实现森林资源动态更新管理的时态GIS技术

针对森林资源数据动态更新和管理的难题以及当前几种数据更新管理技术存在的局限,提出了时态GIS技术是解决该难题的有效途径和必然趋势。     

鲁中南山地刺槐萌生更新林经济效果评价

采用企业动态经济评价方法对刺槐萌生林不同轮伐期的经济效果进行了评价；按ＮＰＶ最大、ＩＲＲ最大确定了林分经济成熟龄；通过敏感性分析确定了经济成熟龄区间。     

赤枝栲干物质生产及氮磷营养动态研究

通过对1年生赤枝栲干物质的生产及氮磷营养动态研究,结果表明:不同的生长季节1年生赤枝栲苗木的各器官生长速率有很大差异,5~7月份根、叶生长迅速,以后迅速下降,8~10月份茎、侧根生长迅速;5~7月份大多数的光合产物用于形成根与叶,少量用于充实茎与侧根的生长;净同化率出现在5~7月份,与根系的生长呈显著的正相关;不同器官在其年生长周期中,氮、磷营养动态表现不同,养分吸收与赤枝栲生长发育规律相吻合。     

长条薄片刨花加工过程动态仿真技术研究

提出了动态仿真系统的总体结构和工作流程,简要叙述了基于数字图像处理技术对长条薄片刨花进行三维重建的方法,给出了从图像坐标系到OpenGL纹理坐标系的变换公式.提出了刨花图形在三维坐标系的运动模型,给出了该模型的输入输出参数和详细计算过程,并利用该模型实现了刨花运动的位置控制.最后,结合OpenGL图形接口对系统进行了实现,仿真效果与实际系统相似度很高.     

华山松木蠹象自然种群生命表初报

通过林间定期周年跟踪观察研究,编制出了华山松木蠢象自然种群生命表,并对影响华山松木蠢象自然种群的关键阶段进行了分析,计算出华山松木蠢象自然种群趋势指数,初步对华山松木蠹象种群变化趋势进行了预测.     

杜仲皮内杜仲胶形成积累的规律

为了弄清杜仲皮含胶率的年变化、逐年变化和垂直变化的特点和规律,为杜仲皮内杜仲胶的有效利用提供科学依据,2002年,在河南省嵩县杜仲综合试验示范基地进行了杜仲皮内杜仲胶形成积累的试验.试验方法为选择典型样株法和随机取样法;杜仲皮样品采集后均进行了发汗处理;采用杜仲胶综合提取法测定含胶率.试验结果表明:杜仲树皮含胶率在一年内的变化不明显;树龄为6 a以前的树皮其含胶率随树龄的增长而提高,树龄为6 a以后的树皮其含胶率有所下降并逐步趋于稳定;同一单株杜仲树皮的含胶率和杜仲胶的密度,随其主干高度的增加总体呈上升趋势;由于杜仲皮含胶率在一年中比较稳定,因而在不同的生长季节均可以取皮利用,且以树龄为6 a的杜仲皮最为适宜;由于树皮木栓层不含杜仲胶,随着树龄增加,树皮木栓层逐步形成,树皮含胶率降低,利用率随之降低.     

Hygrothermal effect of bamboo by dynamic mechanical analysis

Dynamic properties of bamboo, Phyllostachys pubescens, with moisture content (MC) ranging from −130 to 130°C, were studied by dynamic mechanical analysis (DMA). The results showed that the hygrothermal effect on dynamic mechanical properties was negative. The storage modulus decreases with increasing temperature and MC, and glass transition temperature decreases with increasing MC. The glass transition temperature and tan delta of bamboo were 30.5°C, 0.02 and 10.61°C, 0.04, when MC was 10% and 34%, respectively. __________ Translated from Journal of Nanjing Forestry University (Natural Sciences Edition), 2006, 30(1): 65–68 [译自: 南京林业大学学报(自然科学版), 2006, 30(1): 65–68]     

Spatial distribution pattern and dynamics of the primary population in a natural Populus euphratica forest in Tarim Basin, Xinjiang, China

One 50 m × 50 m standard plot was sampled in a natural forest of Populus euphratica in Awati County, situated at the edge of the Tarim Basin, Xinjiang Uygur Autonomous Region, China. The field investigation was conducted with a contiguous grid quadrate method. By means of a test of variance/mean value ratio, aggregation intensity index and theoretical distribution models, the spatial distribution pattern and the dynamics of primary populations in P. euphratica forest were studied. The results showed that the spatial distribution pattern of two dominant arbor populations conformed to clumped distribution. The aggregation intensity of the P. euphratica population was higher than that of P. pruinosa population. The spatial distribution pattern of two companion plant populations in the shrub layer also conformed to clump type, though the aggregation intensity of Tamarix chinensis was higher. In the herb layer, the distribution patterns of Glycyrrhiza uralensis and Asparagus persicus conformed respectively to a clumped pattern and a random pattern. The results of a Taylor power method test and Iwao’s regression model also verified that both P. euphratica and P. pruinosa populations belong to a clumped pattern. Although the distribution pattern of P. pruinosa population at different development stages all belonged to a clumped distribution pattern, the aggregation intensity dropped gradually along with age development. The distribution patterns of the P. euphratica population at different development stages changed from random type to clumped type, and further to random type. The differences in spatial distribution patterns of different populations at different development stages were related not only to ecological and biological characteristics of each species in the communities in the light of competitive exclusion principle among the populations, but were also closely related to the habitats in which the species lived in. __________ Translated from Journal of Southwest Forestry College, 2007, 27(2): 1–5 [译自: 西南林学院学报]     

动态图像处理技术在农业工程中的应用

近年来图像处理技术的应用已越来越广泛，如何将动态图像处理技术应用到农业工程对农业的自动化研究具有着重要意义：本文主要讨论了动态图像处理技术及其在农业丁程中的应用概况与未来展望，并对应用中存在的问题提出了几点思考与建议。