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1.
用目测差热热分析法确定LaCl_3—MgCl_2体系熔度图属低共熔型。低共熔温度为673℃,低共熔点组成位于66%克分子MgCl_2处。  相似文献   

2.
低共熔点和三相点   总被引:1,自引:0,他引:1  
二组分凝聚系统相图上的低共熔点表示体系处于三相平衡状态.三相点也表示体系的三相平衡,那么低共熔点是不是三相点,能不能叫作三相点,本文就此谈一下看法,以澄清物理化学中的一些概念.1 低共熔点低共熔点,即相图上的一点.它给出了在指定压力下成低共熔平衡的物系其液相的组成和温度的数值.这就是说,低共熔点的压力是给定的.在给定的压力下,液相和全部低共熔固体成平衡,在全部结晶  相似文献   

3.
用目视变湿法研究了NaSCN-NaNO3-NaI三元系在可能温度范围的固液平衡,三元系为低共熔体系,低共熔点为213℃,41.7mol%,NaSCN和48.6mol%NaNO3。  相似文献   

4.
本文测定了12.5℃—97.5℃范围内十一个温度时CsCl在冰醋酸中的溶度,并绘制了相应的二元体系CsCl—CH_3COOH的溶度图,其低共熔点温度为:11.2℃,组成:CsCl(%重量)—7.8。  相似文献   

5.
本文作者对差热分析确定熔点的方法进行了实验,确定用DTA峰外推起始温度;用差热分析作了三组分交互体系Na,K ∥Cl,SO_4对角截面KCl-Na_2SO_4的状态图,从图上看出该截面为一简单低共熔型二组分体系,低共熔物组成为45%KCl,低共熔温度为525℃.  相似文献   

6.
采用目视变温法及DTA法对NaNO2-NaOAc-HCOONa三元体系的固-液平衡作了研究,实验发现体系为一般共熔型,其低共熔点为160℃,5%NaNO2,50%HCOONa。  相似文献   

7.
提出了一种由完全互熔型二元系相图计算熔化热的方法。将导出的公式应用于NaNO_3—KNO_3体系,计算出的结果与实验吻合,证明了该方法的可靠性和实用性。  相似文献   

8.
本文用DSC方法测定了ACNH_2—H_2C_2O_4二元系的相图,实验发现该二元系有一个新的相化合物ACNH_2·H_2C_2O_4生成,并用X—射线衍射数据进一步证实了该化合物的存在,它和ACNH_2的低共熔点为50.0℃、30%H_2C_2O_4、70%ACNH_2,它和H_2C_2O_4的低共熔点为112.0℃、76.0%H_2C_2O_4、24.0%ACNH_2。  相似文献   

9.
用差热分析法研究了Licl-Bacl_2-Srcl_2三元系及三个侧边二元系的相图。研究表明Licl-Bacl_2和Licl-Srcl_2二元系是两个低共晶体系,其共晶点E_1和E_2对应的温度分别为526℃和489℃。Bacl_2-Srcl_2二元系是具有最低温度点的连续固溶体。Licl-Bacl_2-Srcl_2三元相图中通过E_1和E_2及温度最低点E的二次析出线将三元系分为两个一次结晶面:Licl的一次结晶面和Bacl_2-Srcl_2固溶体的一次结晶面。该三元系的最低熔化温度是482℃,仅略低于Licl-Srcl_2二元系的共晶温度;三元系温度最低点E的组成为58.4mol%Licl,15.8mol%Bacl_2和25.8mol%Srcl_2。  相似文献   

10.
以有机相变材料癸酸-十二醇作为二元液-固体系相图绘制实验的研究对象,通过理论计算体系中各物质的相变温度绘制理论温度-组成(T-x)相图,并得到低共熔混合物温度和组成的理论值.配制不同摩尔分数的癸酸-十二醇混合物,利用热分析方法采用凝固点降低测定物质摩尔质量实验简单装置,测量各混合物冷却过程中相变温度,绘制有机酸-有机醇二元体系相图,得到低共熔点温度和组成,并与理论值进行比较.该实验避免了经典物理化学实验"二组分金属相图的绘制"在教学中金属样品融化温度高且耗时较长等问题,改用熔点较低的相变材料绘制固液相图,在满足二组分液-固相图实验要求的同时,将绿色化学实验设计理念融入到基础物理化学实验教学中.  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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-  相似文献   

19.
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-  相似文献   

20.
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  相似文献   

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