期刊文献+
共找到323篇文章
< 1 2 17 >
每页显示 20 50 100
越南Luc Yen矿区尖晶石常规宝石学及内含物特征研究
1
作者 陈彦宇 周征宇 +3 位作者 杨萧亦 刘奕岑 Dietmar Schwarz 陈亮 《中国宝玉石》 2023年第3期2-11,19,共11页
本文使用折射仪、荧光光谱仪、显微镜、拉曼光谱仪等多种测试仪器,对越南Luc Yen地区的尖晶石样品进行了常规宝石学特征及内含物的成分研究,为其产地鉴别提供理论依据。研究结果显示,越南Luc Yen地区尖晶石的折射率范围主要为1.716~1.7... 本文使用折射仪、荧光光谱仪、显微镜、拉曼光谱仪等多种测试仪器,对越南Luc Yen地区的尖晶石样品进行了常规宝石学特征及内含物的成分研究,为其产地鉴别提供理论依据。研究结果显示,越南Luc Yen地区尖晶石的折射率范围主要为1.716~1.718,在长波紫外光照射下大部分为弱~强的浅橙~红色荧光,短波紫外光下大部分为荧光惰性;样品相对密度约为3.63~3.98;显微观察可见固相包裹体、管状气液包裹体、网格状包裹体等包裹体,经拉曼光谱测试可确认的包裹体种类有八面体负晶包裹体、硬水铝石和CO2的拉长扁平负晶、金红石、磷灰石、锆石、方解石、阳起石、白云石、金云母、歪长石。 展开更多
关键词 尖晶石 Luc yen矿区 内含物 拉曼光谱 越南
下载PDF
基于偏离路径的煤矿水灾Yen-K最优路径算法
2
作者 张娜娜 《信息与电脑》 2023年第21期82-86,共5页
为矿井水灾提供最佳逃生路线,提高应急救援效率,首先引入当量长度,结合水流等巷道相关因素,求解到达安全地点的时间最短路径;其次根据一般矿井具有多个逃生出口的特性,提出一种基于偏离路径的煤矿水灾Yen-K最优路径算法,分别求出从源节... 为矿井水灾提供最佳逃生路线,提高应急救援效率,首先引入当量长度,结合水流等巷道相关因素,求解到达安全地点的时间最短路径;其次根据一般矿井具有多个逃生出口的特性,提出一种基于偏离路径的煤矿水灾Yen-K最优路径算法,分别求出从源节点到每个目标节点的前k则最优路径;最后按照长度大小排序求得的所有路径,并结合矿井具体实例选取所需的前若干条逃生路线。在MATLAB环境下,对文章算法与传统的Dijkstra算法、K最短路径(KShortestPaths,KSP)算法进行仿真对比分析,结果显示改进后的算法在求解矿井水灾逃生最优路径时更具准确性和实用性。 展开更多
关键词 当量长度 K最优路径(KSP) yen算法 矿井水灾
下载PDF
错畸形患者YEN角的测量研究
3
作者 朱晓红 侯晓利 +2 位作者 王培军 刘杰 韩晶莹 《实用口腔医学杂志》 CAS CSCD 北大核心 2012年第5期653-654,共2页
用YEN角头影测量方法描述上下颌骨间的矢状向关系。将152例治疗前头颅侧位片分为安氏Ⅰ类(69例)、安氏Ⅱ类(43例)、安氏Ⅲ类(40例)3组,使用3个骨性标志点:S点(蝶鞍中点)、M点(前颌骨的中心点)和G点(下颌骨骨性联合的中心点)。3种安氏错... 用YEN角头影测量方法描述上下颌骨间的矢状向关系。将152例治疗前头颅侧位片分为安氏Ⅰ类(69例)、安氏Ⅱ类(43例)、安氏Ⅲ类(40例)3组,使用3个骨性标志点:S点(蝶鞍中点)、M点(前颌骨的中心点)和G点(下颌骨骨性联合的中心点)。3种安氏错类型患者YEN角值(°)分别为125.37±3.24、120.07±4.78和134.75±5.39,差异有统计学意义(P<0.05);性别间无显著差异。YEN角在122°~129°间为Ⅰ类骨面型。 展开更多
关键词 yen 错 矢状向不调 头影测量
下载PDF
YEN21新型无磁金属陶瓷材料 被引量:1
4
作者 宾建林 《湖南冶金》 2003年第3期10-10,共1页
关键词 yen21 无磁金属陶瓷材料 硬度 耐磨性 物理性能 机械性能
下载PDF
一种基于光网络的搜索K最短路径的Yen改进算法 被引量:2
5
作者 王为亮 谭绍锋 肖雁鹏 《光通信技术》 2022年第4期101-106,共6页
为提高K最短路径(KSP)算法中路径计算的效率和规划路径的相异性,首先介绍了光网络的图论描述、路径相近性定义和平行边的理论,然后对KSP问题和传统Yen算法进行了简单描述,分析了KSP算法研究现状,最后提出一种Yen改进算法,重点阐述了相... 为提高K最短路径(KSP)算法中路径计算的效率和规划路径的相异性,首先介绍了光网络的图论描述、路径相近性定义和平行边的理论,然后对KSP问题和传统Yen算法进行了简单描述,分析了KSP算法研究现状,最后提出一种Yen改进算法,重点阐述了相异路径计算策略和Yen改进算法实现步骤。通过构建与实际生产环境类似的拓扑图,对Yen改进算法进行验证,并与其它算法进行路径相近性和计算时间对比,证明了其有效性。 展开更多
关键词 K-最短路径 yen算法 光网络 相异路径
下载PDF
Bill YEN——The Stanford Years 1962~1965 被引量:1
6
作者 George F Imbusch 《发光学报》 EI CAS CSCD 北大核心 2008年第4期613-616,共4页
<正>After a boyhood spentin a number of countries,Bill Yen enrolled as an undergraduate student at theUniversity of Redlands,a private liberal arts andsciences university located in southern California.He spent ... <正>After a boyhood spentin a number of countries,Bill Yen enrolled as an undergraduate student at theUniversity of Redlands,a private liberal arts andsciences university located in southern California.He spent the years 1952~1956 there,graduatingwith the BS degree in Physics.His postgraduatetraining 展开更多
关键词 “Bill yen 学生 学习生活 斯坦福大学 物理系
下载PDF
Development of Algorithm of Traditional Kei-Yen Game
7
作者 Lourembam Herojit Singh Pooja Sapra R. K. Brojen Singh 《Journal of Computer and Communications》 2018年第8期45-56,共12页
Manipuri traditional game Kei-Yen, which originates from the ancient Meitei mythological story, is a mind game between two players of different mindsets, one has the mindset of killing (Kei), whereas the other (Yen) h... Manipuri traditional game Kei-Yen, which originates from the ancient Meitei mythological story, is a mind game between two players of different mindsets, one has the mindset of killing (Kei), whereas the other (Yen) has the mindset of protecting itself and block the moves of Kei. We propose and develop an algorithm of this game by incorporating various possible logical tactics and strategies for a possible computer software of this game. Since this game involves various logical mind games, playing this game can improve our way of thinking, strategies, tricks and other skills related to mind game. In this play there is not the case of draw which means one has to win over the other at the end of the game. This game could become one of most interesting indoor national or international game. 展开更多
关键词 Kei-yen TRADITIONAL GAME ALGORITHM DEVELOPMENT
下载PDF
Ann Yen and Her Different Roles
8
作者 Wang Feng 《China & The World Cultural Exchange》 2005年第6期14-17,共4页
It is said that one's paintings always reflect himself. But Ann Yen seems to share only one similarity with plump ladies in her paintings -- both look relaxed and joyful. It was a happy experience to talk with Yen... It is said that one's paintings always reflect himself. But Ann Yen seems to share only one similarity with plump ladies in her paintings -- both look relaxed and joyful. It was a happy experience to talk with Yen. Her hearty laughing and sincere talking greatlv imoressed me. lust like those olumo ladies in her paintings. 展开更多
关键词 ANN yen 中国 画家 绘画风格 生活经历
下载PDF
Environmental factors control and climate change impact on forest type: Dong PraYa Yen-KhaoYai world heritage in Thailand
9
作者 Nathsuda Pumijumnong Paramate Payomrat +1 位作者 Jessada Techamahasaranont Surapol Panaadisai 《Natural Science》 2013年第1期135-143,共9页
Climate is a major determinant of global vegetation patterns and has a significant influence on the distribution and structure of forest ecosystems. Dong PraYa Yen-KhaoYai Forest Complex has been a UNESCO natural worl... Climate is a major determinant of global vegetation patterns and has a significant influence on the distribution and structure of forest ecosystems. Dong PraYa Yen-KhaoYai Forest Complex has been a UNESCO natural world heritage site since 2007, but little is known about its plant community. Our study aims to identify each plant community within the world heritage area and calculate its potential for carbon content. We determine both the relationship between forest type and both physio-chemical soil properties and climate change impact. We employed allometric equations to calculate aboveground biomass and both cluster analysis and canonical correspondence analysis (CCA) to examine the relationship between forest type and physiochemical soil properties. An equation for each physical parameter was used to predict the forest model. The climate scenario under A2 and B2 was applied to calculate future predominant forest types. Our results reveal that the forest ecosystems at Tab Lan (TL) have the highest species count (332 species) followed by Pang Srida (PD), KhaoYai (KY), Dong Yai (DY), and Tapraya (TY), with 293, 271, 169, and 99 species, respectively. We found KY to have the highest recorded carbon storage value at 2507.6 tC/ha followed by TL, PD, TY, and DY (1613.8, 1269.1, 844 and 810.7 tC/ha, respectively). Cluster analysis results indicated that the dominant species in each forest type is different. Moreover, CCA revealed that soil organic matter (SOM) and soil acid-base indicators are the best parameters to establish correlation for each forest type. Based on our results, future climate predictions show a negative impact on evergreen forests, but a positive one on deciduous ones. 展开更多
关键词 Carbon Content Dong PraYa yen- KhaoYai FOREST Complex Cluster Analysis CCA CLIMATE Change
下载PDF
Potential Forecast of Graphite ore Resources in Van Yen Area,Yen Bai
10
作者 Chi Cong Nguyen Xuan Truong Tran +1 位作者 Khac Hoang Giang Nguyen Thi Phuong Thanh Nguyen 《Journal of Geological Resource and Engineering》 2021年第2期51-60,共10页
Van Yen district,Yen Bai province belongs to the Red River zone,which is a promising area for graphite ore,however,the methodologies were applied to previous research,evaluation and forecast potential of graphite are ... Van Yen district,Yen Bai province belongs to the Red River zone,which is a promising area for graphite ore,however,the methodologies were applied to previous research,evaluation and forecast potential of graphite are still limited.Based on that reason,this paper introduces a method to forecast prospective zoning by using mathematical methods,remote sensing combined with GIS(geographic information system)technology.The results of the study are an important basis in research orientation,in mineral exploration and exploitation in a reasonable way in order to meet the demand of the graphite raw materials for domestic and industries abroad. 展开更多
关键词 Graphite ore resources Van yen ANN
下载PDF
Empirical Analysis of NATREX Model on Misalignment of Japanese Yen's Real Exchange Rate
11
作者 JIN Zhi-guo 《青岛大学学报(工程技术版)》 CAS 2007年第4期78-81,共4页
Using Natural Real Exchange Rate model and combining with actual economic situations in Japan,we set up equilibrium real exchange rate model of Japanese Yen.Based on the model we assess the misalignment and also analy... Using Natural Real Exchange Rate model and combining with actual economic situations in Japan,we set up equilibrium real exchange rate model of Japanese Yen.Based on the model we assess the misalignment and also analyze its reason since the beginning of Yen's fluctuation.Finally we get conclusions as follows: Yen/Dollar real exchange rate has always been fluctuating acutely.Overvaluation alternates with undervaluation,either of which may last three to five years.Japanese government's too much intervention in nominal exchange rate is a very important factor of the misalignment.Overvaluation does much negative effect on the economy,especially in a period when the economy shrinks due to lacking for domestic consumption demand.In that case,currency crisis will probably soon break out. 展开更多
关键词 经验主义 NATREX模型 日圆 汇兑标准 汇兑比率
下载PDF
业师和雇主眼中的吕彦直——一份1929年的珍贵史料
12
作者 赖德霖 《建筑师》 2024年第3期133-136,共4页
1928年10月中美协进会会刊《中国》杂志中发表的《南京孙逸仙博士墓》一文中有多个细节,涉及吕彦直建筑师在康奈尔大学学习建筑时的表现、他在毕业后去纽约茂旦事务所工作的介绍人、他在茂旦事务所接触到的一项重要工程、他对中国建筑... 1928年10月中美协进会会刊《中国》杂志中发表的《南京孙逸仙博士墓》一文中有多个细节,涉及吕彦直建筑师在康奈尔大学学习建筑时的表现、他在毕业后去纽约茂旦事务所工作的介绍人、他在茂旦事务所接触到的一项重要工程、他对中国建筑认知得以形成的契机、业师和雇主对他的评价,乃至茂飞对吕的杰作中山陵这一茂飞本人所提倡的适应性建筑的了解,无疑是关于吕彦直生平的一份珍贵史料。 展开更多
关键词 吕彦直 中山陵 中山纪念堂 茂飞 埃弗里特·米克斯 适应性中国建筑
下载PDF
Depreciation of the Yen and its Impact on the Chinese Economy——Interview with Yu Yongding,Director,Institute of World Econnomics and Politics,CASS
13
《China & World Economy》 SCIE 2002年第2期3-7,共5页
Since early January this year,the Japanese yen has beendepreciating steadily, from 128 and 129 to 130 yen perdollar,which is the lowest in the last 38 months. It seemsJapan is finally playing its exchange rate card af... Since early January this year,the Japanese yen has beendepreciating steadily, from 128 and 129 to 130 yen perdollar,which is the lowest in the last 38 months. It seemsJapan is finally playing its exchange rate card after fail-ing to revive its econmy through interest rate cuts andexpanding govemment expenditure. Do you think this"exchange rate card" can be the savior for Japan’seconomy? Is the yen depreciation the best choice to pre-vent its economy from falling further? 展开更多
关键词 Depreciation of the yen and its Impact on the Chinese Economy World CASS
原文传递
上海图书馆藏线装刻本《语言自迩集》考略
14
作者 宋桔 《图书馆杂志》 北大核心 2023年第3期114-122,129,共10页
《语言自迩集》(1867/1888/1903)是19世纪中期来华西人编撰的第一部学习北京官话口语的系统教材,在中西语言文化交流史上影响深远。据调查,除正式出版的三版洋装本外,《语言自迩集》部分中文内容还以线装刻本的形式存世,上海图书馆即藏... 《语言自迩集》(1867/1888/1903)是19世纪中期来华西人编撰的第一部学习北京官话口语的系统教材,在中西语言文化交流史上影响深远。据调查,除正式出版的三版洋装本外,《语言自迩集》部分中文内容还以线装刻本的形式存世,上海图书馆即藏有多个复本,且保存着珍贵的手写笔记资料。结合内容比对、周边文献查考及历史资料调查,确定了翻印该木刻本所依据的底本。同时,通过对木刻本上留存的朱记钤印、时人手写笔记等资料的分析,揭示了上海图书馆藏线装刻本的出版背景及当时徐家汇神学院内汉语学习者使用该书的情况,再现了19世纪中后期中西语言接触的生动画面。 展开更多
关键词 《语言自迩集》 刻本 手写笔记 徐家汇
下载PDF
日元汇率波动新态势
15
作者 颜泽洋 《Contemporary International Relations》 2023年第2期79-99,共21页
Concurrent with the interest rate hike by the Federal Reserve(Fed) at the beginning of 2022, the Japanese yen entered a fast track to depreciation. Since November 2022, however, as the Fed slowed its tightening pace a... Concurrent with the interest rate hike by the Federal Reserve(Fed) at the beginning of 2022, the Japanese yen entered a fast track to depreciation. Since November 2022, however, as the Fed slowed its tightening pace and as the Bank of Japan(BoJ)tweaked its monetary policy, the yen has regained some of the ground it lost. Overall, the yen has been characterized by strong volatility. The primary factor driving the fluctuations of the yen in the short term is the widening United States–Japan interest rate differential. From a mid-to-long-term perspective, the underlying reason behind the exchange rate movements of the yen is the BoJ’s monetary policy and the Japanese economy’s structural changes.The fluctuations of the yen are a mixed blessing for the Japanese economy;in the long run, however, they will do more harm than good. As for the world economy, turbulent yen fluctuations may trigger a fresh round of currency competition and disrupt the financial markets. Looking ahead, for long-term healthy economic development, Japan needs to cut down on its exchange rate dependence and restructure and upgrade its economy. 展开更多
关键词 Japanese yen exchange rate JAPAN economic structure
下载PDF
日元汇率剧烈波动与日本货币政策关系研究
16
作者 裴桂芬 樊悦 《东北亚学刊》 2023年第2期108-119,149,共13页
全球金融危机以来,日元汇率与货币政策关系是日本银行最棘手的问题。金融危机前后的日元升值和2021年以来日元急剧贬值期间,货币政策均成为被指责对象。日元升值背后是日美货币政策趋同引发日美利率差缩小和日元避险货币功能的强化,而... 全球金融危机以来,日元汇率与货币政策关系是日本银行最棘手的问题。金融危机前后的日元升值和2021年以来日元急剧贬值期间,货币政策均成为被指责对象。日元升值背后是日美货币政策趋同引发日美利率差缩小和日元避险货币功能的强化,而当前日元贬值主要源于日美货币政策分化带来的利率差扩大,同时作为非货币政策因素的日元避险货币功能减弱和国际收支状况恶化促进日元贬值,并影响日元汇率走势。 展开更多
关键词 日元汇率 货币政策 利率差 避险货币 国际收支赤字
下载PDF
近代对日汉语教材《华语跬步》北京话语音系统——兼与《语言自迩集》语音之观照
17
作者 邵燕梅 《现代语文》 2023年第7期4-11,共8页
《华语跬步》是清末民初日本汉语教学体现北京话语音系统的典型性教材,其编写彰显了日本近代汉语教育的重心由南京官话转向了北京官话。根据《华语跬步》所列出的声母类别和分析后的实际音值,清末民初北京话的声母系统(包括零声母)共有2... 《华语跬步》是清末民初日本汉语教学体现北京话语音系统的典型性教材,其编写彰显了日本近代汉语教育的重心由南京官话转向了北京官话。根据《华语跬步》所列出的声母类别和分析后的实际音值,清末民初北京话的声母系统(包括零声母)共有23个声母;韵母系统共有40个韵母,包括开口呼14个、齐齿呼11个、合口呼9个、撮口呼6个。根据《华语跬步》《语言自迩集》两部教材的描写与观照,清末民初北京话有阴平、阳平、上声、去声四个声调,其调型、调值亦与今北京话相同。《华语跬步》的音类描写与《语言自迩集》的音值描写互为观照,共同呈现出北京话声母、韵母、声调的系统面貌,该语音系统能够体现清末民初北京话的实际语音格局。 展开更多
关键词 《华语跬步》 北京话语音系统 清末民初 《语言自迩集》
下载PDF
具有多条最短路径的最短路问题 被引量:10
18
作者 王志坚 韩伟一 李一军 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2010年第9期1428-1431,共4页
尽管Dijkstra算法是解决正权单源点最短路问题公认的最好算法,但它仅能求得从源点到指定点的一条最短路径,为了给出从源点到指定点的所有最短路径,通过改进临时标号过程,得到了修正的Dijkstra算法.修正后的算法得到的不再是最短路径树,... 尽管Dijkstra算法是解决正权单源点最短路问题公认的最好算法,但它仅能求得从源点到指定点的一条最短路径,为了给出从源点到指定点的所有最短路径,通过改进临时标号过程,得到了修正的Dijkstra算法.修正后的算法得到的不再是最短路径树,而是最短路径图.相对于原算法,修正后的算法不仅更加简便,而且应用Yen算法能够按照边数由少到多的顺序罗列出所有的最短路径. 展开更多
关键词 算法 最短路问题 DIJKSTRA算法 yen算法
下载PDF
越南安沛铁矿伴生稀土资源开发利用
19
作者 张亮玖 潘务霞 +1 位作者 周慧荣 郭怀兵 《矿产综合利用》 CAS 北大核心 2023年第5期41-46,共6页
这是一篇冶金工程领域的论文。针对越南安沛地区某铁矿尾矿磁选后得到的含稀土富集物无法直接利用问题,采用硫酸焙烧工艺、萃取富集转型技术对其进行实验开发,考查硫酸焙烧、水浸、除杂、转型等过程的工艺参数对实验效果的影响,确定较... 这是一篇冶金工程领域的论文。针对越南安沛地区某铁矿尾矿磁选后得到的含稀土富集物无法直接利用问题,采用硫酸焙烧工艺、萃取富集转型技术对其进行实验开发,考查硫酸焙烧、水浸、除杂、转型等过程的工艺参数对实验效果的影响,确定较佳工艺技术条件。实验表明,采用酸矿比(体积∶质量)=0.7,焙烧温度250℃,焙烧时间2 h,浸出水∶矿=4进行焙烧和水浸,以除杂剂浓度0.1 g/mL,除杂终点pH值=4.2进行除杂,以O∶A=1.5~2进行5级逆流萃取,O∶A=10∶1进行5级逆流反萃,整体收率可达90.1%~92.88%,稀土浓度在1.5 mol/L左右,杂质铁、铝含量均低于100 mg/L,满足工业化应用的需求,实现对越南安沛铁矿伴生稀土资源开发利用。 展开更多
关键词 冶金工程 越南安沛 铁矿 稀土 伴生资源 开发利用
下载PDF
国际航线网络中K条最短路径算法改进与仿真 被引量:5
20
作者 胡欣 徐涛 +1 位作者 丁晓璐 李建伏 《计算机应用》 CSCD 北大核心 2014年第4期1192-1195,共4页
K条最短路径(KSP)问题是国际航线网络实际路径优化问题。通过对航线网络特征与K条最短路径算法的分析,研究了解决KSP问题的典型Yen算法。针对Yen算法求解候选路径占用大量运算时间的问题,提出一种改进Yen算法。改进Yen算法通过借助A*算... K条最短路径(KSP)问题是国际航线网络实际路径优化问题。通过对航线网络特征与K条最短路径算法的分析,研究了解决KSP问题的典型Yen算法。针对Yen算法求解候选路径占用大量运算时间的问题,提出一种改进Yen算法。改进Yen算法通过借助A*算法的启发式策略,减少了产生候选航线路径的时间,从而提高了算法的搜索效率并减小了算法搜索的规模。通过对国际航线网络实例的仿真,实验结果表明改进Yen算法能够快速求解国际航线网络中的KSP问题;同时,与Yen算法相比,运算效率提升了75.19%以上,能够为航线路径优化提供决策支持。 展开更多
关键词 国际航线网络 最短路径算法 K条最短路径问题 yen算法 启发式策略
下载PDF
上一页 1 2 17 下一页 到第
使用帮助 返回顶部