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41.
The nitrogen changes and the nitrogen mass balance in a free water surface flow constructed wetland (CW) using the four-year monitoring data from 2008 to 2012 were estimated. The CW was composed of six cells in series that include the first settling basin (Cell 1), aeration pond (Cell 2), deep marsh (Cell 3), shallow marsh (Cell 4), deep marsh (Cell 5) and final settling basin (Cell 6). Analysis revealed that the NH4+-N concentration decreased because of ammonification which was then followed by nitrification. The NO4+-N and NO4+-N were also further reduced by means of microbial activities and plant uptake during photosynthesis. The average nitrogen concentration at the influent was 37,819 kg/year and approximately 45% of that amount exited the CW in the effluent. The denitrification amounted to 34% of the net nitrogen input, whereas the accretion of sediment was only 7%. The biomass uptake of plants was able to retain only 1% of total nitrogen load. In order to improve the nutrient removal by plant uptake, plant coverage in four cells (i.e., Cells 1, 3, 4 and 5) could be increased.  相似文献   
42.
本文根据生态环境资产负债表的基本概念和理论,提出了生态环境资产负债表编制的总体框架,同时,针对环境容量资产、环境质量产品、生态产品资产的特点,分别建立了相应框架体系,提出了环境资产负债表的应用决策方向。本文研究成果对于确立统一的生态环境资产核算标准和方法、使我国生态环境资产负债核算工作逐步规范化、制度化具有重要的现实意义。  相似文献   
43.
京津冀区域生产和消费CO2排放的时空特点分析   总被引:1,自引:0,他引:1  
汪浩  陈操操  潘涛  刘春兰  陈龙  孙莉 《环境科学》2014,35(9):3619-3631
区分消费和生产二氧化碳排放是对开放的经济区域进行排放责任划分的基础,日渐受到政策制定者的关注.利用经济投入产出-生命周期分析模型,对京津冀区域1997年、2002年和2007年的消费和生产二氧化碳排放时空特征及二氧化碳排放平衡进行分析.结果表明,京津冀区域消费和生产二氧化碳排放呈约4%的年均增长;贸易隐含二氧化碳排放比例为30%~83%,并以国内贸易隐含二氧化碳排放为主;河北的消费和生产二氧化碳排放占区域主导,增速和二氧化碳排放强度高于北京和天津;京津冀区域为二氧化碳排放净流入区域,存在部分排放责任转移;京津为二氧化碳排放净转入地区,冀为二氧化碳排放净转出地区;京津冀三地二氧化碳排放关键部门分布集中且相似度较高,可以考虑区域联合控制.其中,电力、蒸汽、热水生产和供应业和金属冶炼及压延加工业对二氧化碳排放的依赖性最大,承担较大的其他部门的二氧化碳排放责任.投入产出分析解析了地区生产和消费二氧化碳排放情况,有利于区域减排的精细化管理和制定相应对策,并促进区域减排合作.  相似文献   
44.
粤北地区干旱监测及预警方法研究   总被引:2,自引:0,他引:2  
从农业生产实际出发,引入能够判断作物受旱程度的毛管破裂含水量、凋萎含水量等土壤含水量指标来确定干旱指标,根据土壤水分平衡理论,建立干旱监测预警模型,利用自动站气象资料和降水趋势预报对干旱情况进行判别和分析,并采用Surfer软件对干旱情况进行直观的图形显示.  相似文献   
45.
自然资源资产及其负债表编制与审计   总被引:1,自引:1,他引:0       下载免费PDF全文
自然资源资产仍然是一个新概念,还需要在理论和方法层面进行系统的研究。就当今及今后一个时期看,自然资源资产负债表的编制和自然资源资产审计,是亟需研究的理论和现实问题。在此,重点对自然资源资产的概念、属性、分类进行探讨,并就自然资源资产负债表及编制的重点与基础,自然资源资产审计及其重点与方式等,进行系统讨论。  相似文献   
46.
In urban ecosystems, the ecological system has become completely unbalanced; this, in turn, has led to an increase in well-known problems such as air pollution, ground pollution, and water pollution. This imbalance has also led to the growth and spread of pathogens harmful to man, animals, and plants. Urban sustainability indicators, both global and local, also “indicate” the percentage of population, but these refer only to the human population, not the animal population. Cities need good waste, water, and air management, effective traffic planning, and good zoning of businesses, crafts, and services; over and above these activities, cities also need for planning to take into account the existence of pets (dogs, cats, and etc.) and nonpet animals (insects, birds, mice, etc.). Cities tend to be designed around humans and “on a human scale,” without taking into account the fact that a huge animal population is living side by side with people. That explains why overcrowding tends to go hand in hand with urbanization; all these populations, including humans, need to adapt to new spaces and often need to drastically change their behavior. This is a fact that must be included when drafting sustainable city plans. The supposed strategy is that of “integrated-participatory” control of the interactions between the environment and animals in the cities. Strategy will focus on the development of integrated approaches and tools for environment and animal management in the context of urban settings. This will require such specific methods as ecological balance sheets and ecoplans for the planning, management, and control of the interrelation among environment, animal, and public health. The objective is to develop a better understanding of urban biodiversity and of urban ecosystem functioning, in order to understand and minimize the negative impacts of human activities on them. The research will focus on assessing and forecasting changes in urban biodiversity, structure, function, and dynamics of urban ecosystems, with relationships among society, economy, biodiversity, and habitats.  相似文献   
47.
The concept of time perspective balance has attracted increased attention from scholars in the past decade, reflected in published evidence suggesting positive outcomes ranging from enhanced mood to life satisfaction for those individuals possessing balance among their past, present, and future time perspectives, and assumedly able to shift their time perspective to match situational demands. In this paper, we consider the notion of time perspective balance in an organizational setting within which much consequential adaptation often occurs—the team environment—and explore different configurations of time perspective balance in teams facing dynamic task contexts. Drawing from work on situational awareness, we first consider the mechanism by which time perspective balance likely influences individual adaptation in dynamic task-focused situations. Next, we postulate what types of team configurations—ones with more balanced time perspective uniformity or ones with more time perspective variety—might be more appropriate in dynamic contexts given key team conditions. We illustrate our analysis with examples from healthcare team settings and offer ideas for future research.  相似文献   
48.
借鉴会计学复式记账核算的优点,在国际资源核算体系的基础上,根据我国自然资源资产核算需求,提出土地资源资产核算的复式记账体系和报表编制框架。研究认为,基于复式记账的土地资源资产核算和报表编制要以“摸清家底、反映自然资源负债、提供土地资源审计和绩效考核信息”为目标,明确区、县级自然资源局为土地资源资产受托管理和进行土地资源资产核算与报表编制的核算单位。在界定土地资源资产、负债和权益相关概念的基础上,提出土地资源资产属性变化的核算内容和每次土地资源资产实物量变化必须遵循占补平衡的基本原则,进行过程核算。以YC县土地资源资产变化为例,对土地资源资产变化进行了基于复式记账的土地资源资产核算与报表编制实证研究,确定核算的事项类型和特征及其借贷核算流程,编制出土地资源资产负债表,并同时进行实物量核算和价值量核算的报表编制,结果表明:YC县土地资源资产实物量1485 km^2,2018年末价值量5639874.22万元、经济权益5271874.22万元、生态权益367991.6万元,土地资源负债8.40万元,通过土地资源资产用途调整,土地资源资产价值量增加21319.42万元,但在调整过程中,形成了土地资源负债0.07 km^2(8.4万元),在以后土地整治中需要增加园地。  相似文献   
49.
A comprehensive evaluation of organic contamination was performed in sediments sampled in two reference and three impacted small streams where endocrine disruptive (ED) effects in fish have been evidenced. The approach combined quantitative chemical analyses of more than 50 ED chemicals (EDCs) and a battery of in vitro bioassays allowing the quantification of receptor-mediated activities, namely estrogen (ER), androgen (AR), dioxin (AhR) and pregnane X (PXR) receptors. At the most impacted sites, chemical analyses showed the presence of natural estrogens, organochlorine pesticides, parabens, polycyclic aromatic hydrocarbons (16 PAHs), bisphenol A and alkylphenols, while synthetic steroids, myco-estrogens and phyto-estrogens were not detected. Determination of toxic-equivalent amounts showed that 28-96% of estrogenic activities in bioassays (0.2-6.3 ng/g 17β-estradiol equivalents) were explained by 17β-estradiol and estrone. PAHs were major contributors (20-60%) to the total dioxin-like activities. Interestingly, high PXR and (anti)AR activities were detected; however, the targeted analysed compounds could not explain the measured biological activities. This study highlighted the presence of multiple organic EDCs in French river sediments subjected to mixed diffuse pollution, and argues for the need to further identify AR and PXR active compounds in the aquatic environment.  相似文献   
50.
中国工业化进程与能源矿产供需均衡的研究   总被引:2,自引:0,他引:2  
工业化与能源需求的均衡关系及解决工业化进程中能源供需失衡的战略途径是中国工业化进程中需要探讨的重大问题.文章运用协整技术,就1990-2008年间中国工业化进程与能源需求协整关系的检验,认为中国工业化与能源需求增长具有长期稳定的均衡关系,能源需求将继续保持增长,能源利用效率也将持续提高.然而工业化进程中重工业化高能耗结构特征与能源低效利用并存的困境以及能源供需矛盾不利于能源供需平衡的平稳发展.我国应适应工业化进程的基本规律,转变能源消费方式;走新型工业化道路,适当限制低附加值产业发展,鼓励产业向离附加值、低能耗、高技术产业转移;在实现能源开发利用技术进步和创新的同时.有效利用国内外能源资源;建立能源应急机制等战略途径来实现工业化进程中能源供需平衡发展.  相似文献   
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