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Empirical Likelihood Inference for the Semiparametric Varying-Coefficient Spatial Autoregressive Model

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Journal of Systems Science & Complexity 2021年第6期34卷 2310-2333页

作者： LUO Guowang WU Mixia pang Zhen College of Big Data Statistics Guizhou University of Finance and EconomicsGuiyang 550025China College of Statistics and Data Science Faculty of ScienceBeijing University of TechnologyBeijing 100124China Department of Applied Mathematics Hong Kong Polytechnic UniversityHong KongChina

In this paper empirical likelihood(EL)-based inference for a semiparametric varyingcoefficient spatial autoregressive model is *** maximum EL estimators for the parametric component and the nonparametric component are ***,asymptotic properties of the proposed estimators and EL ratios are derived,and the corresponding confidence regions/bands are *** finite sample performances are studied via simulation and an example.

关键词： Confidence regions empirical likelihood instrumental variable residual-adjusted Wilks theorem

Numerical study on hydrodynamic characteristics of spherical bubble contaminated by surfactants under higher Reynolds numbers

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Chinese Journal of Chemical Engineering 2022年第5期35卷 268-283页

作者： Tao Sun Mingjun pang Yang Fei School of Mechanical Engineering and Rail Transit Changzhou UniversityChangzhou 213164China

It is of significance to investigate deeply the hydrodynamic featu res of the bubble co ntaminated by impurities in view of the fact that the industrial liquid is difficult to keep absolutely *** the basis of the finite volume method,the bubble interface contaminated by the surfactant(1-pentanol)is achieved through solving the concentration transport equations in liquid and along the bubble interface,and solving the absorption and desorption equation at the bubble *** the three-dimensional momentum equation is solved at the same *** is investigated in detail on the influence of interfacial contamination degrees(described with the cap angleθ)on hydrodynamic characteristics of the spherical bubble when the bubble Reynolds number(Re)is larger than ***θis realized by changing the surfactant concentration(C_(0)) in *** present results show that the hydrodynamic characteristics,such as interfacial concentration,interfacial shear stress,interfacial velocity and wake flow,are related to both Re and C_(0) for the contaminated *** C_(0) is relatively low in liquid(i.e.,the contamination degree of the bubble interface is relatively slight),the hydrodynamic characteristics of the bubble can still keep the 2 D features even if Re>*** decrease ofθor the increase of Re can promote the appearance of the unsteady wake *** the present investigation,when Re>200 andθ≤60°,the hydrodynamic characteristics of the bubble show the 3D phenomena,which indicates that axisymmetric model is no longer valid.

关键词： Bubble Higher Reynolds number Interfacial parameters Wake flow Adsorption Desorption

Theoretical uncertainties of(d,^(3)He)and(^(3)He,d)reactions owing to the uncertainties of optical model potentials

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Nuclear Science and Techniques 2023年第6期34卷 147-153页

作者： Wei-Jia Kong Dan-Yang pang School of Physics Beihang UniversityBeijing100191China School of Physics and Beijing Key Laboratory of Advanced Nuclear Materials and Physics Beihang UniversityBeijing100191China

The theoretical uncertainties of single proton transfer cross sections of the(^(3)He,d)and(d,^(3)He)reactions,owing to the uncertainties of the entrance-and exit-channel optical model potentials,are examined with the^(30)Si(^(3)He,d)^(31)P,^(13)B(d,^(3)He)^(12)Be,and^(34)S(^(3)He,d)^(35)Cl reactions at incident energies of 25,46,and 25 MeV,respectively,within the framework of the distorted wave Born *** differential cross sections at the first peaks in the angular distributions of these reactions are found to have uncertainties of approximately 5%,owing to the uncertainties in the optical model potentials from 20,000 calculations of randomly sampled *** amount of uncertainty is found to be nearly independent of the angular momentum transfer and the target masses within the studied range of incident *** in the single proton spectroscopic factors obtained by matching the theoretical and experimental cross sections at different scattering angles are also discussed.

关键词： Proton transfer reactions Optical model potentials Spectroscopic factors

Additive manufacturing of energetic materials:Tailoring energetic performance via printing

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Journal of Materials Science & Technology 2022年第32期127卷 29-47页

作者： Nihan Chen Chunlin He Siping pang Experimental Center of Advanced Materials School of Materials Science&EngineeringBeijing Institute of TechnologyBeijing 100081China Yangtze Delta Region Academy of Beijing Institute of Technology Jiaxing 314019China Chongqing Innovation Center Beijing Institute of TechnologyChongqing 401120China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Additive manufacturing(AM),also called three-dimensional(3D)printing,has been developed to obtain energetic materials within the past decade.3D printing represents a family of flexible manufacturing techniques that enable fast and accurate fabrication of structures with complex 3D features and a broad range of sizes,from submicrometer to several *** methods have already been explored,including templating,melting extrusion,inkjet printing and electrospray *** was demonstrated that the structure achieved by AM could be used to manipulate the reactivity of energetic or reactive materials by changing the flow of gases and entrained particles via *** employing different AM techniques,energetic materials with controllable nanostructures and uniformly dispersed ingredients can be *** is exciting to tailor the energy release without defaulting to change the formulation of the conventional *** combustion and mechanical properties of conventional energetic materials can be retained at the same *** this review,the preparation and characterization of AM energetic materials that have been developed in the last decade are *** AM techniques used in the fabrication of energetic materials are compared and *** particular,formulations of energetic materials applied in AM,metallic fuels,binders and energetic fillers and their advantages in terms of combustion efficiency and other properties are proposed.

关键词： Additive manufacturing Energetic materials Nanothermite Propellant

Application of Coordinate-Momentum Intermediate Representation in Solving Eigenstate Problem of a Coupled Oscillator System

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Communications in Theoretical Physics 2005年第3X期44卷 440-444页

作者： pang Qian-Jun Department of Physics Shanghai Jiao Tong University Shanghai 200030 China

We study the eigenstate problem of a kind of coupled oscillators in the new quantum mechanical representation ｜q,μ,υ〉, which is defined as the eigenvector of the operator （μQ ＋ υP）, whereμ and υ are two real parameters. We also use the U operator transformation method to deal with the same problem. We obtain the normally ordered product expressions of U operator and eigenvector. It is shown that the ground state of system Hamiltonian is a squeezed state.

关键词： coordinator-momentum intermediate representation coupled oscillator operator transformation method

Microwave Absorption of Crystalline Fe/MnO@C Nanocapsules Embedded in Amorphous Carbon

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Nano-Micro Letters 2020年第4期12卷 152-167页

作者： Gaihua He Yuping Duan Huifang pang Key Laboratory of Solidification Control and Digital Preparation Technology (Liaoning Province) School of Materials Science and Engineering Dalian University of Technology

Crystalline Fe/MnO@C core–shell nanocapsules inlaid in porous amorphous carbon matrix(FMCA)was synthesized successfully with a novel confinement *** heterogeneous Fe/MnO nanocrystals are with approximate single-domain size which gives rise to natural resonance in 2–18 *** addition of MnO2 confines degree of graphitization catalyzed by iron and contributes to the formation of amorphous *** heterogeneous materials composed of crystalline–amorphous structures disperse evenly and its density is significantly reduced on account of porous ***,adjustable dielectric loss is achieved by interrupting Fe core aggregation and stacking graphene conductive *** dielectric loss synergistically with magnetic loss endows the FMCA enhanced *** optimal reflection loss(RL)is up to−45 dB,and the effective bandwidth(RL<−10 dB)is 5.0 GHz with 2.0 mm *** proposed confinement strategy not only lays the foundation for designing high-performance microwave absorber,but also offers a general duty synthesis method for heterogeneous crystalline–amorphous composites with tunable composition in other fields.

关键词： Crystalline nanocapsule Amorphous carbon Core–shell structure Interfacial polarization Microwave absorption

Negative corrections to black hole entropy from string theory

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 71-76页

作者： Liang Ma Yi pang Hong Lu Center for Joint Quantum Studies and Department of Physics School of ScienceTianjin UniversityTianjin 300350China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China

We report for the first time that in heterotic string compactified on 4-torus or equivalently IIA string compactified on K3,the leading α′corrections to the rotating black string entropy at fixed conserved charges can be *** further implies that the correction to the mass of extremal rotating string is positive,opposite to the standard expectation from the weak gravity *** result suggests that the validity of positivity of entropy shift due to higher order operators depends on other factors omitted previously in the effective field theory analysis.

关键词： supergravities higher-derivative corrections effective theories black holes quantum gravity string theory

Tailpipe emission characterizations of diesel-fueled forklifts under real-world operations using a portable emission measurement system

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Journal of Environmental Sciences 2021年第2期33卷 34-42页

作者： Kaili pang Kaishan Zhang Shuai Ma Department of Environm ental Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China

Non-road equipment is one of the key contributing sources to air ***,an accurate development of emission inventory from non-road equipment is imperative for air quality management,especially for equipment with a large population such as diesel-fueled *** objective of this paper is to characterize duty-cycle based emissions from diesel-fueled forklifts using a portable emission measurement system(PEMS).Three dutycycles were defined in this study,including idling,moving,and working(active duty operation)and used to characterize in-use emissions for diesel-fueled forklifts.A total of twelve diesel-fueled forklifts were selected for real-world emission *** showed that fuel-based emission factors appear to have smaller variability compared to time-based *** example,the time-based emission factors for CO,HC,NO,and PM 2.5 for forklifts were estimated to be 16.6-43.9,5.3-15.1,26.2-49.9,5.5-11.1 g/hr with the fuel-based emission factors being 12.1-20.3,4.1-8.3,19.1-32.4,3.5-6.5 g/kg-fuel,*** emissions appear to be the biggest concern for emissions ***,most of the emissions factors estimated from this study are significantly different from those in both National Guideline for Emission Inventory Development for Non-Road Equipment in China and welldeveloped emission factor models such as NONROAD by US *** implies that localized,preferably fuel-based emission factors should be adjusted based on real-world emission measurements in order to develop a representative emission inventory for non-road equipment.

关键词： Non-road equipment Forklifts Portable emission measurement system(pems) Emission factors Emission inventory

A new online modelling method for aircraft engine state space model

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Chinese Journal of Aeronautics 2020年第6期33卷 1756-1773页

作者： Shuwei pang Qiuhong LI Haibo ZHANG Jiangsu Province Key Laboratory of Aerospace Power System Nanjing University of Aeronautics and AstronauticsNanjing 210016China

To overcome the drawbacks of current modelling method for aircraft engine state space model,a new method is *** form of state space model is derived by using Talyor series to expand the nonlinear model that is implicit equations and involves many iterations.A partial derivative calculation method for iterations is developed to handle the influence of iterations on *** derivative calculation and the aerothermodynamics calculations are combined in the component level model with fixed number Newton-Raphson(N-R)*** derivation and simulations show the convergence ability of proposed *** show that comparing with the linear parameter varying model and centered difference based state space model,much higher accuracy of proposed online modelling method is *** accuracy of the state space model built by proposed method can be maintained when the step amplitudes of inputs are within 2%,and the responses of the state space model can match those of the component level model when each input steps larger *** addition,an online verification was carried out to show the capability of modelling at any operating point and that state space model can predict future outputs ***,the effectiveness of the proposed method is demonstrated.

关键词： Aircraft engines Component level model Online modelling Partial derivative State space models