小麦—白三叶草复合群体中种群关系的初步研究

小麦和白三叶草（Ｔｒｉｆｏｌｉｕｍｒｅｐｅｎｓ）复合共生,是一种新型的农田人工群落。其功能表现为种养（养地与养殖）的有效结合,并通过小麦与三叶草的群体优势抑制农田杂草种群。因此,在理论上,这种复合群体是多功能效益,而且是相对稳定的农田生态系。在生产实...     

不同排放源周边大气环境中NH3浓度动态

氨气是大气中重要的碱性气体和细颗粒物（如PM2.5）的重要前提物质。氨主要来自于农业源（氮肥和养殖业）的排放,但随着城市化和工业化进程的加剧,其他氨排放源如城市垃圾填埋场、污水处理厂、城郊集约化养殖场和交通源（汽车尾气）等的贡献已越来越引起人们的关注。为此,本文于2010年4月-2011年3月期间利用ALPHA被动采样器,研究了北京市不同排放源附近NH3浓度的时空变异及其在大气环境保护中的启示。结果表明：大气中NH3的年均浓度可以分为三个层次,以养殖场猪舍内（2479 μg m-3）和垃圾填埋场的原水调节池（2801 μg m-3）浓度最高;其次为养殖场粪水池边（205 μg m-3）和垃圾填埋场厌氧换热工房（198 μg m-3）,而交通源附近的公路边（15.2 μg m-3）、垃圾填埋场办公区（11.1 μg m-3）和远郊农田（7.8 μg m-3）浓度相对最低。受垃圾组成,温度及降水的影响,垃圾填埋场原水调节池的NH3浓度变化较大,最高浓度（137 μg m-3）和最低浓度（6581 μg m-3）相差达47倍以上。养殖场猪舍内NH3浓度受温度及窗户开闭的影响,表现出冬季高,夏季低的变化趋势,而猪舍外粪池边则相反。交通源附近由于受高浓度的颗粒物含量和温度影响,NH3浓度表现出夏季高、冬季低的变化规律。农田受施肥和温度的影响,也表现出夏季高、冬季低的季节变化。 从大气浓度推断,单位面积猪舍和填埋场原水调节池NH3排放量远高于施肥农田,均为NH3的重要排放源。另外,我们还发现交通源附近(公路边)的NH3浓度几乎为远郊农田的两倍,提醒人们在关注机动车尾气造成NOX污染的同时,也应重视其NH3排放所致的大气污染,后者与机动车普遍安装的尾气后处理装置（三元催化器）有关。     

A comparison of the global warming effects of wood fuels and fossil fuels taking albedo into account

Traditionally, wood fuels, like other bioenergy sources, have been considered carbon neutral because the amount of CO₂ released can be offset by CO₂ sequestration due to the regrowth of the biomass. Thus, until recently, most studies assigned a global warming potential (GWP) of zero to CO₂ generated by the combustion of biomass (biogenic CO₂). Moreover, emissions of biogenic CO₂ are usually not included in carbon tax and emissions trading schemes. However, there is now increasing awareness of the inadequacy of this way of treating bioenergy, especially bioenergy from boreal forests. Holtsmark (2014) recently quantified the GWP of biogenic CO₂ from slow‐growing forests (GWP_bio), finding it to be significantly higher than the GWP of fossil CO₂ when a 100 year time horizon was applied. Hence, the climate impact seems to be even higher for the combustion of slow‐growing biomass than for the combustion of fossil carbon in a 100 year timeframe. The present study extends the analysis of Holtsmark (2014) in three ways. First, it includes the cooling effects of increased surface reflectivity after harvest (albedo). Second, it includes a comparison with the potential warming impact of fossil fuels, taking the CO₂ emissions per unit of energy produced into account. Third, the study links the literature estimating GWP_bio and the literature dealing with the carbon debt, and model simulations estimating the payback time of the carbon debt are presented. The conclusion is that, also after these extensions of the analysis, bioenergy from slow‐growing forests usually has a larger climate impact in a 100 year timeframe than fossil oil and gas. Whether bioenergy performs better or worse than coal depends on a number of conditions.     

内生多粘类芽孢杆菌S-7对甜菜光合作用及产量和品质的影响

研究了内生多粘类芽孢杆菌（Paenibacillus polymyxa）S-7对甜菜叶片光合参数和产量的影响.结果表明：接种内生多粘类芽孢杆菌S-7能显著促进甜菜光合作用,其中叶片净光合速率(P_n)、气孔限制值(L_s)、气孔导度(G_s)和蒸腾速率(T_r )的平均值分别提高了16.11%、23.82%、41.91%和34.80%;叶片胞间CO₂浓度(C_i)平均值降低了21.09%.生物学产量和含糖率分别提高了25.63%和17.46%,促进了甜菜产量和品质提高.表明内生菌不仅影响甜菜光合参数,而且对甜菜产量和品质的提高具有明显的促进作用.     

The macrolepidoptera of farm woodlands: determinants of diversity and community structure

The Farm Woodland Scheme, which provided incentives to convert agricultural land to timber production, contained an implicit assumption that farm woodlands produce important benefits for wildlife. The moth fauna of 18 farm woodlands in the Vale of York was surveyed between May and November 1991. The aims were twofold. The first was to determine if there were benefits for moth species diversity. The second was to ascertain whether concepts of island biogeography and the plant species richness of the woods were related to the moth species composition.Eleven families, 214 species and over 16 000 individuals of moths were recorded. Classification of the species presence/absence matrix indicated that small woods (less than 1ha) did not have characteristic woodland moth communities. Woods larger than 5ha were judged to be more valuable for the long-term conservation of woodland moth diversity. The best predictor of moth species richness was the herbaceous plant species richness within woodlands. Species richness of the family Geometridae was positively related to woodland area, as well as to woodland shape (compact shapes being preferable to elongated shapes). Characteristic woodland species are influenced by isolation (less isolated woods being richer in species). The implications of different powers of dispersal between moth families are discussed. Farm woodlands will be of more value for the conservation of the Macrolepidoptera if they are large, compact and incorporate remnants of existing woodland with extant herbaceous vegetation. These should be factors which are taken into consideration when providing incentives to establish and manage farm woodlands.     

Continuous cultivation of microorganisms

This review presents selected studies on continuous cultivation including the genetics and selection of microorganisms, production of biomass, liquid fuels and other products, published in 1982-1984 and bearing a relationship to biotechnology.     

Lactate Utilization by Isolated Cells from Early Neonatal Rat Brain

The utilization of lactate, glucose, 3-hydroxybutyrate, and glutamine has been studied in isolated brain cells from early newborn rats. Isolated brain cells actively utilized these substrates, showing saturation at concentrations near physiological levels during the perinatal period. The rate of lactate utilization was 2.5-fold greater than that observed for glucose, 3-hydroxybutyrate, or glutamine, suggesting that lactate is the main metabolic substrate for the brain immediately after birth. The apparent Km for glucose utilization suggested that this process is limited by the activity of hexokinase. However, lactate, 3-hydroxybutyrate, and glutamine utilization seems to be limited by their transport through the plasma membrane. The presence of fatty acid-free bovine serum albumin (BSA) in the incubation medium significantly increased the rate of lipogenesis from lactate or 3-hydroxybutyrate, although this was balanced by the decrease in their rates of oxidation in the same circumstances. BSA did not affect the rate of glucose utilization. The effect of BSA was due not to the removal of free fatty acid, but possibly to the binding of long-chain acyl-CoA, resulting in the disinhibition of acetyl-CoA carboxylase and citrate carrier.     

Keratinophilic fungi of poultry farm and feather dumping soil in Tamil Nadu,India

Soils of 10 poultry farms from Namakkal and 12 feather dumping sites from Chennai were studied for the presence of keratinophilic fungi. A total of 34 species belonging to 19 genera and one non-sporulating fungus were recovered. Sixteen species of fungi and one non-sporulating fungi were common to both sites, eight species were specific to Namakkal and nine species were specific to Chennai. Dermatophytes and closely related fungi were represented by six species belonging to five genera. Fungal species commonly found in the soil samples included Chrysosporium keratinophilum (73%), Trichophyton mentagrophytes (68.2%), Microsporum gypseum (64%), Myceliopthora vellerea (32%), Chrysosporium state of Arthroderma tuberculatum (27.3%) and Geomyces pannorum (23%). Non-dermatophyte fungi were represented by 28 species belonging to 14 genera and one non-sporulating fungus.     

Ten lessons in 20 years: Insights from monitoring fauna and temperate woodland revegetation

In the last two decades, there has been enormous effort dedicated to better understanding how to restore and manage temperate native woodland vegetation in Australia's eastern wheat–sheep belt, and the consequences for fauna. This study presents ten of the most important lessons learned from the work to date by the Lindenmayer group at the Fenner School of Environment and Society at The Australian National University.     

Industrial Wastes and By‐products as Alternative Fuels in Cement Plants: Evaluation of an Industrial Symbiosis Option

A ravenous fuel consumer, the cement industry may substitute fossil fuels by industrial wastes and by‐products, identifying the industry as a key example of industrial symbiosis (IS). Benefits from industrial waste alternative fuels (IWAFs) include safe disposal, fossil fuel cost savings, gate fees, and greenhouse gas credits. Poor IWAFs, (high moisture, ash and halogen content) bring higher gate fees, but lessen clinker production. Thermal rating and blower capacity constraints should be satisfied in such a case study of IS. Cement plants must comply with potentially tighter emission limits, compared to fossil fuel utilization, despite higher pollutant precursors in IWAFs. Emissions’ compliance, operational, and production implications are a few among several challenges when assessing multiple IWAF valorization as a symbiotic option from a systems’ perspective. A novel method is proposed to quantitatively assess critical trade‐offs. Species and energy transformations convey a rigorous picture of clinker level, kiln flue gas, and offgas volumes and lay the groundwork for screening, a priori selection, and process tuning. Necessary and sufficient compliance conditions and safety margins are presented in terms of process parameters and actual emissions’ data. Main challenges posed by high flue gas, high offgas volumes, high moisture, low heating value, increased nitrogen oxides emissions, and high halogen and metal content are quantified. As demonstrated in a case study of an actual 1.5 × 10⁶ tonnes per annum clinker plant in this paper, concurrent use of several IWAFs may increase clinker production, while satisfying operational constraints and maintaining compliance. The method may serve for devising IWAF preparation, or tuning mechanisms expanding IWAF valorization.