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Intelligent classification model of surrounding rock of tunnel using drilling and blasting method

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Underground Space 2021年第5期6卷 539-550页

作者： Mingnian Wang Siguang Zhao Jianjun Tong Zhilong Wang Meng Yao jiawang li Wenhao Yi Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China

Classification of surrounding rock is the cornerstone of tunnel design and *** traditional methods are mainly qualitative and manual and require extensive professional knowledge and engineering *** minimize the effect of the empirical judgment on the accuracy of surrounding rock classification,it is necessary to reduce human *** intelligent classification technique based on information technology and artificial intelligence could overcome these *** this regard,using 299 groups of drilling parameters collected automatically using intelligent drill jumbos in tunnels for the Zhengzhou-Wanzhou high-speed railway in China,an intelligent-classification surrounding-rock database is constructed in this *** on a machine learning algorithm,an intelligent classification model is then developed,which has an overall accuracy of 91.9%.Finally,using the core of the model,the intelligent classification system for the surrounding rock of drilled and blasted tunnels is integrated,and the system is carried by intelligent jumbos to perform automatic recording and transmission of drilling parameters and intelligent classification of the surrounding *** approach provides a foundation for the dynamic design and construction(both conventional and intelligent)of tunnels.

关键词： Drilled and blasted tunnel Drilling parameter Machine learning Intelligent classification Surrounding rock

Sulfur doped iron-nitrogen-hard carbon nanosheets as efficient and robust noble metal-free catalysts for oxygen reduction reaction in PEMFC

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Journal of Energy Chemistry 2024年第2期89卷 422-433,I0010页

作者： Bin liu jiawang li Bowen Yan Qi Wei Xingyu Wen Huarui Xie Huan He Pei Kang Shen Zhi Qun Tian Collaborative Innovation Center of Sustainable Energy Materials School of Physical Science and TechnologyGuangxi UniversityGuangxi Key Laboratory of Electrochemical Energy MaterialsState Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite StructuresNanning 530004GuangxiChina

Transition metal-nitrogen-carbon(M-N-C)as a promising substitute for the conventional noble metalbased catalyst still suffers from low activity and durability for oxygen reduction reaction(ORR)in proton exchange membrane fuel cells(PEMFCs).To tackle the issue,herein,a new type of sulfur-doped ironnitrogen-hard carbon(S-Fe-N-HC)nanosheets with high activity and durability in acid media were developed by using a newly synthesized precursor of amide-based polymer with Fe ions based on copolymerizing two monomers of 2,5-thiophene dicarboxylic acid(TDA)as S source and 1,8-diaminonaphthalene(DAN)as N source via an amination *** as-synthesized S-Fe-N-HC features highly dispersed atomic Fe Nxmoieties embedded into rich thiophene-S doped hard carbon nanosheets filled with highly twisted graphite-like microcrystals,which is distinguished from the majority of M-N-C with soft or graphitic carbon *** unique characteristics endow S-Fe-N-HC with high ORR activity and outstanding durability in 0.5 M H_(2)SO_(4).Its initial half-wave potential is 0.80 V and the corresponding loss is only 21 m V after 30,000 ***,its practical PEMFC performance is a maximum power output of 628.0 mW cm^(-2)and a slight power density loss is 83.0 m W cm^(-2)after 200-cycle practical ***,theoretical calculation shows that the activity of Fe Nxmoieties on ORR can be further enhanced by sulfur doping at meta-site near FeN_(4)*** results evidently demonstrate that the dual effect of hard carbon substrate and S doping derived from the precursor platform of amid-polymers can effectively enhance the activity and durability of Fe-N-C catalysts,providing a new guidance for developing advanced M-N-C catalysts for ORR.

关键词： Transition metal-nitrogen-carbon Oxygen reduction reaction Hard carbon Amide based polymer reaction Proton exchange membrane cells

Three-Dimensional Trajectory Tracking Control of Underactuated Autonomous Underwater Vehicles with Input Saturation

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Journal of Shanghai Jiaotong university(Science) 2020年第4期25卷 470-477页

作者： HUANG Hantao ZHOU Jingye DI Qing ZHOU Jiawei li jiawang Faculty of Maritime and Transportation Ningbo UniversityNingbo 315211ZhejiangChina

This paper addresses a three-dimensional(3D)trajectory tracking problem of underactuated autonomous underwater vehicles(AUVs)subjected to input saturation and external *** proposed controller can achieve practical convergence of tracking errors for general reference trajectories,including persistently exciting(PE)time varying trajectories and fixed *** first,a modified error state formulation is introduced to tackle the situation that desired velocities do not satisfy PE ***,on the basis of the backstepping technique and a Nussbaum-type even function,a saturated controller is designed so that the tracking errors can converge to a bounded neighborhood of the *** stability analysis based on Lyapunov theory shows that the tracking errors are globally ultimately uniformly ***,some simulation results illustrate the effectiveness and robustness of the proposed control strategy.

关键词： underactuated autonomous underwater vehicles(AUVs) trajectory tracking control stabilization control input saturation Nussbaum-type function

Isobaric enzymatic assays reveal depth-dependent variation in microbial ectoenzyme activities in the deepest ocean on Earth

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Science China Earth Sciences 2025年第1期68卷 185-194页

作者： Junwei CAO Jiahua WANG Hongge ZHANG Junhao DENG Binbin PAN jiawang CHEN li ZHANG Jiasong FANG College of Oceanography and Ecological Science Shanghai Ocean University Ocean College Zhejiang University Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and Technology

Microbial ectoenzymes play essential roles in the transformation and mineralization of organic matter in the ***, conventional methods for measuring microbial ectoenzyme activities(MEAs) in the deep ocean under atmospheric conditions can misrepresent the metabolic activities of indigenous microbial communities. To overcome this limitation, we measured the activities of three microbial ectoenzymes(aminopeptidase, α-glucosidase, and β-glucosidase) under both atmospheric and in situ pressure conditions in seawater collected using pressure-retaining and non-pressure-retaining samplers in the Challenger Deep, Mariana Trench. In the case of aminopeptidase and α-glucosidase, the highest isobaric MEAs were observed in the surface layer(50 m), followed by those at abyssopelagic depths(4,000–6,000 m) for aminopeptidase, hadal realm(10,903 m)for α-glucosidase, while β-glucosidase activity exhibited the highest value at 10,903 m. Furthermore, the isobaric MEAs in hadal waters were commonly found to be higher than the decompressed counterparts, highlighting the importance of pressure-retaining sampling and isobaric enzymatic assays. The half-saturation constant(Km) showed a general decreasing trend with depth,suggesting that the deep ocean microbes might have adapted to the high-pressure and oligotrophic environment by increasing their ectoenzyme's affinity to substrate. Furthermore, particle-free MEAs contribute more to the total MEAs in the deep ocean than particle-associated MEAs, suggesting the significance of cell-associated and dissolved ectoenzymes in ocean *** study provides a foundation for future investigations of MEAs in the ocean and has important implications for understanding the dynamics of microbially mediated biogeochemical cycling in marine ecosystems.

关键词： Pressure-retaining sampling Microbial ectoenzyme activity Deep-sea microbes High pressure Mariana Trench

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竖轴潮流能水轮机叶片安装位置研究

太阳能学报 2019年第7期40卷 2091-2096页

作者：李广年李家旺宁波大学海运学院

将竖轴潮流能水轮机简化为二维形式,以二维机翼非定常运动数值分析方法为基础,构建多机翼非定常运动的边界元法模型,并在此基础上开发竖轴潮流能水轮机结构受力数值预报方法。利用该方法研究竖轴潮流能水轮机叶片安装位置对水轮机叶片... 详细信息

将竖轴潮流能水轮机简化为二维形式,以二维机翼非定常运动数值分析方法为基础,构建多机翼非定常运动的边界元法模型,并在此基础上开发竖轴潮流能水轮机结构受力数值预报方法。利用该方法研究竖轴潮流能水轮机叶片安装位置对水轮机叶片、水轮机转子受力的影响规律。研究表明:安装位置靠近叶片翼型可提升水轮机的获能效率,安装位置靠近翼型中部可使叶片、转子的受力减小。

关键词：潮流能水轮机叶片安装位置力学性能

Deformation Analysis and Fixture Design of Thin-walled Cylinder in Drilling Process Based on TRIZ Theory

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Mechanical Engineering Science 2021年第1期3卷 57-64页

作者： Fulin WANG Bo SHENG Yongwen WU jiawang li Zhou XU Zhaoxia ZHU College of Mechanical and Vehicle Engineering Hunan UniversityChangshaHunan AECC South Industry limited company ZhuzhouHunan

Thin-walled cylindrical workpiece is easy to deform during machining and clamping processes due to the insufficient ***,it’s also difficult to ensure the perpendicularity of flange holes during drilling *** this paper,the element birth and death technique is used to obtain the axial deformation of the hole through finite element *** measured value of the perpendicularity of the hole was compared with the simulated value to verify then the rationality of the simulation *** reduce the perpendicularity error of the hole in the drilling process,the theory of inventive principle solution(TRIZ)was used to analyze the drilling process of thin-walled cylinder,and the corresponding fixture was developed to adjust the supporting surface height *** different fixture supporting layout schemes were used for numerical simulation of drilling process,and the maximum,average and standard deviation of the axial deformation of the flange holes and their maximum hole perpendicularity errors were comparatively analyzed,and the optimal arrangement was *** results show that the proposed deformation control strategy can effectively improve the drilling deformation of thin-walled cylindrical workpiece,thereby significantly improving the machining quality of the parts.

关键词： Thin-walled cylindrical parts Fixture Deformation analysis Drilling TRIZ theory

基于复杂约束条件的欠驱动AUV三维路径规划

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兵工学报 2022年第6期43卷 1407-1414页

作者：张家闻房浩霖李家旺宁波大学海运学院浙江宁波315211

为解决欠驱动自主水下航行器(AUV)在复杂水域下的三维路径规划和避碰问题,结合欠驱动的运动特性与自身约束条件,提出一种改进的蚁群结合3次B样条曲线拟合的算法,模拟现实海域环境信息进行水下空间环境建模。针对传统蚁群算法规划出的全... 详细信息

为解决欠驱动自主水下航行器(AUV)在复杂水域下的三维路径规划和避碰问题,结合欠驱动的运动特性与自身约束条件,提出一种改进的蚁群结合3次B样条曲线拟合的算法,模拟现实海域环境信息进行水下空间环境建模。针对传统蚁群算法规划出的全局路径转角大、曲折多所造成的欠驱动AUV舵轮使用寿命低的问题,采用垂直面安全域设置的方法,设计基于低崎岖度的适应度函数结合路径长度与平缓度的双边评价体系规划出全局路径。采用3次B样条曲线,基于原型值点及目标点速度矢量约束拟合出一条曲率连续、无碰撞的优化路径。仿真结果表明,在保证收敛速度和全局搜索能力的前提下,所规划的路径合理,满足欠驱动AUV运动条件。

关键词：欠驱动自主水下航行器改进蚁群算法 B样条曲线理论速度矢量约束

Heterogeneity identification method for surrounding rock of large-section rock tunnel faces based on support vector machine

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Railway Sciences 2023年第1期2卷 48-67页

作者： Wenhao Yi Mingnian Wang Jianjun Tong Siguang Zhao jiawang li Dengbin Gui Xiao Zhang Southwest Jiaotong University ChengduChina

Purpose–The purpose of the study is to quickly identify significant heterogeneity of surrounding rock of tunnel face that generally occurs during the construction of large-section rock tunnels of high-speed ***/methodology/approach–Relying on the support vector machine(SVM)-based classification model,the nominal classification of blastholes and nominal zoning and classification terms were used to demonstrate the heterogeneity identification method for the surrounding rock of tunnel face,and the identification calculation was carried out for the five test ***,the suggestions for local optimization of the support structures of large-section rock tunnels were put ***–The results show that compared with the two classification models based on neural networks,the SVM-based classification model has a higher classification accuracy when the sample size is small,and the average accuracy can reach 87.9%.After the samples are replaced,the SVM-based classification model can still reach the same accuracy,whose generalization ability is ***/value–By applying the identification method described in this paper,the significant heterogeneity characteristics of the surrounding rock in the process of two times of blasting were identified,and the identification results are basically consistent with the actual situation of the tunnel face at the end of blasting,and can provide a basis for local optimization of support parameters.

关键词： Rock tunnel Surrounding rock Heterogeneity Support vector machine High-speed railway

Research on degradation mechanism of trichlorobenzene and Hg^(0) by nonthermal plasma catalysis

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Plasma Science and Technology 2023年第11期25卷 114-121页

作者：边文璟竹涛朱繁崔岩王建华史光李加旺郝景章 Institute of Environmental Protection and HVAC Engineering Technology MCC Capital Engineering&Research Incorporation Limited(CERI)Beijing 100176People’s Republic of China Institute of Atmospheric Environmental Management and Pollution Control China University of Mining&TechnologyBeijing 100083People’s Republic of China

Aiming at mercury and dioxin in fire coal gas as research objects,nonthermal plasma(NTP)catalytic technology was used to investigate the degradation effect of operating condition parameters on mixed pollutants in mixed flue gas condition,and to explore the synergistic degradation of Hg0and TCB(1,2,3-trichlorobenzene,TCB)under mixed flue gas *** research results showed that the conversion efficiency of mercury and TCB increased with the additional output of voltage,and decreased with the increase of the gas flow *** optimal reaction conditions:voltage=17 k V,frequency=300 Hz,gas flow rate=21 min^(-1),the conversion efficiency of Hg^(0)and TCB reached the highest 91.4%and 84.98%,*** the NTP catalytic system,active free radicals played an important role in the synergistic conversion of mercury and TCB,which have a competitive effect,to make the conversion efficiency of mixed pollutants lower than a single *** the mixed flue gas condition,the mixed gas has an inhibitory effect on the synergistic conversion of mercury and *** modeling of NTP catalytic synergistic reaction was *** three conditions of TCB,mercury and TCB,mixed simulated flue gas,the NTP catalytic technology showed a quasi-firstorder kinetic reaction for the degradation of *** to the synergistic effect of NTP and composites,the transformation and degradation of TCB mainly included two processes:TCB and ring opening,and Hg^(0)was finally oxidized to Hg^(2+).

关键词： fire coal Hg°and TCB non-thermal plasma catalytic technology radical kinetic modeling(Some figures may appear in colour only in the online journal)