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IMITATIO ALEXANDRI–THE IMAGE OF DRUSUS MINOR ON BRASS TOKENS OF THE MüNZKABINETT,STAATLICHE MUSEEN ZU BERLIN
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作者 Alexa Kuter 《Journal of Ancient Civilizations》 2016年第1期85-122,共38页
Within the group of Roman brass tokens with numerals on the reverse, one type depicting a youthful commander on the obverse stands out. Obviously, it depicts a member of the Julio-Claudian dynasty. The young male is s... Within the group of Roman brass tokens with numerals on the reverse, one type depicting a youthful commander on the obverse stands out. Obviously, it depicts a member of the Julio-Claudian dynasty. The young male is seen from the back, holding a spear. The paper not only discusses this peculiar iconography but also tries to give a new identification: while the commander is usually identified with Tiberius or Germanicus, there are strong reasons to connect the portrait to Drusus minor. 展开更多
关键词 令牌 亚历山大 黄铜 模仿 形象 柏林 组成部分 物质文化
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考虑关联波段特性的光谱相似图像分类方法
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作者 周文芳 杨耀宁 《激光杂志》 CAS 北大核心 2024年第2期124-128,共5页
光谱相似图像分类性能过差会增加光谱信息冗余度,降低地物勘探与军事防御等多种领域的光谱探测效率。为了多元素匀质区分光谱信息与光谱曲线,提出考虑关联波段特性的光谱相似图像分类方法。该方法首先利用光谱匹配消除光谱相似图像白色... 光谱相似图像分类性能过差会增加光谱信息冗余度,降低地物勘探与军事防御等多种领域的光谱探测效率。为了多元素匀质区分光谱信息与光谱曲线,提出考虑关联波段特性的光谱相似图像分类方法。该方法首先利用光谱匹配消除光谱相似图像白色光源过曝现象。然后提取优化图像的关联波段,并将其作为聚类特征输入支持向量机中。最后根据支持向量机的输出结果,实现光谱相似图像分类。实验结果表明,所提方法分类结果清晰度较高,分类误差或像素块填色错误小,混淆矩阵中同行同列矩形块的分类精度较高。 展开更多
关键词 光谱相似图像 光谱匹配 关联波段 聚类特征 支持向量机
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国际视野下的三种高考改革路径及其启示
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作者 左璜 莫雷 +2 位作者 高瑞翔 戴晓颖 王圣 《考试研究》 2024年第1期46-57,共12页
为应对21世纪激烈的国际竞争,世界各国基于自身的文化背景与教育现状,纷纷启动高考改革。纵观国际,高考改革可以分为3种路径:一是以终身学习理念为驱导,融合普教与职教,开展以标准为本的证书制度评价模式;二是面向未来人才需求,协同基... 为应对21世纪激烈的国际竞争,世界各国基于自身的文化背景与教育现状,纷纷启动高考改革。纵观国际,高考改革可以分为3种路径:一是以终身学习理念为驱导,融合普教与职教,开展以标准为本的证书制度评价模式;二是面向未来人才需求,协同基础教育与高等教育,开展学力为本的多元评价模式;三是立足教育理想,整合课程改革与考试改革,开展以核心素养为本的评价模式。这3种模式虽各具特色,但总体呈现出育人为本、协同改革、素养导向等趋势,为我国新时代高考改革带来以下启示:第一,适当探索标准为本的证书制度评价,创新普职融合的路径;第二,适当探索未来人才导向的高中大学衔接评价策略,纵向打通人才培养路径;第三,进一步优化核心素养为本的高考评价内容改革,探索跨学科素养的选科考试制度。 展开更多
关键词 育人为本 新高考 核心素养 普职融合 教学评一体化
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交联聚乙烯直流电树枝降压阶段的局部放电特性
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作者 林国海 张洪亮 +3 位作者 郑喆 王亚林 周明瑜 尹毅 《高电压技术》 EI CAS CSCD 北大核心 2024年第1期348-358,共11页
电树枝是交联聚乙烯(XLPE)高压直流电缆的典型缺陷,有效检测电树枝对电缆绝缘状态评估至关重要。为此对含有电树枝的XLPE针-板绝缘试样进行直流局部放电实验,分析不同阶段下的局部放电特性以及电压参数对放电特性的影响。实验发现:含电... 电树枝是交联聚乙烯(XLPE)高压直流电缆的典型缺陷,有效检测电树枝对电缆绝缘状态评估至关重要。为此对含有电树枝的XLPE针-板绝缘试样进行直流局部放电实验,分析不同阶段下的局部放电特性以及电压参数对放电特性的影响。实验发现:含电树枝的试样在降压过程中会出现局部放电现象,不含电树枝的试样则不会放电;降压过程中的放电具有良好的重复性,对电树枝尺寸无明显影响,且放电脉冲极性与恒压阶段的相反。该实验现象表明利用降压阶段的局部放电检测,可为高压直流电缆电树枝的评估提供一种有益的尝试。此外,实验表明多次局部放电可能导致通道电导率增加,放电熄灭电压增大。不同电压参数下的降压阶段实验结果表明:更高的直流电压,合适的降压速率可以增加放电次数;针电极为负极性时平均放电量更高;恒压时长对放电特性没有显著影响。采用数值仿真分析了降压前后绝缘区域的电场分布,结果表明降压前期,泊松电场的衰减速率低于外施电场的衰减速率,使得针尖附近形成场强较高的反向电场,从而导致降压过程中的局部放电。 展开更多
关键词 交联聚乙烯 直流电树枝 局部放电 空间电荷 绝缘诊断
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高速光子晶体面发射激光器研究进展
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作者 潘绍驰 田思聪 +5 位作者 王品尧 王子烨 陆寰宇 佟存柱 王立军 BIMBERG Dieter 《发光学报》 EI CAS CSCD 北大核心 2024年第3期484-492,共9页
光子晶体面发射激光器(PCSEL)利用二维光子晶体光栅的布拉格共振实现面发射激光,具有其独特的优势,包括单模性能、在片测试、高功率、低发散角等。相比垂直腔面发射激光器(VCSEL),PCSEL有将近两倍的有源区光限制因子,展现出高速运行的... 光子晶体面发射激光器(PCSEL)利用二维光子晶体光栅的布拉格共振实现面发射激光,具有其独特的优势,包括单模性能、在片测试、高功率、低发散角等。相比垂直腔面发射激光器(VCSEL),PCSEL有将近两倍的有源区光限制因子,展现出高速运行的潜力。本文探讨了PCSEL的基本结构和工作原理,并详细分析了影响PCSEL激光器实现高速性能的关键因素。随后,文章系统地介绍了近年来研究者们为实现PCSEL高速性能所做的努力,重点聚焦于通过增强PCSEL的面内限制来缩小激光腔,并提供了相关的研究方向和指导。 展开更多
关键词 光子晶体 高速 面发射激光器
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考虑构网型和跟网型变流器的孤岛微电网小信号稳定性分析
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作者 张心怡 杨波 《综合智慧能源》 CAS 2024年第2期12-18,共7页
由电力电子设备主导的孤岛微电网面临系统惯量小、无频率支持而导致的稳定性问题,恒功率负荷的渗透也加剧了系统的失稳风险。研究了由构网型变流器和跟网型变流器为主导的,计及恒功率负荷的孤岛微电网稳定性。首先,建立了孤岛微电网系... 由电力电子设备主导的孤岛微电网面临系统惯量小、无频率支持而导致的稳定性问题,恒功率负荷的渗透也加剧了系统的失稳风险。研究了由构网型变流器和跟网型变流器为主导的,计及恒功率负荷的孤岛微电网稳定性。首先,建立了孤岛微电网系统的全阶小信号模型,通过特征值分析法研究了构网型变流器控制中下垂系数对稳定性的影响并得到了下垂系数的数值上界;其次,通过参与因子法揭示了系统参数和控制参数对小信号稳定性的影响;最后,在Matlab Simulink中建立了该孤岛微电网的开关模型,仿真验证了小信号分析结果的准确性。 展开更多
关键词 构网型变流器 跟网型变流器 孤岛微电网 恒功率负荷 小信号稳定性 下垂系数 新型电力系统
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城市社区养老服务设施需求层次研究与启示——以北京中心城区为例
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作者 李佳楠 程晓青 +1 位作者 李世熠 秦岭 《世界建筑》 2024年第6期41-46,共6页
针对当前社区养老服务设施体系定位不清晰、功能供需不匹配的问题,本研究从需求出发,通过Kano模型问卷对北京中心城区老年人的社区养老服务需求层次进行分类,并结合满意度系数给出优先级排序。结果显示,在21项养老服务中,餐食供应是绝... 针对当前社区养老服务设施体系定位不清晰、功能供需不匹配的问题,本研究从需求出发,通过Kano模型问卷对北京中心城区老年人的社区养老服务需求层次进行分类,并结合满意度系数给出优先级排序。结果显示,在21项养老服务中,餐食供应是绝大多数老年人的必备需求,且不同年龄、收入老年人群体的需求也存在显著差异。基于上述结果,研究结合各项服务对空间环境的要求以及常见的设施规模,从体系建设和分类设计两方面总结社区养老服务设施建设启示,将设施分为轻量级、中量级、重量级3类,并提出了相应的功能配置建议。 展开更多
关键词 社区养老服务设施 KANO模型 需求层次 功能配置 老年人
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Data-driven analysis of chemicals,proteins and pathways associated with peanut allergy:from molecular networking to biological interpretation
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作者 Emmanuel Kemmler Julian Braun +5 位作者 Florent Fauchère Sabine Dölle-Bierke Kirsten Beyer Robert Preissner Margitta Worm Priyanka Banerjee 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1322-1335,共14页
Peanut allergy is majorly related to severe food induced allergic reactions.Several food including cow's milk,hen's eggs,soy,wheat,peanuts,tree nuts(walnuts,hazelnuts,almonds,cashews,pecans and pistachios),fis... Peanut allergy is majorly related to severe food induced allergic reactions.Several food including cow's milk,hen's eggs,soy,wheat,peanuts,tree nuts(walnuts,hazelnuts,almonds,cashews,pecans and pistachios),fish and shellfish are responsible for more than 90%of food allergies.Here,we provide promising insights using a large-scale data-driven analysis,comparing the mechanistic feature and biological relevance of different ingredients presents in peanuts,tree nuts(walnuts,almonds,cashews,pecans and pistachios)and soybean.Additionally,we have analysed the chemical compositions of peanuts in different processed form raw,boiled and dry-roasted.Using the data-driven approach we are able to generate new hypotheses to explain why nuclear receptors like the peroxisome proliferator-activated receptors(PPARs)and its isoform and their interaction with dietary lipids may have significant effect on allergic response.The results obtained from this study will direct future experimeantal and clinical studies to understand the role of dietary lipids and PPARisoforms to exert pro-inflammatory or anti-inflammatory functions on cells of the innate immunity and influence antigen presentation to the cells of the adaptive immunity. 展开更多
关键词 Allergy informatics Knowledge-graph Data analysis Food allergy Peroxisome proliferator-activated receptors Fatty acids
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Management and classification of the fracture of lateral process of talus:An overview and literature update
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作者 Chao-Qun Wang Ulrich Stockle +2 位作者 Sheng-Nan Dong Xu-Gui Li Ze-Xi Ling 《World Journal of Clinical Cases》 SCIE 2024年第15期2487-2498,共12页
Fracture of the lateral process of the talus(FLPT)is uncommon in clinical practice and can be easily missed or misdiagnosed.In recent years,as researchers from all over the world have further deepened their research o... Fracture of the lateral process of the talus(FLPT)is uncommon in clinical practice and can be easily missed or misdiagnosed.In recent years,as researchers from all over the world have further deepened their research on FLPT,there has been a breakthrough in the classification,and the methods and principles of clinical management have changed accordingly;however,there is still no standardized guideline for the diagnosis and management of FLPT,and there have been few relevant literature review articles related to this kind of fracture in the past at least 5 years.In this article,we review the clinical classification,classification-based therapeutic recommendations,and prognosis of FLPT,with the aim of providing a reference for the clinical diagnosis and management of this infrequent fracture. 展开更多
关键词 Fracture of the lateral process of the talus Fracture of the talus Hindfoot injuries Intraarticular fracture Subtalar joint
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Prevalence and intensity of urinary schistosomiasis and soil-transmitted helminths among women of reproductive age in Mwaluphamba,Kwale
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作者 Samuel M.Ngui Joseph M.Mwangangi +1 位作者 Joachim Richter Josephine W.Ngunjiri 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2024年第2期71-83,共13页
Objective:To assess the epidemiology of urinary schistosomiasis and soil-transmitted helminthiasis among women of reproductive age in Mwaluphamba,Kwale County,Kenya.Methods:A community-based cross-sectional study desi... Objective:To assess the epidemiology of urinary schistosomiasis and soil-transmitted helminthiasis among women of reproductive age in Mwaluphamba,Kwale County,Kenya.Methods:A community-based cross-sectional study design was employed to randomly sample 422 women of reproductive age(15-<50 years)from four villages in Mwaluphamba location.Stool specimens were collected and examined using the Kato-Katz method,while filtration technique was used to analyze urine specimens.Participants’sociodemographic details were obtained using a standardized questionnaire.Results:Urinary schistosomiasis prevalence was at 4.7%(20/422,95%CI 2.8%-6.9%)while the prevalence of soil-transmitted helminthiasis infection was 4.5%(19/422,95%CI 2.6%-6.7%).The infection intensities of urinary schistosomiasis among the study participants ranged from 1 to 120 eggs/10 mL of urine with median egg count of 18.45 eggs/10 mL.The patients were diagnosed with light infection,of 56.16 egg/gram and 48.48 egg/gram for Trichuris trichiura and hookworms,respectively.Women without latrines had 15.7 times higher risk of having urinary schistosomiasis compared to those with a latrine.Similarly,use of surface water(aOR=1.0,95%CI 0.2-1.4,P=0.010)and crossing the river to go to a place(aOR=1.1,95%CI 0.3-1.6,P=0.009)were statistically significant risk factors for getting urinary schistosomiasis.In bivariable regression analysis,defecating around the water source(OR=4.3,95%CI 1.5-12.9)had a statistically significant association with the prevalence of soil-transmitted helminthiasis(P=0.008).Conclusions:This study has given an insight on the prevalence and intensity of urinary schistosomiasis and soil-transmitted helminthiasis in Mwaluphamba location that form a basis for strengthening the control and elimination programmes for these neglected tropical diseases. 展开更多
关键词 Urinary schistosomiasis PREVALENCE Soiltransmitted helminths Mwaluphamba
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Linkage Between European and East Asian Heatwaves on Synoptic Scales
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作者 蔡奋颖 刘彩红 +2 位作者 杨崧 邓开强 KURTHS Jürgen 《Journal of Tropical Meteorology》 SCIE 2024年第2期97-105,共9页
Concurrent extreme weather events in geographically distant areas potentially cause high-end risks for societies.By using network analysis,the present study managed to identify significant nearly-simultaneous occurren... Concurrent extreme weather events in geographically distant areas potentially cause high-end risks for societies.By using network analysis,the present study managed to identify significant nearly-simultaneous occurrences of heatwaves between the grid cells in East Asia and Eastern Europe,even though they are geographically far away from each other.By further composite analysis,this study revealed that hot events first occurred in Eastern Europe,typically with a time lag of3-4 days before the East Asian heatwave events.An eastward propagating atmospheric wave train,known as the circumglobal teleconnection(CGT)pattern,bridged the sequent occurrences of extreme events in these two remote regions.Atmospheric blockings,amplified by surface warming over Eastern Europe,not only enhanced local heat extremes but also excited a CGT-like pattern characterized by alternative anomalies of high and low pressures.Subsequent downstream anticyclones in the middle and upper troposphere reduced local cloud cover and increased downward solar radiation,thereby facilitating the formation of heatwaves over East Asia.Nearly half of East Asian heatwave events were preceded by Eastern European heatwave events in the 10-day time range before East Asian heatwave events.This investigation of heatwave teleconnection in the two distant regions exhibits strong potential to improve the prediction accuracy of East Asian heatwaves. 展开更多
关键词 concurrent heatwaves Eastern Europe East Asia circum-global teleconnection pattern
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Quantum Chromodynamics on Lattice: Direct Minimization of QCD-QED-Action with New Results
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作者 Jan Helm 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期228-256,共29页
This paper describes a new numerical QCD calculation method (direct minimization of QCD-QED-action) and its results for the first-generation (u, d) hadrons. Here we start with the standard color-Lagrangian LQCD = LDir... This paper describes a new numerical QCD calculation method (direct minimization of QCD-QED-action) and its results for the first-generation (u, d) hadrons. Here we start with the standard color-Lagrangian LQCD = LDirac + Lgluon, model the quarks q<sub>i</sub> as parameterized gaussians, and the gluons Ag<sub>i</sub> as Ritz-Galerkin-series. We minimize the Lagrangian numerically with parameters par = (par (q), {α<sub>k</sub>}, par (Ag)) for first-generation hadrons (nucleons, pseudo-scalar mesons, vector mesons). The resulting parameters yield the correct masses and correct magnetic moments for the nucleons, the gluon-distribution and the quark-distribution with interesting insights into the hadron structure. 展开更多
关键词 QCD QED QCD On-Lattice Color Lagrangian HADRONS
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Three- and Four-Dimensional Generalized Pythagorean Numbers
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作者 Alfred Wünsche 《Advances in Pure Mathematics》 2024年第1期1-15,共15页
The Pythagorean triples (a, b | c) of planar geometry which satisfy the equation a<sup>2</sup>+b<sup>2</sup>=c<sup>2</sup> with integers (a, b, c) are generalized to 3D-Pythagorean ... The Pythagorean triples (a, b | c) of planar geometry which satisfy the equation a<sup>2</sup>+b<sup>2</sup>=c<sup>2</sup> with integers (a, b, c) are generalized to 3D-Pythagorean quadruples (a, b, c | d) of spatial geometry which satisfy the equation a<sup>2</sup>+b<sup>2</sup>+c<sup>2</sup>=d<sup>2</sup> with integers (a, b, c, d). Rules for a parametrization of the numbers (a, b, c, d) are derived and a list of all possible nonequivalent cases without common divisors up to d<sup>2</sup> is established. The 3D-Pythagorean quadruples are then generalized to 4D-Pythagorean quintuples (a, b, c, d | e) which satisfy the equation a<sup>2</sup>+b<sup>2</sup>+c<sup>2</sup>+d<sup>2</sup>=e<sup>2</sup> and a parametrization is derived. Relations to the 4-square identity are discussed which leads also to the N-dimensional case. The initial 3D- and 4D-Pythagorean numbers are explicitly calculated up to d<sup>2</sup>, respectively, e<sup>2</sup>. 展开更多
关键词 Number Theory Pythagorean Triples Tesseract 4-Square Identity Diophantine Equation
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Graphene-calcium carbonate coating to improve the degradation resistance and mechanical integrity of a biodegradable implant
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作者 Lokesh Choudhary Parama Chakraborty Banerjee +5 位作者 R.K.Singh Raman Derrek E.Lobo Christopher D.Easton Mainak Majumder Frank Witte Jörg F.Löffler 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期394-404,共11页
Biodegradable implants are critical for regenerative orthopaedic procedures,but they may suffer from too fast corrosion in human-body environment.This necessitates the synthesis of a suitable coating that may improve ... Biodegradable implants are critical for regenerative orthopaedic procedures,but they may suffer from too fast corrosion in human-body environment.This necessitates the synthesis of a suitable coating that may improve the corrosion resistance of these implants without compromising their mechanical integrity.In this study,an AZ91 magnesium alloy,as a representative for a biodegradable Mg implant material,was modified with a thin reduced graphene oxide(RGO)-calcium carbonate(CaCO_(3))composite coating.Detailed analytical and in-vitro electrochemical characterization reveals that this coating significantly improves the corrosion resistance and mechanical integrity,and thus has the potential to greatly extend the related application field. 展开更多
关键词 Graphene coating Biodegradable implant HYDROXYAPATITE Corrosion Magnesium alloy
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基于VSD框架的滇中城市群绿色建筑经济脆弱性测度研究
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作者 徐郁竺 张军 +2 位作者 杨耀宁 曾泽伟 徐浩 《科学与管理》 2024年第3期95-102,共8页
绿色建筑经济是实现“双碳”和“中国式现代化”的有效途径,其评价带有技术性、经济性和社会性等多因素。本研究选取滇中城市群为对象,以VSD框架模型为基础,提出体现经济发展-生态环境-社会认知耦合系统的“暴露性、敏感性、适应性”三... 绿色建筑经济是实现“双碳”和“中国式现代化”的有效途径,其评价带有技术性、经济性和社会性等多因素。本研究选取滇中城市群为对象,以VSD框架模型为基础,提出体现经济发展-生态环境-社会认知耦合系统的“暴露性、敏感性、适应性”三要素二十四子项的绿色建筑经济脆弱性评价指标体系。并通过定性定量相结合的方法,进行脆弱性分析。研究结果表明,滇中四州市绿色建筑经济脆弱性指数有明显差异:昆明脆弱性最低,即发展绿色建筑产业条件较好;楚雄脆弱性最高,发展条件最弱;玉溪与曲靖次之;整体呈现“中间低四周高”的空间格局。基于此,对各州市针对不同分项评价和短板提出参考建议。 展开更多
关键词 绿色建筑 脆弱性 VSD框架 评价体系
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德国科普发展情况概述
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作者 桂潇璐 《科学教育与博物馆》 2024年第1期98-101,共4页
在德国,科学活动很早就融入人们的社会生活,它们通过传播科学知识,加强公众参与和体验,广受社会欢迎。德国政府对科普非常重视,主导并支持了多项重要科学活动的开展。选取了较为主要的一些科普手段进行介绍,旨在为德国科学传播活动的做... 在德国,科学活动很早就融入人们的社会生活,它们通过传播科学知识,加强公众参与和体验,广受社会欢迎。德国政府对科普非常重视,主导并支持了多项重要科学活动的开展。选取了较为主要的一些科普手段进行介绍,旨在为德国科学传播活动的做法、形式和特点提供概览。 展开更多
关键词 德国 科学传播 科普活动 教育 研究 公众
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文化互鉴与民族认同:德法词汇交流考
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作者 张皓莹 林琳 《红河学院学报》 2024年第3期87-92,共6页
语言是社会变迁之镜与文化的载体,也是构建集体身份认同的基本依据。德法词汇交流的历时与共时比较揭示了非语言学(政治、经济、文化等)因素在中世纪以来法语占输出地位的词汇交流格局的形成和巩固中所起的关键作用。法语外来词通常以... 语言是社会变迁之镜与文化的载体,也是构建集体身份认同的基本依据。德法词汇交流的历时与共时比较揭示了非语言学(政治、经济、文化等)因素在中世纪以来法语占输出地位的词汇交流格局的形成和巩固中所起的关键作用。法语外来词通常以“自上而下”的途径借入德语,而德语外来词则大多“自下而上”借入法语,导致二者在语义范围、色彩义、融合度等方面的诸多差异。接受国语言纯净运动与近现代民族主义话语实践的联系既佐证了非语言学因素的决定性作用和语言的身份认同功能,也为当今时代提供了借鉴。 展开更多
关键词 外来词 德语 法语 词汇交流 语言纯净运动
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Ashtekar-Kodama Gravity as a Classical and Quantum Extension of Loop Quantum Gravity
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作者 Jan Helm 《Journal of Modern Physics》 2024年第6期864-937,共74页
This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and i... This paper presents a new theory of gravity, called here Ashtekar-Kodama (AK) gravity, which is based on the Ashtekar-Kodama formulation of loop quantum gravity (LQG), yields in the limit the Einstein equations, and in the quantum regime a full renormalizable quantum gauge field theory. The three fundamental constraints (hamiltonian, gaussian and diffeomorphism) were formulated in 3-dimensional spatial form within LQG in Ashtekar formulation using the notion of the Kodama state with positive cosmological constant Λ. We introduce a 4-dimensional covariant version of the 3-dimensional (spatial) hamiltonian, gaussian and diffeomorphism constraints of LQG. We obtain 32 partial differential equations for the 16 variables E<sub>mn</sub> (E-tensor, inverse densitized tetrad of the metric) and 16 variables A<sub>mn</sub> (A-tensor, gravitational wave tensor). We impose the boundary condition: for large distance the E-generated metric g(E) becomes the GR-metric g (normally Schwarzschild-spacetime). The theory based on these Ashtekar-Kodama (AK) equations, and called in the following Ashtekar-Kodama (AK-) gravity has the following properties. • For Λ = 0 the AK equations become Einstein equations, A-tensor is trivial (constant), and the E-generated metric g(E) is identical with the GR-metric g. • When the AK-equations are developed into a Λ-power series, the Λ-term yields a gravitational wave equation, which has only at least quadrupole wave solutions and becomes in the limit of large distance r the (normal electromagnetic) wave equation. • AK-gravity, as opposed to GR, has no singularity at the horizon: the singularity in the metric becomes a (very high) peak. • AK-gravity has a limit scale of the gravitational quantum region 39 μm, which emerges as the limit scale in the objective wave collapse theory of Gherardi-Rimini-Weber. In the quantum region, the AK-gravity becomes a quantum gauge theory (AK quantum gravity) with the Lie group extended SU(2) = ε-tensor-group(four generators) as gauge group and a corresponding covariant derivative. • AK quantum gravity is fully renormalizable, we derive its Lagrangian, which is dimensionally renormalizable, the normalized one-graviton wave function, the graviton propagator, and demonstrate the calculation of cross-section from Feynman diagrams. 展开更多
关键词 Quantum Gravity Loop Quantum Gravity General Relativity Gravitational Wave Gauge Field Theory Graviton Hamiltonian Constraint Gaussian Constraint Diffeomorphism Constraint
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A New Version of the Lambda-CDM Cosmological Model, with Extensions and New Calculations
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作者 Jan Helm 《Journal of Modern Physics》 2024年第2期193-238,共46页
This article gives a state-of-the-art description of the cosmological Lambda-CDM model and in addition, presents extensions of the model with new calculations of background and CMB functions. Chapters 1-4 describe the... This article gives a state-of-the-art description of the cosmological Lambda-CDM model and in addition, presents extensions of the model with new calculations of background and CMB functions. Chapters 1-4 describe the background part of the model, i.e. the evolution of scale factor and density according to the Friedmann equations, and its extension, which results in a correction of the Hubble parameter, in agreement with new measurements (Cepheids-SNIa and Red-Giants). Based on this improved background calculation presented in chapters 5-9 the perturbation part of the model, i.e. the evolution of perturbation and structure according to the perturbed Einstein equations and continuity-Euler equations, and the power spectrum of the cosmic microwave background (CMB) is calculated with a new own code. 展开更多
关键词 Lambda-DCM Friedmann Equations CMB Metric Perturbation Hubble Parameter
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Calculation of the Standard Model Parameters and Particles Based on a SU(4) Preon Model
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作者 Jan Helm 《Journal of Modern Physics》 2024年第1期64-124,共61页
This paper describes an extension and a new foundation of the Standard Model of particle physics based on a SU(4)-force called hyper-color, and on preon subparticles. The hyper-color force is a generalization of the S... This paper describes an extension and a new foundation of the Standard Model of particle physics based on a SU(4)-force called hyper-color, and on preon subparticles. The hyper-color force is a generalization of the SU(2)-based weak interaction and the SU(1)-based right-chiral self-interaction, in which the W-and the Z-bosons are Yukawa residual-field-carriers of the hyper-color force, in the same sense as the pions are the residual-field-carriers of the color SU(3) interaction. Using the method of numerical minimization of the SU(4)-action based on this model, the masses and the inner structure of leptons, quarks and weak bosons are calculated: the mass results are very close to the experimental values. We calculate also precisely the value of the Cabibbo angle, so the mixing matrices of the Standard model, CKM matrix for quarks and PMNS matrix for neutrinos can also be calculated. In total, we reduce the 29 parameters of the Standard Model to a total of 7 parameters. 展开更多
关键词 SU(4) Generalization of Weak Interaction Extension of Standard Model Numerical Minimization of Action Hyper-Color Preon
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