检索结果-南通市图书馆

Coordination and Cooperation are Essential: A Call for a Global Network to Enhance Integrated Human Health Risk Resilience Based on China’s COVID-19 Pandemic Coping Practice

在线全文

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2021年第4期12卷 593-599页

作者： yelin Sun Tian Liu tao ye Peijun Shi State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing100875China Academy of Plateau Science and Sustainability Qinghai Normal UniversityXining810008China Faculty of Geographical Science Beijing Normal UniversityBeijing100875China

More than a year after its appearance and still rampant around the world,the COVID-19 pandemic has highlighted tragically how poorly the world is prepared to handle systemic risks in an increasingly hyper-connected global social-ecological *** absence or clear inadequacy of global governance arrangements and mechanisms is painfully distinct and *** this short article,we summarize a set of COVID-19 pandemic-related analyses and lessons that are inspired by Chinese ***,strong government response is one of the most important methods to control a ***,countries should be concerned about human-to-frozen goods-to-human ***,sharing resources and experiences through cooperation is crucial to ensure an adequate health *** on these insights,we stress the critical importance of coordination and cooperation,and call for a global network to enhance integrated human health risk resilience.

关键词： COVID-19 Human-to-frozen goods-to-human transmission Government response Medical resources Coordination and cooperation

Variable selection for skew-normal mixture of joint location and scale models

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2021年第4期36卷 475-491页

作者： WU Liu-cang YANG Song-qin tao ye Faculty of Science Kunming University of Science and TechnologyKunming 650093China School of Economics and Statistics Guangzhou UniversityGuangzhou 510006China

Although there are many papers on variable selection methods based on mean model in the nite mixture of regression models,little work has been done on how to select signi cant explanatory variables in the modeling of the variance *** this paper,we propose and study a novel class of models:a skew-normal mixture of joint location and scale models to analyze the heteroscedastic skew-normal data coming from a heterogeneous *** problem of variable selection for the proposed models is *** particular,a modi ed Expectation-Maximization(EM)algorithm for estimating the model parameters is *** consistency and the oracle property of the penalized estimators is *** studies are conducted to investigate the nite sample performance of the proposed *** example is illustrated by the proposed methodologies.

关键词： heterogeneous population skew-normal(SN)distribution mixture of joint location and scale models variable selection EM algorithm

在线全文

学校读者我要写书评

暂无评论

双渠道下异质品制造商的直销产品选择策略

物流工程与管理 2024年第3期46卷 54-64页

作者：江臻怡叶涛锋江苏科技大学经济管理学院江苏镇江212000

考虑由单个零售商和单个异质品制造商组成的双渠道供应链,研究制造商直销渠道中的产品选择策略以及零售渠道中所供应的产品类型如何影响该策略。研究表明,当直销成本较低时,制造商的最优决策是在直销渠道同时销售高端产品和低端产品;当... 详细信息

考虑由单个零售商和单个异质品制造商组成的双渠道供应链,研究制造商直销渠道中的产品选择策略以及零售渠道中所供应的产品类型如何影响该策略。研究表明,当直销成本较低时,制造商的最优决策是在直销渠道同时销售高端产品和低端产品;当产品制造成本和直销成本都很高时,制造商的最优决策是仅直销高端产品。在零售渠道中只提供低端产品或同时提供两种产品情况下,当产品的制造成本较低但直销成本较高时,制造商选择仅直销高端产品;当产品的制造成本中等但直销成本较高时,制造商选择仅直销低端产品。在零售渠道中仅提供高端产品情况下,当制造成本较低时,制造商选择在直销渠道同时销售两类产品;当制造成本中等但直销成本较高时,制造商选择仅直销高端产品。

关键词：双渠道供应链异质品产品选择

Low-altitude small-sized object detection using lightweight feature-enhanced convolutional neural network

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2021年第4期32卷 841-853页

作者： ye tao ZHAO Zongyang ZHANG Jun CHAI Xinghua ZHOU Fuqiang School of Mechanical and Electrical Information Engineering China University of Mining and Technology-BeijingBeijing 100083China The 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang 050081China School of Instrumentation Science and Opto-electronics Engineering Beihang UniversityBeijing 100083China

Unauthorized operations referred to as“black flights”of unmanned aerial vehicles(UAVs)pose a significant danger to public safety,and existing low-attitude object detection algorithms encounter difficulties in balancing detection precision and ***,their accuracy is insufficient,particularly for small objects in complex *** solve these problems,we propose a lightweight feature-enhanced convolutional neural network able to perform detection with high precision detection for low-attitude flying objects in real time to provide guidance information to suppress black-flying *** proposed network consists of three modules.A lightweight and stable feature extraction module is used to reduce the computational load and stably extract more low-level feature,an enhanced feature processing module significantly improves the feature extraction ability of the model,and an accurate detection module integrates low-level and advanced features to improve the multiscale detection accuracy in complex environments,particularly for small *** proposed method achieves a detection speed of 147 frames per second(FPS)and a mean average precision(mAP)of 90.97%for a dataset composed of flying objects,indicating its potential for low-altitude object ***,evaluation results based on microsoft common objects in context(MS COCO)indicate that the proposed method is also applicable to object detection in general.

关键词： unmanned aerial vehicle(UAV) deep learning lightweight network object detection low-attitude

Elastic scattering and total reaction cross sections of^(6)Li examined via a microscopic continuum discretized coupled-channels model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第1期48卷 71-81页

作者：陈文棣庞丹阳郭海瑞叶涛孙伟力应阳君 School of Physics Beihang UniversityBeijing 100191China Institute of Applied Physics and Computational Mathematics Beijing 100094China

We present a systematic study of 6Li elastic scattering and total reaction cross sections at incident energies around the Coulomb barrier within the continuum discretized coupled-channels(CDCC)framework,where 6Li is treated in anα+d two-body *** with 27Al,64Zn,138Ba,and 208Pa are *** microscopic optical potentials(MOP)based on Skyrme nucleon-nucleon interaction forαand d are adopted in CDCC calculations and satisfactory agreement with the experimental data is obtained without any adjustment on *** comparison,αand d global phenomenological optical potentials(GOP)are also used in CDCC analysis and a reduction of no less than 50%on the surface imaginary part of deuteron GOP is required for describing the *** all cases,the 6Li breakup effect is significant and provides repulsive correction to the folding model *** reduction on the surface imaginary part of GOP of deuteron reveals a strong suppression of the reaction probability of deuteron as a component of 6Li when compared with that of a free *** investigation is performed by considering the d breakup process equivalently within the dynamic polarization potential approach,and the results show that d behaves in a manner similar to a tightly bound nucleus in 6Li induced reactions.

关键词： continuum discretized coupled channels method microscopic optical potential 6Li induced reaction elastic scattering total reaction cross section

面向轨道智能交通大学生创新训练实践教学平台设计

在线全文

学校读者我要写书评

暂无评论

实验室研究与探索 2024年第1期43卷 152-158,198页

作者：叶涛郑志康郝天成徐欣宇李东圣中国矿业大学(北京)机械与电气工程学院北京100083

以轨道智能交通中的入侵异物智能检测为对象,设计了一种新型的大学生创新训练实践教学平台,提出了一种基于深度学习的轨道异物入侵检测模型,并结合人工智能和机械设计等交叉学科专业知识,自主研发了一种小型轨道异物入侵智能检测系统物... 详细信息

以轨道智能交通中的入侵异物智能检测为对象,设计了一种新型的大学生创新训练实践教学平台,提出了一种基于深度学习的轨道异物入侵检测模型,并结合人工智能和机械设计等交叉学科专业知识,自主研发了一种小型轨道异物入侵智能检测系统物理样机,实现了复杂环境下的高效轨道异物入侵检测。实验和实践结果表明,该模型很好地平衡了检测速度和精度,在NVIDIA GTX1080Ti平台上对自建轨道异物入侵数据集的平均检测精度为96.1%,检测速度为209 FPS。通过上述大创实践教学平台的设计、实施和考核,培养和激发了大学生的创新实践和团队协作能力。

关键词：智能视觉检测轨道交通异物检测样机机械设计实践教学平台

树冠位置对香樟叶形态性状和异速生长关系的影响

在线全文

学校读者我要写书评

暂无评论

热带亚热带植物学报 2024年第3期32卷 319-329页

作者：王梦亭刘小敏金欣悦王苓汝项小燕陶冶中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室干旱区生态安全与可持续发展重点实验室乌鲁木齐830011 安庆师范大学生命科学学院皖西南生物多样性研究与生态保护安徽省重点实验室安徽安庆246133

为深入了解树冠位置对植物叶形态性状的影响,在常绿乔木香樟树冠上下2层和东南西北4个方位开展调查取样,系统分析了不同树冠位置间叶形态性状(叶长、叶宽、叶厚、叶柄长、叶柄直径和叶形指数)及其异速生长关系的差异性。结果表明,叶形... 详细信息

为深入了解树冠位置对植物叶形态性状的影响,在常绿乔木香樟树冠上下2层和东南西北4个方位开展调查取样,系统分析了不同树冠位置间叶形态性状(叶长、叶宽、叶厚、叶柄长、叶柄直径和叶形指数)及其异速生长关系的差异性。结果表明,叶形态性状在不同树冠方位间均差异显著,但上下2层变化趋势不完全一致。在树冠上层,除叶形指数和叶炳长外,其余4个性状均表现为东侧最大。在树冠下层,除叶形指数外,其余5个性状指标均表现为东侧最小。在同一方位上,叶形态性状在上下2层间也存在一定差异,其中叶形指数多为下层高于上层,而其他形态性状多呈相反趋势。此外,树冠层次和方位的交互作用对叶片长、叶片厚、叶柄长和叶柄直径有显著影响。各层次和各方位叶形态性状间多为异速生长关系(即异速生长指数不等于1),且多无显著差异。在所有树冠层次和树冠方位,叶宽与叶厚、叶宽与叶炳长、叶长与叶厚及叶长与叶柄长之间均呈异速生长关系。可见,树冠位置对香樟叶形态性状的影响较大,但形态性状间的异速生长关系相对稳定,这是香樟叶形态性状表型可塑性和内在关系稳定性的重要体现。

关键词：香樟树冠层次树冠方位形态性状异速生长关系

维普期刊数据库博看期刊

甲巯咪唑对甲状腺功能亢进症大鼠尿液代谢组学的影响研究

在线全文

学校读者我要写书评

暂无评论

中国药房 2024年第9期35卷 1064-1069页

作者：卢旭李玲叶涛彭佑锋何佳馨张宁贵州中医药大学药学院贵阳550025 贵州中医药大学第一附属医院药学部贵阳550001 贵州中医药大学第一附属医院康复科贵阳550001 贵州省大方县中医医院药剂科贵阳551699

目的研究甲巯咪唑对甲状腺功能亢进症大鼠尿液代谢组学的影响,并初步探讨其可能机制。方法将30只SD大鼠随机分为对照组、模型组、甲巯咪唑组,每组10只。除对照组外其余各组大鼠连续灌胃左甲状腺素钠片(160 mg/kg)15 d复制甲状腺功能亢... 详细信息

目的研究甲巯咪唑对甲状腺功能亢进症大鼠尿液代谢组学的影响,并初步探讨其可能机制。方法将30只SD大鼠随机分为对照组、模型组、甲巯咪唑组,每组10只。除对照组外其余各组大鼠连续灌胃左甲状腺素钠片(160 mg/kg)15 d复制甲状腺功能亢进症模型,且甲巯咪唑组在造模同时每天灌胃甲巯咪唑(3.6 mg/kg)。观察大鼠基本情况,测量体重和肛温;末次给药后,检测大鼠血清中三碘甲腺原氨酸(T_(3))、四碘甲腺原氨酸(T_(4))、游离三碘甲腺原氨酸(FT_(3))、游离四碘甲腺原氨酸(FT_(4))和促甲状腺激素(TSH)水平。于给药第15天收集各组大鼠24 h尿液,采用超高效液相色谱-飞行时间质谱(UPLC-TOF-MS)技术对大鼠尿液进行代谢组学分析,利用主成分分析和正交偏最小二乘-判别分析筛选差异代谢物,并通过HMDB、KEGG数据库进行代谢通路分析。结果与对照组相比,模型组大鼠肛温和血清中T_(3)、T_(4)、FT_(3)、FT_(4)水平,尿液中差异代谢物癸二酸、利胆酸3-O-葡萄糖醛酸和N6,N6,N6-三甲基-L-赖氨酸表达均显著升高/上调,体重、血清中TSH水平和尿液中脱氧胞苷和2-氧代-4-甲硫基丁酸表达均显著降低/下调(P<0.01)。与模型组相比,甲巯咪唑组大鼠上述指标水平均显著逆转(P<0.05或P<0.01)。上述5个差异代谢物主要涉及戊糖和葡萄糖醛酸相互作用、赖氨酸降解、半胱氨酸和甲硫氨酸代谢以及嘧啶代谢这4条代谢通路。结论甲巯咪唑可能是通过调节戊糖和葡萄糖醛酸相互作用、赖氨酸降解、半胱氨酸和甲硫氨酸代谢以及嘧啶代谢,从而发挥改善甲状腺功能亢进症的作用。

关键词：甲巯咪唑甲状腺功能亢进症尿液代谢组学差异代谢物超高效液相色谱-飞行时间质谱

Agricultural Production Behavior under Premium Subsidy:Incorporating Crop Price When Subsistence Constraint Holds

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2012年第3期3卷 131-138页

作者： tao ye Muneta Yokomatsu Norio Okada State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Disaster Prevention Research Institute Kyoto UniversityUji 6110011Japan

Producers’ acreage decisions in response to the availability of insurance and government subsidy has been a topic of considerable attention. This study revisits the issue of agriculture producers’ production behavior under crop insurance and premium subsidy conditions. The discussion begins by differentiating between the assumptions of the classic insurance model and that model’s application to crop insurance. A discussion of a closed dual economy model follows. Price difference in cases of disaster and no disaster essentially determines producers’ response to the availability of a premium subsidy. A producer can obtain higher production revenue due to the significant increase in price induced by yield loss if the economy is closed and a subsistence constraint is taken into account. In this case, a premium subsidy could induce producers to lower their output level. The result is further generalized by two model extensions in which assumptions are relaxed to allow openness in the economy or intertemporal storage of grains with grain reserve policy. The findings of this article suggest that governments should carefully examine the actual risk-bearing pattern of crop producers before any subsidy policy is implemented.

关键词： disaster insurance producer