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Boundary Points,Minimal L^(2)Integrals and Concavity PropertyⅢ—Linearity on Riemann Surfaces and Fibrations over Open Riemann Surfaces

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2091-2152页

作者： Qi An GUAN zhi Tong MI zheng yuan School of Mathematical Sciences Peking UniversityBeijing 100871P.R.China School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044P.R.China Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190P.R.China

In this article,we consider a modified version of minimal L^(2) integrals on sublevel sets of plurisubharmonic functions related to modules at boundary points,and obtain a concavity property of the modified *** applications,we give characterizations for the concavity degenerating to linearity on open Riemann surfaces and on fibrations over open Riemann surfaces.

关键词： Minimal L^(2)integrals plurisubharmonic functions boundary points weakly pseudoconvex Kähler manifold

Investigation of copper sulfate pentahydrate dehydration by terahertz time-domain spectroscopy

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Chinese Physics B 2019年第6期28卷 110-113页

作者： yuan-yuan Ma Hao-Chong Huang Si-Bo Hao Wei-Chong Tang zhi-yuan zheng Zi-Li Zhang School of Science China University of GeosciencesBeijing 100083China

Copper sulfate pentahydrate is investigated by terahertz time-domain spectroscopy. It is shown that the terahertz absorption coefficients are correlated with the particle size of the samples, as well as the heating rates of the ambient temperature. Furthermore, the water molecules of copper sulfate pentahydrate can be quantitatively characterized due to the high sensitivity of the terahertz wave to water molecules. Based on such results, the status of water incorporated in mineral opal is also characterized using terahertz time-domain spectroscopy. It indicates that terahertz technology can be considered as an efficient method to detect the dehydration of minerals.

关键词： copper sulfate pentahydrate water status terahertz time-domain spectroscopy

Terahertz Lens Fabricated by Natural Dolomite

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Chinese Physics Letters 2019年第12期36卷 40-42页

作者： Si-Bo Hao Zi-Li Zhang yuan-yuan Ma Meng Yu Chen Yang Liu Hao-Chong Huang zhi-yuan zheng School of Science China University of GeosciencesBeijing 100083

Optical operations have served as the basis of spectroscopy and imaging in terahertz regimes for a long *** lenses are practical tools for *** fabricate a kind of biconvex lens from the natural dolomite *** lens works well at 0.1 THz based on the relatively high refractive index and low absorption *** with the lens fabricated by a dolomite stone,such a lens can focus dispersive terahertz beam efficiently in terahertz imaging systems,which indicates that natural minerals hold promising applications in terahertz optics.

关键词： optics operations refractive

Dual-curvilinear beam enabled tunable manipulation of high-and low-refractive-index particles

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Photonics Research 2024年第7期12卷 1427-1436页

作者： zheng yuan CHENCHEN ZHANG yuan GAO WENXIANG YAN XIAN LONG zhi-CHENG REN XI-LIN WANG JIANPING DING HUI-TIAN WANG National Laboratory of Solid State Microstructures and School of Physics Nanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Electronics Nanjing 210093China

We present an innovative approach for the simultaneous agile manipulation of high-refractive-index(HRI) and low-refractive-index(LRI) particles. Our method involves introducing a dual-curvilinear optical vortex beam(DC-OVB) generated by superimposing a pair of curved beams: HRI and LRI particles are controlled by the bright curve and the dark channel between the two curves, respectively. The proposed DC-OVB provides customizable motion paths and velocities for both LRI and HRI particles. Each curve of the DC-OVB can support a distinct orbital flow density(OFD), enabling the application of torques to HRI and LRI particles, guiding them to orbit along specified trajectories and prompting them to execute various curvilinear motions simultaneously,including curvilinear movement, revolution, and rotation.

关键词： tunable refractive beam

Prediction of novel layered indium halide superconductors

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Chinese Physics B 2024年第10期33卷 388-393页

作者： zhi-Hong yuan Jing-Jing Meng Rui Liu Peng-Yu zheng zhi-Ping Yin School of Physics&Astronomy and Center for Advanced Quantum Studies Beijing Normal UniversityBeijing 100875China School of Physics and Information Engineering Shanxi Normal UniversityTaiyuan 030031China Key Laboratory of Multiscale Spin Physics(Ministry of Education) Beijing Normal UniversityBeijing 100875China

We design two new layered indium halide compounds LaOInF_(2)and LaOInCl_(2)by means of first-principles calculations and evolutionary crystal structure *** find both compounds crystallize in a tetragonal structure with P4/nmm space group and have indirect band gaps of 2.58 eV and 3.21 eV,*** substituting O with F,both of them become metallic and superconducting at low *** F-doping leads to strong electron-phonon coupling in the low-energy acoustic phonon modes which is mainly responsible for the induced *** total electron-phonon coupling strength are 1.86 and 1.48,while the superconducting transition temperature(T_(c))are about 7.2 K and 6.5 K with 10%and 5%F doping for LaOInF_(2)and LaOInCl_(2),respectively.

关键词： superconductor LaOInF_(2) LaOInCl_(2) electron-phonon coupling

A multi-mechanism numerical simulation model for CO_(2)-EOR and storage in fractured shale oil reservoirs

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Petroleum Science 2024年第3期21卷 1814-1828页

作者： yuan-zheng Wang Ren-Yi Cao zhi-Hao Jia Bin-Yu Wang Ming Ma Lin-Song Cheng College of Petroleum Engineering China University of Petroleum(Beijing)Beijing102249China John&Willie Leone Department of Energy&Mineral Engineering The Pennsylvania State UniversityUniversity Park16802PA.USA

Under the policy background and advocacy of carbon capture,utilization,and storage(CCUS),CO_(2)-EOR has become a promising direction in the shale oil reservoir *** multi-scale pore structure distribution and fracture structure lead to complex multiphase flow,comprehensively considering multiple mechanisms is crucial for development and CO_(2) storage in fractured shale *** this paper,a multi-mechanism coupled model is developed by *** to the traditional Eclipse300 and MATLAB Reservoir Simulation Toolbox(MRST),this model considers the impact of pore structure on fluid phase behavior by the modified Peng—Robinson equation of state(PR-EOS),and the effect simultaneously radiate to Maxwell—Stefan(M—S)diffusion,stress sensitivity,the nano-confinement(NC)***,a modified embedded discrete fracture model(EDFM)is used to model the complex fractures,which optimizes connection types and half-transmissibility calculation approaches between non-neighboring connections(NNCs).The full implicit equation adopts the finite volume method(FVM)and Newton—Raphson iteration for discretization and *** model verification with the Eclipse300 and MRST is *** results show that the interaction between the mechanisms significantly affects the production performance and storage *** effect of molecular diffusion may be overestimated in oil-dominated(liquid-dominated)shale *** well spacing and injection gas rate are the most crucial factors affecting the production by sensitivity ***,the potential gas invasion risk is *** model provides a reliable theoretical basis for CO_(2)-EOR and sequestration in shale oil reservoirs.

关键词： CO_(2)-EOR CO_(2)storage Shale oil reservoir Complex fracture model Multiple mechanisms

Analyzing the surface passivity effect of germanium oxynitride:a comprehensive approach through first principles simulation and interface state density

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Nuclear Science and Techniques 2024年第5期35卷 74-84页

作者： Sheng-Jie Du Xiu-Xia Li Yang Tian yuan-yuan Liu Ke Jia Zhong-zheng Tang Jian-Ping Cheng zhi Deng Yu-Lan Li zheng-Cao Li Sha-Sha Lv College of Nuclear Science and Technology Joint Laboratory of Jinping Ultra‑Low Radiation Background Measurement of Ministry of Ecology and Environment Key Laboratory of Beam Technology of Ministry of Education Beijing Normal UniversityBeijing Normal UniversityBeijing 100875China Joint Research Center Nuctech Company LimitedBeijing 100084China Department of Engineering Physics Key Laboratory of Particle&Radiation Imaging of Ministry of EducationTsinghua UniversityBeijing 100084China Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

High-purity germanium(HPGe)detectors,which are used for direct dark matter detection,have the advantages of a low threshold and excellent energy *** surface passivation of HPGe has become crucial for achieving an extremely low energy *** this study,first-principles simulations,passivation film preparation,and metal oxide semiconductor(MOS)capacitor characterization were combined to study surface *** calculations of the energy band structure of the -H,-OH,and -NH_(2) passivation groups on the surface of Ge were performed,and the interface state density and potential with five different passivation groups with N/O atomic ratios were accurately analyzed to obtain a stable surface *** on the theoretical calculation results,the surface passivation layers of the Ge_(2)ON_(2) film were prepared via magnetron sputtering in accordance with the optimum atomic ratio *** microstructure,C-V,and I-V electrical properties of the layers,and the passivation effect of the Al/Ge_(2)ON_(2)/Ge MOS were characterized to test the interface state *** mean interface state density obtained by the Terman method was 8.4×10^(11) cm^(-2) eV^(-1).The processing of germanium oxynitrogen passivation films is expected to be used in direct dark matter detection of the HPGe detector surface passivation technology to reduce the detector leakage currents.

关键词： Surface passivation High purity germanium detector Germanium nitrogen oxide Interface state density

A Trust Evaluation Mechanism Based on Autoencoder Clustering Algorithm for Edge Device Access of IoT

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Computers, Materials & Continua 2024年第2期78卷 1881-1895页

作者： Xiao Feng zheng yuan Cyber Security Academy Beijing University of Posts and TelecommunicationsBeijing100876China Department of Cyberspace Security Beijing Electronic Science and Technology InstituteBeijing100070China State Grid Info-Telecom Great Power Science and Technology Co. Ltd.Beijing102211China

First,we propose a cross-domain authentication architecture based on trust evaluation mechanism,including registration,certificate issuance,and cross-domain authentication processes.A direct trust evaluation mechanism based on the time decay factor is proposed,taking into account the influence of historical interaction *** weight the time attenuation factor to each historical interaction record for updating and got the new historical record *** refer to the beta distribution to enhance the flexibility and adaptability of the direct trust assessment model to better capture time trends in the historical *** we propose an autoencoder-based trust clustering *** perform feature extraction based on *** leibler(KL)divergence is used to calculate the reconstruction *** constructing a convolutional autoencoder,we introduce convolutional neural networks to improve training efficiency and introduce sparse constraints into the hidden layer of the *** sparse penalty term in the loss function measures the difference through the KL *** clustering is performed based on the density based spatial clustering of applications with noise(DBSCAN)clustering *** the clustering process,edge nodes have a variety of trustworthy attribute *** assign different attribute weights according to the relative importance of each attribute in the clustering process,and a larger weight means that the attribute occupies a greater weight in the calculation of ***,we introduced adaptive weights to calculate comprehensive trust *** experiments prove that our trust evaluation mechanism has excellent reliability and accuracy.

关键词： Cross-domain authentication trust evaluation autoencoder

Highly transparent anti-reflection coating enhances the underwater efficiency and stability of perovskite solar modules

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Nano Research 2024年第9期17卷 8126-8133页

作者： Feng Qian Shihao yuan Ting Zhang Lei Wang Xiaobo Li Hualin zheng Qien Xu zhi David Chen Shibin Li School of Optoelectronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 610054China Department of Electrical and Computer Engineering and Center for Nanoscale Science and Engineering University of KentuckyLexingtonKentucky 40506USA

Perovskite solar cells have shown great potential in the field of underwater solar cells due to their excellent optoelectronic properties;however,their underwater performance and stability still hinder their practical *** this research,a 1H,1H,2H,2H-heptadecafluorodecyl acrylate(HFDA)anti-reflection coating(ARC)was introduced as a high-transparent material for encapsulating perovskite solar modules(PSMs).Optical characterization results revealed that HFDA can effectively reduce reflection of light below 800 nm,aiding in the absorption of light within this wavelength range by underwater solar ***,a remarkable efficiency of 14.65%was achieved even at a water depth of 50 ***,the concentration of Pb^(2+)for HFDA-encapsulated film is significantly reduced from 186 to 16.5 ppb after being immersed in water for 347 ***,the encapsulated PSMs still remained above 80%of their initial efficiency after continuous underwater illumination for 400 ***,being exposed to air,the encapsulated PSMs maintained 94%of their original efficiency after 1000 h light *** highly transparent ARC shows great potentials in enhancing the stability of perovskite devices,applicable not only to underwater cells but also extendable to land-based photovoltaic devices.

关键词： underwater photovoltaics perovskite solar modules anti-reflection coating underwater stability