中国白蛉亚科数值分类研究（双翅目: 毛蠓科）

【目的】 对中国白蛉亚科（Phlebotominae）昆虫进行数值分类研究, 探索其在系统发育过程中的亲缘关系。【方法】 选取中国白蛉40个蛉种作为分类单元以及白蛉的68项形态特征为分类指标, 进行系统聚类分析。【结果】 聚类分析结果与传统属级及白蛉属Phlebotomus的亚属级分类一致。司蛉属Sergentomyia的亚属分类与传统分类有一些区别, 聚类分析将司蛉属分为8类, 其中尼克组nicnic group与司蛉亚属subgenus Sergentomyia和传统分类一致; 泉州司蛉S. quanzhouensis和唐氏司蛉S. tangi聚入帕蛉亚属subgenus Parrotomyia; 尹氏司蛉S. yini聚入新蛉亚属subgenus Neophlebotomus, 应氏司蛉S. iyengari、马来司蛉S. malayensis、吐鲁番司蛉S. turfanensis、兰州司蛉S. lanzhouensis和南京司蛉S. nankingensis聚为一类; 歌乐山司蛉S. koloshanensis、方亮司蛉S. fanglianensis和云南司蛉S. yunnanensis与尼克组nicnic group聚成一类, 此类群和此属中其他蛉种系统发育关系距离远。【结论】 中国白蛉亚科昆虫的聚类分析结果与传统分类基本一致, 验证了传统分类系统的可靠性, 并揭示了传统分类中一些蛉种不确定分类问题。司蛉属聚类分析结果与传统分类有差别, 提示有个别蛉种需重新考虑其分类地位。     

ICP-AES测定广西巴豆不同部位中的十种微量元素

高压密封消化罐消解法将晒干的广西巴豆的根、茎、叶、种子壳及种子进行消解,ICP-AES同时测定其中K、Cu、Fe、Zn、Ca、Mg、Mn、Al、Sr、Na元素的含量,该方法的加标回收率在90.2%～114%之间,RSD<5.57%,测定结果符合分析要求。结果显示,Mn、Mg、Ca在巴豆叶中含量最高,种子中则富含Zn、Cu、K、Na,在种子壳中Sr的含量最高,根中含量最高的是Al,而K、Cu、Fe、Zn、Ca、Mg、Mn、Al、Sr、Na十种元素在茎中分布均匀。     

具有社会行为的HIV传播模型

考虑到HIV传播的社会行为的影响,建立了一个HIV传播的偏微分方程系统.利用预测校正方法我们给出了系统的数值解法,由此说明人的行为在HIV传播中的重要作用.     

酿酒酵母菌核糖体RNA沉降系数的初步研究

为研究酿酒酵母菌核糖体RNA(rRNA)的沉降系数,用酶解法和液氮研磨法裂解酿酒酵母菌的细胞壁,Trizol Reagent提取其总RNA,同时提取小白鼠和斑马鱼的总RNA进行比较.经紫外分光光度计检测和甲醛琼脂糖变性胶电泳后,RNA纯度好,条带清晰,无弥散或降解现象.试验发现,与酶解法相比,用液氮研磨法破碎酿酒酵母菌细胞壁提取总RNA所用的成本低,时间少,产率和纯度高,适用于少量样品RNA的提取.同时,酿酒酵母菌与斑马鱼和小白鼠总RNA电泳图谱表明,三者的"18S rRNA"在条带大小方面差异较小,而"28S rRNA"差异较大.利用分析型离心机测得的酿酒酵母菌两个较大rRNA的沉降系数分别为24.7S和18.1S.研究结果表明了真核生物rRNA种类的多样性.     

我国鸡蛋价格趋势周期分解和冲击效应分析

为研究鸡蛋价格趋势周期和相关因素对鸡蛋价格波动的影响程度,采用B-N分解法对鸡蛋价格波动周期进行分解,用 VAR模型研究了蛋鸡配合饲料价格、蛋雏鸡价格对鸡蛋价格波动的脉冲响应,同时采用方差统计比的方法,计算出随机冲击效应对鸡蛋价格的影响。研究结果表明：2000年1月—2014年12月的鸡蛋价格可以划分为8个周期,鸡蛋价格自身供求变化对于鸡蛋价格波动的脉冲响应达到69.37%,蛋鸡配合饲料、蛋雏鸡分别是11.70%、3.05%。短期内随机冲击对于鸡蛋价格波动的影响是100%以上,长期内随机冲击对于鸡蛋价格波动的影响为40%。     

Shrub encroachment effect on the evapotranspiration and its component—A numerical simulation study of a shrub encroachment grassland in Nei Mongol,China

Aims Shrub encroachment is a common global change phenomenon occurring in arid and semi-arid regions. Due to the difficulty of partitioning evapotranspiration into shrub plants, grass plants and soil in the field, there are few studies focusing on shrub encroachment effect on the evapotranspiration and its component in China. This study aims to illustrate shrub encroachment effect on evapotranspiration by the numerical modeling method. Methods A two-source model was applied and calibrated with the measured evapotranspiration (ET) by the Bowen ratio system to simulate evapotranspiration and its component in a shrub encroachment grassland in Nei Mongol, China. Based on the calibrated model and previous shrub encroachment investigation, we set three scenarios of shrub encroachment characterized by relative shrub coverage of 5%, 15% and 30%, respectively, and quantified their effects caused by shrub encroachment through localized and calibrated two-source model.Important findings The two-source model can well reconstruct the evapotranspiration characteristics of a shrub encroachment grassland. Sensitivity analysis of the model shows that errors for the input variables and parameters have small influence on the result of partitioning evapotranspiration. The result shows that shrub encroachment has relatively small influence on the total amount of ET, but it has clear influence on the proportion of the components of evapotranspiration (E/ET). With shrub coverage increasing from 5% to 15% and then 30%, the evapotranspiration decreased from 182.97 to 180.38 and 176.72 W·m^-2, decreasing amplitude values of 0.34% and 0.44%, respectively. On average, E/ET rises from 52.9% to 53.9% and 55.5%, increasing amplitude values to 2.04% and 3.25%. Data analysis indicates that shrub encroachment results in smaller soil moisture changes, but clear changes of ecosystem structure (decreasing ecosystem leaf area index while increasing vegetation height) which lead to the decrease of transpiration fraction through decreasing canopy conductance. The research highlights that, with the shrub encroachment, more water will be consumed as soil evaporation which is often regarded as invalid part of evapotranspiration and thus resulting in the decrease of water use efficiency.     

Frequency Analysis and Anti-Shock Mechanism of Woodpecker＇s Head Structure

The mechanical properties of the skull and the anti-shock characteristics of woodpecker＇s head were investigated by ex- periment and numerical simulation. We measured the micro-Young＇s modulus of the skull by nano-indentation method and calculated the macro-equivalent Young＇s modulus of the skull at different positions using homogenization theory. Based on the Computerized Tomography （CT） images of woodpecker head, we then built complete and symmetric finite element models of woodpecker＇s skull and its internal structure and performed modal analysis and stress spectrum analysis. The numerical results show that the application of pre-tension force to the hyoid bone can increase the natural frequency of woodpecker＇s head. The first natural frequency under the pre-tension force of 25 N reaches 57 Hz, which is increased by 21.3% from the non-pre-tension state and is more than twice the working frequency of woodpecker （20 Hz 25 Hz）. On the application of impact force to the tip of beak for 0.6 ms, high magnitudes of stress component occur at around 100 Hz and 8,000 Hz, far away from both the working frequencies and the natural frequencies of woodpecker head. The large gaps among the natural, working and stress response frequencies enable the woodpecker to effectively protect its brain from the resonance injury.     

一类时滞红松生态系统的稳定性和Hopf分支（英文）

本论文研究了一类高维时滞松籽,鼠类和幼苗的红松生态系统的动力学行为,讨论了时滞对平衡点的稳定性和Hopf分支影响,指出了随着时滞的变化,平衡点由稳定变为不稳定,产生Hopf分支现象且一定条件下会出现分支周期解.数值模拟例证了分析结果.     

云南境内紫苏种下变异的研究

选取26个性状,应用不加权算术平均配对法对来自云南各地的20份紫苏试材进行了数值分类学研究。结果表明:这20份紫苏试材可分成紫苏、回回苏、耳齿紫苏、野生紫苏和白苏5个变种;并对白苏变种的设立和耳齿紫苏变种的分布进行了探讨。     

用数值分类法解析肠杆菌的裂解色谱图

用TRS80型计算机,根据数值分类原理,对5属、10种、15株肠杆菌的58张裂解气相色谱图进行解析。结果表明：同一菌株连续多次(2—9次)分析所得裂解色谱图的符合系数为88—99％,根据符合系数可以区分不同菌株。例如,变形菌标准株和临床新分离株裂解色谱图的符合系数为．77—88％,说明在相同实验条件下用标准菌株作对照,有可能用此法对临床菌株进行鉴别。用符合系数对实验菌株的鉴别结果和传统分类法所得结果基本一致,但也有例外情况。例如,我们发现3株普通变形菌和2株奇异变形菌符合系数高达77—87％,表明二者在化学组分上极为相似,而这两种菌和摩氏、雷氏变形菌裂解色谱图的符合系数却均较低,这与Brennet根据[)NA杂交相关性的结果将变形菌重新分类的建议是一致的。