基于模糊物元模型的用频方案评估

提出了一种用频方案评估的方法,该方法建立了一套涵盖需求匹配性、方案经济性、方案抗扰性的用频方案评估指标体系,并利用基于模糊物元模型实现了多目标用频方案评估.仿真试验结果表明：该指标体系易于量化分析,采用模糊元方法直观地反映用频方案对不同目标的实现程度,能够较为客观地对用频方案进行评估.这对用频辅助决策有重要的应用价值.     

随机质心映射优化法(RCO)提取皮亚曼石榴皮中黄酮类化合物

利用随机质心映射优化法(RCO),以乙醇浓度、超声时间、提取温度和料液比为影响因子,研究新疆皮亚曼石榴皮中黄酮类化合物的超声波提取工艺。结果表明:经过RCO两轮循环后得出超声波法提取石榴皮中黄酮类物质最佳工艺:乙醇浓度为87%、超声时间为37 min、提取温度为59℃、料液比为1∶24(g/m L)。优化后皮亚曼石榴皮中总黄酮的得率为25.56%。经过相关性分析得知,提取温度和乙醇浓度对总黄酮的得率影响较大,且呈负相关,表明皮亚曼石榴皮中黄酮类化合物的极性较大。当石榴皮黄酮浓度为12 mg/m L时,对DPPH自由基的清除率可达91.6%。      

产天冬氨酸酶菌株大肠杆菌HY-05C发酵培养基及培养条件的优化

为提高大肠杆菌HY-05C在L-天冬氨酸生产过程中的菌体浓度,进而提高单位体积培养液中L-天冬氨酸酶酶活,本文对该菌株的培养基和培养条件进行了优化。首先通过正交实验对大肠杆菌HY-05C培养基组成进行优化,确定了最佳培养基配方（g/L）:富马酸铵10,玉米浆干粉8,酵母粉2,蛋白胨7,氯化钠5,磷酸二氢钾1,硫酸镁0.2。又进一步考察了对菌体浓度和酶活影响较大的因素初始p H和接种量,得到了最适p H=6.0,最佳接种量为1.0‰,在上述最佳培养基及培养条件下对大肠杆菌HY-05C的酶转化进程进行测定,优化后培养液的转化效率较初始提高150%,同时也验证了通过发酵条件优化提高单位体积的菌体浓度,提高L-天冬氨酸转化效率方法的可行性。      

气相色谱-质谱法分析比较传统同山高粱酒及其改良工艺酒样中的香气成分

采用顶空固相微萃取法（HS-SPME）提取传统清香型同山高粱酒及其经发酵工艺改良后的酒样Ⅰ、酒样Ⅱ中的香气成分,结合气相色谱-质谱联用仪对香气成分进行分析。结果显示,除乙醇外,三种清香型白酒中共检测出61种香气成分,其中:传统同山高粱酒中共检测出香气成分35种,主要呈香化合物有酯类化合物、醇类化合物和芳香族化合物,主要香气成分有己酸乙酯、乙酸乙酯、3-甲基丁醇、1,1-二乙氧基乙烷、丁酸乙酯;酒样Ⅰ中共检测出香气成分45种,主要呈香化合物有酯类化合物、醇类化合物、烷烃类化合物和烯烃类化合物,主要香气成分有乙酸乙酯、1,1-二乙氧基乙烷、3-甲基丁醇、双戊烯、十二烷;酒样Ⅱ中共检测出香气成分41种,主要呈香化合物有酯类化合物、烷烃类化合物、烯烃类化合物和芳香族化合物,主要香气成分有乙酸乙酯、1,1-二乙氧基乙烷、3-甲基丁醇、双戊烯、十四烷。研究结果表明,传统同山高粱酒经发酵工艺改良后,酒中香气成分种类明显增多,酒的口感和风味得到改善。      

植物乳杆菌LB-17产γ-氨基丁酸培养基优化

以植物乳杆菌（Lactobacillus plantarum Lb-17）为发酵菌株,以发酵产物γ-氨基丁酸产量为检测参数,对植物乳杆菌发酵产γ-氨基丁酸的发酵培养基进行优化。利用单因素实验和Box-Behnken响应曲面实验对发酵培养基进行优化得到最优培养基为:葡萄糖12.0 g/L、酵母粉18.0 g/L、Ca²⁺ 55.0 mmol/L、Mg²⁺ 60.0 mmol/L、L-谷氨酸钠26.0 g/L。优化后,植物乳杆菌Lb-17发酵γ-氨基丁酸产量达8.037 g/L,是优化前5.49 g/L提高1.5倍。      

枯草芽孢杆菌液态发酵豆粕的种子培养基和发酵培养基优化研究

为提高枯草芽孢杆菌液态发酵豆粕的效率,对发酵所用种子培养基和发酵培养基进行优化。通过单因素实验研究种子培养基氮源、碳源、无机盐种类及温度对生物量的影响,确定种子培养基组成为1%酵母膏、1%玉米黄粉、1%KH2PO4,培养温度36℃,其生物量、中性和碱性蛋白酶酶活较常规蛋白胨培养基分别提高210.10%、459.20%和67.50%。在此基础上运用正交实验对发酵培养基碳源量、接种量及温度进行优化,得到最优发酵工艺条件为20%豆粕、2%玉米黄粉、1%KH2PO4、接种量10%,培养温度36℃,其生物量、可溶性蛋白及多肽含量较仅含22%豆粕的培养基分别提高40.90%、28.60%和36.40%。结果表明采用优化后的种子培养基和发酵培养基能够显著提高枯草芽孢杆菌液态发酵豆粕的效率。      

乳酸菌氧化锆珠破壁方法的优化及适用性研究

本实验旨在优化氧化锆珠破壁方法,以期筛选出较佳的破壁条件,提高蛋白得率。实验在菌体重量、研磨buffer和研磨时间这3方面对该破壁方法进行了优化,并通过SDS-PAGE来分析其破壁效果。在优化后的条件下,同时对6株乳酸菌进行破壁处理并通过SDS-PAGE来分析其破壁效果。结果表明:在菌体重量、研磨buffer、锆珠三者的加入比例（W/V/W）为0.013 g∶300μL∶1 g的条件下,研磨15 min,提取的蛋白图谱条带清晰,丰度高;RIPA、PBS、PENP、GUS作为研磨buffer时,提取的蛋白图谱条带清晰且丰度高,而8 mol/L尿素作为研磨buffer时,图谱条带模糊且丰度低;6株乳酸菌经该方法破壁处理后,蛋白图谱条带均具有较高的丰度和清晰度。因此,对于乳酸菌的破壁,氧化锆珠破壁法具有快速、高效的优点。      

Temperature Rise Inside Shear Bands in a Simple Model Glass

One of the key factors, which hampers the application of metallic glasses as structural components, is the localization of deformation in narrow bands of a few tens up to one hundred nanometers thickness, the so-called shear bands. Processes, which occur inside shear bands are of central importance for the question whether a catastrophic failure of the material is unavoidable or can be circumvented or, at least, delayed. Via molecular dynamics simulations, this study addresses one of these processes, namely the local temperature rise due to viscous heat generation. The major contribution to energy dissipation is traced back to the plastic work performed by shear stress during steady deformation. Zones of largest strain contribute the most to this process and coincide with high-temperature domains (hottest spots) inside the sample. Magnitude of temperature rise can reach a few percent of the sample’s glass transition temperature. Consequences of these observations are discussed in the context of the current research in the field.     

The Lattice Model of Particles with Orientation-Dependent Interactions at Solid Surfaces: Wetting Scenarios

Wetting phenomena in a lattice model of particles having two chemically different halves (A and B) and being in contact with solid substrates have been studied with Monte Carlo methods. The energy of the interaction between a pair of neighboring particles has been assumed to depend on the degree to which the AA, AB and BB regions face each other. In this work, we have assumed that uAA=−1.0 and considered three series of systems with uAB=uBB, uAB=0 and uBB=0. The phase behavior of bulk systems has been determined. In particular, it has been shown that at sufficiently low temperatures the bulk systems order into the superantiferromagnetic (SAF) phase, or into the antiferromagnetic (AF) phase, depending on the magnitudes of AA, AB and BB interaction energies, uAA, uAB and uBB. The SAF structure occurs whenever ϵ=uAA+uBB−2uAB is lower than zero and the AF structure is stable when ϵ is greater than zero. The wetting behavior has been demonstrated to depend strongly on the structure of the bulk condensed phase, the interactions between fluid particles and the strength of the surface potential. In all series, we have found the dewetting transition, resulting from the limited stability of different ordered structures of surface phases. However, in the systems that exhibit the gas–liquid transition in the bulk, the reentrant wetting transition has been observed at sufficiently high temperatures. The mechanism of dewetting and reentrant wetting transitions has been determined. Moreover, we have also demonstrated, how the dewetting transition in the series with uAB=0 is affected by the wall selectivity, i.e., when the interaction between the parts A and B of fluid particles and the solid is different.