Crytic period analysis model of hydrological process and its application

It is difficult to analyse the crytic period of the hydrological process, because hydrological time series is probably characterized by heteroscedasticity. To find out the crytic period, a model is constructed as follows: (1) after using zero‐mean transformation for the data, to do Augmented Dickey–Fuller stationary test for the sequence, to build the corresponding AR(p) model and then to do ARCH effects test and white noise test for residual series; (2) for those time series that cannot pass through ARCH test, using logarithm transformation to reduce the heteroscedasticity, and then to redo step (1) until they pass through ARCH test and stationary test; (3) using periodogram analysis to determine all the possible the prime periods and further to put forward three kinds of tests to determine significance level of those prime periods. As examples, the hydrological processes of streamflow from 1784 to 1997 for the gauging stations of Alaer and Xinquman along Tarim River are analysed. After reducing their heteroscedasticity, AR(4) and AR(2) models are developed, respectively. Our results show that the streamflows from the two gauging stations have the same cryptic period of 42·7 years. Furthermore, the reliability for the crytic period model is testified by variance analysis, which shows that the crytic period model is useful and reliable. Copyright © 2009 John Wiley & Sons, Ltd.     

Chemical spots on the surface of the strongly magnetic Herbig Ae star HD 101412

Due to the knowledge of the rotation period and the presence of a rather strong surface magnetic field, the sharp‐lined young Herbig Ae star HD 101412 with a rotation period of 42 d has become one of the most well‐studied targets among the Herbig Ae stars. High‐resolution HARPS polarimetric spectra of HD 101412 were recently obtained on seven different epochs. Our study of the spectral variability over the part of the rotation cycle covered by HARPS observations reveals that the line profiles of the elements Mg, Si, Ca, Ti, Cr, Mn, Fe, and Sr are clearly variable while He exhibits variability that is opposite to the behaviour of the other elements studied. Since classical Ap stars usually show a relationship between the magnetic field geometry and the distribution of element spots, we used in our magnetic field measurements different line samples belonging to the three elements with the most numerous spectral lines, Ti, Cr, and Fe. Over the time interval covered by the available spectra, the longitudinal magnetic field changes sign from negative to positive polarity. The distribution of field values obtained using Ti, Cr, and Fe lines is, however, completely different compared to the magnetic field values determined in previous low‐resolution FORS 2 measurements, where hydrogen Balmer lines are the main contributors to the magnetic field measurements, indicating the presence of concentration of the studied iron‐peak elements in the region of the magnetic equator. Further, we discuss the potential role of contamination by the surrounding warm circumstellar matter in the appearance of Zeeman features obtained using Ti lines. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

冬小麦农田裸温与气温差异分析及其应用

以矮秆代表作物冬小麦为研究对象,利用郑州农业气象试验站2010年10月15日—2011年6月2日农田小气候观测的各层裸温、气温、总辐射和覆盖度资料,采用对比差值、温度垂直梯度等方法统计分析,并对温度对比差值和总辐射曝辐量相关关系和温度的垂直梯度分布特征进行了研究,结果表明:25cm、150cm和300cm高度的日平均裸温和气温变化趋势基本一致,其对比差值呈由小变大趋势;各层裸温和气温的日分布符合温度日变化分布的一般规律,垂直梯度变化比较明显;各层对比差值呈单峰分布,峰值出现在正午12时左右;裸温和气温的对比差值与总辐射曝辐量呈线性相关。裸温与气温的垂直梯度变化有很好的一致性,可利用裸温不同层次间垂直梯度变化特征确定气温传感器合理的安装高度;根据麦田裸温垂直梯度变化特征,考虑到温度防辐射罩高度限制,矮秆作物田间小气候气温应在距离地表面25cm、50cm和150cm高度附近分别设置观测层次。     

Finding the most variable stars in the Orion Belt with the All Sky Automated Survey

We look for high‐amplitude variable young stars in the open clusters and associations of the Orion Belt. We use public data from the ASAS‐3 Photometric V ‐band Catalogue of the All Sky Automated Survey, infrared photometry from the 2MASS and IRAS catalogues, proper motions, and the Aladin sky atlas to obtain a list of the most variable stars in a survey area of side 5° centred on the bright star Alnilam (ε Ori) in the centre of the Orion Belt. We identify 32 highly variable stars, of which 16 had not been reported to vary before. They are mostly variable young stars and candidates (16) and background giants (8), but there are also field cataclysmic variables, contact binaries, and eclipsing binary candidates. Of the young stars, which typically are active Herbig Ae/Be and T Tauri stars with Hα emission and infrared flux excess, we discover four new variables and confirm the variability status of another two. Some of them belong to the well known σ Orionis cluster. Besides, six of the eight giants are new variables, and three are new periodic variables (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

青蛤(Cyclina sinensis)cDNA文库构建及免疫相关因子基因的筛选

在鳗弧菌侵染下,利用SMART方法构建了青蛤的cDNA文库,并采用高通量测序方法和BLASTX比对筛选出ESTs及免疫相关因子的基因.结果表明,所构建的cDNA文库的库容量为1.12×106,插入片段均在500bp以上;大于100bp的有效ESTs序列1113条,平均长度725bp,拼接后获得一致性序列420条,其中包括126个叠联群和294个单拷贝EST,BLASTX比对后获得注释序列271条,进一步筛选获得青蛤免疫相关因子基因序列45条,为克隆其免疫防御相关因子的基因提供了重要的基础.     

塔里木盆地塔中-巴楚地区上奥陶统良里塔格组米兰科维奇旋回性沉积记录研究

通过露头、钻井岩芯沉积相观察及高频旋回识别,结合全岩碳氧同位素旋回、自然伽玛能谱测井ln(Th/K)值频谱分析及地震反射特征,研究了塔里木盆地塔中—巴楚地区分布的上奥陶统良里塔格组开阔台地及外缓坡相碳酸盐岩中发育的四～六级高频层序(旋回)特征及其叠置关系。认为其六级米级旋回、五级准层序及四级准层序组可能分别与20～40ka、100ka及400ka周期的Milankovitch日-地轨道气候旋回有关,并识别出该区良里塔格组由11～12个400ka周期的准层序组构成。提出海相碳酸盐岩全岩或生物壳碳同位素值可作为反映全球海平面相对变化的指标及识别形成三级层序的主控因素(全球海平面变化、地区性构造沉降-抬升运动)的方法——碳同位素-沉积旋回对比分析法。晚奥陶世良里塔格组沉积时期,塔中台地北缘总体表现为向上变浅的加积型沉积叠置型式,主要与塔中I号断裂活动控制形成的高陡型镶边台地边缘有关;巴楚台地西北缘则表现为向上变浅的加积-进积复合型沉积叠置型式,主要与其断裂活动弱、受沉积作用控制为主的缓坡台地边缘有关。塔中-巴楚台地良里塔格组表现为一个完整三级层序的形成与演化,主要受控于该台地的构造(沉降-抬升)运动而不是全球海平面变化,属于典型的地区性构造层序及不具有全球对比意义。     

南华北盆地青白口系—侏罗系层序界面时空分布特征研究

以位于秦岭—大别造山带之北、华北陆块南部、地跨华北陆块稳定块体、陆块南部边缘变形带的南华北盆地为研究对象,通过对研究区42条不同时代的野外剖面详细观测,运用层序地层学理论,把南华北盆地作为一个整体系统,对青白口系—侏罗系层序界面特征及时空分布规律进行了系统分析,共识别出了8种类型层序界面的物质表现形式,分别是不整合面、渣状层、古喀斯特作用面、冲刷侵蚀面、超覆面、岩性岩相转换面、最大海泛面、最大湖泛面。并重点讨论了各类型界面的时空分布特征。结果表明：在时间演化上,从早到晚由海相—海陆过渡相—陆相,层序界面经历了海相沉积不整合、古喀斯特作用面、渣状层到陆相不整合面、冲刷侵蚀面等;在空间上,同一层序界面在不同相带表现形式不同,同一种类型的界面可在不同相带出现,但不同相带表现特征有一定差异性。     

冀北宽城中元古界杨庄组地球化学特征

为分析碳酸盐岩地球化学特征对地层及层序界线、沉积环境的影响,选取冀北宽城中元古界杨庄组剖面进行了实测。冀北宽城中元古界杨庄组常量、微量元素和碳、氧同位素在纵向上具有特征的演变规律,特别是在岩石地层界线与层序界面附近变化明显。CaO含量从杨庄组一段到二段为21.07%～16.45%,从二段至三段则为16.45%～24.21%,Sr、Ba含量分别从杨庄组底部向上由44.59×10-6突变至98.16×10-6和0.51×10-6至10.45×10-6,δ13C值在0‰～-1.5‰之间变化,δ18O在-3.5‰～-8.5‰之间变化。上述常量、微量元素及碳、氧同位素组成、变化与同时期海平面变化基本一致,表明地球化学特征可作为划分地层界面或层序界面的标志,特别是可以优化地层界线或层序界线。杨庄组CaO/MgO、Sr/Ba及V、Rb、Be、B等组成和演化研究表明,杨庄组形成于干热气候下的近岸浅水环境。     

塔里木盆地巴楚地区T_7~4界面生屑灰岩微相分析及成岩作用研究

前人对塔里木盆地巴楚地区T74界面的研究主要以在地震反射剖面中大的不整合面形式为基础进行的,对界面具体的岩性、微相和成岩作用研究较少。位于塔里木盆地巴楚县东北方向一间房地区的T74露头剖面为上奥陶统与中—下奥陶统的分界面,岩性以生物碎屑泥粒灰岩和粒泥灰岩为主。镜下分析表明:T74界面生屑灰岩中生物碎屑以棘皮动物(主要为海百合碎片)和介形虫为主,其他生物碎屑包括腕足动物、软体动物、三叶虫、钙球粒、粗枝藻、龙介虫、有孔虫、海绵和苔藓等。通过镜下微相、C-O同位素以及X射线荧光等多种分析方法,认为T74界面地层沉积相为较温暖的低能陆棚相,后期经历了埋藏压实成岩作用、地层抬升后的淡水成岩作用和风化剥蚀作用等。岩石的缝合线发育,孔渗性较好,利于地下流体的运移和渗透,对中—下奥陶统的岩溶发育起着控制作用。     

华北板块南缘安徽青白口纪-早奥陶世层序地层与格架

华北地台南缘,主要出露青白口纪—早古生代地层,属被动大陆稳定克拉通盆地发育过程,以台地碳酸盐沉积为主。通过对十余条实测剖面及主干、辅助路线的观察研究,青白口纪—早古生代奥陶纪早期,测区可区分出二个巨层序、十二个三级层序。本文通过三级层序的划分,建立了华北地台南缘青白口纪—早古生代奥陶纪早期层序地层格架、探讨了各岩石地层单位的变化规律。