检索结果-南通市图书馆

Chinese Journal of Polymer Science 2013年第7期31卷 974-983页

作者： da-hai gao 贾梦秋 Ying Luo College of Materials Science and Engineering Beijing University of Chemical Technology Nuclear Power Institute of China

Hybrid materials based on polymethylphenylsiloxane （PMPS） and organic functionalized silica were synthesized via condensation reaction between silanol and alkoxysilyl groups in the presence of quaternary ammonium hydroxide. The structure of prepared materials was investigated by FTIR and NMR, which indicate that the products have incorporated modified silica into the polymer matrix. The prepared hybrid materials show a satisfactory thermal resistance because the initial decomposition of typical product occurred at nearly 100 K higher than that of the pure polymer according to the thermogravimetric analysis （TGA） results. Differential thermogravimetric analysis （DTGA） data confirm that the thermal degradation of prepared hybrid materials comprises of two steps, of which the first one could be controlled by adjusting the content of silica particles and the ratio of surface groups on the particles. The coating films obtained from hybrid products exhibit good thermal mechanical properties. Therefore, the materials are hoped to be used for the application in thermal resistant coating.

关键词： Hybrid material Crosslinked polysiloxane Condensation polymerization Thermal stability.

Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2006年第3期18卷 428-432页

作者： gao da-wen WEN Xiang-hua QIAN Yi State Key Joint Laboratory of Environmental Simulation and Pollution Control Department of Environment Science and Engineering TsinghuaUniversity Beijing 100084 China.

Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is treated under sterile conditions. A feasible study was made for using white rot fungus Phanerochaete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions. The results showed that there was no decolorizing effect under non-sterile condition if white rot fungus was incubated under non-sterile condition, and the decolorization was always near to 0% during decolorizing test for 3 d; in the meantime, a lot of yeast funguses were found in liquid medium when white rot fungus was incubated under non-sterile conditions; however, if white rot fungus was incubated under sterile condition firstly, its decolorization was above 90% under non-sterile condition, which was similar to that of sterile condition. So we point out that the treating process for wastewater with dyes should be divided into two stages. The first stage is that white rot fungus should be incubated under sterile conditions, and the second stage is that reactive brilliant red K-2BP is decolorized under non-sterile conditions. The method not only save the operation cost which decolorizing reactive brilliant red K-2BP under sterile condition, but also provide the feasibility for using white rot fungus to degrade wastewater with dyes under non-sterile conditions.

关键词： white rot fungus Phanerochaete chrysosporium reactive brilliant red K-2BP decolorization non-sterile condition

Lifetime estimation of IGBT module using square-wave loss discretization and power cycling test

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2022年第10期33卷 126-138页

作者： Jie Wang da-Qing gao Wan-Zeng Shen Hong-Bin Yan Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

The insulated gate bipolar transistor(IGBT)module is one of the most age-affected components in the switch power supply, and its reliability prediction is conducive to timely troubleshooting and reduction in safety risks and unnecessary costs. The pulsed current pattern of the accelerator power supply is different from other converter applications;therefore, this study proposed a lifetime estimation method for IGBT modules in pulsed power supplies for accelerator magnets. The proposed methodology was based on junction temperature calculations using square-wave loss discretization and thermal *** results showed that the junction temperature error between the simulation and IR measurements was less than 3%. An AC power cycling test under real pulsed power supply applications was performed via offline wearout monitoring of the tested power IGBT module. After combining the IGBT4 PC curve and fitting the test results,a simple corrected lifetime model was developed to quantitatively evaluate the lifetime of the IGBT module,which can be employed for the accelerator pulsed power supply in engineering. This method can be applied to other IGBT modules and pulsed power supplies.

关键词： IGBT module Junction temperature Power cycling test Lifetime prediction Power loss discretization

Regularized inversion for coseismic slip distribution with active constraint balancing

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2017年第12期24卷 2961-2968页

作者： TONG Xiao-zhong XIE Wei gao da-wei School of Geosciences and Info-physics Central South University School of Earth and Ocean Sciences University of Victoria

Estimating the spatial distribution of coseismic slip is an ill-posed inverse problem, and solutions may be extremely oscillatory due to measurement errors without any constraints on the coseismic slip distribution. In order to obtain stable solution for coseismic slip inversion, regularization method with smoothness-constrained was imposed. Trade-off parameter in regularized inversion, which balances the minimization of the data misfit and model roughness, should be a critical procedure to achieve both resolution and stability. Then, the active constraint balancing approach is adopted, in which the trade-off parameter is regarded as a spatial variable at each model parameter and automatically determined via the model resolution matrix and the spread function. Numerical experiments for a synthetical model indicate that regularized inversion using active constraint balancing approach can provides stable inversion results and have low sensitivity to the knowledge of the exact character of the Gaussian noise. Regularized inversion combined with active constraint balancing approach is conducted on the 2005 Nias earthquake. The released moment based on the estimated coseismic slip distribution is 9.91×1021 N·m, which is equivalent to a moment magnitude of 8.6 and almost identical to the value determined by USGS. The inversion results for synthetic coseismic uniform-slip model and the 2005 earthquake show that smoothness-constrained regularized inversion method combined with active constraint balancing approach is effective, and can be reasonable to reconstruct coseismic slip distribution on fault.

关键词： coseismic slip inversion trade-off parameter active constraint balancing model resolution matrix spread function

Evaluation of the in-place adsorbed gas content of organic-rich shales using wireline logging data: a new method and its application

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2021年第2期15卷 301-309页

作者： Xin NIE Yu WAN da gao Chaomo ZHANG Zhansong ZHANG Key Laboratory of Exploration Technologies for Oil and Gas Resources Yangtze UniversityWuhan 430100China Cooperative Innovation Center of Unconventional Oil and Gas Yangtze UniversityWuhan 430100China

Adsorbed gas content is an important parameter in shale gas reservoir evaluations,and its common calculation method is based on core ***,in different areas,the correlations between the adsorbed gas content and well logging data might ***,a model developed for one specific area cannot be considered *** on previous studies,we studied the relationships between temperature,TOC,organic matter maturity and adsorbed gas content and revealed qualitative equations between these ***,the equations were combined to establish a new adsorbed gas content calculation model based on depth and total organic carbon(TOC).This model can be used to estimate the adsorbed gas content using only conventional well logging data when core experimental data are rare or even *** method was applied in the southern Sichuan Basin,and the adsorbed gas content results agree well with those calculated using the Langmuir isothermal model and core experimental *** actual data processing results show that the adsorbed gas content model is reliable.

关键词： shale reservoir adsorbed gas well logging temperature pressure TOC depth

Broadband Source Ranging in Shallow Water Using the Ω-Interference Spectrum

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第6期27卷 110-113页

作者： ZHAO Zhen-Dong WANG Ning gao da-Zhi WANG Hao-Zhong College of Information Science and Engineering Ocean University of China Qingdao 266100

The concept of the waveguide invariant is revisited and a simple relationship between the range of source and the quasi-period of the acoustic interference spectrum in the frequency domain （Ω-interference spectrum） is derived. Then a method for a broadband source ranging in shallow water using a single receiver and a broadband guide source, requiring no modeling and no knowledge about the ocean environment, is proposed. The method is validated by simulation and verified with the experimental data.

关键词： Methods Broadband Source Ranging Ω-Interference Spectrum

data-Derived Estimation of Source Depth Using Vertical Line Array data in Shallow Water

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第11期28卷 148-151页

作者： WANG Hao-Zhong WANG Ning gao da-Zhi College of Information Science and Engineering Ocean University of ChinaQingdao 266100

Following the closure relation of normal mode theory,the source depth can be estimated approximately provided that the eigenfunction and the excited amplitude with correct polarity of each effective mode are *** the eigenfunction and the excited amplitude of each effective mode can be extracted using the data-derived method,which does not require a priori knowledge about ocean environment and source range but the sound pressure data observed by vertical line *** polarities,undetermined by data-derived method,can be estimated using a cost ***,the source depth is determined by locating the peak of the object function defined by the closure relation with the correct *** simulation and experiment are carried out to illustrate the performance of this method.

关键词： function source Vertical

Impacts of Market-based Environmental Regulation on Green Total Factor Energy Efficiency in China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China & World Economy 2023年第3期31卷 92-114页

作者： Ge Li da gao Yi Li School of Business and Management Donghua UniversityChina School of Law and Business Wuhan Institute of TechnologyChina Food and Resource Economics University of FloridaUS.

This study employed a difference-in-differences design to assess the effect of marketbased environmental regulation on green total factor energy efficiency(GTFEE)in a quasi-natural experiment that investigated China's carbon emissions trading scheme(ETS).The empirical results show that ETS had a positive effect on GTFEE.A series of robustness tests revealed that the results were *** mechanisms through which ETS can improve GTFEE include the promotion of technological innovation and the upgrading of industrial *** positive effects varied in different cities and diferent regions-the result was pronounced in eastern China and developed cities,but it was insignificant in central and western areas and developing *** study confirms the satisfactory performance of China's ETS in improving GTFEE,and this is relevant for other emerging countries.

关键词： carbon emissions trading schemes difference-in-differences green tota factor energy efficiency market-based environmental regulation

Reliability of DC-link capacitor in pulsed power supply for accelerator magnet

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第9期35卷 28-40页

作者： Jie Wang da-Qing gao Wan-Zeng Shen Hong-Bin Yan Li-Jun Mao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Capacitors are widely used in pulsed magnet power supplies to reduce ripple voltage,store energy,and decrease power *** this study,DC-link capacitors in pulsed power supplies were *** deriving an analytical method for the capacitor current on the H-bridge topology side,the root-mean-square value of the capacitor current was calculated,which helps in selecting the DC-link *** proposed method solves this problem quickly and with high *** current reconstruction of the DC-link capacitor is proposed to avoid structural damage in the capacitor’s current measurement,and the capacitor’s hotspot temperature and temperature rise are calculated using the FFT *** test results showed that the error between the calculated and measured temperature increases was within 1.5℃.Finally,the lifetime of DC-link capacitors was predicted based on Monte Carlo *** proposed method can evaluate the reliability of DC-link capacitors in a non-isolated switching pulsed power supply for accelerators and is also applicable to film capacitors.

关键词： Aluminum electrolytic capacitor DC-link current DC–DC power converter Hotspot temperature

A Sound Field Separation and Reconstruction Technique Based on Reciprocity Theorem and Fourier Transform

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2018年第11期35卷 42-45页

作者： Xiao-Lei Li Ning Wang da-Zhi gao Qi Li Department of Marine Technology Ocean University of ChinaQingdao 266100 College of Underwater Acoustic Engineering Harbin Engineering UniversityHarbin 150006

We show a method to separate the sound field radiated by a signal source from the sound field radiated by noise sources and to reconstruct the sound field radiated by the signal source. The proposed method is based on reciprocity theorem and the Fourier transform. Both the sound field and its gradient on a measurement surface are needed in the method. Evanescent waves are considered in the method, which ensures a high resolution reconstruction in the near field region of the signal source when evanescent waves can be measured. A simulation is given to verify the method and the influence of measurement noise on the method is discussed.

关键词： A Sound Field Separation and Reconstruction Technique Based on Reciprocity Theorem and Fourier Transform