查询词典 Y-tube

Recombination suppression in the sex-determining region and accumulation of deleterious mutations lead to degeneration of the Y chromosomes in many species with heteromorphic X/Y chromosomes.

这个问题一直困扰着科学家，在2008年最后一期的世界著名杂志《基因组研究》上，王秀娥和张文立博士发表了《番木瓜原始Y染色体的雄性特异区中DNA甲基化和异染色质化》的研究论文，初步揭示了性染色体的起源变化机制。

Give an efficient algorithm to compute the least common multiple of two n-bit number x and y, that is ,the smallest number divisible by both x and y.

给出一个计算最小公倍数：能同时整除x和y的最小的数。

If N is a nonempty subset of a left R module M, then N is a submodule of M if and only if the following conditions hold:(1) x+y is in N for any element x,y in N;(2) rx is in N for any r in the ring R, and any x in N.

假设 N 是左模的非空子集合，那么N 是子模的充分必要条件是，对N 中的任何两个元素x，y有

Therefore, we designed a measurement based on the measurement of grating XY table to meet the measurement of the rail line rolling X, Y coordinates of the accuracy requirements.

因此，本文设计了一种基于计量光栅的计量型X-Y工作台，满足了测量直线滚动导轨对X，Y坐标精度的要求。

It is clear that a necessary condition for the function y which makes the integral a minimum is that it be a Equation.

第一章 科技英语单句写作显然，函数y使该积分为最小值显然，函数y使该积分为最小值的必要条件是它应该是尤拉方程的一个解。

The spiny eel , belonging to Perciformes, Osteichthyes, is a kind of little freshwater fish distributed in Southern China. In 1998, Our lab detected XX/XY differentiated sex chromosomes in this specie with karyotypic analysis, and then with chromosomal binding and SC observation, we identified that its two largest metacentric chromosomes were X, Y sex chromosomes in 1999. X, Y chromosomes differ each other not only in the distribution of heterochromatin but also in their shapes, which make them could be recognized directly under the light-microscope without any banding treatment.

刺鳅，属鲈形目、刺鳅科(Perciformes，Mastacembelidae)，是广泛分布于中国南方的小型淡水鱼类。1998年，我室通过核型分析，首次发现该物种具有明显分化的异形性染色体，其性别决定类型为XX／XY型。1999年，本室通过染色体显带、精母细胞联会复合体观察，再次确认刺鳅染色体组中最大的一对中部着丝粒染色体为X、Y性染色体，两者不仅已经出现结构异染色质分布上的不同，同时在外部形态上也存在明显差异，识别特征鲜明，在光镜观察下无需显带即能清晰辨认性染色体。

The human Y chromosome is paternally inherited in a haplotype model.

人类Y染色体为正常男性特有、其大部分非重组区呈父系单倍型遗传等特点，使得Y染色体特异的多态性遗传标记成为人类学、群体遗传学及法。。。

XEX ~ Arg min{FIy E ~2} where the upper level is about topological structure optimization(a~ is a topological structure varable), and the lower level is a constrained programming about continuous variable y. 2 Apply graph, the action of permutation group on a graph, equiva- lent class, orbit etc.

取得的主要成果有： 1 依点到集的映射、集值映射、二元映射和分离定理等理论首次建立了具有拓扑结构双层规划的数学模型 min F s.t.x∈X y∈Arg min｛F|y∈Ω｝其上层规划为关于离散变量x的拓扑结构优化，下层规划是关于连续变量的约束规划。

In complex 1,Cucan be described as a four-coordinated square planar geometry.Compound 8 is the sodium salt of plumbagin and exists as ionic compound.Compounds 9-16 are the rare earth complexes of plumbagin with La,Y,Dy,Sm,Gd,Nd,Erand Eu.Compound 17 is binuclear Y complex.18 is mononuclear Ycomplex with plumbagin and another ligand from Plumbago Zeylanica.Compounds 19-21 are the ternary complexes with plumbagin and 2,2\'-bpy and phen as assistant ligand.In 19, the geometry of Cucan be described as five-coordinated distorted square pyramid that exists in a dimer through the weak bonding,and 1-D chain structure is formed by intermolecular hydrogen bonds.

化合物1的单晶结构分析表明1具有四配位平面四边形结构，化合物8是白花丹素的Na盐，以离子化合物形式存在；化合物9～16为白花丹素的La，Y，Dy，Sm，Gd，Nd，Er，Eu的稀土金属配合物；化合物17是白花丹素的双核钇结构；化合物18为白花丹素的单核钇结构，该配合物除了含白花丹素外，还有来自白花丹植物中的另一个单体化合物也参与配位；化合物19～21是以2，2\'-联吡啶和邻菲咯啉等含N配体为辅助配体，具有白花丹素—含N配体—金属离子的三元配合物，化合物19是白花丹素和2，2\'-联吡啶与Cu的配合物，具有五配位的四方锥构型，通过Cu…O弱的成键作用形成二聚体，再通过分子间的氢键作用进一步形成一维链状结构，化合物20和化合物21是白花丹素分别与2，2\'-联吡啶和邻菲咯啉的Zn配合物，都具有六配位八面体构型的双核锌配合物，呈一维链状结构，化合物20中链与链之间的大量氢键将一维链扩展成二维层，分子间的π-π堆积作用进一步形成三维结构。

Agitation system of pyrolusite pulp: a ratio of the agitation diameter to reactor diameter : d/D= 0.35; a ratio of distance of agitation from the bottom of reactor to agitation diameter : y/d=0.5; agitation rate of 500～600r/min.

矿浆搅拌系统：采用上旋式搅拌器；搅拌器的直径d与反应器直径D之比为d/D=0.35；搅拌器下端离反应器底部的距离y与搅拌器直径d之比为y/d=0.5；搅拌转速500-600r/min。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。