检索结果-南通市图书馆

Remaining useful life prediction for train bearing based on an ILSTM network with adaptive hyperparameter optimization

引用

Transportation Safety and Environment 2024年第2期6卷 75-86页

作者： Deqiang he jingren Yan Zhenzhen jin Xueyan Zou sheng Shan Zaiyu Xiang Jian Miao State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi Key Laboratory of Manufacturing System&Advanced Manufacturing Tec hnologySc hool of Mec hanical EngineeringGuangxi Univ ersityNanning 530004GuangxiChina Zhuzhou CRRC Times Electric Co. Ltd.Zhuzhou 412001HunanChina

Remaining useful life(RUL)prediction for bearing is a significant part of the maintenance of urban rail transit trains.Bearing RUL is closely linked to the reliability and safety of train running,but the current prediction accuracy makes it difficult to meet the re-quirements of high reliability operation.Aiming at the problem,a prediction model based on an improved long short-term memory(ILSTM)network is proposed.Firstly,the variational mode decomposition is used to process the signal,the intrinsic mode function with stronger representation ability is determined according to energy entropy and the degradation feature data is constructed com-bined with the time domain characteristics.Then,to improve learning ability,a rectified linear unit(ReLU)is applied to activate a fully connected layer lying after the long short-term memory(LSTM)network,and the hidden state outputs of the layer are weighted by attention mechanism.The Harris Hawks optimization algorithm is introduced to adaptively set the hyperparameters to improve the performance of the LSTM.Finally,the ILSTM is applied to predict bearing RUL.Through experimental cases,the better perfor-mance in bearing RUL prediction and the effectiveness of each improving measures of the model are validated,and its superiority of hyperparameters setting is demonstrated.

关键词： train bearing remaining useful life prediction long short-term memory(LSTM) attention mechanism Harris Hawks op-timization(HHO)

来源：

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

On the combined effect of soil fertility and topography on tree growth in subtropical forest ecosystems—a study from SE China

引用

Journal of Plant Ecology 2017年第1期10卷 111-127页

作者： Thomas Scholten Philipp Goebes Peter Kühn Steffen Seitz Thorsten Assmann Jürgen Bauhus helge Bruelheide Francois Buscot Alexandra Erfmeier Markus Fischer Werner Härdtle jin-sheng he Keping Ma Pascal A.Niklaus Michael Scherer-Lorenzen Bernhard Schmid Xuezheng Shi Zhengshan Song Goddert von Oheimb Christian Wirth Tesfaye Wubet Karsten Schmidt Department of Geosciences Soil Science and GeomorphologyUniversity of TübingenRümelinstraße 19-2372070 TübingenGermany Institute of Ecology Leuphana University LüneburgScharnhorststr.121335 LüneburgGermany Faculty of Forest and Environmental Sciences SilvicultureUniversity of FreiburgTennenbacherstraße 479085 Freiburg im BreisgauGermany Institute of Biology/Geobotany and Botanical Garden Martin Luther University Halle WittenbergAm Kirchtor 106108 HalleGermany German Centre for Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig Deutscher Platz 5e04103 LeipzigGermany helmholtz Centre for Environmental Research UFZ Theodor-Lieser-Straße 406120 HalleGermany Department of Plant Sciences University of BernAltenbergrain 213013 BernSwitzerland Peking University No.5 Yiheyuan RoadHaidian DistrictBeijing 100871China Institute of Botany Chinese Academy of SciencesNo.20 NanxincunXiangshanBeijing 100093China Institute of Evolutionary Biology and Environmental Studies University of ZürichWinterthurerstrasse 1908057 ZürichSwitzerland Faculty of Biology Department of GeobotanyUniversity of FreiburgSchänzlestraße 179104 FreiburgGermany Institute of Soil Science Chinese Academy of SciencesNo.71 East Beijing RoadNanjingChina TU Dresden Biodiversity and Nature ConservationPienner Straße 701737 TharandtGermany Department of Systematic Botany and Functional Biodiversity University of LeipzigJohannisallee 2104103 LeipzigGermany

Aims The aim of our research was to understand small-scale effects of topography and soil fertility on tree growth in a forest biodiversity and ecosystem functioning(BEF)experiment in subtropical SE China.Methods Geomorphometric terrain analyses were carried out at a spatial resolution of 5×5 m.Soil samples of different depth increments and data on tree height were collected from a total of 566 plots(667 m2 each).The soils were analyzed for carbon(soil organic carbon[SOC]),nitrogen,acidity,cation exchange capacity(CEC),exchangeable cations and base saturation as soil fertility attributes.All plots were classified into geomorphological units.Analyses of variance and linear regressions were applied to all terrain,soil fertility and tree growth attributes.Important Findings In general,young and shallow soils and relatively small differences in stable soil properties suggest that soil erosion has truncated the soils to a large extent over the whole area of the experiment.This explains the concurrently increasing CEC and SOC stocks downslope,in hollows and in valleys.However,colluvial,carbon-rich sediments are missing widely due to the convexity of the footslopes caused by uplift and removal of eroded sediments by adjacent waterways.The results showed that soil fertility is mainly influenced by topography.Monte-Carlo flow accumulation(MCCA),curvature,slope and aspect significantly affected soil fertility.Furthermore,soil fertility was affected by the different geomorphological positions on the experimental sites with ridge and spur positions showing lower exchangeable base cation contents,especially potassium(K),due to leaching.This geomorphological effect of soil fertility is most pronounced in the topsoil and decreases when considering the subsoil down to 50 cm depth.Few soil fertility attributes affect tree height after 1-2 years of growth,among which C stocks proved to be most important while pH_(KCl)and CEC only played minor roles.Nevertheless,soil acidity and a high proportion of Al on the exchange complex affec

关键词： soil fertility topography soil erosion matter transport biodiversity DSM carbon stocks tree forest BEF-China China

来源：

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

Effect of heat Treatment on Gradient Microstructure and Tensile Property of Laser Powder Bed Fusion Fabricated 15-5 Precipitation Hardening Stainless Steel

引用

Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 181-195页

作者： sheng Cao Hongyu Liu jin Jiang Ke he Binghua Lv Hao Zhang Lujie Zhang jingrong Meng Hao Deng Xiaodong Niu Department of Mechanical Engineering College of EngineeringShantou UniversityShantou515063China China State Shipbuilding Co. Ltd.Huangpu Wenchong Shipbuilding Company Ltd.Guangzhou510715China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing100080China Shantou Ruixiang Mould Co. Ltd.Shantou515041China Military Representative Office X of Unit 93147 Deyang618000China China National Erzhong Group Co. Deyang Wanhang Die Forging Co.Ltd.Deyang618013China

This work investigated the gradient microstructure evolution and tensile property of LPBF fabricated 15-5 precipitation hardening stainless steel in post-process direct ageing(DA)and solution treating&ageing(STA).The varied microstructures for austenite and small-sized oxide inclusions at different sample heights in the as-built(AB)condition was generally preserved after DA treatment.However,austenite was almost disappeared,and oxide particle grew significantly after the STA treatment.As a result,the tensile property differences in sample top and bottom for AB and DA conditions did not occur in the STA samples.For the influence of post-process heat treatment,the STA condition had the highest yield strength due to the highest volume fraction of nano-sized Cu precipitates.However,the DA specimen had the highest ultimate tensile strength and elongation owing to the considerable amount of austenite phase and associated transformation induced plasticity effect.

关键词： 15-5 PH stainless steel Laser powder bed fusion heat treatment Gradient microstructures Tensile properties

来源：

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

A micro-crosslinked amphoteric hydrophobic association copolymer as high temperature-and salt-resistance fluid loss reducer for water-based drilling fluids

引用

Petroleum Science 2024年第3期21卷 1980-1991页

作者： Jian Li Yu-Xi Ji Xiao-Xiao Ni Kai-he Lv Xian-Bin Huang jin-sheng Sun School of Petroleum Engineering China University of Petroleum(East China) Key Laboratory of Unconventional Oil & Gas Development China University of Petroleum(East China) Inspection and Testing Center of Huabei Oil Field Company PetroChina Drilling Fluid Research Institute CNPC Engineering Technology R&D Company Limited

During ultradeep oil and gas drilling, fluid loss reducers are highly important for water-based drilling fluids, while preparing high temperature-and salt-resistance fluid loss reducers with excellent rheology and filtration performance remains a challenge. herein, a micro-crosslinked amphoteric hydrophobic association copolymer(i.e., DADC) was synthesized using N,N-dimethyl acrylamide, diallyl dimethyl ammonium chloride, 2-acrylamido-2-methylpropane sulfonic acid, hydrophobic monomer, and pentaerythritol triallyl ether crosslinker. Due to the synergistic effects of hydrogen bonds, electrostatic interaction, hydrophobic association, and micro-crosslinking, the DADC copolymer exhibited outstanding temperature-and salt-resistance. The rheological experiments have shown that the DADC copolymer had excellent shear dilution performance and a certain degree of salt-responsive viscosity-increasing performance. The DADC copolymer could effectively adsorb on the surface of bentonite particles through electrostatic interaction and hydrogen bonds, which bring more negative charge to the bentonite, thus improving the hydration and dispersion of bentonite particles as well as the colloidal stability of the drilling fluids. Moreover, the drilling fluids constructed based on the DADC copolymer exhibited satisfactory rheological and filtration properties(FLHTHP= 12 m L) after aging at high temperatures(up to200°C) and high salinity(saturated salt) environments. Therefore, this work provided new insights into designing and fabricating high-performance drilling fluid treatment agents, demonstrating good potential applications in deep and ultradeep drilling engineering.

关键词： Fluid loss reducer Temperature- and salt-resistance Hydrophobic association Amphoteric Micro-crosslinking

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Investigating the Mechanism of Qu Du Qiang Fei 1 Hao Fang Formula against Coronavirus Disease 2019 Based on Network Pharmacology Method

引用

World Journal of Traditional Chinese Medicine 2024年第1期10卷 93-103页

作者： Yuan-Hua Wang he-Yang Zhou jin-Yun Ma Gui-Qing Ding Hua Yu Yong-sheng jin Xiao-Dong Cheng Institute of Clinical Immunology Yue-Yang Hospital of Integrative MedicineShanghai University of Traditional Chinese MedicineShanghaiChina School of Pharmacy Naval Medical UniversityShanghaiChina

Objective:Qu Du Qiang Fei 1 Hao Fang(QDQF1)is a novel Chinese herbal medicine formula used to treat coronavirus disease 2019(COVID-19).However,the pharmacological mechanisms of action of QDQF1 remain unclear.The objective of this study was to identify the effective ingredients and biological targets of QDQF1 for COVID-19 treatment.Materials and Methods:The effective ingredients and mechanisms of action of QDQF1 were analyzed by using network pharmacology methods,which included an analysis of the effective ingredients and corresponding targets,COVID-19-related target acquisition,compound-target network analyses,protein-protein interaction network analysis,Kyoto Encyclopedia of Genes and Genomes(KEGG)and Gene Ontology(GO)enrichment analyses,and molecular docking studies.Results:In total,288 effective QDQF1 ingredients were identified.We identified 51 core targets from the 148 targets through an overlap between putative QDQF1 targets and COVID-19-related targets.Six key components,including formononetin,kaempferol,luteolin,naringenin,quercetin,and wogonin were identified through component-target network analyses.GO functional enrichment analysis of the core targets revealed 1296 items,while KEGG pathway enrichment analysis identified 148 signaling pathways.Nine central targets(CCL2,CXCL8,IL1B,IL6,MAPK1,MAPK3,MAPK8,STAT3,and TNF)related to the COVID-19 pathway were identified in the KEGG pathway enrichment analysis.Furthermore,molecular docking analysis suggested that the docking scores of the six key components to the nine central targets were better than those to remdesivir.Conclusions:QDQF1 may regulate multiple immune-and inflammation-related targets to inhibit the progression of severe acute respiratory syndrome coronavirus 2,and thus,may be suitable for the treatment of COVID-19.

关键词： Coronavirus disease 2019 molecular docking molecular mechanism network pharmacology Qu Du Qiang Fei 1 Hao Fang formula

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Recent progress of Pt-based oxygen reduction reaction catalysts for proton exchange membrane fuel cells

引用

Rare Metals 2024年第6期43卷 2444-2468页

作者： Feng Zhan Kun-Song Hu jin-Hua Mai Li-sheng Zhang Zhen-Guo Zhang Huan he Xin-Hua Liu School of Resources Environment and MaterialsGuangxi University School of Transportation Science and Engineering Beihang University IDTECH (Suzhou) Co.Ltd Dyson School of Design Engineering Imperial College London

With the increasing consumption of fossil fuels,proton exchange membrane fuel cells(PEMFCs) have attracted considerable attention as green and sustainable energy conversion devices.The slow kinetics of the cathodic oxygen reduction reaction(ORR) has a major impact on the performance of PEMFCs,and although platinum(Pt) can accelerate the reaction rate of the ORR,the scarcity and high cost of Pt resources still limit the development of PEMFCs.Therefore,the development of low-cost high-performance ORR catalysts is essential for the commercial application and development of PEMFCs.This paper reviews the research progress of researchers on Pt-based ORR catalysts in recent years,including Pt/C catalysts,Pt-based alloy catalysts,Pt-based intermetallic compounds,and Pt-based single-atom catalysts(SACs),with a focus on Pt-based alloy catalysts with different nanostructures.We described in detail the difficulties and solutions in the research process of various ORR catalysts and explained the principle of their activity enhancement with density functional theory(DFT).In addition,an outlook on the development of Pt-based catalysts is given,and reducing the amount of Pt used and improving the performance of catalysts are the directions to work on in the coming period.

关键词： Pt-based catalysts PEMFCs Pt-based intermetallic compounds Single-atom catalysts

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Oxidation behavior of low-grade vanadiferous titanomagnetite concentrate with high titanium

引用

Journal of Iron and Steel Research(International) 2024年第2期31卷 329-341页

作者： jin-sheng Liu Zhen-xing Xing Gong-jin Cheng Xue-yong Ding Xiang-xin Xue School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina Liaoning Key Laboratory of Recycling Science for Metallurgical Resources Shenyang110819LiaoningChina Innovation Research Institute of Vanadium and Titanium Resource Industry Technology Northeastern UniversityShenyang110819LiaoningChina

In order to clarify the oxidation mechanisms and make better use of the low-grade vanadiferous titanomagnetite concentrate with high titanium(LVTC),the oxidation behavior of LVTC was investigated.The results showed that oxidation degree was achieved within 90 min when temperature was not lower than 700°C,and the main phases of the oxidized LVTC consisted of Fe9TiO15,Fe2O3,CaSiTiO5 and a small amount of Fe2.75Ti0.25O4.Increasing temperature is favorable to the formation of Fe2TiO5.The surface of LVTC gradually becomes rough,with fine particles of needle-like and granular shape appearing on the surface,which finally turn from laminar to creamy,spread out,and are interspersed with many tiny holes.The phase oxidation paths in LVTC were as follows:(1)Fe2.75Ti0.25O4→Fe9TiO15+Fe2O3;(2)Fe2.75Ti0.25O4→Fe2O3+FeTiO3→Fe2TiO5;(3)FeTiO3→Fe2O3+Fe2Ti3O9→Fe2TiO5.LVTC is predominantly mesoporous whether oxidized or not,with the pores mainly distributed in the range of 2–40 nm,and the specific surface area of LVTC decreases significantly with increasing temperature.

关键词： Low-grade vanadiferous titanomagnetite concentrate Oxidation degree Phase transformation Micromorphology Oxidation path Pore structure

来源：

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

Vibration Suppression for Active Magnetic Bearings Using Adaptive Filter with Iterative Search Algorithm

引用

CES Transactions on Electrical Machines and Systems 2024年第1期8卷 61-71页

作者： jin-Hui Ye Dan Shi Yue-sheng Qi jin-Hui Gao Jian-Xin Shen IEEE Department of Electrical Engineering Zhejiang UniversityHangzhou 310027China CES and IEEE

Active Magnetic Bearing(AMB) is a kind of electromagnetic support that makes the rotor movement frictionless and can suppress rotor vibration by controlling the magnetic force. The most common approach to restrain the rotor vibration in AMBs is to adopt a notch filter or adaptive filter in the AMB controller. However, these methods cannot obtain the precise amplitude and phase of the compensation current. Thus, they are not so effective in terms of suppressing the vibrations of the fundamental and other harmonic orders over the whole speed range. To improve the vibration suppression performance of AMBs,an adaptive filter based on Least Mean Square(LMS) is applied to extract the vibration signals from the rotor displacement signal. An Iterative Search Algorithm(ISA) is proposed in this paper to obtain the corresponding relationship between the compensation current and vibration signals. The ISA is responsible for searching the compensating amplitude and shifting phase online for the LMS filter, enabling the AMB controller to generate the corresponding compensation force for vibration suppression. The results of ISA are recorded to suppress vibration using the Look-Up Table(LUT) in variable speed range. Comprehensive simulations and experimental validations are carried out in fixed and variable speed range, and the results demonstrate that by employing the ISA, vibrations of the fundamental and other harmonic orders are suppressed effectively.

关键词： Active Magnetic Bearing(AMB) Adaptive filter Iterative search algorithm Least mean square(LMS) Vibration suppression

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Vulnerability assessment of UAV engine to laser based on improved shotline method

引用

Defence Technology（防务技术） 2024年第3期33卷 588-600页

作者： Le Liu Chengyang Xu Changbin Zheng sheng Cai Chunrui Wang jin Guo Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China University of Chinese Academy of Sciences Beijing 100049China

Laser anti-drone technology is entering the sequence of actual combat,and it is necessary to consider the vulnerability of typical functional parts of UAVs.Since the concept of"vulnerability"was proposed,a variety of analysis programs for battlefield targets to traditional weapons have been developed,but a comprehensive assessment methodology for targets'vulnerability to laser is still missing.Based on the shotline method,this paper proposes a method that equates laser beam to shotline array,an efficient vulnerability analysis program of target to laser is established by this method,and the program includes the circuit board and the wire into the vulnerability analysis category,which improves the precision of the vulnerability analysis.Taking the UAV engine part as the target of vulnerability analysis,combine with the"life-death unit method"to calculate the laser penetration rate of various materials of the UAV,and the influence of laser weapon system parameters and striking orientation on the killing probability is quantified after introducing the penetration rate into the vulnerability analysis program.The quantitative analysis method proposed in this paper has certain general expansibility,which can provide a fresh idea for the vulnerability analysis of other targets to laser.

关键词： Laser weapon Laser damage Vulnerability UAV Engine Killing probability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

SERPINH1 promoted the proliferation and metastasis of colorectal cancer by activating PI3K/Akt/mTOR signaling pathway

引用

World Journal of Gastrointestinal Oncology 2024年第5期16卷 1890-1907页

作者： Xiao-sheng jin Lu-Xi Chen Ting-Ting Ji Rong-Zhou Li Department of Gastroenterology The Third Affiliated Hospital of Wenzhou Medical UniversityRuian 325000Zhejiang ProvinceChina

BACKGROUND Serpin peptidase inhibitor clade H member 1(SERPINH1)was initially recognized as an oncogene implicated in various human malignancies.Nevertheless,the clinical relevance and functional implications of SERPINH1 in colorectal cancer(CRC)remain largely elusive.AIM To investigate the effects of SERPINH1 on CRC cells and its specific mechanism.METHODS Quantitative real-time polymerase chain reaction,western blotting analysis,The Cancer Genome Atlas data mining and immunohistochemistry were employed to examine SERPINH1 expression in CRC cell lines and tissues.A series of in-vitro assays were performed to demonstrate the function of SERPINH1 and its possible mechanisms in CRC.RESULTS SERPINH1 demonstrated elevated expression levels in both CRC cells and tissues,manifested at both mRNA and protein tiers.Elevated SERPINH1 levels correlated closely with advanced T stage,lymph node involvement,and distant metastasis,exhibiting a significant association with poorer overall survival among CRC patients.Subsequent investigations unveiled that SERPINH1 overexpression notably bolstered CRC cell proliferation,invasion,and migration in vitro,while conversely,SERPINH1 knockdown elicited the opposite effects.Gene set enrichment analysis underscored a correlation between SERPINH1 upregulation and genes associated with cell cycle regulation.Our findings underscored the capacity of heightened SERPINH1 levels to expedite G1/S phase cell cycle progression via phosphatidylinositol 3-kinase/AKT/mechanistic target of rapamycin pathway activation,thereby facilitating CRC cell invasion and migration.CONCLUSION These findings imply a crucial involvement of SERPINH1 in the advancement and escalation of CRC,potentially positioning it as a novel candidate for prognostic assessment and therapeutic intervention in CRC management.

关键词： Serpin peptidase inhibitor clade H member 1 Colorectal cancer Proliferation Cell cycle Phosphatidylinositol 3-kinase/AKT/mechanistic target of rapamycin

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：