1-芳基-3-(1H-1,2,3,4-四唑-5-基)脲的合成与除草活性

用5-氨基-1H-1,2,3,4-四氮唑与取代芳香异氰酸酯反应,合成了5种新的1-芳基-3-(1H-1,2,3,4-四唑-5-基)尿类化合物,其结构用IR、1HNMR、元素分析进行了表征,结果表明所合成的化合物即为目标化合物.用平皿法初步测定了除草活性.     

猴子种梨树

猴子看见老爷爷种的梨树枝叶茂盛,秋天挂满了黄澄澄的梨,心里很羡慕。春天来了,他也在山坡上种了梨树苗。树苗活了,长出了嫩绿的叶子。猴子见了很高兴,忙着给它们除草、松土、施肥,还三天两头浇水。     

Pollen indicators of human activity

The study of past human activities and their environmental effect is high in the agenda of global change research. A record of pollen assemblages is one of the most common proxies employed for detecting the impact of human activities on the landscape. In this review, we provide a summary and discussion on the recent progress on the use of pollen as indicators of human activity. For most of the studies related to human impact, the following features have been focused on： （1） decline of certain tree pollen; （2） flourishing of pioneer plant pollen; （3） concomitant occurrence of cereal-type pollen and cropland weed pollen; （4） abrupt changes in pollen concentration and richness; and （5） occurrence of nitrophi- Ious plants and pastoral weed. Pollen of anthropogenic plants （weeds and cereal-type plants） is ideal indicators of human activities. Different types of human activities will result in different pollen assem- blages. Patterns of human-impacted pollen spectra would vary between forested areas and grassland. In the study of human impact with pollen data, high resolution in both time and space must be consid- ered. High resolution in space will help to inform the complexity of the landscape. More importantly, it can help to reveal the interference of human activities on the landscape, hence avoiding the bias created by the limited data points. Fine resolution in time will make accurate recording of short-lived events possible, hence avoiding the exclusion of events related to human activities. The combination of palynology with other proxies will help to decipher more accurately landscape changes through time. Charcoal is a particularly useful proxy for recording the disturbance of humans on vegetation. Its peak values usually occur with pronounced drop of tree pollen and significant rise of anthropogenic pollen.     

冬种化学除草技术

草害是影响春花作物高产稳产的重要因子,因此开展冬种化学除草是提高单产的关键措施。90年代前,危害杭州市麦田、油菜田的恶性杂草主要是看麦娘、早熟禾、雀舌草、牛繁缕。进入90年代后,由于耕作制度的改变、栽培技术的革新及化学除草剂的大量使用,草相变化较大,主要杂草有菵草、看麦娘、日本看麦娘、棒头草、碎米荠、牛繁缕、猪殃殃等,尤其是菵草、棒头草、日本看麦娘已成为杭州市冬种主要恶性杂草。针对本市麦田、油菜田的草相及其变化特点,主要采用以下化学除草技术。1大小麦田化学除草技术1.1免耕麦田播前除草在水稻收割后麦子播…     

30%氨氯·二氯·氯氨吡啶酸可溶液剂的除草活性评价

为筛选防除青海省农田恶性杂草的高效除草剂，采用茎叶喷雾法室内测定了30%氨氯·二氯·氯氨吡啶酸可溶液剂(SL)对密花香薷、藜、苣荬菜、地肤、野芥菜的除草活性。结果表明：30%氨氯·二氯·氯氨吡啶酸SL施药后7 d对供试的5种杂草株高均有不同程度的抑制，施药后14 d对杂草的抑制作用比施药后7 d明显增强。施药后21 d 30%氨氯·二氯·氯氨吡啶酸SL 45.0、67.5、90.0、112.5、135.0 g a.i/hm²处理对密花香薷的鲜重防效分别为71.85%、75.87%、82.80%、89.81%、90.42%;对藜的鲜重防效分别为87.25%、100.00%、100.00%、100.00%、100.00%;对苣荬菜的鲜重防效分别为71.95%、72.14%、80.39%、85.84%、89.26%;对地肤的鲜重防效分别为68.48%、75.30%、78.33%、80.00%、85.76%;对野芥菜的鲜重防效分别为48.76%、66.56%、72.47%、78.22%、84.71%。30%氨氯·二氯·氯氨吡啶酸SL对密花香薷、藜、苣荬菜、地肤、野芥菜的E...