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Acoustic Purcell effect induced by quasibound state in the continuum

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Fundamental Research 2024年第1期4卷 57-62页

作者： Sibo Huang Shuhuan Xie He Gao Tong Hao Shuang Zhang Tuo Liu yong Li Jie Zhu Institute of Acoustics School of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong Kong 999077China College of Surveying and Geo-Informatics Tongji UniversityShanghai 200092China Department of Physics The University of Hong KongHong Kong 999077China Key Laboratory of Noise and Vibration Research Institute of AcousticsChinese Academy of SciencesBeijing 100190China The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518057China

We study theoretically and experimentally the acoustic Purcell effect induced by quasi-bound states in the continuum(quasiBICs).A theoretical framework describing the acoustic Purcell effect of a resonant system is developed based on the system’s radiative and dissipative factors,which reveals the critical emission condition for achieving optimum Purcell *** show that the quasiBICs contribute to highly confined acoustic field and bring about greatly enhanced acoustic emission,leading to strong Purcell *** concept is demonstrated via two coupled resonators supporting a Friedrich-Wintgen quasiBIC,and the theoretical results are validated by the experiments observing emission enhancement of the sound source by nearly two orders of *** work bridges the gap between the acoustic Purcell effect and acoustic BICs essential for enhanced wave-matter interaction and acoustic emission,which may contribute to the research of high-intensity sound sources,high-quality-factor acoustic devices and nonlinear acoustics.

关键词： Acoustic Purcell effect Bound state in the continuum Mode coupling Sound emission enhancement High-quality-factor acoustic device

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螺旋桨桨叶根部断裂飞脱轨迹数值仿真

航空发动机 2024年第4期50卷 142-149页

作者：温庆刘冠冕程志航杨康智魏猛中航通飞华南飞机工业有限公司广东珠海519040

螺旋桨桨叶断裂飞脱轨迹对飞机的安全性有重要的影响。为了研究螺旋桨桨叶根部断裂后的运动过程,采用数值模拟方法进行了仿真分析,并与风洞试验结果对比。将求解区域划分为10个网格区域,对其中3个螺旋桨旋转区域单独划分网格,通过滑移... 详细信息

螺旋桨桨叶断裂飞脱轨迹对飞机的安全性有重要的影响。为了研究螺旋桨桨叶根部断裂后的运动过程,采用数值模拟方法进行了仿真分析,并与风洞试验结果对比。将求解区域划分为10个网格区域,对其中3个螺旋桨旋转区域单独划分网格,通过滑移网格进行数据传递,对有飞脱桨叶的螺旋桨的6个桨叶分别设置重叠网格。采用螺旋桨真实旋转的非定常方法获得周期性稳定的空间流场,当飞脱桨叶到达指定位置后,求解桨叶的6自由度运动方程,计算桨叶的飞行轨迹。结果表明:在短时间内,该螺旋桨的桨叶飞脱后的运动轨迹主要受惯性力的影响,而气动力的影响不大;飞脱桨叶的桨根在第0.015 s左右与后继桨叶的桨尖相撞,与测力风洞试验的断桨事故诊断结果相符。

关键词：螺旋桨重叠网格根部断裂飞行轨迹数值模拟航空发动机

A Modified Tikhonov Regularization Method for a Cauchy Problem of the Biharmonic Equation

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Journal of Mathematical Research with Applications 2024年第3期44卷 359-386页

作者： Fan yang Jianming XU Xiaoxiao LI School of Science Lanzhou University of Technology

In this paper, the Cauchy problem of biharmonic equation is considered. This problem is ill-posed, i.e., the solution(if exists) does not depend on the measurable data. Firstly, we give the conditional stability result under the a priori bound assumption for the exact ***, a modified Tikhonov regularization method is used to solve this ill-posed *** the a priori and the a posteriori regularization parameter choice rule, the error estimates between the regularization solutions and the exact solution are obtained. Finally, some numerical examples are presented to verify that our method is effective.

关键词： Biharmonic equations inverse problem Cauchy problem Tikhonov regularization method

Study on the Interactivity of Controlled and Automatic Information Processing in L2 Reading

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Sino-US English Teaching 2024年第7期21卷 314-321页

作者： DONG Tiantian WANG yong University of Shanghai for Science and Technology ShanghaiChina

L2 reading is not only an important channel for people to obtain information and knowledge,but also the main way for people to learn a foreign *** information processing can be divided into controlled processing and automatic *** information processing is a conscious and resource-intensive processing model,while automatic information processing is an unconscious and automatic processing *** study investigates the characteristics and interactivity of controlled and automatic information processing in L2 reading,and explores the roles of controlled and automatic information processing strategies in improving L2 reading *** findings are as follows:(a)controlled and automatic information processing is interactive in L2 reading;and(b)the uses of controlled and automatic information processing strategies are beneficial to the improvement of the reading ability of L2 *** study has important theoretical and practical value in improving the efficiency of L2 reading teaching and learning.

关键词： L2 reading controlled information processing automatic information processing interactivity

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单取代β-环糊精衍生物的制备综合实验设计

化学教育（中英文） 2024年第20期45卷 51-59页

作者：刘智敏叶柯希杨怡许志刚昆明理工大学理学院云南昆明650500

为培养学生在制备综合性实验方面的能力,并推行化学教学实验的绿色化和规范化,改进了原有环糊精衍生物制备实验,将反应介质从吡啶变为NaOH水溶液,设计了2种6位单取代-β-环糊精衍生物的制备实验方案。该实验以β-环糊精为原料,对甲苯磺... 详细信息

为培养学生在制备综合性实验方面的能力,并推行化学教学实验的绿色化和规范化,改进了原有环糊精衍生物制备实验,将反应介质从吡啶变为NaOH水溶液,设计了2种6位单取代-β-环糊精衍生物的制备实验方案。该实验以β-环糊精为原料,对甲苯磺酰氯为衍生化试剂制得单-(6-O-对甲苯磺酰)-β-环糊精,后续在此基础上再与乙二胺反应制备得单-(6-乙二胺-6-去氧)-β-环糊精。实验涉及过滤、重结晶等操作,并通过红外光谱、核磁共振氢谱、熔点测定、高效液相色谱对产物进行表征。该综合实验实现了有机化学和分析化学学科知识的融合,能帮助有科研深造需求和从事相关工作的学生奠定良好的实验基础。

关键词： β-环糊精衍生物单取代制备综合实验

Eco-friendly calcium alginate microspheres enable enhanced profile control and oil displacement

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Petroleum Science 2024年第3期21卷 1928-1943页

作者： Xiao-Han Zhang Chang-Jing Zhou Yuan-Xiang Xiao Bo Hui yong-Gang Xie Yu-Bin Su Xin-Ru Li Jie Huang Mao-Chang Liu International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an710049ShaanxiPR.China Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs School of Petroleum EngineeringXi'an Shiyou UniversityXi'an 710065ShaanxiPR.China Oil&Gas Technology Research Institute Changqing Oilfield Branch CompanyPetroChinaXi'an710021ShaanxiPR China Suzhou Academy of Xi'an Jiaotong University Suzhou215123JiangsuPR China

Polymer microspheres(PMs),such as polyacrylamide,have been widely applied for enhanced oil recovery(EOR),yet with environmental ***,we report a microfluid displacement technology containing a bio-based eco-friendly material,i.e.,calcium alginate(CaAlg)microspheres for *** dominant mechanisms responsible for EOR over Ca Alg fluid have been verified,including the microscopic oil displacement efficacy augmented by regulating capillary force(determined by the joint action of interfacial tension and wettability between different phases)and macroscopic sweep volume increment through profile control and mobility ratio *** comprehensive effectiveness can be further impacted when the CaAlg microsphere is embellished ulteriorly by using appropriate amount of sodium dodecyl sulfonate(SDS).The core flooding and nuclear magnetic resonance(NMR)tests demonstrate that CaAlg-SDS microsphere can balance the interphase property regulation(wettability alteration and IFT reduction)and rheology properties,enabling simultaneous profile control and oil *** introduction of SDS will have a negative impact on rheological properties,which is not favored for *** results show that the involvement of 4-m M SDS will provide the best behavior,with an EOR rate of 34.38%.This cost-effective and environmentally-friendly bio-microspherebased microfluidic displacement technology is expected to achieve“green”oil recovery in future oilfield exploitation.

关键词： Calcium alginate microspheres Wettability Interfacial tension Rheology Viscoelasticity Enhanced oil recovery(EOR)

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焦虑状态与高血压关系及应对措施分析

中国现代药物应用 2024年第11期18卷 60-63页

作者：邹智勇厦门市思明区梧村街道社区卫生服务中心 363000

目的分析焦虑状态与高血压的相关性及应对措施。方法回顾性分析150例原发性高血压患者的临床资料,根据患者是否伴焦虑分为伴焦虑组(n=43)及不伴焦虑组(n=107)。通过动态血压监测仪监测患者动态血压,通过汉密尔顿焦虑量表(HAMA)评估焦虑... 详细信息

目的分析焦虑状态与高血压的相关性及应对措施。方法回顾性分析150例原发性高血压患者的临床资料,根据患者是否伴焦虑分为伴焦虑组(n=43)及不伴焦虑组(n=107)。通过动态血压监测仪监测患者动态血压,通过汉密尔顿焦虑量表(HAMA)评估焦虑状态。比较伴焦虑组与不伴焦虑组患者临床资料,分析高血压合并焦虑的影响因素及高血压影响因素与焦虑的相关性。结果150例高血压患者中共计43例患者伴焦虑,其中,轻度焦虑患者22例、中度焦虑患者14例、重度焦虑患者7例,焦虑发生率为28.67%;不伴焦虑患者共计107例,占比为71.33%。两组性别、受教育程度、婚姻状况、吸烟史、饮酒史、规律运动习惯、24 h舒张压(DBP)、24 h收缩压(SBP)、总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)比较差异无统计学意义(P>0.05);伴焦虑组年龄、体质量指数(BMI)高于不伴焦虑组,高血压病程长于不伴焦虑组,睡眠质量差于不伴焦虑组,差异有统计学意义(P<0.05)。对伴焦虑组与不伴焦虑组高血压患者具有统计学意义的单因素实施多因素Logistic回归分析,研究结果表明年龄、BMI、高血压病程与睡眠质量为高血压合并焦虑的影响因素(P<0.05)。高血压影响因素中的年龄、BMI及高血压病程与焦虑呈正相关(r=0.291、0.301、0.278,P<0.05),睡眠质量与焦虑呈负相关(r=-0.235,P<0.05)。结论高血压合并焦虑的影响因素包括年龄、BMI及高血压病程,且各项指标与焦虑发生情况呈正相关,临床应采取针对性措施改善患者焦虑状态。

关键词：焦虑状态高血压相关性影响因素应对措施

Achieving 500X Acceleration for Adversarial Robustness Verification of Tree-Based Smart Grid Dynamic Security Assessment

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 800-802页

作者： Chao Ren Chunran Zou Zehui Xiong Han Yu Zhao-yang Dong Niyato Dusit Nanyang Technological University Singapore 639798Singapore Nanjing University of Aeronautics and Astronautics Nanjing 211106China Singapore University of Technology and Design Singapore 487372Singapore

Dear Editor,This letter presents a novel and efficient adversarial robustness verification method for tree-based smart grid dynamic security assessment(DSA).Based on tree algorithms technique,the data-driven smart gri... 详细信息

关键词： Smart smart Dynamic

Insight into the Alkali Resistance Mechanism of CoMnHPMo Catalyst for NH_(3) Selective Catalytic Reduction of NO

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Transactions of Tianjin University 2024年第4期30卷 324-336页

作者： Kaixin Wang Yunchong Wang Zongxiang yang Xinyue Wang Caixia Liu Qingling Liu Tianjin Key Laboratory of Indoor Air Environmental Quality Control School of Environmental Science and EngineeringTianjin UniversityTianjin 300350China State Key Laboratory of Engines Tianjin UniversityTianjin 300350China

The existence of alkali metals in fl ue gases originating from stationary sources can result in catalyst deactivation in the low-temperature selective catalytic reduction(SCR)of nitrogen oxides(NO_(x)).It is widely accepted that alkali metal poisoning causes damage to the acidic sites of ***,in this study,a series of CoMn catalysts doped with heteropolyacids(HPAs)were prepared using the coprecipitation *** these,CoMnHPMo exhibited superior catalytic performance for SCR and over 95%NO_(x) conversion at 150-300􁕑.Moreover,it exhibited excellent catalytic activity and stability after alkali poisoning,demonstrating outstanding alkali metal *** characterization indicated that HPMo increased the specifi c surface area of the catalyst,which provided abundant adsorption sites for NO_(x) and NH_(3).Comparing catalysts before and after poisoning,CoMnHPMo enhanced its alkali metal resistance by sacrifi cing Brønsted acid sites to protect its Lewis acid *** situ DRIFTS was used to study the reaction pathways of the *** results showed that CoMnHPMo maintained high NH_(3) adsorption capacity after K poisoning and then reacted rapidly with NO intermediates to ensure that the active sites were not ***,SCR performance was ensured even after alkali metal *** sum-mary,this research proposed a simple method for the design of an alkali-resistant NH_(3)-SCR catalyst with high activity at low temperatures.

关键词： NH3-SCR Alkali resistance Phosphomolybdic acid CoMn