Constraints on the age of the Tuchengzi Formation by LA-ICP-MS dating in northern Hebei-western Liaoning,China

Accurately determining the age of the Tuchengzi Formation has direct influence on confirming the boundary between the Jurassic and the Cretaceous systems in northern Hebei-western Liaoning, and on related geological problems in China. However, the Tuchengzi Formation mainly consists of sedimentary rocks, with a poor fossil record and especially lack of index fossils. The Tuchengzi Formation is also lack of the type of volcanic rocks that can provide an isotopic age. Therefore, the age of the Tuchengzi Formation has been uncertain. Based on our systematic dating of the tuff interbedded in the Tuchengzi Formation of Chengde and Jinlingsi-Yangshan basins in northern Hebei-western Liaoning, combined with the dating results of previous researchers, here we suggest that the age range of the Tuchengzi Formation in northern Hebei-western Liaoning is from 147 Ma to 136 Ma. It implied that the Tuchengzi Formation was mainly formed in the Early Cretaceous. Supported by National Natural Science Foundation of China (Grant No. 90714010)     

Modern pollen rain in the Lake Qinghai basin,China

Lake Qinghai is the largest inland brackish lake in China and lies within the NE Tibetan Plateau. Our study shows that pollen assemblages in each vegetation belt are significantly correlated with the vegetation types of this area. Among the herbaceous and shrubby pollen assemblages, Artemisia is over-represented, while Poaceae, Cyperaceae and Polygonaceae are under-represented. Artemisia/ Chenopodiaceae (A/C) ratios with the regional vegetation characteristic can be used as a proper index to reconstruct the...     

改进的能量守恒方法及其在CHAMP重力场恢复中的应用

An efficient method for gravity field determination from CHAMP orbits and accelerometer data is referred to as the energy balance approach. A new CHAMP gravity field recovery strategy based on the improved energy balance approach IS developed in this paper. The method simultaneously solves the spherical harmonic coefficients, daily Integration constant, scale and bias parameters. Two 60 degree and order gravitational potential models, XISM-CHAMPO1S from the classical energy balance approach, and XISM-CHAMPO2S from the improved energy balance, are determined using about one year＇s worth of CHAMP kinematic orbits from TUM and accelerometer data from GFZ. Comparisons among XISM-CHAMPO1S, XISM-CHAMPO2S, EIGEN-CGO3C, EIGEN-CHAMPO3S, EIGEN2, ENIGNIS and EGM96 are made. The results show that the XISM-CHAMPO2S model is more accurate than EGM96, EIGENIS, EIGEN2 and XISM-CHAMPO1S at the same degree and order, and has almost the same accuracy as EIGEN-CHAMPO3S.     

FOST PALEOZOIC FORMATIONS OF THE MN YIN AND LAI WU VALLEYS OF SHANTUNG.

INTRODUCTION. I was appointed to accompany Dr. J. G. Andersson to take a trip incentral Shantung. especially in Men Yin (蒙阴) and Lai Wu (莱芜),valleys,for the purpose of collecting fossils and observing the post-Palaeozoic forma-tions. We came back to Peking in December, 1922. The conclusion     

A COMPREHENSIVE STUDY OF MUD CRACKS AND OTHER SIMILAR STRUCTURES

In text-books of geology and in most papers dealing with geologicstructures, mud cracks seem to have been regarded as merely one kindof structures developed only in soft sediments, such as muds or clays. Itseems also that the studies of mud-crack structure have been mostly     

Preparation,characterization,and antifungal evaluation of a new type of aminourea chitooligosaccharide derivatives

Phytopathogenic fungi cause heavy negative impact on the agricultural economy,but most existing fungicides are toxic and pose a threat to both human health and environments.A green and efficient fungicide is urgently needed.Chitooligosaccharides(COSs),the degradation products of natural polysaccharide chitosan,are nontoxic and biodegradable antifungal substances.In this study,a novel type of aminourea chitooligosaccharide derivatives(AUCOS)was synthesized by successively grafting a hydrazine group and an amine-carbonyl group onto a chitooligosaccharide backbone to enhance the antifungal capability of COSs.The structures of the target compounds were identified by FTIR,1H NMR,and 13C NMR,and the degree of substitution of each product was calculated from the results of the elemental analysis.The antifungal activities of the prepared chitooligosaccharide derivatives against Fusarium solani,Verticillium albo-atrum and Phytophthora capsici were tested in vitro.The AUCOSs had better inhibitory efficiencies against the three plant pathogen fungi than that of chitooligosaccharide,of which aminourea chitooligosaccharide 2(AUCOS2)was the most promising antifungal compound,whose highest inhibition rates were 60.12%,82.95%,and 85.23%against F.solani,V.albo-atrum and P.capsici,respectively.The synthesized derivatives have good application prospects in crop protection and deserve further research.     

The study of Seyfert 2 galaxies with and without infrared broad lines

From the literature,we construct a sample of 25 Seyfert 2 galaxies (S2s)with a broad line region (BLR) detected in near infrared (NIR) spectroscopy and 29with NIR BLRs which were not detected. We find no significant difference between the nuclei luminosity (extinction-corrected [OIII] 5007) and infrared color f60/f25 between the two populations,suggesting that the non-detections of NIR BLRs could not be due to low AGN luminosity or contamination from the host galaxy. As expected,we find significantly lower X-ray obscurations in Seyfert 2s with NIR BLR detection,supporting the unification scheme. However,such a scheme was challenged by the detection of NIR BLRs in heavily X-ray obscured sources,especially in six of them with Compton-thick X-ray obscuration. The discrepancy could be solved by the clumpy torus model and we propose a toy model demonstrating that IR-thin Xray-thick S2s could be viewed at intermediate inclinations and compared with those IR-thick X-ray-thick S2s. We note that two of the IR-thin X-ray-thick S2s (NGC 1386 and NGC 7674) experienced X-ray transitions,i.e. from Compton-thin to Comptonthick appearance or vice versa based on previous X-ray observations,suggesting that X-ray transitions could be common in this special class of objects.     

ON THE SINIAN SYSTEM OF THE LIAOTUNG PENINSULA AND ITS EQUIVALENTS IN OTHER PART OF THE NORTH CHINA

The Sinian stratigraphy of the Liaotung peninsula was studies by many Chinese and Japanesegeologists. In this paper three sections of Sinian period in Lioatung peninsula and three sectionsof Lower and Middle Sinian period in Lioahsi area are discussed and several stratigraphical termsare assigned.     

Ultrahigh pressure (>7 GPa) gneissic K-feldspar (-bearing) garnet clinopyroxenite in the Altyn Tagh, NW China: Evi- dence from clinopyroxene exsolution in garnet

Since the ultra-high pressure metamorphic rocks with coesite and diamond indicators,which are formed under the condition of deep-subduction of continental crust,have been recognized[1―4],exsolution structures of the ultra-high pressure minerals such as pyroxene,olivine,garnet and sphene in the various kinds of rocks have attracted the great interests and attention of many researchers[5―18].Some exsolution structures,such as clinopyroxene+rutile+apatite[13]or quartz+rutile+apatite[15]exsolutio…