紧耦合真空气雾化制备Fe-Cr合金粉末的特性表征

采用紧耦合真空气雾化法制备Fe-Cr合金粉末,通过不同目数的筛网进行筛分,得到0~25 μm、25~53μm、53~105 μm、105~150 μm四个粒度段的粉末.使用氧氮分析仪、碳硫分析仪、电感耦合等离子体发射光谱仪分析雾化前后粉末化学成分,测定全粒度段及各粒度段的氧含量变化情况;采用扫描电镜、激光粒度仪等分析测试手段观察粉末表面形貌及表面微观组织并测定粉末粒径.结果表明:紧耦合真空气雾化制备Fe-Cr金属粉末化学成分可精确控制,全粒度段氧含量为0.024wt.%;冷却速度随粉末粒径的减小呈现指数级增长,随着粉末粒度段的增大,表面组织主要由胞状晶、柱状晶向树枝晶发展;各粒度段氧含量随粒径增大逐渐减小;空心粉的形成主要与袋式破碎机制和晶粒凝固收缩差有关.     

气体喷雾－水淬工艺制造Al－Si合金粉末

采用气体喷雾－水淬工艺制造一系列Ａｌ－Ｓｉ共晶和过共晶合金粉末，重点研究喷雾条件对粉末粒度的影响及初晶硅大小和粉末含氧量与粉末粒度的关系，结果表明，用这种经过改进的工艺制造的合金粉末组织十分均匀细致，初晶硅的尺寸为２～７μｍ，氮气喷雾粉末的含氧量为０．１５％（质量分数），小于０．２００～０．２２０ｍｍ的细粉占全部粉末的９０％以上。     

机械合金化无铅纤料Sn—9Zn研究

利用X射线衍射仪、差示扫描量热计（DSC）、扫描电镜（SEM）对Sn-9Zn粉末的机械合金化进程进行了研究。结果表明：机械合金化和热铸法一样是一种制备钎料合金的方法；金属粉末的最终颗粒尺寸可以通过合适的工艺参数来控制；粉末尺寸可减小到5-20μm；1%松香（助磨剂）的加入使MA进程的加速作用最为显著，但松香也可能对金属粉末起污染作用。     

以抗坏血酸为还原剂的超细铜粉的制备及其热稳定性

采用液相化学还原法，以抗坏血酸为还原剂，制备了５００ｎｍ至７μｍ不同粒径范围的超细铜粉，研究了该法的制备工艺及偻末在空气中的热稳定性。采用葡萄糖预还原法制备了粒径为１μｍ的均匀超细铜粉，改善了铜粉末的粒度分布。研究了干燥过程对粉末团聚程度的影响。     

机械合金化无铅钎料Sn-9Zn研究

利用 X射线衍射仪、差示扫描量热计 ( DSC)、扫描电镜 ( SEM)对 Sn-9Zn粉末的机械合金化进程进行了研究 .结果表明 :机械合金化和热铸法一样是一种制备钎料合金的方法 ;金属粉末的最终颗粒尺寸可以通过合适的工艺参数来控制 ;粉末尺寸可减小到 5～ 2 0μm ;1 %松香 (助磨剂 )的加入使 MA进程的加速作用最为显著 ,但松香也可能对金属粉末起污染作用 .     

尺寸和球磨对细晶钨粉烧结体致密度的影响

采用溶胶喷雾干燥-煅烧-氢热还原法制备了粒径为0.14μm的超细纯钨粉末。研究不同球磨(干磨,湿磨)方式对钨粉形貌以及粉末成形性的影响,探讨纯钨样品性能随样品不同尺寸(2.5mm厚小样品和2cm厚大样品)的变化。此外还详细研究了纯钨烧结体组织形貌、晶粒尺寸等性能随球磨方式及样品尺寸的变化规律。结果表明,使用干磨法和湿磨法球磨处理都可以有效提高粉末的成形性。使用干磨法球磨制备的粉末的烧结体致密度高于湿磨法所制备的,且在大尺寸样品中其致密度分布也较湿磨法所制备粉末的烧结体更加均匀。湿磨粉颗粒粒径分布较广,颗粒容易长大。干磨粉由于活化效果较弱,烧结体颗粒更加细小。     

采用固相配位法制备超细LiMn2 O4正极材料

采用固相配位反应法制备锂离子电池正极材料LiMn2O4,并对配位络合剂用量和反应温度对最终产物的物相、比表面积、粒径和电性能的影响进行研究.研究结果表明:采用回相配位法可制备超细LiMn2O4粉末,配位化合物前驱体在550℃时焙烧12 h,粉末的粒度细小,粒径在0.06～0.50μm的粉末占82.10%;粉末的平均粒径为138.12 nm,比表面积为10.15 m2/g,颗粒形貌规则,内部有很多微孔;材料的首次充、放电比容量分别为126.0 mA·h/g和124.2 mA·h/g,首次充放电效率为98.6%,经15次循环后,材料的容量保持率为91%.     

纳米级WO3-CuO复合氧化物粉末的制备

用超声喷雾热转换法直接制成纳米级非晶复合氧化物粉末,并采用XRD,TEM和TG-DsC手段研究纳米WO3-CuO复合氧化物粉末的热解与非晶向微晶的转化过程.结果表明用超声喷雾热转换法可以工业化大规模生产纳米级WO3-CuO复合氧化物粉末,粉末平均粒径＜50nm,颗粒形状为球形.     

电爆制备超细粉的方法以及过程参数对制备的影响

利用金属丝脉冲放电的爆破过程,可制备出纯度高、化学活性高的金属超细粉.研制了一种金属丝电爆实验装置.采用不同的过程参数进行了电爆铜丝试验,制备出铜及氧化铜超细粉,研究了电爆过程参数对粉末粒度和形态的影响.激光粒度测试的粉末平均粒径为0.5μm,粒度分布为0.2~0.8μm;扫描电镜的粉末微观形态为球形和多面体.通过调节过程参数放电初始电压、储能电容的电容量、金属丝的几何尺寸和放电回路中的电感,可提高金属丝发生电爆时的能量密度和瞬时功率,从而使粉末粒径减小.     

W—Ni—Fe系纳米级复合氧化物粉末的制取及粉末特性

用Ｈ２ＷＯ４，ＮｉＣｌ２的碱性水溶液与ＦｅＣｌ２水溶液快速混合的方法，在超声喷雾热转换装置中，制备了（Ｗ，Ｎｉ，Ｆｅ）系纳米级复合氧化物粉末，通过Ｘ射线衍射及电镜分析，研究了它的物相组成与使用溶剂的关系；同时研究了粉末的颗粒形貌特征及粒度范围。     

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.     

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.     

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.