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Paleoclimate data assimilation: Principles and prospects

Science China Earth Sciences 2025年

作者： Haoxun ZHANG Mingsong LI Yongyun hu Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education School of Earth and Space Sciences Peking University State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic Sciences School of PhysicsPeking University Institute of Ocean Research Peking University

Reconstructing climate states during geological periods is a key focus in studying Earth system evolution. Substantial progress has been achieved in reconstructing paleoclimate and paleoenvironment using both Earth system models and paleoclimate proxies. However, current paleoclimate reconstructions face several challenges:the accuracy of Earth system model simulations relies on model parameter settings. Paleoclimate proxy data exhibit significant variability across different periods and regions, and proxy data are often sparse, hindering the accuracy and global relevance of proxy-based *** the pros and cons of these methods, paleoclimate data assimilation can effectively integrate Earth system models and paleoclimate proxy data, enhancing the precision and global relevance of reconstructions. Using approaches such as the ensemble Kalman filter as an example, this paper introduces the principles of paleoclimate data assimilation and reviews recent advancements in reconstructing paleoclimate states using these techniques. Paleoclimate data assimilation offers new insights and advanced techniques for paleoclimate reconstruction, with potential applications extending to the entire Cenozoic, Mesozoic, and even Paleozoic eras. These applications could deepen our understanding of the past climatic backgrounds of extreme climate events such as glacial-interglacial cycles, hyperthermals, and oceanic anoxic events, providing a reference for predicting future climate change.

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基于无线定位终端的公路事件检测方法研究

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系统仿真学报 2009年第12期21卷 3828-3832页

作者：何杰胡如夫李传志杭文陶向丽东南大学交通学院南京210096 宁波工程学院交通学院宁波315016

提高交通事件检测性能对于保持道路畅通至关重要。鉴于此,提出了一种集GPS模块、车辆气囊传感器模块和手机定位模块为一体的车载终端,采用GSM定位与GPS定位相结合,驾驶员主动报警与车辆加速度发生居大变化时自动报警相结合的交通事件检... 详细信息

提高交通事件检测性能对于保持道路畅通至关重要。鉴于此,提出了一种集GPS模块、车辆气囊传感器模块和手机定位模块为一体的车载终端,采用GSM定位与GPS定位相结合,驾驶员主动报警与车辆加速度发生居大变化时自动报警相结合的交通事件检测方法。构建了该检测方法的交通事件检测率和误警率分析模型,并分无事件确认机制、设置事件确认阀值K、调用CCTV确认事件三种情景建立了系统检测时间分析模型;基于这些模型和FRESIM交通仿真软件,对影响系统性能的主要因素进行了仿真分析。建模和仿真分析的结果表明,基于车载无线定位集成终端的高速公路交通事件检测系统具有较好的检测效果。

关键词： GPS定位 GSM定位交通事件检测高速公路仿真

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Phase selection and solidification path transition of Ti-48Al-xNb alloys with different cooling rates

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Rare Metals 2023年第1期42卷 288-295页

作者： Tan he Rui hu jie-Ren Yang heng-Zhi Fu The State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an710072China

Ti-48Al-xNb alloys were solidified by containerless electromagnetic levitation with quenching system of the conical copper *** influence of cooling rates on phase selection of T1-48Al-xNb alloys was *** near-equilibrium solidification condition,the dendrite βphase is observed as the leading *** other metastable phase(e.g.,α phase) is *** contrast,in rapid solidification condition,the metastable α phase is observed in as-quenched Ti-48Al-2Nb ***,the metastable α phase is replaced by the primary β phase with Nb addition *** Ti-48Al-(x=4,6,8)Nb alloys,increasing cooling rate results in a solidification path *** peritectic reaction(L+β→α) is therefore significantly *** relationships between primary dendrite arm spacing(λ_(1)) and cooling rate(τ) can be described.

关键词： TiAl alloy Cooling rate Microstructure Phase selection

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Optimized Protection Strategies for HVDC Grid with Fault-blocking Modular Multilevel Converters for Overhead Line Applications

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Journal of Modern Power Systems and Clean Energy 2020年第6期8卷 1168-1177页

作者： Sheng Yan Zhiyuan he jie Yang Ming Kong Minqiang hu Southeast University NanjingChina Global Energy Interconnection Research Institute BeijingChina

The high-voltage direct current(HVDC)grid has been recognized as an effective solution for renewable energy ***,two main development trends for HVDC grids are being studied:a DC breaker based HVDC grid and fault-blocking converter based HVDC *** the former has a perfect performance for fault clearance,its development is still highly constrained by the cost and maturity of DC *** latter can extinguish DC faults by the fault-blocking *** using DC breakers,there is no bottleneck in its technical ***,in fault scenarios,such types of HVDC grids will be blocked at length for air-deionization,which is its main *** aim of this paper is to minimize its power interruption time,by optimizing protection coordination *** cover the most complex cases,the overhead line applications,in which the reclosure actions are required to be implemented,are *** this paper,the protection requirements of HVDC grids are first discussed,then the benefits of fault-blocking modular multilevel converters(MMCs)and their fault features are *** on this,a control function is designed to reduce the air-deionization *** minimize the influence of the DC faults,a separation methodology for restarting the system is *** effectiveness of the proposed protection coordination schemes is validated by PSCAD/EMTDC simulations.

关键词： Modular multilevel converter(MMC) high-voltage direct current(HVDC) overhead line fault-blocking converter protection coordination

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农业强国与金融强国建设中的农村金融高质量发展——第十八届中国农村金融发展论坛综述

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西北农林科技大学学报（社会科学版） 2025年第1期25卷 151-160页

作者：胡杰庄腾跃罗剑朝西北农林科技大学经济管理学院陕西省农村金融研究中心陕西杨凌712100

在农业强国和金融强国建设背景下探讨农村金融高质量发展问题,对促进农业农村现代化,完善农村金融体系,助力乡村全面振兴,推动城乡融合发展具有深远意义。2024年8月9-11日,第十八届中国农村金融发展论坛在西北农林科技大学隆重召开,来... 详细信息

在农业强国和金融强国建设背景下探讨农村金融高质量发展问题,对促进农业农村现代化,完善农村金融体系,助力乡村全面振兴,推动城乡融合发展具有深远意义。2024年8月9-11日,第十八届中国农村金融发展论坛在西北农林科技大学隆重召开,来自国内200余名师生代表汇聚于此,围绕农业强国与金融强国的内涵、特征和建设经验,农业强国与金融强国背景下农村金融高质量发展的现实挑战、战略路径以及重点领域和关键环节等方面展开深入讨论。本届论坛的一致共识是:农村金融高质量发展是农业强国和金融强国建设的内在要求,农业强国和金融强国建设是农村金融高质量发展的双轮驱动力,二者具有高度协同性;面对多重现实挑战,需要不断强化基础设施,创新金融产品和服务,推动科技赋能和数字化转型,同时要加强风险管理,创新保险产品,完善政策与监管环境,扩大普惠金融与试验示范区范围。此外,需在数字金融、农业保险、农村金融机构改革创新以及农业农村现代化等核心领域持续发力,以实现农村金融的全面繁荣与可持续发展。

关键词：农业强国金融强国农村金融高质量发展

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Multicomponent polymerization of elemental sulfur,difluoromethylene phosphobetaine and aryl silyl ethers toward aromatic poly(O,O′-monothiocarbonate)s

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Science China Chemistry 2025年

作者： Yongjiang Yu Rongrong hu Ben Zhong Tang State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology School of Science and Engineering Shenzhen Institute of Aggregate Science and Technology The Chinese University of Hong Kong AIE Institute

Polythiocarbonates with similar structures to polycarbonates, have emerged as a group of promising sulfur-containing polymers with a range of practical applications, taking advantages of their excellent optical properties, good thermal stability and filmforming ability, and so on. However, the synthesis of polythiocarbonates generally suffered from mixed isomeric structures of repeating units, and hazardous sulfur-containing reagents. In this work, an efficient multicomponent reaction of elemental sulfur,difluoromethylene phosphobetaine（PDFA）, and aryl silyl ethers was designed with the assistance of organic base 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene（MTBD） to produce 12 kinds of O,O′-monothiocarbonate compounds in up to 93% yields,taking advantages of the unique chemical property of difluorocarbene, and the deprotection of silyl group by F-generated from PDFA. Most importantly, the MTBD-assisted multicomponent polymerization of bis（aryl silyl ether）s, elemental sulfur, and PDFA was developed, affording 12 kinds of poly（O,O′-monothiocarbonate）s with well-defined structures, high Mws of up to16900 g/mol and high yields（up to 99%）. These poly（O,O′-monothiocarbonate）s possessed good film-forming properties and thermal stability, high light refractive indices and transmittance. The facile synthesis of these polymonothiocarbonates might pave the way for the development of promising sulfur-containing polymer materials.

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Transforming waste particles into valuable adsorbents via amyloid-mediated molecular engineering

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Science China Chemistry 2025年第1期68卷 317-328页

作者： Qingmin Yang Jian Zhao Yujia Zhang Xingyu Zhou Hao Ren Bowen hu Zhongli Lei Lixin Chen Peng Yang School of Material and Chemical Engineering Bengbu University Anhui Provincial Engineering Laboratory of Silicon-Based Materials School of Chemistry and Chemical Engineering Northwestern Polytechnical University Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education School of Chemistry and Chemical EngineeringShaanxi Normal University Xi'an Key Laboratory of Polymeric Soft Matter School of Chemistry and Chemical Engineering Shaanxi Normal University International Joint Research Center on Functional Fiber and Soft Smart Textile School of Chemistry and Chemical EngineeringShaanxi Normal University

The high-value utilization of industrial solid waste using a facile and eco-friendly process is of great interest and significance in reducing environmental pollution and developing a green circular economy. herein, we propose an amyloid-mediated molecular engineering strategy to transform particulate waste into valuable adsorbents for metal ions. Our method has the advantage of aqueous solution fabrication under mild conditions without the use of high-temperature hydrothermal methods and toxic chemical reagents. Amyloid-mediated molecular engineering manipulates the phase transition of bovine serum albumin(BSA)on particulate waste surfaces, resulting in a remarkable ～3.1 times improvement in the adsorption capacity of fly ash, a typical industrial solid waste for gold ions after modification with the phase-transitioned BSA(PTB). The resultant adsorption ability was 69–1,980 times higher than those of conventional and emerging adsorbent materials such as ion exchange resins, activated carbon(AC), covalent organic frameworks(COFs), and metal-organic frameworks(MOFs). We further demonstrated the application of our PTB-modified materials in the recovery of precious metals from low-grade gold ore and electronic waste leachates. Consequently, this strategy could increase the value of waste materials nearly 27 times. In addition, this method is generally extendable to other conventional industrial adsorbents such as resin, clay, and Al2O3, and enhances their adsorption capabilities at least twofold. Overall, this work provides a simple and green approach for improving the adsorption performance of solid particles, and is expected to develop into a universal strategy for transforming waste particles into high-value-added products.

关键词： amyloid-like protein aggregates surface engineering fly ash solid waste adsorption

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CO2-mediated bicarbonate conversion to concentrated formate in a CEM-based electrolyzer

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Journal of Energy Chemistry 2025年第1期100卷 605-611页

作者： Haocheng Xiong Donghuan Wu Haonan Li Andrew Li Qikun hu Siyao Song Bingjun Xu Qi Lu State Key Laboratory of Chemical Engineering Department of Chemical Engineering Tsinghua University College of Chemistry and Molecular Engineering Peking University Ordos Laboratory

Renewable energy-driven bicarbonate conversion to valuable chemicals presents an attractive strategy for mitigating CO2emissions,as bicarbonate can be efficiently generated from the capture of atmospheric CO2using alkaline solutions with reactive *** this work,we present a CO2-mediated bicarbonate conversion to pure formate using a cation exchange membrane-based electrolyzer with a 25 cm2electrode *** electrolysis achieved selectivities exceeding 75%for formate at a total current of 2.5 A,achieving formate concentrations up to 1.2 M and yields as high as 95%over extended *** techno-economic assessment confirmed the economic viability of the process,highlighting the potential for bicarbonate electrolysis as a sustainable method for producing valuable chemicals.

关键词： Electrocatalysis Techno-economic assessments Electrochemistry Flow electrolyzer

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SensFL:Privacy-Preserving Vertical Federated Learning with Sensitive Regularization

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 385-404页

作者： Chongzhen Zhang Zhichen Liu Xiangrui Xu Fuqiang hu Jiao Dai Baigen Cai Wei Wang School of Automation and Intelligence Beijing Jiaotong UniversityBeijing100044China Shuohuang Railway Development Co. Ltd.National Energy GroupCangzhou062350China Beijing Key Laboratory of Security and Privacy in Intelligent Transportation School of Computer Science and TechnologyBeijing Jiaotong UniversityBeijing100044China

In the realm of Intelligent Railway Transportation Systems,effective multi-party collaboration is crucial due to concerns over privacy and data *** Federated Learning(VFL)has emerged as a promising approach to facilitate such collaboration,allowing diverse entities to collectively enhance machine learning models without the need to share sensitive training ***,existing works have highlighted VFL’s susceptibility to privacy inference attacks,where an honest but curious server could potentially reconstruct a client’s raw data from embeddings uploaded by the *** vulnerability poses a significant threat to VFL-based intelligent railway transportation *** this paper,we introduce SensFL,a novel privacy-enhancing method to against privacy inference attacks in ***,SensFL integrates regularization of the sensitivity of embeddings to the original data into the model training process,effectively limiting the information contained in shared *** reducing the sensitivity of embeddings to the original data,SensFL can effectively resist reverse privacy attacks and prevent the reconstruction of the original data from the *** experiments were conducted on four distinct datasets and three different models to demonstrate the efficacy of *** results show that SensFL can effectively mitigate privacy inference attacks while maintaining the accuracy of the primary learning *** results underscore SensFL’s potential to advance privacy protection technologies within VFL-based intelligent railway systems,addressing critical security concerns in collaborative learning environments.

关键词： Vertical federated learning privacy defenses

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Separation of the ionospheric and thermospheric contributions in the data from the Triple Ionosophere Photo Meter onboard the Feng-Yun 3E satellite

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Science China Earth Sciences 2025年第1期68卷 172-184页

作者： Fang JIANG Tian MAO Jin-Song WANG Xiu-Qing hu Xiao-Xin ZHANG Liping FU Nan JIA Tianfang WANG National Space Science Center Chinese Academy of Sciences Beijing Key Laboratory of Space Environment Exploration Key Laboratory of Environmental Space Situation Awareness Technology National Satellite Meteorological Center China Meteorological Administration

The Triple Ionosphere Photo Meter （TRIPM） is a far ultraviolet nadir-view photometer that is onboard the secondgeneration,polar-orbiting Chinese meteorological satellite Feng-Yun 3E （FY-3E）,which was launched on July 5,*** has three channels,and each is used to measure different types of emissions:（1） 135.6 nm airglow produced by the recombination of the O+ions and electrons in the absence of sunlight （nighttime channel）;（2） 135.6 nm airglow from the OI when sunlight is present （daytime/dusk-dawn 135.6 nm channel）;and （3） Airglow in the N2LBH of the TRIPM （daytime/dusk-dawn N2LBH channel）.FY-3E is a satellite operating in the early morning ***,the data are mostly distributed on the dawndusk side or at times when the solar zenith angle is relatively *** this study,combined with simulation calculations,the data are *** further explore the application value of the data products,a model is used to separate the ionospheric radiative recombination contribution from the thermosphere photoelectron impact excitation contribution in the data from the daytime/dusk-dawn 135.6 nm *** approach not only improves the accuracy of O/N2derived from the 135.6 nm channel and N2LBH channel but also provides the ionospheric 135.6 nm radiance at the same time as the *** results show that the 135.6 nm radiance originating from the combination of O+and electrons extracted from the measurement data exhibits similar equatorial anomaly peak structure characteristics and seasonal variations as the corresponding GPS total electron content （TEC） *** the other hand,the separated 135.6 nm radiance generated from the thermosphere photoelectron collision excitation does not contain radiative recombination contributions;thus,the ionosphere influence is greatly avoided when the O/N2is obtained.

关键词： Far ultraviolet 135.6 nm emission intensity Photoelectron impact excitation Radiative recombination excitation

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