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Search Results: 1 - 10 of 25331 matches for " 尤锋? "
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黑鲪规模育苗获得成功

海洋科学 , 1993,
Abstract:
黑鲷三倍体的人工诱导研究

海洋与湖沼 , 1993,
Abstract: 分别于1989年3—6月、1990年3—5月在天津和青岛两地采用冷、热休克法对黑鲷进行三倍体的人工诱导研究。结果表明,冷休克法诱导三倍体的效果好于热休克法,其最适诱导条件为卵子在受精后5min,温度为3—4°C的海水中处理10—20min,三倍体诱导率最高可达50.35%;正交试验证明,三倍体率受冷、热休克法的三因素影响程度的顺序由大到小依次为,处理时间、处理时刻、处理温度;黑鲷染色体数目:2n=48,3n=72,它们的染色体组型也同时获得。
黑鲪规模育苗获得成功

海洋科学 , 1993,
Abstract:
海产鱼类多倍体育种的研究

海洋科学 , 1997,
Abstract:
三倍体牙鲆的核型证明
,刘静
海洋与湖沼 , 1995,
Abstract: 于1990,1993 - 1994年以捕自青岛近海的牙鲆亲鱼,采用冷休克法(0-4°C)进行多倍体的人工诱导实验,以期掌握牙鲆细胞遗传学特征和研究遗传育种方法。通过实验得到了三倍体牙鲆并进行培育。在原肠胚期采用空气干燥法、Giemsa染色获得正常二倍体、三倍体的染色体制片。镜检得,牙鲆二倍体染色体以2n=48,均为端部着丝点染色体,核型为24t,其管数NF=48;三倍体的染色体3n=72,也都为端部着丝点染色体,其臂数NF=72,并依据二倍体的枝型得出了三倍体的核型图。
人工培育条件下黑鲷仔稚鱼摄食习性的观察
阮洪超,
海洋科学 , 1990,
Abstract: 本实验用牡蛎幼虫、轮虫以及卤虫无节幼体投喂黑鲷仔稚鱼,观察摄食情况。消化道内含物分析结果表明,孵出后3周日至6周日,主要摄食牡蛎幼虫;9周日至19周日主要摄食轮虫;20周日以后主要摄食卤虫无节幼体。3种饵料中,初次摄食的最适宜饵料是牡蛎幼虫。
挤压当前还是保障未来:中低收入阶层养老保险幸福效应研究
Squeezing Present or Protecting Future: A Study on the Impact of Old-age Insurance System on Happiness of Low and Moderate-income Group

岳经纶 
- , 2018,
Abstract: 摘要 为了应对日益严峻的老龄化形势,1997年以来我国逐渐建立起了一套广覆盖的基本养老保险制度,皆在于保障老年人退休后的基本生活。尽管养老保险覆盖面得到了较大的提升,但目前学界对于养老保险的保障功能却持有两种相反的意见。本文基于2017年广东省公众福利态度调查数据,运用Ordered Probit模型分析发现:养老保险缴费水平认知越低,中低收入阶层的幸福感越强;养老保险待遇水平认知对中低收入阶层的幸福感不存在影响;相比没有参保,参加养老保险无法提升中低收入阶层的幸福感。以上结论揭示出了中低收入阶层更加关注于养老保险的缴费而非待遇,反映了养老保险对中低收入阶层当前的基本生活水平、就业机会和工资福利水平造成挤压的同时,没有发挥出应有的保障未来养老的预期和功能。本文的发现为未来我国养老保险制度的完善和发展提供了理论依据,对应对我国老龄化危机和实现人民美好生活具有重要的现实意义。
Abstract:In order to tackle the increasingly serious aging structure of population, China has gradually built up a basic old-age insurance system, which aims at protecting the basic life of the elderly after their retirement. Although the coverage has been greatly increased, current researches hold two opposite arguments on the security function of old-age insurance system. Based on the survey data of public welfare attitudes in Guangdong Province in 2017, this research uses Ordered Probit model to analyze the relationship between happiness of the low and moderate-income group and their perception of the payment and treatment of old-age insurance system. Our research finds that the perception of payment of old-age insurance system has significantly negative effect on happiness of low and moderate-income group, while there is no correlation between the treatment of old-age insurance system and happiness of low and moderate-income group. Moreover, compared with low and moderate-income group who doesn’t join the old-age insurance system, joining the old-age insurance system cannot increase happiness of low and moderate-income group. These findings reveal that low and moderate-income group pay more attention to the payment of old-age insurance system rather than the treatment of it,indicating joining the old-age insurance system will reduce the quality of life,job opportunity and salary of low and moderate-income group,but fail to play its role in ensuring their pension at the same time. Our research can provide a theoretical basis for the reform and improvement of China's old-age insurance system, as well as having practical significance on tackling aging crisis and realizing better life.
中国鲳属鱼类同工酶谱分析
刘静,,李春生
海洋科学 , 1999,
Abstract:
美国红鱼(Sciaenops ocellatus)的核型研究
,刘静,徐成
海洋科学 , 1998,
Abstract:
湖南新技术产业发展及其对策

科技进步与对策 , 1988,
Abstract:
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