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Modeling wave propagation across rock masses using an enriched 3D numerical manifold method

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Science China(Technological Sciences) 2024年第3期67卷 835-852页

作者： YANG YongTao li junfeng WU WenAn State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing 100124China University of Chinese Academy of Sciences Beijing 100049China

The three-dimensional numerical manifold method(3DNMM) method is further enriched to simulate wave propagation across homogeneous/jointed rock masses. For the purpose of minimizing negative effects from artificial boundaries, a viscous nonreflecting boundary, which can effectively absorb the energy of a wave, is firstly adopted to enrich 3DNMM. Then, to simulate the elastic recovery property of an infinite problem domain, a viscoelastic boundary, which is developed from the viscous nonreflecting boundary, is further adopted to enrich 3DNMM. Finally, to eliminate the noise caused by scattered waves, a force input method which can input the incident wave correctly is incorporated into 3DNMM. Five typical numerical tests on P/S-wave propagation across jointed/homogeneous rock masses are conducted to validate the enriched 3DNMM. Numerical results indicate that wave propagation problems within homogeneous and jointed rock masses can be correctly and reliably modeled with the enriched 3DNMM.

关键词： 3D numerical manifold method viscous nonreflecting boundary rock masses force input method wave propagation

Single-Component Color-Tunable Smart Organic Emitters with Simultaneous Multistage Stimuli-Responsiveness and Multimode Emissions

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Research 2024年第2期2023卷 719-728页

作者： Yu Yan Chengfang liu Jianzhong Fan Yusheng li Huanling liu Qian Wang Xiangchun lil junfeng li Wen-Yong Lai State Key Laboratory of Organic Electronics and Information Displays(SKLOEID) Institute of Advanced Materials(IAM)School of Chemistry and Life SciencesNanjing University of Posts&Telecommunications9 Wenyuan RoadNanjng 210023China Shandong Province Key Laboratory of Medical Physics and Image Processing Technology School of Physics and ElectronicsShandong Normal UniversityJinan 250358China

Achieving color-tunable emission in single-component organic emitters with multistage stimuli-responsiveness is of vital significance for intelligent optoelectronic applications,but remains enormously ***,we present an unprecedented example of a color-tunable single-component smart organic emitter(DDOP)that simultaneously exhibits multistage stimuli-responsiveness and multimode *** based on a highly twisted amide-bridged donor-tcceptor-donor structure has been found to facilitate intersystem crossing,form multimode emissions,and generate multiple emissive species with multistage *** pristine crystalline powders exhibit abnormal excitation-dependent emissions from a monomer-dominated blue emission centered at 470 nm to a dimer-dominated yellow emission centered at 550 nm through decreasing the ultraviolet(UV)excitation wavelengths,whereas DDOP single crystals show a wide emission band with a main emission peak at 585 nm when excited at different *** emission behaviors of pristine crystalline powders and single crystals are different,demonstrating emission features that are closely related to the aggregation *** work has developed color-tunable single-component organic emitters with simultaneous multistage stimuli-responsiveness and multimode emissions,which is vital for expanding intelligent optoelectronic applications,including multilevel information encryption,multicolor emissive patterns,and visual monitoring of UV wavelengths.

关键词： donor excitation Smart

Neuroimaging features in a patient with non-ketotic hyperglycaemic seizures: A case report

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World Journal of Clinical Cases 2024年第5期12卷 1004-1009页

作者： Jing Wu Huijie Feng Yaxiong Zhao junfeng li Ting li Kefeng li Department of Radiology Heping Hospital Affiliated to Changzhi Medical CollegeChangzhi 046000Shanxi ProvinceChina Changzhi Key Lab of Functional Imaging for Brain Diseases Heping Hospital Affiliated to Changzhi Medical CollegeChangzhi 046000Shanxi ProvinceChina Faculty of Applied Sciences Macao Polytechnic UniversityMacao 999078China

BACKGROUND Non-ketotic hyperglycaemic(NKH)seizures are a rare neurological complication of diabetes caused by hyperglycaemia in non-ketotic and non-hyperosmotic *** clinical characteristics of NKH seizures are atypical and lack unified diagnostic criteria,leading to potential misdiagnoses in the early stages of the *** SUMMARY This report presents a rare case of NKH seizures in a 52-year-old male patient with a history of type 2 diabetes *** performed comprehensive magnetic resonance imaging(MRI)studies at admission,12 d post-admission,and 20 d *** imaging techniques included contrast-enhanced head MRI,T2-weighted imaging(T2WI),fluid-attenuated inversion recovery(FLAIR),diffusion-weighted imaging,susceptibility-weighted imaging,magnetic reso-nance spectroscopy(MRS),and magnetic resonance *** the time of admission,T2WI and FLAIR of the cranial MRI showed that the left parieto-occipital cortex had gyrus-like swelling and high signal,and subcortical stripes had low *** showed a reduced N-acetylaspartate peak and increased creatine and choline peaks in the affected areas.A follow-up MRI 20 d later showed that the swelling and high signal of the left parieto-occipital cortex had disappeared,and the low signal of the subcortex had *** This case study provides valuable insights into the potential pathogenesis,diagnosis,and treatment of NKH *** comprehensive MRI findings highlight the potential utility of various MRI sequences in diagnosing and characterizing NKH seizures.

关键词： Non-ketotic hyperglycaemia seizures Magnetic resonance imaging Magnetic resonance spectroscopy Diabetes Case report

Suppression of Multi-Harmonic Currents in the High-Speed Magnetically Suspended Motor Based on Adaptive Cascaded Notch Filters with Variable Phase Angle

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Guidance, Navigation and Control 2024年第2期4卷 104-122页

作者： Xianzhang Wang Xiangbo Xu Shao Chen lingbo Zheng junfeng li Bolun li School of Technology Beijing Forestry University Beijing 100084 P.R.China

Rotor imbalance is identified as one of the predominant vibration sources in high-speed magnetically suspended *** to factors such as rotor machining accuracy errors and uneven material distribution,synchronous vibration interference is ***,sensor runout generates harmonic currents,which are attributed to material irregularities and inhomogeneity in the roundness of the sensor detection *** currents can generate harmonic vibrational forces that are transmitted to the motor housing,jeopardizing control accuracy and the device's operational *** order to achieve real-time reduction of harmonic currents at specified frequencies and improve the accuracy of harmonic suppression,this paper proposes an algorithm for variable phase anglefiltering of an adaptive cascaded mode *** paper performed dynamic modeling and analysis of the magnetically suspended rotor system with rotor imbalance and verified the correctness of the dynamic ***,the structure of an adaptive notchfilter with variable phase angle is introduced,highlighting the capability to maintain stability by adjusting the compensatory phase of the *** comparing the harmonic current suppression performance of cascaded and parallel mode notchfilters,the cascaded method can better enhance the overall frequency selectivity,emphasizing its ability to adjust the compensation phase based on the phase angle of the input signal at different frequencies to maintain system *** and experimental results show that harmonic currents can be successfully suppressed in the cascade mode,and the amplitude of the synchronous frequency current is reduced by 94.4%.

关键词： Multi-harmonic current suppression rotor imbalance sensor runout cascaded mode notchfilter variable phase angle

Two-dimensional transition metal MXene-based gas sensors:A review

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Chinese Chemical Letters 2024年第1期35卷 208-221页

作者： junfeng li Xiaojie Chen Xiaojie Zhu Yingchang Jiang Xueting Chang Shibin Sun College of Logistics and Engineering Shanghai Maritime UniversityShanghai 201306China Institute of Marine Materials Science and Engineering Shanghai Maritime UniversityShanghai 201306China

As an emerging star in the family of two-dimensional(2D)materials,2D transition metal carbides,carbonitrides and nitrides,collectively referred to as MXenes,have large specific surface area,rich active sites,metallic conductivity and adjustable surface chemical *** features make MXenes promising candidates for gas-sensing *** the past few years,MXene-based sensors have drawn increasing attention due to their enhanced sensor *** on this,this review systematically represents the structure,synthesis methods and properties of MXenes,and summarizes their applications in gas ***,the types,structure,main synthesis methods and properties of MXenes are introduced in a comprehensive ***,the corresponding design principle and working mechanism of MXene-based gas sensor are ***,the sensing performances of pristine MXenes and the MXene-based nanocomposite are ***,some future opportunities and challenges of MXene-based sensors are pointed out.

关键词： MXene Gas sensors Synthesis Stability Gas-sensing mechanism Gas-sensing performance

New insight into polystyrene ion exchange resin for efficient cesium sequestration:The synergistic role of confined zirconium phosphate nanocrystalline

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Chinese Chemical Letters 2024年第1期35卷 406-411页

作者： Mengzhou Wang Mingyan Fu junfeng li Yihui Niu Qingrui Zhang Qina Sun Hebei Key Laboratory of Heavy Metal Deep-Remediation in Water and Resource Reuse School of Environmental and Chemical EngineeringYanshan UniversityQinhuangdao 066004China Laboratory of Environmental Technology INETTsinghua UniversityBeijing 100084China

Polystyrene resins(PS)have been practical ion exchangers for radionuclides removal from ***,nonspecific effects of ion exchange groups continue to be a major obstacle for emergency treatment with coexisting ions of high *** selectivity for Cs+enables zirconium phosphate(ZrP)to be the most promising inorganic sorbent for radioactive cesium extraction,despite being difficult to synthesize and causing excessive pressure loss in fixed-bed reactors due to fine ***,through facile confined crystallization in host macropores,we prepared PS confinedα-ZrP nanocrystalline(ZrP-PS).Size-screen sorption of layeredα-ZrP and sulfonic acid group preconcentration of PS synergistically enable a considerably higher Cs+affinity of ZrP-PS than PS,as confirmed by X-ray photoelectron spectroscopy(XPS)***-PS demonstrated remarkable cesium sequestration performance in both batch and continuous experiments,with a high adsorption capacity of 269.58 mg/g,a rapid equilibrium within 80 min,and a continuous effluent volume of 2300 L/kg *** the excellent selectivity for Cs+and flexibility to separate from treated water,ZrP-PS holds great promise as purification packages for the emergency treatment of radioactively contaminated water.

关键词： Zirconium phosphate Nanocrystalline Polystyrene resin Cesium Removal

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打造金融资产管理公司发展新模式

中国金融 2024年第9期 9-10页

作者：李均锋中国长城资产管理股份有限公司党委

习近平总书记在中央金融工作会议上的重要讲话,为做好新时代新征程金融工作提供了根本遵循和行动指南。中国特色金融发展之路的核心要义“八个坚持”,是金融高质量发展的必由之路,是金融服务中国式现代化的根本之路。金融资产管理公司... 详细信息

习近平总书记在中央金融工作会议上的重要讲话,为做好新时代新征程金融工作提供了根本遵循和行动指南。中国特色金融发展之路的核心要义“八个坚持”,是金融高质量发展的必由之路,是金融服务中国式现代化的根本之路。金融资产管理公司要深刻领会中国特色金融发展之路的新要求,准确把握自身在金融强国建设中的功能定位,抢抓发展新机遇,培育打造核心竞争力,以自身高质量发展更好地服务中国式现代化。

关键词：金融资产管理公司中国式现代化金融服务发展新模式特色金融功能定位根本遵循核心要义

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基于深度强化学习的空中基站部署优化算法

郑州大学学报（理学版） 2024年第4期56卷 28-33页

作者：张博杨锟浩李俊锋郑州大学网络空间安全学院河南郑州450002

针对无人机群(swarm of unmanned aerial vehicle,UAV-swarm)在救灾场景中对地面移动用户进行持续性通信覆盖的问题,设计了一种基于多智能体的深度强化学习的无人机群路径优化算法。该算法框架中无人机具有分布式决策能力,根据用户的移... 详细信息

针对无人机群(swarm of unmanned aerial vehicle,UAV-swarm)在救灾场景中对地面移动用户进行持续性通信覆盖的问题,设计了一种基于多智能体的深度强化学习的无人机群路径优化算法。该算法框架中无人机具有分布式决策能力,根据用户的移动来动态调整自身的移动策略。通过设置合适的强化学习奖励和参数,使无人机在满足覆盖百分比、防碰撞、能源限制等多种约束前提下,最大限度地长期覆盖地面移动用户。与其他无人机部署方案算法进行仿真对比,实验结果表明,该模型在收敛速度和收敛效果上得到了显著提升。

关键词：无人机无线通信深度强化学习轨迹规划

非小细胞肺癌免疫检查点抑制剂假性进展的研究进展

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中国肺癌杂志 2024年第4期27卷 306-320页

作者：童亚军龙咏张帆李军烽岳阳市中心医院肿瘤科岳阳414000 湘雅常德医院肿瘤科常德415000

免疫检查点抑制剂的出现极大地改善了晚期肺癌患者的预后,但其可能会导致假性进展,使临床评估和管理变得复杂化。假性进展表现为肿瘤暂时性增大或出现新病变等,继续治疗后影像学上出现改善,多不伴有临床症状恶化。目前假性进展在早期诊... 详细信息

免疫检查点抑制剂的出现极大地改善了晚期肺癌患者的预后,但其可能会导致假性进展,使临床评估和管理变得复杂化。假性进展表现为肿瘤暂时性增大或出现新病变等,继续治疗后影像学上出现改善,多不伴有临床症状恶化。目前假性进展在早期诊断方面仍存在困难,其发生机制尚不明确,缺乏良好的预测因素和相关生物标志物。本文通过对非小细胞肺癌免疫检查点抑制剂假性进展的研究现状进行综述,以期为使用该类药物治疗患者的临床医生提供有益的参考。

关键词：肺肿瘤免疫检查点抑制剂假性进展免疫治疗