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Separation of the ionospheric and thermospheric contributions in the data from the Triple Ionosophere Photo Meter onboard the Feng-Yun 3E satellite

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Science China Earth Sciences 2025年第1期68卷 172-184页

作者： Fang JIANG tian mao Jin-Song WANG Xiu-Qing HU Xiao-Xin ZHANG Liping FU Nan JIA tianfang WANG National Space Science Center Chinese Academy of Sciences Beijing Key Laboratory of Space Environment Exploration Key Laboratory of Environmental Space Situation Awareness Technology National Satellite Meteorological Center China Meteorological Administration

The Triple Ionosphere Photo Meter （TRIPM） is a far ultraviolet nadir-view photometer that is onboard the secondgeneration,polar-orbiting Chinese meteorological satellite Feng-Yun 3E （FY-3E）,which was launched on July 5,*** has three channels,and each is used to measure different types of emissions:（1） 135.6 nm airglow produced by the recombination of the O+ions and electrons in the absence of sunlight （nighttime channel）;（2） 135.6 nm airglow from the OI when sunlight is present （daytime/dusk-dawn 135.6 nm channel）;and （3） Airglow in the N2LBH of the TRIPM （daytime/dusk-dawn N2LBH channel）.FY-3E is a satellite operating in the early morning ***,the data are mostly distributed on the dawndusk side or at times when the solar zenith angle is relatively *** this study,combined with simulation calculations,the data are *** further explore the application value of the data products,a model is used to separate the ionospheric radiative recombination contribution from the thermosphere photoelectron impact excitation contribution in the data from the daytime/dusk-dawn 135.6 nm *** approach not only improves the accuracy of O/N2derived from the 135.6 nm channel and N2LBH channel but also provides the ionospheric 135.6 nm radiance at the same time as the *** results show that the 135.6 nm radiance originating from the combination of O+and electrons extracted from the measurement data exhibits similar equatorial anomaly peak structure characteristics and seasonal variations as the corresponding GPS total electron content （TEC） *** the other hand,the separated 135.6 nm radiance generated from the thermosphere photoelectron collision excitation does not contain radiative recombination contributions;thus,the ionosphere influence is greatly avoided when the O/N2is obtained.

关键词： Far ultraviolet 135.6 nm emission intensity Photoelectron impact excitation Radiative recombination excitation

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First Passage Density of Brownian Motion with Two-sided Piecewise Linear Boundaries

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1505-1520页

作者： Zhen YU mao Zai tian Center for Applied Statistics School of StatisticsRenmin University of ChinaBeijing 100872P.R.China School of Mathematics and Data Science Changji UniversityChangji 831100P.R.China

The first passage time has many applications in fields like finance,econometrics,statistics,and ***,explicit formulas for the first passage density have only been obtained for a few *** paper derives an explicit formula for the first passage density of Brownian motion with twosided piecewise continuous boundaries which may have some points of *** are used to obtain a simplified formula for estimating the first passage ***,the results are also generalized to the case of two-sided general nonlinear *** can be easily carried out with Monte Carlo method and it is demonstrated for several typical two-sided boundaries that the proposed approximation method offers a highly accurate approximation of first passage density.

关键词： Boundary non-crossing probability first density passage density two-sided piecewise continuous boundaries Brownian motion

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A New Generalized Linear Exponential Distribution and Its Applications

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Acta Mathematicae Applicatae Sinica 2014年第4期30卷 1049-1062页

作者： Yu-zhu tian mao-zai tian Qian-qian ZHU School of Mathematics and Information Science Henan Polytechnic University Center for Applied Statistics School of StatisticsRenmin University of China School of Statistics Lanzhou University of Finance and Economics

A new generalized linear exponential distribution （NCLED） is considered in this paper which can be deemed as a new and more flexible extension of linear exponential distribution. Some statistical properties for the NGLED such as the hazard rate function, moments, quantiles are given. The maximum likelihood estimations （MLE） of unknown parameters are also discussed. A simulation study and two real data analyzes are carried out to illustrate that the new distribution is more flexible and effective than other popular distributions in modeling lifetime data.

关键词： generalized linear exponential distribution (GLED) linear exponential distribution Hazard ratefunction maximum likelihood estimation (MLE)

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Adaptive Local Linear Quantile Regression

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Acta Mathematicae Applicatae Sinica 2011年第3期27卷 509-516页

作者： Yu-nan Su mao-zai tian Center for Applied Statistics School of Statistics Remin University of China Beijing 100872 China

In this paper we propose a new method of local linear adaptive smoothing for nonparametric conditional quantile regression. Some theoretical properties of the procedure are investigated. Then we demonstrate the performance of the method on a simulated example and compare it with other methods. The simulation results demonstrate a reasonable performance of our method proposed especially in situations when the underlying image is piecewise linear or can be approximated by such images. Generally speaking, our method outperforms most other existing methods in the sense of the mean square estimation （MSE） and mean absolute estimation （MAE） criteria. The procedure is very stable with respect to increasing noise level and the algorithm can be easily applied to higher dimensional situations.

关键词： quantile regression local linear regression adaptive smoothing automatic choice of window size Robustness

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A Longitudinal Study of the Effects of Family Background Factors on Mathematics Achievements Using Quantile Regression

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Acta Mathematicae Applicatae Sinica 2008年第1期24卷 85-98页

作者： Xi-zhi Wu mao-zai tian Center for Applied Statistics School of Statistics Renmin University of China Beijing 100872 China School of Statistics Renmin University of China Beijing 100872 China

Quantile regression is gradually emerging as a powerful tool for estimating models of conditional quantile functions, and therefore research in this area has vastly increased in the past two decades. This paper, with the quantile regression technique, is the first comprehensive longitudinal study on mathematics participation data collected in Alberta, Canada. The major advantage of longitudinal study is its capability to separate the so-called cohort and age effects in the context of population studies. One aim of this paper is to study whether the family background factors alter performance on the mathematical achievement of the strongest students in the same way as that of weaker students based on the large longitudinal sample of 2000, 2001 and 2002 mathematics participation longitudinal data set. The interesting findings suggest that there may be differential family background factor effects at different points in the mathematical achievement conditional distribution.

关键词： Mathematical achievement family background factors quantile regression confidence intervals,longitudinal study

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Scalable Preparation of SrTiO_3 Submicro-wires from Layered Titanate Nanowires

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Chinese Journal of Aeronautics 2007年第2期20卷 177-180页

作者： TANG mao-yu JI tian-hao XIE Jian School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100083 China

SrTiO3 submicro-wires were prepared by the reaction of layered titanatc nanowircs with Sr（OH）2 powder in an autoclave. The wires were investigated using X-ray diffraction （XRD）, scanning electron microscope （SEM）, transmission electron microscope （TEM）, Ultra-violet visible （UV-vis）, photoluminescence （PL） and Raman spectroscopy. The XRD measurement shows that the prepared SrTiO3 submicro-wircs hardly have impurity phases. The SEM and TEM images demonstrate that the scalable wires, which need to be processed at the reaction temperature of 180℃ for about 48 hours, are not composed of single crystals. The PL shows that the wire-like SrTiO3 has emission peaks at the wavelengths of 568 and 585 nm. Further, the Raman spectroscopy reveals structural changes in the products through different reaction time.

关键词： oxide titanate nanowires strontium titanate SrTiO3 wires

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PIV EXPERIMENTAL RESEARCH OF FLOW STRUCTURE IN RECTANGULAR CHANNEL WITH TRANSVERSELY PLACED SPIRAL COIL INSERT

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Journal of Hydrodynamics 2012年第4期24卷 518-525页

作者： TANG Yu-feng tian mao-cheng ZHANG Guan-min School of Energy Source and Power Engineering Shandong UniversityJinan 250061China

The flow field in a rectangular channel with a transversely placed spiral coil insert is investigated by Particle Image Velocimetry （PIV） measurements in both transverse and longitudinal sections. The experimental results show that multi-longitudinal vortices are induced downstream of the spiral coil and are distributed as a symmetrical vortex array along the horizontal central line of the transverse section. Along the mainstream, due to the spiral motion of the longitudinal vortices, the velocity fluctuates in a manner of the damped sinusoidal curve and the velocity component in the wall normal direction is improved in the channel. Com- pared with the flow field in a smooth channel it is found that the movement of the longitudinal vortices can cause a continuous dis- turbance near the channel walls and thus enhances the fluid velocity in the near wall region, which consequently leads to the redu- ction of the velocity gradient and a more uniform velocity distribution. With the increase of the Reynolds number, the induced longitudinal vortices gain strength and become straighter and closer to the channel walls, thus the turbulence intensity is further enha- nced in this area.

关键词： Particle Image Velocimetry (PIV) spiral coil longitudinal vortices flow disturbance

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Roles of IκB kinase ε in the innate immune defense and beyond

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Virologica Sinica 2016年第6期31卷 457-465页

作者： Junjie Zhang mao tian Zanxian Xia Pinghui Feng State Key Laboratory of Medical Genetics and School of Life Sciences Central South University Changsha 410008 China

IκB kinase ε(IKKε) is a non-canonical IκB kinase that is extensively studied in the context of innate immune response. Recently, significant progress has been made in understanding the role of IKKεin interferon(IFN) signaling. In addition to its roles in innate immunity, recent studies also demonstrate that IKKε is a key regulator of the adaptive immune response. Specifically, IKKεfunctions as a negative feedback kinase to curtail CD8 T cell response, implying that it can be a potential therapeutic target to boost antiviral and antitumor T cell immunity. In this review, we highlight the roles of IKKε in regulating IFN signaling and T cell immunity, and discuss a few imminent questions that remain to be answered.

关键词： innate immunity interferon signaling antiviral defense antitumor regulating phosphorylate highlight

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Capturing and storage of CO_2 by micron-nano minerals:Evidence from the nature

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Chinese Journal Of Geochemistry 2011年第4期30卷 569-575页

作者： mao Xumei tian Xike YU Chengyong School of Environmental Studies and School of Material Sciences and Chemical Engineering China University of Geosciences Wuhan 430074 China

The increase of CO2 in atmosphere is a main factor leading to "greenhouse effect", which causes more and more serious global environmental problems. The reduction of CO2 is a challenge for the survival of human beings, and it is also a big technical problem. CO2 fluid-rock interaction is a key scientific problem involved in geo-logical storage. The CO2 fluid-rock interaction has a variety of multi-scale changes. Due to great differences in the quantity of surface atoms and surface energy between micron-nano-sized minerals, and ions and crystals, the speed and efficiency of CO2 fluid-rock interaction on a micron-nano scale are much higher than those on other scales. As is known from the natural world, the micron-nano structures of pores and the surface chemical modification of natural porous minerals (zeolite, diatomite, sepiolite, palygorskite, halloysite, etc.) should be further investigated, which can be used as the micron-nano -mineral porous materials with high capacity and high efficiency for capturing CO2. Through simulating the adsorption capacity and process of CO2 by minerals in the natural world, the micron-nano technology is applied to calcium- and magnesium-based minerals (olivine, pyroxene, feldspar, clay, etc.) so as to improve the activity of calcium and magnesium and enlarge the reaction contact area. In this way, the efficiency of capturing and storage of CO2 by calcium- and magnesium-based minerals can be greatly improved. These minerals can also be used as the micron-nano-mineral materials with large capacity and high efficiency for capturing and storing CO2.

关键词：二氧化碳排放量纳米尺度矿物质微米储存捕获纳米矿物材料证据

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SIMULATION AND ANALYSIS OF FLOW PATTERN IN CROSS-CORRUGATED PLATE HEAT EXCHANGERS

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Journal of Hydrodynamics 2006年第5期18卷 547-551页

作者： ZHANG Guan-min tian mao-cheng ZHOU Shou-jun School of Energy and Power Engineering Shandong University Jinan 250061 China School of Thermal Energy Engineering Shandong JianZhu University Jinan 250101 China

Using numerical methodology, the flow fields between two corrugated plates with different values of the corrugation inclination angle β were simulated. The simulation results directly indicate that β affects the flow pattern between corrugated plates, and the results are in good agreement with the experimental results reported by interrelated literature. The results show that the flow pattern between the two plates changes from ＂double cross-flow＂ to ＂zigzag flow＂ with the increase in β. The reason for the effect on the flow pattern between the two corrugated plates was discussed from the view of the variation of momentum in the direction of corrugation with the variation in β.

关键词： plate heat exchanger simulation flow pattern

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