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41.
42.
4种植物源杀虫剂对亚洲型舞毒蛾幼虫的毒性与拒食作用   总被引:1,自引:0,他引:1  
为筛选出有效防治亚洲型舞毒蛾的最佳植物源杀虫剂,采用5%鱼藤酮、1%虫菊·苦参碱、5%桉油精、0.6%氧苦·内酯4种植物源杀虫剂,比较它们对舞毒蛾3龄幼虫胃毒和触杀处理后的毒性与拒食作用.结果表明:这4种植物源杀虫剂对舞毒蛾3龄幼虫均具有胃毒和触杀两种作用,其急性毒性总体表现为触杀处理大于胃毒处理,而在各自相对最高的浓度条件下,以0.6%氧苦·内酯的胃毒急性毒性为最大、5%桉油精次之;由于胃毒组的LC50均小于触杀组,因而胃毒处理的毒力更高;此外,0.6%氧苦·内酯和5%桉油精的胃毒和触杀毒力均远远高于其他两种药剂,并以前者为最高.对测定前后的饲料量进行比较后发现,4种药剂对舞毒蛾3龄幼虫均具有很好的拒食作用,尤其以5%桉油精5 000倍液处理的拒食率高达99.31%.因此,0.6%氧苦·内酯和5%桉油精可作为防治亚洲型舞毒蛾的首选植物源杀虫剂推广应用.  相似文献   
43.
Morphology of the mature larvae and pupae of the apterous fly, Badisis ambulans McAlpine (Diptera: Micropezidae) are described and illustrated. In addition, the curious commensal habits of the larvae are described. Each spiracular plate of the mature larva is situated at the base of a small horn; similar horns have been described in other micropezid larvae. The posterior spiracles appear to be non-functional with depressions forming the vestiges of the spiracular openings. The larvae were found inside pitchers of the Albany pitcher plant, Cephalotus follicularis (Cephalotaceae) and have a commensal relationship with the plant. They feed on the decaying pitcher plant prey and leave the pitcher to pupate. It is likely that the larva obtains oxygen from the pitcher fluid. This is the first immature micropezid described from Australia.  相似文献   
44.
《Journal of Natural History》2012,46(37-38):2389-2416
The embryonic development of the parthenogenetic eggs of Leptodora kindtii has been investigated by observing living embryos removed from the female brood pouch. The sequence of morphological changes was analysed, as was the time at which the activity of certain organs began. The timing of these events at 20–22°C is documented. These data were compared with similar information obtained for some representatives of Ctenopoda and Anomopoda. The sequence of appearance of rudiments of organs on the ventral side of the embryos is similar in all these groups but the timing of shedding of the embryonic membranes differs. Hatching from the inner egg membranes takes place at the late metanauplius stage in Leptodora as in Ctenopoda and Cyclestherida, while in Anomopoda this stage is embryonized. The development of Leptodora is more like that of Ctenopoda than of Anomopoda. The embryos of all the above‐mentioned groups begin to grow at approximately the same morphological stage. A new scheme for the periodization of the embryogenesis of L. kindtii is proposed, which includes four well‐separated stages. Previously, the same number of developmental stages has been reported for Ctenopoda and Anomopoda. In Leptodora, as well as in Ctenopoda, the first two of these occur within the egg membranes. Cyclestheria has at least one embryonic moult and one embryonic stage more than Leptodora and other cladocerans. Embryonic stages 3 and 4 of the parthenogenetic eggs of L. kindtii represent a peculiar type of secondary larvae developing inside the female's brood pouch. The appearance of a free‐living nauplius in L. kindtii arises from its mode of hatching from the gamogenetic egg.  相似文献   
45.
46.
The complete zoeal development of a dorippid crab in the subfamily Ethusinae is described for the first time from a known parental female. The ovigerous Ethusa microphthalma was collected in the northern Gulf of Mexico off Louisiana. Larvae passed through four zoeal stages, and the megalopa was reached in 59 days at 20°C and 35 ppt salinity. The larvae differ from those of the few other dorippids for which a zoea is known. Salient distinguishing features include long lateral carapace spines, the presence of six setae on the endopod of the maxillule and maxilla, and a spinose antennal exopod lacking projecting mid-length spines or setae. Zoeal characters are compared to those known for the allied subfamily Dorippinae, and all references to zoeae of the Dorippidae are tabulated.  相似文献   
47.
采用四因子三水平的正交实验法,研究了河蟹大眼幼体至Ⅲ期幼蟹阶段对饲料中蛋白质、脂肪、矿物盐及复合维生素的适宜需求量.结果表明,影响河蟹大眼幼体至Ⅲ期幼蟹成活率的因素主次顺序为蛋白质>矿物盐>脂肪>维生素,其最优水平分别为蛋白质35.50 %;矿物盐6 %;脂肪17.39 %;复合维生素1 %.河蟹从大眼幼体发育到Ⅲ期幼蟹,对饲料中蛋白质的适宜需要量有逐渐减少的趋势,即从45.52 %减至35.50 %;对矿物盐适宜添加量的要求有逐渐上升的趋势,即由2 %升至6 %;而对复合维生素适宜添加量的要求则有下降的趋势,即由3 %降至4 %;但对脂肪的适宜需要量一直是较稳定且较调换,即为17.39 %.  相似文献   
48.
49.
《Journal of Natural History》2012,46(16):2085-2117
As human demands for water have become more intense in modern times, the Canary Islands have become a difficult environment for all the macroinvertebrate fauna dependent upon running water for their survival; few permanent streams remain. Investigations on the simuliid (blackfly) fauna have shown, however, that at least six species exist in the archipelago, but that one, the endemic Simulium paraloutetense, known only from one site now destroyed, is possibly extinct. The paper presents cumulated data on distribution and material obtained over the past 33 years (since aquatic-stage specimens from breeding sites were first collected) with the aim of providing a baseline against which future studies of the Canarian simuliid fauna can be assessed. Revised identification keys for larvae and pupae are given to aid such monitoring. Remarks concerning each species include notes on chromosomal data when these are available. Comments are included on some aspects of the lotic habitats and island colonization.  相似文献   
50.
采用四因子三水平的正交实验法,研究了河蟹蚤状幼体至大眼幼体阶段对饲料中蛋白质、脂肪、矿物盐及复合维生素的适宜需求量.结果表明,影响河蟹其成活率的因素主次顺序为蛋白质>维生素>矿物盐>脂肪,其最优水平分别为蛋白质55.28 %;维生素2 %;矿物盐6 %;脂肪17.39 %.  相似文献   
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