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Teukolsky-like equations with various spins in spherically symmetric spacetime

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Chinese Physics C 2024年第8期48卷 213-223页

作者： Ya Guo Hiroaki Nakajima Wenbin Lin school of physical science and technology Southwest Jiaotong UniversityChengdu 610031China school of Mathematics and Physics University of South ChinaHengyang 421001China

We study wave equations with various spins on the background of a general spherically symmetric *** obtain the unified expression of the Teukolsky-like master equations and the corresponding radial equations with the general *** also discuss the gauge dependence in the gravitational-wave equations,which have appeared in previous studies.

关键词： gravitational wave effective one-body dynamics Teukolsky equation wave equations Klein-Gordon equation Weyl equation Maxwell equation

Evolution of High-energy Electron Distribution in Pulsar Wind Nebulae

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Research in Astronomy and Astrophysics 2024年第7期24卷 201-217页

作者： Yi-Ming Liu Hou-Dun Zeng Yu-Liang Xin Si-Ming Liu Yi Zhang Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of Sciences school of Astronomy and Space science University of Science and Technology of China school of physical science and technology Southwest Jiaotong University

In this paper,we analyze the spectral energy distributions of 17 powerful (with a spin-down luminosity greater than1035erg s-1) young （with an age less than 15,000 yr） pulsar wind nebulae （PWNe） using a simple timein-dependent one-zone emission *** aim is to investigate correlations between model parameters and the ages of the corresponding PWNe,thereby revealing the evolution of high-energy electron distributions within *** findings are as follows:（1） The electron distributions in PWNe can be characterized by a double power-law with a super-exponential cutoff.（2） As PWNe evolve,the high-energy end of the electron distribution spectrum becomes harder with the index decreasing from approximately 3.5 to 2.5,while the low-energy end spectrum index remains constant near 1.5.（3） There is no apparent correlation between the break energy or cutoff energy and the age of PWNe.（4） The average magnetic field within PWNe decreases with age,leading to a positive correlation between the energy loss timescale of electrons at the break energy or the high-energy cutoff and the age of the PWN.（5） The total electron energy within PWNe remains constant near 2×1048erg,while the total magnetic energy decreases with age.

关键词： gamma-rays: general ISM: general ISM: supernova remnants radiation mechanisms: non-thermal

Detecting the core of a network by the centralities of the nodes

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Chinese Physics B 2024年第8期33卷 615-621页

作者：马佩杰任学藻朱军芳蒋艳群 school of Mathematics and science Southwest University of Science and TechnologyMianyang 621010China

Many networks exhibit the core/periphery ***/periphery structure is a type of meso-scale structure that consists of densely connected core nodes and sparsely connected peripheral *** nodes tend to be well-connected,both among themselves and to peripheral nodes,which tend not to be well-connected to other *** this brief report,we propose a new method to detect the core of a network by the centrality of each *** is discovered that such nodes with non-negative centralities often consist in the core of the *** simulation is carried out on different real *** results are checked by the objective *** checked results may show the effectiveness of the simulation results by the centralities of the nodes on the real ***,we discuss the characters of networks with the single core/periphery structure and point out the scope of the application of our method at the end of this paper.

关键词： complex network core/periphery structure the objective function

NH_(4)Cl-assisted synthesis of TaON nanoparticle applied to photocatalytic hydrogen and oxygen evolution from water

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Journal of Energy Chemistry 2024年第7期94卷 541-550页

作者： Yao Xu Kaiwei Liu Jifang Zhang Boyang Zhang Jiaming Zhang Ke Shi Haifeng Wang Guijun Ma school of physical science and technology Shanghaitech UniversityShanghai 201210China

Oxynitride semiconductors are promising photocatalyst materials for visible light-driven water splitting,while the synthesis of well crystalized oxynitride still remains *** present work,narrow-bandgap TaON nanoparticles are synthesized via heating a vacuum-sealed mixture of KTaO_(3),Ta and NH_(4)*** method possesses multiple advantages in terms of lower calcination parameter,higher N conversion efficiency and superior photocatalytic activity in comparison with the traditional thermal ammonolysis using NH_(3) gas as a nitrogen *** the analysis of intermediates produced upon the elevation of heating temperature,a gas-solid-phase reaction between TaCl_(5) and Ta_(2)O_(5) is demonstrated as the final step,which is conducive to decreasing thermal energy barrier and accelerating nitridation *** control of preparation conditions,including calcination temperature and duration,allows for the regulation of surface O/N ratio of TaON particles to unity,resulting in optimized photocat-alytic *** assessment and intensity modulated photocurrent spectroscopy provide convincing evidence for improved charge transfer effciency of photoexcited holes at TaON surface.A Z-scheme overall water splitting is accomplished by employing the TaON as an effective oxygen evolution photocatalyst,SrTiO_(3):Rh as a hydrogen evolution photocatalyst,and reduced graphene oxide(rGO)as a solid-state electron *** work presents a promising strategy for the synthesis of high-quality oxynitride materials in application to photocatalytic water splitting.

关键词： TaON Oxynitride synthesis Photocatalyst Water splitting,Hydrogen Z-scheme

(Parallel) kinetic resolution of 3,3-disubstituted indolines via organocatalyzed reactions with azodicarboxylates

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science China Chemistry 2024年第3期67卷 973-980页

作者： Qianwen Jiang Dekun Zhang Mengyao Tang Hua Liu Xiaoyu Yang school of physical science and technology ShanghaiTech UniversityShanghai 201210China

A novel kinetic resolution(KR) method has been developed for 3,3-disubstituted indolines, whose catalytic asymmetric synthesis remains a significant challenge in organic synthesis. The key to the success of this KR protocol lies in the utilization of chiral phosphoric acid-catalyzed triazane formation reaction with azodicarboxylates, which enables the enantioselective synthesis of various substituted indolines bearing C3-quaternary stereocenters with good to high enantioselectivities(with sfactors up to 70). Moreover, an intriguing parallel kinetic resolution(PKR) has been developed by combining triazane formation and dehydrogenation reactions using different azodicarboxylates. Experimental studies have provided insight into the mechanism of this PKR reaction, demonstrating stereoselectivity in both triazane formation and dehydrogenation steps, favoring the opposite enantiomers. The large-scale synthesis and diverse derivatizations of the products, particularly the imine groupcontaining 3H-indoles, demonstrate the value of these(P)KR methods.

关键词： asymmetric organocatalysis kinetic resolution 3 3-disubstituted indolines azodicarboxylate triazanes

Higher-dimensional Chen-Lee-Liu equation and asymmetric peakon soliton

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Chinese Physics B 2024年第4期33卷 224-229页

作者：韩巧红贾曼 school of physical science and technology Ningbo UniversityNingbo 315211China

Integrable systems play a crucial role in physics and *** particular,the traditional(1+1)-dimensional and(2+1)-dimensional integrable systems have received significant attention due to the rarity of integrable systems in higher *** studies have shown that abundant higher-dimensional integrable systems can be constructed from(1+1)-dimensional integrable systems by using a deformation *** we establish a new(2+1)-dimensional Chen-Lee-Liu(C-L-L)equation using the deformation algorithm from the(1+1)-dimensional C-L-L *** new system is integrable with its Lax pair obtained by applying the deformation algorithm to that of the(1+1)-*** is challenging to obtain the exact solutions for the new integrable system because the new system combines both the original C-L-L equation and its reciprocal *** traveling wave solutions are derived in implicit function expression,and some asymmetry peakon solutions are found.

关键词： higher dimensional Chen-Lee-Liu equation Lax integrable system deformation algorithm implicit traveling wave solutions

Electricity Theft Detection Method Based on Ensemble Learning and Prototype Learning

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 213-224页

作者： Xinwu Sun Jiaxiang Hu Zhenyuan Zhang Di Cao Qi Huang Zhe Chen Weihao Hu the school of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengduChina Southwest University of Science and TechnologyChengduChina

With the development of advanced metering infrastructure(AMI),large amounts of electricity consumption data can be collected for electricity theft ***,the imbalance of electricity consumption data is violent,which makes the training of detection model *** this case,this paper proposes an electricity theft detection method based on ensemble learning and prototype learning,which has great performance on imbalanced dataset and abnormal data with different abnormal *** this paper,convolutional neural network(CNN)and long short-term memory(LSTM)are employed to obtain abstract feature from electricity consumption *** calculating the means of the abstract feature,the prototype per class is obtained,which is used to predict the labels of unknown *** the meanwhile,through training the network by different balanced subsets of training set,the prototype is *** with some mainstream methods including CNN,random forest(RF)and so on,the proposed method has been proved to effectively deal with the electricity theft detection when abnormal data only account for 2.5%and 1.25%of normal *** results show that the proposed method outperforms other state-of-the-art methods.

关键词： Electricity theft detection ensemble learning prototype learning imbalanced dataset deep learning abnormal level

High-sensitivity photonic crystal fiber sensor based on surface plasmon resonance

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Optoelectronics Letters 2024年第7期20卷 393-399页

作者： FENG Huanting GAO Jiachen MING Xianbing school of physical science and technology Tiangong University

In this paper, we propose a photonic crystal fiber(PCF) sensor based on the surface plasmonic resonance(SPR) effect for simultaneous temperature and refractive index(RI) measurement. The coupling characteristics and sensing performance of the sensor are analyzed using the full vector finite element method(FEM). The sensor provides two channels for independent measurement of RI and temperature. When operating independently, channel I supports y-polarized light with a sensitivity of up to 7 000 nm/RIU for detecting RI, while channel II supports x-polarized light with a sensitivity of up to 16 nm/°C for detecting temperature. Additionally, we investigate the influence of gold layer thickness on the sensing performance to optimize the sensor.

关键词： A

Performance enhancement of perovskite solar cells:surface is the key

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science China Materials 2024年第1期67卷 375-376页

作者： Wenzhuo Li Zhijun Ning school of physical science and technology Shanghaitech UniversityShanghai 201210China

Metal halide perovskite solar cells(PSCs)stand out as one of the most promising contenders among photovoltaic technologies for the *** the past decade,PSCs with high power conversion efficiency(PCE)predominantly adopted the normal(ni-p)device ***,a common p-type organic small molecule,Spiro-OMe TAD,which is widely employed at the top layer of n-i-p devices[1],faces issues such as susceptibility to water absorption and poor thermal stability.

关键词： structure stability perovskite