群速度
- 与 群速度 相关的网络例句 [注:此内容来源于网络,仅供参考]
-
The sixteen plants are firstly divided into six types according to evaluation grades and subject function statistical method:the first type is Cajanus cajan and Crotalaria mucronata,the best adaptability ,which can be used pioneer plant or constructive species; the second type is Cynodon dactylon,the better adaptability, which can be used constructive species ;the third type is Eragrostis curvula, Paspalam notatum,which can be used constructive species on rotten rock slope ; the forth type is kummerowia striata,Lotus corniculatus and Vitex negundo.The adaptability is centered,and can be used protection species and auxiliary species;the fifth type is Robinia pseudoacacia,Eremochloa ophiuroides,Vitex negundo,Lespedeza formosa,Leucaena leucocephala,Desmodium sequax, Rhus chinne- nsis,which can't be plant singly and be used accessory species;the sixth is Trifolium repens,which can be used pioneer plant.
根据评价边坡防护植物适应性的十个重要指标,首次运用隶属函数和聚类分析方法,对各供试植物的边坡适应性综合排序并分为六类:第一类为木豆和猪屎豆,边坡适应性最强,适宜作为先锋植物和建群种;第二类为狗牙根,边坡适应性强,适宜与豆科植物混播,作为建群种;第三类为弯叶画眉草和百喜草,边坡适应性较强,适宜与豆科植物混播,作为风化岩边坡的建群种;第四类为鸡眼草、百脉根和马棘,边坡适应性中等,适宜作为保护种与伴生种;第五类为刺槐、假俭草、荆条、美丽胡枝子、银合欢、波叶山蚂蝗和盐肤木,边坡适应性较差,不宜单独在边坡上种植,最好与速生型豆科草本混播,作为边坡防护植物群落的辅助植物;第六类为白三叶,边坡适应性最差,但因其出苗率高、生长速度快,作为先锋植物,起到前期覆盖坡面的作用。
-
Chapter 1 gives the background,current research process of relatedproblems and summarizes this thesis\'s work.In chapter 2,we study the Brownian motion with holding and jumping on the boundary.We use the resolvent method to obtain the infinitesimal generator because the domain of the infinitesimal generator is essentially the same as the range of the resolvent.Knowledge of this range and of the differential operator determines uniquely the infinitesimal generator.Since the semigroup generated by the DHJ is not strongly continuous,to use the nice property of strongly continuous semigroup in analytic theory,in chapter 3 we show that the dual is strongly continuous and derive ergodicity through spectral radius formulas and finally obtain the ergodic theorem by duality. In chapter 4,we discuss a class of a more general process---one dimensional Feller diffusion proposed by W.Feller in 1954.The Feller diffusion allows the possibility of jumps from boundary to boundary,not only from boundary to the interior.We give the stationary distribution of this process.
具体地,本文的结构如下:第一章给出了问题产生的背景,研究现状及本文的主要工作;第二章研究了在边界上逗留后随机跳的布朗运动,我(来源:3dABC论文网www.abclunwen.com)们用预解算子的方法得到其无穷小生成元,因为无穷小生成元的定义域本质上就是预解算子的值域,知道这个值域和微分算子形式就能唯一地决定无穷小生成元;由于DHJ过程产生的半群不是强连续的,为利用强连续半群的一些漂亮性质,在第三章中我们证明其对偶半群是强连续的,然后由谱半径公式得到遍历性并且最后由对偶得到遍历定理;第四章讨论了Feller在1954年引入的更广的一类过程----一维Feller扩散过程,Feller扩散过程允许有从边界到边界的跳发生,即不仅仅局限于从边界到内部的跳,在这一章中,我们给出了一维Feller扩散过程的平稳分布;在第五章,我们讨论了一些相关的问题,给出了DHJ过程对应的PDE问题及特征值与收敛速度的关系。
-
In order to justify the efficiency during the water elutriation process of separating ceramic inclusions from FGH95 alloy powder, the maximum theoretical and experimental size of FGH95 powder elutriated was compared at different water flowing velocity.
摘 要:通过对水淘析法的原理分析,运用流体力学中的摩擦数群法确定了以陶瓷夹杂物在水中的沉降速度来确定水流速度,及在确定的水流速度下,所能淘析出的FGH95合金粉末的最大尺寸;并以比较淘析出的FGH95合金粉末的实际最大尺寸与理论最大尺寸,考察了水淘析法分离FGH95合金粉末中的陶瓷夹杂的有效性。
-
This paper extends the ant colony algorithm which is used for solving 0-1 knapsack problem in reference [7], and gets enlightenment from the ant colony algorithm with 2-opt local optimization for solving traveling salesman problems: Exchange strategy can make the algorithm have faster convergence rate and get better quality solution. So this paper presents the ant colony algorithm based on exchange stragegy.
本文推广了文献[7]中求解单维0-1背包问题的蚁群算法,并从结合2-opt等局部优化的蚁群算法求解旅行商问题中得到启示:通过交换策略可以加快算法的收敛速度和获取更高质量的解,因此提出了基于交换策略的蚁群算法。
-
The irregular galaxy NGC 1427A is a spectacular example of the resulting stellar rumble. Under the gravitational grasp of a large gang of galaxies, called the Fornax cluster, the small bluish galaxy is plunging headlong into the group at 600 kilometers per second or nearly 400 miles per second.
星系NGC 1427A就是这样的一个例子,在一个名为Fornax星群的一大群星系的引力场的作用下,这个小蓝星系正以600公里/秒(400英里/秒)的速度冲向星系群。
-
Because whether polymerization or not , graviton permanent carry most high speed v, the energy function E=mc2 had precise inspect and verify shows v=1.414c , c is velocity of light, and their kinetic energy is
质子既然是恒星辐射的引力子聚合而成,它在空间不能绝对静止而是具有"群速",恒星在空间的"宇宙速度"是"群速"的最大值,在原子内部,质子之间的相对速度同样可能达到这一速度。
-
According to this understanding, this thesis tries to modify PSO algorithm in order to improve its quality of solutions. The main approches include: using uniform design to ensure the uniform distribution of initial particles in the design space; adding mutation operation to increase the diversity of particles; decreasing the maximum velocity limitation and the velocity inertia automatically to balance the local and the global search efforts; developing a new approach to treat the design variables exceeding the bounds; using extensive local searches to escape local minimum. The overall effect of these approaches can yield better results for most test problems.
有鉴於此,本文针对粒子群演化法之流程参考相关文献并稍作改变,使得粒子群演算法在结果的收敛上更具优势,本文的主要改进的方法包括:应用均匀设计的概念使得初始的粒子可以更均匀地分布在空间上;利用突变增加粒子之间的差异性与多样性;利用适当控制的最大速度限制及惯性权重控制,达到区域搜寻与全域搜寻的效果;应用新的边界处理机制处理设计变数超过上、下限的问题;利用区域强化搜寻针对粒子附近地区,再作进一步的搜索以得到更佳之结果;将各种方法综合后配合粒子群演算法使用,可以得到不错的结果。
-
The results showed that it would gain higher sustainable genetic respons and lower inbreeding rate when implementing BLUP selection in larger population. When the sire-dam ratio was too low, it would not only decrease the genetic response, but also increase the inbreeding rate. To gain higher genetic progress and acceptable inbreeding rate, it should keep enough large population size and feasible sire-dam ratio in practice.
结果表明,扩大育种群规模不仅可以获得更大的持续进展,同时还可有效缓解近交系数的过快上升;育种群中公畜比例过低时,不仅会降低遗传进展,群体近交系数的上升速度也会加快,实际中应保证育种群具有一定的规模和适宜的公母比例。
-
Seventh, case analysis and findings show that, on the one hand, ecological agriculture cluster concept in practice has been successful prototype, the competitive edge is increasingly appear; on the other hand, farmers have a weak sense of clusters, the ability to promote agricultural enterprises is not strong, farmers cooperation organization slackly, the incentive and monitoring mechanisms missing, these influence and has hampered the speed and quality of China\'s regional eco-agriculture cluster construction in a large extent.
案例分析和调查结果表明,一方面,生态农业集群理念在实践中已有成功的雏形,竞争优势也日渐显现;另一方面,农户集群意识淡薄、农业龙头企业带动能力不强、农户合作组织涣散、政府激励与监督机制的缺失等,也在很大程度上影响和制约了我国区域生态农业集群建设的速度和质量。
-
the effect of inertia weight on particle swarm optimization is studied,on basis of which adopts four kinds of strategies of inertia weight to regulate the speed of a new quantum delta potential well based particle swarm optimization.a faster and more stabile algorithm,found by comparing the performances of four equations regulated the inertia weight,solves 0/1 knapsack problem.the result of experiment shows that the modified algorithm improves the precision of optimal solution and has a faster speed and a higher efficiency in convergence.in a word,choosing a parameter of inertia weight suitably can improve the performance of new qdpso.
摘 要:在研究惯性权重对基本pso算法影响的基础上,根据惯性权重对粒子群算法影响的特点,采用4种惯性权重策略对一种新的具有量子行为的粒子群算法的速度进行调节,比较每种算法的性能,从中找到一种新的性能更好的改进算法,将其用于求解0-1背包问题。实验结果表明较好地选择惯性权重参数对算法的性能有很大提高,该改进算法在求解0-1背包问题中具有高效性,提高了最优解的精度,同时具有较快的收敛速度。
- 推荐网络例句
-
However, as the name(read-only memory)implies, CD disks cannot be written onorchanged in any way.
然而,正如其名字所指出的那样,CD盘不能写,也不能用任何方式改变其内容。
-
Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.
镀锌钢托盘多用于出口,替代木托盘,免薰蒸,符合欧盟、北美各国对出口货物包装材料的法令要求;喷涂钢托盘适用于重载上货架之用,托盘表面根据需要制作成平板状、波纹状及间隔形式,满足不同的使用要求。
-
A single payment file can be uploaded from an ERP system to effect all pan-China RMB payments and overseas payments in all currencies.
付款指令文件可从您的 ERP 系统上传到我们的电子银行系统来只是国内及对海外各种币种付款。