温室效应对温室气体浓度变化的敏感性分析

工业革命以来人类活动排放到大气中的主要温室气体有CO₂、CH₄、N₂O等,其在大气中的含量增加引起吸收地表辐射能量的增加,改变了地表-大气辐射平衡,造成了地表温度升高。本文研究了温室气体含量增加同其吸收地表辐射能量的关系;比较了不同温室气体含量引起的吸收地表辐射能量变化的差异,提出了温室效应对不同温室气体浓度变化的敏感性的概念。通过对敏感性的分析,得出了不同温室气体含量的变化对温室效应影响的强弱关系。     

大气温室效应的一维辐射传热分析

大气中温室气体对地面长波热辐射的吸收和再发射导致了温室效应.计算了大气不同高度200～50000 cm-1(0.2～50 μm)光谱吸收系数,采用一维大气介质模型和射线踪迹-节点分析法(RTNAM)的多层模型对大气中二氧化碳及水蒸气不同浓度情况下的大气温度进行了计算.结果表明标准大气CO2浓度增加1倍,对流层的温度上升...     

CO_2跨临界(逆)循环的热力学分析

1前言世界各国开展了寻求CFC和HCFC替代物的广泛研究。到目前这项研究已有了实质性的进展。主要提出了包括R134a在内的若干HFC及其混合物来替代R12，R502和R22等，并且已开始商业化生产。但人们已发现这些新工质并没有达到‘长期”替代物的要求，大部分HFC都有较高的温室效应和某些缺陷。随着世界范围制冷空调技术的应用和发展；对各种制冷工质的需求量逐年上升，每年达到数十万吨的消耗量，其中绝大部分将扩散到大气中去。这些物质的寿命或长或短，都会增加温室效应，或分解产生其它的副作用。人类大规模生产地球上本来不存在的气态…     

全球变暖背景下温室效应的光谱能量分布分析

利用一维辐射传递方程及LBLRTM逐线积分模式建立计算模型,对工业革命前与目前大气构成情况下温室效应的能量分布及其光谱吸收机理进行分析,在保持温室气体浓度为当前水平的基础上,研究温室效应能量分布与地表温度之间的相互耦合机理.结果表明:工业革命前地球的温暖环境主要来自于大气温室气体的(100~370)cm^-1、(640~710)cm^-1以及(1370~2000)cm^-1三个强吸收带对于地球长波辐射的吸收,而地球当前的变暖则源自于大气的(370~640)cm^-1和(710~1370)cm^-1两个弱吸收带的作用,其对工业革命以来所额外增加的温室效应贡献分别达到了25%和55%;地表温度升高,温室效应在全波段范围内也会随之增强,但不同谱带处的温室效应贡献以地球平均温度所对应的辐射峰值波数为界线,峰值波数右侧的温室效应贡献将会增加,在其左侧的贡献比例则会减小.     

今日国外物理

 一、美国科学家提出温室效应新观点美国电话电报公司贝尔实验室数学科学研究中心的科学家,采用多窗口时间序列方法,对过去30年来大气中二氧化碳与全球温度相互关系的测量结果进行统计分析,认为地球平均温度尽管出现升高的现象,但还没有充分理由推断出大气中二氧化碳浓度的增加是导致温室效应的根本原因.     

FTIR监测北京地区CO2和CH4及其变化分析

近几十年来,温室效应导致地表温度明显上升,其所引起的全球气候变迁问题越来越受到人们的关注.CO2和CH4是大气中主要的两种人为温室气体,对它们进行连续的测量,获取它们长时间变化情况对大气环境科学具有重要的意义.目前国内监测这两种气体的主要手段是气相色谱方法.鉴于傅里叶变换红外光谱技术的优点,使用开放式长光程FTIR系统在北京地区对这两种气体进行了监测.该系统直接测量开放光路中的环境气体的大气吸收光谱,并使用非线性最小二乘方法进行光谱分析,获取待测组分的浓度信息.在实验部分给出了2005年9月4日到2005年9月10日6天中的北京地区CO2及CH4的测量结果,并对两者的变化趋势和相关性进行了分析.     

可调谐激光吸收光谱法与气相色谱法监测甲烷的对比研究

甲烷是一种重要的温室气体,它对大气中温室效应的贡献仅次于二氧化碳.针对环境空气中甲烷的测定,从测量原理、测量过程和测量装置等方面比较了可调谐二极管激光吸收光谱和气相色谱法两种测量方法.结果表明用上述两种方法测得的甲烷的日变化趋势具有良好的一致性.相比较而言,后者造价更低,并且更方便.     

温室效应模拟实验装置

根据温室效应的产生原理设计制作了温室效应模拟实验装置.装置由温室、模拟地面、模拟太阳、温室保温层以及隔热水槽等部分组成.用数字温度计来测定温室温度变化值.当HFC-134a(四氟乙烷)当作与空气对比的温室气体时,在25～30 min内出现了0.5～0.6℃的温差,在1 h出现了约1℃的温差.该装置具有使用方便、实验操作简单、实验现象明显等特点,能够较好地展示温室效应现象.     

温室效应和TEWI值

1前言当前一个重要的环境变化就是全球变暖，其直接原因是大气中CO_2和其它温室气体浓度的增加。毫无疑问，增加的CO_2来自大量燃烧化石燃料、砍伐森林和绿地的减少，其它温室气体大多亦是人造气体，。总之是人为破坏环境的结果。本文以当今人们最为关心的全球变暖问题为背景，对制冷工质和系统的温室效应问题进行深入的研究和分析。2地球CO_2浓度变化的历史随着年代的变迁，CO_2的浓度在地球历史上一直在变化。分析南极冰层中气泡成份可得到16万年以来CO_2浓度变化数据，在冰川期为180PPmv，在温暖期为280PPmv。CO_2的浓度变化直接…     

大气对流层水汽对温室效应的影响分析

大气温室效应是地球有别于其他星球具有温暖、适合生命生存特性的直接决定因素,而随着地球由温暖再继续变暖,水汽作为地球上含量最丰富的温室气体,其对温室效应的影响也将进一步增强。文章主要针对对流层水汽,利用逐线模型,分析了不同高度下水汽对地气辐射的吸收特点。结果表明,对流层不同高度处水汽对于工业革命前地球环境的"温暖"和目前所面临的"变暖"贡献有着本质的不同:地球的"温暖"主要来自于近地面3 km以下的丰富水汽对于长波辐射的吸收,其吸收比例占到了整个对流层水汽温室效应的50%;但是,目前近地面处水汽的强吸收带已经趋于饱和,因此,地球当前的"变暖"主要是由于对流层高层水汽含量增加所造成的温室效应显著增强所致。     

基于无线传感网的温室花卉自适应调控系统

针对传统温室控制系统大多只是简单地采集环境参数如空气温湿度,并且缺乏长期评估和有效反馈机制的问题,文章提出了一种基于无线传感网的温室花卉自适应调控方法,并实现了一个综合传感、决策、执行反馈的软硬件系统。为此,系统中设计了基于Zigbee的传感器节点模块、传输网关和控制指令集。传感器节点模块可以灵活地布置并实时可靠的传输数据。中间件系统则通过控制指令集接收传感数据和发送反馈控制指令。上层应用管理软件可以实时查看花卉、温室和设备的实时状态以及各种参数。运行结果表明,本系统可以实时采集温室温湿度,并结合专家规则通过中间件系统对花卉生长环境进行有效的评估和精准的反馈调控,达到了在降低温室花卉培育成本的同时,也提高了高端花卉培育成功率的目的。     

Theoretical and Experimental Study on the Impact of Long-Wave Radiation on the Greenhouse Effect of a Prefabricated Temporary House

In this paper, an experimental rig of a prefabricated temporary house (PTH) was first established. Then, predicted models for the thermal environment of the PTH with and without considering long-wave radiation were developed. Next, the exterior-surface, interior-surface and indoor temperatures of the PTH were calculated by using the predicted models. The calculated results were then compared with the experimental results to study the influence of long-wave radiation on the predicted characteristic temperature of the PTH. Finally, the predicted models were used to calculate the cumulative annual hours and the intensity of the greenhouse effect of four different climate cities (Harbin, Beijing, Chengdu, Guangzhou, China). The results showed that: (1) the predicted temperature values of the model considering long-wave radiation were closer to the experimental results; (2) the effect level of the long-wave radiation on the three characteristic temperatures of the PTH from big to small was: exterior-surface temperature, interior-surface temperature, and indoor temperature; (3) the long-wave radiation had the greatest impact on the predicted temperature value of the roof; (4) under different climate conditions, the cumulative annual hours and the intensity of the greenhouse effect considering long-wave radiation were smaller than those without considering long-wave radiation; (5) the duration of the greenhouse effect considering and ignoring long-wave radiation varied significantly with the climate region, and that in Guangzhou was the longest, followed by Beijing and Chengdu, and that in Harbin was the shortest.     

Atmospheric greenhouse effect in the context of global climate change

Summary Great interest in the problem of the atmospheric greenhouse effect (not only in scientific publications, but also in mass media), on the one hand, and the undoubtfully overemphasised contribution of the greenhouse effect to the global climate change, on the other hand, motivate a necessity to analyse the role which the greenhouse effect plays as a factor of climate change. Significant progress in the analysis of existing observational data as well as succesful development of numerical climate modelling which have been achieved during the recent few years create a basis for a new survey of the atmospheric greenhouse effect in the context of global climate change. Such a survey is the principal purpose of this paper. After discussing a notion of the greenhouse effect, the detailed analysis of the present-day and paleoclimatic observational data has been conducted with subsequent consideration of numerical modelling results. A special attention has been paid to assessments of the greenhouse warmingvs. aerosol cooling. Then possibilities of the early detection of a greenhouse climate signal have been analysed and a few comments on the global climate observing system have been made with the general conclusion that more observations and further numerical modelling efforts are necessary to more reliably assess the contributions of various mechanisms to the observed global climate changes. It is only in the context of a coupled totality of significant climate forming factors and processes that the contribution of the greenhouse effect may be estimated.     

温室及其蓄热层中传热与流动的研究

针对被动式太阳能温室系统,分析了玻璃顶部覆盖面倾角不同,对温室中温度及气流分布的影响。温室玻璃顶部覆盖面倾角,可以改变温室中的气流、温度分布。研究了温室蓄热层传热与流动。温室中土壤或岩床具有吸收并贮存太阳能的作用。     

基于PLC和组态软件的大棚环境监测系统设计

设计并实现基于PLC和组态软件的大棚环境监测与决策控制系统。系统以PLC为核心处理器,通过动力控制模块为整个系统提供动力;采用STH-TW2-RHT2-0A-P3-S0型温湿度变送器对大棚内温湿度进行采集,实际应用中,依据检测到的参数结果对执行设备进行参数调整。以汇编语言为主的软件设计过程中,完成了PLC和组态软件的开发,并给出了大棚环境监测与决策控制的程序代码,结果表明,所设计的系统具有精度高、成本低、控制范围大的优点。     

基于ZigBee的温室环境无线测控系统

为了实现温室大棚环境的无线、远程实时监控,提出了一种以CC2430芯片为核心的ZigBee温室环境无线测控系统。描述了终端节点、路由节点和协调器节点的硬件组成和软件流程,并应用改进的Cluster-Tree路由算法组成ZigBee无线传感网络,实现数据的无线传输。利用串口通信技术实现无线传感网络与Yeelink物联网平台的通信,管理者可远程登陆Yeelink平台和手机APP查看温室环境信息以及控制节点状态。经实验测试,大棚内无线节点间的通信距离约80米,并且实现了光强、空气温湿度及土壤湿度的监控。测试表明系统构建简单,稳定可靠,为智能农业的设计提供了参考。     

SO2 cooling and detection of the greenhouse effect

Summary Greenhouse effect calculations normally take into account the greenhouse gases’s (CO₂ mainly) warming effect. Only recently the inclusion of the cooling effect due to different gases (SO₂ mainly) has been suggested. Zecca and Brusa have proposed that the historical evolution of SO₂ production might have caused the apparent global cooling in the period 1940–1970 and might still now hinder the detection of greenhouse warming. In this paper it is shown that the SO₂ hypothesis could lead to a definite detection of the greenhouse warming provided that the globally averaged minimum daily and maximum daily temperatures were studied.     

Global warming is driven by anthropogenic emissions: a time series analysis approach

The solar influence on global climate is nonstationary. Processes such as the Schwabe and Gleissberg cycles of the Sun, or the many intrinsic atmospheric oscillation modes, yield a complex pattern of interaction with multiple time scales. In addition, emissions of greenhouse gases, aerosols, or volcanic dust perturb the dynamics of this coupled system to different and still uncertain extents. Here we show, using two independent driving force reconstruction techniques, that the combined effect of greenhouse gases and aerosol emissions has been the main external driver of global climate during the past decades.     

Comparison of chemical solvents for mitigating CO2 emissions from coal-fired power plants

There is a growing concern about the effect of greenhouse gases on global warming. Among the many greenhouse gases, CO₂ produced from burning fossil fuels is a major contributor due to the huge volumes emitted into the atmosphere. According to the estimates of the Intergovernmental Panel on Climate Change (IPCC), a worldwide reduction in the emission of greenhouse gases by more than 60% is necessary to avert significant global climate changes.This paper examines the key issues involved in greenhouse gas emissions from coal-fired power plants. At the present time, absorption by chemical solvents appears to be best option for the separation of CO₂ from low pressure flue gas streams. The costs of separation and disposal of CO₂ from existing coal fired, air blown boilers are estimated to increase the cost of electricity by about 75%. Therefore, there is a need to optimize the selection of processing solvents and operating parameters to minimize the cost of separation. Increasing the inlet flue gas pressure did not improve mass transfer rates sufficiently to compensate for the higher compression costs. The effects of other process variables were also examined.In this work, we have examined the cost effectiveness of six ethanolamine-based solvents. Overall, monoethanolamine (MEA) was found to be the best solvent.