一种树的存储结构

采用静态数组的方式给出树的一种存储结构，并给出这种存储结构下的几种常用运逄的Ｃ语言程序，这种存储结构避开了链式存储结构中链域个数不定的困难，容易用ＦｏｘＢＡＳＥ等关系型数据库来实现相应的运算，可以将二叉树与树统一起来处理。     

Tree Diversity,Carbon Storage,and Soil Nutrient in an Old‐Growth Forest at Changbai Mountain,Northeast China

Abstract

The study of plant diversity and its role in ecosystem functioning is becoming a central issue in ecology. The relationships between carbon storage and tree diversity of natural forest at small scale are still unclear. This research investigated these relationships in an old‐growth forest at Changbai Mountain, Northeast China. It was found that at small scale, tree carbon storage generally increases with increasing tree species richness, but for stands with same species richness, tree carbon storage varies dramatically. At the small scale, tree species evenness has a significantly linear relationship with nature logarithm of total tree carbon storage. The stand carbon storage of trees is mainly controlled by stand tree composition. Fraxinus mandshurica, Pinus koraiensis, Quercus mongolica, Tilia amurensis, and Acer mono contribute more than 85% of stand carbon storage of trees. Stands with similar tree composition at small scale have different soil organic carbon storage and nutrient contents. Tree species evenness has great impact on soil N content at the soil horizon less than 30 cm deep, but its impacts on C/N, P, K, and S contents are small. Tree density has a negative linear relationship with soil organic C and C∶N ratio at the soil horizon is less than 30 cm deep. The implication of our findings here for carbon sequestration in the Kyoto Protocol is also discussed.     

山地杏树栽培管理

山地杏树栽培应注意土肥水管理、整形修剪、生长期管理、病虫害防治几个关键环节,根据多年的生产实践现介绍几点经验,以供生产经营者参考。     

鹅掌楸及其在园林绿化中的应用

鹅掌楸树形端直、叶形奇特、花朵酷似郁金香,是世界著名的观赏树种,利用历史悠久。依据相关文献概述了鹅掌楸的种质类型、分布特征,总结了其文化内涵和生态习性,重点阐述了鹅掌楸在园林绿化中的应用,并对进一步开发利用进行了展望。     

城市森林对周边小气候时空格局的影响

以对城市森林生态效应的动态评价为目的,研究绿地和非绿地之间的物质交换特点与规律,描述和揭示植物群落的生态效应时空格局。试验对森林周边温度和湿度在空间和时间的梯度变化进行测试。结果表明,杨树林对其周边环境有着明显的降温和增湿效应,中午时段绿地生态场效应最高,下午测试时段对周边空气温湿度的影响与常规是逆反的。     

人参种植的经济分析

针对人参市场价格经常变化,利用最优概率控制模型对人参可持续生产的最低销售价进行经济分析。结果表明,人参生长速度越缓慢,其成本也越高,且人参市场价格对采参年龄起很大作用。若市场人参价格增幅大,最优采参年龄变小;若市场人参价格越低,则最优采参年龄越大,直到停止种植。     

Shafer气液联动执行机构异常关断事故树分析

输气管道干线截断球阀的气液联动执行机构经常出现误关断的情况,严重影响了管道的安全运行和企业效益.利用事故树定量分析的方法对异常关断事故进行了系统分析.阐述了气液联动执行机构自动关断的原理,利用事故树法详细分析了造成气液联动执行机构异常关断的各种因素,并对各个因素的影响程度进行了定量计算.对可能导致异常关断的29个基本事件进行定量分析后可知：人为失误、ESD误触发、电磁阀掉电、引压管冰堵等因素是造成气液联动执行机构误关断的重要原因.事故树分析结果与管道实际运行情况一致,表明事故树分析方法在实际生产应用中是合理有效的.     

刺槐叶蛋白提取工艺条件的初步研究

对配合使用酸法、碱法以及加热法提取刺槐叶蛋白的工艺及其工艺条件进行了研究．结果表明，刺槐叶蛋白的提取条件为：常温下料液比为１∶５，ｐＨ值为７；刺槐叶蛋白的分离条件为：温度为６０℃时，沉淀分离得到叶绿体蛋白，调节ｐＨ值为１０时分离出细胞质叶蛋白Ｉ，调节ｐＨ值为２时分离出细胞质叶蛋白质Ｉ；刺槐叶蛋白产品的干燥条件为：５０～７０℃条件下真空干燥．采用此工艺提取刺槐叶蛋白得率为４．７％，提取物中蛋白质含量为５０％～８０％，原料总氮提取率为７５．９％．     

Identification of differentially expressed genes associated with bud dormancy release in tree peony （Paeonia suffruticosa） by suppression subtractive hybridization

A subtractive cDNA library was developed to study genes associated with bud dormancy release in tree peonies.In order to identify genes that are highly expressed in buds released from dormancy,588 clones were examined by differential screening.Of these,185 clones were selected to be sequenced.A total of 37 unique sequences were obtained of which only 31 sequences have matches in the NCBI database or the Arabidopsis thaliana protein database.Semi-quantitative RT-PCR was used to confirm further the expression...     

论橡胶树气刺微割技术发展策略

简要介绍了国内外橡胶树气刺微割技术的研究现状,重点阐述了气刺微割技术的发展策略,总结了气刺微割的高产性、高效性和安全性。