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Investigation of the influence of intermediate principal stress on the dynamic responses of rocks subjected to true triaxial stress state

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International Journal of Mining Science and Technology 2021年第5期31卷 913-926页

作者： Wei You Feng Dai Yi Liu hongbo du Ruochen Jiang State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China

Precisely understanding the dynamic mechanical properties and failure modes of rocks subjected to true triaxial stress state(σ1>σ2>σ3,whereσ1,σ2,andσ3 are the major principal stress,intermediate principal stress,and minor principal stress,respectively)is essential to the safety of underground engineering.However,in the laboratory,it is difficult to maintain the constant true triaxial stress state of rocks during the dynamic testing process.Herein,a numerical servo triaxial Hopkinson bar(NSTHB)was developed to study the dynamic responses of rocks confronted with a true triaxial stress state,in which lateral stresses can maintain constant.The results indicate that the dynamic strength and elastic modulus of rocks increase with the rise of intermediate principal stressσ2,while the dynamic elastic modulus is independent of the dynamic strain rate.Simulated acoustic emission distributions indicate that the intermediate principal stressσ2 dramatically affects dynamic failure modes of triaxial confined rocks.Asσ2 increases,the failure pattern switches from a single diagonal shear zone into two parallel shear zones with a small slant.Moreover,a recent triaxial Hopkinson bar experimental system using three bar pairs is also numerically established,and the measuring discrepancies are identified between the two numerical bar systems.The proposed NSTHB system provides a controllable tool for studying the dynamic triaxial behavior of rocks.

关键词： Triaxial Hopkinson bar Intermediate principal stress Dynamic strength Failure modes Numerical simulation True triaxial stress

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静水压环境下岩石动态压剪耦合力学响应与本构模型

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工程科学与技术 2024年第2期56卷 186-195页

作者：杜洪波王鑫婷魏明东阿比尔的王浩然重庆交通大学国家内河航道整治工程技术研究中心重庆400074 重庆交通大学水利水运工程教育部重点实验室重庆400074 四川大学山区河流保护与治理全国重点实验室四川成都610065

静水压环境是深部岩石的典型应力赋存状态,并且岩石内存在多尺度的结构面,易遭受压剪耦合的复杂动力扰动。因此,探究静水压环境下岩石动态压剪耦合力学响应及损伤本构模型对于深部岩石结构安全评估和动力灾害防控极为重要。本文应用霍... 详细信息

静水压环境是深部岩石的典型应力赋存状态,并且岩石内存在多尺度的结构面,易遭受压剪耦合的复杂动力扰动。因此,探究静水压环境下岩石动态压剪耦合力学响应及损伤本构模型对于深部岩石结构安全评估和动力灾害防控极为重要。本文应用霍普金森压杆试验装置,对倾斜砂岩试样进行动态压剪耦合试验,揭示静水围压、动态荷载压剪耦合比及加载率对岩石力学特性的影响规律;基于Drucker–Prager准则和Weibull分布,建立静水压环境下深部岩石动态压剪耦合损伤本构模型。结果表明:1)岩石动态强度及变形模量随着加载率及静水围压的增大呈增加趋势,强度的围压效应及加载率效应明显,动态荷载中的剪切分量能削减岩石承载能力并提升岩石的变形能力。2)随着动态荷载剪压比和静水围压的增加,岩石冲击破坏模式由拉伸主导的内部锥形破裂面及表面劈裂转变为剪切主导的单一平面破坏;动态荷载中的剪切分量对静水围压作用下岩石的动态破碎存在明显的限制作用。3)采用极值解析法推导了模型分布参数F0和m的解析表达式,探究了模型分布参数F0、m和损伤修正系数q的物理意义及其对本构模型的影响规律;同时,对比不同工况下试验和理论应力应变曲线,验证了该模型的合理性。本文揭示的静水压环境下岩石动态压剪耦合动力响应与建立的损伤本构模型,可为复杂动力扰动下深部岩石工程安全建设与灾害防护提供理论支撑。

关键词：深部岩石静水围压霍普金森压杆动态压剪耦合动力响应损伤本构模型

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基于“肝脾同调”阐析慢性肝病的中医治疗

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世界中医药 2024年第5期19卷 652-655页

作者：叶永安靳茜李小科杜宏波北京中医药大学东直门医院脾胃病科北京100700 北京中医药大学中医肝病研究院北京100700

慢性肝病是临床常见疾病,“郁、虚、湿、毒、瘀”是其核心病机,在疾病的不同阶段各有侧重,其中,以“郁、虚”为核心的肝脾失调是慢性肝病发生发展的关键。“肝脾同调”是治疗慢性肝病的基本治法,在慢性肝病不同阶段,其“肝脾同调”内涵... 详细信息

慢性肝病是临床常见疾病,“郁、虚、湿、毒、瘀”是其核心病机,在疾病的不同阶段各有侧重,其中,以“郁、虚”为核心的肝脾失调是慢性肝病发生发展的关键。“肝脾同调”是治疗慢性肝病的基本治法,在慢性肝病不同阶段,其“肝脾同调”内涵同中有异。根据肝、脾生理病理特性,治脾明辨虚实,厘清轻重,活用运脾、健脾、温脾、醒脾、补脾等法;调肝体用并重,精准辨证,活用疏肝、缓肝、散肝、柔肝等法。临床上,治脾与调肝相辅相成,治调并举,常获良效。

关键词：慢性肝病核心病机郁虚肝脾同病肝脾同调治脾调肝中医治疗

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Life-Cycle Analysis of Bio-Ethanol Fuel Emissions of Transportation Vehicles in Greater Houston Area

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Journal of Environmental Protection 2016年第6期7卷 793-804页

作者： Raghava Kommalapati Shahzeb Sheikh hongbo du Ziaul Huque Center for Energy & Environmental Sustainability Prairie View A&M University Prairie View USA Department of Civil & Environmental Engineering Prairie View A&M University Prairie View USA Department of Mechanical Engineering Prairie View A&M University Prairie View USA

Study is conducted on the life cycle assessment of bio-ethanol used for transportation vehicles and their emissions. The emissions that are analyzed include greenhouse gases, volatile organic compounds, sulfur oxide, carbon monoxide, nitrous oxide, particulate matter with the size less than 10 and 2.5 microns. Furthermore, various blends of bio-ethanol and gasoline are studied to learn about the impacts of higher blend on emissions. The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model software are used to simulate for emissions. The research analyzes two pathways of emissions: Well-to-Pump and Pump-to-Vehicle analyses. It is found that the fuel cell vehicles using 100% bio-ethanol have shown the most reduction in the amount of all the pollutants from the Pump-to-Vehicle emission analysis. The Well-to-Pump analysis shows that only greenhouse gases (GHGs) reduce with higher blends of bio-ethanol. All other pollutants VOC, CO, NOx, SOx, PM10 and PM2.5 emissions increase with the higher blending ratios. The Pump-to-Vehicle analysis shows that all the pollutant emissions reduce with the percentage increase of bio-ethanol in the fuel blends.

关键词： Life Cycle Assessment Bio-Ethanol Greenhouse Gases Emissions Pollutant Emissions

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Anthropogenic Source Contributions to Ozone Formation in the Greater Houston Area

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Journal of Environmental Protection 2021年第4期12卷 249-264页

作者： Iqbal Hossan hongbo du Raghava R. Kommalapati Center for Energy & Environmental Sustainability Prairie View A & M University Prairie View USA Department of Civil & Environmental Engineering Prairie View A & M University Prairie View USA

The Houston-Galveston-Brazoria (HGB) area of Texas has historically experienced severe air pollution events with high concentrations of ozone (O3) during the summer season. This study evaluates the contribution of different anthropogenic sources to ozone formation in the HGB area. The Emission Processing System (EPS3) is used to process emission files in four different scenarios (Base case as including All emission sources (BC), All sources— Area sources (AMA), All sources—Point sources (AMP), and All sources— Mobile sources (AMM). These files are used as input in photochemical modeling with the Comprehensive Air Quality Model with Extensions (CAMx) to simulate ozone formation. The data is analyzed for daily maximum ozone concentrations and contribution of source categories at three air quality monitoring locations (La Porte Sylvan beach-C556, Houston Texas avenue-C411, and Texas city in Galveston-C683) for a study period of June 1-June 30, 2012. The contribution of the point sources to ozone formation is dominated at all three locations, followed by mobile sources and area sources on high ozone days. The relative contributions of point sources are 27.51% ± 3.53%, 21.45% ± 7.36%, and 30.30% ± 9.36%;and mobile sources are 18.27% ± 2.22%, 20.60% ± 6.89%, and 18.61% ± 7.43%;and area sources were 4.2% ± 1.65%, 5.21% ± 1.59%, and 3.72% ± 1.52% at C556, C411, and C683, respectively. These results demonstrate the importance of regulatory focus on controlling point and mobile source emissions for NAAQS attainment in the study region.

关键词： Anthropogenic Sources CAMx Model Sensitivity Ozone Precursors

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基于MediaPipe的手势识别算法研究与应用

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智能计算机与应用 2024年第4期14卷 157-161页

作者：高加瑞杜洪波蔡锦李佳翰沈阳工业大学理学院沈阳110870

随着人机交互的飞速发展,手势识别技术逐渐引起研究人员的关注。然而复杂的环境会对手势识别的准确性产生很大的影响,本文旨在探索一种基于MediaPipe的高精度手势识别算法,算法采用MediaPipe的手部关键点检测模块,对手部姿态进行检测和... 详细信息

随着人机交互的飞速发展,手势识别技术逐渐引起研究人员的关注。然而复杂的环境会对手势识别的准确性产生很大的影响,本文旨在探索一种基于MediaPipe的高精度手势识别算法,算法采用MediaPipe的手部关键点检测模块,对手部姿态进行检测和识别,利用本文的手势识别算法对手势进行分类识别。通过实验证明,该算法可以有效地克服光照变化、背景干扰和手部遮挡等问题,并可同时对多只手进行识别,提高了手势识别算法的准确性和鲁棒性。

关键词： MediaPipe 手势识别 OpenCV 手势跟踪人机交互

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Air Quality Impact of Biomass Co-Firing with Coal at a Power Plant in the Greater Houston Area

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Open Journal of Air Pollution 2018年第3期7卷 263-285页

作者： Iqbal Hossan Venkata Sai Vamsi Botlaguduru hongbo du Raghava Rao Kommalapati Ziaul Huque Center for Energy & Environmental Sustainability Prairie View A & M University Prairie View TX USA Dept. of Civil & Environmental Engineering Prairie View A & M University Prairie View TX USA Dept. of Mechanical Engineering Prairie View A & M University Prairie View TX USA

The Houston-Galveston-Brazoria (HGB) area of Texas is a moderate nonattainment region for ozone, and has a history of severe summer ozone episodes. W. A. Parish power plant (WAP) located in the greater Houston area is the largest coal and natural gas based electricity generating unit (EGU) in Texas. Forest residue is an abundant renewable resource, and can be used to offset coal usage at EGUs. This study evaluates the impact of co-firing 5%, 10%, and 15% (energy-basis) of forest residue at WAP on the air quality of the HGB area. Photochemical modeling with Comprehensive Air Quality Model with Extensions (CAMx) was conducted to investigate the air quality at three air quality monitoring sites (C696, C53, C556) in the HGB area, under two source scenarios (all-sources, point + biogenic sources). Significant reduction of SO2 and O3 was observed for 10% and 15% co-firing ratios at monitoring station (C696) close to WAP. The maximum reduction of ozone observed for 15% co-firing is 4.7% and 6.3% for all-sources and point + biogenic sources scenarios respectively. The reduction in other criteria air pollutants is not significant at all locations. The overall results from this study indicate that biomass co-firing at WAP would not lead to a significant reduction in ozone concentrations in the region during periods of peak ozone.

关键词： Ozone Houston Photochemical Modeling Biomass Co-Firing

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气泡帷幕对爆破冲击波的削减效果及鱼类安全防护研究

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水运工程 2024年第1期 8-14页

作者：卢林李文杰万宇杜洪波杨宵重庆交通大学水利水运工程教育部重点实验室重庆400074 重庆交通大学国家内河航道整治工程技术研究中心重庆400074

航道整治工程中多采用水下爆破的方式对碍航礁石予以清除,爆破产生的冲击波会对鱼类安全存在一定的影响,目前多采用气泡帷幕的方式削减冲击波峰值压力。研究通过构建更接近实际的气泡帷幕数值模型,探明不同布置方式下气泡帷幕对爆破冲... 详细信息

航道整治工程中多采用水下爆破的方式对碍航礁石予以清除,爆破产生的冲击波会对鱼类安全存在一定的影响,目前多采用气泡帷幕的方式削减冲击波峰值压力。研究通过构建更接近实际的气泡帷幕数值模型,探明不同布置方式下气泡帷幕对爆破冲击波压力的削减效果及其作用下的鱼类存活最小体长。研究结果表明:气泡帷幕对冲击波压力的消减程度在前半段(65%~69%)大于后半段(10%~12%)。随着气泡体积占比的上升,气泡帷幕对冲击波峰值压力的削减率也随之提升,但当气泡体积占比达到40%后,削减率增幅减小且趋于平缓。气泡帷幕距爆源10、15、20 m下的鱼类存活最小体长分别为20~34、14~30、12~24 cm,气泡帷幕厚度为2、3、4 m下鱼类存活的最小体长分别为12~24、10~22、6~17 cm。研究结果可为航道整治工程实施下鱼类资源的保护提供理论依据。

关键词：气泡帷幕爆破冲击波削减作用鱼类安全

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不同土壤改良剂对烟草黑胫病的防治效果

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安徽农学通报 2024年第1期30卷 64-68页

作者：刘怡杜鸿波王国良李先锋姚峰汉中市烟草公司西乡分公司陕西汉中723000 汉中市烟草公司南郑分公司陕西汉中723000 汉中市烟草公司烟叶分公司陕西汉中723000

为探究土壤改良剂及其施用方法对烟草黑胫病的防治效果,本试验对比了10种土壤改良剂(氧化钙、咯菌腈、甲基硫菌灵、烯酰吗啉、乙酸铜、辛菌胺醋酸盐、噁霉灵、福美双、乙蒜素和敌磺钠)搭配5种不同施药方式(灌根、穴施、蘸根、行施和四合... 详细信息

为探究土壤改良剂及其施用方法对烟草黑胫病的防治效果,本试验对比了10种土壤改良剂(氧化钙、咯菌腈、甲基硫菌灵、烯酰吗啉、乙酸铜、辛菌胺醋酸盐、噁霉灵、福美双、乙蒜素和敌磺钠)搭配5种不同施药方式(灌根、穴施、蘸根、行施和四合一)对烟草生长发育的影响。结果表明,不同土壤改良剂搭配不同施用方式对烟株生育期没有明显的影响。烟株农艺性状方面,清水、敌磺钠及氧化钙处理的烟株农艺性状表现较好;烯酰吗啉、辛菌胺醋酸盐及噁霉灵处理的烟株农艺性状表现较差;施用方法上,穴施处理的农艺性状综合表现较好,四合一处理的农艺性状表现较差。烟株发病率方面,施用氧化钙、甲基硫菌灵的发病率较低,行施、穴施的发病率低。综上可知,氧化钙、福美双和乙酸铜3种药剂的表现良好,从最适施用方式来看,氧化钙与福美双适用于行施,乙酸铜适用于蘸根。

关键词：烟草黑胫病土壤改良剂农艺性状

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Photo-thermal synergistic excitation:Feasible strategy to detect ethanol for wide bandgap ZIF-8at low work temperature

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Journal of Environmental Sciences 2024年第4期138卷 112-120页

作者： Shuhao Shi Qian du Ming Hou Xiaolei Ye Li Yang Shenghui Guo Jianhong Yi Ullah Ehsan hongbo Zeng State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization Faculty of Metallurgical and Energy EngineeringKunming University of Science and TechnologyKunming 650093China Department of Chemical and Materials Engineering University of AlbertaEdmonton T6G 2V4Canada FEMTO-ST Institute(UMR CNRS 6174) Universite de Bourgogne Franche-Comte(UBFC)Universite de technologie de Belfort Montbéliard(UTBM)Site de MontbeliardBelfort F-90010France Faculty of Materials Science and Engineering Kunming University of Science and TechnologyKunming 650093China

Zeolitic Imidazolate Framework-8(ZIF-8)material was prepared by chemical precipitation method.The microstructure and physical properties of the as-prepared samples were characterized by XRD,BET,FESEM and UV spectrophotometer.The self-made four-channel measurement device was used to test the gas sensitivity of ZIF-8 material toward ethanol gas under photo-thermal synergistic excitation.The results showed that the sample was typical ZIF-8(E_(g)=4.96 eV)with a regular dodecahedron shape and the specific surface is up to 1793 m^(2)/g.The as-prepared ZIF-8 has a gas response value of 55.04 to 100 ppm ethanol at 75℃ and it shows good gas sensing selectivity and repeated stability.The excellent gas sensitivity can be attributed to the increase of free electron concentration in the ZIF-8 conduction band by photo-thermal synergistic excitation,and the large specific surface area of ZIF-8 material provides more active sites for gas-solid surface reaction.The reaction mechanism of ZIF-8 material under multi-field excitation was also discussed.

关键词： ZIF-8 material Photo-thermal synergistic excitation UV-light irradiation Photon-generated electron and hole Gas-sensitive property

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