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Granger causal representation learning for groups of time series

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Science China(Information Sciences) 2024年第5期67卷 56-68页

作者： Ruichu CAI Yunjin WU Xiaokai HUANG Wei CHEN Tom Z.j.FU Zhifeng hao School of Computer Science Guangdong University of Technology Peng Cheng Laboratory College of Science Shantou University

Discovering causality from multivariate time series is an important but challenging *** existing methods focus on estimating the Granger causal structures among multivariate time series,while ignoring the prior knowledge of these time series, e.g., the group of the time series. Focusing on discovering the Granger causal structures among groups of time series, we propose a Granger causal representation learning method to solve this problem. First, we use the multiset canonical correlation analysis method to learn the Granger causal representation of each group of time series. Then, we model the Granger causal relationships among the learned Granger causal representations using a recurrent neural network with temporal information. Finally, we formulate the above two stages into one unified optimization problem, which is efficiently solved using the augmented Lagrangian method. We conduct extensive experiments on synthetic and real-world datasets to validate the correctness and effectiveness of the proposed method.

关键词： Granger causal discovery Granger causal representation learning time series data recurrent neural network multiset canonical correlation analysis

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A High Order Accurate Bound-Preserving Compact Finite Difference Scheme for Two-Dimensional Incompressible Flow

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Communications on Applied Mathematics and Computation 2024年第1期6卷 113-141页

作者： hao Li Xiangxiong Zhang Department of Mathematics Purdue University150 N.University StreetWest LafayetteIN47907-2067USA

For solving two-dimensional incompressible flow in the vorticity form by the fourth-order compact finite difference scheme and explicit strong stability preserving temporal discretizations,we show that the simple bound-preserving limiter in Li et al.(SIAM j Numer Anal 56:3308–3345,2018)can enforce the strict bounds of the vorticity,if the velocity field satisfies a discrete divergence free *** reducing oscillations,a modified TVB limiter adapted from Cockburn and Shu(SIAM j Numer Anal 31:607–627,1994)is constructed without affecting the bound-preserving *** bound-preserving finite difference method can be used for any passive convection equation with a divergence free velocity field.

关键词： Finite difference Monotonicity Bound-preserving Discrete maximum principle Passive convection Incompressible flow Total variation bounded limiter

Sandwich-like Heterochromophore Metallo-Supramolecules Based on Dense Chromophore Arrangements with Energy and Chirality Transfer Properties

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CCS Chemistry 2024年第5期6卷 1264-1277页

作者： Ningxu Han jianjun Ma hao Yu junjuan Shi Qixia Bai Xin jiang Zhe Zhang Pingshan Wang jing Yu ming Wang State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchunJilin 130012 Institute of Environmental Research at Greater Bay Area Key Laboratory for Water Quality and Conservation of the Pearl River DeltaMinistry of EducationGuangzhou UniversityGuangzhouGuangdong 510006 School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798

Multichromophoric architectures with wellorganized chromophoric arrangements are of vital importance to gain insights into interchromophoric ***,we report a novel heteroleptic self-assembly strategy and construct three achiral and one chiral sandwich-like heterochromophore complexes(Zn_(4)L^(G)L^(A-C)_(2)and Zn_(4)L_(G)L^(D)_(2)).Possible dynamic products,including homoleptic oligomers and isomers,are eliminated,producing achiral complexes with exceptional *** are observed in chiral complexes due to the flexible geometry of *** aligned chromophore arrangements with precise spacing and orientations are evidenced by single-crystal X-ray *** distinct segments in the ligands lead to different interchromophoric ***,energy transfer and tunable emission,including white-light emission,are achieved for Zn_(4)L^(G)L^(A)_(2)and Zn_(4)L^(G)L^(B)_(2).In addition,chirality transfer is observed for Zn_(4)L_(G)L^(D)_(2),due to conformational restriction from chiral LD,leading to chiral rotational conformations of tetraphenylethylene moiety in LG.

关键词： heterochromophore complexes fluorescence single crystal dissymmetrical ligands chirality

Elevational patterns of warming effects on plant community and topsoil properties: focus on subalpine meadows ecosystem

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journal of Mountain Science 2024年第1期21卷 146-159页

作者： hao Aihua LUO Zhengming CHEN Xiaojiang Department of Geography Xinzhou Normal UniversityXinzhou 034000China Department of Biological Sciences Xinzhou Normal UniversityXinzhou 034000China

Climate warming profoundly affects plant biodiversity, community productivity, and soil properties in alpine and subalpine grassland ecosystems. However, these effects are poorly understood across elevational gradients in subalpine meadow ecosystems. To reveal the elevational patterns of warming effects on plant biodiversity, community structure, productivity, and soil properties, we conducted a warming experiment using open-top chambers from August 2019 to August 2022 at high(2764 m a. s. l.), medium(2631 m a. s. l.), and low(2544 m a. s. l.) elevational gradients on a subalpine meadow slope of Mount Wutai, Northern China. Our results showed that three years of warming significantly increased topsoil temperature but significantly decreased topsoil moisture at all elevations(Pming-induced decreasing proportions of soil organic carbon(SOC, by 19.24%), and total nitrogen(TN, by 24.56%) were the greatest at high elevational gradients. Experimental warming did not affect topsoil C: N, p H, NO_(3)^(-)-N, or NH_(4)^(+)-N at the three elevational gradients. Warming significantly increased species richness(Pming caused significant increases in the aboveground biomass in the three elevational plots. Warming significantly increased the aboveground biomass of graminoids in medium(by 92.47%) and low(by 98.25%) elevational gradients, that of sedges in high(by 72.44%) and medium(by 57.16%) elevational plots, and that of forbs in high(by 75.88%), medium(by 34.38%), and low(by 74.95%) elevational plots. Species richness had significant linear correlations with SOC, TN, and C: N(P<0.05), but significant nonlinear responses to soil temperature and soil moisture in the warmed treatm

关键词： Warming effect Plant diversity pattern Community structure change Elevation gradient Alpine meadow ecosystem Mount Wutai

Layer chicken microbiota:a comprehensive analysis of spatial and temporal dynamics across all major gut sections

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journal of Animal Science and Biotechnology 2024年第3期15卷 1056-1070页

作者： Yadav Sharma Bajagai Thi Thu hao Van Nitish joat Kapil Chousalkar Robert j.Moore Dragana Stanley Institute for Future Farming Systems Central Queensland UniversityRockhamptonQLD 4701Australia School of Science RMIT UniversityBundooraVIC 3083Australia School of Animal and Veterinary Sciences The University of AdelaideRoseworthySouth Australia 5371Australia

Background The gut microbiota influences chicken health,welfare,and productivity.A diverse and balanced microbiota has been associated with improved growth,efficient feed utilisation,a well-developed immune system,disease resistance,and stress tolerance in *** studies on chicken gut microbiota have predominantly focused on broiler chickens and have usually been limited to one or two sections of the digestive system,under con-trolled research environments,and often sampled at a single time *** extend these studies,this investigation examined the microbiota of commercially raised layer chickens across all major gut sections of the digestive system and with regular sampling from rearing to the end of production at 80 *** aim was to build a detailed picture of microbiota development across the entire digestive system of layer chickens and study spatial and temporal *** The taxonomic composition of gut microbiota differed significantly between birds in the rearing and pro-duction stages,indicating a shift after laying *** microbiota compositions were observed between proven-triculus and gizzard,as well as between jejunum and ileum,likely due to their anatomical ***-lus dominated the upper gut in pullets and the lower gut in older *** oesophagus had a high proportion of Proteobacteria,including opportunistic pathogens such as *** abundance of Gallibacterium increased after peak production in multiple gut *** was enriched in the late-lay phase compared to younger birds in multiple gut *** influenced microbial richness and diversity in different *** upper gut showed decreased diversity over time,possibly influenced by dietary changes,while the lower gut,specifi-cally cecum and colon,displayed increased richness as birds ***,age-related changes were inconsist-ent across all organs,suggesting the influence of organ-specific factors in micro

关键词： Chicken microbiota Gut microbiota Layers Spatial variation Temporal variation

Potentiation of the lateral habenula-ventral tegmental area pathway underlines the susceptibility to depression in mice with chronic pain

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Science China(Life Sciences) 2024年第1期67卷 67-82页

作者： Chun-Kui Zhang Pan Wang Yuan-Yuan ji jian-Shuai Zhao jun-Xiang Gu Xian-Xia Yan Hong-Wei Fan ming-ming Zhang Yu Qiao Xiao-Die Liu Bao-juan Li ming-Hui Wang Hai-Long Dong hao-Hong Li Peng-Cheng Huang Yun-Qing Li Wu-Gang Hou jin-Lian Li Tao Chen Department of Anatomy and K.K.Leung Brain Research Centre Fourth Military Medical UniversityXi’an 710032China Beijing Institute of Basic Medical Sciences Beijing 100850China Key Laboratory of Ministry of Public Health for Forensic Science Xi’an Jiaotong UniversityXi’an 710061China Department of Anesthesiology Xijing HospitalFourth Military Medical UniversityXi’an 710032China Department of Neurosurgery the Second Affiliated Hospital of Xian Jiaotong UniversityXi’an 710004China School of Biomedical Engineering Fourth Military Medical UniversityXi’an 710032China Affiliated Mental Health Centre and Hangzhou Seventh People’s Hospital Zhejiang University School of MedicineHangzhou 310013China The MOE Frontier Research Center of Brain&Brain-machine Integration Zhejiang University School of Brain Science and Brain MedicineHangzhou 310058China Department of Neurology The First Affiliated Hospital of Nanchang UniversityNanchang 330006China Department of Anatomy School of MedicineNorthwest UniversityXi’an 710069China

Chronic pain often develops severe mood changes such as ***,how chronic pain leads to depression remains elusive and the mechanisms determining individuals’responses to depression are largely *** we found that depression-like behaviors could only be observed in 67.9%of mice with chronic neuropathic pain,leaving 32.1%of mice with depression *** determined that the spike discharges of the ventral tegmental area(VTA)-projecting lateral habenula(LHb)glutamatergic(Glu)neurons were sequentially increased in sham,resilient and susceptible mice,which consequently inhibited VTA dopaminergic(DA)neurons through a LHbGlu-VTAGABA-VTADA ***,the LHbGlu-VTADA excitatory inputs were dampened via GABAB receptors in a pre-synaptic *** of LHb-VTA pathway largely affected the development of depressive symptoms caused by chronic *** study thus identifies a pivotal role of the LHb-VTA pathway in coupling chronic pain with depression and highlights the activity-dependent contribution of LHbGlu-to-VTADA inhibition in depressive behavioral regulation.

关键词： chronic pain depression lateral habenula ventral tegmental area dopamine susceptibility

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层状地基中海洋大直径管桩水平动力响应分析

岩土力学 2024年第6期45卷 1873-1883页

作者：林浩郑长杰丁选明福建理工大学福建省土木工程新技术与信息化重点实验室福建福州350118 福建理工大学土木工程学院福建福州350118 重庆大学土木工程学院重庆400045

考虑桩−海水−层状土相互作用,研究了水平动荷载作用下层状地基中海洋大直径管桩的动力响应特性。将海水视为无黏性可压缩流体介质建立桩周、桩芯海水的运动方程,通过分离变量法并结合海水的边界条件求得桩周、桩芯海水作用在管桩上的动... 详细信息

考虑桩−海水−层状土相互作用,研究了水平动荷载作用下层状地基中海洋大直径管桩的动力响应特性。将海水视为无黏性可压缩流体介质建立桩周、桩芯海水的运动方程,通过分离变量法并结合海水的边界条件求得桩周、桩芯海水作用在管桩上的动水压力。将海床土体视为黏弹性介质并考虑其成层非均质性,利用微分变化并结合土体振动边界条件解得桩周、桩芯土体作用在管桩上的水平抗力。进而根据各桩段上水平力的平衡建立管桩控制方程,利用传递矩阵法并结合桩身的连续条件以及桩顶、桩底的边界条件,得到层状海床土中海洋大直径管桩的水平动力响应解析解,给出了桩顶位移解析表达式。将所得解与有限元模拟结果以及退化解与已有文献解进行对比,验证了本研究计算方法的合理性。并基于所得解分析了管桩−海水−层状土系统水平动力响应对动水压力、水深、土体模量、土层厚度等关键参数的敏感性。

关键词：桩顶位移海洋大直径管桩水平振动特性桩芯海水层状海床地基

Genetic source,migration and accumulation of helium under deep thermal fluid activities:A case study of Ledong diapir area in Yinggehai Basin,South China Sea

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Petroleum Exploration and Development 2024年第3期51卷 753-766页

作者： FENG Ziqi hao Fang HU Lin HU Gaowei ZHANG Yazhen LI Yangming WANG Wei LI hao XIAO junjie TIAN jinqiang State Key Laboratory of Deep Oil and Gas China University of Petroleum(East China)Qingdao 266580China School of Geosciences China University of Petroleum(East China)Qingdao 266580China Laboratory for Marine Mineral Resources Qingdao Marine Science and Technology CenterQingdao 266237China Hainan Branch of CNOOC(China)Co. Ltd.Haikou 570312China

Based on the geochemical parameters and analytical data,the heat conservation equation,mass balance law,Rayleigh fractionation model and other methods were used to quantify the in-situ yield and external flux of crust-derived helium,and the initial He concentration and thermal driving mechanism of mantle-derived helium,in the Ledong Diapir area,the Yinggehai Basin,in order to understand the genetic source,migration and accumulation mechanisms of helium under deep thermal fluid *** average content of mantle-derived He is only 0.0014%,the 3 He/4 He value is(0.002–2.190)×10^(−6),and the R/Ra value ranges from 0.01 to 1.52,indicating the contribution of mantle-derived He is 0.09%–19.84%,while the proportion of crust-derived helium can reach over 80%.Quantitative analysis indicates that the crust-derived helium is dominated by external input,followed by in-situ production,in the Ledong diapir *** crust-derived helium exhibits an in-situ 4 He yield rate of(7.66–7.95)×10^(−13)cm^(3)/(a·g),an in-situ 4 He yield of(4.10–4.25)×10^(−4)cm^(3)/g,and an external 4 He influx of(5.84–9.06)×10^(−2)cm^(3)/*** results may be related to atmospheric recharge into formation fluid and deep rock-water *** ratio of initial mole volume of 3 He to enthalpy(W)is(0.004–0.018)×10−11 cm^(3)/j,and the heat contribution from the deep mantle(XM)accounts for 7.63%–36.18%,indicating that deep hot fluid activities drive the migration of mantle-derived 3 *** primary helium migration depends on advection,while the secondary migration is controlled by hydrothermal degassing and gas-liquid *** deep to shallow layers,the CO_(2)/3 He value rises from 1.34×10^(9)to 486×10^(9),indicating large amount of CO_(2)has *** the influence of deep thermal fluid,helium migration and accumulation mechanisms include:deep heat driven diffusion,advection release,vertical hydrothermal degassing,shallow lateral migration,accumulation in traps far from faults,partial pr

关键词： deep thermal fluid helium genetic source migration and accumulation mechanism Yinggehai Basin

Vertically aligned montmorillonite aerogel-encapsulated polyethylene glycol with directional heat transfer paths for efficient solar thermal energy harvesting and storage

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International journal of Minerals,Metallurgy and Materials 2024年第5期31卷 907-916页

作者： Qijing Guo Cong Guo hao Yi Feifei jia Shaoxian Song Key Laboratory of Green Utilization of Critical Non-metallic Mineral Resources Ministry of EducationWuhan University of TechnologyWuhan 430070China School of Resources and Environmental Engineering Wuhan University of TechnologyWuhan 430070China Hubei Key Laboratory of Mineral Resources Processing and Environment Wuhan University of TechnologyWuhan 430070China

The conversion and storage of photothermal energy using phase change materials(PCMs)represent an optimal approach for harnessing clean and sustainable solar ***,we encapsulated polyethylene glycol(PEG)in montmorillonite aerogels(3D-Mt)through vacuum impregnation to prepare 3D-Mt/PEG composite *** used as a support matrix,3D-Mt can effectively prevent PEG leakage and act as a flame-retardant barrier to reduce the flammability of ***,3D-Mt/PEG demonstrates outstanding shape retention,increased thermal energy storage density,and commendable thermal and chemical *** phase transition enthalpy of 3D-Mt/PEG can reach 167.53 j/g and remains stable even after 50 heating-cooling ***,the vertical sheet-like structure of 3D-Mt establishes directional heat transport channels,facilitating efficient phonon *** configuration results in highly anisotropic thermal conductivities that ensure swift thermal responses and efficient heat *** study addresses the shortcomings of PCMs,including the issues of leakage and inadequate flame *** achieves the development and design of 3D-Mt/PEG with ultrahigh strength,superior flame retardancy,and directional heat ***,this work offers a design strategy for the preparation of high-performance composite *** 3D-Mt/PEG with vertically aligned and well-ordered array structure developed in this research shows great potential for thermal management and photothermal conversion applications.

关键词： montmorillonite aerogel polyethylene glycol phase change materials solar thermal energy storage flame retardant