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Numerical Study of Flow and Heat Transfer Characteristics of Shell-and-Tube Molten Salt Electric Heater with Circularly Perforated Baffles

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Journal of Thermal Science 2025年第1期34卷 24-33页

作者： LIN Yongjie ZHANG Cancan WU Yuting ZHANG Yi lu Yuanwei Key Laboratory of Heat Transfer and Energy Conversion National User-Side Energy Storage Innovation Research and Development CenterBeijing University of Technology

Numerical simulations of the flow and heat transfer characteristics of four shell-and-tube molten salt electric heaters with different perforation rates was ***-and-tube electric heaters have the same geometry and tube arrangement,and all of them use single segmental baffles,but there exist four different baffle openings（φ）,i.e.,0%,2.52%,4.06%,and 6.31%.The results indicated that the reasonable baffle opening could significantly reduce the shell-side pressure drop,effectively decreasing the shell-side flow dead zone *** can eliminate the local high-temperature phenomenon on the surface of electric heating tubes,but the heat transfer coefficient is slightly *** perforated schemes significantly reduce shell-side pressure drop compared to the baseline solution without open *** particular,the φ=6.31% scheme exhibits the optimal performance among all the schemes,with a maximum reduction of up to 50.50% in shell-side pressure drop relative to the unopened holes *** heat transfer coefficient is the highest for φ=0%,exhibiting a range of5.26% to 5.73%,5.14% to 5.99%,and 7.31% to 8.54% higher than φ=2.52%,4.06%,and 6.31%,respectively,within the calculated *** composite index h/（Δp）1/3was higher for all open-hole solutions than that for the unopened-hole *** best overall performance was for φ=6.31%,which improved the composite index by15.29% to 17.18% over the unopened-hole solution.

关键词： molten salt electric heater perforated baffles heat transfer

Infrared small target detection based on spatial attention density peaks searching

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Optoelectronics Letters 2025年第2期21卷 90-96页

作者： RAO Junmin lu Siyu LIU Shijian LI Fanming CAS Key Laboratory of Infrared System Detection and Imaging Technology Shanghai Institute of Technical Physics University of Chinese Academy of Sciences Shanghai Institute of Technical Physics Chinese Academy of Sciences School of Information Science and Technology Shanghai Tech University

The detection of small targets poses a significant challenge for infrared search and tracking (IRST) systems,as they must strike a delicate balance between accuracy and *** this paper,we propose a detection algorithm based on spatial attention density peaks searching (SADPS) and an adaptive window selection ***,the difference-of-Gaussians (DoG) filter is introduced for preprocessing raw infrared ***,the image is processed by ***,an adaptive window selection scheme is applied to obtain window templates for the target scale ***,the small target feature is used to enhance the target and suppress the ***,the true targets are segmented through a *** experimental results show that compared with the seven state-of-the-art small targets detection baseline algorithms,the proposed method not only has better detection accuracy,but also has reasonable time consumption.

关键词： Infrared imaging

An embedded electron current layer observed at the edge of the plasma sheet in the Earth’s magnetotail

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Earth and Planetary Physics 2025年第1期9卷 148-158页

作者： ChenChen Zhan RongSheng Wang QuanMing lu San lu XinMin Li Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Chinese Academy of Sciences(CAS)Center for Excellence in Comparative Planetology/CAS Key Laboratory of Geospace Environment/Anhui Mengcheng National Geophysical Observatory University of Science and Technology of ChinaHefei 230026China Collaborative Innovation Center of Astronautical Science and Technology Harbin 150001China

The formation of an embedded electron current sheet within the magnetotail plasma sheet has been poorly *** this article,we present an electron current layer detected at the edge of the magnetotail plasma *** ions were demagnetized inside the electron current layer,but the electrons were still frozen in with the magnetic field ***,this decoupling of ions and electrons gave rise to a strong Hall electric field,which could be the reason for the formation of the embedded thin current *** magnetized electrons,the absence of the nongyrotropic electron distribution,and negligible energy dissipation in the layer indicate that magnetic reconnection had not been triggered within the embedded thin current *** highly asymmetric plasma on the two sides of the current layer and low magnetic shear across it could suppress magnetic *** observations indicate that the embedded electric current layer,probably generated by the Hall electric field,even down to electron scale,is not a sufficient condition for magnetic reconnection.

关键词： magnetotail plasma sheet magnetic reconnection

Spatio-temporal patterns and climatic drivers of spring phenology in eight forest communities across the north-south transitional zone of China

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Journal of Geographical Sciences 2025年第1期35卷 17-38页

作者： ZHU Wenbin lu Yu Institute of Geographic Sciences and Natural Resources Research CAS School of Geographical Science Nanjing University of Information Science & Technology

The Qinba Mountains are climatically and ecologically recognized as the northsouth transitional zone of *** of its phenology is critical for comprehending the response of vegetation to climatic *** retrieved the start of spring phenology （SOS）of eight forest communities from the MODIS products and adopted it as an indicator for spring *** analysis,partial correlation analysis,and Geo Detector were employed to reveal the spatio-temporal patterns and climatic drivers of *** results indicated that the SOS presented an advance trend from 2001 to 2020,with a mean rate of–0.473 d yr–*** SOS of most forests correlated negatively with air temperature （TEMP） and positively with precipitation （PRE）,suggesting that rising TEMP and increasing PRE in spring would forward and delay SOS,*** dominant factors influencing the sensitivity of SOS to climatic variables were altitude,forest type,and latitude,while the effects of slope and aspect were relatively *** response of SOS to climatic factors varied significantly in space and among forest communities,partly due to the influence of altitude,slope,and aspect.

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Electrocatalytic selective synthesis and tandem utilization of hydroxylamine

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Science China Chemistry 2025年

作者： Yuxuan lu Hengquan Yang Engineering Research Center of Ministry of Education for Fine Chemicals School of Chemistry and Chemical Engineering Shanxi Key Laboratory of Green Catalytic Synthesis of Coal-based High Value Chemicals Shanxi University

The transformation of renewable nitrogen feedstock to nitrogenous chemicals plays a significant role in our modern society,considering the crucial impact of nitrogenous chemicals on life sciences,biomedicine,agriculture,and *** （NH2OH）,a typical nucleophile,has been widely served as the nitrogenous feedstock to produce nitrogenous *** NH2OH synthesis methods rely on harsh reaction conditions,leading to an unfavorable environmental *** contrast,nitric oxide electroreduction promises to produce NH2OH powered by renewable *** achievements have revealed the possibility of this process,but have also identified significant *** activity and selectivity are fundamentally limited by competing hydrogenation reactions,while the performance evaluation with high accuracy and reproducibility is ***,this review aims to provide insight into the mechanism of NH2OH electrosynthesis,especially regarding understanding reaction pathways and the design principle towards efficient ***,the performance evaluation parameters and standard measurement methods for NH2OH synthesis are summarized to screen efficient ***,the prospects and emerging opportunities to synthesize nitrogen-containing organic compounds by tandem reaction are *** review aims to provide a guide for evaluating and exploring efficient electrocatalytic systems for NH2OH production and utilization technology.

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Limit theorems of the 2D stochastic Navier-Stokes equation driven by a time-periodic force and a degenerate noise

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Science China Mathematics 2025年

作者： Rongchang Liu Kening lu Department of Mathematics University of Arizona School of Mathematics Sichuan University

The periodically forced 2D Navier-Stokes equation with a degenerate noise is studied. For the Markov chain obtained by restricting the solution process to the Poincarésection, we prove a quantitative version of the strong law of large numbers and the central limit theorem with explicit convergence rates. A law of the iterated logarithm is also obtained. The proof is based on a martingale approximation procedure.

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Nanocarrier-mediated siRNA delivery:a new approach for the treatment of traumatic brain injury-related Alzheimer's disease

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Neural Regeneration Research 2025年第9期20卷 2538-2555页

作者： Jie Jin Huajing Zhang Qianying lu Linqiang Tian Sanqiao Yao Feng Lai Yangfan Liang Chuanchuan Liu Yujia lu Sijia Tian Yanmei Zhao Wenjie Ren Institute of Disaster and Emergency Medicine Tianjin UniversityTianjinChina Key Laboratory for Disaster Medicine Technology TianjinChina Henan Medical Key Laboratory for Research of Trauma and Orthopedics The Third Affiliated Hospital of Xinxiang Medical UniversityXinxiangHenan ProvinceChina Clinical Medical Center of Tissue Engineering and Regeneration Xinxiang Medical UniversityXinxiangHenan ProvinceChina Institutes of Health Central Plain Xinxiang Medical UniversityXinxiangHenan ProvinceChina School of Public Health Xinxiang Medical UniversityXinxiangHenan ProvinceChina

Traumatic brain injury and Alzheimer's disease share pathological similarities,including neuronal loss,amyloid-βdeposition,tau hyperphosphorylation,blood-brain barrier dysfunction,neuroinflammation,and cognitive ***,traumatic brain injury can exacerbate Alzheimer's disease-like pathologies,potentially leading to the development of Alzheimer's *** offer a potential solution by facilitating the delive ry of small interfering RNAs across the blood-brain barrier for the targeted silencing of key pathological genes implicated in traumatic brain injury and Alzheimer's disease.U nlike traditional approaches to neuro regeneration,this is a molecula r-targeted strategy,thus avoiding non-specific drug *** review focuses on the use of nanocarrier systems for the efficient and precise delive ry of siRNAs,discussing the advantages,challenges,and future *** principle,siRNAs have the potential to target all genes and non-targetable protein s,holding significant promise for treating various *** the various therapeutic approaches currently available for neurological diseases,siRNA gene silencing can precisely"turn off"the expression of any gene at the genetic level,thus radically inhibiting disease progression;however,a significant challenge lies in delivering siRNAs across the blood-brain *** have received increasing attention as an innovative drug delive ry tool fo r the treatment of brain *** are considered a potential therapeutic strategy with the advantages of being able to cross the blood-brain barrier,targeted drug delivery,enhanced drug stability,and multifunctional *** use of nanoparticles to deliver specific modified siRNAs to the injured brain is gradually being recognized as a feasible and effective *** this strategy is still in the preclinical exploration stage,it is expected to achieve clinical translation in the future,creating a new field of molecular tar

关键词： blood-brain barrier cognitive dysfunction exosomes gene silencing immunotherapy inorganic nanomaterials liposome nanoparticles neuroinflammation polymer nanoparticles stem cells

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Computational protein design and structure prediction—the 2024Nobel prize in chemistry

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Science China Chemistry 2025年

作者： Peilong lu Lei Liu School of Life Sciences and Research Center for Industries of the Future Westlake University Tsinghua-Peking Joint Center for Life Sciences Ministry of Education Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology Center for Synthetic and Systems Biology Department of Chemistry Tsinghua University

The 2024 Nobel prize in chemistry recognizes groundbreaking advancements in protein science, highlighting the power of artificial intelligence (AI) to decipher and design the molecular machinery of life. Half of the prize was awarded to David Baker for the computational design of proteins; the other to Demis Hassabis and John Jumper for their AI-driven predictions of protein structures. This article briefly reviews their achievements, and discusses the opportunities and directions that their work has enabled (Figure1).

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First observation results of Macao Science Satellite-1 on lightning-induced electron precipitation

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Science China Earth Sciences 2025年第1期68卷 1-10页

作者： Yongping WANG Yixin SUN Qiugang ZONG Gaopeng lu Xudong GU Ze-Jun HU Bin LI Key Laboratory for Polar Science Ministry of Natural Resources Polar Research Institute of China Institute of Space Physics and Applied Technology Peking University State Key Laboratory of lunar and Planetary Science Macau University of Science and Technology School of Earth and Space Sciences University of Science and Technology of China School of Electronic Information Wuhan University

The Medium-energy Electron Spectrometers(MES) is a space-borne instrument onboard Macao Science Satellite-1(MSS-1) dedicated to monitoring the typical charged particle radiation characteristics in the satellite orbit and the process of their occurrence and development, including short bursts of lightning-induced electron precipitation(LEP).This paper presents the first results of the LEP measurements by the MSS-1.47 LEP events are identified with the routine operation for 3 months since satellite launch, all within the range of 1.5

关键词： Lightning-induced electron precipitation Inner radiation belts Energetic electrons Macao Science Satellite-1