三氟啶磺隆钠盐与扑草净混配的联合作用及混用配方筛选

为筛选针对新疆棉田多样性杂草高效、安全的苗后除草剂混用配方,在田间试验条件下,测定了三氟啶磺隆钠盐和扑草净混用对棉田杂草活性及对棉株安全性的影响,采用Gowing法评价二者混用后的联合作用类型。结果表明:两药剂混用后对供试杂草的株数防效与鲜重防效比单剂有所提高,株数防效与鲜重防效增长率范围分别为-3.24%～4.53%和-5.86%～3.11%。施药后30 d,单独施用三氟啶磺隆钠盐15 g/hm2的株数防效最低,仅为70.82%;单独施用扑草净150 g/hm2的鲜重防效较低,仅为79.21%。在两者混配处理中,三氟啶磺隆钠盐15 g/hm2+扑草净150 g/hm2的株数防效与鲜重防效较高,分别为99.05%与96.09%;同时其增长率最高,分别为4.53%与3.11%。单施三氟啶磺隆钠盐处理对棉株安全,与其他处理呈显著性差异,其中扑草净250 g/hm2处理的药害指数为47.53%,导致叶片褪绿,对棉株有较大伤害。综合考虑除草活性和对棉花的安全性,三氟啶磺隆钠盐15 g/hm2+扑草净150 g/hm2复配处理表现较好,可作为新疆北部棉田高效、安全的除草剂复配组合。     

Characterizing urban expansion of Korla City and its spatial-temporal patterns using remote sensing and GIS methods

Cities provide spatial contexts for populations and economic activities. Determining the spatial-temporal patterns of urban expansion is of particular significance for regional sustainable development. To achieve a better understanding of the spatial-temporal patterns of urban expansion of Korla City, we explore the urban expansion characteristics of Korla City over the period 1995–2015 by employing Landsat TM/ETM+ images of 1995, 2000, 2005, 2010, and 2015. Urban land use types were classified using the supervised classification method in ENVI 4.5. Urban expansion indices, such as expansion area, expansion proportion, expansion speed, expansion intensity, compactness, and fractal dimension, were calculated. The spatial-temporal patterns and evolution process of the urban expansion(e.g., urban gravity center and its direction of movement) were then quantitatively analyzed. The results indicated that, over the past 25 years, the area and proportion of urban land increased substantially with an average annual growth rate of 15.18%. Farmland and unused land were lost greatly due to the urban expansion. This result might be attributable to the rapid population growth and the dramatic economic development in this area. The city extended to the southeast, and the urban gravity center shifted to the southeast as well by about 2118 m. The degree of urban compactness tended to decrease and the fractal dimension index tended to increase, indicating that the spatial pattern of Korla City was becoming loose, complex, and unstable. This study could provide a scientific reference for the studies on urban expansion of oasis cities in arid land.     

腐霉利在新疆北部地区黄瓜上的最终残留量研究

为了探明腐霉利在新疆北部地区黄瓜上残留特性和使用安全性,通过田间试验和室内检测,研究了腐霉利在黄瓜中的最终残留量。结果表明:以腐霉利50%可湿性粉剂562.5～750.0 g/hm2(有效成分),连续施药2～3次,最后一次施药后3 d收获的黄瓜中腐霉利残留量均低于0.13 mg/kg,推荐该药在黄瓜上的安全间隔期为3 d。     

吐鲁番市13个品种桑树叶的营养和活性成分分析与评价

为明确吐鲁番市桑叶的营养和活性成分含量,促进桑叶资源的开发利用,以13个桑树品种为研究对象,测定了叶片中游离氨基酸、可溶性固形物、叶绿素、VC、花青素、生物碱、β-胡萝 卜素、黄酮苷、褪黑激素、总多糖、总酚、γ-氨基丁酸和类黄酮含量,并采用主成分分析和聚类分析方法对桑叶品质进行了综合评价.结果表明,13个不同品种桑叶的营养和活性成分存在一定程度的差异.品质综合得分排序为:药桑＞无核大10＞黑桑＞白桑＞台湾长果＞育711＞嘉陵30＞龙桑1号＞大青条＞强桑1号＞粉桑＞公桑＞选792,聚类分析将供试的13个桑树样品划分为5大类,各品种间在营养指标上有较大差异.由主成分分析综合评分得出,药桑、无核大10、黑桑、白桑、台湾长果等品种桑叶品质较佳.