MOCVD法制备金属-陶瓷功能梯度材料的研究

利用金属有机化学气相沉积（MOCVD）方法，以Mo（CO）6，Si（OC2H5）4为物源，在Al2O3陶瓷基片上制备了金属一陶瓷功能梯度材料，并用XPS，XRD，SEM等技术对其成分分布，物相组成和表面形貌进行测试和表征，结果表明：材料的组成沿厚度方向呈连续梯度变化，符合功能梯度材料的变化规律。     

羰基金属气相沉积方法进行Al2O3基片表面合金化研究

利用羰基金属气相沉积的方法，以Fe(CO)5和Mo(CO)6为源，在Al2O3陶瓷基片上，制备了具有一定的化学组成和稳定的显微结构的Fe/Mo表面合金化层，大大提高了材料的表面性能。作为表面改性的新技术，可以广泛应用于许多重要的技术领域。     

五元杂环取代的茂金属配合物的合成及表征

将(C5Me4H) C4H3S,(C4H3S)C(CH3)(C2H5)(C5H5)和2- CH3C4H2O(C5Me4H)分别与Mo(CO)6,Ru3(CO)12和Fe(CO)5在二甲苯中加热回流,合成了3个新型的双核配合物[(η5-C5Me4C4H3S) Mo(CO)3]2,[(η5- C5H4)C(CH3) (C2H5) (C4H3S)Ru(CO)2]2和[(η5- C5 Me4(2 - CH3CH2O))Fe(CO)(μ-CO)]2.通过元素分析、红外光谱、核磁共振氧谱对其结构进行了表征.     

热处理对Fe-Mo-Cr-B堆焊合金组织的影响

以Mo、B、Cr、Ni、C及Fe粉末为药芯,低碳冷轧H08A钢为外皮,采用药芯焊丝埋弧堆焊方法制备FeMo-Cr-B堆焊合金,并分别对堆焊试样进行淬火与退火处理。结合光学显微镜、SEM、EDS、XRD及硬度测试等手段,研究热处理前后堆焊层组织、物相、成分及硬度变化。结果表明,Fe-Mo-Cr-B堆焊合金组织由α-Fe、Mo2FeB2、(Fe,Cr)2B及少量(Fe,Cr)_(23)(B,C)_6组成;堆焊试样在经950℃保温30min淬火或退火处理后,网状硼化物共晶组织消失,其物相组成为α-Fe和颗粒Mo2FeB2,且退火试样中Mo2FeB2数量较多;热处理后试样堆焊层硬度分布较为均匀,硬度显著提高,且其与基体结合界面过渡层的厚度增加。     

锡表面Mo(W)-S-Sn彩色簇合物膜的组成与结构研究

通过(NH4)2Mo(W)S4溶液浸渍,在金属Sn表面获得了不溶性且具有金属光泽的Mo(W)-S-Sn彩色簇合物膜。FT-IR、F-IR、FT-Raman、XPS和AES研究表明,簇合物膜中存在Mo(W)-S-Sn、端基Mo(W)-S和端基Mo(W)-O键,膜层由Mo(W)、S、Sn和O元素组成,膜为多分子层结构,从AES深度分布曲线的组成恒定区求得了元素的相对原子百分数和膜层厚度。     

铁的1,5,9-环十二碳三烯配合物合成及性质的研究

摘要本文研究了Fe(CO)_5与all-trans-CDT(Cyclododecantrine)的热反应,分离得到了一种高产率的all-trans-CDT配合物,此配合物通过IR.NMR和MS谱研究确定为[(CDT)Fe(CO)_3],其中1,5,9-all-tran-CDT中有二个非共轭烯键参与了配合,而另一个保持自由烯键.且研究了配合物[(CDT)Fe(CO)_3]与pph_3和Br_2的反应.     

M(CO)_4(Mic)_2(M=Cr,Mo,W)发光性质的理论研究

用二阶微扰方法(MP2)和单组态相互作用方法(CIS)方法优化了M(CO)_4(Mic)_2(M=Cr,Mo,W)的基态和激发态的几何结构,并用含时密度泛函方法(TD-DFT)计算了M(CO)_4(Mic)_2(M=Cr,Mo,W)的光谱.结果表明:在激发态,金属原子与相邻原子间的键相对基态减弱;Cr(CO)_4(Mic)_2的最低能量磷光光谱为773.1nm,主要归结为伴有CO(p)→Cr(d)跃迁(LMCT)的Mic(p)→Cr(d)(LMCT)跃迁;Mo(CO)_4(Mic)_2的最低能量磷光光谱为639.3nm,主要归结为伴有Mic-other(p)→Mo(d)跃迁(LMCT)的Mic-other(p)→O(p)跃迁(ILCT);W(CO)_4(Mic)_2的磷光光谱为640.5nm,主要归结为伴有Mic-other(p)→W(d)跃迁(LMCT)的Micother(p)→O(p)跃迁(ILCT);Mo和W配合物的发光跃迁属性表现出相似性,但与Cr配合物存在明显差异.由于Cr原子与相邻原子的相互作用明显强于Mo和W原子,所以Cr原子对配合物跃迁的贡献较Mo和W的更大.     

添加Co,Ni和Mo对钛铁矿原位合成Al_2O_3-Ti(C,N)-Fe复合材料的影响

在钛铁矿原位反应合成Al2O3-Ti(C,N)-Fe复合材料的基础上,添加Co,Ni和Mo来改善Al2O3-Ti(C,N)-Fe复合材料的性能。通过物相分析、扫描电镜和力学检测手段研究不同金属添加剂对合成产物物相、组织和性能的影响。研究结果表明:添加Co和Ni以后在烧结过程中分别形成了含Co和Ni的[Fe,Co]及[Fe,Ni]固溶相,材料的硬度有所降低,抗弯强度有所提高但提高的幅度不大。Mo的添加阻碍了Ti(C,N)相的长大,细化了Ti(C,N)晶粒;在烧结过程中生成的Mo2C包覆在Ti(C,N)相的周围,改善了Ti(C,N)相与Al2O3相和Fe相的润湿性,这同时导致了材料硬度和抗弯强度升高。当Mo添加量为8%时,烧结材料的力学性能最佳,抗弯强度和硬度分别为476 MPa和19.4 GPa。     

自蔓延预热粉体爆炸固结Mo/Cu FGM

采用新型水介质双向爆炸固结装置,结合自蔓延预热粉体技术制备了Mo/Cu功能梯度材料(FGM).观测了Mo/Cu FGM的显微结构,分析了爆炸固结机制.所制备样品的相对密度从Mo层的94.2%到Cu层的98.4%,呈现良好的梯度变化,样品整体相对密度达95.5%.Mo/Cu FGM电导率为国际退火铜标准(IACS)的27%.第3层、第4层的热导率分别为204.76和249.71 W·m-1·K-1.Mo/Cu FGM第1层与第2层的剪切强度为214.8Mpa.     

功能梯度材料圆(环)板的屈曲分析

基于经典板理论,推导了功能梯度材料圆形板在边界面内均布压力作用下的轴对称屈曲方程.假设功能梯度材料性质沿板厚度方向按成分含量百分比的幂指数形式连续变化,用打靶法求解所得方程,得到了功能梯度材料圆(环)板的临界屈曲载荷,并分析了材料的梯度性质、内外半径比以及边界条件对板临界载荷的影响.     

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.     

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