共查询到20条相似文献,搜索用时 15 毫秒
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HOMBURGER F 《Science (New York, N.Y.)》1953,118(3062):272-273
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研究了蒙古裸腹溞MoinamongolicaDaddy在室内水泥池中的大规模培养技术,并进行了用其部分或全部替代卤虫投喂大菱鲆Scophtalmusmaximus和牙鲆Paralichthysolivaceus稚幼鱼的试验,结果表明:蒙古裸腹溞在室内大规模培养是可行的;全用小球藻培养的蒙古裸腹溞以及经小球藻营养强化的用酵母培养的蒙古裸腹溞作饵料,完全可以满足大菱鲆及牙鲆鱼苗的营养需要。用不同食物组合投喂大菱鲆的试验表明,鱼类生长速度为50%裸腹溞+50%卤虫组>裸腹溞组>卤虫+配合饲料组,但差异不显著;用该溞投喂牙鲆组的鱼类生长与用卤虫投喂组的没有显著差异。而蒙古裸腹溞培养费用仅为卤虫的1/10,因此,用蒙古裸腹溞可以部分替代或全部替代卤虫作为大菱鲆及牙鲆鱼苗的优质饵料,大幅度降低育苗成本。 相似文献
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本文对巴里坤湖卤虫染色体核型进行了初步研究。实验结果表明,巴里坤湖卤虫二倍体体细胞染色体数为42条,可配成21对.共分为3组。枝型为2n=42。核型公式为K2n=14M+8SM+20T,NF=64。最大的一对为具中部着丝点的同型性染色体。 相似文献
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Fagen RM 《Science (New York, N.Y.)》1978,200(4342):658-659
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[目的]根据DNA序列数据库上已公布的布鲁氏菌外膜蛋白(outer membrane protein,Omp)Omp 25基因,设计一对引物和荧光探针,通过反应体系优化,建立一种布鲁氏菌荧光定量PCR检测方法.[方法]以构建的外膜蛋白目的片段重组质粒为标准品,验证该方法的灵敏度、特异性,通过优化反应条件,建立标准曲线.通过对34份已知临床背景的样品检测,验证该方法的敏感性.[结果]建立的布鲁氏菌荧光定量PCR检测方法,特异性验证符合率100%,最低检测限约为100 copies/μL,敏感度的检出率为100%,建立标准曲线的R2为0.994,扩增效率99.73%.[结论]建立的布鲁氏菌荧光定量PCR检测方法特异性强、敏感性高、重复性好,可以用于布鲁氏菌的检测. 相似文献
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Boake CR 《Science (New York, N.Y.)》1985,227(4690):1061-1063
To investigate whether female mate choice could be directed at male genetic quality, male chemical signals and progeny fitness were studied in the red flour beetle (Tribolium castaneum). Differences among males in the attractiveness of their pheromone to females were statistically significant. Developmental time of progeny was significantly heritable, indicating that some males have "good genes" for this trait. There was no statistically significant correlation between progeny fitness and male attractiveness. These results do not support the hypothesis that in this species the evolution of female preferences for male pheromone is adaptive. 相似文献
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卤虫做为一种经济动物已广泛应用于水产养殖业中,但是做为一种遗传学教学的实验材料尚无人报道过。通过多次实验,本文作者提出了一种改进后的观察卤虫染色体形态和数目的实验方法。同时,作者还例举了各种事实表明卤虫是一种很好的遗传学教学的实验材料。 相似文献
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一种定量检测拟除虫菊酯类农药降解酶降解效果的方法 总被引:2,自引:0,他引:2
建立了一种定量检测拟除虫菊酯类农药降解酶降解效果的方法。研究了在37℃拟除虫菊酯类农药降解酶对菊酯类农药的降解效果,用石油醚提取降解后的残留农药,并采用气相色谱法测定了其浓度,计算降解率。检测结果表明,样液浓度在0.05~0.60mg/L范围内时,校准曲线相关系数为0.9987~0.9999,回收率为93.3%~113.8%,相对标准偏差为0.50%~3.9%,检出限为0.0007~0.003mg/L。此方法灵敏度高,适用于不同菊酯类农药降解酶酶液的检测,从而为拟除虫菊酯类降解酶的研究和评价提供科学依据。 相似文献
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One of the series of "Yale natural radiocarbon measurements, II" [Science 122, 954 (1955)], by Richard S. Preston, Elaine Person, and E. S. Deevey, was incorrectly reported through a technical error. The date for sample Y-293A (South Haven, Mich.: peat) was 10,790 +/- 200 yr, not 9500 + 250 yr as reported on page 958. 相似文献
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Water vapor altered the form and greatly increased the rate of decay of the electron-spin resonance pattern of long-lived free radicals obtained upon gamma irradiation of Artemia salina cysts ( brine shrimp eggs). These results, combined with data on radiation survival, indicate that the water vapor protects the cysts from radiation damage, or heals the damage. They also indicate that water protects the cysts from the effect of oxygen by neutralizing the radiation-induced free radicals before they can interact with oxygen to produce irreversible damage. 相似文献
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D S Grosch 《Science (New York, N.Y.)》1967,155(762):592-593
Brine shrimp die within 5 days after being given doses of above 10(-5) parts of DDT per million. At this and lower doses, shrimp deposited broods at a normal frequency, and cysts predominated. The number of cysts that emerged and the survival of larvae to adulthood from broods of treated parents exceeded those from controls. Therefore lethality based on induced dominant or sex-linked recessive gene mutation was not evident. Decreased fecundity is due to maternal debility. 相似文献
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Planktotrophic larvae that occur beneath the annual sea ice in the Antarctic assimilate organic solutes and preferentially ingest bacteria, whereas they actively exclude phytoplankton. In regions where phytoplankton biomass is temporally limited by light or nutrient concentrations, the growth and development of planktotrophic larvae may not be directly coupled to phytoplankton production. 相似文献
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《甘肃农业大学学报》2020,(1):161-169
【目的】为优化定量卤制驴肉的最佳生产工艺条件.【方法】以驴腱子肉为原料,对蒸制时间、蒸制温度以及高压灭菌时间在单因素试验的基础上采用响应面设计,以感官评分为指标,对其最佳工艺参数进行了优化,并对定量卤制驴肉的出品率和质构进行了测定.【结果】定量卤制驴肉的最佳工艺条件为:蒸制时间49 min、蒸制温度90℃、高压灭菌时间35 min.在该工艺条件下,产品出品率约为60.99%,硬度为(2 054.12±108.62),弹性为(0.85±0.05),内聚性为(0.52±0.02),剪切力为(1 064.68±62.45),感官综合评分可达88分.【结论】为定量卤制驴肉工业化生产提供了依据. 相似文献
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蝙蝠蛾幼虫食料初步筛选及其取食研究 总被引:1,自引:0,他引:1
为获得适合低海拔地区蝙蝠蛾规模化人工饲养的幼虫食料,对常见且营养丰富的食料或中药材进行初步筛选,并分析比较蝙蝠蛾5龄幼虫对所筛选食料的取食情况与效果,结果表明:在试验的15 d内,胡萝卜(CK)、人工饲料及太子参干品不发生变质;幼虫不取食太子参干品,喜食胡萝卜与白菜叶,但白菜叶湿度极大不利幼虫生长;白菜叶组、番薯组、鲜玉米粒组和人工饲料组幼虫增重极显著高于槟榔芋组及胡萝卜组;鲜玉米粒组、人工饲料组的食物转化率均高于8%,番薯组约为7%,三者的食物转化率极显著高于胡萝卜组。 相似文献