脱氧核糖核酸变性和损伤的吸附伏安法研究

本文用汞电极（ＨＭＤＥ）二次导数阴极吸附伏安（ＳＤ－ＡｄＣＳＶ）和碳电极（ＧＣＥ、ＣＰＥ）导数循环伏安（ＦＤ－ＣＶ）法研究了核酸受热、紫外线、超声波和丝裂霉素Ｃ（ＭＭＣ）作用下的变性作用。在０．１ｍｏｌ／Ｌ（Ｋ２ＨＰＯ４＋ＫＨ２ＰＯ４）－０．１ｍｏｌ．Ｌ ＮａＣｌ（ｐＨ７．０）底液中，吸附的单股（ｓｓ－）和双螺旋（ｄｓ－）ＤＮＡ分别在ＨＭＤＥ上得到特征还原峰Ｐ３和Ｐ２，和在碳电极上得到氧化峰Ａ。物     

HYDROLYTIC CLEAVAGE OF ACMET-GLY PROMOTED BY CIS-[Pd(MET)(D_2O)_2](NO_3)_2

ＨＹＤＲＯＬＹＴＩＣＣＬＥＡＶＡＧＥＯＦＡＣＭＥＴ－ＧＬＹＰＲＯＭＯＴＥＤＢＹＣＩＳ－［Ｐｄ（ＭＥＴ）（Ｄ２Ｏ）２］（ＮＯ３）２￥ＸｉａｏＨｕａＣＨＥＮ；ＬｏｎｇＧｅｎＺＨＵ；Ｎ．Ｍ．Ｋｏｓｔｉｃ（ＣｏｏｒｄｉｎａｔｉｏｎＣｈｅｍｉｓｔｒｙＩｎｓｔｉ...     

镉（Ⅱ）—7—碘—8—羟基喹啉—5—磺酸络合物吸附波的研究

在ｐＨ４．３的ＨＡｃ－ＮａＡｃ介质中，Ｃｄ（Ⅱ）与７－碘－８－羟基喹啉－５－磺酸（７－Ｉ－Ｈ２ＱＳ）生成络合物。有二苯胍存在下，于－０．６８Ｖ（ｖｓ．ＳＣＥ）产生一灵敏的极谱波，峰电流与Ｃｄ（Ⅱ）浓度在８．９×１０－９～２．２×１０－６ｍｏｌ／Ｌ浓度范围内呈线性关系。通过对该极谱波性质及反应机理的研究，证实其为络合物吸附波，络合比为１∶１，络合物带负电荷。方法用于铜矿中镉的测定，结果满意     

［M_x（FeCO_2）_yL_z］型配合物的合成、表征及CV性质研究（M＝Cu

［Ｍ＿ｘ（ＦｅＣＯ＿２）＿ｙＬ＿ｚ］型配合物可在ＴＨＦ中通Ｎ２条件下由ＦｅＣＯ＿２Ｈ和ＭＸ＿２·ｎＨ＿２Ｏ（Ｘ＝Ｃｌ￣－和Ａｃ￣－）经长时间反应制得．ＩＲ和１ＨＮＭＲ谱表明Ｃｕ（Ⅲ）、Ｃｏ（Ⅲ）属螯环配合物，Ｃｄ（Ⅱ）属四面体型配合物，Ｐｂ（Ⅱ）属线型化合物．Ｍ（Ⅱ）离子位于配合物中心．ＣＶ表明Ｍ（Ⅱ）呈多价态变化，受配体及敖合效应影响Ｆｅ（Ⅲ）Ｆｅ（Ⅱ）和Ｍ（Ⅱ）　Ｍ（０）Ｅｐ／２下降，Ｍ（Ⅱ）还原力上升．Ｍ（Ⅱ）　Ｍ（０）Ｅ＿ｐ／２随Ｍ（Ⅱ）＿（ａｑ）．性质呈现律性变化．     

镉（Ⅱ）－1－苯基－3－甲基－4－苯甲酰基－吡唑啉酮－5配合物吸附波的研究

在ｐＨ４．８的ＨＡｃ－ＮＨ＿（４）Ａｃ介质中，Ｃｄ（Ⅱ）与１－苯基－３－甲基－４－苯甲酰基－吡唑啉酮－５（ＰＭＢＰ）生成配合物，于－０．６７Ｖ（ｖｓ．ＳＣＥ）出现一尖锐、灵敏的极谱波。镉含量在０．００１～１．μｇ／ｍＬ范围内与峰高成线性关系。用多种电化学方法研究了极谱波的性质及电极反应机理，证明－０．６７Ｖ处的极谱波为配合物吸附波，峰电流由中心离子Ｃｄ（Ⅱ）还原产生。配合物组成为Ｃｄ（Ⅱ）：ＰＭＢＰ＝１：１。试验了３０多种离子对峰电流的影响，用ＳｒＳＯ＿４共沉淀分离Ｐｂ（Ⅱ），再经巯基棉分离其它干扰离子。用于矿样中镉的测定，结果满意。     

酞菁锰-表面活性剂薄膜电极的电化学表征及其对三氯乙酸的电化学催化作用的研究

将酞菁锰（ＭｎＰｃ）掺入阳离子表面活性剂双十二烷基二甲基溴化铵（ＤＤＡＢ）的氯仿溶液，并涂布于热解石墨电极表面，待氯仿挥发后即制得ＭｎＰｃ－ＤＤＡＢ薄膜电极。循环伏安实验表明，在ＫＢｒ溶液中，该薄膜电极有两对还原氧化峰，第一对峰的Ｅｐｃ１＝－０．２７Ｖ，Ｅｐａ１＝０．０１Ｖ；第二对峰的Ｅｐｃ２＝－０．７６Ｖ，Ｅｐａ２＝－０．６２Ｖ（ｖｓ．ＳＣＥ）。本文着重探讨了第二对峰的电化学行为，估计了该体系的电荷传递扩散系数Ｄｃｔ和表观非均相电极反应速率常数Ｋ０′等电化学参数，并可将该薄膜电极用于催化三氯乙酸的电化学还原。     

SYNTHESIS AND CHARACTERIZATION OF (PPh_3)_3Co(μ-CO)_2 V(CO)_2Cp AND (PPh_3)

ＳＹＮＴＨＥＳＩＳＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦ（ＰＰｈ_３）_３Ｃｏ（μ－ＣＯ）_２Ｖ（ＣＯ）_２ＣｐＡＮＤ（ＰＰｈ_３）ＨＰｔ（μ－ＣＯ）（μ－ＰＰｈ_２）Ｖ（ＣＯ）_２ＣｐＣｈａｎｇＰｉｎｇＳＨＡＯ（ＤａｌｉａｎＩｎｓｔｉｔｕｔｅｏｆＣｈ?..     

酞菁锰—表面活性剂薄膜电极的电化学表征及其对三氯乙酸的电化学催 …

将酞菁锰（ＭｎＰｃ）掺入阳离子表面活性剂双十二烷基二甲基溴化铵（ＤＤＡＢ）的氯仿溶液，并涂布于热解石墨电极表面，待氯仿挥发后即制得ＭｎＰｃ－ＤＤＡＢ薄膜电极，循环伏安实验表明，在ＫＢｒ溶液中，该薄膜电极有两对还原氧化峰，第一对峰的Ｅｐｃｔ＝－０．２７Ｖ，Ｅｐａ１＝０．０１Ｖ；第二对峰的Ｅｐｃ２＝－０．７６Ｖ，Ｅｐａ２＝－０．６２Ｖ（ｖｓ．ＳＣＥ）。本文着重探讨了第二对峰的电化学行为，估计了该体系电     

镉（Ⅱ）—1—苯基—3—甲基—4—苯甲酰基—吡唑啉酮—5配合物吸附波的研究

在ＰＨ４．８的ＨＡｃ－ＨＮ４Ａｃ介质中，Ｃｄ（Ⅱ）与１－苯基－３－甲基－４－苯甲酰基－吡唑啉酮－５（ＰＭＢＰ）生成配合物，于－０．６７Ｖ（ｖｓ．ＳＣＥ）出现一尖锐、灵敏的极谱波。镉含量在０．００１－１．０μｇ／ｍＬ范围内与峰高成线性关系。     

MCSCF AND VTST STUDIES OF THE REACTION CH(2~π)+H_2→CH_3

ＭＣＳＣＦＡＮＤＶＴＳＴＳＴＵＤＩＥＳＯＦＴＨＥＲＥＡＣＴＩＯＮＣＨ（２~π）＋Ｈ_２→ＣＨ_３￥ＳｉＹｕＭＡａｎｄＲｕｏＺｈｕａｎｇＬｉｎ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｅｄ．ＢｅｉｊｉｎｇｆｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ，Ｂｅｉｊｉｎｇ１００?..     

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。     

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.     

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.     

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.     

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.     

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^-。     

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.     

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.