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Impacts of agri-food e-commerce on traditional wholesale industry:Evidence from China

Journal of Integrative Agriculture 2024年第4期23卷 1409-1428页

作者： Ruyi Yang Jifang Liu Shanshan Cao Wei Sun fantao kong Institute of Agricultural Information Chinese Academy of Agricultural SciencesBeijing 100081China Institute of Special Animal and Plant Sciences Chinese Academy of Agricultural SciencesChangchun 130112China

Rapidly expanding studies investigate the effects of e-commerce on company operations in the retail market.However,the interaction between agri-food e-commerce(AEC)and the traditional agri-food wholesale industry(AWI)has not received enough attention in the existing literature.Based on the provincial panel data from 2013 to 2020 in China,this paper examines the effect of AEC on AWI,comprising three dimensions:digitalization(DIGITAL),agrifood e-commerce infrastructure and supporting services(AECI),and agri-food e-commerce economy(AECE).First,AWI and AEC are measured using an entropy-based combination of indicators.The results indicate that for China as a whole,AWI has remained practically unchanged,whereas AEC exhibits a significant rising trend.Second,the findings of the fixed-effect regression reveal that DIGITAL and AECE tend to raise AWI,whereas AECI negatively affects AWI.Third,threshold regression results indicate that AECI tends to diminish AWI with three-stage inhibitory intensity,which manifests as a first increase and then a drop in the inhibition degree.These results suggest that with the introduction of e-commerce for agricultural product circulation,digital development will have catfish effects that tend to stimulate the vitality of the conventional wholesale industry and promote technical progress.Furthermore,the traditional wholesale industry benefits financially from e-commerce even while it diverts part of the traditional wholesale circulation for agricultural products.

关键词： agri-food e-commerce traditional wholesale industry panel threshold model dual-channel circulation

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Effect of V and Nb additions on microstructure,properties,and deformability of Ti-45Al-9 (V,Nb,Y) alloy

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China Foundry 2010年第4期7卷 357-361页

作者： Yang Fei kong fantao Chen Yuyong Xiao Shulong School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China Department of Powder Metallurgy. Guangzhou Research Institute of Non-ferrous Metals Guangzhou 510650 China

Ti-45Al-9(V, Nb, Y) alloys with four different x=V/Nb (atomic ratio x = 1, 1.5, 2 and 3.5) have been prepared, and the microstructures, properties and hot deformation behaviors were investigated. SEM, XRD and TEM results showed that Ti-45Al-9(V, Nb, Y) alloys were mainly composed of γ, α 2 , and β phase, and the volume fraction of β phase increased with the increase of the atomic ratio of V/Nb. The alloys were featured with lamellar microstructure with β and γ phases locating at the colony boundaries, and some β precipitates appearing at γ/γ interfaces. It was found that the colony size decreased with the increase of x. The alloys exhibited moderate mechanical properties at room temperature, with a yield strength of over 600 MPa, and fractures showed mainly translamellar character. The alloy with x=3.5 exhibited the best deformability at elevated temperature and that with x=1 had superior oxidation resistance at 800 ℃.

关键词： TiAl 合金微观结构和性质热变丑行为氧化

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Characterization of zirconia-based slurries with different binders for titanium investment casting

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China Foundry 2012年第2期9卷 125-130页

作者： Zhao Ertuan kong fantao Chen Yanfei Chen Ruirun Chen Yuyong National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of Technology Harbin 150001China

The materials and physical properties of primary slurry are crucial to the surface quality of the finished castings,especially for high reactivity titanium alloys.The aim of this study is to investigate the influence of different binders on the physical properties of primary slurry for titanium alloy investment casting.The zirconia-based slurries with different binders were evaluated by comparing the parameters:viscosity,bulk density,plate weight, suspensibility,gel velocity and strength.The results indicate that a higher viscosity of binder leads to a higher viscosity and suspensibility of slurry with the same powder/binder ratio.The retention rate and thickness of primary layer increase with an increase in the viscosity of the slurry,and a higher retention rate is associated with a thicker primary layer.The gel velocity of the slurry is correlated with the gel velocity of the binder.The green strength and the baked strength of the primary layer are determined by the properties of the binder after gel and by the production of the binder after fired,respectively.

关键词： primary slurry binder investment casting titanium alloy

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铸造中熵金属间化合物FeCoNi_(2)Al组织、力学性能及工艺性

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材料工程 2024年第1期52卷 175-182页

作者：高威宗骁孔凡涛张凤祥丁贤飞南海中国航发北京航空材料研究院北京100095 北京航空材料研究院股份有限公司北京100094 北京市先进钛合金精密成型工程技术研究中心北京100095 哈尔滨工业大学材料科学与工程学院哈尔滨150001

为进一步推动中/高熵金属间化合物的工程化应用,以FeCoNi_(2)Al中熵金属间化合物为研究对象,制备了16 kg级大尺寸合金铸锭,细致研究和分析了铸态合金显微组织和力学性能,并采用熔模精密铸造技术浇注了特征结构元件,评价了合金的铸造工... 详细信息

为进一步推动中/高熵金属间化合物的工程化应用,以FeCoNi_(2)Al中熵金属间化合物为研究对象,制备了16 kg级大尺寸合金铸锭,细致研究和分析了铸态合金显微组织和力学性能,并采用熔模精密铸造技术浇注了特征结构元件,评价了合金的铸造工艺性能。结果表明,大尺寸FeCoNi_(2)Al中熵金属间化合物铸锭具有良好的成分均匀性,铸态合金由具有树枝状形貌的B2初生相和枝晶间具有片层结构的L1_(2)+B2相共晶组织构成,室温下铸态合金抗拉强度达1115 MPa,伸长率为4.6%,650℃下合金抗拉强度为434 MPa,伸长率可达14.6%,FeCoNi_(2)Al中熵金属间化合物熔体的流动性低于TC4合金,优于TiAl-4822合金。当特征结构元件壁厚为2 mm时,板状试样出现欠铸且内部存在大量缩松型铸造缺陷,熔体以端部固相质点聚集堵塞为主的方式停止流动。相关研究结果为中/高熵金属间化合物熔模精铸成形工艺优化和工程化应用奠定一定技术基础。

关键词：中/高熵合金金属间化合物熔模精密铸造共晶组织力学性能

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In-situ growth and spectrum characterization of ZnSe nanocrystals in silica gel-glasses

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Chinese Science Bulletin 2004年第7期49卷 747-750页

作者： WANG Minqiang WANG Yunpeng YAO Xi kong fantao ZHANG Liangying ElectronicMaterialsResearchLaboratory(EMRL) KeyLaboratoryofEducationMinistryXi'anJiaotongUniversityXi'an710049China

ZnSe nanocrystals were in-situ grown in silica gel-glasses by using sol-gel process and the reductive thermal treatment. The transparent, homogeneous ZnSe/SiO2 nano-composites with the yellow color were first obtained. We used X-ray diffraction pattern (XRD), UV-VIS optical absorption and Raman scattering to characterize the spectrum proper-ties of ZnSe nanocrystals. The broadening of XRD peaks, the blueshift of interband optical absorption edge and the change of Raman spectrum were observed. From these experimental results, we theoretically calculated the size of ZnSe nanocrystals. The results of XRD, optical absorption and Raman spectra were approximately consistent, with the mean diameter of about 4.6 nm. The discrepancies from dif-ferent methods were discussed.

关键词：二氧化硅凝胶玻璃硒化锌纳米晶体光吸附拉曼散射溶胶-凝胶体参数限制 X-射线衍射半导体

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Effect of yttrium on microstructure and mold filling capacity of a near-α high temperature titanium alloy

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China Foundry 2012年第4期9卷 344-348页

作者： Zhao Ertuan Chen Yuyong kong fantao Zhang Changjiang Xiao Shulong National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China

The addition of rare earth yttrium(Y) can improve the performances of high temperature titanium alloys,such as the tensile ductility,thermal stability and creep property,etc.However,few studies on the effect of Y on the castability of titanium alloys have been carried out,which is significant to fabrication of thin-walled complex titanium castings by investment casting.In this study,the microstructure and mold filling capacity of a Ti-1100 alloy with different Y additions(0,0.1wt.%,0.3wt.%,0.5wt.% and 1.0wt.%) were investigated systematically through investment casting experiments,and the casting experiments were carried out in a centrifugal titanium casting machine.The microstructures of the alloy were observed via the optical microscopy,scanning electron microscopy and transmission electron microscopy.The mold filling capacity was tested by using of a grid pattern and was evaluated by the number of segments completely filled by the cast alloy.The results indicate that the grain size is decreased and the mold filling capacity is improved significantly with increasing the addition of Y from 0 to 1.0wt.%.The average primary grain size of Ti-1100 alloy is reduced from 250 μm to 50 μm and the mold filling capacity is increased from 61.5% to 100%.Considering the potential harmful effect on tensile properties of titanium alloys due to high concentrations of Y,it is suggested that Y addition should be about 0.3wt.%.

关键词：金属材料钛材料钛合金组织结构

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我国蔬菜产业市场运行态势研究

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中国蔬菜 2024年第2期 6-13页

作者：安民曹姗姗孙伟孔汇鑫孔繁涛刘继芳中国农业科学院农业信息研究所北京100081 国家农业科学数据中心北京100081 中国农业科学院农业经济与发展研究所北京100081

近10年来,我国蔬菜种植面积、产量逐年增加,消费需求也明显上升,总供给和总需求基本平衡,市场运行总体比较稳健。蔬菜市场运行具有季节性波动、产地转换等五大特征。2023年,我国蔬菜市场产销两旺,市场价格高位运行,农业农村部重点监测... 详细信息

近10年来,我国蔬菜种植面积、产量逐年增加,消费需求也明显上升,总供给和总需求基本平衡,市场运行总体比较稳健。蔬菜市场运行具有季节性波动、产地转换等五大特征。2023年,我国蔬菜市场产销两旺,市场价格高位运行,农业农村部重点监测的28种蔬菜全国批发价格全年平均是近10年来的最高价;展望2024年,蔬菜总供给和总需求基本平衡,略有结余。蔬菜市场主要面临气候变化、种植意愿、产销衔接等五大风险点。建议今后要进一步强化“菜篮子”建设、蔬菜地产地销、均衡上市、监测预警和政策扶持,努力实现蔬菜产业保供稳价和高质量发展。

关键词：蔬菜产业市场运行价格分析市场预测政策建议

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1998–2020年全国种蛋鸡场统计数据集

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中国科学数据（中英文网络版） 2024年第2期9卷 209-217页

作者：贺霞韩昀孔繁涛孙伟曹姗姗新疆农业大学计算机与信息工程学院乌鲁木齐830052 中国农业科学院农业资源与农业区划研究所北京100081 中国农业科学院特产研究所长春130112 中国农业科学院农业信息研究所北京100081 国家农业科学数据中心北京100081

种蛋鸡场历史统计数据对未来市场调控和促进蛋鸡行业的高质量发展具有重要意义。本数据集利用《中国畜牧兽医年鉴(中国畜牧业年鉴)》,整理收集1998–2020年种蛋鸡场统计数据,借助工具软件Excel对录入数据进行整理、汇总、复核等操作,遵... 详细信息

种蛋鸡场历史统计数据对未来市场调控和促进蛋鸡行业的高质量发展具有重要意义。本数据集利用《中国畜牧兽医年鉴(中国畜牧业年鉴)》,整理收集1998–2020年种蛋鸡场统计数据,借助工具软件Excel对录入数据进行整理、汇总、复核等操作,遵循完整性、一致性等基本原则,对数据进行加工处理和质量检验,并使用SPSS软件对数据进行多元线性回归分析,填补缺失数据,构建了1998–2020年全国种蛋鸡场统计数据集。数据集包含3个数据文件,涉及全国和31个省(自治区、直辖市)的种蛋鸡场、祖代及以上蛋鸡场和父母代蛋鸡场的数量、年末存栏量、出栏量统计数据,共计61条数据信息。本数据集可为种蛋鸡场区域分布、蛋鸡行业形势预测和制定生产规划和产业布局等研究提供数据支撑。

关键词：蛋鸡行业种蛋鸡场年末存栏量出栏量形势预测

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Unadulterated carbon as robust multifunctional electrocatalyst for overall water splitting and oxygen transformation

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Nano Research 2020年第2期13卷 401-411页

作者： fantao kong Yu Qiao Chaoqi Zhang Xiaohong Fan Aiguo kong Yongkui Shan School of Chemistry and Molecular Engineering East China Normal UniversityShanghai 200241China

Developing the highly efficient and durable non-precious metal electrocatalysts by taking advantage of inexpensive and abundant resources is of paramount importance for the widespread application of energy conversion and storage techniques such as fuel cells and metal-air batteries.Herein,the sponge-like unadulterated carbontube-graphene complexes(D/G-CTs-1,000)with multifarious intrinsic defect active sites are fabricated by boric acid-hydrothermal and pyrolysis treatments.The close contact or juncture between open nanotubes and few-layer graphene in D/G-CTs-1,000 constructs the hierarchical networks with plentifuchannels,the larger surface area and outstanding conductivity.As a result,the as-prepared D/G-CTs-1,000 electrocatalyst exhibits an excellent trifunctional electrocatalytic performance for oxygen reduction reaction(ORR),oxygen evolution reactior(OER)and hydrogen evolution reaction(HER).The primary Zn-air batteries and overall water splitting system using D/G-CTs-1,000 as the electrode materials delivers higher power density outperforming the advanced Pt/C-based batteries and the overall watersplitting performance comparable to those using the non-precious metal/carbon-based materials as electrode.This work provides a universal and efficient synthetic strategy to produce the unadulterated carbons with high activity and long-time durability as trifunctional electrocatalysts and promote the widespread applications of metal-free electrocatalysts in sustainable energy conversior technology.

关键词： boric acid-splicing unadulterated carbon electrocatalysis rechargeable Zn-air battery overall water splitting

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Electron Structure of γ/α2 Phase Boundaries in TiAl Based Alloys

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Journal of Materials Science & Technology 2003年第Z1期19卷 85-87页

作者： fantao kong Ziyong CHEN Yuyong CHEN Jing TIAN Yufeng SI School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

The valence electron structure of γ/α2 phase boundaries in lamellar colonies in Ti-47Al-2M (M=Nb, Cr, V) (at. pct) was investigated by empirical electron theory of solid and molecules (EET) and its bond-length-difference (BLD) method. On this basis, the boundary condition of electron movement was employed in the improved Thomas-Fermi-Dirac (TFD) theory to decide the continuity of the electron density of the lamellar colonies interface and it is found that of γ/α2 interface is continuous. Furthermore, it is found that adding alloying elements (including Nb, Cr, and V) can improve the electron density (ρ) of γ/α2 interface, decrease Aρ of γ/α2 interface. With the electron structure analysis together with properties analysis,the effect mechanism of alloying elements (Nb, Cr, V) improving mechanical properties was explained.

关键词： TiAl based alloy, Valence electron structure, Phase boundaries, Site occupancy

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