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磺酰脲类除草剂对玉米敏感性研究 总被引：3，自引：0，他引：3
采用室内模拟添加法和盆栽法分别研究了不同玉米品种对磺酰脲类除草剂的敏感和和磺酰脲类除草剂对敏感玉米品种苗期影响。结果表明：供试玉米品种对磺酰脲类除草剂存在不同程度的敏感性差异,该类除草剂ＥＤ５０／５０以上浓度对玉米苗期的根长、株高、叶面积有明显影响。 相似文献
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陈锡岭 《河南科技学院学报》2004,32(2):24-26
研究了三种麦田常用的磺酰脲类除草剂对玉米生长的影响.结果表明,同一种除草剂对不同品种玉米根的生长有不同的抑制作用;在玉米苗期试验中,供试的三种除草剂对玉米的生长均呈现一定的抑制作用;在大田残留试验中,异丙隆的残效期最长,麦佬次之,杜帮巨星最短. 相似文献
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三种磺酰脲类除草剂对玉米敏感性及残留的研究 总被引：7，自引：0，他引：7
陈锡岭 《河南职业技术师范学院学报》2004,32(2):24-26
研究了三种麦田常用的磺酰脲类除草剂对玉米生长的影响。结果表明，同一种除草剂对不同品种玉米根的生长有不同的抑制作用；在玉米苗期试验中，供试的三种除草剂对玉米的生长均呈现一定的抑制作用；在大田残留试验中，异丙隆的残效期最长，麦佬次之，杜帮巨星最短。 相似文献
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目的:明确安徽地区稻田马唐对噁唑酰草胺的抗性发生情况及其对不同类型除草剂的敏感性,为安徽地区稻田马唐的抗药性治理提供依据。方法:采用整株生物测定法测定采自安徽不同地区稻田的16个马唐种群(其中1个为敏感种群)对噁唑酰草胺的抗性水平,并筛选出抗性水平最高的种群,明确其对18种不同类型除草剂的敏感性。结果:共有8个种群对噁唑酰草胺产生抗药性(抗性指数为2.68～62.57),其中抗性种群MT-2对氰氟草酯、五氟磺草胺、二氯喹啉酸、双草醚、三唑磺草酮、双环磺草酮、氯氟吡啶酯、嘧啶肟草醚、噁草酮敏感性较低,对嗪吡嘧磺隆、丙草胺、丁草胺、莎稗磷、二甲戊灵、仲丁灵、禾草丹、双唑草腈、敌稗表现敏感。结论:安徽部分稻区马唐种群已对噁唑酰草胺产生不同程度的抗药性,且高抗种群对不同类型的除草剂敏感性差异较大。该结果可作为生产中稻田马唐抗性治理与化学防除的参考依据。 相似文献
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不同作物对苯磺隆残留敏感性室内模拟研究 总被引：1，自引：0，他引：1
采用室内模拟添加生物酗定法初步研究了冀东地区花生、大豆、水稻、玉米等作物及其品种对苯磺隆的敏感性。结果表明，所有供试作物及其品种对苯磺隆均存在一定的敏感性，其中花生、大豆双子叶植物对苯磺隆最为敏感，平均ED10值分别为0．0143μg/kg，0．0181μg/kg；水稻对其耐性较强，平均ED10值为0．0684μg/kg；玉米对苯磺隆残留的耐药性最强，主根长没有受到残留的抑制作用，但侧根受到了一定的影响。同一作物的不同品种对苯磺隆的残留敏感性也有较大的差异。 相似文献
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通过敏感性测定,明确了不同水稻品种对除草剂的耐药性存在较大差异,结果表明新稻90261、豫粳6号对杀草丹耐药性较强,新稻6811对氯嘧磺隆、扑草净耐药性较强,黄金晴耐药性较弱,田间若使用不当易产生药害.分析结果表明,大多数供试水稻品种种芽耐药性均大于种根. 相似文献
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通过敏感性测定，明确了不同水稻品种对除草剂的耐药性存在较大差异，结果表明；新稻90261、豫粳6号对杀草丹耐药性较强，新稻6811对氯嘧磺隆、扑草净耐药性较强，黄金晴耐药性较弱，田间若使用不当易产生药害。分析结果表明，大多数供试水稻吕种种芽耐药性均大于种根。 相似文献
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采用误差反传前向人工神经网络模型研究了18种磺酰脲类化合物的结构与除草活性之间的关系.以18种磺酰脲类化合物的量子化学参数作为输入,除草活性作为输出,构建网络模型,取得了较好的预测结果.网络的自相容能力和交叉检验结果良好.该方法还可作为QSAR研究及对有机化合物其他性质进行预测的一种有效手段. 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献