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Statistical analysis of recombination properties of the boron-oxygen defect in p-type Czochralski silicon

Nitin NAMPALLI,Tsun Hang FUNG,Stuart WENHAM,Brett HALLAM,Malcolm ABBOTT

《能源前沿（英文）》 2017年 第11卷 第1期   页码 4-22 doi: 10.1007/s11708-016-0442-6

摘要： This paper presents the application of lifetime spectroscopy to the study of carrier-induced degradation ascribed to the boron-oxygen (BO) defect. Specifically, a large data set of p-type silicon samples is used to investigate two important aspects of carrier lifetime analysis: ① the methods used to extract the recombination lifetime associated with the defect and ② the underlying assumption that carrier injection does not affect lifetime components unrelated to the defect. The results demonstrate that the capture cross section ratio associated with the donor level of the BO defect ( ) vary widely depending on the specific method used to extract the defect-specific recombination lifetime. For the data set studied here, it was also found that illumination used to form the defect caused minor, but statistically significant changes in the surface passivation used. This violation of the fundamental assumption could be accounted for by applying appropriate curve fitting methods, resulting in an improved estimate of (11.90±0.45) for the fully formed BO defect when modeled using the donor level alone. Illumination also appeared to cause a minor, apparently injection-independent change in lifetime that could not be attributed to the donor level of the BO defect alone and is likely related to the acceptor level of the BO defect. While specific to the BO defect, this study has implications for the use of lifetime spectroscopy to study other carrier induced defects. Finally, we demonstrate the use of a unit-less regression goodness-of-fit metric for lifetime data that is easy to interpret and accounts for repeatability error.

关键词： Czochralski silicon     boron-oxygen defect     injection dependent lifetime spectroscopy     goodness-of-fit     repeatability error    

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Thermal degradation kinetics and lifetime estimation for polycarbonate/polymethylphenylsilsesquioxane

Jiangbo WANG, Zhong XIN

《化学科学与工程前沿（英文）》 2009年 第3卷 第2期   页码 167-171 doi: 10.1007/s11705-009-0006-y

摘要： The thermal degradation behaviors of polycarbonate/polymethylphenylsilsesquioxane (FRPC) composites were investigated by thermogravimetric analysis (TGA) under isothermal conditions in nitrogen atmosphere. The isothermal kinetics equation was used to describe the thermal degradation process. The results showed that activation energy ( ), in the case of isothermal degradation, was a quick increasing function of conversion (α) for polycarbonate (PC) but was a strong and decreasing function of conversion for FRPC. Under the isothermal condition, the addition of polymethylphenylsilsesquioxane (PMPSQ) retardanted the thermal degradation and enhanced the thermal stability of PC during the early and middle stages of thermal degradation. It also indicated a possible existence of a difference in nucleation, nuclei growth, and gas diffusion mechanism in the thermal degradation process between PC and FRPC. Meanwhile, the addition of PMPSQ influenced the lifetime of PC, but the composite still met the demand in manufacturing and application.

关键词： polycarbonate     polymethylphenylsilsesquioxane     thermal degradation kinetics     activation energy     lifetime    

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Full lifetime cost analysis of battery, plug-in hybrid and FCEVs in China in the near future

Zhihua CAI, Xunmin OU, Qian ZHANG, Xiliang ZHANG

《能源前沿（英文）》 2012年 第6卷 第2期   页码 107-111 doi: 10.1007/s11708-012-0182-1

摘要： This paper analyzes the full lifetime cost of battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and fuel cell electric vehicles (FCEVs) in China in the near future. The full lifetime cost comprises the initial and periodic cost of owning and operating the vehicle. Compared with the conventional gasoline vehicles, the full lifetime cost of the BEVs, PHEVs and FCEVs are approximately 1.5, 0.5 and 2.3 times more in the short term, respectively, due to the higher initial costs and higher non-energy-related costs though the fuel costs are lower. The results also suggest that with reasonably anticipatable technological progress in the long term, the lifetime cost of advanced electric vehicles (EVs) can be close to that of gasoline vehicles. It is found that two aspects of action are most important to make BEVs cost-effective: to support technology improvement to decrease the high cost of BEV and to formulate high energy cost of operating the conventional gasoline car. Moreover, it is important to decrease the non-energy operating costs including registration fee, tax rate and etc., of BEVs at the same time.

关键词： electric vehicle (EV)     life time cost     China    

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Data-driven approach to solve vertical drain under time-dependent loading

《结构与土木工程前沿（英文）》 2021年 第15卷 第3期   页码 696-711 doi: 10.1007/s11709-021-0727-7

摘要： Currently, the vertical drain consolidation problem is solved by numerous analytical solutions, such as time-dependent solutions and linear or parabolic radial drainage in the smear zone, and no artificial intelligence (AI) approach has been applied. Thus, in this study, a new hybrid model based on deep neural networks (DNNs), particle swarm optimization (PSO), and genetic algorithms (GAs) is proposed to solve this problem. The DNN can effectively simulate any sophisticated equation, and the PSO and GA can optimize the selected DNN and improve the performance of the prediction model. In the present study, analytical solutions to vertical drains in the literature are incorporated into the DNN–PSO and DNN–GA prediction models with three different radial drainage patterns in the smear zone under time-dependent loading. The verification performed with analytical solutions and measurements from three full-scale embankment tests revealed promising applications of the proposed approach.

关键词： vertical drain     artificial neural network     time-dependent loading     deep learning network     genetic algorithm     particle swarm optimization    

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Three-dimensional numerical simulation for plastic injection-compression molding

Yun ZHANG, Wenjie YU, Junjie LIANG, Jianlin LANG, Dequn LI

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 74-84 doi: 10.1007/s11465-018-0490-1

摘要：

Compared with conventional injection molding, injection-compression molding can mold optical parts with higher precision and lower flow residual stress. However, the melt flow process in a closed cavity becomes more complex because of the moving cavity boundary during compression and the nonlinear problems caused by non-Newtonian polymer melt. In this study, a 3D simulation method was developed for injection-compression molding. In this method, arbitrary Lagrangian-Eulerian was introduced to model the moving-boundary flow problem in the compression stage. The non-Newtonian characteristics and compressibility of the polymer melt were considered. The melt flow and pressure distribution in the cavity were investigated by using the proposed simulation method and compared with those of injection molding. Results reveal that the fountain flow effect becomes significant when the cavity thickness increases during compression. The back flow also plays an important role in the flow pattern and redistribution of cavity pressure. The discrepancy in pressures at different points along the flow path is complicated rather than monotonically decreased in injection molding.

关键词： injection-compression molding     simulation     injection molding     melt flow     cavity pressure    

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Novel methods by using non-vacuum insulated tubing to extend the lifetime of the tubing

Chenglong ZHOU,Guojin ZHU,Yongxiang XU,Jifei YU,Xiaoliang ZHANG,Hongzhi SHENG

《能源前沿（英文）》 2015年 第9卷 第2期   页码 142-147 doi: 10.1007/s11708-015-0357-7

摘要： The analysis of the failure mechanics, namely hydrogen permeation of vacuum insulated tubing (VIT), indicated that the failure of VIT could be decreased but could not be avoided. To solve this problem, some measures by using non-vacuum materials were proposed and analyzed in this paper. The results show that to fill the tubing with foam-glass beads or high pressure argon may lead to a good performance.

关键词： vacuum insulated tubing     cyclic steam stimulation     insulation material     thermal conductivity     foam-glass     hydrogen permeation    

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Factors influencing near infrared spectroscopy analysis of agro-products: a review

Xiao XU, Lijuan XIE, Yibin YING

《农业科学与工程前沿（英文）》 2019年 第6卷 第2期   页码 105-115 doi: 10.15302/J-FASE-2019255

摘要：

The near infrared (NIR) spectroscopy technique has wide applications in agriculture with the advantages of being nondestructive, sensitive, safe and rapid. However, there are still more than 40 error sources influencing the robustness and accuracy of its calibration and operation. Environmental, sample and instrument factors that influence the analysis are discussed in this review, including temperature, humidity and other factors that introduce uncertainty. Error sources from livestock products, fruit and vegetables, which are the most common objects in the field of NIR analysis, are also emphasized in the second part. In addition, studies utilizing different instruments, spectral pretreatments, variable selection methods, wavelength ranges, detection modes and calibration methods are tabulated to illustrate the complications they introduce and how they influence NIR analysis. It is suggested that large scale of data with abundant varieties can be used to build a more robust calibration model, in order to improve the robustness and accuracy of the NIR analytical model, and overcome problems caused by confining analysis to too many uniform samples.

关键词： agro-product     error source     influence factor     near infrared spectroscopy    

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density measurement for plastic injection molding via ultrasonic technology

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0714-2

摘要： Density variation during the injection molding process directly reflects the state of plastic melt and contains valuable information for process monitoring and optimization. Therefore, in-situ density measurement is of great interest and has significant application value. The existing methods, such as pressure−volume−temperature (PVT) method, have the shortages of time-delay and high cost of sensors. This study is the first to propose an in-situ density measurement method using ultrasonic technology. The analyses of the time-domain and frequency-domain signals are combined in the proposed method. The ultrasonic velocity is obtained from the time-domain signals, and the acoustic impedance is computed through a full-spectral analysis of the frequency-domain signals. Experiments with different process conditions are conducted, including different melt temperature, injection speed, material, and mold structure. Results show that the proposed method has good agreement with the PVT method. The proposed method has the advantages of in-situ measurement, non-destructive, high accuracy, low cost, and is of great application value for the injection molding industry.

关键词： ultrasonic measurement     melt density     in-situ measurement     injection molding    

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Review: Tip-based vibrational spectroscopy for nanoscale analysis of emerging energy materials

Amun JARZEMBSKI, Cedric SHASKEY, Keunhan PARK

《能源前沿（英文）》 2018年 第12卷 第1期   页码 43-71 doi: 10.1007/s11708-018-0524-8

摘要： Vibrational spectroscopy is one of the key instrumentations that provide non-invasive investigation of structural and chemical composition for both organic and inorganic materials. However, diffraction of light fundamentally limits the spatial resolution of far-field vibrational spectroscopy to roughly half the wavelength. In this article, we thoroughly review the integration of atomic force microscopy (AFM) with vibrational spectroscopy to enable the nanoscale characterization of emerging energy materials, which has not been possible with far-field optical techniques. The discussed methods utilize the AFM tip as a nanoscopic tool to extract spatially resolved electronic or molecular vibrational resonance spectra of a sample illuminated by a visible or infrared (IR) light source. The absorption of light by electrons or individual functional groups within molecules leads to changes in the sample’s thermal response, optical scattering, and atomic force interactions, all of which can be readily probed by an AFM tip. For example, photothermal induced resonance (PTIR) spectroscopy methods measure a sample’s local thermal expansion or temperature rise. Therefore, they use the AFM tip as a thermal detector to directly relate absorbed IR light to the thermal response of a sample. Optical scattering methods based on scanning near-field optical microscopy (SNOM) correlate the spectrum of scattered near-field light with molecular vibrational modes. More recently, photo-induced force microscopy (PiFM) has been developed to measure the change of the optical force gradient due to the light absorption by molecular vibrational resonances using AFM’s superb sensitivity in detecting tip-sample force interactions. Such recent efforts successfully breech the diffraction limit of light to provide nanoscale spatial resolution of vibrational spectroscopy, which will become a critical technique for characterizing novel energy materials.

关键词： vibrational spectroscopy     atomic force microscopy     photo-thermal induced resonance     scanning near-field optical microscopy     tip-enhanced Raman spectroscopy     photo-induced force microscopy     molecular resonances     surface phonon polaritons     energy materials    

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凝析气藏的经济开采模式

刘廷元

《中国工程科学》 2001年 第3卷 第3期   页码 85-91

摘要：

液态凝析油是凝析气藏的重要产品，它的开采应该是有效而经济的。介绍了国外近20 a来在凝析气藏开采技术领域的各种经济模式，包括回注φd=75%干气、自流回注、注N2、注水、水气交替注和注CO2等开采模式。研究结果表明，这些开采模式同传统的降压开采方法相比，能够有效地适应地面-地下的各种复杂情况。

关键词： 凝析气藏     开采模式     注气     注氮     注水     注二氧化碳     经济    

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Terahertz time-domain spectroscopy of high-pressure flames

Jason BASSI, Mark STRINGER, Bob MILES, Yang ZHANG

《能源前沿（英文）》 2009年 第3卷 第2期   页码 123-133 doi: 10.1007/s11708-009-0033-x

摘要： Laser spectroscopy in the visible and near infrared is widely used as a diagnostic tool for combustion devices, but this approach is difficult at high pressures within a sooty flame itself. High soot concentrations render flames opaque to visible light, but they remain transparent to far-infrared or terahertz (THz) radiation. The first far-infrared absorption spectra, to the best of our knowledge, of sooty, non-premixed, ethylene high-pressure flames covering the region of 0.2-2.5 THz is presented. A specially designed high-pressure burner which is optically accessible to THz radiation has been built allowing flame transmission measurements up to pressures of 1.6 MPa. Calculations of the theoretical combustion species absorption spectra in the 0.2-3 THz range have shown that almost all the observable features arise from H O. A few OH (1.84 and 2.51 THz), CH (2.58 THz), and NH (1.77 and 2.95 THz) absorption lines are also observable in principle. A large number of H O absorption lines are observed in the ground vibrational in a laminar non-premixed, sooty flame (ethylene) at pressures up to 1.6 MPa.

关键词： terahertz time-domain spectroscopy     high-pressure flames     H2O absorption lines    

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Modeling of oil near-infrared spectroscopy based on similarity and transfer learning algorithm

Yifei Wang, Kai Wang, Zhao Zhou, Wenli Du

《化学科学与工程前沿（英文）》 2019年 第13卷 第3期   页码 599-607 doi: 10.1007/s11705-019-1807-2

摘要： Near-infrared spectroscopy mainly reflects the frequency-doubled and total-frequency absorption information of hydrogen-containing groups (O‒H, C‒H, N‒H, S‒H) in organic molecules for near-infrared lights with different wavelengths, so it is applicable to testing of most raw materials and products in the field of petrochemicals. However, the modeling process needs to collect a large number of laboratory analysis data. There are many oil sources in China, and oil properties change frequently. Modeling of each raw material is not only unfeasible but also will affect its engineering application efficiency. In order to achieve rapid modeling of near-infrared spectroscopy and based on historical data of different crude oils under different detection conditions, this paper discusses about the feasibility of the application of transfer learning algorithm and makes it possible that transfer learning can assist in rapid modeling using certain historical data under similar distributions under a small quantity of new data. In consideration of the requirement of transfer learning for certain similarity of different datasets, a transfer learning method based on local similarity feature selection is proposed. The simulation verification of spectral data of 13 crude oils measured by three different probe detection methods is performed. The effectiveness and application scope of the transfer modeling method under different similarity conditions are analyzed.

关键词： near-infrared spectroscopy     transfer learning     similarity     modeling    

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Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 171-175 doi: 10.1007/s11465-009-0091-0

摘要： Trend prediction technology is the key technology to achieve condition-based maintenance of mechanical equipment. Large-sized water injection units are key equipment in oilfields. The traditional preventive maintenance is not economical and cannot completely avoid vicious accidents. To ensure the normal operation of units and save maintenance costs, trend prediction technology is studied to achieve condition-based maintenance for water injection units. The main methods of the technology are given, the trend prediction method based on neural network is put forward, and the expert system based on the knowledge is developed. The industrial site verification shows that the proposed trend prediction technology can reflect the operating condition trend change of the water injection units and provide technical means to achieve condition-based predictive maintenance.

关键词： water injection units     condition-based maintenance     trend prediction    

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Intelligent methods for the process parameter determination of plastic injection molding

Huang GAO, Yun ZHANG, Xundao ZHOU, Dequn LI

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 85-95 doi: 10.1007/s11465-018-0491-0

摘要：

Injection molding is one of the most widely used material processing methods in producing plastic products with complex geometries and high precision. The determination of process parameters is important in obtaining qualified products and maintaining product quality. This article reviews the recent studies and developments of the intelligent methods applied in the process parameter determination of injection molding. These intelligent methods are classified into three categories: Case-based reasoning methods, expert system-based methods, and data fitting and optimization methods. A framework of process parameter determination is proposed after comprehensive discussions. Finally, the conclusions and future research topics are discussed.

关键词： injection molding     intelligent methods     process parameters     optimization    

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Chloride binding and time-dependent surface chloride content models for fly ash concrete

S. MUTHULINGAM,B. N. RAO

《结构与土木工程前沿（英文）》 2016年 第10卷 第1期   页码 112-120 doi: 10.1007/s11709-015-0322-x

摘要： Corrosion of embedded rebars is a classical deterioration mechanism of reinforced concrete structures exposed to chloride environments. Such environments can be attributed to the presence of seawater, deicing or sea-salts, which have high concentrations of chloride ion. Chloride ingress into concrete, essential for inducing rebar corrosion, is a complex interaction between many physical and chemical processes. The current study proposes two chloride ingress parameter models for fly ash concrete, namely: 1) surface chloride content under tidal exposure condition; and 2) chloride binding. First, inconsistencies in surface chloride content and chloride binding models reported in literature, due to them not being in line with past research studies, are pointed out. Secondly, to avoid such inconsistencies, surface chloride content and chloride binding models for fly ash concrete are proposed based upon the experimental work done by other researchers. It is observed that, proposed models are simple, consistent and in line with past research studies reported in literature.

关键词： binding isotherms     chloride ingress     concrete     fly ash     surface chloride content    

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标题 作者 时间 类型 操作

Statistical analysis of recombination properties of the boron-oxygen defect in p-type Czochralski silicon

Nitin NAMPALLI,Tsun Hang FUNG,Stuart WENHAM,Brett HALLAM,Malcolm ABBOTT

期刊论文

Thermal degradation kinetics and lifetime estimation for polycarbonate/polymethylphenylsilsesquioxane

Jiangbo WANG, Zhong XIN

期刊论文

Full lifetime cost analysis of battery, plug-in hybrid and FCEVs in China in the near future

Zhihua CAI, Xunmin OU, Qian ZHANG, Xiliang ZHANG

期刊论文

Data-driven approach to solve vertical drain under time-dependent loading

期刊论文

Three-dimensional numerical simulation for plastic injection-compression molding

Yun ZHANG, Wenjie YU, Junjie LIANG, Jianlin LANG, Dequn LI

期刊论文

Novel methods by using non-vacuum insulated tubing to extend the lifetime of the tubing

Chenglong ZHOU,Guojin ZHU,Yongxiang XU,Jifei YU,Xiaoliang ZHANG,Hongzhi SHENG

期刊论文

Factors influencing near infrared spectroscopy analysis of agro-products: a review

Xiao XU, Lijuan XIE, Yibin YING

期刊论文

density measurement for plastic injection molding via ultrasonic technology

期刊论文

Review: Tip-based vibrational spectroscopy for nanoscale analysis of emerging energy materials

Amun JARZEMBSKI, Cedric SHASKEY, Keunhan PARK

期刊论文

凝析气藏的经济开采模式

刘廷元

期刊论文

Terahertz time-domain spectroscopy of high-pressure flames

Jason BASSI, Mark STRINGER, Bob MILES, Yang ZHANG

期刊论文

Modeling of oil near-infrared spectroscopy based on similarity and transfer learning algorithm

Yifei Wang, Kai Wang, Zhao Zhou, Wenli Du

期刊论文

Trend prediction technology of condition maintenance for large water injection units

Xiaoli XU, Sanpeng DENG

期刊论文

Intelligent methods for the process parameter determination of plastic injection molding

Huang GAO, Yun ZHANG, Xundao ZHOU, Dequn LI

期刊论文

Chloride binding and time-dependent surface chloride content models for fly ash concrete

S. MUTHULINGAM,B. N. RAO

期刊论文