樟子松冬季叶栖真菌群落研究

从冬季樟子松针叶分离、鉴定出2 4种真菌,其中接合菌1种、子囊菌2种、半知菌2 1种。中冠层的真菌种类最多,其它部位次之。冬季真菌群落与生长季节的种类和分离率有较大差别,优势真菌群落不同,生长季以樟子松枯梢病菌Sphaeropsissapinea为主,而冬季以Truncatella、Coniothrium等为主。     

4种灌木树种的耐荫性研究

以进入城市园林绿化树种行列的大花溲疏、荆条、蚂蚱腿子、小桐子4种喜光灌木树种为对象,研究其耐荫性能。对此4种植物进行不同程度的遮荫处理后,测定其叶片的光合作用、呼吸作用及其相关生理指标的变化,比较了遮荫对此4种喜光灌木树种所造成的一些生理变化,并对这4种喜光灌木树种耐荫性的强弱进行了综合排序。研究发现,遮荫对此4种灌木树种的光合特性等生理指标都有不同程度的影响,其耐荫性的综合排序结果为:蚂蚱腿子的耐荫性最强,大花溲疏次之,再次是小桐子,而荆条的耐荫性最弱。     

Recovery of canopy trees and root collar sprout growth in response to changes in the condition of the parent tree after a fire in a cool-temperate forest

The relationship between the recovery of canopy trees after fire and root collar sprout dynamics was investigated during 1998–2000 in a secondary cool-temperate broad-leaved forest consisting of Quercus mongolica var. grosseserrata and Betula platyphylla var. japonica trees, in northern Hokkaido, Japan, which burned in April 1998. All of the Betula trees that were severely damaged, two-thirds of those slightly damaged, and half of those intact in 1998, died within three growing seasons after the fire. By contrast, half of the Quercus trees that were slightly damaged and half of those severely damaged recovered their foliage, and no slightly damaged or intact trees died during the three growing seasons after the fire. Many Betula trees developed several fruiting bodies of wood-destroying fungi on their stems, irrespective of damage severity. Fungi also infected some of the surviving Quercus, although the crowns tended to recover. Although many sprouting Betula were observed in 1998, the number of sprouts declined rapidly over the study period. Multiple regression analyses showed that the survival and growth of Betula sprouts were positively influenced by the number of sprouts in 1998, damage severity in 1998, and the degree of recover or decline during the study period, and were negatively influenced by parent tree size. On the other hand, a few sprouts of Quercus remained alive. Quercus remained dominant and the dominance of Betula was rapidly reduced after the fire. However, many Betula sprouts remained alive. Stand structure will change drastically for the time being.     

思茅松天然次生林林分生长模型的研究

从影响林分生长的立地、年龄、密度3个主要因素出发，利用优势高生长与密度关系相对较小这一特点，在不同立地条件、林分密度、林龄的思茅松天然次生林中设立98块标准地，依据标准地测定的数据，以Logistic和Richards理论方程为基本模型，在模型中引入立地质量，林分密度，林分年龄构建了思茅松天然次生林林分的生长模型系统。研究表明Logistic模型不仅具有良好的预测性，而且具有广泛的适用性，用它作为描述思茅松天然次生林林分生长的基本模型，能很好地表达其生长过程。     

中国紫堇属植物新纪录—芍叶紫堇

内蒙古额尔古纳国家级自然保护区野外监测时发现一紫堇属(Corydalis DC.)植物,拍照定点采集标本并室内解剖观察,鉴定为芍叶紫堇(Corydalis paeonifolia(Steph.)Pers.)。花淡紫色,长2.0-2.8 cm;花序1~3分枝,每个花序7~10朵花;复叶,薄纸质,小叶不对称;根绳索状,外皮易脱落;苞片戟形;花药黄色,雌蕊1,柱头近5裂。此次制作的凭证标本(20170714001)保存于内蒙古额尔古纳国家级自然保护区标本室。     

樟子松遗传改良研究概述

对樟子松遗传改良20多年的研究工作进行了全面总结，在樟子松种源选择与区划、樟子松形态类型、种子园及母树林营建技术、子代测定与家系选择及综合选育遗传增益等方面的研究，取得了可喜成果，为樟子松生产提供了有益的参考。     

毛竹笋体生长发育过程中内源激素的动态分析

本文应用生物鉴定和高效液相色谱（HPLC）技术，分析了毛竹（Phyllostachyshetero－cyclavar．pubescens）笋体顶部从3月8日至5月14日内源激素（IAA、GA3、ABA）活性及含量的动态变化。结果表明激素含量动态与相应笋体生长是有规律的变化。ABA仅在冬笋期（3月8日）和高生长基本停止期（5月14日）检测到，含量分别为0．28μg／G．F．W．和0．092μg／G．F．WIAA、GA3含量随笋体生长发育而同步增加，至4月25日均同时达最大。分别为3．6μg／G．F．W．和11．4μg／G．F．W。之后又下降，至5月14日，IAA、GA3含量仅分别为0.85μg／G．FW．和4．2μg／GF．W。笋体不同部位IAA、GA3含量都是从顶部到基部递减，而ABA的含量变化趋势则相反。竹笋中IAA、GA3不但合成能力强．而且较一般高等植物含量高10倍左右，竹笋中有多种GA类存在，且GA3类的转化参与竹笋生长。竹笋生长极迅速的原因可能是：内源激素中IAA、GA3含量极高，ABA极少；高浓度的IAA形成养分壑保证养分的供应；IAA、GA3在空间、时间上有机协同。     

Two lignan rhamnosides from birch leaves

The extractives of shirakamba (Betula platyphylla Sukatchev var.japonica Hara) leaves were investigated. Two lignan glycosides were isolated, and their structures were elucidated to be 1-(4-hydroxy-3-methoxyphenyl)-2-[1-(3--l-rhamnopyranosyloxypropyl)-3-hydroxyphenoxy]-1,3-propanediol (I) and a new 2,3-dihydro-2-arylbenzofuran configuration neolignan,cis-2,3-dihydro-2-(4--l-rhamnopyranosyloxy-3-methoxyphenyl)-3-hydroxymethyl-7-hydroxy-5-benzofuranpropanol (II). These neolignan rhamnosides were newly found in shirakamba.     

ON THE PROBLEM OF SWITCHING CONDITIONS FOR A KIND OF MINIMUM-TIME CONTROL SYSTEMS

The paper provides a detailed study of switching conditions of minimum-time control systems based on application in engineering. By analysis in theory and experiment, the authors deduce a set of switching conditions with state and control variabes inequality constraints, the variations of system parameters and the time-delay of computer in real time control. As an example, a DC motor speed control system is considered. By digital simulation and physical experiments,these conditions proved to be correct. The method in this paper is also suitable for other control systems using compound control algorithm.     

解淀粉芽孢杆菌菌剂对雪菜生长和土壤氧化亚氮排放的影响

由于化肥的过度使用对环境的不利影响,微生物肥料的研究得到了广泛关注。实验利用甘薯淀粉废水培养解淀粉芽孢杆菌并将其作为微生物肥料用于雪菜种植。通过盆栽实验考察了尿素(CN)、解淀粉芽孢杆菌菌液(BF)、解淀粉芽孢杆菌灭活菌液(BI)、甘薯淀粉废水(SW)、尿素结合微生物肥料(BC)对蔬菜产量、NO3-、NO2-含量,以及土壤性状,N2O排放的影响。实验表明:BC和CN在蔬菜产量方面比CK提高了5倍。BF和SW对蔬菜产量影响不显著。半量氮肥配合菌肥处理(BCL)表现出与CN相近的增产效果,而蔬菜NO3-含量同CN处理相比下降了16.4%~73.6%,土壤NO3-含量降低了22%~29%,降低了土壤中氮淋溶风险;土壤N2O平均排放通量(FLUX30)较CN处理降低了58.3%~73.1%。综上,利用淀粉废水培养解淀粉芽孢杆菌不仅可以资源化利用废水,并且其产物可作为一种绿色肥料应用于蔬菜种植,为淀粉废水资源化利用和农田温室气体减排提供了一个新思路。