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数字技术赋能农户增收的理论机制与实证检验:基于CRRS 2022农户调查数据

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中国软科学 2024年第7期 69-78页

作者：马翠萍刘文霞方燕中国社会科学院农村发展研究所北京100732 贵州大学西部现代化研究院贵州贵阳550025 浙江财经大学中国政府监管研究院浙江杭州310018

从粮食单产与农业生产效率两方面构建种粮农户增收的理论框架,并借助CRRS 2022年农户调查数据样本,实证检验农业生产中数字技术采用对种粮农户的增收效应。基准回归结果显示:农业生产中数字技术采用显著促进了种粮农户收入增加。分别使... 详细信息

从粮食单产与农业生产效率两方面构建种粮农户增收的理论框架,并借助CRRS 2022年农户调查数据样本,实证检验农业生产中数字技术采用对种粮农户的增收效应。基准回归结果显示:农业生产中数字技术采用显著促进了种粮农户收入增加。分别使用工具变量估计、倾向得分匹配估计和安慰剂检验进行稳健性检验,发现结论依然稳健。作用机制分析表明,农业生产中数字技术通过提高农业机械作业效率、农业机械作业水平,进而提高农业生产效率和粮食单产水平,实现种粮农户增收。进一步研究发现,数字技术采用对种粮农户增收具有异质性。数字技术对那些在村里担任职务、经营规模更大的种粮农户增收效应更明显。未来应通过夯实农业数字发展根基、培育高素质农民队伍等途径推动农业生产数字化转型,促进种粮农户增收。

关键词：共同富裕数字技术农业生产农户收入

推进教育数字化战略行动构建智慧教育发展新生态——以青岛科技大学建设情况为例

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中国现代教育装备 2024年第5期 5-7页

作者：马翠萍青岛科技大学教务处山东青岛266061

随着数字时代的到来,新兴信息技术为高校教育教学提供了新的发展空间。教育随着数字时代的发展、数字技术的进步而变革和发展,开始进入智慧教育阶段。青岛科技大学有效推进智慧教育,更新教育数字化建设理念与目标,实现了高等教育管理的... 详细信息

随着数字时代的到来,新兴信息技术为高校教育教学提供了新的发展空间。教育随着数字时代的发展、数字技术的进步而变革和发展,开始进入智慧教育阶段。青岛科技大学有效推进智慧教育,更新教育数字化建设理念与目标,实现了高等教育管理的转型变革,智慧校园建设初见成效,教育教学成果丰硕,构建了智慧教育新生态。

关键词：数字化智慧教育教育新生态

加入WTO以来中美经贸关系演变下的大豆贸易研究

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世界农业 2024年第5期 69-80页

作者：马翠萍杨水清中国社会科学院农村发展研究所北京100732 中国社会科学院美国研究所北京100020

中美大豆贸易是中美经贸的重要组成部分。自中国加入WTO以来,中美大豆贸易深受中美经贸关系变动影响。中美经贸关系常态化下,中美大豆贸易依存度较高,中国市场对美国大豆出口的重要性和稳定性不断加强。中美经贸摩擦期间,双边大豆贸易... 详细信息

中美大豆贸易是中美经贸的重要组成部分。自中国加入WTO以来,中美大豆贸易深受中美经贸关系变动影响。中美经贸关系常态化下,中美大豆贸易依存度较高,中国市场对美国大豆出口的重要性和稳定性不断加强。中美经贸摩擦期间,双边大豆贸易对中美经贸摩擦紧张程度作出即时反应,一定程度上重塑了世界大豆贸易格局,但中美经贸摩擦并没有改变中美大豆贸易紧密关系。中美经贸关系止跌企稳后,新兴大豆生产国短期内仍无法撼动美国对中国进口大豆贸易的重要地位。长期来看,巴西、阿根廷与美国出口大豆将互补式满足中国大豆需求。据此,中国应维护好与美国、新兴大豆生产国的关系,减少地缘政治风险与基建落户对大豆贸易的影响;积极拓展与“一带一路”沿线国和自贸区国家的伙伴关系,鼓励具有国际经验的大中型企业“走出去”;完善大豆产业政策,引导和调动国内农民大豆种植积极性,增强国内大豆生产能力。

关键词：中美经贸关系经贸摩擦双边大豆贸易应对策略

The Impact of Farmland Transfers on Agricultural Investment in China:A Perspective of Transaction Cost Economics

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China & World Economy 2019年第1期27卷 93-109页

作者： Liangliang Gao Dingqiang Sun cuiping ma Chinese Academy of Social Sciences China College of Economics and management Nanjing Agricultural UniversityChina

There is growing concern that farmland transfers lead to less agricultural investment, which may adversely affect agricultural productivity growth in *** research has primarily focused on the differences between owned cultivated land and rented plots,but little is known about how farmland transfers between relatives,which are popular in rural China,specifically affect agricultural *** this paper,we present a conceptual framework of transaction cost economics to compare different contracting strategies in China's farmland rental *** farmland rental markets in China are immature,land transfer between relatives establishes bilateral governance,which has the advantage of addressing the opportunistic activities of both parties and can ultimately increase investment by *** on data from two waves of household surveys,we empirically examine the impact of bilateral governance on the application of organic fertilizer,an indicator for agricultural *** findings show that apart from economic factors, kinship is important to the functioning of farmland rental markets in rural areas.

关键词： agricultural investment farmland rental market governance structure transaction cost economics

基于紧凑型Nd∶YAG/PPMgLN模组的561 nm基模激光器

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人工晶体学报 2024年第9期53卷 1512-1518页

作者：伍秋林冯新凯陈怀熹陈家颖马翠坪梁万国中国科学院福建物质结构研究所福州350002 中国福建光电信息科学与技术创新实验室(闽都创新实验室) 福州350108 中国科学院大学北京100049 福建农林大学数字经济学院福州350028 福建师范大学光电与信息工程学院福州350117 福建师范大学物理与能源学院福州350117

本文提出了一种非线性晶体的切角方法,通过切去谐振腔中掺氧化镁周期极化铌酸锂(PPMgLN)晶体输出端面的一角,改变输出端面的激光模式分布,从而实现了稳定的561 nm黄光激光的基模输出。利用有限差分本征模法,仿真出各种切角方案输出端面... 详细信息

本文提出了一种非线性晶体的切角方法,通过切去谐振腔中掺氧化镁周期极化铌酸锂(PPMgLN)晶体输出端面的一角,改变输出端面的激光模式分布,从而实现了稳定的561 nm黄光激光的基模输出。利用有限差分本征模法,仿真出各种切角方案输出端面的激光模式分布,讨论其输出基模的原理,并通过实验测出各方案输出功率随泵浦功率的变化曲线。结果表明,当抽运功率为4.8 W时,实现了最高121 mW的基模输出,光-光转换效率为2.6%,中心波长为560.95 nm,半峰全宽为0.92 nm,3 h内波动性小于1.91%。与已报道的实验结果对比,该实验结果具有更小的结构尺寸,为紧凑型基模激光器提供重要参考。

关键词： PPMgLN晶体 561 nm激光器倍频晶体切角基模输出

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光纤端面耦合周期极化铌酸锂(PPLN)薄膜波导器件的研究

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人工晶体学报 2024年第8期53卷 1319-1325页

作者：马翠坪陈家颖陈怀熹梁万国伍秋林冯新凯福建师范大学物理与能源学院福州350117 中国科学院福建物质结构研究所福州350002 中国福建光电信息科学与技术创新实验室福州350108 中国科学院大学北京100049 福建师范大学光电与信息工程学院福州350117 福建农林大学安溪茶学院泉州362406

通过有限元模拟器从理论上分析了在理想光学系统中实现光纤与周期性极化铌酸锂(PPLN)波导之间高效耦合的可行性。仿真模拟了单模保偏光纤和透镜光纤在空间中的发散情况。针对截面尺寸为10μm×10μm、长度为20 mm的PPLN脊形波导,进行了... 详细信息

通过有限元模拟器从理论上分析了在理想光学系统中实现光纤与周期性极化铌酸锂(PPLN)波导之间高效耦合的可行性。仿真模拟了单模保偏光纤和透镜光纤在空间中的发散情况。针对截面尺寸为10μm×10μm、长度为20 mm的PPLN脊形波导,进行了与两种不同光纤的直接端面耦合模拟分析。分析发现,尽管透镜光纤的耦合效率高达95%,但其基模占比却不足5%。鉴于PPLN倍频器件主要依赖于激光的基模进行工作,这使透镜光纤的耦合效率在实际应用中显得相对较低。相比之下,单模保偏光纤的基模占比高达93.8%,显示出更为优越的性能。因此,本文选择了单模保偏光纤与PPLN脊形波导进行封装测试。实验结果表明:当温度为24.8℃,从光纤放大器输出的泵浦功率最大为1.6 W时,计算扣除输入端光纤与波导的耦合损耗后的输入泵浦功率为1.2 W,光纤到波导的耦合效率为75%,略高于当前已知的最高效率72%。1 560 nm基频光的输入功率为1.2 W时,最大输出653 mW的倍频光,光光转换效率达到了54.4%,归一化转换效率为20.2%/(W·cm^(2))。

关键词：光纤周期性极化铌酸锂波导端面耦合耦合效率

Active spatial control of photothermal heating and thermo-actuated convective flow by engineering a plasmonic metasurface with heterodimer lattices

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Photonics Research 2022年第11期10卷 2642-2657页

作者： ZHIMIN JING PEIHANG LI cuiping ma JIAYING WANG ROBERTO CAPUTO ALEXANDER OGOVOROV ARUP NEOGI HONGXING XU ZHIMING WANG Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China Physics Department University of CalabriaRende I-87036Italy Department of Physics and Astronomy and Nanoscale and Quantum Phenomena Institute Ohio UniversityAthensOhio 45701USA School of Physics and Technology Center for Nanoscience and NanotechnologyWuhan UniversityWuhan 430072China Institute for Advanced Study Chengdu UniversityChengdu 610106China

Thermo-plasmonics, using plasmonic structures as heat sources, has been widely used in biomedical and microfluidic applications. However, a metasurface with single-element unit cells, considered as the sole heat source in a unit cell, functions at a fixed wavelength and has limited control over the thermo-plasmonically induced hydrodynamic effects. Plasmonic metasurfaces with metal disk heterodimer lattices can be viewed to possess two heat sources within a unit cell and are therefore designed to photo-actively control thermal distributions and fluid dynamics at the nanoscale. The locations of heat sources can be switched, and the direction of the convective flow in the central region of the unit cell can be reversed by shifting the wavelength of the excitation source without any change in the excitation direction or physical actuation of the structural elements. The temperature and velocity of a fluid are spatiotemporally controlled by the wavelength selectivity and polarization sensitivity of the plasmonic metasurface. Additionally, we investigate the effects of geometric parameters on the surface lattice resonances and their impact on the temperature and fluid velocity of the optofluidic system. Our results demonstrate excellent optical control of these plasmonic metasurface heating and thermal convection performances to design flexible platforms for microfluidics.

关键词： excitation reversed flow

How Did Poverty Reduction in China Contribute to the World? Viewing from the Implementation of the UN MDGs and SDGs

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Chinese Journal of Urban and Environmental Studies 2019年第1期7卷 118-146页

作者： GAO Liangliang ma cuiping ZENG Junxia WANG Bin LI Yue Research Office for Land Economy and Human Resources Rural Development Institute Chinese Academy of Social Sciences Rural Development Institute Chinese Academy of Social Sciences Agricultural Information Institute Chinese Academy of Agricultural Sciences

Countries all over the world are highly concerned about poverty. Both the Millennium Development Goals(MDGs) and Sustainable Development Goals(SDGs) of the United Nations set ending poverty and hunger as their top priority. Whether in its own modernization drive or in the implementation of the United Nations’ MDGs and SDGs, the Chinese Government has always attached great importance to poverty issues, and actively explored measures to reduce *** paper is designed to use relevant statistics to sum up China’s achievements and experience in implementing the MDGs so as to provide a policy basis for poverty reduction in China and beyond. This paper discovers that China’s achievements in poverty reduction involve four aspects:Eliminating hunger ahead of schedule, improving people’s nutritional status, enhancing food security and laying a solid foundation for sustainable agricultural development; China’s experience in poverty reduction includes the following: the government had paid high attention; economic development had served as the key to solve all problems; the development had been guided by planning and guaranteed by policies and regulations; the market mechanism had played its due role; emphasis had been placed on the pilot projects and step-by-step promotion strategy, as well as on development cooperation and experience exchanges. The Chinese Government had formulated specific plans to achieve the poverty reduction targets set in the 2030 Agenda for Sustainable Development. Besides, the Rural Revitalization Strategy proposed by the Chinese Government in 2017 has become the essential strategy to solve the poverty-related issues in China’s development.

关键词： Millennium Development Goals (MDGs) Sustainable Development Goals (SDGs) poverty hunger China’s experience

Purification and Refolding of a Novel β-Agarase from Inclusion Body of E. coli

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Journal of Ocean University of China 2007年第1期6卷 80-84页

作者： ZHANG Li LU Xinzhi HAN Feng ma cuiping YU Wengong marine Drug and Food Institute Ocean University of ChinaQingdao 266003P.R.China

β-agarase AgaB appears to represent a new family of glycoside hydrolase; it is structurally and functionally different from other known agarases. In the present study, AgaB was expressed with a temperature-inducible expression system in E. coli BL21 (DE3) as a fusion protein bearing a C-terminal hexahistidine tag. The protein existed mainly in the form of inclusion body. After being washed and solubilized, AgaB in inclusion body was denatured and purified to electrophoretic purity by immobilized metal affinity chromatography. The purified AgaB was then refolded using a simple pulse dilution method, and the refolded AgaB showed a high specific hydrolysis activity of about 1600 units /mg protein. Forty milligrams of refolded pure protein were obtained from 1L of culture.

关键词： β-agarase inclusion body refolding immobilized metal affinity chromatography