Quantitative Analysis of Paleoatmospheric CO2 Level Based on Stomatal Characters of Fossil Ginkgo from Jurassic to Cretaceous in China

A better theoretical and practical understanding of the linkage between paleo-CO2 and climate during geological history is important to enhance the sustainable development of modern human society. Development in plant physiology since the 1980s has led to the realization that fossil plants can serve as a proxy for paleoatmosphere and paleobiosphere. As a relict gymnosperm with evolutionary stasis, Ginkgo is well suited for paleoenvironmental reconstruction. This paper analyzes fossil Ginkgo species from integrated strata in the north of China using anatomic data of plant physiology. Using stomatal parameters, a trend for the paleo-CO2 level during the Early-Middle Jurassic and the Early Cretaceous was obtained, which is consistent with the estimates by GEOCARB. The trend is also similar to that of Mean Global Surface Temperature in geological time. Compared with three other atmospheric CO2 concentration parameters, the trend of paleo-CO2 level based on the stomatal parameter of the fossil Ginkgo specimens from three contiguous strata is more exact.

Holocene Abrupt Climate Shifts and Mid-Holocene Drought Intervals Recorded in Barkol Lake of Northern Xinjiang of China

Study results in this paper have indicated that the Holocene climate in Xinjiang,Northwestern China has been alternating between wet and dry conditions,and was punctuated with a series of abrupt climate shifts.A sediment core taken from Barkol Lake in the northern Xinjiang of Northwest China was analyzed at 1cm interval for grain-size distribution.Abrupt climate shifts revealed by the grain-size proxy occurred at ca 1.4,3.0,4.3,5.6,8.0 cal kyr B.P.,which were well correlated to both the abrupt shifts recorded in the North Atlantic Ocean(NAO)and the Holocene sea surface temperature(SST)cooling events in the Arabian Ocean.The correlation indicated that the climatic changes in the extreme arid Northwest China were associated with the NAO,probably via the North Atlantic Oscillation-affected westerly winds.The strength and position of westerly winds probably modulated the Siberian-Mongolian high-pressure system(winter monsoon),and played an important role in climate change of Northwest China.Moreover,an evident drought interval during the middle Holocene was also revealed by grain-size proxy.

Cenozoic Ephedraceae adaptation to global cooling in northwestern China

Ephedraceae has been applied largely as a drought indicator to reconstruct Cenozoic paleoenvironment and paleoclimate. However, temperature indication of Ephedraceae has been largely ignored. Here, we provide a record of Ephedraceae percentage spanning from the Early Eocene to Middle Miocene （52-17 Myr B.P.） in the Xining Basin, northeastem Tibetan Plateau. This record is comparable to a compiled Cenozoic Ephedraceae record from five other basins in northwestern China. Both records show Ephedraceae percentages were high during the Early Eocene, and decreased gradually from the Middle Eocene to Late Oligocene, then maintained a stable level since the Late Oligocene. By comparing these two Ephedraceae records with the marine oxygen isotope record, we discuss the variation of Ephedmceae percentage in Middle Cenozoic in response to global temperature change. Ephedraceae percentage was high in the Early Paleogene, associated with subtropical or tropical vegetation types in a global greenhouse climate, and decreased in Early Oligocene, associated with global cooling, suggesting that Ephedmceae is warm-tolerant during the Paleogene. The low Ephedraceae percentages in the Late Oligocene and Miocene were uncoupled with global warming, which may imply that Ephedraceae began to adapt to a eurythermic climate in the inland desert environment of westem China. Such adaptation may be a response to the high topography of the Tibetan Plateau.

Interaction of DNA with aromatic hydrocarbons fraction in atmospheric particulates of Xigu District of Lanzhou,China

Voluminously epidemiological studies show that the relationships exist between the air pollution and human health and cancer. Aromatic hydrocarbons （AHs） in air form a large class of organic pollutants, which are widely in environment and many of them are known to be carcinogenic and/or mutagenic and contribute to ambient air pollution. In the past decades, bioassays mainly have been used to evaluate the toxicity of chemical mixtures in atmospheric particulates or aqueous environment. However, it is well known that the covalent complexes formed by carcinogens with DNA may be exert negative results in bioassay. So the main aim of this paper is to develop an evaluation method of toxicity effects of chemical mixtures in atmospheric particulates from chemical standpoint. In this study, the in vitro interaction of the AHs with DNA was investigated by absorption, fluorescence and resonance light scattering （RLS） spectroscopic techniques. The results showed that the AHs in the atmospheric particulates could combine with calf thymus DNA （ctDNA） and herring sperm DNA （hsDNA） without being activated or metabolized by organism, respectively. Intercalation may be present in the mechanism of interaction. The binding constants of the AHs with ctDNA and hsDNA were 2.5x102 and 2.0x103, respectively, which indicated that the interaction of the AHs with hsDNA is stronger than that with ctDNA. In addition, the relationships of dose-effect between the total mole concentration of chemical components and the ability of binding ctDNA and hsDNA were confirmed. This research made it possible to study the toxicity effects of chemical mixtures in atmospheric particulates by chemical method. It is believed that the composition and contents of unknown AHs and the interaction of DNA with AHs in atmospheric particulates of Xigu District of Lanzhou City, China are first reported in the past twenty years.

China's Relations with Africa:Building a Harmonious World

The Sino-African relationship is one of the most important inter-continental relationships in the world.It is unique both in its origin and evolution and plays an important role on the world stage.Since the establishment of diplomatic relations in the mid-1950s,traditional,friendly and cooperative relations between China and African countries have developed rapidly,reaching an historic high in 2000 when both sides proclaimed the establishment of a new type of strategic partnership. Transcending Western traditional value and logic of thinking,such as the supremacy of international interests and power control,Sino-African relations have created a new model in international relations,featuring equality,peaceful coexistence and friendly cooperation.This promotes African development and the democratization process in both international relations and the global community.From China's perspective,it spreads China's idea of harmonious culture and harmonious diplomacy,thus promoting world peace and development,and contributing towards building a harmonious world.

How Will the Sovereign Debt Crisis Influence China?

If we use one phrase to generalize the world’s real economy in 2011, the most appropriate one might be the sovereign debt crisis.As this crisis is going on,some European countries still have an extremely high debt-to-GDP ratio,which has hit 159% in Greece,120%in Italy and exceeded 100%in Portugal,Ireland and Spain. Even in some better-off countries

A new edge recognition technology based on the normalized vertical derivative of the total horizontal derivative for potential field data

边察觉和改进技术通常在用潜在的域数据认出地质的身体的边被使用。我们在场一种新边识别技术基于有边察觉和改进技术的功能的全部的水平衍生物的规范的垂直衍生物。首先，我们计算潜在地的数据的全部的水平衍生物(THDR ) 然后计算 n 顺序 THDR 的垂直衍生物(VDRn ) 。为 n 顺序垂直衍生物，全部的水平衍生物(PTHDR ) 的山峰价值用比 0 大的阀值价值被获得。这 PTHDR 能被用于边察觉。第二， PTHDR 价值被全部的水平衍生物划分并且由最大的价值使正常化。最后，我们使用了数字模型的不同类型验证新边识别技术的有效性和可靠性。

Cenozoic Stratigraphy Deformation History in the Central and Eastern of Qaidam Basin by the Balance Section Restoration and its Implication

The Qaidam Basin, located in the northern margin of the Qinghai-Tibet Plateau, is a large Mesozoic-Cenozoic basin, and bears huge thick Cenozoic strata. The geologic events of the Indian- Eurasian plate-plate collision since -55 Ma have been well recorded. Based on the latest progress in high-resolution stratigraphy, a technique of balanced section was applied to six pieces of northeast- southwest geologic seismic profiles in the central and eastern of the Qaidam Basin to reconstruct the crustal shortening deformation history during the Cenozoic collision. The results show that the Qaidam Basin began to shorten deformation nearly synchronous to the early collision, manifesting as a weak compression, the deformation increased significantly during the Middle and Late Eocene, and then weakened slightly and began to accelerate rapidly since the Late Miocene, especially since the Quaternary, reflecting this powerful compressional deformation and rapid uplift of the northern Tibetan Plateau around the Qaidam Basin.

Association of NOD1 and NOD2 genes polymorphisms with Helicobacter pylori related gastric cancer in a Chinese population

AIM:To investigate the association between the tag single nucleotide polymorphisms(TagSNPs) of NOD1 and NOD2 and the risk of developing gastric cancer.METHODS:We conducted a hospital-based case-control study including 296 incident gastric cancer patients and 160 gastritis controls.Eight TagSNPs in the NOD1 and NOD2 genes were selected from the Hapmap database using the haploview software and genotyped by the Sequenom MassArray system.The serum levels of anti-Helicobacter pylori(H.pylori) IgG were measured by enzyme-linked immunosorbent assay to indicate H.pylori infection.The odds ratios(OR) and 95% confidence intervals(CI) were calculated by unconditional logistic regression,including sex and age as confounding factors.RESULTS:The NOD1 rs2907749 GG genotype showed a decreased risk for gastric cancer(OR 0.50,95% CI:0.26-0.95,P = 0.04) while the rs7789045 TT genotype showed an increased risk(OR 2.14,95% CI:1.20-3.82,P = 0.01).An elevated susceptibility to gastric cancer was observed in the subjects with H.pylori infection and the NaOD1 rs7789045 TT genotype(OR 2.05,95% CI:1.07-3.94,P = 0.03) or the NOD2 rs7205423 GC genotype(OR 2.52,95% CI:1.05-6.04,P = 0.04).Haplotype analysis suggested that the distribution of AGT(rs2907749,rs2075820 and rs7789045) in NOD1 between the cases and control groups was significantly different(P corrected:0.04),and the diplotype AGT/AGT was associated with an elevated gastric cancer risk(OR 1.98,95% CI:1.04-3.79,P = 0.04).The association of the NOD1 rs7789045 TT genotype and the diplotype AGT/AGT was significant with H.pylori-related diffuse-type gastric cancer(OR 3.00,95% CI:1.38-6.53,P = 0.01;OR 4.02,95% CI:1.61-10.05,P < 0.01,respectively).CONCLUSION:Genetic polymorphisms in NOD1 and NOD2 may interact with H.pylori infection and may play important roles in promoting the development of gastric cancer in the Chinese population.

The impacts of climate change on the Neolithic cultures of Gansu-Qinghai region during the late Holocene Megathermal

The Holocene Megathermal is divided into early, middle and late periods, each having different impacts on the Neolithic cultures due to their different climate changing trends This study is based on a comparative analysis of the environmental evolution information recorded in the Qinghai Lake, the western edge of the Loess Plateau and Zoige and the spatial distribution of Neolithic sites of the Gansu-Qinghai region. Results show that the early and middle periods towards warm and humid promoted the development of Neolithic cultures with agriculture as the main sector in the Gansu-Qinghai region, furthermore a heyday of Yangshao Culture prosperity emerged. The Holocene entered the late period after the cold climate event at 5.9 ka BP in the Gansu-Qinghai region. Later the climate began to turn cold. However, at the 5.8-4.2 ka BP a relatively stable warm and humid climate created the conditions for the development of Majiayao Culture of the Neolithic Age in this region, thus the distribution of its cultural heritage sites expanded towards high altitudes and high latitudes. From 4.2 ka BP onwards, the climate became cold and dry, which had a significant influence on the Neolithic cultures of the Gansu-Qinghai region, leading to a dramatic change in the cultural characters and spatial distribution of Qijia Culture around 4.2 ka BP. After a nearly 300 years of cold and dry period, the unified Neolithic farming culture completely collapsed. Afterwards an industrial division of animal husbandry and farming and regional multiple cultures formed, and ultimately led to the end of primitive society and the starting of a civilized society.

Numerical study of current fields near the Changjiang Estuary and impact of Quick-EnKF assimilation

A 30-d current numerical simulation is running for the Yangshan Port,the Changjiang Estuary,the Hangzhou Bay and their adjacent seas using a finite volume coastal ocean model （FVCOM）,with Changjiang River runoff and wind effect being considered.At the open boundary,this model is driven by the water level obtained from prediction including eight main partial tides.After the harmonic analysis,the cotidal chart and the iso-amplitude line as well as the current ellipse distribution map are displayed to illustrate the propagation property of a tidal wave.Horizontal velocity of both the U and V components coincides with the actual measurement,which shows that the model result is credible to describe the hydrodynamic pattern in this sea area.On this basis,real-time current data from high-frequency radar is assimilated with the implementation of quick ensemble Kalman filter,which takes the variation tendency of the state vector to compute the analysis field,instead of integrating the field for N （the number of ensemble） times as it used to in the standard EnKF,aiming at raising the efficiency of computation,reducing the error of prediction and at the same time,improving the forecast effect.

Petroleum System of the Sufyan Depression at the Eastern Margin of a Huge Strike-slip Fault Zone in Central Africa

The present paper mainly studies the petroleum system of the Sufyan Depression in the Muglad Basin of central Africa and analyzes its control of hydrocarbon accumulation. On the basis of comprehensive analysis of effective source rock, reservoir bed types and source-reservoir-seal assemblages, petroleum system theory has been used to classify the petroleum system of the Sufyan Depression. Vertically, the Sufyan Depression consists of two subsystems. One is an Abu Gabra subsystem as a self generating, accumulating and sealing assemblage. The other subsystem is composed of an Abu Gabra source rock, Bentiu channel sandstone reservoir and Darfur group shale seal, which is a prolific assemblage in this area. Laterally, the Sufyan Depression is divided into eastern and western parts with separate hydrocarbon generation centers more than 10 000 m deep. The potential of the petroleum system is tremendous. Recently, there has been a great breakthrough in exploration. The Sufyan C-1 well drilled in the central structural belt obtained high-yielding oil flow exceeding 100 tons per day and controlled geologic reserves of tens of millions of tons. The total resource potential of the Sufyan Depression is considerable. The central structural belt is most favorable as an exploration and development prospect.

Vegetation and environmental changes in western Chinese Loess Plateau since 13.0 ka BP

Pollen records from the Chinese Loess Plateau revealed a detailed history of vegetation variation and associated climate changes during the last 13.0 ka BP. Before 12.1 ka BP, steppe or desert-steppe vegetation dominated landscape then was replaced by a coniferous forest under a generally wet climate （12.1-11.0 ka BP）. The vegetation was deteriorated into steppe landscape and further into a desert-steppe landscape between 11.0 and 9.8 ka BP. After a brief episode of a cool and wet climate （9.8-9.6 ka BP）, a relatively mild and dry condition prevailed during the early Holocene （9.6-7.6 ka BP）. The most favourable climate of warm and humid period occurred during mid-Holocene （7.6-4.0 ka BP） marked by forest-steppe landscape and vegetation alternatively changed between steppe and desert-steppe from -4.0 to -1.0 ka BP.

Magnetic property of loess strata recorded by Kansu profile in Tianshan Mountains

Kansu （KS） profile is located in the east of Yili basin, western Xinjiang, where typical loess sediments are distributed. The magnetic parameters （such as IRM, SIRM SOFT, and M） and grain size in the KS profile were analyzed in the study. The results showed that the magnetic property of KS loess is dominated by ferrimagnetic minerals, such as magnetite and maghemite. Antiferromagnetic and superparamagnetic minerals also exist in the profile, but had less impact on magnetic susceptibility. Compared with the typical loess sediments of the central Loess Plateau in China, the strata of Kansu profile contained more magnetic minerals and hard magnetic minerals. The analysis of grain size for magnetic minerals indicated that the properties of loess and paleosol were respectively dominated by PSD/MD and coarse SSD magnetite. The research found that the contents of magnetic minerals in loess and paleosol sequences in Kansu profile were similar, but the proportion of fine grained magnetite and soft magnetic minerals were varying, which implies a positive relationship between the value of magnetic susceptibility and intensity of pedogenesis.

Numerical study of M_2 internal tide generation and propagation in the Luzon Strait

Based on the z-coordinate ocean model HAMSOM,we introduced the internal-tide viscosity term and applied the model to numerically investigate the M2 internal tide generation and propagation in the Luzon Strait （LS）.The results show that （1） in the upper 250 m depth,at the thermocline,the maximum amplitude of the generated internal tides in the LS can reach 40 m;（2） the major internal tides are generated to the northwest of Itbayat Island,the southwest of Batan Island and the northwest of the Babuyan Islands;（3） during the propagation the baroclinic energy scattering and reflection is obvious,which exists under the effect of the specific topography in the South China Sea （SCS）;（4） the westward-propagating internal tides are divided into two branches entering the SCS.While passing through 118 E,the major branch is divided into two branches again.The strongest internal tides in the LS are generated to the northwest of Itbayat Island and propagate northeastward to the Pacific.However,to the east of 122 E,most of the internal tides propagate southeastward to the Pacific as a beam.

Red Clay Sediment in the Central Chinese Loess Plateau and Its Implication for the Uplift of the Tibetan Plateau

The widely distributed red clay sediment underlying the Chinese Loess Plateau truly records the Neogene environmental evolution, and its genesis and development are intrinsically related to the uplift processes of the Tibetan Plateau and the evolution of East Asia monsoon system. In this paper, a detailed magnetostratigraphy of a loess-red clay section (107°13′E, 35°02′N) from the central Loess Plateau is reported. The loess-red clay sequence is composed of 175 m Quaternary loess-paleosol sequence and 128 m Neogene red clay sediments. Based on the correlation with the standard geomagnetic polarity time scale, the paleomagnetic results indicate that the age of Chaona red clay sequence extends to 8.1Ma, which is the older red clay deposition in the central Chinese Loess Plateau. The commencement of red clay at ～8.1 Ma may imply that the Ordos planation surface was broken by the movement of the Haiyuan-Liupanshan Faults, which was related to the uplift of the Tibetan Plateau induced by the collision of India Plate and Eurasian Plate. And the western part adjacent to the Tibetan Plateau was uplifted to form the embryo of the Liupan Shan (Mts.) and the eastern part was down-faulted to receive red clay deposition. We link this faulting to an initial uplift of the Tibetan Plateau. The undulating nature of the broken Ordos planation surface may explain the chronological differences and depth discrepancies among various cross-sections of red clay.