植被恢复与重建过程中小流域降雨及水沙变化特征研究

以女儿寨小流域为研究对象，着重研究了植被恢复与重建过程中小流域系统的降雨和水沙变化特征，并对植被恢复过程中的总体减沙水平做了分析。结果表明：①受大气环流的影响，小流域年际降雨量差异较大；小流域降雨年内时间分布极为不均，集中性很大，主要集中在汛期（4-8月），但年内降雨量的月间分布趋势基本一致。②小流域迳流年际变化很大，迳流年内分配不均。迳流集中是该小流域迳流变化的一个显著特征：小流域的植被恢复与重建对洪峰的出现和洪峰流量具有明显的延缓和削减作用。③径流（Qi）主要来源于降水（Pi），二者呈明显的一元线型关系：Pi=115．7678＋2．7386Qi。④小流域的年输沙模数与年迳流量的变化规律基本一致，小流域年内产沙也高度集中，且与降水、迳流关系密切，小流域的土壤侵蚀主要由汛期的强降水引起。⑤随着小流域大面积、高标准的生态环境建设，1990年至2004年间小流域的输沙模数呈锐减之势，植被恢复与重建起到了显著的减沙效应。     

The method for designing the profile of forest roads supported by genetic algorithm

This study examines a method for designing an optimum profile of a forest road in a short matter of time. In this method, a genetic algorithm (GA) searches for points where the gradient changes and dynamic programing (DP) designs the longitudinal slope. This method can be applied to the ground heights of an actual forest road. The evaluation function of the DP assesses the total expenditure. The inverse of this function is the fitness function. Crossover and mutation are operators of an evolution simulation of a GA. They are each repeated 20 times and 420 profiles are designed and assessed, all within about 10 min. A comparison of the profile designed by the GA with that of an actual forest road shows only one section where the formation level differed substantially. Overall, both profiles seem to show a high degree of correspondence. From this result, we believe that the profile designed by the GA is best, or the one of the best. A conventional method takes about 65 h to calculate all changing points of gradients. However, by using the GA, the calculation time was reduced to about 1/389 that of the coventional method, showing that the method which uses the GA through the profile design is very useful.     

加快转产项目建设积极进行产业、产品结构调整

本文结合大兴安岭地区的实际情况,以实施“天保工程”为出发点,分析了转产项目建设面临的诸多问题,并提出了改革建议和转产项目开发建设应遵循的原则及发展方向。     

杉木细菌性叶枯病的发生及防治措施

杉木细菌性叶枯病是杉木的主要病害之一,由丁香假单胞杆菌杉木致病变种(Pseudomonas syringae pv. cunning-hamiae)引起。本文综合阐述了其发病原因和发病规律,并针对其发病特点提出了综合防治措施。     

基于Web的森林防火专家系统知识库的构建

介绍了基于森林防火专家系统的知识表示、知识获取和知识库组织的基本原理和方法，阐述了一种基于网络的知识库构建的一种新方案，使推理机的设计实现容易、知识库的维护更加灵活，实现了知识的获取功能以及网络多用户访问时的并发控制功能，克服了传统专家系统的弊端。     

People’s attitude and use of forestland: Co-evolution of forest administration in Bangladesh

This paper explores the influence over time of past policies on people’s attitudes towards the use of forestland in Bangladesh. The discourses of the attitudes of people were captured from the observed social tradition towards forest resources. Forests were reserved systematically and solely through the Forest Department. The conservation processes were not participatory, and rights and tenure were strictly controlled. People were socially excluded and alienated from the forest, and the socio-political factors stimulated negative attitudes among people. Forests were considered to be government property, and therefore managing forests was the responsibility of the government. People only used forest resources to meet their own requirements, either with formal permission or illegally. This situation continued even after the independence of Bangladesh in 1971. As a result, the forests of Bangladesh have been degraded heavily in recent decades.     

核桃叶片中氮、磷、钾含量及年动态变化规律研究

以早实核桃辽宁1号和晚实核桃礼品1号为例，分别测定早实核桃和晚实核桃叶片中不同生育期N、P、K的含量，结果表明，核桃叶片中N、P、K含量在幼龄叶中最高，整个生育期内核桃叶片中N、P、K含量总体上呈逐渐降低。早实核桃的N、P含量比同期的晚实核桃高，且差异极显著；而K含量无差异。     

换土垫层法处理地基及分析

本文作者通过多年实验,结合大庆工程实际,详细对比了四种施工方案,以及计算方法,并从中论述了如何选择最佳方案,具有指导意义。     

规则约束下水禽养殖户饲料添加剂使用意愿与行为研究——基于TPB-NAM整合模型

饲料添加剂具有提高动物免疫功能、促进动物健康生长等诸多优势。然而,滥用饲料添加剂已经对动物、人类健康和环境构成了严重的威胁,规范使用饲料添加剂是养殖户亲环境生产行为的重要表现。基于计划行为理论(TPB)和规范激活理论(NAM)的整合框架,利用江西省、湖北省和云南省水禽养殖户微观调查数据,采用结构方程模型,从个体理性和社会理性两个维度,分析在规则约束下水禽养殖户饲料添加剂的使用意愿与行为。结果表明,受访者表现出较高的规范使用饲料添加剂意愿,均值为3.764,但实际行为偏低,均值为3.216。态度、主观规范和感知行为控制均对水禽养殖户规范使用饲料添加剂意愿产生显著正向影响,但影响效应依次减弱;结果意识正向影响责任归属,而责任归属和感知收益共同激活个人规范。意愿与个人规范对水禽养殖户规范使用饲料添加剂行为均具有显著正向影响,且意愿的影响更大,但意愿与行为之间存在悖离现象。据此,提出应采取措施提升水禽养殖户规范使用饲料添加剂的积极态度,强化水禽养殖户在生产过程中所承担的环境责任,营造规范使用饲料添加剂氛围,加大政策支持和补贴力度,加强监管与督察力度等政策建议。     

渔业专题电子海图的数据结构设计

为实现渔业专题电子海图的标准化生产与应用,本文以IHO S-57国际电子海图标准为基础,通过分析海图数据模型和数据结构,以及渔业专题信息的主要内容和特点,扩展了数据集信息记录中的数据集标识字段,定义了海洋渔业专题电子海图产品的编码规则,在物标和属性类目中增加了渔业专题物标和专题属性,并添加了部分专题属性项(值),从而设计了渔业专题电子海图的数据结构。研究成果将有利于整合、共享与应用海洋渔业信息,促进渔业专题电子海图产品的研发与生产,为渔业生物资源研究与利用、渔业生产与管理以及海洋渔业经济发展等提供规范化信息服务支持。