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Improved data gap-filling schemes for estimation of net ecosystem exchange in typical East-Asian croplands

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Science China Earth Sciences 2016年第8期59卷 1652-1664页

作者： ZHAO Peng Johannes lüERS Department of Micrometeorology University of Bayreuth Institute of Ecology University of Innsbruck Member of Bayreuth Center of Ecology and Environmental Research (BayCEER) University of Bayreuth

The estimation of carbon exchange between ecosystems and the atmosphere suffers unavoidable data gaps in eddy-covariance technique, especially for short-living and fast-growing croplands. In this study we developed a modified gap-filling scheme introducing a leaf area index factor as the vegetation status information based on the conventional light response function for two East-Asian cropland sites (rice and potatoes). This scheme’s performance is comparable to the conventional time window scheme, but has the advantage when the gaps are large compared to the total length of the time series. To investigate how the time binning approach performs for fast-growing croplands, we tested different widths of the time window, showing that a four-day window for the potato field and an eight-day time window for the rice field perform the best. The insufficiency of the conventional temperature binning approach was explained as well as the influence of vapor pressure deficit. We found that vapor pressure deficit plays a minor role in both the potato and the rice fields under Asian monsoon weather conditions with the exception of the early pre-monsoon growing stage of the potatoes. Consequently, we recommend using the conventional time-window scheme together with our new leaf-light response function to fill data gaps of net ecosystem exchange in fast-growing croplands.

关键词： Eddy-covariance Gap-filling Net ecosystem exchange lAI

Cosmological application on five-dimensional teleparallel theory equivalent to general relativity

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Chinese Physics B 2012年第10期21卷 122-129页

作者： Gamal G.l.Nashed Mathematics Department Faculty of ScienceKing Faisal UniversityP.O.Box 380 Al-Ahsaa 31982the Kingdom of Saudi Arabia Mathematics Department Faculty of ScienceAin Shams UniversityCairo 11566Egypt Center for Theoretical Physics British University of EgyptSherouk City 11837P.O.Box 43Egypt

A theory of（4＋1）-dimensional gravity has been developed on the basis of which equivalent to the theory of general relativity by *** fundamental gravitational field variables are the 5-dimensional（5D） vector fields（pentad）,defined globally on a manifold M,and gravity is attributed to the *** lagrangian density is quadratic in the torsion *** then apply the field equations to two different homogenous and isotropic geometric structures which give the same line element,i.e.,FRW in five *** cosmological parameters are calculated and some cosmological problems are discussed.

关键词： 5D teleparallel equivalent of general relativity 5D solutions cosmological parameters cosmological problems

Energy and momentum of general spherically symmetric frames on the regularizing teleparallelism

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Chinese Physics B 2012年第1期21卷 101-109页

作者： Gamal G.l.Nashed Centre for Theoretical Physics The British University in EgyptEl-Sherouk City 11837Egypt Mathematics Department Faculty of ScienceAin Shams University

In the context of the covariant teleparallel framework, we use the 2-form translational momentum to compute the total energy of two general spherically symmetric frames. The first one is characterized by an arbitrary function H（r）, which preserves the spherical symmetry and reproduces all the previous solutions, while the other one is characterized by a parameter ξ which ensures the vanishing of the axial of trace of the torsion. We calculate the total energy by using two procedures, i.e., when the WeitzenbSck connection Гα^β is trivial, and show how H（r） and ξ play the role of an inertia that leads the total energy to be unphysical. Therefore, we take into account Гα^β and show that although the spacetimes we use contain an arbitrary function and one parameter, they have no effect on the form of the total energy and momentum as it should be.

关键词： gravitation teleparallel gravity energy-momentum conserved currents

Brane world black holes in teleparallel theory equivalent to general relativity and their Killing vectors,energy,momentum and angular momentum

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Chinese Physics B 2010年第2期19卷 77-91页

作者： Gamal G.l.Nashed Centre for Theoretical Physics The British University in EgyptEl-Sherouk CityMisr-Ismalia Desert Road Postal No.11837P.O.Box 43Egypt Mathematics Department Faculty of ScienceAin Shams UniversityCairoEgypt

The energy--momentum tensor, which is coordinate-independent, is used to calculate energy, momentum and angular momentum of two different tetrad fields. Although, the two tetrad fields reproduce the same space--time their energies are different. Therefore, a regularized expression of the gravitational energy--momentum tensor of the teleparallel equivalent of general relativity （TEGR）, is used to make the energies of the two tetrad fields equal. The definition of the gravitational energy--momentum is used to investigate the energy within the external event horizon. The components of angular momentum associated with these space--times are calculated. In spite of using a static space--time, we get a non-zero component of angular momentum! Therefore, we derive the Killing vectors associated with these space--times using the definition of the lie derivative of a second rank tensor in the framework of the TEGR to make the picture more clear.

关键词： teleparallel equivalent of general relativity brane world black holes gravitational energy--momentum tensor regularized expression of the gravitational energy--momentum

A NEW CONCEPT TOWARD INDUSTRIAlIZATION OF Cu-III-VI_2 THIN FIlM SOlAR CEllS AND SOME PRElIMINARY EXPERIMENT RESUlTS

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Acta Metallurgica Sinica(English letters) 2005年第3期18卷 199-203页

作者： l.X.Shao H.l.Hwang SchoolofInformationTechnologyandScience ZhanjiangNormalCollegeZhanjiang524048China DepartmentofElectricalEngineering NationalTsingHuaUniversityTaiwan300China

A new concept of full vacuum manufacturing for Cu-III-IV2 thin-film solar cells has been discussed. Cu-III-IV2 thin-film solar cells manufactured using full in- line reactive sputtering will result in lower cost than that of the conventional method with CdS layer fabricated with chemical bath deposition (CBS) method. Us ing reactive sputtering process with organo- metallic gases, the compositions a nd electronic properties of Cu-III-IV2 thin-film can be fine-tuned and precisely controlled. n-type Cu-III-IV2 film and ZnS suffer layer can also be deposited u sing the in-line sputtering instead of using the CdS layer. The environmental po llution problems arising from using CdS can be eliminated and the ultimate goal of full in-line process development can then be realized. Some preliminary exper imental results on a modal solar cell fabricated by the new technique in the new concept have been presented.

关键词： Cu-III-VI2 thin film solar cells full reactive sputtering

JOINT HOlDER CONTINUITY OF PARABOlIC ANDERSON MODEl

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Acta Mathematica Scientia 2019年第3期39卷 764-780页

作者： Yaozhong HU Khoa lê Department of Mathematical and Statistical Sciences University of Alberta Department of Mathematics South Kensington Campus Imperial College London

We obtain the H?lder continuity and joint H?lder continuity in space and time for the random field solution to the parabolic Anderson equation ■ in d-dimensional space, where ■ is a mean zero Gaussian noise with temporal covariance γ0 and spatial covariance given by a spectral density μ(ξ). We assume that ■ and ■ , where αi, i = 1, · · ·, d(or α) can take negative value.

关键词： Gaussian process stochastic heat equation parabolic Anderson model multiplicative noise chaos expansion hypercontractivity H?lder continuity joint Holder continuity

A vacuum nano-casting route to magnetite cores/mesoporous silica shell composites

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Nano-Micro letters 2009年第1期1卷 27-29页

作者： l.M.Guo J.l.Shi State Key laboratory of High Performance and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Science

Hollow mesoporous silica spheres with magnetite cores(HMSMC) have been fabricated by Vacuum Nano-casting Route. The amount of magnetite cores and saturation magnetization value can be easily adjusted by changing the concentration of iron nitrate solution used in the synthesis procedure. Furthermore, the as-prepared HMSMCs still maintain narrow mesopore distribution, high surface area and large pore volume after the hollow cores of hollow mesoporous silica spheres were filled with magnetite particles. Specially, when the saturation magnetization value of as-prepared HMSMCs reaches 22.0 emu/g, the surface area and pore volume of corresponding HMSMCs are 149 m^2/g and 0.19 cm^3/g, respectively, and the pore size is 2.30 nm. The corresponding samples are characterized by X-ray diffraction, N_2 sorption isotherms, transmission electron microscopy and vibrating-sample magnetometer.

关键词： Hollow mesoporous silica spheres Magnetite cores Vacuum nano-casting

Thermodynamic Calculation of Segregation in Multicomponent Steels

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Journal of Materials Science & Technology 1996年第3期12卷 238-240页

作者： li, l Delaey, l Wollants, P Biest, VD KATHOlIEKE UNIV lEUVEN DEPT MTMB-3001 HEVERLEEBELGIUM

The thermodynamic equation for segregation in multicomponent steels is extended from that in ternary system and the segregation amounts of Cr, C and P in the intergranular phase in a Cr-steel are estimated.

关键词： Cr Thermodynamic Calculation of Segregation in Multicomponent Steels

Null Controllability for Some Systems of Two Backward Stochastic Heat Equations with One Control Force

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Chinese Annals of Mathematics,Series B 2012年第6期33卷 909-918页

作者： Hongheng lI Qi lÜ College of Mathematics and Information Science Leshan Normal University School of Mathematical Sciences University of Electronic Science and Technology of China Basque Center for Applied Mathematics Mazarredo 14 48009BilbaoBasque CountrySpain.

Abstract The authors establish the null controllability for some systems coupled by two backward stochastic heat equations. The desired controllability result is obtained by means of proving a suitable observability e... 详细信息

关键词： Backward stochastic heat equation, Null controllability Observabilityestimate