Low temperature heat capacities and thermodynamic properties of rare earth triisothiocyanate hydrates——Pr(NCS)_3· 7H_2O and Nd(NCS)_3· 7H_2O

Heat capacities of Pr(NCS)3·7H2O and Nd(NCS)3· 7H2O haw been measured from 13 to 300 K by using a fully automated adiabatic calorimeter. Schottky anomaly was observed for Pr(NCS)3·7H2O below 50 K. The polynomial equations for calculating the heat capacity values of the two compounds in the range of 13-300 K were obtained by the least-squares fitting based on the experimental Cp data. The Cp values below 13 K were estimated by using the Debye-Einstein and Schottky heat capacity functions. The standard molar thermodynamic functions were computed from 0 to 300 K. The standard entropies and Gibbs energies of formation of the two compounds were also calculated.     

表面涂覆CeO2对Co—40Cr合金氧化行为的影响

研究了表面涂覆ＣｅＯ２对Ｃｏ－４０Ｃｒ合金在１０００℃、空气中恒温氧化和循环氧化的影响。并用扫描电镜／能谱（ＳＥＭ／ＥＤＸＳ）、电子探针（ＥＰＭＡ）、高分辩率显微镜（ＨＲＥＭ）等测试手段对氧化膜的形貌和成分进行了观察了监测。结果表明，涂覆ＣｅＯ２后极大地提高了合金的抗循环氧化性能。研究表明，涂覆的ＣｅＯ２主要以细小颗粒 蒿度弥散存在于氧化膜的外表面，并且主要分布于氧化物晶界上，其中Ｃ     

稀土在熔盐被覆铬碳化物中的作用研究

研究了熔盐被覆铬碳化物的工艺过程，着重探讨了稀土对Ｔ１２Ａ钢熔盐渗铬的催渗及微合金化作用机理。结果表明，在加入稀土的熔盐中渗中提高渗速３０％－５６％，同时还能提高工件表面的抗氧化和耐腐蚀性能以及工件的使用寿命。     

VINYL MONOMERS BEARING CHROMOPHORE MOIETIES AND THEIR POLYMERS——Ⅹ.INITIATION AND PHOTOCHEMICAL PROPERTIES OF p-(N,N-DIMETHYLAMINO)STYRENE AND ITS POLYMERS*

A vinyl monomer having an electron-donating moiety, p-(N,N-dimethylamino)styrenc (DMAS),was synthesized. It was combined with benzoyl peroxide (BPO) to form a redox initiation system to initiatethe polymerization of methyl methacrylate (MMA). UV spectra measurements show that DMAS enters thePMMA chain as well. Both DMAS and its polymer P(DMAS) display strong fluorescence, and thefluorescence can be quenched by electron-deficient compounds such as methacrylonitrile, fumaronitrile andmethyl methacrylate etc. Moreover, DMAS can also form charge transfer complex (CTC) with strongelectron acceptors such as tetracyanoethylene (TCNE). The difference between the photochemical propertiesof DMAS and P(DMAS) were explained in terms of molecular structure change and polymer conformationeffect in solution. In addition, the CTC and exciplex formation of DMAS or P(DMAS) with C_(60) were alsostudied.     

气相色谱手性衍生化试剂N－七氟丁酰基－L－脯氨酰氯的合成与应用

 合成了用于气相色谱（ＧＣ）的手性衍生化试剂Ｎ－七氟丁酰基－Ｌ－脯氨酰氯（Ｎ－ＨＦＢ－Ｌ－ＰＣｌ）。各种特性试验表明，Ｎ－ＨＦＢ－Ｌ－ＰＣｌ是灵敏的ＧＣ手性衍生化试剂，可直接于水相拆分微量的手性胺对映体。     

二(2,4,4-三甲基戊基)膦酸萃取分离稀土元素(Ⅲ)的研究

本文研究了二(2,4,4-三甲基戊基)磷酸(Cyanex 272)的煤油溶液在不同介质(HCI,HNO_3)中对三价混合稀土的萃取分离性能.观测了平衡水相酸度对萃取平衡的影响,由酸度曲线求出相邻元素的平均分离系数,并考察了酸度对反萃取平衡的影响.比较了HCI和HNO_3介质中,Cyanex 272对混合稀土(Ⅲ)的萃取性能.     

Fast electron transfer repair of oxidizing OH adduct of dGMP by chlorogenic acid

ＥｘｔｅｎｓｉｖｅｓｔｕｄｉｅｓｏｆｒａｄｉａｔｉｏｎｏｒｃｈｅｍｉｃａｌｉｎｊｕｒｙｏｆｂｉｏｌｏｇｉｃａｌｔａｒｇｅｔｍｏｌｅｃｕｌｅｓｄｅｍｏｎｓｔｒａｔｅｔｈａｔＯＨｒａｄｉｃａｌ,ｔｈｅｍｏｓｔｒｅａｃｔｉｖｅｏｘｙｇｅｎｓｐｅｃｉｅｓ,ｒｅａｃｔｓｗｉｔｈｂｉｏｌｏｇｉｃａｌｍａｃｒｏｍｏｌｅｃｕｌｅｓ,ｓｕｃｈａｓＤＮＡ,ｉｎｄｕｃｉｎｇｂａｓｅａｌｔｅｒａｔｉｏｎｓ,ｂａｓｉｃｓｉｔｅｓ,ａｎｄｓｔｒａｎｄｂｒｅａｋｓ,ｒｅｓｕｌｔｅｄｉｎｖａｒｉｏｕｓｐａｔｈｏｇｅｎｅｓｉｓ,ｓｕｃｈ…     

如何建立一种稀土元素和显色剂之间的反应条件使各稀土元素的呈色螯合物具有基本一致的桑德尔灵敏度？

通过选择适当的显色反应条件和选用合适的掩蔽剂，并根据熔炼中所用的中间合金中各稀土元素组份的实际存在比例作为光度法测定总稀土中制作工作曲线的标准溶液中各稀土元素的配比依据，可以建立较适宜的测定稀土元素总量的显色反应条件。现以CPA-mN光度法测定非铁合金中稀土元素总量为例说明这种显色反应条件的建立。     

Synthesis and Characterization of Poly（butylene adipate-co-terephthalate） Catalyzed by Rare Earth Stearates

Rare earth （Nd, Y, La, Dy） stearates have been synthesized and used as single component catalysts for the polycondensation of dimethyl terephthalate, adipic acid and 1,4-butanediol for the first time preparing biodegradable poly（butylene adipate-co-terephthalate） （PBAT） with high molecular weight, The microstructures of PBAT were characterized by ^1H NMR spectra. The PBAT exhibits good mechanical properties such as high tensile strength （ca. 20 MPa） and long break elongation （〉700%）.     

胶束增溶光度法同时测定铂、铑、钯和金的研究

本文研究了贵金属Pt、Rh、Pd和Au在SnCl_2-BRB-AG-乳化剂OP离子缔合物体系中显色反应的条件,采用偏最小二乘回归法对上述体系重迭光谱进行解析及数据处理。结果表明,该体系灵敏度高,表观摩尔吸光系数可达1.74×10～6～2.47×10～6L·mol～-1·cm～-1;体系稳定性较好。应用本文方法对混合试样中Pt、Rh、Pd、Au进行同时测定,取得较满意的结果。