检索结果-南通市图书馆

Vertical gradients of neutral winds observed by ICON and estimated by the Horizontal Wind Model during the geomagnetic storm on August 26−28,2021

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Earth and Planetary Physics 2025年第1期9卷 69-80页

作者： JiaWei Wu chao Xiong YuYang huang YunLiang Zhou Department of Space Physics School of Electronic InformationHubei Luojia LaboratoryWuhan UniversityWuhan 430072China

The Michelson Interferometer for Global High-resolution Thermospheric Imaging(MIGHTI)onboard the Ionospheric Connection Explorer(ICON)satellite offers the opportunity to investigate the altitude profile of thermospheric *** this study,we used the red-line measurements of MIGHTI to compare with the results estimated by Horizontal Wind Model 14(HWM14).The data selected included both the geomagnetic quiet period(December 2019 to August 2022)and the geomagnetic storm on August 26-28,*** the geomagnetic quiet period,the estimations of neutral winds from HWM14 showed relatively good agreement with the observations from *** to the ICON observations,near the equator,zonal winds reverse from westward to eastward at around 06:00 local time(LT)at higher altitudes,and the stronger westward winds appear at later LTs at lower *** around 16:00 LT,eastward winds at 300 km reverse to westward,and vertical gradients of zonal winds similar to those at sunrise hours can be *** the middle latitudes,zonal winds reverse about 2-4 h *** winds vary more significantly than zonal winds with seasonal and latitudinal *** to the ICON observations,in the northern low latitudes,vertical reversals of meridional winds are found at 08:00-13:00 LT from 300 to 160 km and at around 18:00 LT from 300 to 200 km during the June *** reversals of meridional winds are found at 04:00-07:00 LT from 300 to 160 km and at 22:00-02:00 LT from 270 to 200 km during the December *** the southern low latitudes,meridional wind reversals occur at 08:00-11:00 LT from 200 to 160 km and at 21:00-02:00 LT from 300 to 200 km during the June *** the December solstice,reversals of the meridional wind appear at 20:00-01:00 LT below 200 km and at 06:00-11:00 LT from 300 to 160 *** the northern middle latitudes,the northward winds are dominant at 08:00-14:00 LT at 230 km during the June *** winds persist until

关键词： horizontal neutral winds vertical gradients Ionospheric Connection Explorer satellite Horizontal Wind Model 14 geomagnetic storm

Unraveling the impacts of intermolecular interaction on morphology evolution for highly efficient organic solar cells and modules

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第1期68卷 264-272页

作者： Xueqing Ma Yingying Cheng Yuqiang Liu Xinming Zheng Guangliu ran Hongxiang Li Xinyue Cui Andong Zhang Wenkai Zhang Pei Cheng Wenchao huang Zhishan Bo Beijing Key Laboratory of Energy Conversion and Storage Materials College of Chemistry Beijing Normal University College of Textiles and Clothing State Key Laboratory of Bio-fibers and Eco-textiles Qingdao University Key State Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and EngineeringWuhan University of Technology Department of Physics and Applied Optics Beijing Area Major Laboratory Center for Advanced Quantum Studies Beijing Normal University State Key Laboratory of Polymer Materials Engineering College of Polymer Science and Engineering Sichuan University

Understanding the effect of intermolecular interaction on the growth dynamic of active layers is critical for advancing organic solar cells(OSCs). However, the diverse structure of donors and acceptors makes the research challenging. Additives with customizable structures and properties could simplify this complexity. Herein, we meticulously tailor two additives of 3,4-ethylenedioxythiophene(EDOT) and 2,5-dibromo-3,4-ethylenedioxythiophene(DBEDOT), possessing distinct intermolecular interaction features to elaborate the inherent relationship. It is found that varied interaction strengths can alter film formation processes. The enhanced intermolecular interaction between the DBEDOT and non-fullerene acceptor BTP-e C9-4F results in pre-aggregation and longer crystallization duration of BTP-e C9-4F, facilitating the formation of films with compact molecular packing and decent phase separation. Thus, exciton dissociation and charge transport become more efficient. Finally, devices processed with DBEDOT exhibit a remarkable power conversion efficiency of 19.35% in small-area OSCs and 14.11% in bladecoated 5 cm × 5 cm organic solar mini-modules. Especially, OSCs can maintain 80% of their initial efficiency after continuous annealing at 85 °C for over 2,100 h.

关键词： organic solar cell non-fullerene acceptor film growth molecular packing intermolecular interaction

Thermally triggered topological polymerization in diacetylene-functionalized covalent organic framework toward enhanced memristive properties

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Panke Zhou Yuxing huang Ziyue Yu Cong Zhang Qian Chen Yiping Li chao Lin Xiong Chen State Key Laboratory of Photocatalysis on Energy and Environment Key Laboratory of Advanced Carbon-Based Functional MaterialsCollege of Chemistry Fuzhou University

The development of stimuli-responsive switching memory devices and the elucidation of their switching mechanisms in specific environments are crucial for advancing the field of molecular electronics. Herein, we propose two distinct two-dimensional covalent organic frameworks (COFs), namely Py-EDA and Py-BDA, incorporating acetylene (-C≡C-) or diacetylene(-C≡C-C≡C-) moieties, respectively, targeting fabricate memory devices exhibiting stimuli-responsive switching *** findings demonstrate that the incorporation of acetylene units effectively modulates the electronic band structure and enhances the degree ofπ-conjugation, resulting in devices that exhibit typical bipolar nonvolatile memory performance. Notably,upon thermal treatment, the memory behavior of the ITO/Py-BDA/Ag device transitions to a write-once-read-many-times(WORM) mode, displaying decreased SET voltage, increased ON/OFF current ratio, and remarkable retention reliability and cycle stability. This switching behavior is attributed to the occurrence of interlayer solid-state topological polymerization at 350℃, leading to the transformation of diacetylene columnar arrays into enyne chains within Py-BDA, thereby further promoting interlayer charge transfer and separation.

关键词：

Quickly obtaining densely dispersed coherent particles in steel matrix and its related mechanical property

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 111-118页

作者： Xiaoxiao Wang Qingsong huang School of Chemical Engineering Sichuan UniversityChengdu 610065China

Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel *** the routes to this end can be generally classified into the liquid-solid route and the solid-solid ***,the formation of DCN structures in steel requires long processes and complex *** far,obtaining steel with coherent particle enhancement in a short time remains a bottleneck,and some necessary steps remain ***,we show a high-efficiency liquid-phase refining process reinforced by a dynamic magnetic ***-Y-Mn-O particles had an average size of around(3.53±1.21)nm and can be obtained in just around 180 *** small nanoparticles were coherent with the matrix,implying no accumulated dislocations between the particles and the steel *** findings have a potential application for improving material machining capacity,creep resistance,and radiation resistance.

关键词： ferritic steels coherent particles microstructure compression test work hardening

Economic effect of China's carbon neutrality target under shared socioeconomic pathways

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第1期68卷 142-157页

作者： Zemiao LIU Xianjin huang Xinxian QI School of Geography and Ocean Science Nanjing University Key Laboratory of Carbon Neutrality and Territory Optimization Ministry of Natural Resources Frontiers Science Center for Critical Earth Material Cycling Nanjing University

Economic feasibility is crucial for achieving the carbon neutrality target. However, current integrated assessments often underestimate the economic impacts of mitigation policies due to the lack of consideration of their economic benefits. This study integrates a warming-labour productivity model with a typical integrated assessment model using shared socioeconomic pathways. It simulates China's economic development and carbon emission levels under both baseline and carbon-neutral policy scenarios, evaluating the economic costs and benefits of emission reduction policies aimed at achieving carbon neutrality. These findings reveal the following:(1) The economic costs of emission reduction policies are projected to peak between 2050 and 2060, ranging from 0.41% to 9.37% of total GDP in the baseline scenario, primarily due to increased energy prices and R&D investments. These costs are expected to decline rapidly after 2070.(2) China's carbon-neutral policies will mitigate global warming, with the economic benefits of mitigation projected to reach 5.65% to 17.24% of China's total GDP by 2100.(3) Lowcarbon scenarios SSP1 and SSP4 could significantly reduce initial economic costs and advance the onset of net economic gains to 2060. This integrated assessment confirms that China's carbon neutrality target offers substantial net economic benefits in the long term. To minimize initial economic costs, efforts should focus on enhancing consumption-side transitions, upgrading lowcarbon technologies, and adopting new energy sources.

关键词： Climate change China Carbon neutrality Economic effects Policy

同方期刊数据库

Tectonic modes of mantle convection and their implications for Earth's tectonic evolution based on three-dimensional numerical simulations

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第1期68卷 270-296页

作者： Song XIANG Jinshui huang Bingcheng WU School of Earth and Space Sciences University of Science and Technology of China CAS Center of Excellence in Comparative Planetary Studies

Five tectonic modes of mantle convection are obtained and analyzed with three-dimensional numerical models in a spherical shell domain. The five tectonic convective modes are non-plate mobile-lid, plate-like mobile-lid, episodic plate-like mobile-lid, episodic stagnant-lid, and stagnant-lid convective modes, respectively. The typical characteristics of these five tectonic modes and their numerical classification criteria based on plateness, mobility, and their standard deviations are presented and discussed. The results show that the yield stress of the lithosphere has profound effects on the tectonic convective *** the gradual increase of yield stress, the tectonic mode of mantle convection changes from one to another sequentially through the aforementioned five modes. Additionally, as the Rayleigh number increases, the range of yield stress for the platelike mobile-lid convective mode decreases, and the dimensionless transition stress between different tectonic modes ***, the dimensional transition stress between the non-plate mobile-lid convective mode and plate-like mobile-lid convective mode increases with the increase of Rayleigh number, but decreases between other tectonic modes. Furthermore, we find that the transition stress between different tectonic modes is inversely proportional to the internal heating rate, with the transition stress decreasing as the internal heating rate increases. The fitting analysis of the transition stress between tectonic modes shows that Earth's current plate tectonics correspond to a lithospheric yield stress of 150–250 MPa, which aligns with the strength of serpentinized mantle rock determined by experimental petrography. If the Archean mantle was 300°C warmer than it is today, then the Earth was in an episodic stagnant-lid convective mode. The tectonic evolution of the Earth's surface is closely related to the lithospheric strength and the process of thermal evolution. If the lithospheric strength w

关键词： Tectonic mode of mantle convection Plate-like mobile-lid convection Episodic plate-like mobile-lid convection Episodic stagnant-lid convection Plate tectonics and tectonic evolution of the Earth

Local-contrastive-learning machine with both generalization and adversarial robustness: A statistical physics analysis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 109-123页

作者： Mingshan Xie Yuchen Wang Haiping huang PMI Lab School of Physics Sun Yat-sen University Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices Sun Yat-sen University

Distinct from human cognitive processing, deep neural networks trained by backpropagation can be easily fooled by adversarial examples. To design a semantically meaningful representation learning, we discard backpropagation, and instead, propose a local contrastive learning, where the representations for the inputs bearing the same label shrink(akin to boson) in hidden layers,while those of different labels repel(akin to fermion). This layer-wise learning is local in nature, being biologically plausible.A statistical mechanics analysis shows that the target fermion-pair-distance is a key parameter. Moreover, the application of this local contrastive learning to MNIST benchmark dataset demonstrates that the adversarial vulnerability of standard perceptron can be greatly mitigated by tuning the target distance, i.e., controlling the geometric separation of prototype manifolds.

关键词： machine learning statistical mechanics adversarial robustness neural networks

Neuropeptide cholecystokinin:a key neuromodulator for hippocampal functions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第7期20卷 1991-1992页

作者： Fengwen huang Stephen Temitayo Bello Department of Neuroscience City University of Hong KongKowloon TongHong Kong Special Administrative RegionChina Center for Regenerative Medicine and Health Hong Kong Institute of Science&InnovationChinese Academy of SciencesHong Kong Special Administrative RegionChina

Spatial memory is crucial for survival within external surroundings and wild *** hippocampus,a critical hub for spatial learning and memory formation,has received extensive investigations on how neuromodulators shape its functions(Teixeira et al.,2018;Zhang et al.,2024).However,the landscape of neuromodulations in the hippocampal system remains poorly understood because most studies focus on classical monoamine neuromodulators,such as acetylcholine,serotonin,dopamine,and *** neuropeptides,comprising the most abundant neuromodulators in the central nervous system,play a pivotal role in neural information processing in the hippocampal ***(CCK),one of the most abundant neuropeptides,has been implicated in regulating various physiological and neurobiological statuses(Chen et al.,2019).CCK-A receptor(CCK-AR)and CCK-B receptors(CCK-BR)are two key receptors mediating the biological functions of CCK,both of which belong to class-A sevenfold transmembrane G protein-coupled receptors(Nishimura et al.,2015).CCK-AR preferentially reacts to sulfated CCK,whereas CCK-BR binds both CCK and gastrin with similar affinities(Ding et al.,2022).The expression patterns of CCK-AR and CCK-BR are distinct,implying that CCK has various functions in target *** instance,CCK-AR is widely expressed in the GI and brain subregions and is hence implicated in the control of digestive function and satiety ***,CCK-BR is abundantly and widely distributed in the central nervous system,which majorly regulates anxiety,learning,and memory(Ding et al.,2022).However,the roles of endogenous CCK and CCK receptors in regulating hippocampal function at electrophysiological and behavioral levels have received less attention.

关键词： abundant functions modulator

The role of axon guidance molecules in the pathogenesis of epilepsy

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1244-1257页

作者： Zheng Liu Chunhua Pan Hao huang Department of Neurology Affiliated Hospital of Zunyi Medical UniversityZunyiGuizhou ProvinceChina

Current treatments for epilepsy can only manage the symptoms of the condition but cannot alter the initial onset or halt the progression of the disease. Consequently, it is crucial to identify drugs that can target novel cellular and molecular mechanisms and mechanisms of action. Increasing evidence suggests that axon guidance molecules play a role in the structural and functional modifications of neural networks and that the dysregulation of these molecules is associated with epilepsy susceptibility. In this review, we discuss the essential role of axon guidance molecules in neuronal activity in patients with epilepsy as well as the impact of these molecules on synaptic plasticity and brain tissue remodeling. Furthermore, we examine the relationship between axon guidance molecules and neuroinflammation, as well as the structural changes in specific brain regions that contribute to the development of epilepsy. Ample evidence indicates that axon guidance molecules, including semaphorins and ephrins, play a fundamental role in guiding axon growth and the establishment of synaptic connections. Deviations in their expression or function can disrupt neuronal connections, ultimately leading to epileptic seizures. The remodeling of neural networks is a significant characteristic of epilepsy, with axon guidance molecules playing a role in the dynamic reorganization of neural circuits. This, in turn, affects synapse formation and elimination. Dysregulation of these molecules can upset the delicate balance between excitation and inhibition within a neural network, thereby increasing the risk of overexcitation and the development of epilepsy. Inflammatory signals can regulate the expression and function of axon guidance molecules, thus influencing axonal growth, axon orientation, and synaptic plasticity. The dysregulation of neuroinflammation can intensify neuronal dysfunction and contribute to the occurrence of epilepsy. This review delves into the mechanisms associated with

关键词： axon guidance drug-resistant epilepsy epilepsy nerve regeneration nervous system diseases neural pathways neuroinflammatory diseases neuronal plasticity neurons synaptic remodeling