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可持续发展 2

固体氧化物燃料电池 2

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design of novel proton-pump inhibitors with reduced adverse effects

Xiaoyi Li, Hong Kang, Wensheng Liu, Sarita Singhal, Na Jiao, Yong Wang, Lixin Zhu, Ruixin Zhu

《医学前沿(英文)》 2019年 第13卷 第2期   页码 277-284 doi: 10.1007/s11684-018-0630-3

摘要: The development of new proton-pump inhibitors (PPIs) with less adverse effects by lowering the pKa values of nitrogen atoms in pyrimidine rings has been previously suggested by our group. In this work, we proposed that new PPIs should have the following features: (1) number of ring II= number of ring I+ 1; (2) preferably five, six, or seven-membered heteroatomic ring for stability; and (3) 1

关键词: proton-pump inhibitor     adverse effect     pharmacological mechanism     toxicological mechanism     pKa calculation    

TiO supported IrO for anode reversal tolerance in proton exchange membrane fuel cell

《能源前沿(英文)》 2022年 第16卷 第5期   页码 852-861 doi: 10.1007/s11708-021-0811-7

摘要: Fuel starvation can occur and cause damage to the cell when proton exchange membrane fuel cells operate under complex working conditions. In this case, carbon corrosion occurs. Oxygen evolution reaction (OER) catalysts can alleviate carbon corrosion by introducing water electrolysis at a lower potential at the anode in fuel shortage. The mixture of hydrogen oxidation reaction (HOR) and unsupported OER catalyst not only reduces the electrolysis efficiency, but also influences the initial performance of the fuel cell. Herein, Ti4O7 supported IrOx is synthesized by utilizing the surfactant-assistant method and serves as reversal tolerant components in the anode. When the cell reverse time is less than 100 min, the cell voltage of the MEA added with IrOx/Ti4O7 has almost no attenuation. Besides, the MEA has a longer reversal time (530 min) than IrOx (75 min), showing an excellent reversal tolerance. The results of electron microscopy spectroscopy show that IrOx particles have a good dispersity on the surface of Ti4O7 and IrOx/Ti4O7 particles are uniformly dispersed on the anode catalytic layer. After the stability test, the Ti4O7 support has little decay, demonstrating a high electrochemical stability. IrOx/Ti4O7 with a high dispersity has a great potential to the application on the reversal tolerance anode of the fuel cell.

关键词: proton exchange membrane fuel cell (PEMFC)     fuel starvation     cell reverse     reversal tolerance anode     oxygen evolution reaction    

Fabrication and performance of PEN SOFCs with proton-conducting electrolyte

ZHONG Li, LUO Jingli, Karl Chuang

《化学科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 40-44 doi: 10.1007/s11705-007-0008-6

摘要: A positive-electrolyte-negative (PEN) assembly solid oxide fuel cell (SOFC) with a thin electrolyte film for intermediate temperature operation was fabricated. Instead of the traditional screen-printing method, both anode and cathode catalysts were pressed simultaneously and formed with the fabrication of nano-composite electrolyte by press method. This design offered some advantageous configurations that diminished ohmic resistance between electrolyte and electrodes. It also increased the proton-conducting rate and improved the performance of SOFC due to the reduction of membrane thickness and good contact between electrolyte and electrodes. The fabricated PEN cell generated electricity between 600?C and 680?C using HS as fuel feed and air as oxidant. Maximum power densities 40 mW " cm and 130 mW " cm for the PEN configuration with a Mo-Ni-S-based composite anode, nano-composite electrolyte (LiSO+AlO) film and a NiO-based composite cathode were achieved at 600?C and 680?C, respectively.

关键词: proton-conducting     positive-electrolyte-negative     temperature operation     Mo-Ni-S-based composite     advantageous    

Elliptical lobe shape gerotor pump design to minimize wear

Mohammad Reza KARAMOOZ RAVARI

《机械工程前沿(英文)》 2011年 第6卷 第4期   页码 429-434 doi: 10.1007/s11465-011-0247-6

摘要:

The gerotor pumps are the most important parts of mechanical equipment that have a vast number of applications in industries and automobiles. Because the gerotor pumps cannot be adjusted for wear so it is important to reduce the wear as much as possible. In this paper first mathematical equations for elliptical lobe shape rotors profile and curvature of them have been derived and then Specific flow and wear rate proportional factor (WRPF) have been formulated. To reach the minimum wear in rotors teeth, the ellipse shape factor is changed for each value of number of outer rotor teeth in a feasible range and wear rate proportional factor has been resulted. Also in order to have better comparison specific flow has been presented. The obtained results have been compared with circular pumps with similar geometrical parameters and show the significant improvement in wear of the rotors with negligible changes in the specific flow.

关键词: gerotor pump     elliptical lobe shape pump     wear rate proportional factor (WRPF)     specific flow    

Extended two-fluid model applied to analysis of bubbly flow in multiphase rotodynamic pump impeller

Zhiyi YU, Guoyu WANG, Shuliang CAO

《机械工程前沿(英文)》 2009年 第4卷 第1期   页码 53-59 doi: 10.1007/s11465-009-0006-0

摘要: This paper presents an extended two-fluid model based on the Navier-Stokes equations and the standard turbulence model, to simulate the three-dimensional air-water bubbly flow in turbo machinery. In the governing equations, the drag force and added mass force are added and the additional source terms arising from fluctuations of gas volume fraction are considered. The discrete equations are solved using a developed two-phase semi-implicit method for pressure-linked equations, consistent (SIMPLEC) algorithm in body-fitted coordinates with a staggered grid system. Simulation is then carried out for the pure liquid flow and air-water two-phase flow with the inlet gas volume fraction being 15% in a multiphase rotodynamic pump impeller and the pump head performance is predicted. Comparison with experimental results shows the reliability and commonality of the numerical model.

关键词: two-fluid model     multiphase rotodynamic pump     SIMPLEC algorithm     numerical simulation    

R&D of the ground-coupled heat pump technology in China

Nairen DIAO, Ping CUI, Junhong LIU, Zhaohong FANG,

《能源前沿(英文)》 2010年 第4卷 第1期   页码 47-54 doi: 10.1007/s11708-009-0080-3

摘要: The ground-coupled heat pump (GCHP) systems have been identified as one of the best sustainable energy technologies for space heating and cooling in residential and commercial buildings. In this paper, research on and development of the GCHP technology in China are summarized. New models are presented for efficient thermal analysis of ground heat exchangers, of which one- and two-dimensional solid cylindrical source models and their analytical solutions are devised to deal with pile ground heat exchangers. Analytical solutions are also derived for vertical and inclined finite line source models as well as for a groundwater advection model. Explicit solutions of a quasi-three-dimensional model can be used to better evaluate the thermal resistance inside boreholes. Studies on hybrid GCHP systems and the thermal response test in China are also commented.

关键词: ground source heat pump     ground heat exchanger     HVAC     China    

Spin polarization strategy to deploy proton resource over atomic-level metal sites for highly selective

《化学科学与工程前沿(英文)》 2022年 第16卷 第12期   页码 1772-1781 doi: 10.1007/s11705-022-2197-4

摘要: Unlocking of the extremely inert C=O bond during electrochemical CO2 reduction demands subtle regulation on a key “resource”, protons, necessary for intermediate conversion but also readily trapped in water splitting, which is still challenging for developing efficient single-atom catalysts limited by their structural simplicity usually incompetent to handle this task. Incorporation of extra functional units should be viable. Herein, a proton deployment strategy is demonstrated via “atomic and nanostructured iron (A/N-Fe) pairs”, comprising atomically dispersed iron active centers spin-polarized by nanostructured iron carbide ferromagnets, to boost the critical protonation steps. The as-designed catalyst displays a broad window (300 mV) for CO selectivity > 90% (98% maximum), even outperforming numerous cutting-edge M–N–C systems. The well-placed control of proton dynamics by A/N-Fe can promote *COOH/*CO formation and simultaneously suppress H2 evolution, benefiting from the magnetic-proximity-induced exchange splitting (spin polarization) that properly adjusts energy levels of the Fe sites’ d-shells, and further those of the adsorbed intermediates’ antibonding molecular orbitals.

关键词: CO2 electrolysis     single-atom catalysts     spin polarization     proton dynamics     in situ IR spectroscopy     kinetic isotope effect    

Evaluation of the performance of a centralized ground-water heat pump system in cold climate region

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

《能源前沿(英文)》 2014年 第8卷 第3期   页码 394-402 doi: 10.1007/s11708-014-0310-1

摘要: The aim of this study is to evaluate the performance of a centralized open-loop ground-water heat pump (GWHP) system for climate conditioning in Beijing with a cold climate in China. Thus, a long-time test was conducted on a running GWHP system for the heating season from December 2011 to March 2012. The analysis of the testing data indicates that the average heat-pump coefficient of performance (COP) and the COP of the system (COPs) are 4.27 and 2.59. The low value and large fluctuation in the range of COP are found to be caused by the heat transfixion in the aquifer and the bypass in the circulation loop. Therefore, some suggestions are proposed to improve the performance for GWHPs in the cold climate region in China.

关键词: ground-water heat pump (GWHP)     actual coefficient of performance     heat transfixion    

A valveless piezoelectric pump with novel flow path design of function of rectification to improve energy

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0685-3

摘要: Existing valveless piezoelectric pumps are mostly based on the flow resistance mechanism to generate unidirectional fluid pumping, resulting in inefficient energy conversion because the majority of mechanical energy is consumed in terms of parasitic loss. In this paper, a novel tube structure composed of a Y-shaped tube and a ȹ-shaped tube was proposed considering theory of jet inertia and vortex dissipation for the first time to improve energy efficiency. After verifying its feasibility through the flow field simulation, the proposed tubes were integrated into a piezo-driven chamber, and a novel valveless piezoelectric pump with the function of rectification (NVPPFR) was reported. Unlike previous pumps, the reported pump directed the reflux fluid to another flow channel different from the pumping fluid, thus improving pumping efficiency. Then, mathematical modeling was established, including the kinetic analysis of vibrator, flow loss analysis of fluid, and pumping efficiency. Eventually, experiments were designed, and results showed that NVPPFR had the function of rectification and net pumping effect. The maximum flow rate reached 6.89 mL/min, and the pumping efficiency was up to 27%. The development of NVPPFR compensated for the inefficiency of traditional valveless piezoelectric pumps, broadening the application prospect in biomedicine and biology fields.

关键词: composite tube     valveless piezoelectric pump     rectification     energy efficiency    

Absorption heat pump for waste heat reuse: current states and future development

Zhenyuan XU, Ruzhu WANG

《能源前沿(英文)》 2017年 第11卷 第4期   页码 414-436 doi: 10.1007/s11708-017-0507-1

摘要: Absorption heat pump attracts increasing attention due to its advantages in low grade thermal energy utilization. It can be applied for waste heat reuse to save energy consumption, reduce environment pollution, and bring considerable economic benefit. In this paper, three important aspects for absorption heat pump for waste heat reuse are reviewed. In the first part, different absorption heat pump cycles are classified and introduced. Absorption heat pumps for heat amplification and absorption heat transformer for temperature upgrading are included. Both basic single effect cycles and advanced cycles for better performance are introduced. In the second part, different working pairs, including the water based working pairs, ammonia based working pairs, alcohol based working pairs, and halogenated hydrocarbon based working pairs, for absorption heat pump are classified based on the refrigerant. In the third part, the applications of the absorption heat pump and absorption heat transformer for waste heat reuse in different industries are introduced. Based on the reviews in the three aspects, essential summary and future perspective are presented at last.

关键词: absorption     heat pump     heat transformer     waste heat     working pair    

Efficiency characteristics of piezostack pump for linear actuators

Junwu KAN, Kehong TANG, Chenghui SHAO, Guoren ZHU, Taijiang PENG,

《机械工程前沿(英文)》 2009年 第4卷 第4期   页码 407-414 doi: 10.1007/s11465-009-0049-2

摘要: A piezostack pump for linear actuators is presented and studied in terms of mechanical energy efficiency (MEE), energy conversion efficiency (ECE) and design method. MEE is defined as the ratio of the output mechanical energy to that converted from input electrical energy, and ECE is the ratio of output mechanical energy to input electrical energy. The analysis results show that both MEE and ECE decrease with the increase of stiffness of the chamber diaphragm (), which is a function of the radius ratio (rigid disk radius to chamber radius). There is respective optimal external load () for them to achieve peak value for a given piezostack with blocked force () and stiffness (). The optimal force ratio (/) is a constant of 0.5 for maximum MEE, and between 0.57 and 0.5 for maximum ECE. Considering the deflection of the pump chamber and dynamic response of the piezostack, the stiffness ratio (/) should be limited between 0.3 and 1, and the relative radius ratio is between 0.7 and 0.8. With the increase of the radius ratio in the range, the maximal MEE decreases from 0.38 to 0.25, and the peak ECE decreases from 0.20 to 0.14.

关键词: piezostack actuator     piezostack pump     mechanical efficiency     energy conversion efficiency (ECE)    

Ionic liquid modified Pt/C electrocatalysts for cathode application in proton exchange membrane fuel

Huixin Zhang, Jinying Liang, Bangwang Xia, Yang Li, Shangfeng Du

《化学科学与工程前沿(英文)》 2019年 第13卷 第4期   页码 695-701 doi: 10.1007/s11705-019-1838-8

摘要: The modification of Pt/C catalyst by using ionic liquids to improve their catalyst activities has been reported by many researchers, but their practical behavior in operating fuel cells is still unknown. In this work, we study the ionic liquid modified Pt/C nanoparticle catalysts within cathodes for proton exchange membrane fuel cells. The influence of the ionic liquid amount, adsorption times and dispersing solvents are investigated. The experiment results show the best performance enhancement is achieved through two-time surface modification with 2 wt-% ionic liquid solution. The mechanisms are explored with the attribution to the high oxygen solubility in the ionic liquid enabling an improved oxygen diffusion in micropores and to good hydrophobicity facilitating water expelling from the active sites in fuel cell operation.

关键词: ionic liquid     PEMFC     electrode     oxygen reduction reaction     electrocatalyst     adsorption    

Design and analysis of linear oscillating motor for linear pump application-magnetic field, dynamics

Zongxia JIAO,Tianyi WANG,Liang YAN

《机械工程前沿(英文)》 2016年 第11卷 第4期   页码 351-362 doi: 10.1007/s11465-016-0407-9

摘要:

A linear oscillating motor is an electromagnetic actuator that can achieve short-stroke reciprocating movement directly without auxiliary transmission mechanisms. It has been widely used in linear pump applications as the source of power and motion. However, because of the demand of high power density in a linear actuation system, the performance of linear oscillating motors has been the focus of studies and deserves further research for high power density. In this paper, a general framework of linear oscillating motor design and optimization is addressed in detail, including the electromagnetic, dynamics, and thermal aspects. First, the electromagnetic and dynamics characteristics are modeled to reveal the principle for optimization. Then, optimization and analysis on magnetic structure, resonant system, and thermal features are conducted, which provide the foundation for prototype development. Finally, experimental results are provided for validation. As a whole, this process offers complete guidance for high power density linear oscillating motors in linear pump applications.

关键词: linear oscillating motor     linear pump     magnetic field     motor optimization    

Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

《化学科学与工程前沿(英文)》 2022年 第16卷 第3期   页码 364-375 doi: 10.1007/s11705-021-2052-z

摘要: The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells. In this paper, accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading. The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires, as well as their electrochemical performances in a single cell, are investigated. The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires. With increasing reduction temperature, the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40 °C. A mechanism of the Pt nanowires growth is proposed. The optimized Pt nanowires electrode exhibits a power density (based on electrochemical active surface area) 79% higher than conventional Pt/C one. The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.

关键词: Pt nanowires     morphology     structure control     in situ growth mechanism     proton exchange membrane fuel cells    

A solar assisted heat pump drying system for grain in-store drying

Haifeng LI, Yanjun DAI, Jianguo DAI, Xibo WANG, Lei WEI,

《能源前沿(英文)》 2010年 第4卷 第3期   页码 386-391 doi: 10.1007/s11708-010-0003-3

摘要: For grain in-store drying, a solar assisted drying process has been developed, which consists of a set including a solar-assisted heat pump, a ventilation system, a grain stirrer, etc. In this way, low power consumption, short cycle time and water content uniformity can be achieved in comparison with the conventional method. A solar-assisted heat pump drying system has been designed and manufactured for a practical granary, and the energy consumption performance of the unit is analyzed. The analysis result shows that the solar fraction of the unit is higher than 20%, the coefficient of performance about system (COP) is 5.19, and the specific moisture extraction rate (SMER) can reach 3.05 kg/kWh.

关键词: solar energy     heat pump     airflow     in-store drying    

标题 作者 时间 类型 操作

design of novel proton-pump inhibitors with reduced adverse effects

Xiaoyi Li, Hong Kang, Wensheng Liu, Sarita Singhal, Na Jiao, Yong Wang, Lixin Zhu, Ruixin Zhu

期刊论文

TiO supported IrO for anode reversal tolerance in proton exchange membrane fuel cell

期刊论文

Fabrication and performance of PEN SOFCs with proton-conducting electrolyte

ZHONG Li, LUO Jingli, Karl Chuang

期刊论文

Elliptical lobe shape gerotor pump design to minimize wear

Mohammad Reza KARAMOOZ RAVARI

期刊论文

Extended two-fluid model applied to analysis of bubbly flow in multiphase rotodynamic pump impeller

Zhiyi YU, Guoyu WANG, Shuliang CAO

期刊论文

R&D of the ground-coupled heat pump technology in China

Nairen DIAO, Ping CUI, Junhong LIU, Zhaohong FANG,

期刊论文

Spin polarization strategy to deploy proton resource over atomic-level metal sites for highly selective

期刊论文

Evaluation of the performance of a centralized ground-water heat pump system in cold climate region

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

期刊论文

A valveless piezoelectric pump with novel flow path design of function of rectification to improve energy

期刊论文

Absorption heat pump for waste heat reuse: current states and future development

Zhenyuan XU, Ruzhu WANG

期刊论文

Efficiency characteristics of piezostack pump for linear actuators

Junwu KAN, Kehong TANG, Chenghui SHAO, Guoren ZHU, Taijiang PENG,

期刊论文

Ionic liquid modified Pt/C electrocatalysts for cathode application in proton exchange membrane fuel

Huixin Zhang, Jinying Liang, Bangwang Xia, Yang Li, Shangfeng Du

期刊论文

Design and analysis of linear oscillating motor for linear pump application-magnetic field, dynamics

Zongxia JIAO,Tianyi WANG,Liang YAN

期刊论文

Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

Ruiqing Wang, Xiaolan Cao, Sheng Sui, Bing Li, Qingfeng Li

期刊论文

A solar assisted heat pump drying system for grain in-store drying

Haifeng LI, Yanjun DAI, Jianguo DAI, Xibo WANG, Lei WEI,

期刊论文