检索结果-南通市图书馆

Automatic recognition of landslides based on YOLOv7 and attention mechanism

Journal of Mountain Science 2024年第8期21卷 2681-2695页

作者： SONG Yewei guo Jie wu Gaofeng ma Fengshan LI Fangrui Key Laboratory of Shale Gas and Geoengineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Sciences Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Landslide disasters comprise the majority of geological incidents on slopes,posing severe threats to the safety of human lives and property while exerting a significant impact on the geological *** rapid identification of landslides is important for disaster prevention and control;however,currently,landslide identification relies mainly on the manual interpretation of remote sensing *** interpretation and feature recognition methods are time-consuming,labor-intensive,and challenging when confronted with complex ***,automatic landslide recognition has emerged as a pivotal avenue for future *** this study,a dataset comprising 2000 landslide images was constructed using open-source remote sensing images and *** YOLOv7 model was enhanced using data augmentation algorithms and attention *** optimization models were formulated to realize automatic landslide *** findings demonstrate the commendable performance of the optimized model in automatic landslide recognition,achieving a peak accuracy of 95.92%.Subsequently,the optimized model was applied to regional landslide identification,co-seismic landslide identification,and landslide recognition at various scales,all of which showed robust recognition ***,the model exhibits limitations in detecting small targets,indicating areas for refining the deep-learning *** results of this research offer valuable technical support for the swift identification,prevention,and mitigation of landslide disasters.

关键词： Deep learning Landslide detection Natural disasters Attention mechanism Remote sensing

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

Promoted catalytic performance of Ag-Mn bimetal catalysts synthesized through reduction route

引用

Journal of Environmental Sciences 2024年第3期137卷 358-369页

作者： Wenkai Hu Tao guo Kaiyao ma Xu Li Wangting Luo Mingzhi wu Hao guo Yaxin Zhang Wenfeng Shangguan School of Chemical Engineering and Technology Xinjiang UniversityUrumchi 830017China Research Center for Combustion and Environmental Technology Shanghai Jiao Tong UniversityShanghai 200240China

VOCs can exert great harm to both human and environment,and catalytic oxidation is believed to be an effective technique to eliminate these *** this paper,Ag-Mn bimetal catalysts with 10 wt.%of silver were synthesized using doping,impregnation,and reduction methods respectively,and then they were applied to the catalytic oxidation of *** series of characterizations it showed that the loading of silver using reduction method significantly resulted in improved physico-chemical properties of manganese oxides,such as larger surface area and pore volume,higher proportion of surface Mn~(3+)and Mn~(4+),stronger reducibility and more active of surface oxygen species,which were all beneficial to its catalytic *** a result,the Ag-Mn catalysts synthesized by reduction method showed a lower T_(90)value(equals to the temperature at which 90%of initial benzene was removed)of 203℃.Besides,both the used and fresh Ag-Mn catalysts synthesized by reduction method showed preferable stability in this research.

关键词： Ag-Mn Benzene oxidation Catalytic performance Reduction route

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

Experimental and computational investigation on flow characteristics of rotating cavities with high inlet pre-swirl axial throughflow

引用

Chinese Journal of Aeronautics 2024年第4期37卷 276-293页

作者： Sipeng WANG Xiang LUO Linji guo Zeyu wu Yang BAI Zongchao LI Lichun ma School of Energy and Power Engineering Beihang UniversityBeijing 100191China Research Institude of Aero-Enigine Beihang UniversityBeijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China Shenyang Aeroengine Research Institute Aero Engine Corporation of ChinaShenyang 110015China

As an integral part of the internal air system of aero-engines,the axial throughflow of the cooling air can interact with the cavity flow between the rotating compressor disks,forming a threedimensional,unsteady,and unstable flow *** flow characteristics in an engine-like rotating multi-stage cavity with throughflow were investigated using particle image velocimetry,flow visualization technology and three-dimensional unsteady Reynolds-Averaged Navier-Stokes (RANS)*** focus of current research was to understand the distribution of the mean swirl ratio and its variation with a wide range of non-dimensional parameters in the co-rotating cavity with high inlet pre-swirl axial *** maximum axial Reynolds number and rotational Reynolds numbers could reach 4.41×10^(4)and 1.24×10^(6),*** velocity measurement results indicate that the mean swirl ratio is greater than 1 and decreases with an increase in the radial *** flow structure is dominated by the Rossby number,and two different flow patterns (flow penetration and flow stratification) are identified and confirmed by flow visualization *** the absence of buoyancy,the flow penetration caused by the precession of the throughflow makes it easier for the throughflow to reach a high radius *** consistency of results between measurements and numerical calculations is *** study provides a theoretical basis and data support for toroidal vortex breakdown,which is of practical significance for the design of high-pressure compressor cavities.

关键词： Compressor Axial throughflow Rotating cavity flow Particle image velocimetry Unsteady RANS Flow pattern

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

The behaviors of gas-liquid two-phase flow under gas kick during horizontal drilling with oil-based muds

引用

Petroleum 2024年第1期10卷 49-67页

作者： Yu Su Huiyun ma Jianhua guo Xinyu Shen Zhaoliang Yang Jie wu Engineering Technology Research Institute PetroChina Southwest Oil&Gas Field CompanyChengdu610017PR China

Natural gas is easily soluble in oil-based muds(OBM),leading to complex flow behavior in wellbores,especially in horizontal *** this study,a new transient flow model considering wellbore-formation coupling and gas solubility on flow behavior is developed to simulate gas kicks during horizontal drilling with ***,the effect of gas solubility on parameters such as bottom-hole pressure(BHP),gas void fraction and mixture velocity in the flow behavior is ***,several critical factors affecting flow behavior are investigated and compared to gas kicks in water-based muds(WBM)where the effect of solubility is *** results show that the invading gas exists as dissolved gas in the OBM and as free gas in the *** the gas escapes from the OBM,the pit gain is zero and there is barely any change in the BHP,annulus return flow rate and mixture velocity,which means that detecting gas kicks through these warning signs can be challenging until they get very close to the surface and develop ***,in WBM drilling,these parameters change quickly with the increasing gas kick ***,for both cases,the longer the horizontal length and the greater reservoir permeability,the greater the decrease in BHP,and the shorter the time for gas to migrate from the bottom-hole to the wellhead.A larger flow rate contributes to a greater initial BHP and a lesser BHP *** research is of value in characterizing gas kick behavior and identifying novel ways for early gas kick detection during horizontal drilling with OBM.

关键词： Flow behavior Gas solubility Gas kick Horizontal drilling Oil-based muds Water-based muds

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

Efficient and rapid capture of uranium(Ⅵ) in wastewater via multiamine modified β-cyclodextrin porous polymer

引用

Chinese Journal of Chemical Engineering 2024年第4期68卷 144-155页

作者： Xing Zhong Yubin Tan Siyuan wu Caixia Hu Kai guo Yongchuan wu Neng Yu Mingyang ma Ying Dai School of Chemistry and materials Science East China University of TechnologyNanchang 330013China

It is quite important to ensure the safety and sustainable development of nuclear energy for the treatment of radioactive wastewater. To treat radioactive wastewater efficiently and rapidly, two multi-amine β-cyclodextrin polymers(diethylenetriamine β-cyclodextrin polymer(DETA-TFCDP) and triethylenetetramine β-cyclodextrin polymer(TETA-TFCDP)) were prepared and applied to capture uranium. Results exhibited that DETA-TFCDP and TETA-TFCDP displayed the advantages of high adsorption amounts(612.2and 628.2 mg·g-1, respectively) and rapid adsorption rates, which can reach(88 ± 1)% of their equilibrium adsorption amounts in 10 min. Moreover, the adsorbent processes of DETA-TFCDP and TETATFCDP on uranium(Ⅵ) followed the Langmuir model and pseudo-second-order model, stating they were mainly chemisorption and self-endothermic. Besides, TETA-TFCDP also showed excellent selectivity in the presence of seven competing cations and could be effectively reused five times via Na2CO3as the desorption reagent. Meanwhile, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy illustrated that the enriched multi-amine groups and oxygen-containing functional groups on the surface of TETA-TFCDP were the main active sites for capturing uranium(Ⅵ). Hence, multi-amine β-cyclodextrin polymers are a highly efficient, rapid, and promising adsorbent for capturing uranium(Ⅵ)from radioactive wastewater.

关键词： Adsorption Waste water Pollution Uranium(VI) b-Cyclodextrin

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

Sensory innervation around immediately vs. delayed loaded implants: a pilot study

引用

International Journal of Oral Science 2015年第1期7卷 49-55页

作者： Yan Huang Jeroen van Dessel Wendy martens Ivo Lambrichts Wei-Jian Zhong guo-wu ma Dan Lin Xin Liang Reinhilde Jacobs Department of Imaging & Pathology Faculty of Medicine University of Leuven and Oral & Maxillo-facial Surgery University Hospitals Leuven State Key Laboratory of Oral Diseases West China Hospital of Stomatology Sichuan University Biomedical Research Institute Hasselt University School of Stomatology Dalian Medical University Center for Statistics Hasselt University

Although neurophysiological and psychophysical proof of osseoperception is accumulating, histomorphometric evidence for the neural mechanisms of functional compensation following immediate and delayed implant loading is still lacking. For this randomized split-mouth study, six mongrel dogs randomly received one of four treatment protocols at 36 implant-recipient sites over 16 weeks （third maxillary incisor, third and fourth mandibular premolar）： immediate implant placement and immediate loading （liP＋ IL）; delayed implant placement and delayed loading （DIP＋DL）; delayed implant placement and immediate loading （DIP＋IL）; and natural extraction socket healing （control）. Histomorphometry was performed in the peri-implant bone and soft tissues within 300 pm around the implants. Immunocytochemistry and transmission electron microscopy were used to confirm the presence of neural structures and to reveal their ultrastructural characteristics, respectively. Myelinated nerve fibres densely populated the peri-implant crestal gingival and apical regions, although they were also identified in the woven bone and in the osteons near the implant threads. Compared with the control group in the mandible, the group that received IIP＋IL showed a higher innervation （in ***^-2, 5.94±1.12 vs. 3.15±0.63, P〈0.001） and smaller fibre diameter （in pm, 1.37±0.05 vs. 1.64±0.13, P=0.016）, smaller axon diameter （in pm, 0.89±0.05 vs. 1.24±0,10, P=0.009） and g-ratio （0.64±0.04 vs. 0.76±0.05, P〈0.001） in the middle region around the implants. Compared with DIP＋IL in the mandible, IIP＋IL had a higher nerve density （in ***^-2, 13.23±2.54 vs. 9.64±1.86, P=0.027）, greater fibre diameter （in pm, 1.32±0.02 vs. 1.20±0.04, P=0.021）, greater axon diameter （in μm, 0.92±0.01 vs. 0.89±0.03, P=-0.035） and lower g-ratio （0.69±0.01 vs. 0.74±0.01, P=-0.033） in the apical region around the implants. It may be assumed that the treatment protocol with liP＋ IL is the preferred method to allow optimized peri-implant re-i

关键词： animal experiments dental implants histomorphometry immediate loading mechanoreceptor myelinated nerve fibres osseoperception

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

Electrode particulate materials for advanced rechargeable batteries:A review

引用

Particuology 2024年第3期86卷 160-181页

作者： Mingyang ma Miao Du Yan Liu Hongyan Lü Jialin Yang Zelin Hao Jinzhi guo Xinglong wu MOE Key Laboratory for UV Light-Emitting materials and Technology Northeast Normal UniversityChangchunJilin130024China Department of Chemistry Northeast Normal UniversityChangchunJilin130024China

The demand for large-scale energy storage is increasing due to the decreasing non-renewable resources and deteriorating environmental *** rechargeable batteries with high energy density and long cycle performance is an ideal choice to meet the demand of energy storage *** development of excellent electrode particles is of great significance in the commercialization of nextgeneration *** ideal electrode particles should balance raw material reserves,electrochemical performance,price and environmental *** them,the development of electrode particulate materials with excellent electrochemical properties is the top priority at *** this review,the typical researches of electrode materials are summarized in terms of crystal structure,morphology,pore structure,surface and interface ***,the structural characteristics and improvement methods of transition metal oxides,polyanionic compounds,Prussian blue and their analogues are ***,the different effects of particulate morphology,pore,surface and interface structure on the performance of electrode materials are *** designing high-performance electrode materials,preparation route should be set according to the particle properties of the materials and the synergistic effect of various optimization methods should be *** the same time,in addition to the electrode materials,other components of the rechargeable batteries,such as current collector,separator and electrolytes,should be optimized to improve the overall performance of the *** review would provide important guiding principle for designing high-performance electrode particulate materials.

关键词： Particulate properties Electrode materials Rechargeable batteries

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

Laboratory and numerical modelling of irrigation infiltration and nitrogen leaching in homogeneous soils

引用

Pedosphere 2024年第1期34卷 146-158页

作者： Lei wu Ruizhi LI Yan WANG Zongjun guo Jiaheng LI Hang YANG Xiaoyi ma Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling 712100China Blackland Research and Extension Center Texas A&M AgriLife ResearchTexas A&M UniversityTemple TX 76502USA State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F UniversityYangling 712100China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China

Nitrogen (N) plays a key role in crop growth and production;however,data are lacking especially regarding the interaction of biochar,grass cover,and irrigation on N leaching in saturated soil *** soil columns with 20-cm diameter and 60-cm height were designed to characterize the effects of different grass cover and biochar combinations,i.e.,bare soil+0%biochar (control,CK),perennial ryegrass+0%biochar (C1),Festuca arundinacea+0%biochar (C2),perennial ryegrass+1%biochar (C3),perennial ryegrass+2%biochar (C4),perennial ryegrass+3%biochar (C5),***+1%biochar (C6),***+2% biochar (C7),and ***+3%biochar (C8),on periodic irrigation infiltration and N leaching in homogeneous loess soils from July to December *** in CK were 10.2%–35.3%higher than those in C1 and *** perennial ryegrass and *** decreased the volumes of leachates and delayed the leaching process in the 1%,2%,and 3%biochar treatments,and the vertical leaching rate decreased with biochar *** N leaching losses were concentrated in the first few leaching tests,and both total N (TN) and nitrate (NO_(3)^(-))-N concentrations in CK and C1–C8 decreased with increasing leaching test *** addition (1%,2%,and 3%) could further reduce the leaching risk of NO_(3)^(-)-N and the NO_(3)^(-)-N loss decreased with biochar ***,compared to 1%biochar,2% biochar promoted the leaching of TN under both grass cover *** N leaching losses in CK,C1,C2,C3,C4,C6,and C7 were primarily in the form of NO_(3)^(-)-*** these treatments,CK,C1,and C2had the highest cumulative leaching fractions NO_(3)^(-)-N (>90%),followed by those in C3,C4,C6,and C7 (>80%).The cumulative leaching fraction of NO_(3)^(-)-N decreased with increasing leaching test times and biochar addition,and 3%biochar addition (i.e.,C5 and C8) reduced it to approximately 50%.The one-dimensional advective-dispersive-reactive transport equation can be used as an effective nume

关键词： leaching loss nitrate nitrogen biochar grass cover analytical modelling

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

3D simulation of image-defined complex internal features using the numerical manifold method

引用

Science China(Technological Sciences) 2024年第4期67卷 1023-1039页

作者： wu Jie ma guoWei School of Civil and Transportation Engineering Hebei University of TechnologyTianjin 300401China Tianjin Key Laboratory for Prefabricated Building and Intelligent Construction Tianjin 300401China

The numerical simulation of internal features,such as inclusions and voids,is important to analyze their impact on the performance of composite ***,the complex geometries of internal features and the induced continuous-discontinuous(C-D)deformation fields are challenges to their numerical *** this study,a 3D approach using a simple mesh to simulate irregular internal geometries is developed for the first *** the help of a developed voxel crack model,image models that are efficient when recording complex geometries are directly imported into the *** reconstructions,which are usually labor-intensive,are excluded from this ***,using image models as the geometric input,image processing techniques are applied to detect material interfaces and develop contact ***,the C-D deformations of the complex internal features are directly calculated based on the numerical manifold *** accuracy and convergence of the developed3D approach are examined based on multiple *** 3D C-D simulation of sandstones with naturally formed complex microfeatures demonstrates the capability of the developed approach.

关键词： 3D continuous-discontinuous simulation image-based simulation complex internal features numerical manifold method voxel crack model structured mesh

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

Grain growth behavior and properties of high-entropy pseudobrookite(Mg,Co,Ni,Zn)Ti_(2)O_(5) ceramics

引用

Journal of Advanced Ceramics 2024年第6期13卷 757-768页

作者： Xiaohui ma Jinyu wu Lingyi Meng Jinfeng Zhang Heng Chen Liwen Yan Anran guo Jiachen Liu Key Laboratory of Advanced Ceramics and machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin 300072China Xiamen Key Laboratory of Rare Earth Photoelectric Functional materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021China

It is well known that the grain size of high-entropy ceramics is quite small owing to the sluggish diffusion effect. However, abnormal grain growth often occurs in high-entropy pseudobrookite ceramics, ultimately resulting in the formation of many abnormally grown grains with a grain size as large as 50 μm. To study this phenomenon, the grain growth behavior of high-entropy pseudobrookite ceramics was systematically investigated in this paper. The results demonstrate that the starting material powders first react with each other to form a high-entropy intermediate phase and calcined TiO_(2) powders (TiO_(2)-1100 ℃), and then as the sintering temperature increases, the formed high-entropy intermediate phase further reacts with TiO_(2)-1100 ℃ to form high-entropy pseudobrookite ceramics. Thus, in this system, in addition to the sluggish diffusion effect, the grain sizes of the high-entropy intermediate phase and TiO_(2)-1100 ℃ also affect the morphology of high-entropy pseudobrookite. Compared to nanosized TiO_(2), micron-sized TiO_(2) has a lower sintering activity. Therefore, the high-entropy intermediate phases (Mg,Co,Ni,Zn)TiO_(3) and TiO_(2)-1100 ℃ prepared with micron-sized starting materials exhibit lower grain sizes, finally resulting in the formation of high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) with small grain sizes. Moreover, nano-indentation and thermal conductivity tests were carried out on high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) with different morphologies. The results show that the hardness of high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) increases from 6.05 to 9.95 GPa as the grain size increases, whereas the thermal conductivity decreases from 2.091±0.006 to 1.583±0.006 W·m^(−1)·K^(−1). All these results indicate that high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) with a small grain size is a potential material for thermal protection.

关键词： grain size sluggish diffusion effect two-step solid phase process high-entropy intermediate phase high-entropy pseudobrookite ceramic

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：