Chemical compositional characterization of eight pear cultivars grown in China

The sugar, organic acid, amino acid and fatty acid compounds of eight commercial pear cultivars were identified and quantified using high-performance liquid chromatography (HPLC) equipped with RI and UV detectors and gas-chromatography (GC) equipped with FID detector. The mineral composition was determined by inductively coupled plasma-mass spectrometry (ICP-MS). The results showed great quantitative differences in the composition of the pear cultivars. Fructose was the dominant sugar in the eight pear varieties, followed by glucose and sucrose, while malic acid was the principal organic acid. The C16:0, C18:0, C18:1, C18:2 and C18:3 fatty acids were clearly the most abundant fatty acids, and the C18 family comprised more than 70% of the total fatty acids content. Asparagine and serine were the principal amino acids. Potassium is the most abundant mineral, followed by magnesium and calcium. The results provide important information on how to make the best use of pear cultivars investigated for different uses, which is of significance for both technological research and processing practice.     

食品中辣椒红色素含量测量不确定度的评定

本文对高效液相色谱法测定食品中辣椒红色素含量的测定不确定度进行了评定,按照JJF1059-1999方法建立了数学模型,通过实验过程中取样器具、对照品的纯度,标准曲线拟合等不确定因素的分析,确定不确定度分量,合成不确定度.本评定方法客观、准确,在实际工作中有较强的实用性.     

茶多酚的应用及提取方法

茶多酚是一种天然的抗氧化剂,在食品加工、医药、日用化工等领域具有重要的应用.主要介绍了茶多酚的组成、性质及应用并对它主要的提取方法作了简要介绍.     

保鲜剂及紫外线对库尔勒香梨黑头病菌抑菌效果的研究

以不同浓度的水杨酸、壳聚糖及不同时间紫外线处理库尔勒香梨致病菌—多主枝孢菌(Cladosporiumherbarum Link),研究上述处理方法抑制库尔勒香梨采后黑头病致病菌菌丝生长的效果。结果表明:不同浓度的保鲜剂及不同时间紫外线处理对黑头病菌茵丝生长均有一定的抑制效果,而且随着浓度的增大,紫外照射时间的延长,抑制效果增强。其中以紫外线照射效果最好。     

淀粉接枝共聚高吸水树脂的研究进展及应用

介绍了淀粉系高吸水性树脂的制备引发方式,阐述了利用化学引发法合成的淀粉接枝丙烯腈类、丙烯酸类和丙烯酸酯或丙烯酰胺类3个系列吸水树脂的研究进展,并且介绍了淀粉接枝共聚高吸水树脂在个人卫生、医药、农业园林等方面的应用。简要指出了高吸水树脂的研究及发展方向。     

行政管理学研究性教学方法探析

目前越来越多的高校开始尝试实行研究性教学。与传统的教学方法相比,研究性教学更能体现m学生在教学活动中的主体地位,更能充分地发挥学生学习的积极性和主动性。根据行政管理学的学科特点,结合研究性教学的具体环节,提出行政管理学研究性教学方法,包括专题讨论、辩论、讲座、角色转换、案例讨论等方法。     

Solution plasma-assisted preparation of highly dispersed NiMnAl-LDO catalyst to enhance low-temperature activity of CO2 methanation

In this work, the solution plasma-assisted method was used to prepare NiMnAl-LDO (layered double oxides) catalysts with different treatment times, which were used for the CO₂ methanation reaction. Solution plasma treatment can enhance the dispersibility of the catalyst, create oxygen defects and improve the chemical adsorption capacity of the catalyst. The results show that the low-temperature activity of the catalyst has been improved after the solution plasma treatment. We demonstrate that the NiMnAl-LDO-P(20) catalyst with high dispersion has the highest catalytic activity in CO₂ methanation (81.3% CO₂ conversion and 96.7% CH₄ selectivity at 200 °C). Even though working for 70 h, the catalyst is still highly stable. This work provides a great promise for improving the low-temperature activity of Ni-based catalysts.     

Scalable Yielding of Highly Stable Polyelectrolyte-Coated Copper Sulfide Nanoparticles by Flash Nanoprecipitation for Photothermal-Chemotherapeutics

Photothermal-chemotherapeutic nanoparticles (NPs) are attracting increasing attention and becoming more widely used for cancer therapy in the clinic due to their noninvasiveness, notable tissue penetration abilities, and low systemic adverse effects. However, functional ligands are conventionally modified onto photothermal NPs to well stabilize the inorganic particles suffering from complex chemical modifications, low productivity, and batch-to-batch inconsistencies, and thus significantly restricting their clinical applications. Herein, flash nanoprecipitation (FNP) is taken advantage of to afford rapid and uniform mixing for generating local supersaturated CuS clusters for small and highly stable CuS NPs effectively stabilized by polyacrylic acid through a continuous strategy. It greatly reduces the complexity for CuS NPs synthesis and functionalization in a facile intensified mixing process. These as-synthesized particles are high-drug loading, scalable, and most importantly, it is easy to control their sizes and charges through external conditions. Toxicity and tumor inhibition experiments confirm the high cell toxicity and good suppression of tumor growth under near-infrared irradiation indicating a promising prospect of FNP in the large-scale and continuous yielding of highly stable and high-performing photothermal-chemotherapeutic NPs for cancer therapy.