元素粉末Ti,Al热压致密化过程分析

采用热模拟手段研究了温度为８００ ℃时元素粉末Ｔｉ，Ａｌ 在热压过程中的致密化行为，测定了元素粉末Ｔｉ，Ａｌ 在热压中后期的各种力学曲线，并获得了此时材料的致密化方程及应力应变速率方程．结果表明：热压初期，由于元素粉末Ｔｉ，Ａｌ 反应后压坯强度很低，大量的致密化在加压后的短时间内完成；热压中后期，由于压坯强度的提高，致密化进入由扩散蠕变控制的缓慢阶段，且在该阶段元素粉末Ｔｉ，Ａｌ 的致密化行为近似遵循线性粘性体关系．     

稀释剂Al_2O_3对Al/TiO_2自蔓延高温合成反应影响的研究

在研究稀释剂Ａｌ＿２Ｏ＿３对自蔓延高温合成反应４Ａｌ＋３ＴｉＯ＿２＝３Ｔｉ＋２Ａｌ＿２Ｏ＿３的绝热温度及反应模式的影响的基础上，研究了稀释剂Ａｌ＿２Ｏ＿３对该ＳＨＳ反应过程的影响以及对合成Ｔｉ／Ａｌ＿２Ｏ＿３金属陶瓷复合材料组织结构的影响．结果表明，稀释剂Ａｌ＿２Ｏ＿３含量增加，ＳＨＳ反应所必需的预热温度提高，燃烧速率降低，且燃烧不稳定；制备的Ｔｉ／Ａｌ＿２Ｏ＿３金属陶瓷复合材料致密度下降，但产生裂纹的倾向减少．     

高温气溶胶反应器中制备纳米TiO2颗粒的形态和结构

在高温管式气溶胶反应中,利用ＴｉＣｌ４,气相氧化制备纳米ＴｉＯ２颗粒,研究了ＴｉＯ２颗粒的形态和结构特征,实验结果表明氧气预热温度升高,ＴｉＯ２粒子粒径减小,分布变窄,反应气氛中加入ＡｌＣｌ３后ＴｉＯ２粒变得圆整,ＴｉＯ２粒径随ＡｌＣｌ３用量增加而减小,粒子中金红石含量随ＡｌＣｌ３用量增加而增大,反应温度升高时ＴｉＯ２粒子粒度增大,但金红石含量在反应温度为１２００℃时出现最大值,控制反应温度为１１     

3%C-Cu机械球磨复合粉末的烧结

为了给后续的致密化工序(如热挤压)提供较高质量的烧结坯,用扫描电镜和光学显微镜分析了3%C-Cu机械球磨复合粉末所制备烧结坯的显微组织,并研究了工艺参数对其相对致密度的影响规律.结果表明,烧结温度对未机械球磨混合粉烧结行为的影响很大,而机械球磨复合粉对烧结温度不敏感.真空热压烧结可以明显地促进致密化过程.提高烧结温度、延长烧结保温时间或增加热压压强,均有助于提高烧结坯的相对致密度.在相同条件下,烧结坯的相对致密度随着复合粉末机械球磨时间的延长而降低.     

快速凝固Ti3Al基合金中ω相的形成

通过电子衍射的方法研究了ＴｉＡｌ基合金中ω相的形成规律及形成过程。在快速凝固态、热压态以及淬火态的ＴｉＡｌ基合金中均未见到ω个，而在淬火后４０００～６００℃回火时则可清楚地看到ω相的存在，并且在此温度范围内随着回火温度的升高，ω相的析出越长彻底，结构越完善。     

用Wagner方程研究Ti衬底与Al膜间的反应和互扩散

本文根据Ｔｉ与Ａｌ膜间的反应和互扩散动力学提供的浓度分布曲线，用Ｗａｇｎｅｒ方程计算Ｔｉ衬底与Ａｌ膜间在Ｔｉ相变点上、下Ａｌ的互扩散系数Ｄ和激活能Ｑ，找出了互扩散系数与温度与成分的变化规律，计算结果表明，扩散激活能的大小次序是：ＱＴｉ３Ａｌ＞ＱＴｉＡｌ＞Ｑａ－Ｔｉ（Ａｌ）＞Ｑｂ－Ｔｉ（Ａｌ）。     

多相复合陶瓷刀具材料热压过程的计算机模拟与工艺设计Ⅰ——温度场模拟与工艺设计

建立了陶瓷刀具材料热压过程的传热模型,并以Al2O3／SiC／(W,Ti)C多相复合陶瓷刀具材料为例,通过采用计算机模拟技术对坯体温度场的研究,进行了相应的热压工艺设计．结果表明：升降温速率的大小及烧结前气孔的存在对坯体内温度场影响较大．综合考虑材料性能和制各效率的要求,在本试验条件下,升温速率以0．5～0．75℃／s而降温速率以0．33℃／s为宜．从温度场的角度来看,在陶瓷刀具材料热压成型之前,应先冷压成坯,以提高坯体的初始相对密度,降低热压过程中的温差,改善材料的物理力学性能。     

镁颗粒在烧结过程中的变化方式及其对泡沫铝制备的影响

 研究了粉末冶金法制备泡沫铝材料过程中,提高可发泡预制坯致密度的方法.分析了预制坯制备过程中影响致密度的因素以及致密化过程;研究了烧结处理过程中烧结温度、烧结时间对预制坯内部组织结构及其致密度的影响.着重分析了烧结处理对Mg颗粒以及泡沫铝孔径结构的影响.对于粉末粒度为75~150μm的原料粉末来说,将在400MPa的压制压力下制备的预制坯进行450℃烧结处理2h以上,可提高预制坯的致密度并能够增加基体的连续性,烧结后Mg颗粒尺寸为原来的2~3倍.实验结果表明：采用冷压的方式,在400MPa的压力下,对经过450℃烧结2h后的预制坯进行发泡,可以得到孔径均匀、孔隙率高的泡沫铝材料.     

快速凝固Ti_3Al基合金中ω相的形成

通过电子衍射的方法研究Ｔｉ３Ａｌ基合金中ω相的形成规律及形成过程。在快速凝固态、热压态以及淬火态的Ｔｉ３Ａｌ基合金中ω相，而在淬火后期４００～６００℃回火时则可清楚地看到ω相的存在，并且在此温度范围内随着回火温度的升高，ω相的析出越彻底，结构越完善。快速凝固Ti_3Al基合金中ω相的形成@徐瑞@赵越超@迟长志     

Al_2O_3-TiC 和 Al_2O_3-TiB_2 的热力学分析

从理论上对铝热剂燃烧合成复相陶瓷Ａｌ２Ｏ３－ＴｉＣ和Ａｌ２Ｏ３－ＴｉＢ２的绝热温度及产物中Ａｌ２Ｏ３的熔化率进行了研究．随着预热温度的升高或稀释剂含量的降低,反应体系的绝热温度升高,但在２３０３Ｋ处均出现一个平台,其原因是Ａｌ２Ｏ３的熔化率不固定,在０～１之间变化．随预热温度的升高,燃烧反应能够自我维持的临界稀释剂的添加量也增多．     

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.