烤烟留种田棉铃虫幼虫分布型与抽样技术研究

棉铃虫是陕西省烤烟留种田后期主要害虫之一。幼虫分布型调查表明,它主要为波松和负二项分布,且随密度而变化,但适合于Taylor幂法则:S2=1.07523m0.9931。经推导演算,得出理论抽样公式为:n=1.07523(t/D)2·m-1.0069适合烟田棉铃虫幼虫调查的序贯抽样模型为T'₀(n)=0.15n+1.96√0.1634nT₀n(n)=0.15n-1.96-1.96√0.1634n最多只需抽取16株。对各种机械抽样方法比较后,认为实践中用平行线10点100株取样比较合适。      

四川凉山烟区烟蚜种群空间分布型及抽样技术研究

为明确四川省凉山主要烟区烟蚜空间分布格局,给通过释放天敌控制烟蚜技术提供理论依据,运用2种回归方法和8个聚集度指标对烟蚜盛发期种群的空间格局进行了分析,同时通过Southwood的Kc法、Iwao回归法和Taylor幂法计算烟蚜种群理论抽样数,用Iwao和kuno序贯抽样技术拟合烟蚜的序贯抽样模型。结果表明,烟蚜种群呈聚集分布,聚集强度随种群密度的升高而增加,且符合负二项分布,其聚集原因是由烟蚜习性与环境因素共同引起的;通过种群密度与聚集度指标相关性分析表明,用平均拥挤度(m~*/m)、负二项分布指标(K),久野指数(CA)及L~*/(m+1)分析烟蚜空间分布型更具说服力。本研究利用空间格局参数确定了理论抽样数和序贯抽样模型,明确了四川省凉山主要烟区烟蚜种群呈聚集分布,是由烟蚜习性与环境因素共同决定的。     

蔗田鼠害空间分布型及抽样技术

对本地八块蔗田进行测定,田间鼠害主要呈负二项分布,部分为奈曼分布。理论抽     

烤烟色差参数与其表面细胞形态指标的关系

为分析初烤烟叶色差参数与其表面细胞形态指标的关系,利用色差计、扫描电镜、Photoshop软件测定初烤烟叶10个区位的色差参数及表面细胞形态指标（细胞面积、细胞周长、细胞形状因子、细胞密度）,并对色差参数与细胞形态指标进行Pearson相关性分析和回归分析。结果表明：①对于云烟87 C3F初烤烟叶,明度值L^*及表面细胞密度呈叶基和叶尖高,叶中部低的变化趋势;红度值a^*、黄度值b^*、总色差值ΔE及表面细胞面积、周长、形状因子呈叶基和叶尖低,叶中部高的变化趋势。②L^*值与细胞面积、周长、形状因子显著负线性相关,与细胞密度显著正线性相关;a^*、b^*、ΔE值与细胞面积、周长、形状因子显著正线性相关,与细胞密度显著负线性相关。烟叶色差参数与表面细胞形态指标存在较强的相关性,为应用色差法评价烟叶表面的细胞形态提供了技术依据。     

高蛋白中间水分食品贮藏过程中品质和AGEs含量的变化

通过改变贮藏环境的水分活度和添加外源抗氧化剂白藜芦醇到高蛋白食品模型体系中,评价不同白藜芦醇用量、水分活度和贮藏时间对食品美拉德反应程度、质构、颜色、可溶和不可溶性蛋白聚集等指标的影响。结果表明,高蛋白食品在水分活度0.560的环境中贮藏时,美拉德反应、硬度和不可溶性蛋白聚集呈现不断增加趋势,晚期糖基化终末产物（AGEs）含量较水分活度0.751时明显增加;白藜芦醇的添加可降低食品贮藏过程中的美拉德反应程度,增加食品颜色的L*值,降低b*值和a*值;综合各组测定指标,水分活度0.751、白藜芦醇用量500 μg/g时,30 ℃条件下贮藏的高蛋白中间水分食品模型的品质及安全性最优;水分迁移是导致高蛋白食品贮藏过程中蛋白聚集和质地硬化的主要原因。     

白肋烟晾制期间烟叶中细菌的分离和鉴定

对晾制烟叶中分离到的33株优势菌株进行16S rDNA鉴定,鉴定结果为Pseudomonas、Bacillus、Enterobacter、Rhizobium、Corynebacterium、Pantoea、Acinetobacter、Arthrobacter、Xanthomonas、Paracoccus、Achromobacter、Rhodococcus。经硝酸盐和亚硝酸盐还原能力测定,结果表明:6株不能还原硝酸盐和亚硝酸盐,占总菌株数的18.18%;20株能还原硝酸盐而不能还原亚硝酸盐,占总菌株数的60.61%;7株既可以还原硝酸盐又可以还原亚硝酸盐(2株Rhizobium、1株Paracoccus、4株Pseudomonas),占总菌株数的21.21%,可能是抑制白肋烟叶中TSNA形成的菌株。      

小麦DH群体馒头主要品质性状之间的相关分析

依照行业标准SB/T 10139—1993制作馒头,采用感官评定、色彩色差计测定、质构分析相结合的方法测定分析馒头主要品质性状之间的相关性。分析结果表明:对馒头评分影响最主要的因素分别为硬度、体积、L*值、A*值和B*值,其中与评分呈极显著正相关的为体积和L*值,呈极显著负相关的为硬度、A*值和B*值;馒头主要品质性状间的相关性分析表明:硬度与黏着性、弹性、黏聚性、回复性均呈极显著负相关水平,而与胶着性和咀嚼度的相关性为极显著正相关;L*值与A*值、B*值、l*值、a*值的相关性均为极显著正相关,并且,L*值与l*值,A*值与a*值,B*值与b*值之间均存在极显著正相关关系;体积与弹性、黏聚性、胶着性、咀嚼度以及回复性间的相关性均为极显著负相关。     

连续流动分析法测定烟草中的氨

建立并验证了采用连续流动分析法(CFA)测定烟草中的氨含量。连续测定的RSD<2%,13个实验室共同实验的重复性和再现性值分别为:r=0.0477x+0.0043(R2=0.930)和R=0.0698x+0.0246(R2=0.980)。不同水平试验的回收率>98%,平均回收率99.7%。分别与HPLC和IC法比较,t检验结果表明CFA与2方法之间均无显著性差异。      

新疆酿酒葡萄瘿螨发生规律初探

通过对葡萄瘿螨,即毛毡病空间分布型进行的研究与分析,结果表明:葡萄瘿螨种群在田间分布呈聚集分布,符合负二项分布.以此空间分布型进行序贯分析,确定了阈值密度:即百株葡萄瘿螨虫苞数在30个以下时,未达到防治指标;百株虫苞数超过50个以上时,达到防治指标.其概率保证为95%,即必须防治而误认为无需防治的误差为α(0.05),尚未达到防治指标而误认为需要防治的误差为β(O.05),计算出了有关参数和两条平行线的截点和斜率.在以累积虫苞数为纵坐标、抽样次数为横坐标的图上,标出"接受"和"拒绝"的区域.     

服务时间分布为H_2~*的带有顾客流失的高负荷极限

研究服务时间分布服从H~*_2的带有顾客流失的队列模型。探讨等待空间有限的单服务台G/H~*_2/1/k队列模型,得到队长和流失人数的极限表达;将该模型推广至到达率随时间变化的多服务台G_t/H~*_2/m/k队列模型,应用连续映射等方法对极限进行研究。结合随机过程极限对分裂过程和叠加到达过程的相应队列模型进行分析,得到队长和流失人数的高负荷极限。     

烟草青枯菌致病型及分布的研究

1997~2001年从我国南方烟区青枯病采集分离出97个菌株,依据各菌株在鉴别品种红花大金元、K326、岩烟97和G3上的反应特征,可区分为3个致病型。Ⅰ型菌致病力弱,在K326上反应为LR-MR;Ⅱ型菌致病力中,在K326上反应HS,而在岩烟97上反应为LR-MR;Ⅲ型菌致病力强,在岩烟97上反应HS。调查表明,感病品种连作地以Ⅰ型菌占优势,抗I型菌的品种连作地以Ⅱ型菌居多;Ⅲ型菌主要表现在小气候闷热、阴、湿、砂的烟草连作地。温度对不同菌株与高感品种互作看不出明显影响,而对不同菌株与抗性型品种互作则有明显影响;只有在较高的温度>24℃下,II型菌对K326,Ⅲ型菌对K326和岩烟97产生强侵染。      

Pattern of egg distribution by Adzuki bean beetle,Callosobruchus chinensis (L.) (Coleoptera: Chysomelidae) in stored chickpea under natural infestation

Under laboratory experimental condition female Adzuki bean beetles, Callosobruchus chinensis (L.) are known to evenly distribute their eggs over grains available for egg laying. However, currently there are no data on pattern of egg distribution by Adzuki bean beetle in large quantity of chickpea grain stored for extended period of time. The objective of this study was to determine the number and distribution of eggs among grains of chickpea stored in large quantity for 8 months and subjected to natural infestations. The experiment was conducted under room temperature and relative humidity at Debre Zeit Agricultural Research Center. The chickpea cultivars used were Natoli (desi type, 22 g per 100 seeds with Tuberculated seed coat texture) and Arerti (kabuli type, 26 g per 100 seeds with smooth seed coat texture) and for each cultivar there were 21 replicas of bags (40 cm wide and 70 cm high). From each bag, which contains 10 kg each, 25 chickpea grain samples were randomly selected at monthly intervals and examined for the presence or absence of Adzuki bean beetle eggs. Grains with eggs were categorized into frequency classes (i.e. 0, 1, 2, …, n) based on the number of eggs present on them. The variance to mean ratio was used to decide the type of egg dispersion pattern. In all the sampling dates and on both cultivars, the variance to mean ratios were highly significantly greater than one indicating that egg distribution by female Adzuki bean beetles on grains of chickpea was aggregated type. Moreover, further analysis of data had shown that the egg distribution pattern perfectly fits the negative binomial distribution, which confirms that the pattern of egg distribution on chickpea grains was aggregated/clumped type.     

不同香料烟品种和品系对烟草黑胫病菌的抗病性研究

以浙江绍兴地区15个香料烟品种和品系对烟草黑胫病菌进行抗病性鉴定,采用游动孢子液灌根接种、茎注射接种和茎伤口菌丝块接种。结果表明,供试的5个亲本和10个杂交后代中,亲本品种沙姆逊、Toy、Argjiro和巴斯马高度感病,杂交后代中Toy×沙姆逊和泰国沙姆逊×巴斯马也较易感病,而沙姆逊×Toy、ms沙姆逊×沙姆逊和巴斯马×沙姆逊3个品系却高度抗病。采用的3种接种方法中,茎伤口接种的病情指数显著高于游动孢子液灌根接种和茎注射接种。      

Attachment efficiency of nanoparticle aggregation in aqueous dispersions: modeling and experimental validation

To describe the aggregation kinetics of nanoparticles (NPs) in aqueous dispersions, a new equation for predicting the attachment efficiency is presented. The rationale is that at nanoscale, random kinetic motion may supersede the role of interaction energy in governing the aggregation kinetics of NPs, and aggregation could occur exclusively among the fraction of NPs with the minimum kinetic energy that exceeds the interaction energy barrier (E(b)). To justify this rationale, we examined the evolution of particle size distribution (PSD) and frequency distribution during aggregation, and further derived the new equation of attachment efficiency on the basis of the Maxwell-Boltzmann distribution and Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The new equation was evaluated through aggregation experiments with CeO(2) NPs using time-resolved-dynamic light scattering (TR-DLS). Our results show that the prediction of the attachment efficiencies agreed remarkably well with experimental data and also correctly described the effects of ionic strength, natural organic matter (NOM), and temperature on attachment efficiency. Furthermore, the new equation was used to describe the attachment efficiencies of different types of engineered NPs selected from the literature and most of the fits showed good agreement with the inverse stability ratios (1/W) and experimentally derived results, although some minor discrepancies were present. Overall, the new equation provides an alternative theoretical approach in addition to 1/W for predicting attachment efficiency.     

Distribution of aflatoxin in whole peanut kernels, sampling plans for small samples

It is well known that the distribution of aflatoxin in a lot of whole peanut kernels is extremely heterogeneous. Several different statistical distribution models have been proposed, fitting the experimental data reasonably well as long as the samples are very large, but differing considerably when applied to small samples. Therefore, it is important to know the real distribution between single kernels for the evaluation of the effectiveness of sampling plans for small samples. It is shown by the analysis of 368 samples of 1-10,000 kernels from the same lot of peanuts that the negative binomial distribution represents a good statistical model. The variance can be estimated from the mean concentration of the analysed samples, as confirmed by the comparison of data from several independent investigations. Decisions based on small samples are especially unfavourable to the consumer, as even a lot with a high mean concentration will tend to give negative results. A reasonably small risk of a false decision, both to the consumer and to the producer, can be reached only if very large samples are analysed.     

半嵌套式PCR检测转几丁质酶基因烟草研究

用含卡那霉素的培养基首先对转几丁质酶基因烟草种子和烟苗进行初步筛选鉴定,再用Western Blot进一步证实抗卡那霉素的转基因烟苗中外源转几丁质酶基因的表达。然后研究半嵌套式PCR(Semi-nested PCR)检测转几丁质酶基因烟草植株及其烤后烟叶中的所转目的基因;利用限制性内切酶Hind Ⅲ对半嵌套式PCR产物进行酶切,从而验证半嵌套式PCR产物是否为真正的目的基因。研究结果表明,半嵌套式PCR是一种快速、灵敏的检测转几丁质酶基因烟草植株及烤后烟叶的方法。      

渭北烟区烟草蚀纹病毒和黄瓜花叶病毒侵染循环的研究

用酶联免疫吸附实验(ELISA)对渭北烟区6科18种植物461个病毒标样的TEV和CMV检测,对蚜虫种类,主要传毒蚜虫发生规律、蚜虫传毒测定以及烟草蚀纹病毒(TEV)和烟草黄瓜花叶病毒(CMV)的侵染循环进行了调查研究。结果表明,TEV的自然寄主有辣椒、番茄、龙葵、蔓陀罗、酸浆以及刺儿菜和菠菜,刺儿菜是主要越冬寄主;CMV的寄主有辣椒、番茄、豇豆、菜豆以及油菜、萝卜(留种)、菠菜、刺儿菜,其中油菜是主要越冬寄主。越冬后的TEV和CMV通过有翅蚜虫(主要是桃蚜)传给烟草、辣椒、番茄等蔬菜以及杂草,秋季又通过有翅蚜虫传给越冬寄主。      

咖啡浓度对咖啡牛奶体系稳定性及消化行为的影响

研究12.5%、25%、50%浓度咖啡对咖啡牛奶体系稳定性以及消化行为的影响,采用Turbiscan Lab多重光散射仪、马尔文纳米粒度/电位仪、共聚焦显微镜等仪器及体外模拟胃、肠消化等手段进行分析。结果表明,随着咖啡浓度升高,体系稳定性指数(TSI)在1 h内从1.2升至2.1;平均粒径从306 nm升至643.6 nm,且粒径分布由单一峰变为双峰;电位值降低了6。体外模拟胃、肠消化过程中,不同咖啡浓度体系的蛋白电泳条带无显著差异(p>0.05),但25%、50%浓度咖啡体系在1 h胃消化阶段出现了较为明显的油滴聚集。咖啡浓度升高导致体系稳定性下降,胃消化阶段油滴聚集,但对体系中蛋白的消化无负面影响。     

Movement and distribution of Sitophilus zeamais adults and relationship between their density and trapping frequency in wheat bulks under different grain temperatures and moisture contents

Movement and distribution of Sitophilus zeamais adults and relationship between their trapping frequency and insect density were determined in one tonne wheat with 11.5 ± 0.2, 12.5 ± 0.1 and 13.5 ± 0.2% moisture contents (wet basis) inside cylindrical bins at 20, 25 and 30 °C. The introduced adult densities were 0.5, 1.0, and 2.0 adults/kg wheat (A/kg). Inside each bin, 15 probe traps were vertically installed in three layers. In each layer, five traps were installed at the center and half radii of the bin individually. The trapped adults were counted daily up to 7 d, and then 15 kg wheat was sampled at each trap location. The insect number in each sample was counted.The recovered adults in the top layer were less than that in the middle layer, while no significant difference between at middle and bottom layers. In each layer, adults preferred the center location at 0.5 A/kg, while this trend was unidentified at other densities. There was an autocorrelation of insect densities at adjacent locations at ≥ 1.0 A/kg, while no autocorrelation in the vertical direction. The adults had an aggregation distribution at any temperature, moisture content and adult density. The normal and Poisson model could not be used to describe the distribution of the count frequency of the adults in the samples, while the negative binomial model could describe this distribution in 18 out of 27 sampling sets at ≤ 1.0 A/kg. The trapping frequency was strongly influenced by the trapping period and increased with the increase of insect densities. The relationship between adult densities and trapping frequencies at the sampling locations had a significant difference at different grain temperatures, while no difference at different moisture contents, grain depths, and locations.