玉米幼芽提取物对小鼠皮肤UVA照射损伤的保护作用

研究了玉米幼芽提取物(extract of maize plumule,EMP)对长波紫外线(UVA)损伤的小鼠皮肤超微结构、抗氧化酶活性及脂质过氧化作用的影响。结果表明,UVA模型小鼠真皮细胞内出现空泡变性,线粒体肿胀、嵴减少,粗面内质网和核周间隙扩张;表皮细胞微绒毛减少,细胞固缩,细胞核染色质边集。EMP保护的小鼠皮肤细胞损伤程度明显减轻,结构基本正常。EMP可显著提高UVA辐射小鼠皮肤组织中的SOD活性(P<0.01)及CAT活性(P<0.05),降低MDA含量(P<0.05),与VC的抗氧化作用一致。表明EMP能够抵抗UVA对皮肤组织的氧化损伤。     

高浓度乳化废水的破乳-氧化-吸附深度处理研究

[目的]寻求有效的高浓度乳化废液的深度处理方法。[方法]采用酸化盐析破乳-Fenton氧化-粉煤灰吸附3级工艺对实验室模拟高浓度乳化含油废水进行处理研究。[结果]模拟的高浓度乳化含油废水在初始pH值为3、末期pH值为10、H2O2与Fe^2＋的物质量投加浓度比为52：1、H2O2投加量50ml／L和Fenton试剂投加量500mg／L的条件下氧化2h后,COD去除率达85．0％;对氧化后的废水进行吸附实验表明,进水COD336mg／L,在粉煤灰投加量40g/L、pH值为10的条件下振荡吸附30min后,出水COD109mg／L,COD去除率达67．5％。[结论]使用这种工艺对实际的机械洗削废液进行处理,出水水质良好达国家排放标准（COD≤120mg／L,含油量≤10mg／L）。     

肉桂酸催化合成条件的研究

研究了苯甲醛与乙酸酐的物质的量比、反应时间、催化剂种类以及混合催化剂物质的量比对合成肉桂酸的影响。实验结果表明,苯甲醛与乙酸酐的物质的量比为1∶3,反应时间为60 min,反应温度为170℃,催化剂为氟化钠/碳酸钾(其物质的量比为1∶2)时,肉桂酸的产率达76.6%。该工艺降低了反应温度,缩短了反应时间,提高了产率,并且该方法简单,环境污染小,产品纯度高。     

焦化场地PAHs污染土壤的电动-化学氧化联合修复

焦化场地土壤多环芳烃(PAHs)污染严重,目前的修复技术都存在不同程度的弊端。通过研究化学氧化、电动及其联合技术对焦化场地高浓度多环芳烃污染土壤的修复效果,比较了两种技术组合方式对修复效果的影响。结果表明,单一技术及联合技术对焦化场地PAHs均有一定的去除效果。在单一技术处理中,电动处理、芬顿和活化过硫酸钠对多环芳烃的去除率分别为24.86%、10.27%和22.19%;在联合技术处理中,活化过硫酸钠-电动组合、电动-活化过硫酸钠组合、芬顿-电动组合和电动-芬顿组合对多环芳烃的去除率分别为49.65%、41.73%、36.72%和31.39%。电动-化学氧化联合技术对PAHs的去除效果较单一技术提高了6.53%~27.46%。两种技术的组合方式及氧化剂类型均对联合处理效果产生影响,化学氧化-电动处理的多环芳烃去除率较电动-化学氧化处理高5.33%~7.92%,其差异主要由化学氧化去除率差异所引起;应用活化过硫酸钠试剂的组合对多环芳烃的去除率高出应用芬顿试剂的组合12.93%~10.34%。经联合处理后,污染物的残留量及毒性当量浓度均有不同程度降低,说明电动-化学氧化联合技术是一种有效的预处理方法。     

脂质在加热过程中的反应机理研究

研究了在有氧和无氧条件下脂质加热过程中热解反应的反应机理.通过脂质的Diels-Alder反应和自由基反应机理的研究表明,通过改变反应条件,可改变挥发物的成分,进而改善食品的风味和营养价值.     

化学氧化法测定土壤有机质的研究进展

有机质是土壤的重要组成成分,其含量水平是衡量土壤肥力的重要指标之一。化学氧化法在测定土壤有机质研究领域中应用普遍。本文综述化学氧化法测定土壤有机质的改进方法,讨论各方法利弊及一些干扰因子的去除,并对新的研究方向加以展望,对于研究出更简便、快捷、准确的有机质测定方法具有重要意义。     

Changes of Intramuscular Fat Composition,Lipid Oxidation and Lipase Activity in Biceps femoris and Semimembranosus of Xuanwei Ham During Controlled Salting Stages

Fatty acid composition of neutral lipids （NLs）, phospholipids （PLs） and free fatty acids （FFAs） from intramuscular fat （IMF）, lipid oxidation and lipase activity in muscle Semimembranosus （SM） and msucle Biceps femoris （BF） of dry-cured Xuanwei ham during the 90-d salting stages were analysed. The salt content increased from 0.34 to 3.52%in BF and from 0.10 to 5.42%in SM during the 90 d salting stage, respectively. PLs of IMF in both BF and SM decreased 54.70%（P〈0.001） and 34.64%（P〈0.05）, furthermore, the saturated fatty acids （SFA）, monounsaturated fatty acids （MUFA） and polyunsaturated fatty acids （PUFA） of PLs in both muscles were hydrolysed almost isochronously. FFAs were increased from 0.46 g 100 g-1 lipids to 2.92 g 100 g-1 lipids in BF at the end of salting, which was lower than SM （from 1.29 g 100 g-1 lipids to 9.70 g 100 g-1 lipids）. The activities of acid lipase, neutral lipase and acid phospholipase all remained active in the 90 d. The thiobarbituric acid reactive substances （TBARS） was slowly increased to 1.34 mg kg-1 muscle in BF and to 2.44 mg kg-1 muscle in SM during the salting stage. In conclusion, the controlled salting process prompted the hydrolysis of PLs of IMF notably and increased the lipid oxidation of muscles within some limits.     

纳米TiO2悬浮液对烟草青枯菌杀菌活性的研究

纳米T iO2是一种半导体光催化剂,在近紫外光的激发下,可以产生强的杀菌活性。以烟草青枯菌P seudomonas solanacearum为试验对象,采用平板稀释法对自制的纳米T iO2悬浮液进行杀菌活性测定。结果表明:在阳光或汞灯下照射4h后,T iO2对烟草青枯菌的杀菌率可达90%以上。说明用纳米T iO2防治烟草青枯病具有一定的可行性。     

Production and oxidation of wool grease after shearing

OBJECTIVE: To measure the production and amount of oxidation of wool grease secreted immediately after shearing. To identify components of wool grease that might act as a carrier to facilitate lateral diffusion of topically applied insecticides. DESIGN: Fine-wool Merino sheep were shorn and residual greasy wool was collected from the sheep's flank. The quantity of grease produced, and the amount of oxidation was measured during 18 days after shearing. Wool grease was fractionated into five component groups based on their polarity and the degree of oxidation in these fractions determined. RESULTS: There was a 24% increase in grease production within 2 days after shearing but secretions returned to pre-shearing amounts after 4 days. During this period wool grease oxidized rapidly. Of the grease fractions examined, sterol and wax esters remained essentially unoxidized whereas free sterols such as cholesterol and lanosterol, fatty acids and polar lipids, aldehydes and alcohols were extensively oxidized within 7 days after shearing. CONCLUSION: The transient increase in grease production after shearing may facilitate diffusion of topically applied synthetic pyrethroid insecticides. Oxidation of grease components may then contain the insecticide and limit further diffusion. Incorporating the insecticide in non-oxidising fractions of wool grease may make insecticide dispersion more efficient.     

预氧丝原位炭化无粘结剂C/C复合材料氧化动力学研究

采用恒温热重法测定了在空气中，０．１ＭＰａ，６７３Ｋ到９７３Ｋ下预氧丝（即预氧化聚丙烯腈纤维）原位炭化无粘结剂Ｃ／Ｃ复合的氧化失重率；并利用扫描电镜分析了这种复合材料氧化前后的结构，氧化动力学测定结果表明：该材料在氧化开始时，其氧化速率随时间的增长而增大，然后随时间的延长而减小，并趋向恒定，研究表明：该材料中预氧丝与基体炭界面结合处是空气中氧的扩散通道，杂质为空气中氧的吸附起到了有附活性中心的催化