检索结果-南通市图书馆

The Micro-Scale Mechanism of Metal Mine Tailings Thickening Concentration Improved by Shearing in Gravity Thickener

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 Renewable Materials 2021年第4期9卷 637-650页

作者： Huazhe Jiao yachuang wu Wei Wang Xinming Chen Yunfei Wang Juanhong Liu Wentao Feng International Joint Research Laboratory of Henan Province for Underground Space Development and Disaster Prevention Henan Polytechnic UniversityJiaozuo454000China College of Safety Science and Engineering Henan Polytechnic UniversityJiaozuo454000China Civil and Resource Engineering School University of Science and Technology BeijingBeijing100000China No.11 Coal Mine of Pingdingshan Tianan Coal Mining Co. Ltd.Pingdingshan467000China

Higher concentration is beneficial for the Paste and Thickened Tailings(PTT)operation in metal *** paste thickeners are produced lower density *** tailings are intended to form a water entrapped network structure in thickener,which is detrimental to underflow *** this study,the continuous thickening experiment was carried out for ultra-fine tungsten tailings to study the influence of rake shearing on *** micro pores structure and seepage flow in tailings bed before and after shearing are studied by CT and simulation approach to reveal the shearing enhancement mechanism of thickening *** results shown that,the underflow concentration is increased from 61.4 wt%to 69.6 wt%by rake shearing in a pilot scale thickener,the porosity decreased from 46.48%to 37.46%.The entrapped water discharged from sticks structure more than sphere *** items of seepage,after shearing,the seepage flow channel of tailings underflow is becoming longer,which caused the decreasing average flow rate decreases and absolute *** absolute permeability is negatively correlated with *** rake shearing can destroy the flocs structure;change the effective stress to increase the *** underflow concentration improves the waste recycling and water recovery rate,especially for arid areas.

关键词： Metal mine tailings gravity thickening shearing effect pore microstructure reverse direction seepage flow channel

基于可视化分析的玄武岩纤维喷射混凝土微观结构研究

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

土木工程学报 2020年第S1期53卷 371-377页

作者：焦华喆吴亚闯陈峰宾王金星褚怀保河南理工大学河南焦作454150

玄武岩纤维(BF)掺入引起的孔隙结构变化是影响玄武岩纤维喷射混凝土(BF/SC)力学性能提高的关键因素。纤维与基体密度相近,CT扫描图像区分度较小,传统方法无法直接识别纤维原位分布。可采用分水岭算法和骨架提取算法相结合突破这一瓶颈... 详细信息

玄武岩纤维(BF)掺入引起的孔隙结构变化是影响玄武岩纤维喷射混凝土(BF/SC)力学性能提高的关键因素。纤维与基体密度相近,CT扫描图像区分度较小,传统方法无法直接识别纤维原位分布。可采用分水岭算法和骨架提取算法相结合突破这一瓶颈。文章采用喷射混凝土制作方式,研究了不同BF掺量对BF/SC力学性能的影响;借助CT扫描技术对BF/SC微观结构进行可视化分析,测定了BF不同掺量下的孔隙大小组分结构、纤维分布;分析纤维掺量与孔隙结构的响应关系,揭示纤维增强微细观机理。结果表明:玄武岩掺量比为3kg/m3时,喷射混凝土的抗压和抗折性能最好;此时孔隙率为4.36%,大孔隙占比最少;内部结构的纤维分散的比较均匀,且纤维分布方向有利于控制裂缝的产生。当BF掺量大于该值时,其抗压和抗折性能大大降低,引起了总孔隙率提高,出现纤维严重结团现象,导致BF/SC内部大孔隙的增加,这是导致混凝土力学性能恶化的主要原因。

关键词：玄武岩纤维 CT 骨架化算法力学性能孔隙结构纤维分布

基于搜索锥算法的纤维分布特征及对BFRC的增强机制

在线全文

学校读者我要写书评

暂无评论

材料导报 2021年第4期35卷 4061-4066页

作者：陈新明史玉良焦华喆靳翔飞吴亚闯谭毅河南理工大学土木工程学院焦作454003

混凝土基体内部纤维的取向、分布及纤维的接触点是影响纤维混凝土力学性能的重要因素,也是目前研究的薄弱环节。本实验研究纤维掺量对玄武岩纤维增强混凝土(BFRC)三轴力学性能的增强机制,采用CT技术和搜索锥算法实现BF的获取与识别,重... 详细信息

混凝土基体内部纤维的取向、分布及纤维的接触点是影响纤维混凝土力学性能的重要因素,也是目前研究的薄弱环节。本实验研究纤维掺量对玄武岩纤维增强混凝土(BFRC)三轴力学性能的增强机制,采用CT技术和搜索锥算法实现BF的获取与识别,重点分析纤维掺量在1.5 kg/m3、3 kg/m3、4.5 kg/m3时BF分布角度、效率指数及接触点变化规律,揭示纤维形态学特征对BFRC力学性能的增强机理。结果表明:纤维掺量保持不变,峰值应力随围压的增大而增大;围压保持2 MPa不变,随着纤维掺量的提高,材料的峰值应力先增加后下降,最佳掺量为3 kg/m3,此时峰值应力为44.48 MPa,相比普通混凝土增加了99.64%。纤维追踪后发现:纤维在混凝土基体中乱向分布;在笛卡尔坐标系Z轴的方向角γ下,80~90°范围内纤维分布较多,纤维倾向于水平放置,近似与竖向裂缝垂直;在方向角α下,30~50°范围内纤维分布较多,对于控制斜向裂缝最为有利;不同掺量下的纤维效率指数eiy分别为0.57、0.65、0.55,进一步说明纤维倾向于平行Y轴;随着纤维掺量的增加(1.5 kg/m^3、3 kg/m^3、4.5 kg/m^3),纤维接触率分别为0%、25%、49%,纤维结团现象愈发明显,三轴强度分别为26.63 MPa、44.48 MPa、42.43 MPa,纤维接触在一定程度上影响BFRC的三轴力学性能。

关键词：玄武岩纤维增强混凝土搜索锥算法纤维接触点三维乱向分布增强机制

在线全文

学校读者我要写书评

暂无评论

奥默替尼的合成

中国医药工业杂志 2016年第8期47卷 981-984页

作者：王永吴亚闯范旭旭张锋刘亚婧沈阳药科大学基于靶点的药物设计与研究教育部重点实验室辽宁沈阳110016

1-甲基-1H-吲哚和2,4-二氯嘧啶通过偶联得3-(2-氯嘧啶-4-基)-1-甲基吲哚,与4-氟-2-甲氧基-5-硝基苯胺-(由4-氟-2-甲氧基苯胺经硝化制得)发生取代反应后,再与N,N,N'-三甲基乙二胺缩合得N-(2-二甲胺基-乙基)-2-甲氧基-N-甲基-N-[4-(1-甲基... 详细信息

1-甲基-1H-吲哚和2,4-二氯嘧啶通过偶联得3-(2-氯嘧啶-4-基)-1-甲基吲哚,与4-氟-2-甲氧基-5-硝基苯胺-(由4-氟-2-甲氧基苯胺经硝化制得)发生取代反应后,再与N,N,N'-三甲基乙二胺缩合得N-(2-二甲胺基-乙基)-2-甲氧基-N-甲基-N-[4-(1-甲基-1H-吲哚-3-基)-嘧啶-2-基]-5-硝基-苯-1,4-二胺,经还原、酰胺化和成盐得抗肿瘤药物奥默替尼。总收率38%(以4-氟-2-甲氧基苯胺计),纯度99.5%。

关键词：非小细胞肺癌表皮生长因子受体(EGFR)抑制剂奥默替尼合成工艺

Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第1期31卷 312-325页

作者： He-xiang wu Jia Qu Lin-zhi wu Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China School of Civil Engineering Northeast Forestry UniversityHarbin150040China

In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inclination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.

关键词： Hourglass lattice sandwich structures Ballistic performances high-velocity Finite element analysis

Resilience-incorporated seismic risk assessment of precast concrete frames with“dry”connections

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2024年第2期23卷 403-425页

作者： wu Chenhao Tang Yuchuan Cao Xuyang wu Gang Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education Nanjing 211102China Department of Civil and Environmental Engineering University of CaliforniaLos AngelesCA 90095USA School of Civil Engineering Southeast UniversityNanjing 211102China College of Civil and Transportation Engineering Hohai UniversityNanjing 210024China

A resilience-incorporated risk assessment framework is proposed and demonstrated in this study to manifest the advantageous seismic resilience of precast concrete frame(PCF)structures with“dry”connections in terms of their low damage and rapid *** framework integrates various uncertainties in the seismic hazard,fragility,capacity,demand,loss functions,and post-earthquake *** this study,the PCF structures are distinguished from ordinary reinforced concrete frame(RCF)structures by characterizing multiple limit states for the PCF based on its unique damage ***,probabilistic story-wise pushover analyses are performed to yield story-wise capacities for the predefined limit *** the seismic resilience analysis,a step-wise recovery model is proposed to idealize the functionality recovery process,with separate considerations of the repair and non-repair *** recovery model leverages the economic loss and downtime to delineate the stochastic post-earthquake recovery curves for the resilience loss *** such,contingencies in the probabilistic post-earthquake repairs are incorporated and the empirical judgments on the recovery parameters are largely *** proposed framework is demonstrated through a comparative study between two“dry”connected PCFs and one RCF designed as alternative structural systems for a prototype *** results from the risk quantification indicate that the PCFs show reduced loss hazards and lower expected losses relative to the ***,the PCF equipped with energy dissipation devices at the“dry”connections largely reduces the expected economic loss,downtime,and resilience loss by 29%,56%,and 60%,respectively,compared to the RCF.

关键词： precast concrete frame non-emulative precast system seismic resilience seismic risk functional recovery

New findings on the influence of El Nino events on tropical cyclone formation

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第3期67卷 892-893页

作者： Liguang wu Department of Atmospheric and Oceanic Sciences Institute of Atmospheric SciencesFudan UniversityShanghai 200438China

Tropical cyclones typically form over warm tropical and subtropical ocean surfaces, as their formation and intensification rely primarily on the energy provided by the ocean. Pioneering research by Gray (1968) revealed that the formation of tropical cyclones requires the sea surface temperature (SST) to be no less than 26.5℃. Consequently, SST is commonly recognized as a crucial parameter among the environmental factors influencing tropical cyclone formation(Gray, 1979;Emanuel and Nolan, 2004).

关键词： tropical cyclone ocean

Two-dimensional semiconductor heterostructures for photocatalytic CO_(2)conversion

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2434-2447页

作者： Yang wu Mingyu wu Yongfu Sun Yi Xie Hefei National Research Center for Physical Sciences at Microscale University of Science and Technology of ChinaHefei 230026China

The CO_(2)reduction into carbon-contained fuel via solar energy offers the powerful tools to realize the zero-emission carbon *** to the intriguing features of the two-dimensional(2D)heterostructures,it is susceptible to modulate the electronic structure as well as the surface geometry for optimizing the photocatalytic CO_(2)*** this perspective,we surveyed the fundamental insights of 2D semiconductor heterostructures,involving the fabrication strategies and classification of the 2D semiconductor ***,we have detailly discussed the overview of 2D semiconductor heterostructure for optimizing CO_(2)photocatalytic influenced factors,including the solar energy utilization,photogenerated carriers separation,and redox reaction ***,we showed the significant advantages of 2D heterostructures in elevating CO_(2)photoreduction performance,focusing on activity,selectivity and *** analyzing the limitations and developments,we ended by putting forward insights into the further researches about the CO_(2)photocatalysts and reactor design,even industrial applications.

关键词： two-dimensional semiconductor heterostructures photocatalysis CO_(2)conversion

Two-layer autonomous intelligence dynamic trajectory planning method based on shield-tunnel ring-geology interactions

在线全文

学校读者我要写书评

暂无评论

Underground Space 2024年第6期19卷 227-250页

作者： Min Hu Bingjian wu Huiming wu Liefeng Pei SILC Business School Shanghai UniversityShanghai 201800China SHU-SUCG Research Centre for Building Industrialization Shanghai 201800China Shanghai Tunnel Engineering Co. Ltd.Shanghai 200032China

To solve the problem that current attitude planning methods do not fully consider the interaction and constraints among the shield,segmental tunnel ring,and geology,and cannot adapt to the changes in the actual engineering environment,or provide feasible long-term and short-term attitude planning,this paper proposes autonomous intelligent dynamic trajectory planning(AI-DTP)to provide tunnel ring and centimeter-layer planning targets for a self-driving shield to meet long-term accuracy and short-term ***-DTP introduces the Frenet coordinate system to solve the problem of inconsistent spatial representation of tunnel data,segmental tunnel ring location,and surrounding geological conditions,designs the long short-term memory attitude prediction model to accurately predict shield attitude change trend based on shield,tunnel,and geology,and uses a heuristic algorithm for trajectory ***-DTP provides ring-layer and centimeter-layer planning objectives that meet the needs of long-term accuracy and short-term correction of shield attitude *** the Hangzhou-Shaoxing Intercity Railroad Tunnel Project in China,the‘‘Zhiyu”shield equipped with the AI-DTP system was faster and more accurate than the manually controlled shield,with a smoother process and better quality of the completed tunnel.

关键词： Shield tunnel Trajectory planning Attitude control Self-driving Machine learning