镇海棘螈和大凉疣螈年龄结构研究

通过趾骨切片可以准确鉴定年龄，了解一个物种的最长寿命，也为我们研究确定一个物种的生长特点、性成熟期,以及一个地区一个物种的年龄结构、种群生态(Marnell，1998)和群落生态提供重要信息(Morrison，et a1.，2004)。 本论文使用骨骼鉴龄法对中国浙江省宁波市北仑瑞岩寺林场的镇海棘螈（Echinotriton chinhaiensis）雌性繁群进行了年龄结构研究。结果显示：第一次参加繁殖的年龄为3龄；繁群中数量占优势的是5龄、6龄。而在6龄以后参加繁殖的雌性个体数便开始随着年龄的增大而逐渐减少。参加繁殖的雌性年龄最大个体为8龄。平均年龄为5.13龄。同时对其年龄和头体长、体全长的相关性检验,发现其年龄与头体长和体全长不相关,镇海棘螈雌性的生长方式表现为性成熟后能量主要用于繁殖。 另外,对李子坪大凉疣螈(Tylototriton taliangensis) 雄性繁群进行了年龄结构研究。结果显示：大凉疣螈雄性第一次参加繁殖的年龄为4龄；繁群中数量占优势的是5龄、6龄、7龄。而在7龄以后参加繁殖的雄性个体数便开始随着年龄的增大而逐渐减少。参加繁殖的雄性中年龄最大的个体为10龄。平均年龄为6.7龄。对其年龄和头体长、体全长的相关性检验,发现其年龄与头体长和体全长不相关,大凉疣螈雄性生长特点也表现为性成熟后生长缓慢的特点。 研究材料方面，本文采用野外采样与标本馆标本相结合的方式获得了中国蝾螈科2个重要保护物种繁殖群体的剪（指）趾材料，使得建立于其上的年龄结构工作更加可靠、更加具有代表性。 此外,本论文讨论了镇海棘螈瑞岩寺种群繁殖总量年度间的差异及其产生原因。将1998、1999、2000、2008、2009年镇海棘螈（Echinotriton chinhaiensis） 瑞岩寺种群的繁殖量进行比较，发现虽然雌性平均窝卵数比较稳定，但繁殖总量小于1998、1999、2000年任何一年总产卵量的50%。对2008年镇海棘螈繁殖量大幅下降的原因分析发现, 2007年9、10月影响严重台风的两次强台风、瑞岩寺景区开发等因素可能是造成近年该种群繁殖量大幅下降的原因。而2008年初50年不遇的低温是否影响镇海棘螈的繁殖值得进一步追踪研究。2009年繁殖量较2008年没有明显的增长，可能是由于2007年的台风影响了其繁殖营养的积累。台风的影响可能存在滞后现象,对此有待进一步监测证明。 本研究首次对中国蝾螈科物种进行的年龄结构鉴定，为进一步了解中国蝾螈科动物的种群生态打下了坚实的基础。 Using skeletochronology, we can know the life span of a species, age of reaching sexual mature, and of course age structure, which are vital(Morrison，et a1.，2004). Skeletochronology was performed on Echinotriton chinhaiensis Ruiyansi female population. The result shows that: The oldest individuals were 8 years old and the youngest ones were 3 years old. Individuals of age class 5(39.13%) and 6(21.74%) were most numerous. The number of individuals participated in reproduction decreased with the increase of age after the sixth year. Average age is 5.13 years. There is no correlation between age and body size (SVL and TL). For female chinhai salamander, energy is devoted to reproduction after reaching sexual maturation. While using skeletochronology to study Tylototriton taliangensis Liziping male population, the oldest individuals is 10 years old, and the youngest ones is 4 years old. Individuals of the age class 5, 6, and 7 dominat this population. The number of individuals decrease with the increase of age also after the seventh year. Average age is 6.7 years old in this population. there is also no correlation between age and body size (SVL and TL).It turned out that T. taliangensis tend to grow slowly after reaching sexual maturation. In this thesis, specimens from both wild and museum were used to gain enough toe clipping samples. A big sample size guarantees the reliability of this study. In the meantime, E. chinhaiensis’s annual reproduction of the year 1998, 1999, 2000 ,2008,and 2009 was compared. The result shows there is a huge decline in E. chinhaiensis’s annual reproduction in 2008,even the egg clutch is very stable. After analyzing, it turned out the huge decline in 2008 was probably caused by typhoon in 2007, besides the effect of tourism development and cash crop planting. While the impact of extreme weather of 2008 on reproduction needs further investigation. In the year 2009, there is no obvious increase in annual reproduction. It maybe due to lasting impact of typhoon in 2007. It is the first age-structure study on these two Chinese salamanders. A solid foundation was laid for further population ecology study of these two species.

Extreme weathering/erosion during the Miocene Climatic Optimum: Evidence from sediment record in the South China Sea

Investigating the interplay between continental weathering and erosion, climate, and atmospheric CO2 concentrations is significant in understanding the mechanisms that force the Cenozoic global cooling and predicting the future climatic and environmental response to increasing temperature and CO2 levels. The Miocene represents an ideal test case as it encompasses two distinct extreme climate periods, the Miocene Climatic Optimum (MCO) with the warmest time since 35 Ma in Earth's history and the transition to the Late Cenozoic icehouse mode with the establishment of the east Antarctic ice sheet. However the precise role of continental weathering during this period of major climate change is poorly understood. Here we show changes in the rates of Miocene continental chemical weathering and physical erosion, which we tracked using the chemical index of alteration ( CIA) and mass accumulation rate ( MAR) respectively from Ocean Drilling Program (ODP) Site 1146 and 1148 in the South China Sea. We found significantly increased CIA values and terrigenous MARs during the MCO (ca. 17-15 Ma) compared to earlier and later periods suggests extreme continental weathering and erosion at that time. Similar high rates were revealed in the early-middle Miocene of Asia, the European Alps, and offshore Angola. This suggests that rapid sedimentation during the MCO was a global erosion event triggered by climate rather than regional tectonic activity. The close coherence of our records with high temperature, strong precipitation, increased burial of organic carbon and elevated atmospheric CO2 concentration during the MCO argues for long-term, close coupling between continental silicate weathering, erosion, climate and atmospheric CO2 during the Miocene. Citation: Wan, S., W. M. Kurschner, P. D. Clift, A. Li, and T. Li (2009), Extreme weathering/ erosion during the Miocene Climatic Optimum: Evidence from sediment record in the South China Sea, Geophys. Res. Lett., 36, L19706, doi: 10.1029/2009GL040279.

Burst event detection in wall turbulence by WVITA method

Wavelet Variable Interval Time Average (WVITA) is introduced as a method incorporating burst event detection in wall turbulence. Wavelet transform is performed to unfold the longitudinal fluctuating velocity time series measured in the near wall region of a turbulent boundary layer using hot-film anemometer. This unfolding is both in time and in space simultaneously. The splitted kinetic of the longitudinal fluctuating velocity time series among different scales is obtained by integrating the square of wavelet coefficient modulus over temporal space. The time scale that related to burst events in wall turbulence passing through the fixed probe is ascertained by maximum criterion of the kinetic energy evolution across scales. Wavelet transformed localized variance of the fluctuating velocity time series at the maximum kinetic scale is put forward instead of localized short time average variance in Variable Interval Time Average (VITA) scheme. The burst event detection result shows that WVITA scheme can avoid erroneous judgement and solve the grouping problem more effectively which is caused by VITA scheme itself and can not be avoided by adjusting the threshold level or changing the short time average interval.

Attosecond pulse extreme-ultraviolet photoionization in a two-color laser field

Attosecond-pulse extreme-ultraviolet (XUV) photoionization in a two-color laser field is investigated. Attosecond pulse trains with different numbers of pulses are examined, and their strong dependence on photoelectronic spectra is found. Single-color driving-laser-field-assisted attosecond XUV photoionization cannot determine the number of attosecond pulses from the photoelectronic energy spectrum that are detected orthogonally to the beam direction and the electric field vector of the linearly polarized laser field. A two-color-field-assisted XUV photoionization scheme is proposed for directly determining the number of attosecond pulses from a spectrum detected orthogonally. (C) 2005 Optical Society of America.

Enhancement and broadening of extreme-ultraviolet supercontinuum in a relative phase controlled two-color laser field

We experimentally demonstrate the generation of an extreme-ultraviolet (XUV) supercontinuum in argon with a two-color laser field consisting of an intense 7 fs pulse at 800 nm and a relatively weak 37 fs pulse at 400 nm. By controlling the relative time delay between the two laser pulses, we observe enhanced high-order harmonic generation as well as spectral broadening of the supercontinuum. A method to produce isolated attosecond pulses with variable width and intensity is proposed. (C) 2008 Optical Society of America.

Generation of intense extreme supercontinuum radiation via resonant propagation effects

Confinement of electromagnetic energy into a single well-controlled oscillation of light is very important for generation of intense supercontinuum radiation. We find that the pulse breakup of few-cycle ultrashort laser pulses via resonant propagation effects can achieve this aim. By extracting such pulses and then focusing them to drive the He atoms, about 200 eV intense supercontinuum radiation can be generated, which is capable of supporting similar to 20 attosecond isolated pulse generation.

Generation of an extreme ultraviolet supercontinuum in a two-color laser field

We theoretically investigate the high-order harmonic generation in a helium atom with a two-color optical field synthesized by an intense 6 fs pulse at 800 nm and a relatively weak 21.3 fs pulse at 400 nm. When the frequency-doubled pulse is properly time shifted with respect to the fundamental pulse, an ultrabroad extreme ultraviolet supercontinuum spectrum with a 148 eV spectral width can be generated which directly creates an isolated 65 as pulse even without phase compensation. We explain this extraordinary phenomenon by analyzing maximum electron kinetic energies at different return times.

Attention deficit/hyperactivity disorder children with a 7-repeat allele of the dopamine receptor D4 gene have extreme behavior but normal performance on critical neuropsychological tests of attention

An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an etiological factor in attentional deficits manifested in some children diagnosed with this disorder. In the current study, we evaluated ADHD subgroups defined by the presence or absence of the 7-repeat allele of the DRD4 gene, using neuropsychological tests with reaction time measures designed to probe attentional networks with neuroanatomical foci in D4-rich brain regions. Despite the same severity of symptoms on parent and teacher ratings for the ADHD subgroups, the average reaction times of the 7-present subgroup showed normal speed and variability of response whereas the average reaction times of the 7-absent subgroup showed the expected abnormalities (slow and variable responses). This was opposite the primary prediction of the study. The 7-present subgroup seemed to be free of some of the neuropsychological abnormalities thought to characterize ADHD.

Differential cognitive responses to guqin music and piano music in Chinese subjects: an event-related potential study

目的 研究古琴(一种古老的中国乐器)和钢琴音乐对认知的影响.方法 记录和分析了中国被试在两种音乐背景(古琴音乐,钢琴音乐)下完成听觉oddball任务的行为和事件相关电位(event-related potential,ERP)数据.结果 中国被试在本土文化的音乐环境(古琴音乐)下,前额区诱导出更大的P300,这一结果和已有的相关研究是相符的.同时,不同音乐背景对ERP产生的影响在N1和LPC(包括P300和P500)上也表现出差别:中国被试在古琴音乐背景下比钢琴音乐背景下表现出更多的右前侧颞叶的参与.结论 因为古琴音乐的五声调式和汉语发音的音调具有对应关系,因此我们推断在古琴音乐下所表现出的这种特性与被试的汉语环境有关.

Crossmodal effects of Guqin and piano music on selective attention: An event-related potential study

To compare the effects of music from different cultural environments (Guqin: Chinese music; piano: Western music) on crossmodal selective attention, behavioral and event-related potential (ERP) data in a standard two-stimulus visual oddball task were reco