试论西文图书套录编目中多卷书集中到分散著录方式的转换

针对西文图书套录编目中存在的一个常见问题——多卷书由集中到分散著录问题进行了阐述,分别介绍了修改头标区、245字段、300字段等方法。     

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.     

An inexact two-stage water management model for planning agricultural irrigation under uncertainty

In this study, an inexact two-stage water management (ITWM) model is developed for planning agricultural irrigation in the Zhangweinan River Basin, China. The ITWM model is derived from the incorporation of interval-parameter programming (IPP) within a two-stage stochastic programming (TSP) framework. It can reflect not only uncertainties expressed as probability distributions but also interval numbers. Moreover, it can provide an effective linkage between conflicting economic benefits and the associated penalties attributed to the violation of the predefined policies. Four decision scenarios associated with different water-resources management policies are examined. Targeted incomes, recourse costs, and net system benefits under different scenarios are analyzed, which indicates that different policies for agricultural irrigation targets correspond to different water shortages and surplus, and thus lead to varied system benefit and system-failure risk. The results are valuable for supporting the adjustment or justification of the existing irrigation patterns and identify a desired water-allocation plan for agricultural irrigation under uncertainty.     

大变异遗传退火法及其在水库优化调度中的应用

根据水电站优化调度特点,建立水库调度优化模型,并针对遗传算法易早熟收敛和进化后期搜索效率较低的问题,将遗传操作与模拟退火(SA)思想相结合,并加入大变异(LPM)思想,最后将大变异遗传退火算法(LPM GASA)用于隔河岩水库。通过LPM GASA在隔河岩水库优化调度中的模拟,表明改进策略在解决水库优化调度问题方面的有效性。最后与动态规划(DP)法以及几种策略下的浮点编码遗传算法(FGA)作比较,体现出改进GA的优点及优越性。     

Optimal farm management responses to emerging soil salinisation in a dryland catchment in eastern Australia

Secondary salinisation of soil and water resources is an acute management issue over large parts of Australia. This paper focusses on the situation in the Liverpool Plains, where secondary soil salinity is on the increase due to rising saline groundwater tables. The Liverpool Plains are famous for the vast alluvial floodplains where self-mulching black clays provide the production basis for an extensive dryland cropping industry. The farmers there are asking how best to manage their resources under the present hydrological conditions, and are concerned whether their businesses will remain viable in the future. A multi-period programming model is applied to a model farm situation. The objective function reflects the economic paradigm of farming. The model includes a simulation sub-routine which links land use, rainfall and lateral groundwater flow into a point water balance and estimates the salt-affected area. A feedback relationship applies between soil salinity and land productivity. The results of the model suggest that the prevailing cropping practices that rely on long fallowing for soil moisture retention are sub-optimal. Increased cropping frequency increases farm income and reduces on-farm recharge to groundwater. Diversification into lucerne is favourable for the same reasons. Unless trees have commercial value, tree planting is not a favoured option except on salt-affected land. The farm achieves complete on-farm recharge control. However, assuming that the groundwater table rises at a rate of 10 cm per year independent of on-farm recharge, salinisation continues despite these land management changes. The subsequent land productivity losses render the model farm financially unviable in the medium term. Sustaining the productivity of the Liverpool Plains is an issue of reducing recharge to the groundwater system by changing land-use practices throughout the entire catchment. © 1997 John Wiley & Sons, Ltd.     

基于LabVIEW的增压器生产线数据采集和监控系统设计

课题组在LabVIEW软件开发平台下,结合RFID技术和PLC控制,开发出了一套针对增压器生产的数据采集和监控系统.研究结果:1)该系统通过深入对LabVIEW和三菱PLC的通信交互,基于以太网MXComponent控件,实现了对PLC寄存器的批量读写功能,可以高效地打通上位机和下位机间的数据交互,提升了设备运行效率;...     

Optimal harvest scheduling in Eucalyptus plantations: A case study in Galicia (Spain)

This paper focuses on strategic management planning of Eucalyptus globulus Labill. plantations in Galicia (northwestern Spain). Several problems associated with the management of these plantations were identified first. Current management plans for plantations of this species consist of the systematic and somewhat arbitrary application of the area control method. Thus, these plans do not take into consideration the optimum length for one full plantation cycle that maximizes the land expectation value, neither do they formulate the area control method through any mathematical programming model for scheduling regeneration harvests. In this paper, we present a modelling approach based on linear and goal programming. The models consider area and volume control regulation strategies, and take into account variations in land productivity among site classes and successive rotation intervals. To illustrate this approach, we applied the models to a neighbourhood community-owned forest currently managed by the Regional Forest Service with a recent management plan. The results showed that the models provided more flexible harvest schedules, and the profitability of eucalypt stands was 64% higher than that under the current management plan. Finally, extensions to this study were identified.     

影响翻译过程中对原文理解的若干因素

翻译的质量取决于译者对原语的理解,这一点在翻译过程中显得尤为重要。为了保证译文质量、提高翻译者的素质和水平,文章从翻译者的角度出发,拟从语言因素、非语言因素、文化因素这三个方面进行讨论,最后得出结论：翻译者在翻译过程中应全面考虑以上三方面因素,不断提高自身素质和能力,以保证译文质量。     

二语词汇习得的体验性分析

二语词汇习得与语言体验性具有内在的关联性。词汇习得是基于感知体验的,它是一个基于体验的心理计算过程。因此,二语词汇习得是学习者大脑心智对相关词汇知识（包括二语词汇的语义、句法、形态信息）进行体验的结果。     

香烟评吸质量指标的主成分和聚类分析

应用R统计建模语言,对293条数据记录的11个评吸指标进行主成分分析和聚类分析,按照方差累积贡献率85%提取了3个主成分,通过计算各品牌的主成分得分和综合得分值,分析出香气韵调、香气质等几个主要指标.根据聚类分析结果,将11个评吸指标聚为3类.