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Search Results: 1 - 10 of 285259 matches for " 刘慧平 "
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背景任务难度与时间管理倾向对时间性前瞻记忆的影响
The Influences of Ongoing Task Difficulty and Time Management on Time-Based Prospective Memory
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Advances in Psychology (AP) , 2016, DOI: 10.12677/AP.2016.67098
Abstract:
本研究采用双任务范式研究时间管理与背景任务对时间性前瞻记忆的影响。发现时间管理倾向与前瞻记忆没有显著相关,不同难度背景任务中,即使前瞻记忆没有显著差别,但是进行中任务成绩存在显著差异。说明不同背景难度任务对前瞻记忆有影响,前瞻记忆中存在注意分配。
This research used dual-task paradigm to study the influence of ongoing task difficulty and time management on time-based prospective memory. It showed that the relationship between time management and prospective memory is not significant. In ongoing task of different difficulties, even if the differences of prospective memory are not significant, the ongoing task is significant. It showed that ongoing tasks of different difficulties have influence on prospective memory, and there is an attention distribution in the prospective memory.
珠光体、贝氏体、马氏体相变的形核* Nucleation Mechanism of Pearlite, Bainite and Martensite*  [PDF]
宗昌,计云萍,
Material Sciences (MS) , 2013, DOI: 10.12677/ms.2013.32014
Abstract: 研究过冷奥氏体转变产物的形核规律具有重要理论价值。采用20MnCrMo、60Si2CrV等材料,奥氏体化后在不同温度进行等温处理,得珠光体、贝氏体、马氏体等产物,应用QUANTA-400型扫描电镜、JEM-2100透射电镜等观察各种相变的形核。发现:珠光体、贝氏体、马氏体均优先在奥氏体晶界处形核,下贝氏体、马氏体也在晶内形核。珠光体晶核由共析铁素体+共析渗碳体两相组成,共析共生,在700℃~650℃,珠光体临界晶核尺寸r* = 150~70 nm;临界形核功 155~292 J/mol。贝氏体在奥氏体的贫碳区形核,晶核是单相(BF),其临界尺度a* = 16.7~25 nm,临界形核功 2.7 × 102 J/mol。马氏体的临界晶核尺寸约为17~20 nm,形核功约为200~600 J/mol。表明随着温度的降低,临界晶核尺寸越来越小,而形核功越来越大。过冷奥氏体转变产物的形核是一个逐渐演化的过程,符合相变形核的一般规律。 It is significant theoretically to study the nucleation mechanism of the phase transformation products of the supercooled austenite. 20MnCrMo, 60Si2CrV and other material were respectively austenized and isothermal quenched at the different temperature to obtain pearlite, bainite and martensite. The nucleation of the phase transformation products was observed by QUANTA-400 environmental scanning electron microscope and JEM-2100 transmission electron microscope. It is found that pearlite, bainite and martensite can all nucleate at the crystal grain boundary of austenite preferentially, moreover, lower bainite and martensite can nucleate in the austenite crystal grain interior. The pearlite crystal nucleus consists of two phases of eutectoid ferrite and eutectoid cementite, which can coexist. At the temperature range of 700 C - 650 C, the dimension of the pearlite critical nucleus is about 150 - 70 nanometer and the critical nucleation energy is 155 - 292 J/mol. Bainite nucleates in carbon-poor region and the bainite crystal nucleus is single phase (BF). The dimension of the bainite ferrite critical nucleus is 16.7 - 25 nanometer and the critical nucleation energy is 2.7 × 102 J/mol. The dimension of the martensite critical nucleus is 17 - 20 nanometer and the critical nucleation energy is 200 - 600 J/mol. The results show that, with the decrease of the transformation temperature, the dimension of the critical nucleus is becoming smaller and smaller and the critical nucleation energy is getting larger and larger. The nucleation of the phase transformation products of the supercooled austenite is a gradual evolutionary process, which accords with the general rule of the phase transformation nucleation.
马氏体相变唯象“理论”的评述—五评马氏体相变的切变学说
The Commentary on Phenomenological Theory of Martensite Phase Transformation—The Fifth Commentary on Shear Theory
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宗昌, 计云萍,
Material Sciences (MS) , 2014, DOI: 10.12677/MS.2014.44018
Abstract:
研究马氏体相变晶体学具有重要理论意义。本文简述并评价了唯象学说,指出:1) 以贝茵应变使母相转变为马氏体,缺乏热力学可能性,贝茵应变B作为计算数据,不可靠; 2) 马氏体浮凸是相变体积变化所致,与切变无关,浮凸普遍为帐篷型(∧),矩阵计算式中的形状应变F与马氏体相变晶体学没有直接的联系;3) 点阵不变切变缺乏热力学可能性,在实际的马氏体相变中不存在简单切变(S)。同样,刚性转动也是虚构的;4) 唯象学说与马氏体相变实际不符,应予摈弃。
It is of theoretical significance to study the crystallography of martensite phase transformation. The phenomenological theory was briefly described and evaluated. The proposed viewpoints are as follows. 1) The transformation from austenite to martensite through the Bain strain lacks of the thermodynamics possibility. Moreover, it is unreliable to use the Bain strain (B) as the calculating data; 2) The surface relief of martensite, which is generally in tent (∧) type, results from the bulk expansion during martensite phase transformation and has nothing to do with the shear. The shape strain (F) in the matrix calculation formula is not directly relevant to the crystallography of martensite phase transformation; 3) The lattice invariance shear is short of the thermodynamic feasibility. No simple shear (S) exists in the actual martensite phase transformation, similarly, the rigid rotation is imaginary; 4) The phenomenological theory doesn’t conform to the reality of martensite phase transformation and should be abandoned.
贝氏体相变时原子的位移
Atomic Displacement during Bainite Transformation
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宗昌, 计云萍,
Material Sciences (MS) , 2013, DOI: 10.12677/MS.2013.36044
Abstract:
研究贝氏体相变过程中原子的位移具有重要理论意义。本文综合试验事实理论地分析了过冷奥氏体在中温区发生贝氏体相变时原子位移的方式,并指出在孕育期内,依靠浓度涨落,碳原子扩散位移形成了贫碳区和富碳区。在贫碳区中原子以新旧相化学势之差为驱动力,依靠热激活跃迁形成贝氏体铁素体晶核。从热力学上分析,贝氏体铁素体的形成不是切变过程,从相变动力学和扩散速度分析,也非扩散过程。贝氏体相变中,碳原子扩散,界面铁原子以非协同热激活跃迁方式形成贝氏体铁素体和贝氏体碳化物。
>It is significant theoretically to study the atomic displacement during bainite transformation. The atomic displacement mode during bainite transformation in medium temperature region was synthetically analyzed in theory. It is pointed out that, in incubation period, the carbon-poor areas come into being by carbon atoms diffusion displacement for the concentration fluctuation. In the carbon-poor area, the bainite ferrite crystal nucleus is generated by heat activation transition of the iron atoms under the driving force of the difference between the old and new phase chemical potential. From the view of thermodynamics, the formation of bainite ferrite is not shear. From the aspects of transformation kinetics and diffusion velocity, the formation of bainite ferrite is not diffusion either. In bainite transformation, the displacement mode of carbon atoms is diffusion, but that of the interface iron atoms is non-synergic thermal activation transition, which results in the formation of bainite ferrite and bainite carbide.
气相色谱法测定水果皮中溴氰菊酯、氨菊酯残留量方法的探讨
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中国公共卫生 , 2000, DOI: 10.11847/zgggws2000-16-08-06
Abstract: ?气相色谱仪应用于测定水果中农药残留量分析已有多年的历史.我们在查阅文献的基础上,结合工作经验,提出用气相色谱法测定氨菊酯、溴氰菊酯在水果皮中残留量,检测方法操作简便,灵敏度高.现报告如下.
叶霉菌粗毒素对番茄幼苗防御酶及活性氧的诱导
,,韩巨才
华北农学报 , 2009, DOI: 10.7668/hbnxb.2009.06.044
Abstract: 以番茄不同抗性品种的幼苗为材料,采用浸渍法研究了低浓度的叶霉菌粗毒素对番茄叶片防御酶(SOD、POD、PAL)活性及活性氧(O2-和H2O2)的诱导作用,为探讨病菌毒素诱导植物抗病性的生理生化机制提供科学依据.结果表明,番茄经叶霉菌粗毒素诱导后,抗、感品种叶片的SOD活性下降,但抗病品种的下降比率小,且比感病品种具有较高的酶活性;抗、感品种的POD活性变化趋势均为先上升后下降,二者间的酶活性变化差异不大;抗、感品种PAL活性均升高,但抗病品种增加更快,且增加比率高于感病品种;抗、感品种的O2-产率和H2O2含量的变化呈增加趋势,抗病品种的增加比率均高于感病品种,且增加峰值出现早.说明叶霉菌粗毒素诱导的番茄体内防御酶和活性氧变化与番茄抗叶霉病有着密切的关系.
叶霉粗毒素对番茄幼苗cat酶及保护性物质的影响
芹?,,韩巨才?
西北农林科技大学学报(自然科学版) , 2005,
Abstract: 以番茄叶片为材料,研究了番茄不同抗、感品种于苗期经叶霉病菌粗毒素处理后,叶部细胞cat酶及保护性物质的动态变化。结果表明,经叶霉病菌毒素处理后,抗、感品种叶部细胞内cat酶活性均降低,抗病品种(中杂8号)下降比率大于感病品种(823番茄),但抗病品种的cat酶活性高于感病品种;从平均水平上看,两品种处理的可溶性糖含量均较对照增加,而vc含量和可溶性蛋白含量均较对照下降;处理后,抗病品种的可溶性糖含量和可溶性蛋白含量均高于感病品种,vc含量二者相当。
基于误差反馈控制的变系数城市扩张模型构建及应用
冯徽徽,
地理科学 , 2014,
Abstract: 通过模拟结果与实际情况的误差分析,将研究区划分为4种像元类型,包括漏算误差像元(OmissionError,OE)、超算误差像元(CommissionError,CE)、正确模拟的城市像元(UrbanCorrect,UC)及正确模拟的非城市像元(Non-urbanCorrect,NUC)。利用线性规划方法,将误差反馈到城市扩张模型中,动态修正模型系数,构建基于误差反馈控制的变系数城市扩张空间布局模型反映城市扩张的内在特征,最后以北京市为例,模拟了其1997~2009年的城市扩张过程,通过与传统Logistic-CA模型的模拟结果对比,验证变系数模型的有效性与实用性。研究结果表明传统Logistic-CA模型在2001年、2005年和2009年的模拟精度分别为73.842%、64.704%和63.953%,而基于误差反馈控制的变系数城市扩张模型的模拟精度分别为75.624%、66.537%和69.142%,较Logistic-CA回归模型提高了1.782、1.833和5.189个百分点,取得了更好的模拟效果。
利用角点最近距离统计平均法计算建筑物阴影长度
王永刚,
国土资源遥感 , 2008, DOI: 10.6046/gtzyyg.2008.03.08
Abstract: 针对高分辨率图像上部分规则建筑物阴影轮廓的特点,基于曲率尺度空间角点探测法(CSS,CurvatureScaleSpace),提出了一种阴影长度半自动量算方法。该方法首先计算角点最近距离,然后进行长度和角度筛选,最后进行统计平均。在以北京师范大学校园为例的实验中,较准确地得到建筑物高度信息,从而显示该方法不仅可以弥补传统手工量算阴影宽度工作繁琐和效率低下的缺陷,而且可以有效地提高计算精度。
遥感分类图像条带噪声的去除
王永刚,
遥感技术与研究 , 2007,
Abstract: 在介绍了几种常用于tm、mss、spot等多传感器遥感图像中条带噪声去除方法的基础上,提出了一种综合利用idl语言和常用遥感软件(主要为envi、erdas等)对分类后图像进行条带处理的新方法。并以2005年北京市spot图像为试验数据,对该方法进行了尝试。结果表明,利用该方法可弥补一些条带噪声去除方法的弊端,有效地去除分类后图像上的条带噪音;同时避免了分类前期条带去除过程中对条带像元值的不正确计算,以及对图像上正确像元的影响而导致的后期遥感分类过程中的错分误分问题,从而可以有效地提高遥感分类精度。这种方法在其它多传感器遥感图像的条带噪声去除中也有很强的适用性。
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