牛乳中添加不同果汁对明串珠菌发酵产双乙酰的影响

双乙酰是一种对发酵乳口感有较大影响的风味化合物,但目前市售的发酵乳制品双乙酰含量都比较低.为提高乳制品中双乙酰的含量,改善风味乳制品的口感和品质,本研究以牛乳为原料,分别加入不同配比的苹果、小西红柿、西瓜、草莓和菠萝汁,并添加0.2%柠檬酸进行明串珠菌发酵,测定了发酵液中双乙酰的含量.结果表明,牛乳中加入5种果汁发酵明串珠菌,都能产生双乙酰;产双乙酰最高的是菠萝汁,可达到20mg/L;其次是草莓汁,达到12.45 mg/L;牛乳-西瓜汁混合液双乙酰最高可达到4.83 mg/L;牛乳-苹果汁和牛乳-小西红柿汁两种混合液双乙酰的产量较低.     

Design on the low-leakage diode string for using in the power-railESD clamp circuits in a 0.35-μm silicide CMOS process

A new design of the diode string with very low leakage current is proposed for use in the ESD clamp circuits across the power rails. By adding an NMOS-controlled lateral SCR (NCLSCR) device into the stacked diode string, the leakage current of this new diode string with six stacked diodes at 5 V (3.3 V) forward bias can be reduced to only 2.1 (1.07) nA at a temperature of 125°C in a 0.35 μm silicide CMOS process, whereas the previous designs have a leakage current in the order of mA. The total blocking voltage of this new design with NCLSCR can be linearly adjusted by changing the number of the stacked diodes in the diode string without causing latch-up danger across the power rails. From the experimental results, the human-body-model ESD level of the ESD clamp circuit with the proposed low-leakage diode string is greater than 8 kV in a 0.35 μm silicide CMOS process by using neither ESD implantation nor the silicide-blocking process modifications     

Photocatalytic degradation of Reactive Red 22 in aqueous solution by UV-LED radiation

Photocatalytic processes using TiO(2) as a catalyst have attracted extensive attention for decomposition of organic contaminants. The determination of optimum reactor design and operational conditions are the major concerns for the development and potential application of the photocatalytic process. Various photoreactor types, photocatalyst arrangements, light sources, and operation conditions were reported. This study was focused on the application of the ultraviolet light emitting diode (UV-LED) as the UV light source for the photocatalytic decomposition of Reactive Red 22 (RR 22). The temporal behavior of the photocatalytic decomposition of RR 22 in aqueous solution by the UV-LED/TiO(2) with a rectangular planar fixed-film reactor operated in a recirculation mode was studied under various conditions including initial dye concentration, periodic illumination, light intensity, and arrangements of TiO(2) coating. The decomposition of RR 22 in aqueous solution by TiO(2) photocatalytic processes with the UV-LED was found to be technically feasible with a high TiO(2) coated weight (1.135g) and low pH value (pH 2). A Langmuir-Hinshelwood-type kinetic equation was adequate for modeling the photocatalytic decomposition of RR 22 by the UV-LED/TiO(2) photocatalytic processes. The experimental results indicated that the photonic efficiency with periodic illumination was much higher than those with continuous illumination. The photonic efficiencies with the quartz-liquid-catalyst (QLC) arrangement were higher than those with the quartz-catalyst-liquid (QCL) arrangement for experiments conducted at lower applied light intensity; however, the photonic efficiencies for these two arrangements were nearly identical for experiments conducted at higher light intensities.     

表面增强拉曼光谱快速检测香蕉中的苯醚甲环唑和毒死蜱残留

目的 基于双重基底的表面增强拉曼光谱(surface-enhanced Raman spectroscopy, SERS)对香蕉中苯醚甲环唑与毒死蜱进行定性和定量检测。方法 采用银溶胶作为柔性衬底,增强芯片作为固体基底,实现双信号放大策略。选用香蕉这种常见的热带水果作为基质,向香蕉基质中加入不同浓度苯醚甲环唑和毒死蜱标准溶液,利用QuEChERS法对香蕉中农药残留进行提取,通过SERS技术对两种农药进行定量分析。结果 在0.10～5.00μg/mL范围内,苯醚甲环唑和毒死蜱的特征峰强度和浓度之间均满足线性关系,相关系数分别为0.9794、0.9773,方法检出限分别为0.16 mg/kg、0.032 mg/kg。结论 本研究建立了一种基于双重基底的SERS,为香蕉中苯醚甲环唑和毒死蜱农药残留快速检测提供了依据,也为热带水果中农药残留的快速检测提供了方法支持。     

Effect of gelatin nano-coating containing Gardenia pigment on the preservation of pork slices

Food Science and Biotechnology - The nano-coating composed of gelatin and Gardenia pigment (GP) was successfully prepared and showed strong antioxidant activity. The average particle sizes of the...     

基于气相色谱-嗅闻-质谱法和风味活度值分析安丘大姜中关键风味活性物质

目的：利用香气活性值和气相色谱-嗅闻-质谱联用法鉴定安丘大姜关键香气活性成分,为安丘大姜的种植、质量控制及风味评价提供指导。方法：运用气相色谱-质谱法（gas chromatography-mass spectrometry,GC-MS）对各挥发物进行分离鉴定,以内标法对其进行半定量,用气相色谱-嗅闻-质谱法（gas chromatography-olfactometry-mass spectrometry,GC-O-MS）和风味活度值（odor activity value,OAV）进一步筛选得到关键气味物质。结果：通过GC-MS鉴定出59种挥发性化合物,OAV法和GC-O-MS法分别确定了31种和13种风味活性物质。综合两种方法发现安丘大姜关键性风味物质为莰烯、月桂烯、β-蒎烯、芳樟醇、α-松油醇、橙花叔醇、香茅醇、香茅醛、乙酸香茅酯、冰片。结论：确定了安丘大姜关键风味活性物质,为安丘大姜产业发展提供指导,为生姜风味物质鉴定提供理论支持。     

Design and implementation of a new high-accuracy interpolation encoder IC for magneto-resistive sensors

Microsystem Technologies - A new algorithm named the eight-section (ES) method for carrying out the interpolation for a magneto-resistive (MR) encoder is successfully developed and fabricated in a...     

2-amino-3,4,5-trimethoxybenzophenones as potent tubulin polymerization inhibitors

A series of novel 2‐amino‐3,4,5‐trimethoxybenzophenone analogues exhibited excellent activity as tubulin polymerization inhibitors by targeting the colchicine binding site of microtubules. The lead compound 17 exhibited an IC₅₀ value of 1.6 μM , similar to that of combretastatin A‐4 (IC₅₀=1.9 μM ). It also displayed remarkable anti‐proliferative activity, with IC₅₀ values ranging from 7–16 nM against a variety of human cancer cell lines and one MDR(+) cancer cell line. SAR information indicated that the introduction of an amino group at the C2 position of benzophenone ring A and the C3’ position of benzophenone ring B play important roles in maximizing activity.     

基于艇载遥感成像数据的高空间分辨率全色遥感图像仿真

高空间分辨率全色遥感图像在军事侦察、地面监视等领域具有较高的应用价值.为模拟星载全色遥感图像, 提出了一种由艇载遥感成像系统获取的低空遥感图像为数据源的高空间分辨率全色遥感图像仿真方法.首先将低空宽视场图像按典型地物类型进行监督分类, 其次将低空宽视场图像与多光谱图像按不同地物类型分类拟合, 并将多光谱拟合结果合成高空间分辨率全色仿真图像, 最后对高空间分辨率全色仿真图像进行仿真精度评价.相比星载全色遥感图像, 仿真图像同样具备高空间分辨率、全色波段、宽视场等特点.仿真方法可为星载全色遥感图像仿真提供较准确的数据支撑.     

White light generation with CdSe-ZnS nanocrystals coated on an InGaN-GaN quantum-well blue/Green two-wavelength light-emitting diode

We grew and processed a blue/green two-wavelength light-emitting diode (LED) based on the mixture of two kinds of quantum wells (QW) in epitaxial growth. The X-ray diffraction and photoluminescence measurements indicated that the crystalline structure and the basic optical property of individual kinds of QW are not significantly changed in the mixed growth. The relative electroluminescence (EL) intensity of the two colors depends on the injection current level, which controls the hole concentration distribution among the QWs. At low injection levels, the top green-emitting QW dominates in EL. As the injection current increases, the blue-emitting QWs beneath become dominating. We also coated CdSe-ZnS nanocrystals on the top of the two-wavelength LED for converting blue photons into red light. With the coating of such nanocrystals, the device emits blue, green, and red lights for white light generation.