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我国大豆生产波动动因分析——基于省际面板模型的实证研究 被引量:4
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作者 李维刚 张晓东 +1 位作者 宋继华 孙丹 《农业经济与管理》 北大核心 2023年第2期48-63,共16页
在我国大豆生产波动频繁的情况下,找出影响大豆单产、种植面积的影响因素是实现“提单产、稳面积”的首要举措。研究采用1999~2020年21个省份面板数据,在分析大豆单产、种植面积的变化趋势基础上,根据大豆单产增减趋势,把大豆产区划分... 在我国大豆生产波动频繁的情况下,找出影响大豆单产、种植面积的影响因素是实现“提单产、稳面积”的首要举措。研究采用1999~2020年21个省份面板数据,在分析大豆单产、种植面积的变化趋势基础上,根据大豆单产增减趋势,把大豆产区划分成增产区、减产区和波动区,采用改进的面板数据模型分别对三个产区的大豆单产和种植面积的影响因素进行实证分析。结果表明,机械化收割、产研结合、农药投入、小型拖拉机的投入是影响不同区域大豆单产的显著因素;机械化耕作是提升所有区域种植面积的显著因素,玉米种植面积、化肥投入、农药投入、灌溉条件、科研资金与人员投入、产研结合、机械化收割是影响不同区域大豆种植面积显著因素。根据分析,提出了相应政策建议。 展开更多
关键词 大豆生产 大豆单产 大豆种植面积
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思想品德课教学中开展社会实践活动模式的探析
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作者 王凤琴 《中国科教创新导刊》 2009年第12期51-51,共1页
随着思想品德课教学具有时代性、实践性、思想性。在思想品德课中增加社会实践活动,收集社会实践的模式,符合新课标提出的以德育为核心,以培养创新精神和实践能力为重点,全面推进素质教育,有利于学生的自我发展、自我完善、健全学生人格... 随着思想品德课教学具有时代性、实践性、思想性。在思想品德课中增加社会实践活动,收集社会实践的模式,符合新课标提出的以德育为核心,以培养创新精神和实践能力为重点,全面推进素质教育,有利于学生的自我发展、自我完善、健全学生人格,实现人生价值。 展开更多
关键词 实践活动 学生主体 关注社会 责任意识
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基于切分模板的实时跟踪算法 被引量:1
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作者 徐瑞鑫 刘伟宁 《吉林工学院学报(自然科学版)》 2002年第3期26-29,共4页
相关匹配算法是一种经典的匹配算法 ,通过计算模板图像和待匹配图像的互相关值来确定匹配的程度 ,具有很高的准确性和适应性 ,在目标跟踪中得到了广泛应用。但是相关匹配算法计算耗时过于庞大 ,难以达到实时要求 ,并且当目标在模板中所... 相关匹配算法是一种经典的匹配算法 ,通过计算模板图像和待匹配图像的互相关值来确定匹配的程度 ,具有很高的准确性和适应性 ,在目标跟踪中得到了广泛应用。但是相关匹配算法计算耗时过于庞大 ,难以达到实时要求 ,并且当目标在模板中所占比例很小时 ,很难确定模板的准确位置 ,使得此算法在实时目标跟踪中难以得到应用。文中在相关匹配的基础上提出了一种基于切分模板的实时跟踪算法。匹配的模板被分为几个部分 ,每个部分均有不同的加权值 ,最后的相关匹配度为各部分匹配度的加权和。算法中还设置了一个不是实时更新的加权模板 ,以提高算法的抗干扰能力 ,并采用金字塔搜索算法进行加速。实验结果显示 ,此算法有效地克服了相关匹配算法的缺点 。 展开更多
关键词 切分模析 实时跟踪算法 相关匹配算法 自动目标识别 图像识别 目标跟踪
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模折射率透镜的研制
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作者 鲁平 许承杰 范俊清 《发光学报》 EI CAS CSCD 北大核心 1995年第4期317-320,共4页
本文报道在K7玻璃衬底上制作光波导模折射率透镜的实验结果,包括透镜的设计、制备及性能的测量.
关键词 集成光学 光波导 透镜 模析射率
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Operation optimization of prefabricated light modular radiant heating system:Thermal resistance analysis and numerical study
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作者 LI Yao HU Ru-kun +4 位作者 XIN Li XUE Jie HUANG Fei XIA Jian-wei YANG Xiao-hu 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期1983-1997,共15页
The utilization of prefabricated light modular radiant heating system has demonstrated significant increases in heat transfer efficiency and energy conservation capabilities.Within prefabricated building construction,... The utilization of prefabricated light modular radiant heating system has demonstrated significant increases in heat transfer efficiency and energy conservation capabilities.Within prefabricated building construction,this new heating method presents an opportunity for the development of comprehensive facilities.The parameters for evaluating the effectiveness of such a system are the upper surface layer’s heat flux and temperature.In this paper,thermal resistance analysis calculation based on a simplified model for this unique radiant heating system analysis is presented with the heat transfer mechanism’s evaluation.The results obtained from thermal resistance analysis calculation and numerical simulation indicate that the thermal resistance analysis method is highly accurate with temperature discrepancies ranging from 0.44℃ to−0.44℃ and a heat flux discrepancy of less than 7.54%,which can meet the requirements of practical engineering applications,suggesting a foundation for the prefabricated radiant heating system. 展开更多
关键词 radiant heating system thermal resistance analysis simplified model numerical simulation heat flux temperatur
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复杂山地山前带“两宽一高”井炮—可控震源联合地震采集技术应用实例 被引量:7
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作者 孔德政 刘新文 +2 位作者 吕景峰 周旭 邸江伟 《非常规油气》 2017年第1期8-13,共6页
针对塔里木盆地YZ区块复杂油气藏特征及勘探需求,新实施的三维地震采集项目采用了"两宽一高"地震采集技术,提出了突出小线距的高密度、宽方位三维观测系统优化设计方向,并应用了复杂地表区井炮—可控震源联合激发高效采集施... 针对塔里木盆地YZ区块复杂油气藏特征及勘探需求,新实施的三维地震采集项目采用了"两宽一高"地震采集技术,提出了突出小线距的高密度、宽方位三维观测系统优化设计方向,并应用了复杂地表区井炮—可控震源联合激发高效采集施工设计、巨厚山体区模型约束浅层层析三维表层调查与建模和数字化地震队高效施工辅助方法,确保了"两宽一高"地震采集技术在该区的成功实施。该技术大幅提高了地震采集效率,节约了地震勘探成本,地震资料品质也得到了明显改善,证明了"两宽一高"地震采集技术在复杂地表、复杂构造背景下岩性勘探中的有效性,为类似复杂区"两宽一高"地震采集技术的实施提供了借鉴。 展开更多
关键词 复杂山地山前带 岩性油气藏 “两宽一高”地震采集技术 井炮—可控震源联合激发 型约束浅层层三维表层建 数字化地震
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Word模板的应用
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作者 干雪芳 《软件与光盘》 1999年第10期21-21,共1页
关键词 文字处理软件 WORD 模析 文档 文秘工作
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Numerical Analysis of Steady Smoldering of Biomass Rods
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作者 Zhao Wentao Yu Guangxin +3 位作者 Zhang Yi Wang Youtang Zhou Dan He Fang 《燃烧科学与技术》 CAS 2024年第5期507-519,共13页
Understanding the steady mechanism of biomass smoldering plays a great role in the utilization of smoldering technology.In this study numerical analysis of steady smoldering of biomass rods was performed.A two-dimensi... Understanding the steady mechanism of biomass smoldering plays a great role in the utilization of smoldering technology.In this study numerical analysis of steady smoldering of biomass rods was performed.A two-dimensional(2D)steady model taking into account both char oxidation and pyrolysis was developed on the basis of a calculated propagation velocity according to empirical correlation.The model was validated against the smoldering experiment of biomass rods under natural conditions,and the maximum error was smaller than 31%.Parameter sensitivity analysis found that propagation velocity decreases significantly while oxidation area and pyrolysis zone increase significantly with the increasing diameter of rod fuel. 展开更多
关键词 steady smoldering biomass rod numerical analysis 2D steady model sensitivity analysis
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Cross-section distortion and springback characteristics of double-cavity aluminum profile in force controlled stretch-bending
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作者 Zhi-wen LIU Zi-xuan DONG +2 位作者 Cong-chang XU Jie YI Luo-xing LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS 2024年第8期2476-2490,共15页
3D elastic-plastic FE model for simulating the force controlled stretch-bending process of double-cavity aluminum profile was established using hybrid explicit−implicit solvent method.Considering the computational acc... 3D elastic-plastic FE model for simulating the force controlled stretch-bending process of double-cavity aluminum profile was established using hybrid explicit−implicit solvent method.Considering the computational accuracy and efficiency,the optimal choices of numerical parameters and algorithms in FE modelling were determined.The formation mechanisms of cross-section distortion and springback were revealed.The effects of pre-stretching,post-stretching,friction,and the addition of internal fillers on forming quality were investigated.The results show that the stress state of profile in stretch-bending is uniaxial with only a circumferential stress.The stress distribution along the length direction of profile is non-uniform and the maximum tensile stress is located at a certain distance away from the center of profile.As aluminum profile is gradually attached to bending die,the distribution characteristic of cross-section distortion along the length direction of profile changes from V-shape to W-shape.After unloading the forming tools,cross-section distortion decreases obviously due to the stress relaxation,with a maximum distortion difference of 13%before and after unloading.As pre-stretching and post-stretching forces increase,cross-section distortion increases gradually,while springback first decreases and then remains unchanged.With increasing friction between bending die and profile,cross-section distortion slightly decreases,while springback increases.Cross-section distortion decreases by 83%with adding PVC fillers into the cavities of profile,while springback increases by 192.2%. 展开更多
关键词 hollow aluminum profile force controlled stretch-bending numerical parameters springback analysis approach cross-section distortion springback process parameters
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Failure mode and effect analysis of the risk management of non-integral-dosage drug dispensing in PIVAS
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作者 Kuikui Geng Juan He +3 位作者 Sheng Rong Zhaohu Jia Xiangxiang Zhang Tianlu Shi 《Journal of Chinese Pharmaceutical Sciences》 CAS 2024年第7期597-608,共12页
To mitigate risks associated with the prescription examination,marking,dispensing,checking,and review of non-integral-dosage drugs in Pharmacy Intravenous Admixture Service(PIVAS),we formed a project team.Employing th... To mitigate risks associated with the prescription examination,marking,dispensing,checking,and review of non-integral-dosage drugs in Pharmacy Intravenous Admixture Service(PIVAS),we formed a project team.Employing the failure mode and effect analysis(FMEA)management method,we identified potential risks in four critical steps of the non-integral-dosage drug dispensing process within PIVAS drug management:prescription verification,mixed allocation,and verification.For each step,we assigned scores for severity,incidence,and detectability,subsequently calculating the Risk Priority Number(RPN)to prioritize identified risks.Targeted measures for improvement were developed for steps with the highest RPN values.A total of 31 risk factors were documented in the management of non-integral-dosage drugs,with the dispensing process being particularly vulnerable.Specific measures were devised for eight high RPN risks.Following a 3-month optimization and improvement period,RPN values and incidences of internal differences were significantly reduced.The implemented measures demonstrated effective risk control.Notably,we established a comprehensive conversion system for partial-dose drug dispensing,directly translating into a volume of suction fluid for dispensing personnel based on doctor orders.This eliminated the need for manual secondary calculations,thereby standardizing and automating the dispensing of non-integral-dosage drugs in PIVAS.Simultaneously,our project team conducted a dissolution test on 23 types of drugs with non-integral dosage,revealing that the solvent volume increased for 11 types after dissolution.The dosage conversion for partial dosage was recalibrated based on the volume of the final solution to ensure dosage accuracy.Through the application of failure mode and effect analysis,we systematically managed the risks associated with non-integral-dosage drugs in PIVAS.This approach addressed safety concerns in the dispensing process,reduced errors,and ensured the safe and precise administration of medication to patients. 展开更多
关键词 PIVAS FMEA The non-integral-dosage drugs Risk management Dispensing
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