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热作模表面激光熔覆司太立合金粉的工艺研究 被引量:7
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作者 戚克强 《热加工工艺》 CSCD 北大核心 2013年第16期146-148,共3页
采用不同的工艺参数对H13钢热作模表面进行连续CO2激光熔覆Stellite6司太立合金粉处理,并进行了高温表面硬度、高温耐磨性、耐高温腐蚀性和抗热疲劳性的测试与分析。结果表明,表面连续CO2激光熔覆Stellite6司太立合金粉处理,能有效改善... 采用不同的工艺参数对H13钢热作模表面进行连续CO2激光熔覆Stellite6司太立合金粉处理,并进行了高温表面硬度、高温耐磨性、耐高温腐蚀性和抗热疲劳性的测试与分析。结果表明,表面连续CO2激光熔覆Stellite6司太立合金粉处理,能有效改善H13钢热作模的高温表面硬度、高温耐磨性、耐高温腐蚀性和抗热疲劳性,较佳的工艺参数为:激光功率2 kW、光斑形状为圆形、光斑直径3 mm、激光扫描速度250 mm/min、送粉速度11.3 g/min。 展开更多
关键词 作模 连续CO2激光熔覆 司太立合金粉 工艺
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非晶态电刷镀层在热作模具上的应用
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作者 郑明新 朱永华 《中国表面工程》 EI CAS CSCD 1990年第3期8-13,共6页
工业试验结果表明,采用非晶态电刷镀技术,可将热作模具的使用寿命提高33—180%以上。非晶态电刷镀层具有很高的硬度、较低的常温和高温摩擦系数、较好的抗氧化能力,并且能提高表面光洁度,所以可改善模具的摩擦学性能。工作中研究了镀... 工业试验结果表明,采用非晶态电刷镀技术,可将热作模具的使用寿命提高33—180%以上。非晶态电刷镀层具有很高的硬度、较低的常温和高温摩擦系数、较好的抗氧化能力,并且能提高表面光洁度,所以可改善模具的摩擦学性能。工作中研究了镀层的晶化过程和动力学及硬度变化的规律。分析认为,非晶态电刷镀层提高热作模具寿命的主要原因,是工作时瞬时发生晶化和沉淀过程,导致强烈的二次硬化效应,提高模具表层的红硬性,因而保证了模具有高的热磨损抗力。 展开更多
关键词 电刷镀层 晶化 作模 红硬性
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3Cr2W8V钢热作模具强韧化处理研究
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作者 迟仲玉 孙景 王洪礼 《天津大学学报》 EI CAS CSCD 1991年第4期103-108,共6页
对3Cr2W8V钢热作模具的强韧化进行了研究。结果表明,采用1200℃高温渗碳、淬火、660℃高温回火工艺可以较大幅度地提高3Cr2W8V模具的使用寿命。
关键词 作模 3CR2W8V钢 韧化
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提高热作模热疲劳寿命的途径
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作者 尤显卿 《模具科技》 1990年第2期32-37,共6页
关键词 作模 热疲劳寿命 热处理
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三基共性技术在热作模具制造中的应用
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作者 陈国州 《模具制造》 2015年第10期86-88,共3页
介绍了热作模具传统成形或制造的弊端,指出了三基共性技术在热作模具制造中的应用前景,三基共性技术的应用需要政府部门对锻造、热处理等模具厂搭建"三基"创新平台,积极引导与支持,才能将该技术发挥出应用的作用。
关键词 作模 三基共性技术 转型升级 应用
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H-13热作加厚模淬火开裂成因分析
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作者 温新林 王秀梅 +3 位作者 张大庆 温鹏 孙法林 王鸿雁 《金属热处理》 EI CAS CSCD 北大核心 2005年第C00期319-321,共3页
通过对H-13热作加厚模在淬火过程中产生裂纹的原因进行分析,指出了合适的热处理工艺是确保获得最佳的强韧性及热疲劳抗力的关键,也是确保淬火质量的关键,结果表明,在H—13钢淬火过程中操作不当是热作加厚模产生裂纹的主要因素。
关键词 H-13钢 淬火开裂 加厚 应力集中
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家属协同干预在抗磷脂综合征合并妊娠患者中的应用效果
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作者 李伏一 肖兰凤 《中国医药导报》 CAS 2024年第5期160-164,共5页
目的探讨家属协同干预在抗磷脂综合征(APS)合并妊娠患者中的应用效果。方法选择2020年1月至2022年12月内蒙古医科大学附属医院收治的100例APS合并妊娠患者,根据随机数字表法将其分为甲组和乙组,每组50例。甲组予以常规护理,乙组在甲组... 目的探讨家属协同干预在抗磷脂综合征(APS)合并妊娠患者中的应用效果。方法选择2020年1月至2022年12月内蒙古医科大学附属医院收治的100例APS合并妊娠患者,根据随机数字表法将其分为甲组和乙组,每组50例。甲组予以常规护理,乙组在甲组基础上行家属协同干预。观察两组干预前后情绪状态、自我护理能力、服药依从性及妊娠并发症发生情况。结果干预后,两组正性负性情绪量表中正性情绪评分高于干预前,负性情绪评分低于干预前,且乙组正性情绪评分高于甲组,负性情绪评分低于甲组,差异有统计学意义(P<0.05);干预后,两组自我护理能力测定量表及中文版8条目Morisky服药依从性量表评分均高于干预前,且乙组高于甲组,差异有统计学意义(P<0.05)。结论家属协同干预可改善APS妊娠者情绪状态、自我护理能力及用药依从性,并可减少其他妊娠并发症。 展开更多
关键词 抗磷脂综合征 妊娠 家属协同干预 服药依从性 并发症
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Study on the effect of four kinds of raw materials in hypertonic dehydration cell model
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作者 Yuanyuan Gao Qidan Tan +3 位作者 Chencan Cao Haifeng Chen Yuying Jia Lei Liu 《日用化学工业(中英文)》 CAS 北大核心 2024年第10期1218-1226,共9页
It aims to investigate the protective effects of sodium hyaluronate,panthenol,Portulaca oleracea L.and Calendula officinalis L.on hyperosmotic dehydration-induced injury of human immortalized keratinocytes(HaCaT).The ... It aims to investigate the protective effects of sodium hyaluronate,panthenol,Portulaca oleracea L.and Calendula officinalis L.on hyperosmotic dehydration-induced injury of human immortalized keratinocytes(HaCaT).The safety mass concentrations of four raw materials were screened by detecting cell viability,and the secretion of hyaluronic acid(HA)was determined using the ELISA method.The expression of HaCaT barrier function related genes(OVOL1,EREG,TGM1,TGM2,IVL,IRF6,THBS1,CASP14)was detected at the mRNA level to explore the regulatory effect of four raw materials on these genes.The results demonstrate that pretreatment with the four kinds of raw materials could increase the cell viability after hyperosmotic dehydration,promote the secretion of HA,and improve the expression of barrier function related genes after hyperosmotic dehydration,among which panthenol and Calendula officinalis L.are better.The results show that the four raw materials have a certain protective effect on the hyperosmotic dehydration cell model,which provides data support for its application in cosmetics. 展开更多
关键词 hypertonic dehydration cell model protective effect barrier repair efficacy evaluation of cosmetics soothing ingredients
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FEM simulation and experimental verification of temperature field and phase transformation in deep cryogenic treatment 被引量:4
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作者 黎军顽 汤磊磊 +1 位作者 李绍宏 吴晓春 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第10期2421-2430,共10页
Combining with the low temperature material properties and the boiling heat transfer coefficient of specimen immersed in the liquid nitrogen, a numerical model based on metallo-thermo-mechanical couple theory was esta... Combining with the low temperature material properties and the boiling heat transfer coefficient of specimen immersed in the liquid nitrogen, a numerical model based on metallo-thermo-mechanical couple theory was established to reproduce the deep cryogenic treatment (DCT) process of a newly developed cold work die steel Cr8Mo2SiV (SDC99). Moreover, an experimental setup for rapid temperature measurement was designed to validate the simulation results. The investigation suggests that the differences in temperature and cooling rate between the surface and core of specimen are very significant. However, it should be emphasized that the acute temperature and cooling rate changes during DCT are mainly concentrated on the specimen surface region about 1/3 of the sample thickness. Subjected to DCT, the retained austenite of quenched specimen continues to transform to martensite and finally its phase volume fraction reduces to 2.3%. The predicted results are coincident well with the experimental data, which demonstrates that the numerical model employed in this study can accurately capture the variation characteristics of temperature and microstructure fields during DCT and provide a theoretical guidance for making the reasonable DCT procedure. 展开更多
关键词 deep cryogenic treatment boiling heat transfer coefficient finite element method phase transformation cold work tool steel
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INSTRUMENT FOR MEASURING GEOMETRIC ERRORS OF GUIDE RAIL OF ELEVATOR 被引量:2
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作者 杨鑫 张国雄 +1 位作者 汪建新 李真 《Transactions of Tianjin University》 EI CAS 1999年第2期40-44,共5页
A new instrument for checking the quality of elevator guide rails is introduced.With this instrument,the general geometric errors such as straightness,flatness,squareness,twist,thickness and height can be measured aut... A new instrument for checking the quality of elevator guide rails is introduced.With this instrument,the general geometric errors such as straightness,flatness,squareness,twist,thickness and height can be measured automatically,simultaneously in a short time with high accuracy.It is very useful for elevator guide rail factories to improve their work efficiency and the quality of their products. 展开更多
关键词 elevator guide rail geometric error operation module
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ANALYSIS OF WORKING MODES OF HYBRID EXCITATION DOUBLY SALIENT MOTOR 被引量:2
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作者 秦海鸿 赵志英 +1 位作者 龚春英 严仰光 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2006年第4期264-271,共8页
A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machi... A more accurate analysis method on working modes is proposed by considering the winding terminal voltage and the eondueting power device as state parameters. For the three-phase hybrid excitation doubly salient machine (HEDSM) motor and its three-phase full-bridge inverter, in the proposed analytical method, all possible working modes are generally listed. Then, with the H_PWM-L_ON control strategy, the working modes are detailed with eorresponding equivalent circuits. Experimental results verify the robustness of the analysis. 展开更多
关键词 hybrid excitation doubly salient motor working mode COMMUTATION current tail
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Effects of Different Nutrient Management Systems and Cultivation Methods on Crop Yield and Soil Fertility 被引量:6
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作者 刘小玲 贾良良 +3 位作者 韩宝文 李春杰 刘文菊 刘孟朝 《Agricultural Science & Technology》 CAS 2011年第11期1674-1679,共6页
[Objective] The aim was to provide scientific basis for improving the middle and low yielding fields fertility and farmland productivity. [Method] A field experiment was carried out to study the effects of different m... [Objective] The aim was to provide scientific basis for improving the middle and low yielding fields fertility and farmland productivity. [Method] A field experiment was carried out to study the effects of different management practices (including nutrient management systems and cultivation methods) on crop yield and soil fertility in winter wheat/summer maize rotation system. [Result] The crop yield in the treatment of the high yield and high efficiency system was remarkably higher than farmer conventional management practice. After five crop seasons experiment, the contents of soil organic matter for high yield and high efficiency system increased 2.72-3.01 g/kg, and that of soil total nitrogen increased 0.12-0.16 g/kg, the soil Olsen-P increased 5.2 mg/kg and the soil available K (NH4OAC-K) increased about 37.8 mg/kg. [Conclusion] Considering the yield and soil fertility comprehensively, the management system of high yield and high efficiency could effectively increase the crop yield and improve the soil fertility. 展开更多
关键词 Nutrient management Winter wheat-summer maize rotation Soil fertility Tillage and cultivation mode
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SAR Data Assimilation for Crop Biomass Simulation Based on Crop Growth Model 被引量:3
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作者 谭正 刘湘南 +1 位作者 张晓倩 吴伶 《Agricultural Science & Technology》 CAS 2012年第5期1127-1132,共6页
Biomass from SAR data was assimilated into crop growth model to describe relationship between crop biomass and crop growth time to improve estimation accuracy of biomass. In addition, inverse model was established in ... Biomass from SAR data was assimilated into crop growth model to describe relationship between crop biomass and crop growth time to improve estimation accuracy of biomass. In addition, inverse model was established in order to estimate biomass according to relationship between biomass and backscattering coefficients from SAR data. Based on cost function, parameters of growth model were optimized as per conjugate gradient method, minimizing the differences between estimated biomass and inversion values from SAR data. The results indicated that the simulated biomass using the revised growth model with SAR data was consistent with the measured one in time distribution and even higher in accuracy than that without SAR data. Hence, the key parameters of crop growth model could be revised by real-time growth information from SAR data and accuracy of the simulated biomass could be improved accordingly. 展开更多
关键词 Data assimilation BIOMASS SAR Crop growth model
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Large-scale complex physical modeling and precisionanalysis 被引量:6
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作者 吴满生 狄帮让 +4 位作者 魏建新 梁向豪 周翼 刘依谋 孔昭举 《Applied Geophysics》 SCIE CSCD 2014年第2期245-251,255,共8页
Large-scale 3D physical models of complex structures can be used to simulate hydrocarbon exploration areas. The high-fidelity simulation of actual structures poses challenges to model building and quality control. Suc... Large-scale 3D physical models of complex structures can be used to simulate hydrocarbon exploration areas. The high-fidelity simulation of actual structures poses challenges to model building and quality control. Such models can be used to collect wideazimuth, multi-azimuth, and full-azimuth seismic data that can be used to verify various 3D processing and interpretation methods. Faced with nonideal imaging problems owing to the extensive complex surface conditions and subsurface structures in the oil-rich foreland basins of western China, we designed and built the KS physical model based on the complex subsurface structure. This is the largest and most complex 3D physical model built to date. The physical modeling technology advancements mainly involve 1) the model design method, 2) the model casting flow, and 3) data acquisition. A 3D velocity model of the physical model was obtained for the first time, and the model building precision was quantitatively analyzed. The absolute error was less than 3 mm, which satisfies the experimental requirements. The 3D velocity model obtained from 3D measurements of the model layers is the basis for testing various imaging methods. Furthermore, the model is considered a standard in seismic physical modeling technology. 展开更多
关键词 complex structure seismic physical modeling modeling construction ACQUISITION
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Simulating leaf net CO_2 assimilation rate of C_3 & C_4 plants and its response to environmental factors 被引量:1
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作者 张佳华 姚凤梅 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第1期9-12,共5页
Basic structure and algorithm of leaf mechanism photosynthesis model were described in first part of this study based on former researcher results. Then, considering some environmental factors influencing on leaf ph... Basic structure and algorithm of leaf mechanism photosynthesis model were described in first part of this study based on former researcher results. Then, considering some environmental factors influencing on leaf photosynthesis, three numerical sensitivity experiments were carried out. We simulated the sing le leaf net CO2 assimilation, which acts as a function of different light, carbo n dioxide and temperature conditions. The relationships between leaf net photosy nthetic rate of C3 and C4 plant with CO2 concentration intercellular, leaf tempe rature, and photosynthetic active radiation (PAR) were presented, respectively. The results show the numerical experiment may indicate the main characteristic o f plant photosynthesis in C3 and C4 plant, and further can be used to integrate with the regional climate model and act as land surface process scheme, and bett er understand the interaction between vegetation and atmosphere. 展开更多
关键词 Photosynthesis model Net CO2 assimilation rate C3 and C4 plants Num erical simulation
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Modes of Action of Phytochromes in Establishing Different Phototropic Responsiveness of Maize Coleoptiles 被引量:3
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作者 刘玉军 赵南明 《Acta Botanica Sinica》 CSCD 2001年第9期923-928,共6页
Previous studies have examined the effects of red light (R) on phototropism of maize ( Zea mays L. cv. Royaldent Hit 85) coleoptiles. The R effect on time-dependent phototropism (TDP) was further studied by characteri... Previous studies have examined the effects of red light (R) on phototropism of maize ( Zea mays L. cv. Royaldent Hit 85) coleoptiles. The R effect on time-dependent phototropism (TDP) was further studied by characterizing its fluence-response relationship. The results showed the R effect was a low-fluence-response, unlike those on pulse-induced phototropisms that show a very-low-fluence-response mode. A subsequent pulse of far-red light (FR) could reverse the R effect. TDP responsiveness, however, recovered as the following FR was extended, The FR-dependent increase in TDP responsiveness was obtained even coleoptiles were pretreated only with FR. It suggested that TDP responsiveness could also be established in response to a FR signal. The fluence-response relationship for the effect of FR was then investigated. The effect of FR depended on the time of irradiation and required high photon fluences. Because reciprocity was invalid at the higher fluence range, the effect of FR would be a high-irradiance-response mode. Relation between phytochrome action modes and possible multiple pathways for phototropic signal transduction was analyzed based on the experiment results. 展开更多
关键词 far-red light high irradiance response PHOTOTROPISM PHYTOCHROME phytochrome action mode maize coleoptile
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Application of molecular interaction volume model in separation of Pb-Sn-Sb ternary alloy by vacuum distillation 被引量:3
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作者 孔令鑫 杨斌 +4 位作者 徐宝强 李一夫 李亮 刘大春 戴永年 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第8期2408-2415,共8页
Based on the molecular interaction volume model (MIVM), the activities of components of Pb Sn Sb ternary alloy were predicted. The vapo^liquid phase equilibrium of Pb-Sn-Sb alloy system was calculated using the acti... Based on the molecular interaction volume model (MIVM), the activities of components of Pb Sn Sb ternary alloy were predicted. The vapo^liquid phase equilibrium of Pb-Sn-Sb alloy system was calculated using the activity coefficients of Pb Sn-Sb alloy system in the process of vacuum distillation. The calculated results show that the content of Sn in vapor phase increases with the increasing distillation temperature and content of Sn in liquid phase. However, the content of Sn in vapor phase is only 0.45% (mass fraction) while 97% in liquid phase at 1100 ℃, which shows that the separating effect is very well. Experimental investigations on the separation of Pb-Sn-Sb ternary alloy were carried out in the distillation temperature range of 1100-1300 ℃ under vacuum condition. It is found that the Sn content in vapor phase is 0.54% while 97% in liquid phase at 1100 ℃. Finally, the predicted data were compared with the experimental results showing good agreement with each other. 展开更多
关键词 molecular interaction volume model vacuum distillation Pb-Sn-Sb alloy phase equilibrium
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An Effective Approach to Verify the Correctness of Workflow Process Models Based on Petri Net 被引量:1
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作者 姜浩 董逸生 罗军舟 《Journal of Southeast University(English Edition)》 EI CAS 2002年第4期361-366,共6页
Along with the extensive use of workflow, analysis methods to verify the correctness of the workflow are becoming more and more important. In the paper, we exploit the verification method based on Petri net for workfl... Along with the extensive use of workflow, analysis methods to verify the correctness of the workflow are becoming more and more important. In the paper, we exploit the verification method based on Petri net for workflow process models which deals with the verification of workflow and finds the potential errors in the process design. Additionally, an efficient verification algorithm is given. 展开更多
关键词 WORKFLOW process modeling Petri net VERIFICATION
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CoMP-transmission-based energy-efficient scheme selection algorithm for LTE-A systems
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作者 童恩 龚淑蕾 +1 位作者 潘志文 尤肖虎 《Journal of Southeast University(English Edition)》 EI CAS 2015年第3期297-303,共7页
In order to achieve higher system energy efficiency (EE),a new coordinated multipoint (CoMP)-transmission-based scheme selection energy saving (CTSES)algorithm is proposed for downlink homogeneous cellular netwo... In order to achieve higher system energy efficiency (EE),a new coordinated multipoint (CoMP)-transmission-based scheme selection energy saving (CTSES)algorithm is proposed for downlink homogeneous cellular networks.The problem is formulated as an optimization of maximizing system EE,under the constraints of the data rate requirement and the maximum transmit power.The problem is decomposed into power allocation and alternative scheme selection problems.Optimal power allocation is calculated for CoMP-JT (joint transmission)and CoMP-CS (coordinated scheduling) transmissions,and the scheme with higher EE is chosen. Since the optimal problem is a nonlinear fractional optimization problem for both CoMP transmission schemes, the problem is transformed into an equivalent problem using the parametric method. The optimal transmit power and optimal EE are obtained by an iteration algorithm in CoMP-JT and CoMP-CS schemes.Simulation results show that the proposed algorithm offers obvious energy-saving potential and outperforms the fixed CoMP transmission scheme.Under the condition of the same maximum transmit power limit,the empirical regularity of user distribution for scheme choice is presented, and using this regularity, the computational complexity can be reduced. 展开更多
关键词 energy efficiency green radio coordinated multipoint scheme selection nonlinear fractional programming
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The Operation Model of Pig Supply Chain Based on Temporal and Spatial Perspectives
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作者 高阔 甘筱青 《Agricultural Science & Technology》 CAS 2014年第9期1624-1628,共5页
This paper constructed pig supply chain based on theoretical study and practical research, then analyzed the operation model of pig supply chain from tem- poral and spatial perspectives. The results showed that from t... This paper constructed pig supply chain based on theoretical study and practical research, then analyzed the operation model of pig supply chain from tem- poral and spatial perspectives. The results showed that from the spatial perspective, pig supply chain had five models of operation, such as vertical integration pig sup- ply chain, quasi-vertical integration pig supply chain (tightly-knit pig supply chain), semi-tightly pig supply chain, loosely-organized pig supply chain and market-oriented pig supply chain. In contrast, from temporal aspect, pig supply chain experiences the pure market transaction, contract form, cooperatives, vertical integration and hori- zontal integration model of operation; the future pig supply chain model in China might be the longitudinal transverse group alliance pig supply chain, namely, the upper vertical integration or quasi-vertical integration (leading processing enterprise + farmer) and down horizontal integration (leading processing enterprises + logistics company + sales), and it would be a kind of competition among interest groups by division of cooperation. 展开更多
关键词 Pig supply chain Operation model TIME SPACE
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