“安琪酵母抽提物杯”调味品科技术论文大赛引发行业关注

近日,由中国调味品协会、中国调味品协会专家工作委员会主办,安琪酵母股份有限公司冠名的"安琪酵母抽提物"杯第二届调味品行业科技论文大赛全国宣讲及科技交流活动最后一站在李锦记食品有限公司举行。协会宣讲团此次由专家工作委员会三位专家分别带队,从五月份开始,奔赴天     

YHp as a highly stable,hyper-copy,hyper-expression plasmid constructed using a full 2-μm circle sequence in cir0 strains of Saccharomyces cerevisiae

In the yeast Saccharomyces cerevisiae, the yeast episomal plasmid (YEp), containing a partial sequence from a natural 2-μm plasmid, has been frequently used to induce high levels of gene expression. In this study, we used Japanese sake yeast natural cir⁰ strain as a host for constructing an entire 2-μm plasmid with an expression construct using the three-fragment gap-repair method without Escherichia coli manipulation. The 2-μm plasmid contains two long inverted repeats, which is problematic for the amplification by polymerase chain reaction. Therefore, we amplified it by dividing into two fragments, each containing a single repeat together with an overlapping sequence for homologous recombination. TDH3 promoter-driven yEmRFP (TDH3p-yEmRFP) and the URA3 were used as a reporter gene and a selection marker, respectively, and inserted at the 3′ end of the RAF1 gene on the 2-μm plasmid. The three fragments were combined and used for the transformation of sake yeast cir⁰ ura3^- strain. The resulting transformant colonies showed a red or purple coloration, which was significantly stronger than that of the cells transformed with YEp-TDH3p-yEmRFP. The 2-μm transformants were cultured in YPD medium and observed by fluorescence microscopy. Almost all cells showed strong fluorescence, suggesting that the plasmid was preserved during nonselective culture conditions. The constructed plasmid maintained a high copy state similar to that of the natural 2-μm plasmid, and the red fluorescent protein expression was 54 fold compared with the chromosomal integrant. This vector is named YHp, the Yeast Hyper expression plasmid.     

植物多酚作还原剂制备铬鞣剂及应用研究

铬鞣剂的制备可选用葡萄糖、蔗糖、SO2及其它有机物,将重铬酸钠中的六价铬还原而获得。选用植物多酚中的水解类橡惋栲胶作还原剂,来还原红矾制备铬鞣剂,并在同样条件下用糖作还原剂进行了对比,通过对鞣剂性质的研究和鞣革性能的测试,结果发现:用植物多酚作还原剂,其水解产物比糖还原的水解产物成分更复杂,因而更能起到络合和蒙囿作用,鞣剂更稳定和耐碱。鞣剂的性能也优于用糖还原铬制备的鞣剂,将鞣剂制威粉状鞣剂,其性能稳定,回溶鞣革效果良好。     

面料与粘合衬的配伍性与三维建模的研究现状

服装由面料和辅料构成．粘合衬是最重要的辅料．在服装造型方面起着决定性的作用。随着粘合衬在服装业中的应用越来越广泛,粘合衬的选用已成为这一行业必须重视的问题,综述了当前粘合衬领域内各个方面的研究．并提出新的研究方向。     

由杏仁壳及其他农产品废弃物制备生物纺织纤维

绿色产品是否存在其他价值?能否将废弃物转化为具有额外价值的原材料?来自大学实验室和工业公司的研究者们正尝试采用木屑、杏仁壳或其他农产品废弃物作为原料制备纺织品。Ecolastane项目主要致力于研究可再生产业用纺织纤维的生产。     

Redox control in breakpoint chlorination of ammonia and metal ammine complexes

Redox control of breakpoint chlorination of ammonia and metal ammine complexes (Cu²⁺, Ni²⁺, Cr³⁺, Zn²⁺, Cd²⁺) is investigated. In simulated waste streams it is shown that at pH 8 control is feasible with a large (400 mV) and reproducible increase in the potential of a gold or platinum indicator electrode occurring at the breakpoint. At pH 10 control is less practicable due to the slowness of response, irreproducibility and smaller magnitude of the potential change. Simultaneous pH control is critical.     

超临界二氧化碳萃取辣椒碱工艺的可视化分析

对采用超临界二氧化碳技术萃取辣椒碱进行较为系统的研究。选择萃取压力、萃取温度、分离压力、分离温度4个主要影响因素,运用均匀设计法安排试验,以高效液相色谱测定辣椒碱的含量。选择分离釜1中产物的辣椒碱含量为试验指标,用自主提出的多因素多水平试验结果可视化分析方法对多维空间试验数据进行分析。得出最佳工艺范围为萃取压力10～21MPa、萃取温度41～52℃、分离釜1压力8～8.7MPa、分离釜1温度53～60℃。     

Electrochemical impact of the carbonate in ceria-carbonate composite for low temperature solid oxide fuel cell

Ceria-carbonate composite has been suggested as a promising electrolyte for solid oxide fuel cells operating at low temperatures. However, the roles of carbonate in the enhancement of the superionic conductivity and fuel cell performance of ceria-carbonate composite electrolytes are not yet confirmed. In this work, we look into the chemical and ionic state, transmission and segregation of carbonate and alkali cations under normal and electrochemical conditions. The XRD measurement confirms that there are not any carbonate crystals in the sample electrolyte. It is interesting to see that part of the carbonate and alkali ions are not formed into the stoichiometric carbonate in sample materials under the typical electrical field condition from the EDS and XPS analysis. Instead, carbonate (CO₃^2?) and alkali ions accumulate in the cathode side, which we believe, was caused by the electrochemical “catalyst” of CO₂ and alkali ions that accelerated the electrochemical oxygen reduction reaction, while the CO₃^2? ions as one of the charge carriers which diffuse from fuel cell cathode to anode are on account of the concentration gradient. Those together contribute to the excellent electrochemical performances of ceria-carbonate composite electrolyte for low temperature solid oxide fuel cell.     

N,O Co-doped carbon felt for high-performance all-vanadium redox flow battery

We, for the first time, demonstrate a facile preparation of N, O dual-doped carbon felt (CF) as electrodes in all-vanadium redox flow batteries (VRFB). N₂ and O₂ plasma was employed to treat the CF, introducing nitrogen and oxygen atoms doped into the carbon felt to result in the improved electrocatalytic activity and enhanced interaction of CF-electrolyte during the battery operation. The energy efficiency of the as-assembled VRFB is improved from 65% (pristine) to 78% (doped) at a current density of 50 mA cm^-2 with excellent cycling stability.     

Effect of α- and γ-alumina on the precipitation of positive electrolyte in vanadium redox battery

In this study, the effect of α-alumina (α-Al₂O₃) and γ-alumina (γ-Al₂O₃) on the precipitation of the positive electrolyte, which is one of the most important problems in vanadium redox battery (VRB) systems, was investigated. α-Al₂O₃ and γ-Al₂O₃ were used as additive materials to improve the thermal stability of V(V) ion and the performance of VRB at high temperatures. Cyclic voltammetry and electrochemical impedance spectroscopy were used to determine the properties of positive electrolyte systems. The optimum amount of additives was identified as wt% 0.004 and 0.010 for α-Al₂O₃ and γ-Al₂O₃, respectively. The surface morphology and composition of electrodes were investigated by scanning electron microscopy and energy-dispersive X-ray analysis. A plausible reaction mechanism was also proposed for redox reaction occurring on the positive electrode of a VRB. The adsorption of V(V) ions to the electrode surface from the solution increased by the time additives were added into the system. γ-Al₂O₃ showed the best anti-precipitation effects for the V(V) ion at 40 °C and 60 °C in the precipitation tests. In the battery test, the discharge capacity of γ-Al₂O₃ with a positive electrolyte, was the highest at 87.2 mAh. According to thermal and electrochemical studies, γ-Al₂O₃ can be a useful additive for the positive electrolyte of a VRB.