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Effects of 1-Methylcyclopropene on NO Content,NOS Activity,and H_2O_2 Content in Postharvest Suli Pears

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Agricultural Sciences in China 2011年第5期10卷 797-804页

作者： DONG Yu LIU Li-qin guan Jun-feng Institute of Genetics and Physiology Hebei Academy of Agricultural and Forestry Sciences Shijiazhuang 050051 P.R.China College of Life Science Hebei Normal University Shijiazhuang 050016 P.R.China

Studies were conducted over the effects of 1-methylcycolpropene （1-MCP） treatment on postharvest life of Suli pears （Pyrus bretschneideri Rehd.） stored at room and cold temperatures on nitric oxide （NO）,nitric oxide synthase （NOS） activity,and hydrogen dioxide （H2O2）.Results showed that the 1-MCP treatment had little effect on total soluble solids （TSS） at both room and cold temperatures.1-MCP delayed softening of Suli pear fruits,decreased respiratory rate and H2O2 accumulation,and increased NO and NOS activity at room temperature storage,while the effect of cold temperature storage was relatively *** was a significant positive correlation between NOS activity and NO *** is concluded that 1-MCP had effects on endogenous NO content and accumulation of ***,H2O2 acting as a signaling molecule via regulating NO level affects the ripening and senescence of Suli pears.

关键词： pear 1-MCP NO NOS H2O2

Circulating RNA ZFR promotes hepatocellular carcinoma cell proliferation and epithelial-mesenchymal transition process through miR-624-3p/WEE1 axis

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Hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 52-63页

作者： Li Zhang Sai He hao guan Yao Zhao Di Zhang Department of General Surgery the Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710004China Department of Breast Cancer Shaanxi Provincial Cancer HospitalXi’an 710000China

Background:Hepatocellular carcinoma(HCC),the most common type of primary liver cancer,is the fourth leading cause of cancer-related deaths *** evidence shows that the expression of circulating RNA ZFR(circZFR)is upregulated in HCC ***,the molecular mechanism of circZFR in HCC is ***:Quantitative reverse transcriptase polymerase chain reaction(qRT-PCR)was employed to detect the expression of circZFR,microRNA-624-3p(miR-624-3p)and WEE1 in HCC tissues and *** R assay and actinomycin D treatment assay were used to analyze the characteristics of *** functional analysis,the capacities of colony formation,cell proliferation,cell apoptosis,migration and invasion were assessed by colony formation assay,5-ethynyl-2-deoxyuridine(EdU)assay,flow cytometry assay and transwell *** blot was used to examine the protein levels of WEE1 and epithelial-mesenchymal transition(EMT)-related *** interactions between miR-624-3p and circZFR or WEE1 were validated by dual-luciferase reporter assay and RNA immunoprecipitation(RIP)*** models were established to determine the role of circZFR in ***:circZFR and WEE1 were upregulated,while miR-624-3p expression was reduced in HCC tissues and *** could sponge miR-624-3p,and WEE1 was a downstream gene of *** of circZFR significantly reduced the malignant behaviors of HCC and that co-transfection with miR624-3p inhibitor restored this *** of WEE1 abolished the inhibitory effect of miR624-3p mimic on HCC ***,circZFR acted as a competitive endogenous RNA(ceRNA)to regulate WEE1 expression by targeting ***,in vivo studies have illustrated that circZFR knockdown inhibited tumor ***:circZFR knockdown reduced HCC cell proliferation,migration and invasion and promoted apoptosis by regulating the miR-624-3p/WEE1 axis,suggesting that the circZFR/miR-624-3p/WEE1 axis might

关键词： Hepatocellular carcinoma circZFR miR-624-3p WEE1 Liver cancer

Clarifying effect of welding conditions on microstructure and mechanical properties of friction stir spot-welded DH590 automotive high-strength steel plates

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Journal of Iron and Steel Research International 2021年第2期28卷 232-243页

作者： Ya-peng Zhao Lian-feng Chen Shi-jie Zhu Yu-feng Sun Shao-kang guan School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001HenanChina Henan Key Laboratory of Advanced Magnesium Alloys Zhengzhou UniversityZhengzhou 450001HenanChina Beijing Shougang Co. Ltd.Beijing 100041China

Friction stir spot welding was successfully applied to the 1.2-mm-thick DH590 dual-phase steel plates by using a polycrystalline cubic boron nitride rotating *** welding,the rotation speed ranged from 600 to 1000 r/min and the penetration depth ranged from 0.1 to 0.3 *** the spot joints,the size of the stir zone increased with the increase in rotation speed as well as the penetration depth of the *** with the banded ferrite and martensite structure of the base metal,a mixed microstructure of ferrite and tempered martensite,refined bainite structure and coarse martensite structure were found in the heat-affected zone,thermomechanically affected zone and stir zone of the joints,*** kinds of interfacial shapes were formed between the upper and lower steel plates,and the formation of the bonded interface was dominated mainly by the penetration depth of the rotating tool rather than the rotation *** was revealed that the joints with straight interfaces showed higher shear tensile loads comparing with those with hook-like *** tensile tests showed that the maximum shear tensile load reached about 15.56 kN when the rotation speed and penetration depth were set as 800 r/min and 0.3 mm,*** specimen was fractured through plug failure mode with a total elongation of about 5.6 mm.

关键词： Friction stir spot welding DH590 dual-phase steel Microstructure Joint strength Microhardness

Magnetic reduction of gas back-mixing in bubbling fluidized beds with Geldart-B magnetizable particles

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Particuology 2024年第12期95卷 92-102页

作者： Qiang Zhang Yalong Cao Wankun Liu hao guan Donghui Liu Quanhong Zhu College of Chemical Engineering Qingdao University of Science and TechnologyQingdao266042China

This study investigated the performance of magnetic fields in reducing gas back-mixing in bubbling fluidized beds with Geldart-B magnetizable *** Peclet number(Pe)and axial dispersion coefficient(Da,g)were determined using the one-dimensional dispersion model.A weak magnetic field reduced gas back-mixing to a certain extent,while a moderate field resulted in minimal *** performance of a strong magnetic field varied significantly depending on the operation *** the magnetization-FIRST operation mode,gas back-mixing was significantly *** corresponding Pe and Da,g were calculated as∼76 and∼3.6×10^(−4) m^(2)/s,indicating that the gas flow approached the ideal plug-flow ***,when the magnetization-LAST operation mode was used,the strong magnetic field failed to mitigate gas ***,the performance of magnetic fields in reducing gas back-mixing depended not only on their intensity but also on their application sequence to the gas flow field.

关键词： Magnetized fluidized bed Gas back-mixing Gas residence time distribution Operation mode Axial dispersion coefficient Steady-state tracing method

Influence of sulfuric-acid-bath pretreatment and soaked in sulfuric acid on surface morphology and photocatalytic activity of titania coatings

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Science China(Technological Sciences) 2020年第12期63卷 2657-2663页

作者： guan SuJun hao Liang KASUGA Shota YOSHIDA Hiroyuki CHENG YanLing LU Yun Department of Physics Tokyo University of ScienceTokyo 162-8601Japan College of Mechanical Engineering Tianjin University of Science and TechnologyTianjin 300222China Department of Mechanical Engineering Chiba UniversityChiba 263-8522Japan Chiba Industrial Technology Research Institute Chiba 263-0016Japan Beijing Key Laboratory of Biomass Waste Resource Utilization Beijing Union UniversityBeijing 100023China

Titania(TiO2) photocatalyst coatings have been fabricated by the low-cost approach of sulfuric-acid-bath pretreatment(SAP)followed soaked in sulfuric acid(SA) at room temperature then oxidated in air. The influence of the SAP and soaked conditions on the surface morphology and photocatalytic activity of TiO2 on Ti coatings was investigated. With different SAP conditions,the surface morphologies of the TiO2 on Ti coatings clearly show the formed porous-like structure. With higher SA concentration,the porous-like structure becomes obviously. With extending soaked time,the porous-like structure tends to disappear. Raman spectroscopy reveals that the formed TiO2 coatings are with mixed-phase of anatase and rutile. Compared with those of SA concentration and SAP time,the influence of the soaked time on the phase transformation is obvious. Notably,the photocatalytic activity of TiO2 on Ti coatings had been efficiently enhanced by extending the soaked time,compared with those of higher SA concentration and longer SAP time. The enhanced photocatalytic activity of TiO2 on Ti coatings could be related with the changed surface morphology,mixed-phase of anatase and rutile,and formed hydroxyl groups.

关键词： TiO2 coatings sulfuric-acid-bath pretreatment mixed-phase photocatalytic activity surface morphology

Elliptical model for surface topography prediction in five-axis flank milling

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Chinese Journal of Aeronautics 2020年第4期33卷 1361-1374页

作者： Liping WANG Shuyi GE hao SIa Liwen guan Feiyu DUAN Yuzhe LIU Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China School of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Beijing Institute of Astronautical Systems Engineering Beijing 100076China

In five-axis flank milling operations,the intersecting surfaces of different cutting edges create roughness on the milled surfaces that cannot be ignored in situations with strict requirements,especially in aeronautical *** focus on motion problems in milling operations,this paper presents a new model that utilizes elliptical paths as cutting edge trajectories on 3D surface topography machined by peripheral ***,the cutter parallel axis offset and location angle are considered,which change the location of the ellipse center and intersection point of the cutting ***,through the proposed model,the predicted surface topography is obtained,and the factors that affect the development tendency of roughness are ***,the effects of the cutter location position(CLP)geometric parameters,cutter parallel axis offset and curvature on the roughness are evaluated by a numerical ***,machining tests are carried out to validate the model predictions,and the results show that the surface topography predictions correspond well with the experimental results.

关键词： Cutter runout Elliptical paths Five-axis flank milling Surface topography Workpiece curvature

A Field Study on Effects of Nitrogen Fertilization Modes on Nutrient Uptake,Crop Yield and Soil Biological Properties in Rice-Wheat Rotation System

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Agricultural Sciences in China 2011年第8期10卷 1254-1261页

作者： guan guan TU Shu-xin YANG Jun-cheng ZHANG Jian-feng YANG Li College of Resource and Environment Huazhong Agricultural UniversityWuhan 430070P.R.China Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural SciencesBeijing 100081P.R.China Institute of Plant Protection and Soil Fertilizer Hubei Academy of Agricultural SciencesWuhan 430064P.R.China

Rational application of nitrogen （N） fertilizers is an important measure to raise N fertilizer recovery rate and reduce N loss.A two-year field experiment of rice-wheat rotation was employed to study the effects of N fertilization modes including a N fertilizer reduction and an organic manure replacement on crop yield,nutrient uptake,soil enzyme activity,and number of microbes as well as diversity of *** result showed that 20% reduction of traditional N fertilizer dose of local farmers did not significantly change crop yield,N uptake,soil enzyme activity,and the number of microbes （bacteria,actinomycetes,and fungi）.On the basis of 20% reduction of N fertilizer,50% replacement of N fertilizer by organic manure increased the activity of sucrose,protease,urease,and phosphatase by 46-62,27-89,33-46,and 35-74%,respectively,and the number of microbes,i.e.,bacteria,actinomycetes,and fungi by 36-150,11-153,and 43-56%,***,organic fertilizer replacement had a Shannon＇s diversity index （H） of 2.18,which was higher than that of other modes of single N fertilizer *** results suggested that reducing N fertilizer by 20% and applying organic manure in the experimental areas could effectively lower the production costs and significantly improve soil fertility and biological properties.

关键词： rice-wheat rotation N fertilization mode organic manure replacement soil enzyme activity microbial diversity

Centrifuge and numerical modeling of h-type anti-slide pile reinforced soil-rock mixture slope

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Journal of Mountain Science 2023年第5期20卷 1441-1457页

作者： ZHANG hao XING hao-feng XUE Dao-rui TANNANT Dwayne Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China School of Urban Construction and Transportation Hefei UniversityHefei 230601China School of Engineering University of British ColumbiaKelowna BC V1V 1V7Canada guangdong Communication Planning and Design Institute Group Co. Ltd.Guangzhou 510507China

Due to the loose structure,high porosity and high permeability of soil-rock mixture slope,the slope is unstable and may cause huge economic losses and *** h-type anti-slide pile is regarded as an effective means to prevent the instability of soilrock mixture *** this paper,a centrifuge model test was conducted to investigate the stress distribution of the h-type anti-slide pile and the evolution process of soil arching during the loading.A numerical simulation model was built based on the similar relationship between the centrifuge model and the prototype to investigate the influence factors of the pile spacing,anchored depth,and crossbeam stiffness,and some recommendations were proposed for its *** results show that the bending moment distribution of the rear pile exhibits Wshaped,while for the front pile,its distribution resembles *** soil arching evolution process during loading is gradually dissipated from bottom to top and from far to *** the loading,the change of bending moment can be divided into three stages,namely,the stabilization stage,the slow growth stage,and the rapid growth *** engineering projects,the recommended values of the pile spacing,anchored depth,and crossbeam stiffness are 4.0d,2.0d,and 2.0EI,where d and EI are the diameter and bending stiffness of the h-type anti-slide pile respectively.

关键词： Centrifugemodel test Numerical simulation h-type anti-slide pile Soil-rock mixture slop Soil arching

Formation mechanism of twin domain boundary in 2D materials: The case for WTe2

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Nano Research 2019年第3期12卷 569-573页

作者： guan-Yong Wang Weiyu Xie Dan Xu Hai-Yang Ma hao Yang Hong Lu hao-Hua Sun Yao-Yi Li Shuang Jia Liang Fu Shengbai Zhang Jin-feng Jia Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education) School of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China Department of Physics Applied Physics and Astronomy Rensselaer Polytechnic Institute Troy New York 12180 USA Institute of Chemical Materials China Academy of Engineering Physics (CAEP) P. O. Box 919-327 Mianyang 621900 China International Center for Quantum Materials School of Physics Peking University Beijing 100084 China Department of Physics Massachusetts Institute of Technology Cambridge MA 02139 USA Tsung-Dao Lee Institute Shanghai 200240 China

Our scanning tunneling microscopy (STM) study observes, for the first time, twin domain boundary (TDB) formations on the surface of WTe2 single crystal, which is glued by solidifying indium to Si substrate. In these TDB regions, a large inhomogeneous strain field, especially a critical shear strain of about 7%, is observed by geometric phase analysis. This observation does not obey the old believe that a small mechanical stress is sufficient to drive thermally-induced TDB formations in two-dimensional materials. To resolve the contradiction, we perform density functional theory calculations combined with elasticity theory analysis, which show that TDBs on WTe2 are entirely displacement-induced, for which a critical strain is necessary to overcome the onset barrier.

关键词： twin domain boundary seanning tunneling microscopy (STM) density functional theory strain WTe2