76 research outputs found

    Effect of pore structure on slippage effect in unsaturated tight formation using pore network model

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    ACKNOWLEDGMENTS We acknowledge the Beijing Natural Science Foundation of China (No. 2204093), Science Foundation of China University of Petroleum, Beijing (No.2462018YJRC033) and financial support from China Scholarship Council ((No. 201906440134)Peer reviewedPostprin

    IDENTIFICATION AND QUANTIFICATION OF PINE NEEDLE ESSENTIAL OIL FROM DIFFERENT HABITATS AND SPECIES OF CHINA BY GC-MS AND GC METHOD

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    Background: Fresh pine needles, which evergreen, renewable and can be collected at any time, have abundant essential oil. The pine needle essential oil possess various biological activities, including antimicrobial, antioxidant, anti-inflammatory, cardioprotective properties etc., and can be widely used as medicine or medical raw materials, fragrances etc. So in order to make full use of pine needle plant resources, especially essential oil, the identification and quantification of essential oil were investigated. Materials and Methods: GC-MS was used to identified compounds in pine needle essential oil of Pinus massoniana Lamb. from Zhejiang, and GC method was developed for determining 5 compounds (namely α-pinene, β-pinene, limonene, bornyl acetate, β-caryophyllene) in pine needle essential oil from different habitats of Pinus massoniana Lamb. and different species (Pinus koraiensis Sieb. et Zucc., Pinus sylvestris var. mongolica Litv., Abies holophylla Maxim.). Hierarchical clustering analysis (HCA) was used to evaluate homogeneity of pine needles in China. Results: 42 compounds(monoterpenes and sesquiterpenes) were identified by GC-MS, which accounted for 99.62% of total essential oil, particularly contained α-and β-pinene (45.23%). Quantification results showed content of bornyl acetate were the lowest, while content of α-pinene, β-pinene were all high except Sichuan, among them α-pinene were higher than β-pinene except for Shandong and Jiangsu, and total content of essential oil in Guangxi is the highest, Jiangsu was the lowest within Pinus massoniana from different habitats. Within pine needle from different species, the highest total content was Pinus koraiensis, the lowest was Pinus sylvestris, Interestingly, the highest content of bornyl acetate was Abies holophylla. By HCA, samples were sorted into two clusters, Abies holophylla and the other, that is Abies holophylla is different from Pinus massoniana, Pinus koraiensis and Pinus sylvestris. Pinus massoniana from Sichuan is different from other Pinus, in which limonene was the highest in all samples. Conclusions: Compounds of pine needle essential oil vary greatly between genus, while smaller between species, so composition differences among pine needle essential oil was related with genus and species. Abies holophylla is different from other pinus species, and Pinus massoniana from Sichuan is different from other habitats. Pine needle essential oil contains abundant α-and β-pinene, which can be used as an alternative raw materials source of pinene. And Abies holophylla and Pinus massoniana from Sichuan can become bornyl acetate and limonene alternative source of raw materials

    Transformation of animal utilization strategies from the late Neolithic to the Han Dynasty in the Hexi Corridor, northwest China: Zooarchaeological and stable isotopic evidence

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    The trajectory and influencing factors for changes to ancient human livelihoods in the Hexi Corridor of northwest China have been intensively discussed. The Hexi Corridor is a key crossroads for trans-Eurasian exchange in both the prehistoric and historical periods. Although most studies have focused on the reconstruction of human paleodiet and plant subsistence, the diachronic change of animal utilization strategies spanning the prehistoric and historical periods remains unclear, due to the absence of zooarchaeological and isotopic studies, especially in Han Dynasty (202 BCE–220 CE). Here we report new zooarchaeological, stable isotope, and radiocarbon dating data from the Heishuiguo Cemetery of the Han Dynasty in the Hexi Corridor, indicating that humans mainly used domestic chickens, pigs and sheep as funerary objects, with other buried livestock including cattle, horses and dogs. Stable carbon and nitrogen isotope data suggest humans might have fed chickens, pigs and dogs more C4 foods (likely millets or their byproducts) than herbivorous livestock in the Heishuiguo during the Han Dynasty. Compared to other prehistoric zooarchaeological and isotopic studies in the Hexi Corridor, we detected an increasing significance of herbivorous livestock in animal utilization strategies compared with omnivorous livestock, and a basic declining weight of C4 foods in fodders from ∼2,300 to 200 BCE, which was probably induced by long-distance exchange and climate fluctuation. However, the trend was reversed during the Han Dynasty in the Hexi Corridor, primarily due to the control of the area by the Han Empire and the subsequent massive immigration from the Yellow River valley of north China

    Examining the generalizability of research findings from archival data

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    This initiative examined systematically the extent to which a large set of archival research findings generalizes across contexts. We repeated the key analyses for 29 original strategic management effects in the same context (direct reproduction) as well as in 52 novel time periods and geographies; 45% of the reproductions returned results matching the original reports together with 55% of tests in different spans of years and 40% of tests in novel geographies. Some original findings were associated with multiple new tests. Reproducibility was the best predictor of generalizability—for the findings that proved directly reproducible, 84% emerged in other available time periods and 57% emerged in other geographies. Overall, only limited empirical evidence emerged for context sensitivity. In a forecasting survey, independent scientists were able to anticipate which effects would find support in tests in new samples

    THE INVESTMENT VALUE OF CONSUMER EXPERIENCES: EVIDENCE FROM U.S. AIRLINE INDUSTRY

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    Master'sMASTER OF SCIENCE (BUSINESS

    Carbon Mitigation in the Operation of Chinese Residential Buildings: An Empirical Analysis at the Provincial Scale

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    The rapidly growing carbon emissions of residential building operations have become an obstacle to China’s commitment to achieving its carbon-neutral goals by 2060, but they also demonstrate great carbon mitigation potential. To help buildings reach carbon neutrality targets, this study decomposes the drivers of carbon emissions and evaluates the changes in carbon mitigation of residential buildings across 30 Chinese provinces from 2000 to 2018. The results indicate that (1) the operational carbon intensity increased in most provinces and the average annual growth rate across the 30 provinces was 4.2%; (2) from 2001 to 2018, North China and Northeast China had the highest average annual carbon mitigation intensity, at 602.7 and 376.9 kg of carbon dioxide per household, respectively. However, Northwest China had the highest carbon mitigation efficiency, with a carbon mitigation rate of 23.5%; and (3) in most cases, the total carbon mitigations of the operational residential buildings assessed at the provincial scale higher than those assessed nationwide, with a difference of 14.4 million tons of carbon dioxide on average. In addition, this study reviewed the energy efficiency codes for residential buildings and summarized effective energy efficiency measures. Overall, this study fills a gap in our understanding of carbon mitigation tools and provides a reference for the evaluation of historical carbon mitigation effects in the operation of residential buildings

    Distinct functions of TIR1 and AFB1 receptors in auxin signalling.

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    Auxin is the major plant hormone regulating growth and development (Friml, 2022). Forward genetic approaches in the model plant Arabidopsis thaliana have identified major components of auxin signalling and established the canonical mechanism mediating transcriptional and thus developmental reprogramming. In this textbook view, TRANSPORT INHIBITOR RESPONSE 1 (TIR1)/AUXIN-SIGNALING F-BOX (AFBs) are auxin receptors, which act as F-box subunits determining the substrate specificity of the Skp1-Cullin1-F box protein (SCF) type E3 ubiquitin ligase complex. Auxin acts as a “molecular glue” increasing the affinity between TIR1/AFBs and the Aux/IAA repressors. Subsequently, Aux/IAAs are ubiquitinated and degraded, thus releasing auxin transcription factors from their repression making them free to mediate transcription of auxin response genes (Yu et al., 2022). Nonetheless, accumulating evidence suggests existence of rapid, non-transcriptional responses downstream of TIR1/AFBs such as auxin-induced cytosolic calcium (Ca2+) transients, plasma membrane depolarization and apoplast alkalinisation, all converging on the process of root growth inhibition and root gravitropism (Li et al., 2022). Particularly, these rapid responses are mostly contributed by predominantly cytosolic AFB1, while the long-term growth responses are mediated by mainly nuclear TIR1 and AFB2-AFB5 (Li et al., 2021; Prigge et al., 2020; Serre et al., 2021). How AFB1 conducts auxin-triggered rapid responses and how it is different from TIR1 and AFB2-AFB5 remains elusive. Here, we compare the roles of TIR1 and AFB1 in transcriptional and rapid responses by modulating their subcellular localization in Arabidopsis and by testing their ability to mediate transcriptional responses when part of the minimal auxin circuit reconstituted in yeast
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