数值模拟的可视化及其实现技术

此文介绍了一个用于数值模拟过程的二维图形界面,它由两大部分组成:“MANU”实现计算结果的手工操作显示及编辑,“AUTO”用于数值计算过程的自动跟踪.文中详细介绍了系统的设计方法、结构、工作原理和主要功能.     

Determinants of Farmers’ Adoption of Improved Soil Conservation Technology in a Middle Mountain Watershed of Central Nepal

This study explores different socio-economic and institutional factors influencing the adoption of improved soil conservation technology (ISCT) on Bari land (Rainfed outward sloping terraces) in the Middle Mountain region of Central Nepal. Structured questionnaire survey and focus group discussion methods were applied to collect the necessary information from farm households. The logistic regression model predicted seven factors influencing the adoption of improved soil conservation technology in the study area including years of schooling of the household head, caste of the respondent, land holding size of the Bari land, cash crop vegetable farming, family member occupation in off farm sector, membership of the Conservation and Development Groups, and use of credit. The study showed that technology dissemination through multi-sectoral type community based local groups is a good option to enhance the adoption of improved soil conservation technology in the Middle Mountain farming systems in Nepal. Planners and policy makers should formulate appropriate policies and programs considering the farmers' interest, capacity, and limitation in promoting improved soil conservation technology for greater acceptance and adoption by the farmers.     

Regulating groundwater use: The challenges of policy implementation in Guanajuato,Central Mexico

Around the world it has proven very difficult to develop policies and interventions that ensure socio-environmentally sustainable groundwater use and exploitation. In the state of Guanajuato, Central Mexico, both the national government and the decentralized state government have pursued to regulate groundwater use through direct state control, groundwater markets, energy pricing, and user self-regulation. We present and analyze these regulatory mechanisms and their outcomes in the field. We argue that the close interdependencies of these regulatory mechanisms have pre-empted the effectiveness of these policy instruments as well as that of other measures aimed at reducing groundwater use in order to advance towards sustainable exploitation levels.     

基于MATLAB GUI的土壤质地类型自动识别系统

土壤质地类型反映了不同粒径颗粒在土壤中的分布,是土壤的最基本性质之一,直接影响土壤中水、气、热和溶质的迁移特征,因此确定土壤质地类型是土壤调查中最基础的工作.我国常用的土壤质地分类标准有美国制、国际制、卡庆斯基制和中国制标准,其中美国制和国际制土壤质地分类需借助平面三角坐标系来确定,不利于批量土壤样品的土壤质地分类.现...     

Local IWRM organizations for groundwater regulation: The experiences of the Aquifer Management Councils (COTAS) in Guanajuato, Mexico

Evidence of groundwater management by aquifer users emerging under Integrated Water Resources Management (IWRM) initiatives is presented, by analyzing the Consejos Técnicos de Aguas (COTAS; Technical Water Councils or Aquifer Management Councils) in the state of Guanajuato, Mexico, established between 1998 and 2000 by the Guanajuato State Water Commission (CEAG). Two contrasting models influenced this attempt to promote user self-regulation of groundwater extractions: locally autonomous aquifer organizations with powers to regulate groundwater extractions versus aquifer organizations with advisory powers only. The COTAS were conceived as locally autonomous IWRM organizations consisting of all aquifer users that would work together to reduce groundwater over-extraction and stabilize aquifer levels, at a later stage. CEAG followed an expedient IWRM approach to develop the COTAS, setting achievable targets for their development and explicitly focusing on active stakeholder participation. The article shows that, due to struggles between the state and federal levels, the COTAS have become advisory bodies that have not led to reductions in groundwater extractions. It concludes that achieving user self-regulation of groundwater extractions requires a fuller delegation of responsibilities to the COTAS which would not be possible without addressing the institutional struggles over water governance at the state and federal levels.     

液化石油气脱硫

阐述了醇胺法液化石油气脱硫体系的特点。借助于大型通用流程模拟系统ＡＳＰＥＮＰＬＵＳ软件，开发了液—液平衡计算ＫＬＬ子程序，已成功地实现了与ＡＳＰＥＮＰＬＵＳ联机运行。所建模型适用于以ＭＤＥＡ为溶剂的液化石油气脱硫工艺过程计算，还给出了模拟计算结果。     

一种新型实用的用户自行配气实验装置

通过实验设计了一套用户自配气实验装置，对于无固定气源条件下配制较为稳定浓度的ＮＯ气流提供了一种新的方法。     

Heavy duty vehicles: Impact on the environment and the path to green operation

The increase in the number of heavy duty vehicles (HDV) is inherently accompanied by increase in congestion, pollutant emissions and energy use as well as infrastructure overuse, all of which have broad societal implications. In addition to affecting the environment, contributing markedly to global warming, significant implications for the health of many residents living along traffic corridors as well as increases in the cost of infrastructure maintenance are logical consequences. In this interdisciplinary work a holistic approach is presented for the assessment of the combined effects of HDV employing pollutant emissions, noise and dynamic load of vehicles as criteria. Results show that vehicles that are environmentally friendly due to their pollutant emissions are not necessarily environmentally friendly when their noise emissions are considered. Each relevant parameter has to be assessed individually. Using a proposed model, the parameters are combined to obtain a holistic impression of the vehicles’ total environmental footprint. This information can be used by policy makers to introduce a bonus/malus system that would encourage vehicles with a total low environmental footprint using the “polluter/user pays” principle.