立卧式浸渍干燥机的研究设计

分析了立式、卧式浸渍干燥机的优缺点，并在此基础上设计出了立卧式浸渍干燥机，该机能生产出符合覆面竹胶合模板表面性能的胶膜纸。     

Effects of changes in land use and land cover on sediment discharge of runoff in a typical watershed in the hill and gully loess region of northwest China

Land use plays a much more important role than other factors, such as climate, soil properties, topographic features, vegetation coverage, human activities and others, in affecting soil erosion and sediment discharge. In order to understand the effects of changes in land use on sediment discharge and to provide a theoretical basis for land use planning, management and ecological restoration, we used the controlled Qiaozidong watershed and the uncontrolled Qiaozixi watershed in the third sub-region of the Loess Plateau as examples and analyzed the effects of land use and land cover on the discharge of sediments. The results show that the impact of land use and land cover on the annual amount of sediment discharge is significant. Compared with the uncontrolled watershed during similar periods, the amount of sediment discharged from the controlled watershed was reduced by 44%, 75% and 86%, respectively, in wet, normal and dry years. In the controlled watershed, compared with the period from 1986 to 1994, the amount of sediments discharged was less during the period from 1995 to 2004. The impact of land use and land cover on sediment discharge demonstrated characteristics of seasonal fluctuation. The effects of sediment reduction in the controlled watershed were greater than those in the uncontrolled watershed in May and September. In the controlled watershed, the reduction effect coincided with the distribution of rainfall. The amount of discharged flood sediments is closely correlated with rainfall, rainfall intensity in a 60 min period and the volume of flood. The rainstorm-runoff process and the rainstorm-sediment discharge process demonstrate that land cover has a strong regulatory and control function in the flood process and sediment discharge in rainstorms. For the controlled watershed, given the same precipitation frequency distribution, the average amount of sediment discharged during the land use period from 1995 to 2004 was less than that during the earlier land use period from 1986 to 1994 under every recurrent period. __________ Translated from Journal of Beijing Forestry University, 2007, 29(6): 115–122 [译自: 北京林业大学学报]     

中国南五味子属植物的种质资源及开发利用

南五味子属是现存双子叶植物中的原始类群,全世界有28种,呈东亚——北美间断分布,主产亚洲东南部至东部,我国产10种,是南五味子属的自然分布中心,该属植物对于理解被子植物的起源、演化、迁移和植物区系等方面的研究都有重要的科学意义.系统介绍了南五味子属植物分类、种质资源、地理分布及开发利用等4个热点问题.将南五味子属植物应用于药物开发、食品开发和园林造景等方面有十分广阔的前景,但目前关于南五味子属的栽培、繁殖及应用研究十分匮乏.最后,对其合理化开发利用提出了加大资源保护力度,加强引种驯化及加强综合开发等建议.     

一类有十一个赤道环的七次多项式系统

研究了一类七次系统无穷远点的中心条件与赤道极限环分支问题.通过将实系统转化为复系统研究,给出了计算无穷远点奇点量的递推公式,并在计算机上用Mathematica推导出该系统无穷远点前13个奇点量,进一步导出了无穷远点成为中心的条件和十三阶细焦点的条件,在此基础上首次得到了七次系统无穷远点分支出11个极限环的一个实例.     

柞树林直径分布模拟研究

柞树林是我国东北地区分布较广的次生林,对它的研究具有重要意义。分析了两种类型柞树林的直径结构特征,并分别利用4种分布函数即正态分布、Weibull分布、Gamma分布以及对数正态分布对两种类型柞树林的直径分布进行了拟合,同时用卡方统计量对4种分布进行了检验,拟合结果和检验结果表明:在4个拟合分布函数中,Gamma分布用于拟合两种类型柞树林的直径分布效果更好。     

华东植物区木兰科植物的地理分布

对华东植物区木兰科植物的地理分布状况进行了整理,分析了不同属种在本区的分布范围及分布规律,并探 讨了华东植物区的木兰科植物的来源、特有和分化以及和其它植物区的联系.华东植物区木兰科植物分布不均衡,南部分布的种类较多,且以常绿种类为主,向北的种类逐步减少,并以落叶树种居多,和本区植被地带分布相一致.本区还存在一个特有现象中心和一个次级分化中心.     

Predicting the distributions of suitable habitat for three larch species under climate warming in Northeastern China

The larch (Larix) genus is the most important species group in the forest ecosystems in Northeastern China, occupying about 25% of the forest areas. The high tolerance to coldness and relatively fast growth rate make this genus the main species group for forestation. According to the predictions of the global circulation model CGCM3, temperature could rise by 2–4 °C over the next 100 years. Few studies have been conducted on the response of larch species to climate warming in Northeastern China. Such studies are becoming increasingly needed due to the economic and ecological significance of this genus. This paper studies the potential distribution ranges of three larch species under the current and the warming climate conditions. A new classification and regression tree technique, Random Forest, was used to investigate the potential distributions of three larch species, based on 18 environmental variables which reflect the climate, topography and soil conditions of Northeastern China. The results showed that the biological coldness index (BCI) is the most important factor for Dahurian larch, annual precipitation (AP) is the most important factor for Korean larch and elevation (DEM) is the most important factor for Prince Rupprecht larch.     

10kV、630kvA及以下配电变压器保护配置方式的合理选择

10kV配电变压器的保护配置主要有断路器、负荷开关或负荷开关加熔断器等。对10kV环网供电单元和终端用户10 kV配电变压器采用断路器、负荷开关加熔断器组合的保护配置方式进行技术、经济比较,供配电网的设计和运行管理部门参考。     

卡拉麦里山有蹄类自然保护区蒙古野驴的数量与分布

2005年9—10月在新疆北部卡拉麦里山有蹄类自然保护区调查了蒙古野驴的数量和分布。调查过程共设置样线8条,总长640.90km,共发现野驴53群1 039头,平均群体大小为(11.90±7.84)头/群,最大群为189只,2～10头的小群遇见率最高,占总群体数的43.40%。采用实体观测垂距法计算,蒙古野驴的平均密度为(1.231±0.196)头/km~2。结合有效分布面积,可计算得出保护区内约有野驴(5 234±834)头。调查显示蒙古野驴主要分布于保护区北部和中部食物和水源条件较好的区域。     

通道万佛山丹霞地貌森林植被调查研究

采用线路调查和样地调查相结合的方法,对通道县万佛山丹霞地貌区的森林植被进行了详细的调查研究。植物种类多,本区有维管束野生植物189科602属1297种（含变种）;古老残遗性强,特有种类多,区系成分具有明显热带特征,而且密集度很高;珍稀濒危种类多,兰科植物种类多等特点。