期刊文献+
共找到2,530篇文章
< 1 2 127 >
每页显示 20 50 100
Thalweg migration under the collaborative changes in the hydro-sediment regime and erosion base level in the Xiaobeiganliu reach of the Middle Yellow River
1
作者 WEN Zhichao LU Jun +4 位作者 WAN Zhanwei GAO Xing HUANG Zhe XIAo Yong LIU Junzheng 《Journal of Geographical Sciences》 2025年第7期1516-1532,共17页
Collaborative changes in the hydro-sediment regime and erosional base level are vital factors that influence the evolution of wandering rivers.In the wandering Xiaobeiganliu reach of the Middle Yellow River(MYR),the r... Collaborative changes in the hydro-sediment regime and erosional base level are vital factors that influence the evolution of wandering rivers.In the wandering Xiaobeiganliu reach of the Middle Yellow River(MYR),the rapidly decreasing sediment discharge and lowering base level,i.e.,the Tongguan elevation,have resulted in new features of thalweg migration in river morphology.In this work,on the basis of topographic measurements of the reach from 2003–2021,the thalweg migration distance and intensity were calculated at both the section scale and reach scale.The results revealed that the annual sediment discharge decreased by 72%from 1986–2002,and the reach exhibited sustained scouring from deposition,leading to the Tongguan elevation decreasing by 1.69 m compared with that in 2002.Accordingly,the distance and intensity of thalweg migration have been reduced to varying degrees in both section and reach scales.The maximum section-scale thalweg migration distance was reduced by 11%,whereas the average thalweg migration distance and intensity at the reach scale decreased by 14%and 43%,respectively.During this sustained scouring period,the fluvial erosion intensity at the reach scale increased as the sediment discharge decreased.However,because the base level remained high,riverbed undercutting was deeply limited,which exacerbated lateral erosion of the bank and floodplain,enhancing thalweg migration.Flow-sediment regulation and training can be coupled to increase undercutting efficiency in the main channel and to protect banks from lateral erosion in river reach management. 展开更多
关键词 wandering river thalweg migration Xiaobeiganliu reach flow-sediment regime base level
原文传递
Buckling Optimization of Curved Grid Stiffeners through the Level Set Based Density Method
2
作者 Zhuo Huang Ye Tian +2 位作者 Yifan Zhang Tielin Shi Qi Xia 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期711-733,共23页
Stiffened structures have great potential for improvingmechanical performance,and the study of their stability is of great interest.In this paper,the optimization of the critical buckling load factor for curved grid s... Stiffened structures have great potential for improvingmechanical performance,and the study of their stability is of great interest.In this paper,the optimization of the critical buckling load factor for curved grid stiffeners is solved by using the level set based density method,where the shape and cross section(including thickness and width)of the stiffeners can be optimized simultaneously.The grid stiffeners are a combination ofmany single stiffenerswhich are projected by the corresponding level set functions.The thickness and width of each stiffener are designed to be independent variables in the projection applied to each level set function.Besides,the path of each single stiffener is described by the zero iso-contour of the level set function.All the single stiffeners are combined together by using the p-norm method to obtain the stiffener grid.The proposed method is validated by several numerical examples to optimize the critical buckling load factor. 展开更多
关键词 STIFFENER buckling optimization shape and cross section level set based density
在线阅读 下载PDF
Structural Topology Design of Container Ship Based on Knowledge-Based Engineering and Level Set Method 被引量:5
3
作者 崔进举 王德禹 史琪琪 《China Ocean Engineering》 SCIE EI CSCD 2015年第4期551-564,共14页
Knowledge-Based Engineering (KBE) is introduced into the ship structural design in this paper. From the implementation of KBE, the design solutions for both Rules Design Method (RDM) and Interpolation Design Meth... Knowledge-Based Engineering (KBE) is introduced into the ship structural design in this paper. From the implementation of KBE, the design solutions for both Rules Design Method (RDM) and Interpolation Design Method (IDM) are generated. The corresponding Finite Element (FE) models are generated. Topological design of the longitudinal structures is studied where the Gaussian Process (GP) is employed to build the surrogate model for FE analysis. Multi-objective optimization methods inspired by Pareto Front are used to reduce the design tank weight and outer surface area simultaneously. Additionally, an enhanced Level Set Method (LSM) which employs implicit algorithm is applied to the topological design of typical bracket plate which is used extensively in ship structures. Two different sets of boundary conditions are considered. The proposed methods show satisfactory efficiency and accuracy. 展开更多
关键词 Knowledge-based Engineering (KBE) level Set Method (LSM) Gaussian Process GP)
在线阅读 下载PDF
Saturable Absorption Enchantment of Au Nanorods Based on Energy Transfer between Longitudinal and Transverse Energy Levels
4
作者 Si Xiao Hui Wang +6 位作者 Sheng Liu Min Li Ying-Wei Wang Jia-Zhang Chen Lu-Hua Guo Jian-Bo Li Jun He 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第6期98-101,共4页
Four kinds of Au nanorods(NRs)with different aspect ratios are designed to adjust the relationship between resonance energy level of longitudinal(L)and transverse(T)modes.During the femto-second Z-scan experimen... Four kinds of Au nanorods(NRs)with different aspect ratios are designed to adjust the relationship between resonance energy level of longitudinal(L)and transverse(T)modes.During the femto-second Z-scan experiments,huge saturable absorption phenomena are observed while the energy level T is located between one to two times of the energylevel L.This means that the energy may transfer between longitudinal and transverse energylevels in the same and/or different Au NRs.It effectively depresses the production of revised saturated absorption and increases the saturable absorption efficiency.This method is significant for the preparation of high-efficiency saturable absorption devices. 展开更多
关键词 Saturable Absorption Enchantment of Au Nanorods based on Energy Transfer between Longitudinal and Transverse Energy levels
原文传递
Base level changes based on Basin Filling Modelling:a case study from the Paleocene Lishui Sag,East China Sea Basin
5
作者 Jing-Zhe Li Pi-Yang Liu +4 位作者 Jin-Liang Zhang Shu-Yu Sun Zhi-Feng Sun Dong-Xing Du Ming Zhang 《Petroleum Science》 SCIE CAS CSCD 2020年第5期1195-1208,共14页
Estimation of base level changes in geological records is an important topic for petroleum geologists.Taking the Paleocene Upper Lingfeng Member of Lishui Sag as an example,this paper conducted a base level reconstruc... Estimation of base level changes in geological records is an important topic for petroleum geologists.Taking the Paleocene Upper Lingfeng Member of Lishui Sag as an example,this paper conducted a base level reconstruction based on Basin Filling Modelling(BFM).The reconstruction was processed on the ground of a previously interpreted seismic stratigraphic framework with several assumptions and simplification.The BFM is implemented with a nonlinear diffusion equation solver written in R coding that excels in shallow marine stratigraphic simulation.The modeled results fit the original stratigraphy very well.The BFM is a powerful tool for reconstructing the base level,and is an effective way to check the reasonableness of previous interpretations.Although simulation solutions may not be unique,the BFM still provides us a chance to gain some insights into the mechanism and dynamic details of the stratigraphy of sedimentary basins. 展开更多
关键词 Sequence stratigraphy base level Basin Filling Modelling Wheeler diagram Paleocene Lishui Sag
原文传递
Malicious Node Detection Using Confidence Level Evaluation in a Grid-Based Wireless Sensor Network 被引量:1
6
作者 Min-Cheol Shin Yoon-Hwa Choi 《Wireless Sensor Network》 2013年第3期52-60,共9页
In this paper, we present a malicious node detection scheme using confidence-level evaluation in a grid-based wireless sensor network. The sensor field is divided into square grids, where sensor nodes in each grid for... In this paper, we present a malicious node detection scheme using confidence-level evaluation in a grid-based wireless sensor network. The sensor field is divided into square grids, where sensor nodes in each grid form a cluster with a cluster head. Each cluster head maintains the confidence levels of its member nodes based on their readings and reflects them in decision-making. Two thresholds are used to distinguish between false alarms due to malicious nodes and events. In addition, the center of an event region is estimated, if necessary, to enhance the event and malicious node detection accuracy. Experimental results show that the scheme can achieve high malicious node detection accuracy without sacrificing normal sensor nodes. 展开更多
关键词 Sensor Networks MALICIOUS NODE Detection Grid-based WSN FAULTS CONFIDENCE levelS
暂未订购
Analysis of sea level changes in the Caspian Sea related to Cosmo-geophysical processes based on satellite and terrestrial data
7
作者 Vladimir Kaftan Boris Komitov Sergey Lebedev 《Geodesy and Geodynamics》 2018年第6期449-455,共7页
Analysis results of the average annual sea levels in the Caspian Sea obtained from ground and satellite observations, corresponding to solar activity characteristics, magnetic field data, and length of day are present... Analysis results of the average annual sea levels in the Caspian Sea obtained from ground and satellite observations, corresponding to solar activity characteristics, magnetic field data, and length of day are presented. Spectra of the indicated processes were investigated and their approximation models were also built. Previously assumed statistical relationships between space-geophysical processes and Caspian Sea level(CSL) changes were confirmed. A close connection was revealed between the low-frequency models of the solar and geomagnetic activity parameters and the CSL changes. Predictions extending into the next decades showed a high probability of an increase in the CSL and a decrease of the compared space-geophysical parameters. 展开更多
关键词 CSL Analysis of sea level changes in the Caspian Sea related to Cosmo-geophysical processes based on satellite and terrestrial data LOD SSN
原文传递
METHOD OF HIGH-LEVEL TECHNOLOGY MAPPING BASED ON KNOWLEDGE(RULE)
8
作者 Ma Cong Wang Zuojian Liu Mingye (ASIC research Center of Beijing Institute of Technology, Beijing 100081) 《Journal of Electronics(China)》 2001年第1期24-31,共8页
This paper studies the linkage problem between the result of high-level synthesis and back-end technology, presents a method of high-level technology mapping based on knowl edge, and studies deeply all of its importan... This paper studies the linkage problem between the result of high-level synthesis and back-end technology, presents a method of high-level technology mapping based on knowl edge, and studies deeply all of its important links such as knowledge representation, knowledge utility and knowledge acquisition. It includes: (1) present a kind of expanded production about knowledge of circuit structure; (2) present a VHDL-based method to acquire knowledge of tech nology mapping; (3) provide solution control strategy and algorithm of knowledge utility; (4)present a half-automatic maintenance method, which can find redundance and contradiction of knowledge base; (5) present a practical method to embed the algorithm into knowledge system to decrease complexity of knowledge base. A system has been developed and linked with three kinds of technologies, so verified the work of this paper. 展开更多
关键词 HIGH-level synthesis TECHNOLOGY mapping VHDL HIGH-level TECHNOLOGY map PING KNOWLEDGE base KNOWLEDGE representation
在线阅读 下载PDF
On the Accuracy Assessment of the Latest Releases of GOCE Satellite-Based Geopotential Models with EGM2008 and Terrestrial GPS/Levelling and Gravity Data over Egypt 被引量:2
9
作者 Mohamed El-Ashquer Basem Elsaka Gamal El-Fiky 《International Journal of Geosciences》 2016年第11期1323-1344,共23页
The Global Geopotential Models (GGMs) of GOCE (Gravity Recovery and steady- state Ocean Circulation Explorer) differ globally as well as regionally in their accuracy and resolution based on the maximum degree and orde... The Global Geopotential Models (GGMs) of GOCE (Gravity Recovery and steady- state Ocean Circulation Explorer) differ globally as well as regionally in their accuracy and resolution based on the maximum degree and order (d/o) of the fully normalized spherical harmonic (SH) coefficients, which express each GGM. The main idea of this study is to compare the free-air gravity anomalies and quasi geoid heights determined from several recent GOCE-based GGMs with the corresponding ones from the Earth Gravitational Model 2008 (EGM2008) over Egypt on the one hand and with ground-based measurements on the other hand. The results regarding to the comparison of GOCE-based GGMs with terrestrial gravity and GPS/levelling data provide better improvement with respect to EGM2008. The 4th release GOCE-based GGM developed with the use of space-wise solution strategy (SPW_R4) approximates the gravity field well over the Egyptian region. The SPW_R4 model is accordingly suggested as a reference model for recovering the long wavelength (up to SH d/o 200) components of quasi geoid heights when modelling the gravimetric quasi-geoid over the Egypt. Finally, three types of transformation models: Four-, Five- and Seven-parameter transformations have been applied to reduce the data biases and to provide a better fitting of quasi geoid heights obtained from the studied GOCE-based GGMs to those from GPS/levelling data. These models reveal that the standard deviation of vertical datum over Egypt is at the level of about 32 cm. 展开更多
关键词 GOCE-based GGMs Free-Air Gravity Anomalies GPS/levelling Data Spectral Enhancement Method (SEM)
在线阅读 下载PDF
3D Surface Editing Based on Level-Sets
10
作者 林茂松 张典华 《Journal of Southwest Jiaotong University(English Edition)》 2005年第2期139-146,共8页
A novel method which integrates the topological flexibility of the level-set approach and the simplicity of point-sampled surfaces is proposed. The grid structure resulted from the level-set approach not only offers a... A novel method which integrates the topological flexibility of the level-set approach and the simplicity of point-sampled surfaces is proposed. The grid structure resulted from the level-set approach not only offers a wide range of powerful surface editing techniques for the point set surface editing, but also facilitates the topological change with ease. With the aid of point-based resampling, the method updates the surface shape of the point-based geometry quickly without worrying about point connectivity at all. The point set surface can also change its topology properly whenever a collision with other parts of itself is detected. The experiment demonstrates their effectiveness on several scanned objects and scan-converted models. Four examples of surface editing operations: smoothing, tapering, deforming, and Boolean operations, are presented. 展开更多
关键词 Computational geometry level-set methods Point-based geometry DEFORMATION
在线阅读 下载PDF
Regional Evaluation of GOCE-Based GGMs with Ground-Based Gravity and GPS/Levelling Data over Egypt
11
作者 Ahmed Saadon Basem Elsaka +1 位作者 Mohamed El-Ashquer Gamal El-Fiky 《International Journal of Geosciences》 2019年第6期652-668,共17页
The gravity field and steady-state ocean circulation explorer (GOCE) satellite mission has provided numerous Global Geopotential Models (GGMs) with different processing methodologies and model accuracies. In the curre... The gravity field and steady-state ocean circulation explorer (GOCE) satellite mission has provided numerous Global Geopotential Models (GGMs) with different processing methodologies and model accuracies. In the current contribution, the latest releases of GOCE-based GGMs are evaluated on the regional scale using the available terrestrial GPS/Levelling and gravity data collected over Egypt. To overcome the spectral inconsistency between the GOCE-based GGMs and the ground-based data, the spectral enhancement method (SEM) is applied. Five of GOCE-based GGMs have been used, namely GOSG01S, IGGT_R1, IfE_GOCE05s_ GO_CONS_GCF_2_SPW_R5 (SPW_R5 in the following) and NULP-02. The evaluation process of GOCE-based GGMs with the available ground data over Egypt considering the SEM method shows remarkable improvements obtained from the SPW_R5 model. The model provides lower differences of the standard deviations with respect to the EGM2008 and the other applied geopotential gravity models as well as the applied ground-based gravity and GPS/Levelling data. The findings regarding the ground-based data show obvious reductions of about 15.16% and 32.22% achieved by the GOCE-based model in term of standard deviations differences of gravity anomalies and geoid heights, respectively. Therefore, the SPW_R5 model is recommended to be applied as a reference model for compensating the long-to-short wavelength (up to spherical harmonics degree/order 280) components when modelling the gravimetric geoid over Egypt. 展开更多
关键词 GOCE-based GGMs GRAVITY Anomalies GNSS/levelling Spectral Enhancement Method (SEM)
暂未订购
Building National Level Human Rights Bases and Popularization Centers
12
作者 CHEN YUGANG 《The Journal of Human Rights》 2014年第5期14-15,共2页
Building national human rights education and train- ing bases is part of China's human rights development,which shows the strong will of the Chinese government for promoting human fights and strengthening hu- man rig... Building national human rights education and train- ing bases is part of China's human rights development,which shows the strong will of the Chinese government for promoting human fights and strengthening hu- man rights protection. Such an action is not only a practical measure for implementing international human fights action plans, but also a practice of the Chinese government in re- specting and implementing relevant international obligations set by the United Nations. 展开更多
关键词 Building National level Human Rights bases and Popularization Centers
原文传递
Base-level Chang and Sequence Stratigraphy of Lishu Fault Lacustrine Basin
13
作者 Wang Simin Liu Zhaojun Liu Kui 《Global Geology》 2000年第1期70-76,共7页
Base-level is a kind of surface which controls sedimentation and erosion. So, it can be concluded that it is base-level change that controls the formation and internal structure of a sequence. A single cycle of base-l... Base-level is a kind of surface which controls sedimentation and erosion. So, it can be concluded that it is base-level change that controls the formation and internal structure of a sequence. A single cycle of base-level change can generate four sets of different stacking patterns. They are two sets of aggradation, one progradation and one retrogradation, which affects the features of the internal structure of a sequence. Lishu fault subsidence of Songliao basin is a typical half-graben lacustrine basin. Comprehensive base-level change analysis indicates that six base-level cycles and their related six sequences can be recognized between T 4 and T 5 seismic reflection surface. The contemporaneous fault is the main controlling factor of the fault lacustrine basin. There are obvious differences exist in the composition of sedimentary systems and all systems tracts between its steep slope (the side that basin control fault existed) and flat slope. Except highstand systems tract is composed of fan delta-lacustrine system, lowstand systems tract, transgressive systems tract and regressive systems tract are all made up of fan delta-underwater fan-lacustrine sedimentary systems in the side of steep slope. 展开更多
关键词 base-level FAULT LACUSTRINE basin SEQUENCE STRATIGRAPHY SEQUENCE STRATIGRAPHIC model Songliao bas
在线阅读 下载PDF
Evaluation study on properties of a macroporous silica-based CMPO extraction resin to be used forminor actinides separation from high level liquid waste
14
作者 LIU Ruiqin WEI Yuezhou +6 位作者 Daisuke Tozawa XU Yuanlai Shigekazu Usuda Hiromichi Yamazaki Keizo Ishii Yuichi Sano Yoshikazu Koma 《Nuclear Science and Techniques》 SCIE CAS CSCD 2011年第1期18-24,共7页
Basic properties of a silica-based octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) extraction resin (CMPO/SiO2-P) was investigated.Adsorption behavior for some rare earth elements (RE) which are con... Basic properties of a silica-based octyl(phenyl)-N,N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) extraction resin (CMPO/SiO2-P) was investigated.Adsorption behavior for some rare earth elements (RE) which are constituents of high level liquid waste (HLLW) and the long-term stability of the extraction resin in nitric acid solution were examined.The CMPO extraction resin was significantly stable in 3 mol·L?1 HNO3 solution at 50oC.Furthermore,the RE(III) were efficiently separated from non-adsorptive fission product (FP) elements such as Sr(II) in a column experiment using a highly nitric acid solution.The separation behaviors of the elements are considered to result from the difference in their adsorption and elution selectivity based on the complex formation with CMPO.There was no strong dependency of RE(III) separation efficiency on feed solution flow rate.Only from the perspectives of the acid-resistant behavior of CMPO extraction resin and the elution kinetics for the metal ions with the extraction resin,the CMPO extraction resin can be used in the modified MAREC process for HLLW partitioning. 展开更多
关键词 萃取树脂 高放废液 锕系元素 分离性能 大孔硅 提取 基础 选择性吸附
在线阅读 下载PDF
基于分子水平模型生成催化重整Delta-Base数据
15
作者 宋雨雨 崔晨 +2 位作者 吕文进 宋建 周祥 《石油炼制与化工》 CAS CSCD 北大核心 2024年第7期99-105,共7页
采用信息熵最大化理论和重整原料部分物性相结合的方法,研究了在生成Delta-Base数据过程中重整原料分子层面上的变化。模型计算过程中以信息熵最大化为目标,以重整原料的相对分子质量、H/C比、PIONA组成、密度以及芳烃潜含量作为约束条... 采用信息熵最大化理论和重整原料部分物性相结合的方法,研究了在生成Delta-Base数据过程中重整原料分子层面上的变化。模型计算过程中以信息熵最大化为目标,以重整原料的相对分子质量、H/C比、PIONA组成、密度以及芳烃潜含量作为约束条件,并以遗传算法作为优化方法进行模型求解,从分子层面计算两种不同芳烃潜含量重整原料的Delta-Base数据。结果显示,随着原料芳烃潜含量的增加,产品中芳烃含量也增加,可以利用分子水平机理模型生成Delta-Base数据。 展开更多
关键词 分子水平 催化重整 Delta-base 信息熵
在线阅读 下载PDF
片区统筹推进城乡融合:政策内涵、理论机制与实践探索 被引量:3
16
作者 蔡键 吴蕴奇 罗明忠 《农业现代化研究》 北大核心 2025年第1期12-21,共10页
城乡融合发展是重塑城乡关系、实现中国式现代化的重要举措。本研究深入解析了城乡融合的本质,全面梳理了中国城乡关系的演变历程与现实困境,指出当前城乡融合面临的主要问题,包括城乡收入差距过大、城乡要素流动受阻、城乡公共服务均... 城乡融合发展是重塑城乡关系、实现中国式现代化的重要举措。本研究深入解析了城乡融合的本质,全面梳理了中国城乡关系的演变历程与现实困境,指出当前城乡融合面临的主要问题,包括城乡收入差距过大、城乡要素流动受阻、城乡公共服务均等化未达成及农村基础设施薄弱等。在此基础上,结合《国家城乡融合发展试验区改革方案》,本研究提出了片区统筹推进城乡融合的新思路,重点阐述了片区统筹的政策内涵与理论机制,并结合广清接合片区的实践进行分析与论证。研究表明,片区统筹具有“以县域为载体”“突破行政边界”和“集群式发展”等特点,有助于缓解城乡“融而不合”的问题,推动城乡经济与社会的深度融合。未来推进城乡融合的重点可聚焦在三方面:一是明确县域在城乡融合中的主战场地位;二是探索破除行政区划壁垒的制度创新;三是强化中心城市的辐射带动作用。 展开更多
关键词 城乡融合 片区统筹 县域为载体 突破行政边界 集群式发展
原文传递
原料性质大幅变化情况下催化重整Delta-Base数据的生成方法
17
作者 宋雨雨 吕文进 +2 位作者 崔晨 宋建 周祥 《石油炼制与化工》 CAS CSCD 北大核心 2024年第8期157-163,共7页
针对催化重整原料性质变化幅度较大的情况,提出采用变步长计算结合分子水平机理模型生成装置Delta-Base数据的方法。该方法通过计算原料性质扰动时产品质量分数变化量绝对值随原料性质变化量绝对值的变化率;并将该变化率的值域分成若干... 针对催化重整原料性质变化幅度较大的情况,提出采用变步长计算结合分子水平机理模型生成装置Delta-Base数据的方法。该方法通过计算原料性质扰动时产品质量分数变化量绝对值随原料性质变化量绝对值的变化率;并将该变化率的值域分成若干等份,根据每次计算得到变化率值域的范围不同,选择下一步计算时的变量扰动步长;继而在计算过程中取每次变量扰动的中点值产品质量分数进行验证,从而在提高计算效率的同时保证了计算结果的准确性。结果表明:利用该方法计算得到的各产品质量分数相对误差较小,基本不超过2.5%;对计算数据拟合可得到不同产品质量分数数据拟合方程,通过拟合方程可生成芳烃潜含量变化三阶段Delta-Base数据;比较原料芳烃潜含量(w)为42%时的产品预测结果,发现Delta-Base数据预测值和拟合方程计算值的平均偏差均为0.16%,说明该方法具有很好的准确性,利用分子水平机理模型生成的Delta-Base数据更能反映真实的分子反应历程。 展开更多
关键词 催化重整 分子水平模型 线性规划 Delta-base数据
在线阅读 下载PDF
数字化水平调节下企业家精神对双元创新与企业成长的影响研究——来自科技型中小企业的检验证据 被引量:2
18
作者 陈雄鹰 何佳亮 +1 位作者 吴克强 韩广奎 《北京联合大学学报(人文社会科学版)》 2025年第2期71-86,共16页
随着我国企业数字化转型的持续推进,企业的创新成长活动受到了企业数字化水平的深刻影响。基于资源基础理论和资源编排理论,本文利用166家科技型中小企业的调查数据,探索数字化水平在企业家精神与双元创新、企业成长之间所发挥的边界效... 随着我国企业数字化转型的持续推进,企业的创新成长活动受到了企业数字化水平的深刻影响。基于资源基础理论和资源编排理论,本文利用166家科技型中小企业的调查数据,探索数字化水平在企业家精神与双元创新、企业成长之间所发挥的边界效应。研究结果表明,数字化水平中的数字化装备水平负向调节企业家精神对于利用式创新的正向影响,并在企业家精神与探索式创新和企业成长的影响关系中存在U型调节作用;而数字化应用水平在企业家精神与探索式创新、利用式创新和企业成长的影响关系中均存在U型调节作用。研究结论为企业在不同的数字化水平下优化配置双元创新、促进企业成长发展提供依据。 展开更多
关键词 科技型中小企业 企业家精神 双元创新 数字化水平 企业成长
在线阅读 下载PDF
事务分类与主体分化:一种村级组织体系的结构优化逻辑 被引量:1
19
作者 杜鹏 柳泽凡 《求实》 北大核心 2025年第2期81-95,M0006,共16页
当前,乡村治理进入新的阶段,农村基层组织面临新的挑战。本研究基于组织运作的视角,探析村级治理体系的组织结构和实践过程。研究发现,村庄治理事务影响村级治理的组织规模与结构形态,在村庄多元治理事务的现实背景下,村级组织呈现“分... 当前,乡村治理进入新的阶段,农村基层组织面临新的挑战。本研究基于组织运作的视角,探析村级治理体系的组织结构和实践过程。研究发现,村庄治理事务影响村级治理的组织规模与结构形态,在村庄多元治理事务的现实背景下,村级组织呈现“分工治理”的运作特征。根据村级治理事务的类型,村级组织结构呈现材料办公型、村民关系型及经营发展型等类型,不同的治理形态适配多元的干部主体。同时,“分工型”村级组织的实践过程表现为“手段分异”的治理形式、“价值分化”的激励方式以及“功能互补”的组织整合。实践表明,我国多数村级组织的队伍建设正在从“统合型”走向“分工型”的组织样态。通过村级组织体系的优化重组,建立更加合理、高效的干部队伍,有助于实现村级治理能力的提升和村庄治理体系的优化,以更加适应基层治理现代化的实践要求。 展开更多
关键词 乡村振兴 乡村治理 村级组织 组织运作 “分工型”治理体系 事务分类 主体分化
在线阅读 下载PDF
纽约滨海韧性规划研究进展与实践综述
20
作者 陈飞 曹诗茵 +2 位作者 蔡军 许世光 胡秦兰 《西部人居环境学刊》 北大核心 2025年第3期188-195,共8页
海平面上升冲击滨海地区安全,全球越来越多的滨海城市开展以防洪减灾为核心的韧性规划研究与实践。本文聚焦纽约滨海韧性规划研究和实践,回顾纽约市早期开展的气候变化研究,重点分析2012年“桑迪飓风”之后滨海韧性规划研究与实践,包括... 海平面上升冲击滨海地区安全,全球越来越多的滨海城市开展以防洪减灾为核心的韧性规划研究与实践。本文聚焦纽约滨海韧性规划研究和实践,回顾纽约市早期开展的气候变化研究,重点分析2012年“桑迪飓风”之后滨海韧性规划研究与实践,包括重新绘制洪水地图,颁布多项目技术指南文件、提升建筑和海岸防护要求,组织构建覆盖全域的滨海防护体系,并开展试点建设等方面内容。综合分析纽约市多年研究与实践经验,以期在构建多层次跨部门的滨海韧性研究、治理体系,建设多机构衔接的灾后保障快速响应体系,开展广泛公众参与提升公众滨海韧性的防护意识工作等方面为我国滨海韧性规划研究和实践提供借鉴。 展开更多
关键词 海平面上升 沿海洪水 滨海韧性规划 基于自然的解决方法
在线阅读 下载PDF
上一页 1 2 127 下一页 到第
使用帮助 返回顶部