查询词典 population mean

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。

The results are as follows: 1 mean length and weight tend to increase while dominant length and weight groups are noted to be increasing from Oct. 2004 to Sep. 2007; 2 by using length-weight formula, calculated weight value at the same length is higher for track-data than that for background-data; 3 growth parameters of L∞, W∞ and K respectively increase from 140.5 mm, 36.5 g and 0.28 a-1 to 186.0 mm, 118.5 g and 0.36 a-1 after artificial reef deployment; 4 appreciable increases are noted in body length and weight growth rate after artificial reef deployment, and inflexion age of weight growth increases from 2.55 to 2.58 years after artificial reef deployment; 5 there is an increase in critical biomass age from 3.21 to 3.77 years after artificial reef deployment; 6 there is a decrease in total instantaneous population mortality from 1.065 to 0.75 per year after artificial reef deployment; and 7 the overall population biomass of small yellow croaker stands at 131.5 tons.

结果表明：投礁后小黄鱼的平均体长和体重均呈上升趋势，优势体长组和体重组均向高值移动；同等体长情况下由投礁后体长体重关系式估算的体重比用投礁前的体长体重关系式估算的值大；投礁后小黄鱼个体生长方程的参数 L∞、W∞、K 值分别从投礁前的140.5 mm、36.5 g和0.28 a-1增加到186.0 mm、118.5 g和0.36 a-1；投礁后体长与体重生长速度与投礁前相比有所增大，且体重生长的拐点年龄从投礁前2.55 a提高到2007年的2.58 a；小黄鱼种群生物量增长的临界年龄从投礁前的3.21 a提高到3.77 a；小黄鱼种群的总瞬时死亡率从投礁前的1.065 a-1减小到0.75 a-1；鱼礁区小黄鱼资源量约

The mean observed heterozygosity of hatched population from Wales is distinctly higher than that of natural population from Ireland.

两种群之间相比，威尔士养殖群体的平均杂合度观察值明显大于爱尔兰自然群体的。

By integral in mean and comparison theorem, boundednesses of consumer population and resources, as well as a sufficient condition for population's weak persistent in mean are given when the environment is with a small capacity.

利用积分均值法和比较定理，给出消费者种群和资源量的有界性，以及环境容量较小情形下种群弱平均持续生存的充分条件。

CFacing to 21 century,that of our thinking and knowledge aboutpopulation aging must be outdate with the global fertility decline,and akind of the population aging which can be better expressed"the increaseof median age or mean age"of population aging itself and human'slongevity will be emerging,that is so called"aging of the aged".

面对新世纪，随着全球生育率的持续下降，以往我们所认知的那种"老龄化"将会渐渐淡出，而一种能更好地体现老龄化"增龄"本意并反映人类长寿现象的新形式的老龄化将日益凸现，这就是人口的"高龄化"。

The estimation of population mean is obtained using a cluster sampling method with supplementary stratified sample.

针对这一缺陷，提出了一种辅以分层抽样样本的整群抽样方案，得到了总体均值的估计量，以及这一估计量的一些良好性质。

China 's modernization, economic growth, enormous size and population mean that no major problem facing the world, whether it is global warming, the financial crisis, or issues of international security, can be solved without its cooperation.

中国的现代化建设、经济发展、庞大的国土面积和人口数量意味着世界上所有重大问题，不论是全球变暖、经济危机还是国际安全，都离不开中国的参与。

We give the approximation formulas of the variance of the sample ratio estimator for a population mean and its asymptotically non-biased estimator in multi-stage sampling.

讨论多阶段抽样比率估计及其样本量选择的问题，给出了比率估计抽样均方误差的近似公式及其渐近无偏估计的公式。

The main achievements of the project are as follows: 1 the hypothesis that a decrease in seed mass causes an increase in mean dispersal distance has been tested based on the experiments of weed dispersal by wind. The experimental results partly support the hypothesis. The results will help farmers to make an optimal strategy of weed control; 2 a statistic method for inferring probabilistic distribution function of a random variable has been developed, by which probabilistic distribution functions of weed species dispersal have been determined; 3 the reproduction structure of Bromus sterilis has been studied; 4 a more complex CA model with 25 neighborhood cells were built, which can simulate spread of a weed population. This work promotes developments in both theory and application of CA models; 5 the "mean law" in weed control has been proposed. Accordingly, the algorism of patch spring may be calibrated; 6 the "patch" and "true patch" have been mathematically defined so that herbicide can be efficiently applied; 7 simulation validates that initial configurations of weed will affect dispersal of its population and strategies of controlling it, or its distribution patterns affect its dispersal progresses.

主要完成的工作和取得的成果有：1）用实验证实了重量较轻的杂草种子并不一定飞得比较重的远，其结果有助于农民制订杂草的优化控制策略；2）发展了一种推断随机变量分布函数的统计方法并用它来获得了几个杂草种的扩散分布函数；3）对杂草Bromus sterilis的繁殖结构进行了研究；4）建立了一个具有25邻的较复杂的能模拟杂草扩散的CA模型，并在理论和应用方面促进了CA模型的发展；5）在杂草控制方面提出了&平均法则&，据此可对按块施药方法进行校正；6）精确地定义了&块&和&真块&以便在杂草控制中能更有效地使用除草剂；7）模拟证实杂草种群的初始配置影响其扩散和控制策略，或者格局影响过程。

The results show that the atomic population is time-independent provided that the atoms are in |β11〉 state. For the other three Bell states, there will appear the periodical collapse revival of atomic populationif the initial mean photon number reaches some special values. With the increase of the initial mean photon number, the oscillation frequency of the time-evolution of atomic population increases correspondingly, and the amplitude decreases. The degree of the entanglement of the two-mode entangled coherent field has no

结果表明，当双原子体系的初态为|β11〉时，原子布居均不随时间变化；当双原子体系的初态为|β00〉，|β01〉或|β10〉且初始平均光子数达到一定值时，演化特性呈现周期性的崩塌-回复效应，并随初始光子数的增加，其演化曲线的振荡频率增大，振幅减小；双模纠缠相干光场的纠缠程度不影响Rabi振荡频率，但对振幅影响显著； Kerr介质与光场耦合系数达到一定值时，对Rabi振荡频率和幅度及原子布居的崩塌-回复周期产生强烈影响。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。