MECHANISMS OF THE GAS-PHASE REACTIONS OF AROMATIC HYDROCARBONS AND PAHS WITH OH AND NO 3 RADICALS

Chemical removal for the simple monocyclic aromatic hydrocarbons (benzene and the C ₁ -C ₃ alkylbenzenes) and naphthalene and the C ₁ -C ₂ alkylnaphthalenes in the atmosphere is by reaction with hydroxyl (OH) radicals. Naphthalene and the C ₁ -C ₂ alkylnaphthalenes may also be removed, but to a much lesser extent, by reaction with nitrate (NO ₃ ) radicals. While rate constants for the gas-phase reactions of OH radicals and NO ₃ radicals with many of the simple monocyclic aromatic hydrocarbons and with naphthalene and the C ₁ -C ₂ alkylnaphthalenes have been measured, the detailed mechanisms of these OH radical-and NO ₃ radical-initiated reactions in the atmosphere are less well understood, especially for naphthalene and the alkylnaphthalenes. Here we present the available data on the reaction mechanisms occurring under laboratory conditions and attempt to reconcile these data with ambient atmospheric measurements. The OH radical reactions with benzene and alkylbenzenes and the OH radical and NO ₃ radical reactions with naphthalene and alkylnaphthalenes proceed mainly by initial addition of the OH or NO ₃ radical to the aromatic ring(s) at room temperature and below. The NO ₃ radical reactions with alkylbenzenes proceed by H-atom abstraction from the C-H bonds of the alkyl substituent group(s), while the NO ₃ radical reactions of naphthalene and the alkylnaphthalenes proceed by addition and with rates proportional to the NO ₂ concentration. The OH-monocyclic aromatic adducts react with O ₂ under atmospheric conditions, while the OH-naphthalene/alkylnaphthalene and NO ₃ -naphthalene/alkylnaphthalene adducts appear to undergo significant reaction with NO ₂ under urban atmospheric conditions.     

一些氮氧自由基和受阻胺化合物对单重态氧的猝灭能力及其与光稳定作用的关系

本工作测定了一系列稳定氟氧自由基(>N—O·)化合物及一些受阻胺光稳定剂对单重态氧(~1O_2)的猝灭速率常数(k_q~~1O_2),发现不同结构的>N—O·对~1O_2的猝灭能力很接近,但它们对聚丙烯(PP)膜的光稳定作用却相差很大。四甲基哌啶醇(TMP)及其衍生物对~1O_2的猝灭能力远不如相应的五甲基哌啶醇(PMP)及其衍生物,但前者对PP的光稳定能力却胜于后者。这说明在对聚合物的光稳定作用中,>N—O·和受阻胺光稳定剂对~1O_2的粹灭作用不占重要地位,也说明~1O_2在PP的光氧化过程中很可能不是主要因素。     

锂离子电池首次充、放电时石墨负电极与电解液界面所发生的反应

采用恒电流充、放电——原位XRD法对锂离子电池（LIB）首次充、放电过程进行了研究。实验结果表明，LIB首次充电时电解液于石墨负电极的界面处发生还原反应，生成了电子不可导而锂离子可导的固体电解质中介相（SEI）薄膜。FTIR分析结果证明SEI膜系由无定形碳酸锂和烷基碳酸锂组成。恒电流充、放电实验和循环伏安实验结果表明，如果所选择的电解液（例如EC基电解液）在石墨负电极表面的还原反应很缓和，反应中所产生气体的量和速率很小，则在石墨负电极表面将形成薄而致密的SEI膜。薄而致密的SEI膜所消耗的Li^＋量小，可以降低首次充电时的不可逆容量，同时减小Li^＋对石墨进行插层和脱层时的阻力，增大LIB的充、放电容量，提高充、放电效率。     

EVALUATION OF THE USE OF 1-NITROPYRENE,PYRENE, AND 1-HYDROXYPYRENE AS MARKERS OF DIESEL EXHAUST EXPOSURE IN UNDERGROUND MINING: RESULTS FROM THE BIOMODEM STUDY

The exposure to diesel exhaust was studied in underground mining of oil shale in Estonia. The purpose of this study was to evaluate different approaches to exposure assessment. Fifty men who drove diesel-powered excavators underground were compared with 50 surface workers who had no known occupational exposure to diesel exhaust. Samples of respirable air were analyzed for 1-nitropyrene and pyrene. Urine samples were collected at the start and after the first and the last shift of the same week, and were analyzed for 1-hydroxypyrene. Although ambient monitoring of 1-nitropyrene indicated a relatively high exposure of underground workers to diesel exhaust compared to surface workers (approximately 10-fold higher), only a small increase in the excretion of 1-hydroxypyerene was observed. Nonoccupational exposures such as smoking, recent consumption of grilled food, and recent proximity to an open fire had a greater impact on urinary excretion of 1-hydroxypyrene than occupational exposure to diesel exhaust.     

氯铬酸甲胺／硅胶氧化１—萘甲醇制备１—萘甲醛

采用一般新型氧化剂氯铬酸甲胺／硅胶（ＭＣＣ／硅胶）氧化１－萘甲醇制备１－萘甲醛,考察了温度、溶剂、氧化剂用量和１－萘甲醇浓度对反应的影响,结果发现ＭＣＣ／硅胶可在室温、高选择性地将１－萘甲醇氧化为１－萘甲醛,选择性达９０．２％。     

DRYING EXPERIMENTS WITH ALO(OH) SUSPENSION OF HIGH PURITY AND FINE PARTICULATE SIZE TO DESIGN AN INDUSTRIAL SCALE DRYER

ABSTRACT

AIO(OH) suspension of high purity and fine particle size was dried in a Mechanically Spouted Bed (MSB) dryer with inert particles. During drying the maximum required moisture content and the mean particle size of the dried product had to be taken into consideration. Also another important aspect was to avoid contamination of the dried solid with metals. PTFE cylinders of 8 mm in diameter and of 8 mm in height were used as inert particles, and also the whole dryer itself was coated with teflon. As a result of the drying experiments the optimum values of the process parameters were used for scaling-up. The specific rate of evaporation in the drying zone of the inert bed was the basis of the calculations. The suspension with capacity of 125 kg/h was successfully dried in the designed industrial scale MSB dryer with inert panicles and the required quality of the material was produced.     

用载体型钛催化剂合成高反式－1．4聚异成二烯

本文研究了载体型钛催化剂合成高反式－１．４聚异戊二烯（ＴＰＩ）的聚合活性，初期聚合速率并对所得ＴＰＩ微观结构进行了表征。结果表明在一定范围内该催化体系催化效率较高，可达３０００ｇＴＰＩ／ｇＴｉ。聚合表观活化能为３３．５ｋＪ／ｍｏｌ，聚合速率及分子量随温度升高同时增加，合成的ＴＰＩ反式－１．４结构含量可达９８％左右     

用煤炭生产化肥联产C1化学品的发展前景

本文从化肥与Ｃ＿１化学的关系出发论述了发挥我国煤炭资源的优势，发展大型水煤浆制氨联产Ｃ＿１化学品，以增强农产品的供给和提高人民物质生活多样化高度化的需求。随着科技经济的发展，我国将出现一个新的煤化工时代。本文供国家宏观规划和决策参考。     

正辛醇为稀释剂条件下二元羧酸的萃取平衡特性

以二元羧酸乙二酸、丙二酸、丁二酸、顺丁烯二酸和苹果酸为分离对象,三烷基氧膦（TRPO）为络合剂,正辛醇为稀释剂进行了系统的萃取相平衡实验.结果表明,溶质的pK_a1和羧酸的亲油性同时影响络合萃取平衡.红外光谱分析表明,萃取剂TRPO与正辛醇之间形成氢键,抑制了对羧酸的萃取,使得TRPO与有机羧酸之间形成1∶1的络合物;负载有机羧酸的红外谱图表明,TRPO萃取有机羧酸为氢键溶剂化历程,负载有机羧酸的TRPO中的P=O键吸收峰的位移与有机羧酸的酸性有关.采用质量作用定律分析方法建立了负载量的表达式,模型拟合精度令人满意.     

BUBBLE TEMPERATURES OF THE BINARY MIXTURES OF 1,2-DIMETHYLBENZENE WITH 2-PROPANOL, 1-BUTANOL, 2-BUTANOL, 2-METHYLPROPAN-1-OL AND 2-METHYLPROPAN-2-OL AT 95 kPa

Bubble temperatures at 95 kPa over the entire composition range are measured for the five binary systems formed by 1,2-dimethylbenzene with 2-propanol, 1-butanol, 2-butanol, 2- methylpropan-1-ol, and 2-methylpropan- 2-ol. A Swietoslawski - type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model.     

REACTIVE EXTRACTION OF LEVULINIC ACID FROM AQUEOUS SOLUTIONS WITH TRI-n-OCTYLAMINE (TOA) IN 1-OCTANOL: EQUILIBRIA,KINETICS, AND MODEL DEVELOPMENT

Levulinic acid, a carboxylic acid containing a ketone structure, can be used as an acidulant in foods and beverages. Reactive extraction is a promising alternative for the recovery of carboxylic acids from aqueous streams. The design of an amine extraction process requires kinetic data for the acid-amine + solvent system used. In this study, equilibrium and kinetic data on the extraction of levulinic acid from aqueous solutions using tri-n-octylamine (TOA) in 1-octanol have been determined. The mass transfer coefficients of levulinic acid, TOA, and 2:1 levulinic acid-amine complex in 1-octanol were calculated from the acetic acid mass transfer coefficient, which was determined by measuring its fluxes of simple diffusion from kerosene to water. Based on the Hatta number and the criterion given by Doraiswamy and Sharma, the reaction regime has been found to be instantaneous reaction regime occurring at the interface on the organic phase side. An extraction model comprising equilibrium complexation constant w.r.t 2:1 levulinic acid-TOA complex formation, K_E2i (14.794 (m³ kmol^?1)²), and complex mass transfer coefficient, k_B2A (2.193 × 10^?6 m s^?1), has been developed.