黑荆树单宁浸取技术的研究

采用分段浸取新工艺是黑荆树皮单宁提取的关键技术。即以平转型连续最提为常压段、以水平渗滤（进、出）垂直釜为加压段，经生产考核，其工艺先进、运行可靠、经济合理、操作简便，产品质量稳定。     

小麦随机多交后代中抗条锈(Puccinia striiformis)性的选择

本试验用16个被认为可能具有水平抗性的小麦品种为基础材料,采用乙烯利化学杀雄或太谷核不育为手段进行随机多交,以相对抗病性综合指数(RRCI)表示抗病性强度,研究了小麦条锈病水平抗性的遗传力及人工选择下的遗传进度,结果指出:1)随机多交的后代系统中,出现了一些抗条锈性显著高于优良亲本的系统。2)抗条锈性的遗传力较高:化     

根据土壤水平一维入渗推求紫色土水动力学参数

选择3种不同质地的紫色土,通过室内土壤水平一维入渗试验,探讨简单入渗法和入渗特性法推求水动力学参数对于紫色土的适用性。结果显示,简单入渗法和入渗特性法推求的水动力学参数中,水分特征曲线准确性较高,水分扩散率和非饱和导水率准确性较差。简单入渗法推求的水分扩散率和非饱和导水率均低于实测值1～2个数量级,但推求值与实测值曲线趋势较为一致。入渗特性法推求的水分扩散率和非饱和导水率在高含水量小于实测值,在低含水量大于实测值,推求值随含水量变化趋势响应缓慢。     

机械吸捕过程中蝗虫逃逸问题的探讨

野外试验时发现,蝗虫在吸捕的过程中有逃逸现象,并且主要出现在吸头两侧,因而吸捕率的高低跟吸捕机两侧流场的分布有密切关系。从吸嘴水平面更能直观地观察出吸头两侧流场的分布情况,利用F1uent软件中的RNGk-ε湍流模型对吸嘴水平面流场进行数值模拟,并结合试验数据分析草地蝗虫吸捕机吸头两侧流场的速度分布规律,寻求解决蝗虫两侧逃选问题的最佳方法,同时证明该数值算法的可靠性。     

马铃薯群体B品系对晚疫病水平抗性遗传稳定性试验

 1997～1999年,在昆明地区对马铃薯中心提供的马铃薯群体B育种材料进行了晚疫病水平抗性遗传稳定性的田间检验。实验采用完全随机区组（RCBD）的方法,在当地晚疫病菌生理小种存在的条件下,经过3年的田间小区试验筛选,获得了Pn-01、Pn-06等表现水平抗性遗传稳定性与优良农艺性状相结合的品系,为进—步进行试验示范和大面积推广打下了基础。     

油松毛虫幼虫种群动态格局的研究

本文在以6种分布型指数测定油松毛虫(Dendrolimus tabulaeformis Tsai et Liu)幼虫种群静态空间格局的基础上,通过聚类分析,可将油松毛虫幼虫种群在上树过程中的水平格局和垂直格局聚为两类:即前期型和中后期型;其6种分布型指数可分为三类:即(1)m~*/m,C_A,I_δ;(2)入;(3)C,L。     

特殊园林道路平曲线施工放线新方法

园林道路平曲线的施工放线是一项比较繁难的工作.当园林绿地中的园路紧靠建筑物、水体等特殊环境,园路平曲线的交点和圆心都被遮挡或无法定位时,常规的园路平曲线放线方法有的不适用,有的则太复杂.针对这种特殊园路平曲线的放线工作情况,根据在工作中的探索,介绍了一种新颖的、简便的园路平曲线施工放线方法,并对此方法的操作步骤和适用范围及注意事项进行了详细的说明,旨在利用简单的工具准确高效地完成施工放线工作.     

Does forest type and vegetation patchiness influence horizontal distribution of soil Collembola in two neighbouring forest sites?

The influence of forest type and heterogeneity of understory vegetation on the horizontal distribution of soil living Collembola was studied in two neighbouring mountain forest sites—a 180-year old beech forest and a 70-year old natural spruce forest. Four homogenous patches with different understory vegetation were chosen within each forest site and sampled 12 times between 1997 and 1998. A total of 56 collembolan species were identified, 51 in the beech forest and 48 in the spruce site. Twenty-three species were rare—they were recorded with low constancy and density. Although both forest sites differed in soil type, humus form and soil chemical parameters, the species composition of their collembolan communities was quite similar (77% shared species). Nevertheless, soil collembolan communities of both forest sites were clearly delimited on both qualitative (presence–absence) and quantitative (in density of individual species) levels as well as in terms of total collembolan density. Mean collembolan density reached 26 650–44 030 ind/m² in the beech patches compared to 44 470–68 050 ind/m² found in the spruce patches. Considerably higher densities of several species in one forest site may indicate more suitable habitat. In spite of similar species composition and minor differences in qualitative parameters among different vegetation patches within one forest site, there was clear variation in density of individual species, particularly between patches with and without herb vegetation. This could reflect different microclimatic conditions, additional litter supply from herbs or indirect interactions of Collembola with their roots.     

红松的地理分布

文章考证了天然红松(Pinus koraiensis Sieb.et Zucc)及红松林在世界上的地理分布。红松主要分布在中国东北东部、俄罗斯远东南部及朝鲜半岛,日本岛的四国及本州也有零散分布。整个分布区的北界在52°N(俄罗斯);南界在33°50′N(日本);东界在140°20′E(俄罗斯);西北界在49°28′N,126°40′E(中国);西南界在41°20′N,124°E(中国)。红松林的分布以中国东北东部为中心,北到51°N(俄罗斯),南至39°N(朝鲜半岛),森林面积约50万km~2。红松林由南向北随着纬度的递增表现出组成的分异;且随着纬度的递增,红松林垂直分布的海拔高度逐渐下降。人为因素的干扰是导致红松分布范围逐渐缩小的主要因素。     

Promotion of plant growth and in situ degradation of phenol by an engineered Pseudomonas fluorescens strain in different contaminated environments

We show that Pseudomonas fluorescens strain P13, a plant growth-promoting bacterium, enhanced the growth of corn in uncontaminated soil but not in contaminated soil, perhaps because of its inability to reduce phytotoxicity. Another bacterial strain, Pseudomonas aeruginosa strain SZH16, showed in situ phenol-degrading activity and contained a plasmid loaded with a gene encoding for catechol 2, 3-dioxygenase, an important enzyme in the degradation pathway of aromatic compounds. We implanted this biodegradation ability into strain P13, using horizontal gene transfer techniques using strain SZH16 as the donor and P13 as the recipient, to generate a phenol-degrading transconjugant which obtained the effective plasmid from strain SZH16. Introduction of the transconjugant P13 strain into an artificially phenol-spiked soil promoted the growth of corn and in situ phenol degradation, and the increase in plant biomass correlated with the decrease in soil phenol content. Furthermore, the transconjugant P13 strain was also found to stimulate corn growth and reduce phenol concentration in water containing phenol and in historically contaminated field soils, indicating that the transconjugant strain could promote plant growth in both contaminated and uncontaminated environments. The transconjugant P13 strain was more efficient than either strain P13 or SZH16, and shows how plant growth-promoting bacteria which show no, or only limited, ability to degrade organic pollutants may be modified. This technique is attractive for many environmental remediation and agronomic applications.