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Failure analysis and control technology of intersections of large‑scale variable cross‑section roadways in deep soft rock

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International Journal of Coal Science & Technology 2022年第2期9卷 124-146页

作者： Shengrong Xie Yiyi Wu Dongdong Chen Ruipeng Liu xintao han Qiucheng Ye School of Energy and Mining Engineering China University of Mining and TechnologyBeijingBeijing 100083China Mine Safety Technology Branch of China Coal Research Institute Beijing 100013China

In deep underground mining,achieving stable support for roadways along with long service life is critical and the complex geological environment at such depths frequently presents a major *** to the coupling action of multiple factors such as deep high stress,adjacent faults,cross-layer design,weak lithology,broken surrounding rock,variable cross-sections,wide sections up to 9.9 m,and clusters of nearby chambers,there was severe deformation and breakdown in the No.10 intersection of the roadway of large-scale variable cross-section at the−760 m level in a coal *** there are insufcient examples in engineering methods pertaining to the geological environment described above,the numerical calculation model was oversimplifed and support theory underdeveloped;therefore,it is imperative to develop an efective support system for the stability and sustenance of deep *** this study,a quantitative analysis of the geological environment of the roadway through feld observations,borehole-scoping,and ground stress testing is carried out to establish the FLAC 3D variable cross-section crossing roadway *** model is combined with the strain softening constitutive(surrounding rock)and Mohr–Coulomb constitutive(other deep rock formations)models to construct a compression arch mechanical model for deep soft rock,based on the quadratic parabolic Mohr *** integrated control technology of bolting and grouting that is mainly composed of a high-strength hollow grouting cable bolt equipped with modifed cement grouting materials and a high-elongation cable bolt is developed by analyzing the strengthening properties of the surrounding rock before and after bolting,based on the Heok-Brown *** a result of on-site practice,the following conclusions are drawn:(1)The plastic zone of the roof of the cross roadway is approximately 6 m deep in this environment,the tectonic stress is nearly 30 MPa,and the surrounding rock is severely fractured.(2)The def

关键词： Deep soft rock Variable cross-section Roadway intersection Bolting-grouting integration New grouting material

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断层对煤层瓦斯封闭性定量方法研究

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煤炭科学技术 2023年第2期51卷 193-203页

作者：刘永茜韩鑫涛煤炭科学研究总院北京100013 煤炭科学技术研究院有限公司北京100013

断层对煤层瓦斯具有封闭和通道的双重作用,这主要取决于断层的封闭能力。针对断层对瓦斯封闭能力定量化表征方法,结合断裂带结构发育多元学说,分析了断裂带结构参数(两盘煤层对接系数、泥质含量、紧闭系数等)对断层封闭性的影响规律;考... 详细信息

断层对煤层瓦斯具有封闭和通道的双重作用,这主要取决于断层的封闭能力。针对断层对瓦斯封闭能力定量化表征方法,结合断裂带结构发育多元学说,分析了断裂带结构参数(两盘煤层对接系数、泥质含量、紧闭系数等)对断层封闭性的影响规律;考虑了诱导裂隙带宽度与渗透率的相关性,提出了一个断裂带泥岩等效厚度的计算公式和一种渗透率补偿算法,以此为基础,依据低速渗流理论,实现了断层极限封闭压力计算,继而对断层封闭性进行量化表征。研究结果表明:(1)断层封闭性主要受控于断裂带内部结构与断层端面受力状态,考虑顶底板围岩封闭能力和煤储层压力,利用断裂带结构参数和断层封闭压力可对断层封闭性进行综合定量表征;(2)诱导裂隙带煤层渗透率与距端面距离负相关,离端面越远,综合渗透率越低,最后趋近于原始煤层渗透率;(3)等效泥岩厚度越大,断层极限封闭压力越高,断层封闭性越好;(4)沁水盆地郑庄-樊庄区块的寺头断层封闭性计算结果显示,该断层封闭压力高于4.67 MPa,大于储层压力3.83 MPa。然而,该断层走向上的封闭能力存在差异,北东向断层端面封闭性好,西南向断层端面封闭能力则相对较差。研究成果对于科学判识断层的瓦斯封闭能力,指导井下煤与瓦斯突出预测及地面煤层气高效开发具有重要技术支撑作用。

关键词：煤层瓦斯断层封闭性等效泥岩厚度渗透率补偿断层封闭压力

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Physicochemical principles of hydrogen metallurgy in blast furnace

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Journal of Iron and Steel Research(International) 2024年第1期31卷 46-63页

作者： han-jie Guo School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials Beijing100083China

Based on the stoichiometric method and the free energy minimization method,an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established,and the reduction efficiency and theoretical energy consumption of the all-carbon blast furnace and the hydrogen-rich blast furnace were *** results show that after the reduction reaction is completed at the bottom of the blast furnace,the gas produced by reduction at 1600℃still has a certain excessive reduction capacity,which is due to the hydrogen brought in by the hydrogen-rich blast as well as the excess carbon monoxide generated by the reaction of the coke and the oxygen brought in by the *** the process of the gas with excessive reduction capacity rising from the bottom of the blast furnace and gas reduction process,the excessive reduction capacity of the gas gradually decreases with the increase in the dydrogen content in the *** the all-carbon blast furnace,the excess gas reduction capacity is the strongest,and the total energy consumption per ton of iron reduction is the *** shows that,for the current operation mode of the blast furnace,adding hydrogen in the blast furnace cannot reduce the consumption of carbon required for reduction per ton of iron,but rather increases the consumption of carbon.

关键词： Hydrogen metallurgy Excess gas reduction capacity Theoretical energy consumption Hydrogen-rich blast furnace Thermodynamic model Gibbs minimum free energy method

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Engineered plant extracellular vesicles for autoimmune diseases therapy

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Nano Research 2024年第4期17卷 2857-2873页

作者： Ruina han Yan Wu Yafei han Xiangfei Liu han Liu Jiacan Su Institute of Translational Medicine Shanghai UniversityShanghai 200444China Organoid Research Center Shanghai UniversityShanghai 200444China National Center for Translational Medicine(Shanghai)SHU Branch Shanghai UniversityShanghai 200444China Department of Orthopedics Shanghai Zhongye HospitalShanghai 200941China Department of Orthopedics Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghai 200092China

Autoimmune diseases(AID)encompass a diverse array of conditions characterized by immune system dysregulation,resulting in aberrant responses of B cells and T cells against the body’s own healthy *** extracellular vesicles(PEVs)are nanoscale particles enclosed by phospholipid bilayers,secreted by plant cells,which facilitate intercellular communication by transporting various bioactive *** to their nanoscale structure,safety,abundant sources,low immunogenicity,high yield,biocompatibility,and effective targeting of the colon and liver,PEVs are regarded as a promising platform for the treatment of *** review provides a comprehensive summary of PEV biogenesis,physicochemical and biological properties,internalization mechanisms,isolation methods,and their applications in various diseases,with a specific focus on their potential roles in ***,we propose engineering approaches and administration methods for ***,we present an overview of the advantages and challenges associated with utilizing PEVs for the treatment of *** gaining a comprehensive understanding of PEVs,we anticipate the development of innovative therapeutic strategies for *** and engineered PEVs hold substantial promise as a valuable resource for innovative technologies in AID treatment.

关键词： autoimmune diseases plant extracellular vesicles extracellular vesicles engineering modification

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Random Raman Fiber Laser as a Liquid Refractive Index Sensor

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Photonic Sensors 2024年第1期14卷 13-22页

作者： Bing han Yuxi MA han WU Yong ZHAO College of Information Science and Engineering Northeastern UniversityShenyang 110819China Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology Qinhuangdao 066004China College of Electronics and Information Engineering Sichuan UniversityChengdu 610064China

In this paper,a new concept of forward-pumped random Raman fiber laser(RRFL)-based liquid refractive index sensing is proposed for the first *** liquid refractive index sensing,the flat fiber end immersed in the liquid can act as the point reflector for generating random fiber lasing and also as the sensing *** to the high sensitivity of the output power of the RRFL to the reflectivity provided by the point reflector in the ultralow reflectivity regime,the proposed RRFL is capable of achieving liquid refractive index sensing by measuring the random lasing output *** theoretically investigate the effects of the operating pump power and fiber length on the refractive index sensitivity for the proposed *** a proof-of-concept demonstration,we experimentally realize high-sensitivity half-open short-cavity RRFL-based liquid refractive index sensing with the maximum sensitivity and the sensing resolution of-39.88W/RIU and 2.5075×10^(-5) RIU,*** also experimentally verify that the refractive index sensitivity can be enhanced with the shorter fiber length of the *** work extends the application of the random fiber laser as a new platform for highly-sensitive refractive index sensing in chemical,biomedical,and environmental monitoring applications,etc.

关键词： Fiber optic sensors refractive index measurements fiber lasers Rayleigh scattering stimulated Raman scattering

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FAST unveils a new era in the discovery of long-period pulsars in globular clusters

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 185-186页

作者： Zhanwen han International Centre of Supernovae Yunnan Key LaboratoryYunnan ObservatoriesChinese Academy of SciencesKunming 650011China

Globular clusters(GC)are among the oldest celestial bodies in the Milky *** possessing millions of stars and have been going through abundant stellar interactions,GCs are futile ground for hunting for compact objects,particularly,neutron stars.A significant number of fast-spinning millisecond pulsars(MSPs)have been discovered,comprising the majority of known GC pulsars.

关键词： stars pulsars abundant

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基于5R并联机构的二自由度树冠振动装置设计与试验

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农业机械学报 2023年第4期54卷 96-106,131页

作者：杜小强韩鑫涛沈腾飞李松涛贺磊盈浙江理工大学机械与自动控制学院杭州310018 浙江省种植装备技术重点实验室杭州310018

振动式采收是一种高效的林果机械化采收形式。在现有的激振形式中,非圆周激励可以使果树产生有效的振动,实现整体采收效果。为进一步提高果实的采收效率,针对非圆周激励中不同类型旋轮线轨迹进行深入研究。通过SolidWorks、ANSYS、ADAM... 详细信息

振动式采收是一种高效的林果机械化采收形式。在现有的激振形式中,非圆周激励可以使果树产生有效的振动,实现整体采收效果。为进一步提高果实的采收效率,针对非圆周激励中不同类型旋轮线轨迹进行深入研究。通过SolidWorks、ANSYS、ADAMS等软件建立果树柔性体模型。将不同轨迹参数的旋轮线位移载荷导入ADAMS,施加于果树模型激振点。比较不同轨迹的旋轮线位移载荷下果树模型的振动响应,确定3支线1号外旋轮线轨迹E为最优激振轨迹。根据最优激振轨迹,设计了由平面5R并联机构驱动的二自由度树冠振动装置。以油茶树为激振对象,确定频率6 Hz、振幅90 mm为激振参数,设计并搭建样机进行试验。试验结果表明,7×7交错分布的激振杆布局方式的激振效果最优,该布局下树冠平均合成加速度响应为22.38 m/s^(2),激振加速度传递效率为77.63%,验证了二维激振轨迹的有效性。

关键词：振动式采收机旋轮线轨迹 5R机构激振轨迹激振杆布局加速度传递效率

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Track-before-detect for bistatic radar based on pseudo-spectrum

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Chinese Journal of Aeronautics 2024年第1期37卷 236-246页

作者： Tao han Gongjian ZHOU School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Marine Environmental Monitoring and Information Processing Ministry of Industry and Information TechnologyHarbin 150001China

Track-Before-Detect(TBD) is an efficient method to detect dim targets for radars. Conventional TBD usually follows an approximate motion model of the target, which may cause an inaccurate integration of the target energy. A TBD technique on basis of pseudo-spectrum in mixed coordinates adopting an accurate motion model for bistatic radar system is developed in this *** predicted position in bistatic polar plane is derived according to a nonlinear function that exactly describes the constant Cartesian velocity motion. Then around the predicted position, a pseudo-spectrum is formulated and its samples are accumulated to the integration frame for energy integration. The evolution of the state and the procedure of accumulation of the target energy are derived elaborately. The superior performance of the proposed method is demonstrated by some simulations.

关键词： Weak target detection Bistatic radar Track-before-detect Pseudo-spectrum Multiframe integration

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跨式油茶果收获机履带底盘行走液压系统设计与试验

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农业机械学报 2023年第3期54卷 139-147页

作者：杜小强宁晨杨振华马锃宏贺磊盈韩鑫涛浙江理工大学机械工程学院杭州310018 浙江省种植装备技术重点实验室杭州310018 龙泉市菇源自动化设备有限公司龙泉323700

跨式油茶果收获机在丘陵山地作业时需要较大的牵引力,且要求行走平稳。本文基于机液联合仿真技术对跨式油茶果收获机底盘行走液压系统进行设计,以达到动力匹配及行走性能较优的目的。在RecurDyn软件中建立了跨式收获机履带底盘虚拟样机... 详细信息

跨式油茶果收获机在丘陵山地作业时需要较大的牵引力,且要求行走平稳。本文基于机液联合仿真技术对跨式油茶果收获机底盘行走液压系统进行设计,以达到动力匹配及行走性能较优的目的。在RecurDyn软件中建立了跨式收获机履带底盘虚拟样机模型,采用谐波叠加法构建了B级路面谱,仿真分析了跨式履带底盘直线行驶和差速转向的动力学特性。通过AMESim与RecurDyn软件对收获机行走系统进行机液联合仿真,研究底盘在直线行驶与差速转向工况时行走马达液压特性。研制了全液压驱动的跨式油茶果收获机,进行了地面直线行驶与差速转向测试,结果表明:底盘直线行驶偏移率为1.7%;直线行驶时,行走马达流量稳定在23 L/min,压力稳定在1.5 MPa;差速转向时,行走马达流量稳定在22 L/min,压力在2~12 MPa范围内波动,验证了跨式履带底盘行走液压系统的稳定性。

关键词：油茶果收获机跨式履带底盘液压系统联合仿真

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Thermodynamic and experimental study of high-temperature roasting of blast furnace gas ash for recovery of metallic zinc and iron

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Journal of Iron and Steel Research(International) 2024年第1期31卷 108-120页

作者： Zi-han Wang Jing Guo han-jie Guo Bin Li School of Metallurgical Engineering University of Science and Technology BeijingBeijing100083China School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina

A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash(BFA).The reduction processes for Zn-containing and Fe-containing oxides were analyzed in detail by using ther-modynamic equilibrium calculation and the principle of minimum free *** results showed that the main reaction in the system is the reduction of ZnFe_(2)_(4)and iron *** the full temperature range,iron oxides were more easily reduced than zinc *** of the amount of CO contained in the system,the reduction of ZnO to Zn was difficult to proceed below the boiling point(906℃)of *** the reduction temperature is below 906℃,the reduction process of zinc ferrate was ZnFe_(2)_(4)→ZnO;when the reduction temperature is above 906℃,its reduction process becomed ZnFe_(2)_(4)→ZnO→Zn(g).The metallization and dezincification rates of the BFA gradually increased with increasing reaction *** the C/O ratio increased,the metallization and dezincification rates first increased and then *** effect of reduction time on BFA reduction was similar to that of reaction temperature.

关键词： Blast furnace gas ash Thermodynamics Zinc removal Iron reduction High-temperature reduction roasting Integrated utilization

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