高灵敏度分光光度法测定茶叶中锌的含量

研究了在聚乙烯醇(PVA)存在下,Zn2+ - SCN—- RhB高灵敏度显色反应体系,采用分光光度法测定茶叶中微量锌的新方法.结果表明,络合物的最大吸收峰在605 nm处,摩尔吸光系数为1.59×106 L·mol—1·cm—1,Zn2+的质量浓度在0.0~0.04 μg/mL范围内服从比尔定律.该法用于测定茶叶中锌...     

新型非致密相磷酸锗锌化合物的合成与表征

在已合成的锗分子筛中 ,Ge O4 四面体 ,Ge O6 八面体或 Ge O5三角双锥通过共角形成骨架结构[1～ 3] .但磷酸锗类化合物仍很稀少 ,仅有 MGe2 ( PO4 ) 3[M=Ag,Cu( ) ,Na,Li][4 ,5] 通过固相方法被合成出来 ,锌骨架的分子筛报道很少 .L i Jian- min等 [6 ]报道了首例 ( DABCO) Zn Ge( HPO4 ) 3的合成和表征 .本文报道新型非致密相磷酸锗锌化合物的合成与表征 .1　实验部分1 .1　仪器与试剂　 Siemens D5 0 0 5 X射线衍射仪 ( Cu Kα射线 ) ;光学显微镜和 SEM Hi- 60 0高分辨扫描电子显微镜 ;Perkin- Elmer Optima330 0 DV I…     

极谱法测定蒙药那如三味丸中锗的研究

采用差分脉冲极谱法,在pH 1.50、含3,4 –二羟基苯甲醛(DHB)的H2SO4中,测得无机锗的峰电位为Ep=-0.54 V,Ge(Ⅳ)浓度在1.04×10 5～1.05×10 4 mol·L 1范围内与峰电流呈线性关系,利用该法用于测定蒙药那如三味丸中总锗、无机锗和有机锗,得到了满意的结果.     

表面活性剂增敏3'-甲氧基-4'-羟基苯基荧光酮光度法测锗的研究

研究了阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)存在下3'-甲氧基-4'羟基苯基荧光酮(MHPF)与Ge(Ⅳ)的显色反应.在HCl介质中,CTMAB的存在对MHPF与Ge(Ⅳ)的显色反应有显著的增敏作用,Ge(Ⅳ)与MHPF形成稳定的1:2红色配合物.配合物最大吸收波长位于505 nm,表观摩尔吸光系数为1.72×105L·mol-1·cm-1.锗量在0～0.48 mg/L范围符合比耳定律.方法已用于铅锌矿渣中微量锗的测定.     

5—Br—PAN—S光度法测定微量锌的研究

研究了锌与5-Br-PAN-S的显色反应.在pH8.5,Zn(Ⅱ)与5-Br-PAN-S反应生成1:2的红色络合物,其最大吸收峰为568nm,表观摩尔吸光系数为4.80×10~4,Zn(Ⅱ)浓度在0～30μg/25ml服从比耳定律.用本法测定了水样和头发中的微量锌,结果满意.     

锗－芦丁极谱络合吸附波的研究

在醋酸盐缓冲底液中,可获得Ge-芦丁的2个灵敏的络合吸附波P₁和P₂,分别对应于络合物中Ge(Ⅳ)还原至Ge(Ⅱ)再还原至Ge(0).两波的检出限分别为8.0×10^-8和4.0×10^-8mol/L.测得电活性络合物的组成为Ge:Rt=1:3,表面电极反应的速率常数(k_s)₁=10.5s^-1,(k_s)₂=1.9s^-1.还测定了有机锗口服液中锗的含量。     

分光光度法测定芦荟中微量元素锌

研究了表面活性剂十二烷基苯磺酸钠存在下,以1-(2-吡啶偶氮)-2-萘酚(PAN)为显色剂,分光光度法测定芦荟中微量元素锌的最佳显色条件及应用。结果表明,在pH 6.8~8.5的KH2PO4-NaOH缓冲溶液中,Zn(Ⅱ)与PAN形成红色的络合物,该络合物在常温下可稳定24 h以上。其最大吸收波长为550nm,表观摩尔吸光系数为5.26×104L.mol-1.cm-1,检出限为0.01μg/mL,Zn(Ⅱ)含量在0~25μg/mL范围内符合比尔定律。适用于基层单位测定芦荟样品中微量锌的含量。     

2,3,7-三羟基-9-(3,4-二羟基)苯基荧光酮光度法测定锌

研究了新型苯基荧光酮类显色试剂2,3,7-三羟基-9-(3,4-二羟基)苯基荧光酮(3,4-DHPF)与锌离子显色反应的条件及应用. 结果表明, 在阳离子表面活性剂溴化十六烷基三甲胺(CTMAB)存在下, 在pH 8.2的Na2HPO4-KH2PO4缓冲溶液中, 锌与3,4-DHPF形成1∶1的红色络合物, 所形成的络合物的最大吸收值位于560 nm处, 表观摩尔吸光系数为1.23×105 L·mol-1·cm-1;红色络合物至少稳定8 h以上, 锌含量在0～1.40 μg/5 mL范围内符合比尔定律;拟定方法已用于茶叶中微量锌的测定.     

OP存在下苯基萤光酮光度法测定多金属矿物中微量锗

在阳离子表面活性剂存在下,应用苯基萤光酮光度测定锗的方法已日益增多,而非离子表面活性剂OP在测定矿石中锗方面的应用尚未见报导。本实验结果表明,OP同样能显著提高苯基萤光酮(PF)-锗的显色反应的灵敏度。在25毫升显色液中维持酸度为0.08—2.5NHCl,1—4毫升10%OP和0.5—6毫升0.06%PF时,络合物吸光度最大且恒定,在505nm处有最大吸收,在0—10微克锗/25毫升范围内遵守比尔定律,络合物的摩尔吸光系数ε_(505)=1.3×10~5,组成比为Ge:PF=1:2。显色后5分钟即达完全并可     

Ge(IⅣ)-DB-o-NPF-CTMAB显色反应及其应用研究

在阳离子表面活性剂CTMAB存在下,研究了DB-o-NPF与Ge(Ⅳ)的显色反应.试验表明,在磷酸介质中,Ge(Ⅳ)与DB-o-NPF形成1:2稳定的红色配合物.该配合物最大吸收波长为550nm,其表观摩尔吸光系数为1.04×105L@mol-1@cm-1.锗量在0～6μg/25ml范围内符合比耳定律.试验结果表明,Ge(Ⅳ)-DB-o-NPF-CTMAB体系显色测定Ge(Ⅳ),很多离子不干扰测定.方法灵敏度高,选择性好,有色配合物稳定48h以上.直接用于烟道灰中微量锗的测定,结果满意.     

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.     

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.

     

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.     

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。     

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。     

黄酮化合物的合成研究进展

黄酮化合物是一类具有多种生物活性的天然产物,其经典的合成方法主要为查耳酮路线和β-丙二酮路线.近年来出现了许多新技术、新方法.本文介绍了2'-羟基查尔酮的氧化关环法、黄烷酮氧化法、改进的Baker-Venkataraman法及其他合成黄酮化合物的方法.