某电厂600MW火电机组脱硫增容改造方案探讨

按照国家环保部文件要求，大唐集团河北某电厂600 MW机组湿法脱硫系统需进行增容改造。该电厂根据实际情况，归纳了3种可行的脱硫增容改造方案，即原吸收塔增加喷淋层和高度、双吸收塔串联、双吸收塔双循环，阐述了各自的技术特点，结合性能保证、工程投资、施工周期等影响因素，比较了各方案的优缺点。经过对比和论证，双吸收塔方案比单吸收塔方案更适合于本次工程改造。     

兰州城市主要大气污染治理方案和环境效益

根据兰州市经济技术条件，提出多种大气污染治理工程方案。用数值模式计算分析了这些单项方案和综合方案可减少的大气污染物排放量和空气质量改善程度，推荐了当前可行的投资低、环境效益好的优化综合方案，该综合方案可使兰州市区空气中SO2浓度下降24.6%-75.4%，TSP降10.4%-45.4%；降少数网格点外，SO2浓度都不出现超标。     

Societal Concerns about Pork and Pork Production and Their Relationships to the Production System

Pork producers in Western Europe moreand more encounter a variety of societalconcerns about pork and pork production. Sofar, however, producers predominantly focusedon low consumer prices, therewith addressingjust one concern. This resulted in an intensiveand large-scale production system, decreasinglyrelated to the area of farm land, andaccompanied with increasing concerns aboutsafety and healthiness of pork, animal welfare,environmental pollution, and others.An overview was given of possible concernsabout West-European pork production with theconsumers, citizens, and producers, and thoseconcerns are traced back to the pork productionsystem. The various kinds and qualities ofinformation about the pork production system onwhich possible concerns are based have beenworked out extensively in this paper. Knowledgeabout the aspects of pork production that cangive rise to concerns can be used in two ways.First, the communication about those aspectstowards consumers and citizens can be adjustedor extended to give them better possibilitiesto make food choices or to develop their ownopinions about pork production. Second,producers could change the pork productionsystem such that it better satisfies consumersand citizens. Such adaptations are wellpossible, as three pork quality schemes, whichhave been evaluated, illustrate. However, mostof these adaptations can only be carried out atthe cost of the present low consumer prices andwill not occur spontaneously on a large scale.Therefore, accounting for the type andrelevance of the concerns, legislation isnecessary to address societal concerns in abalanced way such that pork production systemsbecome acceptable for the majority of oursociety.     

Reviving wood-pastures for biodiversity and people: A case study from western Estonia

Wood-pastures are associated with high cultural and biodiversity values in Europe. However, due to their relatively low productivity, large areas of wood-pastures have been lost over the last century. In some areas, incentive schemes have been developed to revive wood-pastures. We investigated the effects of one such scheme in western Estonia. We compared the structure of grazed wood-pastures (old and restored) to those of abandoned wood-pastures and ungrazed forest stands to explore the effects of management, and conducted interviews with 24 farmers to investigate their motivations to carry out the management. We found a positive influence of active management on the semi-open structure of wood-pastures. Financial support was vital for management, but personal values related to tradition also played an important role. The interviewees differed widely in their range of motivations, suggesting that other strategies in addition to financial incentives would further improve the management of wood-pastures in the region.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0719-8) contains supplementary material, which is available to authorized users.     

Does intensity of change matter? Factors affecting adoption of agri-environmental schemes in Spain

Agri-environmental schemes (AES) are the main policy instrument currently available in the EU to promote environmentally-friendly farming practices. However, the rate of adoption of these measures is still relatively low in southern Europe, and understanding how these rates can be increased is still an open issue. The goal of this paper is to increase that understanding by testing whether the factors which determine AES sign-up decisions are influenced by the intensity of change in farming practices that are brought about by adopting the scheme. A micro-economic model reflecting farmer AES sign-up decisions is proposed and applied to two schemes in Spain respectively requiring major or minor intensity of change in practices by surveying farmers eligible for both schemes. The results show that farm structural factors play a role when major practice change is required by the scheme, yet when dealing with minor change, individual farmer characteristics play a more determining role. Social capital and farmer attitude are important factors in both the AES surveyed. Therefore, it may be concluded that improving agronomic design would be an important tool to improve farmer participation in AES where major change is involved, whereas improved targeting and extension would help uptake for AES involving a lesser degree of change.     

存在截渗墙情况下地下咸水恢复的优化方案

本文首先分析了咸水分布区的自然地理和水文地质条件，然后对研究区的水文地质条件进行了概化，建立了相应的地下水水量和水质的数值模型，最后通过地下水模拟软件Visual—MODFLOW3.1对存在截渗墙情况下的不同咸水恢复方案进行了数值分析。研究结果表明。单纯的抽水方案对于高浓度咸水的去除非常有效，但是低浓度咸水残留量较大；抽水——注水方案对高低浓度的去除效果都比较好；而抽水优化方案对高浓度和低浓度的咸水的去除更加经济、快速和彻底。     

机场内部噪声现状多指标评价与防治研究

为分析飞机噪声对机场内部人员的影响，在某军用机场场区内选取九个主要建筑物作为研究对象，对其进行现场噪声测量，在实测数据的基础上，采用多项指标进行机场内部噪声环境评价和分析。结果表明：机场工作人员一直暴露在高噪声环境中，而且各类噪声事件均对其工作和身体健康产生影响，内场营区的声环境质量比外场工作区稍好，但离标准声环境仍有较大距离。最后结合军用机场的特点提出一些有针对性的防治措施。     

Storage of CO2 in saline aquifers: Effects of gravity, viscous, and capillary forces on amount and timing of trapping

CO₂ can be effectively immobilized during CO₂ injection into saline aquifers by residual trapping – also known as capillary trapping – a process resulting from capillary snap-off of isolated CO₂ bubbles. Simulations of CO₂ injection were performed to investigate the interplay of viscous and gravity forces and capillary trapping of CO₂. Results of those simulations show that gas injection processes in which gravitational forces are weak compared to viscous forces (low gravity number N_gv) trap significantly more CO₂ than do flows with strong gravitational forces relative to the viscous forces (high N_gv). The results also indicate that over a wide range of gravity numbers (N_gv), significant fractions of the trapping of CO₂ can occur relatively quickly. The amount of CO₂ that is trapped after injection ceases is demonstrated to correlate with N_gv. For some simulated displacements, effects of capillary pressure and aquifer dip angle on the amount and the rate of trapping are reported. Trapping increases when effects of capillary pressure and aquifer inclination are included in the model. Finally we show that injection schemes such as alternating injection of brine and CO₂ or brine injection after CO₂ injection can also enhance the trapping behavior.     

复杂环境下浅埋大跨地铁渡线隧道施工地层沉降控制方法研究

以北京地铁4号线白石桥至学院南路区间渡线隧道作为工程背景,阐述在复杂环境下浅埋大跨隧道施工的地层沉降控制方法。该隧道具有"隧道跨度大(最大跨度22.1 m),埋深浅,断面类型多、结构复杂"等特点,隧道上方有雨水管等市政管线,地层沉降控制难度极大。首先介绍了渡线隧道总体施工顺序安排、超前加固方案和各断面施工方法,并利用FLAC3D三维数值模拟程序,对最大断面开挖支护过程进行了模拟计算,研究了地表沉降规律和塑性区分布情况,用于指导施工。在施工期间对地表沉降进行监测,其结果表明:渡线隧道施工方法是合理的,地表沉降在控制范围内,确保了隧道周边环境的安全。     

改进突变理论在井下排水方案优选中的应用

为了更精确合理地对新桥硫铁矿排水方案进行优选,对利用突变理论的方法进行优化,建立突变理论和熵权法相结合的改进模型。从经济和工程量方面出发,综合考虑了影响排水方案优选的3个层次的12个指标,统计样本数据。运用熵权法分层确定同一上层变量下各指标的客观权重,导入突变理论中,建立综合评价结构模型,消除了主观因素的影响。同时运用突变理论和EM-TOPSIS进行方案优选,通过对比3种方法的优选结果,证明了改进突变理论的可靠性与合理性。