检索结果-南通市图书馆

Chinese Journal of Mechanical Engineering 2024年第1期37卷 203-214页

作者： Xiaokang Huang Xiaoyong Tian Qi Zhong Shunwen He cunbao huo Yi Cao Zhiqiang Tong Dichen Li State Key Laboratory of Manufacturing Systems Engineering Xi’an Jiaotong UniversityXian 710049China

Improvement of fabrication efficiency and part performance was the main challenge for the large-scale powder bed fusion(PBF)process.In this study,a dynamic monitoring and feedback system of powder bed temperature field using an infrared thermal imager has been established and integrated into a four-laser PBF equipment with a working area of 2000 mm×2000 mm.The heat-affected zone(HAZ)temperature field has been controlled by adjusting the scanning speed dynamically.Simultaneously,the relationship among spot size,HAZ temperature,and part performance has been established.The fluctuation of the HAZ temperature in four-laser scanning areas was decreased from 30.85℃to 17.41℃.Thus,the consistency of the sintering performance of the produced large component has been improved.Based on the controllable temperature field,a dynamically adjusting strategy for laser spot size was proposed,by which the fabrication efficiency was improved up to 65.38%.The current research results were of great significance to the further industrial applications of large-scale PBF equipment.

关键词： Powder bed fusion Efficiency Large-scale Spot size Heat-affected zone(HAZ)

Effects of fracture evolution and non-Darcy flow on the thermal performance of enhanced geothermal system in 3D complex fractured rock

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

International Journal of Mining Science and Technology 2024年第4期34卷 443-459页

作者： Yachen Xie Jianxing Liao Pengfei Zhao Kaiwen Xia cunbao Li Department of Civil and Mineral Engineering University of TorontoToronto M5S1A4Canada College of Water Resources and Hydropower Sichuan UniversityChengdu 610225China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsWuhan 430071China College of Civil Engineering Guizhou UniversityGuiyang 550025China Institute of Geosafety School of Engineering and TechnologyChina University of GeosciencesBeijing 100083China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering Shenzhen UniversityShenzhen 518060China

In fractured geothermal reservoirs,the fracture networks and internal fluid flow behaviors can significantly impact the thermal performance.In this study,we proposed a non-Darcy rough discrete fracture network(NR-DFN)model that can simultaneously consider the fracture evolution and non-Darcy flow dynamics in studying the thermo-hydro-mechanical(THM)coupling processes for heat extraction in geothermal reservoir.We further employed the model on the Habanero enhanced geothermal systems(EGS)project located in Australia.First,our findings illustrate a clear spatial-temporal variation in the thermal stress and pressure perturbations,as well as uneven spatial distribution of shear failure in 3D fracture networks.Activated shear failure is mainly concentrated in the first fracture cluster.Secondly,channeling flow have also been observed in DFNs during heat extraction and are further intensified by the expansion of fractures driven by thermal stresses.Moreover,the combined effect of non-Darcy flow and fracture evolution triggers a rapid decline in the resulting heat rate and temperature.The NR-DFN model framework and the Habanero EGS's results illustrate the importance of both fracture evolution and non-Darcy flow on the efficiency of EGS production and have the potential to promote the development of more sustainable and efficient EGS operations for stakeholders.

关键词： Coupled THM model Non-Darcy flow Deformable DFN Enhanced geothermal systems

A novel box-counting method for quantitative fractal analysis of threedimensional pore characteristics in sandstone

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2024年第4期34卷 479-489页

作者： Huiqing Liu Heping Xie Fei Wu cunbao Li Renbo Gao State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China School of Resources and Safety Engineering Chongqing UniversityChongqing 400030China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Shenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Deep Underground Engineering Sciences and Green Energy College of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518060China

Fractal theory offers a powerful tool for the precise description and quantification of the complex pore structures in reservoir rocks,crucial for understanding the storage and migration characteristics of media within these rocks.Faced with the challenge of calculating the three-dimensional fractal dimensions of rock porosity,this study proposes an innovative computational process that directly calculates the three-dimensional fractal dimensions from a geometric perspective.By employing a composite denoising approach that integrates Fourier transform(FT)and wavelet transform(WT),coupled with multimodal pore extraction techniques such as threshold segmentation,top-hat transformation,and membrane enhancement,we successfully crafted accurate digital rock models.The improved box-counting method was then applied to analyze the voxel data of these digital rocks,accurately calculating the fractal dimensions of the rock pore distribution.Further numerical simulations of permeability experiments were conducted to explore the physical correlations between the rock pore fractal dimensions,porosity,and absolute permeability.The results reveal that rocks with higher fractal dimensions exhibit more complex pore connectivity pathways and a wider,more uneven pore distribution,suggesting that the ideal rock samples should possess lower fractal dimensions and higher effective porosity rates to achieve optimal fluid transmission properties.The methodology and conclusions of this study provide new tools and insights for the quantitative analysis of complex pores in rocks and contribute to the exploration of the fractal transport properties of media within rocks.

关键词： 3D fractal analysis Fractal dimension Rock pore structure Box-counting method Permeability simulation Computational geosciences

Anisotropic time-dependent behaviors of shale under direct shearing and associated empirical creep models

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1262-1279页

作者： Yachen Xie Michael Z.Hou Hejuan Liu cunbao Li Shenzhen Key Laboratory of Deep Engineering Sciences and Green Energy Shenzhen UniversityShenzhen518060China Institute of Subsurface Energy Systems Clausthal University of TechnologyClausthal-Zellerfeld38678Germany State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

Understanding the anisotropic creep behaviors of shale under direct shearing is a challenging issue.In this context,we conducted shear-creep and steady-creep tests on shale with five bedding orientations (i.e.0°,30°,45°,60°,and 90°),under multiple levels of direct shearing for the first time.The results show that the anisotropic creep of shale exhibits a significant stress-dependent behavior.Under a low shear stress,the creep compliance of shale increases linearly with the logarithm of time at all bedding orientations,and the increase depends on the bedding orientation and creep time.Under high shear stress conditions,the creep compliance of shale is minimal when the bedding orientation is 0°,and the steady-creep rate of shale increases significantly with increasing bedding orientations of 30°,45°,60°,and 90°.The stress-strain values corresponding to the inception of the accelerated creep stage show an increasing and then decreasing trend with the bedding orientation.A semilogarithmic model that could reflect the stress dependence of the steady-creep rate while considering the hardening and damage process is proposed.The model minimizes the deviation of the calculated steady-state creep rate from the observed value and reveals the behavior of the bedding orientation's influence on the steady-creep rate.The applicability of the five classical empirical creep models is quantitatively evaluated.It shows that the logarithmic model can well explain the experimental creep strain and creep rate,and it can accurately predict long-term shear creep deformation.Based on an improved logarithmic model,the variations in creep parameters with shear stress and bedding orientations are discussed.With abovementioned findings,a mathematical method for constructing an anisotropic shear creep model of shale is proposed,which can characterize the nonlinear dependence of the anisotropic shear creep behavior of shale on the bedding orientation.

关键词： Rock anisotropy Direct shear creep Creep compliance Steady-creep rate Empirical model Creep constitutive model

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

铜基载氧体催化电厂烟气脱氧研究

燃料化学学报（中英文） 2024年第6期52卷 839-849页

作者：司马皓王雪峰邓存宝太原理工大学安全与应急管理工程学院山西太原030024

电厂烟气主要成分为N_(2)、CO_(2)和部分O_(2),将电厂烟气注入矿井采空区可实现CO_(2)封存,并替代注氮气防治遗煤自燃,但是烟气中的O_(2)是造成遗煤自燃的因素之一。因此,亟待开发一种经济有效的催化剂来脱除电厂烟气中的O_(2)。本研究... 详细信息

电厂烟气主要成分为N_(2)、CO_(2)和部分O_(2),将电厂烟气注入矿井采空区可实现CO_(2)封存,并替代注氮气防治遗煤自燃,但是烟气中的O_(2)是造成遗煤自燃的因素之一。因此,亟待开发一种经济有效的催化剂来脱除电厂烟气中的O_(2)。本研究采用共沉淀法,通过调变载体和负载量可控制备了铜基催化剂和系列xCuO/CeO_(2)催化剂,利用BET、XRD、ICP、TEM、H_(2)-TPR和XPS等手段对催化剂进行了表征,并建立催化剂结构与催化电厂烟气脱氧性能之间的构效关系。结果表明,CeO_(2)的加入提高了CuO的分散性、增加了催化剂的氧空位,提高了催化剂的活性和还原氧化性能,Cu-Ce界面结构的协同效应促进了还原氧化过程,表现出良好的活性和循环稳定性。30CuO/CeO_(2)由于其CuO颗粒尺寸最小、分散性最高、氧空位浓度最高,表现出较优的催化电厂烟气脱氧性能。本研究为开发低成本可循环使用、高活性和高稳定性的脱氧催化剂提供了参考。

关键词：化学链燃烧 CuO/CeO_(2) 氧化还原界面结构氧空位

直接剪切下页岩的各向异性破坏特征和强度预测模型

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

工程科学与技术 2024年第2期56卷 257-267页

作者：叶春烽谢和平李存宝深圳大学深地工程智能建造与健康运维全国重点实验室广东深圳518060 重庆大学煤矿灾害动力学与控制全国重点实验室重庆400044

了解页岩剪切破坏特性对页岩气储层改造和井壁稳定性控制具有重要意义。然而,由于页岩本身的各向异性属性,页岩的剪切破坏行为复杂。本文对6种不同层理倾角(0°、30°、60°、90°、120°和150°)的立方体页岩进行了系统的直接剪切破坏... 详细信息

了解页岩剪切破坏特性对页岩气储层改造和井壁稳定性控制具有重要意义。然而,由于页岩本身的各向异性属性,页岩的剪切破坏行为复杂。本文对6种不同层理倾角(0°、30°、60°、90°、120°和150°)的立方体页岩进行了系统的直接剪切破坏测试,详细分析了在层理弱面影响下页岩的剪切应力–剪切位移、抗剪强度、剪切模量和破坏模式的各向异性特征。结果表明:页岩的剪切破坏表现为典型的非线性渐进破坏特征;页岩平均抗剪强度和剪切模量随层理倾角的增加均呈现“M”型变化趋势;在90°~180°的层理倾角区间,平均抗剪强度的极值差明显大于0°~90°区间,而剪切模量近似关于90°呈对称变化;当层理倾角从0°变化到180°时,页岩剪切各向异性行为呈现非对称演化规律。在层理倾角和直接剪切荷载作用下,页岩的破坏模式有3类:层理倾角为0°时,沿层理面剪切滑移破坏;层理倾角为30°、60°和90°时,表现为穿透层理和基质的剪切滑移破坏;其他倾角下呈现穿透层理和基质的剪切滑移与沿层理的拉伸劈裂相结合的复合破坏。基于试验结果和组构张量,构建了一个可考虑页岩本征各向异性和剪应力诱导各向异性影响的直接剪切破坏准则,其理论预测值与试验结果的平均偏差率低于3%,能够定量表征黏聚力和摩擦系数的各向异性程度,合理评估页岩直接剪切强度对外加法向应力的敏感性,可推广应用于理论表征所有层状岩土材料的直接剪切强度。

关键词：各向异性直接剪切抗剪强度非对称破坏模式剪切破坏准则

经验知识监督的RC墩柱力学性能神经网络分析方法

在线全文

学校读者我要写书评

暂无评论

工程科学与技术 2024年第1期56卷 35-43页

作者：刘振亮李素超赵存宝石家庄铁道大学安全工程与应急管理学院河北石家庄050043 河北省大型结构健康诊断与控制重点实验室河北石家庄050043 哈尔滨工业大学(威海)土木工程系山东威海264209

基于试验或数值模拟的单一墩柱力学性能分析方法难以兼顾计算精度和效率,纯数据驱动的分析方法存在可解释性差和对数据依赖性强等问题。为此,本文通过研究钢筋混凝土(RC)墩柱力学性能试验数据、经验知识和机器学习的融合机制,提出了经... 详细信息

基于试验或数值模拟的单一墩柱力学性能分析方法难以兼顾计算精度和效率,纯数据驱动的分析方法存在可解释性差和对数据依赖性强等问题。为此,本文通过研究钢筋混凝土(RC)墩柱力学性能试验数据、经验知识和机器学习的融合机制,提出了经验知识监督的RC墩柱力学性能神经网络(knowledge-guided neural network,KGNN)分析方法。首先,建立了包含761组RC墩柱拟静力试验样本的数据库;随后,基于经验知识分析了RC墩柱主要特征对其力学性能的影响规律,构建了相应的数学表征方法;最后,将RC墩柱试验数据及经验知识融入人工神经网络架构和训练过程,建立了高精度、可解释、可通用且不依赖大量训练数据的RC墩柱力学性能KGNN分析模型。本文提出的KGNN分析方法与纯数据驱动神经网络(BPNN)的结果对比表明:BPNN在测试集上表现更好,在分析墩柱承载力时均方根误差(E)和拟合系数(R^(2))分别为0.070和0.978,KGNN模型的E和R^(2)分别为0.108和0.942;但由于BPNN所预测的墩柱特征对承载力的影响规律与经验知识并不吻合,即未能准确反映墩柱特征与其力学性能间的关系,BPNN模型发生了过拟合;而KGNN方法不仅可以快速准确获得RC墩柱力学性能,且预测规律与经验知识吻合较好,具有更高的可靠性和实用性。因此,融合试验数据与经验知识的神经网络有望成为一种新的RC结构力学性能分析方法。

关键词：钢筋混凝土墩柱数物融合的神经网络经验知识力学性能试验数据库

在线全文

学校读者我要写书评

暂无评论

单纯疱疹病毒膜融合蛋白相互作用的研究进展

中国生物制品学杂志 2024年第1期37卷 92-98页

作者：胡婧萍(综述) 刘存宝(审校) 中国医学科学院北京协和医学院医学生物学研究所云南昆明650500

单纯疱疹病毒(herpes simplex virus,HSV)是一种普遍存在的含双链DNA的包膜病毒。单纯疱疹病毒-1型(HSV-1)感染人体可引起口唇炎、结膜炎及脑炎等疾病,HSV-2感染可导致多年龄段的生殖器疱疹,这两种病毒均可在人体建立终身潜伏感染。HSV... 详细信息

单纯疱疹病毒(herpes simplex virus,HSV)是一种普遍存在的含双链DNA的包膜病毒。单纯疱疹病毒-1型(HSV-1)感染人体可引起口唇炎、结膜炎及脑炎等疾病,HSV-2感染可导致多年龄段的生殖器疱疹,这两种病毒均可在人体建立终身潜伏感染。HSV的多种膜蛋白相互作用触发膜融合是病毒进入宿主细胞的重要方式,本文通过分析糖蛋白的结构及其相互作用方式对由gD、gH、gL、gB 4种病毒糖蛋白组成的HSV保守的核心融合机制作一综述。由于目前全球尚无HSV疫苗获批上市,因此研究HSV与宿主细胞的作用方式对研发疫苗具有重要意义。

关键词：单纯疱疹病毒糖蛋白结构感染机制

在线全文

学校读者我要写书评

暂无评论

重复采动影响下含瓦斯岩层瓦斯运移规律

矿业安全与环保 2024年第1期51卷 61-69页

作者：张伟赵博郭晓阳邓存宝高嘉慧太原理工大学安全与应急管理工程学院山西太原030600

受重复采动影响,煤层邻近岩层中赋存的瓦斯解吸涌出,成为工作面瓦斯主要来源之一。为研究重复采动影响下含瓦斯岩层中瓦斯运移规律,以沙曲一矿5#煤及其邻近煤岩层为工程背景,在测定煤岩体瓦斯基础参数的基础上,通过数值模拟研究了重复... 详细信息

受重复采动影响,煤层邻近岩层中赋存的瓦斯解吸涌出,成为工作面瓦斯主要来源之一。为研究重复采动影响下含瓦斯岩层中瓦斯运移规律,以沙曲一矿5#煤及其邻近煤岩层为工程背景,在测定煤岩体瓦斯基础参数的基础上,通过数值模拟研究了重复采动影响下煤岩体卸压增透范围,得到了含瓦斯岩层渗透率的空间分布情况,进而对含瓦斯岩层瓦斯运移规律进行模拟。研究结果表明:邻近岩层中,L5灰岩层瓦斯赋存量最高,含量约为5#煤层的14.3%;重复采动导致煤岩体卸压程度增大,L5灰岩层卸压区分布在永久煤柱的边缘区;L5灰岩层卸压区内渗透率最高可达4.8×10^(-15)m^(2),为初始渗透率的7.7倍,高渗区域与卸压区域分布一致;L5灰岩层内赋存的瓦斯解吸并上涌至工作面,致使上隅角瓦斯浓度由6.1%升高至7.1%;受巷道通风影响,L5灰岩层瓦斯主要聚积在岩层后方与回风巷侧,是瓦斯抽采时应关注的重点区域。

关键词：重复采动含瓦斯岩层裂隙发育渗流特征瓦斯运移

在线全文

学校读者我要写书评

暂无评论

煤中侧链官能团与水分子间的量子化学模拟

矿业安全与环保 2024年第3期51卷 78-84,91页

作者：乔云霞陈曦葛少成邓存宝范超男太原理工大学安全与应急管理工程学院山西太原030024

煤中侧链官能团是影响煤分子亲疏水性的重要因素。为了揭示煤分子中侧链官能团与水分子的作用机理,基于密度泛函理论计算了24种煤分子侧链官能团和水分子之间的非共价键力。结果表明:侧链官能团与水分子主要通过氢键力作用,伴随范德华力... 详细信息

煤中侧链官能团是影响煤分子亲疏水性的重要因素。为了揭示煤分子中侧链官能团与水分子的作用机理,基于密度泛函理论计算了24种煤分子侧链官能团和水分子之间的非共价键力。结果表明:侧链官能团与水分子主要通过氢键力作用,伴随范德华力,几乎没有排斥力;含氧官能团与水分子形成的总氢键能最弱为-10.91 kJ/mol,最强为-71.03 kJ/mol,其中小部分含氧官能团可以与2个及2个以上水分子结合;含氮官能团与水分子形成的总氢键能为-30.70~-6.44 k J/mol;含硫官能团与水分子形成的总氢键能稳定在-12.00 kJ/mol左右。侧链官能团亲水能力由强到弱依次为:羧基、羟基、碳基键、醛基、醚键及氨基、极性键。研究成果为表面活性剂或抑尘剂通过定向增强官能团亲水性,提高煤体亲水性,从而增强降尘效果提供了一种新思路。

关键词：煤分子侧链官能团量子化学模拟亲水性氢键力前线轨道间隙键能