苗药铁筷子挥发油的化学成分分析及抑制BGC-823细胞增殖研究

目的:研究苗药铁筷子挥发油成分及挥发油抗肿瘤作用.方法:采用水蒸气蒸馏法提取铁筷子挥发油,利用GC-MS联用仪分析铁筷子挥发油的化学成分.CCK8法检测苗药铁筷子挥发油对BGC-823细胞增殖的抑制作用.结果:从苗药铁筷子挥发油中鉴定了33种化合物,共占挥发油的89.71％,苗药铁筷子挥发油中主要含有棕榈酸占总油量的1...     

用密度泛函方法计算乙酰丙酮铁加氢反应的自由能

运用密度泛函量子力学的广义梯度近似方法对乙酰丙酮铁、氢气、乙酰丙酮3种分子以及铁的单晶胞进行结构优化计算,确定它们的对称群和总能量.根据频率分析结果,计算不同温度下乙酰丙酮铁加氢生成铁和乙酰丙酮两种互变异构体的吉布斯自由能.计算结果表明:相同温度下,乙酰丙酮铁加氢生成烯醇式乙酰丙酮的反应自由能小于生成酮式结构乙酰丙酮的反应自由能;乙酰丙酮铁加氢更倾向于生成烯醇式结构的产物.     

基于朗道二级相变理论的铁单晶磁结构分析

利用朗道二级相变理论以及磁点群理论对于4种单晶铁,也就是阿尔法-铁、德尔塔-铁、伽马-铁以及伊普西龙-铁的磁结构进行了分析.其中,着重利用朗道二级相变理论中实现二级相变的条件和Birman的群选择定则来分析一定晶体结构的铁单晶如果发生顺磁铁磁相变后可能具有的空间对称性,进而得到铁单晶可能具有的磁结构.同时,得到的结论与之前文献报道中的结果进行了比较,发现符合得很好.     

分子动力学模拟高压下铁的相变

采用分子动力学(MD)方法,结合原子间多体势函数,模拟了bcc铁(α-Fe)在高压下向hcp铁(ε-Fe)转变的过程,并与实验数据进行了比较.系统的压强通过计算维里压强获得,并通过Berendsen方法进行调整和改变.还采用相同的原子间势模拟bcc和hcp两种不同结构的铁,对高压下铁相变的机制和相变压强进行直接的计算和模拟,以对采用的原子间势进行更严格的检验和修正.模拟计算得到超高压下(＞15 GPa)两种结构的P-V曲线图以及hcp铁的c/a值等相关结果,都与实验结果有较好的符合.而在较低压下(0～15 GPa)P-V关系中常用的铁的原子间势对bcc铁仍有很好的模拟效果,而对hcp铁则效果不是很理想.因此,铁的原子间势还有待进一步改进.     

催化动力学光度法测定紫菜中的微量铁

在稀硫酸介质中,微量铁对溴酸钾氧化甲基红褪色具有明显的催化作用,据此探索了测定微量铁的催化反应条件,建立了催化光度法测定微量铁的方法.催化动力学光度法测定紫菜中的微量铁具有操作简便、快速、灵敏等优点.该方法的线性范围为30～42μg·mL-1,检出限为0.4354μg·mL-1,回收率为98.3%～102.2%.运用于测定紫菜中微量铁,结果满意.     

区域水资源复合系统可持续利用演变轨迹研究

从分析感应电机的铁损耗入手,给出了转子铁损耗等效电阻随转差率的变化关系.通过研究转子铁损耗在整个铁损耗中所占比例和同步角频率的关系,指出在低速区转子铁损耗对电机运行效率有着显著的影响.建立了考虑转子铁损耗时感应电机的损耗模型.利用拉格朗日优化算法,推导出感应电机在矢量控制下稳态运行时效率最高的控制条件.实验结果证实,所建立的损耗模型在全速范围内都有着较高的准确度,所推导的最大效率运行条件也是切实有效的.     

吉安市城区居民膳食铁摄入量的调查与分析

目的了解吉安市城镇居民膳食铁摄入水平,分析铁的食物来源,为普及营养知识,指导居民平衡膳食提供依据.方法选择吉安市200户城镇居民家庭,采用“三日全家称重记帐法”进行膳食营养调查.结果各组铁的平均摄入量均大于 AI;有23.5%的未成年人和14.5%的成年人铁摄入量未达到 AI,女性未达到的比例高于男性,性别间比较差异无统计学意义(P>0.05);有19.1%的未成年人和15.3%的成年人铁摄入量超过 UL;铁来源于植物性食物的比例高于动物性食物.结论青少年与女性膳食铁摄入量未达到 AI 的比例仍较高,铁的食物来源不佳,应积极开展铁营养健康教育,调整居民饮食结构,积极改善铁营养状况     

等离子氮化处理改善铁的耐腐蚀性能研究

通过电化学测试方法对等离子氮化处理前后铁的耐腐蚀性进行研究.采用扫描电子显微镜(SEM)对极化试验后样品表面的腐蚀形貌进行观察.结果表明,等离子氮化处理后的样品的蚀孔数量少,其腐蚀程度明显优于未经处理的样品.应用X射线衍射(XRD)及X射线光电子能谱(XPS)分析其腐蚀机理.结果证实,等离子氮化处理后铁的耐腐蚀性能得以改善,归因于材料表面形成的铁氮及铁氧结合层.     

利用高炉出铁重力势能的旋流反应器冶金特性

从高炉出铁口中射出的铁水具有一定的初动能,且出铁沟有一定的坡度.本项目提出了一种利用高炉出铁沟重力势能脱硫的新型冶金反应器.基于湍流模型与多相流模型的耦合,应用液面追踪技术,实现了对冶金重力势能反应器内流体流动及液面波动行为的模拟计算,并用水模拟结果进行了对比验证.从分析的结果来看,铁水在反应器内能够形成良好的旋流效果.实验所得的RTD曲线与计算所得的结果吻合较好.碗型反应器的旋流效果最好,能够产生高强度稳定的旋流.     

变压器铁损和铜损的几种测定方法

用多种方法对变压器的铁损和铜损进行了实验测定,并进一步分析了实验结果,认识了铁损和铜损的实质.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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