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A novel method for satellite prediction of VDE-TER service traffic information based on multilayers bidirectional LSTM

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INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS anD NETWORKING 2024年第0期

作者： Wu, Ruiwen Li, Zongwang Xie, Zhuochen Liang, xuwen Univ Chinese Acad Sci Sch Elect Elect & Commun Engn Beijing 100049 Peoples R China Chinese Acad Sci Shanghai Innovat Acad Microsatellites Shanghai Peoples R China Shanghai Engn Ctr Microsatellites Shanghai Peoples R China

Satellite prediction of very high frequency (VHF) Data Exchange (VDE)-Terrestrial (VDE-TER) ship-to-ship Self-Organized Networks (SON) service traffic information is crucial for wireless resource allocation of VHF Data Exchange System (VDES). Due to the VDE-TER, channel load observed by the satellite changes rapidly and the historical information cached on the satellite is limited;the prediction of VDE-TER service traffic is difficult. This paper proposes a multilayer bidirectional long short-term memory (LSTM) neural network model (MLB-LSTM), which controls the amount of forgetting of historical information and the amount of memory of current information through the LSTM unit, so that the model can better learn the nonlinear changes of service traffic. The bidirectional LSTM module combines forward and backward time series data, reducing the amount of data required for prediction and enhancing the prediction accuracy of the model. Numerical results show that the proposed prediction model significantly outperforms traditional methods and is able to adapt to rapidly changing VDE-TER data. This paper proposes a multilayer bidirectional long short-term memory (LSTM) neural network model (MLB-LSTM), which controls the amount of forgetting of historical information and the amount of memory of current information through the LSTM unit, so that the model can better learn the nonlinear changes of service traffic. The bidirectional LSTM module combines forward and backward time series data, reducing the amount of data required for prediction and enhancing the prediction accuracy of the model. image

关键词： bidirectional LSTM LEO satellite multidimensional time series prediction VHF data exchange system

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Explicit Solutions to the n-dimensional Semi-stationary Compressible Stokes Problem

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INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS 2025年第2期64卷 1-11页

作者： Zhang, Lijun Zhao, Qiong Huo, xuwen Khalique, Chaudry Masood Zhejiang Univ Sci & Technol Hangzhou 310023 Zhejiang Peoples R China Shandong Univ Sci & Technol Coll Math & Syst Sci Qingdao 266590 Shandong Peoples R China Zhejiang Scitech Univ Hangzhou Sch Comp Sci & Technol Zhejiang 3100018 Peoples R China North West Univ Fac Nat & Agr Sci Mat Sci Innovat & Modelling Res Focus Area Mafikeng Campus ZA-2735 Mmabatho South Africa

The n-dimensional semi-stationary compressible Stokes equations, established to model the dynamics of vortices in the Ginzburg-Landau theories in superconductivity, is a simplification of the isentropic compressible Navier-Stokes equations. This model equation can also be derived from the equations for the flows in compressible porous media in petroleum engineering or in compressible tissues. In this work, we investigate the n-dimensional semi-stationary compressible Stokes equations and obtain a family of explicit solutions in which the density does not change with space variables but decays to zero with time increasing exponentially, while the velocity is a quadratic polynomial of the space variables. It is worth pointing out that our results not only include the known results for n=2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n=2$$\end{document} and n=3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$n=3$$\end{document} in Xue and Dong (Int. J. Theor. Phys. 63(6), 151 (2024)), but also present the explicit solutions to the semi-stationary compressible Stokes equations in arbitrary higher dimensional space.

关键词： Compressible fluids Semi-stationary compressible Stokes problem Explicit solutions

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Willmore-type inequality in unbounded convex sets

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JOURNAL OF THE LONDON MATHEMATICAL SOCIETY-SECOND SERIES 2025年第3期111卷

作者： Jia, Xiaohan Wang, Guofang Xia, Chao Zhang, xuwen Southeast Univ Sch Math Nanjing Peoples R China Univ Freiburg Math Inst Ernst Zermelo Str1 D-79104 Freiburg Germany Xiamen Univ Sch Math Sci Xiamen Peoples R China

In this paper, we prove the following Willmore-type inequality: on an unbounded closed convex set K subset of Rn+1$K\subset \mathbb {R}{n+1}$ (n >= 2$(n\geqslant 2$), for any embedded hypersurface Sigma subset of K...

In this paper, we prove the following Willmore-type inequality: on an unbounded closed convex set K subset of Rn+1$K\subset \mathbb {R}<^>{n+1}$ (n >= 2$(n\geqslant 2$), for any embedded hypersurface Sigma subset of K${\Sigma }\subset K$ with boundary partial derivative Sigma subset of partial derivative K$\partial {\Sigma }\subset \partial K$ satisfying a certain contact angle condition, there holds 1n+1 integral Sigma HndA >= AVR(K)|Bn+1|.$$\begin{equation*} {\frac{1}{n+1}\int _{{\Sigma }}{\left|{H}\right|}<^>n d A\geqslant \rm AVR}(K)\vert \mathbb {B}<^>{n+1}\vert . \end{equation*}$$Moreover, equality holds if and only if Sigma${\Sigma }$ a part of a sphere and K\Omega$K\setminus \Omega$ is a part of the solid cone determined by Sigma${\Sigma }$. Here, Omega$\Omega$ is the bounded domain enclosed by Sigma${\Sigma }$ and partial derivative K$\partial K$, H$H$ is the normalized mean curvature of Sigma${\Sigma }$, and AVR(K)${\rm AVR}(K)$ is the asymptotic volume ratio of K$K$. We also prove an anisotropic version of this Willmore-type inequality. As a special case, we obtain a Willmore-type inequality for anisotropic capillary hypersurfaces in a half-space.

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Engineering of Charge-Transfer State to Modify Photophysical Properties in N,N′-Diaryl-dihydrodibenzo[a,c]phenazine

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JOURNAL OF PHYSICAL CHEMISTRY C 2024年第36期128卷 15124-15131页

作者： Sun, xuwen Cong, Muyu Jin, Xin Su, Jianhua Zhang, Zhiyun East China Univ Sci & Technol Feringa Nobel Prize Scientist Ctr Materiobiol & Dy Key Lab Adv Mat Shanghai 200237 Peoples R China East China Univ Sci & Technol Feringa Nobel Prize Scientist Ctr Materiobiol & Dy Joint Int Res Lab Precis Chem & Mol Engn Shanghai 200237 Peoples R China

Herein, we explored the charge transfer (CT) effect on the excited-state structural and electronic evolution of N,N '-diphenyl-dihydrodibenzo[a,c]phenazine (DPAC) featuring various electron-donating groups (EDGs). Upon photoexcitation, DPAC molecules undergo a sequential multistep structural transformation along the Franck-Condon (FC) state, CT-controlled bent state (responsible for E1 & horbar;420 nm), and twisted state (responsible for E2 & horbar;600 nm). By introducing different EDGs to the DPAC core, we can fine-tune the balance between the inherent decay of the CT-controlled bent state and its progression into the twisted state by adjusting the CT effect. As the electron-donating ability of the EDG increases, the strong CT effect can produce a "deep" (stable) CT-controlled bent state, in which the transformation of the excited molecular skeleton from bent into twisted was partly suppressed. This research provides valuable insights into organic chromophores' excited-state structural and electronic evolution, revealing how competitive decay pathways are contingent upon the CT effect.

关键词： Charge transfer

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Whiten Lignin-Based Sunscreen via Fractionation and Ultrasonic Cavitation

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ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2024年第17期12卷 6539-6546页

作者： Wu, xuwen Zhou, Mingsong Ouyang, Xinping Qiu, Xueqing Qian, Yong South China Univ Technol Sch Chem & Chem Engn State Key Lab Pulp & Paper Engn Guangzhou 510640 Peoples R China Guangdong Univ Technol Sch Chem Engn & Light Ind Guangzhou 510006 Peoples R China

Lignin exhibits good potential in natural sunscreens, but its dark color is still an obstacle. Herein, a strategy combining ultrafiltration and ultrasonic cavitation is developed to whiten enzymatic hydrolysis lignin (EHL). Results show that fractions with the smallest molecular weight possess the lightest color due to the lower bulk density and fewer surface chromophores. The hydrophobic aromatic skeleton and abundant phenol and carboxyl groups endow the fraction with good dispersibility and reactivity. Oil chemical sunscreen actives are effectively emulsified and encapsulated via ultrasonic cavitation. As-prepared capsules have an average diameter of 269 nm and a whiteness index of -15, representing 71% and 63% whiteness improvement compared to EHL and EHL-based capsules. The capsule-based sunscreen approaches white even under a dosage of 10 wt %. The sun protection factor of the sunscreen reaches 96 and maintains good performance at both room and high temperatures.

关键词： lignin nature sunscreen ultrafiltration ultrasonic cavitation white color

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Move out of the land: certification and migration in China

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EUROPEan REVIEW OF AGRICULTURAL ECONOMICS 2024年第4期51卷 927-966页

作者： Huangfu, Bingyu Gao, xuwen Shi, Xinjie Jin, Songqing Zhejiang Univ China Acad Rural Dev Sch Publ Affairs Hangzhou Peoples R China Zhejiang Univ Sch Publ Affairs Hangzhou Peoples R China Zhejiang Univ Inst Common Prosper & Dev Sch Publ Affairs Hangzhou Peoples R China Zhejiang Univ Ctr Social Welf & Governance Hangzhou Peoples R China Zhejiang Univ Res Ctr Common Prosper Innovat Ctr Yangtze River Delta Future Reg Dev Lab Jiashan Peoples R China Zhejiang Univ & Huzhou City Ctr Common Prosper Huzhou Peoples R China Michigan State Univ Dept Agr Food & Resource Econ E Lansing MI USA

Motivated by the emphasis on securing property rights as an important tool for the effcient allocation of resources, including land and labour, we use three rounds of China Rural Household Panel Survey data to assess the impact of a land certifcation programme (LCP) on the labour and land allocation in rural China. We fnd that the LCP results in increased rural-urban migration, more active land rental markets, as well as higher household income and consumption in rural China. These effects vary with age and are larger for younger individuals and households with heads aged 50 years or younger. Improving property rights could be a central task for the Chinese government to tackle issues related to labour and land misallocation.

关键词： property right land certification misallocation China

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Catalytic ozonation process for treating coking biochemical wastewater based on an Fe-Mn/Al2O3 catalyst

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COLLOIDS anD SURFACES A-PHYSICOCHEMICAL anD ENGINEERING ASPECTS 2025年 713卷

作者： Qin, Yihe Yuan, Run Luo, Shaojun Huang, Haiming He, xuwen Dongguan Univ Technol Sch Environm & Civil Engn Dongguan 523808 Peoples R China Tianjin Univ Sch Earth Syst Sci Tianjin 300072 Peoples R China China Univ Min & Technol Sch Chem & Environm Engn Beijing 100083 Peoples R China

Catalysts with high catalytic performance are crucial for the catalytic ozonation of organic wastewater. This study synthesized an efficient, stable, and practical Fe-Mn/Al2O3 ozone catalyst for wastewater treatment using an impregnation calcination method, and applied it in the catalytic ozonation of wastewater. When the concentration of manganese nitrate was 0.15 mol/L, the Mn/Fe ratio was 3:1, the immersion time was 24 h, the calcination temperature was 500 degrees C, and the calcination time was 4 h, the prepared Fe-Mn/Al2O3 had the best catalytic effect on simulated wastewater, with a chemical oxygen demand (COD) removal efficiency of 73.6 %. At the same time, the physicochemical properties of the catalyst were investigated, and the catalytic effect of the catalyst on actual coking wastewater was investigated on a laboratory scale. When the ozone concentration was 20 mg/L, the gas flow rate was 0.5 L/min, the catalyst concentration was 400 g/L, and the pH was 7.02, the actual COD removal efficiency of coking wastewater was 71.6 %. The pilot test results showed that the COD of the treated coking wastewater could stably meet the standard (COD<80 mg/L), with an average COD removal rate of about 58.3 %, indicating that the Fe-Mn/Al2O3 had high catalytic activity and good stability. Kinetic analysis showed that the degradation process of organic pollutants followed the pseudo-second-order kinetic equation. The results of water quality analysis such as conventional water quality indicators, fluorescence spectroscopy, and molecular weight classification indicated that the large molecular organic pollutants were efficiently degraded. Mechanism analysis indicated that the active components of the catalyst reacted with ozone through electron transfer to enhance the ozone utilization efficiency and efficiently remove organic pollutants. This study can provide theoretical support and technical reference for the standardized discharge of coking wastewater in the future.

关键词： Catalytic ozonation Coking wastewater Mechanism exploration Water quality analysis

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Fundamental Issues Towards Unified Design Theory of Recycled and Natural Aggregate Concrete Components

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Engineering 2023年第10期29卷 188-197页

作者： Jianzhuang Xiao Kaijian Zhang Tao Ding Qingtian Zhang xuwen Xiao Department of Structural Engineering Tongji UniversityShanghai 200092China College of Civil Engineering and Architecture Guangxi UniversityNanning 530004China College of Civil Engineering Fuzhou UniversityFuzhou 350116China

In the past 20 years,recycled aggregate concrete(RAC),as a type of low-carbon concrete,has become a worldwide focus of ***,the design methodology for RAC structural components remains a ***,demands for a unified design of natural aggregate concrete(NAC)and RAC components have been ***,this study analyses the necessity of a unified design theory and provides an in-depth demonstration of the strength determination,compressive constitutive relationship,and design method of concrete *** coefficient of variation of RAC strength is found to be generally higher than that of NAC *** compressive and tensile strengths of RAC can be defined and determined using the same method as that used for *** uniaxial compressive constitutive relationship between NAC and RAC has a unified mathematical ***,the elastic modulus of RAC decreases,and its brittleness exhibits an increasing trend compared with that of ***,to unify the design formulae of RAC and NAC components for bearing capacity,modification factors for RAC components are proposed considering safety and ***,the feasibility of the proposed unified time-dependent design theory is demonstrated in terms of conceptual design and structural measures considering the effects of strength degradation and reinforcement *** is believed that this study enriches and develops the basic theory of concrete structures.

关键词： Recycled aggregate concrete(RAC) Natural aggregate concrete(NAC) Strength determination Constitutive relation Reliability Unified design theory

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Direct Arylation Polycondensation of Thiophene-Based C−H Monomers

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Chinese Journal of Chemistry 2023年第21期41卷 2908-2924页

作者： xuwen Zhang Yibo Shi Yunfeng Deng Yanhou Geng School of Materials Science and Engineering and Tianjin Key Laboratory of Molecular Optoelectronic Science Tianjin Universityand Collaborative Innovation Center of Chemical Science and Engineering(Tianjin)Tianjin300072 China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhouFujian350207 China

Direct arylation polycondensation(DArP)has emerged as an eco-friendly and atom-efficient methodology for the syntheses ofπ-conjugated polymers(CPs).This approach features the direct C—H arylation of an aromatic hydrocarbon with an aryl *** the prevalence of thiophene-containing CPs,achieving efficient and defect-free DArP of thiophene-based C−H monomers is of great *** review presents a mechanistic insight into DArP and describes the development of DArP catalytic systems for varied thiophene-based C−H ***,the control of the primary defects(i.e.,branching and homo-coupling)in thiophene-based DArP is also *** emphasizing the principles behind monomer selection and catalytic system optimization,this review intends to provide a framework for future advancements in the DArP of thiophene-containing CPs.

关键词： Conjugated polymers Direct arylation polycondensation Sustainable chemistry Catalytic system Thiophene

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The marine environmental microbiome mediates physiological outcomes in host nematodes

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BMC BIOLOGY 2024年第1期22卷 1页

作者： Xue, Yiming Xie, Yusu Cao, xuwen Zhang, Liusuo Chinese Acad Sci Inst Oceanol CAS Qingdao 266071 Peoples R China Chinese Acad Sci Inst Oceanol Shandong Prov Key Lab Expt Marine Biol Qingdao 266071 Peoples R China Qingdao Natl Lab Marine Sci & Technol Lab Marine Biol & Biotechnol Qingdao 266237 Peoples R China Chinese Acad Sci Ctr Ocean Mega Sci 7 Nanhai Rd Qingdao 266071 Peoples R China Univ Chinese Acad Sci Beijing 100049 Peoples R China

Background Nematodes are the most abundant metazoans in marine sediments, many of which are bacterivores;however, how habitat bacteria affect physiological outcomes in marine nematodes remains largely unknown. Results Here, we used a Litoditis marina inbred line to assess how native bacteria modulate host nematode physiology. We characterized seasonal dynamic bacterial compositions in L. marina habitats and examined the impacts of 448 habitat bacteria isolates on L. marina development, then focused on HQbiome with 73 native bacteria, of which we generated 72 whole genomes sequences. Unexpectedly, we found that the effects of marine native bacteria on the development of L. marina and its terrestrial relative Caenorhabditis elegans were significantly positively correlated. Next, we reconstructed bacterial metabolic networks and identified several bacterial metabolic pathways positively correlated with L. marina development (e.g., ubiquinol and heme b biosynthesis), while pyridoxal 5'-phosphate biosynthesis pathway was negatively associated. Through single metabolite supplementation, we verified CoQ10, heme b, acetyl-CoA, and acetaldehyde promoted L. marina development, while vitamin B6 attenuated growth. Notably, we found that only four development correlated metabolic pathways were shared between L. marina and C. elegans. Furthermore, we identified two bacterial metabolic pathways correlated with L. marina lifespan, while a distinct one in C. elegans. Strikingly, we found that glycerol supplementation significantly extended L. marina but not C. elegans longevity. Moreover, we comparatively demonstrated the distinct gut microbiota characteristics and their effects on L. marina and C. elegans physiology. Conclusions Given that both bacteria and marine nematodes are dominant taxa in sedimentary ecosystems, the resource presented here will provide novel insights to identify mechanisms underpinning how habitat bacteria affect nematode biology in a more natural context. Ou

关键词： Litoditis marina Full-length 16S rRNA sequencing Marine bacterial collection Host-microbe interactions Metabolic models Gene knockout Gut microbiota

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