TCD燃烧系统对柴油机燃烧和排放性能改善效果的试验研究   总被引：1，自引：1，他引：0  

康与宁  李向荣  薄大伟  陈彦林  刘栋  常江 《农业工程学报》2021,37(11):50-59

为探究道依茨TCD2015柴油机上配备的导流燃烧系统(简称TCD燃烧系统,T表示涡轮增压器,Turbocharger,C表示进气中冷,Charge air cooling,D为柴油颗粒捕集器,Diesel particle filter)对改善柴油机燃烧性能和降低污染物排放的效果,采用单缸机试验对TCD燃烧系统在不同转速、负荷和过量空气系数下的燃烧和排放性能进行研究。试验结果表明不同工况下TCD燃烧系统燃油消耗率和Soot排放量均低于传统ω燃烧系统,燃油消耗率最大降幅为7.01%,Soot排放量最大降幅为86.67%,且低过量空气系数(1.2～1.6)下TCD燃烧系统仍具有较好的性能。为揭示TCD燃烧系统改善油气混合促进燃烧的机理,采用AVL Fire软件建立了柴油机性能仿真模型。计算结果表明,TCD燃烧系统的环状凸起结构将燃油导向内外两室,从而促进了缸内燃油发展过程,燃油当量比大于4的浓混合气区域燃油质量比例相比ω燃烧系统降幅最大为9.75%,活塞下移时TCD燃烧系统内油束撞击浅盘侧壁形成撞壁射流扩大了燃油扩散面积,从而改善了缸内油气混合质量,燃油当量比小于1的均匀混合气区域燃油质量比例相比ω燃烧系统降幅最大为7.45%,因此TCD燃烧系统能够有效改善柴油机的燃烧和排放性能,可应用于柴油机高负荷和低过量空气系数工况综合性能提升。研究结果可为柴油机燃烧系统开发和改进提供参考。  相似文献   

茶树花青素形成分子机理的研究进展     

庞丹丹  韦康 《中国茶叶》2021,(4):9-15

花青素是由类黄酮合成途径产生的次生代谢产物,含量高时会使茶树新梢呈现红色或紫色。同时,花青素相比儿茶素等具有更明显的抗氧化、预防肿瘤等药理保健作用。文章就茶树花青素合成途径、转录及转录后调控等方面进行综述,以期更好地为高花青素茶树的育种研究提供理论依据。  相似文献   

Evaluating the ecotoxicological effects of Pb contamination on the resistance against Lymantria dispar in forest plant,Larix olgensis     

Dun Jiang  Ming‐tao Tan  Qi Wang  Gui‐rong Wang  Shan‐chun Yan 《Pest management science》2020,76(7):2490-2499

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Cultivation of Agaricus bitorquis mushroom as an strategy for the Integrated Pest Management of the myceliophagous mite Microdispus lambi     

María J Navarro  Francisco R Lpez‐Serrano  Lucía A Escudero‐Colomar  Francisco J Gea 《Pest management science》2020,76(9):2953-2958

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Compatibility of root growth and tuber production of potato cultivars with dynamic and static water‐saving irrigation managements          下载免费PDF全文

S. H. Ahmadi  M. Agharezaee  A. A. Kamgar‐Haghighi  A. R. Sepaskhah 《Soil Use and Management》2017,33(1):106-119

The important root characteristics of root length density (RLD) and root mass density (RMD) generally differ among irrigation managements and potato cultivars. The objective of this study was to investigate the RLD and RMD variations and their functional relationships with gross potato tuber yield for two commercial potato cultivars, Agria and Sante, under different irrigation strategies. Full irrigation and water‐saving irrigation strategies, deficit and partial root drying irrigations, were applied statically (S) and dynamically (D) based on daily crop evapotranspiration. Results showed that SPRD had significantly greater RLD (3.64 cm/cm³) and RMD (132.7 μg/cm³) than other irrigation treatments. Between the potato cultivars, Agria had significantly larger values of RLD (3.50 cm/cm³) and RMD (138.7 μg/cm³) than Sante. The functional relationship between the root growth characteristics and tuber yield showed that under water‐saving irrigations, Agria increased root mass at the expense of gross tuber yield but Sante increased root mass to maintain larger gross tuber yields. However, Agria produced more roots and gross tuber yield than Sante, and it is concluded that Agria is a more drought‐tolerant potato cultivar, which is recommended for tuber production in regions where water might be scarce. It was shown that larger root production in potatoes was associated with improved tolerance to water stress.  相似文献   

Altering of host larval (Spodoptera exigua) calcineurin activity in response to ascovirus infection     

Huan Yu  Lei He  Zi‐Qi Li  Ni Li  Yi‐Yi Ou‐Yang  Guo‐Hua Huang 《Pest management science》2020,76(3):1048-1059

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菊花新品种‘东篱雅致’     

高康  宋雪彬  戴思兰  季玉山  王朔  刘昊 《园艺学报》2020,47(Z2):3031-3032

菊花新品种‘东篱雅致’是以中国传统大菊品种‘绿朝云’为母本，以花形奇特、不同色系的‘钟声’，‘清水莲’和‘笑靥’等传统大菊品种作父本进行人工混合授粉，经连续选择育成。舌状花松针形，粉、绿复色。植株低矮, 直立性强, 适于盆栽观赏, 主要观赏期11月中旬—下旬，可以用于北京地区节日布展或庭院观赏。  相似文献   

Impact of weather variables and season on sporulation of Phytophthora pluvialis and Phytophthora kernoviae     

Stuart Fraser  Mireia Gomez‐Gallego  Judy Gardner  Lindsay S. Bulman  Sandra Denman  Nari M. Williams 《Forest Pathology》2020,50(2)

Phytophthora pluvialis and Phytophthora kernoviae are the causal agents of important needle diseases on Pinus radiata in New Zealand. Little is known about the epidemiology of the diseases, making the development of control strategies challenging. To investigate the seasonality and climatic drivers of sporulation, inoculum traps, consisting of pine fascicles floating on water in plastic containers, were exchanged fortnightly at five sites in P. radiata plantations between February 2012 and December 2014. Sections of needle baits were plated onto selective media and growth of Phytophthora pluvialis and P. kernoviae recorded. To explore the generalizability of these data, they were compared to detection data for both pathogens from the New Zealand Forest Health Database (NZFHDB). Further, equivalent analyses on infection of Rhododendron ponticum by P. kernoviae in Cornwall, UK allowed the comparison of the epidemiology of P. kernoviae across different host systems and environments. In New Zealand, inoculum of P. pluvialis and P. kernoviae was detected between January–December and March–November, respectively. Inoculum of both species peaked in abundance in late winter. The probability of detecting P. pluvialis and P. kernoviae was greater at lower temperatures, while the probability of detecting P. pluvialis also increased during periods of wet weather. Similar patterns were observed in NZFHDB data. However, the seasonal pattern of infection by P. kernoviae in the UK was the opposite of that seen for sporulation in New Zealand. Phytophthora kernoviae was likely limited by warmer and drier summers in New Zealand, but by colder winter weather in the UK. These results emphasize the importance of considering both environmental drivers and thresholds in improving our understanding of pathogen epidemiology.  相似文献   

Innovating in less developed regions: What drives patenting in the lagging regions of Europe and North America     

Andrs Rodríguez‐Pose  Callum Wilkie 《Growth and change》2019,50(1):4-37

Not all economically disadvantaged—“less developed” or “lagging”—regions are the same. They are, however, often bundled together for the purposes of innovation policy design and implementation. This paper attempts to determine whether such bundling is warranted by conducting a regional level investigation for Canada, the United States, on the one hand, and Europe, on the other, to (a) identify the structural and socioeconomic factors that drive patenting in the less developed regions of North America and Europe, respectively; and (b) explore how these factors differ between the two contexts. The empirical analysis, estimated using a mixed‐model approach, reveals that, while there are similarities between the drivers of innovation in North America's and Europe's lagging regions, a number of important differences between the two continents prevail. The analysis also indicates that the territorial processes of innovation in North America's and Europe's less developed regions are more similar to those of their more developed counterparts than to one another.  相似文献   

Backshoring and nearshoring: An overview     

Benedetta Piatanesi  Josep‐Maria Arauzo‐Carod 《Growth and change》2019,50(3):806-823

Increasingly, economies that have traditionally benefited from offshoring are losing some of their strategical advantages, with a consequent increase in backshoring by developed economies. This paper describes the phenomenon and tries to shed light on the current challenges, trends, and debates in the area, and on the main determinants of backshoring. A new phenomenon known as nearshoring is also analysed—this consists of relocating some previously offshored manufacturing activities so that they are now close to previous core locations, but not so close as to suffer from disagglomeration effects. This combines the advantages of offshoring and backshoring.  相似文献