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Numerical and experimental investigation on hydraulic-electric rock fragmentation of heterogeneous granite

International Journal of Mining Science and Technology 2024年第1期34卷 15-29页

作者： Xiaohua Zhu Ling He Weiji Liu Yunxu Luo Youjian zhang Wuji Tang School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China School of Mechanical Engineering Sichuan University of Science and EngineeringYibin 643002China

Hydraulic-electric rock fragmentation(HERF)plays a significant role in improving the efficiency of high voltage pulse rock ***,the underlying mechanism of HERF remains *** this study,considering the heterogeneity of the rock,microscopic thermodynamic properties,and shockwave time domain waveforms,based on the shockwave model,digital imaging technology and the discrete element method,the cyclic loading numerical simulations of HERF is achieved by coupling electrical,thermal,and solid mechanics under different formation temperatures,confining pressure,initial peak voltage,electrode bit diameter,and loading ***,the HERF discharge system is conducive to the laboratory experiments with various electrical parameters and the resulting broken pits are numerically reconstructed to obtain the geometric *** results show that,the completely broken area consists of powdery rock *** the pre-broken zone,the mineral cementation of the rock determines the transition of type CⅠcracks to type CⅡand type CⅢ***,the peak pressure of the shockwave increased with initial peak voltage but decreased with electrode bit diameter,while the wave front time ***,increasing well depth,formation temperature and confining pressure augment and inhibit HERF,but once confining pressure surpassed the threshold of 60 MPa for 152.40,215.90,and 228.60 mm electrode bits,and 40 MPa for 309.88 mm electrode bits,HERF is ***,for the same kind of rock,the volume and width of the broken pit increase with higher initial peak voltage and rock fissures will promote ***,the electrode drill bit with a 215.90 mm diameter is more suitable for drilling pink *** research contributes to a better microscopic understanding of HERF and provides valuable insights for electrode bit selection,as well as the optimization of circuit parameters for HERF technology.

关键词： Hydraulic-electric rock fragmentation Shockwave Thermodynamics Microcracks Weak Linear Parallel Bond Model

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Formation mechanism of Fe-based amorphous powders produced by spark erosion

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Journal of Materials Science & Technology 2024年第3期170卷 33-46页

作者： Chekai Liu Ran Li Jiazi Bi Ding Ma Xiaobin Liu Tao zhang School of Materials Science and Engineering Key Laboratory of Aerospace Materials and Performance(Ministry of Education)Beihang UniversityBeijing 100191China

Spark erosion is a convenient,flexible,and low-cost method to quickly produce fine powders of metals,alloys,and semiconductors in size ranging from nearly a hundred micrometers to submicrometer by repetitive spark *** to the complexity of the powder-forming journey,normally accompanied by high temperature,high pressure,decomposition,diffusion and rapid quenching caused by discharge plasma,the mechanisms of powder formation and possible contaminant infiltration are still controversial,posing a significant challenge to control particle size and chemical composition of the powder produced by this *** this study,Fe-based amorphous powders in different particle-size distributions with high sphericity were fabricated by spark erosion under different discharge-energy *** max-imum particle size of the resultant powders can be correlated with discharge parameters,crater depth,and crater radius,respectively.A multi-ring-breakup model is proposed to reveal the particle-size distribution of the powder formed from the electrode melt under a single-pulse ***,a dielectric-element infiltration model is provided to quantitatively evaluate the infiltration mass ratio of the contaminant elements,stemming from the decomposed products of dielectric liquid,in the resultant powder with different particle *** models verified through the experimental data are significant for the development of high-performance fine Fe-based amorphous powder with controlled particle size and chemical composition.

关键词： Amorphous alloy Particle Spark erosion Infiltration Modeling

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Targeted therapeutic effects of oral magnetically driven pectin nanoparticles containing chlorogenic acid on colon cancer

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Particuology 2024年第1期84卷 53-59页

作者： Huatai Zhu Limei zhang Fujia Kou jingyang Zhao Jiandu Lei jing He Beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijing100083China Institute of Biopharmaceutical and Health Engineering Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen518055China

Oral colonic nano-drug delivery system has attracted growing attention in treating colon cancer for their excellent ***,the unique and complex structure of the gastrointestinal tract is still an obstacle to the safe delivery of drugs targeting sites in colon ***,we designed magnetically driven dual-targeted oral colonic nanoparticles loaded with chlorogenic acid using pectin and oleic acid-modified iron oxide(Fe3O4@OA).Specific degradation of pectin by pectinase produced by colonic flora and magnetic fields applied to the colon confers specific targeting of nanoparticles to the *** order to overcome the challenge of preparing magnetically driven nanoparticles with small and homogeneous particle sizes by a single conventional method,we developed the combined ultrasound-emulsification *** average particle size of the prepared nanoparticles was 81.04±1.02 nm,which showed good drug release in the simulated colonic *** vitro anticancer studies,the drug-loaded nanoparticles possess an obvious toxicity and apoptosis-inducing ability against cancer ***,the hemolysis results demonstrated the safety of the nanoplatform(PET/CGA/Fe_(3)O_(4)@OA).This work holds broad prospects as a new treatment modality for colon cancer.

关键词： Pectin Chlorogenic acid Ultrasound-emulsion Magnetically driven Colon cancer Colon targeted

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Transfer matrix method for free and forced vibrations of multi-level functionally graded material stepped beams with different boundary conditions

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 983-1000页

作者： Xiaoyang SU Tong HU Wei zhang Houjun KANG Yunyue CONG Quan YUAN School of Civil Engineering and Architecture Guangxi UniversityNanning 530004China Scientific Research Center of Engineering Mechanics Guangxi UniversityNanning 530004China State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures Guangxi UniversityNanning 530004China

Functionally graded materials(FGMs)are a novel class of composite materials that have attracted significant attention in the field of engineering due to their unique mechanical *** study aims to explore the dynamic behaviors of an FGM stepped beam with different boundary conditions based on an efficient solving *** the assumptions of the Euler-Bernoulli beam theory,the governing differential equations of an individual FGM beam are derived with Hamilton’s principle and decoupled via the separation-of-variable ***,the free and forced vibrations of the FGM stepped beam are solved with the transfer matrix method(TMM).Two models,i.e.,a three-level FGM stepped beam and a five-level FGM stepped beam,are considered,and their natural frequencies and mode shapes are *** demonstrate the validity of the method in this paper,the simulation results by ABAQUS are also *** this basis,the detailed parametric analyses on the frequencies and dynamic responses of the three-level FGM stepped beam are carried *** results show the accuracy and efficiency of the TMM.

关键词： transfer matrix method(TMM) free vibration forced vibration functionally graded material(FGM) stepped beam

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混合卷积神经网络用于高光谱小麦品种鉴别

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光谱学与光谱分析 2024年第3期44卷 807-813页

作者：李国厚李泽旭金松林赵文义潘细朋梁政秦莉张卫东河南科技学院信息工程学院河南新乡453003 北京邮电大学人工智能学院北京100876 桂林电子科技大学计算机与信息安全学院广西桂林541004 安徽大学互联网学院安徽合肥230039 宁波大学信息科学与工程学院浙江宁波315211

不同品种的小麦满足了市场的不同需求,同时也会带来小麦品种混杂的风险。为了提高小麦品种的纯度进而提高选种、育种、加工等环节的经济价值,小麦种子的鉴别起到关键作用。传统的小麦品种纯度理化分析鉴别方法,鉴定时间长且破坏种子,已... 详细信息

不同品种的小麦满足了市场的不同需求,同时也会带来小麦品种混杂的风险。为了提高小麦品种的纯度进而提高选种、育种、加工等环节的经济价值,小麦种子的鉴别起到关键作用。传统的小麦品种纯度理化分析鉴别方法,鉴定时间长且破坏种子,已不能满足现代农业的迫切需要。高光谱成像作为近年来发展迅速的一种快速、高效、无损的新型鉴别技术,在种子品种鉴别领域取得了显著成效。然而,已有的大多数高光谱分类方法仅利用光谱信息,没有充分考虑空间信息,分类效果较差。为了解决上述问题,利用高光谱成像设备采集8个品种的小麦种子正背面的高光谱图像,基于这些高光谱数据集,提出一种基于注意力机制的混合卷积神经网络的高光谱小麦品种鉴别方法,主要利用三维卷积和二维卷积的互补优势特性提取小麦的有价值特征,进而提高小麦品种的鉴别效果。具体而言,首先提取小麦品种的感兴趣区域,并利用多元散射校正方法削弱由于散射水平差异带来的同一品种的光谱差异。同时,利用主成分分析方法减少三维数据的无用光谱波段,进而保留并压缩对鉴别小麦品种有价值的特征。随后,利用三维卷积获取空间维度和不同光谱间的特征信息,二维卷积获取空间信息和图像的自身固有的特征信息,并在二维卷积模型中引入注意力机制进一步增强图像的特征信息的提取。最后在全连接层实现同一区域不同小麦品种的鉴别。实验表明,所提出的方法比其他方法具有较好的分类性能,分类准确率达97.92%。此外,所提出的方法对小样本数据也具有较好的分类性能。总的来说,提出的方法对于高光谱小麦种子鉴别具有较好的有效性和鲁棒性,为小麦种子的在线鉴别提供了一种新的方法。

关键词：高光谱成像小麦品种注意力机制混合卷积

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区块链中的公钥密码:设计、分析、密评与展望

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计算机学报 2024年第3期47卷 491-524页

作者：黄可李雄袁晟刘星宇张小松电子科技大学计算机科学与工程学院(网络空间安全学院) 成都611731

比特币的成功,吸引了人们研究区块链、加密货币以及相关的公钥密码算法的兴趣.然而,将公钥密码算法成功应用于新的加密货币设计,仍然面临很多挑战.一方面,设计适用于区块链的公钥密码算法并非易事,这是因为区块链具有独特的结构和应用环... 详细信息

比特币的成功,吸引了人们研究区块链、加密货币以及相关的公钥密码算法的兴趣.然而,将公钥密码算法成功应用于新的加密货币设计,仍然面临很多挑战.一方面,设计适用于区块链的公钥密码算法并非易事,这是因为区块链具有独特的结构和应用环境,对密码算法提出了严苛的要求,如短签名长度、无需可信第三方等.随着区块链向多功能发展,需要考虑更多需求和功能.其中,安全性、隐私性和去中心化这三个问题涉及“三元悖论”,同时解决两个或更多问题通常较为困难.当前的研究文献主要关注区块链技术及其原理,对相关密码算法的系统调研和分析不足.为了帮助读者了解和逐步掌握公钥密码算法设计的技巧和经验,并填补相关调研文献的空白,本文对相关密码算法的现状与研究进行了系统而深入的调研.通过8个案例、2个通用构造以及相关证明技巧的讨论,本文为读者提供了由易到难的算法设计教程和相关经验.此外,本文还探讨了商用密码应用与安全性评估(简称“密评”)相关的概念和研究,以促进区块链相关密码技术按照国家技术标准的要求进行实际应用.最后,本文对相关密码算法的设计难点进行了系统总结,并展望了未来的研究热点和具有挑战性的问题.

关键词：区块链公钥密码算法算法设计复杂性分析密评

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广东省优秀运动员免疫球蛋白指标分布特征及其影响因素

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中山大学学报（自然科学版）（中英文） 2024年第1期63卷 78-85页

作者：张援郜艳晖宋爱晶刘晴广东省体育科学研究所/国家体育总局体能与训练适应控制系统重点实验室广东广州510663 暨南大学基础医学与公共卫生学院广东广州510632

基于大样本探讨广东省优秀在训运动员长期大强度训练期间免疫球蛋白(Ig)水平(IgG、IgA、IgM)的分布特征及影响因素,并建立相应的百分位数参考值和范围。选取2012—2019年广东省35个运动项目的优秀运动员共2274名作为研究对象。采用单样... 详细信息

基于大样本探讨广东省优秀在训运动员长期大强度训练期间免疫球蛋白(Ig)水平(IgG、IgA、IgM)的分布特征及影响因素,并建立相应的百分位数参考值和范围。选取2012—2019年广东省35个运动项目的优秀运动员共2274名作为研究对象。采用单样本t检验比较运动员与普通健康人群Ig水平,两独立样本t检验比较不同性别和运动类型的Ig水平,以及单因素方差分析比较不同运动项群、季节和全运备战年份的Ig水平。应用广义估计方程分析Ig水平的影响因素。采用偏度系数-中位数-变异系数方法制定Ig水平的百分位数参考值和参考值范围。结果显示,运动员IgG(P<0.01)、IgA(P<0.001)、IgM(P<0.001)水平分别为(11.50±2.20)、(1.92±0.66)和(1.30±0.58)g/L,均显著低于普通健康人群;男性运动员的IgG、IgM水平均显著低于女性(P<0.001);体能主导类运动员的IgG水平显著低于技能主导类运动员(P<0.01);不同运动项群运动员的IgG(P<0.001)、IgM水平(P<0.01)分别有统计学差异;不同季节运动员的IgG水平具有统计学差异(P<0.05)。结果还显示,性别(P<0.001)、运动项群(P<0.05)和季节(P<0.01)是影响运动员IgG水平的关键因素;性别(P<0.001)和运动项群(P<0.01)是影响运动员IgM水平的关键因素。此外,运动员IgG、IgA、IgM水平95%参考值范围分别为7.34~16.56、0.82~3.47和0.46~2.91 g/L,其中男性分别为7.34~15.71、0.88~3.47和0.46~2.27 g/L;女性分别为7.96~16.56、0.82~3.36、0.63~2.91 g/L。本研究结果提示:在对运动员开展免疫机能状态监控时需关注性别、运动项目、不同季节气候条件和温度对运动员免疫力的影响。本研究构建的运动员IgG、IgA、IgM指标百分位数参考值和参考值范围,能更精准评估运动员的身体免疫机能状态,为运动员的训练监控、免疫系统评估和营养调控提供科学依据。

关键词：免疫球蛋白(Ig) 运动员训练监控参考值影响因素

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Real-time pore structure evolution difference between deep and shallow coal during gas adsorption:A study based on synchrotron radiation small-angle X-ray scattering

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Particuology 2024年第4期87卷 114-123页

作者： Yingfeng Sun Shuaipeng Zhu Fei Xie Chujian Han Yixin Zhao Zetian zhang Research Institute of Macro-Safety Science University of Science and Technology BeijingBeijing100083China Schoolof Civiland Resource Engineering University of Science and Technology BeijingBeijing100083China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei230029China Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources China University of Mining and Technology(Beijing)Bejing10003 China School of Energy and Mining Engineering China University of Mining and Technology(Beijing)Beijing100083China Key Laboratory of Deep Earth Science and Engineering(Sichuan University) Ministry of EducationChengdu610065China

Coal seam CO_(2) sequestration is an important option to address global warming.A better knowledge on coal pore structure evolution during gas adsorption can provide guidance for coal seams CO_(2) ***,few investigations on the pore structure evolution differences between the deep and shallow coal were conducted during gas *** this study,based on the real-time synchrotron radiation small-angle X-ray scattering(SAXS)observation,the average pore diameter and pore surface fractal dimension evolution differences between deep and shallow coal were investigated from the as-pects of coal compositions and stress *** types of coal deformation(inner-swelling and outer-swelling)coexist during gas *** compositions have significant impact on the dominance of deformation *** dominance of inner-swelling in deep coal is induced by the higher ash contents,and there is the decrease of average pore diameter during gas *** impact of stress-history(burial depth)on adsorption-induced deformation is more prominent than that of gas adsorption *** deep coal,the surface fractal dimension evolution presents a negative correlation with the evolution of pore *** shallow coal,the surface fractal dimension evolution presents a Langmuir-type correlation with the adsorption time.

关键词： Coal Gas adsorption Synchrotron radiation small-angle X-ray scattering Pore diameter Surface fractal dimension

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More Than Lightening:A Self-Supervised Low-Light Image Enhancement Method Capable for Multiple Degradations

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 622-637页

作者： Han Xu Jiayi Ma Yixuan Yuan Hao zhang Xin Tian Xiaojie Guo the Electronic Information School Wuhan UniversityWuhan 430072China IEEE the Department of Electronic Engineering Chinese University of Hong KongHong Kong 999077China the College of Intelligence and Computing Tianjin UniversityTianjin 300350China

Low-light images suffer from low quality due to poor lighting conditions,noise pollution,and improper settings of *** enhance low-light images,most existing methods rely on normal-light images for guidance but the collection of suitable normal-light images is *** contrast,a self-supervised method breaks free from the reliance on normal-light data,resulting in more convenience and better *** self-supervised methods primarily focus on illumination adjustment and design pixel-based adjustment methods,resulting in remnants of other degradations,uneven brightness and *** response,this paper proposes a self-supervised enhancement method,termed as *** can handle multiple degradations including illumination attenuation,noise pollution,and color shift,all in a self-supervised *** attenuation is estimated based on physical principles and local neighborhood *** removal and correction of noise and color shift removal are solely realized with noisy images and images with color ***,the comprehensive and fully self-supervised approach can achieve better adaptability and *** is applicable to various low light conditions,and can reproduce the original color of scenes in natural *** experiments conducted on four public datasets demonstrate the superiority of SLIE to thirteen state-of-the-art *** code is available at https://***/hanna-xu/SLIE.

关键词： Color correction low-light image enhancement self-supervised learning.

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Correlation analysis of human papillomavirus E6/E7 mRNA detection with diagnosis,prognosis and recurrence risk in patients with cervical epithelioma

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World Journal of Clinical Cases 2024年第20期12卷 4146-4153页

作者： Ling-Li zhang Ming-Yan Du Xin Du Jie Duan Dong-Mei Yao jing jing Chun Feng Lin song Department of Gynaecology Maternal and Child Health Hospital of Hubei ProvinceWuhan 430075Hubei ProvinceChina Department of Gynaecology China Resources WISCO General HospitalWuhan 430080Hubei ProvinceChina Department of Surgery Maternal and Child Health Hospital of Hubei ProvinceWuhan 430075Hubei ProvinceChina

BACKGROUND Cervical intraepithelial neoplasia(CIN)is an important precursor of cervical *** detection and treatment can reduce the incidence of cervical *** To investigate the detection rate of human papillomavirus(HPV)E6/E7 mRNA in cervical tissue of patients with different types of epithelial cell neoplasia(CIN)and its relationship with CIN progression and *** One hundred women with HPV infection detected by cervical exfoliation cytology between January 2022 and January 2023 were retrospectively *** patients were graded CIN based on colposcopy and cervical *** positive expression rates of HPV E6/E7 mRNA and HPV[polymerase chain reaction(PCR)-reverse dot crossing]were compared among all *** with HPV E6/E7 mRNA expression in the grade 1 CIN group were followed up for 1 *** relationship between atypical squamous epithelium and high malignant epithelial neoplasia was investigated by univariate and multivariate *** The diagnostic sensitivity,specificity,and sensitivity of PCR-reverse point hybrid ization technology for secondary CIN were 70.41%,70.66%,and 0.714,*** and specificity for secondary CIN were 752%and 7853%,respectively,the area under the curve value was *** Multifactorial model analysis revealed that the HPV positive rates and the HPV E6/E7 mRNA positive rates were independent risk factors of CIN grade I(P<0.05).In CIN grade I patients with positive for HPV E6/E7 mRNA,in its orientation to grade CIN patients,in its orientation to grade CIN patients,at 69.2%,compared with patients negative for HPV E6/E7 mRNA(30.8%),significant difference(P<0.05).CONCLUSION HPV E6/E7 mRNA and HPV(PCR-reverse dot hybrid)positive expression have a close relationship with CINgrade disease progression and is an independent risk factor for high-grade CIN lesions.

关键词： Cervical epithelial neoplasia Human papilloma change with virus E6/E7 mRNA Cervical cancer Correlation analysis

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