猴头菇的研究进展

猴头菇在中国及国外均有悠久的食用历史,是一种营养价值非常高的药食兼用型真菌,一直备受人们的青睐。不仅营养价值高,而且菌丝体和子实体中含有诸多活性成分,具有抗氧化、抗肿瘤、抗衰老、提高克疫力、保护胃黏膜、神经保护等生理功效。因此,猴头菇是开収药物及功能性食品的重要资源,具有广阔的市场前景,已广泛涉及到医药和食品领域。本文从猴头菇的培育、活性成分、药理作用以及猴头菇产品的研収4个方面综述了猴头菇的研究现状,为猴头菇迚一步开収与利用提供新思路,也为其他食用菌的研究开収提供了有益的借鉴。     

Isolation and identification of procyanidins in apple pomace

The chemical nature of the procyanidin components in apple pomace was investigated as part of a programme seeking alternative uses of the large quantity of pomace that is being generated from the apple juice industry. The homogeneous nature of the procyanidin fractions was demonstrated by the isolation and identification of a range of epicatechin oligomers, namely epicatechin-(4β-6) epicatechin, epicatechin (4β-8) epicatechin, epicatechin (4β-8) epicatechin (4β-8) epicatechin and epicatechin (4β-8) epicatechin (4β-8) epicatechin (4β-8)-epicatechin. The procyanidin polymers were also isolated and purified by a Sephadex LH20 column and shown to consist exclusively of epicatechin units. The chemical structures of these procyanidins were established by ¹³C-NMR spectroscopy, by acid-catalysed degradation reaction with phloroglucinol and by electrospray mass spectrometry.     

湖北省恩施州水环境基尼系数研究

从水资源对社会经济发展的支撑作用出发,将基尼系数法引入到水资源-社会经济发展评价中,对恩施州社会经济发展与水资源之间的关系进行研究。研究结果表明,基于水资源的人口、GDP、COD的基尼系数分别为0.207、0.109、0.189,说明恩施州社会经济发展水平与水资源的分布是相适宜的,恩施州水资源状况能够很好地维系目前恩施州社会经济的可持续发展。     

Synthesis,Characterization, and Electroluminescent Properties of Iridium(III) 2-Phenylpyridine-type Complexes Containing Trifluoromethyl Substituents and Various Main-Group Moieties

New heteroleptic cyclometalated iridium(III) 2-phenylpyridine-type complexes with trifluoromethyl substituents and various main-group moieties were synthesized and their photophysical, electrochemical, and electroluminescent (EL) properties studied. The emission color can be tuned by a facile derivatization of the phenyl moiety of 2-phenylpyridine with various main-group moieties, and we have prepared new yellowish green to orange triplet emitters with enhanced charge injection/charge transporting features, which can furnish attractive EL performance in phosphorescent organic light-emitting devices (OLEDs). Attempts were also made to fabricate two-color white-light OLEDs based on a combination of fluorescent blue and phosphorescent orange emitters.     

LiMgxMn2−xO4 (x≤0.10) cathode materials with high rate performance prepared by molten-salt combustion at low temperature

LiMg_xMn_2−xO₄ (x≤0.10) cathode materials for lithium-ion batteries were prepared by molten-salt combustion and then structurally characterized by powder X-ray diffraction. All the cathode materials were identified as the spinel structure of LiMn₂O₄ and the lattice parameter decreased as the Mg content of LiMg_xMn_2−xO₄ increased. Scanning electron microscopy revealed that the average particle size and agglomeration decreased with increasing Mg content. Galvanostatic charge–discharge experiments showed that Mg doping could effectively enhance the cycling performance of the cathode materials. LiMg_0.05Mn_1.95O₄ demonstrated excellent electrochemical performance with an initial discharge specific capacity of 122.0 mA h g⁻¹ and capacity retention of 86.4% after 100 cycles at 0.5 C (1 C=148 mA g⁻¹). Rate performance, cyclic voltammetry and electrochemical impedance spectroscopy measurements showed that the Mg-doped spinels had high rate capability and reversible cycling performance.     

Synthesis and characterization of spinel Li4Ti5O12 anode material by oxalic acid-assisted sol–gel method

Anode material Li₄Ti₅O₁₂ for lithium-ion batteries has been prepared by a novel sol–gel method with oxalic acid as a chelating agent and Li₂CO₃ and tetrabutyl titanate [Ti(OC₄H₉)₄] as starting materials. Various initial conditions were studied in order to find the optimal conditions for the synthesis of Li₄Ti₅O₁₂. Oxalic acid used in this method functioned as a fuel, decomposed the metal complexes at low temperature and yielded the free impurity Li₄Ti₅O₁₂ compounds. Thermal analyses (TG–DTA) and XRD data show that powders grown with a spinel structure (Fd3m space group) have been obtained at 800 °C for 16 h. SEM analyses indicated that the prepared Li₄Ti₅O₁₂ powders had a uniform cubic morphology with average particle size of 200 nm. The influence of synthesis conditions on the electrochemical properties was investigated and discussed. The discharge capacity of Li₄Ti₅O₁₂ synthesized with an oxalic acid to titanium ratio R = 1.0 was 171 mAh g⁻¹ in the first cycle and 150 mAh g⁻¹ after 35 cycles under an optimal synthesis condition at 800 °C for 20 h. The very flat discharge and charge curves indicated that the electrochemical reaction based on Ti⁴⁺/Ti³⁺redox couple was a typical two-phase reaction.     

植物源生物活性肽的研究进展

生物活性肽是一类对生物机体有益且易被机体吸收的小分子聚合物,是由2～20个氨基酸组成的蛋白质片段,其功能性质由氨基酸组成和排列顺序决定。植物是生物活性肽的天然宝库,植物源生物活性肽种类丰富、结构新颖,是近年来的研究热点。生物活性肽被视为营养保健品和功能食品成分,除了含有丰富的营养价值之外,还具有抗氧化、降血压、抑菌、降血脂和维持血糖水平平衡等功能,可利用其功能治疗、控制和预防慢性疾病,对食品、医药和美容等领域的发展具有重要意义。本文综述了近5年从植物中获取生物活性肽的最新进展,系统地总结了抗氧化肽、降压肽、抗菌肽、降血糖肽和降血脂肽的作用机制,与目前最常见的健康问题进行对应说明。对生物活性肽的制备方法、分离纯化和鉴定技术进行总结比较,并对生物活性肽的未来发展趋势以及在实际应用中遇到的问题进行展望,为未来植物源生物活性肽的进一步研究开发与应用提供参考。     

Photoluminescence of 2,4,6-tris[4-(phenylethynyl)phenyl]-1,3,5-triazines dispersed in polymer films

Photoluminescence of three types of 1,3,5-triazine derivatives with three kinds of diphenylacetylene side chains was investigated. They showed quantum yields higher than 46% in chloroform, and the Stokes shift (66–114 nm) in chloroform depended on the kind of the diphenylacetylene side chain. In cast films, the three compounds gave a larger Stokes shift of 132–211 nm, suggesting formation of an excimer in the solid. The 1,3,5-triazine derivatives were dispersed in films of polymers such as polystyrene and poly(vinyl acetate), and photoluminescence of the films containing the 1,3,5-triazine derivatives was investigated. Dispersion of the compound in a poly(vinyl acetate) film still gave a rather larger Stokes shift of 128–203 nm. In contrast, dispersion in polystyrene reduced the Stokes shift to about 60 nm, revealing an excellent dispersing effect of polystyrene for the compounds.