桑籽皮多酚的提取工艺研究

通过单因素试验,分析了不同浸提剂、浸提剂浓度、料液比、浸提时间、浸提温度5个因素对桑籽皮多酚提取量的影响,通过正交试验,确定了桑籽皮多酚的最佳提取条件为:浸提剂(丙酮)体积分数为70%,料液比1∶35,回流温度45℃,回流时间1.5h。在此提取条件下,提取量达到1.332mg/g干籽皮,为桑籽皮多酚的工业化提取提供科学依据。     

油松毛虫越冬幼虫上树下树历期的预测

通过1984～1986年对越冬幼虫的系统调查数据,分别求得油松毛虫越冬幼虫上树历期约为51d;下树历期约为87d;上树高峰期为每年的3月28日～4月19日;下树高峰期为每年的10月份。并同时对越冬幼虫上树过程中的物候学进行了观察。     

酶制剂在农业中的应用及生物技术改良

酶是由多种氨基酸、维生素及矿物质等构成的活性蛋白质,广泛地存在于自然界。酶制剂工业是生物工程的重要组成部分,其应用非常广泛。主要从畜禽养殖、水产养殖、农药残留降解、生物农药、作为抗生素替代品和农业食品加工以及生物技术在该领域应用进行简短的综述。     

非饱和黄土中的吸力与有效应力

用压力板法和回归分析法研究了基质吸力对非饱和黄土强度性质的影响。结果表明，非饱和黄土的基质吸力与饱和度在双对数座标上呈直线关系；起始基质吸力与液限、塑性指数及粘粒含量呈线性规律变化；有效应力影响系数与其起始基质吸力呈线性关系，且随粘粒含量的增大而增大。     

同羊春毛理化特性的研究

研究结果表明,同羊春毛纤维类型数量比例较30年前有所改善.比秋毛弯曲明显整齐,弯曲率大,光泽好,摩擦效应大;17种氨基酸含量及总量也多于秋毛;伸度和强度的集中性及含硫量差于秋毛;表面结构也不及秋毛好,特别是含硫量还低于羊毛一般水平.     

火地塘林区油松林的群落类型及结构特征的研究

通过Noy－Meir分离法和PCA排序分析，把火地塘林区油松天然林的优势灌木划分为照山白、绿叶胡枝子、粉背黄栌、华北绣线菊等4个生态种组；据此将油松群系划分为3个群丛组。绿叶胡枝子—油松林和黄栌—油松林这两个群丛组多为单层同世代异龄林，其演替趋向为松栎混交林；照山白十六道木—油松林群丛组为复层多世代异龄林，是相对稳定的以油松为优势的群落。     

薄皮甜瓜杂交一代新品种"甜罐"特征特性及栽培技术

甜瓜，因其生态类型不同，分薄皮甜瓜和厚皮甜瓜两大类型。我们经过几年的科研开发，培育出薄皮甜瓜杂交一代新品种——甜罐，不仅完全保留了薄皮甜瓜的特点，又增加了抗重茬性和耐贮运性能。     

Expression of interleukin-10 activity by Epstein-Barr virus protein BCRF1

Cytokine synthesis inhibitory factor (CSIF; interleukin-10), a product of mouse TH2 T cell clones that inhibits synthesis of cytokines by mouse TH1 T cell clones, exhibits extensive sequence similarity to an uncharacterized open reading frame in the Epstein-Barr virus BCRF1. Recombinant BCRF1 protein mimics the activity of interleukin-10, suggesting that BCRF1 may have a role in the interaction of the virus with the host's immune system.     

Comparison of biological parameters between the invasive B biotype and a new defined Cv biotype of <Emphasis Type="Italic">Bemisia tabaci</Emphasis> (Hemiptera: Aleyradidae) in China

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a widely distributed and destructive agricultural pest on various host plants. The biology of two biotypes of B. tabaci: the invasive B and a new defined Cv biotype, on a range of host plants (hibiscus, laurel, poinsettia, collard, cucumber and tomato) were studied in the laboratory. Results revealed that the developmental periods of the B biotype immatures were not significantly different on the tested host plants except those between laurel and collard. The Cv biotype immatures developed significantly slower on cucumber and tomato than on the other plants. B. tabaci B biotype had the highest survivorship on collard (68.55%), and the lowest on laurel (33.24%), while the Cv biotype had the highest and lowest survivorships on laurel (61.63%) and tomato (36.74%). Host plants did not significantly affect the pre-ovipostion period regardless of biotype. The longest averaged longevity and highest fecundity of B biotype were both recorded on collard: 25.15 days and 143.0 eggs. The highest fecundity of Cv biotype was 196.49 eggs on laurel and its longest longevity was on hibiscus (19.62 days). The intrinsic rate of natural increase (r _m) of B biotype on the three vegetables were all higher than those on the three ornamentals whereas the r _m of Cv biotype on the three ornamentals were all higher that those on the three vegetables. Our research indicates that B. tabaci B and Cv biotypes have different host plant suitabilities. The three tested vegetables were more suitable for B biotype while the three tested ornamental plants were more suitable for Cv biotype. The potential mechanism for the different suitability of B and Cv biotypes on various host plants is also discussed.     

三种黑土中有机碳、氮、磷的形态分布与肥力的关系

土壤腐殖质是土壤的重要组分。土壤的许多属性都直接或间接地与腐殖质的性质有关。我们曾指出^[2]黑土的腐殖物质及其组分与土壤的物理、化学及生物化学有显著的相关性,这表明它们对氮、磷等营养物质的转化、供应及贮存起着重要的作用。