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实验室测定,240g/L虫螨腈悬浮剂对3龄起蚕添毒24 h的LC50>3750 mg/L,连续添毒48 h和72 h的LC50分别为1858.2552 mg/L、1207.4615 mg/L,表明240 g/L具有累积效应。田间试验表明,240 g/L虫螨腈悬浮剂750倍(320 mg/L)和1500倍(160 mg/L)对桑螟幼虫的防效显著优于77.5%敌敌畏乳油750倍+40%辛硫磷乳油1500倍。240 g/L虫螨腈悬浮剂320 mg/L和160 mg/L喷于桑树后1 d采叶,对3龄起蚕均无中毒症状和死亡现象,但连续饲养至5龄,茧层率有所下降。240 g/L虫螨腈悬浮剂320 mg/L和160 mg/L喷药的桑叶应间隔7 d后采叶养蚕,以免影响蚕茧质量。 相似文献
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室内毒性测定结果表明：40％辛硫磷乳油对3龄起蚕24h的LC50为0．8872mg／L,30％辛硫磷微囊悬浮剂的LC50为2．1978mg／L,两者相差1．48倍。30％辛硫磷微囊悬浮剂15001倍（200mg／L）、1000倍（300mg／L）和500倍（600mg／L）对3龄起蚕的安全间隔期分别为11d、15d和17d,40％辛硫磷乳油2000倍（200mg／L）、1333倍（300mg／L）和667倍（600mg／L）的安全间隔期分别为2d、4d和6d;即在同等质量浓度下,30％辛硫磷微囊悬浮剂比40％辛硫磷乳油的安全间隔期延长9-11d。 相似文献
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本文测定了阿维菌素和甲氨基阿维菌素苯甲酸盐（简称＂甲维盐＂）4种杀虫剂制剂对家蚕的急性食下毒性和残毒期,结果表明：对3龄起蚕的LC50值分别为阿维菌素乳油7.2343×10-4mg/L,阿维菌素水乳剂7.6512×10-4mg/L,甲维盐微乳剂8.5940×10-4mg/L,甲维盐乳油14.0112×10-4mg/L。阿维菌素和甲维盐4种制剂的相同质量浓度（13.33 mg/L）稀释液喷洒桑树,在桑叶上的残毒期分别为3.2%阿维菌素乳油2400倍约为50 d,1.8%阿维菌素水乳剂1350倍、2.3%甲维盐乳油1725倍约为60 d,2.2%甲维盐微乳剂1650倍＞60 d;阿维菌素类4种制剂对家蚕的急性食下毒性极强,处理间差异较小,但在桑叶上的残毒期很长,处理间差异较大。 相似文献
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《广西蚕业》2015,(2)
通过田间试验,对柳城县凤山镇市面上使用于桑园害虫防治的几种农药进行了防治效果及残效期的测试。结果表明:40%桑宝(灭多威)乳油1 500倍、40%乐桑(毒死蜱)乳油1 500倍、80%敌敌畏乳油1 000倍对鳞翅目幼虫的防效较好,防效依次为94.31%、92.84%、92.23%;73%桑宁(炔螨特)乳油3 000倍、40%乐果乳油1 000倍对桑蓟马和朱砂叶螨等刺吸性害虫的防效特效,防效依次为95.46%、91.33%;80%敌敌畏乳油、40%乐果乳油、730 g/L桑宁(炔螨特)乳油、40%桑宝(灭多威)乳油、40%乐桑(毒死蜱)乳油对桑蚕的残毒期依次为:5 d、5 d、10 d、12 d、15 d。 相似文献
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通过将桑园杀虫剂、杀螨剂、杀菌剂等多种药剂混合使用,开展对蚕桑生产安全性及对桑园褐斑病和白粉病的防治试验。结果表明:多种药剂混合使用对桑树不产生药害,桑树全年均能正常生长;试验药剂的残效期在正常条件下7d后采叶喂蚕,家蚕均能正常发育和上蔟结茧。对桑白粉病防治效果较好的药剂组合是77.5%敌敌畏乳油1000倍液、73%克螨特·炔螨特乳油4000倍液、50%多菌灵可湿性粉剂500倍液、10%世高·苯醚甲环唑2000倍液、40%辛硫磷乳油1000倍液混合使用(相对防效50%、病情指数12.8)及瓜果飘香百菌清600倍液单独使用(相对防效50%、病情指数12.8);对桑褐斑病防治效果较好的药剂组合是77.5%敌敌畏乳油1000倍液,73%克螨特·炔螨特乳油4000倍液,百菌清600倍液,50%多菌灵可湿性粉剂500倍液,40%辛硫磷乳油1000倍液混合使用(相对防效68%、病情指数5.7)。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献