Syntheses and characterizations of two-dimensional polymers based on tetraimidazole tetraphenylethylene ligand with aggregation-induced emission property

Two new coordination polymers [Co(TIPE)(H₂O)₂]·Hbtc·CH₃CN·3H₂O (1) and [Cd(TIPE)_0.5(m-bdc)(H₂O)]·CH₃OH·H₂O (2) (TIPE = tetra(3-imidazoylphenyl)ethylene, H₃btc = 1,3,5-benzenetricarboxylate, m-H₂bdc = 1,3-benzenedicarboxylate) have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analysis, IR, TGA, and PXRD. Furthermore, the luminescent properties of complexes 1, 2 and TIPE ligand have also been investigated in the solid at room temperature.     

基于响应面分析法优化的蕨茎叶黄酮提取条件

目的:利用响应面法优化蕨老茎叶总黄酮的提取工艺条件。方法:以提取溶剂乙醇体积分数、液固比、提取温度及提取时间为影响因子,以提取总黄酮得率作为响应值,应用Box-Behnken中心组合设计建立数学模型,进行响应面法分析（RSM）。结果:蕨老茎叶总黄酮提取的最佳工艺为:乙醇体积分数53%,液固比68∶1,提取温度81℃,提取时间48min,理论得率13.83%,实际测得值为13.81%,两者较接近。结论:Box-Behnken设计结合响应面分析法可以很好地对蕨老茎叶总黄酮提取工艺进行优化。      

The gas-sensing properties of thick film based on tetrapod-shaped ZnO nanopowders

Tetrapod-shaped ZnO nanopowders were prepared by the method of vapor-phase oxidation from metallic zinc as raw materials. The gas-sensing properties of thick film based on tetrapod-shaped ZnO nanopowders to volatile organic compounds (VOCs), benzene, toluene, xylene, alcohol and acetone were measured, and compared with that of commercial ZnO powders with granular shape. The results showed that tetrapod-shaped ZnO had the better gas-sensing properties: the maximum sensitivity temperature was reduced, the gas sensitivity was improved and the time of response–recovery was shortened. The differences in gas-sensing properties between the thick films were discussed in according to the morphological characteristics, size and agglomeration of raw powder as well as microstructure of sintered thick films.     

Porous sunflower plate-like NiFe2O4/CoNi–S heterostructure as efficient electrocatalyst for overall water splitting

Constructing high-efficient and nonprecious electrocatalysts is of primary importance for improving the efficiency of water splitting. Herein, a novel sunflower plate-like NiFe₂O₄/CoNi–S nanosheet heterostructure was fabricated via facile hydrothermal and electrodeposition methods. The as-fabricated NiFe₂O₄/CoNi–S heterostructure array exhibits remarkable bifunctional catalytic activity and stability toward oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline media. It presents a small overpotential of 219 mV and 149 mV for OER and HER, respectively, to produce a current density of 10 mA cm^?2. More significantly, when the obtained electrodes are used as both the cathode and anode in an electrolyzer, a voltage of 1.57 V is gained at 10 mA cm^?2, with superior stability for 72 h. Such outstanding properties are ascribed to: the 3D porous network structure, which exposes more active sites and accelerates mass transfer and gas bubble emission; the high conductivity of CoNi–S, which provides faster charge transport and thus promotes the electrocatalytic reaction of the composites; and the effective interface engineering between NiFe₂O₄ (excellent performance for OER) and CoNi–S (high activity for HER), which leads to a shorter transport pathway and thus expedites electron transfer. This work provides a new strategy for designing efficient and inexpensive electrocatalysts for water splitting.     

水菖蒲黄总酮的提取工艺及稳定性

在单因素试验的基础上,利用响应面分析法优化水菖蒲总黄酮的提取条件,并考察其稳定性。结果表明,水菖蒲总黄酮的最佳提取工艺为:提取温度81℃,料液比1∶25g/mL,提取时间118min,乙醇浓度67%。在此条件下总黄酮提取率的实测值为5.17mg/g,理论值为5.20mg/g。稳定性试验表明:水菖蒲总黄酮提取液在pH9.0左右稳定,温度超过70℃稳定性较差,光照会使总黄酮稳定性下降。山梨酸钾和Cu2+使总黄酮稳定性明显下降,苯甲酸、Zn2+和Fe3+对其下降不明显,NaCl、蔗糖、柠檬酸、Vc、K+、Na+和Al 3+对其基本无影响,Mg2+和Ca2+对总黄酮具有护色作用。     

基于统计学和营养学的三种藻粉蛋白质营养价值评价与方法分析

采用主成分分析法、模糊识别法、氨基酸含量比值法和氨基酸比值系数法,分析了丝路寒旱区的小球藻、螺旋藻和杜氏盐藻藻粉蛋白质的营养价值,并对4种分析方法进行了比较。结果表明:丝路寒旱区的小球藻、螺旋藻和杜氏盐藻藻粉蛋白含量差异显著(P<0.05),以小球藻藻粉蛋白含量最高为70.77 g/100 g·DW,且均含有17种氨基酸,包括除色氨酸外的7种人体必需氨基酸,必需氨基酸占总氨基酸的质量分数均接近FAO/WHO氨基酸模式谱。三种藻粉蛋白质的贴近度分别为0.879、0.982和0.906;第一限制氨基酸均为甲硫氨酸;氨基酸比值系数分由高到低为小球藻（82.89）>螺旋藻（81.78）>杜氏盐藻（74.46）。主成分分析提取出4个主成分,累计方差贡献率为98.305%,可较好反映藻粉蛋白质氨基酸综合品质。综合四种评价方法的特点,氨基酸比值系数法和模糊识别法均对蛋白质中必需氨基酸从生物吸收的角度开展分析,但就计算方法而言,氨基酸比值系数法更严谨。本研究中模糊识别法与主成分分析法的结果虽然是一致的,但采用主成分分析法分析蛋白质中代表性氨基酸种类可能更好些。FAO/WHO推荐的蛋白质E/N和E/T值分析法,仅关注的是必需氨基酸的量,没考虑生物吸收必需氨基酸的特点。综上,丝路寒旱区三种藻粉蛋白质的营养价值依次为小球藻>螺旋藻>杜氏盐藻。     

文冠果芽茶与叶茶主要营养功能成分分析及抗氧化活性评价

以张掖高台种植的文冠果芽茶与叶茶为试验材料,对其营养功能成分及抗氧化活性进行比较;使用INQ法对其营养成分进行质量评价,并对功能成分与抗氧化能力进行相关性分析。结果表明,芽茶中K、Zn、Cu含量及K/Na显著高于叶茶（P<0.05）,二者均呈现高K低Na特点。芽茶中粗蛋白含量显著高于叶茶（P<0.05）、而粗脂肪含量叶茶显著高于芽茶（P<0.05）。营养质量评价表明,芽茶、叶茶K、Ca、Fe、Mn、Zn、Cu、粗脂肪、粗蛋白INQ均>1;Na、Mg和可溶性总糖INQ芽茶<叶茶<1。芽茶多酚含量显著高于叶茶（P<0.05）,黄酮含量差异不明显。芽茶与叶茶对DPPH自由基、ABTS自由基、O₂?·清除能力的IC₅₀分别为2.52和2.69、1.65和1.74、1.64和2.10 μg·mL?1,阳性对照芦丁在此浓度范围内无IC₅₀,抗氧化能力强弱为芽茶>叶茶>芦丁。相关性分析表明,芽茶、叶茶多酚、黄酮含量与DPPH自由基、ABTS自由基、O₂?·清除率均呈极显著正相关（P<0.01）,芽茶相关系数为0.892~0.990,叶茶相关系数为0.879~0.994。以上研究表明,文冠果芽茶的营养功能价值及抗氧化能力优于叶茶,有开发新产品的潜力。     

基于主成分与聚类分析的甘肃地区产地木耳品质综合评价

为优化评价地木耳品质的指标,采用主成分和聚类分析,对甘肃8个地区产地木耳的粗蛋白、总灰分、磷、总糖、脂类、总脂、水溶性灰分、水不溶性灰分以及Ca、Na、K、Mg、Fe、Zn、Mn、Cu、Pb、Ni和Cd 19个品质指标进行分析。结果表明,不同地区来源的地木耳品质指标中,总脂、脂类、总糖以及Mn、Na、Zn变异系数较大,均超过30%,其他指标的变异系数相对较小,在3%左右。主成分分析表明19个反映不同地区产地木耳品质的指标可以用5个主成分（累计贡献率达到92.71%）表示。根据聚类分析得到总糖、水溶性灰分、脂类、Fe、Ca和磷6 个品质指标可以用来衡量地木耳品质的优劣。甘肃8 个地区产地木耳中,山丹的品质最好,其次是天祝,甘州区地木耳的品质最差。     

芦苇不同部位醇提物抗氧化性对比分析

以VC为对照,分别研究芦苇花、叶、茎和根黄酮提取物对·OH、O2-·、DPPH·清除效果和总抗氧化能力。实验结果表明:芦苇不同部位提取物均有较强的抗氧化能力和清除·OH、O2-·、DPPH·能力,各样品的黄酮含量与抗氧化活性有较明显的正相关性。在相同条件下,各提取物对·OH清除能力为:VC>芦叶>芦花>芦根>芦茎;对O2-·清除能力为:VC>芦花>芦叶>芦根>芦茎;对DPPH·清除能力分别为:VC>芦花>芦叶>芦茎>芦根;总抗氧化能力为:芦叶>VC>芦花>芦根>芦茎。芦苇不同部位提取物在实验测定浓度范围内具有抗氧化活性。      

聚丙烯酸/聚丙烯酰胺/凹凸棒复合材料对亚甲基蓝的吸附性能

将聚(丙烯酸-co-丙烯酰胺)/凹凸棒复合吸附剂用于亚甲蓝的吸附,研究了时间、浓度、酸度、表面活性剂和离子强度等因素对吸附性能的影响。复合吸附剂对亚甲蓝的吸附是吸热过程,60℃时吸附量达到1 273.3 mg.g-1,吸附过程符合Langmuir单分子层吸附等温模式,并计算了热力学常数ΔG、ΔH和ΔS。在实验考察范围内吸附过程均符合准二级动力学特征。该复合吸附剂具有高吸附容量和较快的吸附速率,是良好的亚甲蓝吸附剂。