber hybridization on energy absorption and synergy in concrete

Ahmadreza RAMEZANI, Mohammad Reza ESFAHANI

《结构与土木工程前沿(英文)》 2019年 第13卷 第6期   页码 1338-1349 doi: 10.1007/s17009-019-0558-2

摘要: In the present study, steel and polypropylene (PP) fibers have been utilized with the intent of obtaining hybrid fiber-reinforced concrete (HFRC) with desirable mechanical properties. An attempt has been made to scrutinize the properties of HFRC with the main concentration being on energy absorption characteristics of concrete and the efficacy of fiber hybridization in producing synergy. Accordingly, a total of 180 specimens, representing 20 different mixtures have been cast and evaluated through compressive, split tensile, and flexural tests. The relevant flexural toughness of the specimens was calculated using ASTM C1018, ASTM C1609, JSCE, and PCS methods, and the effectiveness of these methods was evaluated based on the experimental results. It was observed that steel fibers are more effective in the improvement of flexural toughness in the presence of PP fibers. Furthermore, synergy associated with the combination of fibers at different stages of deflection of the beam specimens was observed and analyzed.

关键词: hybrid fiber-reinforced concrete     synergy     toughness     steel fibers     polypropylene fibers    

Numerical study of a hybrid absorption-compression high temperature heat pump for industrial waste heat

Zhiwei MA, Huashan BAO, Anthony Paul ROSKILLY

《能源前沿(英文)》 2017年 第11卷 第4期   页码 503-509 doi: 10.1007/s11708-017-0515-1

摘要: The present paper aims at exploring a hybrid absorption-compression heat pump (HAC-HP) to upgrade and recover the industrial waste heat in the temperature range of 60°C–120°C. The new HAC-HP system proposed has a condenser, an evaporator, and one more solution pump, compared to the conventional HAC-HP system, to allow flexible utilization of energy sources of electricity and waste heat. In the system proposed, the pressure of ammonia-water vapor desorbed in the generator can be elevated by two routes; one is via the compression of compressor while the other is via the condenser, the solution pump, and the evaporator. The results show that more ammonia-water vapor flowing through the compressor leads to a substantial higher energy efficiency due to the higher quality of electricity, however, only a slight change on the system exergy efficiency is noticed. The temperature lift increases with the increasing system recirculation flow ratio, however, the system energy and exergy efficiencies drop towards zero. The suitable operation ranges of HAC-HP are recommended for the waste heat at 60°C, 80°C, 100°C, and 120°C. The recirculation flow ratio should be lower than 9, 6, 5, and 4 respectively for these waste heat, while the temperature lifts are in the range of 9.8°C–27.7 °C, 14.9°C–44.1 °C, 24.4°C–64.1°C, and 40.7°C–85.7°C, respectively, and the system energy efficiency are 0.35–0.93, 0.32–0.90, 0.25–0.85, and 0.14–0.76.

关键词: absorption compression     high temperature heat pump     efficiency     industrial waste heat     thermodynamic analysis    

标题 作者 时间 类型 操作

Improving retrieval precision of NO

Jinpeng YANG

期刊论文

natural magnetite and siderite: Evidence from sorption kinetics, sequential extraction and extended X-ray absorptionfine-structure spectroscopy analysis

期刊论文

Compressive behavior and energy absorption of polymeric lattice structures made by additive manufacturing

Sheng WANG, Jun WANG, Yingjie XU, Weihong ZHANG, Jihong ZHU

期刊论文

Nanostructured gold films exhibiting almost complete absorption of light at visible wavelengths

Hanbin Zheng, Christine Picard, Serge Ravaine

期刊论文

Effect of light scattering on the performance of a direct absorption solar collector

Kwang Hyun WON, Bong Jae LEE

期刊论文

Performance analysis of solar absorption-subcooled compression hybrid refrigeration system in subtropical

Xiangyang YE,Liming LIU,Zeyu LI

期刊论文

饲料的分子结构与动物营养物质利用率和有效性的关系——一种新方法

俞培强, Luciana L. Prates

期刊论文

β-Nickel hydroxide cathode material for nano-suspension redox flow batteries

Yue LI, Cheng HE, Elena V. TIMOFEEVA, Yujia DING, Javier PARRONDO, Carlo SEGRE, Vijay RAMANI

期刊论文

Effect of fine solid particles on absorption rate of gaseous CO

LU Sumin, MA Youguang, SHEN Shuhua, ZHU Chunying

期刊论文

optimization of 1,3-dimethylimidazolylium dimethylphosphate-water binary mixture for a single effect absorption

Gorakshnath TAKALKAR, Ahmad K. SLEITI

期刊论文

A district heating system based on absorption heat exchange with CHP systems

Lin FU, Yan LI, Yi JIANG, Shigang ZHANG,

期刊论文

Improved rate-based modeling of carbon dioxide absorption with aqueous monoethanolamine solution

Stefania MOIOLI, Laura A. PELLEGRINI, Simone GAMBA, Ben LI

期刊论文

Design of efficient Pt-based electrocatalysts through characterization by X-ray absorption spectroscopy

Nebojsa S. MARINKOVIC, Kotaro SASAKI, Radoslav R. ADZIC

期刊论文

Effect of fiber hybridization on energy absorption and synergy in concrete

Ahmadreza RAMEZANI, Mohammad Reza ESFAHANI

期刊论文

Numerical study of a hybrid absorption-compression high temperature heat pump for industrial waste heat

Zhiwei MA, Huashan BAO, Anthony Paul ROSKILLY

期刊论文