GCr15轴承钢中MnS-Al_2O_3复合夹杂物析出行为

对于钢液铝脱氧精炼过程产生的Al_2O_3夹杂物严重影响钢的性能,而在钢液凝固过程中MnS夹杂物容易包裹着Al_2O_3夹杂物形成复合夹杂物,这种复合夹杂物改善钢材的性能有重要意义。通过场发射扫描电镜和能谱对国内某钢厂连铸坯中夹杂物形貌以及组成进行观察与分析,发现大量MnS包裹Al_2O_3复合夹杂物。同时通过理论热力学阐述MnS包裹Al_2O_3复合夹杂物的析出机理,计算得出:Al_2O_3夹杂物在钢液中形成,Mn S夹杂物在钢液凝固过程中形成,由于Al_2O_3夹杂物先析出,Mn S夹杂物可以在先析出的Al_2O_3夹杂物进行形核与长大,为钢中MnS包裹Al_2O_3复合夹杂物生成提供了理论依据。     

Al脱氧弹簧钢钙处理过程中铝酸钙硫化物析出热力学分析

通过钢液与夹杂物间的热力学平衡计算,对Al脱氧弹簧钢钙处理过程中铝酸钙硫化物的析出行为进行热力学分析,探讨[Al]、[Ca]、[S]浓度和钢液温度对Al2O3夹杂物变性行为的影响。结果表明,1600℃钢液温度下,w[Al]=0.03%时,Al2O3生成为低熔点12CaO·7Al2O3时的w[Ca]0.0034%,其值随钢液温度降低而减小,随铝含量增大而增大。CaS析出时的临界钙含量随钢液温度降低而显著减小,当w[S]0.005%时,w[Ca]随w[S]变化而显著变化。要使钢中夹杂物控制在低熔点12CaO·7Al2O3区域,需控制w[S]0.0037%,该值随钢液温度的降低或铝含量的增大而减小。     

帘线钢凝固过程中夹杂物析出

为了充分了解帘线钢中夹杂物,对钢液凝固过程析出夹杂物进行了分析. 结果发现:Al2O3夹杂物在凝固过程中先析出,且Al2O3夹杂物长大的限制性环节为[Al]在钢液中的扩散;当凝固分数为0.44时SiO2开始析出,且SiO2长大的限制性环节为[O]在钢液中的扩散;析出夹杂物的半径随着冷却强度的增大而减小;当冷却速度为100 K·min-1时,凝固末期析出Al2O3夹杂物的半径为2.5 μm,析出复合Al2O3-SiO2夹杂物的半径为4.7 μm;随着凝固的进行,夹杂物中SiO2含量增加,Al2O3含量下降.     

超纯铁素体不锈钢中TiN夹杂析出的热力学分析

为了控制TiN夹杂对材料性能的不利影响,对TiN在超纯铁素体不锈钢冶炼和凝固过程中析出的热力学条件进行分析。结果表明,在Cr含量为16%～23%的条件下,超纯铁素体不锈钢的最佳钛含量为0.1%～0.3%;当w（Ti）=0.3%时,将w（N）控制在0.004 6%以下才能避免在液相区中生成TiN夹杂;超纯铁素体不锈钢凝固过程中钛的富集程度稍低于氮;凝固末期残余液相中[Ti]和[N]的浓度分别提高到其初始浓度的2.5倍和3.2倍;随着钢液的逐渐凝固,凝固前沿温度和凝固前沿钛氮平衡浓度积下降,凝固前沿钛氮实际浓度积升高;降低钢中氮含量能推迟TiN析出时间,使TiN夹杂在凝固末期形成,可减小TiN夹杂尺寸,减少其析出数量。     

含硼微合金钢中硼氮化物形成的热力学分析

应用合金元素在奥氏体中的固溶度积公式,对含硼铝镇静钢,Ti-B和Ti-Nb-V-B系微合金钢中各种析出相的析出关系和析出量及其对奥氏体中固溶硼质量分数的影响进行了热力学分析.结果表明:含硼铝镇静钢中BN的析出优先于Al N的析出,使增加奥氏体稳定性的B的有效质量分数减少;提高含硼钢中的固溶B质量分数的有效方法是加入比B与N的结合力强的Ti;复合微合金钢中Nb,V的质量分数对固溶B的质量分数几乎没有影响,只与钢中加入Ti的质量分数有关,Ti-B和Ti-Nb-V-B系微合金钢中Ti的质量分数最少为钢中N质量分数的3.4~3.8倍.     

低碳低硫钢中MnS析出行为分析

本文研究铝含量、硫含量、冷却速率等对低碳低硫钢中MnS夹杂物的成分、形貌和析出量的影响,并利用Scheil凝固方程及FactSage 6.1软件对MnS析出行为进行了理论计算。结果表明,冷却速率较低(5K/min)时,钢中夹杂物为双层结构,核心氧化物为Al2O3-SiO2和Al2O3-SiO2-MnO,MnS在氧化物表面局部或包裹析出;冷却速率较高(900K/min)时,钢中夹杂物主要为Al2O3-SiO2-MnO,高铝钢样中没有MnS析出,而低铝钢样中有极少量MnS析出;MnS在夹杂物上的析出率随着冷却速率的降低、钢中铝含量的减少(硫含量随之增加)而提高;复合氧化夹杂中的MnO+SiO2对MnS的析出影响较大,MnO+SiO2含量越高,MnS越容易在氧化物上析出;在低硫(w[S]0.0050%)条件下,MnS不能在液相中单独析出,但能在夹杂物上复合析出。     

82A钢凝固过程中TiN夹杂析出热力学和动力学

用热力学和动力学方法研究82A钢液凝固过程元素偏析及其对TiN夹杂析出的影响.热力学分析表明, Ti的偏析比远高于N的偏析比;凝固冷却速度从6 K/min增至600 K/min过程中,凝固冷却速度对Ti、N凝固偏析比影响不大;钢液初始Ti含量降至0.000 2%、初始氮含量为0.002%～0.004%时,在凝固末期仍有TiN夹杂析出.动力学分析表明,随着钢液凝固冷却速度的加快,凝固析出的TiN颗粒尺寸明显变小.     

轴承钢中TiN夹杂物的控制研究

研究了轴承钢中TiN夹杂物的形成热力学,以及钢中Ti和N的控制理论,并在某钢厂进行了GCr15轴承钢的生产实验.结果表明,在凝固过程中钢中Ti或N的含量越高,TiN夹杂物开始析出温度就越高,析出物的尺寸就越大;使用低Ti合金原料能够有效降低钢中的Ti含量;采用低Ti铁水,初炼渣中的TiO2降到1.0%以下,能有效控制钢水中的Ti含量;采用低钛合成渣过程回钛量显著减少,钢中Ti含量由原来的37×10-6下降至30×10-6;优化改进精炼工艺和大包保护浇铸可以降低钢中N含量为33×10-6;降低凝固偏析,能降低TiN夹杂析出.     

镁对H13模具钢中夹杂物变性的影响

本文研究了镁对H13模具钢中夹杂物的影响,对H13钢中夹杂物的变性进行了热力学计算,分析了镁对夹杂物成分、形貌和粒径分布的影响。结果表明,镁处理H13钢后,夹杂物由Al2O3转变为MgO·Al2O3,复合型夹杂物的析出位置也发生了改变,夹杂物粒径变小。镁处理使钢中1μm左右的夹杂物增多,2μm以上的夹杂物减少,随着镁含量的升高,粒径的变化更明显。铝质量分数为0.01%~0.03%的H13钢中,微量的镁就可促使MgO·Al2O3夹杂物形成,镁质量分数超过1×10-4会导致H13钢中MgO·Al2O3完全消失,镁质量分数在3×10-5~5.5×10-5时钢液中镁铝尖晶石的数量达到最多。     

超低氧车轮钢中TiN夹杂析出的热力学分析及控制

通过对高速车轮钢中TiN夹杂物析出进行热力学分析,得到了车轮钢的液相线和固相线温度及1873K时Ti、N的活度.对TiN生成反应和钢中Ti、N溶度积进行了计算.结果表明:TiN只能在固相中生成,但在本车轮钢Ti、N含量下,固相中也没有TiN生成的条件,只有在钢液凝固前沿,由于Ti、N在两相区的富集,TiN夹杂物的生成反应得以进行.因此,在生产中,适当提高连铸二冷的冷却速率,使钢液快速凝固,减少凝固前沿Ti、N的富集时间,可减少纯TiN的析出.对本实验车轮钢中TiN夹杂的检测结果进行计算分析可知,在正常生产时铸坯冷却速率条件下,将钢中Ti的质量分数控制在3.5×10-5以下、N的质量分数控制在3.1×10-5以下,理论上可以消除TiN夹杂物的析出,改善车轮钢的疲劳性能,提高车轮的使用寿命.     

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

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.     

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.     

Design and analysis of generic LBS application developing platform

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

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

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.