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Real-time Abnormal Detection of GWAC Light Curve based on Wavelet Transform Combined with GRU-Attention

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Research in Astronomy and Astrophysics 2024年第5期24卷 151-168页

作者： Hao Li Qing Zhao long shao Tao Liu Chenzhou Cui Yunfei Xu College of Artifcial Intelligence Tianjin University of Science and TechnologyTianjin 300457China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China

Nowadays, astronomy has entered the era of Time-Domain Astronomy, and the study of the time-varying light curves of various types of objects is of great significance in revealing the physical properties and evolutionary history of celestial bodies. The Ground-based Wide Angle Cameras telescope, on which this paper is based, has observed more than 10 million light curves, and the detection of anomalies in the light curves can be used to rapidly detect transient rare phenomena such as microgravity lensing events from the massive data. However, the traditional statistically based anomaly detection methods cannot realize the fast processing of massive data. In this paper, we propose a Discrete Wavelet(DW)-Gate Recurrent Unit-Attention(GRU-Attention) light curve warning model. Wavelet transform has good effect on data noise reduction processing and feature extraction, which can provide richer and more stable input features for a neural network, and the neural network can provide more flexible and powerful output model for wavelet transform. Comparison experiments show an average improvement of 61% compared to the previous pure long-short-term memory unit(LSTM) model, and an average improvement of 53.5% compared to the previous GRU model. The efficiency and accuracy of anomaly detection in previous paper work are not good enough, the method proposed in this paper possesses higher efficiency and accuracy,which incorporates the Attention mechanism to find out the key parts of the light curve that determine the anomalies. These parts are assigned higher weights, and in the actual anomaly detection, the star is detected with83.3.% anomalies on average, and the DW-GRU-Attention model is compared with the DW-LSTM model, and the detection result f1 is improved by 5.75% on average, while having less training time, thus providing valuable information and guidance for astronomical observation and research.

关键词： methods data analysis-stars variables general-techniques photometric

One stone three birds:Ni-catalyzed asymmetric allenylic substitution of allenic ethers,hydroalkylation of 1,3.enynes and double alkylation of enynyl ethers

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Chinese Chemical Letters 2024年第8期35卷 282-287页

作者： Zhirong Yang Shan Wang Ming Jiang Gengchen Li long Li Fangzhi Peng Zhihui shao Key Laboratory of Medicinal Chemistry for Natural Resource Ministry of EducationSchool of Chemical Science and TechnologyYunnan Provincial Center for Research&Development of Natural Productsand State Key Laboratory for Conservation and Utilization of Bio-Resources in YunnanYunnan UniversityKunming 650091China

The development of low-cost,earth-abundant and environmentally benign transition metal catalysts,which can catalyze multiple different types of asymmetric reactions,is an important objective in mod-ern asymmetric *** we demonstrate that a chiral Ni/P-Phos catalyst achieves three types of asymmetric reactions:allenylic substitution of racemic allenic ethers,1,4-hydroalkylation of prochiral 1,3.enynes and double alkylation of newly designed enynyl ether *** methods complement each other and produce various axially chiral allene derivatives bearing a pyrazolidine-3.5-dione unit,which is widely present in drugs and biologically active molecules with versatile pharmacological activities.

关键词： Nickel Asymmetric catalysis Allenylic substitution Hydroalkylation Double alkylation Allene 1,3.Enyne Pyrazolidine-3.5-dione

Solidification behaviour and hot cracking susceptibility of a novel Ni-based superalloy

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Journal of Iron and Steel Research International 2024年第4期31卷 956-966页

作者： Yue Chen shao-min Lv Xing-fei Xie Xiao-can Wen Jng-long Qu Jin-hui Du High-Temperature Materials Institute China Iron and Steel Research Institute Group Co.Ltd.Beijing 100081China Beijing GAONA Materials and Technology Co. Ltd.Beijing 100081China Sichuan CISRI-GAONA Forging Co. Ltd.Deyang 610000SichuanChina

A novel Ni-based superalloy GH4151,with a γ′ volume fraction of about 55%and a service temperature capability up to 8oo oC,was *** to the different cooling conditions of various regions during the solidification of ingots,significant cooling rate variations may lead to the occurrence of hot *** scanning laser microscope was utilised to investigate the solidification process and phase precipitation behaviour of the GH4151 under wide range cooling *** characteristics of L→γ transformation were analysed,and the growth rates of at each stage were *** segregation behaviour was predicted using the Scheil equation,and the predicted results match well with the experimental *** sensitivity coefficient for hot cracking was modified,and cracking sensitivity coefficient values for the alloy under different cooling rates were computed,revealing that the alloy is most susceptible to hot cracking at 10℃/min cooling ***,controlling the cooling rate can reduce the possibility of hot cracking in ingot.

关键词： Ni-based superalloy Solidification behaviour In-situ observation Clyne and Davies's criterion:Hot cracking susceptibility

A highly reduced Mo_(74) polyoxometalate featuring high proton conductivity accessed by building block strategy

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Science China Chemistry 2024年第3期67卷 862-868页

作者： Shi-Yi Liu Xue-Xin Li Wei-Chao Chen Kui-Zhan shao Xin-long Wang Chao Qin Zhong-Min Su Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Department of ChemistryNortheast Normal UniversityChangchun 130024China State Key Laboratory of Supramolecular Structure and Materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction *** we demonstrate that it is possible to employ the building block strategy to generate a highly reduced polyoxomolybdate(C_(2)H_(8)N)_(14)(NH_(4))_(4)H_(14)[Mo_(48)-ⅤMo_(26)ⅥO_(202)(OH)_(12)(SO_(4))_(6)]·46H_(2)O(Mo_(74)).The fundamental Mo-based{Mo_x}(x=4,5,and 6) building blocks,which are templated by tetra-coordinated anions{MoO_(4)}or{SO_(4)},not only lay foundation for the formation of Mo_(74) featuring an unprecedented reduction ratio of 65%,but also give rise to SBBs-mediated(secondary building blocks) supramolecular dense packing interactions among the isolated Mo_(74) clusters that are favorable for proton ***,high proton conductivity(2.04×10^(-2)S cm^(-1)) had been realized at 50℃ and 90% relative humidity,revealing one of the well-known POMs-based crystalline proton conducting *** result highlights that this building block approach possesses great potential in producing highly reduced POM systems that can achieve controllable reduced ratio and desirable properties.

关键词： polyoxometalate building block molybdenum highly reduced state proton conduction

Global,regional and national burdens of bipolar disorders in adolescents and young adults:a trend analysis from 1990 to 2019

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General Psychiatry 2024年第1期37卷 122-132页

作者： Yunxi Zhong Yifan Chen Xiaoying Su Meiqi Wang Qixiu Li Ziming shao long Sun Centre for Health Management and Policy Research School of Public HealthCheeloo College of MedicineShandong UniversityJinanShandongChina National Health Commission of China(NHC)Key Laboratory of Health Economics and Policy Research Shandong UniversityJinanShandongChina nstitute of Health and Elderly Care Shandong UniversityJinanShandongChina

Background Bipolar disorder is identified as a cause of severe damage to the physical,psychological and social functioning of adolescents and young *** The aim of this study is to ascertain the trends in the burden of bipolar disorder among individuals aged 10-24 years at global,regional and national levels from 1990 to *** The data analysed in this study were from the Global Burden of Diseases *** numbers,rates per 100000 population,average annual percentage changes(AAPCs)of incidence,prevalence and years lived with disability(YLDs)of bipolar disorder are reported at the global,regional and national levels among individuals aged 10-24 *** trends by age,sex and Social Development Index(SDI)were further *** Globally,the incidence of bipolar disorder among adolescents and young adults increased from 79.21 per 100000 population(95%uncertainty interval(Ul):58.13.to 105.15)in 1990 to 84.97 per 100000 population(95%Ul:61.73.to 113.46)in 2019,AAPC 0.24(95%confidence interval(Cl):0.22 to 0.26).In the past three decades,there has been an increase in incidence,prevalence and YLDs in both males and *** largest increase in incidence between 1990 and 2019 was observed in those aged 20-24 years old from 51.76 per 100000 population(95%Ul:26.81 to 87.20)in 1990 to 58.3. per 100000 population(95%UI:3..3. to 98.55)in 2019;AAPC 0.42(95%Cl:0.3. to 0.47).By the SDI quintile,the largest increase in incidence was observed in the middle SDl;however,the high SDI countries had the highest ***,the largest increase in incidence was observed in southern Latin *** the national level,the most pronounced increase in the incidence was in *** The global increase in incidence among adolescents and young adults between 1990 and 2019 indicates that strategies to improve their mental health still need to be emphasised.

关键词： adolescent bipolar young

Elastic three-dimensional phononic topological insulators with Dirac hierarchy

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 54-62页

作者： shao-Yong Huo Qiu-Shuang Yang Jiu-Jiu Chen Hong-Kang Li long-Chao Yao Fu-Chun He Chun-Ming Fu College of Mechanical Engineering University of South ChinaHengyang 421001China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China

Three-dimensional(3.)phononic topological insulators(TIs)featuring two-dimensional(2D)surface states and one-dimensional(1D)hinge states have opened up a new route for multi-dimensional robust wave transport,providing unprecedented methods for integrated acoustic sensors and energy harvesting ***,aiming at the elastic 3. phononic TI with gapless surface states and hinge states,the realization of elastic 3. phononic TIs with gapless surface states and hinge states is a significant challenge due to the complicated multi-mode polarization of elastic waves in 3. *** this study,we demonstrate an elastic 3. phononic TI with a Dirac hierarchy by elaborately operating the corresponding spatial symmetries of the chiral honeycomb ***,a 3. double Dirac cone of elastic wave can be achieved by doubling the lattice along the outof-plane direction to fold two iso-frequency Weyl *** topological phase transitions and 2D gapless two-fold Dirac surface states of elastic wave are realized by breaking the half-lattice spatial translation ***,based on the Brillouin zone folding along the in-plane direction,the 2D gapless two-fold surface Dirac cones are folded into four-fold surface Dirac ***,by inducing the relative radius of adjacent holes to break the in-plane spatial inversion symmetry,the fourfold surface Dirac cones are gapped and associated with a surface state inversion,in which the gapless 1D hinge Dirac dispersion is *** research offers a route for engineering the hierarchies of TIs in 3. elastic wave systems and provides new possibilities for designing 3. ultrasonic devices with unconventional functions.

关键词： Dirac topological hierarchy

Multifunctional interfacial molecular bridge enabled by an aggregation-induced emission strategy for enhancing efficiency and UV stability of perovskite solar cells

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Journal of Energy Chemistry 2024年第8期95卷 588-595,I0013页

作者： Shuhang Bian Yuqi Wang Fancong Zeng Zhongqi Liu Bin Liu Yanjie Wu long shao Yongzhi shao Huan Zhang Shuainan Liu Jin Liang Xue Bai Lin Xu Donglei Zhou Biao Dong Hongwei Song State Key Laboratory on Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012JilinChina College of Science Shanghai UniversityShanghai 200444China

The interface defects between the electron transport layer(ETL)and the perovskite layer,as well as the low ultraviolet(UV)light utilization rate of the perovskite absorption layer,pose significant challenges for the commercialization of perovskite solar cells(PSCs).To address this issue,this paper proposes an innovative multifunctional interface modulation strategy by introducing aggregation-induced emission(AIE)molecule 5-[4-[1,2,2-tri[4-(3.5-dicarboxyphenyl)phenyl]ethylene]phenyl]benzene-1,3.dicarboxylic acid(H_(8)ETTB)at the SnO_(2)ETL/perovskite ***,the interaction of H_(8)ETTB with the SnO_(2)surface,facilitated by its carboxyl groups,is effective in passivating surface defects caused by noncoord inated Sn and O *** interaction enhances the conductivity of the SnO_(2)film and adjusts energy levels,leading to enhanced charge carrier ***,H_(8)ETTB can passivate noncoord inated Pb^(2+)ions at the perovskite interface,promoting perovskite crystallization and reducing the interface energy barrier,resulting in a perovskite film with low defects and high crystalline *** importantly,the H_(8)ETTB molecule,can convert UV light into light absorbable by the perovskite,thereby reducing damage caused by UV light and improving the device's utilization of ***,the champion PSC based on SnO_(2)-H_(8)ETTB achieves an impressing efficiency of 23.3.%and significantly improved photostability compared with the control device after continuous exposure to intense UV *** addition,the Cs_(0.05)(FA_(0.95)MA_(0.05))_(0.95)Pb(I_(0.95)Br_(0.05))_(3.based device can achieve maximum efficiency of 24.01%,demonstrating the effectiveness and universality of this ***,this innovative interface bridging strategy effectively tackles interface defects and low UV light utilization in PSCs,presenting a promising approach for achieving highly efficient and stable PSCs.

关键词： Perovskite solar cells Aggregation-induced emission Defect passivation Efficiency UV stability

Topologically Correct Intersection Curves of Two Trimmed Quadrics with Tolerance Control

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Journal of Systems Science & Complexity 2024年第5期37卷 2207-2239页

作者： shao Wenbing CHEN Falai Department of Mathematics University of Science and Technology of ChinaHefei 230026China

Surface/surface intersection is a fundamental problem in Compute Aided Design and Geometric Modeling since it is essential to solid modeling,numerically controlled machining,feature recognition,computer animation,*** practical applications,quadric surfaces,which are the most basic type of surfaces,are typically bounded surfaces trimmed by a sequence of *** this paper,a robust algorithm is proposed for computing the intersection curve segments of two trimmed quadrics based on the parametric representation of the intersection curves of two *** proposed algorithm guarantees correct topology and ensures that the approximation errors of the end points of the intersection curve segments are less than a given *** error control is based on an effective solution to a set of polynomial inequality system using the root isolation *** examples are presented to validate the robustness and effectiveness of the proposed algorithm.

关键词： Polynomial inequality system root isolation surface/surface intersection tolerance control trimmed quadrics

Pseudoeffective thresholds and cohomology of twisted symmetric tensor fields on irreducible Hermitian symmetric spaces

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Science China Mathematics 2024年第11期67卷 2433-2452页

作者： Feng shao Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

Let X be an irreducible Hermitian symmetric space of compact type(IHSS for short).In this paper,we give the irreducible decomposition of *** a by-product,we give a cohomological characterization of the rank of ***,we introduce pseudoeffective thresholds to measure the bigness of tangent bundles of smooth complex projective varieties precisely and calculate them for irreducible Hermitian symmetric spaces of compact type.

关键词： tangent bundle pseudoeffective threshold irreducible Hermitian symmetric space of compact type (IHSS) multiplicity free action