298.15和308.15 K时1,2-丙二醇+MCl (M=Na,K, Rb,Cs)+H2O三元体系的溶解度、密度和折光率

系统研究了1,2-丙二醇+MCl (M=Na, K, Rb, Cs)+H₂O三元体系在298.15 和308.15 K时的等温相平衡. 采用硝酸汞滴定法测定了体系中无机盐的含量, 采用安东帕RXA170 折光率仪及DMA4500 密度计测定了所有体系的折光率和密度数值. 报道了1,2-丙二醇质量分数从0增加到0.9过程中饱和及不饱和三元溶液体系的等温溶解度、密度和折光率数据. 实验结果发现, 随着1,2-丙二醇的不断加入, 饱和溶液的溶解度和密度均呈现出减小的趋势, 而折光率的变化则呈现出相反的趋势. 采用经验方程关联了不同醇水比条件下不饱和溶液的密度和折光率实验数据, 获得了较为理想的拟合结果. 本研究的开展充实了碱金属盐在混合溶剂中的热力学数据, 为相关溶液化学研究奠定了基础.     

四元体系KCl-K2SO4-CO(NH2)2-H2O有25℃时的等温溶度研究

测定了四元体系KCl－K₂SO₄－CO(NH₂)₂－H₂O及边界三元体系K₂SO－CO(NH₂)₂-H₂O在25℃时的溶度及饱和溶液密度值和折光率,绘制了相应的溶度图及相应的组成-性质图.测定并绘制了该四元体系K₂SO₄单饱区的溶度面、折光率面和密度面图.两个体系的溶度图均属于低共饱型,平衡固相为组份化合物.     

铁氰化钾-三氯化铁光度法测定蔬菜中还原糖含量

于氢氧化钠碱性溶液中,铁氰化钾试剂与样品溶液中的还原糖反应(在沸水浴中加热10min),定量生成亚铁氰化钾,此溶液冷却至室温,并用0.1mol.L-1盐酸溶液酸化至pH 3.5～4.0后随即加入三氯化铁溶液,经5min后生成普鲁士蓝。在波长680nm处用1cm吸收皿对试剂空白测定其吸光度,还原糖的质量浓度在0.8～4.0mg.L-1范围内与吸光度呈线性关系,其摩尔吸光率为3.4×104L.mol-1.cm-1。应用此方法测定了3种蔬菜样品中的还原糖含量,所得测定值与兰-埃农法测得值相符。测定值的相对标准偏差(n=5)均小于2.5%,回收试验所测得回收率在99.7%～100.1%之间。     

电化学检测-色谱法测定食醋中氨基酸含量

采用高效阴离子交换色谱及脉冲安培检测法分离并测定了食醋中多种氨基酸.用不同比例的氢氧化钠溶液、乙酸钠溶液及水组成的混合溶液作为淋洗液,以梯度淋洗方式将分离柱上的氨基酸先后洗脱并测定.用提出的方法分析了4种不同品牌的食醋样品,共测得18种氨基酸,此方法毋需柱前或柱后衍生化操作,对18种氨基酸的检出限在1.7～20.0 μg·L-1范围内.根据测定每种氨基酸中所得保留时间值算得的相对标准偏差(n=6)均小于1.2%,作标准加入法测定了各氨基酸的回收率,其值在849/6～108%之间.     

咪唑离子液体+1,2-丙二醇/1-丙醇二元体系在多温下的物理化学性质和超额性质

本文测定了温度288.15～333.15 K和常压下溴化1-己基/辛基-3-甲基咪唑离子液体([C_6mim]Br/[C_8mim]Br)+1,2-丙二醇/1-丙醇二元体系的密度(ρ)、折光率(nD)和黏度(η),计算获得了超额摩尔体积(V_m~E)和折光率偏差(Δn_D),并用Redlich-Kister方程对衍生性质数据进行拟合.密度、折光率和黏度值随组成的变化用多项式方程进行了拟合,讨论了醇、离子液体以及温度对二元体系物化性质的影响.     

典型中成药中Cu~(2+)的可视化数值分析法

中药的现代化对中药材及其制剂中重金属的质量控制提出更高要求.本文以Cu2+测定为例,通过测定颜色变化建立了中成药中重金属离子可视化数值分析方法.研究发现,在生理条件下,Cu2+与氨基黑10B可发生氧化还原反应,溶液颜色由蓝色逐渐变为桃红色.通过计算机常规软件Image-Pro Plus6.0获取溶液颜色变化过程中的红绿蓝三原色(R,G,B)数值,发现单位像素内R值的增加与溶液中8.33×10-8～1.33×10-6mol/L范围内的Cu2+具有良好的线性关系.该法可应用于典型中成药补中益气丸、安神胶囊、健胃消食片等药品中Cu2+的检测.     

三元体系Ln(ClO~4)~3-ACAP-H~2O(Ln=La,Sm,Yb)的相平衡研究(30℃)

测定了三元体系Ln(ClO~4)~3-ACAP-H~2O(Ln=La,Sm,Yb, ACAP=4-乙酰安替比林)在30℃时的溶解度及饱和溶液的折光率,绘制了相应的溶度图和饱和溶液的折光率-组成图.体系的溶度曲线和折光率曲线均由三支组成,分别与ACAP,Ln(ACAP)~3(ClO~4)~3·nH~2O(Ln=La,n=4,Sm,2,Yb,2)和Ln(ClO~4)~3·nH~2O(Ln=La,n=8,Sm,9,Yb,8)相对应.从溶度图上发现了三个未见文献报道的三元化合物, 它们均为固液异组成溶解的化合物.通过化学分析,元素分析,TG-DTG,IR,UV和X射线粉末衍射进行了表征.初步探讨了影响安替比林4位酰代衍生物β-二酮配体配位能力的因素     

用氟离子选择电极方法测定四氟乙烯与全氟[3,6-二氧杂4-甲基-△~7辛基磺酰氟]共聚物的交换容量

分析四氟乙烯与全氟[3,6-二氧杂4-甲基-△~7辛基磺酰氟]共聚物(简称QF-1)的组成,一般是先将此共聚物在氢氧化钠中水解,使磺酰氟基团变为磺酸钠,然后用盐酸转型为磺酸,再用氯化钠溶液进行交换,用标准碱溶液滴定。这个方法是按离子交换膜测定交换容量(IEC)的方法求得聚合物的当量值,从而得知其组成,但步骤较多。为了减少滴定的误差,聚合物用量也较多,一般需在0.5克以上。考虑到QFeel中除磺酞氟以外的氟原子对碱均很稳定。在水解时只发生下列反应.R,一50:F ZNaOH一)一一今R,一50必Na NaF H:O因而氟离子和磺酸基是等当量的.测定该聚合物碱水解液中的氟离子量,即可知交换当量.粉状树脂不需加工成膜,即可作为试样进行测定,操作简便。又由于氟离子选择电极灵敏度很高,     

壳聚糖折光指数增量的研究

本工作制备了具有不同胺基含量的系列壳聚糖样品,测定和研究了它们的脱乙酰度(D.D.)和溶液拆光指数增量(dn/dc)。发现不同D.D.壳聚糖的dn/dc值不同,而且两者间符合二元无规共聚物的dn/dc值与其化学组成之间的一般线性关系,从而建立了一种可从dn/dc值分析测定壳聚糖的脱乙酰度的新方法。     

硫酸铯/乙醇双水相体系的相平衡

采用自制的相平衡研究装置，测定了硫酸铯/乙醇双水相体系在0、10、20和40 ℃四个温度下的等温平衡溶解度，并且获得了醇相溶液和水相溶液的折光率数据，发现温度对该体系的液-液和固-液相平衡均没有显著影响.利用“湿渣结线法”确定出四个温度下平衡固相均为无水盐，同时给出了该体系的完整相图，在相图中观察到五个相区，为该体系的进一步应用研究提供了参考数据.     

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.     

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。     

Synthesis of phenolic components of Grains of Paradise

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.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Study of hydration of two cements of different strengths

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, M_o, 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 600-700^oC. 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.     

恶臭嗅辨实验室建设探讨

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。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

氯氧化镁生成热的研究

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^-。