Characterization of polar organic compounds in the organic film on indoor and outdoor glass windows

Organic films on an impervious surface (window glass) were sampled at paired indoor-outdoor sites in July 2000 and characterized for their paraffinic and polar organic compositions along an urban-rural transect. Four classes of polar compounds (C11-C31 aliphatic monocarboxylic, C6-C14 dicarboxylic, nine aromatic polycarboxylic, and five terpenoid acids) constituted between 81 and 95% (w/w) of the total organic fraction analyzed comprising n-alkanes (C10-C36), 46 PAH, 97 PCBs, and 18 OC pesticides. Concentrations of the polar compounds plus their precursors, n-alkanes, ranged from 8 to 124 microg m(-20 and were dominated by monocarboxylic acids (67-89%, w/w). On outdoor windows, n-alkanes, aromatic acids, and terpenoid acids decreased in concentration along the urban-rural transect. The carbon preference index values and the interpretations of individual compounds indicate that the main sources of n-alkanes were plant waxes followed by petrogenic sources; monocarboxylic and dicarboxylic acids were from plant waxes and animal fats. Results of principal component analysis showed closer correspondence between outdoor and indoor signatures than among locations. In outdoor films, these compounds are suggested to play an important role in mediating chemical fate in urban areas by air-film exchange and facilitating "wash-off" due to their surfactant-like properties. In indoor films, these compounds provide a medium for the accumulation of more toxic compounds.     

Lyocell纤维原纤化问题的探讨

简要介绍了新型溶剂纺再生纤维素纤维Ｌｙｏｃｅｌｌ的有关特点,详细探讨了Ｌｙｏｃｅｌｌ纤维的原纤化产生机理以及原纤化的利害关系,并对原纤化的影响因素和去除方法作了一般性探讨。     

浅析脚型与成鞋合脚性的研究

本文阐述了成鞋合脚性的概念和内涵,介绍了两种人体脚型测量方法。详细分析了脚型三维测量技术的工作原理,及其在国内外发展状况。并从脚型特征角度探讨了脚长、跖围和锺心位置等对成鞋合脚适性的影响。     

Morphology and current-voltage characteristics of nanostructured pentacene thin films probed by atomic force microscopy

Atomic force microscopy was used to study the growth modes (on SiO2, MoS2, and Au substrates) and the current-voltage (I-V) characteristics of organic semiconductor pentacene. Pentacene films grow on SiO2 substrate in a layer-by-layer manner with full coverage at an average thickness of 20 A and have the highest degree of molecular ordering with large dendritic grains among the pentacene films deposited on the three different substrates. Films grown on MoS2 substrate reveal two different growth modes, snowflake-like growth and granular growth, both of which seem to compete with each other. On the other hand, films deposited on Au substrate show granular structure for thinner coverages (no crystal structure) and dendritic growth for higher coverages (crystal structure). I-V measurements were performed with a platinum tip on a pentacene film deposited on a Au substrate. The I-V curves on pentacene film reveal symmetric tunneling type character. The field dependence of the current indicates that the main transport mechanism at high field intensities is hopping (Poole-Frenkel effect). From these measurements, we have estimated a field lowering coefficient of 9.77 x 10(-6) V-1/2 m1/2 and an ideality factor of 18 for pentacene.     

Growth of Aspergillus oryzae during treatment of cassava starch processing wastewater with high content of suspended solids

Aspergillus oryzae IFO 30113 was used for the treatment of the cassava starch processing (CSP) wastewater. The observations on the fungal morphology showed that, in the shake flasks containing the CSP wastewater with the high concentration of suspended solids, the formation of pellets originated from the adherence of germinated spores to solid particles in medium. The attached solid particles were also digested during the fungal fermentation and resulted in the formation of the smooth and hollow pellets. The changes of the culture conditions such as inoculum size, initial pH of wastewater, inoculum type and nutrient elements affected on the fungal morphology, biomass accumulation and treatment efficiencies of A. oryzae IFO 30113. In the typical pH range (pH 4-5) of the CSP wastewater, the formation of smooth pellets was predominant and A. oryzae IFO 30113 was satisfiable for the production of fungal biomass and treatment efficiencies. The supplementation of nitrogen sources has shown an improvement in the fungal biomass accumulation and the treatment efficiency of A. oryzae IFO 30113 growing in the CSP wastewater. Especially, high biomass yields (up to 0.8 g/g-COD) were achieved in flasks supplied with peptone. With ammonium sulfate as nitrogen source, 87% total organic carbon (TOC), 91% COD and 94% starch were removed after 96-h incubation. The possibility of the pellet formation despite the presence of the high content of suspended solids would be of great advantage to perform the treatment process and the fungal biomass production on the airlift-type bioreactors by lowering medium viscosity and better mass exchange of oxygen and nutrients.     

国外溶剂纺纤维素纤维的发展状况

介绍了国外溶剂纺纤维素纤维的发展状况，分析了溶剂纺纤维素纤维的竞争优势和使用的可能性，对促进我国粘胶行业的改造和新型溶剂纺纤维素纤维的研制有一定的实际意义。     

纯涤纶面料“极光”问题的探讨

论述了纯涤纶面料“极光”的产生机理，并且对于“极光”的消除方法以及利用“极光”的特性制作特种服装作了一般性论述。     

浅析三异涤长丝仿毛织物的技术关键

本简析了三异涤长丝仿毛织物开发过程,发现仿毛织物的研制与开发是一项系统工程,其中三异涤长丝、织造形式以及合理的碱减量技术是仿毛织物成功的技术关键。     

浅析三异涤长丝仿毛织物的技术关键

分析了目前较为流行的三异涤长丝仿毛织物开发过程,认为仿毛织物的研制与开发具有一项系统工程,其中三异涤长丝,织造形式以及合理的碱减量技术是仿毛织物成功的技术关键。     

The status of soil contamination by semivolatile organic chemicals (SVOCs) in China: a review

This paper summarizes the published scientific data on the soil contamination by semivolatile organic chemicals (SVOCs) in China. Data has been found for more than 150 organic compounds which were grouped into six classes, namely, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and phthalic acid esters (PAEs). An overview of data collected from the literature is presented in this paper. The Chinese regulation and/or other maximum acceptable values for SVOCs were used for the characterization of soils. In general, the compounds that are mostly studied in Chinese soils are OCPs, PAHs and PCBs. According to the studies reviewed here, the most abundant compounds were PAEs and PAHs (up to 46 and 28 mg kg(-1) dry weight, respectively); PCBs and OCPs occurred generally at concentrations lower than 100 microg kg(-1) dry weight. Nevertheless, quite high concentrations of PCDD/Fs, PCBs and PBDEs were observed in contaminated sites (e.g., the sites affected by electronic waste activities). The average concentrations of PAHs and OCPs in soils of North China were higher than those in South China. The principal component analysis demonstrated different distribution patterns for PAH, PCB and PCDD/F congeners and for the various sites/regions examined. The isomer ratios of DDTs and hexachlorocyclohexanes (HCHs) indicated different sources and residue levels in soils. Finally, this review has highlighted several areas where further research is considered necessary.