锑对AZ81-1.2Y-0.6Sm合金组织和力学性能的影响

通过合金制备、组织观察和拉伸试验,研究了加入0.2%~0.8%Sb(质量分数)对AZ81-1.2Y-0.6Sm合金组织和力学性能的影响。结果表明:向AZ81-1.2Y-0.6Sm合金中加入适量的Sb后,可生成高熔点的Mg3Sb2相,从而细化晶粒,改善组织。随着Sb含量的增加,合金在室温和150℃下的抗拉强度和伸长率均先升高后降低,且在Sb含量为0.5%时取得最大值。     

钐对铸态ZK30镁合金组织和力学性能的影响

基于对高强镁合金的迫切需求,选用Sm作为合金化元素添加到ZK30镁合金中。采用真空感应熔炼炉制备ZK30-x Sm镁合金(x=0%,1%,2%,3%,4%,质量分数),研究了不同含量的Sm对铸态ZK30镁合金微观组织和力学性能的影响。通过OM,SEM,EDS,XRD观察和分析了合金的微观形貌和组织成分,并对材料进行了拉伸试验和硬度测试。结果表明:加Sm镁合金主要由α-Mg基体和Mg_(41)Sm_5相组成,并且合金组织由树枝晶转变为细小的等轴晶;合金的抗拉强度σ_b,屈服强度σ_(0. 2)和伸长率δ随着Sm含量的增加先升高后降低,当Sm含量为1%时,σ_b,σ_(0.2)和δ均达到最大值,分别为250. 4,109. 0 MPa和14. 4%;合金的硬度也在Sm含量为1%时,达到最大值59. 85 kgf·mm~(-2)。但过量的Sm恶化组织,降低了性能。添加元素Sm后合金性能的提高主要归因于细晶强化、固溶强化和析出强化的共同作用。     

稀土对挤压态Cu-7Ni-7Al-2Fe-2Mn合金耐蚀性能影响

研究了稀土元素对Cu-7Ni-7Al-2Fe-2Mn合金耐海水浸泡腐蚀性能的影响。结果表明,合金以均匀腐蚀为主,当浸泡时间小于48 h时(12,24和48 h),合金腐蚀速率对稀土含量敏感度较高,24 h时稀土含量0.0000%,0.0146%和0.0352%的合金腐蚀速率分别为0.1720,0.1311和0.1065 g·m~(-2)·h~(-1),随着稀土含量增加,敏感度降低,24 h时稀土含量0.0000%,0.0146%和0.0352%的合金腐蚀速率相差分别为0.1311,0.0328 g·m~(-2)·h~(-1),分别降低42%和15%;经96和168 h浸泡后,稀土元素含量对合金腐蚀速率没有明显改善,腐蚀速率均在0.0300 g·m~(-2)·h~(-1)左右;合金腐蚀表面钝化膜质量随稀土元素含量增加而提高,48 h前稀土含量越高,钝化膜质量越高,48 h后稀土对钝化膜影响较小;随稀土添加合金电化学性能提高,稀土含量0.0352%时合金电荷转移电阻Rt最大,达到1.651×10~4Ω·cm~2,钝化膜对基体保护作用最好。     

钆对La-Mg-Ni系A_2B_7型储氢合金微观结构和电化学性能的影响

用高频感应熔炼方法制备了稀土系A2B7型La0.83-xGdxMg0.17N i3.05Co0.3A l0.15(x=0~0.5)储氢合金,在Ar气氛中和1173 K下对铸态合金进行退火处理,通过X射线衍射(XRD)、电子探针显微分析方法(EPMA)和电化学测试等分析方法系统研究了稀土Gd部分替代La元素对合金微观组织和电化学性能的影响规律。研究结果表明,合金退火组织主要由Ce2N i7型、Gd2Co7型、Pr5Co19型、PuN i3型和CaCu5型相组成,稀土Gd元素能有效减少和抑制退火组织中CaCu5型相的形成,随Gd含量x增加,合金相组成中A2B7型(Ce2N i7和Gd2Co7型)相丰度呈先增加后减小的规律,当x=0.2时其相丰度最大(91.0%)。合金的PCT吸氢平台压随Gd含量的增加而升高,x=0.5时吸氢平台压力接近0.1 MPa,x=0.2时合金的吸氢量达到最大值1.34%。电化学测试分析表明,随Gd含量x的增加,合金电极最大放电容量和容量保持率均呈先增加后减小的规律,适量的Gd元素可明显改善合金的综合电化学性能。当x=0.2时,合金电极放电容量达到最大值392.9 mAh.g-1,经100...     

La0.6Pr0.05Fe11.5-xCoxSi1.5合金的磁性和磁热效应

使用电弧炉熔炼法制备La0.6Pr0.05Fe11.5-xCoxSi1.5(x=0,0.1,0.2,0.3,0.4,0.5和0.6)系列合金.XRD分析与SEM成分分析表明该系列合金中除含有少量富镧相(P4/nmm)和α-Fe相外.均由NaZh13型立方结构单相组成.品格常数随着Co含量的增加基本保持不变.磁性测量表明该系列合金的Tc随着Co含母的增加旱线性增加,当x=0.6时,Tc达264 K.合金的升、降温磁化曲线随着Co含量的增加逐渐重合,即表明该系列合金的热滞随着Co含量的增加而减小;利用Maxwell方程计算得出在x=0时,合金在△B=1.5 T的外磁场下-△Sm达到38.4 J·kg-1·K-1.这种磁熵变来源于外磁场引起的一级相变,随着Co含量的增加-△Sm线性减小,这是由于Co含量的增加使合金的磁相变出现由一级相变向二级相变转变.     

钇对Mg-5Zn-2Al合金组织和力学性能的影响

利用金相显微镜、电子万能试验机、扫描电镜和X射线等手段,研究了不同含量的Y对Mg-5Zn-2Al镁合金铸态及热处理状态下组织及力学性能的影响.结果表明:合金主要由α-Mg基体相、Mg32(Al,Zn)49相及Al3Y相组成,并且A13Y稀土相随着合金中加Y量的增加而增多.在铸态及热处理条件下,合金的力学性能(抗拉强度和延伸率)均呈现先下降后上升的变化趋势.在铸态条件下,当加Y量为0.3%时合金的抗拉强度达到最大,为205 MPao当加Y量为0.9%时,合金的延伸率达到最大,为14.6%.经过T6热处理后,合金的抗拉强度较铸态均得到了明显提高,而延伸率有所下降.加Y量为0.9%的Mg-5Zn-2Al镁合金的抗拉强度和延伸率均达到最大值,分别为234 MPa和11.4%.     

钇对AZ91镁合金微观组织及腐蚀性能影响的研究

通过金相分析、扫描电镜析及化学成分分析等测试手段,对添加不同含量Y的AZ91镁合金的微观组织和腐蚀性能进行了研究。结果表明,加入Y后,合金中有稀土相Al4MgY生成,并显著细化了合金的微观组织,合金微观组织由典型的枝晶组织转变为细小的等轴晶组织,当Y含量达到1.52%时,合金组织的细化程度最大;Y的加入,减少了合金中的-βMg17Al12相,并使β相断续、弥散,同时合金的耐腐蚀性能提高,在3.5%NaCl水溶液腐蚀实验中,稀土含量为1.52%Y的合金耐腐蚀性能最好。     

锌含量对铸态Mg-10Y-xZn-0.5Zr镁合金微观组织和力学性能的影响EI北大核心CSCD

采用光学显微镜、扫描电镜、X射线衍射仪、透射电镜、电子拉伸实验机等研究了铸态Mg-10Y-xZn-0.5Zr(x=1,1.5,2(%,质量分数))合金的微观组织和力学性能。结果表明:铸态Mg-Y-Zn-Zr合金组织主要由α-Mg,LPSO相和W相组成,其中LPSO相的化学式为Mg_(12)YZn,W相的化学式为Mg_(3)Zn_(3)Y_(2)。LPSO相主要呈块状或层片状,随着Zn含量的增加,块状LPSO相体积分数逐渐增多,同时合金的屈服强度逐渐增加。当Zn含量为2%时,LPSO相形貌表现出以块状相为主,铸态Mg-10Y-2Zn-0.5Zr合金具有最佳的综合力学性能,其屈服强度、抗拉强度和延伸率分别为123.9,206.2 MPa和12.06%。块状LPSO相体积分数的增加是合金力学性能提高的主要原因。     

La_(0.63)Gd_(0.2)Mg_(0.17)Ni_(3.2-x)Co_(0.3)Al_x(x=0～0.4)储氢合金的微观组织和电化学性能

采用真空感应熔炼方法制备了La0.83Mg0.17Ni3.1Co0.3Al0.1和La0.63Gd0.2Mg0.17Ni3.2-xCo0.3Alx(x=0~0.4)贮氢合金,并在氩气气氛900℃进行退火处理。通过X射线衍射(XRD)、显微电子探针(EPMA)分析方法和电化学测试分析研究了Gd和Al元素对合金微观组织和电化学性能的影响。研究结果表明,该系列合金退火组织主要由Ce2Ni7/Gd2Co7型、Pr5Co19型、PuNi3型和CaCu5型相组成;Gd元素的加入使合金中CaCu5型相明显减少,Ce2Ni7型/Gd2Co7型相显著增加,x=0.1时其相丰度达到81.2%;随Al含量x不断增加,合金中CaCu5型相丰度逐渐增多,当x=0.1~0.2时,CaCu5型相丰度为4%~5%,x=0.4时,其相丰度达到66.65%。电化学测试分析表明,Gd和Al元素对合金电极活化性能影响不大,当x=0.1时,含Gd合金电极放电容量达到最大值391 mAh.g-1,随Al含量x进一步增加,合金电极放电容量降低。含Gd和加入适量的Al元素可使合金电极循环稳定性得到明显提高,当Al含量x=0.1,0.2时,经100次充放电循环后其电极容量保持率S100分别为93.7%和90.1%,其中La0.63Gd0.2Mg0.17Ni3.1Co0.3Al0.1合金具有最好的综合电化学性能。     

Mg-10Gd-2Y-0.6Zr合金热压缩变形与其微观组织

采用热压缩模拟试验,对Mg-10Gd-2Y-0.6Zr镁合金在350～450℃,变形程度为40%,变形速率在0.001～0.5s-1条件下的热压缩变形规律进行了研究,对变形后的微观组织进行了金相分析,对显微组织中的第二相进行了扫描能谱成分分析,对变形后试样的硬度进行了测试,根据热加工动态回复再结晶的特点和稀土合金相的作用,分析了该合金的微观组织结构和变形行为.结果表明:热压缩变形温度和速率对合金硬度值总的影响不大,但在相同温度下,有速率越大硬度越大的趋势;该合金在350℃,400℃时变形速率为0.1 s-1时晶粒异常粗大,在400℃变形速率大于0.5 s-1或变形温度450℃,变形速率为O.1 s -1下进行热压缩,该合金可以得到组织结构均匀和热塑性成型良好的匹配.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

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.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

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.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

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。