蜂蜜中酵母菌的分离鉴定及蜂蜜酒的研制

采用稀释涂布平板法分离纯化蜂蜜样品中的菌株,并对其进行鉴定,并对蜂蜜酒进行了研制并对其挥发性成分进行测定。结果表明,从12份采自云南文山的蜂蜜样品中分离出5株酵母菌（Y3、Y5、Y7、Y9、Y10）,经5.8S rDNA-ITS 序列分析,结合形态学特征初步鉴定为暹罗接合酵母（Zygosaccharomyces siamensis）。5株菌用于蜂蜜稀释液发酵,其中菌株Y3发酵的蜂蜜酒酒香和果香浓郁,是较好的蜂蜜酒发酵菌株。以同时蒸馏萃取（SDE）-气质联用（GC-MS）技术对菌株Y3发酵的蜂蜜酒风味成分进行分析,共检测出41种挥发性成分,主要成分为2-苯乙醇（58.11%）和异戊醇（25.43%）。     

云南复烤烟叶不同地点醇化过程中可培养真菌种群分析

为较全面的了解云南复烤烟叶在不同地点醇化过程中真菌多样性,挖掘其中的有益微生物,提高烟草醇化品质,以复烤烟叶为试验材料,利用18S rDNA克隆测序技术,系统研究了其醇化过程中可培养真菌的种群结构。结果表明,醇化过程中,复烤烟叶叶面真菌数量除曲靖仓库在6月有所上升外,其余各地均随着醇化的进行而逐渐下降,其中曲靖和楚雄两地非常接近,元江最少;通过形态特征及18S rDNA鉴定,烟叶叶面真菌包括根霉属真菌、青霉属真菌、曲霉属真菌等24个真菌属（种）。不同地点,不同时期烟叶叶面真菌的数量、种类及优势种群不尽相同,而根霉属真菌始终为优势种群。     

铁皮石斛多糖分离纯化及其药理活性研究进展

铁皮石斛是我国名贵的药食同源资源,具有较高的保健价值。铁皮石斛多糖是铁皮石斛中重要的活性成分之一。本文对铁皮石斛多糖的提取、分离纯化、分子量、单糖组成进行总结归纳,并对铁皮石斛多糖的降血糖及改善糖尿病并发症、保护胃黏膜损伤、抗肿瘤、调节微生态的最新研究进展进行综述。针对目前铁皮石斛多糖含量影响因素较多、分离纯化重复性差、结构分析不够清晰、构效关系的研究不够深入等现状,提出未来研究的展望,以期为铁皮石斛的开发利用提供有益参考。     

Photoluminescence properties of Ce3+/Mn2+ doped calcium zirconium silicate phosphors with energy transfer for white LEDs

A series of Ce³⁺ doped and Ce³⁺/Mn²⁺ co-doped calcium zirconium silicate CaZrSi₂O₇ (CZS) phosphors have been synthesized via conventional high temperature solid state reactions. The luminescence properties, energy transfer between Ce³⁺ and Mn²⁺ have been investigated systematically. Under 320 nm excitation, the phosphor CZS: 0.05Ce³⁺ exhibit strong blue emission ranging from 330 nm to 500 nm, attributed to the spin-allowed 5d-4f transitions of Ce³⁺ ions. There are two different emission centers of Ce³⁺ ions, Ce³⁺(I) and Ce³⁺(II). The emission spectra of Ce³⁺, Mn²⁺ co-doped phosphors shows a broad emission around 550 nm corresponding to the ⁴T₁(⁴G)-⁶A₁(⁶S) spin-forbidden transition of Mn²⁺. The energy transfer between Ce³⁺ and Mn²⁺ is detected and the transfer efficiency of Ce³⁺(II) to Mn²⁺ is faster than that of Ce³⁺(I) to Mn²⁺. The resonant type is identified via dipole-dipole mechanism. Additionally, a blue-shift emission of Ce³⁺ and a red-shift emission of Mn²⁺ have been observed following the increase of Mn²⁺ content in relation to the energy transfer. Thermal quenching has been investigated and the emission spectra show a blue-shift with the temperature increases, which have been discussed in details. CZS: 0.05Ce³⁺, yMn²⁺ phosphors can be tuned from blue to white and even to yellow by adjusting the Mn²⁺ content. All the results indicate that CZS: Ce³⁺, Mn²⁺ phosphor have a potential application for near-UV LEDs.     

混凝沉淀法处理含铅矿坑涌水

实验采用常见的聚合氯化铝(PAC)、聚合硫酸铁(PFS)、聚丙烯酰胺(PAM)通过烧杯混凝实验进行除铅, 比较了3种絮凝剂对矿坑涌水中铅的去除效果;进而比较了3种絮凝剂分别组合之后对铅的去除效果, 筛选出既高效又经济的混凝剂组合, 并最终确定混凝剂组合为PFS和PAM。并且考察了投加顺序和pH值对组合混凝剂除铅效果的影响。结果表明:分别在最佳PAC、PFS投药条件下与PAM混用, 对含铅矿坑涌水的处理效果要比单独使用PAC、PFS任何一种絮凝剂效果好, PAM有利于提高PAC、PFS对铅的去除率。PFS与PAM组合除铅最佳工艺条件为:pH值为9.5, PFS投加量200mg/L, PAM投加量1mg/L, 投加顺序为快速搅拌时投加PFS, 慢速搅拌时投加PAM, 混凝反应时间14min, 静沉15min, 含铅矿坑涌水经该工艺处理后, 铅去除率可达99.05%, 出水铅浓度降至0.238mg/L, 达到国家污水综合排放标准(GB8978—1996)。     

固体吸附式制冷系统制冷剂的解吸特性

搭建了以活性炭-甲醇为工质对的单床吸附式制冷实验系统,对圆柱形吸附管内的吸附剂在不同解吸温度和不同解吸时间条件下的解吸量进行实验研究。解吸温度分别为84、89、94℃,解吸时间分别为4、5、6、7 h。实验结果表明,解吸温度、解吸时间和制冷剂的解吸量对吸附式制冷系统制冷循环性能有着重要影响。在热源温度为84℃加热时间4 h时,系统的制冷性能系数COP最小为0.053。系统在解吸温度为94℃,解吸时间为6 h时,系统的制冷性能系数COP最大为0.19,此时的解吸温度和解吸时间为最佳解吸温度和解吸时间。继续增加解吸时间,解吸量的增长率小于耗能的增长率,COP减小。     

Effect of Yb3+ concentration on the green-yellow upconversion emission of SrGe4O9:Er3+ phosphors

This work presents the structural, morphological and luminescent, properties of SrGe₄O₉ (SGO):Er³⁺,Yb³⁺ phosphors. These phosphors were synthesized by simple combustion synthesis and subsequently annealed at 1100 °C. The XRD patterns revealed that all the SGO samples doped with Yb³⁺ concentrations from 2 to 10 at.% presented a trigonal pure phase (the Er³⁺ concentration was fixed to 1 at.%). The morphology of the SGO samples was analyzed by scanning electron microscopy and found that they are formed by microparticles with irregular shapes and average sizes in the range of 0.2 μm–3 μm. The luminescence measurements of the SGO:Er³⁺,Yb³⁺ samples showed the presence of two main emission bands at 551 nm (green) and at 662 nm (red) under excitation at 980 nm, which are associated to Er³⁺ transitions. For Yb concentration of 2 and 3 at.% the green band dominated, but the red band became more intense for Yb concentrations above 5 at.%. As result, the CIE coordinate changed from the green to the yellow region. The increase for the Yb content from 2 to 10 at.% also enhanced of the NIR emission of Er³⁺ ≈5 times and the maximum upconversion emission was observed for 8% of Yb concentration. Further, the surface of the SGO samples was analyzed by the FTIR technique in order to find OH groups which are common luminescent quenching centers, but these groups were not detected on the samples. Since the SGO samples presented tunable emission, absence of OH groups on their surface and stable crystalline structure for high Yb dopant concentrations, they could be good candidates as phosphors for solid state lighting or displays applications.     

低温等离子体协同催化降解挥发性有机物的研究进展

低温等离子体协同催化技术在挥发性有机物（VOCs）治理中因具有反应高效、反应条件温和、设备简易等优点而受到广泛的研究和应用。文章介绍了低温等离子体协同催化降解VOCs的基本原理、技术研究进展,简述了低温等离子体的高反应活性在与催化剂的高反应选择性结合后所产生的协同作用,二者的结合不但提高了VOCs的降解效率、减少有害副产物生成,还弥补了单一使用低温等离子体技术的高能耗、副产物多的缺陷。此外,分析了低温等离子体与催化剂的联合方式及特点、低温等离子体与催化剂之间的相互作用和影响以及低温等离子体联合不同类型催化剂的协同原理。指出了研究中对完整机理分析的欠缺以及应用过程中对中间过程监测分析的困难,这也是低温等离子体协同催化降解挥发性有机物研究中的重要内容。     

二氧化碳联合核桃壳提取液促进单针藻Monoraphidium sp. QLZ-3的生长和油脂积累

以单针藻Monoraphidium sp. QLZ-3为对象,研究了CO₂对微藻在核桃壳提取液（walnut shell extracts,WSE）中生长及油脂积累的影响。结果显示,在12%的CO₂条件下,微藻在WSE中的生物量产率及油脂产率达到196.85mg/(L·d)和97.52mg/(L·d),分别是对照组的1.33倍和1.57倍。WSE培养下,外源CO₂上调了微藻中核酮糖1,5-二磷酸羧化酶基因（ribulose 1,5-bisphosphate carboxylase/oxygenase,rbcL）的表达量,从而促进了CO₂的固定。此外,12% 的CO₂提高了微藻对WSE中多酚的利用,同时上调了乙酰辅酶A羧化酶（acetyl coenzyme A carboxylase,ACCase）和苹果酸酶（malic enzyme,ME）活性,下调了磷酸烯醇式丙酮酸羧化酶（phosphoenolpyruvate carboxylase,PEPC）活性。研究表明,CO₂可以提高WSE中微藻的生物量产率和油脂产率,降低培养成本,为核桃壳的资源化利用及微藻的工业化生产提供了新的理论基础。     

基于多体动力学的连杆强度分析

连杆作为发动机最重要的零部件之一,工作过程中受急剧变化的动载荷影响,容易发生断裂失效,必须具有较高的强度和可靠性。采用多体动力学仿真进行边界条件求解,确定连杆的最大压载荷和最大拉载荷,在此基础上进行静强度计算得到三个工况下的应力分布,计算出危险截面的安全系数。分析结果表明连杆在4000 r/min时承受载荷最大,在此工况下应力集中截面为连杆小头与杆身过渡处、连杆大头与杆身过渡处、油孔及小头孔内部下半部分,最大应力值为641Mpa,在材料许用应力范围内。几个危险截面中安全系数最小为1.34,设计安全,并具有一定的强度储备。