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Cyclic oxidation behavior of Ni_(3)Al-based single crystal alloy IC21

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Rare Metals 2023年第5期42卷 1656-1662页

作者： Tian-Tian yang Xin Zhou Shu-suo Li yan-Ling Pei Sheng-Kai Gong School of Materials Science and Engineering Beihang UniversityBeijing100191China

In this study,the cyclic oxidation tests of the Ni3Al-based single-crystal super alloy IC21 were carried out at 800,900,950,1000,1050 and 1100℃in *** present study shows that the complex oxide scale on the surface of the alloy is made up of an outer columnar NiO layer,an intermediate mixture of NiO and NiAl2O4layer with a small amount of Mo oxides and an inner continuous layer ofα-Al_(2)O_(3).The cyclic oxidation kinetics curves show that oxidation resistance at 800,900,950,1000 and1050℃seems to follow a similar law and is better than that at 1100℃.The overall weight changes at 1100℃follows a parabolic *** and severe rumpling of the oxide scale are observed on the surface of the alloy at1100℃,revealing the occurrence of disastrous oxidation.

关键词： Ni_(3)Al Thermal cycling Oxidation Microstructure

Spatiotemporal evolution of land transportation networks and accessibility in inland mountainous areas 1917-2017:A case study of Southwest China

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Journal of Mountain Science 2020年第9期17卷 2262-2279页

作者： HUANG yan ZONG hui-ming School of Geographical Sciences Southwest UniversityChongqing 400715China State Cultivation Base of Eco-agriculture for Southwest Mountainous Land Southwest UniversityChongqing 400715China

Located in the western hinterland,Southwest China is a typical mountainous area covered by plateaus,mountains and *** ruggedness hinders regional internal and external connections,and its poor transportation infrastructure has long constrained the socioeconomic development of Southwest *** on the GIS transportation database,this paper explored the spatiotemporal evolution and characteristics of the land transportation networks and the accessibility of Southwest China from 1917 to *** accessibility in Southwest China has significantly improved,and transportation infrastructure has gradually integrated the transportation circles of the52 central *** transportation network has followed an evolutionary process from a"hub-spoke pattern"to a"network pattern",while the construction of a high-speed railway(HSR)has brought about significant spatial *** argue that innovation in transportation technology is one of the most effective factors for promoting a significant change in regional *** addition,the spatial distribution and evolution of accessibility in Southwest China presents a verticalcharacteristic that distinguishes it from the plains,as the spillover effects of new transportation infrastructure on accessibility improvement are partly offset by the mountainous ***,in Southwest China,there is significant"path dependence"in the evolution of the transportation network,since a large portion of the population is concentrated along transportation corridors in mountainous areas.

关键词： Southwest China Mountainous areas Transportation network Spatiotemporal evolution Accessibility Infrastructure

A model for automatic identification of human pulse signals

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第10期9卷 1382-1389页

作者： hui-yan WANG Pei-yong ZHANG College of Computer Science and Information Engineering Zhejiang Gongshang University Hangzhou 310018 China Institute of VLSI Design Zhejiang University Hangzhou 310027 China

This paper presents a quantitative method for automatic identification of human pulse signals. The idea is to start with the extraction of characteristic parameters and then to construct the recognition model based on Bayesian networks. To identify depth, frequency and rhythm, several parameters are proposed. To distinguish the strength and shape, which cannot be represented by one or several parameters and are hard to recognize, the main time-domain feature parameters are computed based on the feature points of the pulse signal. Then the extracted parameters are taken as the input and five models for automatic pulse signal identification are constructed based on Bayesian networks. Experimental results demonstrate that the method is feasible and effective in recognizing depth, frequency, rhythm, strength and shape of pulse signals, which can be expected to facilitate the modernization of pulse diagnosis.

关键词： Pulse signal identification Feature extraction Bayesian network Quantitative diagnosis Wavelet transform

SYMMETRY IN WORLD TRADE NETWORK

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Journal of Systems Science & Complexity 2009年第2期22卷 280-290页

作者： hui WANG Guangle yan yanghua XIAO Business School University of Shanghai for Science and Technology Shanghai 200093 China. Department of Computing and Information Technology Fudan University Shanghai 200433 China.

ymmetry of the world trade network provides a novel perspective to understand the world-wide trading system. However, symmetry in the world trade network （WTN） has been rarely studied so far. In this paper, the authors systematically explore the symmetry in WTN. The authors construct WTN in 2005 and explore the size and structure of its automorphism group, through which the authors find that WTN is symmetric, particularly, locally symmetric to a certain degree. Furthermore, the authors work out the symmetric motifs of WTN and investigate the structure and function of the symmetric motifs, coming to the conclusion that local symmetry will have great effect on the stability of the WTN and that continuous symmetry-breakings will generate complexity and diversity of the trade network. Finally, utilizing the local symmetry of the network, the authors work out the quotient of WTN, which is the structural skeleton dominating stability and evolution of WTN.

关键词： Automorphism group network quotients symmetry world trade network.

SUPERCONVERGENCE AND A POSTERIORI ERROR ESTIMATES FOR BOUNDARY CONTROL GOVERNED BY STOKES EQUATIONS

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Journal of Computational Mathematics 2006年第3期24卷 343-356页

作者： hui-po Liu Ning-ning yan Institute of Systems Science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

In this paper, the superconvergence results are derived for a class of boundary control problems governed by Stokes equations. We derive superconvergence results for both the control and the state approximation. Base ... 详细信息

关键词： Boundary control Finite element method Superconvergence A posteriori error estimates.

Study on the estimation of Euler angles for Macao Science Satellite-1

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Earth and Planetary Physics 2023年第1期7卷 144-150页

作者： Qing yan JiaMing Ou Le suo Yi Jiang PengFei Liu State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacaoChina Institute of Remote Sensing Satellite China Academy of Space TechnologyBeijing 100094China

The Euler angle estimation is a calibration method for vector data measured by the magnetometer on a *** is used to find the relative rotation between the coordinate system of the magnetometer and the satellite(usually determined by Star Imagers).Before launch of the low-orbit,low-inclination Macao Science Satellite-1(known as MSS-1),we simulated the estimation of Euler angles by using the magnetic measurements of the in-orbit Swarm and China Seismo-Electromagnetic Satellite(noted as CSES),with various data *** this study,11 data sets were designed to analyze the estimation results for the MSS-1 orbit by using a joint estimation method of the geomagnetic field model parameters and Euler *** the model results,we found that all the spatial power spectral lines showed behavior consistent with that of the CHAOS-7.8 model at low degrees(corresponding to large-scale magnetic signals).The spectra of models without global data coverage deviated much more(by a maximum of~10^(4) nT^(2))from those of the CHAOS-7.8 model at higher *** models with global data coverage and with various data combinations,the spectral lines were distributed ***,the models with accordant power spectral distributions demonstrated different Euler angle *** more vector data at higher latitudes were included,the estimated Euler angles varied monotonically in all three *** models with vector data in the same latitude range showed similar Euler angle results,regardless of whether the poleward scalar data were *** largest value difference was found between the models using vector data within±40°latitudes and those using vector data within±60°latitudes,which reached to~28″.Therefore,we concluded that the inversion of the spherical harmonic Gauss coefficients in our tests was mainly affected by the spatial coverage range of the data,whereas the estimation of Euler angles largely depended on the latitude range where the vector d

关键词： Macao Science Satellite-1(MSS-1) geomagnetic fields Euler angle estimation low-inclination orbit

Investigation on the automatic parameters extraction of pulse signals based on wavelet transform

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第8期8卷 1283-1289页

作者： WANG hui-yan ZHANG Pei-yong College of Computer Science ＆ Information Engineering Zhejiang Gongshang University Hangzhou 310018 China Institute of VLSI Design Zhejiang University Hangzhou 310027 China

This paper analyses a key problem in the quantification of pulse diagnosis. Due to the subjectivity and fuzziness of pulse diagnosis,quantitative methods are needed. To extract the parameters of pulse signals,the prerequisite is to detect the corners of pulse signals correctly. Up to now,the pulse parameters are mostly acquired by marking the pulse corners manually,which is an obstacle to modernize pulse diagnosis. Therefore,a new automatic parameters extraction approach for pulse signals using wavelet transform is presented. The results testified that the method we proposed is feasible and effective and can detect corners of pulse signals accurately,which can be expected to facilitate the modernization of pulse diagnosis.

关键词： Pulse signal Feature extraction Complex wavelet transform Quantitative diagnosis

Novel method for separation and screening of lubricant-degrading microorganisms and bacterial biodegradation

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Chinese Journal of Chemical Engineering 2016年第3期24卷 353-359页

作者： yan Jiang hui Qi Xianming Zhang Engineering Research Centre for Waste Oil Recovery Technology and Equipment Ministry EducationChongqing Technology and Business University College of Foreign Languages Chongqing Technology and Business University

With the rapid increase of lubricant consumption, oil contamination becomes more serious. Biotreatment is an important method to remove oil contamination with some advantages. In this study, acclimatized oil- contaminated soil and used lubricating oil were sampled to isolate lubricant-degrading strains by several methods. 51 isolates were obtained and 24-well plates were employed to assess bacterial potential in high- throughput screening. The method was noted for the prominence of oil-water two-phase system with saving chemicals, shortening cycles and lessening workloads. In order to decrease inaccuracy, subculture and resting cells were inoculated into mineral salt medium with 200 μ1 oil in well plates for the cultivation at 37 ℃ for 5 and 7 days, and the biodegradation potential was characterized by the changes of oil film and cell density. With appropriate evaluation by shaking flask tests, 5 isolates were retained for their potentials with the maxi- mum biodegradation from 1500 to 2200 mg· L-1 and identified as Acidovorax dtrulli, Pseudomonos balearica, Adnetobacterjohnsonii （two isolates with different biodegradation potentials） and Addovorax avenae using 16S rRNA sequencing analysis. Also, lipase activity was determined using indicator titration and p-nitrophenyl palmitate （p-NPP） methods. The results indicated that only p-NPP was successful to test lipase activity with the range of 1.93-6.29 mg· L-1 Although these five strains could degrade 1000 mg· L-1 lubricating oil in 158-168 h, there existed distinct difference in enzyme activity, which demonstrates that lipase activity could not be used as the criterion to evaluate microbial biodegradation potential for petroleum hydrocarbons.

关键词： Lubricant Degradation Separation 24-well plate Enzyme

Regulation of Water Deficit-Induced Abscisic Acid Accumulation by Apoplastic Ascorbic Acid in Maize Seedlings

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Journal of Integrative Plant Biology 2005年第11期47卷 1335-1344页

作者： Jian-Fang HU Gui-Fen LI Zhi-hui GAO Lin CHEN hui-Bo REN Wen-suo JIA College of Agronomy and Biotechnology State Key Laboratory of Plant Physiology and Biochemistry China Agricultural University Beijing 100094 China

Water deficit-induced abscisic acid （ABA） accumulation is one of the most important stress signaling pathways in plant cells. Redox regulation of cellular signaling has currently attracted particular attention, but much less is known about its roles and mechanisms in plant signaling. Herein, we report that water deficit-induced ABA accumulation could be regulated by ascorbic acid （AA）-controlled redox status in leave apoplast. The AA content in non-stressed leaves was approximately 3 umol/g FW, corresponding to a mean concentration of 3 mmol/L in a whole cell. Because AA is mainly localized in the cytosol and chloroplasts, the volume of which is much smaller than that of the whole cell, AA content in cytosolic and chloroplast compartments should be much higher than 3 mmol/L. Water deficit-induced ABA accumulation in both leaf and root tissues of maize seedlings was significantly inhibited by AA and reduced glutathione （GSH） at concentrations of 500 umol/L and was completely blocked by 50 mmol/L AA and GSH. These results suggest that the AA-induced inhibition of ABA accumulation should not occur at sites where AA exists in high concentrations. Although water deficit led to a small increase in the dehydroascorbic acid （DHA） content, no significant changes in AA content were observed in either leaf or root tissues. When compared with the whole leaf cell, the AA content in the apoplastic compartment was much lower （i.e. approximately 70 nmol/g FW, corresponding to 0.7 mmol/L）. Water deficit induced a significant decrease （approximately 2.5-fold） in the AA content and an increase （approximately 3.4-fold） in the DHA content in the apoplastic compartment, thus leading to a considerably decreased redox status there, which may have contributed to the relief of AA-induced inhibition of ABA accumulation, alternatively, promoting water deficit-induced ABA accumulation. Reactive oxygen species （ROS） could not mimic water deficit in inducing ABA accumulation, suggesting that the

关键词： abscisic acid (ABA) ascorbic acid (AA) maize (Zea mays) reactive oxygen species waterdeficit.