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Ground validation of Fengyun-4A and Global Precipitation Measurement satellite observations over an alpine and canyon basin of the southeastern Tibetan Plateau

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Journal of Mountain Science 2022年第12期19卷 3568-3581页

作者： LONG Yin-ping chen Gong-yan MA Qin-min chen Jun College of Environmental and Resource Science Chengdu University of Information TechnologyChengdu 610225China Linzhi Meteorological Bureau Linzhi 860000China

Satellite-based precipitation observations with high spatiotemporal resolution are essential for studying rainfall-induced natural hazards,especially in alpine and canyon areas of the southeastern Tibetan Plateau,which are prone to such hazards yet sparsely ***,we evaluated precipitation estimated from the Chinese Fengyun-4A meteorological satellite(FY-4A AGRI)versus the Integrated Multi-satellitE Retrievals for GPM(IMERG),by using rain gauge data collected in the Parlung Zangbo Basin from May through September in both 2018 and *** results showed that(1)FY-4A AGRI generated smaller values of RMSE(root mean square error)on hourly to daily scales,and larger correlation coefficients(R-values)and smaller RMSE values for both moderate and heavy rain,indicating its greater accuracy at rainfall estimation,which is most likely due to the denser rain gauge network at a finer temporal scale used when calibrating FY-4A AGRI;(2)Both satellite products underestimated the volume of moderate and heavy rain,with the larger degree of underestimation by FY-4A AGRI,which could lower their performance in flood monitoring and forecasting;(3)Worse performance and greater inconsistency between the two products were observed in high-elevation areas,perhaps because of orographic cloud effects in these mountainous areas;and(4)Both products revealed that the Gangrigabu Range blocked incoming water vapor from the southwest monsoon,with a better representation of the spatial pattern and spatial variability produced by *** improve precipitation estimation,the effects of complex terrain should be explicitly incorporated into the retrieval algorithms,with more gauged observations in a denser network and at a finer temporal scale needed to robustly calibrate the satellite-based estimates.

关键词： Satellite precipitation Evaluation Fengyun satellite IMERG Mountainous area Parlung Zangbo Basin

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Wear and corrosion resistance of laser-cladded Fe-based composite coatings on AISI 4130 steel

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International Journal of Minerals,Metallurgy and Materials 2018年第6期25卷 716-728页

作者： Li Fan Hai-yan chen Yao-hua Dong Li-hua Dong yan-sheng Yin College of Ocean Science and Engineering Shanghai Maritime University Department of Marine Engineering Nantong Shipping College School of Mechanical Engineering Shanghai Jiaotong University

The wear and corrosion resistance of Fe_（72.2）Cr_（16.8）Ni_（7.3）Mo_（1.6）Mn_（0.7）C_（0.2）Si_（1.2） and Fe_（77.3）Cr_（15.8）Ni_（3.9）Mo_（1.1）Mn_（0.5）C_（0.2）Si_（1.2） coatings laser-cladded on AISI 4130 steel were *** coatings possess excellent wear and corrosion resistance despite the absence of expensive yttrium,tungsten,and cobalt and very little *** microstructure mainly consists of dendrites and eutectic phases,such as duplex（γ＋α）-Fe and the Fe–Cr（Ni）solid solution,confirmed via energy dispersive spectrometry and X-ray *** cladded Fe-based coatings have lower coefficients of friction,and narrower and shallower wear tracks than the substrate without the cladding,and the main wear mechanism is mild abrasive *** test results suggest that the soft Fe_（72.2）Cr_（16.8）Ni_（7.3）Mo_（1.6）Mn_（0.7）C_（0.2）Si_（1.2） coating with high Cr and Ni concentrations has high passivation resistance,low corrosion current,and positive corrosion potential,providing a better protective barrier layer to the AISI 4130 steel against corrosion.

关键词： Fe-based coating laser cladding AISI 4130 steel wear resistance corrosion resistance

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Analysis of Key Technologies and Equipments Development of Largescale Melted Extrusion Manufacturing Systems

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Journal of Materials Science & Technology 2003年第Z1期19卷 215-217页

作者： Lei ZHANG Sheng chen Yongnian yan Renji ZHANG Center for Laser Rapid Forming Dept. of Mechanical Engineer Tsinghua University Beijing 100084 China Center for Laser Rapid Forming Dept. of Mechanical Engineer Tsinghua University Beijing 100084 China Center for Laser Rapid Forming Dept. of Mechanical Engineer Tsinghua University Beijing 100084 China Center for Laser Rapid Forming Dept. of Mechanical Engineer Tsinghua University Beijing 100084 China

To develop large-scale RP systems used to producing functional parts and large-sized models has become an urgentcall now. In this paper, a large-scale RP system, MEM600-l, based on the melted extrusion manufacturing (MEM)process has been developed successfully. And the key issues to develop such a system are discussed. Based on theactual forming experiment, it is concluded that the MEM600-l works reliably and the forming efficiency is muchhigher than its parallel equipments.

关键词： Melted extrusion manufacturing, Large-scale RP systems, Forming efficiency

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Nonadiabatic dynamics and geometric phase of an ultrafast rotating electron spin

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Science Bulletin 2019年第6期64卷 380-384页

作者： Xing-yan chen Tongcang Li Zhang-Qi Yin Center for Quantum Information Institute for Interdisciplinary Information Sciences Tsinghua University Max-Planck-Institut für Quantenoptik Fakult?t für Physik Ludwig-Maximilians-Universit?t München Department of Physics and Astronomy Purdue University School of Electrical and Computer Engineering Purdue University Purdue Quantum Center Purdue University Birck Nanotechnology Center Purdue University

The spin in a rotating frame has attracted a lot of attentions recently,as it deeply relates to both fundamental physics such as pseudo-magnetic field and geometric phase,and applications such as gyroscopic ***,previous studies only focused on adiabatic limit,where the rotating frequency is much smaller than the spin *** we propose to use a levitated nano-diamond with a built-in nitrogen-vacancy(NV)center to study the dynamics and the geometric phase of a rotating electron spin without adiabatic *** find that the transition between the spin levels appears when the rotating frequency is comparable to the spin frequency at zero magnetic *** we use Floquet theory to numerically solve the spin energy spectrum,study the spin dynamics and calculate the geometric phase under a finite magnetic field,where the rotating frequency to induce resonant transition could be greatly reduced.

关键词： Nitrogen-vacancy center Nonadiabatic geometric phase Ultrafast rotor Rabi oscillation Optomechanics

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Global research trends and prospects of cellular metabolism in colorectal cancer

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World Journal of Gastrointestinal Oncology 2024年第2期16卷 527-542页

作者： yan-chen Liu Zhi-cheng Gong Chao-Qun Li Peng Teng yan-yan chen Zhao-Hui Huang Wuxi Cancer Institute Affiliated Hospital of Jiangnan UniversityWuxi 214122Jiangsu ProvinceChina Wuxi School of Medicine Jiangnan UniversityWuxi 214122Jiangsu ProvinceChina Wuxi Institute of Integrated Chinese and Western Medicine Affiliated Hospital of Jiangnan UniversityWuxi 214062Jiangsu ProvinceChina

BACKGROUND An increasing number of studies have focused on the role of cellular metabolism in the development of colorectal cancer(CRC).However,no work is currently available to synthesize the field through *** To analyze the development in the field of“glucose metabolism”(GM),“amino acid metabolism”(AM),“lipid metabolism”(LM),and“nucleotide metabolism”(NM)in CRC by *** Articles within the abovementioned areas of GM,AM,LM and NM in CRC,which were published from January 1,1991,to December 31,2022,are retrieved from the Web of Science Core Collection and analyzed by CiteSpace 6.2.R4 and VOSviewer *** The field of LM in CRC presented the largest number of annual publications and the fastest increase in the last decade compared with the other three ***,China and the United States were two of the most prominent contri-butors in these four *** addition,Gang Wang,Wei Jia,Maria Notar-nicola,and Cornelia Ulrich ranked first in publication numbers,while Jing-Yuan Fang,Senji Hirasawa,Wei Jia,and Charles Fuchs were the most cited authors on average in these four fields,respectively.“Gut microbiota”and“epithelial-mesenchymal transition”emerged as the newest burst words in GM,“gut microbiota”was the latest outburst word in AM,“metastasis”,“tumor microenvironment”,“fatty acid metabolism”,and“metabolic reprogramming”were the up-to-date outbreaking words in LM,while“epithelial-mesenchymal transition”and“apoptosis”were the most recently occurring words in *** Research in“cellular metabolism in CRC”is all the rage at the moment,and researchers are particularly interested in exploring the mechanism to explain the metabolic alterations in *** metabolic vulnerability appears to be a promising direction in CRC therapy.

关键词： Cellular metabolism Colorectal cancer Glucose metabolism Amino acid metabolism Lipid metabolism Nucleotide metabolism

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Preparation and Molecular Structure of (SCZ)(TNPG)·2H_2O

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Chinese Journal of Structural Chemistry 2005年第8期24卷 973-979页

作者： chen Hong-yan ZHANG Tong-Lai ZHANG Jian-Guo State Key Laboratory of Prevention and Control of Explosion Disasters and School of Science Beijing Institute of Technology Beijing 100081 China

The （SCZ）（TNPG）.2H2O prepared by mixing semicarbazide （SCZ） and trinitrophloroglucinol （TNPG） was characterized by elemental analysis and IR measurement, and its crystal structure was determined by X-ray single-crystal diffraction analysis. The crystal belongs to triclinic,space group P1, （NH2CONHNH3）^＋（C6H2N3O9）^-·2H2O, Mr = 372.23, a = 0.68853（14）, b =0.93966（19）, c = 1.1925（2） nm, α = 67.48（3）, β = 77.56（3）, γ = 78.93（3）°, V = 0.6908（2） nm^3, Z = 2,Dc = 1.789 g/cm^3, Mr = 373.23, F（000） = 384, S = 0.999 and μ（MoKa） = 0.172 mm^-1. The final R and wR are 0.0394 and 0.1057 for 1724 observed reflections with I 〉 2σ（I）. It is concluded that （SCZ）（TNPG） 2H2O is an ionic compound composed of a cation SCZ^＋, an anion TNPG- and two water molecules. The TNPG anion and SCZ^＋ cation are bonded together by electrostatic attraction and hydrogen bonds, and the compound structure is stable. The thermal decomposition of （SCZ）（TNPG） 2H2O was studied by using TG-DTG and DSC techniques with a heating rate of 10 ℃/min, showing the compound contains one endothermic process of dehydrating stage and two intensive exothermic decomposition stages. The enthalpy of exothermic decomposition reaction is 452.31 kJ/mol.

关键词： semicarbazide trinitrophloroglucinol preparation crystal structure

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Assimilating satellite SST/SSH and in-situ T/S profiles with the Localized Weighted Ensemble Kalman Filter

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Acta Oceanologica Sinica 2022年第2期41卷 26-40页

作者： Meng Shen yan chen Pinqiang Wang Weimin Zhang College of Meteorology and Oceanology National University of Defense TechnologyChangsha 410073China Laboratory of Software Engineering for Complex Systems Changsha 410073China

The Localized Weighted Ensemble Kalman Filter(LWEnKF)is a new nonlinear/non-Gaussian data assimilation(DA)method that can effectively alleviate the filter degradation problem faced by particle filtering,and it has great prospects for applications in geophysical *** terms of operational applications,along-track sea surface height(AT-SSH),swath sea surface temperature(S-SST)and in-situ temperature and salinity(T/S)profiles are assimilated using the LWEnKF in the northern South China Sea(SCS).To adapt to the vertical S-coordinates of the Regional Ocean Modelling System(ROMS),a vertical localization radius function is designed for T/S profiles assimilation using the *** results show that the LWEnKF outperforms the local particle filter(LPF)due to the introduction of the Ensemble Kalman Filter(EnKF)as a proposal density;the RMSEs of SSH and SST from the LWEnKF are comparable to the EnKF,but the RMSEs of T/S profiles reduce significantly by approximately 55%for the T profile and 35%for the S profile(relative to the EnKF).As a result,the LWEnKF makes more reasonable predictions of the internal ocean temperature *** addition,the three-dimensional structures of nonlinear mesoscale eddies are better characterized when using the LWEnKF.

关键词： data assimilation Localized Weighted Ensemble Kalman Filter northern South China Sea sea surface height sea surface temperature temperature and salinity profiles mesoscale eddy

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Effects of aqueous extracts of Aconitum carmichaeli,Rhizoma bolbostemmatis,Phytolacca acinosa,Panax notoginseng and Gekko swinhonis Gūenther on Bel-7402 cells

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World Journal of Gastroenterology 2007年第19期13卷 2743-2746页

作者： Zhu-chen yan Dan chen Xiong-Zhi Wu Guang-Ru Xie Yi Ba Zhao yan Tianjin Medical University Cancer Institute and Hospital Tianjin 300060 China Tianijn Infectious Diseases Hospital Tianjin 300192China

AIM： To investigate the anticancer activity of a chinese medical mixture, WRCP （warming and relieving Cold Phlegm）, on hepatocarcinoma Bel-7402 cells. METHODS： Fingerprints of WRCP, which were composed of aqueous extracts of Aconitum carmichae/i, Rhizoma bolbostemmatis, Phytolacca acinosa, Panax notoginseng and Gekko swinhonis Gdenther, and aconitine, which could be isolated from Aconitum carmichaeli and have the potential toxicity, were identified by high pressure liquid chromatography. Bel-7402 cells were grown in the presence of WRCP, As203 or all-trans-retinoic acid （ATRA）. Cell proliferation and viability were determined by trypan blue stain. Apoptosis and cell cycle of Bel-7402 cells were detected by flow cytometry. Morphologic and ultrastructural variations were determined under optic and electronic microscopy. The secretion of alpha-fetoprotein and albumin was detected by radioimmunoassay. RESULTS： The average quality of aconitine is 1.15：1： 0.10 μg per 7.5 g extracts. WRCP could suppress the proliferation and viability of Bel-7402 cells. The percentage of apoptosis cells and S phase cells increased on WRCP-treated cells. Treated with WRCP, Bel-7402 cells showed ultrastructural features of differentiation. The alpha-fetoprotein secretion decreased while the albumin secretion increased （P 〈 0.001, P 〈 0.001, respectively） markedly in WRCP-treated cells. CONCLUSION： WRCP can affect the proliferation, differentiation and apoptosis of Bel-7402 cells. It can arrest cells in S phase and has strong cytotoxicity to Bel-7402 cells.

关键词： Hepatocarcinoma Chinese herb Proliferation Differentiation Apoptosis L--~totoxicity

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The Tessellation Rule and Properties Programming of Origami Metasheets Built with a Mixture of Rigid and Non-Rigid Square-Twist Patterns

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Engineering 2022年第10期17卷 82-92页

作者： Jiayao Ma Shixi Zang yan chen Zhong You Key Laboratory of Mechanism Theory and Equipment Design of the Ministry of Education Tianjin UniversityTianjin 300350China School of Mechanical Engineering Tianjin UniversityTianjin 300350China Department of Engineering Science University of OxfordOxford OX13PJUK

Metamaterials constructed from origami units of different types and behaviors could potentially offer a broader scope of mechanical properties than those formed from identical unit ***,the geometric design rules and property programming methods for such metamaterials have yet to be extensively *** this paper,we propose a new kind of origami metasheet by incorporating a family of different square-twist *** tessellation rule of these metasheets is established to allow compatible mountain-valley crease assignments and geometric parameters among neighboring *** demonstrate through experiments that the energy,initial peak force,and maximum stiffness of the metasheets can be obtained by a summation of the properties of the constitutional *** on this,we are able to program the mechanical properties of the metasheets over a wide range by varying the types and proportions of the units,as well as their geometric and material ***,for a metasheet with a fixed number of units,all the geometrically compatible tessellations can be folded out of the same pre-creased sheet material by simply changing the mountain-valley assignments,thereby allowing the properties of the metasheet to be re-programmed based on specific *** work could inspire a new class of programmable origami metamaterials for current and future mechanical and other engineering applications.

关键词： Origami metamaterials Metasheets Square-twist pattern Non-periodic tessellation Programmability

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Influence Factors on Photochemical Production of Methyl Iodide in Seawater

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Journal of Ocean University of China 2020年第6期19卷 1353-1361页

作者： chen yan LIU Shanshan yanG Guipeng HE Zhen Key Laboratory of Marine Chemistry Theory and Technology Ministry of EducationCollege of Chemistry and Chemical EngineeringOcean University of ChinaQingdao 266100China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China Institute of Marine Chemistry Ocean University of ChinaQingdao 266100China

Methyl iodide(CH3I)is an important trace greenhouse gas in the atmosphere and an ozone-depleting *** influence of different environmental factors,such as the duration of illumination;the strength of illumination;the concentrations of humic acid,ferric ion(Fe^3+),and iodide ion(I−);and pH,on the photochemical production of CH3I in artificial seawater(ASW)were tested by simulated solar *** addition,yangtze River Estuary waters from inshore to offshore were used to explore the relationship between the photochemical production of CH3I and different sources of dissolved organic matter(DOM)in natural seawater(NSW).The results revealed that higher concentrations of humic acid and I−,as well as higher strengths of illumination and longer illumination durations,promoted the photochemical formation of CH3I in *** addition of Fe^3+accelerated the photochemical production of CH3I,but high concentrations of Fe^3+inhibited the formation of *** on NSW obtained from the yangtze River estuary spiked when concentrations of DOM were high,confirming that DOM plays an important role in facilitating the photochemical production of CH3I within the yangtze River *** photochemical production of CH3I in the seawater was significantly higher under light conditions relative to dark conditions,indicating that illumination accelerated the production of CH3I.

关键词： methyl iodide photochemical production yangtze River Estuary dissolved organic matter

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