检索结果-南通市图书馆

数字经济是否有利于提升制造业出口技术复杂度?

在线全文

学校读者我要写书评

暂无评论

兰州财经大学学报 2024年第1期40卷 43-54页

作者：邓小华费丹安徽大学经济学院安徽合肥230601

数字经济已成为中国制造业价值创造和价值增值的新引擎,为提升中国制造业出口竞争力提供了新机遇。基于2005—2020年中国省际面板数据,以成本节约、人力资本、技术创新为中介机制,知识产权保护为门槛变量,研究数字经济是否对制造业出口... 详细信息

数字经济已成为中国制造业价值创造和价值增值的新引擎,为提升中国制造业出口竞争力提供了新机遇。基于2005—2020年中国省际面板数据,以成本节约、人力资本、技术创新为中介机制,知识产权保护为门槛变量,研究数字经济是否对制造业出口技术复杂度具有提升作用。研究发现:数字经济可以显著促进制造业出口技术复杂度提升;中介效应检验表明成本节约、人力资本、技术创新均可以在数字经济提升制造业出口技术复杂度过程中发挥部分中介效应;进一步分析说明数字经济在跨过知识产权保护门槛后,对制造业出口技术复杂度提升作用有边际递增效应。

关键词：数字经济制造业出口技术复杂度中介效应门槛效应

数字经济发展对安徽省制造业转型升级影响研究

在线全文

学校读者我要写书评

暂无评论

青岛大学学报（自然科学版） 2024年第1期37卷 116-122页

作者：邓小华袁晨露安徽大学经济学院合肥230601

为探究数字化转型如何推动制造业高质量发展,基于2011—2021年安徽省16地市面板数据,采用熵值法测度各地市数字经济发展水平,运用中介效应和面板门槛模型考察作用机制。研究结果显示,数字经济通过提升地区产业高级化和合理化促进制造业... 详细信息

为探究数字化转型如何推动制造业高质量发展,基于2011—2021年安徽省16地市面板数据,采用熵值法测度各地市数字经济发展水平,运用中介效应和面板门槛模型考察作用机制。研究结果显示,数字经济通过提升地区产业高级化和合理化促进制造业转型升级;科技创新发展水平在数字经济促进产业结构升级中起重要中介作用;经济高质量发展地区数字经济影响制造业转型升级效果更加显著,呈现边际效应递增的非线性特征。

关键词：数字经济制造业转型产业高级化产业合理化科技创新

L^p-L^q Estimates for a Class of Pseudo-Differential Equations and Their Applications

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2011年第7期27卷 1435-1448页

作者： Qing Quan deng xiao hua YAO Department of Mathematics Huazhong Normal University Wuhan 430079 P. R. China

This paper is concerned with the L^p-L^q estimates of the solutions for a class of pseudodifferential equations under some suitable degenerate assumptions. As applications, these estimates can be used to show that a generalized Schroedinger operator with some integrable potential generates a fractionally integrated group in L^p（R^n）.

关键词： Pseudo-differential equation,L^p-L^q estimate integrated group

Anomalous Resistivity Associated with Secondary Islands in the Reconnection Region

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第8期29卷 309-312页

作者： ZHOU Meng SU Wei deng xiao-hua YAO Ming Institute of Space Science and Technology Nanchang UniversityNanchang 330031 State Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190 School of Electronic and Information Wuhan UniversityWuhan 430072

We calculate the anomalous resistivity(AR)due to electrostatic waves,including possibly the lower hybrid wave and electron beam mode,around the secondary islands in the reconnection region observed by the Cluster *** main findings are:AR is important on the reconnection separatrix layer but heavily suppressed at the central current sheet where B_(x)~***,there is a highly asymmetric pattern of AR across the island along the outflow direction,with much larger AR on one side of island than on the other *** results may be helpful in understanding the role of AR in reconnection.

关键词： island reconnection Resistivity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

东天山小热泉子铜锌矿床伴生硒富集机制

地球科学与环境学报 2024年第3期46卷 384-399页

作者：陈浩男邓小华何西恒阿卜力米提·艾白长安大学地球科学与资源学院陕西西安710054 中国科学院新疆生态与地理研究所新疆矿产资源研究中心新疆乌鲁木齐830011

小热泉子矿床位于东天山大南湖—头苏泉岛弧带西段,是赋存于石炭纪火山-沉积建造中的火山块状硫化物(VMS)矿床。小热泉子矿床伴生硒等关键金属,但硒赋存状态及富集机制研究较为薄弱,制约了硒的综合利用。在矿床地质特征研究基础上,对不... 详细信息

小热泉子矿床位于东天山大南湖—头苏泉岛弧带西段,是赋存于石炭纪火山-沉积建造中的火山块状硫化物(VMS)矿床。小热泉子矿床伴生硒等关键金属,但硒赋存状态及富集机制研究较为薄弱,制约了硒的综合利用。在矿床地质特征研究基础上,对不同成矿期次的矿石中硫化物开展全自动综合矿物分析、电子探针成分分析,探索小热泉子矿床中硒赋存状态和富集机制。结果表明:小热泉子矿床中硒主要呈硒独立矿物硒方铅矿或赋存于硫化物的晶格中。硒方铅矿呈半自形—他形产出,粒径多小于30μm,包裹于喷流沉积期和热液叠加期的黄铜矿中,其Se含量(质量分数,下同)为20.25%~23.87%,平均值为22.15%,S含量为1.11%~2.61%,平均值为1.92%,Pb含量为72.49%~76.57%,平均值为74.51%,平均化学式为Pb(Se_(0.78)S_(0.17)),S/Se值为0.087。不同期次黄铁矿、黄铜矿、闪锌矿等硫化物中的Se含量分别为0.07%、0.15%和0.29%,S/Se平均值分别为716、222和110。其中,喷流沉积期硫化物的Se平均含量为0.20%,S/Se平均值为212,热液叠加期硫化物的Se平均含量为0.05%,S/Se平均值为938,显示Se含量具有下降趋势。结合前人流体包裹体研究结果,小热泉子矿床中硒富集机制归因于较高温、较高氧逸度的岩浆流体环境,硒富集伴随成矿系统温度和氧逸度的降低而减弱。

关键词：关键金属硒火山块状硫化物矿床铜锌矿赋存状态富集机制东天山

Observation of a Sharp Negative Dipolarization Front in the Reconnection Outflow Region

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第10期28卷 288-291页

作者： ZHOU Meng huaNG Shi-Yong deng xiao-hua PANG Ye Institute of Space Science and Technology Nanchang UniversityNanchang 330031 Sate Key Laboratory of Space Weather Chinese Academy of SciencesBeijing 100190 School of Electronics and Information Wuhan UniversityWuhan 430072 Institute of Astronomy Nanchang UniversityNanchang 330031

A sharp dipolarization front(DF)has recently been detected in the Earth's magnetotail and is associated with complex kinetic *** present one event where a tailward propagating negative DF(with Bz decreasing sharply to negative value)was observed near a reconnection *** thickness of the negative DF is comparable with the local ion gyro-radius/inertial *** is a strong field-aligned current at the *** whistler wave enhancements are observed around the front,associated with counter-streaming electron *** further compare the features of the observed negative DF with the recent kinetic simulation results,as well as the Earthward propagating DFs observed by the THEMIS spacecraft.

关键词： Earth polarization propagating

Large Bi-Polar Signature in a Perpendicular Electric Field of Two-Dimensional Electrostatic Solitary Waves Associated with Magnetic Reconnection: Statistics and Discussion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2013年第1期30卷 231-234页

作者： LI Shi-You ZHANG Shi-Feng deng xiao-hua CAI Hong College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073 Department of Space Physics Wuhan UniversityWuhan 430072 Nanchang University Nanchang 330031

More than 300 electrostatic solitary waves(ESWs)with a large perpendicular component which is a bi-polar waveform structure are observed in the boundary layer within the magnetic reconnection diffusion region in the near-Earth *** ESWs are called two-dimensional ESWs.A Singe-reconnection-based-statistical study of two-dimensional ESWs shows that:(1)ESWs can be continuously observed in the plasma sheet boundary layer(PSBL)associated with the magnetic reconnection diffusion region,and their amplitude ranges are mainly from several tens to hundreds ofμV/m;(2)both one-dimension-like ESWs(very small magnitude on E⊥)and two-dimension-like ESWs(large magnitude on E⊥,which are even comparable to that in the E||)are observed within a small time interval;(3)within the observation time spans,more than 61%of ESWs are regarded as two-dimensional ESWs for the I_(2)D>20%.We discuss the bi-polar structure in E⊥.The observation of ESWs with a large bi-polar structure in the perpendicular electric field gives evidence that the unique waveform differs from previous understanding from observations and simulations which suggests that it should be a uni-polar waveform structure in the E⊥of ESWs.

关键词： structure dimension Polar

Spatial Evolution of Electrostatic Solitary Waves along Plasma Sheet Boundary Layer Adjacent to the Magnetic Reconnection X-Line

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第8期29卷 313-317页

Analysis on the spatial structure of electrostatic solitary waves(ESWs)along the plasma sheet boundary layer(PSBL)near an on-going magnetic reconnection X-line is *** of the ESWs in the PSBL of R3 region near reconnection X-line are propagating earthwards away from the reconnecting *** analysis of their spatial structure shows that,when ESWs propagate along the ambient field in the PSBL,outwards from the magnetic reconnection X-line,their amplitude will finally attenuate and thus the electron hole will fade away but their spatial scale remains ***,the spatial structure of propagating ESWs evolves from 1-D-like to 2-D-like though totally in a 1-D structure.

关键词： Spatial propagating structure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

黔北地区大豆-玉米带状复合种植效益分析

安徽农业科学 2024年第3期52卷 19-23页

作者：母少东赵勤学邓小华王方吴权华蒲泽政遵义市种植业发展服务中心贵州遵义563000

[目的]探讨黔北地区大豆玉米带状复合种植技术推广成效,为黔北地区粮油生产提供科学依据和决策参考。[方法]采取“3+2模式”(即3行大豆+2行玉米),在黔北9个县(区)推广大豆玉米带状复合种植技术。[结果]黔北各地区大豆-玉米带状复合种植... 详细信息

[目的]探讨黔北地区大豆玉米带状复合种植技术推广成效,为黔北地区粮油生产提供科学依据和决策参考。[方法]采取“3+2模式”(即3行大豆+2行玉米),在黔北9个县(区)推广大豆玉米带状复合种植技术。[结果]黔北各地区大豆-玉米带状复合种植玉米产量较2021年玉米产量增加;玉米产量以播州区最高,其次是凤冈县,桐梓县最低;大豆产量以凤冈县最高,其次是绥阳县,正安县、道真自治县较低;纯收益以播州区最多,其次是凤冈县,桐梓县最低。[结论]大豆玉米带状复合种植技术有效提高了黔北地区粮油生产水平,对改变传统种植观念、提高农民收入、促进生态效益和社会效益提升有积极的推动作用。

关键词：大豆-玉米带状复合种植效益分析黔北地区