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Experimental study on the effect of water absorption level on rockburst occurrence of sandstone

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 136-152页

作者： Dongqiao Liu Jie sun pengfei He Manchao He Binghao Cao Yuanyuan Yang State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing100083China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing100083China Institute for Deep Underground Science and Engineering China University of Mining and Technology(Beijing)Beijing100083China

To investigate the mechanism of rockburst prevention by spraying water onto the surrounding rocks,15 experiments are performed considering different water absorption levels on a single ***-speed photography and acoustic emission(AE)system are used to monitor the rockburst *** effect of water on sandstone rockburst and the prevention mechanism of water on sandstone rockburst are analyzed from the perspective of energy and failure *** results show that the higher the ab-sorption degree,the lower the intensity of the rockburst after absorbing water on single side of *** is reflected in the fact that with the increase in the water absorption level,the ejection velocity of rockburst fragments is smaller,the depth of the rockburst pit is shallower,and the AE energy is *** the water absorption level of 100%,the magnitude of rockburst intensity changes from medium to *** prevention mechanism of water on sandstone rockburst is that water reduces the capacity of sandstone to store strain energy and accelerates the expansion of shear cracks,which is not conducive to the occurrence of plate cracking before rockburst,and destroys the conditions for rockburst incubation.

关键词： Rockburst Water Prevention effect Crack evolution

Real-time generation of circular patterns in electron beam lithography

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Nanotechnology and Precision Engineering 2024年第3期7卷 90-98页

作者： Zhengjie Li Bohua Yin Botong sun Jingyu Huang pengfei Wang Li Han Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China

Electron beam lithography(EBL)involves the transfer of a pattern onto the surface of a substrate byﬁrst scanning a thin layer of organicﬁlm(called resist)on the surface by a tightly focused and precisely controlled electron beam(exposure)and then selectively removing the exposed or nonexposed regions of the resist in a solvent(developing).It is widely used for fabrication of integrated cir-cuits,mask manufacturing,photoelectric device processing,and otherﬁ*** key to drawing circular patterns by EBL is the graphics production and *** an EBL system,an embedded processor calculates and generates the trajectory coordinates for movement of the electron beam,and outputs the corresponding voltage signal through a digital-to-analog converter(DAC)to control a deﬂector that changes the position of the electron *** this procedure,it is possible to guarantee the accuracy and real-time con-trol of electron beam scanning deﬂ*** EBL systems mostly use the method of polygonal approximation to expose circles.A circle is divided into several polygons,and the smaller the segmentation,the higher is the precision of the splicing ***,owing to the need to generate and scan each polygon separately,an increase in the number of segments will lead to a decrease in the overall lithography *** this paper,based on Bresenham’s circle algorithm and exploiting the capabilities of aﬁeld-programmable gate array and DAC,an improved real-time circle-producing algorithm is designed for *** algorithm can directly generate cir-cular graphics coordinates such as those for a single circle,solid circle,solid ring,or concentric ring,and is able to effectively realizes deﬂection and scanning of the electron beam for circular graphics *** with the polygonal approximation method,the improved algorithm exhibits improved precision and *** the same time,the point generation strategy is optimized to solve the blank pixel and pseudo-pixel prob

关键词： Electron beam lithography Circle production Micro–nano fabrication Pattern generator

Field testing of shear strength of granite residual soils

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3718-3732页

作者： Song Yin pengfei Liu Xianwei Zhang Wenyuan He Pan Yan Yuzhou sun School of Civil Engineering and Architecture Zhongyuan University of TechnologyZhengzhou450007China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

The characteristics of residual soils are very different from those of sedimentary *** the strength characteristics of sedimentary soils have been studied extensively,the shear strength characteristics of granitic residual soils(GRS)subjected to the weathering of parent rocks have rarely been *** this study,the shear strength characteristics of GRS in the Taishan area of southeast China(TSGRS)were studied by field and laboratory *** field tests consisted of a cone penetration test(CPT),borehole shear test(BST),self-boring pressuremeter test(SBPT),and seismic dilatometer Marchetti test(SDMT).The shortcomings of laboratory testing are obvious,with potential disturbances arising through the sampling,transportation,and preparation of soil *** to the special structure of GRS samples and the ease of disturbance,the results obtained from laboratory tests were generally lower than those obtained from situ *** CPT and scanning electron microscopy(SEM)results indicated significant weathering and crustal hardening in the shallow *** resulted in significant differences in the strength and strength parameters of shallow soil obtained by the *** on the SDMT and SBPT results,a comprehensive evaluation method of shear strength for TSGRS was *** SBPT was suitable for evaluating the strength of shallow *** material index(ID)and horizontal stress index(KD)values obtained by the SDMT satisfied the empirical relationship proposed by Marchetti based on the ID index,and were therefore considered suitable for the evaluation of the shear strength of deep GRS.

关键词： Granite residual soils Shear strength Field tests Self-boring pressuremeter Seismic dilatometer Borehole shear test

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基于事件触发预测控制的高速列车轨迹跟踪

机车电传动 2024年第4期 148-154页

作者：金文斌张佳辉姚柏伶孙鹏飞王青元中车长春轨道客车股份有限公司吉林长春130062 西南交通大学电气工程学院四川成都610031

高速列车运行环境的开放性导致列车容易受到外部阻力的影响,而该阻力难以通过建模的形式进行描述,为此文章研究了以“安全、平稳、准点”为跟踪目标的列车模型预测跟踪控制策略。首先,搭建了高速列车带约束、多目标预测控制模型,计算系... 详细信息

高速列车运行环境的开放性导致列车容易受到外部阻力的影响,而该阻力难以通过建模的形式进行描述,为此文章研究了以“安全、平稳、准点”为跟踪目标的列车模型预测跟踪控制策略。首先,搭建了高速列车带约束、多目标预测控制模型,计算系统的Tube不变集,对列车状态和控制力进行紧束;在此基础上,为降低在线求解最优控制问题的计算量,设计了动态事件触发Tube模型预测控制策略,仅在满足触发条件时求解最优控制序列;最后,基于上海市域列车实际线路开展仿真验证,结果表明文章提出的控制策略可在保证较好跟踪性能的同时,显著减小模型预测控制的触发次数,降低在线计算量。

关键词：高速列车列车自动驾驶轨迹跟踪模型预测控制事件触发控制

台风“美莎克”对黑龙江的影响及其非对称结构特征

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沙漠与绿洲气象 2024年第1期18卷 112-118页

作者：曲哲孙鹏飞张礼宝王爱香袁园石磊杨晓宇伊春市气象局黑龙江伊春153000 成都信息工程大学大气科学学院四川成都610225 黑龙江省气象台黑龙江哈尔滨150030 黑河市气象局黑龙江黑河164300

使用常规观测资料及ERA5(0.25°×0.25°)再分析资料,对2009号台风“美莎克”进行分析。结果表明:此次过程,副热带高压异常强大,位置偏北,并与北侧阻高合并形成高压坝阻挡;“美莎克”沿副高外围北上与中纬度低涡及冷空气相互作用,变性... 详细信息

使用常规观测资料及ERA5(0.25°×0.25°)再分析资料,对2009号台风“美莎克”进行分析。结果表明:此次过程,副热带高压异常强大,位置偏北,并与北侧阻高合并形成高压坝阻挡;“美莎克”沿副高外围北上与中纬度低涡及冷空气相互作用,变性后斜压性明显加大,低涡增强;“美莎克”携带大量水汽,同时中低空急流将海上水汽持续向黑龙江输送,并在黑龙江强烈辐合,形成强的水汽辐合区和水汽辐合带;高低空急流耦合构成强的垂直环流,对应非常强的垂直上升速度;副热带高压向西北伸展,高空引导气流和热成风方向转为西北-东南向,促使“美莎克”登陆后向西北移动,穿过黑龙江,是黑龙江出现大暴雨的主要原因。分析台风中心涡度、散度、垂直速度、位温、湿位涡等物理量的三维结构变化,认识台风在北上登陆中的变性过程以及降水出现非对称结构的原因。

关键词：美莎克台风暴雨副热带高压中纬度低涡非对称性结构

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Study on creep deformation and energy development of underground surrounding rock under four‐dimensional support

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Deep Underground Science and Engineering 2024年第1期3卷 25-38页

作者： Zhanguo Ma Junyu sun Peng Gong pengfei Yan Nan Cui Ruichong Zhang School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhouChina State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhouChina Department of Mining Engineering Colorado School of MinesGoldenUSA

There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways,one of the critical problems in underground *** previously proposed four‐dimensional support(hereinafter 4D support),as a new support technology,can set the roadway surrounding rock under three‐dimensional pressure in the new balanced structure,and prevent instability of surrounding rock in underground ***,the influence of roadway depth and creep deformation on the surrounding rock supported by 4D support is still *** study investigated the influence of roadway depth and creep deformation time on the instability of surrounding rock by analyzing the energy *** elastic strain energy was analyzed using the program redeveloped in *** numerical simulation results indicate that the combined support mode of 4D roof supports and conventional side supports is highly applicable to the stability control of surrounding rock with a roadway depth exceeding 520 *** the increase of roadway depth,4D support can effectively restrain the area and depth of plastic deformation in the surrounding ***,4D support limits the accumulation range and rate of elastic strain energy as the creep deformation time increases.4D support can effectively reduce the plastic deformation of roadway surrounding rock and maintain the stability for a long deformation period of 6 *** confirmed by in situ monitoring results,4D support is more effective for the long‐term stability control of surrounding rock than conventional support.

关键词： coal mines elastic strain energy four‐dimensional support large roadway depth long‐term stability control plastic deformation surrounding rock

Adjusting oxygen vacancy of VO_(2)·xH_(2)O nanoarray architectures for efficient NH_(4)^(+) storage

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Nano Research 2024年第4期17卷 2646-2654页

作者： Jia’ni Gong pengfei Bai Jingjing sun Yanyan Liu Xueying Dong Tao Hu Changgong Meng Yifu Zhang School of Chemistry Dalian University of TechnologyDalian 116024China School of Chemistry and Materials Sciences CAS Key Laboratory of Materials for Energy ConversionCAS Center for Excellence in NanoscienceUniversity of Science and Technology of ChinaHefei 230026China College of Environmental and Chemical Engineering Dalian UniversityDalian 116622China

Aqueous rechargeable batteries are the promising energy storge technology due to their safety,low cost,and environmental *** ion(NH_(4)^(+))is an ideal charge carrier for such batteries because of its small hydration radius and low molar *** this study,VO_(2)·xH_(2)O with rich oxygen defects(d-HVO)is designed and synthesized,and it exhibits unique nanoarray structure and good electrochemical performances for NH_(4)^(+)*** and calculation results indicate that oxygen defects in d-HVO can enhance the conductivity and diffusion rate of NH_(4)^(+),leading to improved electrochemical *** most significant improvement is observed in d-HVO with 2 mmol thiourea(d-HVO-2)(220 mAh·g^(-1) at 0.1 A·g^(-1)),which has a moderate defect content.A full cell is assembled using d-HVO-2 as the anode and polyaniline(PANI)as the cathode,which shows excellent cycling stability with a capacity retention rate of 80%after 1000 cycles and outstanding power density up to 4540 W·kg^(-1).Moreover,the flexible d-HVO-2||PANI battery,based on quasi-solid electrolyte,shows excellent flexibility under different bending *** study provides a new approach for designing and developing high-performance NH_(4)^(+)storage electrode materials.

关键词： hydrate vanadium dioxide oxygen defects ammonium-ion battery anode material

Metabolic memory:mechanisms and diseases

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Signal Transduction and Targeted Therapy 2024年第3期9卷 1086-1114页

作者： Hao Dong Yuezhang sun Lulingxiao Nie Aimin Cui pengfei Zhao Wai Keung Leung Qi Wang State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases West China Hospital of StomatologySichuan UniversityChengduChina Department of Prosthodontics West China Hospital of StomatologySichuan UniversityChengduChina Periodontology and Implant Dentistry Division Faculty of DentistryThe University of Hong KongHong KongChina

Metabolic diseases and their complications impose health and economic burdens *** from past experimental studies and clinical trials suggests our body may have the ability to remember the past metabolic environment,such as hyperglycemia or hyperlipidemia,thus leading to chronic inflammatory disorders and other diseases even after the elimination of these metabolic *** long-term effects of that aberrant metabolism on the body have been summarized as metabolic memory and are found to assume a crucial role in states of health and *** molecular mechanisms collectively participate in metabolic memory management,resulting in different cellular alterations as well as tissue and organ dysfunctions,culminating in disease progression and even affecting *** elucidation and expansion of the concept of metabolic memory provides more comprehensive insight into pathogenic mechanisms underlying metabolic diseases and complications and promises to be a new target in disease detection and ***,we retrace the history of relevant research on metabolic memory and summarize its salient *** provide a detailed discussion of the mechanisms by which metabolic memory may be involved in disease development at molecular,cellular,and organ levels,with emphasis on the impact of epigenetic ***,we present some of the pivotal findings arguing in favor of targeting metabolic memory to develop therapeutic strategies for metabolic diseases and provide the latest reflections on the consequences of metabolic memory as well as their implications for human health and diseases.

关键词： diseases metabolism alterations

“新工科+工程教育专业认证”背景下材料类专业建设的研究与探讨

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中国现代教育装备 2024年第15期 67-69页

作者：夏春艳孙鹏飞邸可新朱永长李洪波佳木斯大学材料科学与工程学院黑龙江佳木斯154007

从材料类专业出发,以产业发展为导向,立足地方经济,基于对专业内涵建设的理解和对工程教育特点的剖析,将OBE理念引入专业建设,明确专业建设思路,创新人才培养模式,构建特色课程体系,优化课程建设,提升师资队伍的工程化,健全质量保障持... 详细信息

从材料类专业出发,以产业发展为导向,立足地方经济,基于对专业内涵建设的理解和对工程教育特点的剖析,将OBE理念引入专业建设,明确专业建设思路,创新人才培养模式,构建特色课程体系,优化课程建设,提升师资队伍的工程化,健全质量保障持续改进机制。基于工程教育专业认证,推动材料类专业新工科建设,探索出具有中国特色、地方特色、行业特色,面向世界、面向未来、面向产业的一流专业建设新途径。

关键词：新工科工程教育专业认证材料类专业专业建设