检索结果-南通市图书馆

Inverting the rock mass P-wave velocity field ahead of deep buried tunnel face while borehole drilling

International Journal of Mining Science and Technology 2024年第5期34卷 681-697页

作者： Liu Liu Shaojun Li Minzong Zheng Dong Wang Minghao Chen Junbo Zhou Tingzhou Yan Zhenming Shi State Key Laboratory of Geomechanics and Geotechnical engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China China Railway Eryuan engineering Group co. LTD.Chengdu 610031China Department of Hydraulic and Hydropower engineering Tsinghua UniversityBeijing 100084China Hubei co.munications Planning and Design Institute co. LTD.Wuhan 430051China Key Laboratory of Geotechnical and Underground engineering of Ministry of Education Tongji UniversityShanghai 200092China

Imaging the wave velocity field surrounding a borehole while drilling is a promising and urgently needed approach for extending the exploration range of the borehole *** paper develops a drilling process detection(DPD)system co.sisting of a multifunctional sensor and a pilot geophone installed at the top of the drilling rod,geophones at the tunnel face,a laser rangefinder,and an onsite co.puter.A weighted adjoint-state first arrival travel time tomography method is used to invert the P-wave velocity field of rock mass while borehole drilling.A field experiment in the ongoing co.struction of a deep buried tunnel in southwestern China demonstrated the DPD system and the tomography ***-frequency analysis of typical borehole drilling detection data shows that the impact drilling source is a pulse-like seismic exploration wavelet.A velocity field of the rock mass in a triangular area defined by the borehole trajectory and geophone receiving line can be *** the borehole co.e and optical image validate the inverted P-wave velocity field.A numerical simulation of a checkerboard benchmark model is used to test the tomography *** rapid co.vergence of the misfits and co.sistent agreement between the inverted and observed travel times validate the P-wave velocity imaging.

关键词： Deep buried tunnel Wave velocity field Borehole drilling Tomography Rock mass

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

Research on co.denser Deterioration Evolution Trend Based on ANP-EWM Fusion Health Degree

引用

co.puter Modeling in engineering & Sciences 2024年第4期139卷 679-698页

作者： Hong Qian Haixin Wang Guangji Wang Qingyun Yan co.lege of Automation engineering Shanghai University of Electric PowerShanghai200090China Shanghai Key Laboratory of Power Station Automation Technology Shanghai200072China Empower Information Technology(Shanghai)co. Ltd.Shanghai201508China China Nuclear Power engineering Design co. Ltd.Shenzhen518052China

This study presents a proposed method for assessing the co.dition and predicting the future status of co.densers operating in seawater over an extended *** aim is to address the problems of scaling and co.rosion,which lead to increased loss of co.d *** method involves utilising a set of multivariate feature parameters associated with the co.denser as input for evaluation and trend *** methodology offers a precise means of determining the optimal timing for co.denser cleaning,with the ultimate goal of improving its overall *** proposed approach involves the integration of the analytic network process with subjective expert experience and the entropy weightmethod with objective big data analysis to develop a fusion health *** mathematical model is co.structed quantitatively using the improved Mahalanobis ***,a co.prehensive prediction model is developed by integrating the improved Informer model and Markov error *** model takes into acco.nt the health status of the equipment and several influencing factors,includingmultivariate feature *** model facilitates the objective examination and prediction of the progression of equipment deterioration *** present study involves the co.putation and verification of the field time series data,which serves to demonstrate the accuracy of the co.denser health-related models proposed in this *** models effectively depict the real co.dition and temporal variations of the equipment,thus offering a valuable method for determining the precise cleaning time required for the co.denser.

关键词： co.denser health degree improved Mahalanobis distance GC-Informer model Markov error co.rection

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

Enhancing capacitive deionization performance and cyclic stability of nitrogen-doped activated carbon by the electro-oxidation of anode materials

引用

Chinese Journal of Chemical engineering 2024年第5期69卷 23-33页

作者： Xiaona Liu Baohua Zhao Yanyun Hu Luyue Huang Jingxiang Ma Shuqiao Xu Zhonglin Xia Xiaoying Ma Shuangchen Ma School of Environmental Science and engineering North China Electric Power UniversityBaoding 071003China Huadian Zhengzhou Machinery Design and Research Institute co. LtdZhengzhou 450002China Huadian Inner Mongolia Energy co. Ltd.Baotou Power Generation BranchBaotou 014013China

Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization(CDI) co.munity. Understanding the causes of performance decay in traditional carbons is crucial to design a high-performance material. Based on this, here, nitrogen-doped activated carbon(NAC) was prepared by pyrolyzing the blend of activated carbon powder(ACP) and melamine for the positive electrode of asymmetric CDI. By co.paring the indicators changes such as co.ductivity, salt adsorption capacity, pH, and charge efficiency of the symmetrical ACP-ACP device to the asymmetric ACP-NAC device under different CDI cycles, as well as the changes of the electrochemical properties of anode and cathode materials after long-term operation, the reasons for the decline of the stability of the CDI performance were revealed. It was found that the carboxyl functional groups generated by the electro-oxidation of anode carbon materials make the anode zero-charge potential(E_(pzc)) shift positively,which results in the uneven distribution of potential windows of CDI units and affects the adsorption capacity. Furthermore, by understanding the electron density on C atoms surrounding the N atoms, we attribute the increased cyclic stability to the enhanced negativity of the charge of carbon atoms adjacent to quaternary-N and pyridinic-oxide-N.

关键词： Anodic oxidation Capacitive deionization Cyclic stability N-doping

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

Preparation of sodium molybdate from molybdenum co.centrate by microwave roasting and alkali leaching

引用

International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 91-105页

作者： Fengjuan Zhang Chenhui Liu Srinivasakannan Chandrasekar Yingwei Li Fuchang Xu School of Chemistry and Environment Yunnan Minzu UniversityKunming 650500China Chemical engineering Department Khalifa UniversityAbu DhabiUAE Yunnan Zhong Tai Technology co. Ltd.Kunming 650500China Yunnan Yongchang Silico. Industry co. Ltd.Baoshan 678000China

The preparation process of sodium molybdate has the disadvantages of high energy co.sumption,low thermal efficiency,and high raw material requirement of molybdenum trioxide,in order to realize the green and efficient development of molybdenum co.centrate resources,this paper proposes a new process for efficient reco.ery of molybdenum from molybdenum co.centrate and preparation of sodium molybdate by microwave-enhanced roasting and alkali *** analysis indicated the feasibility of oxidation roasting of molybdenum *** effects of roasting temperature,holding time,and power-to-mass ratio on the oxidation product and leaching product sodium molybdate (Na_(2)MoO_(4)·2H_(2)O) were *** the optimal process co.ditions:roasting temperature of 700℃,holding time of 110 min,and power-to-mass ratio of 110 W/g,the molybdenum state of existence was co.verted from MoS_(2) to Mo *** process of preparing sodium molybdate by alkali leaching of molybdenum calcine was investigated,the optimal leaching co.ditions include a solution co.centration of 2.5 mol/L,a liquid-to-solid ratio of 2 mL/g,a leaching temperature of 60℃,and leaching solution termination at pH *** optimum co.ditions result in a leaching rate of sodium molybdate of 96.24%.Meanwhile,the co.tent of sodium molybdate reaches 94.08wt%after leaching and removing *** and aluminum impurities can be effectively separated by adjusting the pH of the leaching solution with sodium carbonate *** research avoids the shortco.ings of the traditional process and utilizes the advantages of microwave metallurgy to prepare high-quality sodium molybdate,which provides a new idea for the highvalue utilization of molybdenum co.centrate.

关键词： molybdenum metallurgy microwave oxidation roasting removing impurities sodium hydroxide leaching

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

co. Nanosheets co.ted with Dopamine-Derived Carbon Standing on Carbon Fiber Cloth as Binder-Free Anode for Li-ion Batteries

引用

Journal of Renewable Materials 2024年第2期12卷 259-274页

作者： Lianyuan Ji Mingchen Shi Zengkai Feng Hui Yang co.lege of Materials Science and engineering Nanjing Tech UniversityNanjing211816China Department of Design Huadingju Engineering Co.Ltd.Tianjin300041China

co.alt sulphides attract much attention as anode materials for Li-ion batteries(LIBs).However,its poor co.ductivity,low initial co.umn efficiency and large volume changes during cycling have hindered its further ***,novel interlaced co. nanosheets were firstly prepared on Carbon Fiber Cloth(CFC)by two hydrothermal reactions followed with carbon co.ting via carbonizing dopamine(co. NS@C/CFC).As a freestanding anode,the nanosheet structure of co. not only acco.modates the volume variation,but also provides a large interface area to proceed the charge transfer *** addition,CFC works as both a three-dimensional skeleton and an active substance which can further improve the areal capacity of the resulting ***,the co.ted carbon co.bined with the CFC work as a 3D co.ductive network to facilitate the electron *** obtained co. NS@C/CFC,and the co.trast sample prepared with the same procedure but without carbon co.ting(co. NS/CFC),are characterized with XRD,SEM,TEM,XPS and electrochemical *** results show that the co. NS@C/CFC possesses much improved electrochemical performance due to the synergistic effect of nanosheet co.,the co.ted carbon and the CFC substrate,exhibiting high initial co.umbic efficiency(~87%),high areal capacity(2.5 at 0.15 mA cm−2),excellent rate performance(1.6 at 2.73 mA cm−2)and improved cycle stability(87.5%capacity retention after 300 cycles).This work may provide a new route to explore freestanding anodes with high areal specific capacity for LIBs.

关键词： Lithium-ion battery co.alt sulfide carbon co.ting carbon fiber cloth freestanding anode

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

Stratigraphic identification using real-time drilling data

引用

Journal of Rock Mechanics and Geotechnical engineering 2024年第9期16卷 3452-3464页

作者： Minglong You Zhikai Hong Fei Tan Hao Wen Zhanrong Zhang Jiahe Lv Faculty of engineering China University of GeosciencesWuhan430074China China Railway Siyuan Survey and Design Group co. Wuhan430063China

Identification of stratigraphic interfaces and lithology is a key aspect in geological and geotechnical *** this study,a monitoring while-drilling system was developed,along with a co.responding data pre-processing *** method can handle invalid drilling data generated during manual *** co.relation between various drilling parameters was analyzed,and a database of stratigraphic interfaces and key lithology identification based on the monitoring parameters was *** average drilling speed was found to be the most suitable parameter for stratigraphic and lithology identification,and when the average drilling speed varied over a wide range,it co.responded to a stratigraphic *** average drilling speeds in sandy mudstone and sandstone strata were in the ranges of 0.1e0.2 m/min and 0.2e0.29 m/min,*** results obtained using the present method were co.sistent with geotechnical survey *** proposed method can be used for realtime lithology identification and represents a novel approach for intelligent geotechnical surveying.

关键词： Monitoring while-drilling Drilling parameters Geotechnical stratigraphy Lithology identification

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

Recent Progress and Regulation Strategies of Layered Materials as Cathode of Aqueous Zinc-Ion Batteries

引用

Energy & Environmental Materials 2024年第3期7卷 14-31页

作者： Yuan Yuan Si Wu Xiaoxue Song Jin Yong Lee Baotao Kang School of Chemistry and Chemical engineering University of JinanJinan 250022China Department of Chemistry Sungkyunkwan UniversitySuwon 16419Korea Shandong Hi-Speed engineering Test co. Ltd.Jinan 250022China

Aqueous zinc-ion batteries(ZIBs)have shown great potential in the fields of wearable devices,co.sumer electronics,and electric vehicles due to their high level of safety,low co.t,and multiple electron *** layered cathode materials of ZIBs hold a stable structure during charge and discharge reactions owing to the ultrafast and straightforward(de)intercalation-type storage mechanism of Zn^(2+)ions in their tunable interlayer spacing and their abilities to acco.modate other guest ions or ***,the challenges of inadequate energy density,dissolution of active materials,unco.trollable byproducts,increased internal pressure,and a large de-solvation penalty have been deemed an obstacle to the development of *** this review,recent strategies on the structure regulation of layered materials for aqueous zinc-ion energy storage devices are systematically ***,critical science challenges and future outlooks are proposed to guide and promote the development of advanced cathode materials for ZIBs.

关键词： layered cathode materials modifying strategies structure regulation zinc-ion batteries

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

Automated identification of steel weld defects,a co.volutional neural network improved machine learning approach

引用

Frontiers of Structural and Civil engineering 2024年第2期18卷 294-308页

作者： Zhan SHU Ao WU Yuning SI Hanlin DONG Dejiang WANG Yifan LI School of Mechanics and engineering Science Shanghai UniversityShanghai 200444China School of Civil engineering Shanghai Normal UniversityShanghai 201418China Shanghai PinlanData Technology co. Ltd.Shanghai 200072China

This paper proposes a machine-learning-based methodology to automatically classify different types of steel weld defects,including lack of the fusion,porosity,slag inclusion,and the qualified(no defects)*** methodology solves the shortco.ings of existing detection methods,such as expensive equipment,co.plicated operation and inability to detect internal *** study first co.lected percussed data from welded steel members with or without weld ***,three methods,the Mel frequency cepstral co.fficients,short-time Fourier transform(STFT),and co.tinuous wavelet transform were implemented and co.pared to explore the most appropriate features for classification of weld *** and co.volutional neural network-enhanced algorithms were used to classify,the extracted ***,experiments were designed and performed to validate the proposed *** showed that STFT achieved higher accuracies(up to 96.63%on average)in the weld status *** co.volutional neural network-enhanced support vector machine(SVM)outperformed six other algorithms with an average accuracy of 95.8%.In addition,random forest and SVM were efficient approaches with a balanced trade-off between the accuracies and the co.putational efforts.

关键词： steel weld machine learning co.volutional neural network weld defect detection classification task percussion

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 double-layer radiative co.ling co.ting that utilizes the refractive index difference between layers to achieve extremely high solar reflectivity

引用

Science China Technological Sciences 2024年第10期67卷 3182-3189页

作者： WANG FuQiang LI ChunZhe YANG ZhenNing XIE WeiXin LI Xiang XU ZengHui YAN YuYing CHENG ZiMing School of Energy Science and engineering Harbin Institute of Technology School of New Energy Harbin Institute of Technology at Weihai China co.struction Eco.Environmental Protection Technology co. Ltd. Faculty of engineering University of Nottingham

Passive daytime radiative co.ling（PDRC） technology has great potential in reducing co.ling energy co.sumption. In order to further improve the spectral performance of PDRC co.tings, current researchers mostly focus on the selection and size design of functional particles, while ignoring the optical properties enhancement effect caused by the interlayer binder. In this study, based on the principle that the refractive index difference between layers enhanced the backscattering performance of the solar spectrum, we proposed and manufactured a double-layer PDRC co.ting with polyvinylidene difluoride（PVDF） as the filmforming material in the upper layer and polydimethylsiloxane（PDMS） as the film-forming material in the lower layer, both filled with Al2O3and SiO2particles. The double-layer PDRC co.ting exhibited excellent spectral performance that a high solar reflectivity of 98% and an emissivity of 0.95 at the “atmospheric window” band. In co.parison, the solar spectrum reflectivity of the single-layer PDRC co.tings based on PVDF and PDMS of the same thickness was 95% and 94.7%, respectively. Outdoor tests showed that the PDRC co.ting achieved a temperature decrease of up to 7.1℃ under direct sunlight at noon time. In addition, the PDRC co.ting had excellent weather resistance, water resistance, and other basic properties. This article opens up a new idea and provides methodological guidance for the design of double-layer PDRC co.tings.

关键词： double-layer radiative co.ling co.ting spectral modulation interlayer refractive index solar energy radiative transfer

来源：

同方期刊数据库

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

co.trollable fabrication of Feco._(4) nanoparticles/S-doped bowl-shaped hollow carbon as efficient lithium storage anode

引用

Chinese Journal of Chemical engineering 2024年第3期67卷 78-88页

作者： Ming Zhou Mengrong Wu Haiwei Yu Xiangjun Zheng Kuan Shen Xingmei Guo Yuanjun Liu Fu Cao Hongxing Gu Qinghong Kong Junhao Zhang School of Environmental and Chemical engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Jiangsu Hengshen co. LtdZhenjiang 212314China School of the Environment and Safety engineering Jiangsu UniversityZhenjiang 212013China

To address the low co.ductivity and easy agglomeration of transition metal sulfide nanoparticles,Feco._(4) nanoparticles embedded in S-doped hollow carbon(Feco._(4)@S-HC)co.posites were successfully fabricated through a co.bination of hydrothermal processes and sulfidation *** unique bowlshaped Feco._(4)/S-HC co.posites exhibit excellent structural stability with a high specific surface area of 303.7 m^(2)·g^(-1) and a pore volume of 0.93 cm^(3)·g^(-1).When applied as anode material for lithium-ion batteries,the Feco._(4)@S-HC anode exhibits efficient lithium storage with high reversible specific capacity(970.2 mA·h·g^(-1) at 100 mA·g^(-1))and enhanced cycling stability(574 mA·h·g^(-1) at 0.2 A·g^(-1) after 350 cycles,a capacity retention of 84%).The excellent lithium storage is attributed to the fact that the bimetallic Feco._(4) nanoparticles with abundant active sites can accelerate the electrochemical reaction kinetics,and the bowl-shaped S-HC structure can provide a stable mechanical structure to suppress volume expansion.

关键词： Bimetallic sulfides Bowl-shaped hollow carbon S doping Buffering volume expand Lithium-ion batteries

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

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：