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测量模态不完整情况下空间网架结构的损伤识别

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土木工程学报 2009年第1期42卷 10-15页

作者：宋玉普张亮刘志鑫大连理工大学辽宁大连116023

空间网架结构杆件数量庞大,自由度数目很多,要测得完整的模态数据有很大的困难。如何利用有限的测量信息对结构的损伤情况进行判断是一个实际的问题。对测量自由度不完整情况下网架的损伤识别,提出了两步法:第一,将测量的振型通过动力... 详细信息

空间网架结构杆件数量庞大,自由度数目很多,要测得完整的模态数据有很大的困难。如何利用有限的测量信息对结构的损伤情况进行判断是一个实际的问题。对测量自由度不完整情况下网架的损伤识别,提出了两步法:第一,将测量的振型通过动力扩阶方法得到完整振型,利用模态应变能进行疑似损伤杆件判断;第二,利用最小二乘支持向量机对第一步判断的疑似杆件进行进一步的杆件损伤定位和定量。以一个空间网架结构为模型进行了数值模拟验证,结果表明对于测量模态不完整的网架结构损伤识别本文提出的方法是有效的。

关键词：模态应变能模态扩充空间网架最小二乘支持向量机

The dopaminergic system and Alzheimer's disease

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Neural Regeneration Research 2025年第9期20卷 2495-2512页

作者： Yuhan Zhang Yuan liang Yixue Gu International Medical College Chongqing Medical UniversityChongqingChina College of Pharmacy Chongqing Medical UniversityChongqingChina Department of Neurology The First Affiliated Hospital of Chongqing Medical UniversityChongqing Key Laboratory of NeurologyChongqingChina

Alzheimer's disease is a common neurodegenerative disorder in older *** its prevalence,its pathogenesis remains unclea *** addition to the most widely accepted causes,which in clude excessive amyloid-beta aggregation,tau hyperphosphorylation,and deficiency of the neurotransmitter acetylcholine,numerous studies have shown that the dopaminergic system is also closely associated with the occurrence and development of this *** is a crucial catecholaminergic neurotransmitter in the human ***-associated treatments,such as drugs that target dopamine receptor D and dopamine analogs,can improve cognitive function and alleviate psychiatric symptoms as well as ameliorate other clinical *** r,therapeutics targeting the dopaminergic system are associated with various adverse reactions,such as addiction and exacerbation of cognitive *** review summarizes the role of the dopaminergic system in the pathology of Alzheimer's disease,focusing on currently available dopamine-based therapies for this disorder and the common side effects associated with dopamine-related *** aim of this review is to provide insights into the potential connections between the dopaminergic system and Alzheimer's disease,thus helping to clarify the mechanisms underlying the condition and exploring more effective therapeutic options.

关键词： adverse drug reaction Alzheimer's disease catecholamine dopamine receptor dopamine receptor heterodimers dopaminergic system neurodegenerative disease neurotransmitter signaling pathways traditional Chinese medicine treatment

Superhydrophobic and corrosion-resistant siloxane-modified MgAl-LDHs coatings on magnesium alloy prepared under mild conditions

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 450-463页

作者： Wenxi Zhang Zhangzelong Zhuo Dan Xu liang Wu Zhihui Xie Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province College of Chemistry and Chemical EngineeringChina West Normal UniversityNanchong 637002China College of Materials Science and Engineering/National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China

We have developed a superhydrophobic and corrosion-resistant LDH-W/PFDTMS composite coating on the surface of Mg *** composite comprised a tungstate-intercalated(LDH-W)underlayer that was grown at low temperature(relative to hydrothermal reaction conditions)under atmospheric pressure and an outer polysiloxane layer created from a solution containing perfluorodecyltrimethoxysilane(PFDTMS)using a simple immersion *** successful intercalation of tungstate into the LDH phase and the following formation of the polysiloxane layer were confirmed through X-ray diffraction(XRD),Fourier transform infrared(FTIR)spectroscopy,and X-ray photoelectron spectroscopy(XPS).The corrosion resistance of the LDH-W film,both before and after the PFDTMS modification,was evaluated using electrochemical impedance spectroscopy(EIS),Tafel curves,and immersion *** results showed that Mg coated with LDH-W/PFDTMS exhibited significantly enhanced corrosion protection compared to the unmodified LDHW film,with no apparent signs of corrosion after exposure to 3.5wt%NaCl solution for 15 ***,the LDH-W/PFDTMS coating demonstrated superior superhydrophobicity and self-cleaning properties against water and several common beverages,as confirmed by static contact angle and water-repellency *** results offer valuable insights into preparing superhydrophobic and corrosion-resistant LDH-based composite coatings on Mg alloy surfaces under relatively mild reaction conditions.

关键词： Mg alloy corrosion coating layered double hydroxide

Magneto‑Dielectric Synergy and Multiscale Hierarchical Structure Design Enable Flexible Multipurpose Microwave Absorption and Infrared Stealth Compatibility

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Nano-Micro Letters 2025年第2期17卷 401-416页

作者： Chen Li Leilei liang Baoshan Zhang Yi Yang Guangbin Ji School of Electronic Science and Engineering Nanjing UniversityNanjing 210093People’s Republic of China College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China

Developing advanced stealth devices to cope with radar-infrared(IR)fusion detection and diverse application scenarios is increasingly demanded,which faces significant challenges due to conflicting microwave and IR cloaking mechanisms and functional integration ***,we propose a multiscale hierarchical structure design,integrating wrinkled MXene IR shielding layer and flexible Fe_(3)O_(4)@C/PDMS microwave absorption *** top wrinkled MXene layer induces the intensive diffuse reflection effect,shielding IR radiation signals while allowing microwave to pass ***,the permeable microwaves are assimilated into the bottom Fe_(3)O_(4)@C/PDMS layer via strong magneto-electric *** theoretical and experimental optimization,the assembled stealth devices realize a near-perfect stealth capability in both X-band(8–12 GHz)and long-wave infrared(8–14μm)wavelength ***,it delivers a radar cross-section reduction of−20 dB m^(2),a large apparent temperature modulation range(ΔT=70℃),and a low average IR emissivity of ***,the optimal device demonstrates exceptional curved surface conformability,self-cleaning capability(contact angle≈129°),and abrasion resistance(recovery time≈5 s).This design strategy promotes the development of multispectral stealth technology and reinforces its applicability and durability in complex and hostile environments.

关键词： Microwave absorption Radar-infrared compatible stealth Wrinkled MXene Magneto-dielectric synergy Multifunction

IoT Empowered Early Warning of Transmission Line Galloping Based on Integrated Optical Fiber Sensing and Weather Forecast Time Series Data

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Computers, Materials & Continua 2025年第1期82卷 1171-1192页

作者： Zhe Li Yun liang Jinyu Wang Yang Gao State Grid Henan Electric Power Company Electric Power Scientific Research Institute State Grid Henan Electric Power CompanyZhengzhou450052China

Iced transmission line galloping poses a significant threat to the safety and reliability of power systems,leading directly to line tripping,disconnections,and power *** early warning methods of iced transmission line galloping suffer from issues such as reliance on a single data source,neglect of irregular time series,and lack of attention-based closed-loop feedback,resulting in high rates of missed and false *** address these challenges,we propose an Internet of Things(IoT)empowered early warning method of transmission line galloping that integrates time series data from optical fiber sensing and weather ***,the method applies a primary adaptive weighted fusion to the IoT empowered optical fiber real-time sensing data and weather forecast data,followed by a secondary fusion based on a Back Propagation(BP)neural network,and uses the K-medoids algorithm for clustering the fused ***,an adaptive irregular time series perception adjustment module is introduced into the traditional Gated Recurrent Unit(GRU)network,and closed-loop feedback based on attentionmechanism is employed to update network parameters through gradient feedback of the loss function,enabling closed-loop training and time series data prediction of the GRU network ***,considering various types of prediction data and the duration of icing,an iced transmission line galloping risk coefficient is established,and warnings are categorized based on this ***,using an IoT-driven realistic dataset of iced transmission line galloping,the effectiveness of the proposed method is validated through multi-dimensional simulation scenarios.

关键词： Optical fiber sensing multi-source data fusion early warning of galloping time series data IoT adaptive weighted learning irregular time series perception closed-loop attention mechanism

Domain generalization with semi-supervised learning for people-centric activity recognition

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Science China(Information Sciences) 2025年第1期68卷 171-188页

作者： Jing LIU Wei ZHU Di LI Xing HU liang SONG Academy for Engineering & Technology Fudan University Shanghai East-bund Research Institute on Networking Systems of AI School of Optoelectronic Information and Computer Engineering University of Shanghai for Science & Technology

People-centric activity recognition is one of the most critical technologies in a wide range of real-world applications,including intelligent transportation systems, healthcare services, and brain-computer interfaces. Large-scale data collection and annotation make the application of machine learning algorithms prohibitively expensive when adapting to new tasks. One way of circumventing this limitation is to train the model in a semi-supervised learning manner that utilizes a percentage of unlabeled data to reduce the labeling burden in prediction tasks. Despite their appeal, these models often assume that labeled and unlabeled data come from similar distributions, which leads to the domain shift problem caused by the presence of distribution gaps. To address these limitations, we propose herein a novel method for people-centric activity recognition,called domain generalization with semi-supervised learning(DGSSL), that effectively enhances the representation learning and domain alignment capabilities of a model. We first design a new autoregressive discriminator for adversarial training between unlabeled and labeled source domains, extracting domain-specific features to reduce the distribution gaps. Second, we introduce two reconstruction tasks to capture the task-specific features to avoid losing information related to representation learning while maintaining task-specific consistency. Finally, benefiting from the collaborative optimization of these two tasks, the model can accurately predict both the domain and category labels of the source domains for the classification task. We conduct extensive experiments on three real-world sensing datasets. The experimental results show that DGSSL surpasses the three state-of-the-art methods with better performance and generalization.

关键词： activity recognition deep learning domain generalization semi-supervised learning adversarial training

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Establishing a new testing protocol of the electrochemical stability window for electric double-layer capacitors

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Science China Chemistry 2025年第1期68卷 217-225页

作者： Ruilin Hou Xiaoxi Zhao Tingting liang Qingyun Dou Shan Xu Xingbin Yan School of Materials Science and Engineering Sun Yat-sen University Laboratory of Clean Energy Chemistry and Materials Lanzhou Institute of Chemical Physics Chinese Academy of Sciences College of Engineering and Applied Sciences Nanjing University Center of Industrial Analysis and Testing Guangdong Academy of Science

The electrochemical stability window(ESW) is crucial for determining the energy density of electric double-layer capacitors(EDLCs). However, current ESW testing protocols of EDLCs are strongly affected by artificial factors, thereby leading to unreliable result. To solve this problem, we first identify the key shortcomings of the traditional protocols by analyzing their test principles. Subsequently, taking an aqueous carbon-based EDLC as an example, we design a side reaction descriptor to represent the response difference in the charging capacitance to side reactions between the cyclic voltammetry and galvanostatic chargedischarge methods. With the aid of this descriptor, we propose a new ESW testing protocol, which is not only able to completely avoid the adverse influence of subjective factors but also fully consider the operating condition limitations. The protocol can be extended from the single electrode to the full device. This work proposes a more rigorous definition of ESW and provides a reliable protocol for evaluating the ESW of EDLCs.

关键词： electric double-layer capacitors electrochemical stability window testing protocol side reaction descriptor operating limitation

Sky location of massive black hole binaries in the foreground of Galactic white dwarf binaries

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 97-108页

作者： Pan Guo Hong-Bo Jin Cong-Feng Qiao Yue-liang Wu The International Centre for Theoretical Physics Asia-Pacific University of Chinese Academy of Sciences The School of Physical Sciences University of Chinese Academy of Sciences Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University National Astronomical Observatories Chinese Academy of Sciences Institute of Theoretical Physics Chinese Academy of Sciences

For space-based gravitational wave （GW） detection,the main noise source for massive black hole binaries （MBHBs） is attributed to approximately 10～7double white dwarf binaries in the *** a GW source,the amplitude of the detector response,recorded by a space-based gravitational wave detector,exhibits a modulation effect with a year period when observing the source from various orbital *** the adverse conditions mentioned above,where there is a strong foreground noise and annual modulation in the signals,we employed the wavelet transform and the strong-amplitude relevant orbital position search methods,which allows the weak MBHB sources to achieve higher locating *** detail,for two MBHB sources of lower intensity,the precision of luminosity distance,represented by the ratio ?DL/DLat the 95%confidence level,is enhanced by factors of ～*** angular resolutions,denoted by??s,are enhanced by a factor of ～*** improvements increase the number of detectable GW sources,facilitate multi-messenger follow-up observations and provide constraints on the cosmological constant.

关键词： space-based gravitational wave detection gravitational waves massive black hole binaries

Force and impulse multi-sensor based on flexible gate dielectric field effect transistor

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 214-220页

作者： Chao Tan Junling Lü Chunchi Zhang Dong liang Lei Yang Zegao Wang College of Materials Science and Engineering Sichuan UniversityChengdu 610065China The 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang 050081China

Nowadays,force sensors play an important role in industrial production,electronic information,medical health,and many other ***-dimensional material-based filed effect transistor(2D-FET)sensors are competitive with nano-level size,lower power consumption,and accurate ***,few of them has the capability of impulse detection which is a path function,expressing the cumulative effect of the force on the particle over a period of *** we fabricated the flexible polymethyl methacrylate(PMMA)gate dielectric MoS_(2)-FET for force and impulse sensor *** systematically investigated the responses of the sensor to constant force and varying forces,and achieved the conversion factors of the drain current signals(I_(ds))to the detected impulse(I).The applied force was detected and recorded by I_(ds)with a low power consumption of~30 *** sensitivity of the device can reach~8000%and the 4×1 sensor array is able to detect and locate the normal force applied on ***,there was almost no performance loss for the device as left in the air for two months.

关键词： flexible gate dielectric transistor force sensor impulse sensor force sensor array