两倍的

The vapour and plasma ignition times of the target are got based on the equation of heat conduction and cascade model. We suppose that the plasma is ignited when 210 generations of new electrons are born in vapour generation time. The influence of temperature on the thermodynamics and optics parameters of material also have been considered in the model. The resulting theory has good agreement with the experiment and overseas report. A blade method to measure the laser spot is given in this paper with validation and error analysis. The plasma threshold of metals in atmosphere and water ambients both are diagnosed with the light deflection and piezoelectric transducer. A Q-switched pulsed Nd:YAG laser operating at infrared (1064nm), visible(532nm) and ultraviolet (355nm) wavelengths has been used. Al、Fe、Cu are used as targets and get a similar results with both method. Theoretical and experimental analyses are applied on the influence of wavelength on the threshold have been done, both of which have shown that the plasma threshold of metals decrease as the laser wavelength increases; The plasma threshold of metals are higher in water than in air and the pressure of the shock wave in water is five times higher than in air.

从热传导方程和雪崩电离机制出发，假设当电子增值2~(10)倍时，考虑了温度对材料热力学和光学参数的影响时，得到了气化和等离子体点燃的时间，利用该模型进行计算得到的结果与国内外报道及自行通过实验测得的阈值基本一致；提出了利用刀刃法测量激光光斑面积的方法，并通过实验进行了验证和误差分析；利用光偏转装置和压电换能器分别对空气和水中金属等离子体点燃阈值进行了实验诊断，激光器均为调Q—YAG激光器(波长1064nm，532nm，355nm，脉宽10ns)，靶材分别为Al、Fe和Cu，两种测试方法得到的等离子体点燃阈值基本一致；本文从实验和理论计算两个方面讨论了波长对等离子体点燃阈值的影响，均得到了等离子体点燃阈值随着波长的增加而减小的结论；对空气中和水中不同环境下金属等离子体的点燃阈值进行了比较研究，得到了金属在水中的等离子体点燃阈值比空气中的大，且水中产生的冲击波的压强是空气中的5倍左右的结论。

Through two steps, advancing cultivation and inducing differentiation, principium founded tissue culture system of fodder beet with explant from footstalk, so established foundation for inducing polyploid fodder beet with tissue culture and enlarging reproduction.

通过预培养、诱导分化两步法，初步建立了以叶柄为外植体诱导不定芽再生的饲用甜菜组织培养体系，为进一步利用组织培养诱导饲用甜菜多倍体及多倍体扩繁奠定了基础。

In the first part, two novel methods were proposed for the determination of three kinds of organogermanium compounds βcarboxyethylgermanium sesquioxide,β- carboxyethylgermanium sesquioxide and di-(β-carboxyethyl) germanium hydroxide by using high performance ion-exchange and ion-exclusion chromatography.

第一部分采用高效离子交换和离子排斥色谱法，建立了两种测定三种有机锗化合物β-羧乙基锗倍半氧化物、β-羧乙基锗倍半氧化物、二-锗氢氧化物的新方法。

It will be 50 times faster than DRAM and 10 times denser than static RAM, and it could eventually replace both.

它比DRAM快50倍，比静态RAM的密度高10倍，最终它能替代这两种存储器。

It implies that the relationship between Japanese black cattle and Mongolian cattle is more distant. According to that the rate of sequence divergence of mtDNA is estimated to be 2% per million years, Haplotype II and III of mongolian cattle s mtDNA might be separate about 240 thousand years ago, which is earlier than the 10000-year history of cattle husbandry. Haplotype of yellow cattleand zebu cattle might be separate about 0.73-0.92 million years ago.

按照哺乳动物mtDNA碱基突变率每百万年2％计算，单倍型Ⅱ和Ⅲ(遗传距离为0.478％)所代表的蒙蒙古牛和日本和牛遗传多态性比较研究硕士学位论文古牛群体之间的分化时间大约24万年，这比人类驯化牛10000的历史要久远得多。I单倍型和11、m两种单倍型(遗传距离为1.467%，1.83870)所代表的牛群体之间的分化时间大约73万年至92万年前。

Herbacium were isobilateral leaves, and those of G. hirsutum and C. barbadense were dorsiventral leaves. The reciprocal F〓 of cross G. arboreum×G. herbacium were also isobilateral leaves, while reciprocal F〓 cross of G. hirsutum×G. barbadense were also dorsiventral leaves. The quadrispecific hybrids F〓 were isobilateral leaves, regardless of their cytoplasms. The structures of the leaf stalks and the stems were analogous to each other among the four cultivated cotton species except their diameters varied with species.

四个栽培棉种及其种间杂种F〓的形态学和细胞遗传学观察四个栽培棉种的植株、叶片、茎杆以及花器等器官都有明显的差异；叶片、茎杆以及叶柄的横切面结构观察结果表明，两个二倍体栽培棉种的叶片横切面构造为等面叶，两个四倍体栽培棉种却均为背腹叶；F〓正反交的叶片也为等面叶，F〓正反交F〓仍为背腹叶，而它们的四元杂交种均为等面叶；四个栽培棉种的叶柄和茎的横切面结构基本一致，只是直径形状和和维管束多少的不同，四元杂种的叶柄和茎的横切面结构的差异不明显。

In the offsprings of the aneuploids (P3) with 41~44 chromosomes, there are four types of plants with 29~32 chromosomes. Except the plant with 29 chromosomes, others which appeared abnormal meiosis behavior and poor pollen fertility are mixoploid.

在染色体数为44与41的两种超倍体（P3群体）后代，鉴定出具有29~32条染色体的4种非整倍体，除染色体数为29的植株外，其余均为混倍体，它们的减数分裂异常，花粉育性低。

Percentage of seedling in hexaploid Tritical X common wheat was more high because endosperm developed very well than that in common wheat X hexaploid Tritical because endosperm developed bad. Many seeds and good seedling were obtained by back-crossing.

2六倍体小黑麦×普通小麦与普通小麦×六倍体小黑麦两种杂交方式都有比较高的杂交结实率，但前者种子发育好，种子相对饱满，出苗率高，后者种子胚乳发育不良，出苗率低。

Generally, two hybridization events have happened in the generation of gynogenetic crucian carp: the first one occurred about 6, 000 years ago when maternal ancestor of C. a. gibelio hybridized with males of C. a. auratus (ancestor of C. a. colored variety) and a diploid hybrid was produced; the second one happened over 10, 000 years ago, when the diploid hybrid was backcrossed with one of its parental population, by which the current triploid gynogenetic crucian carp emerged.

初步推断出东北雌核生殖银鲫是通过鲫鱼种群间的两次杂交产生的，第一次杂交是母本的银鲫同源种群与父本的彩鲫同源种群杂交，形成二倍体杂种；第二次杂交是二倍体杂种与两个祖先鲫鱼种群之一回交，形成了今天的三倍体杂种银鲫。

The plasma ignition threshold of metal is got through experimental and numerical study. The vapour and plasma ignition times of the target are got based on the equation of heat conduction and cascade model. We suppose that the plasma is ignited when generations of new electrons are born in vapour generation time. The influence of temperature on the thermodynamics and optics parameters of material also have been considered in the model. The resulting theory has good agreement with the experiment and overseas report. A blade method to measure the laser spot is given in this paper with validation and error analysis. The plasma threshold of metals in atmosphere and water ambients both are diagnosed with the light deflection and piezoelectric transducer. A Q-switched pulsed Nd:YAG laser operating at infrared (1064nm), visible(532nm) and ultraviolet (355nm) wavelengths has been used. Al、Fe、Cu are used as targets and get a similar results with both method. Theoretical and experimental analyses are applied on the influence of wavelength on the threshold have been done, both of which have shown that the plasma threshold of metals decrease as the laser wavelength increases; The plasma threshold of metals are higher in water than in air and the pressure of the shock wave in water is five times higher than in air .

从热传导方程和雪崩电离机制出发，假设当电子增值210倍时，考虑了温度对材料热力学和光学参数的影响时，得到了气化和等离子体点燃的时间，利用该模型进行计算得到的结果与国内外报道及自行通过实验测得的阈值基本一致；提出了利用刀刃法测量激光光斑面积的方法，并通过实验进行了验证和误差分析；利用光偏转装置和压电换能器分别对空气和水中金属等离子体点燃阈值进行了实验诊断，激光器均为调Q－YAG激光器（波长1064nm，532nm，355nm，脉宽10ns），靶材分别为Al、Fe和Cu，两种测试方法得到的等离子体点燃阈值基本一致；本文从实验和理论计算两个方面讨论了波长对等离子体点燃阈值的影响，均得到了等离子体点燃阈值随著波长的增加而减小的结论；对空气中和水中不同环境下金属等离子体的点燃阈值进行了比较研究，得到了金属在水中的等离子体点燃阈值比空气中的大，且水中产生的冲击波的压强是空气中的5倍左右的结论。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。