A Journey into the City. Migrant Workers' Relation with the Urban Space and Struggle for Existence in Xu Zechen's Early Jingpiao Fiction

In contemporary China, rural-urban migrants constitute a new urban subject with entirely new identity-related issues. This study aims at demonstrating how literature can be a valid field in investigating such evolving subjectivities, through an analysis of Xu Zechen’s early novellas depicting migrants’ vicissitudes in Beijing. Combining a close reading of the texts and a review of the main social problems characterising rural-urban migration in China, this paper focuses on the representation of the identity crisis within the migrant self in Xu’s stories, taking into account the network of meanings employed by the writer to signify the objective and subjective tension between the city and the countryside

The Cultural Difference in EDisodic Memory Retrieval and its Neural Mechanisms

不同文化群体的认知风格存在显著差异，具体体现在东亚人由于其集体主义文化而表现出整体化的认知加工风格，而西方人则由于其个体主义文化表现出特征驱动的分析型加工风格。关于文化对情节记忆的影响，研究发现西方人在提取项口(item)的特定信息上具有优势，东方人则更容易关注到背景信息(context)。然而，情节记忆提取过程是否具有文化差异，及其相关的认知神经机制尚不清楚。因此本研究使用项口再认和联结记忆范式以及ERP技术，考察情节记忆提取过程的认知神经机制及其跨文化差异。 实验分别招募中国青年被试35人和德国青年被试21人。使用项民背景组合图片作为刺激材料，任务一考察不同文化下的被试在新、旧背景下的项口再认成绩;任务二要求被试对原配对和重组配对图片进行再认判断，进而考察两组被试的联结再认记忆成绩。记录被试在记忆提取阶段的事件相关电位，采用新旧效应考察情节记忆提取过程的电生理机制的跨文化差异。 结果显示，在项口再认任务中，中国被试和德国被试的项口再认成绩没有显著的文化差异;ERP结果显示，中国被试和德国被试在旧背景及新背景下，均表现出显著的额区和顶区新旧效应，表明项口记忆提取过程不存在显著的文化差异。在联结记忆任务中，中国被试和德国被试联结再认成绩不存在文化差异;ERP结果显示，中国被试和德国被试正确再认的原配对图片均诱发了显著的额区新旧效应，表明联结记忆提取过程中不存在显著的文化差异。 综上所述，本研究发现，中国与德国青年人的情节记忆提取过程不存在显著的文化差异。上述结果为后续开展老年人的情节记忆跨文化比较研究提供了参考

MoC intermediate layer for FePt magnetic recording media

A (001) textured FePt film was deposited on MoC/CrRu/glass at heated-substrate by using magnetron sputtering in 4-guns sputter system with DC power supply. We studied the effect of MoC conductive intermediate layer on CrRuFePt system. My work would step by step with three parts. In the first part, the FePt films were deposited on different MoC thickness at 380℃. And the MoC intermediate layer was used to resist the Cr diffusion up to high deposition temperatures and promotes the epitaxial growth of the (001) texture FePt films. The FePt showed high perpendicular magnetization and the out-of-plane coercivity increased with MoC thickness. The FePt/MoC (5 nm)/CrRu film showed a square out-of-plane magnetic hysteresis loop with a coercivity of 6.0 kOe and a linear-like in-plane loop. We also learned that the FePt particles would concentrate in the rectangular structure by specific orientation at certain temperature. The second part was fixed the FePt (10 nm)/MoC (5 nm)/CrRu film thickness and changed the deposited temperature of FePt films from 260℃ to 410℃. We can obviously observe that the FePt started to order at 320℃ and the ordering degree reach to 0.79 when the FePt deposited at 410℃, also the square magnetization curve showed and the greater out-of-plane Hc value of 6.9 kOe was obtained. In addition, the rectangular structure which shows at 380℃ was surmised to be a transition-shape. Once the deposition temperature slightly increased, the rectangular area would be dispersing into particular-like. In the final part, the substrate temperature of FePt (t)/MoC (5 nm)/CrRu film was fixed and the FePt thickness t changed from 4~10 nm. At such high deposited temperature of 410℃ could obtain a great magnetic property on all of samples on this part. The highest coercivity value was 8.3 kOe when FePt thickness was 5 nm. We found that the magnetic property of FePt/MoC/CrRu films might be more related to ordering degree rather than microstructur. A multi-fuctional MoC intermediate layer exhibited heteroepitaxial relation with FePt and CrRu and was capable of resisting the underlayer diffusion at high deposition temperature.本實驗使用配備四支磁控濺鍍槍之高真空濺鍍系統，皆以直流電源供應器供給各靶材所需之濺鍍功率，在基座加熱至高溫狀態下於玻璃基板上依序沉積CrRu底層、MoC中間層，最後堆疊FePt磁記錄層，研究導體之MoC中間層材料於CrRuFePt的磊晶膜層系統中其對FePt序化之影響。 實驗循序漸進分為三個部分：首先在380℃高溫下，於CrRu (80 nm)/glass底層上沉積MoC 0~5 nm，再沉積FePt 10 nm。實驗結果觀察發現隨MoC厚度增加，FePt (001)織構強度被有效提升，且垂直膜面之矯頑磁力亦隨之升高。於FePt/MoC (5 nm)/CrRu膜層樣品觀察，其呈現方正之垂直膜面磁滯曲線，矯頑磁力高達6.0 kOe，而水平膜面之磁滯迴路接近線性，顯示出極佳之垂直磁異向性。證明5 nm MoC可有效在高沉積溫度下阻擋底層擴散並促使FePt序化。另外可於微結構觀察到在此溫度下FePt顆粒會依特定方向性聚集排列成長方狀的島狀結構。 第二部分實驗為固定膜層厚度FePt (10 nm)/MoC (5 nm)/CrRu並改變FePt沉積溫度 ，觀察發現FePt於320℃便開始序化，沉積溫度提高至410℃時FePt序化度提高至0.79，並得到垂直矯頑磁力6.9 kOe。微結構方面發現第一部分FePt之長方狀結構僅出現在380℃，推斷為一過渡形貌，稍加溫度即會使此狀態崩散成一般顆粒膜，另外可觀察到隨沉積溫度提高，FePt膜層由原本連續性薄膜轉變成島狀之顆粒膜型態。 最後一部分為改變FePt薄膜之厚度，在沉積溫度410℃下樣品皆能得到不錯的磁性質，整體來看，膜層厚度降低序化度以及垂直矯頑磁力有升高的趨勢，於FePt 5 nm時垂直膜面之Hc達8.3 kOe，再進一步降低膜層厚度至4 nm時會因應力釋放使得FePt沿c軸垂直排列崩解而破壞整體膜層的序化度以及磁性質。而第二及第三部分實驗發現此膜層系統之磁性質與微結構較無關聯，磁性質好壞依序化程度而變動。致謝 ............................................................... i 摘要 .............................................................. ii Abstract .......................................................... iii 目錄 .............................................................. iv 表目錄 ........................................................... vii 圖目錄 .......................................................... viii 符號說明 ........................................................ xiii 第一章 緒論 ....................................................... 1 1-1 前言 ................................................................................................................... 1 1-2 硬碟的發展與簡介 ............................................................................................. 2 1-3 背景與研究動機 ................................................................................................. 7 第二章 實驗基礎理論與文獻回顧 ...................................... 9 2-1 材料之晶體結構 ................................................................................................. 9 2-1-1 FePt合金結構.......................................................................................... 9 2-1-2 序化與非序化 ....................................................................................... 11 2-1-3 CrRu合金與MoC化合物之結構與磊晶關係 ....................................... 12 2-2 理論基礎 .......................................................................................................... 15 2-2-1 磁性材料 ............................................................................................... 15 2-2-2 磁異向性 ............................................................................................... 16 2-2-3 磁滯曲線 ............................................................................................... 19 v 2-2-4 FePt薄膜之序化度計算 ........................................................................ 22 2-3 文獻回顧 .......................................................................................................... 27 2-3-1 FePt薄膜之文獻回顧 ............................................................................ 27 2-3-2 CrRu薄膜底層之文獻回顧 ................................................................... 28 2-3-3 FePt/CrRu膜層中間層之文獻回顧 ....................................................... 32 第三章 實驗流程與儀器原理 ......................................... 37 3-1 實驗流程 .......................................................................................................... 37 3-2靶材選擇 ........................................................................................................... 38 3-3基板之選用及清洗 ........................................................................................... 38 3-4 試片製備 .......................................................................................................... 40 3-4-1 磁控濺鍍系統 ....................................................................................... 40 3-4-2 薄膜製備 ............................................................................................... 41 3-4-3 實驗設計 ............................................................................................... 43 3-5 分析設備與分析方法 ....................................................................................... 44 3-5-1膜厚量測及表面粗糙度 ......................................................................... 44 3-5-2 晶體結構分析 ....................................................................................... 45 3-5-3 磁性量測 ............................................................................................... 48 3-5-4 微結構觀察 ........................................................................................... 50 3-5-5 元素分佈 ............................................................................................... 54 3-5-6 基板溫度校正...........................................................................................55 第四章 結果與討論 ................................................. 56 4-1 MOC中間層膜厚變化之探討 ........................................................................... 57 4-1-1 MoC中間層膜厚變化之X-ray繞射分析 .............................................. 57 4-1-2 MoC中間層膜厚變化之VSM磁性質分析 ........................................... 59 vi 4-1-3 MoC中間層膜厚變化之TEM微結構分析 ........................................... 61 4-2 FEPT沉積溫度變化之探討 ............................................................................... 64 4-2-1 FePt沉積溫度變化之X-ray繞射分析 .................................................. 64 4-2-2 FePt沉積溫度變化之VSM磁性質分析 ............................................... 66 4-2-3 FePt沉積溫度變化之TEM微結構分析 ............................................... 68 4-2-4 FePt沉積溫度變化之AFM表面粗糙度分析 ....................................... 71 4-3 FEPT膜厚變化之探討 ....................................................................................... 72 4-3-1 FePt膜厚變化之X-ray繞射分析 .......................................................... 72 4-3-2 FePt膜厚變化之VSM磁性質分析 ....................................................... 73 4-3-3 FePt膜厚變化之TEM微結構分析 ....................................................... 76 第五章 結論 ....................................................... 79 參考文獻 .......................................................... 8

A Welfare Analysis of Social Security in An Economy with Income Inequality:Based on An Overlapping Generation Model of Endogenous Growth

社会保障制度选择是经济协调发展中的重要课题。本文建立了一个考虑存在收入差距的异质性个体的内生增长世代交替模型,综合考察了社会保障制度选择对经济增长和收入再分配的影响。分析表明,现收现付制对稳定状态的经济增长率有负面影响,但其收入再分配功能对提高社会总福利存在正向作用,通过数值模拟发现当收入差距较小时,现收现付制对经济增长的抑制作用较强,随着收入差距的拉大,收入再分配功能将逐渐居于主导地位,其综合效应可以改善社会福利。在一定的收入差异程度范围内,存在一个使社会福利最大化的最优现收现付制比率。基于对中国实际的分析,本文认为我国未来的社会保障制度改革应该注重发挥现收现付制的再分配能。 This paper studies the effects of socia l security on economic growth and income redistribution. We construct an endogenous growth model with heterogeneous individuals that differ in income levels. We show that a pay as you go ( PAYG) system has adverse effects on growth in the steady state, but has positive effects on income redistribution within generations. Our numerical simulation suggests that the adverse effect of the PAYG system is weaker when income inequality is larger. This paper suggests that the redistributive effects of the PAYG system should be fully recognized in China's social security reform.07BJL01

雪岭云杉树轮宽度对气候变化的响应

利用新疆伊犁地区雪岭云杉的6个树轮宽度年表,通过相关分析的方法,分析不同地形条件下雪岭云杉树轮宽度对于气候要素的响应。统计分析表明,雪岭云杉对气候变化比较敏感,在北天山南坡的森林下限,雪岭云杉生长与生长季7~8月降水关系显著;在南天山北坡的森林下限,雪岭云杉生长对生长季前11—次年1月最低温度存在显著正相关。地形对雪岭云杉与气候要素之间的关系影响较大,在南天山北坡,由于森林上下限树木抗寒性的差异,森林下限树木生长对温度的响应强于上限树木;南北坡引起的降水量水平的差异,使得天山不同坡向的树木生长响应不同的气候要素

Neural mechanisms of successful episodic memory aging

随着年龄的增长,大部分老年人的情景记忆会出现衰退,但也会有一部分老年人的情景记忆表现出成功的年老化,即记忆成绩较好或随增龄的衰退程度较小。脑保持理论、神经去分化理论、认知储备理论以及神经补偿理论分别从不同角度解释了情景记忆成功年老化的神经机制。基于选择性优化与补偿模型对现有理论进行整合,发现情景记忆成功年老化可能与个体的认知储备水平直接相关：高认知储备的老年人能够对情景记忆相关的脑区和脑网络进行优化且具备更强的神经补偿能力,因而其脑功能(比如,神经表征和神经加工通路的特异性)可能会保持地更好。未来研究需要更多地采用纵向设计来考察各理论之间的关系及其影响因素,从而更好地解释记忆成功年老化的神经机制并为提升老年人的脑与认知健康提供支持。</p

Study of the Relationship Between Cell Size,Chlorophyll Content of Aegiceras corniculatum Mesophyll and Seawater Salinity by FCM

采用快速离析的方法,用流式细胞仪分析了福建九龙江入海口北岸生长的桐花树(Aegicerascorniculatum)成熟叶片的叶肉细胞大小和叶绿素含量与海水盐度之间的关系.结果表明:盐度为13时,桐花树单位体积叶肉组织叶绿素含量最高,细胞表面积和光合面积最大.海水盐度低于13时,随着盐度升高,叶肉细胞大小和叶绿素含量等向有利于生长方向发展;海水盐度为13～25,随着盐度的升高,细胞大小和叶绿素含量等向加强生理干旱适应性方向发展.快速离析法与流式细胞仪综合应用为研究植物器官、组织内的细胞大小及其内含有的叶绿素等物质的含量提供了可能.This article studies the size and the chlorophyll content in the mesophyllic cell of Aegiceras corniculatum growing under different seawater salinity in north bank of Jiulong river in Xiamen,Fujian by the method of isolation and flow cytometry(FCM).We intent to prove cell configuration's adaption to the environment again,check up the feasibility of this method and expand the application of flow cytometry.These results show that: when seawater salinity is 13,the chlorophyll content in unit volume in the mesophyll cell of Aegiceras corniculatum is in its tiptop,and the surface area and the photosynthesis area of the mesophyll cell are the biggest.The condition of salinity when it is below 13 is favorable for the growth of cell size and chlorophyll content.Better adaptability to physiological drought will be developed with the increase of salinity when it falls at 13～25.All above prove that it is feasible to study the cell size and the chlorophyll content of organic cells of different plants by the method of fast isolation and by using FCM

An SPH model for free surface flows with moving rigid objects

This paper presents a computational model for free surface flows interacting with moving rigid bodies. The model is based on the SPH method, which is a popular meshfree, Lagrangian particle method and can naturally treat large flow deformation and moving features without any interface/surface capture or tracking algorithm. Fluid particles are used to model the free surface flows which are governed by Navier-Stokes equations, and solid particles are used to model the dynamic movement (translation and rotation) of moving rigid objects. The interaction of the neighboring fluid and solid particles renders the fluid-solid interaction and the non-slip solid boundary conditions. The SPH method is improved with corrections on the SPH kernel and kernel gradients, enhancement of solid boundary condition, and implementation of Reynolds-averaged Navier-Stokes turbulence model. Three numerical examples including the water exit of a cylinder, the sinking of a submerged cylinder and the complicated motion of an elliptical cylinder near free surface are provided. The obtained numerical results show good agreement with results from other sources and clearly demonstrate the effectiveness of the presented meshfree particle model in modeling free surface flows with moving object