检索结果-南通市图书馆

Thermo-hydro-mechanical coupled mathematical model for controlling the pre-mining coal seam gas extraction with slotted boreholes

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2017年第3期27卷 473-479页

作者： Xue Yi gao Feng gao yanan Liang Xin Zhang Zhizhen Xing Yan State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining & Technology Xuzhou 221116 China School of Mechanics & Civil Engineering China University of Mining & Technology Xuzhou 221116 China Rock Mass Modeling and Computational Rock Mechanics Laboratories University of Arizona Tucson AZ 85721 USA

Drainage influence radius is the basic parameter for borehole arrangement, while the effect of high pressure water jet slotting technology on borehole drainage influence radius has not been studied systematically. In this paper, a fully thermo-hydro-mechanical(THM) coupled model which represents the non-linear responses of gas extraction was implemented to demonstrate the reliability of this model through history data matching. Based on this model, the susceptibilities of gas extraction with single slotted borehole, including the permeability, the gas pressure, the temperature, the coal adsorption characteristics and the radius of slot, were quantified through a series of simulations. The simulation results revealed that increasing the permeability, initial gas pressure and temperature could develop the influence radius of single slotted borehole. This finite element model and its simulation results can improve the understanding of the coal-gas interactions of underground gas drainage and provide a scientific basis for the optimization of drainage systems.

关键词： Coal seam gasGas extractionThermo-hydro-mechanical modelSlotted boreholes

Rock creep modeling based on discontinuous deformation analysis

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2013年第5期23卷 757-761页

作者： gao yanan gao Feng Manchu Ronald Yeung State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining & Technology Department of Civil Engineering California State Polytechnic University

Creep is one of the major problems of deep underground mining that must be studied theoretically,experimentally,and numerically over a long *** and feld tests are methods which can directly and more accurately describe the engineering practices as compared with ***,these approaches are also time-consuming because creep problem of rock engineering,such as the roadway/tunnel squeezing phenomenon,usually lasts from several months to a few years.A numerical method can be employed to overcome this time-consuming *** discontinuous deformation analysis(DDA)method was originated in 1984 and received considerable attention from geo-engineers and *** current paper discusses the creep calculation methods using the continuous and the discontinuous methods,and proposes a creep analysis method based on *** method proposed in this paper can directly change the stiffness matrix while inheriting the advantages of the original *** this method does not require any changes in the contact part of ***,this method does not have any effect on the open–close iteration and convergence and can solve the creep problem,while maintaining the advantages of the original *** theorized that creep problems are static problems,and based on this,the work using DDA in this study was divided into two parts:(1)addition of a new loop for the original DDA to‘‘discredited’’the total creep time into several time elements,thereby changing the material properties in each time element;and(2)division of each of the time elements by the time steps,similar to the original *** this manner,one creep problem can be solved via assembling of static ***,the method mentioned above is employed to modeling a tunnel *** evolution of the displacement fled and stress feld during creep are analyzed and discussed.

关键词： Creep Deep underground mining DDA Tunnel squeezing

Shaking table test of subgrade slope reinforced by gravity retaining wall with geogrids

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2022年第3期21卷 715-727页

作者： Qu Honglue Huang Xue gao yanan Zhang Zhe Wang Chenxu School of Geoscience and Technology Southwest Petroleum UniversityChengdu 610500China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China

Gravity retaining wall with geogrids has showed excellent seismic performance from Wenchuan great ***,seismic damage mechanism of this kind of wall is not sufficiently *** view of this,a large shaking table test of the gravity retaining wall with geogrids to reinforce the subgrade slope was carried out,and based on the HilbertHuang transform and the marginal spectrum theory,the energy identification method of the slope dynamic failure mode was *** results show that the geogrids can effectively reduce displacement and rotation of the retaining wall,and it can effectively absorb the energy of the ground movement when combined with the surrounding *** addition,it also reveals the failure development of the gravity retaining wall with geogrids to reinforce the subgrade *** damage started in the deep zone near the geogrids,and then gradually extended to the surface of the subgrade slope and other zones,finally formed a continuous failure surface along the *** analysis results of the failure mode identified by the Hilbert marginal spectrum are in good consistency with the experimental results,which prove that the Hilbert marginal spectrum can be applied to obtain the seismic damage mechanism of slope.

关键词： gravity retaining wall with geogrids Hilbert-Huang transform marginal spectrum failure mode shaking table test

Research on the big data of traditional taxi and online car-hailing:A systematic review

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2021年第1期8卷 1-34页

作者： Tao Lyu Peirong(Slade)Wang yanan gao Yuanqing Wang Department of Traffic Engineering College of Transportation EngineeringChang'an UniversityXi'an 710064China Department of Civil Engineering The University of Texas at ArlingtonArlingtonTX 76019USA

The purpose of this paper is to provide a summary of a quick overview of the latest developments and unprecedented opportunities for scholars who want to set foot in the field of traditional taxi and online car-hailing(TTOC).From the perspectives of peoples(e.g.,passenger,driver,and policymaker),vehicle,road,and environment,this paper describes the current research status of TTOC's big data in six hot topics,including the ridership factor,spatio-temporal distribution and travel behavior,cruising strategy and passenger service market partition,route planning,transportation emission and new-energy,and TTOC's data extensional *** topics were included in five mainstreams as follows:(1)abundant studies often focus only on determinant analysis on given transportation(taxi,transit,online car-hailing);the exploration of ridership patterns for a multimodal transportation mode is rare;furthermore,multiple aspects of factors were not considered synchronously in a wide time span;(2)travel behavior research mainly concentrates on the commuting trips and distribution patterns of various travel indices(e.g.,distance,displacement,time);(3)the taxi driver-searching strategy can be divided into autopsychic cruising and system dispatching;(4)the spatio-temporal distribution character of TTOC's fuel consumption(FC)and greenhouse gas(GHG)emissions has become a hotspot recently,and there has been a recommendation for electric taxi(ET)in urban cities to decrease transportation congestion is proposed;and(5)based on TTOC and point of interest(POI)multi-source data,many machine learning algorithms were used to predict travel condition indices,land use,and travel ***,the main bottlenecks and research directions that can be explored in the future are *** hope this result can provide an overview of current fundamental aspects of TTOC's utilization in the urban area.

关键词： Traffic engineering Ridership factor Travel behavior Cruising strategy and route planning Service market partition Transportation emission and new-energy

Visco-elastic-plastic model of deep underground rock affected by temperature and humidity

在线全文

学校读者我要写书评

暂无评论

Mining Science and Technology 2010年第2期20卷 183-187页

作者： gao, yanan gao, Feng ZHANG, Zhizhen ZHANG, Tao school of sciences china university of mining & technologyxuzhou 221008china state key laboratory of geomechanics and deep underground engineering china university of mining & technologyxuzhou 2210

As the depth of exploitation increases,studies on constitutive models of rock affected by temperature and humidity become very *** on the Nishihara model,a visco-elastic-plastic rock model was established by using the coefficients of thermal and humidity expansion,thermal viscosity attenuation,humid viscosity attenuation and acceleration rheology *** used the definition of a controlled heat circle to explain the *** results show that the behavior of rock,affected by temperature and humidity,is stable as a function of time when the stress is lower than the first yield stress σS1;the creep rate will increase due to the effect of temperature and humidity when the stress is greater than or equal to σS1;the creep rate will accelerate at an increasing rate when the stress is greater than or equal to the second yield stress σS2,which results in a failure of the *** model derived in this study can completely describe visco-elastic-plastic characteristics and reflects the three stages of rock creep.

关键词： temperature humidity creep controlled heat circle

Double-side role of short chain fatty acids on host health via the gut-organ axes

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第3期18卷 322-339页

作者： yanan gao Qianqian Yao Lu Meng Jiaqi Wang Nan Zheng Key Laboratory of Quality&Safety Control for Milk and Dairy Products of Ministry of Agriculture and Rural Affairs Institute of Animal SciencesChinese Academy of Agricultural SciencesBeijing 100193China Milk and Milk Products Inspection Center of Ministry of Agriculture and Rural Affairs Institute of Animal SciencesChinese Academy of Agricultural SciencesBeijing 100193China State Key Laboratory of Animal Nutrition Institute of Animal SciencesChinese Academy of Agricultural SciencesBeijing 100193China Department of Food Science Faculty of Veterinary MedicineUniversity of LiègeLiège 4000Belgium

Short chain fatty acids(SCFA)exist in dietary foods and are produced by the fermentation of gut microbiota,and are considered an important element for regulating host *** blood circulation,SCFA produced in the gut and obtained from foods have an impact on the intestinal health as well as vital organs of the *** has been recognized that the gut is the“vital organ”in the *** the gut microbial metabolites,SCFA could create an“axis”connecting the gut and to other ***,the“gut-organ axes”have become a focus of research in recent years to analyze organism *** this review,we summarized the sources,absorption properties,and the function of SCFA in both gut and other peripheral tissues(brain,kidney,liver,lung,bone and cardiovascular)in the way of“gut-organ axes”.Short chain fatty acids exert both beneficial and pathological role in gut and other organs in various ways,in which the beneficial effects are more *** addition,the beneficial effects are reflected in both preventive and therapeutic *** importantly,the mechanisms behinds the gut and other tissues provided insight into the function of SCFA,assisting in the development of novel preventive and therapeutic strategies for maintaining the host health.

关键词： Short chain fatty acid Intestinal barrier Gut-organ axis Host health Beneficial effect Pathological effect

Interfacial reaction mechanism of TiBw/Ti6Al4V composites and Inconel 718 alloys by GTAW heat transmission

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2019年第12期62卷 2293-2301页

作者： gao yanan HUANG LuJun SUN Yuan AN Qi ZHANG Jie GENG Lin State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Institute of Metal Research Chinese Academy of SciencesSheryang 110016China

A good joint of Ti Bw/Ti6Al4V composites and Inconel 718 alloys was obtained by Gas Tungsten Arc Welding(GTAW) heat transmission. The interfacial reaction mechanism of joint was investigated and analyzed in details. Owing to the heat input applied on the surface of Ti Bw/Ti6Al4V composites, a solid-state reaction layer appeared at the interface of Ti Bw/Ti6Al4 V composites to Inconel 718 alloys. The thickness of the reaction layer was obviously increased with increasing heat *** of reaction layer mainly depended on the diffusion of elements of Ti and Ni through the interface during welding to form solid solutions and intermetallic compounds(IMCs). The reaction layer can be divided into Ti-rich zone(layer 2) and Nirich zone(layer 1). In Ni-rich zone, relatively coarse dendrites were the predominant, however, more brittle IMCs like Ti2Ni were found in the Ti-rich zone. Micro hardness of reaction layer was much higher than that of base metal. While a slight decrease of hardness was found between Ti-rich zone and Ni-rich zone due to the formation of TiNi.

关键词： TiBw/Ti6Al4V composites Inconel 718 alloys interfacial reaction heat transmission microstructures

Resveratrol alleviates oxidative stress induced by oxidized soybean oil and improves gut function via changing gut microbiota in weaned piglets

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2023年第4期14卷 1639-1660页

作者： yanan gao Qingwei Meng Jianwei Qin Qianqian Zhao Baoming Shi College of Animal Science and Technology Northeast Agricultural UniversityNo.600 Changjiang RoadXiangfang DistrictHarbinChina

Background Oxidized soybean oil(OSO)has been shown to impair growth and exacerbate inflammation,leading to intestinal barrier injury in *** evidence suggests important roles for resveratrol(RES)in the promoting growth performance,antioxidant capacity,anti-inflammatory,and regulate intestinal barriers in ***,The objectives of this study are to investigate the effects of dietary RES(purity 98%)supplementation on the growth performance,antioxidant capacity,inflammatory state,and intestinal function of weaned piglets challenged with *** A total of 28 castrated weaned male piglets with a similar body weight of 10.197 replications per treatment and±0.10 kg were randomly assigned to 4 dietary treatments for 28-d feeding trial with 1 piglet per *** were arranged as a 2×2 factorial with oil type[3%fresh soybean oil(FSO)vs.3%OSO]and dietary RES(0vs.300 mg/kg).Results The results showed that relative to the FSO group,OSO stress tended to decrease the average daily feed intake(ADFI),and decreased the activity levels of lipase,villus/crypt ratio(VCR),the mRNA expression of FABP1,SOD2,IL-10 and ZO-1 in the jejunum,and SOD2,GPX1,occludin and ZO-1 in the colon,the levels of acetic acid in the colonic digesta,whereas up-regulated the mRNA expression of IL-1βand TNF-αin the jejunum(P<0.05).Moreover,dietary supplementation with RES increased ether extract(EE),the activity levels of sucrase,lipase,α-amylase,villus height(VH)and VCR,the mRNA expression of FABP1,SOD2,IL-10 and occludin in the jejunum,and FABP1,PPAR-γ,GPX1,occludin and ZO-1 in the colon,and the abundance of Firmicutes,acetic and propionic acid,but decreased the levels of D-lactic acid in the plasma,the abundance of Bacteroidetes in the colonic digesta of weaned piglets compared to the non-RES group(P<0.05).Meanwhile,in the interaction effect analysis,relative to the OSO group,dietary RES supplementation in the diets supplemented with OSO increased the activity levels of tr

关键词： Inflammation Intestinal barrier Intestinal health Oxidative stress Oxidized soybean oil Piglets Resveratrol

Mechanical behavior of coal under different mining rates:A case study from laboratory experiments to field testing

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2021年第5期31卷 825-841页

作者： Mingzhong gao Jing Xie yanan gao Wenyong Wang Cong Li Bengao Yang Junjun Liu Heping Xie State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China Institute of Deep Earth Science and Green Energy College of Civil and Transportation EngineeringShenzhen UniversityShenzhen 518052China MOE Key Laboratory of Deep Underground Science and Engineering Sichuan UniversityChengdu 610065China State Key Laboratory for Geo Mechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China

During the development of hot dry rock,the research on thermal fatigue damage caused by thermal shock of cold and heat cycles is the basis that ensures the long-term utilization of geothermal resources,but there are not enough relevant studies at *** on this,the thermal damage tests of granite at different temperatures(250,350,450°C)and quenching cycles(1,5,10,15 cycles)were carried *** reveals the damage mechanism and heat transfer law of the quenching cycle effect on hot dry *** results show that with the increase of temperature and cycles,the uneven thermal expansion of minerals and the thermal shock caused by quenching promote the crack development of granite,resulting in the decrease of P-wave velocity,thermal conductivity and uniaxial compressive strength of ***,the COMSOL was used to simulate the heat transfer of hot dry rock under different heat treatment *** concluded that the increase in the number of quenching cycles reduced the heat transfer capacity of the granite,especially more than 10 quenching cycles,which also reflects that the thermal fatigue damage leads to a longer time for the temperature recovery of the hot dry rock *** addition,the three-dimensional nonlinear fitting relationship among thermal conductivity,temperature and cycle number was established for the first time,which can better reveal the change rule of thermal conductivity after quenching thermal fatigue effect of hot dry *** research results provide theoretical support for hot dry rock reservoir reconstruction and production efficiency evaluation.

关键词： Mining rate Loading rate Fracture evolution Mining pressure Uniaxial compressive strength DIC