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1.
高温钛合金中稀土相的热稳定性   总被引:3,自引:0,他引:3  
对Ti5Al4Sn2Zr1Mo0.25Si1Nd(Ti55)高温钛合金在α相区、α+β相区,β相区不同温度、时间热处理样品的分析表明:在600~980℃/1~100h及1050~1500℃/1~10h条件下,稀土相颗粒尺寸在334~420μm之间波动;圆度系数在0619~0759之间波动;体积分数在14%~18%之间波动。稀土相颗粒尺寸、形状,体积分数基本不变,具有良好的热稳定性。  相似文献   

2.
钇对Fe-Cr-Al合金循环氧化行为的影响   总被引:2,自引:1,他引:1  
用热重分析、扫描电镜及能谱分析等手段研究了合金中弥散分布的Y、弥散分布的Y2O3及离子注入Y^+对Fe-23Cr-5Al合金1100℃循环氧化行为的影响,不含Y的合金比100h循环氧化后氧化膜发生了开裂和剥落,露出合金基体;加入弥散的Y或Y2O3的合金经100h循环化后氧化膜平坦致密,不剥落,离子注入1*10^17Y^+/cm^2后合金氧化膜主要发生层间剥落。Y提高Fe-Cr-Al合金氧化膜粘附性  相似文献   

3.
采用光学显微镜、扫描电和力学性能测试设备,研究了在IMI829和Ti-14Al-21Nb合金中添加Y,对合金显微组织遥影响。结果表明,在IMI829和Ti-14Al-21Nb合金中添加Y,可以细化这两种合金的组织和晶粒,使IMI829-0.2Y合金获得良好的室温力学性能和550℃蠕变性能,wgkqTi-14Al-21Nb-0.1Y合金的高温力学性能得到改善。  相似文献   

4.
Ce2O—TiO2/SiO2的制备及除氟性能研究   总被引:5,自引:0,他引:5  
以SiO2为基质,CeO2TiO2为包覆物质,采用溶胶凝胶法制备CeO2TiO2/SiO2表面复合物,并对所制复合物进行除氟测试。用扫描电镜(SEM)观察表面形貌,讨论实验环境、试剂用量等因素对CeO2TiO2/SiO2制备及除氟性能的影响,结果表明:nTi(OC4H9)4/nCeCl3·7H2O=1、nCH3COOH/nTi(OC4H9)4=45、nC3H8O3/nTi(O4H9)4=03、RH=95%,热处理温度110℃时,所制CeO2TiO2/SiO2对F-的吸附容量(q)为214mg/g,去除率(E)为856%。  相似文献   

5.
研究了稀土(Ce、Gd和Y)改性丝光沸石用作甲醇胺化催化剂在常压固定床反应器中选择性合成二甲胺的催化性能。结果表明,稀土阳离子交换改性能改善丝光沸石的催化性能。丝光沸石经0.1mol/LCe4+溶液处理,与膨润土成型,再于600℃下焙烧2~3h,这样制得的催化剂在常压400℃时的活性及二甲胺选择性分别达到99.8%和50.3%。此外,详细探讨了不同改性及制备条件对催化剂催化性能及机械强度的影响。  相似文献   

6.
Fe-W非晶镀层的磷化及在NaCl溶液中的腐蚀行为   总被引:4,自引:0,他引:4  
王宏智  姚素薇 《应用化学》1999,16(1):104-106
FeW非晶态合金镀层在酸性溶液中具有高耐蚀性能,但在中性和碱性溶液,特别是在氯化钠溶液中耐蚀性能差[1],如在30℃、1mol/LHCl溶液中,FeW非晶镀层的腐蚀速率约为不锈钢SUS304的1/15;在60℃、05mol/LH2SO4溶液中约...  相似文献   

7.
阿斯美胶囊中四种组分的高效液相色谱分析   总被引:2,自引:0,他引:2  
建立了反相高效液相色谱法测定阿斯美胶囊中氨茶碱、盐酸甲氧非那明、马来酸氯苯那敏及那可汀四种组分的含量。色谱柱为SpherisorbC8,5μm,200cm×40mmID,流动相为体积分数05%的三乙胺溶液(磷酸调节pH55)+乙腈+甲醇(550+368+82),检测波长为264nm,线性范围分别为:氨茶碱3125~250mg/L,γ=09996,盐酸甲氧非那明15625~1250mg/L,γ=10000,马来酸氯苯那敏25~200mg/L,γ=09999,那可汀875~700mg/L,γ=09999;回收率(n=3)分别为1012%,1008%,999%,995%;精密度:日内平均RSD(n=6)分别为07%,04%,04%,06%;日间平均RSD(n=3)分别为10%,10%,11%,12%。  相似文献   

8.
Ni/Al2O3催化剂上甲烷部分氧化制合成气   总被引:19,自引:2,他引:19  
研究了Ni/Al2O3催化剂对甲烷部分氧化制合成气的反应性能.结果表明,催化剂在其活性组份Ni为10%时反应性能最好.条件实验表明,在600~900℃范围内,甲烷转化率和CO、H2的选择性随温度升高而增加;转化率和选择性在甲烷空速≤1.5×105h-1时基本不变,空速>1.5×105h-1时,转化率和选择性有所下降.随着压力的增加(0.05~0.40MPa),转化率和选择性下降.SEM和化学分析结果证明在反应过程中,Ni组份存在烧结和流失现象.  相似文献   

9.
定向凝固法制备稀土超磁致伸缩材料   总被引:12,自引:1,他引:11  
对Tb03Dy07Fe195超磁致伸缩材料定向凝固过程进行了研究和分析,结合TbDyFe合金凝固特性,研究了凝固参数(包括定向凝固速率V和固液界面温度梯度G)、样品尺寸及起始晶粒取向三个主要因素对TbDyFe合金样品轴向取向的影响。当定向凝固参数(G/V)控制在适当范围,有利于保持平直的固液界面,因此有利于形成轴向<112>取向;当V增大或G减小,固液界面出现下凹,将影响择优取向的形成。样品尺寸与G和V应该相匹配,样品直径太大不利于保持平直的固液界面,因此不利于形成轴向<112>取向。采用<112>取向的晶粒作籽晶可以加快晶粒的择优竞争生长过程,有利于形成轴向完全<112>取向。这些因素的恰当控制,制备出了轴向具有完全<112>取向的Tb03Dy07Fe195合金样品,对样品进行高温退火处理,磁致伸缩性能达到了近1700×10-6。  相似文献   

10.
吸附络合物体系的示波分析   总被引:5,自引:0,他引:5  
In(Ⅲ)在pH457HAcNaAc0.1%VC0.06%HCuP溶液中,用示波计时电位法可获得良好示波图,其切口电位为E=090(Vs.SCE),切口高度与In(Ⅲ)浓度在800×10-7~14×10-5mol/L范围内成正比,检出限可达50×10-7mol/L吸附络合物组成为In(Ⅲ):铜铁试剂(HCup)=1∶1,条件稳定常数为59×103  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

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