富勒烯[C60] 作为油脂抗氧化剂的研究

研究富勒烯[C60]对油脂的抗氧化效果。通过烘箱加热法研究富勒烯[C60]与叔丁基对苯二酚(TBHQ)、二丁基羟基甲苯(BHT)、没食子酸丙酯(PG)、V_E对橄榄油、文冠果油、亚麻籽油和猪油的过氧化值和防护因子PF20的影响并进行加热实验。结果表明,在亚麻籽油和文冠果油中的抗氧化效果为:TBHQ富勒烯[C60]PGBHTV_E;在橄榄油中的抗氧化效果为:富勒烯[C60]TBHQPGBHTV_E;在猪油中的抗氧化效果为:TBHQPGBHT富勒烯[C60]V_E。在加热实验中,添加抗氧化剂的油脂均没有析出物且色值不发生变化。表明富勒烯[C60]在油脂中具有很好的抗氧化性能,可作为食品加工、生产与储存中油脂的抗氧化剂。     

Impact of fullerene (C60) on a soil microbial community

The nascent state of the nanoproduct industry calls for important early assessment of environmental impacts before significant releases have occurred. Clearly, the impact of manufactured nanomaterials on key soil processes must be addressed so that an unbiased discussion concerning the environmental consequences of nanotechnology can take place. In this study, soils were treated with either 1 microg C60 g(-1) soil in aqueous suspension (nC60) or 1000 microg C60 g(-1) soil in granularform, a control containing equivalent tetrahydrofuran residues as generated during nC60 formation process or water and incubated for up to 180 days. Treatment effects on soil respiration, both basal and glucose-induced, were evaluated. The effects on the soil microbial community size was evaluated using total phospholipid derived phosphate. The impact on community structure was evaluated using both fatty acid profiles and following extraction of total genomic DNA, by DGGE after PCR amplification of total genomic DNA using bacterial variable V3 region targeted primers. In addition, treatment affects on soil enzymatic activities for beta-glucosidase, acid-phosphatase, dehydrogenase, and urease were followed. Our observations show that the introduction of fullerene, as either C60 or nC60, has little impact on the structure and function of the soil microbial community and microbial processes.     

Investigation of the transport and deposition of fullerene (C60) nanoparticles in quartz sands under varying flow conditions

A coupled experimental and mathematical modeling investigation was undertaken to explore nanoscale fullerene aggregate (nC60) transport and deposition in water-saturated porous media. Column experiments were conducted with four different size fractions of Ottawa sand at two pore-water velocities. A mathematical model that incorporates nonequilibrium attachment kinetics and a maximum retention capacity was used to simulate experimental nC60 effluent breakthrough curves and deposition profiles. Fitted maximum retention capacities (S(max)), which ranged from 0.44 to 13.99 microg/g, are found to be correlated to normalized mass flux. The developed correlation provides a means to estimate S(max) as a function of flow velocity, nanoparticle size, and mean grain size of the porous medium. Collision efficiency factors, estimated from fitted attachment rate coefficients, are relatively constant (approximately 0.14) over the range of conditions considered. These fitted values, however, are more than 1 order of magnitude larger than the theoretical collision efficiency factor computed from Derjaguin-Landau-Verwey-Overbeek (DLVO) theory (0.009). Data analyses suggest that neither physical straining nor attraction to the secondary minimum is responsible for this discrepancy. Patch-wise surface charge heterogeneity on the sand grains is shown to be the likely contributor to the observed deviations from classical DLVO theory. These findings indicate that modifications to clean-bed filtration theory and consideration of surface heterogeneity are necessary to accurately predict nC60 transport behavior in saturated porous media.     

Interaction of fullerene (C60) nanoparticles with humic acid and alginate coated silica surfaces: measurements, mechanisms, and environmental implications

The deposition kinetics of fullerene (C60) nanoparticles onto bare silica surfaces and surfaces precoated with humic acid and alginate are investigated over a range of monovalent (NaCI) and divalent (CaCl2) salt concentrations using a quartz crystal microbalance. Because simultaneous aggregation of the fullerene nanoparticles occurs, especially at higher electrolyte concentrations, we normalize the observed deposition rates by the corresponding favorable (transport-limited) deposition rates to obtain the attachment efficiencies, alpha. The deposition kinetics of fullerene nanoparticles onto bare silica surfaces are shown to be controlled by electrostatic interactions and van der Waals attraction, consistent with the classical particle deposition behavior where both favorable and unfavorable deposition regimes are observed. The presence of dissolved humic acid and alginate in solution leads to significantly slower deposition kinetics due to steric repulsion. Precoating the silica surfaces with humic acid and alginate exerts similar steric stabilization in the presence of NaCl. In the presence of CaCl2, the deposition kinetics of fullerene nanoparticles onto both humic acid- and alginate-coated surfaces are relatively high, even at relatively low (0.3 mM) calcium concentration. This behavior is attributed to the macromolecules undergoing complex formation with calcium ions, which reduces the charge and steric influences of the adsorbed macromolecular layers.     

立达C60型梳棉机使用经验

介绍了一印度尼西亚纺纱厂使用瑞士立达机械工程公司生产的C60型梳棉机在环锭细纱操作方面运转性能和质量的经验。     

Solubility of C60 in solvent mixtures

The potential large-scale production of fullerene C60 and its widespread use in consumer products may translate into occupational and public exposure and in long-term environmental exposure. To assess the risk and fate of C60 in the environment, it is important to understand its solvate formation in common industrial solvents as the solvates may affect various properties of C60 including reactivity and toxicity, particularly when solvates occur in C60 clusters. In this study, the solubility measurements in mixed solvent system can provide useful information about solvate formation. The solubility of C60 was measured in pure toluene, tetrahydrofuran, ethanol, and acetonitrile to be 3000, 11, 1.4, and 0.04 mg/L, respectively. Additionally, the solubility of C60 was measured in mixtures of toluene-acetonitrile, toluene-ethanol, toluene-tetrahydrofuran, and acetonitrile-tetrahydrofuran. The solubility data were modeled with some accuracy using Wohl's equation. The estimated crystal energy term for C60 in tetrahydrofuran was different than that in the other solvents, indicating that the C60 solid phase in equilibrium with tetrahydrofuran solution may be a solvated crystal.     

单糖及寡糖定量分析方法综述

单糖和寡糖大多是可溶性糖,在生物体内具储存能量、转移介质的作用;此外,单糖和寡糖可以充当结构物质和功能分子如糖蛋白的配基。因此,糖类化合物的分析在生命科学、食品科学、医药科学和农业科学等领域中具有极其重要的意义。本文通过对单糖及寡糖分析方法相关的文献进行追踪、整理分类,系统介绍了单糖及寡糖的主要分析方法,并对气相色谱法、高效液相色谱法、毛细管电泳法和高效阴离子交换色谱法等4种定量分析方法在食品、蔬菜、水果及药物中的定量分析应用进行了分析评述,得出高效液相色谱-蒸发光散射法为定量分析单糖及寡糖较适宜的方法,期望为后期单糖及寡糖的定量分析研究提供一定的参考。      

改性PAE涂层基布分析的预处理

采用丙酮、乙酸乙酯、二甲基甲酰胺、NaOH溶剂在不同温度下对改性聚丙烯酸酯(PAE)涂层织物进行剥离处理.结果表明,每克改性聚丙烯酸酯涂层的涤棉混纺织物经50 mL 50 g/L NaOH煮沸处理1h,转移至100 mL二甲基甲酰胺常温萃取lh,剥离效果较好.涂层去除后,可用涤棉混纺织物定量分析方法进行定量测定.该方法准确、快速、简便,适合改性聚丙烯酸酯涂层织物的组分定量分析.     

异硫氰酸酯分析方法研究进展

异硫氰酸酯（ITCs）是一类通式为R-N=C=S的有机化合物。它们是十字花科某些蔬菜的独特风味成分,具有多种生理活性。重点对ITCs定性、定量分析方法的最新研究进展进行了系统的分析和介绍。     

Reaction of water-stable C60 aggregates with ozone

While the reactivity of C60 has been described in a variety of organic solvents, little information is available regarding aqueous-based reactions due to solubility limitations. In this study, a reaction between C60, as a nanoscale suspension, and dissolved ozone in the aqueous phase was investigated. Findings indicate a facile reaction occurs, resulting in aggregate dissolution concurrent with formation of water-soluble fullerene oxide species. Product analyses, including 13C NMR, MS (LDI), FTIR, UV-Vis, and XPS, indicate highly oxidized fullerene with an average of approximately 29 oxygen additions per molecule, arranged in repeating hydroxyl and hemiketal functionalities. These findings are significant in that they (1) demonstrate the feasibility of other aqueous-based fullerene chemistries, including those for alternative synthesis routes, which might otherwise be considered prohibitive on the basis of solubility limitations, and (2) imply that the aqueous reactivity of fullerene-based materials must be considered appropriately for accurate assessment of their transport, fate, and potential risk(s) in environmental systems.     

C60型梳棉机设计思想的探讨

探讨C60型梳棉机设计思想.从加宽机幅、采用较小的锡林直径、刺辊模块化的设计、活动盖板根数的选择、棉网清洁器的选用及针布配置等方面分析探讨了C60型梳棉机的设计思想,认为其提高产量的关键是加宽机幅和采用较小锡林直径.加宽机幅可以直接使产量提高且不影响质量.较小锡林直径可使排杂能力加强,减少锡林因高速等引起滚筒膨胀,在踵趾差不变条件下,可使锡林与活动盖板的小隔距区间变长,使锡林与活动盖板问分梳效能大大加强.     

C60梳棉机--新梳理尺寸

C60梳棉机产量高，梳棉质量稳定，投资成本合理，是非常实用的、最经济的梳棉机。     

聚乳酸/棉混纺产品定量分析比较

根据聚乳酸/棉混纺产品中两种纤维不同的溶解性能,选取75%硫酸、二氯甲烷、5%氢氧化钠和88%甲酸作为溶解试剂对聚乳酸和棉纤维进行定量分析,并对这四种分析方法的准确度和精密度进行了比较.结果表明,这四种分析方法的准确度和精密度均能满足GB/T 2910-1997国家标准要求.相比之下,采用二氯甲烷法准确度最高,75%硫酸法和5%氢氧化钠法精密度较高.     

微藻总脂定量分析方法的比较研究

从总脂含量、脂肪酸甲酯(FAMEs)得率和脂肪酸组成等方面对4种总脂定量提取方法进行了比较研究。结果表明:超声波辅助正己烷-乙酸乙酯提取法、三氯甲烷-甲醇提取法、二甲亚砜(DMSO)-甲醇/正己烷-乙醚分步提取法和正己烷索氏抽提法测定小球藻总脂含量,经过破壁处理,总脂含量分别为32.95%、26.81%、29.60%和25.17%,未经过破壁处理,总脂含量分别为16.30%、17.17%、21.81%和8.72%,两组测定结果差异极显著,表明从厚壁微藻提取总脂必须对藻粉进行破壁处理。4种方法提取总脂的脂肪酸甲酯得率分别为24.20%、26.19%、28.02%和21.23%,除正己烷索氏抽提法得率偏低外,其他3种方法得率相近,均能较完全地提取中性脂。正己烷索氏抽提法抽提1 h不能充分提取总脂。三氯甲烷-甲醇提取法和DMSO-甲醇/正己烷-乙醚分步提取法可以提取鲜藻总脂,而其他两种方法则不能。     

Stable colloidal dispersions of C60 fullerenes in water: evidence for genotoxicity

Stable aqueous suspensions of colloidal C60 fullerenes free of toxic organic solvents were prepared by two methods: ethanol to water solvent exchange (EthOH/nC60 suspensions) and extended mixing in water (aqu/nC60 suspensions). The extended mixing method resulted in the formation of larger (dp approximately 178 nm) and less negatively charged (zeta approximately -13.5 mV) nC60 colloids than nC60 prepared by ethanol to water solvent exchange (dp approximately 122 nm, zeta approximately -31.6 mV). Genotoxicity of these suspensions was evaluated with respect to human lymphocytes using single-cell gel electrophoresis assay (Comet assay). The assay demonstrated genotoxicity for both types of suspensions with a strong correlation between the genotoxic response and nC60 concentration, and with genotoxicity observed at concentrations as low as 2.2 microg/L for aqu/nC60 and 4.2 microg/L for EtOH/nC60. The Olive tail moments (OTM) for these two concentrations were 1.54 +/- 0.24 and 1.34 +/- 0.07, respectively, which in comparison to the negative control OTM of 0.98 +/- 0.17 is statistically different with a p value of at least 0.05. Aqu/nC60 suspensions elicited higher genotoxic response than EthOH/nC60 for the same nC60 concentration. The results represent the first genotoxicity data for colloidal fullerenes produced by simple mixing in water.     

Transport of fullerene nanoparticles (nC60) in saturated sand and sandy soil: controlling factors and modeling

Understanding subsurface transport of fullerene nanoparticles (nC(60)) is of critical importance for the benign use and risk management of C(60). We examined the effects of several important environmental factors on nC(60) transport in saturated porous media. Decreasing flow velocity from approximately 10 to 1 m/d had little effect on nC(60) transport in Ottawa sand (mainly pure quartz), but significantly inhibited the transport in Lula soil (a sandy, low-organic-matter soil). The difference was attributable to the smaller grain size, more irregular and rougher shape, and greater heterogeneity of Lula soil. Increasing ionic strength and switching background solution from NaCl to CaCl(2) enhanced the deposition of nC(60) in both sand and soil columns, but the effects were more significant for soil. This was likely because the clay minerals (and possibly soil organic matter) in soil responded to changes of ionic strength and species differently than quartz. Anions in the mobile phase had little effect on nC(60) transport, and fulvic acid in the mobile phase (5.0 mg/L) had a small effect in the presence of 0.5 mM Ca(2+). A two-site transport model that takes into account both the blocking-affected attachment process and straining effects can effectively model the breakthrough of nC(60).     

Apparatus for quantitative headspace analysis of the characteristic odorants of baguettes

 An apparatus, based on the principle of dynamic headspace analysis, has been developed for the analysis of potent odorants released from two types of baguette (“intensifiée”, INT and “artisanal”, ART) which differ in their odour profiles. The odour profiles of model mixtures containing the odorants at concentrations found in bread were evaluated by headspace analysis using the apparatus as an olfactometer and were compared to the odour profiles of the baguettes. The results indicated that losses of methylpropanal, 2- and 3-methylbutanal and an increase of hexanal and (E)-2-nonenal led to a stale flavour. Because the concentrations of methylpropanal and (E)-2-nonenal were higher in the ART crust than in the INT crust, the change from a pleasant baguette odour to a stale odour was slower in ART baguettes. We suggest that the apparatus designed for quantitative headspace analysis could also be suitable for determination of the release of flavour compounds from other foods. Received: 17 March 1997     

C60型梳棉机隔距参数设计理念分析

分析C60型梳棉机隔距参数设计理念.通过对比立达公司各型号梳棉机的主要工艺隔距,探讨了刺辊与给棉罗拉、除尘刀、分梳板、锡林间的隔距以及锡林与后固定盖板、活动盖板、前固定盖板、道夫等分梳元件隔距的选择方法.指出:在产量大幅提高的条件下,C60型梳棉机锡林与活动盖板隔距选择仍坚持"紧隔距、强分梳"的工艺设计思想.认为在工艺参数选择时,一定要坚持系统工程的理念,随着产量增加,锡林与道夫、刺辊间的隔距均应随之增加.