低碳钢烘烤硬化中C元素晶界的偏聚

针对低碳钢,测试了不同预变形量下的烘烤硬化性能;采用电子背散射衍射及电子探针技术分别分析了低碳烘烤硬化钢板的晶界特征和晶界元素偏聚。结果表明,随着预变形量不断增加,烘烤硬化值不断增大;钢中小角度晶界不断增多,但总体上大角度晶界还是占主导地位。退火态和不同预变形量下的烘烤态均存在碳元素在晶界处偏聚的现象,锰元素没有晶界偏聚。     

消除TRIP钢屈服平台的预拉伸实验及微观机理

含铬高硅TRIP钢室温变形时通常具有较长的屈服平台,在成型过程中零件表面容易出现褶皱等缺陷.为了解决这个问题,采用预拉伸实验研究了不同预拉伸变形量对TRIP钢屈服平台的影响,并且对拉伸前后的TRIP钢试样做了TEM透射分析以期找出形成屈服平台的机制.实验表明:随着预拉伸量增加,屈服平台长度减少,当预变形量达到1.0%时屈服平台消失;在相同预拉伸条件下,奥氏体越稳定,屈服平台越短;柯氏气团和奥氏体的应力松弛机制共同对TRIP钢屈服平台的形成起作用.     

分段冷却模式下热轧双相钢的组织演变及力学性能

通过热模拟实验研究了分段冷却模式下变形温度、保温温度及保温时间对Nb-Ti微合金热轧双相钢组织演变及性能的影响.结果表明:降低变形温度可促进铁素体的转变,使马氏体形态由大块状过渡到岛状;保温温度从740℃逐渐降至580℃时,铁素体转变量先增加后减少,保温温度为660℃时铁素体转变量达到峰值;随保温时间延长铁素体转变量增加,且铁素体转变量与时间的关系曲线呈“S”型.采用超快冷+空冷+层流冷的冷却模式并通过调整终轧温度及空冷时间获得了630~710MPa的热轧双相钢,屈强比≤061,相应的组织为铁素体+马氏体或铁素体+马氏体+少量的贝氏体.     

Fe-20Mn-2.6Al-2.6Si钢拉伸变形机理研究

采用金相显微镜、X射线衍射仪和透射电子显微镜研究了Fe-20Mn-2.6Al-2.6Si TRIP/TWIP钢在不同变形量下的微观组织变化.结果表明:在应变初期,主要是形成层错和位错;随应变的增大,γ奥氏体相逐渐减少,ε马氏体相和α马氏体相增多;在断裂阶段,主要组成相为α马氏体,即Fe-20Mn-2.6Al-2.6Si钢在拉伸变形过程中主要发生γ→ε→α或γ→α相变诱导塑性变形.金相组织表明:该钢变形量达到6.5%时,开始出现许多平直的条纹(通常称为形变孪晶);但高分辨透射电镜研究表明:不同程度变形后的微观组织都难以观察到形变孪晶,而那些金相组织和低倍透射电镜照片上的平直条纹往往是ε马氏体相,这进一步证实该钢的变形机制主要是TRIP效应.     

钛钢再结晶温度的测定

实测含Ti0.043%的钢,当变形量为30%时,其开始结晶温度为959℃,比普碳钢提高100—120℃.另外当轧制温度为1050℃时随含Ti量的增加,开始再结晶变形量增加。对Ti的阻止再结晶的作用加以分析。再结晶温度的测定具有实际意义,它是区分再结晶轧制还是未再结晶轧制的界限。     

腐殖土对废水中Cu2+的吸附

研究了腐殖土对废水中Cu2+的吸附,并考察了吸附时间、Cu2+的初始浓度、腐殖土投加量、初始pH值和温度等因素对吸附过程的影响.通过吸附动力学、吸附等温线和红外光谱(FTIR)等方法探讨了吸附机理.试验条件下,单位腐殖土对Cu2+的吸附量随时间的延长而增加直至达到吸附平衡,随Cu2+的初始浓度增大和初始pH值的上升而增加,随腐殖土投加量的增加而减少,吸附过程温度的影响不显著.腐殖土吸附Cu2+的过程符合Lagergren准二级吸附速率方程和Freundlieh吸附等温方程,吸附过程以化学吸附为主,红外光谱分析表明,参与吸附的主要基团是羟基和芳香基等化学基团.     

ULCB钢中的冷变形与ε-Cu的脱熔行为

研究两种工艺的含铜超低碳贝氏体钢（ULCB）时效硬化行为,一种是直接固熔时效处理;一种是在固熔与时效处理之间进行一定量的冷预变形处理.实验结果表明,在一定的时效温度内,该钢的ε-Cu析出动力学曲线均会出现双峰甚至三峰现象.且经过预变形处理的钢,峰值出现的时间大幅度提前,峰值的高度也有明显的提高,在低温450℃时,预变形的这一作用更加明显.变形时效后,试验钢中的ε-Cu析出大量增加,且更加均匀.     

连续退火的无Si TRIP钢的组织和力学性能

在实验室用Gleeble3500热模拟试验机制备了一种无Si TRIP钢.利用拉伸试验机、扫描电镜、透射电镜、X射线衍射以及热膨胀仪对其力学性能、微观组织和相变规律进行研究,在此基础上分析了贝氏体相变温度和时间对力学性能和残余奥氏体的影响.无Si TRIP钢呈现出良好的整体力学性能,抗拉强度分布在740～810 MPa,延伸率均在25%以上,最高可达32%以上;贝氏体等温温度为420℃时能获得最佳的综合力学性能,抗拉强度随贝氏体相变时间增加而下降,延伸率随之上升,而屈服强度没有显著变化.无Si TRIP制的铁素体晶粒大小约为3～4μm,比含Si TRIP钢铁素体晶粒细小;残余奥氏体的体积分数在8%～10%,比含Si TRIP钢低约3%;420℃保温300 s后贝氏体相变基本结束,而碳的扩散仍然在进行;无Si TRIP钢贝氏体相变速率比含Si TRIP钢快,贝氏体相变总量也更多.     

终轧温度对ELC─BH板组织和性能的影响

研究了热轧终轧温度（ＦＴ）对超低碳高强度烘烤硬化钢板（简称ＥＬＣ─ＢＨ板）组织和性能的影响，结果表明：①两相区终轧形成的混晶组织是导致退火板　值和塑性减少的根本原因；②奥氏体区终轧时，随终轧温度降低，退火板成形性改善，但强度和烘烤硬化性有所削弱；③综合考虑终轧温度的影响，在略高于Ａｒ３的温度下终轧是合适的。     

奥氏体不锈钢在高温钠中的质量迁移效应研究

本文应用光学显微镜、扫描电镜、X射线衍射仪、俄歇能谱仪分析国产316Ti和321奥氏体不锈钢在650℃流动钠中浸泡4000、5000、8000、10000n后试样表面组成相类型、化学成分和显微组织沿横截面变化及试样表面腐蚀形貌。研究结果表明,国产316Ti和321奥氏体不锈钢在高温流动钠中浸泡后有明显的质量迁移效应。液态钠中所含碳向钢中扩散,钢中Ni、Cr合金元素向流动钠中扩散,引起钢增碳和Ni、Cr元素减少,钢表面的化学成分和组成相及显微组织发生明显变化。其表面组成相为铁素体、奥氏体和M_(23)C_6型碳化物,无σ相·随浸泡时间延长,表面铁素体量增多。表面组织为粒状α+M_(23)C_6+γ;次表层组织为晶界α+M_(23)C_6+γ;心部组织为σ+γ或晶界α+M_(23)C_6+σ+γ,在晶界铁素体层和心部组织之间有一无α、无σ相的碳化物沉淀区(M_(23)C_6+γ)。随浸泡时间继续延长,表层粒状铁素体层深增加,晶界铁素体层和碳化物沉淀区向心部延伸。试样表面产生腐蚀沟槽、晶界腐蚀和腐蚀坑及腐蚀裂纹,浸泡时间再延长,腐蚀加剧。321钢比316Ti钢质量迁移效应明显,腐蚀抗力差。     

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-