1,208 research outputs found

    Climate and soil moisture content during development ofthe frst palaeosol in the southern Loess Plateau

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    The scientific problems concerning Quaternary soil water content and the water cycle have not been researched. This study examined the soil water content and depth of distribution of gravitational water in the south Loess Plateau during development of the first palaeosol layer (S1) by methods such as field investigation, electron microscopy, energy spectrum analysis, chemical analysis, and so on. The purpose was to reveal the climate, water balance and vegetation type at the time when S1 developed. The depth of migration of CaCO3 and Sr were 4.2 m below the upper boundary of the S1 palaeosol, and the depth of weathered loess beneath the argillic horizon was 4.0 m. Ferri‐argillans developed well in the argillic horizon and their depth of migration was 1 m below the argillic horizon. These findings suggest that the climate during the last interglacial was subtropical and humid, and the soil‐water balance was positive. Gravitational water was present to a depth of least 4.2 m from the top of S1, and the water content was adequate for tree growth. The chemical weathering index showed that this palaeosol has been moderately weathered

    Effect of annealing on the performance of CrO3/ZnO light emitting diodes

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    Heterojunction CrO3/ZnO light emitting diodes have been fabricated. Their performance was investigated for different annealing temperature for ZnO nanorods. Annealing in oxygen atmosphere had significant influence on carrier concentration in the nanorods, as well as on the emission spectra of the nanorods. Surprisingly, annealing conditions, which yield the lowest band edge-to-defect emission ratio in the photoluminescence spectra, result in the highest band edge-to-defect emission ratio in the electroluminescence spectra. The influence of the native defects on ZnO light emitting diode performance is discussed. © 2009 American Institute of Physics.published_or_final_versio

    Molecular cloning and transcriptional activity of a new Petunia calreticulin gene involved in pistil transmitting tract maturation, progamic phase, and double fertilization

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    Calreticulin (CRT) is a highly conserved and ubiquitously expressed Ca2+-binding protein in multicellular eukaryotes. As an endoplasmic reticulum-resident protein, CRT plays a key role in many cellular processes including Ca2+ storage and release, protein synthesis, and molecular chaperoning in both animals and plants. CRT has long been suggested to play a role in plant sexual reproduction. To begin to address this possibility, we cloned and characterized the full-length cDNA of a new CRT gene (PhCRT) from Petunia. The deduced amino acid sequence of PhCRT shares homology with other known plant CRTs, and phylogenetic analysis indicates that the PhCRT cDNA clone belongs to the CRT1/CRT2 subclass. Northern blot analysis and fluorescent in situ hybridization were used to assess PhCRT gene expression in different parts of the pistil before pollination, during subsequent stages of the progamic phase, and at fertilization. The highest level of PhCRT mRNA was detected in the stigma–style part of the unpollinated pistil 1 day before anthesis and during the early stage of the progamic phase, when pollen is germinated and tubes outgrow on the stigma. In the ovary, PhCRT mRNA was most abundant after pollination and reached maximum at the late stage of the progamic phase, when pollen tubes grow into the ovules and fertilization occurs. PhCRT mRNA transcripts were seen to accumulate predominantly in transmitting tract cells of maturing and receptive stigma, in germinated pollen/growing tubes, and at the micropylar region of the ovule, where the female gametophyte is located. From these results, we suggest that PhCRT gene expression is up-regulated during secretory activity of the pistil transmitting tract cells, pollen germination and outgrowth of the tubes, and then during gamete fusion and early embryogenesis

    A review of physical supply and EROI of fossil fuels in China

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    This paper reviews China’s future fossil fuel supply from the perspectives of physical output and net energy output. Comprehensive analyses of physical output of fossil fuels suggest that China’s total oil production will likely reach its peak, at about 230 Mt/year (or 9.6 EJ/year), in 2018; its total gas production will peak at around 350 Bcm/year (or 13.6 EJ/year) in 2040, while coal production will peak at about 4400 Mt/year (or 91.9 EJ/year) around 2020 or so. In terms of the forecast production of these fuels, there are significant differences among current studies. These differences can be mainly explained by different ultimately recoverable resources assumptions, the nature of the models used, and differences in the historical production data. Due to the future constraints on fossil fuels production, a large gap is projected to grow between domestic supply and demand, which will need to be met by increasing imports. Net energy analyses show that both coal and oil and gas production show a steady declining trend of EROI (energy return on investment) due to the depletion of shallow-buried coal resources and conventional oil and gas resources, which is generally consistent with the approaching peaks of physical production of fossil fuels. The peaks of fossil fuels production, coupled with the decline in EROI ratios, are likely to challenge the sustainable development of Chinese society unless new abundant energy resources with high EROI values can be found

    Analysis of financing mode selection for Gang-Zhu-Au Bridge

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    2009-2010 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Treatment Approaches, Risk Factors, and Perinatal Outcomes in Pregnancy Complicated by Nephrolithiasis: A Single-Center Retrospective Study

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    Xian Chen,* Rui-Lan Ni,* Bing-Qing Lv Department of Gynecology and Obstetrics, Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, Fujian, 350000, People’s Republic of China*These authors contributed equally to this workCorrespondence: Bing-Qing Lv, Department of Gynecology and Obstetrics, Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, No. 18 Daoshan Road, Gulou District, Fuzhou, Fujian, 350000, People’s Republic of China, Tel +86 18950330039, Email [email protected]: Nephrolithiasis is a common non-obstetric cause of abdominal pain during pregnancy. This study aimed to investigate various treatment approaches for nephrolithiasis during pregnancy, identify the associated risk factors, and evaluate perinatal outcomes.Methods: A retrospective analysis was conducted on the clinical treatment of 208 patients diagnosed with nephrolithiasis during pregnancy, admitted to Fujian Maternal and Child Health Hospital, China, between January 2020 and December 2023. Data on maternal demographic characteristics were extracted to analyze the risk factors associated with nephrolithiasis in pregnancy and to explore correlations with specific treatment modalities through Chi-squared test, Fisher’s exact probability method, and univariate logistic regression analysis.Results: The study included 208 patients, of whom 130 were managed with observation, 46 patients received symptomatic treatment with appropriate medications, and 32 patients underwent surgical intervention, specifically ureteral stent placement. Statistical analysis identified that the timing of symptom onset, presence of clinical symptoms, dilatation of ureter, location of dilation, stone size, and abnormalities in routine urine tests were significant risk factors influencing treatment modalities for nephrolithiasis in pregnancy. A statistically significant difference was observed in treatment modalities among patients with nephrolithiasis complicated by hypertensive disorders. In contrast, patients with combined hyperglycemic disorders exhibited no statistically significant difference among the different treatment modalities.Conclusion: Effective and timely management of nephrolithiasis in pregnancy, guided by patient-specific clinical characteristics, is essential for optimizing maternal and perinatal outcomes.Keywords: abnormal routine urine test, perinatal outcomes, pregnancy complicated by nephrolithiasis, risk factors, treatment modalitie

    Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

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    The decay channel ψπ+πJ/ψ(J/ψγppˉ)\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) is studied using a sample of 1.06×1081.06\times 10^8 ψ\psi^\prime events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the ppˉp\bar{p} invariant mass spectrum. The enhancement can be fit with an SS-wave Breit-Wigner resonance function with a resulting peak mass of M=186113+6(stat)26+7(syst)MeV/c2M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2 and a narrow width that is Γ<38MeV/c2\Gamma<38 {\rm MeV/}c^2 at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics

    Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. VI. Evidence for the Long-lived Nonsteady Warp of Nongravitational Scenarios

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    By combining LAMOST DR4 and Gaia DR2 common red clump stars with age and proper motion, we analyze the amplitude evolution of the stellar warp independently of any assumption with a simple model. The greatest height of the warp disk increases with galactocentric distance in different populations and is dependent on age: The younger stellar populations exhibit stronger warp features than the old ones, accompanied by the warp amplitude (age) decreasing with age, and its first derivative g (age) is different from zero. The azimuth of the line of nodes fw is stable at-5 without clear time evolution, which perfectly confirms some previous works. All of this selfconsistent evidence supports that our Galactic warp should most likely be a long-lived but nonsteady structure and not a transient one, which is supporting that the warp originated from gas infall onto the disk or other hypotheses that suppose that the warp mainly affects the gas, and consequently, younger populations tracing the gas are stronger than older ones. In other words, the Galactic warp is induced by the nongravitational interaction over the disk models
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