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Ultrafast solid-liquid-vapor phase change of a thin gold film irradiated by femtosecond laser pulses

Jing HUANG, Yuwen ZHANG, J. K. CHEN, Mo YANG

《能源前沿(英文)》 2012年 第6卷 第1期   页码 1-11 doi: 10.1007/s11708-012-0179-9

摘要: Effects of different parameters on the melting, vaporization and resolidification processes of thin gold film irradiated by femtosecond pulses and pulse train were systematically studied. The classical two-temperature model was adopted to depict the non-equilibrium heat transfer in electrons and lattice. The melting and resolidification processes, which was characterized by the solid-liquid interfacial velocity, as well as elevated melting temperature and depressed solidification temperature, was obtained by considering the interfacial energy balance and nucleation dynamics. Vaporization process which leads to ablation was described by tracking the location of liquid-vapor interface with an iterative procedure based on energy balance and gas kinetics law. The parameters in discussion included film thickness, laser fluence, pulse duration, pulse number, repetition rate, pulse train number, etc. Their effects on the maximum lattice temperature, melting depth and ablation depth were discussed based on the simulation results.

关键词: melting     evaporation     nucleation dynamics     nanoscale heat transfer    

Flow boiling heat transfer in circulating fluidized bed

Xiaoguang REN , Jiangdong ZHENG , Sefiane KHELLIl , Arumemi-Ikhide MICHAEL ,

《能源前沿(英文)》 2009年 第3卷 第1期   页码 85-89 doi: 10.1007/s11708-008-0067-5

摘要: In order to enhance heat transfer and mitigate contamination in the boiling processes, a new type of vapor-liquid-solid (3-phase) circulating fluidized bed boiling system has been designed, combining a circulating fluidized bed with boiling heat transfer. Experimental results show an enhancement of the boiling curve. Flow visualization studies concerning flow hydrodynamics within the riser column are also conducted whose results are presented and discussed.

关键词: vapor-liquid-solid three phase     flow boiling heat transfer     circulating fluidized bed    

Shock wave of vapor-liquid two-phase flow

ZHAO Liangju, GAO Hong, TANG Jingwen, YUAN Yuexiang, WANG Fei

《能源前沿(英文)》 2008年 第2卷 第3期   页码 344-347 doi: 10.1007/s11708-008-0065-7

摘要: The shock wave of vapor-liquid two-phase flow in a pressure-gain steam injector is studied by building a mathematic model and making calculations. The results show that after the shock, the vapor is nearly completely condensed. The upstream Mach number and the volume ratio of vapor have a great effect on the shock. The pressure and Mach number of two-phase shock conform to the shock of ideal gas. The analysis of available energy shows that the shock is an irreversible process with entropy increase.

关键词: available     mathematic     conform     vapor-liquid two-phase     analysis    

Development of new transient liquid phase system Au-Sn-Au for microsystem technology

Kirsten BOBZIN, Nazlim BAGCIVAN, Lidong ZHAO, Stefania FERRARA, Jan PERNE

《机械工程前沿(英文)》 2010年 第5卷 第4期   页码 370-375 doi: 10.1007/s11465-010-0107-9

摘要: In the last decade, microsystems evolved to decisive technology in many technical applications. With increasing requirements on the performance of microsystems, more and more dissimilar materials are used in the same assembly. Correspondingly, suitable joining methods are required to fulfil the requirements on good properties of joints. In this study, a new transient liquid phase (TLP) system Au-Sn-Au was developed for potential medical applications in hybrid microsystems. The high and low melting phases Au and Sn were deposited onto diverse substrates by magnetron-sputter-ion plating. The coated substrates were soldered in a microsoldering station under different conditions. The influence of soldering conditions on the microstructure and properties of the joints was investigated. Results show that the developed solder led to high-quality joints that can be used in microsystems for medical applications.

关键词: transient liquid phase     microtechnology     soldering     diffusion     physical vapor deposition (PVD)    

Numerical simulation of three-dimensional gas/liquid two-phase flow in a proton exchange membrane fuel

ZHUGE Weilin, ZHANG Yangjun, LAO Xingsheng, CHEN Xiao, MING Pingwen

《能源前沿(英文)》 2007年 第1卷 第3期   页码 305-310 doi: 10.1007/s11708-007-0044-4

摘要: Investigation into the formation and transport of liquid water in proton exchange membrane fuel cells (PEMFCs) is the key to fuel cell water management. A three-dimensional gas/liquid two-phase flow and heat transfer model is developed based on the multiphase mixture theory. The reactant gas flow, diffusion, and chemical reaction as well as the liquid water transport and phase change process are modeled. Numerical simulations on liquid water distribution and its effects on the performance of a PEMFC are conducted. Results show that liquid water distributes mostly in the cathode, and predicted cell performance decreases quickly at high current density due to the obstruction of liquid water to oxygen diffusion. The simulation results agree well with experimental data.

关键词: diffusion     gas/liquid two-phase     management     exchange     transfer    

Detection of geosmin and 2-methylisoborneol by liquid-liquid extraction-gas chromatograph mass spectrum(LLE-GCMS) and solid phase extraction-gas chromatograph mass spectrum (SPE-GCMS)

MA Xiaoyan, CHEN Beibei, LI Qingsong, ZHANG Qiaoli, GU Guofen

《环境科学与工程前沿(英文)》 2007年 第1卷 第3期   页码 286-291 doi: 10.1007/s11783-007-0048-7

摘要: Two sample preparation methods were introduced and compared in this paper to establish a simple, quick and exact analysis of geosmin and 2-methylisoborneol. LC-18 column was employed in solid phase extraction (SPE), 1.0 mL of hexane was adopted in liquid-liquid extraction (LLE), and the extracts were analyzed by gas chromatograph mass spectrum (GCMS) in selected ion mode. Mean recoveries of SPE were low for 2-methylisoborneol (2-MIB) and geosmin (GSM) with values below 50%. For LLE, the recoveries were satisfyingly above 50% for 2-MIB and 80% for GSM. Detection limits of the LLE method were as low as 1.0 ng/L for GSM and 5.0 ng/L for 2-MIB. A year-long investigation on odor chemicals of drinking water in Shanghai demonstrated that in the summer, there was a serious odor problem induced by a high concentration of 2-MIB. The highest concentration of 152.82 ng/L appeared in July in raw water, while GSM flocculation was minimal with concentrations below odor threshold.

关键词: summer     flocculation     simple     Shanghai     spectrum    

New refrigeration system using CO vapor-solid as refrigerant

HUANG Dongping, DING Guoliang, QUACK Hans

《能源前沿(英文)》 2008年 第2卷 第4期   页码 494-498 doi: 10.1007/s11708-008-0070-x

摘要: A refrigerant must be in the vapor-liquid phase in a vapor-compression refrigeration system, therefore, CO cannot be used as a refrigerant for temperatures lower than -56°C because solid CO will form under the triple point temperature of -56°C. A refrigeration system with CO vapor-solid particles as refrigerant is put forward, by which a temperature lower than the triple point is achieved. An adjustable nozzle, a sublimator, a high-pressure regulating valve and a low-pressure regulating valve are used to replace the conventional evaporator. Theoretical cycle analysis of the refrigeration system shows that its COP can be 50% higher than that of the conventional one.

关键词: refrigerant     adjustable     temperature     vapor-compression refrigeration     sublimator    

Microfluidic production of liposomes through liquidliquid phase separation in ternary droplets

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 1017-1022 doi: 10.1007/s11705-021-2118-y

摘要: Liposomes, the self-assembled phospholipid vesicles, have been extensively used in various fields such as artificial cells, drug delivery systems, biosensors and cosmetics. However, current microfluidic routes to liposomes mostly rely on water-in-oil-in-water double emulsion droplets as templates, and require complex fabrication of microfluidic devices, and tedious manipulation of multiphase fluids. Here we present a simple microfluidic approach to preparing monodisperse liposomes from oil-in-water droplets. For demonstration, we used butyl acetate-water-ethanol ternary mixtures as inner phase and an aqueous solution of surfactants as outer phase to make oil-in-water droplets, which can evolve into water-in-oil-in-water double emulsion droplets by liquid–liquid phase separation of ternary mixtures. Subsequently, the resultant water-in-oil-in-water droplets underwent a dewetting transition to form separated monodisperse liposomes and residual oil droplets, with the assistance of surfactants. The method is simple, does not require complex microfluidic devices and tedious manipulation, and provides a new platform for controllable preparation of liposomes.

关键词: microfluidics     liposomes     ternary droplets     phase separation    

An efficient resin for solid-phase extraction and determination by UPLCMS/MS of 44 pharmaceutical personal

Feng Zhu, Zhijian Yao, Wenliang Ji, Deye Liu, Hao Zhang, Aimin Li, Zongli Huo, Qing Zhou

《环境科学与工程前沿(英文)》 2020年 第14卷 第3期 doi: 10.1007/s11783-020-1228-y

摘要: A hydrophilic resin (GCHM) was facile synthesis and characterized. Average absolute recovery of GCHM (75.6%) performs better than Oasis® HLB. Detection limits of method (SPE-UPLC-MS/MS) ranged between 0.03 and 0.6 ng/L. 22 PPCPs were determined in environmental waters ranging from 0.5 to 1590 ng/L. In this study, a hydrophilic resin named GCHM was fabricated based on poly(N-vinyl pyrrolidone-co-divinylbenzene), characterized, and applied as a solid-phase extraction (SPE) material. Up to 44 pharmaceuticals and personal care products (PPCPs) belonging to 10 classes were recovered in environmental water samples. Different variables affecting extraction, such as adsorbent amount, sample pH, and loading speed, were optimized. Under optimal conditions, the average absolute recovery of 44 PPCPs was 75.6% using GCHM, indicating a better performance than the commercial Oasis® HLB. SPE with home-made hydrophilic polymeric sorbent followed by ultra-performance liquid chromatography and tandem mass spectrometry was validated, and the method achieved good linearity (r2>0.991, for all analytes). In addition, the method detection limits of target compounds ranged from 0.03 to 0.6 ng/L. The developed method was applied to determine PPCPs in 10 environmental water samples taken from the Yangtze River, Huaihe River, and Taihu Lake, 1 groundwater sample from Changzhou in Jiangsu Province, 1 wastewater sample from Xiamen and 2 seawater samples from the Jiulong River in Fujian Province, China. In these samples, 22 compounds were determined at levels ranging from 0.5 to 1590 ng/L.

关键词: Hydrophilic resin     Solid phase extraction     Pharmaceuticals and personal care product     Ultra-performance liquid chromatography and tandem mass spectrometry     Environmental water    

Advances and perspectives in catalysts for liquid-phase oxidation of cyclohexane

Hui LI, Yuanbin SHE, Tao WANG

《化学科学与工程前沿(英文)》 2012年 第6卷 第3期   页码 356-368 doi: 10.1007/s11705-012-0903-3

摘要: The latest progress and developments in catalysts for the oxidation of cyclohexane are reviewed. Catalytic systems for the oxidation of cyclohexane including metal supported, metal oxides, molecular sieves, metal substituted polyoxometalates, photocatalysts, organocatalysts, Gif systems, metal-organic catalysts and metalloporphyrins are discussed with a particular emphasis on metalloporphyrin catalytic systems. The advantages and disadvantages of these methods are summarized and analyzed. Finally, the development trends in the oxidation technology of cyclohexane are examined.

关键词: cyclohexane     liquid-phase oxidation     catalysis    

A multiscale material model for heterogeneous liquid droplets in solid soft composites

《结构与土木工程前沿(英文)》 2021年 第15卷 第5期   页码 1292-1299 doi: 10.1007/s11709-021-0771-3

摘要: Liquid droplets in solid soft composites have been attracting increasing attention in biological applications. In contrary with conventional composites, which are made of solid elastic inclusions, available material models for composites including liquid droplets are for highly idealized configurations and do not include all material real parameters. They are also all deterministic and do not address the uncertainties arising from droplet radius, volume fraction, dispersion and agglomeration. This research revisits the available models for liquid droplets in solid soft composites and presents a multiscale computational material model to determine their elastic moduli, considering nearly all relevant uncertainties and heterogeneities at different length scales. The effects of surface tension at droplets interface, their volume fraction, size, size polydispersity and agglomeration on elastic modulus, are considered. Different micromechanical material models are incorporated into the presented computational framework. The results clearly indicate both softening and stiffening effects of liquid droplets and show that the model can precisely predict the effective properties of liquid droplets in solid soft composites.

关键词: liquid in solid     soft composite     computational modeling     multiscale model     heterogeneity    

Analysis of the radiation heat transfer process of phase change for a liquid droplet radiator in space

Jinying YIN, Linhua LIU

《能源前沿(英文)》 2011年 第5卷 第2期   页码 166-173 doi: 10.1007/s11708-010-0105-y

摘要: The optimization of a space power system is greatly affected by the radiation heat transfer in a liquid droplet radiator (LDR). Radiation heat transfer in a two-dimensional bed of phase-change particle is modeled by solving the radiative transfer equation using the discrete ordinates method and the energy equation using the implicit finite difference method. The Mie theory is used to calculate the radiative properties of the droplet bed, whereas the effective medium theory is used to obtain the optical constants of partial solidification droplets. Multiple factors affect heat flux in the LDR, such as size distribution, flow velocity, phase change of droplets, layer thickness, droplet concentration in the layer, and material type of the work fluid; each of these must be analyzed. Calculations show that once size distribution is neglected, the relative error increases significantly. Size distribution has a remarkably strong effect on heat flux when the flow velocity of the working fluid is above 100 m/s. An increase in flow velocity leads to an increase in the total heat flux for the layer with a fixed volume fraction of droplets. The solidification zone occupies nearly half of the layer, and droplets of different sizes exhibit temperature differences to some extent due to local thermal non-equilibrium among them. Droplet concentration in the layer and the material type of the working fluid have strong effects on heat flux, whereas the thickness of the layer has a mild influence on heat flux.

关键词: radiation heat transfer     particle polydispersion     liquid droplet radiator     phase change    

A novel cryogenic insulation system of hollow glass microspheres and self-evaporation vapor-cooled shieldfor liquid hydrogen storage

Jianpeng ZHENG, Liubiao CHEN, Ping WANG, Jingjie ZHANG, Junjie WANG, Yuan ZHOU

《能源前沿(英文)》 2020年 第14卷 第3期   页码 570-577 doi: 10.1007/s11708-019-0642-y

摘要: Liquid hydrogen (LH ) attracts widespread attention because of its highest energy storage density. However, evaporation loss is a serious problem in LH storage due to the low boiling point (20 K). Efficient insulation technology is an important issue in the study of LH storage. Hollow glass microspheres (HGMs) is a potential promising thermal insulation material because of its low apparent thermal conductivity, fast installation (Compared with multi-layer insulation, it can be injected in a short time.), and easy maintenance. A novel cryogenic insulation system consisting of HGMs and a self-evaporating vapor-cooled shield (VCS) is proposed for storage of LH . A thermodynamic model has been established to analyze the coupled heat transfer characteristics of HGMs and VCS in the composite insulation system. The results show that the combination of HGMs and VCS can effectively reduce heat flux into the LH tank. With the increase of VCS number from 1 to 3, the minimum heat flux through HGMs decreases by 57.36%, 65.29%, and 68.21%, respectively. Another significant advantage of HGMs is that their thermal insulation properties are not sensitive to ambient vacuum change. When ambient vacuum rises from 10 Pa to 1 Pa, the heat flux into the LH tank increases by approximately 20%. When the vacuum rises from 10 Pa to 100 Pa, the combination of VCS and HGMs reduces the heat flux into the tank by 58.08%–69.84% compared with pure HGMs.

关键词: liquid hydrogen storage     hollow glass microspheres (HGMs)     self-evaporation vapor-cooled shield (VCS)     thermodynamic optimization    

Study of the robustness of a low-temperature dual-pressure process for removal of CO

Stefania Moioli, Laura A. Pellegrini, Paolo Vergani, Fabio Brignoli

《化学科学与工程前沿(英文)》 2018年 第12卷 第2期   页码 209-225 doi: 10.1007/s11705-017-1688-1

摘要: The growing use of energy by most of world population and the consequent increasing demand for energy are making unexploited low quality gas reserves interesting from an industrial point of view. To meet the required specifications for a natural gas grid, some compounds need to be removed from the sour stream. Because of the high content of undesired compounds (i.e., CO ) in the stream to be treated, traditional purification processes may be too energy intensive and the overall system may result unprofitable, therefore new technologies are under study. In this work, a new process for the purification of natural gas based on a low temperature distillation has been studied, focusing on the dynamics of the system. The robustness of the process has been studied by dynamic simulation of an industrial-scale plant, with particular regard to the performances when operating conditions are changed. The results show that the process can obtain the methane product with a high purity and avoid the solidification of carbon dioxide.

关键词: CO2 capture     innovative process     cryogenic distillation     dynamic simulation     solid-liquid-vapor equilibrium    

A computational toolbox for molecular property prediction based on quantum mechanics and quantitative structure-property relationship

《化学科学与工程前沿(英文)》 2022年 第16卷 第2期   页码 152-167 doi: 10.1007/s11705-021-2060-z

摘要: Chemical industry is always seeking opportunities to efficiently and economically convert raw materials to commodity chemicals and higher value-added chemical-based products. The life cycles of chemical products involve the procedures of conceptual product designs, experimental investigations, sustainable manufactures through appropriate chemical processes and waste disposals. During these periods, one of the most important keys is the molecular property prediction models associating molecular structures with product properties. In this paper, a framework combining quantum mechanics and quantitative structure-property relationship is established for fast molecular property predictions, such as activity coefficient, and so forth. The workflow of framework consists of three steps. In the first step, a database is created for collections of basic molecular information; in the second step, quantum mechanics-based calculations are performed to predict quantum mechanics-based/derived molecular properties (pseudo experimental data), which are stored in a database and further provided for the developments of quantitative structure-property relationship methods for fast predictions of properties in the third step. The whole framework has been carried out within a molecular property prediction toolbox. Two case studies highlighting different aspects of the toolbox involving the predictions of heats of reaction and solid-liquid phase equilibriums are presented.

关键词: molecular property     quantum mechanics     quantitative structure-property relationship     heat of reaction     solid-liquid phase equilibrium    

标题 作者 时间 类型 操作

Ultrafast solid-liquid-vapor phase change of a thin gold film irradiated by femtosecond laser pulses

Jing HUANG, Yuwen ZHANG, J. K. CHEN, Mo YANG

期刊论文

Flow boiling heat transfer in circulating fluidized bed

Xiaoguang REN , Jiangdong ZHENG , Sefiane KHELLIl , Arumemi-Ikhide MICHAEL ,

期刊论文

Shock wave of vapor-liquid two-phase flow

ZHAO Liangju, GAO Hong, TANG Jingwen, YUAN Yuexiang, WANG Fei

期刊论文

Development of new transient liquid phase system Au-Sn-Au for microsystem technology

Kirsten BOBZIN, Nazlim BAGCIVAN, Lidong ZHAO, Stefania FERRARA, Jan PERNE

期刊论文

Numerical simulation of three-dimensional gas/liquid two-phase flow in a proton exchange membrane fuel

ZHUGE Weilin, ZHANG Yangjun, LAO Xingsheng, CHEN Xiao, MING Pingwen

期刊论文

Detection of geosmin and 2-methylisoborneol by liquid-liquid extraction-gas chromatograph mass spectrum(LLE-GCMS) and solid phase extraction-gas chromatograph mass spectrum (SPE-GCMS)

MA Xiaoyan, CHEN Beibei, LI Qingsong, ZHANG Qiaoli, GU Guofen

期刊论文

New refrigeration system using CO vapor-solid as refrigerant

HUANG Dongping, DING Guoliang, QUACK Hans

期刊论文

Microfluidic production of liposomes through liquidliquid phase separation in ternary droplets

期刊论文

An efficient resin for solid-phase extraction and determination by UPLCMS/MS of 44 pharmaceutical personal

Feng Zhu, Zhijian Yao, Wenliang Ji, Deye Liu, Hao Zhang, Aimin Li, Zongli Huo, Qing Zhou

期刊论文

Advances and perspectives in catalysts for liquid-phase oxidation of cyclohexane

Hui LI, Yuanbin SHE, Tao WANG

期刊论文

A multiscale material model for heterogeneous liquid droplets in solid soft composites

期刊论文

Analysis of the radiation heat transfer process of phase change for a liquid droplet radiator in space

Jinying YIN, Linhua LIU

期刊论文

A novel cryogenic insulation system of hollow glass microspheres and self-evaporation vapor-cooled shieldfor liquid hydrogen storage

Jianpeng ZHENG, Liubiao CHEN, Ping WANG, Jingjie ZHANG, Junjie WANG, Yuan ZHOU

期刊论文

Study of the robustness of a low-temperature dual-pressure process for removal of CO

Stefania Moioli, Laura A. Pellegrini, Paolo Vergani, Fabio Brignoli

期刊论文

A computational toolbox for molecular property prediction based on quantum mechanics and quantitative structure-property relationship

期刊论文