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Implications for fault reactivation and seismicity induced by hydraulic fracturing

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Petroleum Science 2024年第2期21卷 1081-1098页

作者： Zi-Han Sun Ming-Guang Che Li-Hong Zhu Shu-Juan Zhang Ji-Yuan Lu chang-Yu jin Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil Engineering and Key Laboratory of Liaoning Province on Deep Engineering and Intelligent TechnologyNortheastern UniversityShenyang110819LiaoningChina Research Institute of Petroleum Exploration&Development PetroChina Company LimitedBeijing100084China The Exploration and Development Research Institute of Daqing Oilfield Limited Company Daqing163458HeilongjiangChina

Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operations. Current understanding supports the overriding role of the effective stress magnitude in triggering earthquakes, while the impact of change rate of effective stress has not been systematically addressed. In this work, a modified critical stiffness was brought up to investigate the likelihood, impact,and mitigation of induced seismicity during and after hydraulic fracturing by developing a poroelastic model based on rate-and-state fraction law and linear stability analysis. In the new criterion, the change rate of effective stress was considered a key variable to explore the evolution of this criterion and hence the likelihood of instability slip of fault. A coupled fluid flow-deformation model was used to represent the entire hydraulic fracturing process in COMSOL Multiphysics. The possibility of triggering an earthquake throughout the entire hydraulic fracturing process, from fracturing to cessation, was investigated considering different fault locations, orientations, and positions along the fault. The competition between the effects of the magnitude and change rate of effective stress was notable at each fracturing stage. The effective stress magnitude is a significant controlling factor during fracturing events, with the change rate dominating when fracturing is suddenly started or stopped. Instability dominates when the magnitude of the effective stress increases(constant injection at each fracturing stage) and the change rate of effective stress decreases(the injection process is suddenly stopped). Fracturing with a high injection rate, a fault adjacent to the hydraulic fracturing location and the position of the junction between the reservoir and fault are important to reduce the Coulomb failure stress(CFS) and enhance the critical stiffness as

关键词： Hydraulic fracturing Coulomb failure stress Rate-and-state fraction model Linear stability analysis Critical stiffness Seismically induced fault

Acupuncture with different frequencies for tobacco dependence: a randomized controlled trial

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Journal of Traditional Chinese Medicine 2024年

作者： CHEN Shumin LIU Zhenyu JI Jia WANG Yingying YANG jinsheng chang jin LI Zhihua Institute of Acupuncture and Moxibustion， China Academy of Chinese Medical Sciences Institute of Basic Theory for Chinese Medicine， China Academy of Chinese Medical Sciences

OBJECTIVE: To observe the effect of different acupuncture frequencies on the abstinence rate which could be used as a reference for optimizing acupuncture cessation ***: From July 2018 to June 2022， a total of 220 smokers were recruited based on inclusion criteria and randomly divided into the high-frequency acupuncture group (HF group， n = 110): 5 times a week from the 1st to the 4th week， from weeks 5 to 8， three times a week and the low-frequency acupuncture group (LF group， n = 110): 3 times a week from the 1st to the 4th week， from weeks 5 to 8， twice a week， then treated for 8 weeks and follow-up at 1 month in ***: In total， 162 subjects completed the whole study with a drop-out rate of 20.45%. The expiratory CO point abstinence rate was HF group 53/110 (48.18%) vs LF group 41/110 (37.27%) in Week 8 (P = 0.102) and HF group 46/110 (41.82%) vs LF group 45/110 (40.91%) in Week 12 (P = 0.891) and the HF acupuncture and LF acupuncture were nearly equal in the 8-week abstinence rate. In addition， both HF and LF acupuncture significantly reduced Fagerstr?m test for nicotine dependence scale (FTND) scores (P < 0.05)， Minnesota nicotine withdrawal scale (MNWS) scores (P < 0.05)， and Brief Questionnaire of Smoking Urges scale (QSU-Brief) scores (P < 0.05)， but HF acupuncture showed some superiority over LF acupuncture in relieving patients' smoking cravings (P < 0.05).Conclusions: The study initially showed that both high-frequency acupuncture and low-frequency acupuncture treatment were safe and effective on smoking cessation for 8 weeks， but high-frequency acupuncture was advantageous in reducing smoking cravings. More accurate acupuncture frequency needs to be validated through larger clinical studies to optimize acupuncture smoking cessation programs.

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技能型拔尖创新人才培养:时代意蕴、内在逻辑与实施路径

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职业技术教育 2024年第13期45卷 34-39页

作者：常进西南大学马克思主义学院重庆大学重庆400715

随着新一轮科技革命和产业变革的加快,对技能型拔尖创新人才的培养不仅是助推技能型社会建设的关键支撑,还是实现职业教育高质量发展的必然要求,更是提升职教学生核心竞争力的重要途径。具体而言,技能型拔尖创新人才培养要以培养技艺精... 详细信息

随着新一轮科技革命和产业变革的加快,对技能型拔尖创新人才的培养不仅是助推技能型社会建设的关键支撑,还是实现职业教育高质量发展的必然要求,更是提升职教学生核心竞争力的重要途径。具体而言,技能型拔尖创新人才培养要以培养技艺精湛的“职业人”为起点逻辑,以培养爱岗敬业的“社会人”为层进逻辑,以培养综合拔尖的“创新人”为集成逻辑。基于此,应通过建立“多元分类”的人才培养目标、设计“个性灵活”的人才培养模式、完善“包容开放”的人才评价体系等助推技能型拔尖创新人才的培养。

关键词：职业教育技术技能人才拔尖创新人才技能型拔尖创新人才人才培养

Co掺杂Ni(OH)_(2)的超级电容器性能及其第一性原理计算研究

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无机化学学报 2024年第9期40卷 1697-1707页

作者：常进太原科技大学能源与材料工程学院太原030024

采用简单的共沉淀法制备了Co掺杂的Ni(OH)_(2),通过Co/Ni的协同作用改善了材料的电化学性能。Co原子掺杂改善了材料形貌,暴露了更多的缺陷位,提高了材料的电化学活性。同时第一性原理计算表明,Co掺杂也改变了Ni的电子云分布,提高了材料... 详细信息

采用简单的共沉淀法制备了Co掺杂的Ni(OH)_(2),通过Co/Ni的协同作用改善了材料的电化学性能。Co原子掺杂改善了材料形貌,暴露了更多的缺陷位,提高了材料的电化学活性。同时第一性原理计算表明,Co掺杂也改变了Ni的电子云分布,提高了材料的电荷传输和离子扩散性能。得益于适宜的Co掺杂量,Ni_(0.84)Co_(0.16)(OH)_(2)在1 A·g^(-1)的电流密度下质量比容量高达1 589.6 F·g^(-1),同时组装后的非对称超级电容器在功率密度为21.33 kW·kg^(-1)时仍具有8.30 Wh·kg^(-1)的能量密度,显示出了良好的储能性能和循环性能。

关键词：超级电容器氢氧化镍钴掺杂

Remote sensing image encryption algorithm based on novel hyperchaos and an elliptic curve cryptosystem

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Chinese Physics B 2024年第5期33卷 292-304页

作者：田婧希金松昌张晓强杨绍武史殿习 School of Computer Science National University of Defense TechnologyChangsha 410003China Intelligent Game and Decision Laboratory (IGDL) Beijing 100091China School of Information and Control Engineering China University of Mining and TechnologyXuzhou 221116China

Remote sensing images carry crucial ground information,often involving the spatial distribution and spatiotemporal changes of surface *** safeguard this sensitive data,image encryption technology is *** this paper,a novel Fibonacci sine exponential map is designed,the hyperchaotic performance of which is particularly suitable for image encryption *** encryption algorithm tailored for handling the multi-band attributes of remote sensing images is *** algorithm combines a three-dimensional synchronized scrambled diffusion operation with chaos to efficiently encrypt multiple ***,the keys are processed using an elliptic curve cryptosystem,eliminating the need for an additional channel to transmit the keys,thus enhancing *** results and algorithm analysis demonstrate that the algorithm offers strong security and high efficiency,making it suitable for remote sensing image encryption tasks.

关键词： hyperchaotic system elliptic curve cryptosystem(ECC) 3D synchronous scrambled diffusion remote sensing image unmanned aerial vehicle(UAV)

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焦化废水膜分离浓水再浓缩减量化中试研究

中国给水排水 2024年第9期40卷 31-34页

作者：金常林北京首钢国际工程技术有限公司北京市冶金三维仿真设计工程技术研究中心北京100043

焦化废水回收过程中产生的浓缩液再回收及零排放需求越来越迫切。基于此,提出采用臭氧+电催化氧化+碟管式反渗透膜(DTRO)工艺来实现焦化废水膜分离回收后,剩余浓水再浓缩减量化;在进水量为1.0 m^(3)/h条件下,控制臭氧量为200 g/h、电催... 详细信息

焦化废水回收过程中产生的浓缩液再回收及零排放需求越来越迫切。基于此,提出采用臭氧+电催化氧化+碟管式反渗透膜(DTRO)工艺来实现焦化废水膜分离回收后,剩余浓水再浓缩减量化;在进水量为1.0 m^(3)/h条件下,控制臭氧量为200 g/h、电催化氧化电极析氧电位为2.1~2.4 V及高压DTRO产水压力等级为6.8 MPa进行试验。结果表明,臭氧+电催化氧化+DTRO工艺对COD的去除率达到94.96%,废水平均回收率达到80.5%,平均脱盐率达到98%以上;DTRO化学清洗周期不少于1个月且性能恢复好。产水水质稳定达到《工业循环冷却水处理设计规范》(GB/T 50050—2017)中的再生水用于间冷开式循环冷却水系统补充水的水质标准。

关键词：焦化废水再浓缩减量臭氧电催化氧化 DTRO 膜分离

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面向应用的新一代稀磁半导体研究进展

物理学报 2024年第1期73卷 9-22页

作者：彭毅赵国强邓正靳常青中国科学院物理研究所北京100190 中国科学院大学物理学院北京100049

稀磁半导体具有能同时调控电荷与自旋的特性,是破解摩尔定律难题的候选材料之一.我们团队率先提出了稀磁半导体中自旋和电荷掺杂分离的机制,探索并研制了新一代稀磁半导体材料,为突破经典稀磁半导体材料的制备瓶颈提供了有效解决方案.以... 详细信息

稀磁半导体具有能同时调控电荷与自旋的特性,是破解摩尔定律难题的候选材料之一.我们团队率先提出了稀磁半导体中自旋和电荷掺杂分离的机制,探索并研制了新一代稀磁半导体材料,为突破经典稀磁半导体材料的制备瓶颈提供了有效解决方案.以(Ba,K)(Zn,Mn)_(2)As_(2)等为代表的新一代稀磁半导体,通过等价态的Mn掺杂引入自旋、异价态的非磁性离子掺杂引入电荷,成功实现了230 K的居里温度,刷新了可控型稀磁半导体的居里温度记录.本文将重点介绍几种代表性的新一代稀磁半导体的设计与研制、新一代稀磁半导体的综合物性表征、大尺寸单晶生长以及基于单晶的安德烈夫异质结研制.我们团队通过新一代稀磁半导体的新材料设计研制、综合物性研究、简单原型器件构建的“全链条”模式研究,开拓了自旋电荷分别掺杂的稀磁半导体材料研究领域,充分展现了自旋和电荷掺杂分离的新一代稀磁半导体材料潜在应用前景.

关键词：新一代稀磁半导体自旋电荷掺杂分离高居里温度多组合异质结

Enhanced conductivity and weakened magnetism in Pb-doped Sr2IrO4

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Chinese Physics B 2024年第1期33卷 696-701页

作者：岳智来甄伟立牛瑞焦珂珂朱文卡皮雳张昌锦 High Magnetic Field Laboratory Hefei Institutes of Physical ScienceChinese Academy of Sciences Science Island Branch of Graduate School University of Science and Technology of China Collaborative Innovation Center of Advanced Microstructures Nanjing University

Group IV element Pb has been selected as the dopant to dope at the Sr site of Sr2IrO4. It is exciting to find that the single-phase crystal structure could be maintained with a high Pb doping level of up to x=0.3 in Sr2-xPbxIrO4. The mapping data obtained from energy-dispersive x-ray spectroscopy analyses give solid evidence that the Pb ions are uniformly distributed in the Sr2IrO4matrix. The incorporation of Pb leads to a moderate depression of the canted antiferromagnetic ordering state. The electrical conductivity could be greatly enhanced when the Pb doping content is higher than x=*** present results give a fresh material base to explore new physics in doped Sr2IrO4systems.

关键词： iridates doping conductivity magnetism

基于BP神经网络的光伏电站在线监控系统设计研究

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通信电源技术 2024年第16期41卷 34-36页

作者：常进山东电力工程咨询院有限公司山东济南250013

文章设计一种基于反向传播(Back Propagation,BP)神经网络的光伏电站在线监控系统,通过分层架构实现数据采集、预处理、故障诊断以及预测预警功能。系统在某光伏电站的实证研究表明,设计的基于BP神经网络的监控系统在预警准确性、误报... 详细信息

文章设计一种基于反向传播(Back Propagation,BP)神经网络的光伏电站在线监控系统,通过分层架构实现数据采集、预处理、故障诊断以及预测预警功能。系统在某光伏电站的实证研究表明,设计的基于BP神经网络的监控系统在预警准确性、误报率、提前时间方面显著优于传统阈值判断方法,为光伏电站的智能运维提供有效支持。

关键词：反向传播(BP)神经网络光伏电站在线监控