产生变异

In this dissertation, the genetic algorithm is discussed in detail. In order to improve the convergence of GA, considering that it is important to choose the probability of crossover and mutation , new p〓 and p〓 were varied depending on the fitness values.

该方法在遗传模式得到保证的基础上，加快新个体的产生速度，所构造的交叉算子和变异算子随适应值自动变化，对远离最优值的个体采用较大遗传算子值，对接近最优值的个体采用较小遗传算子值，提高得至撮优解的概率。

The partial correlation analysis showed that available N, available P and available K were important influence factors for yield spatial variability.

从偏相关分析可知，土壤中的碱解氮、速效磷和速效钾是产量产生空间变异的重要影响因素。

The evolutionary relationships were investgated by comparing the results from molecular data alone or molecular data combined morphological characters using different analysis methods: maximum parsimony by PAUP(superscript *) 4.0 and Bayesian inference by MrBayes 3.0B4. Base composition and ti/tv of 28S rDNA D2 regions were analyzed by PAUP(superscript *) 4.0. The results showed that GC content of the 28S rDNA D2 gene sequences of subfamily Euphorinae ranges from 40.00% to 49.25%. Transversion frequency of sequence variable sites among species of Euphorinae was higher than that of transition. The subfamily Euphorinae was proved to be a paraphyletic group with close relationship to subfamilies Neoneurinae and Cenocoelinae; only two tribes, Meterorini and Microctonini, were proved to be monophyletic groups; Centistini, Cosmophorini, Euphorini and Dinocampini were paraphyletic groups; the basal position of tribe Meterorini within Euphorinae was partially supported by our phylogenetic trees, and tribe Microctonini was proved to be a group at the top of the trees.

结果表明：优茧蜂亚科的28S rDNA D2基因序列片段的GC%含量在40.00%~49.25%之间变动，而对于碱基替代情况来讲，优茧蜂亚科各个成员间序列变异位点上颠换大于转换；不同的分析和算法所产生的系统发育树都表明目前根据形态定义出的优茧蜂亚科Euphorinae不是一个单系群，而是一个与蚁茧蜂亚科Neoneurinae和高腹茧蜂亚科Cenocoelinae混杂在一起的并系群；在优茧蜂亚科内部，悬茧蜂族Meterorini和食甲茧蜂族Microctonini（排除猎户茧蜂属Orionis）为单系群，而宽鞘茧蜂族Centistini、大颚茧蜂族Cosmophorini、优茧蜂族Euphorini、瓢虫茧蜂族Dinocampini为并系群；悬茧蜂族Meterorini在优茧蜂亚科Euphorinae内位于基部位置的观点得到部分的支持，同时食甲茧蜂族Microctonini被判定为相对进化的类群。

The results showed that the Saccharopolyspora spinosa SP06081 protoplast yield was the highest under these conditions: the collected mycelium from SP06081 grown in Tryptic Soy Broth medium with 0.2% glycin for 48 h was treated by 0.1 mg/mL lysozyme at 28oC for 20 min, then plated on the R2YE medium with sucrose as osmotic stabilizer, the number of regeneration protoplast was up to 108/mL. The protoplast-regenerated strains exhibited changes in morphology and antibiotic production, 29.3% protoplast-regenerated strains was characterized by loose mycelium and abundant broken branches as did their parent. Among them, 58.2% strains presented the trend to positive variation in spinosad yield, with the highest spinosad yield of up to 582.0 mg/L, 85.6% higher than that of their parent.

结果表明：菌体在添加0.2%的甘氨酸的TSB培养基中培养48 h收集， 0.1 mg/mL 溶菌酶， 28oC作用20 min制备原生质体，将原生质体涂布于以蔗糖为渗透压稳定剂的R2YE培养基中，原生质体再生数目最多，达108个/mL以上；原生质体再生菌株在形态和抗生素产量上产生分化， 29.3%的再生菌株形态上保持与亲本菌株一致，具有菌丝松散，断裂分枝多的特点，其中53.2%的再生菌株多杀菌素产量变异向正方向移动，最高产量达到582.0 mg/L，比亲本菌株提高85.6%。

The probability vector can be viewed as a prototype vector for generating solution vectors that have high evaluations with respect to the available knowledge of the search space. Compared with the general genetic algorithm, PBIL discards the complex and problem-correlation operators, which always affect the algorithm's performance highly.

相对于常规遗传算法，PBIL进化算法抛弃了复杂的且对算法性能影响很大的交叉、变异算子，而引入竞争学习的机制，以概率矢量的方式通过采样来产生下一代群体，然后选出群体中最优个体对概率矢量进行更新，直至最后收敛。

Firstly, the authors create various initial colonies and introduce quinary coding strategy to improve searching speed. Then, they adopt random selection mechanism without reimbursement to prevent premature convergence. Twopoint crossover and multipoint mutation are adopted to extend searching range of model space and to keep individual diversity.

首先，产生多样化的初始群体，引入五进制的编码策略提高搜索速度，然后采用无退还随机选择机制防止收敛早熟，采取两点交叉及多点变异方案以扩大模型空间的搜索范围和保持个体的多样性。

It may be that there are rarer variants that have smaller effect size and are relevant.

这可能就是因为有其他较罕见的变异在产生一些较小的影响。

Under the guidance of materialism,culture secularize and value multiplication,many original moral standards start to change from convergence to variation,and as a social problem,moral problems also appears quickly and has the bad effects in various domains of social economy,politics,and culture.

在物质实利化、文化世俗化和价值多元化路径引导下，原有的许多道德标准开始由趋同走向变异，道德问题作为普遍社会问题也很快浮出水面，并在社会经济、政治、文化诸领域产生危害。

Rong proposed an improved level set method for topology optimization of continuum structures.

为了解决上述问题和克服水平集方法不能在结构内产生新孔洞的困难，提出了一种基于结构拓扑随机变异的水平集优化方法。

It is indicated that MRV and street viruses have close phylogenic relation by analyzing the phylogenic tree of eachgene of MRV, and it is short evolutionary time between MRV and DRV by analyzingthe phylogenic tree of L gene. It is illuminated that MRV and street virus in China andAfrica have close phylogenic relation by analyzing phylogenic trees of other genes.Therefore, we can speculate that MRV is a Chinese street rabies virus isolated, whichis a new virus isolated because of variance and evolution of the rabies virus after itinfected mouse.

MRV的各个基因进化树表明，其与野毒株具有较近的亲缘关系，通过L基因的进化树分析，两个毒株的进化时间较短，其他基因进化树分析表明，MRV与亚洲和中国流行的野毒株具有较近的亲缘关系，所以推测MRV应该是中国固有的野毒株，由于某种原因感染野鼠后病毒进化变异而产生的毒株。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。