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Shear band evolution and acoustic emission characteristics of sandstone containing non-persistent flaws

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 497-513页

作者： Shuting Miao Peng-zhi Pan Chuanqing zhang Lei Huo State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China CASIC Research Institute of Intelligent Decision Engineering Wuhan430040China

Direct shear tests were conducted on sandstone specimens under different constant normal stresses to study the coalescence of cracks between non-persistent flaws and the shear sliding characteristics of the shear-formed *** image correlation and acoustic emission(AE)techniques were used to monitor the evolution of shear bands at the rock bridge area and microcracking *** experimental results revealed that the shear stresses corresponding to the peak and sub-peak in the stressdisplacement curve are significantly affected by the normal *** localization bands emerged at both the tip of joints and the rock bridge,and their extension and interaction near the peak stress caused a surge in the AE hit rate and a significant decrease in the AE b *** and curvilinear strain bands were detected at low normal stress,while high normal stress generally led to more microcracking events and longer coplanar cracks at the rock bridge ***,an increase in normal stress resulted in a higher AE count rate and more energetic AE events during friction sliding along the shearformed *** was observed that the elastic energy released during the crack coalescence at the prepeak stage was much greater than that released during friction sliding at the post-peak *** than 75%of AE events were located in the low-frequency band(0e100 kHz),and this proportion continued to rise with increasing normal ***,more AE events of low AF value and high RA value were observed in specimens subjected to high normal stress,indicating that greater normal stress led to more microcracks of shear nature.

关键词： Shear band evolution Acoustic emission(AE) Crack coalescence Normal stress Shear sliding

10B-doped MCP detector developed for neutron resonance imaging at Back-n white neutron source

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Nuclear Science and Techniques 2024年第8期35卷 58-68页

作者： Qiang Li Li‑Jiao Wang Jing‑Yu Tang Xiang‑Biao Qiu Zhen Chen Mao‑Yuan zhao Chang‑Jun Ning Kai Pan Wei Xu Tao Li Su‑Peng Lu Han Yi Rui‑Rui fan Chang‑Qing Feng Rong zhang Xiao‑Yang Sun Qi An Hao‑fan Bai Jiang‑Bo Bai Jie Bao Ping Cao Qi‑Ping Chen Yong‑Hao Chen Zeng‑Qi Cui An‑Chuan fan fan‑Zhen Feng Min‑Hao Gu Chang‑Cai Han Zi‑Jie Han Guo‑Zhu He Yong‑Cheng He Yang Hong Yi‑Wei Hu Han‑Xiong Huang Wei Jiang zhi‑Jie Jiang Zheng‑Yao Jin Ling Kang Bo Li Gong Li Xiao Li Yang Li Jie Liu Rong Liu Shu‑Bin Liu Yi‑Na Liu Guang‑Yuan Luan Jie Ren zhi‑Zhou Ren Xi‑Chao Ruan zhao‑Hui Song Kang Sun zhi‑Xin Tan Sheng‑Da Tang Jin‑Cheng Wang Peng‑Cheng Wang zhao‑Hui Wang Zhong‑Wei Wen Xiao‑Guang Wu Xuan Wu Cong Xia Yong‑Ji Yu Guo‑Hui zhang Hang‑Chang zhang Lin‑Hao zhang Qi‑Wei zhang Xian‑Peng zhang Yu‑Liang zhang Yue zhang zhi‑Yong zhang zhi‑Hao Zhou Ke‑Jun Zhu Chong Zou Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China State Key Laboratory of Particle Detection and Electronics Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Dongguan Songshan Lake Future School Dongguan 523808China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China North Night Vision Science and Technology(Nanjing)Research Institute Co.Ltd Nanjing 211106China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China Institute of Modern Physics Fudan UniversityShanghai 200433China Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China China Academy of Engineering Physics Institute of Nuclear Physics and ChemistryMianyang 621900China USTC archaeometry lab University of Science and Technology of ChinaHefei 230026China Northwest Institute of Nuclear Technology Xi’an 710024China University of Chinese Academy of Sciences Beijing 100049China China Shipbuilding Trading Co. LtdBeijing 100044China

Neutron resonance imaging(NRI)has recently emerged as an appealing technique for neutron *** complexity surpasses that of conventional transmission imaging,as it requires a high demand for both a neutron source and ***,the progression of NRI technology has been sluggish since its inception in the 1980s,particularly considering the limited studies analyzing the neutron energy range above *** white neutron source(Back-n)at the China Spallation Neutron Source(CSNS)provides favorable beam conditions for the development of the NRI technique over a wide neutron energy range from eV to ***-sensitive microchannel plates(MCP)have emerged as a cutting-edge tool in the field of neutron detection owing to their high temporal and spatial resolutions,high detection efficiency,and low *** this study,we report the development of a 10B-doped MCP detector,along with its associated electronics,data processing system,and NRI experiments at the *** heavy elements such as gold,silver,tungsten,and indium can be easily identified in the transmission images by their characteristic resonance peaks in the 1–100 eV energy range;the more difficult medium-weight elements such as iron,copper,and aluminum with resonance peaks in the 1–100 keV energy range can also be *** particular,results in the neutron energy range of dozens of keV(Aluminum)are reported here for the first time.

关键词： Neutron resonance imaging 10B doped MCP detector White neutron source Sample nuclide identification

Early changes in corneal densitometry after FS-LASIK combined with accelerated corneal cross-linking for correction of high myopia

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International Journal of Ophthalmology(English edition) 2024年第7期17卷 1307-1312页

作者： Qing-Bao Wang Hong-Sheng Bi Xiao-fan Wang Hua fan Li Li Peng Ji Shandong University of Traditional Chinese Medicine Jinan 250014Shandong ProvinceChina Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine Shandong Clinical Medicine Research CenterJinan 250002Shandong ProvinceChina Shandong Academy of Eye Disease Prevention and Therapy Shandong Provincial Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Therapy of Ocular DiseasesJinan 250002Shandong ProvinceChina

AIM:To observe the effects of femtosecond laserassisted excimer laser in situ keratomileusis combined with accelerated corneal cross-linking(FS-LASIK Xtra)on corneal densitometry after correcting for high ***:In this prospectively study,130 patients underwent FS-LASIK or FS-LASIK Xtra for high *** right eyes were selected for inclusion in the study,of which 65 cases of 65 eyes in the FS-LASIK group,65 patients with 65 eyes in the FS-LASIK Xtra *** were evaluated for corneal densitometry at 1,3,and 6mo postoperatively using Pentacam Scheimpflug ***:Preoperative differences in corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups in different ranges were not statistically significant(P>0.05).Layer-by-layer analysis revealed statistically significant differences in the anterior(120μm),central,and total layer corneal densitometry between the FS-LASIK and FS-LASIK Xtra groups at 1 and 3mo postoperatively(all P0.05),the FS-LASIK Xtra group is higher than that of the FS-LASIK *** of different diameter ranges showed statistically significant differences between the FS-LASIK group and the FS-LASIK Xtra group at 1mo postoperatively in the ranges of 0–2,2–6,and 6–10 mm(both P0.05);At 3mo postoperatively,the FS-LASIK Xtra group is higher than that of the FS-LASIK group in the ranges of 0–2 and 2–6 mm(P0.05).At 6mo postoperatively,there were no statistically significant differences in corneal densitometry between the FS-LASIK group and the FS-LASIK Xtra group in different diameter ranges(all P>0.05).CONCLUSION:There is an increase in internal corneal densitometry during the early postoperative period after FS-LASIK Xtra for correction of high ***,the densitometry values decreased to the level of conventional FS-LASIK at 6mo after surgery,with the most significant changes observed in the superficial central zone.

关键词： femtosecond laser accelerated corneal cross-linking corneal densitometry high myopia femtosecond laser in situ keratomileusis

本土市场规模与中国制造业创新效率——基于“需求引致创新”理论的实证检验

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山西财经大学学报 2024年第1期46卷 69-83页

作者：韦志文冯帆南京大学经济学院江苏南京210093

基于2001—2016年中国27个制造业行业数据,在测度本土市场规模和创新效率的基础上,运用双向固定效应模型分析制造业行业“需求引致创新”功能的发挥及实现机制。研究发现,本土市场规模扩大显著提升制造业行业创新效率,并且在中、高技术... 详细信息

基于2001—2016年中国27个制造业行业数据,在测度本土市场规模和创新效率的基础上,运用双向固定效应模型分析制造业行业“需求引致创新”功能的发挥及实现机制。研究发现,本土市场规模扩大显著提升制造业行业创新效率,并且在中、高技术制造业行业及私营企业中的正向效应更明显。机制分析表明,本土市场规模对创新效率的正向牵引作用得益于“生产-分配-交换-消费”等国民经济循环的畅通。进一步分析发现,内生于本土市场的自主创新能力提升是双循环下制造业行业“需求引致创新”功能实现的主要创新范式。

关键词：本土市场规模需求引致创新制造业创新效率自主创新双循环新发展格局

Sparse-view neutron CT 3D image reconstruction algorithm based on split Bregman method

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Nuclear Science and Techniques 2024年第9期35卷 41-55页

作者： Teng-Fei Zhu Yang Liu zhi Luo Xiao-Ping Ouyang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Xi’an 710024China

As a complement to X-ray computed tomography(CT),neutron tomography has been extensively used in nuclear engineer-ing,materials science,cultural heritage,and industrial *** of the attenuation matrix for neutron tomography with a traditional analytical algorithm requires hundreds of projection views in the range of 0°to 180°and typically takes several hours to *** a low time-resolved resolution degrades the quality of neutron *** the number of projection acquisitions is an important approach to improve the time resolution of images;however,this requires efficient reconstruction ***,sparse-view reconstruction algorithms in neutron tomography need to be *** this study,we investigated the three-dimensional reconstruction algorithm for sparse-view neu-tron CT *** enhance the reconstructed image quality of neutron CT,we propose an algorithm that uses OS-SART to reconstruct images and a split Bregman to solve for the total variation(SBTV).A comparative analysis of the performances of each reconstruction algorithm was performed using simulated and actual experimental *** to the analyzed results,OS-SART-SBTV is superior to the other algorithms in terms of denoising,suppressing artifacts,and preserving detailed structural information of images.

关键词： Neutron CT OS-SART Sparse-view 3D reconstruction Split Bregman Total variation

Enrichment and reconfiguration of titanium-bearing phase in vortex smelting reduction process of vanadium-titanium magnetite

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Journal of Iron and Steel Research International 2024年第7期31卷 1582-1589页

作者： Yong-chao Han zhi-he Dou Rui zhang Ting-an zhang Shuai fang Key Laboratory for Ecological Metallurgy of Multimetallic Ores(Ministry of Education) Shenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

To comprehensively utilize the low-iron high-vanadium-titanium magnetite,a new method of vortex smelting reduction of vanadium-titanium magnetite was proposed,and the enrichment and reconstitution regularity of Ti-bearing phases in the slag was investigated through X-ray fluorescence spectrometry,X-ray photoelectron spectroscopy,X-ray diffraction analysis,and optical *** phase diagram revealed that the preferential crystallization of MgTi_(2)O_(5) can be achieved by adjusting the CaO,MgO,and TiO_(2) contents of *** predominant Ti-bearing phases in the slag obtained from the reduction process are MgxTi_(3_x)O_(5)(0≤x≤1)and CaTiO_(3).FeTiO_(3) is present at carbon-iron ratio(CR)=1.3,while MgTi_(2)O4 and TiC are formed at CR=*** enrichment of TiO_(2) in the slag increases first and then decreases as the CR increases,and at CR=1.1,the enrichment of TiO_(2) in the slag reaches 51.3 wt.%.Additionally,the concentrations of MgxTi_(3_x)O_(5)(0≤x≤1)and CaTiO_(3) in the slag,along with the grain width of MgxTi_(3_x)O_(5)(0≤x≤1),decrease with the increase in CR.

关键词： Vanadium-titanium magnetite Vortex smelting reduction Phase reconfiguration TiO_(2)enrichment

单纯前庭导水管扩大患儿人工耳蜗植入术后效果研究

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中华耳科学杂志 2024年第3期22卷 431-435页

作者：樊小勤林颖任寸寸查定军空军军医大学第一附属医院耳鼻咽喉头颈外科西安710032

目的探讨单纯前庭导水管扩大患儿在人工耳蜗(cochlear implant,CI)植入术后的听觉及言语能力效果,为术前咨询及术后效果预估提供参考依据。方法选取2017年8月至2021年4月空军军医大学第一附属医院耳鼻咽喉头颈外科收治的植入CI的59例... 详细信息

目的探讨单纯前庭导水管扩大患儿在人工耳蜗(cochlear implant,CI)植入术后的听觉及言语能力效果,为术前咨询及术后效果预估提供参考依据。方法选取2017年8月至2021年4月空军军医大学第一附属医院耳鼻咽喉头颈外科收治的植入CI的59例单纯大前庭导水管综合征(large veatibular aqueduct syndrome,LVAS)患儿为LVAS组,另选取CI植入时年龄、CI使用时长等临床资料相匹配的59例内耳结构正常的CI植入患儿为对照组。使用听觉行为分级标准(categories of auditory performance,CAP)、婴幼儿有意义听觉整合量表(infant-toddler meaningful auditory integration scale,IT-MAIS)或有意义听觉整合量表(meaningful auditory integration scale,MAIS)、言语可懂度分级标准(speech intelligibility rating,SIR)、有意义使用言语量表(meaningful use of speech scale,MUSS)对两组患儿进行CI植入术后的听觉及言语能力评估。结果 CI植入术后,LVAS组和对照组患儿CAP得分比较(4.06±1.42)分vs(3.66±1.34)分,IT-MAIS(或MAIS)得分比较(74.36±22.84)%vs(67.45±24.46)%,SIR得分比较(1.98±1.10)分vs(1.77±1.01)分,MUSS得分比较(28.55±23.70)%vs(23.26±20.97)%,差异均无统计学意义(P>0.05),但LVAS组患儿CAP和IT-MAIS(或MAIS)SIR和MUSS得分平均值均略高于内耳结构正常对照组患儿。结论单纯前庭导水管扩大患儿人工耳蜗植入术后听觉及言语效果与内耳结构正常的对照组患儿相似。

关键词：单纯前庭导水管扩大人工耳蜗听觉言语

Black holes as the source of dark energy:A stringent test with high-redshift JWST AGNs

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 181-188页

作者： Lei Lei Lei Zu Guan-Wen Yuan zhao-Qiang Shen Yi-Ying Wang Yuan-Zhu Wang Zhen-Bo Su Wen-Ke Ren Shao-Peng Tang Hao Zhou Chi zhang zhi-Ping Jin Lei Feng Yi-Zhong fan Da-Ming Wei Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of SciencesNanjing 210023China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China CAS Key Laboratory for Research in Galaxies and Cosmology Department of AstronomyUniversity of Science and Technology of ChinaHefei 230026China

Studies have proposed that there is evidence for cosmological coupling of black holes(BHs)with an index of k≈3;hence,BHs serve as the astrophysical source of dark ***,the data sample is limited for the redshifts of≤*** recent years,the James Webb Space Telescope(JWST)has detected many high-redshift active galactic nuclei(AGNs)and *** the JWST NIRSpec-/NIRCam-resolved AGNs,three are determined to be in early-type host galaxies with a redshift of z~***,their M_(*)and MBH are in tension with the predicted cosmological coupling of black holes with k=3 at a confidence level of~2σ,which challenges the hypothesis that BHs serve as the origin of dark *** work on high-redshift AGNs using the JWST will further assess such a hypothesis by identifying more early-type host galaxies in the higher mass range.

关键词： dark energy supermassive black hole active galactic nuclei James Webb Space Telescope

Inferring Mycobacterium Tuberculosis Drug Resistance and Transmission using Whole-genome Sequencing in a High TB-burden Setting in China

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Biomedical and Environmental Sciences 2024年第2期37卷 157-169页

作者： fan Yu Feng LIU Dong Xin CHEN Yi Wang OU Xi Chao MAO Qi zhi YANG Ting Ting WANG Xi Jiang HE Wen Cong zhaO Bing LIU Zhen Jiang ABULIMITI Maiweilanjiang AIHEMUTI Maimaitiaili GAO Qian zhaO Yan Lin Key Laboratory of Medical Molecular Virology(MOE/NHC/CAMS) School of Basic Medical SciencesShanghai Medical CollegeFudan UniversityShanghai 200032China National Tuberculosis Reference Laboratory Chinese Center for Disease Control and PreventionBeijing 102206China Hangzhou Red Cross Hospital Hangzhou 310005ZhejiangChina Xinjiang Uygur Autonomous Region Center for Disease Control and Prevention Urumqi 830026XinjiangChina Tuberculosis Dispensary of Kashgar Prefecture Kashgar 844099XinjiangChina

Objective China is among the 30 countries with a high burden of tuberculosis(TB)worldwide,and TB remains a public health *** Prefecture in the southern Xinjiang Autonomous Region is considered as one of the highest TB burden regions in ***,molecular epidemiological studies of Kashgar are *** A population-based retrospective study was conducted using whole-genome sequencing(WGS)to determine the characteristics of drug resistance and the transmission *** A total of 1,668 isolates collected in 2020 were classified into lineages 2(46.0%),3(27.5%),and 4(26.5%).The drug resistance rates revealed by WGS showed that the top three drugs in terms of the resistance rate were isoniazid(7.4%,124/1,668),streptomycin(6.0%,100/1,668),and rifampicin(3.3%,55/1,668).The rate of rifampicin resistance was 1.8%(23/1,290)in the new cases and 9.4%(32/340)in the previously treated *** resistance mutations were detected more frequently in lineage 2 strains than in lineage 3 or 4 strains,respectively:18.6%vs.8.7 or 9%,P023–1.954;P=0.036).Among all patients with drug-resistant tuberculosis(DR-TB),78.4%(171/218)were attributed to the transmission of DR-TB *** Our results suggest that drug-resistant strains are more transmissible than susceptible strains and that transmission is the major driving force of the current DR-TB epidemic in Kashgar.

关键词： Mycobacterium tuberculosis Whole-genome sequencing(WGS) Transmission Drug resistance Xinjiang