为研究不同部位烟叶化学成分与烟叶图像提取值的变化,以中烟100为材料,利用统计分析和相关性分析对数据进行处理,结果表明:不同部位烟叶叶绿素a和叶绿素b在开烤至42℃末快速降解,在42℃末至54℃末降解缓慢,在54℃末至68℃末无明显变化;不同部位烟叶中类胡萝卜素在38℃末之前稍有降解,在38℃末至47℃末降解速度快,47℃末至68℃末呈现较稳定的缓慢持续降解趋势;烟叶中化学成分除烟碱和总氮外,总糖、还原糖、淀粉和蛋白质含量在变黄期变化幅度最大,在定色期变化幅度逐渐减小,在干筋期基本保持不变;不同部位烟叶图像特征值R、G、B主要在开烤至38℃末呈逐渐上升趋势,在38℃末至68℃末呈逐渐下降的趋势;相关性分析结果表明,叶绿素a、叶绿素b、类胡萝卜素、总糖、还原糖、蛋白质、淀粉等物质含量与红度值(R)之间存在显著或极显著相关关系.

为提升烤烟苯丙氨酸类香味物质含量和改善烟叶香味,本研究以中烟100为试材,采用氨基酸测定仪、分光光度计、气质联用仪对鲜烟叶和烘烤过程中烤烟主要香气前体物质苯丙氨酸及其降解产生的香味物质含量变化规律进行分析.结果表明,不同部位烟叶在烘烤过程中苯丙氨酸含量的变化均呈现先降后升趋势,在48℃末达到最大值.PAL活性变化测定可知,42～48℃是烟叶苯丙氨酸降解的重要时期.各部位烟叶苯甲醇和苯乙醇含量在烘烤过程中不断上升;下部叶苯甲醛含量变化相对平稳,中上部叶含量呈现先升高后降低趋势;各部位烟叶苯乙醛含量烘烤过程中的变化趋势各不相同,但变幅较小.

为了用色度信号设备在线监测烟叶烘烤进程,采用相关性分析和回归分析法,研究烘烤过程中烟叶色度信号值的变化规律及其与主要化学成分的关系.结果表明,色度信号值在烟叶烘烤过程中逐渐增大并在54℃ 末～68℃ 末之间逐渐趋于稳定;相关性分析表明,色度信号值与颜色参数亮度值(L)、红度值(a)、黄度值(b)、色泽比(H)、色相角(H°)、饱和度(C)和烟叶化学成分中的叶绿素a、叶绿素b、类胡萝卜素、总糖、还原糖、淀粉、烟碱、总氮、蛋白质含量和叶片含水率有很强的相关性;回归分析表明,色度信号值与化学成分模型拟合度较好;对回归模型验证可知,叶绿素b、类胡萝卜素、总糖、淀粉含量相对误差分别为14.66％、12.33％、11.61％、15.57％,预测精度较高.色度信号监测设备可以实现烟叶烘烤进程的在线监测,为提高烟叶品质提供科学的数据支撑.

为研究烟叶烘烤过程中烤房内挥发性成分的变化规律,采用固相微萃取-气相色谱/质谱(SPME-GC/MS)联用的方法检测烤房内和烟叶中的挥发性成分,并对检测到的挥发性成分进行分析.结果表明,在烤房内和烟叶中检测到的挥发性成分分别有76种和96种,共同检测到的挥发性成分有19种;其中烟碱和叶绿醇是烤房内和烟叶中挥发性成分含量最多的物质,总量占比分别为91.59％和92.86％,烤房内烟碱和叶绿醇相对香气活性值(ROAV)分别为1 030.30和138.87;烤房内的烟碱含量和烟叶中的烟碱含量变化趋势一致,总体呈现先升高后降低并逐渐稳定的趋势,在42℃末达到最大值,并在47℃末—68℃末趋于稳定;烟叶中的叶绿醇含量在烘烤过程中呈先升高后降低的趋势,在42℃末达到最大值,烤房中的叶绿醇含量在烘烤过程中呈逐渐升高的趋势,在54℃末—68℃末趋于稳定.聚类分析结果表明,烤房内挥发性成分在开烤—42℃末变化明显,在47℃末—68℃C末趋于稳定.

旨在研究禁食软粪对新西兰白兔生长性能、毛皮质量、屠宰指标及脂代谢及盲肠微生物的影响.选取12只平均体质量为(0.91±0.12) kg的28日龄断奶新西兰白兔,随机分为A、B2组,每组6个重复.其中A组为对照组,正常饲养;B组为试验组,戴项圈禁食软粪.预试期7d,正式试验60 d,每天称量采食量,每周称1次体质量.结果 表明:1)禁食软粪显著降低了生长期新西兰白兔体增重、日增重、料重比(P＜0.05).2)与对照组相比,禁食软粪极显著降低了试验组新西兰白兔毛皮长度、毛皮宽度、毛皮质量(P＜0.01),被毛长度和毛皮厚度差异不显著(P＞0.05).3)禁食软粪极显著降低了新西兰白兔全净膛质量和半净膛质量(P＜0.0l).4)禁食软粪对新西兰白兔屠宰后45 min和24 h的pH值、剪切力、蒸煮损失、滴水损失无显著性影响(P＞0.05).5)与对照组相比,禁食软粪对试验组新西兰白兔高密度脂蛋白胆固醇、白蛋白差异极显著(P＜0.01),对总胆固醇差异显著(P＜0.05),对低密度脂蛋白胆固醇、甘油三酯及总蛋白差异不显著(P＞0.05).6)对2组兔子盲肠微生物进行宏基因组测序,结果表明:与对照组相比,试验组厚壁菌门(Firmicutes)丰度无显著性变化(P＞0.05),拟杆菌门(Bacteroidetes)丰度增加,放线菌门(Actinobacteria)丰度减少.综合考虑本试验所测指标,禁食软粪降低了新西兰白兔的生长性能、毛皮质量、屠宰指标及肉品质.这为研究其他小型哺乳动物食粪行为提供了依据.

Guanosine-3',5'-bis pyrophosphate (ppGpp) is a secondary messenger in bacteria and plants to mediate stringent response,a process for adaptation to stress conditions.However,the biosynthesis and physiological functions of ppGpp are still unknown in fungi.In this study,Pleurotus ostreatus were cultivated on cottonseed husk media,and determined for ppGpp content in mycelia at different cultivation stages and fruiting body by HPLC.Mycelial ppGpp content stepwisely increased from full bagging stage,through primordia stage,and peaked at coral stage,and then decreased at shaping mushroom stage and remained at a stable concentration during young mushroom stage and mature mushroom stage.ppGpp was not detected in mature fruiting bodies.Low concentrations of exogenous ppGpp (0.82～3.28 μmol/L) stimulated mycelial growth,whereas high concentration of exogenous ppGpp (6.56 μmol/L) showed no effect on mycelial growth.

At present, the harvest and transportation of pineapple in China are mainly depengding on artificial labor, which lacks mechanization, leading to the low production efficiency and the high labor cost.In order to promote the de-velopment of Chinese pineapple industry, realize the mechanization of the pineapple planting industry, improve the effi-ciency of pineapple transportation as well as reduce the orchardist ' s laboring intensity, our team designed a type of pine-apple transporter with plucking and adjustable to gap.Based on the field investigation data, we designed a kind of new frame and new carriage structure to make the transporter meet the need of pineapple planting industry.With SolidWorks 3 d modeling and motion simulation, using SolidWorks Simulation software to study the car beam, frame and lifting mech-anism by finite element stress method,we check the rationality of the design and optimize organization structure of the de-sign.The pivotal technology is using hydraulic scissor lift structure to meet the need of adjustable ground clearance of pin -eapple transporter, and using gasoline-electric hybrid provides driving force in order to simplify the transmission and re-duce the fuel consumption.

在食用菌栽培中,双孢蘑菇培养料的制作最复杂,且堆制时间长、成本高、并污染环境。而研究表明,在堆制过程后期,嗜热革节孢的密度和活性的大小直接影响双孢蘑菇的产量。综述了嗜热革节孢的生物学特性、应用嗜热革节孢改进传统双孢蘑菇培养料堆制方法以及嗜热革节孢促进双孢蘑菇菌丝生长的机制。