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基于机器视觉的煤矸石分选方法研究

中国矿业 2024年第1期33卷 114-121页

作者：石亦琨李峥李润田党长营曾志强北京星途探索科技有限公司北京100176 中北大学机械工程学院山西太原030051 先进制造技术山西省重点实验室山西太原030051

传统的煤矸石分选方法存在成本高、效率低以及安全性不足等问题。近年来,随着深度学习相关技术的迅速发展,基于目标检测算法的智能选矸已经成为矸石分选的重要研究方向。为实现矸石与煤块的高效分选,本文提出一种基于机器视觉与深度学... 详细信息

传统的煤矸石分选方法存在成本高、效率低以及安全性不足等问题。近年来,随着深度学习相关技术的迅速发展,基于目标检测算法的智能选矸已经成为矸石分选的重要研究方向。为实现矸石与煤块的高效分选,本文提出一种基于机器视觉与深度学习相结合的检测方法。该方法以YOLOv5s模型为基础,首先,在主干部分中加入卷积注意力模块(CBAM)用于提高网络的特征提取能力;其次,在颈部网络部分采用加权双向特征金字塔结构(BiFPN)来增强网络的多尺度特征融合,避免漏检与误检现象的发生;再次,在预测部分使用EIoU函数作为改进后模型的损失函数,以进一步提高检测精度;最后,在训练前对原有数据集进行扩充,使模型的泛化能力得到进一步加强。实验结果表明:改进后模型平均检测精度为95.3%,较原模型提高了2.1%,能够有效地替代人工分选。

关键词：煤矸石分选深度学习 YOLOv5s模型 BiFPN结构损失函数

Linearized Double-Shock Approximate Riemann Solver for Augmented Linear Elastic Solid

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Numerical Mathematics(Theory,Methods and Applications) 2022年第1期15卷 141-164页

作者： zhiqiang zeng Chengliang Feng Changsheng Yu Tiegang Liu LMIB and School of Mathematical Sciences Beihang UniversityBeijing 100191China

In this work,in order to capture discontinuities correctly in linear elastic solid,augmented internal energy is defined according to the first law of thermodynamics and Hooke’s *** non-conservative linear elastic system is then rewritten into a conservative form with the help of an augmented total energy *** find that the non-physical oscillations occur to the popular HLL and HLLC approximate Riemann solvers when directly applied to simulate the augmented linear elastic *** analyze the intrinsic reason by defining a discrepancy factor which can be used to estimate the difference of the total stress across a contact discontinuity,where it is physically required to be *** discover that non-physical oscillations inevitably appear in the vicinity of the contact discontinuity if this factor is away from zero for an approximate Riemann problem *** order to overcome this difficulty,we propose an approximate Riemann solver based on the linearized double-shock *** analysis and numerical results show that in comparison to the HLL and HLLC approximate Riemann solvers,the present linearized double-shock Riemann solver can eliminate the non-physical oscillations effectively.

关键词： Linear elastic solid approximate Riemann solver discrepancy factor

Improved impossible differential cryptanalysis of large-block Rijndael

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Science China(Information Sciences) 2019年第3期62卷 5-18页

作者： Ya LIU Yifan SHI Dawu GU Bo DAI Fengyu ZHAO Wei LI zhiqiang LIU zhiqiang zeng Engineering Research Center of Optical Instrument and System Ministry of Education Shanghai Key Lab of Modern Optical System University of Shanghai for Science and Technology State Key Laboratory of Cryptology Department of Computer Science and Engineering Shanghai Jiao Tong University School of Computer Science and Technology Donghua University Shanghai Key Laboratory of Scalable Computing and Systems Shanghai Key Laboratory of Integrated Administration Technologies for Information Security Science and Technology on Information Assurance Laboratory

Rijndael is a substitution-permutation network（SPN） block cipher for the AES development process. Its block and key sizes range from 128 to 256 bits in steps of 32 bits, which can be denoted by Rijndael-b-k, where b and k are the block and key sizes, respectively. Among them, Rijndael-128-128/192/256,that is, AES, has been studied by many researchers, and the security of other large-block versions of Rijndael has been exploited less frequently. However, more attention has been paid to large-block versions of block ciphers with the fast development of quantum computers. In this paper, we propose improved impossible differential attacks on 10-round Rijndael-256-256, 10-round Rijndael-224-256, and 9-round Rijndael-224-224 using precomputation tables, redundancies of key schedules, and multiple impossible differentials. For 10-round Rijndael-256-256, the data, time, and memory complexities of our attack were approximately 2;chosen plaintexts, 2;encryptions, and 2;blocks, respectively. For 10-round Rijndael-224-256, the data, time, and memory complexities of our attack were approximately 2;chosen plaintexts, 2;encryptions, and 2;blocks, respectively. For 9-round Rijndael-224-224, the data, time, and memory complexities of our attack are approximately 2;chosen plaintexts, 2;encryptions, and 2;blocks,respectively, or 2;chosen plaintexts, 2;encryptions, and 2;blocks, respectively. To the best of our knowledge, our results are currently the best on Rijndael-256-256 and Rijndael-224-224/256.

关键词： block cipher Rijndael precomputation tables impossible di?erentials multiple impossible differential attacks

基于显微镜标尺法的碳纤维复合材料孔隙率测量不确定度评定

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理化检验（物理分册） 2024年第6期60卷 15-17页

作者：马锐曾志强刘岩岩中国商飞上海飞机制造有限公司上海201324

使用显微镜标尺法对碳纤维复合材料孔隙率试验结果进行测量不确定度评定,对不确定度来源进行分析,对各个不确定度分量进行计算。结果表明:影响不确定度的主要因素是孔隙格子数的测量重复性。

关键词：显微镜标尺法碳纤维复合材料孔隙格子数测量不确定度重复性测量误差

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基于改进YOLOv5的机床刀具识别方法

工具技术 2024年第3期58卷 156-160页

作者：闵筱萌杜文华段能全曾志强刘莞尔中北大学机械工程学院

针对目前机床刀具分类应用较少、预处理复杂、目标检测适用范围小且识别精度不高的问题,提出基于改进的YOLO v5机床刀具图像识别算法,利用卷积神经网络在特征提取层加入CBAM注意力模块,可以更清晰地提取图像特征,在特征融合层加入CARAF... 详细信息

针对目前机床刀具分类应用较少、预处理复杂、目标检测适用范围小且识别精度不高的问题,提出基于改进的YOLO v5机床刀具图像识别算法,利用卷积神经网络在特征提取层加入CBAM注意力模块,可以更清晰地提取图像特征,在特征融合层加入CARAFE上采样模块,使刀具的表面特征恢复更好,可以减少特征融合时部分特征的丢失。实验结果表明,改进后的算法使机床刀具等小目标检测精度和检测速度明显提升,且改进后的模型平均精度为96.8%,比YOLO v4模型提高了14.96%,比YOLO v5模型提高了2%。本方法能对不同刀具进行识别,为工业制造中机械零件的识别提供了新的算法支持。

关键词：机床刀具检测注意力机制 YOLO v5 目标检测特征提取

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乙酸乙酯皂化反应和碘钟反应实验改进

大学化学 2024年第8期39卷 197-203页

作者：张睿桐曾志强张晓光南开大学化学学院

针对乙酸乙酯皂化反应和碘钟反应存在溶液恒温效率低、温度不均匀以及溶液混合不均匀、反应不均匀、数据偏差大等问题，从反应器和反应物的混合方式两方面进行改进，即采用夹套烧杯配合反应瓶作为反应器，使用多点位磁力搅拌器快速混合... 详细信息

针对乙酸乙酯皂化反应和碘钟反应存在溶液恒温效率低、温度不均匀以及溶液混合不均匀、反应不均匀、数据偏差大等问题，从反应器和反应物的混合方式两方面进行改进，即采用夹套烧杯配合反应瓶作为反应器，使用多点位磁力搅拌器快速混合反应物。改进后使溶液恒温均匀稳定、高效，同时反应物分散均匀、反应快速，可以准确地测量溶液的电导率和变蓝时间，从而得到准确的反应级数、速率常数、活化能等数据。

关键词：乙酸乙酯皂化反应碘钟反应夹套烧杯实验改进

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A Genuinely Two-Dimensional HLL-Type Approximate Riemann Solver for Hypo-Elastic Plastic Flow

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Communications in Computational Physics 2023年第7期34卷 318-356页

作者： zhiqiang zeng Chengliang Feng Xiaotao Zhang Shengtao Zhang Tiegang Liu LMIB and School of Mathematical Sciences Beihang UniversityBeijing100191China Haifang(Shanghai)Technology Co. Ltd.Shanghai200000China

In this work,a genuinely two-dimensional HLL-type approximate Riemann solver is proposed for hypo-elastic plastic *** consider the effects of wave interaction from both the x-and y-directions,a corresponding 2D elastic-plastic approximate solver is constructed with elastic-plastic transition *** resultant numerical flux combines one-dimensional numerical flux in the central region of the cell edge and two-dimensional flux in the cell vertex *** stress is updated separately by using the velocity obtained with the above approximate Riemann *** numerical tests,including genuinely two-dimensional examples,are presented to test the performances of the proposed *** numerical results demonstrate the credibility of the present 2D approximate Riemann solver.

关键词： Elastic plastic flow elastic-plastic transition multi-dimensional effect twodimensional approximate Riemann solver

A Cell-Centered Lagrangian Scheme with an Elastic-Perfectly Plastic Solid Riemann Solver for Wave Propagations in Solids

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Advances in Applied Mathematics and Mechanics 2022年第3期14卷 703-724页

作者： Qian Chen Li Li Jin Qi zhiqiang zeng Baolin Tian Tiegang Liu Institute of Applied Physics and Computational Mathematics Beijing 100094China LMIB and School of Mathematics and Systems Science Beihang UniversityBeijing 100191China

A cell-centered Lagrangian scheme is developed for the numerical simula-tion of wave propagations in one dimensional(1D)elastic-plasticﬂ*** classical elastic-plastic material model initially proposed by Wilkins is *** linear elas-tic model(Hooke’s Law),perfectly plastic model and von Mises yield criterion are used to describe the constitutive relationship of elastic-plastic *** second-order ex-tension of this scheme is achieved by a linear reconstruction *** numer-ical tests are simulated to check the capability of this scheme in capturing nonlinear elastic-plastic *** with the well-developed operator splitting method used in simulating elastic-plasticﬂow,this scheme is more accurate due to the con-sideration of a list of 64 different types of the nonlinear elastic-plastic waves when constructing the elastic-perfectly plastic Riemann *** numerical simulations of typical examples show competitive results.

关键词： Elastic-plasticﬂow cell-centered Lagrangian scheme elastic-perfectly solid Riemann problem wave propagation

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低渗透油藏用纳米乳液性能评价与应用

能源化工 2024年第4期45卷 52-55页

作者：王康赵红林逯贵广曾志强中石化南京化工研究院有限公司江苏南京210048

结合低渗透油藏驱油技术特点,研究了纳米乳液降低界面张力能力、耐温抗盐能力、改变岩石润湿性能力和驱油效果。试验结果表明,纳米乳液质量浓度为1 000 mg/L时,与原油的界面张力能够达到10-3mN/m数量级,并且表现出较强的耐温抗盐和改善... 详细信息

结合低渗透油藏驱油技术特点,研究了纳米乳液降低界面张力能力、耐温抗盐能力、改变岩石润湿性能力和驱油效果。试验结果表明,纳米乳液质量浓度为1 000 mg/L时,与原油的界面张力能够达到10-3mN/m数量级,并且表现出较强的耐温抗盐和改善岩石润湿性的性能,质量浓度为2 000mg/L的纳米乳液的水溶液能在岩心水驱的基础上进一步将采收率提高20%以上。该纳米乳液产品已在江苏油田井组应用,取得了显著的驱油效果。

关键词：低渗透油藏纳米乳液驱油界面张力润湿性