检索结果-南通市图书馆

STDNet: A Spatio-Temporal Decomposition Neural Network for Multivariate Time Series Forecasting

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2024年第4期29卷 1232-1247页

作者： Zhuolun Jiang Zefei ning hao Miao Li Wang College of Computer Science and Technology(College of Data Science) Taiyuan University of TechnologyJinzhong 030600China

Long-term multivariate time series forecasting is an important task in engineering applications. It helps grasp the future development trend of data in real-time, which is of great significance for a wide variety of fields. Due to the non-linear and unstable characteristics of multivariate time series, the existing methods encounter difficulties in analyzing complex high-dimensional data and capturing latent relationships between multivariates in time series, thus affecting the performance of long-term prediction. In this paper, we propose a novel time series forecasting model based on multilayer perceptron that combines spatio-temporal decomposition and doubly residual stacking, namely Spatio-Temporal Decomposition Neural Network (STDNet). We decompose the originally complex and unstable time series into two parts, temporal term and spatial term. We design temporal module based on auto-correlation mechanism to discover temporal dependencies at the sub-series level, and spatial module based on convolutional neural network and self-attention mechanism to integrate multivariate information from two dimensions, global and local, respectively. Then we integrate the results obtained from the different modules to get the final forecast. Extensive experiments on four real-world datasets show that STDNet significantly outperforms other state-of-the-art methods, which provides an effective solution for long-term time series forecasting.

关键词： time series forecasting multivariate time series spatio-temporal decomposition

Fabricating functionally graded Fe-Cr-Co permanent magnetic alloys via laser powder bed fusion

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第3期31卷 729-737页

作者： ya-zhou He ya-qing Hou Peng Shen hao Zhang Dong Zhou Hang Su Central Iron and Steel Research Institute Co. Ltd.Beijing 100081China Material Digital R&D Center China Iron and Steel Research Institute Group Co.Ltd.Beijing 100081China

Laser powder bed fusion(LPBF)in-situ alloying technology offers the possibility to construct gradient materials with varied structures and *** graded Fe-Cr-Co permanent magnetic alloys were fabricated by LPBF and in-situ alloying mixed powders of Fe,Cr,and Co *** effects of different Fe,Cr and Co contents on the microstructure,magnetic properties and hardness of Fe-Cr-Co alloys prepared by LPBF were *** as-built Fe-Cr-Co alloys present a single body-centered-cubic phase and have a homogeneous distribution of *** mechanical properties and magnetic properties of the compositionally graded sample show a gradient *** the increase in Cr content,the Vickers hardness of the sample increases,and the saturation magnetization of the sample *** optimal magnetic properties in an isotropic state are given as coercivity HcB=21.65 kA/m,remanence Br=0.70 T and energy product(BH)_(max)=5.35 kJ/m^(3),which are comparable to or higher than the reported magnetic properties in an isotropic state prepared by traditional powder *** in-situ alloying technology has the potential to further explore Fe-Cr-Co magnetic materials,such as those consisting of multiple or more constituent elements,and to maximize the compositional flexibility of magnetic materials.

关键词： Fe-Cr-Co alloy Laser powder bed fusion In-situ alloying Functional material Magnetic property

Triboelectric nanogenerator hybrid array driven by multiform natural energies and its applications in self-powered cathodic protection

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第3期67卷 878-890页

作者： SUN Weixiang yaNG Di LUO ning LI hao WANG DaoAi School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratoryof Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Qingdao Center of Resource Chemistry and New Materials Qingdao 266100China

In view of the increasing energy shortage and environmental pollution, the collection of friction charges to achieve the conversion of various natural energies and provide in-situ cathodic protection for metals is a significant challenge. Here, we designed a dual device-structure TENG composite array with the triboelectric layer of linear siloxane-modified polyurethane(PU) coating. This array could achieve a comprehensive collection for multiple forms of nature energy and cathodic protection of metals in multi-weather conditions. For one thing, the wave-mode TENG based on tanker structure could collect wave energy and showed the output performance with a short-circuit current of 15.5 μA. For another thing, the droplet-mode TENG based on arc-shaped surface structure could collect raindrop kinetic energy and showed the output performance with a short-circuit current of 16.3 μA. Notably, the parallel array of wave-mode TENG(W-TENG) and droplet-mode TENG(D-TENG) could simultaneously collect wave energy and raindrop kinetic energy, which showed a short-circuit current of 30.7 μA. Besides, a selfpowered a cathodic protection system powered by the dual structure TENG array is assembled and the open-circuit potential drop of the carbon steel connected with the TENG array is about 450 mV. Compared with cathodic protection system powered by single structure TENG, the composite array could provide more effective corrosion resistance for marine equipment in rainy weather. Due to the characteristic for comprehensive collection of nature energy, the anti-corrosion system supplied by TENG parallel array possesses great application potential in the all-weather corrosion protection of metal machinery under complex marine conditions.

关键词： triboelectric nanogenerator hybrid structure array siloxane-modified polyurethane cathodic protection

A Recursive DRL-Based Resource Allocation Method for Multibeam Satellite Communication Systems

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第5期33卷 1286-1295页

作者： haowei MENG ning XIN hao QIN Di Zhao State Key Laboratory of Integrated Services Networks Xidian University China Academy of Space Technology Institute of Telecommunication Satellite

Optimization-based radio resource management(RRM) has shown significant performance gains on high-throughput satellites(HTSs). However, as the number of allocable on-board resources increases, traditional RRM is difficult to apply in real satellite systems due to its intense computational complexity. Deep reinforcement learning(DRL) is a promising solution for the resource allocation problem due to its model-free advantages. Nevertheless, the action space faced by DRL increases exponentially with the increase of communication scale, which leads to an excessive exploration cost of the algorithm. In this paper, we propose a recursive frequency resource allocation algorithm based on long-short term memory(LSTM) and proximal policy optimization(PPO), called PPO-RA-LOOP,where RA means resource allocation and LOOP means the algorithm outputs actions in a recursive manner. Specifically, the PPO algorithm uses LSTM network to recursively generate sub-actions about frequency resource allocation for each beam, which significantly cuts down the action space. In addition, the LSTM-based recursive architecture allows PPO to better allocate the next frequency resource by using the generated sub-actions information as a prior knowledge, which reduces the complexity of the neural network. The simulation results show that PPO-RA-LOOP achieved higher spectral efficiency and system satisfaction compared with other frequency allocation algorithms.

关键词： High-throughput satellites Proximal policy optimization Deep reinforcement learning Long-short term memory High-throughput satellites Proximal policy optimization Deep reinforcement learning Long-short term memory OPTIMIZATION POWER

同方期刊数据库

A LOW-REGULARITY FOURIER INTEGRATOR FOR THE DAVEY-STEWARTSON II SYSTEM WITH ALMOST MASS CONSERVATION

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2024年第4期44卷 1536-1549页

作者： Cui ning Chenxi hao yaohong WANG School of Financial Mathematics and Statistics Guangdong University of FinanceGuangzhou 510521China Center for Applied Mathematics Tianjin UniversityTianjin 300072China

In this work,we propose a low-regularity Fourier integrator with almost mass conservation to solve the Davey-StewartsonⅡsystem(hyperbolic-elliptic case).Arbitrary order mass convergence could be achieved by the suitable addition of correction terms,while keeping the first order accuracy in H~γ×H^(γ+1)for initial data in H^(γ+1)×H^(γ+1)withγ>*** main theorem is that,up to some fixed time T,there exist constantsτ_(0)and C depending only on T and‖u‖_(L^(∞)((0,T);H^(γ+1)))such that,for any 0<τ≤τ_(0),we have that‖u(t_(n),·)-u^(n)‖H_γ≤C_(τ),‖v(t_(n),·)-v^(n)‖_(Hγ+1)≤C_(τ),where u^(n)and v^(n)denote the numerical solutions at t_(n)=nτ.Moreover,the mass of the numerical solution M(u^(n))satisfies that|M(u^(n))-M(u_0)|≤Cτ~5.

关键词： Davey-StewartsonⅡsystem low-regularity exponential integrator first order accuracy mass conservation

Widespread and active piezotolerant microorganisms mediate phenolic compound degradation under high hydrostatic pressure in hadal trenches

在线全文

学校读者我要写书评

暂无评论

Marine Life Science & Technology 2024年第2期6卷 331-348页

作者： hao Ling Yongxin Lv Yu Zhang ning‑Yi Zhou Ying Xu State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciences and School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China School of Oceanography Shanghai Jiao Tong UniversityShanghai 200240China State Key of Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Phenolic compounds,as well as other aromatic compounds,have been reported to be abundant in hadal *** high-throughput sequencing studies have hinted at the potential of hadal microbes to degrade these compounds,direct microbiological,genetic and biochemical evidence under in situ pressures remain ***,a microbial consortium and a pure culture of Pseudomonas,newly isolated from Mariana Trench sediments,efficiently degraded phenol under pressures up to 70 and 60 MPa,respectively,with concomitant increase in *** analyzing a high-pressure(70 MPa)culture metatranscriptome,not only was the entire range of metabolic processes under high pressure generated,but also genes encod-ing complete phenol degradation via ortho-and meta-cleavage pathways were *** isolate of Pseudomonas also contained genes encoding the complete degradation *** transcribed genes(dmpKLMNOP_(sed))were functionally identified to encode a multicomponent hydroxylase catalyzing the hydroxylation of phenol and its methylated derivatives by heterogeneous *** addition,key catabolic genes identified in the metatranscriptome of the high-pressure cultures and genomes of bacterial isolates were found to be all widely distributed in 22 published hadal microbial *** microbiological,genetic,bioinformatics,and biochemical levels,this study found that microorganisms widely found in hadal trenches were able to effectively drive phenolic compound degradation under high hydrostatic *** information will bridge a knowledge gap concerning the microbial aromatics degradation within hadal trenches.

关键词： Hadal trench High hydrostatic pressure Phenolic compounds degradation Piezotolerant microorganisms Widespread distribution

Effects of soil metal(loid)s pollution on microbial activities and environmental risks in an abandoned chemical smelting site

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第9期143卷 60-70页

作者： hao Li Jun yao Jianli Liu ning Min Geoffrey Sunahara Dongyang Men Robert Duran School of Water Resources and Environment Research Center of Environmental Science and EngineeringChina University of Geosciences(Beijing)Beijing 100083China Department of Natural Resource Sciences McGill University21111Lakeshore DriveSte-Anne-de-BellevueQuebecH9X 3V9Canada Equipe Environnement et Microbiologie MELODY groupUniversitéde Pau et des Pays de l’AdourE2S-UPPAIPREM UMR CNRS 5254BP 115564013 Pau CedexFrance

Abandoned chemical smelting sites containing toxic substances can seriously threaten and pose a risk to the surrounding ecological *** samples were collected from different depths(0 to 13 m)and analyzed for metal(loid)s content and fractionation,as well as microbial *** potential ecological risk indices for the different soil depths(ordered from high to low)were:1 m(D-1)>surface(S-0)>5 m(D-5)>13 m(D-13)>9 m(D-9),ranging between 1840.65-13,089.62,and representing extremely high environmental risks,of which Cd(and probably not arsenic)contributed to the highest environmental risk.A modified combined pollution risk index(MCR)combining total content and mobile proportion of metal(loid)s,and relative toxicities,was used to evaluate the degree of contamination and potential environmental *** the near-surface samples(S-0 and D-1 layers),the MCR considered that As,Cd,Pb,Sb,and Zn achieved high and alarming degrees of contamination,whereas Fe,Mn,and Ti were negligible or low to moderate pollution *** microcalorimetry and enzymatic activity measurements of contaminated soil samples were used to assess the microbial metabolic activity *** analysis elucidated the relationship between metal(loid)s exchangeable fraction or content and microbial activity characteristics(p<0.05).The microbial metabolic activity in the D-1 layer was low presumably due to heavy metal *** activity indicators and microcalorimetric growth rate(k)measurements were considered sensitive indicators to reflect the soil microbial activities in abandoned chemical smelting sites.

关键词： Abandoned chemical smelting sites Microbial activities Modified combined pollution risk Microcalorimetry Enzymatic activities

Essential oils improve nursery pigs'performance and appetite via modulation of intestinal health and microbiota

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第1期16卷 174-188页

作者： Bi-Chen Zhao Tian-hao Wang Jian Chen Bai-hao Qiu ya-Ru Xu Jin-Long Li College of Veterinary Medicine Northeast Agricultural UniversityHarbin150030China Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine Northeast Agricultural UniversityHarbin150030China Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment Northeast Agricultural UniversityHarbin150030China

Optimal intestinal health and functionality are essential for animal health and performance,and simultaneously intestinal nutrient transporters and intestinal peptides are also involved in appetite and feed intake control *** the potential of essential oil(EO)in improving animal performance and improving feed palatability,we hypothesized that dietary supplementation of cinnamaldehyde and carvacrol could improve performance and appetite of nursery pigs by modulating intestinal health and ***(100 mg/kg),carvacrol(100 mg/kg),and their mixtures(including 50 mg/kg cinnamaldehyde and 50 mg/kg carvacrol)were supplemented into the diets of 240 nursery pigs for 42 d,and data related to performance were ***,the influence of EO on intestinal health,appetite and gut microbiota and their correlations were *** supplementation increased(P<0.05)the body weight,average daily gain(ADG)and average daily feed intake(ADFI)of piglets,and reduced(P<0.05)diarrhea rates in nursery ***,EO increased(P<0.05)the intestinal absorption area and the abundance of tight junction proteins,and decreased(P<0.05)intestinal permeability and local *** terms of intestinal development and the mucus barrier,EO promoted intestinal development and increased(P<0.05)the number of goblet ***,we found that piglets in the EO-supplemented group had upregulated(P<0.05)levels of transporters and digestive enzymes in the intestine,which were significantly associated with daily gain and feed *** addition,EO supplementation somewhat improved appetite in nursery pigs,increased the diversity of the gut microbiome and the abundance of beneficial bacteria,and there was a correlation between altered bacterial structure and appetite-related *** findings indicate that EO is effective in promoting growth performance and nutrient absorption as well as in regulating appetite by improving intestinal health and ba

关键词： Nursery pig Essential oil Intestinal health Appetite Microbiota

Heavy metals potentially drive co-selection of antibiotic resistance genes by shifting soil bacterial communities in paddy soils along the middle and lower yangtze River

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2024年第3期34卷 606-619页

作者： ya ZHANG hao WANG Minghui HU Rui CAI Yuqing MIAO Xiancan ZHU Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Metabolic Diseases Anhui Provincial Key Laboratory of the Conservation and Exploitation of Biological ResourcesCollege of Life SciencesAnhui Normal UniversityWuhu 241000(China) School of Geography and Tourism Anhui Normal UniversityWuhu 241003(China)

Heavy metals(HMs)and antibiotic resistance have become serious environmental problems affecting soil and human *** microorganisms play key roles in pollutant degradation and biogeochemical cycling processes;however,the interactions among HMs,soil microbial communities,and antibiotic resistance genes(ARGs)in agricultural soils remain *** quantitative real-time polymerase chain reaction and NovaSeq sequencing,we evaluated heavy metal contents,abundances of ARGs,soil bacterial community structure and functions,and their correlations in paddy soils at 43 sampling sites along the middle and lower reaches of the yangtze River,central and eastern *** results showed the co-occurrence of HMs,ARGs,and HM resistance genes across all paddy ***,significant positive associations were detected between HMs and resistance ***,czcA,and int1 were positively correlated with bacterial community *** Mantel test showed that bacterial community composition and functions were significantly associated with HMs and resistance genes,such as Cd,Cr,Zn,copA,czcA,int1,and ***,HMs and ARGs were the major factors shaping soil bacterial communities;thus,HMs triggered proliferation of HM and antibiotic resistances by influencing the mobile genetic element(int1)and soil microbial *** study revealed that HMs potentially drive the co-selection of ARGs by shifting soil bacterial community structure and functions,thereby increasing the potential risks to human health as well as ecological environment in the paddy soils along the middle and lower reaches of the yangtze River.

关键词： agricultural ecosystem ecological risk heavy metal resistance microbial community soil contamination soil pollution