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Structural evolution and high-temperature sensing performance of polymer-derived SiAlBCN ceramics

Journal of Advanced Ceramics 2024年第4期13卷 478-485页

作者： Chao Ma kun Liu Pengfei shao Daoyang Han Kang Wang Mengmeng yang Rui Zhao Hailong Wang Rui Zhang Gang shao School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China Zhongyuan Critical Metal Laboratory Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentZhengzhou UniversityZhengzhou 450002China

In situ temperature monitoring has become extremely imperative in high-temperature harsh environments and polymer-derived ceramics(PDCs)as sensing materials have attracted great ***,the stability and oxidation/corrosion resistance of PDCs cannot be simultaneously achieved at the moment,limiting their practical ***,polymer-derived SiAlBCN ceramics were synthesized via polymer conversion method under different pyrolysis *** microstructure evolution,high temperature sensing properties,and stability were investigated in *** results show that the amorphous SiAlBCN phase grows more orderly and the size of the free carbon phase enlarges with the increasing *** defect concentration displays a decreasing ***,the SiAlBCN ceramics as sensing materials exhibit a good temperature-resistance property from roo temperature to 1100℃.The fabricated SiAlBCN temperature sensor possesses excellent stability,repeatability,and ***,SiAlBCN ceramics exhibit distinguished oxidation/corrosion resistance after 100 h treatment at 1200℃in a water/oxygen environment,which is attributed to their low corrosive rate constant(0.57 mg/(cm^(2)·h))and oxidative rate constant(3.43 mg^(2)/(cm^(4)·h)).Therefore,polymer-derived SiAlBCN ceramics as sensing materials,which possess outstanding stability and oxidation/corrosion resistance,have great potential for in-situ monitoring of extreme environmental temperatures in the future.

关键词： polymer-derived SiAlBCN ceramics temperature sensor harsh environments oxidation and corrosion resistance

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Estimating Aboveground Fresh Biomass of Different Cotton Canopy Types with Homogeneity Models Based on Hyper Spectrum Parameters

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Agricultural Sciences in China 2007年第4期6卷 437-445页

作者： BAI Jun-hu LI shao-kun WANG Ke-ru SUI Xue-yan CHEN Bing WANG Fang-yong Institute of Crop Sciences Chinese Academy of Agricultural Sciences/The National Key Facility for Crop Gene Resources and Genetic Improvement NFCRI Beijing 100081 P.R.China Key Laboratory of Oasis Ecology Agriculture of Xinjiang Construction Crops/The Center of Crop High-Yield Research Shihezi 832003 P.R.China

AGB （aboveground fresh biomass） is one of the most important parameters of the crop condition monitored with remote sensing. Hyper spectrum remote sensing with the fine spectrum information becomes the efficient method estimating the vegetation AGB. The research was conducted in Xinjiang, the largest cotton planting region of China. The paper analyzed the correlation between the cotton AGB and reflective spectrum and the first derivative spectrum, and the variation coefficient of the waveband reflectance. According to the analysis above, all of 23 parameters, including the hyper spectrum reflectance, the first derivative spectrum parameters and normalization vegetation indexes, were established. And then the estimation models on cotton AGB of relaxing and compact canopy type were established and tested respectively. The tested results showed that Fgo1, [901,502], [901,629], [901,672] among the reflective spectral parameters and D525, D956, D1019, D1751 among the first derivative spectral parameters had the homogenous effect on different cotton canopy types, and the determination coefficients of the models above all arrive at the significant level of 0.99 confidence interval. At last, the tested results of the homogeneity models for different canopy types indicated the parameters of [901, 502], [901,629], [901,672] have more satisfying veracity than others, and the relative errors are as low as 17.0, 16.3 and 16.7% correspondingly; in contrast, the estimation veracity of the first derivative spectrum parameters of single waveband is low.

关键词： canopy types of cotton AGB hyperspectrum parameters homogeneity estimation models

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Low-noise InGaAs/InP single-photon detector with widely tunable repetition rates

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Photonics Research 2019年第3期7卷 I0001-I0006页

作者： yan LIANG QILAI FEI ZHIHE LIU kun HUANG HEPING ZENG Shanghai Key Laboratory of Modern Optical Systems Engineering Research Center of Optical Instruments and Systems Ministry of EducationSchool of Optical-Electrical and Computer Engineering University of Shanghai for Science and Technology State Key Laboratory of Precision Spectroscopy East China Normal University

InGaAs/InP avalanche photodiodes typically work in the gated Geiger mode to achieve near-infrared singlephoton detection. By using ultrashort gates and combining with the robust spike-canceling technique that consists of the capacitance-balancing and low-pass filtering technique, we demonstrate an InGaAs/InP single-photon detector(SPD) with widely tunable repetition rates in this paper. The operation frequency could be tuned conveniently from 100 MHz to 1.25 GHz with the SPD's performance measured to maintain good performance, making it quite suitable for quantum key distribution, laser ranging, and optical time domain reflectometry. Furthermore,the SPD exhibited extremely low-noise characteristics. The detection efficiency of this SPD could reach 20% with the dark count rate of 2.5 × 10^(-6)∕gate and after-pulse probability of 4.1% at 1 GHz.

关键词： InGaAs/InP single-photon detector achieve near-infrared singlephoton detection robust spike-canceling technique

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Design of multi-vehicle ad hoc experiment system based on VANets

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Science China(Technological Sciences) 2011年第4期54卷 1011-1016页

作者： WANG JiangFeng yan XueDong shao ChunFu WEI LiYing MOE Key Laboratory for Transportation Complex Systems Theory and Technology Beijing Jiaotong UniversityBeijing 100044China

Vehicular ad hoc networks(VANets) experiment system is ***,characteristics and research fields of VANets are introduced *** to the characteristics of VANets,key modules that multi-vehicle ad hoc experiment system needs are designed,and each module's function and practice requirement is *** reliability of experiment system is tested primarily using three experiment scenes of multi-vehicle ad hoc network,car following and wireless *** experiment result shows that multi-vehicle ad hoc experiment system has the capability of the correlated experiment of VANets.

关键词： VANets multi-vehicle ad hoc car following experiment system

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Adaptive Coordinated Control for Hot Strip Finishing Mills

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Journal of Iron and Steel Research International 2011年第4期18卷 36-43页

作者： JIAO Xiao-hong shao Li-ping PENG yan Institute of Electrical Engineering Yanshan University Qinhuangdao 066004 Hebei China Institute of Mechanical Engineering Yanshan University Qinhuangclao 066004 Hebei China

To further improve the control accuracy for strip dimension of hot strip mills,an adaptive control scheme is investigated for a hot strip finishing mill based on the decentralization and coordination among the controllers of gauge,tension and ***,the adaptive controller designed can regulate simultaneously the strip exit thickness,the strip tension and the looper angle to ensure better performance of the strip quality of finishing ***,the control scheme is proposed in consideration of the essential nonlinearity and the unavoidable friction phenomena in the mechanical system,so the controller can be efficient in a wider range of working *** simulation results of a model obtained from a real hot strip finishing mill show the effectiveness of the proposed control scheme in comparison with the conventional control method.

关键词： hot strip finishing mills exist gauge tension looper angle adaptive control

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The Proportional Mean Residual Life Regression Model with Cure Fraction and Auxiliary Covariate

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Acta Mathematicae Applicatae Sinica 2022年第2期38卷 312-323页

作者： shao-jia JIN yan-yan LIU Guang-cai MAO Ming-yu SHAN School of Mathematics and Statistics Wuhan UniversityWuhan 430072China School of Mathematics and Statistics Central China Normal UniversityWuhan 430079China

As biological studies become more expensive to conduct,it is a frequently encountered question that how to take advantage of the available auxiliary covariate information when the exposure variable is not *** this paper,we propose an induced cure rate mean residual life time regression model to accommodate the survival data with cure fraction and auxiliary covariate,in which the exposure variable is only assessed in a validation set,but a corresponding continuous auxiliary covariate is ascertained for all subjects in the study *** studies elucidate the practical performance of the proposed method under finite *** an illustration,we apply the proposed method to a heart disease data from the Study of Left Ventricular Dysfunction.

关键词： auxiliary covariate Kernel smoothing logistic regression mean residual life mixture cure model

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Modeling ε Eri and Asteroseismic Tests of Element Diffusion

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Chinese Journal of Astronomy and Astrophysics 2008年第5期8卷 591-602页

作者： Ning Gai shao-Lan Bi yan-Ke Tang National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China Department of Astronomy Beijing Normal University Beijing 100875 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

Taking into account the helium and metal diffusion, we explore the possible evolutionary status with a seismic analysis, of the MOST （Microvariability and Oscillations of STars） target： the star e Eri. We adopt different input parameters to construct models to fit the available observational constraints in, e.g., Teff, L, R and [Fe/H]. From the computation we obtain the average large spacings of e Eri to be about 194 ± 1μHz. The age of the diffused models was found to be about 1 Gyr, which is younger than the age determined previously by models without diffusion. We found that the effect of pure helium diffusion on the internal structure of the young low-mass star is slight, but that of metal diffusion is obvious. The metal diffusion leads the models to have much higher temperature in the radiative interior, and, correspondingly a higher sound speed there, hence a larger frequency and spacings.

关键词： stars evolution - stars interiors -stars individual ∈ Eridani

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Impact Analysis of Solar Irradiance Change on Precision Orbit Determination of Navigation Satellites

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Transactions of Nanjing University of Aeronautics and Astronautics 2019年第6期36卷 889-901页

作者： ZHANG yan WANG Xiaoya XI Kewei shao Fan Astro-Geodynamics Research Center Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030P.R.China University of Chinese Academy of Sciences Beijing 100049P.R.China Shanghai Key Laboratory of Space Navigation and Positioning Techniques Shanghai Astronomical ObservatoryChinese Academy of SciencesShanghai 200030P.R.China

Solar radiation pressure is the main driving force and error source for precision orbit determination of navigation *** is proportional to the solar irradiance,which is the"sun constant".In regular calculation,the"solar constant"is regard as a ***,due to the existence of sunspots,flares,etc.,the solar constant is not fixed,the change in the year is about 1%.To investigate the variation of solar irradiance,we use interpolation and average segment modeling of total solar irradiance data of SORCE,establishing variance solar radiation pressure(VARSRP)model and average solar radiation pressure(AVESRP)model based on the built solar pressure model(SRPM)(constant model).According to observation data of global positioning system(GPS)and Beidou system(BDS)in 2015 and comparing the solar pressure acceleration of VARSRP,AVESRP and SRPM,the magnitude of change can reach 10-10 m/s^*** addition,according to the satellite precise orbit determination,for GPS satellites,the results of VARSRP and AVESRP are slightly smaller than those of the SRPM model,and the improvement is between 0.1 to 0.5 *** geosynchronous orbit(GEO)satellites of BDS,The AVESRP and VARSRP have an improvement of 3.5 mm and 4.0 mm,respectively,based on overlapping arc,and SLR check results show the AVESRP model and the VARSRP model is improved by 2.3 mm and 3.5 mm,***,the change of inclined geosynchronous orbit(IGSO)satellites and medium earth orbit(MEO)satellites is relatively small,and the improvement is smaller than 0.5 mm.

关键词： solar pressure acceleration total solar irradiance precise orbit determination global positioning system(GPS) Beidou system(BDS)

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The current application of thermal ablation in colorectal liver metastasis

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Hepatobiliary Surgery and Nutrition 2021年第6期10卷 872-874页

作者： Zhongyi Zhang kun yan Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing) Department of UltrasonographyPeking University Cancer Hospital&InstituteBeijingChina

Colorectal liver metastases(CRLM)are one of the most frequent clinical *** the last 20 years,the clinical outcome for patients with CRLM has improved *** resection is the gold standard treatment for resectable CRLM,achieving a 5-year overall survival(OS)rate of 42%(1).However,the majority of patients with CRLM are not candidates for *** the development of thermal ablation,this technique provides an alternative treatment modality by either ablation alone or combined with resection.A recent review by Takahashi et *** the current role of thermal ablation in the management of CRLM(2).

关键词： clinical metastasis Liver

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Temporal and spatial changes in nutrients and chlorophyll-a in a shallow lake,Lake Chaohu, China: An 11-year investigation

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Journal of Environmental Sciences 2013年第6期25卷 1117-1123页

作者： Libiao yang kun Lei Wei Meng Guo Fu Weijin yan River and Coastal Environment Research Center Chinese Research Academy of Environmental Sciences Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Temporal and spatial changes of total nitrogen （TN）, total phosphorus （TP） and chlorophyll-a （Chl-a） in a shallow lake, Lake Chaohu, China, were investigated using monthly monitoring data from 2001 through 2011. The results showed that the annual mean concentration ranges of TN, TP, and Chl-a were 0.08-14.60 mg/L, 0.02-1.08 mg/L, and 0.10-465.90 ~tg/L, respectively. Our data showed that Lake Chaohu was highly eutrophic and that water quality showed no substantial improvement during 2001 through 2011. The mean concentrations of TP, TN and Chl-a in the western lake were significantly higher than in the eastern lake, which indicates a spatial distribution of the three water parameters. The annual mean ratio of TN：TP by weight ranged from 10 to 20, indicating that phosphorus was the limiting nutrient in this lake. A similar seasonality variation for TP and Chl-a was observed. Riverine TP and NH4＋ loading from eight major tributaries were in the range of 1.56× 10^4-5.47 × 10^4 and 0.19 × 104-0.51 × 10^4 tons/yr over 2002-2011, respectively, and exceeded the water environmental capability of the two nutrients in the lake by a factor of 3-6. Thus reduction of nutrient loading in the sub-watershed and tributaries would be essential for the restoration of Lake Chaohu.

关键词： eutrophication Lake Chaohu nitrogen phosphorus

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