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Search Results: 1 - 10 of 125705 matches for " 赵 艳 "
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艺术品投资研究综述
Research Review on Art Investment
 [PDF]

, 秀娟
Management Science and Engineering (MSE) , 2014, DOI: 10.12677/MSE.2014.34016
Abstract:
艺术品已经成为了继证券和房地产之后的第三大投资热点。近年来,我国艺术品市场持续升温、天价频出,中国艺术品市场更是成了全球关注的焦点。我国收藏历史悠久,但已有关于收藏品研究的专著和文献都把研究重点放在了艺术品的鉴赏方面,对艺术品投资的收益风险问题、以及艺术品与其他投资市场之间的关系却很少触及。而自1974年起,就有不少国外学者开始从经济学的角度关注艺术品,涌现了不少研究成果。本文综述国内外学者在艺术品投资方面的研究方法及研究结论,为读者提供了这一领域的研究进展,给同领域研究者提供便利。
Artwork has become the third hot spot for investment after the securities and real estate. The art market has been on the rise in recent years; astronomical art auction prices continue to refresh the record. The art market in China has become the focus in the world. Collection has a long history in China. But the existing researches put their emphasis on collection and appreciation; only few literatures discuss the income risk of investment and the relationship between artwork and other investment markets. Since 1974, foreign scholars began to pay attention to art from the perspective of economics, bringing us a large number of research results. This article systematically summarized the methods the domestic and foreign scholars used and the conclusions they got, providing readers with the latest progress and convenience for researchers in the same field.
柴达木盆地湖泊孢粉记录的生态与气候解释:不同海拔地区的湿度变化差异

第四纪研究 , 2010,
Abstract: 文章综述了青藏高原东北部柴达木盆地3个湖泊(克鲁克湖、托素湖和尕海)不同时间尺度(过去50年、1000年和10000年)、不同分辨率(年际、十年际和百年际)以孢粉为主的多指标记录,以期更系统地了解该区全新世不同时间尺度的植被与气候历史,理解不同海拔地区湿度变化可能存在的差异与机制。孢粉现代过程研究结果表明蒿藜比对湿度变化很敏感,可以作为研究区气候重建的一个敏感指标。该区湖泊不同时间尺度孢粉数据的植物生态指示意义可能不同,即过去50年,晚全新世和整个全新世湖泊孢粉记录表明蒿藜比值分别指示孢粉产量、植被组成或植被类型的变化信息,但它们都反映出年、十年到千年尺度的相对湿度的变化。孢粉的蒿藜比和其他指标揭示出在不同时间尺度上的气候变化与邻近高海拔地区记录(青海湖、敦德冰芯和德令哈树轮)的湿度变化模式不一致。这一差别在季风强盛期尤其明显,如过去50年记录的1970s,过去1000年记录的过去300年,过去10000年记录的早、晚全新世的湿度变化。区域地形导致的上升下沉气流机制可能是形成这种湿度差异的原因。
植物转化中的安全标记基因

生物化学与生物物理进展 , 2002,
Abstract: 转基因植物中的除草剂或抗生素抗性标记基因的生态环境和食用安全性一直颇有争议.糖类分解代谢酶基因作为安全标记基因,近年来在植物转化中显示了巨大应用潜力.这类标记基因编码产物是筛选剂糖类的分解代谢酶,使转化细胞能利用筛选剂糖类作为主要碳源从而获得优势生长,非转化细胞则因饥饿生长被抑制但不被杀死,故称为正筛选系统(positiveselectionsystem).目前木糖异构酶基因(xyloseisomerase,xyla)和磷酸甘露糖异构酶基因(phosphomannoseisomerase,pmi)等安全标记基因已成功应用于植物转化.
推拿手法疏理督脉和足太阳膀胱经治疗郁证体会

中国中医药信息杂志 , 2008,
Abstract:
液化天然气接收站内BOG再液化装置研究
Study of BOG Re-Liquefied Installation in LNG Terminal
 [PDF]

, 郭雷, 顺喜, 曲顺利
Hans Journal of Chemical Engineering and Technology (HJCET) , 2015, DOI: 10.12677/HJCET.2015.53010
Abstract:
液化天然气(LNG)作为天然气的一种存在形式,具有储存和运输的优势便利。目前我国已在沿海城市建设了多个液化天然气接收站和卫星站来接收国外进口LNG。接收站运营过程中将产生大量的蒸发气体(BOG),当没有或者仅有少量出口运输需求时,当天然气终端和外输管网建设不同步的时候,过量的BOG将进入火炬燃烧掉,造成极大的浪费。在接收站内建设一个撬装式的BOG再液化装置,将站内产生的部分BOG再液化后返回LNG储罐,这对接收站的安全和经济运营具有重要的意义。本文以国内某接受站为例,对站内撬装式的BOG再液化装置进行了描述,介绍了混合制冷剂再液化流程、压缩机和换热器等主要设备选型、装置能耗、占地面积和开停车方案。
Liquefied natural gas (LNG) is an existing form of natural gas, which has the advantages of storage and transportation. Nowadays, many LNG terminals and satellite stations have been built along coastal city in our country to receive foreign LNG. Lots of BOG (boil of gas) will be produced during the operation process. Excess BOG burns through the torch when there is no or a small amount export demand, or when the construction of LNG terminal and export network cannot be completed at the same time. This leads to great waste. Part of BOG is re-liquefied and returns to LNG tank through a skid mounted BOG re-liquefied installation in the terminal, which is meaning for the safety and economic operation of LNG terminal. A skid mounted BOG re-liquefied installation in a LNG terminal is described in this article. Also, the mixed refrigerant re-liquefaction process, the main equipment such as compressor and heat exchanger, the consumption, the floor space and open parking scheme are introduced.
热力学第二定律对广义f(R)引力模型的限制
The Constraints on the Generalized f(R) Gravitational Model by the Generalized Second Law of Thermodynamics
 [PDF]

月月,, 冯立军, 李红
Astronomy and Astrophysics (AAS) , 2016, DOI: 10.12677/AAS.2016.42005
Abstract:
本文构建广义的f(R)引力即物质与曲率耦合的f(R)引力理论,在以动态表观视界为边界、其内部充满具有霍金温度的普通物质的FRW宇宙背景下,由广义f(R)引力的场方程可推导出广义热力学第二定律,并利用广义热力学第二定律对具体模型参数进行限制。
The generalized f(R) gravity with curvature-matter coupling is studied in this paper. The genera-lized second law of thermodynamics (GSL) can be given by considering the FRW universe filled only with ordinary matter enclosed by the dynamical apparent horizon with the Hawking temperature. Furthermore, as a concrete example, by utilizing the GSL, the constraints on the gravitational model are also discussed.
基于标题的中文新闻分类研究
Research of Chinese News Classification Based on Titles
 [PDF]

王海涛, , 岳磅
Hans Journal of Data Mining (HJDM) , 2013, DOI: 10.12677/HJDM.2013.33007
Abstract: 如何快捷、准确、全面地检索互联网信息是互联网时代的重要问题。网络新闻比传统纸质媒体新闻速度更快、内容更丰富、形式更灵活生动,正逐渐取代传统新闻媒体成为很多人获取新闻信息的主要途径。然而,面对快速更新的大量新闻信息,传统的手工分类方式无法满足用户的需求。新闻的主要内容一般都是以文本的方式呈现,因此,利用文本自动分类技术对网络新闻进行自动分类是解决手工新闻分类问题的一个有效途径。由于网络新闻信息形式多样,很多新闻内容完全是由图片或者视频组成,不包含文本内容。本文提出通过新闻标题对网络新闻进行分类的方法,比通过内容进行分类的方法分类速度更快,并且有更强的适应性,可对无文本内容的新闻(如图片新闻、标题新闻等)进行分类。本文创建了基于标题的文本分类模型;从网络上获取新闻语料,验证模型的工作情况;并通过与基于内容的文本分类方法比较,验证基于标题的文本分类模型的优劣。本文构建了基于标题的两步分类系统,所提出的类别唯一特征,对于可分样本可以实现高分类准确率。
Retrieving online information efficiently becomes a crucial issue in nowadays online experience. Compared with traditional news in paper form, online news are faster, more convenient and more flexible. It is a trend that online news are replacing their traditional counterpart and becoming the most common way for people to obtain daily information. However, the volume of frequent updated news becomes so large that the traditional manual news classification cannot meet the needs of online users. One of the solutions for this will be applying automatic text classification technologies to classify online news. Many IT companies are developing automatic news classification systems. There are different forms of network news. Some of the news are composed mostly by graphics or videos instead of text and therefore not able to be coped with by classic text classification. A new approach of news classifier based on news titles is proposed to dealing with such news. In this paper, the title based classification model was created. The model was evaluated by a built corpus and compared with contents based classification. A two-phase news classification system is constructed and category key feature is proposed.
基于CPS-SPWM调制的级联H桥有源电力滤波器研究
Research on H-Bridge Cascaded APF Based on CPS-SPWM
 [PDF]

巩晓, , , 马庆玉
Smart Grid (SG) , 2016, DOI: 10.12677/SG.2016.63018
Abstract:
本文介绍了载波相移脉宽调制适用于大功率场合的理论依据,讨论了级联H桥多电平变流器较其他形式变流器的优势,采取了载波相移脉宽调制在级联H桥变流器的实现方法,采用基于CPS-SPWM调制级联型多电平变流器的并联电力有源滤波器的拓扑结构,探讨了三相瞬时无功功率理论在检测层面的应用,并对其进行仿真和分析。仿真结果表明,在较低的开关频率下,基于CPS-SPWM调制级联H桥并联型APF可以对负载谐波和无功功率进行准确、有效的补偿。
The theory basis that fits for large capacity power electronic equipment of CPS-SPWM is introduced. The advantages over other modulation strategies of CPS-SPWM are discussed. The implementation method of carrier phase-shift pulse-width modulation in the cascade H-bridge converter is adopted. The topology based on shunt active power filter of CPS-SPWM modulation cascade multi-level converter is used. The three-phase instantaneous reactive power theory in the detection level is discussed and its simulation and analysis is presented. The results of simulation and experiment indicate that the shunt active power filter with CPS-SPWM based cascade H-bridge multilevel converters can compensate load harmonics and passive power precisely and efficiently at lower switch frequency.
任务观察在矿山安全标准化管理系统中的应用
,,李畅,
安全与环境工程 , 2012,
Abstract: 分析了任务观察工作的发展情况及其在矿山安全标准化管理系统中实施的必要性,介绍了任务观察在杜邦公司及其他行业的应用,并在此基础上设计出了编写程序、组织培训、制定计划、实施观察、行为干预、形成记录及报告、统计分析、评审改进8项PDCA循环发展的矿山安全标准化管理系统中的任务观察管理流程,明确了其与安全检查的异同点及其在实施过程中应注意的事项。任务观察管理流程的应用对矿山企业完善安全标准化管理系统、控制人员不安全行为具有重要的意义。
Progress in the Study of Microbial Linear Plasmids
微生物线形质粒的研究进展

,文明
微生物学报 , 2002,
Abstract: 质粒指染色体外能独立进行复制和遗传的辅助性遗传单位。习惯上,专指细菌等微生物中能进行自主复制的共价闭合环状DNA分子。然而,近20年来在越来越多原核生物的细胞质或真核生物的线粒体中却发现了线形DNA分子,一般具有共价闭合的末端或于5’端结合蛋白质。因此,称这类质粒为线形质粒(linear plasmid)。线形质粒最初在玉米(Zea mays)中发现^1],迄今只有20多年的历史。已报道发现线形质粒的物种有近百个,如引起人类回归热的达氏疏螺旋体(Borrelia duttonii)、乳酸克鲁维酵母(Kluyveromyces lactis)、巴斯德毕赤氏酵母(Pichia pastoris)、紫瘢麦角菌(Claviceps purpurea)、尖镰孢(Fusar-ium oxysporum)等^2,3]。由于大多数线形质粒的5’端带有共价结合蛋白,使其在分离过程中随着脱蛋白反应而被去除,只是近十年来由于脉冲场凝胶电泳技术的成熟才检测出许多大型的线形质粒^2]。
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