武夷岩茶做青控制系统研制

针对武夷岩茶做青过程中人为因素影响大、劳动强度大、茶叶品质不稳定等问题,分析做青工艺温、湿度环境因子对茶叶品质的影响,通过模糊决策,调整做青工艺,研制出由上位机系统,单片机系统、开关控制柜等3部分构成的做青控制系统。试验结果表明:做青控制系统能根据做青现场温、湿度的变化,调整做青工艺参数,满足做青过程智能控制要求。     

The one-step hydrothermal synthesis of CdS nanorods modified with carbonized leaves from Japanese raisin trees for photocatalytic hydrogen evolution

The photocatalytic performance of the semiconductor CdS can be improved with carbon materials capable of limiting photocorrosion and the fast recombination of photogenerated charges. For this purpose, carbon derived from biomass exhibit several advantages including low cost, high abundance, and renewability. Here, photocatalytic CdS nanorods modified with carbon derived from the leaves of Japanese raisin trees were synthesized via a single hydrothermal step. Composite CdS nanorods with 5% biomass-derived carbon photocatalyzed H₂ evolution 1.8 times faster than unmodified CdS at a rate of 5.71 mmol g^?1 h^?1. The apparent quantum efficiency of 5%C/CdS nanorods was 14.96%. Furthermore, the addition of biomass-derived carbon to CdS nanorods augmented the stability of the semiconductor under visible light. The characterization of the composite PC indicated that a larger specific surface area, as well as upgraded charge separation caused by biomass-derived carbon, were involved in the acceleration of photocatalytic hydrogen production.     

响应面法优化竹叶香豆素提取工艺

为优化竹叶香豆素的提取工艺。在单因素试验基础上,进行四因素三水平的中心组合试验,用软件Design-Expert 8.0.1拟合响应值与影响因素的关系得到模型方程,分析模型方程得出提取香豆素最佳工艺:乙醇体积分数43.75%、提取温度80℃、提取时间50 min、液料比20︰1(mL·g^-1)。经验证,竹叶香豆素得率的试验值1.785 mg/g和预测值1.870 mg/g的相对误差为4.54%,说明模型可靠性高,运用响应面法优化竹叶香豆素的提取工艺条件的方法具有可行性。     

Effect of the extract from custard apple (Annona squamosa) leaves prepared with pulsed electric field-assisted process on the diversity of microorganisms and shelf-life of refrigerated squid rings

Antibacterial and antibiofilm properties of ethanolic custard apple leaf extract (CALE) prepared without and with pulsed electric field (PEF) assisted process (6 kV cm⁻¹, 300 pulses, 142 kJ kg⁻¹ for 5 min) (PEF-CALE) were comparatively investigated. PEF-CALE showed higher bacterial inhibition against Bacillus subtilis, Listeria monocytogenes, Escherichia coli, and Pseudomonas aeruginosa, compared to CALE. Antibiofilm properties of both extracts towards the aforementioned bacteria were augmented with increasing concentrations (P < 0.05). The impact of PEF-CALE in extending the shelf-life of squid rings (SQR) was also investigated. Based on the microbiological limit, the shelf-life of refrigerated squid rings pretreated with 400 mg kg⁻¹ PEF-CALE was extended by more than 6 days when compared to the control. Pseudomonas lundensis, Pseudomonas fragi, and Shewanella baltica were the most abundant spoilage bacteria found in SQR. Overall, PEF-CALE exhibited promising antimicrobial activities, which could serve as biopreservative agent for inhibiting bacterial growth in SQR during refrigerated storage.     

Synthesis,characterization and anticorrosion property of olive leaves extract-titanium nanoparticles composite

Ethanolic extracts of olive leaves (OLE) in the presence of TiCl₄ solution was used to form OLE – Ti nanoparticles composite (OLE-Nano). The particle size of Ti nanoparticles in the composite was determined using particle sizer and the nanoparticles were characterized using UV–vis, FTIR, SEM/EDAX and XRD techniques. Results show that the particles were around 70–74 nm in size and show maximum absorption around 420 nm. Prominent FTIR peaks correspond to C=C, N–H, O–H and C=O functionalities. XRD spectrum shows four distinctive diffraction peaks at 27.42°, 36.07°, 41.23°, and 54.30° corresponding to lattice plane value indexed at (101), (104), (200) and (211) planes of face centered cubic (FCC). The anticorrosion property of the OLE-Nano for mild steel in 1 M HCl at 30–60 °C was assessed using weight loss and electrochemical techniques complemented by surface analysis of the corroded steel specimen in the absence and presence of OLE – Nano with SEM and AFM. Results obtained show that OLE inhibited the acid corrosion of mild steel and the inhibition performance was enhanced in the presence of Ti nanoparticles. The corrosion inhibition effect was found to be concentration and temperature dependent. The inhibition efficiency of the OLE and OLE-Nano were 83.5 and 94.3% respectively at 30 °C but decreased to 51.7 and 85.4% at 60 °C respectively. The OLE-Nano adsorbed on mild steel surface by physical adsorption mechanism as predicted by Langmuir adsorption isotherm model. Potentiodynamic polarization results show that OLE-Nano behaves as mixed type inhibitor.     

电视节目包装中花瓣与落叶的设计与制作

花瓣与落叶是目前电视节目或栏目片头中常用的效果之一,使片头画面更具感染力,增强了片头的艺术效果。介绍使用三维动画软件3DS Max实现这种特效的技术原理。     

Purification and characterization of an antioxidant protein (∼16 kDa) from Terminalia chebula fruit

Terminalia chebula fruit is used as folk medicine in India and Southeast Asia. An antioxidant protein was isolated by bioassay guided fractionation of T.chebula fruit by homogenizing in the citrate phosphate buffer. The isolated protein (TCP-III) obtained from fruit was purified by gel chromatography and preparative HPLC, showed apparent molecular weight of 16 kDa by SDS-PAGE and MALDI-TOF/MS analyses. Amino acid sequence obtained by LC-MS^E analysis showed homology with the predicted protein fragments of Populus trichocarpa, putative uncharacterized protein fragments from Oryza sativa and with fragments of 17 kDa thylakoid lumenal protein from Spinacia oleracea. TCP-III exhibited significant radical scavenging in DPPH, NO, H₂O₂ and ABTS assays. In addition, TCP-III inhibited oxidation of linoleic acid in β-carotene bleaching assay, reduced ferric ions and chelated ferrous ions. The present finding demonstrates uniquely, for the first time, characterization of an antioxidant protein from T. chebula fruit.     

Effect of microwave freeze-drying on microbial inactivation,antioxidant substance and flavor quality of Ashitaba leaves (Angelica keiskei Koidzumi)

To decrease microbial quantity and conserve antioxidant substances of Ashitaba leaves, microwave freeze-drying was conducted at 1, 1.5, and 2 W/g in pilot scale. After drying, microbial inactivation and quality parameters of color, chlorophylls, flavonoids, moisture content, and flavor of dried Ashitaba leaves were evaluated. After drying, the highest contents of chlorophylls and flavonoids maintained 14.62?g/kg and 15.75?mg/g, respectively; microbial colonies decreased by about 2-log; various tastes of dried sample were improved. It could be a suitable dehydration in processing of Ashitaba leaves.