bluuebunny/crossref_metadata_2025 huggingface dataset:
Geochemistry of Apatite from the Apatite‐rich Iron Deposits in the Ningwu Region, East Central China
Authors: Jinjie YU , Qi ZHANG , Jingwen MAO , Shenghao YAN
Published: February 2011

Abstract: Four types of apatite have been identified in the Ningwu region. The first type of apatite is widely distributed in the middle dark colored zones (i.e. iron ores) of individual deposits. The assemblage includes magnetite, apatite and actinolite (or diopside). The second type occurs within magnetite‐apatite veins in the iron ores. The third type is seen in magnetite‐apatite veins and (or) nodules in host rocks (i.e. gabbro‐diorite porphyry or gabbro‐diorite or pyroxene diorite). The fourth type occurs within apatite‐pyrite‐quartz veins filling fractures in the Xiangshan Group. Rare earth elements (REE) geochemistry of apatite of the four occurrences in porphyry iron deposits is presented. The REE distribution patterns of apatite are generally similar to those of apatites in the Kiruna‐type iron ores, nelsonites. They are enriched in light REE, with pronounced negative Eu anomalies. The similarity of REE distribution patterns in apatites from various deposits in different locations in the world indicates a common process of formation for various ore types, e.g. immiscibility. Early magmatic apatites contain 3031.48–12080 times 10−6 REE. Later hydrothermal apatite contains 1958 times 10−6 REE, indicating that the later hydrothermal ore‐forming solution contains lower REE. Although gabbro‐diorite porphyry and apatite show similar REE patterns, gabbro‐diorite porphyries have no europium anomalies or feeble positive or feeble negative europium anomalies, caused both by reduction environment of mantle source region and by fractionation and crystallization (immiscibility) under a high oxygen fugacity condition. Negative Eu anomalies of apatites were formed possibly due to acquisition of Eu2+ by earlier diopsite during ore magma cooling.

The apatites in the Aoshan and Taishan iron deposits yield a narrow variation range of 87Sr/86Sr values from 0.7071 to 0.7073, similar to those of the volcanic and subvolcanic rocks, indicating that apatites were formed by liquid immiscibility and differentiation of intermediate and basic magmas.
A Study of Mesoproterozoic Iron Cosmic Micro‐spherules from 1.8 Ga and 1.6 Ga Old Strata in the Ming Tombs District, Beijing
Authors: Tianrui SONG , Zhengjun HE , Yusheng WAN , Yanxue LIU
Published: February 2011

Abstract: Numerous iron cosmic micro‐spherules have been discovered from Mesoproterozoic strata including the Changzhougou Formation (1.8 Ga) and the Dahongyu Formation (1.6 Ga) of the Ming Tombs district, Beijing. There are 1 to 30 grains of cosmic spherules per 2 kg of a sandstone sample taken from the bottom of a coarse sandstone bed of the Changzhougou Formation and 56 grains per 3.69 kg of a rock sample from silicified carbonate rocks of the Dahongyu Formation. The surface textures of cosmic spherules analyzed by means of the secondary electron imagery are identical with those reported from references either domestic or abroad. So far the geo‐ages of 1.8 Ga and 1.6 Ga of cosmic spherules from the Changzhougou and Dahongyu formations might be older than those reported in the world. Table 1 gives the electron probe analysis data of cosmic spherules for 30 spherule grains and 44 testing points as follows (%): FeO, 80–95; Cr2O3; 0–9.56; NiO, 0‐0.78; CoO, 0‐0.46; indicating that the Cr2O3 content is higher and FeO content lower in the Changzhougou Formation than in the Dahongyu Formation. The helium isotopic data of cosmic spherules as well as their host rocks vary greatly between the Changzhougou and the Dahongyu formations as shown in Table 2. The data of cosmic spherules of the Changzhougou Formation vs the Dahongyu Formation are 57.5/1.23 in 3He/4He (10−8); and 55.54/809.60 in 4He (10−6cm3STP/g); those of coarse sandstone of the Changzhougou Formation vs silicified carbonate of the Dahongyu Formation are 3.39/2.59 in 3He/4He (10−8) and 4.56/2.34 in 3He (10−6cm3STP/g). The ratio of analytic data of helium isotopes are different for cosmic spherules and their host rocks; for example, the 3He/4He (10−8) values are 16.96 and 0.48, and the 4He (10−6 cm3STP/g) are 12.18 and 345.98 for the Changzhougou and Dahongyu formations respectively. It was reported that the world's oldest micrometeorites had been found in the Meso‐Proterozoic Satakunta Formation, Finland. However, the cosmic spherules from the Meso‐Proterozoic Changzhougou and Dahongyu formations are 200 to 400 Ma older than those from the Satakunta Formation. Besides, one carbonaceous chondrite grain was discovered for the first time as the earliest remain formed in the solar nebula from the Dahongyu Formation.
Organic Material and Trace Elements of Bituminous Rocks in the Ozanköy Field, Ankara, Turkey
Authors: ALİYEV Saday Azadoǧlu , SARI Ali
Published: February 2011

Abstract: Bituminous rocks in the Ozanköy (Ankara) field are different from those of the Paleocene‐Eocene Mengen and Güneytepe (Bolu) regions in metal enrichment levels. Organic carbon (Corg) content of organic material‐rich rocks in the Ozanköy (Ankara) field is 3.66‐40.72% wt averaging 14.34%. The dominant organic materials are algae/amorphous accompanied by minor amount of herbaceous material (The dominant kerogen type is Type‐I with a limited amount of Type‐II kerogen.). The bituminous rocks in the Ozanköy field are enriched in heavy metals such as Ni, Mn, As and Cr. In comparison with the average enrichment values of elements, Ni, Mn, As and Cr in bituminous shales of the Ozanköy field are as about 4.38, 14.93, 10.90 and 5.58 times as average values. The average concentrations of these heavy metals are also as high as 215 times 10−6, 828 times 10−6, 58.54 times 10−6, and 148 times 10−6 respectively. In addition, sorption properties of clay and organic materials are also important for metal enrichments in the bituminous shales.
Isotope Method for Confined Groundwater Recharge of the Lower Reaches of the Heihe River, Inner Mongolia, China
Authors: Jiansheng CHEN , Xia ZHAO , Zhechao FAN , Jiyang WANG
Published: February 2011

Abstract: Environmental isotopes have been applied to analyze confined groundwater recharge in the lower reaches of the Heihe River, Inner Mongolia. CFC is regarded as a tracer that determines the date of groundwater, the date being less than 45 a. The confined groundwater within the Gurinai area and Ejin Basin other than the surface water of Heihe River might have originated from precipitation from Qilian Mountain or/and the Tibetan Plateau. The deep confined groundwater overflows into an upper aquifer and emerges into the ground, forming springs and lakes within the low‐lying area. The recharge volume is estimated to be around 400 million‐cubic meters.
Preparation of Biomorphic SiC/C Ceramics from Pine Wood via Supercritical Ethanol Infiltration
Authors: Jinhong LI , Hongwen MA , Zhenqing CHI
Published: February 2011

Abstract: Biomorphic (wood derived) carbide ceramics with an overall composition in the SiC/C was produced by supercritical ethanol infiltration of low viscosity tetraethylorthosilicate/supercritical ethanol into biologically derived carbon templates (CB‐templates) and in situ hydrolysis into Si(OH)4‐gel, the Si(OH)4‐gel was calcined at 1400° C to promote the polycondensation of Si(OH)4‐gel into SiO2‐phase and then carbonthermal reduction of the SiO2 with the biocarbon template into highly porous, biomorphic SiC/C ceramics. The phases and morphology conversion mechanism of resulting porous SiC/C ceramics have been investigated by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT‐IR). Experimental results showed that the biomorphic cellular morphology of pinewood charcoal was remained in the porous SiC/C ceramic with high precision that consisted of β‐SiC with minority of α‐SiC and the remain free carbon existed in amorphous phase.
A New Species of Huaxiapterus (Pterosauria: Tapejaridae) from the Early Cretaceous of Western Liaoning, China
Authors: Junchang Lü , Yubo GAO , Lida XING , Zhixin LI , Qiang JI
Published: February 2011

Abstract: A new species of Huaxiapterus: H. benxiensis sp. nov. is erected based on the new specimen. The diagnostic characters of Huaxiapterus benxiensis are well‐developed premaxillary crest and parietal spine, the crest and spine parallel and extending posterodorsally, and a shallow groove present on the dorsal surface of the anterior portion of the mandibular symphysis. The different skull morphologies of Chinese tapejarid pterosaurs indicate that they are much more diverse than the previous thought.
A New Enantiornitine Bird with Four Long Rectrices from the Early Cretaceous of Northern Hebei, China
Authors: Xiaoting ZHENG , Zihui ZHANG , Lianhai HOU
Published: February 2011

Abstract: Paraprotopteryx gracilis, a new enantiornithine bird from the Early Cretaceous Yixian Formation in Fengning, northern Hebei Province is erected, based on the following characters: Y‐shaped furcula with a long hypocleidum and a much narrow interclavicular angle, and the morphology of the sternum are different from other enantiornithines. Additionally, alular digit bearing the biggest manual claw extends distally to the distal end of the major metacarpal; the minor metacarpal is slender than the major metacarpal. Carpometacarpus only fused proximally; astragalus and calcaneum partially fused to one another but unfused to the tibia. This is the first record of Mesozoic birds in having four long rectrices, which may represent morphologically a secondary sexual character, an intermediate stage from elongated scale to branched feather, and possess functional advantage in supplementing the lifting surface to compensate the unskilled flight.
From Basin Black Shales to Platform Carbonate Rocks: A Study on Sequence Stratigraphy for the Lower Cambrian of the Upper‐Yangtze Region in South China
Authors: Mingxiang MEI , Yongsheng MA , Hai ZHANG , Xiaoqing MENG , Yonghong CHEN
Published: February 2011

Abstract: In the Upper‐Yangtze region, especially in Guizhou Province and its adjacent areas, the Lower Cambrian is well developed and is marked by a succession from black shales of the basin facies to carbonate rocks of the platform facies. The drowning event of the platform occurring at the turn from Sinian to Cambrian resulted in a set of black shales, i.e. the Niutitang Formation, which makes up the bottom part of the Lower Cambrian. With the shoaling of the sedimentary environment, a set of carbonate rocks, i.e. the Qingxudong Formation, was formed in the top part of the Lower Cambrian. Thus, the Lower Cambrian in the study area makes up one second‐order sequence that can be further subdivided into five third‐order sequences, and forms a regularly cyclic succession of transgression‐regression. There is a regularly vertical stacking pattern for the third‐order sequences in the second‐order sequence. From bottom to top, the succession of the “CS (condensed section) +HST (high‐stand system tract)” of the third‐order sequences is changed into the succession of the “TST (transgressive system tract)+CS+HST”. Correspondingly, the drowning‐type sequence boundary is changed into the exposure‐type one. Therefore, both the second‐order and the third‐order sequences have similar sedimentary‐facies architectures. A concomitant with these temporal changes, the Lower Cambrian with a thickness of 1000 m that contains five third‐order sequences is changed into a condensed succession that cannot identify third‐order sequences toward the southeast with the deepening of the sedimentary environment. According to the elementary features of the third‐order sequences, i.e. the regularity o sedimentary‐facies successions in space and the synchronism of sedimentary‐environment changes in time, the detailed division of the third‐order sequences at main logged sections in different paleogeographical background becomes the basis to establish the sequence‐stratigraphic framework that can demonstrate two types of facies‐changing surface and two types of diachronism in the stratigraphic records. This sequence‐stratigraphic framework shows a growing process of the carbonate platform from the base of the condensed succession formed by black shales of basin facies. Resulting from the rapid transgression at the turn from Sinian to Cambrian the ecological space became open, which formed the antecedent condition of paleogeographical setting for “the Cambrian Biological Explosion”. Ultimately, the genetic relationship between the depositional events and the biological‐diversity events is very complex and there remain lots of problems that need further research in the future.
Daily Variation of Natural Emission of Methane to the Atmosphere and Source Identification in the Luntai Fault Region of the Yakela Condensed Oil/Gas Field in the Tarim Basin, Xinjiang, China
Authors: Junhong TANG , Zhengyu BAO , Wu XIANG , Qinghong GOU
Published: February 2011

Abstract: The static flux chamber method was applied to study natural emissions of methane to the atmosphere in the Luntai fault region of Yakela Condensed Oil/Gas Field in the Tarim Basin, Xinjiang Municipality, northwestern China. Using an online method, which couples together a gas chromatography/high‐temperature conversion/isotope ratio mass spectrometry (GC/C/MS), 13C/12C ratios of methane in flux chambers were measured and showed that methane gases are liable to migrate from deep oil/gas reservoirs to the surface through fault regions and that a part of the migrated methane, which remains unoxidized can be emitted into the atmosphere. Methane emission rates were found to be highest in the mornings, lowest in the afternoons and then increase gradually in the evenings. Methane emission rates varied dramatically in different locations in the fault region. The highest methane emission rate was 10.96 mg/m2.d, the lowest 4.38 mg/m2, and the average 7.55 mg/m2.d. The 13C/12C ratios of the methane in the flux chambers became heavier as the enclosed methane concentrations increased gradually, which reveals that methane released from the fault region might come from thermogenic methane of the deep condensed oil/gas reservoir.
Exploration Potential of Marine Source Rocks Oil‐Gas Reservoirs in China
Authors: Zongju ZHAO
Published: February 2011

Abstract: So far, more than 150 marine oil‐gas fields have been found onshore and offshore about 350. The marine source rocks are mainly Paleozoic and Mesozoic onshore whereas Tertiary offshore. Three genetic categories of oil‐gas reservoirs have been defined for the marine reservoirs in China: primary reservoirs, secondary reservoirs and hydrocarbon‐regeneration reservoirs. And three exploration prospects have also been suggested: (1) Primary reservoirs prospects, which are chiefly distributed in many Tertiary basins of the South China Sea (SCS), the Tertiary shelf basins of the East China Sea (ECS) and the Paleozoic of Tarim basin, Sichuan basin and Ordos basin. To explore large‐middle‐scale even giant oil‐gas fields should chiefly be considered in this category reservoirs. These basins are the most hopeful areas to explore marine oil‐gas fields in China, among which especially many Tertiary basins of the SCS should be strengthened to explore. (2) Secondary reservoirs prospects, which are mainly distributed in the Paleozoic and Mesozoic of the Tarim basin, Sichuan basin, Qiangtang basin and Chuxiong basin in western China, of which exploration potential is less than that of the primary reservoirs. (3) Hydrocarbon‐regeneration reservoirs prospects, which are chiefly distributed in the Bohai Bay basin, North Jiangsu‐South Yellow Sea basin, southern North China basin, Jianghan basin, South Poyang basin in eastern China and the Tarim basin in western China, of which source rocks are generally the Paleozoic. And the reservoirs formed by late‐stage (always Cenozoic) secondary hydrocarbon generation of the Paleozoic source rocks should mainly be considered to explore, among which middle‐small and small oil‐gas fields are the chief exploration targets. As a result of higher thermal evolution of Paleozoic and Mesozoic source rocks, the marine reservoirs onshore are mainly gas fields, and so far marine oil fields have only been found in the Tarim basin. No other than establishing corresponding marine oil‐gas exploration and development strategy and policy, sufficiently enhancing cognition to the particularity and complexity of China's marine petroleum geology, and applying new thoughts, new theories and new technologies, at the same time tackling some key technologies, it is possible to fast and effectually exploit and utilize the potential huge marine oil‐gas resources of China.
Control Factors of Solutional Voids in Feldspars and Favorable Zone Forecast of Chang 2 Oil Reservoir Group in the Midwest Ordos Basin
Authors: Shaobin GUO , Pengda ZHAO
Published: February 2011

Abstract: The development of pores in a clastic reservoir is one of the most important research subjects in oil‐gas exploration and development, whereas the many reasons for the formation of secondary porosity have increased the degree of difficulty in such research. Thus the research aims are to discover the controlling factors of solutional voids in feldspars and to predict favorable regions for these voids. Macroscopic and systematic researches into the relationship between the kaolinite content in the feldspar solutional void developed area of the Chang 2 reservoir group of the Triassic Yanchang Formation in the Midwest Ordos Basin and the solutional void in feldspar have been made, and from this it can be determined that the kaolinite content has an indicative function to the distribution of the solutional void in feldspar. Solutional void in feldspar is relatively well developed at the area where kaolinite content is high. Although the factors affecting kaolinite content are complicated, yet that of the research area is mainly affected by the impact of the leaching atmospheric water acting on the palaeogeomorphology. Three favorable zone belts for the development of solutional voids in feldspars are forecasted on the basis of restoration of palaeogeomorphology.
Intraspecific Variability and Problematic Dimorphism in the Early Cretaceous (Valanginian) Ammonite Saynoceras verrucosum (d'Orbigny, 1841)
Authors: PLOCH Izabela
Published: February 2011

Abstract: The population of Saynoceras verrucosum (d'Orbigny) from the Polish basin (Wa̧awal section, central Poland) shows no significant intraspecific variability. Dimorphism has not been found in this population. Statistical analyses of material from the shallow epicratonic Polish basin and the relatively deep Vocontian basin (southeastern France) indicated two populations. Forms from the Polish basin are somewhat more inflated and smaller than forms from the Vocontian basin.
A New Specimen of Liaoceratops yanzigouensis (Dinosauria: Neoceratopsia) from the Early Cretaceous of Liaoning Province, China
Authors: Hailu YOU , TANOUE Kyo , DODSON Peter
Published: February 2011

Abstract: A new specimen of basal neoceratopsian dinosaur Liaoceratops yanzigouensis is described. The specimen comes from the Lujiatun Bed of the Lower Cretaceous Yixian Formation in Beipiao City of western Liaoning Province, and is represented by a very well preserved three‐dimensional partial skull and mandible. It is also the smallest among the three specimens of L. yanzigouensis, and several features in the new specimen, such as the short preorbital length and the round rostroventral orbital rim, can be ontogenetically‐related. The superb exposure of the palatal complex may be caused by the removing of its brain by a small predator in the contemporary Jehol Biota.
Dongbeititan dongi, the First Sauropod Dinosaur from the Lower Cretaceous Jehol Group of Western Liaoning Province, China
Authors: Xuri WANG , Hailu YOU , Qingjin MENG , Chunling GAO , Xiaodong CHENG , Jinyuan LIU
Published: February 2011

Abstract:We herein describe a partial postcranial skeleton of a sauropod dinosaur recovered from the Lower Cretaceous Jehol Group in the Beipiao area of western Liaoning Province, northeastern China. A suite of features it possesses, including the camellate internal structure of its presacral elements, the existence of pneumatocoels on the proximal ends of the dorsal ribs, and especially the medially deflected proximal portion of the femur, definitively establish the titanosauriform affinities of the specimen. It differs from other titanosauriforms in having a craniocaudally elongate coracoid with a squared cranioventral extreme and a long, smooth, and slightly convex acetabular edge of the pubis. It represents a new taxon,Dongbeititan dongigen. et sp. nov. Comparative studies suggest thatDongbeititanis a basal titanosauriform, more derived thanEuhelopus, Fusuisaurus, andHuanghetitan, but less derived thanGobititanandJiutaisaurus. Dongbeititanrepresents the first sauropod dinosaur reported from the Lower Cretaceous Jehol Group of western Liaoning Province.
Late Cretaceous Foraminiferal Faunas from the Saiqu “mélange” in Southern Tibet
Authors: Guobiao LI , Xiaoqiao WAN , Ganqing JIANG , Xiumian HU , Nicolas GOUDEMAND , Hongdou HAN , Xi CHEN
Published: February 2011

Abstract: As one of the mélanges in the southern side of the Yarlung‐Zangbo suture zone, the Saiqu mélange in southern Tibet is important for understanding the evolution of the Neo‐Tethys ocean. The age of the Saiqu mélange, however, has been debated due to the lack of reliable fossil evidence in matrix strata. Based on lithological similarities with platform strata in southern Tibet and limited fossils from exotic blocks, previous studies variously ascribed the Saiqu mélange to be Triassic in general, Late Triassic, or Late Cretaceous. Here we reported planktonic foraminiferal faunas from the matrix strata of the Saiqu mélange. The new fossils yield a Late Cretaceous age, which is so far the best age constraint for the mélange. Regional stratigraphic correlation indicates that the Cretaceous Oceanic Red Beds (CORBs) in Saiqu may be time equivalent to the CORBs of the Zongzhuo Formation in neighboring regions. Thus the Saiqu mélange should be correlated to the Upper Cretaceous Zongzhuo Formation rather than the Triassic Xiukang Group, as previously suggested.
Revision of the Conchostracan Genus Tenuestheria from the Upper Cretaceous Lanxi Formation in Zhejiang and Its Biostratigraphic Significance in Southeast China
Authors: Gang LI , Xiaoqiao WAN , WILLEMS Helmut , BATTEN David J.
Published: February 2011

Abstract: The diagnosis of the conchostracan genus Tenuestheria from the Lanxi Formation in Jinhua, Zhejiang Province in Southeast China is revised following an examination of the type species under a scanning electron microscope, which revealed some morphological features on the carapace that had not been recognized previously. The importance of the Tenuestheria Fauna is considered in the context of correlation of six Turonian‐Santonian formations in this region of China. The value of the Cenomanian Nemestheria and Turonian Linhaiella faunas in correlating the underlying early Late Cretaceous formations is also noted.
The Cretaceous System in China
Authors: Xiaoqiao WAN , Peiji CHEN , Mingjian WEI
Published: February 2011

Abstract: This paper provides an outline of Cretaceous stratigraphy and paleogeography in China, which is based on rich data obtained from recent researches. Cretaceous deposits are widespread in China. Most strata are of nonmarine origin and marine sediments occur only in Tibet, western Tarim Basin of Xinjiang, Taiwan and limited localities of eastern Heilongjiang. All deposits are rich in fossils and well‐constrained biostratigraphically. The stratigraphic successions of different regions are illustrated, and general stratigraphic division and correlation have been introduced. The marine deposits are described in the Tibetan Tethys, Kashi‐Hotan Region of Xinjiang, eastern Heilongjiang, western Yunnan and Taiwan; the nonmarine deposits are outlined from northeast China, southeast China, southern interior China, southwest China, the Shaanxi‐Gansu‐Ningxia region, and northwestern China intermontane basins. The sedimentary facies and paleogeography are diversified. In Tibet the basin evolution is largely related to the subduction and collision of the Indian Plate against the Eurasian Continent, and shows a tectonic evolution in the Cretaceous. Foraminifera are a dominant biota in the Tibet Tethys. Nonmarine sediments include variegated and red beds, coal‐ or salt‐bearing horizons, and volcanic rocks. These deposits contain diverse and abundant continental faunas and floras, as well as important coal and oil resources. The Cretaceous stratigraphy and paleogeography in China have presented a foundation for geological studies.
Recognition of Milankovitch Cycles in the Natural Gamma–Ray Logging of Upper Cretaceous Terrestrial Strata in the Songliao Basin
Authors: Huaichun WU , Shihong ZHANG , Suwen SUI , Qinghua HUANG
Published: February 2011

Abstract: Spectrogram analysis of seven natural gamma‐ray logging of Member 1 of the Qingshankou Formation (K2qn1) and Member 1 and 2 of the Nenjiang Formation (K2n1–2) of Late Cretaceous age in the Songliao Basin reveals sedimentary cyclicities controlled by Milankovitch climate periodicities. The recognition of Milankovitch cycles allows estimation of an average accumulation rate of ∼7.55‐8.62 cm/ka for the K2qn1 sections, and ∼6.69‐10.16 cm/ka for the K2n1–2 sections. Two marine transgression events occurred during the deposition of K2qn1 and K2n1–2 and their ages are at ∼0.74‐1.10 Ma and ∼2.38‐4.84 Ma, respectively. Identification of Milankovitch cycles from fine‐grained deep lake sedimentary rocks in the Songliao Basin may provide great potential for high‐resolution stratigraphic subdivisions and correlations.
The Cretaceous Songliao Basin: Volcanogenic Succession, Sedimentary Sequence and Tectonic Evolution, NE China
Authors: Pujun WANG , Xiao'an XIE , FRANK Mattern , Yanguang REN , Defeng ZHU , Xiaomeng SUN
Published: February 2011

Abstract: The Songliao basin (SB) is a superposed basin with two different kinds of basin fills. The lower one is characterized by a fault‐bounded volcanogenic succession comprising of intercalated volcanic, pyroclastic and epiclastic rocks. The volcanic rocks, dating from 110 Ma to 130 Ma, are of geochemically active continental margin type. Fast northward migration of the SB block occurred during the major episodes of the volcanism inferred from their paleomagnetic information. The upper one of the basin fill is dominated by non‐marine sag‐style sedimentary sequence of siliciclastics and minor carbonates. The basin center shifted westwards from the early to late Cretaceous revealed by the GGT seismic velocity structure suggesting dynamic change in the basin evolution. Thus, a superposed basin model is proposed. Evolution of the SB involves three periods including (1) Alptian and pre‐Aptian: a retroarc basin and range system of Andes type related to Mongolia‐Okhotsk collisional belt (MOCB); (2) Albian to Companian: a sag‐like strike‐slip basin under transtension related to oblique subduction of the Pacific plate along the eastern margin of the Eurasian plate; (3) since Maastrichtian: a tectonic inverse basin under compression related to normal subduction of the Pacific plate under the Eurasian plate, characterized by overthrust, westward migration of the depocenter and eastward uplifting of the basin margin.
A Primary Observation on Palynofacies of the Chuangde Section (Late Jurassic‐Cretaceous), Gyangzê, Southern Tibet
Authors: Jianguo LI , Zhenyu GUO
Published: February 2011

Abstract: A primary study on palynofacies, which concerns the paleoenvironments from the sight of association of sedimentary organic matter preserved in sedimentary rocks, is conducted for a Late Jurassic‐Cretaceous succession at Gyangzê, southern Tibet. Two palynofacies are recognized, which are formed in different sedimentary environments. The one in the pelagic is infertile in organic productivity and monotonous in component and is dominated by AOMA, while the other, being closely bound up with the slope, is characterized by abundant black phytoclasts that are possibly of algal origin and contains much AOM. The influence of terrestrial input is clear in the latter, for particles generated from terrestrial plants are common. A number of fossil spores and pollen together with some dinocysts are discovered, but they are normally in a bad condition of preservation. Nevertheless, this convinces us that the late Jurassic‐Cretaceous succession in the Gyangzê area has a potential for palynological stratigraphy. We have also proved that the volume of PM can achieve similar results in presenting the productivity of organic matter as the weight of TOC does. This technique is much easier in the laboratory than that we do with TOC.
Microfacies of Deep‐water Deposits and Forming Models of the Chinese Continental Scientific Drilling‐SKII
Authors: Rihui CHENG , Guodong WANG , Pujun WANG , Youfeng GAO
Published: February 2011

Abstract: Extensive transgression of lake water occurred during the Cretaceous Qingshankou Stage and the Nengjiang Stage in the Songliao basin, forming widespread deep‐water deposits. Eleven types of microfacies of deep‐water deposits have been recognized in the continuous core rocks from the SKII, including mudstone of still water, marlite, dolostone, oil shale, volcanic ashes, turbidite, slump sediment, tempestite, seismite, ostracoda limestone and sparry carbonate, which are divided into two types: microfacies generated due to gradually changing environments (I) and microfacies generated due to geological events (II). Type I is composed of some special fine grain sediments such as marlite, dolomite stone and oil shale as well as mudstone and Type II is composed of some sediments related to geological events, such as volcanic ashes, turbiditie, slump sediment, tempestite, seismite, ostracoda limestone. The formation of sparry carbonate may be controlled by factors related to both environments and events. Generally, mudstone sediments of still water can be regarded as background sediments, and the rest sediments are all event sediments, which have unique forming models, which may reflect controlling effects of climatics and tectonics.
Sedimentary Micro‐facies and Macro Heterogeneity of Reservoir Beds in the Third Member of the Qingshankou Formation, Qian'an Area, Songliao Basin
Authors: Xuanlong SHAN , Jinxiang HU , SACHSENHOFER Reinhard F. , Tiaotiao SHI
Published: February 2011

Abstract: An analysis of drill cores and well logs shows that the main micro‐facies of the third member sand bodies of the Qingshankou Formation in Qian'an are subaqueous distributary channel facies, sheet sand facies and subaqueous fan facies (olistostrome). Maps showing the distribution of these micro‐facies together with inter‐channel bay and prodelta mocro‐facies are presented for different time‐slices (lower, middle and upper parts of the Qingshankou Formation). These maps reveal the instability and change of sediment transport in the Baokang sedimentary system during the depositional period. Sediment transport was from the west in the early stage, from the south in the middle stage and from the northwest in the late stage. Values of thickness, porosity and permeability of the sand bodies in the third member of the Qingshankou Formation show that they have low to medium porosity and low permeability, and are characterized by serious reservoir heterogeneity. The joints between micro‐facies and subaqueous fan micro‐facies are characterized by the highest heterogeneity, the sheet sand and distal sand bar subfacies come next, and the heterogeneity of the subaqueous distributary channel sand bodies is relatively weak.
Campanian Climatic Change: Isotopic Evidence from Far East, North America, North Atlantic and Western Europe
Authors: ZAKHAROV Yuri D. , SHIGETA Yasunari , TANABE Kazushige , IBA Yasuhiro , SMYSHLYAEVA Olga P. , SOKOLOVA Ekaterina A. , POPOV Alexander M. , VELIVETSKAYA Tatiana A. , AFANASYEVA Tamara B.
Published: February 2011

Abstract: Paleoclimatic settings have been reconstructed for the Campanian using original oxygen‐isotopic analyses of well‐preserved molluskan and foraminifera shells from Russian Far East, Hokkaido, USA, Belgium and some DSDP holes (95,98,102, 390A, and 392A) in North Atlantic. Early Early Campanian climatic optimum has been recognized from data on high bottom shelf water paleotemperatures in middle latitudes of both the western circum‐Pacific (to 24.2°C) and the eastern circum‐Pacific (to 26.4°C) areas and high bottom shallow water paleotemperatures in high latitudes of the Koryak Upland (22.4–25.5°C), which agrees with the data on the Campanian Barykovskaya flora in high latitudes (Golovneva and Herman, 1998) and Jonker flora and its equivalents in middle latitudes. Judging from the data on comparatively high bottom shallow water paleotemperature values in high latitudes, South Alaska (19.4°C) and the Koryak Upland (22.4–25.5°C), we also expect Latest Campanian temperature maximum, which has not been confirmed, however, for low and middle latitudes by neither of isotopic nor paleobotanic data now. Main climatic tendency during the Campanian (with the exception of Latest Campanian) has been learned from isotopic composition of Campanian aragonitic ammonoid shells from the Hokkaido‐South Sakhalin (Krilyon) marine basin. In contrary to Huber's et al. (2002) assumption, we expect warm greenhouse conditions during the most part of the Campanian.
Nonlinear Dynamic Study on Geomagnetic Polarity Reversal and Cretaceous Normal Superchron
Authors: Wei SHEN
Published: February 2011

Abstract: It is generally acknowledged that geomagnetic polarity has reversed many times in geological history and an abnormal geologic phenomenon is the Cretaceous normal superchron. However, the causes have been unknown up to now. The nonlinear theory has been applied to analyze the phenomenon in geomagnetic polarity reversal and the Cretaceous normal superchron. The Cretaceous normal superchron implies that interaction of the Earth's core‐mantle and liquid movement in the outer core may be the lowest energy state and the system of Earth magnetic field maintains a sort of temporal or spatial order structure by exchanging substance and energy in the outside continuously. During 121‐83 Ma, there was no impact of a celestial body that would result in a geomagnetic polarity reversal, which may be a cause for occurrence of the Cretaceous normal superchron. The randomness of geomagnetic polarity reversal has the self‐reversion characteristic of chaos and the chaos theory gives a simple and clear explanation for the dynamic cause of the geomagnetic polarity reversal.
Transient Aspects of Heat Flux Bifurcation in Porous Media: An Exact Solution
Authors: Yang Kun , Vafai Kambiz
Published: February 2011

The transient thermal response of a packed bed is investigated analytically. A local thermal nonequilibrium model is used to represent the energy transport within the porous medium. The heat flux bifurcation phenomenon in porous media is investigated for temporal conditions and two primary types of heat flux bifurcations in porous media are established. Exact solutions are derived for both the fluid and solid temperature distributions for the constant temperature boundary condition. The fluid, solid, and total Nusselt numbers during transient process are analyzed. A heat exchange ratio is introduced to estimate the influence of interactions between the solid and fluid phases through thermal conduction at the wall within the heat flux bifurcation region. A region where the heat transfer can be described without considering the convection contribution in the fluid phase is found. The two-dimensional thermal behavior for the solid and fluid phases is also analyzed. The temporal temperature differential between the solid and fluid is investigated to determine the domain over which the local thermal equilibrium model is valid. In addition, the characteristic time for reaching steady state conditions is evaluated.
A Novel Experimental Device for Seebeck Coefficient Measurements of Bulk Materials, Thin Films, and Nanowire Composites
Authors: Pinisetty D. , Haldolaarachchige N. , Young D. P. , Devireddy R. V.
Published: February 2011

An experimental setup has been designed and built for measuring the Seebeck coefficient of bulk thermoelectric materials, thin films, and nanowire composites in the temperature range 200–350 K. The setup utilizes a differential method for measuring the Seebeck coefficient of the sample. The sample holder is a simple clamp design, utilizing a spring-loaded mounting system to load and hold the sample between two copper blocks, on which the electrical leads, as well as thermocouples, are mounted. The spring-loaded design also offers fast turn-around times, as the samples can be quickly loaded and unloaded. To measure the Seebeck coefficient, a temperature difference is generated across the sample by using four 10 kΩ resistive heaters mounted in series on one of the copper blocks. The resulting slope of the thermo-emf versus temperature difference plot is used to obtain the Seebeck coefficient at any temperature. Test measurements were carried out on bulk samples of nickel (Ni), bismuth-telluride (Bi2Te3), antimony-telluride (Sb2Te3), as well as thin films and nanowire composites of Ni.
Diffusion-Thermo Effects on Free Convective Heat and Mass Transfer Flow in a Vertical Channel With Symmetric Boundary Conditions
Authors: Jha Basant K. , Ajibade Abiodun O.
Published: February 2011

This article investigates the influence of diffusion-thermo effect on transient free convective heat and mass transfer flow in a channel bounded by two infinite vertical parallel plates. Fully developed laminar flow is considered when the boundaries are subjected to symmetric concentration and thermal input. The Dufour effect is taken into consideration. The velocity, temperature, and concentration profiles are obtained analytically using the Laplace transforms technique and used to compute the shear stress, Nusselt number, and mass flux. During the course of computation, it was found that transient solution at large time coincides with steady-state solution derived separately. Diffusion-thermo (Dufour effect) is observed to create an anomalous situation in temperature and velocity profiles for small Prandtl numbers. There is also flow reversal for a small Dufour number and negative values of the sustentation parameter (N). At steady-state, there is neither heat nor mass transfer between the fluid and the plates.
Enhancing Endothelial Cell Retention on ePTFE Constructs by siRNA-Mediated SHP-1 Gene Silencing
Authors: Tefft Brandon J. , Kopacz Adrian M. , Liu Wing Kam , Liu Shu Q.
Published: February 2011

Polymeric vascular grafts hold great promise for vascular reconstruction, but the lack of endothelial cells renders these grafts susceptible to intimal hyperplasia and restenosis, precluding widespread clinical applications. The purpose of this study is to establish a stable endothelium on expanded polytetrafluoroethylene (ePTFE) membrane by small interfering RNA (siRNA)-induced suppression of the cell adhesion inhibitor SH2 domain-containing protein tyrosine phosphatase-1 (SHP-1). Human umbilical vein endothelial cells (HUVECs) were treated with scrambled siRNA as a control or SHP-1 specific siRNA. Treated cells were seeded onto fibronectin-coated ePTFE scaffolds and exposed to a physiological range of pulsatile fluid shear stresses for 1 h in a variable-width parallel plate flow chamber. Retention of cells was measured and compared between various shear stress levels and between groups treated with scrambled siRNA and SHP-1 specific siRNA. HUVECs seeded on ePTFE membrane exhibited shear stress-dependent retention. Exposure to physiological shear stress (10 dyn/cm2) induced a reduction in the retention of scrambled siRNA treated cells from 100% to 85% at 1 h. Increased shear stress (20 dyn/cm2) further reduced retention of scrambled siRNA treated cells to 55% at 1 h. SHP-1 knockdown mediated by siRNA enhanced endothelial cell retention from approximately 60% to 85% after 1 h of exposure to average shear stresses in the range of 15–30 dyn/cm2. This study demonstrates that siRNA-mediated gene silencing may be an effective strategy for improving the retention of endothelial cells within vascular grafts.
On the Cooling of Electronics With Nanofluids
Authors: Escher W. , Brunschwiler T. , Shalkevich N. , Shalkevich A. , Burgi T. , Michel B. , Poulikakos D.
Published: February 2011

Nanofluids have been proposed to improve the performance of microchannel heat sinks. In this paper, we present a systematic characterization of aqueous silica nanoparticle suspensions with concentrations up to 31 vol %. We determined the particle morphology by transmission electron microscope imaging and its dispersion status by dynamic light scattering measurements. The thermophysical properties of the fluids, namely, their specific heat, density, thermal conductivity, and dynamic viscosity were experimentally measured. We fabricated microchannel heat sinks with three different channel widths and characterized their thermal performance as a function of volumetric flow rate for silica nanofluids at concentrations by volume of 0%, 5%, 16%, and 31%. The Nusselt number was extracted from the experimental results and compared with the theoretical predictions considering the change of fluids bulk properties. We demonstrated a deviation of less than 10% between the experiments and the predictions. Hence, standard correlations can be used to estimate the convective heat transfer of nanofluids. In addition, we applied a one-dimensional model of the heat sink, validated by the experiments. We predicted the potential of nanofluids to increase the performance of microchannel heat sinks. To this end, we varied the individual thermophysical properties of the coolant and studied their impact on the heat sink performance. We demonstrated that the relative thermal conductivity enhancement must be larger than the relative viscosity increase in order to gain a sizeable performance benefit. Furthermore, we showed that it would be preferable to increase the volumetric heat capacity of the fluid instead of increasing its thermal conductivity.
Effective Stiffness and Effective Mass of the Double-Walled Carbon Nanotube Sensor
Authors: Elishakoff I. , Versaci C. , Muscolino G.
Published: February 2011

In this study, the effective stiffness of the double-walled carbon nanotube sensor is determined by both the Bubnov–Galerkin method and the finite difference technique. It is shown that in addition to the familiar expression of the effective stiffness of the clamped-free beam, there is an additional term for the double-walled carbon nanotube’s effective stiffness. Additionally, it is demonstrated that there are two effective stiffness expressions, depending on where the load is applied, at the inner tube or at the outer tube. Additionally, effective mass is evaluated in the context of the Galerkin method.
Application of Large Gurney Flaps on Low Reynolds Number Fan Blades
Authors: Greenblatt David
Published: February 2011

On the basis of a semi-empirical model, large Gurney flaps of 10%, 20%, and 30% of the fan blade chord length were tested in a specially designed ventilation fan facility. At the highest volumetric flowrates tested, the flapped blades all produced higher pressures than the baseline nonflapped case. When proper accounting was made of fan rotational speed, all flapped blades produced consistently higher dimensionless pressures, with the 30% flap producing the highest pressures at large volumetric flowrates. Based on the assumption that sound power varies with the sixth power of fan rotation speed, it was shown that the sound pressure level could be reduced by nearly 4 dB. All flapped configurations produced higher mechanical efficiency than the baseline case but the mass of the flap relative to that of the blade emerged as an important parameter. A 10% flap, whose mass was negligible relative to the blade, produced the largest increase of 18% in static efficiency. Further research will focus on testing the flaps over the entire operational range, as well as on redesigning stiffer and lighter Gurney flaps. The introduction of three-dimensionality such as spanwise spaced holes, slits, or serrations that have previously been used to reduce airfoil drag will also be considered.
Comparative Analysis of Methods for Estimating Arm Segment Parameters and Joint Torques From Inverse Dynamics
Authors: Piovesan Davide , Pierobon Alberto , DiZio Paul , Lackner James R.
Published: February 2011

A common problem in the analyses of upper limb unfettered reaching movements is the estimation of joint torques using inverse dynamics. The inaccuracy in the estimation of joint torques can be caused by the inaccuracy in the acquisition of kinematic variables, body segment parameters (BSPs), and approximation in the biomechanical models. The effect of uncertainty in the estimation of body segment parameters can be especially important in the analysis of movements with high acceleration. A sensitivity analysis was performed to assess the relevance of different sources of inaccuracy in inverse dynamics analysis of a planar arm movement. Eight regression models and one water immersion method for the estimation of BSPs were used to quantify the influence of inertial models on the calculation of joint torques during numerical analysis of unfettered forward arm reaching movements. Thirteen subjects performed 72 forward planar reaches between two targets located on the horizontal plane and aligned with the median plane. Using a planar, double link model for the arm with a floating shoulder, we calculated the normalized joint torque peak and a normalized root mean square (rms) of torque at the shoulder and elbow joints. Statistical analyses quantified the influence of different BSP models on the kinetic variable variance for given uncertainty on the estimation of joint kinematics and biomechanical modeling errors. Our analysis revealed that the choice of BSP estimation method had a particular influence on the normalized rms of joint torques. Moreover, the normalization of kinetic variables to BSPs for a comparison among subjects showed that the interaction between the BSP estimation method and the subject specific somatotype and movement kinematics was a significant source of variance in the kinetic variables. The normalized joint torque peak and the normalized root mean square of joint torque represented valuable parameters to compare the effect of BSP estimation methods on the variance in the population of kinetic variables calculated across a group of subjects with different body types. We found that the variance of the arm segment parameter estimation had more influence on the calculated joint torques than the variance of the kinematics variables. This is due to the low moments of inertia of the upper limb, especially when compared with the leg. Therefore, the results of the inverse dynamics of arm movements are influenced by the choice of BSP estimation method to a greater extent than the results of gait analysis.
Spectral Method for Analyzing Motions of Ellis Fluid Over Corrugated Boundaries
Authors: Bakhsheshi M. Fazel , Floryan J. M. , Kaloni P. N.
Published: February 2011

A spectral method for solving the steady flow of a shear-thinning Ellis fluid is discussed for the case of a planar channel with corrugated boundaries. Polynomial approximations are employed for the velocity and viscosity distributions in the regions around singularities. The proposed algorithm employs a fixed computational domain with the physical domain of interest submerged inside the computational domain. The flow boundary conditions are imposed using the concept of immersed boundary conditions. The method, thus, eliminates the need for grid generation. The algorithm relies on Fourier expansions in the flow direction and Chebyshev expansions in the transverse direction. Various tests confirm spectral accuracy of the algorithm.