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关键词

Cu(In 4

薄膜润滑 4

Ga)Se2 3

多输入多输出 2

2016年熊本地震 1

ALOS-2 PALSAR-2 1

BFT 1

CCS 1

CO2分离 1

Ga)Se2光伏组件 1

MIMO雷达;波形设计;谱分解;分式二次约束二次规划 1

Ni–Ti–Cu–V合金 1

PDT 1

PM2.52.5浓度聚类 1

PM2.52.5浓度预测 1

VO2薄膜 1

WiFi多频天线 1

三维形变反演 1

上行非正交多址;Generalized Welch界等式;多级接收功率;序列分组 1

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Ag/PMMA hollow waveguide for solar energy transmission

He LAN, Jianjun HAN, Hongping CHEN, Xiujian ZHAO

《化学科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 303-307 doi: 10.1007/s11705-010-0565-y

摘要: This paper describes an elaborate study on obtaining Ag/PMMA (polymethyl methacrylate) leaky hollow waveguide which has a large aperture and low loss in transmitting solar energy. Through analyses and comparison, a quartz capillary with the inner diameter of 2 mm was chosen as hollow waveguide. We used the xenon light source, which has the similar spectrum as the sunlight to test and analyze the performance of the Ag/PMMA leakage hollow waveguide. The results are consistent with the transmitted theory of the dielectric/metal leaky type well. Meanwhile, the Ag/PMMA leaky-type hollow waveguide in this work had good qualities. Therefore, it will be a satisfactory medium for solar energy transmission.

关键词: hollow waveguide     transmit the solar energy     Ag/PMMA multiple film     parabolic collector    

preparation of Ag@AgCl/Bio-veins composites and their photocatalytic activity and recyclability

《化学科学与工程前沿(英文)》 2023年 第17卷 第7期   页码 906-917 doi: 10.1007/s11705-022-2273-9

摘要: The industrial application of nano-photocatalysts in wastewater treatment has been severely restricted for a long time due to their difficult separation, poor reusability, and low efficiency. In this work, a facile strategy was proposed to enhance the photocatalytic activity and recovery performance of Ag@AgCl nanocatalysts. Biological veins (Bio-veins) with a unique 3D porous construction were used as carriers for the in-situ growth of Ag@AgCl nanoparticles. Scanning electron microscopy results showed that the Ag@AgCl nanoparticles were uniformly loaded on the surface and interior of the Bio-veins, and the size of the Ag@AgCl nanoparticles immobilized on the Bio-veins (50–300 nm) was significantly smaller than Ag@AgCl obtained by the co-precipitation method (1–3 μm). The Bio-veins played a vital role in the photocatalysis reaction system. The degradation efficiency of the Ag@AgCl/Bio-veins(CI4) was up to 3.50 times as high as pure Ag@AgCl. Furthermore, the composites also exhibited excellent recyclability and stability under both visible and solar light. This work provided a suitable strategy for nano-photocatalysts for practical application and may also offer new possibilities for the high-value utilization of biomass materials.

关键词: Ag@AgCl     biological veins     photocatalytic activity     recyclability    

Morphological and mechanical characterization of a PMMA/CdS nanocomposite

Vishal MATHUR, Manasvi DIXIT, K.S. RATHORE, N. S. SAXENA, K.B. SHARMA

《化学科学与工程前沿(英文)》 2011年 第5卷 第2期   页码 258-263 doi: 10.1007/s11705-010-1014-7

摘要: Thick film of poly(methyl methacrylate) (PMMA)/CdS nanocomposite have been synthesized by the solution casting process. The nanostructure of the CdS particles has been ascertained through the small angle X-ray scattering (SAXS) technique. The surface morphological characterization of the PMMA/CdS nanocomposite has been done through scanning electron microscopy (SEM) analysis. The variation of mechanical loss factor (Tan ) with temperature and tensile properties of prepared samples have been studied using Dynamic Mechanical Analyzer (DMA). This study reveals that the glass transition temperature ( ), Young’s modulus, and fracture energy of the PMMA/CdS nanocomposite are greatly influenced by the existence of interfacial energetic interaction between dispersed CdS nanoparticles and the matrix of PMMA.

关键词: poly(methyl methacrylate) (PMMA)     filler nanoparticles     polymer semiconducting nanocomposite     tensile properties     glass transition temperature    

Boosting the direct conversion of NHHCO electrolyte to syngas on Ag/Zn zeolitic imidazolate framework

《化学科学与工程前沿(英文)》 2023年 第17卷 第9期   页码 1196-1207 doi: 10.1007/s11705-022-2289-1

摘要: The electrochemical reduction of NH4HCO3 to syngas can bypass the high energy consumption of high-purity CO2 release and compression after the ammonia-based CO2 capture process. This technology has broad prospects in industrial applications and carbon neutrality. A zeolitic imidazolate framework-8 precursor was introduced with different Ag contents via colloid chemical synthesis. This material was carbonized at 1000 °C to obtain AgZn zeolitic imidazolate framework derived nitrogen carbon catalysts, which were used for the first time for boosting the direct conversion of NH4HCO3 electrolyte to syngas. The AgZn zeolitic imidazolate framework derived nitrogen carbon catalyst with a Ag/Zn ratio of 0.5:1 achieved the highest CO Faradaic efficiency of 52.0% with a current density of 1.15 mA·cm–2 at –0.5 V, a H2/CO ratio of 1–2 (–0.5 to –0.7 V), and a stable catalytic activity of more than 6 h. Its activity is comparable to that of the CO2-saturated NH4HCO3 electrolyte. The highly discrete Ag-Nx and Zn-Nx nodes may have combined catalytic effects in the catalysts synthesized by appropriate Ag doping and sufficient carbonization. These nodes could increase active sites of catalysts, which is conducive to the transport and adsorption of reactant CO2 and the stability of *COOH intermediate, thus can improve the selectivity and catalytic activity of CO.

关键词: Ag catalyst     zeolitic imidazolate framework     CO2 electroreduction     ammonium bicarbonate electrolyte     syngas    

Novel Ag-AgBr decorated composite membrane for dye rejection and photodegradation under visible light

Yixing Wang, Liheng Dai, Kai Qu, Lu Qin, Linzhou Zhuang, Hu Yang, Zhi Xu

《化学科学与工程前沿(英文)》 2021年 第15卷 第4期   页码 892-901 doi: 10.1007/s11705-020-2011-0

摘要: Photocatalytic membranes have received increasing attention due to their excellent separation and photodegradation of organic contaminants in wastewater. Herein, we bound Ag-AgBr nanoparticles onto a synthesized polyacrylonitrile-ethanolamine (PAN-ETA) membrane with the aid of a chitosan (CS)-TiO layer via vacuum filtration and partial reduction. The introduction of the CS-TiO layer improved surface hydrophilicity and provided attachment sites for the Ag-AgBr nanoparticles. The PAN-ETA/CS-TiO /Ag-AgBr photocatalytic membranes showed a relatively high water permeation flux (~ 47 L·m ·h ·bar ) and dyes rejection (methyl orange: 88.22%; congo red: 95%; methyl blue: 97.41%; rose bengal: 99.98%). Additionally, the composite membranes exhibited potential long-term stability for dye/salt separation (dye rejection: ~97%; salt rejection: ~6.5%). Moreover, the methylene blue and rhodamine B solutions (20 mL, 10 mg·L ) were degraded approximately 90.75% and 96.81% in batch mode via the synthesized photocatalytic membranes under visible light irradiation for 30 min. This study provides a feasible method for the combination of polymeric membranes and inorganic catalytic materials.

关键词: Ag-AgBr     dye rejection     photodegradation     visible light    

Simultaneous removal of trihalomethanes by bimetallic Ag/Zn: kinetics study

Ahmed H A DABWAN, Satoshi KANECO, Hideyuki KATSUMATA, Kiyoyuki EGUSA, Tohru SUZUKI, Kiyohisa OHTA,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 322-327 doi: 10.1007/s11705-009-0261-y

摘要: In the present work, bimetallic silver/zinc was applied into the degradation of trihalomethanes, THMs: CHCl, CHBrCl, CHBrCl, and CHBr. The kinetics reaction rates and removal efficiencies of the THM compound mixtures, in the aqueous solutions, were investigated. Batch experiments were conducted under mild conditions, ambient temperature, and pressure. The primary degradation reaction followed a pseudo-first-order kinetic law. The first-order rate constants and the degradation efficiencies followed the decreasing order of CHBr>CHBrCl>CHBrCl>CHCl. The bond dissociation energy and hydrophilic/hydrophobic characteristics of the THM compounds may become the most important parameters affecting the degradation kinetics and efficiency by bimetallic Ag/Zn.

关键词: reaction     first-order     dissociation     degradation reaction     aqueous    

Numerical simulation of liquid falling film on horizontal circular tubes

Fengdan SUN, Songlin XU, Yongchuan GAO

《化学科学与工程前沿(英文)》 2012年 第6卷 第3期   页码 322-328 doi: 10.1007/s11705-012-1296-z

摘要: The objective of this study is to investigate numerically the flow characteristics of falling film on horizontal circular tubes. Numerical simulations are performed using FLUENT for 2D configurations with one and two cylinders. The volume of fluid method is used to track the motion of liquid falling film and the gas-liquid interface. The effect of flow characteristics on heat and transfer coefficient may be remarkable, although it has been neglected in previous studies. The velocity distribution and the film thickness characteristics on the top tube, some special flow characteristics on the bottom tube, intertube flow modes and effect of liquid feeder height on flow characteristics have been studied. Our simulations indicate that 1) the velocity distributions of the upper and lower parts of the tube are not strictly symmetric and non-uniform, 2) the film thickness depends on flow rate and angular distributions, 3) the flow characteristics of the top tube are different from those of the bottom tube, 4) three principal and two intermediate transition modes are distinguished, and 5) the liquid feed height plays an important role on the formation of falling film. The numerical results are in a good agreement with the theoretical values by the Nusselt model and the reported results.

关键词: falling film     horizontal tube     flow characteristics     film thickness     liquid feeder height    

Experiment and optimal design of a collection device for a residual plastic film baler

Qi NIU,Xuegeng CHEN,Chao JI,Jie WU

《农业科学与工程前沿(英文)》 2015年 第2卷 第4期   页码 347-354 doi: 10.15302/J-FASE-2015077

摘要: It is imperative to carry out research on residual plastic film collection technology to solve the serious problem of farmland pollution. The residual plastic film baler was designed as a package for film strip collection, cleaning and baling. The collection device is a core component of the baler. Response surface analysis was used in this study to optimize the structure and working parameters for improving the collection efficiency of residual film and the impurity of film package. The results show that the factors affecting the collection rate of residual film and the impurity of the film package are the speed ratio ( ) between the trash removal roller and eccentric collection mechanism, the number ( ) and the mounting angle ( ) of spring teeth in the same revolution plane. For the collection rate, the importance of the three factors are in the order, . Meanwhile, for the impurity, the importance of three factors are in the order, . When the speed ratio, the mounting angle and the number of spring teeth was set at 1.6°, 45°, and 8°, respectively, the collection rate of residual film was 88.9% and the impurity of residual film package was 14.2% for the baler.

关键词: residual film     collection device     collection rate of residual film     impurity of film package     optimization     baler    

Lignin-based electrospun nanofiber membrane decorated with photo-Fenton Ag@MIF-100(Fe) heterojunctions

《化学科学与工程前沿(英文)》 2023年 第17卷 第7期   页码 930-941 doi: 10.1007/s11705-023-2309-9

摘要: Membrane technology for wastewater remediation has aroused wide interest owing to its unique properties and potential applications. However, it remains challenging to explore green, efficient and robust membrane material and technique for complex wastewater treatment. Herein, we proposed using a simple electrospinning and in situ seeding method to fabricate a lignin-based electrospun nanofiber membrane (LENM) decorated with photo-Fenton Ag@MIL-100(Fe) heterojunctions for efficient separation of oil/water emulsions and degradation of organic dye. Thanks to the embedded lignin in LENM, an ultrahigh MIL-100(Fe) loading (53 wt %) with good wettability and high porosity was obtained. As a result, the hybrid Ag@MIL-100(Fe)/LENM exhibited excellent oil/water emulsions separation efficiency (more than 97%) without a compromise of water flux. Moreover, the hybrid membrane showed an excellent dye removal with degradation of 99% methylene blue within 30 min under illumination, which is attributed to a synergy of dye adsorption/enrichment and photo-Fenton catalytic degradation from Ag@MIL-100(Fe). Therefore, the lignin-based photo-Fenton hybrid membrane can lay the foundation for the preparation and application of green, sustainable and versatile membrane materials and technologies for efficient complex wastewater remediation.

关键词: lignin     electrospinning     heterojunctions     photo-Fenton catalysis     wastewater remediation    

薄膜润滑研究的回顾与展望

雒建斌,张朝辉,温诗铸

《中国工程科学》 2003年 第5卷 第7期   页码 84-89

摘要:

薄膜润滑是20世纪90年代以来广泛研究的新型润滑状态。它是界于弹流润滑和边界润滑之间的一种过渡润滑状态,有着自己独特的润滑规律。文章回顾了薄膜润滑的研究历史,包括薄膜润滑概念的提出、测试技术的发展、薄膜润滑的膜厚特性、润滑机理探索以及计算理论等方面的研究成果与主要进展。

关键词: 薄膜润滑     有序膜     膜厚测量     微结构    

Synthesis of Ag and Cd nanoparticles by nanosecond pulsed discharge in liquid nitrogen

Mahmoud Trad, Alexandre Nominé, Natalie Tarasenka, Jaafar Ghanbaja, Cédric Noël, Malek Tabbal, Thierry Belmonte

《化学科学与工程前沿(英文)》 2019年 第13卷 第2期   页码 360-368 doi: 10.1007/s11705-019-1802-7

摘要: The synthesis of CdO, Ag O (5 nm) and Ag (~20‒30 nm) nano-objects is achieved simultaneously by nanosecond-pulsed discharges in liquid nitrogen between one cadmium electrode and one silver electrode. Oxidation occurs when liquid nitrogen is fully evaporated and nanoparticles are in contact with the air. No alloy is formed, whatever the conditions, even though both elements are present simultaneously, as showed by time-resolved optical emission spectroscopy. This lack of reactivity between elements is attributed to the high pressure within the discharge that keeps each metallic vapor around the electrode it comes from. Each element exhibits a specific behavior. Cubic Cd particles, formed at 4 kV, get elongated with filamentary tips when the applied voltage reaches 7 and 10 kV. Cd wires are formed by assembly in liquid nitrogen of Cd nanoparticles driven by dipole assembly, and not by dielectrophoresis. On the contrary, silver spherical particles get assembled into 2D dendritic structures. The anisotropic growth of these structures is assumed to be due to the existence of pressure gradients.

关键词: spark discharges     submerged discharges     time-resolved optical emission spectroscopy     liquid nitrogen    

Thin-liquid-film evaporation at contact line

Hao WANG, Zhenai PAN, Zhao CHEN

《能源前沿(英文)》 2009年 第3卷 第2期   页码 141-151 doi: 10.1007/s11708-009-0020-2

摘要: When a liquid wets a solid wall, the extended meniscus near the contact line may be divided into three regions: a nonevaporating region, where the liquid is adsorbed on the wall; a transition region or thin-film region, where effects of long-range molecular forces (disjoining pressure) are felt; and an intrinsic meniscus region, where capillary forces dominate. The thin liquid film, with thickness from nanometers up to micrometers, covering the transition region and part of intrinsic meniscus, is gaining interest due to its high heat transfer rates. In this paper, a review was made of the researches on thin-liquid-film evaporation. The major characteristics of thin film, thin-film modeling based on continuum theory, simulations based on molecular dynamics, and thin-film profile and temperature measurements were summarized.

关键词: meniscus     thin film     contact line     disjoining pressure     evaporation    

Separation/degradation behavior and mechanism for cationic/anionic dyes by Ag-functionalized FeO-PDA

《环境科学与工程前沿(英文)》 2022年 第16卷 第11期 doi: 10.1007/s11783-022-1572-1

摘要:

● PDA-Fe3O4-Ag was made by hydrothermal and oxidation self-polymerization method.

关键词: PDA     Fe3O4     Magnetic adsorbent     Cationic dyes     Anionic dyes    

Selective catalytic reduction of NOx from exhaust of lean-burn engine over Ag-Al2O3/cordierite catalyst

LI Junhua, KANG Shoufang, FU Lixin, HAO Jiming

《环境科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 143-146 doi: 10.1007/s11783-007-0025-1

摘要: A highly effective Ag-AlO catalyst was prepared using the sol-gel method, and characterized by surface area using nitrogen adsorption, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The catalyst performance was tested on a real lean-burn gasoline engine. Only unburned hydrocarbons and carbon monoxide in the exhaust were directly used as reductant (without any external reductant), the maximum NO conversion could only reach 40% at 450?C. When an external reductant, ethanol was added, the average NO conversion was greater than 60%. At exhaust gas temperature range of 350 500?C, the maximum NO conversion reached about 90%. CO and HC could be efficiently oxidized with Pt-AO oxidation catalyst placed at the end of SCR converter. However, NO conversion drastically decreased because of the oxidation of some intermediates to NO again. The possible reaction mechanism was proposed as two typical processes, nitration, and reduction in HC-SCR over Ag-AlO.

关键词: lean-burn gasoline     external reductant     nitrogen adsorption     conversion     catalyst performance    

Properties of Ag-doped Bi-Sb alloys as thermoelectric conversion materials for solid state refrigeration

Wen XU, Laifeng LI, Rongjin HUANG, Min ZHOU, Liyun ZHENG, Linghui GONG, Chunmei SONG

《能源前沿(英文)》 2009年 第3卷 第1期   页码 90-93 doi: 10.1007/s11708-009-0005-1

摘要: The energy conversion properties of Bi-Sb system thermoelectric materials doped by Ag was investigated. Bi Sb Ag ( =0, 1, 2, 3, 4) alloys with Ag substitution for Sb were synthesized by mechanical alloying and then pressed under 5 GPa at 523 K for 30 min. The phase structure of the alloys was characterized by X-ray diffraction. The electric conductivities and the seebeck coefficients were measured at the temperature range of 80-300 K. The results reveal that the electric conductivities of the Ag-doped Bi-Sb alloys are highly improved. The power factor of Bi Sb Ag reaches a maximum value of 2.98×10 W/(K ?m) at 255 K, which is about three times that of the un-doped sample Bi Sb at the same temperature.

关键词: thermoelectric conversion materials     high-pressure sintering     thermoelectric properties    

标题 作者 时间 类型 操作

Ag/PMMA hollow waveguide for solar energy transmission

He LAN, Jianjun HAN, Hongping CHEN, Xiujian ZHAO

期刊论文

preparation of Ag@AgCl/Bio-veins composites and their photocatalytic activity and recyclability

期刊论文

Morphological and mechanical characterization of a PMMA/CdS nanocomposite

Vishal MATHUR, Manasvi DIXIT, K.S. RATHORE, N. S. SAXENA, K.B. SHARMA

期刊论文

Boosting the direct conversion of NHHCO electrolyte to syngas on Ag/Zn zeolitic imidazolate framework

期刊论文

Novel Ag-AgBr decorated composite membrane for dye rejection and photodegradation under visible light

Yixing Wang, Liheng Dai, Kai Qu, Lu Qin, Linzhou Zhuang, Hu Yang, Zhi Xu

期刊论文

Simultaneous removal of trihalomethanes by bimetallic Ag/Zn: kinetics study

Ahmed H A DABWAN, Satoshi KANECO, Hideyuki KATSUMATA, Kiyoyuki EGUSA, Tohru SUZUKI, Kiyohisa OHTA,

期刊论文

Numerical simulation of liquid falling film on horizontal circular tubes

Fengdan SUN, Songlin XU, Yongchuan GAO

期刊论文

Experiment and optimal design of a collection device for a residual plastic film baler

Qi NIU,Xuegeng CHEN,Chao JI,Jie WU

期刊论文

Lignin-based electrospun nanofiber membrane decorated with photo-Fenton Ag@MIF-100(Fe) heterojunctions

期刊论文

薄膜润滑研究的回顾与展望

雒建斌,张朝辉,温诗铸

期刊论文

Synthesis of Ag and Cd nanoparticles by nanosecond pulsed discharge in liquid nitrogen

Mahmoud Trad, Alexandre Nominé, Natalie Tarasenka, Jaafar Ghanbaja, Cédric Noël, Malek Tabbal, Thierry Belmonte

期刊论文

Thin-liquid-film evaporation at contact line

Hao WANG, Zhenai PAN, Zhao CHEN

期刊论文

Separation/degradation behavior and mechanism for cationic/anionic dyes by Ag-functionalized FeO-PDA

期刊论文

Selective catalytic reduction of NOx from exhaust of lean-burn engine over Ag-Al2O3/cordierite catalyst

LI Junhua, KANG Shoufang, FU Lixin, HAO Jiming

期刊论文

Properties of Ag-doped Bi-Sb alloys as thermoelectric conversion materials for solid state refrigeration

Wen XU, Laifeng LI, Rongjin HUANG, Min ZHOU, Liyun ZHENG, Linghui GONG, Chunmei SONG

期刊论文