烟草叶面积不同测定方法的比较研究

研究了烟草叶面积的6种测定方法，并对其测定结果进行了对比分析。结果表明：叶面积指数法与准确的测定方法间测定结果差异不显著，叶面积指数法可以用于烟草叶面积的实际测定和计算。     

Virus Location and Lymphocyte Apoptosis in Lymph Nodes of Piglets Infected with PCV-2

The present study has been performed to understand the location of the virus, type of apoptotic cells, and their relation to lymph nodes of piglets infected with porcine circovirus type Ⅱ （PCV-2）. Nine 32-day-old conventional piglets free of infection with PCV-2 were used, and distributed into three groups： control group （n = 3）, piglets inoculated with PCV-2 alone （PCV-2, n = 3）, and PCV-2 inoculated and KLH immunostimulated group （PCV-2 ＋ KLH, n = 3）. Superficial inguinal lymph nodes from all piglets were collected for histological examination after 32 days postinoculation, and immunohistochemistry for PCV-2 detection. Location of apoptotic cells was detected with TdT-mediated dUTP nick end labeling （TUNEL） and cell cycle, and the apoptotic rates were measured by flow cytometry. The characteristic histopathological lesions of the piglets in PCV-2 and PCV-2 ＋ KLH were lymphocyte depletions in the cortex and paracortex of the lymph nodes, epithelioid-like macrophage infiltration, and intracytoplasmic inclusion bodies presented in epithelioid-like macrophages. PCV-2 was mainly found in epithelioid-like macrophages by immunohistochemistry. In the lymph nodes, lymphocytes presented higher apoptotic rates in the cortex by TUNEL, special B-cell areas, and similar apoptotic cells were found in this compartment in the control. The apoptotic rates of the lymph nodes were 0.41, 3.34, and 4.88% in the control, PCV-2, and PCV-2 ＋ KLH groups by flow cytometry, respectively. The apoptotic rates of lymph nodes for PCV-2 and PCV-2 ＋ KLH piglets were significantly higher than those for the control group （P〈0.05 and P〈0.01）. The proliferation index （PI） was 0.17_＋0.01, 0.12_＋0.01 and 0.12_＋0.04 in the control, PCV-2, and PCV-2 ＋ KLH group, the PI of the control group was higher than that of the other groups, but without the statistical difference. PCV-2 can induce lymphocyte depletion in lymph nodes of piglets by blocking cell proliferation and promoting apoptosis. This is one o     

不同产地苹果渣营养成分差异性分析研究与评价

为评价我国不同产地苹果渣营养成分组成和含量的差异,对我国9个省14个地区苹果渣的营养成分进行检测,衡量营养成分受产地影响的大小。结果表明,不同产地苹果渣中水分含量范围为3.49%~14.21%;灰分为1.20%~3.35%;蛋白为4.93%~8.78%;脂肪为3.73%~6.99%;膳食纤维为60.21%~69.59%;不可溶性膳食纤维为49.24%~61.03%;可溶性膳食纤维为6.72%~13.58%;还原糖为1.20%~16.07%;淀粉为0.48%~5.29%;多酚为2.07~6.28 g·kg-1。不同产地的苹果渣营养成分存在差异,其中水分、还原糖、淀粉含量变异系数较大,而蛋白、脂肪、膳食纤维、不可溶性膳食纤维、可溶性膳食纤维含量变异系数相对较小。本研究依据不同产地苹果渣营养成分组成和含量差异,对其开发利用提出了合理建议。     

一类半线性变系数抛物型方程的二阶差分格式

本文对一类半线性变系数抛物型方程初边值问题建立了一个二阶差分格式,证明了差分格式解的存在唯一性、关于初值的无条件稳定性和在L∞范数下阶数为O(2τ+h2)的收敛性,最后给出的数值算例验证了理论结果。     

企业文化差异性对企业并购的影响

随着时代迈入21世纪，企业并购频频发生，并且其规模有着越来越大的趋势。然而并购前大量一致被看好的案例，在并购发生后，结果都差强人意。其根本原因在于人们习惯于从企业硬件方面来看问题，而忽略了企业文化（软件）的差异性。本文通过分析企业文化差异性对企业并购的影响，最后提出规避企业文化差异性对并购不利影响的几点建议。     

甘肃省土地资源可持续利用定量评价

从资源、环境、经济和社会4方面构建土地资源可持续利用评价指标模型,并选择23个参评因子,对甘肃省土地资源可持续利用空间差异进行定量分析,发现甘肃省土地资源可持续利用水平有明显的空间差异,认为各地在资源开发、经济发展、社会进步和环境保护方面有待进一步协调。     

中国南方竹区4种竹笋夜蛾的形态比较研究

竹笋夜蛾是我国重要的一类竹子笋期害虫,种类多,形态相似,难以区分,为更为准确地识别主要竹笋夜蛾的种类,本研究通过野外取样和室内饲养,对竹笋基夜蛾Kumasia kumaso、竹笋禾夜蛾Oligia vulgaris、笋连秀夜蛾Apamea repetita conjuncta及竹笋秀夜蛾Apamea apameoides 4种竹笋夜蛾卵、幼虫趾钩、臀棘及成虫翅脉和生殖器形态进行了观察和比较。结果表明,竹笋基夜蛾在卵形态、幼虫体色和雌雄生殖器形态上与其他3种竹笋夜蛾形态差异明显,其余3种夜蛾幼虫体表背线和亚背线形态有差异,趾钩、臀棘、翅脉和雌、雄外生殖器形态差异不显著。本研究明确了我国南方竹区4种竹笋夜蛾的形态差异,为竹笋夜蛾的精准防控提供了参考。     

与年龄无关的马尾松优势高生长模型研究

目的 通过构建与年龄无关的理论生长方程,用于预测在年龄未知或不是有效影响因子时的马尾松人工林优势高。 方法 基于常用的Hossfeld IV、Lundqvist-Kolf、Richards、Schumacher等4个理论生长方程,推导其不含年龄因子的差分形式,构建与地位指数相关的可变参数、与年龄无关的马尾松优势高模型。 结果 在4种基础理论生长模型中,以Richards模型建立的与年龄有关的马尾松人工林优势高生长模型效果最优。与年龄无关模型的拟合精度均高于与年龄有关模型的拟合精度,Richards模型和Korf模型差分形式建立的与年龄无关的马尾松人工林优势高生长模型效果最优。在引入地位指数时,Hossfeld模型的拟合精度提高效果最明显,且以设定k为可变参数时,建立与年龄无关的马尾松人工林优势高生长模型效果最优。 结论 在异龄林或年龄难以获得时,与年龄无关的理论生长模型能够预测优势高的生长,将地位指数与可变参数建立函数关系代入模型拟合后,模型精度提高,可以更好地应用于预测林分生长。     

松木防蓝变和脱色处理技术的研究

解决松木蓝变问题已成为松材加工高档用材的基础和提高松材商品附加值的关键。通过探索性试验和正交试验以及(?)差的分析比较,得到防蓝变的优配方为:0.75％A1 0.50％A3 0.10％B。此配方在试验所观察的10周内防治效力达到了100％。同时,对松木蓝变色斑的脱除研究表明,在浓度5％的C药剂中加入D药剂,调节其溶液的pH值为10左右,加热到50-60℃对板材进行处理可有效脱除蓝变色斑。     

Seasonal variation in pigmentation and anthocyanidin phenetics in commercial Eustoma flowers

The seasonal change in petal color and pigmentation of 29 commercial Eustoma cultivars was studied. The flowers are basically divided into four groups according to the major anthocyanidin phenotype in association with petal coloration, i.e., delphinidin (Dp)-based (purple flower), cyanidin (Cy)-based (reddish purple flower), pelargonidin (Pg)-based (pink flower), and none (white flower) groups. The constitution of petal anthocyanidins was not changed by forcing treatment in most of the flowers. Lightness (L^*) and chroma (C^*, color saturation) showed a change along with the increase/decrease of hue angle difference (ΔH^*), thus simultaneously the chromatic tonalities tended to move to redder and bluer, respectively. Floral pigment clustering described two flower groups in a dendrogram, based on anthocyanidin constitutions as phenetic markers, which are apparently the Dp- and Pg-based phenotypes of anthocyanidin syntheses. The Cy-based flowers made a subcluster with the Pg-based flowers, indicating a close relationship in the biosynthesis of the two anthocyanidins, and suggesting the Dp- and Pg-syntheses complement one another.