新疆茶藨中紫红色素的萃取工艺及稳定性研究

本文介绍了新疆野生植物茶子果实中,紫红色素提取及定性检验和色素的提取工艺。     

基于气相色谱-离子迁移色谱分析不同贮藏方式对洋葱浆馕风味的影响

采用气相色谱-离子迁移谱（gas chromatography-ion mobility spectrometry，GC-IMS）对洋葱浆馕6 种不同贮藏条件下挥发性物质进行分析，包括低温贮藏、室温贮藏、真空贮藏、脱氧贮藏、保鲜剂贮藏和保鲜剂结合脱氧贮藏。研究表明：在洋葱浆馕中共鉴定出66 种挥发性风味物质，其中包括醇类9 种、酮类4 种、醛类18 种、酯类4 种、呋喃衍生物3 种，酸类1 种和未能识别的化合物27 种。随着贮藏时间的延长，低温贮藏和真空贮藏洋葱浆馕在贮藏期内醛类挥发性有机物基本不变，其他处理组的醛类挥发性有机物在贮藏期内变化呈降低的趋势。结合主成分分析和欧氏距离可以发现低温贮藏和其他贮藏方式的第0天挥发性物质种类和浓度较为接近，主成分分析图中点的位置也相聚在一起，说明低温贮藏馕的挥发性物质变化不明显。该研究建立不同贮藏方式洋葱浆馕挥发性气味指纹图谱，可视化出洋葱浆馕挥发性成分轮廓，为洋葱浆馕贮藏期间风味变化规律提供信息。     

角石蕊中松萝酸的提取工艺及含量测定

以新疆天山后峡地区英雄桥采集的角石蕊(Cladonia cornuta(L.)Hoffm.)为材料,采用有机溶剂提取法,考察了提取次数、料液比、提取温度和提取时间对角石蕊中松萝酸提取率的影响。试验结果表明:角石蕊中提取松萝酸的最佳提取工艺条件为提取3次,料液比1:20,温度70℃,提取时间3h。此条件下角石蕊中松萝酸的含量为26.95%。     

Acidochromicity of a low‐molecular‐weight pyrimidine‐based copolymer

A new type of low‐molecular‐weight polypyrimidine in a π‐conjugated main chain was prepared by a Grignard reaction between 2‐amino‐4,6‐dichloropyrimidine and 1,4‐dibromo‐2,5‐didodecyloxybenzene in the presence of [1,2‐Bis(diphenylphosphino) ethane]dichloronickel(II). The structure of the copolymer was fully elucidated by Fourier transform infrared spectroscopy, ¹H‐NMR, and elemental analysis. The copolymer had good solubility in common organic solvents. The copolymer displayed a bathochromic shift when protonated with an organic or inorganic acid in chloroform or tetrahydrofuran. The copolymer depicted facile p‐doping and good electron‐transporting electrochemical properties in a 1M H₂SO₄ aqueous solution. The copolymer showed a narrow polydispersity of 1.04. Thermogravimetric analysis showed that the copolymer had a certain thermal stability with no decomposition at a temperature of 250°C under N₂. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41174.     

Evaluating the cost to industry of electricity outages

The unreliability of electricity supplies is a major cause of the high cost of manufacturing in developing countries. In this paper, we propose a more accurate approach, the contribution method, to measure the cost imposed by power outages. We employ a rich, if not unique, set of data from the detailed operating accounts of three large manufacturing enterprises in Nepal. Estimating the true opportunity costs to the enterprises from lost production caused by power outages sheds light on the issue of cost measurement that is critical for the determination of the feasibility of mitigating measures. Furthermore, having such micro-based information on the value of lost load per kWh by firm or sector is critical for reducing the economic costs of planned outages by the electric utility.     

新疆马林果中总皂苷的比色测定

采用分光光度法对马林果中所含的总皂苷成分进行了研究。回归方程为y=0.225 0.1725X,r=0.9973,在0.0094￣0.056mg/mL范围内有很好的线性关系。通过正交设计法选择出最佳试验条件为A3B2C2D3。最大吸收波长为550nm,回收率为90%￣104%。     

煮羊肉不同组织低温贮藏品质特性的变化

为了深入研究煮制羊肉不同组织在低温贮藏期间的品质变化特征,本实验以煮制羊肉的瘦肉,肥瘦相间和肥肉部分为主要原材料,采用真空包装的方式,对其在4 ℃或低温下贮藏28 d（每隔1周取一次样）期间的pH、质构特征、色差、挥发性盐基氮（Total Volatile Base Nitrogen, TVB-N）、菌落总体数量及其感官评价等相关指标的变化进行了研究。结果显示:在4 ℃下贮藏,熟制羊肉不同组织的pH变化相似,都是呈现先下降后上升的趋势;肥肉的质构特性都高于瘦肉和肥瘦相间肉的特性;在贮藏期间,羊肉不同组织的L*值和a*值都表现为逐渐减小的趋势（P<0.05）,瘦肉的b*值表现为增大的趋势（P<0.05）,而肥瘦相间和肥肉都表现为减小的趋势（P<0.05);羊肉三种不同组织的挥发性盐基氮（Total Volatile Base Nitrogen,TVB-N）和菌落总数的含量则一直处于增加的状态,肥肉的增加速度及数量高于瘦肉和肥瘦相间组织,它们的感官评价都呈现逐渐下降的趋势。并且在贮藏时间达到14 d时,羊肉的品质已经发生腐败现象。结果表明,在贮藏期间瘦肉组织的品质更好。     

新疆野山杏果肉总有机酸对高血脂症大鼠血清中脂质水平及抗氧化指标的影响

目的:研究新疆野山杏果肉总有机酸(TOAAS)对高血脂大鼠血清中脂质和抗氧化指标随时间变化而产生的影响。方法:高脂乳剂灌服实验大鼠180只(雌雄对半),随机分为三个周期组(20、40、60 d),每周期组再次随机分为6组(空白对照组,高血脂模型组,血脂康阳性对照组,及野山杏有机酸高、中、低三个剂量组)。连续灌胃,分别以第20、40和60 d心脏采血,制备血清,采用试剂盒分别测定TOAAS对20、40和60 d实验大鼠血清脂质水平和抗氧化指标的影响。结果:TOAAS能极显著(p<0.01)降低高血脂症大鼠血清中甘油三酯(TG)、总胆固醇(TCH)以及低密度脂蛋白胆固醇(LDL-C),并极显著提高(p<0.01)高密度脂蛋白胆固醇(HDL-C)含量,且有一定的时间依赖性,无剂量依赖性;TOAAS能升高脂肪酶(LPS)、总脂酶(LPL+HL)的活性,但不存在剂量与时间的依赖性;TOAAS能够极显著提高(p<0.01)超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-PX)的活性,并能降低(p<0.05)血清中丙二醛(MDA)含量,且存在剂量与时间依赖性。结论:表示野山杏总有机酸可能通过提高HDL-C浓度,提高机体抗氧化酶类及分解甘油三酯酶类活性,降低高脂血症大鼠血清中血脂水平,从而达到降血脂作用。     

Novel Synthesis of ZrB2 Powder Via Molten‐Salt‐Mediated Magnesiothermic Reduction

Zirconium diboride (ZrB₂) powder was synthesized at a low temperature via a molten‐salt‐mediated reduction route using ZrO₂, Na₂B₄O₇ and Mg powders as starting raw materials. By using appropriately excessive amounts of Mg and Na₂B₄O₇ to compensate for their evaporation losses, ZrO₂ could be completely converted into ZrB₂ after 3 h at 1200°C. In addition, the formation of undesirable Mg₃B₂O₆ could be effectively avoided. As‐prepared ZrB₂ powders were phase pure, 300–400 nm in size and generally well dispersed. SEM images showed that to a large extent the reactively formed ZrB₂ retained the morphology and size of the starting ZrO₂. The salt melt formed from MgCl₂ and Na₂B₄O₇ at test temperatures is believed to be responsible for the reduced synthesis temperature and good dispersion of the final ZrB₂ product powder.