基于AMS的14C法对生物质与煤混燃掺烧比测定的研究进展

生物质与煤耦合燃烧不仅可以提高生物质资源利用率，还可以达到减排效果，以符合碳交易市场要求。将生物质与煤混燃技术广泛应用于发电厂，需要对生物质掺混比进行高精度测定。然而，当前工业技术测量的速度和精度还有待提高。基于加速器质谱(AMS)的¹⁴C检测法能够更准确迅速地进行¹⁴C含量的测定，从而得出生物质掺混比例。本文阐述了生物质掺混比的高精度快速测定方法，并从采样方法、¹⁴C含量测定、掺烧比计算模型、误差分析等方面对基于AMS的¹⁴C检测方法进行了分析，并提出了测量方法的改进建议和展望，以期对生物质与煤耦合燃烧输入侧掺混比精确快速测定提供科学参考和建议。     

480t/h循环流化床机组煤热值与煤耗关系研究及改进措施

某电厂2×480 t/h循环流化床锅炉燃用煤种繁多,配煤掺烧的标准是以负荷达到中调要求及排渣系统能满足负荷需求为主,而掺烧比例不定,配煤较为盲目,机组供电标煤耗长期居高不下,给公司的经济效益造成重大影响。通过对锅炉进行长期燃烧试验,对入炉煤发热量、掺烧比例与机组供电煤耗进行量化分析,摸索出该公司480 t/h循环流化床锅炉燃煤热值与供电煤耗关系曲线,为运行中配煤掺烧提供参考依据,提出公司配煤掺烧的管理方向及改进措施,为同类锅炉机组运行提供参考。     

一种非标再热参数掺烧工艺废气煤粉锅炉开发

依托某化工园区热电联产项目配套1台150 MW背压式汽轮发电机组,为了处理化工园区生产过程中制造的工艺废气,自主开发设计了一种非标再热参数掺烧废气煤粉锅炉,锅炉为超高温亚临界参数,锅炉最大连续蒸发量为450 t/h,过热器压力温度参数为17.5 MPa/571℃,再热器蒸汽流量439.3 t/h,再热器压力温度参数为10.02 MPa/530℃,燃料为煤粉掺烧工艺废气,锅炉投运后,能够安全有效地掺烧工艺废气且各项指标运行正常,满足用户需求。     

燃煤锅炉掺烧粘胶纤维水处理污泥及工艺废气可行性研究

指出了纤维素行业污水处理难度大,污泥产生量较大,且可循环利用价值低,此外粘胶纤维行业产生的恶臭影响也较大。一般利用燃煤锅炉来协同处置水处理污泥及工艺废气,资源化利用污泥燃烧产生的热值,降低恶臭对大气环境的影响。分析研究了目前应用较多的热电厂污泥掺烧模式,对比了实施“高干脱水+半干污泥入炉掺烧”的3个厂家的实际运行效果,以供参考。     

燃煤锅炉掺烧干气工艺分析

探讨了延安炼油厂干气的产生、特点、危害性以及现阶段利用方法,以其车间75t／h循环流化床锅炉运行为实例详尽分析了干气利用和燃煤锅炉掺烧的优缺点及其环境效益、经济效益。     

人类经营活动对森林土壤碳的影响

文章从森林采伐、林地生物质燃烧、造林前整地、森林采伐后的不同土地利用方式等方面阐述了人类经营活动对森林土壤碳的影响。对我国亚热带杉木林地力衰退情况进行了分析，并提出了免耕免烧的栽培方式。     

污泥强力脱水干化及燃煤锅炉掺烧处理方法

分析了污泥的分类、特点,对环境的危害,以及现阶段国内外的处理方法。以西安市眉坞化工纸业废水处理过程为实例,详尽地探讨了污泥焚烧和燃煤锅炉掺烧的优缺点及其环境效益、经济效益。     

生物质气化多联产技术的集成创新与应用

生物质气化作为生物质能源的一种主要形式,近几十年来得到了国内外的广泛关注和研究。但是由于传统技术燃气中焦油含量高、气化产物单一致使经济效益不佳、存在一定的环境污染及设备系统不够完善等难题,极大地阻碍了生物质气化技术的发展以及实现工业化规模的步伐。笔者所在的团队在国内外率先提出了基于"生物质气化(能源)多联产技术"的新发展思路,并进行了相应的技术研究与产业化应用。根据生物质资源特性不同,研究开发了适合农作物秸秆类的流化床气化多联产炉、果壳类下吸式气化多联产炉和木质类上吸式气化多联产炉,并针对不同的生物质气化产物研发了相应的产品利用路线。其中气相产物(可燃气)用于发电、供气或者热燃气(未经气液分离)直接烧锅炉供热或带动蒸汽轮机发电,该技术解决了燃气净化和焦油的两大难题;液相产物(生物质提取液)制备液体肥料;固相产物(生物质炭)根据生物质原料的不同可分别用于制备炭基有机-无机复混肥(秸秆类原料)、高附加值活性炭(果壳类和木片类)以及工业用还原剂和民用燃料(木质类)。生物质气化多联产技术新理念的提出以及相关核心技术设备的开发与应用也为生物质利用探索出了一条符合绿色、环保和循环、可持续产业发展的良好路径,生物质能源的发展只有与环境保护(空气、水、土壤及食品安全)相结合才是最根本的出路。     

秸秆与粉煤灰互掺在混凝土材料中的研究进展

随着可持续发展理念越来越深入人心，生物质资源利用也逐渐成为人们关注的热点问题。秸秆与粉煤灰作为可再生资源，对其进行回收再利用，不仅能充分利用废弃物资源，同时也避免了环境污染。通过对秸秆与粉煤灰互掺在混凝土材料中的研究，从力学性能、耐久性能、保温性能三个方面介绍了秸秆与粉煤灰的掺入对混凝土材料的影响，并对其未来发展方向提出建议，旨在为研究秸秆与粉煤灰互掺的混凝土材料提供参考。     

生命周期评价在硫铁矿掺烧亚铁渣制硫酸中的应用研究

采用生命周期评价的方法,对硫铁矿掺烧亚铁渣制98%工业硫酸从电力生产、硫铁矿采选、运输以及硫酸生产4个阶段进行了研究。定量分析了硫酸整个生命周期的资源能源投入、环境负荷等问题,从而找出在硫酸生命周期中的主要环境问题,为硫酸生产改进生产技术、提高清洁生产水平提供数据支持。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.