生物质能的利用现状及展望

在概述生物质能概念、特性及开发利用生物质能意义的基础上,重点从生物质能的直接燃烧、物化转化、生化转化、植物油技术和利用生物质合成新产品等几方面来介绍国内外生物质能利用的现状,最后展望生物质能研究的主要方向。     

Contrasting Effects of Long-Term Fire on Sagebrush Steppe Shrubs Mediated by Topography and Plant Community

The role of fire in restoration of sagebrush plant communities remains controversial mainly because of paucity of information from long-term studies. Here, we examine 15-year post-fire responses of big sagebrush (Artemisia tridentata ssp wyomingensis) and broom snakeweed (Gutierrezia sarothrae), the two most abundant native shrubs at the John Day Fossil Beds National Monument, a protected area in north-central Oregon, USA. Fire effects were studied along gradients of topography and community type through time post-burn. Community types were distinguished as brush, plots dominated by big sagebrush and woodland, plots with a significant presence of Western juniper (Juniperus occidentalis) trees. Fire reduced big sagebrush cover in brush plots up to 100% and in woodland plots up to 86%. Broom snakeweed cover declined by 92% and 73% in brush plots and woodland plots, respectively. Big sagebrush did not show signs of recovery 15 years after burning regardless of topography and community type while broom snakeweed populations were clearly rebounding and prospering beyond pre-burn levels. Our results showed that an area initially dominated by big sagebrush (cover of big sagebrush 10-20%, cover of broom snakeweed 2-4%) dramatically shifted to an area dominated by broom snakeweed (cover of big sagebrush < 1%, cover of broom snakeweed 5%) in brush-dominated plots. Our results indicated that brush-dominated plots at lower elevation and southern exposures are the least post-fire resilient. We also observed a declining population of big sagebrush on unburned areas, suggesting the lack of post-fire recovery on burned areas was perhaps a result of low seeding potential by extant populations. Although more years of observation are required, these data indicate that recovery time, the encroachment of opportunistic competing shrubs, and the initial condition of vegetation are essential considerations by land managers when prescribing fire in big sagebrush communities.     

大别山硅化木的研究

本文研究了6种大别山硅化木,其中南麓有杉木、湖北柏木和海南红豆;北麓有竹柏、油杉和河南松。杉木(Cunninghamia lanceolata Hook.)(图版I-1—3)标本号:HG013 外观特征:硅化木外观灰黄及黄白色。系树木大枝,圆柱状,长31cm,大头直径9cm,小头直径7cm。生长轮明显,轮间介以极窄的深色晚材带,轮宽2—3mm,有假年轮存在。     

The local industrial complex? Questioning the link between local foods and energy use

Local food has become the rising star of the sustainable agriculture movement, in part because of the energy efficiencies thought to be gained when food travels shorter distances. In this essay I critique four key assumptions that underlie this connection between local foods and energy. I then describe two competing conclusions implied by the critique. On the one hand, local food systems may need a more extensive and integrated transportation infrastructure to achieve sustainability. On the other hand, the production, transportation, and consumption of local foods are fundamentally as reliant on fossil fuels as are long distance foods. A more holistic approach to energy use in the food system is needed to determine which particular sociotechnical factors optimize energetic sustainability.

Ekerekeia nom. nov., a replacement name for Farquharsonia Currie, 1928 (Echinodermata: Euechinoidea), preoccupied by Farquharsonia Collin, 1922 (Insecta: Diptera)

A junior homonym was detected among fossil echinoid genera and the following replacement name is proposed: Ekerekeia nom. nov. for Farquharsonia Currie, 1927 (nec Collin, 1922). Accordingly, new combinations are herein proposed for the species currently included in this genus: Ekerekeia crenulata (Kier 1972) comb. nov. from Farquharsonia crenulata Kier, 1972 and Ekerekeia somaliensis (Currie, 1927) comb. nov. from Farquharsonia somaliensis Currie, 1927.     

Energy requirements for transport and surface application of liquid pig manure in Manitoba,Canada

The objective of this study was to conduct a thorough accounting of energy used to transport liquid pig manure from farm storage to the field and to surface-apply the manure. Energy consumption was determined using both energy data from the literature plus data from field-scale research. Energy consumption was compared between two manure application systems (the drag hose and the slurry wagon systems) and two application timing treatments (single vs. twice-annual manure application). The single annual application of liquid pig manure applied at 81.5 m³ ha⁻¹ and transported 1.8 km from storage to field consumed 2180 MJ ha⁻¹ with the drag hose system and 2185 MJ ha⁻¹ with the slurry wagon system. The twice-annual manure application regime used 2726 and 2209 MJ ha⁻¹ for the drag hose and slurry wagon systems, respectively. When energy use was calculated on the basis of MJ per kg of available N, liquid pig manure applied once annually with the slurry wagon system provided N at 17.76 MJ kg⁻¹ of available N, which was 33% of the energy cost of N from anhydrous ammonia and 23% of the energy cost of N from urea. Manure transport distance could be increased to 8.4 km before the energy cost per kg of available N from pig manure was equivalent to anhydrous ammonia, and up to 12.3 km before the energy cost of manure N was equivalent to urea N. Despite the high energy cost to deliver liquid pig manure from storage to field, the much lower cost per kg of available N compared to inorganic fertilizer N highlights the opportunities that exist for improving the energy efficiency of industrial agriculture by replacing inorganic fertilizers with manure.     

基于古生物化石资源的辽西地区旅游开发研究

通过对辽西地区古生物化石资源现状的说明,分析了辽西地区开发古生物化石资源的优势,提出了辽西地区应如何利用古生物化石资源来进行旅游深度开发的措施和建议。     

The impact of fossils on the Evolutionary Distinctiveness and conservation status of the Australian lungfish

The recognition of phylogenetic information for evaluating conservation priorities has stressed the importance of basal taxa. The “Evolutionary Distinctiveness” index (ED) is a species-specific index that includes branch length expressed as an absolute value measured in millions of years that can be applied to a single terminal taxon in a phylogeny. The ED depends on the tree pattern, i.e. of a cladogram included into a time-scale. When calculated for the Australian lungfish (Neoceratodusforsteri), a threatened dipnoan that occurs naturally only in southeast Queensland, the ED index shows variable value according to the chosen tree. On the basis of a recently proposed phylogeny including a new fossil find from the Early Cretaceous of Thailand, the ED value reaches the highest value for piscine sarcopterygians, and for all vertebrates, and thus reinforces the “originality” of this fish. This example points out the importance of fossils in the resolution of phylogenies and beyond, in the calculation of indexes supporting conservation decisions.     

Reconstructing the soil food web of a 100 million-year-old forest: The case of the mid-Cretaceous fossils in the amber of Charentes (SW France)

Over the past decade, the mid-Cretaceous amber deposits of Charentes (SW France) have been intensively studied. The fossils investigated were not only limited to arthropods preserved in amber, but also included microorganisms, plant debris and vertebrate remains. This plethora of analyses provided important data about the ecology of the overall system, including sources of litter input into the soil and of the above-ground ecology. More precisely, they showed that most of the microfossils were those of soil organisms or organisms that participated in the ecology of the forest soil. This new discovery provided the opportunity to study the ecology of the soil as preserved in the 100 million years old Charentes amber. Indeed, the trophic links of the fossil forest soil have been reconstructed on the basis of the fossil assemblage discovered in amber outcrops and overlayed on a model ecological forest soil food web. We relied on existing phylogenetic information to discuss the absence of certain taxonomic groups in the fossilized specimens. Our synthesis shows that although the organisms of this ancient forest of Charentes were different from those of modern soils, the soil food web was organized functionally the same as modern soils. It also demonstrated that trophic links of the soil community were already diverse, including various means of predation, parasitism and organic matter decomposition. The most obvious differences are the absence of evidence for symbiotic root nitrogen fixation and mycorrhizae.     

辽宁省二氧化碳排放现状调查及减排措施研究

根据辽宁省各城市2004年空气污染源排放清单,以各城市各类化石燃料消耗量为基础,利用不同化石燃料二氧化碳排放系数,核算出辽宁省各城市2004年二氧化碳总排放量为3.47亿t,并以《辽宁统计年鉴》为基础数据对其进行校核,证明其数据合理,方法可行,计算结果能在一定程度上反映出辽宁省二氧化碳的排放情况。通过数据分析,掌握了辽宁省二氧化碳排放的现状,分析了辽宁省二氧化碳主要排放行业（电力、水泥、钢铁行业）的特点和规律,并确定了辽宁省减排二氧化碳的技术措施和控制战略。