可再生资源非线性收获的策略研究

本文运用非线性理论建立了可再生资源二次非线性收获的动力摸式。研究结果表明：为了保证可再生资源的可持缓利用、收获，必须把收获强度控制在一定的水平上，我们因此可以得到持续的最大产量。我们发现虽然对可再生资源的收获策略有线性和非线性之分，但是得到的可再生资源的最大持续收获量是相同的。因此，我们必须采用合理的可再生资源收获策略。避免可再生资源的过度利用和枯竭。我国可再生资源十分短缺，需正确处理好经济发展与可再生资源保护之问的关系，保护好我国珍贵的可再生资源对于我国的可持续发展具有重大的现实意义。     

High-resolution alpha spectrometry under field conditions - fast identification of alpha particle emitting radionuclides from air samples

Alpha particle emitting radionuclides may be released into the atmosphere as a result of a severe nuclear accident, the malevolent use of radioactive material or some other incident. Rapid detection methods are then of crucial importance for carrying out well-timed protective actions. The present paper demonstrates that a method in which an aerosol sample is collected on a filter and directly analysed by high-resolution alpha spectrometry in a vacuum chamber, but without radiochemical sample treatment, is suitable for field measurements. A detection limit of less than 0.1 Bqm(-3) for (239)Pu is achieved assuming 1-h sampling using a glass-fibre filter and 1-h data acquisition. This value is higher than in the case when sampling is performed using a porous membrane filter. A measurement system consisting of standard components is mounted in a vehicle designed for rapid field measurements.     

A simple and rapid method for analyzing radon in coastal and ground waters using a radon-in-air monitor

We have developed a simple and portable technique for measuring moderately high levels of 222Rn (t1/2=3.8d) in natural waters such as coastal water, groundwater, and river water. The water sample is carefully collected in a glass bottle, and the sample bottle is connected to a radon-in-air monitor in a closed air-loop mode. By purging air through the sample, radon is emanated from the water until a chemical equilibration is obtained between the two phases. The radon in the air loop is determined using the radon-in-air monitor. Then, the radon in water is calculated by a radon-partitioning factor between water and air for a measured water temperature. This technique is especially convenient for determination of 222Rn in natural waters on field sites, since it eliminates the preparation of He gas, cold traps, and alpha-scintillation cells and counter, which are required for traditional radon emanation methods.     

A procedure to estimate worst-case air quality in complex terrain

Using a straightforward synoptic climatological analysis scheme, it is shown that the potential for an area to experience air quality degradation due to local sources is highest under polar subtropical highs. With respect to polar highs, the problem is most severe when the sun angle is low and snow covers the ground, and the polar high persists for a long period of time. A simple algorithm is introduced which is designed to estimate worst-case impact in a trapping valley. The potential for the accumulation of air pollution in such valleys due to the persistence of a polar high in a region, is ignored in current regulatory air quality assessments. Trapping valleys and synoptic flow stagnation often occur in wilderness areas. Refined air quality assessments are shown to be possible using a mesoscale meteorological model and a pollution dispersion model. These tools permit quantitative assessments of pollution build-up from local sources as a result of the recirculation of the local air. This tool, along with the synoptic climatological classification scheme, also permits an evaluation of the fractional contribution of long range versus local sources in the air quality degradation in a region. Areas near the center of a polar or subtropical surface high pressure system, for instance, appear to be dominated by local sources, if they exist, whereas in the vicinity of extratropical cyclones, long-range transport is usually much more important.     

A framework to minimise total energy consumption and total tardiness on a single machine

A great amount of energy is wasted in industry by machines that remain idle due to underutilisation. A way to avoid wasting energy and thus reducing the carbon print of an industrial plant is to consider minimisation of energy consumption objective while making scheduling decisions. To minimise energy consumption, the decision maker has to decide the timing and length of turn off/turn on operation (a setup) and also provide a sequence of jobs that minimises the scheduling objective, assuming that all jobs are not available at the same time. In this paper, a framework to solve a multiobjective optimisation problem that minimises total energy consumption and total tardiness is proposed. Since total tardiness problem with release dates is an NP‐hard problem, a new greedy randomised multiobjective adaptive search metaheuristic is utilised to obtain an approximate pareto front (i.e. an approximate set of non‐dominated solutions). Analytical Hierarchy Process is utilised to determine the ‘best’ alternative among the solutions on the pareto front. The proposed framework is illustrated in a case study. It is shown that a wide variety of dispersed solutions can be obtained via the proposed framework, and as total tardiness decreases, total energy consumption increases.     

Tour Level Mode Choice Analysis of Madison Area in Wisconsin

This study is to investigate what factors and how they affect tours （trip chains） behavior. The key issue is the understanding and definition of tour and tour level mode. Also, these definitions should fit for the data. A semi-home based tour definition is stated, and a competing mode based tour mode is defined. Based on the definition, this study used Madison Area Data from National Household Survey to estimate a MNL structured model. It is found that travel distance could be a positive factor for car mode. Meanwhile, the number of trips is also a positive factor for choosing car.     

Comparing urban air quality in Europe in real time a review of existing air quality indices and the proposal of a common alternative

The EU directives on air quality force member states to inform the public on the status of the ambient air quality. The Internet is commonly used for this purpose and often air quality is being presented as an index ranging from good to bad. A review of existing websites and air quality indices shows that the way air quality is interpreted differs considerably. The paper presents a new air quality index. The index is part of a project to develop a website dedicated to comparing air quality in European cities. The common air quality index (CAQI) is not aimed at replacing existing local indices. The CAQI is a set of two indices: one for roadside monitoring sites and one for average city background conditions. Differentiating between roadside and general city conditions is a first step in assuring consistence in the parameters that are being compared.     

循环经济创新评价指标体系研究

循环经济是绿色、低碳的可持续发展模式。实践充分证明,发展循环经济必须以创新为动力。循环经济创新是一项涉及面广、综合性很强的系统工程。为了科学地评价循环经济创新状况,构建一套设计合理、操作性较强的循环经济创新评价指标体系,为循环经济管理及其创新提供数据支持是十分必要的。本文根据循环经济理论,依据目前我国循环经济发展及循环经济创新情况,提出了构建循环经济创新评价指标的原则,并提出了涵盖9个一级指标、52个二级指标的评价体系。根据我国循环经济发展实际以及国家经济政策等综合考量,设置出了体现我国国情的循环经济创新评价指标体系的指标评分标准。主要用于对全社会和各地循环经济创新状况进行总体的定量判断,为循环经济发展提供依据和指导。     

中国能源高消耗的经济原因及对策研究

中国能源处于高消耗增长态势,这对当前国家能源安全、经济安全和完成节能减排的任务构成了严峻挑战。节能减排是一定经济发展阶段和水平的反应,是一个牵涉到产业结构调整、能源利用与经济发展关系协调等多方面的问题。研究节能减排对我国转变经济发展方式具有相当重要的意义。该文基于工业化和能源经济相关理论,利用相关指标和统计数据,对中国能源高消耗的经济原因进行了深入分析,并提出了基本对策。研究表明,当前中国能源高消耗的主要经济原因在于工业化的发展阶段问题,即中国已基本进入了工业化的重化工业化阶段,高能耗产业快速增长。中国要解决当前节能减排困境,其根本出路在于转变经济发展方式,走新型工业化道路,促使工业结构高端化,压缩工业化进程中高能耗、高污染状况持续的时间。     

Global warming and carbon dioxide through sciences

Increased atmospheric CO(2)-concentration is widely being considered as the main driving factor that causes the phenomenon of global warming. This paper attempts to shed more light on the role of atmospheric CO(2) in relation to temperature-increase and, more generally, in relation to Earth's life through the geological aeons, based on a review-assessment of existing related studies. It is pointed out that there has been a debate on the accuracy of temperature reconstructions as well as on the exact impact that CO(2) has on global warming. Moreover, using three independent sets of data (collected from ice-cores and chemistry) we perform a specific regression analysis which concludes that forecasts about the correlation between CO(2)-concentration and temperature rely heavily on the choice of data used, and one cannot be positive that indeed such a correlation exists (for chemistry data) or even, if existing (for ice-cores data), whether it leads to a "severe" or a "gentle" global warming. A very recent development on the greenhouse phenomenon is a validated adiabatic model, based on laws of physics, forecasting a maximum temperature-increase of 0.01-0.03 degrees C for a value doubling the present concentration of atmospheric CO(2). Through a further review of related studies and facts from disciplines like biology and geology, where CO(2)-change is viewed from a different perspective, it is suggested that CO(2)-change is not necessarily always a negative factor for the environment. In fact it is shown that CO(2)-increase has stimulated the growth of plants, while the CO(2)-change history has altered the physiology of plants. Moreover, data from palaeoclimatology show that the CO(2)-content in the atmosphere is at a minimum in this geological aeon. Finally it is stressed that the understanding of the functioning of Earth's complex climate system (especially for water, solar radiation and so forth) is still poor and, hence, scientific knowledge is not at a level to give definite and precise answers for the causes of global warming.     

Economic and environmental value stream map (E2VSM) simulation for multi-product manufacturing systems

Value stream mapping (VSM) is a well-accepted tool within lean manufacturing concept which is often used for analysing and designing the flow of materials and information required to manufacture a product. However, the analysis is static and single product oriented, which fails to cope with either the variation of production plan or a multi-product environment. In addition, the environmental impact of a manufacturing system is highly associated with the dynamic consumption of energy and resources. Despite the recent integration of VSM with simulation or environmental studies (in the domain of energy efficiency), still neglected is the dynamic assessment of all the resources involved in a multi-product production environment. This paper presents a methodology for modelling multi-product manufacturing systems with dynamic material, energy and information flows with the aim to generate economic and environmental value stream maps (E²VSM). The proposed methodology is validated with an industrial case.     

Tour Level Mode Choice Analysis of Madison Area in Wisconsin

Abstract

This study is to investigate what factors and how they affect tours (trip chains) behavior. The key issue is the understanding and definition of tour and tour level mode. Also, these definitions should fit for the data. A semi-home based tour definition is stated, and a competing mode based tour mode is defined. Based on the definition, this study used Madison Area Data from National Household Survey to estimate a MNL structured model. It is found that travel distance could be a positive factor for car mode. Meanwhile, the number of trips is also a positive factor for choosing car.     

An operative lagrangian model for simulating radioactivity dispersion in the Strait of Gibraltar

GISPART (GIbraltar Strait PARticle Tracking model) is a three-dimensional particle tracking code to simulate the dispersion of radionuclides in the Strait of Gibraltar. It consists of a hydrodynamic module that is run off-line to determine tidal constants and residuals in the domain. This information is stored in several files that are read by the dispersion module to reconstruct water movements. The dispersion module uses a lagrangian approach. Thus, a radionuclide release is simulated by a number of particles, whose paths are computed individually. Radionuclide concentrations are obtained from the density of particles per water volume unit. Some examples of results are shown. The model is also available on-line.     

Sustainability: definition and five core principles,a systems perspective

A systems perspective is used to discuss the concept of sustainability. From this perspective, it is argued, sustainability can be regarded as a system state that is mediated by specific structures. This is fundamentally different from regarding sustainability merely as a normative goal, as it is presently regarded by most. Insight into the kinds of structures which mediate a system’s state open the door to proactive design of new structures and mechanisms, which are necessary for yielding effective change: in this case, promoting the sustainability agenda. The kind of change required to transform the prevailing trajectory of human affairs is presented as a second order change: a change that requires a major shift, and a complete transformation of the system itself, not only in a few aspects of its behavior. A new definition of sustainability is offered, anchored in the interaction of a population and the carrying capacity of its environment. From this definition, five core sustainability principles are derived, along with their respective policy and operational implications. Together, these principles prescribe the conditions that must be met to attain sustainability as an enduring state. The principles themselves form an integrated, systemic set, which requires them to be acted on simultaneously. A piecemeal approach—focusing on one aspect while neglecting others—is not likely to yield effective results for the whole.     

Starting with the answers, perceptions about energy system risks

Persistent social conflict over energy issues, and gaps in perception among energy researchers, led the author to seek a top-down model that would adequately describe these phenomena. The model chosen (grid-group model of the cultural anthropologist) is called the cultural bias model by the author, and it describes several clusterings of human values (cultural categories). This model is used to give insight into these conflicts, and is also used to explain perceptions of risks. The idea of what constitutes a problem (or risk) and what constitutes a solution, is strongly dependent on the cultural category of the individual. Rather than seek out who is right and who is wrong, the author suggests a multirationality view of energy conflicts as a first step to better analysis and to conflict resolution.     

Life cycle energy and CO2 emissions analysis of food packaging: an insight into the methodology from an Italian perspective

Packaging is strictly connected to environmental issues as it is a product characterised by high material consumption rate; it is often transported over long distances and has a short life. Providing environmental analysis is, therefore, urgent to identify energy and resources efficient solutions. The paper, taking advantage of a real case study, presents a life cycle-based comparative analysis among three different food packaging systems. The paper compares the life cycle of tin steel, polypropylene and glass-based packaging of an Italian preserves producer. The analysis leads to the conclusion that, for the baseline scenario, polypropylene packaging represents the greenest solution, whereas glass packaging is the worst choice. The paper presents a scenario analysis varying both the method used for accounting for recycling as well as the recycling rates of the packaging materials. Changes in overall results with parameters analysis changing are calculated and highlighted throughout the paper. The impact of a reuse policy of the glass-based solution is also analysed; a model for disposable glass packaging is proposed and the obtained results are compared with the single use polypropylene and tin steel-based packaging. In order to analyse the impact of different End of Life scenarios on the present case study, collecting as well as recycling rates of some European countries have been used. The results revealed a significant fluctuation both in energy consumption and in CO₂ emission as the nation changes. Summing up, a methodology for packaging environmental impact analysis is applied to a real case study, some crucial aspects of the methodology have been analysed in depth in order to give a contribution in packaging environmental impact analysis.     

Effect of deep freezing of lakes on food supply in habitats of waterbirds

The phenomenon of bottom substrate exposure in deeply freezing lakes during the melting of ice in spring is described. It leads to the formation in the lake of a large temporary biotope—a combination of shoals and exposed portions of the silty bed—with a high trophic capacity for ducks, shorebirds, gulls, etc. The lake in such a state is a rich foraging area for nesting and migrating bird populations. This phenomenon, which is widespread in the Central Yakutian plain, is an ecological manifestation of cryoarid conditions developing in the plains due to extreme climate continentality.     

Lifestyle: suggesting mechanisms and a definition from a cognitive science perspective

The concept of lifestyle is rather difficult to pin down. It is used in a variety of disciplines and related to many different problems. In our highly modern society, lifestyle is more often mentioned as something we need to change in order to achieve a sustainable development. Our main interest then is how we create and change a lifestyle. How can we understand why it is sometimes difficult to achieve change? In relation to terms like beliefs, desires, intentions, habits and artefacts six factors will be suggested. Within these factors we may have a foundation for a mechanism underlying the creation and change of lifestyle. A definition of the concept of lifestyle from a cognitive science perspective will also be suggested, as derived from the same foundation and terms related to it.     

Design for optimal quality by recycling returned products

For many manufacturers, the cost of replacing returned products may more than offset the cost of producing parts with a higher quality. This is especially true if good parts from returned products are used to remanufacture aftermarket products. Furthermore, such policy allows for satisfying a customer population with a variable expectation for acceptable quality. In this study, the total cost of supplying a given demand is derived as an analytical function of the targeted primary production rate and product quality when the demand is satisfied with a combination of primary and remanufactured products. The decision variables of this function consist of the primary production rate and the designed product and production quality. This cost is then minimised to determine the production rate and the optimum quality to target. A numerical example is provided and used to demonstrate the application of this function. This example also demonstrates the use of the proposed solution for optimising quality when there is a limit on primary production size. The example also demonstrates the use of the function for optimising service levels. The results show a close match between the theoretical functions developed in this study and those obtained from a Monte Carlo simulation model.