检索结果-南通市图书馆

Chinese Optics Letters 2024年第9期22卷 37-41页

作者： Menghan Yu siwen ai Yuanliu Chen Feng Chen Hongliang Liu Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology Institute of Modern OpticsNankai UniversityTianjin 300350China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310027China School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China

In this Letter,waveguide beam splitters(1×3)with type I modifications are fabricated in a LiNbO_(3) crystal by femtosecond laser direct *** influence of the relative positions of three sub-waveguides on power splitting ratios are investigated in detail and the corresponding output intensities as functions of the relative positions in the numerical simulation are plotted,which are in good accordance with the experimental *** addition,the waveguide beam splitter with a 1:1:1 splitting ratio is fabricated by changing the relative widths of the three *** performances at 532 nm are measured and analyzed by a typical end-face coupling *** simulation and experimental results demonstrate that the beam splitting ratio of the waveguide splitter can be precisely regulated by the positions and widths of the sub-waveguides.

关键词： femtosecond laser direct writing beam splitter lithium niobate crystal.

Crustal magma oxidation state and endowments in porphyry copper deposits

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 226-236页

作者： Yumin ai Massimo CHIARADIA Chao WU Huayong CHEN Key Laboratory of Mineralogy and Metallogeny Guangzhou Institute of Geochemistry Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Earth Sciences University of Geneva Guangdong Provincial Key Laboratory of Mineral Physics and Materials

Porphyry copper deposits（PCDs） supply the majority of the world's copper（Cu） as well as significant amounts of molybdenum（Mo） and gold（Au）. The formation of these deposits is controlled by a variety of geological factors, among which the magmatic oxidation is one of the focuses of current research. This study investigates the redox characteristics of arc magmas by analyzing the ratio of vanadium（V） to scandium（Sc） and its correlation with the oxygen fugacity （fO2） of magmas from arcs of various crustal thicknesses globally. We compiled an extensive dataset of published V/Sc values and studied the partition coefficients of Vand Sc between minerals and silicate melts across various magmatic environments. The results demonstrate that fractional crystallization of magnetite markedly reduces V/Sc values of the residual melt. Furthermore, magnesium number（Mg#） at the onset of magnetite fractionation is strongly positively correlated with fO2of the equilibrium magma. Based on this,the oxidation of arc magmas from different crustal thicknesses can be evaluated. The result suggests that magmas generated in crusts thicker than 20 km tend to be more oxidized with increasing crust thickness. This trend is attributed to enhanced intracrustal differentiation processes involving garnet and amphibole, particularly in mature island and continental arcs. In contrast,magmas in thinner arc crusts（<20 km）, which are significantly influenced by subducted slab materials, display higher oxidation states than most of their thicker crust counterparts. These findings suggest that both subduction dynamics and crustal thickness play a vital role in determining the oxidation state of arc magmas and, consequently, their capacity to generate PCDs. Highly oxidized, primitive arc magmas are less favorable for PCD formation due to that they tend to experience magnetite fractionation and thus sulfide saturation in the early stage of magma evolution, a process leading to copper depletion. On the contra

关键词： Magma evolution V/Sc systematics Magnetite Oxygen fugacity Porphyry copper deposits

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

VR技术在体育教学中的应用及影响

湖北体育科技 2019年第3期38卷 279-282页

作者：石海燕艾思文陕西师范大学体育学院陕西西安710119

随着当今社会科学技术的不断发展,各种科技产品涌入我们的生活。从2D、3D技术,到现在的VR(虚拟现实)技术,应用领域都极其广泛。本文对VR的定义及研究依据进行阐述,探究VR技术在体育教学过程中的应用,并对此技术在应用过程中出现的问题... 详细信息

随着当今社会科学技术的不断发展,各种科技产品涌入我们的生活。从2D、3D技术,到现在的VR(虚拟现实)技术,应用领域都极其广泛。本文对VR的定义及研究依据进行阐述,探究VR技术在体育教学过程中的应用,并对此技术在应用过程中出现的问题和取得的成效进行探讨,对虚拟现实技术在体育教学中的价值与弊端加以分析,最后对VR技术在体育学习中的应用提出自己的假设与展望,旨在为拓展新的体育学习方式,增加体育学习的乐趣和效果提供思路。

关键词： VR技术体育教学学习方式影响展望

Synergistic effect of bonding heterogeneity and phonon localization in introducing excellent thermoelectric properties in layered heteroanionic NdZnSbO material

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 259-272页

作者： Da Wan Shuwei Tang Shulin Bai Xiaodong Li Peng ai Wanrong Guo Tuo Zheng College of Materials Science and Engineering Liaoning Technical University Faculty of Chemistry Northeast Normal University

Layered rare-earth metal oxides, harnessing the dual properties of oxides and two-dimensional layered materials, exhibit remarkable thermal stability and quantum confinement effects. Therefore, this work adopts the first-principles calculation combined with the Boltzmann transport theory to predict the thermoelectric properties of NdZnSbO compound. The coexistence of weak interlayer van der Waals interactions, robust intralayer ionic bonding, and partial covalent bonding leads to remarkable bonding heterogeneity, which engenders pronounced phonon scattering and imposes constraints on thermal transport along the out-of-plane direction. The weakened chemical bonds induced by the antibonding states, together with the rattling-like behavior of the Zn atom, culminate in the profound anharmonicity in the layered NdZnSbO compound. The weakening bond and heavy element contribute to the softness of phonon modes, which significantly diminishes the phonon group velocity. The redistribution-dominated four-phonon scattering process spans a large optical gap, which effectively reduces the lattice thermal conductivity. The NdZnSbO compound exhibits direct semiconductor characteristic with a bandgap of 0.73 e V by adopting the Heyd-Scuseria-Ernzerhof(HSE06) functional in combination with spin–orbit coupling(SOC) effect. The multi-valley feature of NdZnSbO compound augur favorably for band degeneracy, thus amplifying the power factor. Consequently, an optimal figure-of-merit(ZT) of 3.40 at 900 K is achieved for the n-type NdZnSbO compound. The present study delves deeply insights into the origins for the low thermal conductivity of NdZnSbO compound and proposes an optimization scheme to enhance overall thermoelectric performance.

关键词： Bond strength (chemical)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

武侠作品对社会公众认知武术文化的影响研究

武术研究 2019年第2期4卷 25-28页

作者：石海燕艾思文孟凡强陕西师范大学体育学院陕西西安710119 陕西理工大学体育学院陕西汉中723001

武术文化起源于早期的技击文化。从武术文化的历史起源和发展入手,系统研究武侠作品对社会公众认知武术文化的影响。通过佛家文化、儒家文化、道家文化、对武术文化发展过程中产生的影响研究,揭示武术文化的独特魅力及内涵。武术作为东... 详细信息

武术文化起源于早期的技击文化。从武术文化的历史起源和发展入手,系统研究武侠作品对社会公众认知武术文化的影响。通过佛家文化、儒家文化、道家文化、对武术文化发展过程中产生的影响研究,揭示武术文化的独特魅力及内涵。武术作为东方文化中的一大特色,它不仅自身拥有独特的技术风格,而且还包含着无穷的魅力。如今,武侠作品作为中国传统武术文化传承的一种基本方式,也越来越受到社会公众普遍认同。但是在今天这个科技发达的社会,人们将武侠作品过度的进行渲染,过分夸大,使社会公众对其武术文化的认识产生了一定的曲解和异化。文章研究武侠作品对社会公众认知武术文化的影响,便是为了发现其中的问题并解决问题,以便更好地突破和发展武术。

关键词：武侠作品武术文化社会公众影响

De novo synthesis of atropisomeric benzofurans via Cu/SPDO complex catalyzed asymmetric formal [3 + 2] annulation

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 174-180页

作者： Fan-Xiao Meng Xing-Yu Wang Ka Lu Ju-Song Yang Fu-Min Zhang ai-Jun Ma Bao Du Yong-Qiang Tu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University School of Chemistry and Chemical Engineering Shanghai Jiao Tong University School of Biotechnology and Health Sciences Wuyi University

Herein, the de novo synthesis of atropisomeric benzofurans through the Cu/spirocyclic-pyrrolidine-oxazoline(SPDO) complex catalyze asymmetric formal [3 + 2] cycloaddition between quinones and ynamides is explored, producing a range of structurally diverse axially chiral benzofurans in satisfactory yields with good to excellent enantioselectivities. Furthermore, density functional theory calculations were applied to explain the possible reaction mechanism.

关键词： benzofuran atropisomers novel de novo synthetic strategy asymmetric formal [3 + 2] cycladdition Cu/SPDO complex DFT calculations

The interaction between KIF21A and KANK1 regulates dendritic morphology and synapse plasticity in neurons

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1期20卷 209-223页

作者： Shi-Yan Sun Lingyun Nie Jing Zhang Xue Fang Hongmei Luo Chuanhai Fu Zhiyi Wei ai-Hui Tang Hefei National Research Center for Physical Sciences at the Microscale CAS Key Laboratory of Brain Function and DiseaseMinistry of Education Key Laboratory for Membrane-less Organelles and Cellular DynamicsDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui ProvinceChina Institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefeiAnhui ProvinceChina CAS Center for Excellence in Molecular Cell Sciences Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui ProvinceChina Department of Neurobiology School of Life SciencesSouthern University of Science and TechnologyShenzhenGuangdong ProvinceChina Brain Research Center Southern University of Science and TechnologyShenzhenGuangdong ProvinceChina

Morphological alterations in dendritic spines have been linked to changes in functional communication between neurons that affect learning and ***-4 KIF21A helps organize the microtubule-actin network at the cell cortex by interacting with KANK1;however,whether KIF21A modulates dendritic structure and function in neurons remains *** this study,we found that KIF21A was distributed in a subset of dendritic spines,and that these KIF21A-positive spines were larger and more structurally plastic than KIF21A-negative ***,the interaction between KIF21A and KANK1 was found to be critical for dendritic spine morphogenesis and synaptic *** of either KIF21A or KANK1 inhibited dendritic spine morphogenesis and dendritic branching,and these deficits were fully rescued by coexpressing full-length KIF21A or KANK1,but not by proteins with mutations disrupting direct binding between KIF21A and KANK1 or binding between KANK1 and *** down KIF21A in the hippocampus of rats inhibited the amplitudes of long-term potentiation induced by high-frequency stimulation and negatively impacted the animals’cognitive *** together,our findings demonstrate the function of KIF21A in modulating spine morphology and provide insight into its role in synaptic function.

关键词： actin cytoskeleton dendrite KANK1 KIF21A microtubule spine morphology spine synaptic plasticity talin1

BER performance analysis of non-Hermitian symmetry OFDM-VLC systems with ADC quantization noise

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2025年

作者： Wang Zhongpeng ai Caihua Zhang Lijuan School of Information and Electronic Engineering， Zhejiang University of Science and Technology

Quantization noise caused by analog-to-digital converter (ADC) gives rise to the reliability performance degradation of communication systems. In this letter， a quantized non-hermitian Symmetry (NHS) orthogonal frequency-division multiplexing-based visible light communication (OFDM-VLC) system is presented. In order to analyze the effect of the resolution of ADC on NHS OFDM-VLC， a quantized mathematical model of NHS OFDM-VLC is established. Based on the proposed quantized model， a closed-form bit rate error (BER) Expression is derived. The theoretical analysis and simulation results both confirm the effectiveness of the obtained BER formula in high-resolution ADC. In addition， channel coding is helpful in compensating for the BER performance loss due to the utilization of lower resolution ADC.

关键词：

Day-ahead Electricity Price Prediction Method Based on Similar Day Screening and Combined Deep Learning Modeling

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Dianwang Jishu/Power System Technology 2025年第1期49卷 242-251页

作者： ai, Yu Jia, Yanbing Han, Xiaoqing Shanxi Key Laboratory of Power System Operation and Control Taiyuan University of Technology Shanxi Province Taiyuan 030024 China Key Laboratory of Cleaner Intelligent Control on Coal & Electricity Taiyuan University of Technology Ministry of Education Shanxi Province Taiyuan 030024 China

Accurate day-ahead electricity price prediction is the basis for market operation and policy planning, while market disclosure information is essential for electricity price prediction. This paper proposes a combined CNN-GRU deep-learning electricity price prediction model introducing the Self-attention mechanism. Firstly, for the trading process of the Shanxi electricity spot market and the formation mechanism of electricity price before the day, it is proposed to adopt the maximum mutual information coefficient method to extract features from the market disclosed information data such as boundary conditions before the day, to determine the key influencing factors of electricity price and its weight coefficients;and then based on the weighted grey correlation of the history of similar day screening method to generate the historical dataset of electricity price prediction, and to excavate the internal change rule of electricity price and its features;Finally, the CNN-GRU model introducing Self-attention mechanism is used to get the predicted electricity price based on the historical data set. The effectiveness and accuracy of the prediction method proposed in this paper are verified through examples. © 2025 Power System Technology Press. All rights reserved.

关键词：

Recent progress on photoactive nonprecious transition-metal complexes

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年第1期68卷 46-95页

作者： Zhong-Liang Gong Hong-Jie Zhang Yan Cheng Jianxun Liu Yuhan ai Yaqin Li Zhihui Feng Qiong Zhang Shaolong Gong Yong Chen Chang-Jiang Yao Yuan-Yuan Zhu Liang-Jin Xu Yu-Wu Zhong CAS Key Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences State Key Laboratory of Structural Cemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences School of Chemistry and Chemical Engineering Anhui Key Laboratory of Advanced Catalytic Materials and Reaction EngineeringHefei University of Technology State Key Laboratory of Explosion Science and Safety Protection School of Mechatronical Engineering Beijing Institute of Technology College of Chemistry and Molecular Sciences Hubei Key Lab on Organic and Polymeric Optoelectronic Materials Wuhan University School of Chemistry and Chemical Engineering Anhui University Key Laboratory of Photochemical Conversion and Optoelectronic Materials & CAS-HKU Joint Laboratory on New Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences

Photoactive complexes of nonprecious transition metals, mainly including those in the first-row and partially the second-row of the Periodic table of elements, have received increasing attention in view of their low cost and long-term sustainability. They are recognized as promising alternatives to noble transition metal complex congeners that have been extensively studied in optoelectronic devices, artificial photosynthesis, photocatalysis, biodiagnostics, and therapeutics, etc. This review is devoted to a comprehensive summary on the classical and recent advances on photoactive nonprecious transition metal complexes, including photoactive Zr, V, Cr, Mo, and W complexes, Mn complexes and hybrids, Fe, Co, Ni, and Cu complexes, and Zn and Cd complexes and hybrids. A particular focus is given on the molecular design, modulation of photophysical and photochemical properties, and applications of the representative and lately-developed nonprecious metal complexes. In addition, a perspective on the future development in this field is provided at the end of this review.

关键词： photoactive metal complexes earth-abundant metals nonprecious metal complexes luminescence photochemistry