Seismic evidence for olivine phase changes at the 410- and 660-kilometer discontinuities

The view that the seismic discontinuities bounding the mantle transition zone at 410- and 660-kilometer depths are caused by isochemical phase transformations of the olivine structure is debated. Combining converted-wave measurements in East Asia and Australia with seismic velocities from regional tomography studies, we observe a correlation of the thickness of, and wavespeed variations within, the transition zone that is consistent with olivine structural transformations. Moreover, the seismologically inferred Clapeyron slopes are in agreement with the mineralogical Clapeyron slopes of the (Mg,Fe)2SiO4 spinel and postspinel transformations.     

Thermal properties of water: discontinuities questioned

Reports of discontinuities have been tabulated, and those dealing with vibrational spectrum and volume have been examined in detail. No evidence has been found of any discontinuity greater than experimental error.     

Mid-ocean ridges: discontinuities, segments and giant cracks

Geological observations reveal that mid-ocean ridges are segmented by numerous rigid and nonrigid discontinuities. A hierarchy of segmentation, ranging from large, long-lived segments to others that are small, migratory, and transient, determines the pattern and timing of creation of new ocean floor. To the extent that spreading segments behave like giant cracks in a plate, the crack propagation force at segment tips increases with segment length, which may explain why long segments tend to lengthen and prevail over shorter neighboring segments. Partial melting caused by decompression of the upper mantle due to plate separation and changes in the direction of spreading result in the spawning of new short segments so that a balance of long and short segments is maintained.     

Light scattering to determine the relative phase of two Bose-Einstein condensates

We demonstrated an experimental technique based on stimulated light scattering to continuously sample the relative phase of two spatially separated Bose-Einstein condensates of atoms. The phase measurement process created a relative phase between two condensates with no initial phase relation, read out the phase, and monitored the phase evolution. This technique was used to realize interferometry between two trapped Bose-Einstein condensates without need for splitting or recombining the atom cloud.     

Sugar sweetness and pleasantness: evidence for different psychological laws

Sweetness and the pleasantness of sweetness of sucrose solutions and sweetened food conform to different functions. Sweetness rises with concentration, whereas pleasantness first rises and then decreases. The breakpoint appears to occur at a constant sweetness (that is, constant sensory) level.     

4个国庆盆菊品种扦插繁殖

以自主选育的国庆盆菊Chysanthemum morifolium品种金陵皇冠Jinling Huangguan金陵阳光Jinling Yangguang金陵娇黄Jinling Jiaohuang金陵紫衫Jinling Zishan为材料,以生根率、根数、最长根长、平均根长、根径、根鲜质量6项指标衡量扦插生根效果,研究了扦插基质、穴盘规格（50孔、72孔、128孔、288孔）、萘乙酸（NAA）处理（0,250,500,750,1 000 mgL－1）和插穗冷藏（4 ℃条件下分别冷藏0,14,28,42 d）对扦插生根的影响。结果表明:除插穗冷藏处理外,其余处理对插条生根率无影响,生根率均为100％;草炭 ∶ 蛭石=1 ∶ 1为最佳基质组合,其次为草炭 ∶ 珍珠岩=1 ∶ 1;随着穴盘孔数增多,生根效果下降;不同品种对NAA质量浓度的反应存在差异,但在500～750 mgL－1范围内,可显著增加根长和根鲜质量;冷藏42 d后成活率下降,但可促进金陵阳光的生根数量,冷藏14 d可促进金陵阳光的最长根长和平均根径。表4参8     

Precambrian columnar stromatolite diversity: reflection of metazoan appearance

Columnar stromatolites (organosedimentary structures built by bluegreen algae) show a marked decrease in diversity in the Late Precambrian; this decrease in diversity occurs at approximately the same time as the appearance of metazoans, 600 to 700 million years ago.     

凤仙组织培养快繁技术的研究

通过对“非洲凤仙”组织培养快繁技术的研究，筛选出诱导芽最适培养基MS 6-BA1mg/L NAA0.02mg/L，诱导率达80%以上；最适生根培养基MS NAA0.1mg/L生根率达95%。通过生根苗移栽试验，筛选出最适移栽基质为粗沙 园土（1：1）。     

西伯利亚百合花托的组织培养与离体快繁

以西伯利亚百合花托为外植体进行组织培养,适合愈伤组织诱导和分化的培养基为MS＋6-BA 1．0mg／L＋NAA 2．0mg／L,最佳增殖培养基为MS＋6-BA 1．0mg／L＋NAA 0．2mg／L,最佳生根培养基为1／2MS0＋NAA 0．2mg／L,最佳移栽营养土配方为园土：沙子=2：1。     

度量生物性状广义相关系数的抽样分布及假设检验

【目的】完善生物性状非线性相关性的广义相关系数理论体系,为实际育种工作提供一套完整的理论体系。【方法】采用构造综合指标,借助于一元线性回归模型,对度量生物性状线性、非线性相关性的广义相关系数的抽样分布及假设检验问题进行研究。【结果】该广义相关系数服从F分布或t分布,可用F检验或者t检验对该相关系数与0之间的差异显著性进行检验。【结论】建立的广义相关系数检验方法计算简单、无信息损失,线性与非线性广义相关系数的定义、性质、抽样分布及假设检验问题都予以解决,丰富了多元统计学内容。