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A consecutive joint shear strength model considering the 3D roughness of real contact joint surface

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International Journal of Mining Science and Technology 2023年第5期33卷 617-624页

作者： liren Ban Zhigang Tao Weisheng Du Yuhang Hou School of Civil and Transportation Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China State Key Laboratory of Deep Geotechnical Mechanics and Deep Underground Engineering Beijing 100083China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing 100083China Deep Mining and Rock Burst Research Branch China Coal Research InstituteBeijing 100013China State Key Laboratory of Hydroscience and Engineering Tsinghua UniversityBeijing 100084China

A consecutive joint shear strength model for soft rock joints is proposed in this paper,which takes into account the degradation law of the actual contact three-dimensional(3D)*** essence of the degradation of the maximum possible dilation angle is the degradation of the 3D average equivalent dip angle of the actual contact joint ***,models for calculating the maximum possible dilation angle at the initial and residual shear stress stages are proposed by analyzing the 3D joint morphology characteristics of the corresponding shear ***,the variation law of the maximum possible dilation angle is quantified by studying the degradation law of the joint micro convex *** on the variation law of the maximum possible dilation angle,the maximum possible shear strength model is ***,a method to calculate the shear stiffness degradation in the plastic stage is *** to the maximum possible shear strength of rock joints,the shear stress-shear displacement prediction model of rock joints is *** new model reveals that there is a close relationship between joint shear strength and actual contact joint roughness,and the degradation of shear strength after the peak is due to the degradation of actual contact joint roughness.

关键词： Shear strength Actual contact area 3D roughness Shear test

Anomalous activity of East Asian winter monsoon and the tropical Pacific SSTA

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Chinese Science Bulletin 1999年第10期44卷 890-898页

作者： Cholaw Bueh liren Ji Chinese Acad Sci Inst Atmospher Phys LASG Beijing 100029 Peoples R China

The relationship between the anomalous East Asian winter monsoon (EAWM) activity and the tropical Pacific SST anomalies has been identified using the results of 40-year integration of the IAP CGCM1 model and 10-year observational data, In the strong EAWM year, the western and central Pacific are dominated by positive SST anomalies while the eastern Pacific is negative ones. In the weak EAWM year, the SSTA pattern is quite different and shows El Nio-like SSTanomalies. The strong EAWM activity tends to create extra easterly flow to the east and extra westerly flow to the west of the warm SSTA region over the equatorial western and central Pacific, thus leading to the enhancement of convergence and convection of the flow in this region and favorable to the maintenance and development of such an SSTA pattern. On the other hand, the warm SST anomaly over the western and central Pacific, as a forcing, may lead to a specific pattern of the northern extratropical atmosphere, which is favorable to the strong

关键词： East Asian winter monsoon ocean-atmosphere coupled model tropical Pacific SSTA composite analysis.

Improving thermal stability and light fastness of Acid Red 114 by incorporating its anions in a ZnAl-layered double hydroxides matrix

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Particuology 2012年第4期10卷 503-508页

作者： Haifeng Zhu liren Wang Pinggui Tang Yongjun Feng Dianqing Li State Key Laboratory of Chemical Resource Engineering Belting University of Chemical TechnologyBeijing 100029China

Incorporation of anions of Acid Red 114 dye （1,3-naphthalenedisulfonic acid, 8-[2-[3,3＇-dimethyl-4＇-[2-[4- [l（4-methylphenyl）sulfonyl]oxy] phenyl]diazenyl] [1,1＇-biphenyl]-4-yl]diazenyl]-7-hydroxy-, disodium salt）（denoted as NPDA） into ZnAl-layered double hydroxides （LDHs） has been carried out by an anion- exchange method in an effort to improve their thermal stability and light fastness. After intercalation of NPDA anions, the interlayer distance of the LDHs increases from 0.87 to 2.18 nm, confirming their incorporation into the interlayer galleries of the LDHs host. Infrared spectroscopy and thermogravimetric analysis revealed the presence of host-guest interactions between LDHs layers and NPDA anions. The thermal stability of NPDA and ZnAI-NPDA-LDHs was compared by thermogravimetric-differential ther- mal analysis, UV-visible spectroscopy and infrared spectroscopy. It was found that the thermal stability of NPDA anions was markedly improved by incorporation into the ZnA1-LDHs matrix, while the light fastness was also enhanced.

关键词： Layered double hydroxidesAnion-exchangeIncorporationThermal stabilityLight fastness

Non-Noether Conserved Quantity for Relativistic Nonholonomic System with Variable Mass

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Communications in Theoretical Physics 2005年第2期43卷 197-200页

作者： QIAOYong-Fen liren-Jie MAYong-Sheng DepartmentofMechanicalEngineeringandAutomation ZhejiangInstituteofScienceandTechnologyHangzhou312207China／／FacultyofScienceLaiyangAgriculturalCollegeLaiyang265200China FacultyofScience LaiyangAgriculturalCollegeLaiyang265200China EngineeringCollege NortheastAgriculturalUniversityHarbin150030China

Using form invariance under special infinitesimal transformations in which time is not variable, the non-Noether conserved quantity of the relativistic nonholonomic system with variable mass is studied. The differential equations of motion of the system are established. The definition and criterion of the form invariance of the system under infinitesimal transformations are studied. The necessary and sufficient. condition under which the form invariance is a Lie symmetry is given. The condition under which the form invariance can be led to a non-Noether. conserved quantity and the form of the conserved quantity are obtained. Finally, an example is given to illustrate the application of the result.

关键词： analytical mechanics relativity nonholonomic system variable mass non-Noether conserved quantity

Non-Noether Conserved Quantity of Nonholonomic System Having Variable Mass and Unilateral Constraints

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Communications in Theoretical Physics 2004年第6X期42卷 801-804页

作者： QIAOYong-Fen liren-Jie MAYong-Sheng DepartmentofMechanicalEngineeringandAutomation ZhejiangInstituteofScienceandTechnologyHangzhou310027China//PhysicsTeachingDivisionLaiyangAgriculturalCollegeLaiyang265204China// PhysicsTeachingDivision LaiyangAgriculturalCollegeLaiyang265204China EngineeringCollege NortheastAgriculturalUniversityHarbin150030China

Using the Lie Symmetry under infinitesimal transformations in which the time is not variable, the nonNoether conserved quantity of nonholonomic system having variable mass and unilateral constraints is studied. The differential equations of motion of the system are given. The determining equations of Lie symmetrical transformations of the system under infinitesimal transformations are constructed. The Hojman's conservation theorem of the system is established. Finally, we give an example to illustrate the application of the result.

关键词：质量变化单边约束不完整系统决策函数解析力学

Collagen-based injectable and self-healing hydrogel with multifunction for regenerative repairment of infected wounds

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Regenerative Biomaterials 2023年第1期10卷 626-639页

作者： Haojie Gu Han Li liren Wei Jian Lu Qingrong Wei National Engineering Research Center for Biomaterials(NERCB) Sichuan UniversityChengdu 610065P.R.China College of Biomedical Engineering Sichuan UniversityChengdu 610065P.R.China School of Life Science and Engineering Southwest University of Science and TechnologyMianyang 621000P.R.China

At present,the development trend of dressing materials is being multifunctional for convenient and long-term nursing care process of some complicated ***,basing on the theory of wound moist healing,an injectable and self-healing hydrogel comprising of collagen(COL),chitosan(CS)and oxidation modified Konjac glucomannan(OKGM),which acts as a macromolecular cross-linker to construct dynamic Schiff-base bonds was smartly *** strategy of introducing the silver nanoparticles(Ag NPs)into the COL-CS-OKGM hydrogel matrix achieved a markedly enhanced antibacterial activity derived from the synergistical effect between the Ag^(+)and the mild photothermal efficacy of Ag NPs,which also improved the local capillary blood circulation of the wound area to further facilitate wound healing *** excellent syringeability and self-healing behaviors endowed the COL-CS-OKGM-Ag hydrogel with self-adapting ability for the wounds with irregular and large area needing frequent applying and changing without secondary *** vitro and in vivo evaluations verified that so-designed COL-CS-OKGM-Ag hydrogel also with hemostatic performance is a promising multifunctional dressing for the treatments of infected wound with not only good biocompatibility and convenient use,but also with desired regenerative healing prognoses benefited from hydrogel moist environment and physiotherapy.

关键词： collagen injectable and self-healing hydrogel regenerative repair wounds

A roughness parameter considering joint material properties and peak shear strength model for rock joints

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International Journal of Mining Science and Technology 2021年第3期31卷 413-420页

作者： liren Ban Weisheng Du Tianwei Jin Chengzhi Qi Xiaozhao Li School of Civil and Transportation Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China Deep Mining and Rock Burst Research Institute China Coal Research InstituteBeijing 100013China State Key Laboratory of Coal Mining and Clean Utilization China Coal Research InstituteBeijing 100013China

This study aims at proposing a reasonable roughness parameter that can reflect the peak shear strength(PSS)of rock ***,the contribution of the asperities with different apparent dip angles to shear strength is *** the shear strength of the entire joint asperities is *** results showed that the PSS of the entire joint asperities is proportional to a key parameter hs,which is related to the geometric character of the joint surface and the joint material *** parameter hsis taken as the new roughness parameter,and it is reasonable to associate the PSS with the geometric characteristics of the joint *** on the new roughness parameter and shear test results of 20 sets of joint specimens,a new PSS model for rock joints is *** new model is validated with the artificial joints in this paper and real rock joints in published *** showed that it is suitable for different types of rock joints except for gneiss *** new model has the form of the Mohr-Coulomb model,which can directly reflect the relationship between the 3 D roughness parameters and the peak dilation angle.

关键词： Roughness Joint material properties Rock joints Peak shear strength Asperities

Wintertime extreme precipitation event over southern China and its typical circulation features

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Chinese Science Bulletin 2014年第10期59卷 1036-1044页

作者： Haifeng Zong Cholaw Bueh liren Ji The International Center for Climate and Environment Sciences Institute of Atmospheric Physics Chinese Academy of Sciences State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences

This study objectively defined an extreme precipitation event(EPE)over southern China and investigated the associated typical circulation pattern on the intraseasonal time *** occurrence of the EPE resulted from the joint operations of anomalous circulations over the subtropics and mid-high *** the EPE,simultaneous enhancements of the trough over the Bay of Bengal(BBT)and the Western Pacific subtropical high(WPSH)facilitated the abundant water vapor conditions over southern China,whereas the weakened East Asian major trough(EAT)led to a moderate cold air invasion to that region,producing a persistent convergence zone over southern *** train pattern in North Atlantic and Europe may be viewed as precursory signals for the EPE over southern China,and it contributed to the Rossby wave propagation in association with the *** wave packets propagated toward East Asia mainly along the North African-Asian subtropical westerly jet ***-frequency disturbances along this waveguide contributed to the enhancement of the BBT and WPSH and the weakening of the EAT,constituting favorable circulation conditions for the EPE.

关键词： Extreme precipitation event Troughover the Bay of Bengal - Western Pacific subtropicalhigh Precursory signal

Single-shot real-time femtosecond imaging of temporal focusing

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Light(Science & Applications) 2018年第1期7卷 593-602页

作者： Jinyang Liang liren Zhu Lihong V.Wang Caltech Optical Imaging Laboratory Andrew and Peggy Cherng Department of Medical EngineeringDepartment of Electrical EngineeringCalifornia Institute of Technology1200 East California BoulevardMail Code 138-78PasadenaCA 91125USA Present address:CentreÉnergie Matériaux Télécommunications Institut National de la Recherche Scientifique1650 Boulevard Lionel-BouletVarennesQC J3X1S2Canada

While the concept of focusing usually applies to the spatial domain,it is equally applicable to the time *** imaging of temporal focusing of single ultrashort laser pulses is of great significance in exploring the physics of the space–time duality and finding diverse *** drastic changes in the width and intensity of an ultrashort laser pulse during temporal focusing impose a requirement for femtosecond-level exposure to capture the instantaneous light patterns generated in this exquisite *** far,established ultrafast imaging techniques either struggle to reach the desired exposure time or require repeatable *** have developed single-shot 10-trillion-frame-per-second compressed ultrafast photography(T-CUP),which passively captures dynamic events with 100-fs frame intervals in a single camera *** synergy between compressed sensing and the Radon transformation empowers T-CUP to significantly reduce the number of projections needed for reconstructing a high-quality three-dimensional spatiotemporal *** the only currently available real-time,passive imaging modality with a femtosecond exposure time,T-CUP was used to record the first-ever movie of nonrepeatable temporal focusing of a single ultrashort laser pulse in a dynamic scattering medium.T-CUP’s unprecedented ability to clearly reveal the complex evolution in the shape,intensity,and width of a temporally focused pulse in a single measurement paves the way for single-shot characterization of ultrashort pulses,experimental investigation of nonlinear light-matter interactions,and real-time wavefront engineering for deep-tissue light focusing.

关键词： ultrashort passive scattering