纯电动汽车传动系参数的区间优化方法

在分析纯电动汽车传动系减速比传统优化模型的基础上,提出了区间优化方法。优化的目的是在满足电动汽车基本动力性能的前提下,求优化变量的最大可行区间,而不是一个确定的最优值。区间优化方法便于产品的系列化,可以解决传动系齿轮配齿问题。以XL2000型纯电动汽车传动系参数的优化设计为例,对所建模型进行了验证。     

对学生职业发展能力的培养初探

文章探讨了构建黄山市农机校本校特色的机电专业教育模式,发挥职业教育为科技、经济的发展服务,为学生的能力发展服务的作用,说明了在对学生职业发展能力的培养工作中的一些困难与问题。     

Spatial optimization by simulated annealing and linear programming

Forest management planning comprises selection among treatment alternatives in management units. A traditional linear programming (LP) approach may effectively account for a profit maximization objective combined with sustainability constraints, e.g. on the temporal distribution of harvest volume flows, cash‐flow, and net present value development, but it fails to account for spatial constraints, especially those associated with final felling. By applying a simulated annealing adjacency model based on net present value maximization and combined with an LP consequence computation model, it is possible to delineate optimal strategies of final felling scheduling. Evaluation is made of the trade‐off between (1) the incremental cost (determined by use of the LP model) of an optimal adjacency model solution, and (2) the potential damage cost resulting from adjacency characteristics such as windthrow and bark injuries. The decision support system may contribute significantly to reduce damage costs and may improve the reliability of forest management planning.     

东方红1004/1204拖拉机逆行器设计开发

介绍了一种采用并联功率流定轴轮系结构的拖拉机新型逆行器的设计开发,着重叙述了该型逆行器的结构特点和设计方法。     

对数学学法指导的研究

数学学法指导是数学教学理论研究和实践中的一个重要课题。结合教学实践，对数学学法指导的意义、指导的内容、指导的原则及指导的实施四个方面进行了探讨。     

职业农民的形成、培养与塑造

本文阐述了职业农民的内涵、形成的理论依据及原因，提出了培养与塑造职业农民的有效措施。     

Development of Sequence-characterized DNA Markers Linked to Temperature Insensitivity for Fruit Production in Longan (Dimocarpus longan Lour.) Cultivars

In this paper, we characterize a temperature dependence in longan (Dimocarpus longan Lour.) cultivars using the high annealing temperature random‐amplified polymorphic DNA (HAT‐RAPD) methodology. This form of genomic analysis allows a random sampling of the complete genome to provide information about phenotypic traits of interest. Using a set of 18 unique decamer primers, polymorphic bands ranging from 100 to 2500 bp were examined for 14 longan varieties from which banding patterns of interest were selected for conversion to the more reproducible and robust sequence characterized amplified region (SCAR) markers. In particular, one SCAR marker produced an electrophoresis banding pattern which could distinguish between longan varieties requiring a sustained interval at low temperatures for fruit production vs. those that do not. This band was composed of a nucleotide region 275 bases in length (DQ539047) in which the initial 90 nucleotides were >85 % identical to the 12‐oxophytodienoic acid (OPDA) reductase gene. OPDA is an immediate precursor to jasmonic acid which has been described as the ‘master switch’ for lipid‐derived environmental signalling to factors such as flowering and osmotic stress. The possible involvement of the jamonic acid signalling pathway could explain the recent success of potassium chlorate to induce off‐season flowering and fruit formation.     

轮系分析系统化的研究

本文提出了一种轮系分析的系统化方法。这种方法以轮系组成机构符号为基础,直接构造出轮系分析的数学模型,利用现有的计算机程序进行处理。它不仅能处理各种不同轮系的分析问题,还能将同一轮系不同分析问题(如运动学问题,动力学问题和功率问题)的求解一体化、程序化,可作为轮系CAD的基础。     

知识经济与大学生能力的培养

知识经济时代是以“人力资源”为根本的时代，知识经济对个人的知识和能力提出了更高的要求。面对知识经济的挑战，作为大学生不仅要努力提高自己的科学文化素质，而且更要注重综合能力的培养，只有这样才能在未来的竞争中立于不败之地。