一种汽车车内一氧化碳监控系统

汽车车内由于CO导致的意外安全事故常常被忽略。汽车发动机和空调在运行过程中产生的CO进入车内,极易被忽视而诱发中毒的事故。利用单片机传感器技术设计一种汽车车内CO浓度监控系统,当车内CO浓度达到200 ppm时系统发出第一次报警,当车内CO浓度达到300 ppm,系统发出第二次报警提示,并开启天窗通风,保证车内人员安全。     

Cultivation Influences on Soil Organic Carbon Associated with Texture in Seasonally Frozen Zones

[Objective] This study aimed to examine indicative roles of texture representing soil organic carbon presence and variability subsequent to cultivation under cold temperate climates with seasonal freeze-thaw events.[Method] Three chronosequences were selected for paired comparisons.Soil samples were collected at six depths with a 10 cm increment.Analysis of variance with general linear model and regression was performed for statistical analysis.[Result] In seasonally frozen soils where fragmentation of macroaggregates was stimulated,soil organic carbon level was positively associated with clay ＋ silt proportion due to a wider textural range,better than sole clay content.Exponential function better fitted the experimental data to present progressively increased effectiveness of clay ＋ silt content in maintaining carbon.Clay content explained 12％-41％ and 14％-43％ of variation via linear and exponential functions,respectively.Accordingly,clay ＋ silt content explained 47％-65％ and 46％-70％.[Conclusion] Texture reflected soil organic carbon occurrence as consequences of reclamation.For seasonally frozen soils with wider textural ranges,it is robust to adapt clay ＋ silt content as dependent variable and exponential function.The generated algorithms provided an available pathway to estimate soil organic carbon losses following cultivation and to evaluate soil fertility.     

我国旅游业碳排放测算方法构建与实证研究——基于投入产出视角

按照旅游业"碳减排"的"测定—减排—补偿"三步走的逻辑主线,旅游业碳排放的计量是旅游业节能减排的第一步,也是关键一步。以生命周期评价理论和投入产出分析方法为基础,结合国民经济核算体系、旅游卫星账户、环境经济综合账户等经济与环境计量技术,构建"自上而下"的旅游业碳排放计量方法体系,并实证计量了2002年我国旅游业碳排放量。研究发现,2002年我国旅游业碳排放总量为135.90 Mt,占我国所有产业碳排放总量的3.95%,占我国碳排放总量(包含生活消费碳排放)的3.50%;其中,旅游业直接碳排放为55.65 Mt,分别为交通42.25 Mt,游览1.08 Mt,住宿2.5 Mt,餐饮2.76 Mt,商品销售4.12 Mt,娱乐0.59 Mt,邮电通讯0.43 Mt,其他服务1.92 Mt;旅游业间接碳排放为80.24 Mt,主要贡献国民经济部门为炼焦、煤气及石油加工业、交通运输及仓储业、机器设备制造业、食品制造及烟草加工业等,约占总贡献率的60%。     

Carbon stocks and carbon fluxes from a 10‐year prescribed burning chronosequence on a UK blanket peat

Prescribed burning is a common land management technique in many areas of the UK uplands. However, concern has been expressed at the impact of this management practice on carbon stocks and fluxes found in the carbon‐rich peat soils that underlie many of these areas. This study measured both carbon stocks and carbon fluxes from a chronosequence of prescribed burn sites in northern England. A range of carbon parameters were measured including above ground biomass and carbon stocks; net ecosystem exchange (NEE), net ecosystem respiration (R_eco) and photosynthesis (P_g) from closed chamber methods; and particulate organic carbon (POC). Analysis of the CO₂ data showed that burning was a significant factor in measured CO₂ readings but that other factors such as month of sampling explained a greater proportion of the variation in the data. Carbon budget results showed that whereas all the plots were net sources of carbon, the most recent burn scars were smaller sources of carbon compared with the older burn scars, suggesting that burning of Calluna‐dominated landscapes leads to an ‘avoided loss’ of carbon. However, this management intervention did not lead to a transition to a carbon sink and that for carbon purposes, active peat‐forming conditions are desirable.     

Greater humification of belowground than aboveground biomass carbon into particulate soil organic matter in no-till corn and soybean crops

Quantifying the amount of carbon (C) incorporated from decomposing residues into soil organic carbon (C_S) requires knowing the rate of C stabilization (humification rate) into different soil organic matter pools. However, the differential humification rates of C derived from belowground and aboveground biomass into C_S pools has been poorly quantified. We estimated the contribution of aboveground and belowground biomass to the formation of C_S in four agricultural treatments by measuring changes in δ¹³C natural abundance in particulate organic matter (C_POM) associated with manipulations of C₃ and C₄ biomass. The treatments were (1) continuous corn cropping (C₄ plant), (2) continuous soybean cropping (C₃), and two stubble exchange treatments (3 and 4) where the aboveground biomass left after the grain harvest was exchanged between corn and soybean plots, allowing the separation of aboveground and belowground C inputs to C_S based on the different δ¹³C signatures. After two growing seasons, C_POM was primarily derived from belowground C inputs, even though they represented only ∼10% of the total plant C inputs as residues. Belowground biomass contributed from 60% to almost 80% of the total new C present in the C_POM in the top 10 cm of soil. The humification rate of belowground C inputs into C_POM was 24% and 10%, while that of aboveground C inputs was only 0.5% and 1.0% for soybean and corn, respectively. Our results indicate that roots can play a disproportionately important role in the C_POM budget in soils. Keywords Particulate organic matter; root carbon inputs; carbon isotopes; humification rate; corn; soybean.     

Indicators and trade-offs of ecosystem services in agricultural soils along a landscape heterogeneity gradient

Soil functions can be classified as supporting (nutrient cycling) and provisioning (crop production) ecosystem services (ES). These services consist of multiple and dynamic functions and are typically assessed using indicators, e.g. microbial biomass as an indicator of supporting services. Agricultural intensification negatively affects indicators of soil functions and is therefore considered to deplete soil ES. It has been suggested that incorporating leys into crop rotations can enhance soil ES. We examined this by comparing indicators of supporting soil services – organic carbon, nitrogen, water holding capacity and available phosphorous (carbon storage and nutrient retention); net nitrogen mineralisation rate and microbial biomass (nutrient cycling and retention) – in barley fields, leys and permanent pastures along a landscape heterogeneity gradient (100, 500 and 1000 m radii). In addition, barley yields (provisioning service) were analysed against these indicators to identify trade-offs among soil services. Levels of most indicators did not differ between barley and ley fields and were consistently lower than in permanent pastures. Leys supported greater microbial biomass than barley fields. Landscape heterogeneity had no effect on the indicators or microbial community composition. However, landscape heterogeneity correlated negatively with yield and soil pH, suggesting that soils in heterogeneous landscapes are less fertile and therefore have lower yields. No trade-offs were found between increasing barley yield and the soil indicators. The results suggest that soil ES are determined at the field level, with little influence from the surrounding landscape, and that greater crop yields do not necessarily come at the expense of supporting soil services.     

Cross‐linked polyacrylates in post‐mining substrates: persistence and effects on plant growth

Application of hydrophilic polymers composed of cross‐linked polyacrylate can improve soil water‐holding capacity and accelerate the restoration of post‐mining substrates. In this work, we studied the persistence of a polyacrylate polymer incorporated into a soil and its impact on plant nutrients at a reclamation site of former lignite mining in Lusatia (Germany). In contrast to autumn application, the incorporation of the polymer enhanced the sequestration of plant‐derived carbon in the soil, which was reflected by a significant increase in the concentration of a lignin marker. Attenuated total reflexion–Fourier transform infrared spectra (ATR‐FTIR) and total elemental contents in the applied polymer suggested an intensive cation exchange between the polymer framework and the soil‐forming substrate. In addition, there was an enrichment of carbonaceous material, which seems to reduce the swelling and thus the water‐holding capacity of the cross‐linked polyacrylate. Conversely, this process protected the polymer structure from rapid decomposition.     

住宅建筑热泵的热源选择

指出了住宅建筑的暖通空调能耗占建筑能耗的比重大，较燃煤取暖而言，热泵技术的节能效果显著。从原理特点、适用性、限制条件、土建和设备建设难度和周期、后期管理维护等方面分析了空气、地表（下）水、土壤、太阳能和污水等热泵热源，探讨了住宅建筑热泵热源选择的总的原则。     

呼伦贝尔地区苜蓿人工草地CO_2通量变化特征

试验采用密闭箱技术对呼伦贝尔地区种植的苜蓿人工草地进行碳通量研究,采用反硝化-分解作用模型(DNDC)进行模拟。试验结果表明:对苜蓿人工草地CO2通量24h连续观测发现,CO2通量全天变化的平均值(238.15mg/(m2·h)与11∶00(245.32mg/(m2·h)的通量变化值接近,试验从早上9∶00~11∶00进行温室气体的采集方法合理、可行;在整个生长季变化表明,7、8月CO2通量变化较显著(P0.05),且受到降水的影响较大,伴随降水的发生,CO2通量会发生不同幅度的变化,土壤温度和含水量对CO2通量有一定的影响(r0.45,P0.05);通过DNDC模型的模拟,能较好的反映苜蓿人工草地CO2通量的变化情况,但模拟结果数值普遍有些偏高。     

低碳背景下县域经济发展方式转变的对策研究

加强节能减排,实现低碳发展,不仅是国家“十二五”规划纲要所提出的约束性目标,更是促进经济提质增效升级的必经途径.目前,我国县域经济仍以“高投入、高消耗、高排放”为主要特征,转变经济发展方式已成为县级政府所面临的迫切任务.为此,必须依据低碳发展理念和《2014 ～2015年节能减排低碳发展行动方案》的具体要求,培育有利于经济发展方式转变的要素基础和制度基础,加快推进产业结构的优化和升级,深化经济管理体制改革,不断进行制度创新,实施有利于科技进步的政策,完善环境管理制度,实现县域经济又好又快发展.