土壤特性空间变异对降雨下渗影响的统计理论研究

本文利用饱和土壤导水率K_5的对数正态特性,通过函数转换方法建立了降雨下渗中积水时间f_p的分布和两个统计特征值(即平均下渗率及估计方差)的表达式。研究了土壤特性空间变异对降雨下渗的影响。结果表明,土壤特性空间变异程度越大,影响越大,在产流计算中如果不考虑这种影响,将会引起较大误差。     

Research progress in nonlinear analysis of heart electric activities

1INTRODUCTION THE WORLD IS NONLINEAR,AND THE HUMAN LIFE ACTIVITY IS ALSO NONLINEAR.FROM THE VIEWPOINT OF SYSTEM,HUMAN BEINGS(OR THE OTHER HIGHER ANIMAL)ARE THE MOST COM-PLEX SYSTEM IN THE NATURE.FOR SUCH A PHYSIOLOGICAL SYS-TEM WITH THE UTTERMOST COMPLEXI…     

Cir X-1的时变性质

利用RXTE在不同时期的观测数据，分析了Cir X-1功率密度谱和交叉谱。功率密度谱表明，如果Cir X-1是Z源，那么所采用的数据将处于Z源的不同态，即垂直水平分支态、水平分支态、正常分支态和耀斑分态。各个态上的交叉谱显示，随着吸积率的变化，Cir X-1的交叉谱由硬向软转化，这和Cir X-1在一个完整Z形状上的时变性质一致。     

回收沥青材料相关特性研究(英文)

利用红外光谱仪(FT-IR)和动态剪切流变仪(DSR)研究沥青的化学组成和流变性能。同时引入统计分析的方法研究矿料级配的变异性。试验结果表明:与新沥青相比,回收沥青材料中的沥青化学表现为红外光谱中羰基及亚砜基团吸收峰的提高,芳香基团的降低。流变试验表明回收沥青材料中的沥青有较高的复合模量和较低的相位角。统计分析表明,0.075cm筛孔的通过率具有很高的变异系数。     

Coupling and propagating of mesoscale sea level variability between the western Pacific and the South China Sea

The coupling and propagating features of mesoscale sea level variability between the western Pacific (WP) and the South China Sea (SCS) were studied based on time series analyses of satellite altimeter measured, along-track sea surface height anomalies (SSHA) along 21°N and the slope of the northern SCS. The analyses show that mesoscale sea level fluctuations in the WP have rather limited coherent effects on the SCS, and no statistically significant propagation of mesoscale variability through the Luzon Strait was observed except in the 45-day band. Evidence suggests that the 45-day fluctuation is very much likely a character of the Kuroshio originating from its low-latitude beginning. It is also sug- gested that the westward propagating Rossby waves will deform when they encounter the dynamical barrier of the Kuroshio. The Kuroshio will then acts on the SCS in its own way. The SCS is a relatively isolated system in the sense of coupling and propagating of oceanic mesoscale waves.     

四川栽培小麦幼胚培养再分化能力变异性的研究

以N6为基本培养基，对四川栽培小麦品种、品系以及农家品种共45个基因型的幼胚离体培养，进行了植株再生能力变异性的研究。结果表明，供试材料间的形态发生能力存在明显变异，表现为器官建成速度明显不同，芽器官和根器官再生率存在极显著差异，分别变异在15．00％－95．45％和0－95．45％之间，由每个幼胚外植体起源的愈伤组织再生出1．0cm以上的芽数及其芽长均存在极显著差异。     

中等亮类星体的光变

研究了极限星等为Ｂ＝１７．６的中等亮类星体样本的光亮。以Ｑ〉３．０作为变的判据，大约有１／３的类本被探测到有光变；     

No sex difference in the waveform of the pulse type electric fish,Gnathonemus petersii (Mormyridae)

Summary A communication signal in an African freshwater electric fish, its pulse-like Electric Organ Discharge (EOD), was investigated in order to determine whether inter- or intraindividual variability of the EOD waveform provides a putative cue for communication, in addition to the electric cues already identified. In contrast to an individual's highly stereotyped EODs showing extremely low variation (fig. 1), variability between individuals was considerable (fig. 2). The dependence of an individual's EOD duration on temperature was weak with a Q₁₀ of close to 1.5. In none of four quantitative EOD waveform measures can a sexual dimorphism be discerned (table).Gnathonemus petersii very likely relies on mechanisms other than discrimination of intraspecific EOD waveforms for mate recognition.     

Morphological variability and genetic diversity in five species of Skeletonema （Bacillariophyta）

Twelve strains of Skeletonema from Chinese coastal waters and another strain from the West Sea of Korea were examined using light microscopy （LM）, scanning and transmission electron microscopy （SEM, TEM）, and small subunit （SSU） rDNA sequence analysis. We identified four species of Skeletonema： S. marinoi Sarno et Zingone, S. subsalsum （A.Cleve） Bethge, S. dohrnii Sarno et Kooistra, S. trop- icum Cleve, as well as a Skeletonerna-like species. These are the first records of S. rnarinoi, S. dohrnii and S. subsalsurn in China. The Skeletonema-like species, MMDLS067, was isolated from the estuary of the Changjiang River. The morphologic and phylogenetic characteristics of this species are not correspond to those of any previously published Skeletonerna species. The intercalary fultoportula pro- cesses （IFPPs） has long open tubes, and the intercalary rimoportula process （IRP） is short and located inside the rim of the IFPPs. Phylogenetic analysis revealed that MMDL5630 clustered with S. tropicurn in the NJ and MP trees, but its IRPs differed from those of previously described specimens of S. tropicum. The IRP is partially open, with an elongated opening at the base of the tube, and is longer than the IFPPs. Some specimens of S. marinoi and S. dohrnii also have longer tubular IRPs than the IFPPs. Compared to pre- viously described specimens of S. rnar＆oi and S. dohrnii, these two specimens we identified have shorter IRPs. Our results reflect the ambiguity and diversity of Skeletonema taxonomy. They are also significant for the future identification and management of red tides caused by Skeletonerna in the seas around China.