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软磁复合材料硝酸钠钝化绝缘包覆新技术 Article

严密, 陈起明, 刘冬, 吴琛, 王健

《工程(英文)》 2023年 第20卷 第1期   页码 134-142 doi: 10.1016/j.eng.2022.01.016

摘要:

本研究发明了制备FeSiAl软磁复合材料(SMC)的硝酸钠钝化绝缘包覆新技术。结合成分组成和微观结构分析,研究了不同pH条件下包覆层的生成规律,发现酸性NaNO3溶液钝化形成的绝缘包覆层由Fe2O3、SiO2、Al2O3和AlO(OH)组成。随着pH值升高,由于NO3的氧化能力减弱,Fe2O3转化为Fe3O4,而碱性NaNO3溶液钝化形成Al2O3、AlO(OH)和SiO2。进一步地,从热力学和动力学角度揭示了包覆层生长机理及其与FeSiAl SMC软磁性能的内在关联。通过调整钝化条件,可实现在50 kHz和100 mT测试条件下,有效磁导率为97.2、损耗为296.4 mW·cm−3的最优性能。

关键词: 软磁复合材料     表面钝化     绝缘包覆技术     生长机理     磁性能    

EFFECT OF EXOGENOUS ADDITIVES ON HEAVY METAL PASSIVATION AND NITROGEN RETENTION IN PIG MANURE COMPOSTING

《农业科学与工程前沿(英文)》 doi: 10.15302/J-FASE-2023487

摘要:

● Research on heavy metal passivation and nitrogen emissions is necessary for the pig industry.

关键词: additives     composting     heavy metals passivation     nitrogen retention     pig manure    

SiO2 passivation layer grown by liquid phase deposition for silicon solar cell application

Yanlin CHEN,Sihua ZHONG,Miao TAN,Wenzhong SHEN

《能源前沿(英文)》 2017年 第11卷 第1期   页码 52-59 doi: 10.1007/s11708-016-0429-3

摘要: Surface passivation is one of the primary requirements for high efficient silicon solar cells. Though the current existed passivation techniques are effective, expensive equipments are required. In this paper, a comprehensive understanding of the SiO passivation layer grown by liquid phase deposition (LPD) was presented, which was cost-effective and very simple. It was found that the post-annealing process could significantly enhance the passivation effect of the LPD SiO film. Besides, it was revealed that both chemical passivation and field-effect passivation mechanisms played important roles in outstanding passivation effect of the LPD SiO film through analyzing the minority carrier lifetime and the surface recombination velocity of n-type and p-type silicon wafers. Although the deposition parameters had little influence on the passivation effect, they affected the deposition rate. Therefore, appropriate deposition parameters should be carefully chosen based on the compromise of the deposition rate and fabrication cost. By utilizing the LPD SiO film as surface passivation layer, a 19.5%-efficient silicon solar cell on a large-scale wafer (156 mm × 156 mm) was fabricated.

关键词: Si solar cell     passivation     SiO2     liquid phase deposition     carrier lifetime    

Defect passivation on cast-mono crystalline screen-printed cells

Alison WENHAM,Lihui SONG,Malcolm ABBOTT,Iskra ZAFIROVSKA,Sisi WANG,Brett HALLAM,Catherine CHAN,Allen BARNETT,Stuart WENHAM

《能源前沿(英文)》 2017年 第11卷 第1期   页码 60-66 doi: 10.1007/s11708-016-0443-5

摘要: Cast-mono crystalline silicon wafers contain crystallographic defects, which can severely impact the electrical performance of solar cells. This paper demonstrates that applying hydrogenation processes at moderate temperatures to finished screen print cells can passivate dislocation clusters within the cast-mono crystalline silicon wafers far better than the hydrogenation received during standard commercial firing conditions. Efficiency enhancements of up to 2% absolute are demonstrated on wafers with high dislocation densities. The impact of illumination to manipulate the charge state of hydrogen during annealing is investigated and found to not be significant on the wafers used in this study. This finding is contrary to a previous study on similar wafers that concluded increased H or H from laser illumination was responsible for the further passivation of positively charged dangling bonds within the dislocation clusters.

关键词: silicon solar cell     dislocation     cast-mono     laser     hydrogen passivation    

Plasma enhanced chemical vapor deposition of excellent a-Si:H passivation layers for a-Si:H/c-Si heterojunction

Lei ZHAO,Wenbin ZHANG,Jingwei CHEN,Hongwei DIAO,Qi WANG,Wenjing WANG

《能源前沿(英文)》 2017年 第11卷 第1期   页码 85-91 doi: 10.1007/s11708-016-0437-3

摘要: The intrinsic a-Si:H passivation layer inserted between the doped a-Si:H layer and the c-Si substrate is very crucial for improving the performance of the a-Si:H/c-Si heterojunction (SHJ) solar cell. The passivation performance of the a-Si:H layer is strongly dependent on its microstructure. Usually, the compact a-Si:H deposited near the transition from the amorphous phase to the nanocrystalline phase by plasma enhanced chemical vapor deposition (PECVD) can provide excellent passivation. However, at the low deposition pressure and low deposition power, such an a-Si:H layer can be only prepared in a narrow region. The deposition condition must be controlled very carefully. In this paper, intrinsic a-Si:H layers were prepared on n-type Cz c-Si substrates by 27.12 MHz PECVD at a high deposition pressure and high deposition power. The corresponding passivation performance on c-Si was investigated by minority carrier lifetime measurement. It was found that an excellent a-Si:H passivation layer could be obtained in a very wide deposition pressure and power region. Such wide process window would be very beneficial for improving the uniformity and the yield for the solar cell fabrication. The a-Si:H layer microstructure was further investigated by Raman and Fourier transform infrared (FTIR) spectroscopy characterization. The correlation between the microstructure and the passivation performance was revealed. According to the above findings, the a-Si:H passivation performance was optimized more elaborately. Finally, a large-area SHJ solar cell with an efficiency of 22.25% was fabricated on the commercial 156 mm pseudo-square n-type Cz c-Si substrate with the open-circuit voltage ( ) of up to 0.732 V.

关键词: PECVD     high pressure and high power     a-Si:H microstructure     passivation     heterojunction solar cell    

High frequency group pulse electrochemical machining

WU Gaoyang, ZHANG Zhijing, ZHANG Weimin, TANG Xinglun

《机械工程前沿(英文)》 2007年 第2卷 第3期   页码 293-296 doi: 10.1007/s11465-007-0051-5

摘要: In the process of machining ultrathin metal structure parts, the signal composition of high frequency group pulse, the influence of frequency to reverse current, and the design of the cathode in high frequency group pulse electrochemical machining (HGPECM) are discussed. The experiments on process were carried out. Results indicate that HGPECM can greatly improve the characteristics of the inter-electrode gap flow field, reduce electrode passivation, and obtain high machining quality. The machining quality is obviously improved by increasing the main pulse frequency. The dimensional accuracy reaches 30 40 ?m and the roughness attained is at 0.30 0.35 ?m. High frequency group pulse electrochemical machining can be successfully used in machining micro-parts.

关键词: HGPECM     process     machining quality     passivation     inter-electrode    

Ni-Bi 助剂用于α-Fe2O3 Letter

党珂,王拓,李澄澄,张冀杰,刘珊珊,巩金龙

《工程(英文)》 2017年 第3卷 第3期   页码 285-289 doi: 10.1016/J.ENG.2017.03.005

摘要:

本文提出了镍-硼酸(Ni-Bi) 助催化剂负载于α 型三氧化二铁(Fe2O3) 具有提升表面动力学和钝化表面态的双重作用。Ni-Bi助剂的负载使Fe2O3 光电阳极的光电流起始电位产生230 mV 的负移,1.23 V(vs. RHE)下的光电流密度也提升了2.3 倍。Ni-Bi助剂层中的Bi 促进了产氧反应的脱质子步骤。

关键词: 镍-硼酸     &alpha     型三氧化二铁     产氧反应     助催化剂    

Application of electrochemical depassivation in PRB systems to recovery Fe

Xin LU, Miao LI, Hao DENG, Pengfei LIN, Mark R. MATSUMOTO, Xiang LIU

《环境科学与工程前沿(英文)》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0843-0

摘要: Utilizing electrochemical depassivation to recovery Fe activity was effective, and minerals were cleaned layer by layer, with no ions secondary contamination, and no transformation from Cr(III) to Cr(VI). Electrochemical depassivation process under various electrolysis conditions was revealed. Electro-PRB configuration for caisson excavation construction technique was designed. Permeable reactive barriers (PRBs) show remarkable Cr(VI) removal performance. However, the diminished removal rate because of mineral fouling over time is the bottleneck for application of PRBs. The present study demonstrated that electrochemical depassivation was effective for recovering the Fe reactivity, and minerals can be cleaned layer by layer with no secondary ion contamination and no transformation from Cr(III) to Cr(VI). The removal recovery rate increased with increasing electrolysis voltage before reaching the optimal electrolysis voltage, and then decreased as the electrolysis voltage further increased. The recovery effect at electrolysis voltages of 5, 10, and 15 V show the same trend as a function of electrolysis time, where recovery rate first increased and then decreased after reaching the optimal electrolysis time. The Cr(VI) removal rate significantly decreased with increasing electrolysis distance. Furthermore, Fe brush meshes electrode, Fe fillings, and polyvinyl chloride (PVC) meshes separators were combined to create an Electro-PRB configuration for the caisson excavation construction technique, which lays the foundation for establishment of promising Electro-PRB systems to treat Cr(VI)-contaminated groundwater.

关键词: PRB     Cr(VI)     Fe     Passivation     Electrochemical depassivation    

Impact of thermal processes on multi-crystalline silicon

Moonyong KIM,Phillip HAMER,Hongzhao LI,David PAYNE,Stuart WENHAM,Malcolm ABBOTT,Brett HALLAM

《能源前沿(英文)》 2017年 第11卷 第1期   页码 32-41 doi: 10.1007/s11708-016-0427-5

摘要: Fabrication of modern multi-crystalline silicon solar cells involves multiple processes that are thermally intensive. These include emitter diffusion, thermal oxidation and firing of the metal contacts. This paper illustrates the variation and potential effects upon recombination in the wafers due to these thermal processes. The use of light emitter diffusions more compatible with selective emitter designs had a more detrimental effect on the bulk lifetime of the silicon than that of heavier diffusions compatible with a homogenous emitter design and screen-printed contacts. This was primarily due to a reduced effectiveness of gettering for the light emitter. This reduction in lifetime could be mitigated through the use of a dedicated gettering process applied before emitter diffusion. Thermal oxidations could greatly improve surface passivation in the intra-grain regions, with the higher temperatures yielding the highest quality surface passivation. However, the higher temperatures also led to an increase in bulk recombination either due to a reduced effectiveness of gettering, or due to the presence of a thicker oxide layer, which may interrupt hydrogen passivation. The effects of fast firing were separated into thermal effects and hydrogenation effects. While hydrogen can passivate defects hence improving the performance, thermal effects during fast firing can dissolve precipitating impurities such as iron or de-getter impurities hence lower the performance, leading to a poisoning of the intra-grain regions.

关键词: gettering     grain boundaries     hydrogen     impurities     oxidation     passivation     solar cell    

Cell surface protein engineering for high-performance whole-cell catalysts

Hajime Nakatani,Katsutoshi Hori

《化学科学与工程前沿(英文)》 2017年 第11卷 第1期   页码 46-57 doi: 10.1007/s11705-017-1609-3

摘要: Cell surface protein engineering facilitated by accumulation of information on genome and protein structure involves heterologous production and modification of cell surface proteins using genetic engineering, and is important for the development of high-performance whole-cell catalysts. In this field, cell surface display is a major technology by exposing target proteins, such as enzymes, on the cell surface using a carrier protein. The target proteins are fused to the carrier proteins that transport and tether them to the cell surface, as well as to a secretion signal. This paper reviews cell surface display systems for prokaryotic and eukaryotic cells from the perspective of carrier proteins, which determine the number of displayed molecules, and the localization, size, and direction ( or terminal anchoring) of the passengers. We also discuss advanced methods for displaying multiple enzymes and a new method for the immobilization of whole-cell catalysts using adhesive surface proteins.

关键词: cell surface engineering     surface display     whole-cell catalysts     bioprocess    

An Exploration of Surface Integrity Remanufacturing for Aeroengine Components

Qiao Xiang,Yong He,Ting-hong Hou

《工程管理前沿(英文)》 2016年 第3卷 第2期   页码 107-114 doi: 10.15302/J-FEM-2016025

摘要: Surface integrity is the major factor impacting on the operation quality, service life and reliability of the aeroengine components. The surface integrity of aeroengine component is damaged by the failures such as crack, deformation, oxidation, corrosion, erosion, and microstructural degeneration. It adopts advanced remanufacturing technologies to restore or improve the surface integrity and regenerate these high value parts. This paper firstly puts forward the concept, namely surface integrity remanufacturing for aeroengine components, and its connotation. The key remanufacturing technologies have been developed to repair the components with surface damages. Ultimately, some application examples of surface integrity remanufacturing technologies as well as their effects in aeroengine maintenance are introduced. The discarded components have been reused and their service lives have been extended and their reliability has been increased by implementing surface integrity remanufacturing. It has realized “The Repaired Components Outpacing the New Ones”, material saving, energy saving, and emission reduction.

关键词: aeroengine component     surface integrity     remanufacturing     surface integrity remanufacturing    

Review on mechanism and process of surface polishing using lasers

Arun KRISHNAN, Fengzhou FANG

《机械工程前沿(英文)》 2019年 第14卷 第3期   页码 299-319 doi: 10.1007/s11465-019-0535-0

摘要: Laser polishing is a technology of smoothening the surface of various materials with highly intense laser beams. When these beams impact on the material surface to be polished, the surface starts to be melted due to the high temperature. The melted material is then relocated from the ‘peaks to valleys’ under the multidirectional action of surface tension. By varying the process parameters such as beam intensity, energy density, spot diameter, and feed rate, different rates of surface roughness can be achieved. High precision polishing of surfaces can be done using laser process. Currently, laser polishing has extended its applications from photonics to molds as well as bio-medical sectors. Conventional polishing techniques have many drawbacks such as less capability of polishing freeform surfaces, environmental pollution, long processing time, and health hazards for the operators. Laser polishing on the other hand eliminates all the mentioned drawbacks and comes as a promising technology that can be relied for smoothening of initial topography of the surfaces irrespective of the complexity of the surface. Majority of the researchers performed laser polishing on materials such as steel, titanium, and its alloys because of its low cost and reliability. This article gives a detailed overview of the laser polishing mechanism by explaining various process parameters briefly to get a better understanding about the entire polishing process. The advantages and applications are also explained clearly to have a good knowledge about the importance of laser polishing in the future.

关键词: laser polishing     surface roughness     process parameters     mechanism    

Tribological study on the surface modification of metal-on-polymer bioimplants

《机械工程前沿(英文)》 2022年 第17卷 第2期 doi: 10.1007/s11465-022-0682-6

摘要: The tribological performance of artificial joints is regarded as the main factor of the lifespan of implanted prostheses. The relationship between surface roughness and coefficient of friction (COF) under dry and lubricated conditions is studied. Results show that under dry test, friction coefficient is not reduced all the time with a decrease in surface roughness. On the contrary, a threshold of roughness value is observed, and frictional force increases again below this value. This critical value lies between 40 and 100 nm in Sa (roughness). This phenomenon is due to the transfer of friction mechanisms from abrasion to adhesion. Under wet test, COF always decreases with reduction in surface roughness. This result is mainly attributed to the existence of a thin layer of lubricant film that prevents the intimate contact of two articulating surfaces, thus greatly alleviating adhesion friction. Furthermore, surface texturing technology is successful in improving the corresponding tribological performance by decreasing friction force and mitigating surface deterioration. The even-distribution mode of texturing patterns is most suitable for artificial joints. By obtaining the optimal surface roughness and applying texturing technology, the tribological performance of polymer-based bioimplants can be greatly enhanced.

关键词: artificial joints     surface roughness     friction     surface texturing    

Development of surface reconstruction algorithms for optical interferometric measurement

Dongxu WU, Fengzhou FANG

《机械工程前沿(英文)》 2021年 第16卷 第1期   页码 1-31 doi: 10.1007/s11465-020-0602-6

摘要: Optical interferometry is a powerful tool for measuring and characterizing areal surface topography in precision manufacturing. A variety of instruments based on optical interferometry have been developed to meet the measurement needs in various applications, but the existing techniques are simply not enough to meet the ever-increasing requirements in terms of accuracy, speed, robustness, and dynamic range, especially in on-line or on-machine conditions. This paper provides an in-depth perspective of surface topography reconstruction for optical interferometric measurements. Principles, configurations, and applications of typical optical interferometers with different capabilities and limitations are presented. Theoretical background and recent advances of fringe analysis algorithms, including coherence peak sensing and phase-shifting algorithm, are summarized. The new developments in measurement accuracy and repeatability, noise resistance, self-calibration ability, and computational efficiency are discussed. This paper also presents the new challenges that optical interferometry techniques are facing in surface topography measurement. To address these challenges, advanced techniques in image stitching, on-machine measurement, intelligent sampling, parallel computing, and deep learning are explored to improve the functional performance of optical interferometry in future manufacturing metrology.

关键词: surface topography     measurement     optical interferometry     coherence envelope     phase-shifting algorithm    

Hysteretic behavior of cambered surface steel tube damper: Theoretical and experimental research

《结构与土木工程前沿(英文)》 2023年 第17卷 第4期   页码 606-624 doi: 10.1007/s11709-023-0925-6

摘要: A novel cambered surface steel tube damper (CSTD) with a cambered surface steel tube and two concave connecting plates is proposed herein. The steel tube is the main energy dissipation component and comprises a weakened segment in the middle, a transition segment, and an embedded segment. It is believed that during an earthquake, the middle weakened segment of the CSTD will be damaged, whereas the reliability of the end connection is ensured. Theoretical and experimental studies are conducted to verify the effectiveness of the proposed CSTD. Formulas for the initial stiffness and yield force of the CSTD are proposed. Subsequently, two CSTD specimens with different steel tube thicknesses are fabricated and tested under cyclic quasi-static loads. The result shows that the CSTD yields a stable hysteretic response and affords excellent energy dissipation. A parametric study is conducted to investigate the effects of the steel tube height, diameter, and thickness on the seismic performance of the CSTD. Compared with equal-stiffness design steel tube dampers, the CSTD exhibits better energy dissipation performance, more stable hysteretic response, and better uniformity in plastic deformation distributions.

关键词: cambered surface steel tube damper     energy dissipation capacity     finite element model     hysteretic performance     parametric study    

标题 作者 时间 类型 操作

软磁复合材料硝酸钠钝化绝缘包覆新技术

严密, 陈起明, 刘冬, 吴琛, 王健

期刊论文

EFFECT OF EXOGENOUS ADDITIVES ON HEAVY METAL PASSIVATION AND NITROGEN RETENTION IN PIG MANURE COMPOSTING

期刊论文

SiO2 passivation layer grown by liquid phase deposition for silicon solar cell application

Yanlin CHEN,Sihua ZHONG,Miao TAN,Wenzhong SHEN

期刊论文

Defect passivation on cast-mono crystalline screen-printed cells

Alison WENHAM,Lihui SONG,Malcolm ABBOTT,Iskra ZAFIROVSKA,Sisi WANG,Brett HALLAM,Catherine CHAN,Allen BARNETT,Stuart WENHAM

期刊论文

Plasma enhanced chemical vapor deposition of excellent a-Si:H passivation layers for a-Si:H/c-Si heterojunction

Lei ZHAO,Wenbin ZHANG,Jingwei CHEN,Hongwei DIAO,Qi WANG,Wenjing WANG

期刊论文

High frequency group pulse electrochemical machining

WU Gaoyang, ZHANG Zhijing, ZHANG Weimin, TANG Xinglun

期刊论文

Ni-Bi 助剂用于α-Fe2O3

党珂,王拓,李澄澄,张冀杰,刘珊珊,巩金龙

期刊论文

Application of electrochemical depassivation in PRB systems to recovery Fe

Xin LU, Miao LI, Hao DENG, Pengfei LIN, Mark R. MATSUMOTO, Xiang LIU

期刊论文

Impact of thermal processes on multi-crystalline silicon

Moonyong KIM,Phillip HAMER,Hongzhao LI,David PAYNE,Stuart WENHAM,Malcolm ABBOTT,Brett HALLAM

期刊论文

Cell surface protein engineering for high-performance whole-cell catalysts

Hajime Nakatani,Katsutoshi Hori

期刊论文

An Exploration of Surface Integrity Remanufacturing for Aeroengine Components

Qiao Xiang,Yong He,Ting-hong Hou

期刊论文

Review on mechanism and process of surface polishing using lasers

Arun KRISHNAN, Fengzhou FANG

期刊论文

Tribological study on the surface modification of metal-on-polymer bioimplants

期刊论文

Development of surface reconstruction algorithms for optical interferometric measurement

Dongxu WU, Fengzhou FANG

期刊论文

Hysteretic behavior of cambered surface steel tube damper: Theoretical and experimental research

期刊论文