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考虑焊接残余应力的桅杆结构拉耳节点风致疲劳裂纹萌生寿命评定 被引量:7
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作者 王文利 瞿伟廉 皮永林 《土木工程学报》 EI CSCD 北大核心 2010年第S2期22-27,共6页
提出对评定桅杆结构拉耳节点焊缝处的裂纹萌生累积疲劳损伤程度的方法。在建立桅杆结构拉耳节点风致应力场的多尺度分析方法的基础上,考虑拉耳节点的焊接残余应力,用基于临界面法的应变疲劳分析方法进行在焊接残余应力和纤绳外荷载双重... 提出对评定桅杆结构拉耳节点焊缝处的裂纹萌生累积疲劳损伤程度的方法。在建立桅杆结构拉耳节点风致应力场的多尺度分析方法的基础上,考虑拉耳节点的焊接残余应力,用基于临界面法的应变疲劳分析方法进行在焊接残余应力和纤绳外荷载双重作用下的累积疲劳损伤量的计算,然后依据Mason-coffin公式及Miner疲劳累积损伤准则估算桅杆结构纤绳连接拉耳各不同风向不同平均风速作用下的多轴疲劳累积损伤,由总损伤计算出裂纹萌生寿命。 展开更多
关键词 桅杆结构拉耳 焊接残余应力 裂纹萌生 疲劳寿命
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四立柱式平板硫化机拉耳处应力分析及结构改进 被引量:2
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作者 孟兆明 李杰 代博兴 《橡胶工业》 CAS 2015年第10期618-621,共4页
传统四立柱式平板硫化机底座采用铸铁材料铸造、底座拉耳处通常采用翻砂口下置式结构,因材料分布不合理、底座拉耳抗拉能力较低,导致出现底座拉耳处断裂的现象。通过常规应力分析与ANSYS建模分析,对比下置式与上置式翻砂口底座拉耳处应... 传统四立柱式平板硫化机底座采用铸铁材料铸造、底座拉耳处通常采用翻砂口下置式结构,因材料分布不合理、底座拉耳抗拉能力较低,导致出现底座拉耳处断裂的现象。通过常规应力分析与ANSYS建模分析,对比下置式与上置式翻砂口底座拉耳处应力分布规律。结果表明,充分利用铸铁的抗拉能力远小于抗压能力这一特性,将拉耳处翻砂口改为上置式结构,能够有效地改善底座拉耳的受力,防止底座在拉耳处断裂。 展开更多
关键词 平板硫化机 底座 底座拉耳 ANSYS分析 翻砂口
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基于应变测量的桅杆结构拉耳焊缝损伤识别
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作者 王雪亮 谭柱 +1 位作者 王小丽 刘晖 《建筑科学与工程学报》 CAS 北大核心 2017年第2期79-85,共7页
基于桅杆结构拉耳表面应变对其焊缝裂纹扩展长度的敏感度分析,提出了桅杆结构拉耳焊缝损伤的两级模糊模式识别方法,并通过试验研究进行验证。采用有限元模拟建立了拉耳索力-关键点应变-焊缝裂纹扩展长度的模糊模式库;对16个不同裂纹长... 基于桅杆结构拉耳表面应变对其焊缝裂纹扩展长度的敏感度分析,提出了桅杆结构拉耳焊缝损伤的两级模糊模式识别方法,并通过试验研究进行验证。采用有限元模拟建立了拉耳索力-关键点应变-焊缝裂纹扩展长度的模糊模式库;对16个不同裂纹长度的拉耳模型进行试验,以实测拉耳表面关键点应变为待识别样本,采用模糊模式识别方法对索力及焊缝裂纹扩展长度进行分步识别。结果表明:模糊数据库中的模拟数据能够反映拉耳的实际受力状态,识别焊缝裂纹扩展长度与实际裂纹长度具有较好的吻合度;对于不同索力及裂纹长度,识别焊缝裂纹扩展长度的误差在1mm之内,最大隶属度均大于0.8,识别峰值明显;该识别技术具有可行性,是实现桅杆结构损伤智能识别的一种有效手段。 展开更多
关键词 桅杆结构 焊缝裂纹扩展长度 模糊模式识别 拉耳应变
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清晨拉耳净三窍
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作者 韩振奎 《家庭医药(就医选药)》 2007年第10期50-50,共1页
“拉耳”,可防止老人耳聋,令人耳聪延年。此法操作简单,每天清晨睡醒后,不忙起床,静卧5分钟,坐起后先叩齿(上下牙相互叩齿),两腮作漱口状,使唾液满口。然后咽下;同时鼻吸气后闭气一刻,右手从头上牵拉左耳14次,左手从头上... “拉耳”,可防止老人耳聋,令人耳聪延年。此法操作简单,每天清晨睡醒后,不忙起床,静卧5分钟,坐起后先叩齿(上下牙相互叩齿),两腮作漱口状,使唾液满口。然后咽下;同时鼻吸气后闭气一刻,右手从头上牵拉左耳14次,左手从头上牵拉右耳12次。 展开更多
关键词 叩齿 拉耳 清晨 老年人 长寿
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一种异形拉耳的精密车削工艺
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作者 王德廷 郭东亮 +3 位作者 赵怡 李昂 姚亚超 王元军 《机械工程师》 2020年第5期140-141,共2页
针对一种异形拉耳零件装夹定位困难、刀具磨损严重、切削加工过程中易变形等问题,制定合理的车削加工工艺方案,设计适宜的车床组合夹具,选择合适的刀具类型,实现了拉耳的可靠装夹,保证了异形拉耳零件的高精度要求。
关键词 异形拉耳 可靠装夹 组合夹具
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拉深中织构系数对立方晶粒正交板材制耳的影响
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作者 岳文霞 《材料导报》 EI CAS CSCD 北大核心 2012年第6期134-136,共3页
板材在冲深过程中由于材料本身的各向异性而引起制耳,这种情况使得材料加工中多一道工序,而且造成材料的浪费,增加成品的造价。引入取向分布函数和织构系数,说明正交板材的各向异性仅与织构系数c040、c240、c440有关,建立正交板材冲深... 板材在冲深过程中由于材料本身的各向异性而引起制耳,这种情况使得材料加工中多一道工序,而且造成材料的浪费,增加成品的造价。引入取向分布函数和织构系数,说明正交板材的各向异性仅与织构系数c040、c240、c440有关,建立正交板材冲深过程中相对径向应变与织构系数的关系式,定量说明制耳与织构间的关系。计算了几种典型织构的相对径向应变,并通过调整各织构组分的比例,达到最小制耳的比例。 展开更多
关键词 深制织构系数正交板材立方晶粒
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刮板输送机输煤槽拉移耳形状优化 被引量:3
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作者 穆润青 贾海朋 +2 位作者 刘波 郄彦辉 李晓雷 《煤矿机械》 北大核心 2009年第1期5-7,共3页
对某型号刮板输送机输煤槽拉移耳进行形状优化设计,获得"L"形拉移耳。通过形状优化设计,改进了原拉移耳拉孔的形状,改善了拉孔处的受力状况,减少了拉孔处的应力水平,并且使应力分布均匀化。实践证明,这种形状拉移耳能够减少... 对某型号刮板输送机输煤槽拉移耳进行形状优化设计,获得"L"形拉移耳。通过形状优化设计,改进了原拉移耳拉孔的形状,改善了拉孔处的受力状况,减少了拉孔处的应力水平,并且使应力分布均匀化。实践证明,这种形状拉移耳能够减少零件的失效率,提高工作的可靠性。 展开更多
关键词 结构优化 有限元分析 形状优化 输煤槽
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压缩机壳体拉深凸耳和缺料的影响因素及控制
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作者 胡开广 杨业 +3 位作者 黄旭 武巧玲 郑学斌 郑春海 《锻压技术》 CAS CSCD 北大核心 2023年第6期69-75,共7页
针对压缩机壳体用酸洗板SPHC低碳铝镇静钢在冲压过程中的拉深凸耳及其导致的缺料问题,首先,根据仿真建模和拉深凸耳的产生原因,分析了压边力、摩擦因数、坯料形状、模具间隙、板料厚度和各向异性因素对凸耳的影响,结果显示,坯料形状和... 针对压缩机壳体用酸洗板SPHC低碳铝镇静钢在冲压过程中的拉深凸耳及其导致的缺料问题,首先,根据仿真建模和拉深凸耳的产生原因,分析了压边力、摩擦因数、坯料形状、模具间隙、板料厚度和各向异性因素对凸耳的影响,结果显示,坯料形状和各向异性是造成压缩机壳体拉深凸耳的主要因素。然后,通过变换不同的r_(0)、r_(45)和r_(90)值,发现当dr_(max)<0.45时,可有效改善压缩机壳体由于拉深凸耳所导致的最终成形边缺料问题,且dr_(max)越大,缺料问题越明显。最后,通过轧制工艺优化改善了钢卷边部与中部的均匀性,使拉深凸耳得到了有效控制,并针对拉深缺料问题提出了两种坯料优化方案,并给出了两种方案的缺料尺寸与补料尺寸的关系。该研究可为解决压缩机壳体拉深凸耳和缺料问题提供有效的参考依据。 展开更多
关键词 酸洗板 压缩机壳体 深凸 缺料 各向异性 坯料形状
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焊接残余应力对桅杆节点板风致疲劳损伤的影响 被引量:1
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作者 王文利 杨家胜 +1 位作者 何杰 瞿伟廉 《人民长江》 北大核心 2014年第5期95-98,110,共5页
为了定量评定残余应力对疲劳损伤的影响,运用ANSYS有限元软件进行了焊接温度场和焊接应力场的模拟,并通过改变加载顺序、预热等方法得到了不同消残比例的焊接残余应力,用基于临界面法进行了考虑不同消残比例的拉耳子结构风致疲劳累积损... 为了定量评定残余应力对疲劳损伤的影响,运用ANSYS有限元软件进行了焊接温度场和焊接应力场的模拟,并通过改变加载顺序、预热等方法得到了不同消残比例的焊接残余应力,用基于临界面法进行了考虑不同消残比例的拉耳子结构风致疲劳累积损伤分析。结果发现在同一消除焊接残余应力的比例下,疲劳损伤以180°风向角呈对称变化,在90°风向角时,疲劳累积损伤最小,在0°风向角时,疲劳累积损伤值最大;随着焊接残余应力消除比例的增大,所对应的疲劳累积损伤越小。研究表明,在基于临界面法的桅杆拉耳子结构焊接节点的疲劳累积损伤计算中,引进平均应力这一参数可以很好地定量评估不同消残比例、不同风向、不同风速等级下的损伤程度。 展开更多
关键词 焊接残余应力 消残 桅杆拉耳 临界面法 疲劳累积损伤
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叶片导流式组合造型双NURBS曲线插补数控加工 被引量:1
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作者 阴俊霞 《工具技术》 2018年第1期97-101,共5页
针对不能用解析法定义的轴流式叶片的复杂曲面,按导流方向将其划分成多张流向一致的曲面,采用双NURBS曲线插补方式,克服了传统数控系统直线、圆弧插补的局限性。以叶片旋转轴线和法兰端面作为定位基准,在五轴数控龙门铣床上采用焊接拉... 针对不能用解析法定义的轴流式叶片的复杂曲面,按导流方向将其划分成多张流向一致的曲面,采用双NURBS曲线插补方式,克服了传统数控系统直线、圆弧插补的局限性。以叶片旋转轴线和法兰端面作为定位基准,在五轴数控龙门铣床上采用焊接拉耳、千斤顶和拉杆拉压夹紧工件,运用"3+2"五轴联动、按导流方向走刀的数控加工方法。结果表明,加工出的叶片曲面几何形状精度显著提高,颠覆了"砂型铸造、砂轮铲磨、立体样板检测"的传统加工方法,生产效率提高了5倍以上。 展开更多
关键词 叶片曲面 导流方向 NURBS插补 焊接拉耳 NGC系统 五轴数控
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新型同步防转螺旋扣设计和应用 被引量:1
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作者 彭敏林 罗莉莉 赵健 《中国重型装备》 2020年第1期3-5,共3页
针对起重运输防风拉杆使用的常规螺旋扣,设计了一种新型重型同步防转螺旋扣装置,只需固定一端即可操作左右螺纹同时伸长和缩短,通过实际应用表明,同步防转螺旋扣操作简便灵活,安全可靠,适用范围广。
关键词 螺旋扣 螺杆 滑套 滑杆 拉耳
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一种刮板输送机的升级改造与应用 被引量:1
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作者 韩振华 《机械工程师》 2022年第10期130-132,共3页
原矿方刮板输送机与采煤机、单体支柱配套,组成工作面“高档普采”装备,工作效率低,安全隐患高。通过改造设计,将原有刮板输送机改造为与液压支架配套的“综采”刮板输送机,并综合多种方案比较,最终确定一种可靠、可行性强的方案。通过... 原矿方刮板输送机与采煤机、单体支柱配套,组成工作面“高档普采”装备,工作效率低,安全隐患高。通过改造设计,将原有刮板输送机改造为与液压支架配套的“综采”刮板输送机,并综合多种方案比较,最终确定一种可靠、可行性强的方案。通过应用,实现了工作面顶板支撑、输送机推移、拉架等工序的机械化,大大改善了工作面的工作条件。 展开更多
关键词 综采配套 刮板输送机 改造设计 拉耳 垂直布置
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Influence of blank holder type on drawability of 5182-O aluminum sheet at room temperature 被引量:2
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作者 王游根 黄光胜 +4 位作者 刘定凯 陈琳 韩廷状 彭建 潘复生 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第5期1251-1258,共8页
To study the influence of blank holder type on the drawability of 5182-O aluminum sheet at room temperature, the flat blank holder and curved blank holder were employed during the deep drawing process. The microstruct... To study the influence of blank holder type on the drawability of 5182-O aluminum sheet at room temperature, the flat blank holder and curved blank holder were employed during the deep drawing process. The microstructures were characterized by optical microscopy (OM). The results reveal that the limiting drawing ratio (LDR) of 5182-O aluminum alloy sheet is 1.7 using the flat blank holder. The drawn cup have severe earring. Compared with using flat blank holder, the LDR of 5182-O aluminum alloy sheet is enhanced to 2.0 using curved blank holder. In addition, the earring ratio also reduces and flange wrinkling is prevented when the curved blank holder is used. These are due to a more uniform sheet flow in different directions with curved blank holder. 展开更多
关键词 5182-O aluminum alloy deep drawing blank holder earring WRINKLING
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General Overview of Olive Cultivation in the Southeastern Anatolia Region
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作者 Ebru Sakar Hulya Unver +1 位作者 Zeynep Mujde Sakar Akgul TaS 《Journal of Environmental Science and Engineering(B)》 2014年第5期256-263,共8页
The olive is an agricultural product that can be processed into olive oil and table olives. In addition, the by-products of olive production also find many uses. Due to the specific climatic requirements of the olive ... The olive is an agricultural product that can be processed into olive oil and table olives. In addition, the by-products of olive production also find many uses. Due to the specific climatic requirements of the olive tree, olives are primarily cultivated in Mediterranean countries. The olive tree is widely distributed across Turkey. The Aegean, Marmara, Mediterranean, and southeastern Anatolia regions are the leading olive-producing regions of Turkey. Similar to most olive-cultivating countries around the world, the majority (nearly 73%) of the olives produced in Turkey are processed into olive oil. The average annual production of olive oil in Turkey is 150,000 t. The leading olive-producing provinces in the southeastern Anatolia region are, in descending order of importance, Gaziantep, Kills, Sanllurfa, Mardin, Adlyaman, Slrnak, and Diyarbaklr. 展开更多
关键词 OLIVE production southeast Anatolia region.
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An Econometric Analysis of Cotton Production Technologies in Harran Plain, Turkey: Translog versus Cobb-Douglas Functions
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作者 T. Isgin R. Ozel +1 位作者 A. Bilgic S. Ipekcioglu 《Journal of Agricultural Science and Technology(B)》 2011年第3期420-427,共8页
This research explores the question of how the three production factors, capital, labor, and land may impact the current level of cotton output on the Harran Plain, a major cotton production area in Turkey. The object... This research explores the question of how the three production factors, capital, labor, and land may impact the current level of cotton output on the Harran Plain, a major cotton production area in Turkey. The objective of this paper is to estimate a Translog production function and compare the results to those from a Cobb-Douglas specification. Nested tests we performed resulted in the conclusion that the constant returns to scale, weak separability and Cobb-Douglas hypotheses are all satisfied. Thus the Cobb-Douglas specification is a superior functional form yielding results more robust than those from the translog model. Dwelling on Cobb-Douglas estimation results, farm size is found the most influential variable determining cotton output, followed by the variable representing capital as the second influential. Results also demonstrate that the returns-to-scale parameter calculated for this sample is not statistically different from unity, suggesting that cotton production technology in this region exhibits constant returns to scale. This result is consistent with current literature findings that render support to an inverse relationship between farm size and productivity in developing countries. 展开更多
关键词 Cotton translog model cobb-douglas model weak separability TURKEY constant returns to scale.
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Turkish Van Cat and Turkish Angora Cat: A Review
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作者 Bahattin Cak 《Journal of Agricultural Science and Technology(A)》 2017年第3期151-159,共9页
Turkish Van and Angora cats are one of most important genetic resources in Turkey. The study aimed to evaluate some morphological properties and also behavioural characteristics in both Turkish Van and Angora cats. Th... Turkish Van and Angora cats are one of most important genetic resources in Turkey. The study aimed to evaluate some morphological properties and also behavioural characteristics in both Turkish Van and Angora cats. This research used both literature and the records from the Van Cat Home at Van Cats Research Centre of Yuzuncu Yil University for Turkish Van cats, as well as literature information for Turkish Angora cat. Van cats which have a special place among world cat races have gained appreciation of people with their original eye colors, long white hair and affectionate attitudes. Origin of Turkish Angora cat breeding in Turkey is Ankara province. Angora cat is strong, energetic, kind, known as a moderately long silky haired cat. According to the results of this study and literature, withers height and body length of Turkish Van cat are higher than the Turkish Angora cat, while tale length and breast girth of Turkish Angora cat are higher than the Turkish Van cat. Body weight (g) of female Turkish Angora cat is heavier than the Turkish Van cat, but male Turkish Van cat is heavier than Turkish Angora cat. 展开更多
关键词 Turkish Van cat Turkish Angora cat morphological traits.
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Application of Fiber Bragg Grating for Determining Positions of Gas Absorption Lines
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作者 韩文念 汪曣 +4 位作者 马凤 刘琨 贾大功 刘铁根 张红霞 《Transactions of Tianjin University》 EI CAS 2010年第5期373-375,共3页
Fiber Bragg grating(FBG) is used as a wavelength reference device to calibrate the position of gas absorption peak in the intracavity absorption gas sensor(ICAGS) based on erbium-doped fiberring laser.This system can ... Fiber Bragg grating(FBG) is used as a wavelength reference device to calibrate the position of gas absorption peak in the intracavity absorption gas sensor(ICAGS) based on erbium-doped fiberring laser.This system can detect both the reflectance spectrum of FBGs and absorption spectrum of measured gas during a single wavelength sweeping process by linearly varying the driving voltage of optic filter.The voltages corresponding to center wavelength positions of four FBGs in the spectrum are determined through ... 展开更多
关键词 fiber Bragg grating gas absorption erbium-doped fiber Gaussian fitting
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Present Situation and Future of Animal Fiber Production in Turkey: A Review
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作者 Gursel Dellal Feryal Soylemezoglu +3 位作者 Zeynep Erdogan Erkan Pehlivan Ozdal Koksal Selcuk Seckin Tuncer 《Journal of Life Sciences》 2014年第2期192-200,共9页
Primarily the production of wool, mohair, silk, goat coarse hair and cashmere fibers is made in Turkey. However, there has been a significant level of decrease in the production of these fibers for many years. The fac... Primarily the production of wool, mohair, silk, goat coarse hair and cashmere fibers is made in Turkey. However, there has been a significant level of decrease in the production of these fibers for many years. The factors mainly causing this decrease can be said to include rapid increase in the use of chemical fibers, changes in fashion which have negative impacts on the consumption these fibers and systematic problems which negatively affect the production of sheep, Angora goat, hair goat and silkworm. However although the production resources are continuing to decrease, Turkey still has a significant level of animal fiber production potential. Attainment of a more effective utilization of this potential will significantly contribute to the establishment of a sustainable textile industry and rural development and the preservation and development of folkloric culture and native farm animals which produce fibers. 展开更多
关键词 TURKEY animal fiber textile industry rural development.
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Turkish Diplomacy: Becoming a Model for the Middle East
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作者 Mesut Hakkl Cabin 《Journalism and Mass Communication》 2011年第3期213-225,共13页
Arabs are rising up against the old totalitarian regimes throughout the whole region, from Tunisia to Bahrain and North Africa, covering the Persian Gulf axes. The demonstrations were triggered by the social disconten... Arabs are rising up against the old totalitarian regimes throughout the whole region, from Tunisia to Bahrain and North Africa, covering the Persian Gulf axes. The demonstrations were triggered by the social discontent over the lack of democracy and political freedom, not to mention the corruption, the high unemployment rate among the young population, and poor living conditions for the general public. 1 fear that the Arab revolutions could turn into uncontrollable clashes, leading to further chaos and Islamic radicalization. Turkey has been emerging as an important diplomatic actor in the Arab Street. My argument is based upon the question Can Turkey be a model for the Middle East, following a century-long bumpy-ride on the road to a full democracy. Under the neo-realistic view Turkey is a secular democratic state, the North Atlantic Treaty Organization (NATO) member and also candidate for the EU. In this paper we try, briefly, to understand the possible role of Turkish diplomacy with the Middle East and the Great Powers within international political dimensions. 展开更多
关键词 TURKEY Turkish Diplomacy MODEL revolution in the Middle East Arab Spring
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海上漂来的殖民者——从1847年朝法“丁未事件”看近代东西接触的一个侧面
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作者 田兆心 路伟东 《暨南史学》 2023年第2期193-212,共20页
1847年,寻求远东殖民利益的法国军舰因风漂到朝鲜古群山,得到朝鲜救助,月余始脱险。其间,双方通过笔谈问情的形式进行了反复沟通,这是朝法之间第一次官方层面的直接接触。法国高层、远东将领、传教士、中国通事、朝鲜地方官、中央官和... 1847年,寻求远东殖民利益的法国军舰因风漂到朝鲜古群山,得到朝鲜救助,月余始脱险。其间,双方通过笔谈问情的形式进行了反复沟通,这是朝法之间第一次官方层面的直接接触。法国高层、远东将领、传教士、中国通事、朝鲜地方官、中央官和儒者等直接或间接参与事件的各方共同形塑了该事件的面貌。通过考察他们之间的交流过程、沟通内容和利益诉求,本文试图展现潜隐于进步、殖民、近代化等宏大叙事之下,19世纪中期东西接触中具体而鲜活的一个侧面,从而为我们重新理解这些宏大议题提供更丰富的史实依据和更多元的观察视角。 展开更多
关键词 1847 朝法关系 东西接触 漂流
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