固溶和时效处理对碳纳米管/2024铝合金复合材料组织和性能的影响

对碳纳米管/2024铝合金复合材料进行固溶和时效处理，通过维氏硬度和室温拉伸实验测试了复合材料的性能，对固溶和时效处理后复合材料的微观组织和析出相进行了表征。研究发现，复合材料的强塑性与固溶和时效处理密切相关，碳纳米管/2024铝合金复合材料经530 ℃×4 h固溶处理后维氏硬度达到最高，为179.45，较原始复合材料维氏硬度提高约31%。时效处理后加速了时效硬化行为，经130 ℃×4 h时效处理后复合材料的抗拉强度、屈服强度和伸长率最高，分别为430.4 MPa，606.1 MPa和9.5%。结果表明，碳纳米管/2024铝合金复合材料适宜的固溶和时效制度为：固溶处理530 ℃×4 h，时效处理130 ℃×4 h。     

罐体用3104大铸锭均匀化过程中的组织性能演变

采用金相、扫描电镜、透射电镜、显微硬度测试等方法对3104合金大尺寸铸锭的均匀化制度进行研究.研究结果表明:在均匀化过程中,晶粒内部析出大量Al(Mn,Si)相和Al(Mn,Fe,Si)相;铸锭表面区域的析出相分布较均匀,而铸锭中部经过580℃/(4～12 h)均匀化后的析出相分布不均匀,晶界和晶粒中心存在无析出带,析出相细小;随着温度升高,析出相分布更加均匀,密度降低,粒度长大;铸锭晶粒内部的初始显微硬度不均匀,经过均匀化处理,晶粒边界硬度下降,而晶粒中心硬度上升,显微硬度差别减少;经过600℃/(8～12 h)均匀化,显微硬度最低,且最均匀;铸锭均匀化处理对后续的再结晶退火有显著影响,铸锭经过600℃/12 h均匀化,与经过450℃/12h相比,后续冷轧产品经过再结晶退火后具有更高的延伸率,晶粒更细小均匀;合适的均匀化处理制度为600℃/(8～12 h).     

2E12铝合金均匀化过程微观组织演变规律

采用SEM,EPMA,TEM和硬度测试等技术,研究2E12铝合金铸锭在均匀化过程中的非平衡相溶解、元素分布特征以及第二相析出行为。研究结果表明:合金铸锭的晶界处连续分布着粗大的α+θ+S共晶组织。合金中的Cu和Mg元素存在明显的偏析,而Mn元素分布较为均匀。随着均匀化处理的进行,合金中的粗大共晶组织逐渐溶解,Cu,Mg和Si元素逐步溶入合金基体,而Fe和Mn元素则从合金基体中脱溶。在均匀化处理过程中,合金基体中析出大量T相粒子。伴随着T相的析出,合金的硬度逐渐升高,同时电导率也明显增加。当合金于490℃均匀化1 000 h后,晶界附近出现明显的PFZ。     

真空离心铸造冷却速率对7055铝合金组织和力学性能的影响

采用真空离心铸造技术制备了7055铝合金铸管,通过添加中间包进行保温来改变合金凝固冷却速率,并对铸管进行组织和性能测试.结果表明,冷却速率较慢的1#铸管组织分布不均,其晶粒沿着外、中、内层由等轴晶逐渐变为粗大树枝晶,且晶粒间分布着更多的第二相;而冷却速率较快的2#铸管组织均为细小的等轴晶,且分布着少量的第二相.经过均匀化后,两种铸管的第二相分布数量由外、中、内层逐渐增多,且1#铸管残余的第二相数量更多;合金硬度值较铸态时有所增大,但2#铸管硬度值增大幅度更大,拉伸性能优于1#铸管.     

超声铸造2219铝合金均匀化工艺及第二相演变

采用DSC、金相、扫描电镜及能谱分析等方法,研究超声铸造2219铝合金均匀化工艺及合金铸锭中的第二相在不同均匀化制度处理过程中的演变规律。研究结果表明:超声铸造2219铝合金铸锭中存在大量非平衡凝固共晶体,其中的低熔点非平衡共晶相为Al_2Cu相,其过烧温度为560.79℃;在均匀化热处理过程中,该非平衡凝固共晶体不断向合金基体溶解,其数量、形态和分布均发生很大变化;铸锭中还存在少量长条状含铁相,该相在某些均匀化制度处理下变得粗大;该合金较合理的均匀化制度为550℃,24 h。     

均匀化处理对7A52铝合金组织和性能的影响

采用硬度、电导率测量、金相和高温原位X射线衍射分析技术研究不同均匀化处理条件下7A52铝合金组织与性能的变化规律，着重讨论不同均匀化处理条件下合金的物相组成及其演变、基体固溶体固溶度的变化与合金硬度和电导率的关系。研究结果表明：铸态合金由α-Al过饱和固溶体及少量平衡相MgZn2组成；在均匀化处理过程中，铸态合金显微组织结构发生了2个方面的变化：一方面，在300℃以下均匀化，过饱和固溶体分解，析出MgZn2平衡相；在400℃以上均匀化，上述平衡相又逐步回溶到基体固溶体中；另一方面，在400℃以上均匀化，铸态合金枝晶组织和枝晶间粗大的平衡相随均匀化温度的升高而逐步消失，与此同时，铸态合金的硬度先降低然后升高，电导率则先升高然后降低。这种性能的变化与铸态合金的组织结构变化一一对应。7A52合金铸锭适宜的均匀化处理工艺为470℃／24h。     

3003铝合金多道次热轧工艺的实验模拟

参照美国某铝业公司热轧工艺规程,在Ｇｌｅｅｂｌｅ１５００热模拟机上,对３００３铝合金多道次热轧过程进行了实验模拟,通过对变形后试样的金相组织与ＴＥＭ观察及显微硬度测量,发现亚晶的形成与再结晶不仅取决于轧制温度,而且还与铸锭均匀化处理工艺、变形不均匀带、累积变形量及道次间停留时间有关．均匀化Ａ处理（单级均匀化：５００℃）与Ｂ处理（两级均匀化：６００→５００℃）相比,前者由于产生细小弥散的第二相粒子,致使亚晶的形成与再结晶在整个热轧过程中都相应地减弱．     

3003铝合金铸锭均匀化退火工艺及力学性能

为了节能减排,利用光学显微镜、扫描电镜、万能力学试验机等手段,研究分析了3003铝合金不同均匀化退火工艺后的组织演变及力学性能变化。结果表明:随均匀化退火温度的升高,对应的最佳工艺时间减少;620℃下退火5 h时的组织与610℃下退火7 h时基本相同,晶界处无偏析第二相粒子且晶内弥散分布第二相粒子;常温及高温瞬时拉伸时,620℃退火5 h的合金拉伸强度、延伸率均高于610℃退火7 h的。该研究通过升高退火温度、减少时间改善了3003合金铸锭均匀化退火工艺,最佳工艺为650℃下保温5 h。     

3104铝合金铸锭均匀化过程中的溶解析出行为

通过电导率测试,扫描电子显微镜、透射电子显微镜观察分析,研究3104铝合金铸锭单级和双级均匀化过程中溶解和析出行为.结果表明:600℃均匀化时,在保温时间1.5～24h范围内,随保温时间的延长,非平衡结晶相逐渐溶解、球化;在450℃均匀化时,在晶内和晶界处析出大量含Mn第2相,但锭坯中的骨骼状和片状的非平衡结晶相仍存在:600℃/12 h+450℃/12 h双级均匀化后,锭坯中初生相和析出相的第2相粒子均匀分布,初生第2相粒子的平均粒径约为4μm,析出第2相粒径约为0.5 μm.     

Al-7.8Zn-1.6Mg-1.8Cu合金铸锭及其均匀化的微结构研究

采用光学金相(OM)、扫描电镜(SEM)、透射电镜(TEM)、X线衍射(XRD)、差示扫描量热(DSC)等技术研究Al-7.8Zn-1.6Mg-1.8Cu(7085型)合金铸锭及其均匀化的微结构。研究结果表明:该铝合金铸锭中主要结晶相为分布在晶界的网状Mg(Zn,Al,Cu)2相,晶内有少量微米量级球状和纳米量级条状的Al2Cu结晶相,此外,还有纳米量级Al2Cu和Fe-rich析出相;在均匀化过程中,Al3Zr粒子析出,Mg(Zn,Al,Cu)2相溶解消失,且部分转化成Al2CuMg相;当均匀化温度升高到470℃时,除Fe-rich相和Al3Zr粒子外,其他第二相都溶入基体;于400℃/12h+470℃/12h双级均匀化比于470℃/12h单级均匀化更有利于提高Al3Zr粒子析出的数量和改善其分布均匀性。     

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.     

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.     

The Analects and the Moment in Peking——The influence of a Confucian education system on the personality formation,the way of thinking and the fate of the main characters

0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation＇s behavior in their social life throughout the long history is beyond list.