1.The quantitative study of the experimental population of Culex pipiens pallens has been made with the method of approximate calculation of Leslie Birch. The experimental results were as follows:the innate increasing capacity( r m ) was 0.1131; the net reproductive rate( R o ) was 80.4844;
采用Leslie?Birch近似计算法，对淡色库蚊实验种群进行了定量研究，求出了该蚊的内禀增长能力rm为0．1131d，净增殖率Ro为80．4844，平均世代周期T为38．7873d，有限增殖率λ为1．1198，揭示了该蚊的数量变动规律。
2.Soil incubation experiments were conducted in lab to delineate the effect of soil temperature and soil water content on soil respirations in broad-leaved/Korean pine forest(mountain dark brown forest soil),dark coniferous forest(mountain brown coniferous forest soil)and ermans birch forest(mountain soddy forest soil)in Changbai Mountain in September 2001.The soil water content was adjusted to five different levels(9％,21％,30％,37％ and 43％)by adding certain amount of water into the soil cylinders,and the soil sample was incubated at 0,5,15,25 and 35 ℃ for 24 h The results indicated that in broad-leaved/Korean pine forest the soil respiration rate was positively correlated to soil temperature from 0 to 35 ℃.Soil respiration rate increased with increase of soil water content within the limits of 21％ to 37％,while it decreased with soil water content when water content was over the range.The result suggested the interactive effects of temperature and water content on soil respiration.There were significant differences in soil respiration among the various forest types.The soil respiration rate was highest in broad-leaved/Korean pine forest,middle in ermans birch forest and the lowest in dark coniferous forest.The optimal soil temperature and soil water content for soil respiration was 35℃ and 37％ in broad-leaved/Korean pine forest,25 ℃ and 21％ in dark coniferous forest,and 35 ℃ and 37％ in ermans birch forest.Because the forests of broad-leaved/Korean pine,dark coniferous and ermans birch are distributed at different altitudes,the soil temperature had 4-5 ℃ variation in different forest types during the same period.Thus,the soil respiration rates measured in brown pine mountain soil were lower than those in dark brown forest and those measured in mountain grass forest soil were higher than those in brown pine mountain soil.
为了研究土壤温度和土壤含水量对阔叶红松林(山地暗棕壤)、云冷杉暗针叶林(山地棕针叶林土壤)和岳桦林(生草森林土)的土壤呼吸的影响,于2001年9月在长白山进行了土壤实验.利用增加土壤样柱的含水量,将土壤含水量分为9％,、21％、30％、37％和43％5个等级,土壤样品分别在0、5、15、25和35℃的温度下保持24小时.阔叶红松林土壤在0(35℃范围内,土壤呼吸速率与温度呈正相关.在一定的含水量范围内(21％(37％),土壤呼吸随含水量的增加而升高,当含水量超出该范围,土壤呼吸速率则随含水量的变化而降低.土壤温度和水分对土壤呼吸作用存在明显的交互作用.不同森林类型土壤呼吸作用强弱存在显著差异,大小顺序为阔叶红松林>岳桦林>云冷杉暗针叶林.红松阔叶林土壤呼吸作用的最佳条件是土壤温度35℃,含水量37％;云冷杉暗针叶林下的山地棕色针叶土壤呼吸作用的最佳条件是25℃,21％;岳桦林土壤呼吸作用的最佳条件是35℃,含水量37％.但是,由于长白山阔叶红松林,云冷杉林和岳桦林处在不同的海拔带上,同期不同森林类型土壤温度各不相同,相差4~5℃,所以野外所测的同期的山地棕色针叶林土呼吸速率应低于暗棕色森林土呼吸速率,山地生草森林土呼吸速率应高于山地棕色针叶林土的呼吸速率.图2表1参25.
3.Shuaiqi Company can supply the following products in large quantity throughout the year as: (1) Species of the Northeast:manchurian-tree wood, oak solid wood, birch, basswood, mongolian scotch pine, Korean pine, cembra pine, white beech, elm wood, and aspen wood, etc. (2) Species of Yuannan: Birch wood, white birch, rubber wood timber, gold teak veneered wood, etc.(3) Rotary species: peach, Okoume, basswood, birch wood, poplar, padauk wood, etc.(4) Imported species: red rubber, cherry, black Walnut, Thailand teak, sapelli, ayous, etc.
帅琦公司可以为您常年大量供货：（1）东北品种：水曲柳、柞木、桦木、椴木、樟子松、红松、节松、楸木、榆木、杨木等天然树种；（2）云南品种：西南桦、白木莲、白桦、橡胶木、金丝柚、黄云香、山香果树瘤等天然树种；（3）旋切品种：桃花芯、奥谷曼、柳桉、山桂花、大白木、黄云香、椴木、桦木、白杨木、花梨木等；（4）进口品种：红橡、樱桃、黑胡桃、沙贝利、泰柚、黑檀、花梨、铁刀、艳阳花等天然树种。
4.The difference between highest and lowest monthly mean values is about 72% in Broad-leaved Korean Pine forest,73% in Asian white birch forest,26% in David poplar forest,56% in Spruce-fir forest,and 144% in Ermans Birch forest.
不同群落细根现存量月动态变化也有较大差异,月均最高最低相差阔叶红松林约为72%、白桦林近73%、山杨林26%、云冷杉林56%、岳桦林144%。
5.birch of western United States resembling the paper birch but having brownish bark.
美国西部的一种桦树,类似于纸皮桦,但是树皮棕色。
6.a smooth leather tanned with willow, birch, or oak, and scented on the flesh side with birch oil.
一种光滑的皮革，经过柳木、桦木、橡木硝制，内壁用桦树油加上香味。
7.Starting with the manufacturing technique and classification of the birch hark wares of Elunchun Nationality, this article expounded the connation and value of the birch hark culture.
摘要本文从鄂伦春族桦树皮文化的制作工艺和分类入手，论述了桦树皮文化的内涵及价值。
8.A fragrance introduced by the sensuality of birch wood, bergamot and bitter orange; juniper wood and artemisia mingle with cardamom, underlined by cold spices for the middle note; the base note finally emerges, sensually, releasing oak, cedarwood and vetiver, as an echo of the birch wood.
前香味以桦木、香柠檬和苦柑橘为主，洋溢着感性的芬芳；中段以刺柏木、苦艾与小豆蔻为主调，搭配温凉的辛香；后段则由橡木、雪松与岩兰草所组成，逐渐散发出感性的馥郁，回应前段的桦木香。
9.He experiments with a vast range of woods, including Baltic birch and black walnut.
他还尝试用各种木材来制作，比如桦木和黑胡桃木等。
