CO2开关型溶剂及表面活性剂的研究进展与应用

CO_2开关型溶剂及表面活性剂在通入和排出CO_2前后,其化学性质能发生可逆变化,是一类新型的智能溶剂。介绍4种类型CO_2开关型溶剂的开关机理,分析了脒基体系、胍基体系、胺基体系3种类型的CO_2开关表面活性剂的开关机理及研究进展。探讨了CO_2开关型溶剂与表面活性剂在油类提取、制备纳米材料、乳液聚合、含油土壤修复、智能给药、基因载体等方面的应用。分析讨论了当前开关型有机溶剂存在的问题以及研究趋势,并对其发展前景进行了展望。     

浅谈挪威船级社CO2管道泄漏实验

管道输送作为所捕集的CO_2与利用封存场地的纽带,在碳捕集、驱油与封存项目中起着重要的作用。鉴于我国CO_2长输管道的设计标准和规范处于空白,文章对挪威船级社于2006年和2010年的管道泄漏实验进行归纳总结,介绍了工业规模泄放实验的研究目的、实验装置、恒压及泄压释放的操作流程、管道内对压力和温度的监测布点以及大气中对CO_2浓度监测的布点方式等。这为我国研究人员开展CO_2管道泄放的实验设计及研究方法提供了参考借鉴,有助于加快我国CO_2管道输送安全性研究的步伐。     

混交林内大气的CO_2浓度及其对幼树生长的影响

1985年3月至11月末,即从生长季初持续到休眠时期,我们在美国新英格兰的落叶混交林里,对地表以上0.05、0.2、3至12m的CO_2浓度,进行了有计划的、系统的连续观测。数据经过了与处在北半球而代表全球大气CO_2水平的夏威夷冒纳罗亚地区对比。结果表明,林内所有测点CO_2浓度的季节变化与日变化剧烈。在生长季节,林内CO_2的平均水平,一般高于冒纳罗亚的空间。CO_2最高水平在林内底层附近12m处水平最低。休眠季节,林内每天的CO_2水平,在每天的所有时间和所有测点高度上,均基本相同和稳定少变。然而在生长季节则每天的中午时期CO_2浓度最低,特别是在12m的高处。因此,这一研究证明,林内的CO_2浓度与空间大气相比可能是完全不同的,而幼苗、幼树、以及成年树木由于它们对光合作用,生长和水分的利用可有不同的反应,故可经受不同的CO_2环境。而且,单株树木在伸向冠层生长时,同样可以经受这不同的CO_2环境,它的各个不同组成部位也可生长在不同的CO_2大气层中。     

识别CO2驱油泄漏风险的环境监测方法学研究

针对CO_2驱油封存技术,我国在环境监测、环境影响评价等领域的环境监管能力建设还处于空白,亟待加强。文章从CO_2泄漏路径分析、环境监测方法的筛选以及环境背景值缺失情况下的监测数据分析方法等三个方面阐述了各环节的主要研究思路。其中重点介绍了"过程分析法"在CO_2泄漏识别中的应用,强调环境背景值不仅是注气前的环境状况,在注气过程中,每个时间点之前的监测数据均可以看作是背景值。为我国制定相关的法律法规提供重要信息和参考依据。     

出口增长对我国环境影响的分析--以CO2排放为例

本文分析了我国出口增长对环境(CO_2)的影响,结果表明:出口的增长并没有带来人均CO_2排放量的大量增加,相反,在一定程度上却减少了人均CO_2的排放。     

二氧化碳平衡及其污染

到目前为止,已经散发到大气中的二氧化碳大约为每平方厘米地球表面5×10~4克。大多数CO_2溶解在海洋里,其中多数又作碳酸钙从海洋里沉淀出来。只有约0.45克/Cm~2CO_2存留于大气之中。平均每平方厘米地球表面有27克CO_2溶解在海洋之中。溶解在海洋中的CO_2是存留于大气中的CO_2的60倍。海洋和岩石矿物为     

森林人类和水

在地球生态的发展史中,很早以来,水无疑就起着重要的作用。而且,陆地植被的进化必然与最初水的循环紧密联系在一起。水是林冠高度和结构的主要决定性因素。石炭纪的沼泽林林冠高度可达30—40米。看来就在于它们利用了象今天的热带雨林所利用的那样多的水,     

论二氧化碳问题

美国科学界一直认为,在不远的将来大气中 CO_2含量的快速增加将引起空前的全球性的变热,气侯的突然变化将伴随着各种有害的结果。这种论述已经持续很长一段时间。然而,对 CO_2“温室效应”作一个仔细的分析表明以上的说法是一个没有切实证据的论断,它所预测的结果与我们在自然界中所观察到的是完全相反的。更确切地说,农学实验的几十年文字记载,也无疑地证实大气中 CO_2的富集对农业生产将是非常有利的。这使我们只要用目前所需要的一小部分水就可使作物的产量大幅度提高。因此,终将证实大气中 CO_2含量的增加实际上是一种赐福而不是一种灾难。     

自动电位滴定法测定含硼卤水中的CO_3~=、HCO_3~-

利用自动电位仪进行电位滴定、测定含硼卤水中的CO_3~=、HCO_3~-,判断清楚,速度快,同时解决了以往滴定过程中出现的负值,比单独用指示剂指示终点,结果准确,可靠。     

CO2吞吐减排技术研究与应用

为保障天然气脱碳后有效开发,对产生的CO_2资源进行处理,减少外排造成的污染,在CO_2驱油的基础上,拓展应用领域,开展CO_2吞吐技术研究,通过实验评价,应用于吞吐增产机理主要有解膨胀、降低原油黏度及回流返排等三个方面,利用数模与物模等方式对注入量、注入压力及闷井时间等参数进行优化设计。技术研究成功,在吉林油田规模应用100井次/年均,增产原油0.7万t,投入产出比1:1.5,可达到减排目的。     

温室效应与全球变化（三）：全球碳循环与人为二氧化碳排放的控制

本文综述了全球碳循环的现状及人类活动对它的影响，指出人为释放大量的二氧化碳又不使大气中二氧化碳浓度升高是不可能的，人为促进海洋光合作用的增加和在陆地上植树造林在控制大气二氧化碳浓度上升上所能起的作用也是有限的。只有在不放慢经济发展的速度，不降低能源总有效消费量的情况下，努力减少人为二氧化碳的排放才是现实的。本文探讨了这一途径在技术上的可能性。     

Net primary productivity of China's terrestrial ecosystems from a process model driven by remote sensing

The terrestrial carbon cycle is one of the foci in global climate change research. Simulating net primary productivity (NPP) of terrestrial ecosystems is important for carbon cycle research. In this study, China's terrestrial NPP was simulated using the Boreal Ecosystem Productivity Simulator (BEPS), a carbon-water coupled process model based on remote sensing inputs. For these purposes, a national-wide database (including leaf area index, land cover, meteorology, vegetation and soil) at a 1 km resolution and a validation database were established. Using these databases and BEPS, daily maps of NPP for the entire China's landmass in 2001 were produced, and gross primary productivity (GPP) and autotrophic respiration (RA) were estimated. Using the simulated results, we explore temporal-spatial patterns of China's terrestrial NPP and the mechanisms of its responses to various environmental factors. The total NPP and mean NPP of China's landmass were 2.235 GtC and 235.2 gCm(-2)yr(-1), respectively; the total GPP and mean GPP were 4.418 GtC and 465 gCm(-2)yr(-1); and the total RA and mean RA were 2.227 GtC and 234 gCm(-2)yr(-1), respectively. On average, NPP was 50.6% of GPP. In addition, statistical analysis of NPP of different land cover types was conducted, and spatiotemporal patterns of NPP were investigated. The response of NPP to changes in some key factors such as LAI, precipitation, temperature, solar radiation, VPD and AWC are evaluated and discussed.     

Quantification of the regional carbon cycle of the biosphere: policy, science and land-use decisions

This paper addresses some issues related to the carbon cycle and its utilization by society. Traditional uses for agriculture, forestry, as a source of fuel and other products, and for pastoral farming, among others, have recently been supplemented by identifying its potential for mitigating the increasing concentration of greenhouse gases in the atmosphere. Through the Kyoto Protocol, carbon has become a commodity and the CO(2)-absorbing capability of the vegetation and soils an economically valuable asset. The multi-facetted roles of the C cycle and its sensitivity to human activities present a demand for techniques that permit accurate, timely and affordable characterization of the various components of this cycle, especially on land where most human activities take place. Such techniques must satisfy a range of demands in terms of purpose, clients for the information, and biosphere properties. However, if successful, they offer the potential to support monitoring, reporting, policy setting, and management of terrestrial biospheric resources. The context for these requirements and possibilities is illustrated with reference to the China Carbon Sequestration Project and its findings.     

Carbon Pool Dynamics in the Lower Fraser Basin from 1827 to 1990

/ To understand the total impact of humans on the carbon cycle, themodeling and quantifying of the transfer of carbon from terrestrial pools tothe atmosphere is becoming more critical. Using previously published data,this research sought to assess the change in carbon pools caused by humans inthe Lower Fraser Basin (LFB) in British Columbia, Canada, since 1827 anddefine the long-term, regional contribution of carbon to the atmosphere. Theresults indicate that there has been a transfer of 270 Mt of carbon frombiomass pools in the LFB to other pools, primarily the atmosphere. The majorlosses of biomass carbon have been from logged forests (42%), wetlands(14%), and soils (43%). Approximately 48% of the forestbiomass, almost 20% of the carbon of the LFB, lies within old-growthforest, which covers only 19% of the study area. Landfills are nowbecoming a major sink of carbon, containing 5% of the biomass carbonin the LFB, while biomass carbon in buildings, urban vegetation, mammals, andagriculture is negligible. Approximately 26% of logged forest biomasswould still be in a terrestrial biomass pool, leaving 238 Mt of carbon thathas been released to the atmosphere. On an area basis, this is 29 times theaverage global emissions of carbon, providing an indication of the pastcontributions of developed countries such as Canada to global warming andpossible contributions from further clearing of rainforest in both tropicaland temperate regions.KEY WORDS: Carbon pools; Global warming; Carbon release to atmosphere;Greenhouse effect     

Can intensive management increase carbon storage in forests?

A possible response to increasing atmospheric CO₂ concentration is to attempt to increase the amount of carbon stored in terrestrial vegetation. One approach to increasing the size of the terrestrial carbon sink is to increase the growth of forests by utilizing intensive forest management practices. This article uses data from the literature and from forest growth and yield models to analyze the impact of three management practices on carbon storage: thinning, fertilization, and control of competing vegetation. Using Douglas-fir (Pseudotsuga menziesii) and loblolly pine (Pinus taeda) as example species, results from experiments with computer simulation models suggest that, for these two species, thinning generally does not increase carbon storage and may actually cause a decrease. The exception is thinning of very dense young stands. Fertilization generally increases carbon storage, although the response can be quite variable. The largest gains in carbon storage are likely to come from fertilizing lower-quality sites and from fertilizing thinned or less dense stands. Forests usually show increased growth in response to fertilization over a wide range of ages. Simulation of the growth of loblolly pine indicates that controlling competing vegetation at an early age helps to maximize stand growth and carbon storage. The research described in this article has been funded by the US Environmental Protection Agency. This document has been prepared at the EPA Environmental Research Laboratory in Corvallis, Oregon, through contract number 68-C8-0006 to NSI Technology Inc. It has been subjected to the agency’s peer and administrative review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.     

Application of CORINE land-cover mapping to estimate carbon stored in the vegetation of Ireland

The CORINE land cover database for Ireland (in ARC/INFO) is used to estimate the amount of carbon stored (tonnes) by each land-cover (vegetation) type. Carbon store is the area of each CORINE land-cover type multiplied by its carbon density (t C ha⁻¹). Derivations of these carbon densities are described and limitations of data and other empirical evidence discussed. The total vegetation-carbon stores are calculated for Northern Ireland (3·81 Mt), the Republic of Ireland (19·27 Mt) and Ireland (23·08 Mt). Carbon densities are grouped into classes and their distributions across Ireland are mapped. The vegetation-carbon store is taken to include stems, branches, foliage and roots. It does not include litter, microbial biomass and organic carbon in the soil. Forests store 49% of the vegetation carbon on less than 5% of the total CORINE land area, with a further 22% in other semi-natural vegetation. In contrast, pastures account for 56% of the land-cover area, but only 19% of the carbon store. High carbon densities are found in the west and in uplands, reflecting the distribution of forests and semi-natural vegetation, particularly peatland and moors. The inventory of vegetation-carbon stores is an important first step in attempts to monitor changes in carbon sequestration from, and emissions to, the atmosphere by terrestrial vegetation. Greenhouse gas fluxes, including CO₂, and climate warming are global issues which require responses by all countries. Inventories of carbon stores and fluxes therefore need to be comparable between countries so that agreed reductions can be targetted. CORINE land-cover data are available for 19 European Union and adjacent countries and could be used to provide an inventory of carbon stores, and through updating of CORINE, changes in those stores. Commonality in determining the carbon densities of CORINE classes would be required. This study exemplifies how that was achieved in two countries using their national data.     

CO2浓度增加对作物影响的研究动态

大气CO2浓度不断增加将以两种方式影响作物的代谢、生长发育和产量的形成：一是通过温室效应“加热”气候，改变降水类型，进而影响作物；二是浓度变化本身对作物生理过程的影响。介绍了国内外近年来在与CO2浓度有关的作物生理实验方面取得的进展及其主要结果。     

Environmental Flows Can Reduce the Encroachment of Terrestrial Vegetation into River Channels: A Systematic Literature Review

Encroachment of riparian vegetation into regulated river channels exerts control over fluvial processes, channel morphology, and aquatic ecology. Reducing encroachment of terrestrial vegetation is an oft-cited objective of environmental flow recommendations, but there has been no systematic assessment of the evidence for and against the widely-accepted cause-and-effect mechanisms involved. We systematically reviewed the literature to test whether environmental flows can reduce the encroachment of terrestrial vegetation into river channels. We quantified the level of support for five explicit cause-effect hypotheses drawn from a conceptual model of the effects of flow on vegetation. We found that greater inundation, variously expressed as changes in the area, depth, duration, frequency, seasonality, and volume of surface water, generally reduces riparian vegetation abundance in channels, but most studies did not investigate the specific mechanisms causing these changes. Those that did show that increased inundation results in increased mortality, but also increased germination. The evidence was insufficient to determine whether increased inundation decreases reproduction. Our results contribute to hydro-ecological understanding by using the published literature to test for general cause-effect relationships between flow regime and terrestrial vegetation encroachment. Reviews of this nature provide robust support for flow management, and are more defensible than expert judgement-based approaches. Overall, we predict that restoration of more natural flow regimes will reduce encroachment of terrestrial vegetation into regulated river channels, partly through increased mortality. Conversely, infrequent deliveries of environmental flows may actually increase germination and subsequent encroachment.     

Preliminary Estimation of the Realistic Optimum Temperature for Vegetation Growth in China

The estimation of optimum temperature of vegetation growth is very useful for a wide range of applications such as agriculture and climate change studies. Thermal conditions substantially affect vegetation growth. In this study, the normalized difference vegetation index (NDVI) and daily temperature data set from 1982 to 2006 for China were used to examine optimum temperature of vegetation growth. Based on a simple analysis of ecological amplitude and Shelford’s law of tolerance, a scientific framework for calculating the optimum temperature was constructed. The optimum temperature range and referenced optimum temperature (ROT) of terrestrial vegetation were obtained and explored over different eco-geographical regions of China. The results showed that the relationship between NDVI and air temperature was significant over almost all of China, indicating that terrestrial vegetation growth was closely related to thermal conditions. ROTs were different in various regions. The lowest ROT, about 7.0 °C, occurred in the Qinghai-Tibet Plateau, while the highest ROT, more than 22.0 °C, occurred in the middle and lower reaches of the Yangtze River and the Southern China region.