分布式动力供应系统的优化联动控制

基于双自由度PID调节和模式优化方式,提出了分布式供热(电)动力系统的联动控制方案.仿真结果表明:这一方案对伴随用户供热需求变化而产生的经常性干扰有较强的抑制作用,其设定点可根据过程能量需求变化实现优化,从而大大节省能耗,降低排放污染.     

Derivation of sustainable breeding goals for dairy cattle using selection index theory

The objective was to present 2 methods for the derivation of nonmarket values for functional traits in dairy cattle using deterministic simulation and selection index theory. A nonmarket value can be a value representing animal welfare and societal influences for animal production, which can be added to market economic values in the breeding goal to define sustainable breeding goals. The first method was restricted indices. A consequence of adding a nonmarket value to a market economic value for a given functional trait is less selection emphasis on milk yield. In the second method, the loss in selection response in milk resulting from greater emphasis on functional traits was quantified. The 2 methods were demonstrated using a breeding goal for dairy cattle with 4 traits (milk yield, mastitis resistance, conception rate, and stillbirth). Nonmarket values derived separately using restricted indices were 0.4 and 2.6 times the value of market economic values for mastitis resistance and conception rate, respectively. Nonmarket values for mastitis resistance and conception rate were both lower when derived simultaneously than when derived separately. This was due to the positive genetic correlation between mastitis resistance and conception rate, and because both traits are negatively correlated with milk yield. Using the second method and accepting a 5% loss in selection response for milk yield, nonmarket values for mastitis, conception rate, and stillbirth were 0.3, 1.4, and 2.9 times the market economic values. It was concluded that the 2 methods could be used to derive nonmarket values for functional traits in dairy cattle.     

基于TRIZ理论的双向弓形夹结构优化设计

标准弓形夹只能夹持单组工件,而不能夹持多组、有相对位置要求的工件,其应用范围受到限制,针对这一问题,利用TRIZ理论寻求解决方案,设计一种具有双曲线结构的双向弓形夹,可双侧夹持工件,扩大弓形夹的应用范围,并对双向弓形夹受力状态进行有限元分析,结果证明弓形夹所受应力分布较均匀,夹持能力得到显著提高。     

离心泵变频调速参数的优化控制

为了降低供水系统的运行成本,分析了离心泵变频调速特性,利用最优化原理建了多台离心泵并联运行参数优化的数学模型,采用复合形法求解数学模型,在线对离心泵运行参数进行优化控制,取得了较好的经济效益.     

Fate of naphthalene in laboratory-scale bioretention cells: implications for sustainable stormwater management

Bioretention cells are increasingly popular in low-impact development as a means to sustainably mitigate the environmental problems associated with stormwater runoff. Yet, much remains to be known regarding the removal and ultimate fate of pollutants such as petroleum hydrocarbons in bioretention cells. In this work, laboratory-scale bioretention cells were constructed inside sealed glass columns. The columns were periodically spiked with (14)C-naphthalene over a 5-month period and the fate of this representative hydrocarbon and the influence of vegetation on naphthalene fate was studied. Three column setups were used: one planted with a legume (Purple Prairie Clover, Dalea purpureum), one planted with grass (Blue-Joint Grass, Calamagrostis canadensis), and one unplanted (i.e., control). Overall naphthalene removal efficiency was 93% for the planted columns and 78% for the control column. Adsorption to soil was the dominant naphthalene removal mechanism (56-73% of added naphthalene), although mineralization (12-18%) and plant uptake (2-23%) were also important. Volatilization was negligible (<0.04%). Significant enrichment of naphthalene-degrading bacteria occurred due to contaminant exposure and plant growth as evidenced by increased biodegradation activity and increased naphthalene dioxygenase gene concentrations in the bioretention media. This research suggests that bioretention is a viable solution for sustainable petroleum hydrocarbon removal from stormwater, and that vegetation can enhance overall performance and stimulate biodegradation.     

Five elements for organizational decision-making with an environmental management system

Environmental management systems (EMSs) are growing in popularity as tools to manage corporate environmental issues. Despite widespread use, existing frameworks for EMSs may not provide organizations with the knowledge needed for decision-making. Through a synthesis of case studies and workshops, we suggest five elements for EMSs to be expanded for organizational decision-making. The five elements are process diagrams, long- and short-term goals linked to strategy, reliable information systems, risk assessment tools, and collaboration of environmental personnel across the organization. These five elements provide decision makers with relevant information linked to business strategy so that the organization can improve performance. The elements can be integrated with an existing EMS or used as a foundation for implementing one.     

Optimal energy management in grain drying

Grain drying is very specific to the geographic location, kind of drying system, and the type of grain. Under a given set of conditions, the optimal system can be selected based on careful evaluation. However, a good choice of drying systems, procedures, and management practices can be made from the information already available. The review of several grain-drying procedures has provided some insight in making a quick evaluation of the process and arriving at the most suitable system for a particular application. Despite extensive research efforts, the present knowledge of grain drying is yet insufficient to optimally design each drying process with respect to capacity, quality, and energy requirement. There is a need for incorporating grain and air parameters more accurately. It is also important to develop comprehensive drying simulation models to encompass agronomic practices, such as planting and harvesting. Recent efforts indicate a strong influence of planting and harvesting strategies on optimal drying and storage system selection. Results of the varietal trials at Ohio State University indicate that it is now possible to select midseason varieties, which dry down rapidly, without sacrificing yield. Also, low moisture at harvest is important to the energy management process because it affects total drying time and energy required. It is also important from a quality standpoint because kernel damage increases rapidly at harvesting moisture levels above 25%. The trend in grain-dryer design has shifted from focusing on drying capacity and operation reliability to energy consumption. The development in design of energy efficient continuous-flow dryers has been significant. Multistage concurrentflow dryers are excellent examples. Various aspects of dryer staging for efficient operation and control are yet to be determined. Recirculation of the exhaust air is a proven method of improving energy efficiency. Likewise, in batch-in-bin systems, stirring and intermittent drying are worth considering. Further research is required to formulate the best procedures for exhaust air recirculation and intermittent drying. Low temperature drying has a great potential in the U.S. corn belt. The suitability of low temperature drying at other places and for grains other than corn has not yet been well established. Energy savings resulting from low temperature drying entail careful planning and management on the part of the operator. Poor design and operation can result in a serious deterioration in grain quality.(ABSTRACT TRUNCATED AT 400 WORDS)     

打浆过程鲁棒最优控制的研究

本文根据打浆过程的特点，提出了鲁棒最优控制新设想，进行了打浆过程鲁棒最优控制系统设计，并讨论了有关参数（阵）与保证稳定格度的关系。     

环境管理体系在企业的运行

环境管理体系为创建低碳循环经济和企业可持续发展提供了保障,通过企业建立和运行环境管理体系,规范了企业管理机制,提升了企业的管理水平,提高了企业的市场竞争力,产生了很好的经济效益;通过环境管理体系对企业进行全程管理,预防环境污染,减少环境事故的发生,提高了企业的社会形象和社会责任感。     

Optimal power control strategies in microwave drying

A microwave drying system, which can automatically and continuously adjust microwave power, control sample temperature and measure sample mass, was developed and used in apple drying. At three drying temperatures, i.e., 75, 65, 55 °C, applied microwave power was recorded and analyzed, and a relationship of the power with respect to drying rates was built. With this relationship, apples were further dried at the same three temperatures but using variable power during drying process based on the online obtained drying rates. A better temperature control was achieved and less energy was consumed with this method. Depending on the resulted power profiles, a linear and a three-step power control methods were further developed to simplify the control system. With the developed methods, mass measurements were no longer required and power control could be easily implemented, while temperature control and energy consumption were still acceptable.     

The role of non-timber forest products in sustainable tropical forest management

The importance of non-timber forest products (NTFPs) for forest-dwelling people in the tropics and the relatively small ecological impact of their exploitation has raised high expectations as to their potential to contribute to tropical forest conservation. Three major issues in relation to NTFPs are addressed: their potential to contribute to the conservation of tropical rainforests; their potential to improve the livelihood of forest-dwelling peoples and their potential for participatory forest management. It is concluded that for the proper management of NTFP resources, it is necessary to be specific about the aim of NTFP development and to take account of ecological as well as social and economic factors. Policymaking and land-use planning must furthermore take into account that NTFP extraction is part of an overall livelihood strategy of the people involved, in which other economic activities also play a role.     

工程项目管理中的风险因素与成本控制

从工程成本影响及风险因素的角度分析，提出控制成本的具体办法，并结合合同管理提出相应的风险对策，从而提高企业的经济效益。     

Agri-food loss and waste management: Win-win strategies for edible discarded fruits and vegetables sustainable reuse

In the world, a large amount of food is lost or becomes waste along the agri-food supply chain. Circular Economy models in the agri-food systems can reduce the amount of food loss and waste generated in the agri-food supply chain by using them as a new resource. In the case of fruits and vegetables, loss and waste account for 45% in the whole supply chain, being processing stage responsible of up to 18% of losses. A Systematic Literature Review (SLR) has been carried out to investigate the most effective sustainable strategies aiming to reuse the food losses in the fruits and vegetables industry. Four main research areas emerged from the SLR: reuse for human consumption, animal feeding, recovery for matter-energy use, and integration into new business models. A sustainable assessment framework is proposed to compare the different strategies. Among these, the human consumption area includes more sustainable strategies, classified according to four classes (i.e., environment, business, ICT, and consumer behavior). They have been analysed to identify the existing knowledge gaps and open issues. The results show new scientific perspectives and open research opportunities.     

Evaluating the quality of structured environmental management decisions

Structured decision making (SDM) approaches have been advocated as a means of improving the quality of environmental and related risk management decisions based largely on the self-reported behavior of decision makers. The goal of the research presented here was to test this basis for decision quality by comparing the self-reported assessments of individual decision makers with their actual choice behavior across a set of three related environmental contexts. It was hypothesized that a modified structured decision approach would lead participants to make better informed decisions which accurately reflected their objectives, not based solely on self-reports, but also on internally consistent decision making behavior. Results from this study only partially support this hypothesis. While individuals' self-reports suggest that the structured approach outperformed results from an unstructured control condition, there was a lack of agreement between these self-reported evaluations and actual choice behavior. Beyond the obvious policy implications of decisions that are inconsistent with stated objectives, these findings point to the need for improved metrics when evaluating the quality of environmental decision processes.     

Uncertainty-accounting environmental policy and management of water systems

Environmental policies for water quality and ecosystem management do not commonly require explicit stochastic accounts of uncertainty and risk associated with the quantification and prediction of waterborne pollutant loads and abatement effects. In this study, we formulate and investigate a possible environmental policy that does require an explicit stochastic uncertainty account. We compare both the environmental and economic resource allocation performance of such an uncertainty-accounting environmental policy with that of deterministic, risk-prone and risk-averse environmental policies under a range of different hypothetical, yet still possible, scenarios. The comparison indicates that a stochastic uncertainty-accounting policy may perform better than deterministic policies over a range of different scenarios. Even in the absence of reliable site-specific data, reported literature values appear to be useful for such a stochastic account of uncertainty.