查询词典 over-population problem

With its basis on city attraction-φ and adoption of surface tension in physics, a math model about the floating population in city is established in this paper. This model takes the coacervation and escape of the molecule as the inflow and outflow of the population, the electric field intensity as the policy, and the electric conductivity in electrolytic solution as the enforcement of the policy.

以φ-城市吸引力为依据，借用物理学中"表面张力"的概念，把分子的凝聚和逃逸理解为人口的流进与流出，把电场强度理解为城市的政策、法规、法令，把电解溶液的电导率理解为对政策、法规、法令的执行情况，建立了城市流动人口的数学模型。

It permits a population to spread as the population increases, and it enables the colonization of new sites.

它使得种群在其增长的时候得以扩展它的分布区域并移居到新的场所。

This study is of great importance in realizing the basic laws about the population forming and developing of the two planthoppers. It also gives the theorical basis for analyzing and forecasting the population dynamics of the two planthoppers under the commensalism condition.

本研究对深入认识水稻混作区的两种飞虱种群发生与发展的基本规律具有重要意义，亦为分析与预测两种飞虱在共栖条件下的种群动态提供了依据，还为全面理解稻飞虱的致害性做了一定深度的探讨。

Boundednesses of population and toxin in population and in the environment are shown by comparison theorem.

通过比较定理得到了种群的有界性，及种群体内毒素和环境中毒素的有界性。

In the first chapter, we research the dynamics of population which were in the polluted environment, we will: give the corresponding mathematical model;(2): obtain the explicit conditions for the threshold of the population by means of comparison theorem.

第一章是研究污染环境中种群的动力学行为，首先给出相应受污染系统的数学模型，然后研究系统中种群的持久生存和灭绝问题，在具体模型中，运用比较定理研究种群生存的阈值。

With the modernization of scientific and technological progress and industrial development, physics, chemistry, biology, engineering, aerospace, medical, economic and financial areas of the many principles and laws can be described as an appropriate ordinary differential equations, such as Newton's laws of motion, gravity law, law of conservation of mechanical energy, energy conservation law, the law of population development, ecological population competition, disease transmission, genetic variation, the trend of the stock's up V, the floating interest rates, the market equilibrium price changes.

随着科技进步和工业现代化的发展，物理、化学、生物、工程、航空航天、医学、经济和金融领域中的许多原理和规律都可以描述成适当的常微分方程，如牛顿的运动定律、万有引力定律、机械能守恒定律，能量守恒定律、人口发展规律、生态种群竞争、疾病传染、遗传基因变异、股票的涨伏趋势、利率的浮动、市场均衡价格的变化等。

China's productive forces, science and technology, and education is relatively backward, industrialization and modernization still has a long way to go; The urban and rural economic structure has not changed, regional disparities have not reversed the trend, also quite poor; Total population continued to increase, rising proportion of the elderly population, employment and social security pressure; Ecological environment, natural resources and economic and social development have become increasingly conspicuous; we still face in the developed countries in the economic and scientific superiority pressure; economy and other aspects of the management system is not perfect; the building of democratic legal system and ideology and morality, there are still some problems which can not be overlooked.

我国生产力和科技、教育还比较落后，实现工业化和现代化还有很长的路要走；城乡二元经济结构还没有改变，地区差距扩大的趋势尚未扭转，贫困人口还为数不少；人口总量继续增加，老龄人口比重上升，就业和社会保障压力增大；生态环境、自然资源和经济社会发展的矛盾日益突出；我们仍然面临发达国家在经济科技等方面占优势的压力；经济体制和其他方面的管理体制还不完善；民主法制建设和思想道德建设等方面还存在一些不容忽视的问题。

The urbanization is a process of quantitative and qualitative changes of population, industries and agents of production, a procedure of population, economy, environment and resources' development coordinately.

城镇化是人口、产业和生产要素向城镇聚集的量变和质变过程，以及在此基础的人口、经济、环境、资源的协调发展过程。

Meihua still suffers from deep social problems, including population drain, population aging, and alcoholism. In Wu Afu's corrugated iron home, alcohol used to be his only escape.

梅花部落还陷入深入的社会问题，有人口凋零，人口老化和喝酒文化问题，住在铁皮屋的吴阿福，酗酒成了他逃避生活的方式。

By using the Neighbor-joining method, a dendrogram was obtained based on genetic distances. The bootstrap values were evaluated for each crunode of the dendrogram by means of bootstrap test. The results showed that the mean heterozygosity of the whole native egg-typing duck breeds population was lower than those of native chicken breeds and goose breeds, suggesting that the genetic diversity in those duck breeds population is relativly rare and should be strengthened. The rank of the heterozygosity was consistent with that of the polymorphism information content. The results of the genetic distances between them indicated that the differentiation occurred long time ago. In the dendrogram, Weishan pocked, Youxian pocked, Huainan pocked, Guangxi pocked and Jingjiang pocked were classified into one goup, Chaohuand Enshi pocked were the second group, Liancheng white, Putian black, Jinding, Shanma, Sansui and Shaoxing were the flnra grong.

结果表明：我国所有蛋鸭品种全部群体的平均杂合度较低，其遗传多样性相对贫乏，各保种场要加强多样性的保护；各品种的平均多态信息含量的高低与群体平均杂合度的顺序完全一致；遗传距离的计算说明了13个品种的遗传距离较远，分化时间较长；13个地方蛋鸭品种被聚类为3个类，微山麻鸭、攸县麻鸭、淮南麻鸭、广西小麻鸭、荆江麻鸭聚为一类；巢湖鸭和恩施麻鸭聚为一类；福建省的鸭种连城白鸭、莆田黑鸭、金定鸭、山麻鸭与三穗鸭、绍兴鸭聚为一类。

Hanna: That's over now, isn't it?

都结束了，对吗

You must be ill. You look so pale.

你一定是病了，你的脸色苍白。