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Assessing the range of blasting-induced cracks in the surrounding rock of deeply buried tunnels based on the unified strength theory

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Journal of Central South University 2024年第7期31卷 2341-2364页

作者： li liang CHEN Jia-jun ZHAO lian-heng HE Ke-pei HU Shi-hong li hua-long School of Civil Engineering Central South UniversityChangsha 410075China Key Laboratory of Heavy-haul Railway Engineering Structure Ministry of EducationCentral South UniversityChangsha 410075China Hunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering Structure Central South UniversityChangsha 410075China

Blasting-induced cracks in the rock surrounding deeply buried tunnels can result in water gushing and rock mass collapse,posing significant safety ***,previous theoretical studies on the range of blasting-induced cracks often ignore the impact of the in-situ stress,especially that of the intermediate principal *** particle displacement−crack radius relationship was established in this paper by utilizing the blasthole cavity expansion equation,and theoretical analytical formulas of the stress−displacement relationship and the crack radius were derived with unified strength theory to accurately assess the range of cracks in deep surrounding rock under a blasting *** analysis showed that the crushing zone size was positively correlated with in-situ stress,intermediate principal stress,and detonation pressure,whereas negatively correlated with Poisson ratio and decoupling *** dilatancy angle-crushing zone size relationship exhibited nonmonotonic *** relationships in the crushing zone and the fracture zone exhibited opposite trends under the influence of only in-situ stress or intermediate principal *** the in-situ stress increased from 0 to 70 MPa,the rate of change in the crack range and the attenuation rate of the peak vibration velocity gradually slowed.

关键词： deep drilling and blasting cracks in surrounding rock unified strength theory intermediate principle stress in-situ stress cavity expansion dilatancy characteristics

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基于Fourier-TOuNN的鲁棒性拓扑优化设计

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计算力学学报 2024年第2期41卷 241-247页

作者：高兴军李隆华李颖雄广东工业大学土木与交通工程学院广州510006 西南交通大学智慧城市与交通学院成都611756

为推广拓扑优化设计方法的工程应用,需要在设计过程中考虑结构鲁棒性以应对实际工程荷载的随机性。本文基于神经网络提出了鲁棒性结构拓扑优化设计的高效方法。该方法通过优化Fourier-TOuNN神经网络的权值更新描述结构拓扑的密度变量,... 详细信息

为推广拓扑优化设计方法的工程应用,需要在设计过程中考虑结构鲁棒性以应对实际工程荷载的随机性。本文基于神经网络提出了鲁棒性结构拓扑优化设计的高效方法。该方法通过优化Fourier-TOuNN神经网络的权值更新描述结构拓扑的密度变量,并引入随机荷载下结构柔顺度平均值和标准差的加权总和作为目标函数,从而定义了随机荷载下的结构鲁棒性优化问题。利用神经网络的自动反向微分功能,实现了优化过程中灵敏度的直接求解。借助Fourier-TOuNN细部尺寸可控特性,可在结构中生成细小支撑以抵抗随机荷载。数值算例表明,采用本文提出的方法可以高效地获得鲁棒性稳健的优化设计结果。

关键词：拓扑优化鲁棒性设计随机荷载神经网络傅里叶投影

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Structure engineering of cathode host materials for li-S batteries

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Rare Metals 2024年第4期43卷 1370-1389页

作者： Jia-Jun long hua Yu Wen-Bo liu School of New Energy and Materials Southwest Petroleum UniversityChengdu610500China School of Mechanical Engineering Sichuan UniversityChengdu610065China

Although lithium-sulfur batteries are one of the favorable candidates for next-generation energy storage devices,a few key challenges that have not been addressed have limited its *** challenges include lithium dendrite growth in the anode side,volume change of the active material,poor electrical conductivity,dissolution and migration of poly sulfides,and slow rate of solid-state reactions in the cathode *** the electrochemical performance of lithium-sulfur batteries is greatly affected by the design of the cathode host material,it has also been widely discussed in addressing the abovementioned *** this paper,three design ideas of cathode host materials in terms of microstructure,crystal structure and electronic structure are introduced and ***,the current progress of these three structural design strategies and their effects on the electrochemical performance of lithium-sulfur batteries are discussed in ***,future directions in the structural design of cathode materials for lithium-sulfur batteries are discussed and further perspectives are provided.

关键词： lithium-sulfur batteries Structure engineering Cathode Host materials

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基于改进NSGA-Ⅲ算法的抽油机井群控变频启动技术

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化工自动化及仪表 2024年第2期51卷 319-324,337页

作者：张彩婷李化龙吕阳伟孙赟长庆工程设计有限公司

为提升抽油机井群控变频启动运行的安全性,增加抽油机井的抽油量,研究基于改进NSGA-Ⅲ算法的抽油机井群控变频启动技术,降低变频启动的电压偏差,通过分析抽油机井群控变频启动条件,明确降低抽油机井群控变频电机与供电管网的电压偏差可... 详细信息

为提升抽油机井群控变频启动运行的安全性,增加抽油机井的抽油量,研究基于改进NSGA-Ⅲ算法的抽油机井群控变频启动技术,降低变频启动的电压偏差,通过分析抽油机井群控变频启动条件,明确降低抽油机井群控变频电机与供电管网的电压偏差可以降低变频启动时的冲击电流,提升变频启动运行的安全性。以最小电压偏差与最大抽油量为目标函数,建立抽油机井群控变频电机启动转速确定模型;在NSGA-Ⅲ算法引入参考点选择策略,得到改进的NSGA-Ⅲ算法;用改进NSGA-Ⅲ算法求解转速确定模型,得到最小电压偏差与最大抽油量对应的变频电机启动转速;根据合闸时刻变频电机的相角差,得到变频电机合闸指令,并按照确定的转速启动抽油机井群控变频电机。实验证明:该技术可有效求解抽油机井群控变频电机转速确定模型,且反转世代距离较小、超体积较大,即该技术的收敛性与分布性较优;该技术可有效启动抽油机井群控变频电机,平均抽油量15.8 t/d,最大电压偏差260 V(DC)。

关键词：改进NSGA-Ⅲ算法抽油机井群控变频启动电压偏差抽油量参考点选择电机启动转速

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咸阳30年土壤湿度变化特征及影响因子分析

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陕西气象 2024年第2期 50-53页

作者：白晓英马筛艳梁奇琛李四虎李化龙陕西省咸阳农业气象科学研究所陕西咸阳712034 陕西省气象局秦岭和黄土高原生态环境气象重点实验室西安710016 陕西省农业遥感与经济作物气象服务中心西安710014

利用陕西省咸阳国家一级农业气象试验站1992—2021年的土壤湿度资料,采用线性评估、回归分析等方法分析了咸阳30 a来土壤湿度在自然状态下的变化规律。结果表明:三个层次土壤湿度均呈现明显下降趋势,0~10 cm年平均土壤湿度的变化趋势率... 详细信息

利用陕西省咸阳国家一级农业气象试验站1992—2021年的土壤湿度资料,采用线性评估、回归分析等方法分析了咸阳30 a来土壤湿度在自然状态下的变化规律。结果表明:三个层次土壤湿度均呈现明显下降趋势,0~10 cm年平均土壤湿度的变化趋势率为-0.99%/10 a, 20~30 cm为-1.03%/10 a, 40~50 cm为-0.87%/10 a;各季节三个层次土壤湿度也呈下降趋势,其中春季降幅最大,其次为冬季、夏季,秋季降幅最小。0 cm土壤解冻有推迟趋势,平均变化趋势率-2.92 d/10 a;0 cm土壤冻结有提早趋势,平均变化趋势率为-1.81 d/10 a。土壤湿度影响因子中,气压、降水量与土壤湿度成正相关,地温、气温与土壤湿度成负相关;某些年份在降水量增加的前提下,由于地面温度和地温增加的影响,也会造成土壤湿度下降。

关键词：土壤水分变化规律影响因子咸阳市

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A highly selective electrochemical impedimetric sensor for imidacloprid determination based on WO_(3)/MoS_(2)nanosheets/molecularly imprinted polymer composite

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Rare Metals 2024年第3期43卷 1309-1315页

作者： long-hua Ding Ya-Wen Wang Qiu-Wen li li-li Zhang Ai-Zhu Wang Institute for Advanced Interdisciplinary Research School of Chemistry and Chemical EngineeringUniversity of JinanJinan250022China HCA Florida Healthcare Westside/Northwest Hospital Internal Medicine PlantationFL33324USA

In this study,an electrochemical impedimetric sensor was established for imidacloprid(IMI)detection based on WO_(3)/MoS_(2)and molecular imprinted polymer(MIP)*** layer was prepared on electrode surface by electropolymerization of o-phenylenediamine(o-PD)in the presence of IMI template,which ensured the specific rec-ognization toward IMI.

关键词： electrochemical polymer polymerization

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Recent advances in carbonized non-noble metal–organic frameworks for electrochemical catalyst of oxygen reduction reaction

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Rare Metals 2021年第10期40卷 2657-2689页

作者： Chan li Dao-Hui Zhao hua-li long Ming li Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional MoleculesHubei Key Laboratory of Polymer MaterialsCollege of Chemistry and Chemical EngineeringHubei UniversityWuhan 430062China

The non-noble metal oxygen reduction reaction(ORR) catalysts prepared by carbonization of metal–organic framework(MOF) have attracted more and more attentions in the fields of fuel cells and metal-air batteries due to their unique intrinsic advantages such as high catalytic activity, low price, simple synthesis and good adaptability. Different from the study of traditional high active noble metal catalysts, this review systematically summarizes recent developments on non-noble metal(Fe,Co, Cu, Ni, Mn and Mo) ORR catalysts prepared by various MOFs carbonization in different metal centers. The effects of synthesis strategies and pyrolysis conditions on the catalyst properties are discussed. Meanwhile, the key parameters of catalytic performances(including active sites, dispersed state and specific surface area) are discussed and the prospect is presented. It is expected that this review will provide effective guidance for future studies on carbonized non-noble MOFs for ORR electrochemical catalyst.

关键词： Non-noble metal MOF Pyrolysis Catalyst ORR

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Congener-derived template to construct lithiophilic organic-inorganic layer/interphase for high volumetric capacity dendrite-free li metal batteries

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Chinese Chemical Letters 2024年第3期35卷 453-460页

作者： Kang Yang long li Yuanbin Xiao Qiaoli Zhang Chenpeng Xi Borong li Yan Yu Chengkai Yang Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China

The development of lithium-metal batteries(LMBs)is seriously restricted by the out-of-control dendrites growth and infinite volume ***,a pervasive organic-inorganic layer construction strategy is reported for the composite lithium metal anode with congener-derived organic-inorganic solid electrolyte interphase(SEI).In this strategy,the organic-inorganic Ag@polydopamine(Ag@PDA)layer is coated on the arbitrary substrates by a simple two-step *** thin and stable congener-derived SEI is insitu formed with fewer inorganic components and more organic components during charging/*** polydopamine with sufficient adhesion groups and lithiophilic Ag layer realize near-zero nucleation overpotential during lithium *** low interface resistance and stable lithium deposition are ***,the practical areal and volumetric capacities of the composite anode with three-dimensional copper(3DCu)as the substrate are 10 mAh/cm^(2)and 1538 mAh/cm^3(*** mass of anode).The symmetrical cell shows very low polarization voltage(10 mV)and more than 2500 h cycles life at 1 mA/cm^(2)(1 mAh/cm^(2)).The liNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)-based full cells show improved capacity retention(82%)after 100 cycles at 0.5 *** modified lithiophilic anode with congener-derived interphase provides a promising strategy to realize the next-generation dendrite-free LMBs.

关键词： lithium metal anode Congener-derived lithiophilicity Volumetric capacity Organic-inorganic interphase

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Evolution of interfacial heat transfer,contact behavior and microstructure during sub-rapid solidification of molten steel with different hydrogen contents

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Journal of Iron and Steel Research(International) 2024年第1期31卷 215-223页

作者： Cheng Lu Wan-lin Wang Chen-yang Zhu Jie Zeng Xin-yuan liu hua-long li School of Metallurgy and Environment Central South UniversityChangsha410083HunanChina National Center for International Research of Clean Metallurgy Central South UniversityChangsha410083HunanChina Institute of Research of Iron and Steel ShasteelZhangjiagang215625JiangsuChina

Typical Q235 low-carbon steel samples with different hydrogen contents(0.0004,0.0008,and 0.0013 wt.%)were prepared by adjusting the environment humidity and *** effects of hydrogen on interfacial heat transfer,contact behavior,and microstructure evolution were investigated using a novel droplet solidification *** results revealed that when the hydrogen content increases from 0.0004 to 0.0013 wt.%,the maximum heat flux between the molten steel and cooling substrate decreases from 8.01 to 6.19 MW/m^(2),and the total heat removed in the initial 2 s reduces from 10.30 to 8.27 MJ/m^(2).Moreover,the final contact angle between the molten steel and substrate increases from 103.741°to 113.697°,and the number of pores on the droplet bottom surface increases significantly from 21 to 210 with the increase in *** surface roughness of the droplet bottom surface increases from 20.902 to 49.181 *** addition,the average grain size of the droplet increases from 14.778 to 33.548 pm with the increase in the hydrogen *** interfacial contact condition becomes worse due to the escape of hydrogen from the steel matrix during the cooling process,which leads to the reduction in the interfacial heat transfer and the increase in the grain size.

关键词： Strip casting Hydrogen content Interfacial heat transfer behavior Contact behavior Microstructure evolution

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Quantum Neural Network for Quantum Neural Computing

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Research 2024年第1期2023卷 71-80页

作者： Min-Gang Zhou Zhi-Ping liu hua-Lei Yin Chen-long li Tong-Kai Xu Zeng-Bing Chen National Laboratory of Solid State Microstructures School of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China MatricTime Digital Technology Co.Ltd. Nanjing 211899China

Neural networks have achieved impressive breakthroughs in both industry and *** to effectively develop neural networks on quantum computing devices is a challenging open ***,we propose a new quantum neural network model for quantum neural computing using(classically controlled)single-qubit operations and measurements on real-world quantum systems with naturally occurring environment-induced decoherence,which greatly reduces the difficulties of physical *** model circumvents the problem that the state-space size grows exponentially with the number of neurons,thereby greatly reducing memory requirements and allowing for fast optimization with traditional optimization *** benchmark our model for handwritten digit recognition and other nonlinear classification *** results show that our model has an amazing nonlinear classification ability and robustness to ***,our model allows quantum computing to be applied in a wider context and inspires the earlier development of a quantum neural computer than standard quantum computers.

关键词： quantum thereby breakthrough

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