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1.
研究了热处理和热循环Ni-Al-30Mn高温形状记忆合金相变行为的影响。结果表明:(1)在600-1100℃固溶淬火时,随固溶温度升高,该合金的马氏体相变温度升高;在1000℃固溶淬火后,马氏体相变开始温度和马氏体逆相变结束温度为分别为465℃和549℃,(2)在1000℃固溶处理处理和400℃时效处理后,该合金可获得良好的相变特性;热循环使相变行为的稳定性提高。(3)该合金的淬火组织由马氏体和γ相组成,其中马氏体的体积约占60%,马氏体的硬度高于γ相,时效处理后合金的相组成未变,硬度有所增加。  相似文献   

2.
利用音频内耗仪测试了Fe-Mn-Si基形状记忆合金热诱发马氏体、一般应力诱发马氏体和热-机械训练后的应力诱发马氏体的逆相变过程.结果表明,热诱发马氏体的逆相变在400~500K完成;经训练后的应力诱发马氏体逆相变开始温度与热诱发马氏体逆相变开始温度相近,但高于一般应力诱发马氏体的逆相变开始温度;一般应力诱发马氏体的逆相变温度低于热马氏体的逆相变温度,随应变量的增加,As降低  相似文献   

3.
Cu-Zn-Al合金马氏体在稳定化过程中的反常浮凸   总被引:1,自引:0,他引:1  
利用电阻温度曲线测量、记忆效应测量、金相观察、X射线衍射等方法研究了Cu-14.5%Zn-7.1%Al合金热弹性马氏体稳定化过程.发现在马氏体稳定化过程中除马氏体晶格常数a与c增大,b减小,a/b→0.866,β→90°外,尚存在马氏体浮凸、逆向记忆效应及马氏体电阻增大等现象.根据马氏体相变晶体学对上述现象进行了分析,认为马氏体稳定化是一个类似于贝氏体转变的扩散型切变转变,它可看成是β1→M转变的继续.  相似文献   

4.
用微型高压釜,以四氢萘和十氢萘为溶剂,在氢初压6.0 M Pa,反应温度390~ 450℃,反应时问0-60min下,添加铁化合物为催化剂进行煤炭加氢液化,考察各 种影响因素,并用穆斯堡尔谱测试液化残渣,探索其催化机理。结果表明,液化时 FeS2完全转变为磁黄铁矿Fe1-xS;Fe2O3-S或Fe3O4-S直接或经过中间物FeS2间接转变为磁黄铁矿。Fe1-xS生成量增多,液化转化率增大。进一步有力地证 实,Fe1-xS是以铁化合物为催化剂进行煤炭液化时的活性物种。  相似文献   

5.
本文研究了Ti-24Al-11Nb-3V-1Mo合金在500—650℃温度范围内的气相充氢过程.结果表明:在一定温度下,合金中的氢浓度随充氢时间的变化呈抛物线关系.通过求解扩散方程,得到氢在合金中的表观扩散激活能为90.40kJ/mol.研究还表明合金中的平衡氢浓度与充氢温度有关.  相似文献   

6.
以室温组织为马氏体的多晶CuZnAl形状记忆合金为试验材料,通过保持一定拉伸应变并在相变温度范围进行热循环实现了记忆合金在周期变化的温度和应力复合作用下的热机循环.用电阻法及应力测定法研究了热机循环中电阻-温度曲线及应力-温度曲线随循环次数的变化规律,对热机循环后合金中的热弹性马氏体转变特征及获得的双程记忆效应进行了研究.  相似文献   

7.
以较为简便的方法制备了几种离子交换树脂-Pd催化剂,并将此类双功能催化剂用于丙酮和氢气一步法合成甲基异丁基酮(MIBK).实验发现,催化剂的吸氢越大,反应选择性越好;而其交换容量过高则降低了选择性,升高温度有利于提高反应活性和选择性,但有一适宜值增大丙酮空速(LHSV)降低了反应活性和选择性,压力对反应影响不大.在各种树脂-Pd催化剂中Pd-干氢树脂(Pd-DH)的性能最好.在较佳的反应条件:温度130℃,压力2MPa,LHSV5h-1,氢酮比0.4下,用pd—DH催化合成MIBK,丙酮转化率为48%,MIBK选择性可达98%.  相似文献   

8.
对5Cr8MoVSi钢热处理工艺研究表明,经840℃退火,碳化物类型以M23C6为主,并有少量的MC和M7C3.淬火组织中剩余碳化物以MC和M7C3为主,M23C6型碳化物在淬火加热时大部分溶解.该钢随淬火加热温度升高,淬火马氏体由板条状和针状马氏体混合组织过渡到以板条状马氏体为主.在沉淀硬化的回火温度(485℃)下,淬火针状马氏体仍显示出原马氏体针;而淬火板条状马氏体的板条状方向性几乎被完全切断,显微组织呈均匀化.该钢在1000~1050℃淬火时,残余奥氏体量为10.7%~12.3%,经485℃一次回火时,残余奥氏体量减少不大,因此,应进行二次或三次回火.淬回火HRC硬度最高为58~60.  相似文献   

9.
研究了热处理对粘结剂质量分数为10%的WC-(Fe,Co,Ni)合金组织和性能的影响,结果表明:淬火-回火过程中,硬质相WC的形态、大小和分布基本上没有变化,但粘结相的结构有变化;烧结态粘结相为马氏体和少量残留奥氏体组成;淬火处理使烧结态合金中的残留奥氏体量减小;淬火后回火,粘结相中出现逆转变回火奥氏体;随回火温度升高,逆转变回火奥氏体增加。文中还讨论了烧结态粘结相中马氏体的形成和逆转变回火奥氏体产生的原因,以及不同回火处理态合金中逆转变回火奥氏体与合金性能的关系。  相似文献   

10.
热处理对CuAlNiMnTi形状记忆合金相变滞后的影响   总被引:2,自引:0,他引:2  
用电阻法、金相分析、电镜分析及X射线衍射等研究了热处理对CuAl-NiMnTi形状记忆合金相变滞后(Af—Ms)的影响.研究结果表明:淬火合金时效处理时,相变点急剧下降,时效初期相变滞后明显增大,后趋于稳定.淬火合金600℃中温处理时,相变点下降,相变量减小.而热弹性马氏体相变类型则从I型转变到Ⅱ型,然后再转变到I型;伴随着热弹性马氏体相变类型的变化,相变滞后开始降低,然后增加.这是因为时效处理时析出NiAl基相,中温处理时析出a相所致.  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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。  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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