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51.
用致仔猪水肿病的溶血性大肠杆菌制备氢氧化铝苗、蜂胶苗、油佐剂苗和超声波灭活苗,分别以0.1mL、0.2mL剂量免疫小白鼠,在免疫后24d用强毒株培养液攻击,结果显示:0.1mL氢氧化铝苗、0.2mL 蜂胶苗可使小白鼠获得100%的保护。0.1mL超声波灭活苗可使小白鼠获得80%的保护。用不同菌液免疫家兔,在免疫后21d、27d采血测其凝集抗体效价,21d、27d皆以油佐剂苗效价最高,达1:32、1:64,其次为蜂胶苗,为1:32(++)、1:32(++++)。  相似文献   
52.
The relationship between family support systems and female mortality in Chinese and American cultures is studied using 1980 official data from Taiwan and the United States. The differences in female mortality by marital status support the hypotheses that Chinese families provide greater support for older than younger females, and that the emphasis on filial piety in Chinese society provides more support for the elderly by Chinese than American children.  相似文献   
53.
The total fertility rate of women of childbearing age of Dongguan County in China has been decreasing gradually from 5.9 during the period following the liberation in 1949 to 2.05 in 1982. In order to encourage young couples to implement the policy of family planning consciously, the people's government of Dongguan county decided in July 1980 that all cadres and employees in county towns who received 1-child certificates would be exempted from house rent of 45 square meters from the time they get their certificates and would be allocated a living space of a 2-children family until their children reached age 16. It also stipulated that every couple could enjoy 1 month's holiday every year for 3 years and during the holiday, their salary, bonus and rate of attendance would not be affected. Because women bear less children today, they are relieved from heavy household chores and become the main working force in collective production. As a result, the development of town-run enterprises was stimulated and the total industrial output value of these enterprises increased. The average monthly salary of each female worker is about 100 yuan. In 1984, the average income per capita of the country rose to 649.2 yuan. The implementation of family planning work has eased the tension in the education field. Previously, because of the large number of school-age children in rural areas, teachers had to teach 2 classes. In the past 4 years, great emphasis was laid on intellectual investment. During this period, 2351 schools were built and several fundraising projects were implemented. Since 1981, more than 200 new running water projects were built, and new public services have been developed, including old age homes.  相似文献   
54.
农业资本化的本质是农业资本投入的不断增加,金融资源是实现农业资本化的根本保障,只有顺应农业资本化方向的金融资源才可减少无效或低效供给,增加有效或高效供给。本文首先从理论出发论述了金融资源与农业资本化存在相互作用的耦合机制。金融资源通过资本形成机制、技术进步机制和要素替代机制促进农业资本化发展,农业资本化的发展能带来农业生产效率和数量的提高,促进农业经营性收益增加,从而刺激农村地区金融服务产品的需求和供给得到提升,为金融资源总量增加提供累积空间。再基于长江经济带10省市2008—2019年样本数据,通过构建金融资源与农业资本化两大指标体系,运用熵值法和耦合协调度模型对金融资源与农业资本化的耦合协调程度进行实证检验。结果表明,金融资源与农业资本化的发展整体呈上升趋势,但二者存在背离的现象,农村金融资源不足或错配阻碍着金融资源与农业资本化相互促进的良性循环。  相似文献   
55.
56.
刘庆邦着眼于我国城乡社会结构的变迁,多年来坚持书写农村题材和普通矿工的平凡生活,新世纪以来创作的“保姆在北京”系列小说则将创作视点转移至进城打工的保姆群体,不变的是他对底层百姓的人道主义关怀及对人性问题的深入思索。不论是城乡交叉地带的煤矿叙事所呈现出的物理空间、心理空间和社会空间,还是“保姆在北京”系列小说中空间权力对进城乡下女性的规约与限制,都表现出刘庆邦小说明显的空间意识,也体现了他小说创作的独特价值。  相似文献   
57.
Generalized Leverage and its Applications   总被引:2,自引:0,他引:2  
The generalized leverage of an estimator is defined in regression models as a measure of the importance of individual observations. We derive a simple but powerful result, developing an explicit expression for leverage in a general M -estimation problem, of which the maximum likelihood problems are special cases. A variety of applications are considered, most notably to the exponential family non-linear models. The relationship between leverage and local influence is also discussed. Numerical examples are given to illustrate our results  相似文献   
58.
提出了由于信息化社会、Internet、Intranet和多媒体技术的出现,从而要求卫星通信向多体制、多功能发展。文中着重分析了具有独特优点的激光通信在宽带卫星通信和星际链路中的现实商用前景。  相似文献   
59.
对獭兔的适应性、饲养管理、疾病防治、产品加工等养殖综合技术进行了研究,提出了獭兔的“三改、两杯、两早一分和两选两适”规范化饲养管理制度和疾病综合防治技术措施,探索出了优质獭兔毛皮和“富钙兔肉脯”的加工工艺以及獭兔良种推广的有效途径。  相似文献   
60.
"In this paper, we use simulation models to demonstrate the complexity of the relationship between the marriage selection process and the resulting RMRs [relative mortality ratios]. In particular, we show that marriage selection alone can produce a relative mortality ratio which remains large and relatively constant at ages far beyond the marriage span....Our general objective...is to determine the range of age patterns of relative mortality which could, in theory, result from marriage selection on the basis of health characteristics. We also evaluate the effects of variations in the marriage selection mechanisms on the resulting mortality patterns....We develop and apply several simple mathematical models of the marriage selection process. In order to distinguish the potential consequences of marriage selection from marriage protection, we consider hypothetical populations in which causal effects are absent....We begin by considering an extremely simple marriage selection process and subsequently explore a more realistic selection model based on recent death and marriage rates for Japan."  相似文献   
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