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Preparation and combustion properties of laminated sticks of B-CuO and B-Bi2O3

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Environmental records of snow pits in Yuzhufeng Glacier and Xiao Dongkemadi Glacier in the Tibetan Plateau

Defence technology 2024年第8期 67页

作者： Haoyu Song Chenyang Li Fubing Gao Chongwei An Shijiao Li Xuan Zhan jianchen he

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Research in Cold and Arid Regions 2011年第5期3卷 392-399页

作者： QuanLian Li XiaoBo Wu jianchen Pu JianQiao he State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou Gansu 730000 China

The contents and distribution characteristics of ions, n-alkanes, and polycyclic aromatic hydrocarbons in snow pits on the Yuzhufcng （YZF） Glacier and the Xiao Dongkernadi （XDKMD） Glacier are studied. Parameter characteristics and correlation coefficients between ions and two organic compounds are used to explore the possible sources of these chemical compositions. The results indicated that both glaciers are influenced by west wind circulation, but the contents of ions, n-alkanes, and polycyclic aromatic hydrocarbons in the YZF Glacier are higher than in the XDKMD Glacier because of differences in geographical position. The ratios of ∑nC21^-/∑nC22^＋ and CPI values （CPI： carbon preference index） indicate that the n-alkanes from natural sources in these two glaciers are mainly derived from higher plants, whereas the contribution from lower organisms was small, also, n-alkanes from anthropogenic sources in the YZF Glacier are higher than in the XDKMD Glacier. The ratios of LPAHs/HPAHs and （Fly＋Pyr）/（BghiP＋INP） indicate that the polycyclic aromatic hydrocarbons in these two glaciers are mainly derived from low temperature combustion of coal and biomass, and, in the XDKMD Glacier, partially from the vehicle exhaust.

关键词： Tibetan Plateau snow pit ion n-alkanes polycyclic aromatic hydrocarbons

Halogen-bond induced unusual polyhalogen anions formation in hydrogen-bonded frameworks to secure iodine sequestration

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Nano Research 2024年第7期17卷 6766-6772页

作者： Yi Xie Pengling Huang Qiang Gao Shiyu Wang jianchen Wang Gang Ye Collaborative Innovation Center of Advanced Nuclear Energy Technology Institute of Nuclear and New Energy TechnologyTsinghua UniversityBeijing 100084China

Safe confinement of fission iodine isotopes for long-term radioactive waste disposal remains a formidable challenge,as conventional sorbents provide inherently weak iodine-host *** report here a novel halogen bond(X-bond)directed strategy to sequester volatile iodine in hydrogen-bonded(H-bonded)frameworks with unprecedented ***-assisted Hbonded frameworks bearing open halide sites are developed,showing distinctive iodine encapsulation behaviors without compromising the *** crystallographic evidence indicates the formation of X-bonds,i.e.,I–I···Cl^(−) and I–I···Br^(−),within the confined pore *** polyhalogen anions,i.e.,[I_(2)Cl_(2)]^(2−)and[I_(2)Br_(2)]^(2−),sustained in H-bonded frameworks are identified for the first *** X-bond reinforced host-guest interaction affords robust iodine trapping without leaking out even at elevated temperatures up to 180℃.By integrating the halogen-bond chemistry with H-bonded frameworks,this study offers fresh concepts for developing effective host reservoirs to secure fission iodine isotopes from spent fuel reprocessing off-gases.

关键词： halogen-bond chemistry anion coordination chemistry hydrogen-bonded organic frameworks polyhalogen anions iodine confinement

Long-term glacier variations and the response to climate fluctuation in Qilian Mountains, China

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Journal of Geographical Sciences 2024年第10期 1904-1924页

作者： WANG Sheng WANG Jianwen ZHU Meilin YAO Tandong PU jianchen WANG Jinfeng College of Geography Science Shanxi Normal University Center for the Pan-Third Pole Environment Lanzhou University Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau Research CAS State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-environment and ResourcesCAS

Glaciers are considered to be ‘climate-sensitive indicators' and ‘solid reservoirs',and their changes significantly impact regional water security. The mass balance（MB） from 2011 to 2020 of the Qiyi Glacier in the northeast Tibetan Plateau is presented based on field observations. The glacier showed a persistent negative balance over 9 years of in-situ observations, with a mean MB of-0.51 m w.e. yr-1. The distributed energy-mass balance model was used for glacier MB reconstruction from 1980 to 2020. The daily meteorological data used in the model were from HAR v2 reanalysis data, with automatic weather stations located in the middle and upper parts of the glacier used for deviation correction. The average MB over the past 40 years of the Qiyi Glacier was-0.36 m w.e. yr-1with the mass losses since the beginning of the 21st century, being greater than those in the past. The glacier runoff shows a significant increasing trend, contributing ～81% of the downstream river runoff. The albedo disparity indicates that the net shortwave radiation is much higher in the ablation zone than in the accumulation zone, accelerating ablation-area expansion and glacier mass depletion. The MB of the Qiyi Glacier is more sensitive to temperature and incoming shortwave radiation variation than precipitation. The MB presented a non-linear reaction to the temperature and incoming shortwave radiation. Under future climate warming, the Qiyi Glacier will be increasingly likely to deviate from the equilibrium state, thereby exacerbating regional water balance risks. It is found that the mass losses of eastern glaciers are higher than those of western glaciers, indicating significant spatial heterogeneity that may be attributable to the lower altitude and smaller area distribution of the eastern glaciers.

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MDGA2 Constrains Glutamatergic Inputs Selectively onto CA1 Pyramidal Neurons to Optimize Neural Circuits for Plasticity,Memory,and Social Behavior

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Neuroscience Bulletin 2024年第7期40卷 887-904页

作者： Xuehui Wang Donghui Lin Jie Jiang Yuhua Liu Xinyan Dong jianchen Fan Lifen Gong Weida Shen Linghui Zeng Tonghui Xu Kewen Jiang Steven A.Connor Yicheng Xie School of Life Sciences Nanchang UniversityNanchang330031China Department of Neurology Children's HospitalZhejiang University School of MedicineNational Clinical Research Center for Child HealthHangzhou 310052China Department of Biology York University4700 Keele StreetTorontoON M3J 1P3Canada Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province School of MedicineHangzhou City UniversityHangzhou 310015China

Synapse organizers are essential for the development,transmission,and plasticity of *** as rare synapse suppressors,the MAM domain containing glycosylphosphatidylinositol anchor(MDGA)proteins contributes to synapse organization by inhibiting the formation of the synaptogenic neuroligin-neurexin complex.A previous analysis of MDGA2 mice lacking a single copy of Mdga2 revealed upregulated glutamatergic synapses and behaviors consistent with ***,MDGA2 is expressed in diverse cell types and is localized to both excitatory and inhibitory *** the network versus cell-specific effects of MDGA2 loss-of-function requires a cell-type and brain region-selective *** address this,we generated mice harboring a conditional knockout of Mdga2 restricted to CA1 pyramidal *** we report that MDGA2 suppresses the density and function of excitatory synapses selectively on pyramidal neurons in the mature *** deletion of Mdga2 in CA1 pyramidal neurons of adult mice upregulated miniature and spontaneous excitatory postsynaptic potentials,vesicular glutamate transporter 1 intensity,and neuronal *** effects were limited to glutamatergic synapses as no changes were detected in miniature and spontaneous inhibitory postsynaptic potential properties or vesicular GABA transporter ***,evoked basal synaptic transmission and AMPAR receptor currents were enhanced at glutamatergic *** a behavioral level,memory appeared to be compromised in Mdga2 cKO mice as both novel object recognition and contextual fear conditioning performance were impaired,consistent with deficits in long-term potentiation in the CA3-CA1 *** affiliation,a behavioral analog of social deficits in autism,was similarly *** results demonstrate that MDGA2 confines the properties of excitatory synapses to CA1 neurons in mature hippocampal circuits,thereby optimizing this network for plasticity,c

关键词： MDGA2 CA1 pyramidal neurons Glutamatergic inputs Synaptic plasticity Memory Social behaviors Autism Synapse organizers

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银行网络结构与系统性金融风险传染

系统工程理论与实践 2024年第7期44卷 2120-2136页

作者：杨科王健辰田凤平华南理工大学经济与金融学院广州510006 中山大学国际金融学院广州510275 人工智能与数字经济广东省实验室(广州) 广州510330

随着我国银行业资金规模和成员数量的不断增加,愈发复杂的机构间关联网络逐渐成为潜在的风险传染渠道.本文采用GARCH-Copula-CoVaR模型测算了16家上市商业银行在系统性金融风险中的贡献规模,结合网络拓扑理论和滑动窗口法研究了银行网... 详细信息

随着我国银行业资金规模和成员数量的不断增加,愈发复杂的机构间关联网络逐渐成为潜在的风险传染渠道.本文采用GARCH-Copula-CoVaR模型测算了16家上市商业银行在系统性金融风险中的贡献规模,结合网络拓扑理论和滑动窗口法研究了银行网络结构特征的演化趋势,并进一步分析了银行网络结构对系统性金融风险传染的影响机制.研究结果表明:虽然银行部门“去中心化”效应愈发显著,网络稳定性和抗风险能力整体上得到改善,但仍应重视网络结构特征在系统性金融风险产生及辐射过程中起到的多重作用;处于网络中不同风险传染地位的银行同时满足宏微观审慎监管要求的难度存在较大差异,对极端风险敏感且在银行网络中扮演核心角色的银行更倾向于向整个系统输出更多风险,通常在风险传染过程中起主导作用;在危机时期,网络密度通常会出现剧烈变化,关联网络的稳定性失衡进一步加速了系统性金融风险的传染.本研究可为监管部门实时更新系统重要性银行名单和全面监管风险传染渠道提供思路,对提升金融市场抵御风险的能力以及防范和化解系统性风险等方面都具有重要的现实意义.

关键词：银行网络结构系统性金融风险影响机制

基于深度学习的说话人确认方法研究现状及展望

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数据采集与处理 2024年第5期39卷 1062-1084页

作者：李建琛韩纪庆哈尔滨工业大学计算机科学与技术学院哈尔滨150001

随着深度学习的不断发展,说话人确认(Speaker verification)技术已经取得了长足的进步。该技术相较于其他生物特征识别技术,具有可远程操作、成本低和易于人机交互等优势,在公安刑侦、金融服务等领域展现出广泛的应用前景。本文系统综... 详细信息

随着深度学习的不断发展,说话人确认(Speaker verification)技术已经取得了长足的进步。该技术相较于其他生物特征识别技术,具有可远程操作、成本低和易于人机交互等优势,在公安刑侦、金融服务等领域展现出广泛的应用前景。本文系统综述了基于深度学习的说话人确认技术的发展脉络。首先,介绍了基于深度学习的说话人特征表示模型在模型输入与结构、池化层、有监督损失函数和自监督学习与预训练模型4个方面的发展历程和研究现状;其次,探讨了说话人确认技术在实际应用中面临的跨域不匹配问题,如噪声干扰、信道不匹配和远场语音等,并概述了相应的领域自适应和领域泛化方法;最后,指出了进一步的研究方向。

关键词：说话人识别说话人确认深度学习领域不匹配自监督学习

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液化石油气瓶自动探伤原理和装置

无损检测 1981年第2期 6-8页

作者：周立伟杜凤河建成机械厂

介绍超声波探伤在液化石油气瓶环形焊缝上的应用、探头的选择和测定、焊缝内缺陷的判定。叙述了一台全自动探伤装置的原理、动作程序及特性参数。

关键词：自动探伤液化石油气瓶气缸划伤继电器常开触点吸合钢印汽缸气动元件电子元件环形焊缝探伤装置分选

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运载火箭静力试验加载装置结构拓扑优化设计

宇航学报 2024年第5期45卷 692-699页

作者：张琪刘健晨龙政冀凯歌北华航天工业学院航空宇航学院廊坊065000

针对运载火箭结构静力试验中工装部件多、重量大的情况,开展轻量化设计,提出一种加载装置精细拓扑优化方法。基于变密度法,构造了以柔顺度最小为目标函数、以体积比为约束条件的拓扑优化模型,通过分段选取材料密度值,实现了结构精细拓... 详细信息

针对运载火箭结构静力试验中工装部件多、重量大的情况,开展轻量化设计,提出一种加载装置精细拓扑优化方法。基于变密度法,构造了以柔顺度最小为目标函数、以体积比为约束条件的拓扑优化模型,通过分段选取材料密度值,实现了结构精细拓朴。根据优化结果确定主承力结构及可减重部分,采用最小二乘法对结构不规则边界进行曲面拟合以提高其工艺性。最终承载1 500 t轴压的加载装置单个减重19.7%,结构应力和变形减小且分布更为均匀。本研究对于飞行器结构力学试验高承载部件的设计具有参考意义和实用价值。

关键词：运载火箭静力试验结构拓扑优化变密度法加载装置轻量化设计