检索结果-南通市图书馆

Investigation of meso-failure behaviors of Jinping marble using SEM with bending loading system

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2015年第5期7卷 593-599页

作者： jianping zuo Xu Wei Jianliang Pei Xiaoping Zhao School of Mechanics and Architectural Engineering China University of Mining and Technology State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology College of Water Resources and Hydropower Sichuan University

In th is study, th e m eso-failure m ech an ism an d fracture surface o f Jinping m arble w ere investigated bym ean s o f scanning electro n m icroscope （SEM） w ith ben d in g loading system and laser-scanner equipment. The Y antang an d B aishan m arbles specim ens from Jinping II hyd ro p o w er sta tio n w ere used. Testresu lts show th a t th e fracture to u g h n ess and m echanical behaviors o f Y antang m arble w ere basicallyh ig h er th a n th o se o f Baishan m arble. This is m ainly d u e to th e fact th a t Baishan m arble co n tain s a largep ercen tag e o f d o lom ite an d m in o r mica. Crack pro p ag atio n p a th and fracture m orphology in d icated th a tth e d irection o f ten sile stress has a significant effect on th e m echanical behaviors an d fracture toughnesso f B aishan m arble. For Yantang an d B aishan m arbles, a large n u m b e r o f m icrocracks a ro u n d th e m aincrack tip w ere observed w h e n th e directio n o f ten sile stress w as parallel to th e bed d in g plane.C onversely, few m icrocracks o ccurred w h e n th e directio n o f ten sile stress w as p erp en d icu lar to th ebed d in g plane. The presen ce o f a large n u m b e r o f m icrocracks a t th e m ain crack tip d ecreased th e globalfracture to u g h n ess o f m arble. The results o f th re e -p o in t ben d in g te sts show ed th a t th e average bearingcapacity o f intact m arble is 3.4 tim es th e notch ed m arble, b u t th e ductility p ro p e rty o f th e defectivem arble afte r p eak load is b e tte r th a n th a t o f th e intact m arble. H ence, large d efo rm atio n m ay beg en erated before failure o f in tact m arbles a t Jinping II h y d ro p o w er station. The fractal d im en sio n o ffracture surface w as also calculated by th e cube covering m eth o d . O bservational resu lt show ed th a t th elargest fractal dim en sio n o f Y antang m arble is cap tu red w h e n th e directio n o f ten sile stress is parallel toth e bedding plane. H ow ever, th

关键词： Jinping marble Bedding plane Meso-failure mechanism Scanning electron microscope (SEM) In-situ observation

Nonlinear model characterizing stress-strain relationship and permeability change of contact compression fracture at closing stage

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2016年第6期8卷 896-903页

作者： jianping zuo Guanghui Jiang Haicheng Su Yan Chen School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyBeijing100083China

Understanding the stress-strain relationship and permeability change for contact compression fracture at closing stage has been a hot issue for a long *** investigations of this topic were mainly focused on experimental tests;however,theoretical approaches were rarely *** on this,this paper focuses on the contact fracture at closing stage when rock is uniaxially loaded,and then a theoretical model is *** on the change of fracture elasticity modulus,it shows that as crack apertures are gradually reduced in the loading process,the permeability of rock sample will decrease *** scenario shows that theoretical computation matches well with the experimental ***,the effects of ratio of sample size to fracture aperture(n).pore pressure(P),and initial aperture(b) on stress-strain relationship and permeability change for contact compression fracture at closing stage are analyzed.

关键词： Uniaxial loading Closing stage Permeability change Stress-strain relationship

Full-field mapping of internal strain distribution in red sandstone specimen under compression using digital volumetric speckle photography and X-ray computed tomography

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2015年第2期7卷 136-146页

作者： Lingtao Mao jianping zuo Zexun Yuan Fu-Pen Chiang State Key Laboratory of Coal Resources and Safe Mining China University of Mining & Technology (Beijing) Laboratory for Experimental Mechanics Research Stony Brook University Department of Mechanical Engineering Stony Brook University

It is always desirable to know the interior deformation pattern when a rock is subjected to mechanicalload. Few experimental techniques exist that can represent full-field three-dimensional （3D） straindistribution inside a rock specimen. And yet it is crucial that this information is available for fully understandingthe failure mechanism of rocks or other geomaterials. In this study, by using the newlydeveloped digital volumetric speckle photography （DVSP） technique in conjunction with X-ray computedtomography （CT） and taking advantage of natural 3D speckles formed inside the rock due to materialimpurities and voids, we can probe the interior of a rock to map its deformation pattern under load andshed light on its failure mechanism. We apply this technique to the analysis of a red sandstone specimenunder increasing uniaxial compressive load applied incrementally. The full-field 3D displacement fieldsare obtained in the specimen as a function of the load, from which both the volumetric and the deviatoricstrain fields are calculated. Strain localization zones which lead to the eventual failure of the rock areidentified. The results indicate that both shear and tension are contributing factors to the failuremechanism. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

关键词： Red sandstone Strain localization Uniaxial compression Digital volumetric speckle photography(DVSP) X-ray micro-tomography

Mesoscale fracture behavior of Longmaxi outcrop shale with different bedding angles:Experimental and numerical investigations

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2020年第2期12卷 297-309页

作者： jianping zuo Jingfang Lu Rojin Ghandriz Jintao Wang Yanhong Li Xiaoyan Zhang Jun Li Hongtao Li School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyBeijing100083China Department of Mechanical Engineering University of MassachusettsDartmouth02747USA

The mechanical properties and fracturing mechanism of shale containing beddings are critically important in shale gas exploitation and wellbore *** investigate the effects of shale bedding on crack behavior and fracturing mechanism,scanning electron microscope(SEM)with a loading system was employed to carry out three-point bending tests on Longmaxi outcrop *** crack initiation and propagation of Longmaxi shale were observed and recorded by taking photos during *** cracking paths were extracted to calculate the crack length through a MATLAB *** peak load,fracture toughness and fracture energy all increase with the bedding angle from 0°to 90°.The crack length and energy were also found to increase with the bedding angle in the range of 0°-600 and then drop *** fracturing mechanism of shale includes the main crack affected by the bedding angle and disturbed by randomly distributed *** main cracking path was accompanied by several microcrack branches which could form an interconnected crack *** the main crack encounters larger sedimentary particles,it will deflect around the particles and then restore to the initial direction.A numerical technique using extended finite element method(XFEM)coupled with anisotropic cohesive damage criteria was developed,which is able to capture the dependence of crack propagations on bedding angle and sedimentary *** study sheds light on understanding and predicting mesoscale fracture behavior of shale with different bedding angles.

关键词： Longmaxi shale Three-point bending test Fracture toughness Fracture energy Crack propagation Anisotropic cohesive damage Extended finite element method(XFEM)

Psoralen inhibits hepatitis B viral replication by down-regulating the host transcriptional machinery of viral promoters

在线全文

学校读者我要写书评

暂无评论

Virologica Sinica 2022年第2期37卷 256-265页

作者： Xinna Ma Heng Li Ying Gong Feifei Liu Xiankun Tong Fenghua Zhu Xiaoqian Yang Li Yang jianping zuo Laboratory of Immunology and Virology Shanghai University of Traditional Chinese MedicineShanghai201203China Laboratory of Immunopharmacology State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai201203China University of Chinese Academy of Sciences Beijing100049China

The hepatitis B virus(HBV) is a global public health challenge due to its highly contagious nature. It is estimated that almost 300 million people live with chronic HBV infection annually. Although nucleoside analogs markedly reduce the risk of liver disease progression, the analogs do not fully eradicate the virus. As such, new treatment options and drugs are urgently needed. Psoralen is a nourishing monomer of Chinese herb and is known to inhibit virus replication and inactivate viruses. In this study, we evaluated the potential of psoralen as an anti-HBV *** PCR and Southern blot analysis revealed that psoralen inhibited HBV replication in Hep G2.2.15 cells in a concentration-dependent manner. Moreover, psoralen was also active against the 3TC/ETV-dual-resistant HBV mutant. Further investigations revealed that psoralen suppressed both HBV RNA transcription and core protein expression. The transcription factor FOXO1, a known target for PGC1α co-activation, binds to HBV precore/core promoter enhancer II region and activates HBV RNA transcription. Co-immunoprecipitation showed that psoralen suppressed the expression of FOXO1, thereby decreasing the binding of FOXO1 co-activator PGC1αto the HBV promoter. Overall, our results demonstrate that psoralen suppresses HBV RNA transcription by downregulating the expression of FOXO1 resulting in a reduction of HBV replication.

关键词： Psoralen Hepatitis B virus(HBV) Forkhead box-O1(FOXO1) PPARγco-activator 1α(PGC1α) Transcription

Protective role of berberine on ulcerative colitis through modulating enteric glial cells-intestinal epithelial cells-immune cells interactions

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2020年第3期10卷 447-461页

作者： Heng Li Chen Fan Huimin Lu Chunlan Feng Peilan He Xiaoqian Yang Caigui Xiang jianping zuo Wei Tang Laboratory of Anti-inflammation and Immunopharmacology State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China School of Pharmacy University of Chinese Academy of SciencesBeijing 100049China Laboratory of Immunology and Virology Shanghai University of Traditional Chinese MedicineShanghai 201203China

Ulcerative colitis(UC)manifests as an etiologically complicated and relapsing gastrointestinal *** enteric nervous system(ENS)plays a pivotal role in rectifying and orchestrating the inflammatory responses in gut ***,an isoquinoline alkaloid,is known as its antiinflammatory and therapeutic effects in experimental ***,little research focused on its regulatory function on ***,we set out to explore the pathological role of neurogenic inflammation in UC and the modulating effects of berberine on neuro-immune *** defects of enteric glial cells(EGCs),with decreased glial fibrillary acidic protein(GFAP)and increased substance P expression,were observed in DSS-induced murine *** of berberine can obviously ameliorate the disease severity and restore the mucosal barrier homeostasis of UC,closely accompanying by maintaining the residence of EGCs and attenuating inflammatory infiltrations and immune cells *** vitro,berberine showed direct protective effects on monoculture of EGCs,bone marrowderived dendritic cells(BMDCs),T cells,and intestinal epithelial cells(IECs)in the simulated inflammatory ***,berberine could modulate gut EGCs-IECs-immune cell interactions in the co-culture *** summary,our study indicated the EGCs-IECs-immune cell interactions might function as a crucial paradigm in mucosal inflammation and provided an infusive mechanism of berberine in regulating enteric neurogenic inflammation.

关键词： Ulcerative colitis Berberine Mucosal inflammation Enteric glial cells Enteric nervous system

Artemisinin analogue SM934 protects against lupus-associated antiphospholipid syndrome via activation of Nrf2 and its targets

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2021年第10期64卷 1702-1719页

作者： Zemin Lin Yuting Liu Li Chen Shiqi Cao Yueteng Huang Xiaoqian Yang Fenghua Zhu Wei Tang Shijun He jianping zuo Laboratory of Immunopharmacology State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai 201203China University of Chinese Academy of Sciences Beijing 100049China Laboratory of Immunology and Virology Shanghai University of Traditional Chinese MedicineShanghai 201203China

Kidney is a major target organ in both antiphospholipid syndrome(APS)and systemic lupus erythematosus(SLE).The etiology of antiphospholipid syndrome nephropathy associated lupus nephritis(APSN-LN)is intricate and remains largely *** proposed in present work,that generation of antiphospholipid antibodies(aPLs),especially those directed towards the oxidized neoepitopes,are largely linked with the redox status along with disease ***,we observed that compromised antioxidative capacity coincided with turbulence of inflammatory cytokine profile in the kidney of male NZW×BXSB F1 mice suffered from ***934 is an artemisinin derivative that has been proved to have potent immunosuppressive *** current study,we elaborated the therapeutic benefits of SM934 in male NZW×BXSB F1 mice,a murine model develops syndrome resembled human APS associated with SLE,for the first ***934 treatment comprehensively impeded autoantibodies production,inflammatory cytokine accumulation and excessive oxidative stress in *** others,we interpreted in present work that both anti-inflammatory and antioxidative effects of SM934 is closely correlated with the enhancement of Nrf2 signaling and expression of its ***,our finding confirmed that therapeutic strategy simultaneously exerting antioxidant and anti-inflammatory efficacy provide a novel feasible remedy for treating APSN-LN.

关键词： artemisinin analog antiphospholipid syndrome antiphospholipid syndrome nephropathy associated lupus nephritis oxidative stress inflammation Nrf2

“以学生为中心,以矿业为特色”的工程力学虚拟仿真一流课程建设与实践

在线全文

学校读者我要写书评

暂无评论

力学与实践 2024年第4期46卷 851-858页

作者：李明耀左建平祝捷刘德军薛东杰中国矿业大学(北京)力学与土木工程学院北京100083

面向国家能源开发领域,立足于巷道工程有关的岩石力学前沿问题,创设了“以学生为中心,以矿业为特色”的工程力学虚拟仿真实验教学课程,构建了以教学目标为引导、以实验模块为主线、以实验内容为应用的课程体系,坚持“以学生为中心”的... 详细信息

面向国家能源开发领域,立足于巷道工程有关的岩石力学前沿问题,创设了“以学生为中心,以矿业为特色”的工程力学虚拟仿真实验教学课程,构建了以教学目标为引导、以实验模块为主线、以实验内容为应用的课程体系,坚持“以学生为中心”的教学理念,采用多样化的教学方式,构建了沉浸式、体验式、探究式的学习场域,完善了开放共享的信息化实验教学新模式和新体系。课程建设与实践表明,本虚拟仿真实验课程有利于培养学生家国情怀、能源特质、创新思维和工程实践能力。

关键词：工程力学虚拟仿真实验学生为中心全过程交互多样化教学

Repression of interferon regulatory factor-4(IRF4)hyperactivation restricts murine lupus

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2023年第6期8卷 2475-2477页

作者： Shijun He Huihua Ding Li Chen Yiwei Shen Yuting Liu Fenghua Zhu Xiaoqian Yang Nan Shen Zemin Lin jianping zuo Innovation Research Institute of Traditional Chinese Medicine Shanghai University of Traditional Chinese MedicineShanghaiChina Laboratory of Immunopharmacology State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghaiChina Department of Rheumatology Ren Ji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghaiChina

Dear Editor,Hyperactivation of the type I interferon(IFN)signature has been observed in several systemic autoimmune conditions,and the type I IFN receptor antagonist Saphnelo(anifrolumab-fnia)has been approved in 2021 by the Food and Drug Administration(FDA)in the *** launch of Saphnelo marked the only new treatment approved for systemic lupus erythematosus(SLE)in more than 10 years.

关键词： lupus interferon activation