木工气力吸尘装置设计程序的编制

本文在分析木工气力吸尘装置的结构单元的基础上,根据有关计算公式,编制了用计算机辅助设计普通型气力吸尘装置的应用程序,它不仅能大大节约设计计算的时间,而且可以提高设计的精度,为进行此类工程设计提供了方便。     

用线性规划方法优化景谷县"山区综合开发‘十五''规划"

景谷县“山区综合开发‘十五’规划”提出 10个主要建设项目 ,以此为基础 ,利用线性规划方法 ,对此10个项目进行优化配置。在不增加投资 ,不增加年生产经费的前提下 ,找出年均产值和年均净收益有明显增长的最佳方案 :停建葡萄种植基地、削减咖啡、柴胶寄主树改造两个建设项目规模 ,保持橡胶、蔬菜、小耳猪、沼气、杨梅基地 5个项目的建设规模 ,适当增加茶叶和芒果基地两个项目的建设规模。     

用动态规划方法确定华北落叶松最优轮伐期及最佳林分密度

本文采用Richards函数的修正式拟合林分胸高断面积生长方程,并考虑株数密度对断面积生长的影响;用每公顷胸高断面积和每公顷株数作为状态变量,用森林纯收益作为指标函数,建立了离散确定性动态规划模型,确定了塞罕坝林场华北落叶松人工林的最优轮伐期,并为各地位指数及不同年龄、不同初始状态的林分提供了确定最适经营密度的方法。     

基于合同电量的梯级水电站优化调度研究

针对电力市场中买卖双方通过签订远期合同进行交易的市场交易类型,结合水库优化调度理论与方法,建立物理合同和金融合同下的梯级水库优化模型,并以清江梯级水电站为例进行应用研究,验证了模型的合理性与有效性,为今后市场环境下水电商针对不同的合同签订方式做出决策提供了参考和依据.     

应用Eclipse 3.5编辑运行jQuery程序的方法

介绍了Web前台开发技术jQuery在Eclipse3.5下的编程环境设置和编辑与运行jQuery程序的方法。     

The fate of freshly added phosphorus in representative agricultural soils

Surface and subsurface samples from 26 representative agricultural soils (13 Entisols, 9 Alfisols and 4 Vertisols) from Central and South Western Greece were equilibrated for a week with P solutions ranging from zero to 800 mg P kg^?1 soil. The Freundlich and in the cases of high fine carbonate content (> 6%) the linear equations described the sorption isotherms in a satisfactory way. Sequential fractionation indicated that a 0.1 M NaOH plus 1 M NaCl + 0.3 M Na-citrate + 1 M NaHCO₃ (buffer) solution extracted more than 60% of the P retained by Entisols containing low to medium fine carbonates and by Vertisols, and less than 60% by Entisols with a high fine carbonate content. In all Entisols, this percentage decreased significantly at P additions higher than 150 mg kg^?1. The opposite was observed in Vertisols, in which this fraction was the most important part of the retained P up to the maximum P addition. In contrast, in Alfisols this fraction reached 100%, but in the case of high Bray-P (> 50 ppm) it was more than 100% of the retained P. The second fraction extracted with the 0.3 M Na-citrate + 1 M NaHCO₃ buffer plus Na-dithionite was found to be much smaller than the first fraction, increasing with P additions in absolute amounts but remaining constant as a percentage of the retained P, ranging from 15–35% among the studied samples. The third fraction obtained with 1 M HCl solution showed a peculiar behaviour. It was close to zero of the retained P in samples containing carbonates (Entisols and Vertisols) at P additions up to 300 mg kg^?1 soil, but increased significantly at higher P additions and almost doubled in Entisols. Finally, the P fraction obtained after seven successive extractions with 0.01 M CaCl₂, correlated well by a polynomial of 2nd degree equation with NaOH+CB-P and linearly with Olsen-P and Bray-P.     

Modeling the impact of HIV/AIDS upon food security of diverse rural households in Western Kenya

Although the impact of HIV/AIDS upon rural smallholder food security in sub-Saharan Africa is understood to be severe and multi-faceted, few empirical studies have undertaken the task of identifying upon which types of households the impact is most severe. In order to understand and examine the impact of HIV/AIDS upon food security of rural households in Western Kenya, an ethnographic linear programming model was developed to simulate household responses to an adult household member contracting HIV. Three male-headed households and one female-headed household with dynamic compositions and representative of the diversity of households in Amukura, Teso District, were simulated. Findings highlighted that the initial stage of HIV infection was the most devastating time for households as HIV infection of an adult member was a shock for which households were ill-prepared. Results further indicated that household food insecurity was more severe in Amukura when an adult female contracted HIV than when an adult male contracted HIV. In particular, household food availability and utilization were more severely reduced when an adult female contracted HIV. Reductions in available female labor critically undermined household food production to a greater degree than reductions in available male labor. This was compounded by the gender division of labor on certain agricultural tasks as well as the inability of adult males to rapidly change their agricultural activities due to labor requirements to maintain long-term investments in sugar cane and animal production. Food access was also reduced under both HIV+ models and was linked to both declining food availability and end-of-year cash. The severity of impact of HIV upon food access depended upon resources available to an individual household. Impacts of HIV upon household agricultural activities in Amukura are therefore dynamic, multiple and diverse. If interventions to counter the impact of HIV on a community are to be successful, there is an urgent need for organizations and governments to adopt holistic approaches to development which appreciate the complexity and diversity of livelihood systems.     

Combining market and traditional values in tribal forestry using interactive forest decision synthesis (INFODS)

Forestry joint production choices require clear relative values for multiple, and often conflicting, management objectives. Optimization is most difficult where values of forest attributes are: intangible, non-market, or sensitive. When most mathematical programming models are adapted for non-commensurable objectives, there is little guarantee that vague relative preference sets are met. We demonstrate how an iterative multiple objective programming approach finds preferred joint solutions in a Native American tribal forestry case where marketable outputs are managed in the context of traditional culturally based forest values. Without a priori specification of traditional tribal cultural values, conducting a series of feedback processes does appear to identify more preferable solutions than other types of multiple-objective models that do not use feedback.     

考虑鲜度竞争的生鲜农产品双渠道供应链保鲜方式选择的研究

物流保鲜是影响农产品质量的重要因素之一。考虑消费者的鲜度敏感性和渠道偏好,构建了自营保鲜和保鲜外包两种情形下,生产商、零售商和冷链物流服务商的序贯博弈模型,求解出最优定价和鲜度水平。借助数值试验,分析了保鲜成本和保鲜服务价格对生产商和零售商的保鲜方式选择及渠道鲜度差异的影响。结果表明：无论生产商还是零售商,选择保鲜外包的农产品鲜度与保鲜成本呈负相关、与保鲜价格呈正相关。零售商总是选择自己保鲜,但是保鲜水平（或保鲜价格）高于（或低于）一定阈值后,生产商会选择保鲜外包,此时线下渠道与线上渠道的鲜度趋近。若保鲜水平较低,冷链物流服务商倾向于承接零售商保鲜外包,反之承接生产商保鲜外包,但是承接生产商保鲜外包的供应链系统利润更大。     

Study on the Sequence of Parts with Constrains of Earliness and Tardiness in Job-Shop

The Earliness/Tardiness problem in job_shop is discussed in this paper.Based on the analysis of practical situations and lot transfer between stages,an integer programming mode is proposed,The solution is obtained by the application of Lagrangian relaxation technique.