PbBr2-PbCl2-PbF2-PbO-P2O5系统玻璃性能研究

研究了ＰｂＢｒ２ － ＰｂＣｌ２－ ＰｂＦ２ － ＰｂＯ－ Ｐ２Ｏ５ 系统的玻璃转变温度、密度、耐水性和透光率．ＰｂＢｒ２ － ＰｂＣｌ２ － Ｐ２Ｏ５ 系统的玻璃转变温度低达１４６ ℃,密度高达４ ．７５ ｇ／ｃｍ３ ． 加入ＰｂＦ２ 和／ 或ＰｂＯ 可显著提高玻璃的转变温度和密度,其中ＰｂＯ 的影响更为显著,可使玻璃的密度增加到５ ．４８ ｇ／ｃｍ３ ． 多数ＰｂＢｒ２ － ＰｂＣｌ２ － ＰｂＦ２－ ＰｂＯ－ Ｐ２Ｏ５ 系统玻璃的耐水性都很好,在水中的溶解速率为１０－５ ｍｍ／ｄａｙ． 玻璃的透光性较好,加入ＰｂＢｒ２ 使玻璃的紫外截断波长明显向长波方向移动．     

Y－TYPE ZEOLITES AS MICRO－REACTORS FOR PHOTOCHEMICAL PREPARATION OF LARGE－RING COMPOUNDS

Ｙ－ＴＹＰＥＺＥＯＬＩＴＥＳＡＳＭＩＣＲＯ－ＲＥＡＣＴＯＲＳＦＯＲＰＨＯＴＯＣＨＥＭＩＣＡＬＰＲＥＰＡＲＡＴＩＯＮＯＦＬＡＲＧＥ－ＲＩＮＧＣＯＭＰＯＵＮＤＳ￥ＴＯＮＧＺｈｅｎｈｅ；（ＴＵＮＧＣｈｅｎｈｏ）；ＷＵＬｉｚｈｕ（ＩｎｓｔｉｔｕｔｅｏｆＰｈｏ...     

ZnF2-BaF2-LaF3玻璃的X射线衍射和分子动力学研究

采用Ｘ射线衍射和分子动力学计算机结构模拟（ＭＤ）等手段研究了５３ＺｎＦ２－３３ＢａＦ２－１４ＬａＦ３玻璃的结构,研究表明Ｚｎ原子主要为６配位,少数为７配位,Ｌａ原子主要为９配位,Ｚｎ－Ｆ的平均键长为２．１３ＡＺｎ－Ｚｎ键长在共边连续时为３．３３Ａ,共角时为３．８２Ａ,在ＭＤ模拟得到的玻璃结构中同时存在桥Ｆ（Ｆｂ）,非桥Ｆ（Ｆａｂ）３配位Ｆ（Ｆｔ）和游离Ｆ（Ｆｆ）,Ｆｆ和Ｂａ,Ｌａ原子成键,获得的平     

GeS2-In2S3-CdS体系玻璃的形成与性能

通过实验确定了ＧｅＳ２－Ｉｎ２Ｓ３－ＣｄＳ体系的玻璃形成区，其玻璃形成区较小，主要是在富含ＧｅＳ２区域。研究了它的热性能和透红外性能，结果表明：ＧｅＳ２－Ｉｎ２Ｓ３－ＣｄＳ体系玻璃转变温度在５７３－６９３Ｋ之间，红外截止波长为１１μｍ，具有较大的红外载波和较低的声子能量。ＧｅＳ２－Ｉｎ２Ｓ３－ＣｄＳ体系玻璃的密度约为３．０ｇ／ｃｍ＾３，玻璃在空气中能稳定存在而无风化现象产生。     

InF3—ZnF2—BaF2—SrF2—RFn系统玻璃性质研究

测定了ＩｎＦ３－ＺｎＦ２－ＢａＦ２－ＳｒＦ２系统中掺入不同价氟化物ＲＦｎ玻璃的各特征温度，密度和红外截止波长。研究了ＲＦｎ的引入对玻璃形成能力，析晶性能和其它性质的影响。     

液膜法分离富集,测定水中微量锶

用状液膜体系对锶进行分离富集，该体系包括协同流动载体（ＰＭＢＰ、ＴＢＰ）、表面活性剂（ＳＰＡＮ８０）、增强剂（丙三醇）、溶剂（正己烷）和内相（１．２ｍｏｌ／Ｌ的盐酸溶液）。实验表明，在适宜的条件下，锶的富集效率可达９９．５％以上，而在此条件下许多共存离子，如Ｆｅ＾３＋、Ａｌ＾３＋、Ｃａ＾２／、Ｍｇ＾２＾＋、Ｃｒ＾３＋、Ｃｏ＾２＋、Ｎｉ＾２＋、Ｚｒ＾４＋、Ｃｕ＾２＋、Ｚｎ＾２＋、Ｐｂ＾２＋和ＲＥ＾３     

液膜分离富集测定镓

用ＴＯＰＯ「（Ｃ８Ｈ１７）３ＰＯ」为流动载体,Ｎ２０５为表面活性剂,液体石蜡为膜增强剂,正己烷为膜溶剂,Ｈ２Ｃ２Ｏ４作内相试剂的乳状液膜体系,迁移富集Ｇａ＾３＋,研究了乳状液膜的稳定性、温度、Ｇａ＾３＋的浓度、外相ｐＨ值、乳水比（Ｒｅｗ）、油内比（Ｒｏｉ）等因素对富集Ｇａ＾３＋的影响。实验结果表明,在适宜的条件下,Ｇａ＾３＋的富集率可达９９．５％～１００．５％,在相同条件下,常见共存的Ｃｕ＾２＋、Ｃｏ＾２＋、Ｎｉ＾２＋、ＭｎＡ＾２＋、Ｆｅ＾３＋、Ａｌ＾３＋、Ｃｒ＾３＋、Ｔｉ＾４＋、Ｚｒ＾４＋、Ｐｂ＾２＋、Ｚｎ＾２＋、碱金属离子、碱土金属离子等不被迁移富集;大量Ｃｌ＾－、Ｆ＾－、、ＮＯ３＾－、ＳＯ４＾２－、ＰＯ４＾３－等都不影响Ｃａ＾３＋的富集,高式样应预先用氯化氢除硅,以防止影响迁移富集Ｇａ＾３＋,只ａ＾３＋可     

BaO—ZnO—La2O3—B2O3系统玻璃配位状态和网络结构

ＺｎＯ－Ｌａ２Ｏ３－Ｂ２Ｏ３ＧＨＧＹ２ＨＷ具有高折射率,低色散的特点,但该系统玻璃容易析晶失透常需加入高价金属氧化研究表明。加入少量ＢａＯ使玻璃网络中「ＢＯ４」和「ＺｎＯ４数量上升,非桥氧数量下降,玻璃网趋于稳定,玻璃形成能力提高。实验表明,在ＢａＯ－Ｚｎｏ－Ｌａ２Ｏ３－Ｂ２Ｏ３玻璃网络中Ｚｎ＾２＋离子的配位与ＢａＯ加入有密切关系,可以」ＺｎＯ４「四面体形式进入玻璃网络。     

PbBr2-PbCl2-PbF2-PbO-P2O5系统玻璃形成特性的研究

研究了ＰｂＢｒ２－ＰｂＣｌ２－ＰｂＦ２－ＰｂＯ－Ｐ２Ｏ５系统的玻璃形成能力和系统的玻璃形成区,测试了一些玻璃的特征温度,结果表明,加入５％ＰｂＯ的５％ＰｂＦ２都使玻璃转变温度升高,玻璃形成区缩小,并向ＰｂＢｒ２方向偏移,同时加入２．５％ＰｂＯ和２．５％ＰｂＦ２同样提高了玻璃转变温度,但却增大了玻璃形成区;继续提高ＰｂＯ和ＰｂＦ２的加入量,玻璃形成区显著减小。     

LARGE SCALE PURIFICATION OF PHOSPHOGLYCERATE KINASE（PGK） AND GLYCERALDEHYDE 3－PHOSPHATE DEHYDROGENASE（GAPDH） FROMYELLOW PEAS BY PEG／REPPAL PES AQUEOUS TWO PHASE SYSTEM AND ION EXCHANGE CHROMATOGRAPHY

ＬＡＲＧＥＳＣＡＬＥＰＵＲＩＦＩＣＡＴＩＯＮＯＦＰＨＯＳＰＨＯＧＬＹＣＥＲＡＴＥＫＩＮＡＳＥ（ＰＧＫ）ＡＮＤＧＬＹＣＥＲＡＬＤＥＨＹＤＥ３－ＰＨＯＳＰＨＡＴＥＤＥＨＹＤＲＯＧＥＮＡＳＥ（ＧＡＰＤＨ）ＦＲＯＭＹＥＬＬＯＷＰＥＡＳＢＹＰＥＧ／ＲＥＰＰＡＬ...     

Ferroelectric Ceramics in the PbMg1/3Nb2/3O3-PbCd1/3Nb2/3O3 System

Solid solutions (1-x)PbMg_1/3Nb_2/3O₃ + xPbCd_1/3Nb_2/3O₃ with x = 0-0.30 are investigated with purpose to work out a capacitor ceramics with good dielectric properties and low sintering temperature. It is found that the perovskite phase forms at sintering near to 980°C and begins to decompose at higher temperatures. When x grows from 0 to 0.30, the Curie temperature linearly grows from -10°C to +25°C, the dielectric permittivity ε_m in the Curie point T_C decreases from 18000 to 6800 and the phase transition becomes more diffused. The dielectric permittivity at room temperature is rather high and the temperature stability is improved. The system is of interest, because it can serve as a base for working out some ceramic materials for capacitors with low sintering temperature, which needs of no special atmosphere at burning.     

3-溴甲基-3-甲基氧杂环丁烷的合成

以2,2-二溴甲基丙醇（BBMP）为初始原料,通过与碱发生关环反应生成3-溴甲基-3-甲基氧杂环丁烷（BrMMO）。讨论了碱的种类和用量对BBMP关环产率的影响以及反应体系中碱的浓度、反应温度和反应时间对合成BrMMO产率的影响。通过实验确定的最佳工艺条件为：BBMP与NaOH摩尔比为1.0∶1.1,NaOH醇溶液的质量分数为12%,反应温度为78℃,反应时间为4h时,BrMMO产率为65%。最终产品经元素分析、IR和1HNMR检测确定为BrMMO。该试验工艺简单,原料易得,且溶剂便于回收、污染小。     

3-叠氮甲基-3-甲基氧丁环的合成

以三羟甲基乙烷与碳酸二乙酯为原料,经环化反应合成了3-羟甲基-3-甲基氧丁环(HMM O)。在低温下,HMM O与对甲苯磺酰氯反应生成3-磺酸酯甲基-3-甲基氧丁环(M TM O)。M TM O和叠氮化钠发生叠氮化反应形成叠氮单体3-叠氮甲基-3-甲基氧丁环(AMM O)。三步反应收率分别为76%,96%,85%。用核磁、红外、元素分析和DSC表征了化合物的结构与性能。结构鉴定表明为目标化合物AMM O。     

3-溴甲基-3-甲基氧杂环丁烷的合成

以2,2-二溴甲基丙醇(BBMP)为初始原料,通过与碱发生关环反应生成3-溴甲基-3-甲基氧杂环丁烷(BrMMO).讨论了碱的种类和用量对BBMP关环产率的影响以及反应体系中碱的浓度、反应温度和反应时间对合成BrMMO产率的影响.通过实验确定的最佳工艺条件为:BBMP与NaOH摩尔比为1.0∶1.1,NaOH醇溶液的质量分数为12%,反应温度为78℃,反应时间为4 h时,BrMMO产率为65%.最终产品经元素分析、IR和1HNMR检测确定为BrMMO.该试验工艺简单,原料易得,且溶剂便于回收、污染小.     

The Preparation and Crystal Structure of TlMnCl3, TlFeCl3, TlCoCl3 and TlNiCl3

The compounds TlMnCl₃, TlFeCl₃, TlCoCl₃ and TlNiCl₃ were prepared by heating T1C1 with the corresponding transition metal dichloride in an evacuated ampoule. Atomic positions were determined from powder photographs. All four compounds were found to be related to the perovskite type structure. TlMnCl₃ has a cubic structure, space group Pm3m, with a_o = 5.025 Å. The other three compounds are hexagonal, probable space group P6₃mc, with cell dimensions (in Å) a₀ = 6.976 and c₀ = 6.008 for the Fe compound, a₀ = 6.907 and c₀ = 5.981 for the Co compound and a₀ = 6.863 and c₀ = 5.881 for the Ni compound. The three hexagonal compounds are isomorphous. A measureable concentration of basal plane stacking faults was found to occur in TlFeCl₃ and also, to a lesser degree, in TlCoCl_3.     

Tunable color emission in LaScO3:Bi3+,Tb3+,Eu3+ phosphor

LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ (x = 0 − 0.04, y = 0 − 0.05, z = 0 − 0.05) phosphors were prepared via high-temperature solid-state reaction. Phase identification and crystal structures of the LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ phosphors were investigated by X-ray diffraction (XRD). Crystal structure of phosphors was analyzed by Rietveld refinement and transmission electron microscopy (TEM). The luminescent performance of these trichromatic phosphors is investigated by diffuse reflection spectra and photoluminescence. The phenomenon of energy transfer from Bi³⁺ and Tb³⁺ to Eu³⁺ in LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ phosphors was investigated. By changing the ratio of x, y, and z, trichromatic can be obtained in the LaScO₃ host, including red, green, and blue emission with peak centered at 613, 544, and 428 nm, respectively. Therefore, two kinds of white light-emitting phosphors were obtained, LaScO₃:0.02Bi³⁺,0.05Tb³⁺,zEu³⁺ and LaScO₃:0.02Bi³⁺,0.03Eu³⁺,yTb³⁺. The energy transfer was characterized by decay times of the LaScO₃:xBi³⁺, yTb³⁺, zEu³⁺ phosphors. Moreover absolute internal QY and CIE chromatic coordinates are shown. The potential optical thermometry application of LaScO₃:Bi³⁺,Eu³⁺ was based on the temperature sensitivity of the fluorescence intensity ratio (FIR). The maximum S_a and S_r are 0.118 K⁻¹ (at 473.15 K) and 0.795% K⁻¹ (at 448.15 K), respectively. Hence, the LaScO₃:Bi³⁺,Eu³⁺ phosphor is a good material for optical temperature sensing.     

2,2,3-三氯-3-苯基-3-(3-甲基苯甲酰基)丙腈的合成研究

以苯甲酰氯、四氯化碳、间甲基苯甲酰氰为原料,合成了标题化合物。重点考察了氰化过程中不同原料配比、反应温度、时间、溶剂和催化剂用量对收率的影响。实验结果表明,其最佳反应条件为:n(1,1,2-三氯-2-苯基乙烯)∶n(3-甲基苯甲酰氰)=1∶1.2,二氯甲烷为反应溶剂,3 mmol催化剂三乙胺,室温反应5 h,总收率达80.6%。     

Thermal analyses of poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)

Thermal analyses of poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB–HV)], and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(HB–HHx)] were made with thermogravimetry and differential scanning calorimetry (DSC). In the thermal degradation of PHB, the onset of weight loss occurred at the temperature (°C) given by T_o = 0.75B + 311, where B represents the heating rate (°C/min). The temperature at which the weight-loss rate was at a maximum was T_p = 0.91B + 320, and the temperature at which degradation was completed was T_f = 1.00B + 325. In the thermal degradation of P(HB–HV) (70:30), T_o = 0.96B + 308, T_p = 0.99B + 320, and T_f = 1.09B + 325. In the thermal degradation of P(HB–HHx) (85:15), T_o = 1.11B + 305, T_p = 1.10B + 319, and T_f = 1.16B + 325. The derivative thermogravimetry curves of PHB, P(HB–HV), and P(HB–HHx) confirmed only one weight-loss step change. The incorporation of 30 mol % 3-hydroxyvalerate (HV) and 15 mol % 3-hydroxyhexanoate (HHx) components into the polyester increased the various thermal temperatures T_o, T_p, and T_f relative to those of PHB by 3–12°C (measured at B = 40°C/min). DSC measurements showed that the incorporation of HV and HHx decreased the melting temperature relative to that of PHB by 70°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 90–98, 2001