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Jurassic sedimentary features and tectonic settings of southeastern China 被引量:17
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作者 SHU LiangShu WANG Yan +3 位作者 SHA JinGeng JIANG ShaoYong YU JinHai WANG YanBin 《Science China Earth Sciences》 SCIE EI CAS 2009年第12期1969-1978,共10页
Two types of the Jurassic basins are distinguished in SE China based on their geodynamic features: the Late Triassic-Early Jurassic post-orogenic basins and the Middle Jurassic intra-continental extensional basins. Th... Two types of the Jurassic basins are distinguished in SE China based on their geodynamic features: the Late Triassic-Early Jurassic post-orogenic basins and the Middle Jurassic intra-continental extensional basins. The Lower Jurassic sequence shows a change from coarseto fine-grained accumulation, suggesting a gradually deepening depositional environment from river to shore-lake and to deep-water lake. In contrast, the Middle Jurassic accumulation was changed from claystone to conglomerate along the coastal provinces in SE China, indicative of an initial crustal uplift. The Wuyi Mountains have been a paleogeograghic separating zone since the Middle Jurassic. The Late Jurassic strata are absent in most areas of SE China. A large-scale bimodal intra-continental rift-type volcanism occurred during the Middle Jurassic along a 40-60 km wide and 200 km long area in western Fujian and southern Jiangxi provinces, which is most likely the strongest volcanism in SE China since the Cambrian. The SHRIMP zircon U-Pb analyses on the rhyolite from the Dongkeng basin in the southern Jiangxi area yield a concord U-Pb age of 160±0.5 Ma, providing an upper age limit for the bimodal volcanic eruption. The analyses of the basin features indicate a change of the depositional environment during the interval from Middle Triassic to Late Triassic from a shallow-sea to an intra-continent in SE China in response to the strong collision between the Yangtze and North China Blocks. Sedimentary structures record a southward direction of Early Jurassic paleo-currents, reflecting that their source areas were to the north side. We propose that the Wuyi region was uplifted as early as Middle Jurassic, followed by a wide E-W-trending extended depression and bimodal volcanism in the western foot of the Wuyi Mountains. Presumably the uplift of the Wuyi domain changed the Middle Jurassic paleo geographic outline and formed the transformational tectonic regime from compression to extension as a tectonic response to the Pacific plate subduction. 展开更多
关键词 sedimentary features paleo-geographic framework tectonic transformation SHRIMP U-Pb dating JURASSIC southeastern
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Response to paleoatmospheric CO_2 concentration of Solenites vimineus(Phillips)Harris(Ginkgophyta)from the Middle Jurassic of the Yaojie Basin,Gansu Province,China 被引量:15
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作者 YAN DeFei SUN BaiNian +2 位作者 XIE SanPing LI XiangChuan WEN WenWen 《Science China Earth Sciences》 SCIE EI CAS 2009年第12期2029-2039,共11页
Solenites vimineus (Phillips) Harris (Ginkgophyta) specimens with well-preserved cuticles were collected from five different beds in the oil shale member of the Middle Jurassic Yaojie Formation in the Yaojie Basin, Ga... Solenites vimineus (Phillips) Harris (Ginkgophyta) specimens with well-preserved cuticles were collected from five different beds in the oil shale member of the Middle Jurassic Yaojie Formation in the Yaojie Basin, Gansu Province, northwestern China. Gross morphology and fine structures of the fossil leaves were studied, and stomatal parameters were analyzed, according to which, the paleoatmospheric CO2 concentration can be deduced as 1512-1896 ppm that would have caused an increase in mean temperature of about 6.5-7.4℃. Carbon isotopes from the fossils indicate that the carbon isotopic discrimination and water use efficiency (WUE) of S. vimineus were raised nearly obtaining the ideal physiologic state in increased CO2 concentrations and temperature conditions, suggesting that S. vimineus records the paleoenvironmental information of the Middle Jurassic Yaojie Basin and can be used for environmental reconstruction. 展开更多
关键词 Solenites vimineus stomatal parameters paleo-CO_(2)concentration carbon isotopes Middle Jurassic northwestern China
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Exceptionally preserved brachiopods from the Chengjiang Lagerst(a|¨)tte(Yunnan,China):Perspectives on the Cambrian explosion of metazoans 被引量:12
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作者 ZHANG ZhiFei HOLMER Lars Erik 《Science Foundation in China》 CAS 2013年第2期66-80,共15页
The Cambrian explosion was coined to describe the geologically sudden appearance of numerous bilaterian body plans(Phyla)around the Ediacaran-Cambrian transition,around 565-520million years ago.Many explanations and c... The Cambrian explosion was coined to describe the geologically sudden appearance of numerous bilaterian body plans(Phyla)around the Ediacaran-Cambrian transition,around 565-520million years ago.Many explanations and conjectures have been postulated in order to explain the pattern and duration of this explosive radiation of many different phyla of early metazoans.Here,we focus on the evolution of a phylum of marine suspension-feeding animals—the brachiopods,as exemplified by the exceptionally preserved taxa from the celebrated Chengjiang Konservat Lagerst(a|¨)tte(Yunnan,China).The abundant soft-bodied preservation at these fossil quarries gives us the only firm insights into what brachiopods looked like and how they functioned and lived when they first appeared on the Earth.Studies of Chengjiang brachiopods demonstrate that the early animals developed a remarkably varied organization of tissues and organs shortly after the onset of Cambrian explosion.In the marine suspension-feeding brachiopods,most importantly the tentaculate feeding structure of early brachiopods is already differentiated into two shapes of lophophore,anteriorly coiled(spiralled)and posteriorly arching tentacle crowns and the unique latter type was previously not documented from fossil and living brachiopods.Also unlike any known Recent brachiopod,all the known Cambrian brachiopods from Chengjiang have an open digestive tract that was disposed either as a Ushaped gut in linguliform and stem group brachiopods,or straight gut with a posterior anus in some calcareous-shelled stocks.Moreover,in contrast toliving lingulids,all the Cambrian brachiopods have an epibenthic lifestyle either cemented by a ventral valve or attached by variable pedicles to establish complex ecological community encompassing primary tierers and variable secondary tierers.It is therefore assumed that brachiopods were the first benthic metazoan that achieved their success in ecological stratification and tiering complexity by late Atdabanian.The setae are also important for 展开更多
关键词 Cambrian explosion Chengjiang fauna Metazoans BRACHIOPODS Soft-tissue preservation
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The effect of Shen-Fu on gastrointestinal tract injury and its potential mechanism during cardio-pulmonary bypass in patients undergoing cardiac surgery 被引量:7
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作者 夏中元 詹丽英 +1 位作者 何宇红 刘先义 《Chinese Journal of Traumatology》 CAS 2003年第4期245-248,共4页
Objective: To investigate the effect of Shen-Fu (SF) injection on gastrointestinal tract injury and its potential mechanism.Methods: Thirty-eight patients undergoing elective open heart surgery were assigned to Group ... Objective: To investigate the effect of Shen-Fu (SF) injection on gastrointestinal tract injury and its potential mechanism.Methods: Thirty-eight patients undergoing elective open heart surgery were assigned to Group C (control group, n = 18) and Group SF (n = 20) randomly. In Group SF, the patients received intravenous injection of SF (0.5 ml/kg) at the beginning of the surgery followed by a continuous infusion of 100 ml SF (1.0 ml/kg) solution diluted by saline at a rate of 0.004 ml · Kg-1 · min-1 with a Grasby pump. The control group was injected with normal saline in the same volume. Gastric intramucosal pH (pHi), activity of blood diamine oxidase ( DAO ), and concentrations of blood LPS and IL-6 were measured before CPB ( S0) and 1 h ( S1 ) and 2 h ( S2) after aortic declamping, respectively.Results: In Group C, pHi value was significantly lower at S1 and S2 than at S0 ( mean P <0.01) and blood DAO and concentrations of LPS and IL-6 were significantly higher at S1 and S2 than at S0 ( meanP < 0.01). In Group SF, pHi was obviously lower at S1 and S2 than at S0(P< 0.05) but LPS and IL-6 levels and DAO were higher at S, (mean P<0.05). Blood DAO and LPS level demonstrated significant negative correlations with pHi ( mean P < 0.01) while LPS concentration showed a positive correlation with blood DAO (P < 0.01) and IL-6 concentration (P < 0.05). At S1 and S2 after aortic declamping, the levels of pHi were higher in Group SF than in Group C (mean P <0.01 ) but DAO and LPS and IL-6 levels were significantly lower in Group SF than in Group C ( P <0.01).Conclusions: SF has a protective effect on gastrointestinal tract and can reduce inflammatory actions. 展开更多
关键词 Gastrointestinal tract Wounds and injuries Cardiopulmonary bypass Shen-Fu injection
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The oxygen cycle and a habitable Earth 被引量:11
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作者 Jianping HUANG Xiaoyue LIU +6 位作者 Yongsheng HE Shuzhong SHEN Zengqian HOU Shuguang LI Changyu LI Lijie YAO Jiping HUANG 《Science China Earth Sciences》 SCIE EI CSCD 2021年第4期511-528,共18页
As an important contributor to the habitability of our planet, the oxygen cycle is interconnected with the emergence and evolution of complex life and is also the basis to establish Earth system science. Investigating... As an important contributor to the habitability of our planet, the oxygen cycle is interconnected with the emergence and evolution of complex life and is also the basis to establish Earth system science. Investigating the global oxygen cycle provides valuable information on the evolution of the Earth system, the habitability of our planet in the geologic past, and the future of human life. Numerous investigations have expanded our knowledge of the oxygen cycle in the fields of geology,geochemistry, geobiology, and atmospheric science. However, these studies were conducted separately, which has led to onesided understandings of this critical scientific issue and an incomplete synthesis of the interactions between the different spheres of the Earth system. This review presents a five-sphere coupled model of the Earth system and clarifies the core position of the oxygen cycle in Earth system science. Based on previous research, this review comprehensively summarizes the evolution of the oxygen cycle in geological time, with a special focus on the Great Oxidation Event(GOE) and the mass extinctions, as well as the possible connections between the oxygen content and biological evolution. The possible links between the oxygen cycle and biodiversity in geologic history have profound implications for exploring the habitability of Earth in history and guiding the future of humanity. Since the Anthropocene, anthropogenic activities have gradually steered the Earth system away from its established trajectory and had a powerful impact on the oxygen cycle. The human-induced disturbance of the global oxygen cycle, if not controlled, could greatly reduce the habitability of our planet. 展开更多
关键词 Oxygen cycle Habitable earth Mass extinction ANTHROPOCENE
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Diversity history of Ordovician graptolites and its relationship with environmental change 被引量:8
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作者 Zhang YuanDong Chen Xu 《Science China Earth Sciences》 SCIE EI CAS 2008年第2期161-171,共11页
Statistical analysis based on global data indicated that the planktonic graptolites presented a distinguished pattern from that of benthic communities during the great Ordovician biodiversification. The graptolites st... Statistical analysis based on global data indicated that the planktonic graptolites presented a distinguished pattern from that of benthic communities during the great Ordovician biodiversification. The graptolites started to diversify from the beginning 展开更多
关键词 South China ORDOVICIAN GRAPTOLITE DIVERSITY DEEP-WATER origin SEA-LEVEL change
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Compaction Rate of an Early Permian Volcanic Tuff from Wuda Coalfield, Inner Mongolia 被引量:5
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作者 WANG Jun HE Xuezhi +1 位作者 Hermann W.PFEFFERKORN WANG Jinrong 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2013年第5期1242-1249,共8页
Compaction rates of sediments or volcaniclastic material are needed to reconstruct original thickness of a bed, which in turn is required to reconstruct subsidence rates, sea-level rise, or in the case of volcanielast... Compaction rates of sediments or volcaniclastic material are needed to reconstruct original thickness of a bed, which in turn is required to reconstruct subsidence rates, sea-level rise, or in the case of volcanielastic, the location or direction of the eruption site. The knowledge of compaction rates can also aid in the reconstruction of deformed fossils. The known shape of deformed fossils can allow the determination of the compaction they experienced. Here we report the compaction rate in an early Permian volcanic tuff from Wuda, Inner Mongolia, determined from the deformation of standing tree fern stems of known anatomy. The compaction rate has been found to be 0.56 in this case, indicating that 44% of original thickness remains. 展开更多
关键词 COMPACTION volcanic tuff Early Permian tree trunk Wuda
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Cut-off of body mass index and waist circumference to predict hypertension in Indian adults 被引量:3
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作者 Tanu Midha Vinay Krishna +4 位作者 Bhola Nath Ranjeeta Kumari Yashwant Kumar Rao Umeshwar Pandey Samarjeet Kaur 《World Journal of Clinical Cases》 SCIE 2014年第7期272-278,共7页
AIM: To determine the cut-off values of body mass index(BMI) and waist circumference to predict hypertension in adults in north India.METHODS: A community based cross-sectional study was conducted in 801 subjects in K... AIM: To determine the cut-off values of body mass index(BMI) and waist circumference to predict hypertension in adults in north India.METHODS: A community based cross-sectional study was conducted in 801 subjects in Kanpur, aged 20 years and above, using multistage stratified random sampling technique. A pre-tested structured question-naire was used to elicit the required information from the study participants and the diagnostic criteria for hypertension were taken according to the Seventh Joint National Committee Report on Hypertension(JNC-7). Receiver operating characteristic(ROC) analysis was used to estimate the cut-off values of BMI and waist circumference to predict hypertension.RESULTS: The ROC analysis revealed that BMI is a good predictor of hypertension for both men(area under the ROC curve 0.714) and women(area under the ROC curve 0.821). The cut-off values of BMI for predicting hypertension were identified as ≥ 24.5 kg/m2 in men and ≥ 24.9 kg/m2 in women. Similarly, the ROC analysis for waist circumference showed that it is a good predictor of hypertension both for men(area under the ROC curve 0.784) and women(area under the ROC curve 0.815). The cut-offs for waist circumference for predicting hypertension were estimated as ≥ 83 cm for men and ≥ 78 cm for women. Adults with high BMI or high waist circumference had a higher prevalence of hypertension, respectively.CONCLUSION: Simple anthropometric measurements such as BMI and waist circumference can be used for screening people at increased risk of hypertension in order to refer them for more careful and early diagnostic evaluation. Policies and programs are required for primary and secondary prevention of hypertension. 展开更多
关键词 ANTHROPOMETRIC indices Body mass index WAIST CIRCUMFERENCE Obesity Hypertension ADULTS
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Mechanism of Three Inhibitors of TACE in Blocking the Converting of pro-TNFα into sTNFα
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作者 王震 王茵 +2 位作者 朱孔黎 郭莲军 杨渝珍 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2003年第2期116-120,共5页
The effects of inhibitors of TNFα converting enzyme (TACE) on TNFα secretion were studied to develop an approach to interfere inflammation processes. The HL-60 cell lines were stimulated in vitro with LPS intravenou... The effects of inhibitors of TNFα converting enzyme (TACE) on TNFα secretion were studied to develop an approach to interfere inflammation processes. The HL-60 cell lines were stimulated in vitro with LPS intravenously for different time to establish the cellular model of inflammation and simultaneously induce in vivo inflammation animal model by LPS The cytotoxic effects of soluble TNFa were checked using MTT colorimetric method to determine the rate of cell proliferation. The level of expression of TACE was detected by using RT-PCR, FCM and immuno-histochemical technique respectively. It was found Chinese medicine Reduqing (RDQ) could inhibit the transcription of TNFa mRNA induced by LPS stimulation (P<0. 01, compared with the control). The anti-oligodeoxyribonucleotide (anti-ODN) of TNFα mRNA could inhibit 78. 9 % of TNFα secretion. The mimic peptides of TACE substrates with hydroxamine group showed potency in vivo and in vitro a-gainst converting of pro-TNFα. It was concluded that all the three types of TACE inhibitors can regulate the expression of TACE at different levels and inhibit sTNFα secretion, indicating TACE is a novel target for inflammation therapy. 展开更多
关键词 TNFα converting enzyme tumor necrosis factor-α REDUQING anti-oligodeoxyri-bonucleotide peptide inhibitor
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Tingia unita sp. nov. (Noeggerathiales) with strobilus from the Lower Permian of Wuda, Inner Mongolia, China 被引量:4
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作者 WANG Jun 《Chinese Science Bulletin》 SCIE EI CAS 2006年第21期2624-2633,共10页
A number of specimens recently collected from the Early Permian Shanxi Formation of Wuda, Inner Mongolia demonstrate that the leafy shoot and strobilus of Tingia unita sp. nov. are both sprouting from a common stem, a... A number of specimens recently collected from the Early Permian Shanxi Formation of Wuda, Inner Mongolia demonstrate that the leafy shoot and strobilus of Tingia unita sp. nov. are both sprouting from a common stem, and consequently improve our understanding of the whole plant mor- phology of this enigmatic taxon of the Cathaysian flora. The strobili are cylinder-like, 1.7-2.5 cm in diameter and over 20 cm in length, with a basal stalk 7―8 mm in width and about 7 cm long. Sporophylls are verticillate, with approximately 8-10 in a whorl. On the adaxial side of each sporophyll a sporangium is attached. The strobilus is heterosporous and the microspores are of the Punctatisporites type. Large leaves vary from linear to oblong with entire lateral margins but are slightly lobed at the apex. Small leaves are generally the same as the large leaves but much narrower. The whole plant is probably a small arborescent tree with leafy shoots and strobili forming a crown, rather than a water plant with larger leaves floating on the surface of the water as previously understood. Features of the new species are in favor of the close affinity between Tingia Halle and Noeg- gerathiales, and accordingly the affinity of Noeg- gerathiales to Progymnospermophyta. 展开更多
关键词 瓢叶目 早二叠纪 内蒙古 化石
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The palaeoenvironmental implication of Early-Middle Ordovician acritarch communities from South China 被引量:3
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作者 YAN Kui LI Jun 《Chinese Science Bulletin》 SCIE EI CAS 2010年第10期957-964,共8页
As primary producers,acritarchs that represented the base of the food chain in the Early Paleozoic marine ecosystem formed the marine phytoplankton communities whose distributions might affect those of other faunas.Te... As primary producers,acritarchs that represented the base of the food chain in the Early Paleozoic marine ecosystem formed the marine phytoplankton communities whose distributions might affect those of other faunas.Ten acritarch ecological assemblages with their distributions controlled by the environmental factors were recognized in the Meitan Formation of the Honghuayuan section,Tongzi,Guizhou Province,the Dawan Formation of the Huanghuachang and Daping section,Yichang,Hubei Province,and the Dacao Formation and the Yingpan Formation of the Houping section,Chengkou,Chongqing through cluster and principle component analysis. 展开更多
关键词 疑源类 古环境意义 中奥陶世 海洋生态系统 中国 社区 浮游植物群落 环境因素控制
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Correlation between hypertension and hyperglycemia among young adults in India 被引量:1
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作者 Tanu Midha Vinay Krishna +5 位作者 Rishi Shukla Praveen Katiyar Samarjeet Kaur Dinesh Singh Martolia Umeshwar Pandey Yashwant Kumar Rao 《World Journal of Clinical Cases》 SCIE 2015年第2期171-179,共9页
AIM: To assess the correlation between blood pressure levels and fasting plasma glucose levels among young adults attending Chatrapati Shahuji Maharaj University, Kanpur, India.METHODS: The present study was cross-sec... AIM: To assess the correlation between blood pressure levels and fasting plasma glucose levels among young adults attending Chatrapati Shahuji Maharaj University, Kanpur, India.METHODS: The present study was cross-sectional in nature, conducted among students in the Institute of Paramedical Sciences, Chatrapati Shahuji Maharaj University, Kanpur. Study subjects included 185 young adults. Among them, 94 were males and 91 were females, in the age group 17 to 19 years.RESULTS: Mean age among males was 18.5 ± 1.5 years and among females was 17.9 ± 1.8 years. Of the total 185 study subjects, 61(32.9%) were classified as pre-diabetic and 20(10.8%) as pre-hypertensive. Mean waist circumference, systolic blood pressure and serum high density lipoprotein did not vary significantly between normoglycemic and pre-diabetic subjects. However, the mean diastolic blood pressure of pre-diabetics(82 ± 5 mm Hg) was significantly higher than normoglycemics(79 ± 6 mm Hg). Mean serum cholesterol, serum triglycerides, serum low density lipoprotein(LDL) and serum very low density lipoprotein was also higher among pre-diabetic subjects in comparison to normoglycemic subjects and the difference was statistically significant. Upon multiple linear regression analysis, it was observed that body mass index(BMI)(β = 0.149), diastolic blood pressure(β = 0.375) and serum LDL(β = 0.483) were significantly associated with fasting plasma glucose. Multiple linear regression with diastolic blood pressure as the outcome variable showed that BMI(β = 0.219), fasting blood glucose(β = 0.247) and systolic blood pressure(β = 0.510) were significantly associated.CONCLUSION: A significant prevalence of pre-diabetes and pre-hypertension in young adults is a matter of concern therefore all young adults need to be targeted for screening of diabetes and hypertension and lifestyle modification. 展开更多
关键词 ADOLESCENT HYPERTENSION DIABETES Coprevalence INDIA
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A New Approach to Reconstruct Paleogene Atmospheric Hydrology at High Latitudes 被引量:2
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作者 Qin Leng Hong Yang 《Science Foundation in China》 CAS 2009年第2期46-49,共4页
Reconstruction of ancient atmospheric conditions through the analysis of precipitation patterns is a novel endeavor in the study of paleoclimate. A new approach is now available for a quantitative reconstruction of Pa... Reconstruction of ancient atmospheric conditions through the analysis of precipitation patterns is a novel endeavor in the study of paleoclimate. A new approach is now available for a quantitative reconstruction of Paleogene atmospheric hydrological conditions in High Arctic. It is based on 1) the discovery of exceptionally-preserved Paleogene plant fossils from the Canadian Arctic which yielded in situ labile biomolecules 2) the development of compound-specific hydrogen isotope analysis which can be applied to small amount of plant material and 3) taxon-specific apparent hydrogen isotope fractionation factors obtained from empirical measurement. A new moisture recycling model is established to explain the reconstructed paleohydrologic pattern in the High Arctic during Paleogene. 展开更多
关键词 Paleogene hydrology Arctic air-mass compound-specific hydrogen isotope analysis ex-ceptionally-preserved plant fossils taxon-specifichydrogen fractionation factors
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Comparative Analysis of the Measured and Simulated Performances of a Grid-Connected Photovoltaic Power Plant
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作者 Mourad Benfares Sanae Janati Edrissi +3 位作者 Mohammed Benbrahim Izeddine Zorkani Anouar Jorio Ali Didi Seddik 《Fluid Dynamics & Materials Processing》 EI 2022年第6期1805-1813,共9页
The present study comparing actual data and simulated parameters was carried out using the PVsyst software for a 5.94 KWp grid-connected photovoltaic system,consisting of three types of mono-Si(2.04 KWp),poly-Si(2.04 ... The present study comparing actual data and simulated parameters was carried out using the PVsyst software for a 5.94 KWp grid-connected photovoltaic system,consisting of three types of mono-Si(2.04 KWp),poly-Si(2.04 KWp)and amorphous-Si(1.86 KWp)photovoltaic panels and a weather station.The research is based on data collected for one year(2020)of energy production Simulations were performed using long-term meteorological data generated by NASA and on-site measurement.A comparison of evaluated monthly and annually performance elements has also been considered:Eac,PR,FC.As shown by the results,each photovoltaic technology has certain advantages in different weather conditions.The uncertainties of the PVSyst software used to estimate the output of the photovoltaic installation have also been critically examined. 展开更多
关键词 PV technologies simulation PRODUCTIVITY performance analysis
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Numerical Study of Temperature and Electric Field Effects on the Total Optical Absorption Coefficient in the Presence of Optical Inter-Conduction-Subband Transitions in InGaN/GaN Single Parabolic Quantum Wells
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作者 Redouane En-nadir Haddou El-ghazi +3 位作者 Anouar Jorio Izeddine Zorkani Hassan Abboudi Fath Allah Jabouti 《Fluid Dynamics & Materials Processing》 EI 2022年第5期1253-1261,共9页
In this paper,we theoretically investigate the total optical coefficient(TOAC)considering 1S-2P and 2S-2P conduction subband transitions in a single parabolic quantum well(SPQW)with an on-center hydrogen-like impurity... In this paper,we theoretically investigate the total optical coefficient(TOAC)considering 1S-2P and 2S-2P conduction subband transitions in a single parabolic quantum well(SPQW)with an on-center hydrogen-like impurity.Within the framework of the effective-mass approximation,the Schrödinger equation is solved numerically to obtain the eigenvalues and their corresponding eigenvectors using the finite difference method.The calculations are performed for finite confinement potential height,taking into account the dielectric and effective mass mismatches between GaN and InGaN materials under the considered electric field and temperature effects.The temperature dependence of the effective mass,dielectric constant and band gap energy are obtained accordingly.On the one hand,the results show that a significant shift is produced with the variation of both the temperature and the intensity of the electric field.On the other hand,the absorption spectrum is shifted to lower energies with increasing both electric field strength and temperature.Moreover,its amplitude is enhanced with an increase in the intensity of the electric field,and show a slight drop with increasing temperature for the two optical transitions considered.The results show that such parameters can be used to adjust the optical properties of single parabolic Quantum Well for solar cell applications. 展开更多
关键词 TOAC optical transitions SPQW electric field intensity TEMPERATURE hydrogenic-impurity
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Paleoecology of Oligocarpia gothanii Halle from the Middle Permian of Southeastern Shanxi,North China 被引量:1
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作者 HE Xuezhi WAN Mingli +3 位作者 YAN Mengxiao CHENG Chen WANG Shijun WANG Jun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2015年第4期1063-1075,共13页
Fossil ferns are abundant and diverse in the Permian Cathaysian Flora of Shanxi, North China. Although plants assemblages of the Carboniferous and Permian have been extensively investigated, their palaeoecology and es... Fossil ferns are abundant and diverse in the Permian Cathaysian Flora of Shanxi, North China. Although plants assemblages of the Carboniferous and Permian have been extensively investigated, their palaeoecology and especially the paleoecology of ferns has not been studied in detail. Recent reinvestigation of Oligocarpia gothanii has revealed its growth habit and cloning reproduction strategy, but most previous studies lack integrated sedimentological and taphonomic data. In this study, new materials of O. gothanii have been collected from a floodplain setting in the middle Permian Lower Shihhotse Formation of southeastern Shanxi. These plant fossils were found in a lenticular claystone associated with rooting structures. They are characterized by aphlebia at the base of the penultimate rachis. Sedimentological, taphonomic and morphological analyses were conducted to understand the growth habit and ecology of the fern. The result indicates that the Oligocarpia gothanii had a prostrate, ground cover growth habit, and was dominant in pioneer floras that colonized disturbed floodplains. 展开更多
关键词 PALAEOECOLOGY plant taphonomy middle Permian Oligocarpia gothanii Halle
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Carboniferous-Permian rugose coral Cyathaxonia faunas in China 被引量:1
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作者 WANG XiangDong ZHANG YiQiang LIN Wei 《Science China Earth Sciences》 SCIE EI CAS 2010年第12期1864-1872,共9页
The Cyathaxonia faunas are widely distributed in the Carboniferous and Permian strata in China.The fauna in China contains 12 families and 40 genera,and can be recognized as three episodes from Early Carboniferous to ... The Cyathaxonia faunas are widely distributed in the Carboniferous and Permian strata in China.The fauna in China contains 12 families and 40 genera,and can be recognized as three episodes from Early Carboniferous to the end-Permian in terms of their occurrence and composition:1) Mississippian;2) Pennsylvanian-Early Permian;3) Middle Permian-Late Permian.They were relatively abundant in episodes 1 and 2.A decrease of family Antiphyllidae and an increase of family Hapsiphyllidae can be observed from Early Carboniferous to the end-Permian.Two case studies are given to illustrate the bio-facies of the Cyathaxonia faunas,which are from the Mississippian of Baoshan,West Yunnan and the Mississippian of Chaohu,South Anhui.In both areas,Cyathaxonia faunas occur just below the large dissepimented solitary and compound coral assemblages in a continuous sequence in a single section,which implies that the occurrence of these small,non-dissepimented solitary corals is not strictly related with Gondwanan or Peri-gondwanan cold water environment,but might be controlled by such benthic conditions as deeper,mud-rich,quieter,and darker sedimentary environments. 展开更多
关键词 Cyathaxonia FAUNA CARBONIFEROUS Permian PALEOECOLOGY China GONDWANA
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Posttraumatic Stress Disorder Mediated by Exposure Level in French Civil Firefighters Following a Terrorist Attack: Some Hypotheses towards a Structural Model
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作者 Angelika Wolman Jean-Marie Stève +3 位作者 Marion Samor Evelyne Bouteyre Themistoklis Apostolidis Abdessadek El Ahmadi 《World Journal of Neuroscience》 2020年第3期121-134,共14页
To date, few studies have investigated the impact of organizational factors such as organizational status or the rank of firefighters on the development of posttraumatic stress disorder (PTSD) following a terrorist at... To date, few studies have investigated the impact of organizational factors such as organizational status or the rank of firefighters on the development of posttraumatic stress disorder (PTSD) following a terrorist attack. To fill this gap in the scientific literature, this field study aimed to investigate the consequences of terrorist attacks on firefighters’ psychological health in terms of PTSD. Data were collected in France following two terrorist attacks. PTSD was assessed with the PCL-S (DSM-IV) 3 to 6 months after the events. Confirmatory factor analyses (CFAs) with existing PTSD models were inconclusive, leading us to find a two-factor model via an exploratory factor analysis (EFA). A cluster analysis showed different symptom profiles that were influenced by the exposure level. Elements for a structural model explaining PTSD symptoms are proposed and suggest a central role of the exposure level. Firefighters I/II represented an at-risk sub-population, suggesting that PTSD was mainly experienced among those who performed tasks not common to their occupation. 展开更多
关键词 PTSD Firefighters Terrorist Attack RANK SEM
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Recent Advances on Non-Marine Late Paleozoic Strata and Floras: Outcome of the 16th International Congress on the Carboniferous and Permian
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作者 Wang, Jun Liu, Lujun Pfefferkorn, Herman W. 《Episodes》 SCIE 2008年第3期348-350,共3页
The 16th International Congress on the Carboniferous and Permian (ICCP XVI) orga- nized by the Nanjing Institute of Geology and Palaeontology under the Chinese Acad- emy of Sciences, the Institute of Geology under t... The 16th International Congress on the Carboniferous and Permian (ICCP XVI) orga- nized by the Nanjing Institute of Geology and Palaeontology under the Chinese Acad- emy of Sciences, the Institute of Geology under the Chinese Academy of Geological Sciences, the China University of Geo- sciences and the Nanjing University took place in Nanjing, June 21-24, 2007. More than 150 colleagues from over 20 countries attended the quadrennial conference. 展开更多
关键词 古生代 植物学 石炭纪 二叠纪 项目研究
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Conduction Band-Edge Non-Parabolicity Effects on Impurity States in(In,Ga)N/GaN Cylindrical QWWs
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作者 Haddou El Ghazi Anouar Jorio 《Communications in Theoretical Physics》 SCIE CAS CSCD 2014年第2期253-256,共4页
In this paper, the conduction band-edge non-parabolicity (NP) and the circular cross-section radius effects on hydrogenie shallow-donor impurity ground-state binding energy in zinc-blende (ZB) InGaN/GaN cylindrica... In this paper, the conduction band-edge non-parabolicity (NP) and the circular cross-section radius effects on hydrogenie shallow-donor impurity ground-state binding energy in zinc-blende (ZB) InGaN/GaN cylindrical QWWs are reported. The finite potential barrier between (In,Ga)N web and CaN environment is considered. Two models of the conduction band-edge non-parabolicity are taking into account. The variational approach is used within the framework of single band effective-mass approximation with one-parametric 1S-hydrogenic triaJ wave-function. It is found that NP effect is more pronounced in the wire of radius equal to effective Bohr radius than in large and narrow wires. Moreover, the binding energy peak shifts to narrow wire under NP effect. A good agreement is shown compared to the findings results. 展开更多
关键词 GROUND-STATE cylindrical wire non-parabolicity effect
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