偏氟乙烯/六氟丙烯乳液共聚反应动力学

对气相含氟单体偏氟乙烯(VDF)/六氟丙烯(HFP)的乳液共聚反应动力学机理进行了研究.结果表明:在80℃下,上述两种单体共聚反应速率r对乳化剂浓度(S)、引发剂浓度(I)和反应总压力(p)分别呈0.05级、0.31级和1.59级反应,由此推导得乳液共聚的反应速率表达式为:r一1.11×10-4S0.05I0.31P1.59,其中速率常数k=1.11×10-4g-0.37L0.37(MPa)-0.59min-1.由上述动力学方程计算得到的乳液共聚反应速率与实验结果一致.同时对两种单体的竞聚率做了初步讨论.     

离子色谱法测定牙膏中可溶性氟含量

采用电导抑制检测器–梯度淋洗离子色谱法测定牙膏中可溶性氟含量。使用Ion Pac AS15(250 mm×4mm)色谱柱,Ion Pac AG15(250 mm×4 mm)保护柱,以氢氧化钾溶液梯度淋洗,采用自循环抑制电导检测的方法对牙膏中游离氟含量进行检测。该方法能够准确地测定牙膏中游离氟含量,线性方程的相关系数在0.996以上,样品的加标回收率为99.6%~103.0%,测定结果的相对标准偏差为0.37%~0.42%(n=6)。该法操作简单,无需使用更多化学试剂,灵敏度高,测定结果准确可靠,能满足牙膏中游离氟含量的测定要求。     

离子选择性电极非线性测定水中氟离子的含量

利用氟离子选择性电极测定系列氟离子标准溶液的电极电位(vs.SCE),用测得的电极电位值与氟离子标准溶液的浓度数据进行非线性工作曲线拟舍,可准确测定1×10~(-6)～1×10~(-5)moL/L氟离子溶液的浓度。该法易于实现氟离子溶液的自动连续监测,适于氟离子溶液浓度的在线测量。     

高效液相色谱法检测氟吗啉在土壤中的降解

建立了氟吗啉在土壤中残留分析的高效液相色谱(HPLC)检测方法,在实验室条件下对氟吗啉在我国具有代表性的3种土壤中的降解动态进行了研究。样品通过V(正己烷)∶V(乙酸乙酯)=1∶2混和溶液萃取,经弗罗里硅土SPE柱净化,浓缩后进行HPLC检测。结果表明,药剂土壤添加浓度在0.2和2.0mg/kg时,氟吗啉在不同土壤中回收率为78.8%～97.1%;标准偏差为2.24%～7.48%。氟吗啉在土壤中的降解遵循一级动力学方程;氟吗啉在3种土壤中的降解速率大小依次为黑龙江黑土>江西红土>河南黄土,其降解半衰期分别为99.02、106.64和157.53d,降解速率常数(k)分别为7.0×10-3、6.5×10-3和4.4×10-3。根据国内农药在土壤中的残留划分标准,氟吗啉属于中等降解类农药。比较氟吗啉在非灭菌与灭菌的黑龙江黑土、江西红土和河南黄土中的降解情况表明,药剂在非灭菌土中降解明显快,分析可能是土壤中微生物对氟吗啉的降解具有显著的影响。     

乙醇-水介质中氟-铝沉淀电位滴定体系研究

由于氟-铝的多级络合反应,在水溶液中用氟化物直接滴定铝没有明显的电位突跃,若用乙醇-水介质,则电位突跃明显^[1～3].本文对乙醇-水介质中氟-铝沉淀电位滴定体系的化学平衡进行了研究.测定了在不同浓度的乙醇介质中氟-铝的络合比及各级络合物的稳定常数等参数.实验表明用F^-电位滴定测定铝可取得较好结果.     

控制电位氟-镓配位滴定法测定镓

以氟离子溶液作滴定剂,氟离子选择性电极作指示电极,利用氟-镓之间的配位反应及控制电位滴定法,对镓的测定进行了研究.控制溶液的pH约为4.2,实验温度为298 K,离子强度调节剂(NaNO3)的浓度为0.1 mol/L.对溶液控制的pH,氟离子的酸效应和镓离子的羟基配位效应对测定结果的影响,共存的Cu2 ,Zn2 ,Ni2 及Co2 等离子的干扰进行了讨论.     

高效液相色谱法检测噻虫嗪-氟虫腈悬浮剂

采用高效液相色谱法测定农药复合制荆120 g/L噻虫嗪-60 g/L氟虫腈悬浮荆.采用ODS C18反相色谱柱(150 mm×4. 6 mm i. d. ,5μm),乙腈一水(体积比为4∶6)为流动相,用紫外检测器在240 nm波长下,对试样中的噻虫嗪和氟虫腈进行分离和定量检测.噻虫嗪、氟虫腈的平均回收率分别为99. 0%～102. 0%、96. 0%～104. 0%,测定结果的相对标准偏差分别为0. 5%、1. 6%(n=6).     

氟罗沙星与人血清白蛋白相互作用研究

以光谱技术和微量热技术相结合的方法研究水溶液中氟罗沙星分子及铁存在时与人血清白蛋白之间结合作用的机制,用荧光淬灭法测得两反应的结合常数分别为K=1.19×l05L·mol-1和1.0565×105L·mol-1,结合位点数0.97和0.835.依据Fōrster非辐射能量转移机制,得到氟罗沙星与人血清白蛋白间的结合距离(r=3.23nm).用同步荧光技术考察氟罗沙星对人血清白蛋白构象的影响.微量热法测得氟罗沙星与人血清白蛋白反应的ΔH≈0,ΔS＞0,氟罗沙星分子在铁离子存在时与人血清白蛋白反应的ΔH＜0,并且ΔS＞0表明它们的作用都主要为静电力.由于焓熵互补的作用,两反应的自由能没有发生大的变化.     

在酸性介质中用氟电极测定氟离子的新方法

基于弱酸根离子在不同酸度溶液中的化学平衡和离子选择电极的响应特征, 本文推导出了以氟电极为指示电极, 玻璃pH电极作参比在酸性介质中测定氟的新方法. 经验证： 当pH＜2时, 氟离子浓度在10^-2～10^-5 mol/L范围内, 电池电动势值与氟离子总量呈能斯特响应, 试液中少量铝的存在对测定不构成干扰. 用该法直接测定了酸蚀法铝型材废水中的氟, 加标回收率达96%～98%.     

离子色谱法测定石墨中氟

石墨试样于500℃用氢氧化钠高温熔融提取,用热水浸泡洗出熔块以离子色谱法测定氟离子含量。用Dinoex AS15色谱柱,以20 mmol·L^-1氢氧化钠溶液为淋洗液等度洗脱,用电导检测器测定。氟离子的质量浓度在0.01～1.0 mg·L^-1范围内与其峰面积呈线性关系。方法用于4个产地的14个石墨样品分析,氟的质量分数在3.16×10²～2.04×10³mg·kg^-1之间。测定值的相对标准偏差（n=11）均低于3.0%。     

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。     

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.

     

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.     

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。     

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^-。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

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.     

解决能源问题的新途径--光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。