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Spatiotemporal variation in vegetation net primary productivity and its relationship with meteorological factors in the Tarim River Basin of China from 2001 to 2020 based on the Google Earth Engine

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Journal of Arid Land 2022年第12期14卷 1377-1394页

作者： CHEN Limei Abudureheman HALIKE YAO Kaixuan WEI Qianqian college of Geography and Remote Sensing Sciences Xinjiang UniversityUrumqi 830017China Xinjiang Key Laboratory of Oasis Ecology Xinjiang UniversityUrumqi 830017China Key Laboratory of Smart City and Environment Modelling of Higher Education Institute Xinjiang UniversityUrumqi 830017China

Vegetation growth status is an important indicator of ecological *** Tarim River Basin is located in the inland arid region of Northwest China and has a highly fragile ecological *** the vegetation net primary productivity(NPP)of the Tarim River Basin can provide insights into the vegetation growth variations in the ***,based on the Google Earth Engine(GEE)cloud platform,we studied the spatiotemporal variation of vegetation NPP in the Tarim River Basin(except for the eastern Gobi and Kumutag deserts)from 2001 to 2020 and analyzed the correlations between vegetation NPP and meteorological factors(air temperature and precipitation)using the Sen slope estimation method,coefficient of variation,and rescaled range analysis *** terms of temporal characteristics,vegetation NPP in the Tarim River Basin showed an overall fluctuating upward trend from 2001 to 2020,with the smallest value of 118.99 g C/(m2•a)in 2001 and the largest value of 155.07 g C/(m2•a)in *** the spatial characteristics,vegetation NPP in the Tarim River Basin showed a downward trend from northwest to southeast along the outer edge of the study *** annual average value of vegetation NPP was 133.35 g C/(m2•a),and the area with annual average vegetation NPP values greater than 100.00 g C/(m2•a)was 82,638.75 km2,accounting for 57.76%of the *** future trend of vegetation NPP was dominated by anti-continuity characteristic;the percentage of the area with anti-continuity characteristic was 63.57%.The area with a significant positive correlation between vegetation NPP and air temperature accounted for 53.74%of the regions that passed the significance test,while the area with a significant positive correlation between vegetation NPP and precipitation occupied 98.68%of the regions that passed the significance ***,the effect of precipitation on vegetation NPP was greater than that of air *** results of this study improve the under

关键词： vegetation net primary productivity(NPP) air temperature precipitation Hurst index Google Earth Engine Tarim River Basin

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Seasonal variability of the Kuroshio Current at the PN Section in the East China Sea based on in-situ observation from 1987 to 2010

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Acta Oceanologica Sinica 2015年第5期34卷 12-21页

作者： WEI Yanzhou PEI Yuhua ZHANG Rong-Hua Key Laboratory of Ocean Circulation and Wave Institute of OceanologyChinese Academy of Sciences University of the Chinese Academy of Sciences State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of OceanographyState Oceanic Administration college of Physical and Environmental Oceanography Ocean University of China

As the spatio-temporal variability of the Kuroshio is highly influenced by mesoscale eddies, representing its seasonal variability characteristics requires sufficiently long term observations to reduce the uncertainties. Geostrophic velocity data estimated from hydrographic observation from 1987 to 2010 and the shipboard ADCP velocity data from 1993 to 2008 at the PN Section in the central East China Sea are collected to view the seasonal variability objectively. From both types of observation, it is found that the seasonal climatology mean of the Kuroshio Current exhibits significant difference in three areas, which are located at the Kuroshio Current core and its two flanks in a shallow layer less than 300 m, with the weakest northeast current at the core in autumn, the strongest counter current on the right flank in spring, and the strongest northeast current on the left flank in autumn, respectively. The seasonal variance of the Kuroshio Current also exhibits significant difference on the off- shore side of the Kuroshio, with larger variance in spring and summer while smaller variance in autumn and winter. For the current parallel to the PN Section, the ratio of the seasonal variability component to the intraseasonal variability component is relatively smaller than that for the current perpendicular to the PN Section. Further analyses indicate that the seasonal variability at the PN Section is tightly linked to the upstream and downstream current variability.

关键词： Kuroshio Current seasonal variability East China Sea significance test

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CFD analysis and field observation of tool erosion caused by abrasive waterjet fracturing

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Petroleum Science 2020年第3期17卷 701-711页

作者： Mao Sheng Zhong-Wei Huang Shou-Ceng Tian Yi Zhang Shi-Wang Gao Yun-Peng Jia State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum-BeijingBeijing 102249China college of Petroleum Engineering China University of Petroleum-BeijingBeijing 102249China Petroleum Engineering Research Institute of PetroChina Dagang Oilfield Company Tianjin 300270China

Abrasive waterjet(AWJ)fracturing has become an accepted horizontal multistage stimulation technique due to its flexibility and high efficiency of extensive fracture *** downhole tool failure of AWJ fracturing becomes an issue in the massive hydraulic fracturing because of high velocity and proppant *** paper proposed a 3D computational fluid dynamics(CFD)-based erosion model by considering high-velocity waterjet impact,proppant shear erosion,and specific inner structure of hydra-jet tool *** discrete phase approach was used to track the proppant transport and its concentration *** observation provides strong evidence of erosion patterns and mechanisms obtained from CFD *** results show that the erosion rate has a space dependence in the inner wall of the tool *** severe erosion areas are primarily located at the entries of the *** erosion patterns are found including a‘Rabbit’s ear’erosion at the upper-layer nozzles and a half bottom loop erosion at the lower-layer *** mechanisms attribute to high flow velocity at the entry of nozzles and the inertia force of *** analysis demonstrates that the pumping rate is a primary factor contributing to erosion intensity.

关键词： Hydraulic fracturing Erosion Computational fluid dynamics(CFD) Waterjet

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Biomechanism of resistance to retinal injury in woodpecker’s eyes

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Science China(Life Sciences) 2020年第4期63卷 592-598页

作者： Shan Lu Xingyu Fan Sijian Liu Xiaoyu Liu Lizhen Wang Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education School of Biological Science and Medical EngineeringBeihang UniversityBeijing 100191China Beijing Advanced Innovation Centre for Biomedical Engineering Beihang UniversityBeijing 102402China college of Bioengineering Chongqing UniversityChongqing 400044China

Retinal injury is the most common ocular impairment associated with shaken baby syndrome(SBS), which could lead to vision loss and blindness. However, a woodpecker does not develop retinal hemorrhages or detachment even at a high acceleration of 1,000×g during pecking. To understand the mechanism of retinal injury and its resistance strategy, we put insight into the special ability of the woodpecker to protect the retina against damage under acceleration–deceleration impact. In this study, the structural and mechanical differences on the eyes of the woodpecker and human were analyzed quantitatively based on anatomical observation. We developed finite element eye models of the woodpecker and human to evaluate the dynamic response of the retina to the shaking load obtained from experimental data. Moreover, several structural parameters and mechanical conditions were exchanged between the woodpecker and human to evaluate their effects on retinal injury in SBS. The simulation results indicated that scleral ossification, lack of vitreoretinal attachment, and rotational acceleration–deceleration impact loading in a woodpecker contribute to the resistance to retinal injuries during pecking. The above mentioned special physical structures and mechanical behavior can distribute the high strain in the posterior segment of the woodpecker’s retina, which decrease the risk of retinal injury to SBS.

关键词： shaken baby syndrome woodpecker retinal injury numerical simulations

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Empirical Analysis on Factors Restricting Low-carbon Agricultural Development in Hubei Province

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meteorological and Environmental Research 2014年第5期5卷 36-38页

作者： Li Qi Li Bianlian School college of Earth Sciences Yangtze University School of Management Yangtze University

From the perspective of input into agricultural production, the growth of agricultural production from 1982 to 2010 in Hubei Province was analyzed by using multiple regression method. The results show that the quantity of fertilizer and the total power of machinery used for farming have significantly contributed to agricultural growth in Hubei Province, but they are also main factors restricting low-carbon agricultural development in Hubei Province. Therefore, the key point to develop low-carbon agriculture in Hubei Province currently should be put on how to fertilize rationally, how to innovate the pattern of agricultural production, how to develop agricultural mechanization rationally and so on.

关键词： Low-carbon agriculture Production function Influencing factor Countermeasures China

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Application of Grey Theory to Ionospheric Short-term Forecasting

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Communications and Network 2013年第3期5卷 11-14页

作者： Yao Xiao Zhonghui Gan Yunjiang Liu Man Li Information and Navigation college Air Force Engineering University Xi’an 710077 China

By analysis of historical data of the ionosphere, it is suggested to apply grey theory to ionospheric short-term forecasting, grey range information entropy is defined to determine the optimum grey length of the sample sequence, the prediction model based on residual error is constructed, and the observation data of multiple ionospheric observation stations in China are adopted for test. The prediction result indicates that the average grey range information entropy calculation results reflect the cyclical effects of solar rotation, precision of the forecasting method in high latitudes is higher than low latitudes, and its error is large relatively in more intense solar activity season, the effect of forecasting 1 day in advance of average relative residuals are less than 1 MHz, the average precision is more than 90%. It provides a new way of thinking for the ionospheric foF2 short-term forecast in the future.

关键词： Ionosphere Short-term Forecasting Grey Theory

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Single-Crystalline Organoiridium Complex for Gas-Triggered Chromogenic Switches and Its Applications on CO Detection and Reversible Scavenging

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Chinese Journal of Chemistry 2019年第8期37卷 763-768页

作者： Li-Ying Sun Yuan-Yuan An Li-Li Ma Ying-Feng Han Key Laboratory of Synthetic and Natural Functional Molecule Chemistry College of Chemistry and Materials ScienceNorthwest UniversityXi'anShaaxi 710127China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002China

Summary of main observation and conclusion Nonporous molecular single crystals of coordinatively unsaturated 16-electron metallacycle are found to undergo highly selective-yet reversible-binding of CO over CH4,H2,N2,CO2,various volatile organic compounds and water,through binding of the molecule to its metal *** monoxide is taken up by black crystals and subsequently liberated from the corresponding orange CO adduct by reversible metal coordination,the structural evidence obtained from in situ X-ray *** single-crystallinity of the metallacycle is retained even after several *** material,when adsorbed on silica,shows remarkable sensitivity and selectivity for CO,allowing visual CO sensing in the solid *** metallacycle offer the possibility of serving as readily regenerable scavenger for removing trace CO from gas mixtures with N2.

关键词： Gas-Triggered Chromogenic Switches Applications CO Detection Reversible Scavenging

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observation by Fluorescent Histochemical Technique and Estimation of Catecholamine Content in Cerebral Cortex following Experimental Cerebral Infarction

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Journal of Medical colleges of PLA 1988年第1期 37-40页

作者：李明杰陈志敏郑建仲 Department of Neurology Second Affiliated Hospital First Medical college of PLA Guangzhou

Fluorescent histochemical observation and estimation of the content ofcatecholamine(CA)in cerebral cortex of twenty rats with unilateral occlusion ofmiddle cerebral artery were performed in this present *** d after localcerebral infarction,the CA granules which were of different fluorescent featurefrom those of normal cortex were seen in the marginal area of infarct. The contentof norepinephrine in bilateral cortexes was significantly reduced, but that ofdopamine was unchanged.

关键词： catecholamine norepinephrine dopamine cerebral infarction cerebral cortex rat

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observation of oxygen evolution over a {Ni12}-cluster-based metal-organic framework

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Science China Chemistry 2022年第6期65卷 1088-1093页

作者： Zongsu Han Zheng Yan Kunyu Wang Xinchen Kang Kai Lv Xiaoping Zhang Zhen Zhou Sihai Yang Wei Shi Peng Cheng Department of Chemistry Key Laboratory of Advanced Energy Materials Chemistry(MOE)Renewable Energy Conversion and Storage Center(RECAST)College of ChemistryNankai UniversityTianjin300071China college of Biological Chemical Sciences and EngineeringJiaxing UniversityJiaxing314001China Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of ColloidInterface and Chemical ThermodynamicsCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing100190China Department of Chemistry University of ManchesterManchesterM139PLUK School of Materials Science and Engineering Institute of New Energy Material ChemistryNankai UniversityTianjin300350China

The development of efficient electrocatalysts based on non-noble metals for oxygen evolution reaction(OER) remains an important and challenging task. Multinuclear transition-metal clusters with high structural stability are promising OER catalysts but their catalytic role is poorly understood. Here we report the crystallographic observation of OER activity over robust {Ni12}-clusters immobilised in a porous metal-organic framework, NKU-100, by single-crystal X-ray diffraction as a function of external applied potential. We observed the aggregation of confined oxygen species around the {Ni12}-cluster as a function of applied potential during the electrocatalytic process. The refined occupancy of these oxygen species shows a strong correlation with the variation of current density. This study demonstrates that the enrichment of oxygen species in the secondary coordination sphere of multinuclear transition-metal clusters can promote the OER activity.

关键词： metal-organic framework oxygen evolution reaction secondary coordination sphere X-ray diffraction binding site

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Microscopic observation and Stability Study on the Fe_3s_4 Nanocrystals Synthesizedunder Thermal and Humid Conditions

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矿物学报 2013年第S1期33卷 26-26页

作者： GAO Shang HUANG Fei SONG Dan LI Guanglu LIU Jia GAO Wenyuan LIU Qiang FENG Taiwei ZHAO Ran college of Resources and Civil Engineering Northeastern University

Fe3S4 is important magnetic mineral that widely exists in the sediments of lakes and oceans. It can not only instruct reducing environment that contains organic matter and sulfate, but also provide paleomagnetic signal for paleoenvironmet research. Simultaneously, as a new type of magnetic material, it causes attention. Because Fe3S4 generally exists as an unstable intermediate, it is stringent in preparation conditions. Although some scholars have conducted on the synthesis experiments of Fe3S4 materials, the research on its stable conditions, formation mechanism and evolution process is not yet depth. Accordingly, defining the stable conditions and revealing evolution law of Fe3S4 nanocrystals have important significance for the determination of environmental conditions and the preparation of pure Fe3S4 nanomaterials.

关键词： microscopic observation stability Fe3S4 thermal and humid conditions

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