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

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。     

不同行距配比对玉米光合生理指标及茎秆特性的影响

以‘大丰30’为试验材料,在同一密度下（75000株/hm²）设置5种不同行距配比,研究不同行距配比对玉米光合生理指标及茎秆力学特性的影响。结果表明：行距配比为40 cm×80 cm时,棒三叶的叶绿素含量(SPAD)在灌浆期达到峰值;行距配比为30 cm×90 cm时,棒三叶净光合速率在灌浆期最高。大口期开始,行距配比为40 cm×80 cm时,叶面积指数(LAI)最高。单株干物质积累量以40 cm×80 cm最高。各行距配比的茎秆硬皮穿刺强度与茎秆弯曲性能随着节位的下降均呈逐渐增强的趋势,从大到小为 40 cm×80 cm>50 cm×70 cm>30 cm×90 cm>60 cm×60 cm>20 cm×100 cm。穗长、穗粗、千粒重和穗粒数各处理间均有不同变化,行距配比为40 cm×80 cm时产量最高,比等行距60 cm×60 cm增产7.96%。由此可见,行距配比为40 cm×80 cm,有利于大穗型品种‘大丰30’的光合性能和茎秆强度的提高,从而达到抗倒伏增产的目的。     

Reduced Germination and Seedling Vigor of Weeds with Root Extracts of Maize and Soybean,and the Mechanism Defined as Allelopathic

Journal of Crop Science and Biotechnology - Due to the negative consequences of synthetic herbicides use and their reducing effectiveness due to development of resistant weeds, promotion of...     

Growth Responses and Differences in Gene Expression depending on Cultivation Temperature between Alternative type Wheat Varieties

Journal of Crop Science and Biotechnology - Two domestic wheat varieties were grown in the growth chamber set at 17°C, 20°C, 23°C and 26°C on average after the emergence of...     

Preparation and properties of solid polymer electrolyte based on imidazolium-based ionic liquids for structural capacitors

We prepared solid polymer electrolytes (SPEs) composed of poly(ethylene glycol) monomethyl ether acrylate (1A9OMe) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIm][OTF]) and 1-ethyl-3-methylimidazolium bis(trifluoromethane sulfonyl) imide ([EMIm][TFSI]) as the ionic liquid. The SPEs formed by appropriately adding ionic liquids in the 1A9OMe prior to thermal cure. The ratio of 1A9OMe and ionic liquid was 1:9, 3:7, and 5:5, respectively. The characterization of solid polymer electrolytes were investigated using Fourier transform infrared spectroscopy in the attenuated total reflectance mode (FTIR-ATR), Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and glavanostatic charge-discharge test. The highest ionic conductivity of SPEs was found to be 4.90×10^?4 S/cm in a 1A9OMe/[EMIm][OTF] of 3:7. As IL contents were increased, the specific capacitance of supercapacitor was increased. The specific capacitance of supercapacitor for ionic liquid with large ion size was lower than that for ionic liquid with smaller ion size.     

甘蔗叶不同还田方式对土壤养分的影响

为减轻秸秆焚烧所带来的环境问题和充分利用甘蔗叶资源,在大田环境下动态监测甘蔗叶粉碎、焚烧和深埋3种还田方式对土壤养分的影响。结果表明:甘蔗叶粉碎还田和深埋还田有利于甘蔗叶中有机碳及氮、磷、钾养分的缓慢释放;甘蔗叶焚烧还田提高了土壤碱解氮含量5.6~20.9 mg/kg和速效磷含量0.8~4.0 mg/kg,促进土壤中氮磷向有效态转化,焚烧还田初期显著增加了土壤速效钾的含量12.3~18.3 mg/kg,但焚烧会损失部分甘蔗叶中碳氮元素,也造成环境污染。综合分析认为甘蔗叶粉碎还田是比较省工、方便的处理方式。     

Compatibility of root growth and tuber production of potato cultivars with dynamic and static water‐saving irrigation managements

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.