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Spectrum analysis of interval process model and its application in uncertain vibration analysis

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Science China Technological Sciences 2024年第8期67卷 2549-2564页

作者： LI JinWu JIANG Chao ni BingYu State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle College of Mechanical and Vehicle Engineering Hunan University

In recent years, the authors have extended the traditional interval method into the time dimension to develop a new mathematical tool called the “interval process model” for quantifying time-varying or dynamic uncertainties. This model employs upper and lower bounds instead of precise probability distributions to quantify uncertainty in a parameter at any given time point. It is anticipated to complement the conventional stochastic process model in the coming years owing to its relatively low dependence on experimental samples and ease of understanding for engineers. Building on our previous work, this paper proposes a spectrum analysis method to describe the frequency domain characteristics of an interval process, further strengthening the theoretical foundation of the interval process model and enhancing its applicability for complex engineering problems. In this approach, we first define the zero midpoint function interval process and its auto/cross-power spectral density(PSD) functions. We also deduce the relationship between the auto-PSD function and the auto-covariance function of the stationary zero midpoint function interval process. Next, the auto/cross-PSD function matrices of a general interval process are defined, followed by the introduction of the concepts of PSD function matrix and cross-PSD function matrix for interval process vectors. The spectrum analysis method is then applied to random vibration problems, leading to the creation of a spectrum-analysis-based interval vibration analysis method that determines the PSD function for the system displacement response under stationary interval process excitations. Finally, the effectiveness of the formulated spectrum-analysis-based interval vibration analysis approach is verified through two numerical examples.

关键词： interval process spectrum analysis power spectral density (PSD) time-varying uncertainty uncertain vibration analysis

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Dynamic Response Impact of Vehicle Braking on Simply Supported Beam Bridges with Corrugated Steel Webs Based on Vehicle-Bridge Coupled Vibration Analysis

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3467-3493页

作者： Yan Wang Siwen Li na Wei School of Civil Engineering Zhengzhou UniversityZhengzhou450001China

A novel approach for analyzing coupled vibrations between vehicles and bridges is presented,taking into account spatiotemporal effects and mechanical phenomena resulting fromvehicle *** modeling and solution of bridge vibrations induced by vehicle deceleration are realized using this *** method’s validity and reliability are substantiated through numerical examples.A simply supported beam bridge with a corrugated steel web is taken as an example and the effects of parameters such as the initial vehicle speed,braking acceleration,braking location,and road surface roughness on the mid-span displacement and impact factor of the bridge are *** results show that vehicle braking significantly amplifies mid-span displacement and impact factor responses in comparison to uniform vehicular motion across the ***,the influence of wheelto-bridge friction forces is of particular significance and cannot be *** the vehicle initiates braking near the middle of the span,both the mid-span displacement and impact factor of the bridge exhibit substantial increases,further escalating with higher braking *** favorable road surface conditions,the midspan displacement and the impact factor during vehicle braking may exceed the design values stipulated by *** is important to note that road surface roughness exerts a more pronounced effect on the impact factor of the bridge in comparison to the effects of vehicle braking.

关键词： Corrugated steel web girder bridges simply supported beam bridges vehicle-bridge coupled vibration braking impact factor

Two MADS-box proteins,AGL9 and AGL15,recruit the FIS-PRC2 complex to trigger the phase transition from endosperm proliferation to embryo development in Arabidopsis

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Molecular Plant 2024年第7期17卷 1110-1128页

作者： Shen Zhang Devasantosh Mohanty Adnan Muzaffar Min ni Department of Plant and Microbial Biology University of Minnesota at Twin CitiesSaint PaulMinnesota MN 55108United States of AmericaUSA

Spatiotemporal regulation of gene expression by polycomb repressive complex 2(PRc2)is critical for animal and plant *** Arabidopsis fertilization independent seed(FIS)-PRC2 complex functions specifically during plant reproduction from gametogenesis to seed *** a double fertilization event,triploid endosperm proliferates early,followed by the growth of a diploid embryo,which replaces the endosperm in Arabidopsis and many *** genes critical for endosperm proliferation such as IKkU2 and MIni3 are activated after *** we report that two MADS-box AGAMOUS-LIKE(AGL)proteins associate with the key endosperm proliferation loci and recruit the FIS-PRC2 repressive complex at 4-5 days after pollination(DAP).Interestingly,AGL9 and AGL15 only accumulate toward the end of endosperm proliferation at 4-5 DAP and promote the deposition of H3K27me3 marks at key endosperm proliferation *** of AGL9 and AGL15 or overexpression of AGL9 or AGL15 significantly influence endosperm proliferation and ***-wide analysis with cleavage Under Targets and tagmentation(CUT&Tag)sequencing and Rna sequencing revealed the landscape of endosperm H3K27me3 marks and gene expression profiles in Col-0 and agl9 ***&Tag qPCR also demonstrated the occupancy of the two MADS-box proteins and FIS-PRC2 on a few representative target *** studies suggest that MADS-box proteins could potentially recruit PRc2 to regulate many other developmental processes in plants or even in fungi and animals.

关键词： AGL9 AGL15 embryo endosperm IKU2 MEDEA MIni3

Stimulating Start-up Investment Through Government-Sponsored Venture Capital: Theory and Chinese Evidence

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Journal of Systems Science & Complexity 2024年第5期37卷 2021-2053页

作者： ni Xuanming ZHENG Tiantian GAO Feng ZHAO Huimin School of Software and Microelectronics Peking University School of Economics and Management Tsinghua University School of Business Sun Yat-sen University

Government-sponsored venture capital(GVC) has been used to support financially constrained start-ups as an important policy tool in China. Typically, to motivate the social capital to invest in start-ups, GVC provides subsidies for them to bridge the funding gap in the early-stage venture capital market. However, the effect and mechanism of GVC affecting social capital investment have not been clearly studied. In this paper, the authors not only develop a game model to analyze this issue in theory, but conduct an empirical study by analyzing the 14741 records matched by propensity score matching(PSM) of Chinese venture capital market data from 2011 to 2021. The proposed findings are as the follows. Firstly, the subsidies offered by GVC will simultaneously increase the returns and risks of investments in start-ups of social capital with more volatile incentive effect of GVC. The incentive effect of GVC is only effective when the returns resulting from the subsidies outweigh the risks they introduce. In the context of the Chinese venture capital market, the incentive effect of GVC is effective. Secondly, the incentive effect of GVC is more pronounced in high-tech industries, which can be attributed to the signaling effect facilitated by GVC. In this context, the subsidy mainly helps social capital to bear the costs associated with screening potential investments. Thirdly, the incentive effect of GVC is more significant in underdeveloped venture capital markets, which can be explained by the “virtuous cycle” effect, in which GVC plays a pioneering role in establishing a more robust early-stage market trading system. By examining these three points, this study contributes to a better understanding of how GVC can effectively guide social capital investment, especially in the Chinese landscape.

关键词： Government-sponsored venture capital fund incentive effect social capital subsidy venture capital

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A New Encrypted Traffic Identification Model Based on VAE-LSTM-DRN

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Computers, Materials & Continua 2024年第1期78卷 569-588页

作者： Haizhen Wang Jinying Yan na Jia College of Computer and Control Engineering Qiqihar UniversityQiqihar161006China Heilongjiang Key Laboratory of Big Data Network Security Detection and Analysis Qiqihar UniversityQiqiharChina

Encrypted traffic identification pertains to the precise acquisition and categorization of data from traffic datasets containing imbalanced and obscured *** extraction of encrypted traffic attributes and their subsequent identification presents a formidable *** existing models have predominantly relied on direct extraction of encrypted traffic data from imbalanced datasets,with the dataset’s imbalance significantly affecting the model’s *** the present study,a new model,referred to as UD-VLD(Unbalanced Dataset-VAE-LSTM-DRN),was proposed to address above *** proposed model is an encrypted traffic identification model for handling unbalanced *** encoder of the variational autoencoder(VAE)is combined with the decoder and Long-short term Memory(LSTM)in UD-VLD model to realize the data enhancement processing of the original unbalanced *** enhanced data is processed by transforming the deep residual network(DRN)to address neural network gradient-related ***,the data is classified and *** UD-VLD model integrates the related techniques of deep learning into the encrypted traffic recognition technique,thereby solving the processing problem for unbalanced *** UD-VLD model was tested using the publicly available Tor dataset and VPN *** UD-VLD model is evaluated against other comparative models in terms of accuracy,loss rate,precision,recall,F1-score,total time,and ROC *** results reveal that the UD-VLD model exhibits better performance in both binary and multi classification,being higher than other encrypted traffic recognition models that exist for unbalanced ***,the evaluation performance indicates that the UD-VLD model effectivelymitigates the impact of unbalanced data on traffic *** can serve as a novel solution for encrypted traffic identification.

关键词： Data enhancement LSTM deep residual network VAE

High-throughput and simultaneous inertial separation of tumor cells and clusters from malignant effusions using spiral-contraction-expansion channels

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Microsystems & nanoengineering 2024年第2期10卷 91-99页

作者： Zhixian Zhu Hui Ren Dan Wu Zhonghua ni nan Xiang School of Mechanical Engineering and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical InstrumentsSoutheast University211189NanjingChina School of Mechanical Technology Wuxi Institute of TechnologyNo.1600 Gaolang West Road214129WuxiChina Department of Oncology Jiangyin People’s Hospital214400JiangyinChina

Tumor cell clusters are regarded as critical factors in cancer pathophysiology,and increasing evidence of their higher treatment resistance and metastasis compared to single tumor cells has been ***,existing cell separation methods that are designed for single tumor cells cannot be used to simultaneously purify tumor cell *** address this problem,we demonstrated a microfluidic approach for the high-throughput,continuous-flow ternary separation of single tumor cells,tumor cell clusters,and WBCs from clinical pleural or abdominal effusions by coupling slanted spiral channels and periodic contraction-expansion *** first systematically explored the influence of particle size and flow rate on particle *** separation performance indicated that 94.0%of WBCs were removed and more than 97%of MDA-MB-231 tumor cells were recovered at a high flow rate of 3500µL/***,more than 90%of tumor cell clusters were effectively preserved after ***,we successfully applied our device for the ternary separation of single tumor cells,tumor cell clusters,and WBCs from different malignant effusions collected from patients with metastatic ***,our spiral-contraction-expansion device has potential as a sample pretreatment tool for the cytological diagnosis of malignant effusions.

关键词： separation contraction removed

Improving IEC thermal model for oil natural air natural transformers using optimised parameters based on dynamic simulation

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High Voltage 2024年第1期9卷 217-229页

作者： Lijing Zhang Yingting Luo Gehao Sheng Zizhan ni Xiuchen Jiang Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghaiChina Electric Power Research Institute of Guangdong Power Grid Corporation GuangzhouChina

Accurate assessment of hot-spot temperature is essential for the safe operation of power *** dynamic thermal models cannot estimate hot-spot temperature accurately since some input parameters are roughly determined by transformer capacity and cooling mode while ignoring the effect of winding structure,tank dimensions,and material physical *** improve the accuracy of temperature assessment,empirical parameters of the IEC thermal model including thermal constants,winding and oil exponents are optimised with the help of numerical simulation in this *** on energy conservation and heat transfer theory,a computational fluid dynamic(CFD)model of a transformer in oil natural air natural(OnaN)cooling mode is *** CFD model simulates the entity's structure,sizes,and multi-stage heat dissipation processes realistically,so it can more precisely calculate the dynamic hot-spot *** to the simulated temperature curves at different operating conditions,the thermal constants and oil exponent are estimated using non-linear regression,and the winding exponent is optimised using linear regression.A case study is conducted on an OnaN *** shows the improved IEC model with optimised parameters can more accurately evaluate hot-spot temperature,and the absolute error is decreased by 2.4 K(38.7%)compared with traditional thermal models.

关键词： temperature properties. thermal

Nonaqueous potassium-ion full-cells:Mapping the progress and identifying missing puzzle pieces

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Journal of Energy Chemistry 2024年第6期93卷 384-399,I0010页

作者： Badre Larhrib Louiza Larbi Lénaïc Madec Universite de Pau et des Pays de l’Adour E2S UPPACNRSIPREMPauFrance Universitéde Haute-Alsace Institut de Science des Matériaux de Mulhouse(IS2M)CNRS UMR 7361F-68100 MulhouseFrance Universitéde Strasbourg F-67081 StrasbourgFrance Réseau sur le Stockage Electrochimique de l’Energie CNRS FR3459AmiensFrance Institut des Matériaux Jean Rouxel(IMN) CNRS UMR 6502Univ.Nantes44322 Cedex 3 NantesFrance

This review addresses the growing interest for potassium-ion full-cells(KIFCs)in view of the transition from potassium-ion half-cells(KIHCs)toward commercial K-ion batteries(KIBs).It focuses on the key parameters of KIFCs such as the electrode/electrolyte interfaces challenge,major barriers,and recent advancements in *** strategies for enhancing KIFC performance,including interfaces co ntrol,electrolyte optimization,electrodes capacity ratio,electrode material screening and electrode design,are *** review highlights the need to evaluate KIBs in full-cell configurations as half-cell results are strongly impacted by the K metal *** also emphasizes the importance of understanding solid electrolyte interphase(SEI)formation in KIFCs and explores promising nonaqueous as well as quasiand all-solid-state electrolytes *** review thus paves the way for practical,cost-effective,and scalable KIBs as energy storage systems by offering insights and guidance for future research.

关键词： K-ion full-cells Potassium-ion batteries Cross-talk Solid-state batteries Potassium reactivity Electrolyte design Electrode design

维普期刊数据库

LncRna HCP5-encoded protein contributes to adriamycin resistance through ERK/mTOR pathway-mediated autophagy in breast cancer cells

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Genes & Diseases 2024年第4期11卷 69-72页

作者： Jia-ni Xing Yi-ni Shang Zheng-Ling Yu Shun-Heng Zhou Wang-Yang Chen Li-Hong Wang Department of Pathophysiology Medical College of Southeast UniversityNanjingJiangsu 210009China Department of Biomedical Engineering Nanjing University of Aeronautics and AstronauticsNanjingJiangsu 211106China School of Medicine Taizhou UniversityTaizhouZhejiang 318000China Jiangsu Provincial Key Laboratory of Critical Care Medicine NanjingJiangsu 210009China

Adriamycin(ADR),also known as doxorubicin,is an anthracycline anticancer drug and a chemotherapeutic drug commonly used in breast cancer treatments.1 However,breast cancer patients can gradually become tolerant to ***,improving the curative effect of ADR remains an urgent problem to be *** is a complex catabolic process;normal living cells break down damaged organelles or aggregated molecules and absorb energy to maintain homeostasis through autophagy.

关键词： breast cancer homeostasis