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During the postgenomics era the information about genomic sequence and gene functions provides a new foundation for evolutionary biology and ecology As the first whole-genome sequenced plant Arabidopsis thaliana and its wild relatives have played a critical role in understanding the evolution of genomics and speciation Both A halleri and A lyrata are closely related to the model species A thaliana A halleri ssp gemmifera occurs in northeastern China Japan and Taiwan; while its sister A halleri ssp halleri is mainly distributed in Europe Geographical barriers such as Tienshan Mountain Range isolate these intraspecific sisters Likewise A lyrata ssp kamchatica and ssp lyrata occur in East Asia and North America respectively Such distribution patterns seem to be consistent with allopartic speciation The comparison between ancestral and extant polymorphism by multilocus can be informative about the population genetics of speciation In this study we collected and analyzed DNA sequences of 98 genes from four wild relatives of A thaliana A halleri ssp gemmifera A halleri ssp halleri A lyrata ssp kamchatica and A lyrata ssp lyrata The ancestral states of these four species were compared to each other in terms of level of genetic variation However the ancestral species at the time of speciation were substantially more polymorphic than the extant geographical populations The observations are not fully compatible with speciation by strict allopatry At some species pairs parapatric speciation seems more reasonable in speciation of Arabidopsis The 98 gene sequences are also used for the congruence test between gene genealogy and species phylogeny Only 28 genes support the species phylogeny but there are 23 genes supports another major genealogy { lyrata} thaliana Based on the phylogenetic position change of A lyrata ssp kamchatica and Ks value for each species pair suggested the recent directional gene flow between A halleri ssp gemmifera and A lyrata ssp kamchatica

阿拉伯芥是第一个完成基因体定序的开花植物，其基因体资讯提供植物学研究的重要依据；在解析阿拉伯芥属物种的亲缘关系以及种化机制等重要的演化议题时，阿拉伯芥近缘的野生物种自然成了不可或缺的关键；跟阿拉伯芥近缘的物种包括A halleri及A lyrata，其中A halleri ssp gemmifera主要分布於中国东北、日本以及台湾，与近缘的A halleri ssp halleri其分布於欧洲隔著天山及大陆的障蔽，而A lyrata ssp kamchatica主要分布於东北亚及台湾，与分布於北美五大湖的A lyrata ssp lyrata被北极圈所分隔，这样的分布模式暗示异域种化的可能。藉由多基因分析比较祖先物种与现生物种遗传歧异度的相关可提供讯息探讨种化时期的族群遗传结构，本研究针对A halleri ssp gemmifera、A halleri ssp halleri及A lyrata ssp kamchatica、A lyrata ssp lyrata四个物种，两对互为亚种的姊妹群，以阿拉伯芥为外群进行研究，在四个物种完成98个同源基因的分子序列，利用套装软体MCMCcoal来估算祖先物种的遗传变异，亦估算现生物种的核苷酸歧异度，观察到？多物种配对中祖先物种遗传多型性大於现生物种DNA歧异度，显示异域种化模型并无法完全解释阿拉伯芥属物种的种化模式，在某些物种配对间邻域种化模式应比异域种化更为可能；在基因树与物种树的比较，98个基因片段的亲缘模式只有28个是与已知物种树一致的，有23个基因其树状图支持{ lyrata} thaliana的型式，藉由kamchatica位置的变化以及估算各物种配对间的平均同义置换率，推测在A halleri ssp gemmifera与A lyrata ssp kamchatica间具有近代的单方向基因交流。

Which it was necessary to know,--if, the porter once passed, one entered a little vestibule on the right, on which opened a staircase shut in between two walls and so narrow that only one person could ascend it at a time, if one did not allow one's self to be alarmed by a daubing of canary yellow, with a dado of chocolate which clothed this staircase, if one ventured to ascend it, one crossed a first landing, then a second, and arrived on the first story at a corridor where the yellow wash and the chocolate-hued plinth pursued one with a peaceable persistency.

是我们必须知道的，假使我们在过了门房那一关后向右走进一间有一道夹在两堵墙中、每次只能容一人上下的窄楼梯的小厅，假使我们不害怕墙上鹅黄色的灰浆和楼梯、以及楼梯两侧墙脚上的可可颜色，假使我们壮着胆子往上走，走过楼梯中段的第一宽级，继又走过第二宽级，我们便到了第一层楼的过道里，过道的墙上也刷了黄灰浆，墙根也作可可色，仿佛楼梯两侧的颜色也悄悄地、顽强地跟着我们上了楼似的。

When the snow lay deepest no wanderer ventured near my house for a week or fortnight at a time, but there I lived as snug as a meadow mouse, or as cattle and poultry which are said to have survived for a long time buried in drifts, even without food; or like that early settler's family in the town of Sutton, in this State, whose cottage was completely covered by the great snow of 1717 when he was absent, and an Indian found it only by the hole which the chimney's breath made in the drift, and so relieved the family.

当积雪最深的时候，往往一连一星期，甚至半个月都没有一个人走近我的屋子，可是我生活得很舒服，像草原上的一只老鼠或者牛，或者鸡，据说它们即使长时期地埋葬在积雪中，没有食物吃，也能活下去哩；或者，我像本州的萨顿城中，那最早的一家移民，据说在一七一七年的大雪中，他自己不在家，可是大雪全部盖没了他的草屋，后来幸亏一个印第安人，认出了烟囱中喷出的热气在积雪中化出的一个窟窿，才把他的一家人救了出来。

They'd kept him in hospital under observation for about a week, and when they released him, he was even angrier and more hollow-eyed than he'd been before, spending hours at a time by Ron's bedside or throwing himself into his Auror duties with a fervor she hadn't seen in a long time.

他们把他留院观察了一周，然后让他出院了，他变得更恼火，眼窝凹陷的更厉害了，在Ron的床边一呆就是几个小时，要么就是把自己扔在了一堆Auror的事务中，她已经很久没见过他那么狂热了。

Afterwards, we propose a new constant coefficients measurement method in dynamic equation of robot manipulators, this measurement method includes three groups of experiments: group one, let each joint of robot manipulator keep static to measure the constant coefficients in gravity term of dynamic equation and Coulomb frictional torque, group two: let only one joint of robot manipulator move at a constant velocity to measure the viscous frictional coefficient and constant coefficients in effective inertia of dynamic equation, group three: let only one joint of robot manipulator move at constant acceleration at a time to measure constant coefficients in Coriolis and centrifugal term and coupling inertia of dynamic equation.

让操作器单个关节恒速运动，在对驱动系统中传动机构，减速装置和电感系数综合考虑的基础上，这组实验对粘滞摩擦系数及有效惯量中常数系数进行测量。这种测量方法只要求旋转关节的驱动电机施加恒定电压，回转关节驱动电机施加正弦波电压。3。让操作器单个关节恒加速运动，这组实验测量动力学方程中哥氏力、离心力项和耦合惯量项中的常数系数，这种测量方法只要求单个关节匀加速运动，而其它各关节保持静止，这种测量方法虽然要求关节匀加速运动，但不必进行关节角加速度检测，而只需进行关节角位移和角速度检测即可，输入量直接给定为输入电压。

Running at one megabit per second with Manchester encoding, this Ethernet standard operates on a baseband basis, providing for a single transmission at a time. Connection to the centralized hub is accomplished over UTP of 22, 24 or 26 gauge at distances of up to 500 meters in a star topology. Two pairs are used, with one providing upstream connectivity to the hub and the other providing downstream connectivity.

该以太网标准属于基带传输，单工工作方式。1Base-5与中央集线器的联接是通过UTP完成的，UTP的规格为22，24和26，采用星型拓扑，最大传输距离为500米。1Base-5使用2对UTP，1对提供与HUB的上行连接，另1对提供下行连接。

2No matter if I was involved in writing a book, conducting a political campaign, teaching at Emory University or dealing with international affairs, I could always go back -- at least for a few hours at a time -- to the woodshop.

无论我在写书，从事政治活动，在爱莫瑞大学教书，还是处理国际事务，我总会设法抽空回到木工场，每次至少呆上几个小时。

No matter if I was involved in writing a book, conducting a political campaign,teaching at Emory University or dealing with international affairs, I could always go back-at least for a few hours at a time-to the woodshop.

我认为手艺——不管是耕地，造房子，做家具，拉小提琴，还是画图——不会因生活的起起落落而改变。

These treks start at a time convenient to you that can be arranged at time of booking.

您可以选择预定您方便的任何时间开始您的游览。

In the early of 1996, lidar systems, respectively used for detecting Rayleigh scattering and Na resonance fluorescence, were successfully designed in Wuhan Institute of Physics and Mathematics. But the lidar system can operate only at one kind of wavelength every time due to lack of laser equipment, so it can detect either the mesosphere of 30～80km or the sodium layer of 80～110km at a time and cant detect both simultaneously.

武汉物理与数学研究所早在1996年就研制成功了瑞利激光雷达和钠共振荧光激光雷达，但有限的设备使得激光雷达系统每次仅能运行在一种激光波长下，每次只能探测30~80km的中层大气或80~110km的高空钠层，而不能同时探测两者，造成了探测数据在空间和时间上的不连续。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。