缓释肥减量施用对覆膜栽培玉米生物性状、干物质积累与养分分配的影响

通过大田试验研究缓释肥覆膜减量条件下的玉米生物性状、干物质分配比例、养分含量差异及其与产量的相关性分析。结果表明,与不覆膜(T2)处理相比,覆膜可使玉米的茎粗提高11.05%~19.34%,株高提高2.78%~5.39%,穗位高提高6.20%~10.28%,覆膜条件下缓释肥减量对玉米生物性状无明显影响。覆膜可以使玉米干物质积累提高25.22%~31.01%,较普通复合肥(T6)相比,施用缓释肥更有利于玉米干物质积累,且缓释肥覆膜减量15%(T4)不会影响玉米干物质积累,减量过度(T5)则会显著降低玉米干物质积累以及子粒和茎秆的氮含量。相关分析发现,玉米产量与生物性状存在显著或极显著的相关性,与不同部位养分含量也存在显著或极显著相关性。覆膜条件下施用缓释肥有利于改善玉米生物性状,提高干物质积累和养分含量,玉米茎粗、株高、穗位高与茎秆氮含量、叶片钾含量、子粒氮含量可以作为玉米产量评估的重要指标。     

Fabrication of hydrophobic/oleophilic cotton fabric by mussel-inspired chemistry for oil/water separation

A straightforward approach was proposed to modify cotton fabric for oil/water separation based on musselinspired reaction. The poly(DMA-Octadecyl acrylate) was designed to contain key chemical constituents present in mussel adhesive proteins by free radical polymerization of dopamine hydrochloride and octadecyl acrylate, which strongly adsorbed to fabric substrates, providing a special surface for fabric. The chemical structure, surface topography, and surface wettability of the fabric were characterized. The results showed that as-prepared cotton fabric displayed a high CA of >150° when dripped water droplets were on the modified fabric surface, and the oil contact angle (OCA) was close to 0°, it had excellent potential to be used in practical applications and has created a new method of fabric modification for oil/water separation.     

An investigation on the comparison of wet spinning and electrospinning: Experimentation and simulation

Polysulfonamide (PSA) has been widely used in many fields because of its excellent thermodynamic properties. In this study, PSA fibers were prepared separately via two different spinning ways, including conventional wet spinning and electrospinning. Fluid motion of wet spinning and electrostatic field of electrospinning were modeled using finite element analysis to investigate the spinning process. The properties of fabricated PSA fibers were characterized systematically by scanning electron microscope (SEM), fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), thermal gravity analysis (TGA) and electronic strength tester. Based on the simulation and theoretical analysis of spinning process, it was found that the extruding force of the wet spinning is larger than that of the electrospinning. The larger extruding force makes the alignment of macromolecules inside fiber relatively uniform, and a higher proportion of crystallization happens. Accordingly, the mechanical properties and thermal stability of PSA fibers could be improved due to a higher proportion of crystallization. The experimental results of mechanical strength and TG test are coincided with the simulation results. PSA fiber prepared by wet spinning has better thermal stability and mechanical properties than that fabricated by electrospinning.     

优化提取裸花紫珠总黄酮含量及对表皮伤口易感染菌抑菌性的研究

为了选出裸花紫珠总黄酮提取的最优方法,比较了ASE、超声、微波萃取和多功能浓缩4种提取方法在裸花紫珠总黄酮提取率上的差异,并利用微孔刃天青法测定总黄酮对表皮易感染菌的MIC值。结果发现ASE法总黄酮提取率最高,约为1.26%,其次为超声和微波萃取法,总黄酮提取率分别约为1.03%和0.98%,多功能浓缩法提取率最低,约为0.36%,且耗时最长。而且研究发现,ASE的MIC值最低。最终得出ASE提取效率最高,且提取物有较好的抑菌性,是裸花紫珠总黄酮提取的最优方法。     

优质杂交晚籼新组合美优138的选育与应用

美优138是广西农科院水稻所用自育的优质不育系美A与强恢复系测13-8配组而成的优质杂交晚籼新组合.该组合具有米质优、产量高、抗性好、适应性广等特点,于2001年12月通过广西区品种审定.介绍了其选育经过、特征特性及应用技术.     

Marine Compound Catunaregin Inhibits Angiogenesis through the Modulation of Phosphorylation of Akt and eNOS in vivo and in vitro

Angiogenesis is the formation of blood vessels from pre-existing vasculature. Excessive or uncontrolled angiogenesis is a major contributor to many pathological conditions whereas inhibition of aberrant angiogenesis is beneficial to patients with pathological angiogenesis. Catunaregin is a core of novel marine compound isolated from mangrove associate. The potential anti-angiogenesis of catunaregin was investigated in human umbilical vein endothelial cells (HUVECs) and zebrafish. HUVECs were treated with different concentrations of catunaregin in the presence or absence of VEGF. The angiogenic phenotypes including cell invasion cell migration and tube formation were evaluated following catunaregin treatment in HUVECs. The possible involvement of AKT, eNOS and ERK1/2 in catunaregin-induced anti-angiogenesis was explored using Western blotting. The anti-angiogenesis of catunaregin was further tested in the zebrafish embryo neovascularization and caudal fin regeneration assays. We found that catunaregin dose-dependently inhibited angiogenesis in both HUVECs and zebrafish embryo neovascularization and zebrafish caudal fin regeneration assays. In addition, catunaregin significantly decreased the phosphorylation of Akt and eNOS, but not the phosphorylation of ERK1/2. The present work demonstrates that catunaregin exerts the anti-angiogenic activity at least in part through the regulation of the Akt and eNOS signaling pathways.     

小麦和土壤中噻虫嗪残留及消解动态分析

为对噻虫嗪在小麦生产上应用的安全性进行评价,通过对小麦籽粒、植株和土壤进行前处理及在样品中添加噻虫嗪,建立其残留量定量检测分析方法;通过两年三地的残留试验,分析了小麦籽粒、植株和土壤中噻虫嗪的残留及消解动态,并对小麦籽粒中的残留量进行风险评估。结果表明,噻虫嗪在小麦籽粒、植株及土壤空白添加平均回收率为79.62%~94.70%,相对标准偏差为0.91%~6.56%,其最小检出量为5.0×10-8g,小麦籽粒、植株及土壤中的最低检测浓度均为0.01mg·kg-1。该检测方法重现性好,准确度、精密度高,可满足噻虫嗪在小麦及土壤中的残留分析要求。2011和2012年,河南、黑龙江和江苏三地噻虫嗪在小麦植株和土壤中的消解半衰期分别为0.85~2.24d和2.77~4.79d;通过不同施药次数、施药量及间隔采样检测,噻虫嗪在小麦籽粒中的最终残留量均≤0.038mg·kg-1,占日允许摄入量的15.04%左右(普通人群噻虫嗪的国家估算每日摄入量是0.25mg),因此按本试验方式进行施药,通常不会对一般人群健康产生不可接受的风险。     

除草剂对花生根瘤菌共生固氮的影响

在室内条件下,研究了精喹禾灵、高效氟比甲禾灵、乙草胺和异丙甲草胺等4种除草剂对花生根瘤菌共生固氮的影响.结果表明,4种除草剂对离体条件下的花生根瘤菌均有不同程度的抑制作用,其中高效氟吡甲禾灵对根瘤菌的毒力最大,在中等剂量10000 mg/L时,抑菌圈直径为2.27 cm;异丙甲草胺在中等剂量10000 mg/L对花生根瘤菌的抑制作用最小,抑菌圈直径为0.30 cm.在对花生根瘤菌共生固氮影响方面,精喹禾灵对花生抑制作用最强,对花生株高、鲜重和干重的抑制率分别为12.42%、32.85%和30.00%,与对照植株的结瘤率和总含氮量80.00%和2.43%相比,其分别为55.00%和0.95%;异丙甲草胺抑制作用最弱,对花生株高、鲜重和干重的抑制率分别为:4.29%、8.68%和1.12%,与对照植株的结瘤率和总含氮量88.62%和2.23%相比,其结瘤率和总含氮量为75.26%和1.59%;花生经过4种除草剂处理后,总含氮量明显低于对照植株的总含氮量.     

几种植物生长促进剂对棉花生长及脱叶催熟剂应用效果的影响

2018年在河北省河间市开展田间试验,研究了植物生长促进剂DA-6（胺鲜酯）、BR（芸苔素内酯）和6-BA（6-苄基腺嘌呤）对棉花生长及脱叶催熟剂50%噻苯·乙烯利（50% T·E）应用效果的影响。试验采用裂区设计,重复4次。主区为50% T·E处理,包括0（对照）、2 250、3 750 mL·hm^－2 3个应用剂量;裂区为植物生长促进剂处理,设DA-6低、高剂量（6.74、20.24 g·hm^－2）、BR低、高剂量（0.09、0.30 g·hm^－2）和6-BA低、高剂量（10.12、30.37 g·hm^－2）共6个处理,于初花期、盛花期和打顶后分3次喷施,以同期喷清水为对照（CK）。与CK相比,各植物生长促进剂处理的株高、果枝数及其长度、营养枝数及其长度与CK无显著差异。50% T·E（2 250、3 750 mL·hm^－2）脱叶效果明显,药后21 d的脱叶率超过90%;药后28 d表现出催熟作用,一次花率较对照增加6.4百分点。50% T·E处理的平均铃重比对照降低7.4%,但铃数和籽棉产量较清水对照分别显著增加14.7%和7.6%;处理上部果枝棉铃的马克隆值降低0.1～0.3。几种促进剂不影响吐絮期叶片的叶绿素含量,对50% T·E的脱叶催熟效果及增产效应也无显著影响。     

海南水田土壤有机质分布规律及碳固定潜力

研究海南水田土壤有机质分布规律及影响因素,并分析其碳固定的潜力。结果表明,海南水田土壤有机质含量平均为22．90g/kg,相对于第二次土壤普查而言,水田土壤起着温室气体“源”的作用。土壤有机质的空间分布与按干湿状况划分的气候类型区关系密切,土壤有机质含量表现为湿润气候区〉潮湿气候区〉半湿润气候区〉半干旱气候区。推行以增加农田土壤有机物质输入的管理方式和种植方式等都可以提高土壤的有机质含量,从而实现水田土壤温室气体“汇”的作用。