八月瓜果皮挥发油的GC-MS分析

以成熟八月瓜果皮为研究原料,用水蒸汽蒸馏法制备了八月瓜果皮挥发油,并用气相色谱-质谱联用仪测定了挥发油的化学成分。结果表明,八月瓜果皮挥发油中共鉴定出39种组分,包括烃、酸、酯、醛(酮)、醇(酚)、醚、其他等七大类物质,相对含量分别为56.63%、25.44%、8.50%、7.34%、0.57%、0.19%和1.33%。烃类物质的含量最高为56.63%;相对含量大于5%的物质共5种,3-甲基庚烷的相对含量为20.89%,(E)-9-十八烷烯酸相对含量为20.74%,2-甲基庚烷的相对含量为12.74%,乙基环戊烷的相对含量为5.1013%,2-甲基-3-乙基戊烷的相对含量为5.3278%。挥发油中鉴别出高级脂肪酸30.9781%,其中不饱和脂肪酸26.3044%。未鉴定出酰胺类物质和酚醇类物质。     

氨水沉淀法由含钛滤液提取二氧化钛

以含钛高炉渣为原料,经硫酸铵熔融法得到含钛滤液,然后以氨水为沉淀剂,控制pH值使钛水解,水解产物经600℃煅烧2 h得到二氧化钛。考察了螯合剂的加入量、溶液pH值和反应时间对钛沉淀率的影响,实验结果表明:反应过程中铁与钛发生共沉淀,造成二氧化钛产物中的铁含量过高。EDTA几乎完全抑制了铁的沉淀,明显降低了二氧化钛产物的全铁含量;2-羟基丙烷-1,2,3-三羧酸的加入降低了产物中二氧化硅的含量,提高了产物中二氧化钛的含量。当2-羟基丙烷-1,2,3-三羧酸与硅的摩尔比为1,EDTA与铁的摩尔比为3,pH值为2.0,反应时间为90 min时产物中二氧化钛的含量为96.35%。     

在二硫化碳/正丁基锂/环己烷体系中合成高顺式聚异戊二烯

研究了聚合温度在30～60℃,以正丁基锂为引发剂、环己烷为溶剂、二硫化碳为结构调节剂的异戊二烯负离子聚合的反应规律,以及二硫化碳用量和聚合条件对聚异戊二烯微观结构的影响。结果表明,随着异戊二烯/环己烷的增加,聚异戊二烯中的顺式-1,4-结构含量降低;随着引发剂浓度的增加,顺式-1,4-结构含量也降低;随着反应温度升高,顺式-1,4-结构含量先增加后降低;随着二硫化碳用量的增加,顺式-1,4-结构含量先增加后略有降低。在50℃、异戊二烯/环己烷(质量比)为1/9、正丁基锂/异戊二烯(摩尔比)为0.68×10-3及二硫化碳/正丁基锂(摩尔比)为0.08×10-3时可制得顺式-1,4-结构摩尔分数最高约为96%的高顺式聚异戊二烯。     

氧化锆-碳化硅复合材料性能研究

从稀土氧化物、氧化锆含量、碳化硅含量、温度及制备工艺方面对氧化锆-碳化硅复合材料电阻率的影响进行了讨论,同时探讨了氧化锆-碳化硅复合材料的高温氧化性能,为氧化锆-碳化硅复合材料的制备及其电性能研究提供了依据。     

不同产地黑蚂蚁中微量元素含量的测定

为研究不同产地黑蚂蚁中微量元素含量的变化情况,采用混酸HNO_3-HClO_4(4+1)湿法消解,利用火焰原子吸收光谱法测定样品中微量元素Cu、Fe、Zn、Mn的含量。研究发现长白山地区四种元素含量大小顺序为:MnFeZnCu,云南地区为FeMnCuZn;大兴安岭地区为FeMnZnCu。其中云南产的黑蚂蚁中Fe、Cu含量较高,分别386.15mg·kg~(-1)、181.53mg·kg~(-1);长白山地区的黑蚂蚁Zn含量较高,为133.38mg·kg~(-1);大兴安岭地区和长白山地区的黑蚂蚁Mn含量相差不大,均为296.6mg·kg~(-1)左右。本文通过对不同产地黑蚂蚁中微量元素Cu、Fe、Zn、Mn的含量研究,为有针对的选用黑蚂蚁提供了一定的参考。     

落葵多糖含量测定方法的研究

比较了糖含量两种测定方法,苯酚-硫酸法和葸酮-硫酸法,以葡萄糖为对照品,并测定落葵中多糖含量。结果显示,苯酚-硫酸法测定糖含量的精密度、稳定性均优于葸酮-硫酸法,并用此法测得落葵多糖的含量为5．35％,加样平均回收率=100．70％,RSD=1．15％。     

新型杀菌剂苯醚甲环唑合成研究

以间二氯苯、乙酰氯等为起始原料,经酰化、醚化、溴化、环化和缩合反应,合成了苯醚甲环唑。关键中间体4-(4氯-苯氧基)-2氯-苯乙酮的粗品含量达到了98.7%,收率高达96.0%;苯醚甲环唑的含量达到97.6%,合成总收率为70%。     

枇杷花茶中7种微量元素的测定

本文采用微波消解-火焰原子吸收光谱法,对枇杷花茶中7种微量金属元素含量进行了测定。实验结果表明,枇杷花茶中钙的含量最为丰富,为57.74mg·kg~(-1),铁、锰、镁、锌、铜、镍的含量依次为49.44mg·kg~(-1)、28.10mg·kg~(-1)、20.78mg·kg~(-1)、11.83mg·kg~(-1)、1.07mg·kg~(-1)、3.97mg·kg~(-1),重金属铜的含量未超标,适宜日常饮用。     

两种桉叶挥发油含量和化学成分周年变化

为了探索窿缘桉和尾叶桉叶挥发油含量和化学成分的周年变化规律,采用水蒸气蒸馏法提取其挥发油,采用GC-MS法分析挥发油化学成分,并以挥发油提取率为指标,确定桉叶的最佳采收期。结果表明,窿缘桉叶挥发油含量周年变化显著,5、9、10月份含量最高,为最佳采收期;尾叶桉叶挥发油含量周年变化较小,4、5、7月份含量相对较高,适宜采收。窿缘桉叶挥发油主要成分为α-蒎烯、β-蒎烯、桉树脑,含量变化显著。尾叶桉叶挥发油主要成分为α-蒎烯、桉树脑、冰片和α-松油醇,含量变化显著。不同时期桉叶挥发油化学成分含量有很大的差异。     

6-姜酚的制备与结构表征

以超临界二氧化碳萃取所得的姜树脂为原料,采用连续液-液萃取法制得6-姜酚粗品,再经过加压硅胶柱层析法,对其进行分离纯化,得到含量为95%以上的6-姜酚,通过质谱与核磁共振波谱对其进行结构表征。考察原料中6-姜酚含量、硅胶目数、操作温度、洗脱溶剂流速等对6-姜酚柱层析分离效果的影响。结果表明,在层析硅胶目数为200～300目、操作温度为10℃、洗脱溶剂的流速为1.35 mL·cm~(-2)·min~(-1)、6-姜酚粗品中6-姜酚含量为64.32%的条件下,进行加压柱层析,制备得到含量为95.12%的6-姜酚,6-姜酚的回收率81.46%。     

EPDM增韧PET的研究

在引发剂过氧化二异丙苯(DCP)的作用下，通过添加少量界面增容剂苯乙烯(St)提高接枝率，使甲基丙烯酸缩水甘油酯(GMA)与(乙烯／丙烯／二烯)共聚物(EPDM)反应，得到接枝物EPDM—g—GMA，将EPDM—g—GMA与PET共混，以提高共混体系的冲击强度。探讨了不同含量的EPDM—g—GMA对共混体系力学性能的影响。结果表明，随着EPDM—g—GMA含量的增加，共混体系的缺口冲击强度显著提高，当其含量为50％时，材料的缺口冲击强度为344．9J／m，约为纯PET的12倍；拉伸强度、弯曲强度和弯曲弹性模量出现一定程度的下降；EPDM—g—GMA含量为20％～30％时．材料的综合力学性能较好。     

硅烷接枝ABS树脂及其水解交联的研究

在Haake密炼机中进行硅烷和ABS树脂的接枝反应,接枝产物在沸水中进行水解交联。研究了硅烷种类和用量、引发剂种类和用量对接枝率和凝胶率的影响,同时考察了反应条件对凝胶率的影响。结果表明,在本研究范围内,对于ABS树脂,只有使用3－甲基丙烯酰氧基三甲氧基硅烷（VMMS）作为接枝单体和丙烯酰胺作为引发剂才能得到一定的凝胶率。接枝率随单体用量增加而增加,凝胶率则先升高后趋于一定值。接枝率和疑胶率还随引发剂用量的增加先迅速增加后趋于一定值。温度和转速较低时,对凝胶率没有明显影响,但温度和转速很高时,凝胶率有所下降。     

THE USE OF A GAS CHROMATOGRAPH TO OBTAIN DRYING RATES DATA THROUGH SIMPLE LABORATORY EXPERIMENTS

A method making use of a gas chromatograph was investigated to acquire bound solvent drying rates. The solid to be dried was used as stationary phase in a chromatographic column, and the TCD detector was used to follow the decrease of solvent content of the effluent as inert gas was flown through the column. The measurement of the break-through curve allows the evolution of drying rate with time or solvent content to be obtained. The comparison of the experimental results with numerical simulation leads to the determination, through parametric adjustment, of the internal mass-transfer coefficient as a function of the solvent content during the second stage of bound solvent drying period. This parameter can lead to the value of the diffusivity as a function of solvent content.     

THE USE OF A GAS CHROMATOGRAPH TO OBTAIN DRYING RATES DATA THROUGH SIMPLE LABORATORY EXPERIMENTS

Abstract

A method making use of a gas chromatograph was investigated to acquire bound solvent drying rates. The solid to be dried was used as stationary phase in a chromatographic column, and the TCD detector was used to follow the decrease of solvent content of the effluent as inert gas was flown through the column. The measurement of the break-through curve allows the evolution of drying rate with time or solvent content to be obtained. The comparison of the experimental results with numerical simulation leads to the determination, through parametric adjustment, of the internal mass-transfer coefficient as a function of the solvent content during the second stage of bound solvent drying period. This parameter can lead to the value of the diffusivity as a function of solvent content.     

The effect of sizing on composite properties for materials used in the shuttle filament wound case

An epoxy resin and a sized carbon fiber have been used to produce a light-weight filament wound case for the Space Shuttle. The sizing facilitates fiber handling during winding but may affect the amount of resin absorbed by the fiber during impregnation and the final mechanical properties of the composite. Naval Ordnance Lab rings were wound to study the effect of the sizing content on the resin absorption by the fiber bundles, the final tensile properties of the composite, and the type of failure observed at burst. The resin content of the rings studied was between 20 to 40 percent, and the sizing content, 0 to 1.6 percent by weight. Results showed that the sizing content was a critical parameter which determined the amount of resin absorbed by the fibers. The final tensile strength was dependent on the amount of sizing present. The tensile strength decreased by as much, as 60 percent when a low resin and high sizing content were present. The type of failure at burst was a function of resin content rather than size content.     

Esterification of sludge palm oil using trifluoromethanesulfonic acid for preparation of biodiesel fuel

Trifluoromethanesulfonic acid (TFMSA) was used to reduce the high free fatty acids (FFA) content in sludge palm oil (SPO). The FFA content of SPO was converted to fatty acid methyl ester (FAME) via esterification reaction. The treated sludge palm oil was used as a raw material for biodiesel production by transesterification process. Several working parameters were optimized, such as dosage of catalyst, molar ratio, reaction temperature and time. Less than 2% of the FFA content was the targeted value. The results showed that the FFA content of SPO was reduced from 16% to less than 2% using the optimum conditions. The yield of the final product after the alkaline transesterification was 84% with 0.07% FFA and the ester content was 96.7%. All other properties met the international standard specifications for biodiesel quality such as EN 14214 and ASTM D6751.     

Measurement of Absorbed Power of Glass Particle Layer on Moisture Content and Drying Rate by Combined Convective and Microwave Drying

Dependency of absorbed power by microwave on the local moisture content in a glass particle layer was measured with a new method; that is, heating the wet layer. The heating experiment was performed using a laboratory-scale combined convective and microwave heater/dryer that was manufactured by modifying a domestic microwave oven at 2.45 GHz. The measured result was strongly dependent on the local moisture content and showed a maximum and a minimum within the measured range of the moisture content. This dependency can be explained by the assumption that moisture in the wet layer behaves as a mass of the free water. The combined drying rate of the wet layer measured with the heater/dryer was simulated with both the power dependency and the experimental convective-only drying rate. Power dependency on temperature is as important as the moisture content in the simulation. Simulated results agree very well with experimental ones.     

Evaluation of chemical and nutritional characteristics of the seed of the rubber tree (Hevea brasiliensis)

Some chemical and nutritional characteristics of the rubber seed Hevea brasiliensis were studied. The protein content, its amino acid composition as well as the iron, calcium, phosphorus and cyanide (free and bound) concentrations, were determined in the dehulled seed. The effect of soaking, cooking, soaking-cooking and cooking-fat extraction procedure of the seed on the cyanide content and its in vivo protein utilization, was also evaluated. The protein quality was biologically assessed using the protein efficiency ratio (PER). The protein content of the seed was 18%, and the most limiting amino acid was threonine, with a chemical score of 71.6. The iron, calcium and phosphorus contents were 6.2, 109 and 429 mg/100 g, respectively. Its fat content was 48% with a total energy value of 702 kcal/100 g (2,948 Kj/100 g). The total cyanide content in the fresh seed was 130-230 mg/100 g; 6% was in the free form and 94% as bound cyanide. The most effective treatment for reducing the cyanide content was found to be 20 hours of soaking in water, combined with one hour of cooking. The raw seed had a low nutritive value and produced weight loss and death when fed to rats. The protein value, however, improved upon the seed treatment, reaching PER values close to those found in traditional cereals such as corn. It is therefore concluded that the seed of Hevea brasiliensis is a good source of energy, calcium, valine, isoleucine, phenylalanine and tyrosine. In contrast, it is a poor source of threonine, leucine and lysine. Its cyanide content is high, but when removed by treatment, such as soaking in water, cooking or fat extraction, the protein utilization can be improved.     

高效液相色谱法测定静脉注射犬血免疫球蛋白的麦芽糖含量

目的采用高效液相色谱法测定静脉注射犬血免疫球蛋白中的麦芽糖含量。方法采用苯乙烯-二乙烯基苯共聚物为基质的阳离子交换色谱柱(300mm×7.8mm,8μm),流动相为0.004mol/L硫酸溶液,流速为0.8ml/min,柱温50℃;将麦芽糖含量与其峰面积进行直线回归,建立标准曲线;样品经磺基水杨酸处理后进样,根据峰面积计算麦芽糖含量。结果该方法的标准曲线相关性良好,r=0.99968,精密性检测RSD为0.35%,回收率为99.58%。结论高效液相色谱法快速、准确、回收率高,适用于检测静脉注射犬血免疫球蛋白的麦芽糖含量。     

Ergebnisse von Anbauversuchen mit Raps und Sonnenblumen in der Türkei

Results of Field Trials with Rapeseed and Sunflower in Turkey At different locations of Turkey some cultivars of rapeseed and sunflowers were tested for yield, oil content and oil quality. Comparing winter types and spring types of rapeseed significant differences between locations were found for yield-capacity. Only in the european part of Turkey the winter types showed higher yields whereas in the egean region and south coast spring types – growed during winter season – showed higher yields and a higher oil content than winter types. The highest yields of both types were obtained on the location Menemen (egean region) in the growing season 1984/85. The highest yield of a spring cultivar was 36.7 dt/ha and of a winter cultivar was 31.9 dt/ha, respectively. The average of oil content in spring types was 43.0% and in winter types 39.4%. In all samples the erucic acid content of oil was below 1%. The main purpose of the sunflower trials was the comparison of yield and quality characteristics when growed as a main crop or as a second crop in the rotation. By growing as amain crop (april to july) the average yield was 29.9 dt/ha against 26.1 dt/ha by growing as a second crop (june to october). Additionally the oil content was higher when plants were grown as a main crop (45.3%) than as a second crop (39.7%). Very important differences between main- and second crop were found in the linoleic acid content of the oil. Plants harvested in july as a main crop showed an average linoleic acid content of 48.6% which increased up to 68.5% when plants were sown as a second crop and harvested in October