A two‐step inoculation of Candida etchellsii to enhance soy sauce flavour and quality

Effects of novel two‐step inoculation to enhance soy sauce special flavour in Candida etchellsii were investigated at the cell growth phase. The first‐stage consists of a 5% culture inoculum of log phase cells at 30‐day. Subsequently, a 20% culture inoculum of stationary phase cells was added at 60‐day. The resulting amino nitrogen and soluble salt‐free solid yield reached 9.15 ± 0.12 and 269.60 ± 3.15 mg L^?1 in 30 °C incubator experiments, increased by 23.1% and 17.6%, respectively, as compared to the control without culture inoculation. Maximal free amino acid yield of 58.21 ± 1.77 g L^?1 was achieved, and 39 types of volatile flavour compounds content was 17.81 ± 0.45 g L^?1, which were 1.76% and 178.7% higher than the control. A novel two‐step inoculation using the C. etchellsii yeast was developed and optimised. It was proven to be a feasible reproducible process for industrial application for the improvement of the flavour and quality of soy sauce production.     

市区交通干道路面沉积物理化特性分析

通过对某市区主要交通干道路面沉积物理化特性的监测分析,得出研究区域路面沉积物的基本物理化学性质,包括街道灰尘的pH、有机质和其粒径分布特征.同时,还分析了不同季节路面沉积物理化特性.     

有机化学实验教学的几点思考

有机化学实验的原料大多是易燃易爆或有毒物质、所以对实验室的操作环境都有一定的要求,针对目前有机化学实验中的硬件设施的不足,提出了一定的改善意见,同时,作者根据自己指导有机化学实验多年的实际验经,对实验前预习、实验中的注意事项以及实验报告的撰写,提出了自己的意见和建议。     

Biodegradable organic acid-crosslinked alkali-treated gelatins with anti-thrombogenic and endothelialization properties

Abstract

Gelatins were crosslinked with organic acids and treated with alkali to impart to them endothelialization and anti-thrombogenic properties. These matrices were characterized by biochemical and physicochemical techniques. The amounts of residual amino groups in the matrices decreased with increasing crosslinker concentration. The matrices with the highest crosslinking densities showed excellent endothelial cell adhesion and proliferation. In addition, the adhesion of platelets and formation of fibrin networks on the matrices were suppressed with increasing crosslinker concentration. The matrices also exhibited excellent biodegradability, and the degradation rate decreased with increasing crosslinking density. All the organic acid-crosslinked alkali-treated gelatins showed excellent anti-thrombogenic and endothelialization properties, superior to those of glutaraldehyde-crosslinked alkali-treated gelatins.     

Synthesis and phase stability of precursor derived HfO2/Si-C-N-O nanocomposites

Hafnium alkoxide modified polysilazane was synthesized by the drop-wise addition of hafnium tetra(n-butoxide) to polysilazane. The solid state thermolysis (SST) temperature and the ceramic yield for both the polysilazane and modified polysilazane were determined by performing thermogravimetry. Fourier transform infrared spectroscopy was performed to understand the polymer to ceramic conversion as well as the bonding characteristics of the ceramics. The modified polymer after crosslinking was subjected to SST at 800 °C at a constant heating rate of 5 °C/min for a dwell time of 2 h in atmospheric ambience. From the X-ray diffractograms, the as-thermolysed ceramics were observed to remain X-ray amorphous and on heat-treatment resulted in the crystallization of tetragonal hafnia. However, on heat-treatment at 1500 °C, reverse phase transformation from tetragonal to monoclinic hafnia was observed. Raman spectroscopy and transmission electron microscopy were employed to further understand the phase evolution. The thermal stability and the influence of amorphous matrix on the coarsening of HfO₂ were also evaluated.     

聚丁二酸丁二醇酯在不同土壤环境中的降解研究

本文考察聚丁二酸丁二醇酯(PBS)在不同土壤中的降解情况,从当地取堆肥土、污泥土、垃圾土和花园土对PBS进行土埋法降解试验,通过测定降解过程中的失重率变化和对PBS降解前后表面形态观察,得出PBS在不同土壤中的降解顺序,为塑料的可降解性能的进一步研究奠定基础。     

Direct structuring of C60 thin film transistors by photo-lithography under ambient conditions

Direct structuring techniques are an indispensable need for future low-cost applications of organic semiconductor materials in e.g. active matrix displays or integrated circuits. We demonstrate direct structuring of a small molecule organic semiconductor by a photo-lithography lift off process under ambient conditions. To show compatibility of this process, we fabricate organic thin film transistors (OTFT) containing the benchmark electron transporting semiconductor C60 as active material in a top-contact geometry. C60 as electron transporting semiconductor serves as good indicator for contamination and degradation caused by the structuring procedure. To disclose influences of structuring, we discuss the OTFT performance for different channel lengths from 100 μm down to 2.7 μm. In particular, we show that lithography processing gives rise to increased contact resistances. Apart from that, mobility of C60 as material parameter is only weakly affected which underlines the compatibility of the suggested structuring procedure. The potential of this structuring procedure for future integration of driving transistors in active matrix displays is demonstrated.     

Production of yellow wine from Camellia Oleifera meal pretreated by mixed cultured solid‐state fermentation

Camellia oleifera meal was evaluated to be a potential feedstock for the production of yellow wine (YW), and process conditions were investigated. In this study, C. oleifera meal was firstly pretreated using mixed cultured Bacillus subtilis and Aspergillus niger under solid‐substrate fermentation to degrade the tea saponin (TS) for the following YW fermentation. Response surface methodology helped evaluate the effects of the selected operating parameters, and the optimal condition at a fixed time of 4 days, which gave a 67.84 ± 0.23% degradation rate of TS, was reached as inoculum concentration of 16%, initial moisture content of 55% and temperature of 30 °C. Finally, 7‐day fermentation was harvested to be the most suitable pretreatment for producing YW from C. oleifera meal, and the twice‐feeding fermentation for YW was obtained as wheat koji 12% and active yeast 1.2%. In addition, ample amino acids, phenolic components and the trace TS endowed the C. oleifera wine, the more nutritional characteristics.     

Introducing immobilized metal phthalocyanines as spin-injection and detection layers in organic spin-valves: Spin-tunneling and spin-transport regimes

In (organic) spin-valve devices, two ferromagnetic electrodes having different coercive fields are used to achieve an anti-parallel configuration necessary to enforce spin-flip of electrons within the semiconductor spacer layer. Here we report a use of immobilized magnetic organic molecules as spin-injection and spin-detection layers to form pre-fabricated spin-valve devices. While immobilized manganese- and nickel-phthalocyanines were used as spin-injection and spin-detection layers both, copper phthalocyanine acted as the spacer layer in the all-organic spin-valve devices.In the current-voltage characteristics of parallel and anti-parallel configurations, the electrical resistance was always higher for the latter one implying positive magnetoresistance in the material. By lowering thickness of the spacer layer down to a monolayer region, a tunneling regime could be achieved; spin-flip process in organic spin-valves has been found to be facile in the tunneling regime as compared to that during the spin-transport process through a thicker spacer layer.