The optimal control problem of linear population dynamic system with age-structure in periodic environment was investigated.
在周期环境下，研究一类具有年龄结构种群线性动力系统的最优控制问题。
Such a policy distorts the age structure: the proportion of population in the younger age groups goes down and proportion of the elderly increases.
这样一项政策改变了年龄结构：年轻人的人口比例下降，而老年人的比例增长。
From age structure, the main forces of the divorce group aged from22 to 35; the stable period of marriage is between 36 and 50; after 50, divorce rate surges again.
从年龄结构看，22 ~35岁人群是离婚主力军，36 ~50岁年龄段是婚姻平稳期，50岁以上人群离婚率上扬。
It's not just wrinkles that reveal age, changes in facial bone structure make faces look older, too, according to researchers at the University of Rochester Medical Center.
揭示人类年龄的不仅仅是皱纹。美国罗切斯特大学医学中心的研究人员发现，面部骨骼结构的变化也会让人看起来更老。
But there is no evidence to show that the structure of eyes is changed by wearing glasses at a young age.
但是没有证据表明在年轻的时候戴眼镜会改变眼睛的结构。
One the most notable trends that's played out during this jobless recovery has been the dramatic shift in the age structure of employment.
在这轮伴随着高失业率的经济复苏中，一种最值得关注的趋势是就业人群年龄结构的巨大变化。
In this paper we formulate an epidemic model with chronological age and infectious age structure.
本文根据流行病的传染过程和机理建立了具有年龄和病程结构的流行病模型。
The paper analyzes the economic effect in the light of the characteristics of the change in population age structure of Gansu province.
本文针对甘肃省人口年龄结构变动特点，分析其经济效应。
The major reason for the coexistence of many types of age structure is ascribed to the differences in natural disturbance regime in each region.
不同地段自然干扰状况的差异是造成多种年龄结构类型共存的主要原因。
The population dynamic of Tsuga tchekiangensis in Wuyishan Nature Reserve was studied and its age structure, the life table, survival curve, mortality rate and killing power curve were analyzed.
对武夷山自然保护区南方铁杉种群动态进行了系统研究，绘制该种群的年龄结构，编制静态生命表，分析存活曲线、死亡率曲线和损失度曲线。
Now, the total of construction human capital is growing, level of human capital is low, and age structure is unreasonable.
建筑业的人力资本则呈现出总量上不断增加，人力资本水平较低，年龄结构不合理的现状。
First, we examined consumption function model which doesn't contain the age structure of population variables and we conduct a brief analysis.
首先，我们检验了不含人口年龄结构变量的消费函数模型，并对结果进行了简要的分析。
This paper discussed the possibility that intelligence structure might be changed with individual differences such as ability and age.
该文探讨了智力结构随能力、年龄等个体差异而变化的可能性。
The authors have studied the structure of tendon insertion in human patella apex in different age and analysed Its biomechanical function.
作者研究了不同年龄人的髌尖末端结构并分析其生物力学功能。
The third chapter indicates that China has got into the age of heavy industry through analyzing the transformation of the industry structure.
第三章从产业结构变动的规律出发，指出中国目前已进入重化工业时代。
Age structure effect — Changes in the age distribution induced by the rate of population growth.
年龄结构效应——由人口出生率引起的年龄分布变化。
Consistence between isotopic model age of lead ore and intrusion age of quartz porphyry shows close relations among structure movements, magmatism and mineralization in Stage of Yenshan.
矿石铅同位素模式年龄和石英斑岩体侵入年龄的一致性反映燕山期构造、岩浆和成矿作用的密切关系。
The main factors affecting on the community structure and dynamics of the pests were the biological characters of pests, age of lichee tree, climates and ecological circumstance of the orchard.
害虫生物学特征、树龄、气候条件和生态环境等都是影响害虫群落结构及动态的主要因素。
There exists different demand character in consumers at the different age, and population factors directly affect the market orientation and demand structure for houses.
不同年龄阶段的消费群体具有不同的需求特征，人口因素直接影响着住宅产品的市场定位和需求结构。
The result revealed that there was obviously changed in age structure and reproduction structure of L. lagurus with the decline of the population quantity.
结果表明，随着草原兔尾鼠数量的下降，种群的年龄结构和繁殖结构都发生了明显的变化。
The height structure and diameter structure of A. senticosus population relate with community environments and with its own age structure characteristics.
刺五加种群的高度结构与径级结构的变化都与群落环境以及本身的年龄结构特点有关。
The result shows that the Tree class structure replacing the age structure is suitable for studying the structure and dynamics of Castanopsis fargesii population.
结果表明，应用立木级结构代替年龄结构研究栲树种群的结构和动态特征是适用的。
The age structure, reproductive age structure, fecundity and reproductive value of Larix chinensis were studied, the reproductive fitness and the reproductive strategy were analyzed in this paper.
研究了太白红杉种群的年龄结构、生殖年龄结构、生殖力和生殖值，分析了太白红杉种群的生殖适合度和生殖对策。
The probability of concrete structure cracking at early age is estimated by cracking probability and critical cracking risk with probabilistic method for a real case of concrete wall.
利用概率的方法，确定开裂概率和临界开裂风险来评价混凝土结构的早龄期开裂的可能性大小，并在混凝土挡土墙工程中应用。
Our data indicated that the EGG waveform may reflect anatomical structure and age change of vocal fold, and may show the relationships between these changes and the characteristics of vocal fold v...
EGG波形可以反映出声带解剖结构情况和增龄性变化，并能显示出这些变化与声带振动特性之间的关系。
Methods with the assistance of polysomnography, the sleep structure of 47 children with adenoid hypertrophy was compared with that of normal children at the same age.
方法通过多导睡眠图分析47例腺样体肥大儿童睡眠结构，并与同龄组儿童睡眠结构正常值进行比较。
Hyaluronic acid and collagen are vital components of skin structure that decline as we age.
透明质酸和胶原蛋白是皮肤组织中的重要组成部分，随着年龄而减少。
Hyaluronic acid and collagen are vital components of skin structure that decline as we age.
透明质酸和胶原蛋白是皮肤组织中的重要组成部分，随着年龄而减少。
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