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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2947-2959页

作者： fujian Yang Jing Luo Guiling Wang Hejuan Liu Dawei Hu Hui Zhou State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China university of Chinese Academy of Sciences Beijing100049China Sinopec Star Hubei New Energy Development Co. Ltd.Wuhan430010China Institute of Hydrogeology and Environmental Geology Chinese Academy of Geological SciencesShijiazhuang050061China

In unconsolidated sandstone reservoirs,presence of numerous movable grains and a complex grain size composition necessitates a clear understanding of the physical clogging process for effective groundwater recharge in groundwater-source heat pump *** investigate this,a series of seepage experiments was conducted under in situ stress conditions using unconsolidated sandstone samples with varying grain *** clogging phenomenon arises from the combined effects of grain migration and compaction,wherein the migration of both original and secondary crushed fine-grain particles blocks the seepage ***,grain composition influences the migration and transport properties of the *** samples composed of smaller grains,the apparent permeability demonstrates a transition from stability to *** contrast,samples with larger grains experience a skip at the stability stage and directly enter the decrease stage,with a minor exception of a slight increase ***,a unique failure mode characterized by diameter shrinkage in the upper part of the sample is observed due to the combined effects of grain migration and in situ stress-induced *** testing results contribute to a better understanding of the clogging mechanism caused by the coupled effects of grain migration and compaction during groundwater recharge in unconsolidated sandstone reservoirs used in groundwater-source heat pump systems.

关键词： Groundwater-source heat pump Clogging Grain migration Compaction effect Groundwater recharge Unconsolidated sandstone

Experimental and Numerical Evaluation of the Cavitation Performances of Self-Excited Oscillating Jets

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1883-1901页

作者： Yuanyuan Zhao fujian Zhao Guohui Li Wei Xu Xiuli Wang School of the Environment and Safety Engineering Jiangsu UniversityZhenjiang212013China Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang212013China GongQing Institute of Science and Technology Jiujiang332020China School of Energy and Power Engineering Jiangsu UniversityZhenjiang212013China

Self-excited oscillating jets(SOJ)are used in several practical *** performances are significantly affected by structural parameters and the target *** this study,a geometric model of the SOJ nozzle accounting for multiple structural parameters is introduced,then the related cavitation performances and the optimal target distance are investigated using a Large-Eddy Simulation(LES)*** are also provided about an experiment,which was conducted to validate the simulation *** analyzing the evolution of the vapor volume fraction at the nozzle outlet,a discussion is presented about the effect of the aforementioned structural parameters on the cavitation performances and the target *** is shown that the distribution of cavitation clouds at the outlet of the SOJ nozzle displays a non-monotonic trend(first increasing,then decreasing).Under working conditions with an inlet pressure of 4 MPa,a SOJ nozzle outlet/inlet diameter ratio(D_(1)/D_(2))of 1.2,and a chamber diameter ratio(D/L)close to 1.8,the nozzle outlet cavitation performance attains a *** optimal structural parameters correspond to the optimal target distance,which is near 50 *** experiments have revealed that the SOJ nozzle with the above parameters displays a good cavitation erosion effect at the target distance of 50 mm,in satisfactory agreement with the numerical simulation results.

关键词： Self-excited oscillating nozzle cavitating jet target distant LES cavitation

Damage characteristics of fused silica under low-temporal coherence light

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High Power Laser Science and Engineering 2024年第3期12卷 77-83页

作者： Chong Shan Lingbao Kong fujian Li Yong Cui Lailin Ji Quan Zheng Daxing Rao Ruijing He Xiaohui Zhao Yuanan Zhao Zhan Sui Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing School of Information Science and TechnologyFudan UniversityShanghaiChina Shanghai Institute of Laser Plasma China Academy of Engineering PhysicsShanghaiChina Key Laboratory of High Power Laser Materials Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina

The damage characteristics of fused silica were investigated under low-temporal coherence light(LTCL).It was found that the laser-induced damage threshold(LIDT)of fused silica for the LTCL was lower than that of the single longitudinal mode pulse laser,and for the LTCLs,the LIDTs decrease with the increasing of laser bandwidth,which is not consistent with the temporal spike *** is due to the nonlinear self-focusing effect and multi-pulse accumulation *** specific reasons were analyzed based on theoretical simulation and experimental *** research work is helpful and of great significance for the construction of high-power LTCL devices.

关键词： laser-induced damage threshold low-temporal coherence light nonlinear self-focusing effect temporal spike

Core level excitation spectra of La and Mn ions in LaMnO3

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Chinese Physics B 2024年第3期33卷 327-332页

作者：李福建程新路张红 Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065Chin

Manganese-based perovskite is popular for research on ferromagnetic materials,and its spectroscopic studies are essential for understanding its electronic structure,dielectric,electrical,and magnetic *** this paper,the M-edge spectra of La ions and the M-edge,L-edge,and K-edge spectra of Mn ions in LaMnO3 are calculated by considering both the free-ion multiplet calculation and the crystal field *** analyze spectral shapes,identify peak origins,and estimate the oxidation states of La and Mn ions in LaMnO3 *** is concluded that La ions in LaMnO3 predominantly exist in the trivalent state,while Mn ions exist primarily in the trivalent state with a minor presence of tetravalent ***,the calculated spectra are in better conformity with the experimental spectra when the proportion of Mn3+is 90%and Mn4+is 10%.This article enhances our comprehension of the oxidation states of La and Mn within the crystal and also provides a valuable guidance for spectroscopic investigations of other manganates.

关键词： lanthanum manganate the core level excitation spectra free-ion multiplet calculation oxidation state

Radiation-Assisted Synthesis of Crown Ether-Modified Covalent Organic Frameworks for Lithium Isotope Separation

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CCS Chemistry 2024年第10期6卷 2594-2606页

作者： Shouchao Zhong Yue Wang Jianhui Lan Mingshu Xie Yiqian Wu Jiuqiang Li fujian Liu Lilong Jiang Jing Peng Liyong Yuan Maolin Zhai Weiqun Shi Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science Key Laboratory of Polymer Chemistry and Physics of the Ministry of EducationCollege of Chemistry and Molecular EngineeringBeijing National Laboratory for Molecular SciencesPeking UniversityBeijing 100871 National Engineering Research Center of Chemical Fertilizer Catalyst College of Chemical EngineeringFuzhou UniversityFuzhou350002 Fujian Laboratory of Nuclear Energy Chemistry Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049

γ-ray radiation-induced grafting strategy was first employed to immobilize 4-aminobenzo-15-crown-5 onto a covalent organic framework(COF).This endeavor culminated in the successful synthesis of a class of two-dimensional crown ether-modified COFs(named[15C5]n%-(TzDa-G-x%)),marking the maiden utilization of COFs in the realm of^(6)Li/^(7)Li isotope *** COFs exhibited swifter adsorption kinetics than alternative *** them,[15C5]_(57%)-(TzDa-G-50%)with its excellent crystallinity,porosity,and stability exhibited the best performance in Li+adsorption and^(6)Li/^(7)Li isotope *** Li+adsorption in acetonitrile achieved a capacity of 3.6 mg·g^(−1)within 30 min and a saturation capacity of 7.3 mg·g^(−1).The single-stage separation factor of^(6)Li/^(7)Li isotopes was 1.014±*** results of dynamic adsorption column experiments showed that the packed column made of[15C5]_(57%)-(TzDa-G-50%)maintained stable performance during four cycles of Li+adsorptionelution,with over 99%Li+removal rate in *** crown ether-modified COF has potential application in^(6)Li/^(7)Li isotope separation,and this radiation-assisted synthesis strategy is expected to become universal in the modification of COFs for diverse applications.

关键词： covalent organic framework gamma radiation modification crown ether ^(6)Li/^(7)Li isotope separation adsorption column

基于SEM模型的张家苗寨古村落导视系统设计研究

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包装工程 2024年第10期45卷 315-324,338页

作者：莫敷建广西艺术学院南宁530001

目的改善村寨导视系统的用户体验,探寻用户评价导视系统满意度的标准体系,提供客观、以用户为导向的设计流程。方法使用文本挖掘技术对用户评价原始数据进行采集,使用探索性因子分析法对结果进行降维分析,通过主成分分析法提取5个成分,... 详细信息

目的改善村寨导视系统的用户体验,探寻用户评价导视系统满意度的标准体系,提供客观、以用户为导向的设计流程。方法使用文本挖掘技术对用户评价原始数据进行采集,使用探索性因子分析法对结果进行降维分析,通过主成分分析法提取5个成分,将其设置为潜在变量,并将相关指标作为观测变量,再使用结构方程模型构建潜在变量与观测变量之间的层次结构,并对其结果进行拟合度分析,最后将结果用于导视系统设计实践。结果根据结构模型结果,分析潜在变量和观测变量的影响权重,得出并验证了“明确的指向性”是影响用户满意度最重要的指标,其次分别为“民族造型美感”“文化功能性”“场景交互合理”,并通过具体的观测变量因子载荷数值排序来指导设计实践。结论导视系统在实现指向性功能的情况下,还应提升民族文化附加值,通过文化符号来扩大民族影响力,传承民族文化,促进民族村寨的发展。

关键词：村寨导视结构方程模型用户需求苗族文化

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考虑资源稀缺性的路面养护措施综合效益全寿命周期费用评估

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北京工业大学学报 2024年第4期50卷 417-430页

作者：董侨姚康黄梦雨倪富健东南大学交通学院南京211189 东南大学道路交通工程国家级实验教学示范中心南京211189

为提高道路工程中不可再生资源利用的合理性,建立养护措施综合效益的全寿命周期费用评价方法,推动交通运输基础设施的可持续发展,基于全寿命周期费用评价(life-cycle cost assessment,LCCA)理论,引入了资源稀缺性的评价指标,并基于存量... 详细信息

为提高道路工程中不可再生资源利用的合理性,建立养护措施综合效益的全寿命周期费用评价方法,推动交通运输基础设施的可持续发展,基于全寿命周期费用评价(life-cycle cost assessment,LCCA)理论,引入了资源稀缺性的评价指标,并基于存量稀缺、进口稀缺和技术稀缺3个评价维度,建立了适用于路用材料的项目级资源稀缺性评价体系,同时,将该指标量化为货币当量计入成本清单中。依托江苏省路面养护管理系统数据,将资源稀缺性、经济效益、性能发展3个维度统一,定量分析了再生类、铣刨重铺类和罩面类共3类、12个常见养护措施的综合效益。研究结果表明:考虑资源稀缺性,再生类养护措施旧料利用率较高,具有极佳的资源合理性;EC A-10薄层罩面处治厚度薄、耗材量小,与普通罩面相比能节省50%左右的资源;铣刨料直接废弃、石料来源选择不当将导致额外支出10%~20%的当量成本。考虑综合效益,各养护方案与施工特性(如施工工期、施工水平、工艺先进性等)相关的成本效益接近60%,其中用户间接的经济损失占比超过30%,直接由施工工期决定。因此,建议谨慎选择材料来源及去向以减少不可再生资源浪费,优化养护施工流程以降低用户的间接经济损失,提高施工水平以降低用户的直接油耗开支,开展科学养护决策以降低政府投入成本。

关键词：路面工程全寿命周期费用评价(life-cycle cost assessment,LCCA) 资源稀缺性成本评估养护措施养护决策

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用于新型符号的频偏补偿和解调的算法与电路

哈尔滨工业大学学报 2024年第5期56卷 121-129页

作者：林敏史靖炜丁福建姜帆陈潇特种光纤与光接入网重点实验室(上海大学) 上海201900

为提高传统脉冲位置调制(pulse position modulation,PPM)符号的频谱效率,提出了一种新型码片内4-PPM符号调制方法,在实现1 Gbit/s通信速率的同时,又大大减少所需频谱资源。可在解调时,该符号调制的误码率性能受到发射端时钟和接收端本... 详细信息

为提高传统脉冲位置调制(pulse position modulation,PPM)符号的频谱效率,提出了一种新型码片内4-PPM符号调制方法,在实现1 Gbit/s通信速率的同时,又大大减少所需频谱资源。可在解调时,该符号调制的误码率性能受到发射端时钟和接收端本地时钟之间的频率偏移的极大影响。针对此问题,又提出了一种在模拟域对该符号进行频偏补偿,并实现符号同步和高速数据解调的算法与电路。该电路系统通过消除接收数据和本地时钟的初始相差、提取两者的频偏信息、周期性改变本地时钟的瞬时相位3步实现频偏补偿,并同时在第3步利用本地时钟对接收数据进行解调。为提高相位插值器(phase interpolator,PI)的线性度,本文将延迟锁定环与PI相结合。在2π的插值范围内,实现插值区间32个,插值步长992个,分辨率2.016 ps,最大差分非线性(differential nonlinearity,DNL)0.183°,最大积分非线性(integral nonlinearity,INL)0.325°。此外,本文提出的相位控制算法有效避免了由电流毛刺所引起的输出相位突变。电路基于UMC 40 nm CMOS RF LP工艺进行设计与仿真。仿真结果表明:本文所提出的算法与电路,在典型工艺角下,将接收数据和本地时钟间的50×10^(-6)频率偏差度降至1.03×10^(-6),频偏补偿准确度达到97.94%,并实现1 Gbit/s的解调速率。该方法对高速PPM数据同步与解调具有良好的工程应用价值。

关键词：脉冲位置调制码片内脉冲位置调制符号同步频偏补偿数据解调相位插值器延迟锁定环

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非政府组织在冲突环境下的组织韧性——以“健康扶贫行动”在缅北的生存与发展为例

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东南亚研究 2024年第2期 1-24,153,154页

作者：李福建杨嘉宜外交学院全球生物安全治理研究中心外交学院《外交评论》编辑部

非政府组织是全球治理中的重要行为体,在冲突环境下的人道主义援助、发展合作乃至建设和平进程中扮演着关键角色。然而,在冲突环境急剧变化、逆境丛生的状况下,为何一些非政府组织呈现出更强的生命力?本文引入“韧性”概念,提出基于“... 详细信息

非政府组织是全球治理中的重要行为体,在冲突环境下的人道主义援助、发展合作乃至建设和平进程中扮演着关键角色。然而,在冲突环境急剧变化、逆境丛生的状况下,为何一些非政府组织呈现出更强的生命力?本文引入“韧性”概念,提出基于“认知—行为—关系”互动的组织韧性进程模型,用以解释一些非政府组织在冲突环境下不仅能够反弹恢复生存,甚至实现改进发展的原因。缅北地区长期遭受战乱,社会发展迟滞,民众流离失所,近年来又成为网络赌博和电信诈骗的“温床”,是名副其实的边缘地带。自20世纪90年代以来,英国非政府组织“健康扶贫行动”云南代表处“致力于一个最贫困与最边缘化的人群享有卫生权利的世界”,进入高风险的缅北地区并持续运营30年,体现出强劲的生存能力和发展势头。无论是在缅甸军政府统治时期,还是在民主化转型时期,抑或是在紧急状态时期,“健康扶贫行动”都能够及时调整自身认知、改变行为模式、构建关系网络,展现出较强的韧性能力,有效应对缅北地区既有的和新出现的各种风险和挑战,实现跨越式发展。其韧性能力也不断进行迭代,最终达到韧性治理的结果。

关键词：非政府组织组织韧性韧性治理缅甸 “健康扶贫行动” 全球治理