山苍子油含醛量分析

本文较全面介绍山苍子精油质量标准及柠檬醛的各种分析方法、并介绍了一些检测山苍子精油掺假的办法。

食用酒精含醛量测定的反滴定法

采用反滴定法测定食用酒精中的含醛量,可减少二次取样测定,只需2min测出结果,节省化验时间,提高生产的指导性。(孙悟)

种子年产度检验技术研究 Ⅱ.种子的年产度及活力与挥发性醛产生量的关系

在生产实践中,常常需要评定种子的质量,这就牵涉到种子的年产度和种子的活力问题。一般地,新收获的种子活力较高,而贮藏时间长的陈种子由于劣变程度大,活力较低。因此,鉴定种子的新老程度或年产度,实际上是测定种子的活力。种子在萌发早期放出挥发性醛的量与种子的活力有关,应用3—甲基—2—苯骈噻唑(3—Methy1-2-benzothiazolonehydrazone)试法测定种子的挥发性醛量,被认为是一种简易、快速、实用的测定种子活力的方法。

国内外木质材料甲醛释放量检测标准比较

在分析木质材料中甲醛来源及存在形式的基础上,通过比较欧美日及国际标准化组织最新木质材料甲醛检测标准,找出我国现行木质材料甲醛检测标准与国外标准的差异,为提高我国木质材料产品的甲醛检测和控制技术水平提供参考。

气袋法测汽车内饰醛酮散发量的不确定度评定

依据测量不确定度评定与表示的方法,建立了气袋采样法测试汽车内饰件醛酮散发量不确定度评定的数学模型,并对测试过程中各不确定度分量的来源进行了分析和合成。结果表明,标准曲线的拟合、采样体积、充气体积、标液配制过程对测试结果有较大影响。通过增加曲线拟合的准确性,使用高精度的采样泵、流量计和流量矫正器保证采样体积、充气体积的精确性,选用合适的移液器具规范标液配制的操作,从而降低测量结果的不确定度,有利于提高检测的准确性和一致性。

正确检测饰面人造板的甲醛释放量

饰面人造板在近年得到大力的推行,但在对其甲醛释放量检测方法的判断上,现在出现了一些错误的做法,笔者就专门针对饰面人造板甲醛释放量检测中出现两种做法进行讨论和分析。

核桃壳液化及其与甲醛反应能力的研究

本文探讨了核桃壳在120℃、液比为3/1和催化剂(浓硫酸,用量为苯酚的3%)条件下液化,通过液化体系内游离苯酚和残渣含量的分析以及液化体系与甲醛反应能力的分析发现:核桃壳的酚解和酚化反应主要发生在反应初期,后期逐渐减弱;液化体系内总的活性量由两部分组成,一是液化体系内游离苯酚贡献的活性量,二是体系内液化产物贡献的活性量;随着反应时间的进行,游离苯酚折算的耗醛量逐渐减少,液化产物的耗醛量逐渐增加,而总的液化体系中消耗甲醛的能力在逐渐的减弱。

核桃壳液化及其与甲醛反应能力的研究

探讨了核桃壳在120℃、苯酚与核桃壳粉质量比为3/1和催化剂(浓硫酸,用量为苯酚的3%)存在下液化,通过分析液化体系内游离苯酚和残渣含量以及液化体系与甲醛反应能力发现,核桃壳的酚解和酚化反应主要发生在反应初期,以后逐渐减弱;液化体系内总的活性量由2部分组成,一是液化体系内游离苯酚贡献的活性量,二是体系内液化产物贡献的活性量。随着反应的进行,游离苯酚折算的耗醛量逐渐减少,液化产物的耗醛量逐渐增加,而总的液化体系中消耗甲醛的能力在逐渐减弱。

聚醚离子液体的合成及其对酚醛树脂性能的影响

采用开环聚合法合成聚环氧氯丙烷中间体,再分别与N-甲基咪唑和吡啶反应合成了聚醚咪唑型离子液体(PIIL)与聚醚吡啶型离子液体(PPIL),并用红外与核磁进行结构表征。然后将合成的2种聚醚离子液体分别与酚醛树脂预聚物共混,制备了改性酚醛树脂。研究了2种聚醚离子液体及其用量对改性酚醛树脂的拉伸剪切强度、冲击强度及游离醛释放量的影响。结果表明:聚醚型离子液体的添加明显改善了酚醛树脂的胶合性能和冲击强度,并降低了游离醛含量。聚醚咪唑离子液体改性酚醛树脂的性能优于聚醚吡啶型离子液体,其拉伸剪切强度从最初的1.15 MPa提高到6.94 MPa,冲击强度从最初的2.10 k J/m2提高到9.51 k J/m2,游离醛含量从最初的1.76%降低到0.14%。

花椒、肉桂对食用菜油的抗氧化作用

食用菜油的稳定性是保证油脂食品卫生质量的重要因素。本实验将添加香料的食用油在恒温(65℃)条件下静置,不同时间测定香料花椒、肉桂对食用菜油的POV(过氧化值)值。实验数据表明,花椒、肉桂对食用菜油具有抗氧化作用,而且肉桂的抗氧化性能大于花椒。产生差异的主要原因是肉桂的含醛量大于花椒,而醛类物质中与羰基直接相连的α-碳原子上具有较活泼的氢,与食用菜油中活泼的自由基形成稳定的氢过氧化物或将油脂还原,自身则形成抗氧化自由基分子,起到了较强的抗氧化作用。

山苍子果实外表颜色变化与其出油率及油质关系的研究

山苍子果实在成熟期内何时采收能使其出油率高且油质好 ,是生产经营者感到比较棘手的问题。本研究为直观起见 ,主要从果实外表颜色变化着手 ,找出其与出油率及油质的关系 ,结果表明 :山苍子果实过早或过晚采收提炼山苍子油 ,都会影响其出油率及油质 ,只有在适宜的时间采收才会使出油率高且油质好。

液化反应条件对核桃壳液化产物成胶特性的影响

研究了液化反应条件(苯酚/核桃壳质量比、催化剂浓硫酸用量、温度和时间)对核桃壳液化产物成胶特性的影响。研究结果表明,随着苯酚/核桃壳质量比的增大,液化残渣率下降,液化产物的耗醛量逐渐上升;随着催化剂浓硫酸用量、液化反应温度和液化反应时间的增加,液化产物的游离酚含量、可被溴化物含量及液化残渣率下降较快,但耗醛量下降缓慢或变化不大;相同液化反应条件下,液化产物的可被溴化物含量总比相应的游离酚含量高;在苯酚与核桃壳质量比3∶1、催化剂浓硫酸用量3%、液化反应温度120℃、液化反应时间30 m in条件下获得的液化产物具有较好的成胶能力。

Analysis and Evaluation Indicator Selection of Chilling Tolerance of Different Cotton Genotypes

[Objectivc] This study aimed to investigate the chilling tolerance of seedlings of different cotton genotypes and screen appropriate indicators for assess- ing chilling tolerance, to establish reliable mathematical evaluation model for chilling tolerance of cotton, thus providing theoretical basis for breeding and promoting new chilling-tolerant cotton germplasms and large-scale evaluation of chilling tolerance of cotton varieties. [Method] Fifteen cotton varieties （lines） were used as experimental materials. The photosynthetic gas exchange parameters, chlorophyll fluorescence ki- netic parameters, chlorophyll content, relative soluble sugar content, malonaldehyde content, relative proiine content, relative conductivity and other 12 physiological indi- cators of seedling leaves under low temperature treatment （5 ℃, 12 h） and recovery treatment （25 ℃. 24 h） were determined; based on the chilling tolerance coefficient （CTC） of various individual indicators, the comprehensive evaluation of chilling toler- ance was conducled by using principal component analysis, hierarchical cluster anal- ysis and stepwise regression analysis. [Result] The results showed that the 12 indi- vidual physiological indicators could be classified into 7 independent comprehensive components by principal component analysis; 15 cotton varieties （lines） were clus- tered into three categories by using membership function method and hierarchical cluster analysis; the mathematical model for evaluating chilling tolerance of cotton seedlings was established： D =0.275 -0.244Fo1 ＋0.206Fv/Fm1＋0.326g,%-0.056SS ＋ 0.225MDA＋O.O38REC （FF=0.995）, and the evaluation accuracy of the equation was higher than 94.25%,0. Six identification indicators closely related to chilling tolerance were screened, including Fo,, Fv/Fm1, Seedling leaves of cotton varieties （lines） gs2, SS, MDA, and REC. [Conclusion] with high chilling tolerance are less dam- aged under low temperature stress, and are able to maintain relatively high photo- synthetic electron transport capacity and high stomatal conductance after recovery treatment, which is contributed to gas exchange and recovery of photosynthetic ca- pacity. Determination of the six indicators under the same stress condition can be adopted for rapid identification and prediction of the chilling tolerance of other cotton varieties, which provides basis for the breeding, promotion, identification and screen- ing of chilling tolerant germplasms.

Physiological characteristics changes of Aesculus chinensis seeds during natural dehydration

A study was conducted to determine the physiological characteristics changes of Aesculus chinensis seeds during natural dehydration in 2003. The results showed that A. chinensis seeds were recalcitrant with being highly desiccation-sensitive. The seed moisture content of fresh fruits was higher than 60%. When the seeds were naturally dried for 30 days, their moisture content declined to 30.2% and their viability was completely lost. The seed germination percentage had a small increase at the beginning of desiccation and then decreased rapidly. The relative electrical conductivity of the A. chinensis seeds increased along with a decrease in seed moisture content. However, there was an abnormal increase in relative electrical conductivity when the seed moisture content was between 53.7% and 50.9%. Superoxide dismutase （SOD） activity decreased rapidly in the period of desiccation except for an abnormality when the seed moisture content was between 53.7% and 50.9%. Malondialdehyde （MDA） content increased slowly at the early stage of desiccation and then rose rapidly after the moisture content was below 50.9%. The soluble sugar content in seeds slowly increased with the increasing period of desiccation. The seed germination percentage was at the high level when seed moisture content was in range of 47%- 60%, which suggests that this was the optimum moisture content for maintaining A. chinensis seed viability.

Effects of Light, Fertilizer and Irrigation on Growth and Physiological Characteristics of Glehnia littoralis

The aim was to promote the cultivation and application of medicinal plants Glehnia littoralis. [Method] Glehnia littoralis was used as experi-mental materials in this study, and orthogonal design was performed to investigate the effects of light, fertilizer and irrigation on the growth of Glehnia littoralis. The biomass, leaf chlorophyl and malondialdehyde （MDA） content were determined to study its response to light, fertilizer and irrigation. [Result] The results showed that the optimum cultivation conditions of Glehnia littoralis were not completely consistent with wild living environments. Lightly shade, highly fertilization （21.38-32.08 g） and proper irrigation （500-750 ml） were suitable for artificial cultivated Glehnia littoralis. Under the condition, the biomass was enhanced, leaf chlorophyl and carotene con-tent were increased, and MDA content changed significantly. Under stress condi-tions, the biomass of Glehnia littoralis reduced, with the decrease of chlorophyl and carotenoid content. The content of chlorophyl a was more sensitive to the variation of light, fertilizer, irrigation and other environmental factors, and MDA content signifi-cantly increased by stress conditions. [Conclusion] This research can provide refer-ence for large-scale artificial cultivation of Glehnia littoralis.

Thermodynamic analysis and transition state study for pyrolysis of levoglucosan and glyceraldehyde through quantum simulation

In order to better understand the pyrolysis process of cellulose, the decomposition of levoglucosan and glyceraldehyde, which are important intermediate products of cellulose, are simulated by quantum simulation. Thermodynamic analysis of four possible reaction pathways for levoglucosan is conducted by quantum chemistry.The reaction process of glyceraldehyde is checked, and the intermediates and the activation energies of the process are given. The simulation results indicate that the three well-established chemical pathways for levoglucosan in literature can spontaneously occur within the pyrolysis temperature range from 500 to 1 000 K. However, the reaction pathway involving the formation of erythrose cannot be accepted since the free energy ΔG is estimated to be above zero during the pyrolysis process. Through the analysis of glyceraldehyde decomposition by the transition state theory, decarbonylation and dehydration may be the dominant pathways for glyceraldehyde decomposition. The quantum simulation for determining the chemical pathway of glyceraldehyde and levoglucosan can give a conceptual and methodological guide for searching possible chemical pathways of cellulose pyrolysis or other macromolecules in biomass.

人造板胶黏剂产业发展新趋势及对策

分析当前人造板用胶黏剂产业的产品低醛化、供胶专业化和生产智能化等发展新趋势,并针对我国制胶企业现状,提出对策及建议。

Antioxidant activity of chito-oligosaccharides on pancreatic islet cells in streptozotocin-induced diabetes in rats

AIM:To investigate the antioxidant activity of chitooligosaccharides(COSs)on pancreatic islet cells in diabetic rats induced by streptozotocin. METHODS:The antioxidant effect of COSs on pancreatic islet cells was detected under optical microscopy and with colorimetric assay and gel electrophoresis.The activities of glutathione peroxidase and superoxide dismutase,total antioxidant capacity,and content of malondialdehyde in serum and tissue slices of pancreas were examined after 60 d to determine the effect of COSs in streptozotocin-induced diabetes in rats. RESULTS:COSs can prohibit the apoptosis of pancreatic islet cells.All concentrations of COSs can improve the capability of total antioxidant capacity and activity of superoxide dismutase and decrease the content of malondialdehyde drastically.Morphological investigation in the pancreas showed that COSs have resulted in the reduction of islets,loss of pancreatic cells,and nuclear pyknosis of pancreatic cells. CONCLUSION:COSs possess various biological activities and can be used in the treatment of diabetes mellitus.

Increased plasma malondialdehyde and fructosamine in anemic H pylori infected patients:Effect of treatment

AIM： TO unravel the possible association of malondialdehyde （MDA） and fructosamine in anemic H pylori infected patients and to observe the alteration in MDA and fructosamine levels in these patients after treatment for one month. METHODS： Fructosamine, MDA and glucose were estimated in 22 anemic H pylori infected patients and 16 healthy controls. Hematological parameters were also evaluated in both the groups using Sysmex-K-100 automated cell counter. The H pylori infected patients were randomly divided into two groups. Hpylori infected patients in Group Ⅰ received both iron supplementation and anti-H pylori therapy, while patients in Group Ⅱ received only iron supplementation. All the biochemical and hematological parameters were estimated after one month of treatment. RESULTS： In anemic H pylori infected patients, while MDA （5.41 ± 2.16 vs 2.26 ± 0.50; P 〈 0.05） and fructosamine （2.64 ± 0.93 vs 1.60 ± 0.35; P 〈 0.05） were significantly increased, iron （32.72 ± 14.93 vs 110.25 ± 26.58; P 〈 0.05）, hemoglobin （6.9 ± 2.6 vs 12.66 ± 0.74; P 〈 0.05） and ferritin （28.82 ± 16.27 vs 140.43 ± 30.72; P 〈 0.05） levels were significantly decreased compared with the controls. With partial correlation analysis, fructosamine was found to have a significant positive correlation with MDA. In Group I, while MDA level decreased significantly （3.11 ± 1.73 vs 5.50 ± 2.46; P 〈 0.05）, there was a significant increase in iron （84.09 ± 29.51 vs 36.09 ± 17.81; P 〈 0.05）, hemoglobin （10.40 ± 1.11 vs 7.42 ± 1.90; P 〈 0.05） and ferritin （116.91 ± 63.34 vs 30.46 ± 17.81; P 〈 0.05） levels after one month. There was no significant change in the levels of fructosamine in group Ⅰ after treatment. Similarly, no significant alterations were noted in the levels of IDA, fructosamine, hemoglobin or ferritin in Group Ⅱ patients after one month of treatment. CONCLUSION： An increased level of fructosamine and MDA was found in anemic H pylori infected patients. Present data supports the premise that lipid peroxides per se do play a role in the glycation of plasma proteins. Furthermore, the findings from this study indicate that treatment for both anemia and H pylori infections is required for lowering the levels of lipid peroxides in these patients.

Study on Brewing Technology of Apple Brandy

[Objective] The aim was to study the brewing technology of apple brandy. [Method] After the activated wine yeast was added to the apple juice by sizing classification, rinsing, falling to pieces and squeezing, the preceding fermentation began. Every other day, parameters of fer- mentation broth such as temperature, pH, acidity, sugar content and bubble nurdbers were detected. Once the sugar content of the fermentation suspension was approaching 5 -6 °Bx, the following fermentation would start via pouring wine. After 20 -30 days, the cider was changed into origi- nal apple brandy by distillation. The last procedure was aging which included man-made speediness aging and oak wood aging about 20 days. The physical and chemical compositions before and after aging were measured. [ Result] 22.5 kg apple resulted into 16.56 L of juice. The juice yield was about 73.6% （10 ml/kg）. The alcohol rate of distilled apple juice was 20.0%. The color of apple brandy was darker than that of original apple brandy. Alcohol level reduced, but total acidity, fixed acid, lipid and furfural content rose. [ Conclusion] The apple brandy was of particular flavor and high quality by selecting befitting fruit, activated wine yeast and feasible brewing, distillation and aging technology. It will be conductive to the development of apple processing industry and the research and development of key brandy technique.