Materials Hydrogen Storage V3TiNi0.56Al0.2 by Self-propagating High-temperature synthesis

With the help of the calculation of adiabatic temperature and thermodynamic analysis of the reactive system the autaurs discuss possibility about system of V 2O 5-TiO 2-Al by Self-propagating High-temperature synthesis(SHS).Hydrogen Storage V 3TiNi 0.56 Al 0.2 by SHS is studied by XRD,SEM and scanning electron microscopy.The experiment result indicates that it has same microstructure between synthesization by SHS and other ways.PCT curve indicated that alloy has certain hydrogen storage capability,saturated capacity of hydrogen storage is 0.092 L/g,which is a little lower than alloy by other ways.     

促凋亡基因(Bad)在卵泡期绵羊生殖器官中的表达

以卵泡期小尾寒羊和萨福克羊为研究对象,采用免疫组织化学技术,对促凋亡基因(Bad)在生殖器官卵巢、输卵管和子宫中的表达与定位进行初步研究。结果表明,在卵巢组织中Bad基因在原始卵泡、初级卵泡和次级卵泡中呈中度着染,在三级卵泡中呈轻度着染,阳性细胞在卵泡上皮细胞和颗粒细胞中分散分布,呈轻度着染;输卵管上皮分泌细胞和部分纤毛细胞胞质中见Bad基因中等强度表达,输卵管壶腹部上皮中,Bad基因多表达于分泌细胞,纤毛细胞中有部分呈阳性且强度弱,宫管结合部、峡部和壶腹部Bad基因阳性细胞染色强度弱,均呈中度着染;子宫内膜子叶和基质中的阳性细胞数量极少,阳性细胞呈轻度着色。利用计算机图像分析技术测量小尾寒羊和萨福克羊生殖器官各组织细胞中Bad基因表达的阳性细胞率和平均光密度,结果Bad基因在这2品种绵羊组织中的表达规律大体相似,但也存在一些明显的差异:萨福克羊三级卵泡颗粒细胞Bad基因阳性细胞率显著高于小尾寒羊(P0.01);萨福克羊三级卵泡和成熟卵泡膜细胞Bad基因阳性细胞率和平均光密度均显著高于小尾寒羊(P0.01);萨福克羊子宫内膜腺体卵泡期Bad基因阳性细胞平均光密度显著高于小尾寒羊(P0.01);由此表明,小尾寒羊和萨福克羊卵泡期生殖器官中细胞凋亡的差异与Bad基因表达的差异,可能是造成两者繁殖力高低差异的基础。     

河源独头火蒜与独头蒜挥发成分测定

[目的]了解河源火蒜与普通蒜的香气成分差异。[方法]采用静态顶空进样-气相色谱-质谱联用法(SHS-GC-MS)对河源独头火蒜和独头蒜的挥发性物质及含量进行分析。[结果]该试验条件下,共检出独头蒜挥发性风味成分主要有23种,12种为含硫化合物,其中主要成分是二烯丙基三硫醚(25.11%)、二烯丙基二硫醚(19.78%)、3,4-二甲基-1,2-二硫环戊烯酮(18.65%)、二氧化硫(5.20%)、3-乙烯基-1,2-二硫环戊烯(2.61%)、烯丙基甲基硫醚(2.31%)、2-乙烯基-1,3-二噻烷(2.07%)、2-恶唑烷硫酮(2.00%)、甲硫基乙腈(1.78%)、硫氰酸乙酯(1.28%),共占总含量81.73%;共检出独头火蒜主要挥发性风味成分也为23种,14种为含硫化合物,其中主要成分是二烯丙基三硫醚(38.03%)、二烯丙基二硫醚(22.63%)、3-乙烯基-1,2-二硫环戊烯(7.95%)、3,4-二甲基-1,2-二硫环戊烯酮(7.55%)、二氧化硫(4.08%)、甲硫基乙腈(4.04%)、二烯丙基硫醚(2.99%)、异硫氰甲酸甲酯(2.08%)、硫氰酸乙酯(1.49%)、烯丙基甲基硫醚(1.41%)、硫化丙烯(1.25%)、2-乙烯基-1,3-二噻烷(1.15%),共占总含量95.59%。[结论]河源独头火蒜的挥发性物质的数量和含量比普通独头蒜都高。     

Experiments on the preparation of Mn-Al master alloy by self-propagating high-temperature synthesis

Self-propagating high-temperature synthesis（SHS） is applied to produce Mn-Al master alloy for the first time. The thermodynamic data of Mn-Al master alloy are estimated, and the adiabatic temperature is calculated by Miedema model and two-parameter model of intermetallics. The reaction product is investigated by using chemical titration optical microscope,X-ray diffraction analysis, in which Mn2O3, Mn3O4 and CaO are taken as raw materials and Al as a reductive agent. Theoretical calculation and experimental results show that the adiabatic temperature is 3 160 K,and the feasibility of the SHS reaction is determined consequently. The content of manganese in master alloy is up to 78%,which broadens the methods of producing Mn-Al master alloy in practice.     

Scent profiling of Cymbidium ensifolium by electronic nose

The performance of electronic nose (E-nose) for Chinese Cymbidium scent profiling has been evaluated. Changes in scent profiles of two Cymbidium ensifolium cultivars have been monitored at different flowering stages (initial flowering, full flowering, and terminal flowering) and different times combined with two gas collecting devices. Samples were collected by static headspace (SHS) method. How E-nose can be used for pattern recognition and for studying the releasing of flower scent were proposed. Data obtained were subjected to principal component analysis (PCA) and discriminant function analysis (DFA). PCA was performed on the initially instrumental data to explore the structure of each data set and such result showed that the sensory data contained information related to the cultivar and to time spots. DFA was performed to improve the results, leading to clear separations between the sample groups. Gas collecting device did not seriously affect the result of PCA and DFA. Relative aroma intensity (RAI) was proposed as an alternative concept to compare scent intensity between samples on different time points. These results demonstrate the potential application of the E-nose to evaluate the scent profile of flower.