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1.
卢建杭  黄克玲 《环境工程》1999,17(1):70-71,22
针对聚合硫酸铁碱化度的国标测定方法提出了一点改进,扩大了碱化度的测定范围,使其适合于某些碱化度较高或铁含量较高的聚铁样品的测定。改进之处在于先加入较多量的盐酸分解试样,用氟化钾掩蔽Fe3+后,再加入定量的NaOH溶液中和部分多余的酸,最后用较稀(01mol/L)的NaOH溶液滴定至终点。  相似文献   

2.
利用2004年秋冬季全国联网资料,给出中国19个典型区域大气气溶胶的光学厚度(AODλ=500nm)、Angstrom混浊系数(β)和Angstrom波长指数(α).结果表明,在青藏高原,海北、拉萨,AOD平均分别为0.09、0.12,β平均分别为0.05、0.13,α平均分别为1.09、0.06.东北地区,海伦、三江,AOD平均分别为0.14、0.15,β平均分别为0.04、0.06,α平均分别为2  相似文献   

3.
An important goal of vulnerability assessment is to create an index of overall vulnerability from a suite of indicators. Constructing a vulnerability index raises several problems in the aggregation of these indicators, including the decision of assigning weights to them. The purpose of this paper is to demonstrate a method of aggregating vulnerability indicators that results in a composite index of vulnerability, but that avoids the problems associated with assigning weights. The investigators apply a technique based on Pareto ranking to a complex, developed socioeconomic landscape exposed to storm surges associated with hurricanes. Indicators of social vulnerability to this hazard are developed and a principal components analysis is performed on proxies for these indicators. Overall social vulnerability is calculated by applying Pareto ranking to these principal components. The paper concludes that it is possible to construct an effective index of vulnerability without weighting the individual vulnerability indicators.  相似文献   

4.
《Journal of Cleaner Production》2007,15(13-14):1205-1216
With respect to the philosophy of the preventive approach, the bottom line has often been illustrated with the saying: ‘…a gram of prevention is better than a kilogram of cure…’ But you cannot manage a problem that you do not know. In case of cleaner production, the approach is not to solve the problem but to prevent it. This is a deduction in two ways. Firstly, a new problem has to be present in order to be recognised, also for prevention. Secondly, the problem that has to be prevented is connected to the life-cycle of the capital and technology investments in production processes, products and services. A dilemma for new concepts in general is that pilot studies never meet the full conditions that are needed. When the obstacles of routines are overcome, often the momentum for fully conditioned approaches is passed and watered-down definitions and applications are introduced.  相似文献   

5.
The question of how the financing of Extended Producer Responsibility (EPR) affects the overall performance of the economy is important as products covered by EPR comprise an increasing part of the economy. In this paper, an Overlapping Generations (OLG) model with endogenous growth is applied to the case and a comparison between two financing schemes, an insurance solution and a pay-as-you-go (PAYG) solution, is made with respect to the effect on the level of production, the growth rate, the impact of a productivity shock and the risk exposure. It is found that in the case of a funded solution, both the level of production and the growth rate in production is higher than in the PAYG case, and the short-run effect of productivity shock is bigger. The policy indication is clear: EPR should be attached to a financing scheme if welfare is to be maximised.  相似文献   

6.
《Journal of Cleaner Production》2006,14(15-16):1396-1408
The most important moment in product development is when demands and specifications are decided for the product that is being planned. The specification defines the goal for the product development process. It is a very important steering opportunity for the continuing work and for environmentally driven demands that are to be addressed in the product development phase. The designers are said to have the key to sustainable product development through EcoDesign. Many tools have been developed in order to help them to achieve this objective. However, most tools are seldom used primarily because of a lack of sustainability oriented requirements in specifications for products. If there is no demand for improved environmental performance, then there is no need for EcoDesign tools. The lack of market demand for environmentally improved products is therefore, a crucial factor. In other words: It makes no sense to grab a screwdriver from your toolbox if you have a nail in your hand. On the other hand if you have a hammer in your hand you tend to see everything as nails! The hypothesis of this paper is that there is a strong need for a tool to facilitate the integration of reasonable environmental demands into the product development process. The presented tool, “The Ten Golden Rules,” can be helpful in this effort. A helpful tool must be well adapted to the task and therefore it is important that the individual product developer/designer can develop personal versions from the generic guidelines. The Ten Golden Rules provide such a possibility. They provide a common foundation, for all in the team, which can be used as a base and guidelines for development of situation specific product-design challenges.  相似文献   

7.
We succeeded in developing a new instrument for dust measurement, based on a study of existing methods. It is portable and gives a real-time response. it is based on the measurement of the scattering intensity of near-infrared radiation. Light from a semiconductor laser is transmitted to the detector unit through a heat-resistant fiberscope, and the infrared energy scattered by the aerosol is returned to a sensor in the same way. The detector is inserted directly into the measured gas stream, and can be moved to various points in the stream to obtain representative cross-sectional measurements. Aerosol measurements can be made over a concentration range of 0.01–1000 mg m−3. The response appears to be the same, based on mass concentration, for flyash, combustion smoke, and dust in a steel mill.  相似文献   

8.
It is now widely accepted that climate change is happening and that future changes will impact on many aspects of society, including agriculture. To maintain food supplies, the agricultural industry must address climate change adaptation. Key to this is the attitudes of those within the industry likely to have responsibility for adapting. This study investigated stakeholder attitudes towards adaptation to climate change in the livestock industry. Findings reveal four attitudinal groups. First, there is a ‘farmer-focused group’ that has a positive attitude about the ability of livestock farmers to adapt to climate change, but that also has the opinion that they will need additional support to adapt. Second, there is an ‘incentive for enterprise, anti-GM (genetic modification) group’ with an attitudinal position stressing that the government should have a role in implementing regulations and providing finance. This group has a negative attitude towards GM technology and does not think it will be the answer to climate change. Third, there is an ‘information and education group’ whose attitude is that the provision of information is crucial for ensuring that the livestock industry adapts. Fourth, there is a ‘pro-technology group’ who have a positive attitude towards GM technology and who are therefore willing to embrace it as the route to adaptation. Three of these four groups favour soft adaptations that maintain flexibility within the system, and only the fourth is of the opinion that adaptive capacity is not an issue and that the industry is ready to implement hard adaptations.  相似文献   

9.
研究声强等值线的分布情况,是声环境预测工作中的一个关键环节。应用AutoCAD开发技术,开发了一套适用于线屏障和封闭屏障影响条件下的一般系统进行模拟的绘图程序,实现了声强分布的图形表达过程。在计算多线屏障影响的过程中,采用了对数加权的近似处理,避免了复杂的求解过程;在等值线的绘制过程中,采用了"线段首尾连接"的方法来追踪等值点,简化了追踪过程。  相似文献   

10.
凡是有地下煤矿开采的地区,都伴之有地下水排放.在面临全球性淡水缺乏的形势下,煤矿排放废水却作为污染源,日夜注入河床,致使环境保护部门为之大伤脑筋,而且各煤矿也为煤矿排放废水的治理,付出了很大的经济代价.因此如何解决煤矿排放废水达标排放的问题,使其能作为矿产资源和水资源得到再利用,解决即将到来的水荒危机就成为了本文讨论的重点.  相似文献   

11.
Photoperiodic time measurement is a well-documented adaptation of multicellular plants and animals to seasonal changes in the environment, but it is unclear whether unicellular organisms can exhibit bona fide photoperiodic responses. We demonstrate that the occurrence of zygospore germination of the unicellular alga Chlamydomonas is a genuine photoperiodic response. Germination efficiency is enhanced in long days as compared with short days. While the total amount of light exposure influences the efficiency of germination, the photoperiod is a significant cue for germination. The developmental stage that senses the photoperiod is just prior to mating and during the first days of zygospore development, so there may be a critical window of zygospore maturation that is regulated by photoperiod. Because zygospores are resistant to freezing injury, whereas vegetative cells are not, it is likely that the suppression of germination by short days is an adaptive response for overwintering of Chlamydomonas. Therefore, Chlamydomonas is a single-celled organism that is capable of photoperiodic responses.  相似文献   

12.
Milling exit burrs usually form along the edges of a workpiece when the tool leaves the part while removing stock material. One of the most efficient methods for minimizing exit burrs is to prevent the tool from exiting the workpiece during material removal. This paper describes a systematic framework to generate tool paths that always enter a part, which is not a thin structure, in a planar milling operation. Three distinct tool exit conditions are analyzed for polygonal parts. A test criterion is then proposed to examine the occurrence of tool exits. For each condition, a tool path planning scheme is developed to avoid tool exits. These schemes are proved to be effective using the test criterion. This work is integrated into a networked manufacturing environment as a burr agent. Test parts are cut to demonstrate that this framework enhances edge quality by minimizing tool exits.  相似文献   

13.
Ecosystem management, by seeking to emulate natural disturbance, has been proposed by the ecological and forest management community as a means of maintaining the biodiversity and productivity of boreal forests, key components of sustainable forest management (SFM). However, it is argued that ecosystem management overlooks the paradox inherent in the concept of Nature, limiting the scope of the SFM debate by maintaining a binary opposition between Nature and Society, humans and the environment. Nature is paradoxical because humans are part of Nature, by the theory of evolution, while at the same time Nature is a social construction created by humans, and thus artificial. Recourse is made to postmodernism in order to examine the metaphysical and sociopolitical implications of the deconstruction of this paradox. Based on a review of the philosophy of Foucault and Derrida, the concept of Nature is demonstrated to be socially mediated, an entwinement of reason and power. In order to address metaphysical challenges of the Nature–Society dualism identified above, I refer to Habermas’s theory of communicative action and cite results from a case study in this regard. Results from this case study prompt a critical examination of the legitimacy of a discourse ethic about Nature, making use of the negative dialectics of Adorno. As a result, at the metaphysical level, a different role for ecologists and forest managers in public participation procedures is proposed, one whereby ecologists talk through Nature to the evolutionary agents to which it is intended to refer as a means of discussing whether specific management options will contribute to sustainable development. It is argued that at the sociopolitical level SFM will necessitate improved transparency and participation in forestry, criteria that can be attained through community-based ecosystem management. Both elements require a science more actively engaged with civil society.  相似文献   

14.
内电解法白腐菌生物处理活性染料染色废水   总被引:7,自引:0,他引:7  
研究采用从自然界中采集 ,经分离、纯化 ,得到的对染料废水脱色效果较为明显的菌株 ,应用内电解法对染料废水进行预处理 ,以改善其可生化性之后 ,进行活性染料染色废水的生物处理实验。确定了最佳组合工艺条件 :内电解进水pH值为 3 5 ,停留时间 15min ,白腐菌纤维球载体固定化生物处理 ,进水pH值为 4 5 ,溶解氧浓度 >8mg L ,停留时间 12h ,脱色率达到近 10 0 % ,CODCr、BOD5去除率分别达到 90 7%及 94 8%。  相似文献   

15.
Climate change is expected to increase the frequency and intensity of natural disasters. Adaptation investments are required in order to limit the projected increase in natural disaster risks. Adaptation measures can reduce risk partially or completely eliminate risk. The literature on behavioural economics suggests that individuals rarely undertake measures that limit risk partially, while they may place a considerable value on measures that reduce risk to zero. This is studied for a case of adaptation to climate change and its effects on flood risk in the Netherlands. In particular, we examine whether households are willing to invest in elevating newly built structures when this is framed as eliminating flood risk. The results indicate that a majority of homeowners (52%) is willing to make a substantial investment of €10,000 to elevate a new house to a level that is safe to flooding. Differences between willingness to pay (WTP) for flood insurance and WTP for risk elimination through elevation indicate that individuals place a considerable value on the latter adaptation option. This study estimates that the “safety premium” which individuals place on risk elimination is approximately between €35 and €45 per month. The existence of a safety premium has important implications for the design of climate change adaptation policies. The decision to invest in elevating homes is significantly correlated with the expected negative effects of climate change, perceptions of flood risks, individual risk attitudes, and living close to a main river.  相似文献   

16.
Biology is searching for a paradigm of life and is proceeding from an inductive, empirical to a deductive, formal science. All life phenomena result from the efficacy of a principle, i.e., systemic information, which is not reducible to physics and chemistry. Systemic information, together with genetic information engraved on macromolecules and matter described by physics and chemistry, represents the existential basis of life. A strategy is developed which makes it possible to determine the systemic information of a living organism provided there is enough knowledge of the organism concerned.  相似文献   

17.
四氢呋喃比浊法测定土壤中的微量油   总被引:1,自引:0,他引:1  
近代石油工业对环境的影响引起人们的重视。土壤被油污染导致农业减产亦已引起人们的关注。然而,迄今土壤中微量油的测定尚无令人满意的方法,已有的方法大多通过氯仿等有机溶剂抽提,而后用重量法或红外法等测定。我们研究用四氢呋喃抽提,然后用比浊法测定,由于四氢呋喃溶油能力  相似文献   

18.
城市垃圾填埋场安全稳定性分析   总被引:1,自引:0,他引:1  
垃圾填埋场是一类特殊工程,其安全稳定性一直是研究的热点和难点。本文借鉴成熟的工程力学思想,将分析山谷型垃圾填埋体的安全稳定性转化为分析垃圾坝稳定性。利用已知的稳定填埋场边坡有关性状,反算出垃圾土可能最小综合内摩擦角,利用这个参数来计算填埋体在三种典型状态下对垃圾坝产生的最大作用力,从而来判断垃圾坝的稳定性。探索了一套分析山谷型填埋场填埋体稳定性的方法并提出了两个公式,对于该类型垃圾填埋场建设具有指导作用。  相似文献   

19.
民事诉讼作为保护环境权利与解决纠纷的衡平机制,它的产生是基于当事人对司法救济的需要.在运用诉讼程序解决民事纠纷时,存在利益衡量的问题.作为环境法的法意基础,环境权在某种意义上是一种社会性权利,有权提起环境诉讼,维护公共利益是环境权从理论到实践的基本标志.本文通过论述环境权理论及其在环境侵权救济中的运用,并对原告资格的适度放宽、举证责任的合理配置、诉讼费用公平负担等方面进行制度创新,以期构建我国的环境公益诉讼制度,这也是公众环境权获得程序上的有力保障.  相似文献   

20.
In smelting processes, a large amount of off-gas emission is often generated, which can cause serious environmental and plant hygiene problems if not properly treated. Off-gas cleaning systems extract and treat the hazardous emissions, and ensure that the smelter operation is in accordance with environmental and industrial hygiene regulations. To this end, it is paramount that a well-designed control structure be incorporated into the system. In this work a plantwide control design procedure is applied to an industrial nickel smelter furnace off-gas cleaning system. We first approach the problem by conducting a steady-state analysis based on a nonlinear model of the process, where the objective is to determine how to achieve safe, clean and economic operation in terms of energy consumption. Results reveal that a large amount of energy can be saved by controlling the temperature in the furnace freeboard at its upper bound (active constraint). For the same reason, the temperatures in the two louvers (active constraints) should be controlled at their respective upper bounds so to minimize air intake into the system. The selection of the “unconstrained” variable to be controlled is found by applying the self-optimizing control technique, and the results indicate that a small loss is acceptable when one of the manipulated variables is fixed at its nominal optimal operating point, a highly desirable choice from an operational viewpoint. The bottleneck of the system is identified as the fans' discharge pressures when we allow the feed rate as a degree of freedom. Furthermore, a design change consisting of the installation of an auxiliary air intake in the smelter furnace shows to be a very effective economic alternative to minimize energy consumption. A control structure is then designed where the issue is to keep pressures in the system well within the negative region by determining the configuration of the regulatory and supervisory control layers such that acceptable dynamic performance in face of known, deterministic disturbance is achieved. Nonlinear dynamic simulations are performed to validate the suggested control structure for both modes of operation in the original system and in the proposed design change. The results showed that both regulatory and supervisory designs should make use of the simplicity of decentralized PI control schemes associated with some cascaded configurations so as to boost the disturbance rejection capabilities of the system.  相似文献   

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