几种铈盐的热分解过程及非等温热分解动力学研究

利用TG—DTG—DTA热分析技术研究了二水合碳酸亚铈、九水合草酸亚铈、六水合硝酸亚铈三种铈盐的热分解过程．发现二水合碳酸亚铈在75-180℃下脱去2mol水生成无水碳酸亚铈，后者在220—300℃下分解脱去CO2生成CeO2；九水合草酸亚铈在100-180℃下脱去9mol水生成无水草酸亚铈，后者在290—380℃下分解并同时脱去CO和CO2生成CeO2；而六水合硝酸亚铈在60—80℃下首先脱去3．5mol水生成含2．5个结晶水的硝酸亚铈，后者在190-250℃下脱去2．5mol结晶水生成无水硝酸亚铈，在258—310℃下硝酸亚铈热分解脱去NO2和O2并生成CeO2．采用外推法研究了九水合草酸亚铈两步热分解过程的动力学，由不同升温速率下的热分析曲线及外推β→0获得了相应的固相热分解反应所遵循的分解机理及动力学参数．发现九水合草酸亚铈脱水过程遵循球形对称的三维扩散机理，即Jander方程G（α）=G（α）=[1-（1-α）^1/3]^2，动力学参数E=180．9kJ／mol、lnA=63．5s^-1；而脱CO和CO2过程遵循成核和生长机理，即Avrami-Erofeev方程G（α）=[-ln（1-α）]^1/1.5，动力学参数E=115．4kJ／mol，lnA=22．0s^-1．     

含邻苯二甲酰亚胺基的新型胺基甲酸乙酯的合成

以碳酸钾为缚酸剂，4-硝基-邻苯二甲酰亚胺与五种卤代试剂在N，N-二甲基甲酰胺(DMF)中回流反应3h．生成相应的N-取代-4-硝基-邻苯二甲酰亚胺(1)，产率为46．4％～92．5％，硝基物在盐酸体系40℃下经氯化亚锡还原，得到N-取代-4-氨基，邻苯二甲酰亚胺(2)，产率为29．6％～92．2％，氮气保护条件下，2与乙醇在固体光气作用下生成(2-取代-1，3-二酮-2，3-二氢-1H-异吲哚-5-)-氨基甲酸乙酯(3)，3的产率为67％～92％．各化合物的结构均经^1H-NMR、IR、元素分析和FAB-MS证实。     

1-(2-嘧啶基)-4-(3-氨丙基)哌嗪的合成

合成1—(2—嘧啶基)—4—(3—氨丙基)哌嗪，目前大多采用4—(2—嘧啶基)—1[3—(2—邻苯二甲酰亚胺基)丙基]哌嗪肼解的合成方法．腈的毒性大以及操作过程中使用球—球蒸馏装置不利于工业化的批量生产．鉴此，本工作通过研究4—(2—嘧啶基)—l—[3—(2—邻苯二甲酰亚氨基)丙基]哌嗪酸性水解(产率63．5％)和碱性水解(产率50．0％)的反应条件，不仅去掉了球—球蒸馏反应，使反应产率提高、使反应过程容易操作，而且得出了最佳水解条件：对于酸性水解，4—(2—嘧啶基)—1—[3—(2—邻苯二甲酰亚氨基)丙基]哌嗪与盐酸摩尔数之比为1：30，对于碱性水解，前与氢氧化钠摩尔数之比为1：22，反应时间均为6h一7h．     

热分析法研究CuSO_4·5H_2O结构

利用热分析法(TG/DSC)研究五水硫酸铜(CuSO_4·5H_2O)的热分解过程,并对其脱水机理及硫酸铜(CuSO_4)在高温下分解机理进行探索.研究表明,在升温速率为1℃/min时,CuSO_4·5H_2O的脱水过程为,在75℃失去2个结晶水,在100℃又失去2个结晶水,在215℃失去最后1个结晶水.CuSO_4分解为,CuSO_4在700℃分解生成氧化铜(CuO)和三氧化硫(SO_3),理论失重率为32.0%,实际失重率为31.0%;CuO在810℃进一步分解生成氧化亚铜(Cu_2O)和氧气(O_2),理论失重率为3.2%,实际失重率为3.2%,理论计算与实际测量值基本吻合.用X-射线衍射仪(XRD)及扫描电子显微镜(SEM)对CuSO_4·5H_2O分解产物进行分析,表征结果与热分析结果相一致,进一步验证了热分析方法的可靠性.     

沉淀法合成的纳米CeO2前驱体的热分解动力学

以Ce(NO3)3.6H2O为铈源,(NH4)2 CO3.H2O为沉淀剂,加入少量PEG4000作为分散剂,采用化学沉淀法并经水洗、超声波醇洗,70℃干燥后得到CeO2的前驱体Ce2(CO3)3.H2 O。对Ce2(CO3)3.H2 O样品运用差示/热重分析(DSC/TG)和X射线衍射(XRD)方法进行其热分解过程研究,并通过多重速率扫描法记录样品在不同升温速率下的DSC/TG曲线,采用Kissinger-Akahira-Sunose(KAS)法和Coats-Redfern法进一步研究Ce2(CO3)3.H2 O的热分解动力学。研究结果表明:Ce2(CO3)3.H2 O热分解反应过程分2步进行,主要反应阶段的反应动力学参数是:反应活化能为105.51 kJ/mol,反应级数为2,频率因子为3.61;由此推断出可能的Ce2(CO3)3.H2 O热分解机理函数为Anti-Jander方程,受三维扩散机制控制。     

酰亚胺的相转移催化N-烷基化反应

A.Butenandt 等发现,邻苯二甲酰亚胺的钾盐与三甲基苄基的季铵盐反应时,季铵盐发生分解而得到 N-苄基邻苯二甲酰亚胺,同时生成挥发性的三甲铵.U.Landini 和 F.Ralla 利用季磷盐为催化剂,用邻苯二甲酰亚胺钾盐为被作用物,进行了固一液相转移提取烷基化反应.考虑到这些情况,我们选用对称性高并且不形成挥发性胺的四丁基溴化铵(TBAB)作为催化剂,在二氯甲烷和40～50%氢氧化钾溶液中,用卤代烃与酰亚胺在35℃进行 N-烷基化反应.用溴丁烷为烃基化试剂,对催化剂用量及反     

Ni(Py)4(SCN)2配合物热分解机理测定

利用差热分析法(DTA)结合热重法(TG)测定Ni(Py)4(SCN)2配合物的热分解机理.通过实验测定,该配合物在130 ℃以下稳定,133 ℃左右开始分解,133～187 ℃先失去四分子吡啶,分解成灰绿色的Ni(SCN)2和吡啶,212～272 ℃再次分解生成棕黄色的Ni(CN)2及单质S,345～415 ℃最后分解得到黑色有光泽的单质Ni.     

ZnC2O4·2H2O-NiC2O4·2H2O在空气中的热分解动力学

通过热重法(TG-DTG)、差示扫描量热法(DSC)、X射线衍射(XRD)技术研究了固态物质ZnC2O4·2H2O-NiC2O4·2H2O机械混合物(摩尔比3:2)在空气中热分解的过程.TG-DTG的曲线表明:其热分解过程TG曲线中4个明显的台阶与理论失重相吻合.XRD结果表明:样品在500℃煅烧生成为较好晶型的ZnO-NiO混合物.用Kissinger-Akahira-Sunose(KAS)法和Ozawa法求取Ea,用热分析动力学三因子求算的比较法判断出可能的机理函数.ZnC2O4和NiC2O4热分解的活化能分别为175.69～176.48 kJ/mol、220.28～200.93 kJ/mol,ZnC 2O4和NiC2O4分解反应过程可能遵循的机理函数微分形式分别为f(α)=3(1-α)[-ln(1-α)]2/3和f(α)=2(1-α)[-ln(1-α)]1/2;积分形式分别为g(α)=[-In(1-α)]1/3和g(α)=[-ln(1-α)]1/2,都属于随机成核和随后生长型机理函数(Avrami-Erofeer),Am,其调节因子m=3、2.     

ZnC2O4·2H2O-NiC2O4·2H2O在空气中的热分解动力学

通过热重法(TG-DTG)、差示扫描量热法(DSC)、X射线衍射(XRD)技术研究了固态物质ZnC2O4·2H2O-NiC2O4·2H2O机械混合物(摩尔比32)在空气中热分解的过程.TG-DTG的曲线表明其热分解过程TG曲线中4个明显的台阶与理论失重相吻合.XRD结果表明样品在500℃煅烧生成为较好晶型的ZnO-NiO混合物.用Kissinger-Akahira-Sunose(KAS)法和Ozawa法求取Ea,用热分析动力学三因子求算的比较法判断出可能的机理函数.ZnC2O4和NiC2O4热分解的活化能分别为175.69～176.48 kJ/mol、220.28～200.93 kJ/mol,ZnC 2O4和NiC2O4分解反应过程可能遵循的机理函数微分形式分别为f(α)=3(1-α)[-ln(1-α)]2/3和f(α)=2(1-α)[-ln(1-α)]1/2;积分形式分别为g(α)=[-In(1-α)]1/3和g(α)=[-ln(1-α)]1/2,都属于随机成核和随后生长型机理函数(Avrami-Erofeer),Am,其调节因子m=3、2.     

稀土配合物[Ln(C3H7NO2)2(C3H4N2)(H2O)](ClO4)3(Ln=Eu,Dy)的合成、表征与热分析

合成了稀土高氯酸盐与咪唑、DL-α-丙氨酸的两种配合物晶体．经傅立叶变换红外光谱(FT—IR)、元素分析和化学分析测定后确定其组成为[Ln(C3H7NO2)2(C3H4N2)(H2O)](ClO4)3(In=Eu，Dy)．用差示扫描量热法(DSC)在高纯流动N2气氛下测定了两种配合物的热分解数据，它们的热分解过程都是由两个放热峰组成，两个配合物开始分解的温度分别为497．2K，491．8K，峰顶温度分别为564．4K和613．2K，544．4K和615．1K，热分解焓值分别为2026kJ／mol和961．2kJ／mol，2596kJ／mol和1097kJ／mol．测定结果表明配合物有较高的热稳定性．     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-