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基于PVAR模型的农业机械化与农民收入关系研究-以山东省16地市为例
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作者 张泽文 崔茂森 《农业工程》 2024年第5期155-160,共6页
基于山东省2000—2020年数据,运用PVAR模型基础上,采用脉冲响应函数、方差分解和Granger因果检验等方法对农业机械化与农民收入的关系进行了实证研究。结果表明,农业机械化水平能够有效地促进农民的工资性收入和经营性收入,有利于农民... 基于山东省2000—2020年数据,运用PVAR模型基础上,采用脉冲响应函数、方差分解和Granger因果检验等方法对农业机械化与农民收入的关系进行了实证研究。结果表明,农业机械化水平能够有效地促进农民的工资性收入和经营性收入,有利于农民收入的增长,但其效应存在一定的时间滞后性;比较脉冲响应图像和方差分解的结果可得,农业机械化的发展对农民工资性收入的促进效应大于对农民经营性收入的效应。鉴于此,提出了因地制宜发挥农机补贴作用、加强农民技术教育培训等建议,以形成山东省农业机械化促进农民收入增长的良好互动关系。 展开更多
关键词 农业机械化 pvar模型 农民收入 工资性收入 经营性收入
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Establishment of a humanized ST6GAL1 mouse model for influenza research
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作者 Lyu Chao Han Feng +10 位作者 Gao Qian Lv Limin Lu Ziwei Lu Shuangshuang Li Xiaoyan Hu Yuechao Yang Mengjie Zhao Yingze Liu Jun Lu Xuancheng Duo Shuguang 《Animal Models and Experimental Medicine》 CAS CSCD 2024年第3期337-346,共10页
Background:This study aimed to construct and characterize a humanized influenza mouse model expressing hST6GAL1.Methods:Humanized fragments,consisting of the endothelial cell-specific K18 promoter,human ST6GAL1-encodi... Background:This study aimed to construct and characterize a humanized influenza mouse model expressing hST6GAL1.Methods:Humanized fragments,consisting of the endothelial cell-specific K18 promoter,human ST6GAL1-encoding gene,and luciferase gene,were microinjected into the fertilized eggs of mice.The manipulated embryos were transferred into the oviducts of pseudopregnant female mice.The offspring were identified using PCR.Mice exhibiting elevated expression of the hST6GAL1 gene were selectively bred for propagation,and in vivo analysis was performed for screening.Expression of the humanized gene was tested by performing immunohistochemical(IHC)analysis.Hematologic and biochemical analyses using the whole blood and serum of humanized hST6GAL1 mice were performed.Results:Successful integration of the human ST6GAL1 gene into the mouse genome led to the overexpression of human SiaT ST6GAL1.Seven mice were identified as carrying copies of the humanized gene,and the in vivo analysis indicated that hST6GAL1gene expression in positive mice mirrored influenza virus infection characteristics.The IHC results revealed that hST6GAL1 was expressed in the lungs of humanized mice.Moreover,the hematologic and biochemical parameters of the positive mice were within the normal range.Conclusion:A humanized influenza mouse model expressing the hST6GAL1 gene was successfully established and characterized. 展开更多
关键词 hST6GAL1 humanized mice influenza animal model
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Estimation of evapotranspiration from artificial forest in mountainous areas of western Loess Plateau based on HYDRUS-1D model
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作者 LU Rui ZHANG Mingjun +4 位作者 ZHANG Yu QIANG Yuquan CHE Cunwei SUN Meiling WANG Shengjie 《Journal of Arid Land》 SCIE CSCD 2024年第12期1664-1685,共22页
Evapotranspiration is the most important expenditure item in the water balance of terrestrial ecosystems,and accurate evapotranspiration modeling is of great significance for hydrological,ecological,agricultural,and w... Evapotranspiration is the most important expenditure item in the water balance of terrestrial ecosystems,and accurate evapotranspiration modeling is of great significance for hydrological,ecological,agricultural,and water resource management.Artificial forests are an important means of vegetation restoration in the western Loess Plateau,and accurate estimates of their evapotranspiration are essential to the management and development of water use strategies for artificial forests.This study estimated the soil moisture and evapotranspiration based on the HYDRUS-1D model for the artificial Platycladus orientalis(L.)Franco forest in western mountains of Loess Plateau,China from 20 April to 31 October,2023.Moreover,the influence factors were identified by combining the correlation coefficient method and the principal component analysis(PCA)method.The results showed that HYDRUS-1D model had strong applicability in portraying hydrological processes in this area and revealed soil water surplus from 20 April to 31 October,2023.The soil water accumulation was 49.64 mm;the potential evapotranspiration(ET_(p))was 809.67 mm,which was divided into potential evaporation(E_(p);95.07 mm)and potential transpiration(T_(p);714.60 mm);and the actual evapotranspiration(ET_(a))was 580.27 mm,which was divided into actual evaporation(E_(a);68.27 mm)and actual transpiration(T_(a);512.00 mm).From April to October 2023,the ET_(p),E_(p),T_(p),ET_(a),E_(a),and T_(a) first increased and then decreased on both monthly and daily scales,exhibiting a single-peak type trend.The average ratio of T_(a)/ET_(a) was 0.88,signifying that evapotranspiration mainly stemmed from transpiration in this area.The ratio of ET_(a)/ET_(p) was 0.72,indicating that this artificial forest suffered from obvious drought stress.The ET_(p) was significantly positively correlated with ET_(a),and the R^(2) values on the monthly and daily scales were 0.9696 and 0.9635(P<0.05),respectively.Furthermore,ET_(a) was significantly positively correlated with temperature,solar radiation,and wind speed,and negatively correlated with relative humidity and precipitation(P<0.05);and temperature exhibited the highest correlation with ET_(a).Thus,ET_(p) and temperature were the decisive contributors to ET_(a) in this area.The findings provide an effective method for simulating regional evapotranspiration and theoretical reference for water management of artificial forests,and deepen understanding of effects of each influence factors on ET_(a) in arid areas. 展开更多
关键词 potential evapotranspiration actual evapotranspiration EVAPORATION TRANSPIRATION HYDRUS-1D model Loess Plateau soil water content
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Tidal modeling based on satellite altimetry observations of TOPEX/ Poseidon, Jason1, Jason2, and Jason3 with high prediction capability: A case study of the Baltic Sea
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作者 Alireza A.Ardalan Asiyeh Hashemifaraz 《Geodesy and Geodynamics》 EI CSCD 2024年第4期404-418,共15页
This research aims to optimize the utilization of long-term sea level data from the TOPEX/Poseidon,Jason1,Jason2,and Jason3 altimetry missions for tidal modeling.We generate a time series of along-track observations a... This research aims to optimize the utilization of long-term sea level data from the TOPEX/Poseidon,Jason1,Jason2,and Jason3 altimetry missions for tidal modeling.We generate a time series of along-track observations and apply a developed method to produce tidal models with specific tidal constituents for each location.Our tidal modeling methodology follows an iterative process:partitioning sea surface height(SSH)observations into analysis/training and prediction/validation parts and ultimately identi-fying the set of tidal constituents that provide the best predictions at each time series location.The study focuses on developing 1256 time series along the altimetry tracks over the Baltic Sea,each with its own set of tidal constituents.Verification of the developed tidal models against the sSH observations within the prediction/validation part reveals mean absolute error(MAE)values ranging from 0.0334 m to 0.1349 m,with an average MAE of 0.089 m.The same validation process is conducted on the FES2014 and EOT20 global tidal models,demonstrating that our tidal model,referred to as BT23(short for Baltic Tide 2023),outperforms both models with an average MAE improvement of 0.0417 m and 0.0346 m,respectively.In addition to providing details on the development of the time series and the tidal modeling procedure,we offer the 1256 along-track time series and their associated tidal models as supplementary materials.We encourage the satellite altimetry community to utilize these resources for further research and applications. 展开更多
关键词 Satellitealtimetry Baltic Sea Ocean tide modeling Jason3 Jason2 Jason1 TOPEX/POSEIDON EOT20 FES2014
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An approach to estimate tree height using PolInSAR data constructed by the Sentinel-1 dual-pol SAR data and RVoG model
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作者 Yin Zhang Ding-Feng Duan 《Journal of Electronic Science and Technology》 EI CAS CSCD 2024年第3期69-79,共11页
We estimate tree heights using polarimetric interferometric synthetic aperture radar(PolInSAR)data constructed by the dual-polarization(dual-pol)SAR data and random volume over the ground(RVoG)model.Considering the Se... We estimate tree heights using polarimetric interferometric synthetic aperture radar(PolInSAR)data constructed by the dual-polarization(dual-pol)SAR data and random volume over the ground(RVoG)model.Considering the Sentinel-1 SAR dual-pol(SVV,vertically transmitted and vertically received and SVH,vertically transmitted and horizontally received)configuration,one notes that S_(HH),the horizontally transmitted and horizontally received scattering element,is unavailable.The S_(HH)data were constructed using the SVH data,and polarimetric SAR(PolSAR)data were obtained.The proposed approach was first verified in simulation with satisfactory results.It was next applied to construct PolInSAR data by a pair of dual-pol Sentinel-1A data at Duke Forest,North Carolina,USA.According to local observations and forest descriptions,the range of estimated tree heights was overall reasonable.Comparing the heights with the ICESat-2 tree heights at 23 sampling locations,relative errors of 5 points were within±30%.Errors of 8 points ranged from 30%to 40%,but errors of the remaining 10 points were>40%.The results should be encouraged as error reduction is possible.For instance,the construction of PolSAR data should not be limited to using SVH,and a combination of SVH and SVV should be explored.Also,an ensemble of tree heights derived from multiple PolInSAR data can be considered since tree heights do not vary much with time frame in months or one season. 展开更多
关键词 Constructed polarimetric SAR data Dual polarization Sentinel-1 SAR data Polarimetric interferometric SAR Random volume over the ground model Tree height estimation
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Numerical Models and Methods of Atmospheric Parameters Originating in the Formation of the Earth’s Climatic Cycle
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作者 Wend Dolean Arsène Ilboudo Kassoum Yamba +1 位作者 Windé Nongué Daniel Koumbem Issaka Ouédraogo 《Atmospheric and Climate Sciences》 2024年第2期277-286,共10页
Atmospheric models are physical equations based on the ideal gas law. Applied to the atmosphere, this law yields equations for water, vapor (gas), ice, air, humidity, dryness, fire, and heat, thus defining the model o... Atmospheric models are physical equations based on the ideal gas law. Applied to the atmosphere, this law yields equations for water, vapor (gas), ice, air, humidity, dryness, fire, and heat, thus defining the model of key atmospheric parameters. The distribution of these parameters across the entire planet Earth is the origin of the formation of the climatic cycle, which is a normal climatic variation. To do this, the Earth is divided into eight (8) parts according to the number of key parameters to be defined in a physical representation of the model. Following this distribution, numerical models calculate the constants for the formation of water, vapor, ice, dryness, thermal energy (fire), heat, air, and humidity. These models vary in complexity depending on the indirect trigonometric direction and simplicity in the sum of neighboring models. Note that the constants obtained from the equations yield 275.156˚K (2.006˚C) for water, 273.1596˚K (0.00963˚C) for vapor, 273.1633˚K (0.0133˚C) for ice, 0.00365 in/s for atmospheric dryness, 1.996 in<sup>2</sup>/s for humidity, 2.993 in<sup>2</sup>/s for air, 1 J for thermal energy of fire, and 0.9963 J for heat. In summary, this study aims to define the main parameters and natural phenomena contributing to the modification of planetary climate. . 展开更多
关键词 Atmospheric Parameter 1 Climatic Cycle 2 Numerical models 3
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成纤维细胞生长因子受体1 抑制剂对胶原诱导关节炎模型大鼠骨破坏的影响
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作者 韩海慧 孟晓辉 +3 位作者 徐博 冉磊 施杞 肖涟波 《中国组织工程研究》 CAS 北大核心 2025年第5期968-977,共10页
背景:课题组前期的研究表明靶向成纤维细胞生长因子受体1(fibroblast growth factor receptor 1,FGFR1)可能是治疗类风湿性关节炎的有效靶点。目的:探讨FGFR1抑制剂(PD173074)对胶原诱导关节炎模型大鼠骨破坏的影响。方法:将25只雌性SD... 背景:课题组前期的研究表明靶向成纤维细胞生长因子受体1(fibroblast growth factor receptor 1,FGFR1)可能是治疗类风湿性关节炎的有效靶点。目的:探讨FGFR1抑制剂(PD173074)对胶原诱导关节炎模型大鼠骨破坏的影响。方法:将25只雌性SD大鼠随机分为5组,正常对照组、模型组、甲氨蝶呤组、PD173074低剂量组、PD173074高剂量组。除正常对照组外,其余各组大鼠建立Ⅱ型胶原诱导关节炎模型。造模成功后正常组及模型组大鼠腹腔注射无菌PBS,甲氨蝶呤组药物注射剂量为1.04 mg/kg,PD173074低剂量组和高剂量组药物注射剂量分别为5,20 mg/kg,1次/周。给药4周后取材,观察大鼠临床症状以及关节肿胀情况,踝关节Micro-CT三维重建及分析,观察踝关节病理变化,检测关节周围血管生成情况及核因子κB受体活化因子配体的表达,检测关节滑膜中p-FGFR1、血管内皮生长因子A、抗酒石酸酸性磷酸酶的表达,观察肝、脾、肾病理变化并计算肝、脾、肾指数。结果与结论:①PD173074能够减轻模型大鼠踝关节临床症状及关节肿胀,延缓骨质丢失,改善骨结构,减轻关节滑膜侵袭以及软骨骨侵蚀,降低关节周围破骨细胞数量,抑制关节滑膜组织中的血管生成,降低核因子κB受体活化因子配体的表达,抑制FGFR1磷酸化蛋白、抗酒石酸酸性磷酸酶和血管内皮生长因子A的蛋白表达。②大鼠肝、脾、肾病理观察表明经过PD173074治疗后无明显的毒副作用。③研究证明了FGFR1抑制剂能够延缓Ⅱ型胶原诱导关节炎模型大鼠关节炎症及骨破坏的进展,并抑制血管的生成。初步验证了PD173074在Ⅱ型胶原诱导关节炎模型中的治疗作用,其可能是通过抑制FGFR1磷酸化发挥作用,为寻找类风湿性关节炎新的治疗靶点提供了方向。 展开更多
关键词 类风湿关节炎 PD173074 成纤维细胞生长因子受体1 胶原诱导型关节炎 动物模型 骨破坏 血管生成
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Application of Modelica Based Multi- Domain Modeling and Simulation for Gravity-1
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作者 ZHANG Chi BU Xiangwei +3 位作者 XU Lijie WU Kao HOU Shiyuan XU Guoguang 《Aerospace China》 2024年第1期47-55,共9页
In the R&D phase of Gravity-1(YL-1), a multi-domain modeling and simulation technology based on Modelica language was introduced, which was a recent attempt in the practice of modeling and simulation method for la... In the R&D phase of Gravity-1(YL-1), a multi-domain modeling and simulation technology based on Modelica language was introduced, which was a recent attempt in the practice of modeling and simulation method for launch vehicles in China. It realizes a complex coupling model within a unified model for different domains, so that technologists can work on one model. It ensured the success of YL-1 first launch mission, supports rapid iteration, full validation, and tight design collaboration. 展开更多
关键词 modelICA Gravity-1 simulation modeling launch vehicle model
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Exploiting fly models to investigate rare human neurological disorders
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作者 Tomomi Tanaka Hyung-Lok Chung 《Neural Regeneration Research》 SCIE CAS 2025年第1期21-28,共8页
Rare neurological diseases,while individually are rare,collectively impact millions globally,leading to diverse and often severe neurological symptoms.Often attributed to genetic mutations that disrupt protein functio... Rare neurological diseases,while individually are rare,collectively impact millions globally,leading to diverse and often severe neurological symptoms.Often attributed to genetic mutations that disrupt protein function or structure,understanding their genetic basis is crucial for accurate diagnosis and targeted therapies.To investigate the underlying pathogenesis of these conditions,researchers often use non-mammalian model organisms,such as Drosophila(fruit flies),which is valued for their genetic manipulability,cost-efficiency,and preservation of genes and biological functions across evolutionary time.Genetic tools available in Drosophila,including CRISPR-Cas9,offer a means to manipulate gene expression,allowing for a deep exploration of the genetic underpinnings of rare neurological diseases.Drosophila boasts a versatile genetic toolkit,rapid generation turnover,and ease of large-scale experimentation,making it an invaluable resource for identifying potential drug candidates.Researchers can expose flies carrying disease-associated mutations to various compounds,rapidly pinpointing promising therapeutic agents for further investigation in mammalian models and,ultimately,clinical trials.In this comprehensive review,we explore rare neurological diseases where fly research has significantly contributed to our understanding of their genetic basis,pathophysiology,and potential therapeutic implications.We discuss rare diseases associated with both neuron-expressed and glial-expressed genes.Specific cases include mutations in CDK19 resulting in epilepsy and developmental delay,mutations in TIAM1 leading to a neurodevelopmental disorder with seizures and language delay,and mutations in IRF2BPL causing seizures,a neurodevelopmental disorder with regression,loss of speech,and abnormal movements.And we explore mutations in EMC1 related to cerebellar atrophy,visual impairment,psychomotor retardation,and gain-of-function mutations in ACOX1 causing Mitchell syndrome.Loss-of-function mutations in ACOX1 result in ACOX1 deficiency,characterized by very-long-chain fatty acid accumulation and glial degeneration.Notably,this review highlights how modeling these diseases in Drosophila has provided valuable insights into their pathophysiology,offering a platform for the rapid identification of potential therapeutic interventions.Rare neurological diseases involve a wide range of expression systems,and sometimes common phenotypes can be found among different genes that cause abnormalities in neurons or glia.Furthermore,mutations within the same gene may result in varying functional outcomes,such as complete loss of function,partial loss of function,or gain-of-function mutations.The phenotypes observed in patients can differ significantly,underscoring the complexity of these conditions.In conclusion,Drosophila represents an indispensable and cost-effective tool for investigating rare neurological diseases.By facilitating the modeling of these conditions,Drosophila contributes to a deeper understanding of their genetic basis,pathophysiology,and potential therapies.This approach accelerates the discovery of promising drug candidates,ultimately benefiting patients affected by these complex and understudied diseases. 展开更多
关键词 ACOX1 Drosophila melanogaster GLIA lipid metabolism model organisms NEUROINFLAMMATION neurologic disorders NEURON rare disease VLCFA
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Study on the Prediction of Rice Blast Based on the Unbiased GM (1,1) Model 被引量:1
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作者 魏代俊 曾艳敏 邹迎春 《Plant Diseases and Pests》 CAS 2010年第6期4-6,共3页
To create a new prediction model, the unbiased GM (1,1) model is optimized by the five-point slide method in this paper. Then, based on the occurrence areas of dce blast in Enshi District during 1995 -2004, the new ... To create a new prediction model, the unbiased GM (1,1) model is optimized by the five-point slide method in this paper. Then, based on the occurrence areas of dce blast in Enshi District during 1995 -2004, the new model and unbiased GM (1, 1 ) model are applied to predict the occurrence areas of rice blast during 2005 -2010. Predicting outcomes show that the prediction accuracy of five-point unbiased sliding optimized GM (1, 1 ) model is higher than the unbiased GM (1,1) model. Finally, combined with the prediction results, the author provides some suggestion for Enshi District in the prevention and control of rice blast in 2010. 展开更多
关键词 Unbiased GM 1 1 model Five-point slide method Optimization PREDICTION Rice blast
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Protective Effects of Oral Fructose-1, 6-diphosphate on Liver Injury in Animal Models
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作者 刘晓岩 李凤云 +1 位作者 池志宏 王银叶 《Journal of Chinese Pharmaceutical Sciences》 CAS 2006年第3期188-193,共6页
Aim To investigate the effects of FDP on different liver injury models to explore the possibility of FDP used as an oral liver protective agent. Methods Chronic liver injury model in rats was induced by carbon tetrach... Aim To investigate the effects of FDP on different liver injury models to explore the possibility of FDP used as an oral liver protective agent. Methods Chronic liver injury model in rats was induced by carbon tetrachloride ( CCl4 ) ; Acute liver injury model in mice was induced by aminogalactose (GAIN) or lipopolysaccharide (LPS). Results In CCl4-induced chronic liver injury model, FDP (1 , 4 g·kg^-1·d^-1, q.d., for 10 weeks) significantly lowered ALT, AST,γ-glutamyl transpeptidase (γ-GT), alkaline phosphatase (ALP), and total bilirubin (T-BIL) in serum compared with vehicle; simultaneously it evidently elevated abnormal total protein (TP), albumin (ALB) and total cholesterol ( T-CHO ) levels in serum; it also dose-dependently reduced hydroxyproline contents in hepatic tissue. 4 g·kg^-1·d^-1 of FDP apparently decreased incidence of hepatic cirrhosis, and alleviated pathological changes of liver tissue. In GaiN-induced model, 1.0 - 4. 0 g·kg^-1·d^-1 of FDP ( bid, for 3 d ) significantly lowered alanine aminotransferase ( ALT ) and aspartate aminotransferase ( AST ) levels in serum ; it also decreased liver coefficient. 4. 0 g·kg^-1·d^-1 of FDP significantly alleviated pathological changes of cell ultra-structures. In LPS-induced model, only high dose of FDP (4. 0 g·kg^-1·d^-1, bid, for 12 d) significantly decreased ALT level in serum. Conclusion This study first demonstrated the protective effect of oral FDP on chronic liver injury caused by CCl4, and confirmed its effect on acute liver injury at the same time, suggesting that Long-term oral FDP is efficacious against liver injury induced by different factors and can be used as an oral liver protective agent in clinic. 展开更多
关键词 liver injury oral fructose-1 6-diphosphate animal models
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城市旅游发展效率与旅游产业集聚的互动关系研究--基于湖南省14市州PVAR模型分析
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作者 伍蕾 倪姣 孙维筠 《旅游论坛》 2021年第4期91-102,共12页
旅游业是城市经济重要产业,其产业联系密切、环节关联性强,具有先天的产业集聚发展优势。较好的产业集聚优势能够促进旅游经济空间结构的优化且提升旅游发展效率;但过度重视集聚程度、夸大集聚产生的经济带动效应也会对经济发展产生消... 旅游业是城市经济重要产业,其产业联系密切、环节关联性强,具有先天的产业集聚发展优势。较好的产业集聚优势能够促进旅游经济空间结构的优化且提升旅游发展效率;但过度重视集聚程度、夸大集聚产生的经济带动效应也会对经济发展产生消极影响。利用DEA模型和区位熵指数测度,分析2009-2019年湖南省14个市州旅游发展效率和产业集聚度指数,借助PVAR模型探讨旅游发展效率与产业集聚度的互动响应关系,研究结论如下:第一,2009-2019年湖南省各市州旅游产业发展效率整体呈全面提升的态势,其中,张家界、长沙、湘潭、衡阳、常德为高效率区;第二,研究期内旅游产业集聚度总体变动不大,其中湘西、张家界旅游业集聚度较高;第三,依据产业发展效率与集聚度互动响应分析,旅游产业效率对旅游产业集聚具有明显的短期促进作用,现阶段湖南地区须警惕旅游业过度集聚的副作用,提升效率是保证旅游业适度规模的有效路径。 展开更多
关键词 旅游产业集聚 旅游发展效率 pvar模型 DEA模型
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交通基础设施、旅游业发展与经济增长的关系研究--基于PVAR模型对广东21市的实证分析
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作者 万红珍 《五邑大学学报(社会科学版)》 2022年第3期50-53,68,93,共6页
采集广东省21市2005—2019年的面板时间序列数据,构建PVAR模型,运用格兰杰因果关系检验、脉冲响应函数对交通基础设施、旅游业发展和经济增长之间的动态影响关系进行了实证分析。研究结果表明:交通基础设施、旅游业发展和经济增长两两... 采集广东省21市2005—2019年的面板时间序列数据,构建PVAR模型,运用格兰杰因果关系检验、脉冲响应函数对交通基础设施、旅游业发展和经济增长之间的动态影响关系进行了实证分析。研究结果表明:交通基础设施、旅游业发展和经济增长两两之间存在双向因果关系,旅游业发展和交通基础设施之间具有长期相互促进作用;交通基础设施和旅游业均对经济增长产生正向影响;而经济增长对交通基础设施产生负向影响,对旅游业短期有正向影响,长期有负向影响。根据研究结论提出了政策建议。 展开更多
关键词 交通基础设施 旅游业发展 经济增长 pvar模型
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基于Sentinel-1/2改进极化指数和纹理特征的土壤含盐量反演模型 被引量:1
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作者 张智韬 贺玉洁 +3 位作者 殷皓原 项茹 陈俊英 杜瑞麒 《农业机械学报》 EI CAS CSCD 北大核心 2024年第1期175-185,共11页
目前Sentinel-1/2协同反演植被土壤含盐量的研究大多是基于Sentinel-2光谱信息和Sentinel-1后向散射系数,没有考虑Sentinel-2光谱信息容易受土壤亮度等信息影响,Sentinel-1后向散射系数容易受土壤粗糙度和水分影响。为进一步提高Sentine... 目前Sentinel-1/2协同反演植被土壤含盐量的研究大多是基于Sentinel-2光谱信息和Sentinel-1后向散射系数,没有考虑Sentinel-2光谱信息容易受土壤亮度等信息影响,Sentinel-1后向散射系数容易受土壤粗糙度和水分影响。为进一步提高Sentinel-1/2协同反演植被土壤含盐量的精度,用水云模型对雷达卫星后向散射系数进行校正,消除植被影响;然后协同Sentinel-2纹理特征,基于VIP、OOB、PCA 3种变量筛选和RF、ELM、Cubist 3种机器学习回归模型构建植被土壤含盐量反演模型。研究结果表明:经过水云模型去除植被影响后的雷达后向散射系数及其极化组合指数与土壤含盐量的相关性有一定程度的提高。不同变量选择方法与不同机器学习方法耦合模型在反演土壤含盐量中,OOB变量筛选方法与RF、ELM和Cubist 3种机器学习方法的耦合模型精度最佳,建模集和验证集的R2都在0.750以上,且验证集的RMSE和MAE均最小;其中OOB-Cubist耦合模型精度最高,且R_(v)^(2)/R_(c)^(2)为0.955,具有良好的鲁棒性。研究可为机器学习协同物理模型、光学卫星协同雷达卫星在土壤含盐量反演中的进一步应用提供思路。 展开更多
关键词 土壤含盐量 Sentinel-1/2 纹理特征 水云模型 机器学习 改进极化指数
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利用“2+1+1”水稻后代材料鉴定模式选育抗倒伏、高食味水稻新品种松粳212
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作者 高洪儒 肖明纲 +4 位作者 刘宝海 孙中义 张擘 郑福余 赵北平 《北方水稻》 CAS 2024年第6期40-42,共3页
松粳212是黑龙江省农业科学院生物技术研究所以五优稻4号为母本、松粳12为父本进行人工杂交,利用“2+1+1”水稻后代材料鉴定模式选育出的抗倒伏、高食味粳稻新品种。该品种于2023年通过黑龙江省农作物品种审定委员会审定,适宜在黑龙江... 松粳212是黑龙江省农业科学院生物技术研究所以五优稻4号为母本、松粳12为父本进行人工杂交,利用“2+1+1”水稻后代材料鉴定模式选育出的抗倒伏、高食味粳稻新品种。该品种于2023年通过黑龙江省农作物品种审定委员会审定,适宜在黑龙江省第一积温带上限区域种植。倒伏会给水稻造成不同程度的减产及品质下降,水稻品种自身的抗倒伏能力是其维持正常生长和产量的关键。利用“2+1+1”水稻后代材料鉴定模式,可在高肥力压力下有效筛选出抗倒伏能力强的水稻品种。 展开更多
关键词 水稻新品种 松粳212 抗倒伏 选育 “2+1+1”水稻后代材料鉴定模式
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大黄灵仙方对胆管炎症大鼠IL-6、EGR-1相关蛋白表达的影响
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作者 王兵 许彦 +2 位作者 黄欣 黄汉基 曾鸿孟 《时珍国医国药》 CAS CSCD 北大核心 2024年第10期2311-2315,共5页
目的通过在没有胆囊的大鼠上构建急性肝胆管炎症模型,探究大黄灵仙方干预肝内胆管结石形成的作用机制。方法取40只雄性SD大鼠随机分为空白正常组、脂多糖模型组、熊去氧胆酸胶囊对照组、大黄灵仙方实验组,每组各10只。正常组予常规饲料... 目的通过在没有胆囊的大鼠上构建急性肝胆管炎症模型,探究大黄灵仙方干预肝内胆管结石形成的作用机制。方法取40只雄性SD大鼠随机分为空白正常组、脂多糖模型组、熊去氧胆酸胶囊对照组、大黄灵仙方实验组,每组各10只。正常组予常规饲料饲养;模型组、对照组和实验组在胆总管一次性注射1.25mg/kg脂多糖,同时对照组予熊去氧胆酸灌胃干预,实验组予大黄灵仙方灌胃干预,共7d。取血液进行ELISA检测,采取肝脏组织进行Masson染色、WB检测IL-6和EGR-1蛋白表达的情况。结果与其他三组相比,模型组胆管细胞纤维化程度明显;各组大鼠血液及肝脏组织IL-6、EGR-1蛋白表达总体差异有统计学意义(P<0.01);与正常组相比较,模型组和对照组血液及肝脏组织IL-6、EGR-1蛋白表达差异均明显增高(P<0.01);与正常组相比较,实验组血液及肝脏IL-6、EGR-1蛋白表达无明显差异(P>0.05)。结论大黄灵仙颗粒可能通过抑制胆管炎症大鼠模型IL-6、EGR-1等炎症因子的释放,减轻肝损伤,使之趋于正常水平,从而达到阻断结石的形成。 展开更多
关键词 炎症模型 大黄灵仙 IL-6 EGR-1
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基于新型“1+X+N”人才培养模式的一流本科课程建设探索 被引量:1
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作者 刘璐玲 陈里 吴健学 《高教学刊》 2024年第19期25-28,共4页
为了适应时代的发展需求,响应国务院提出的在应用型本科高校启动“学历证书+若干职业技能等级证书”制度(即“1+X”证书制度)的试点工作,民办本科院校积极探索“1+X+N”人才培养新模式。在人才培养新模式下,省级一流本科课程光纤通信技... 为了适应时代的发展需求,响应国务院提出的在应用型本科高校启动“学历证书+若干职业技能等级证书”制度(即“1+X”证书制度)的试点工作,民办本科院校积极探索“1+X+N”人才培养新模式。在人才培养新模式下,省级一流本科课程光纤通信技术课程组从明确课程定位、推动教学改革、加大资源建设、优化教学内容与实施过程、推进课程思政、改善课程成绩评定等方面开展工作,努力提升学生在光纤通信方面的综合应用能力,培养出满足新时代通信发展需求的高质量人才。 展开更多
关键词 1+X+N”人才培养新模式 一流课程建设 课程思政 教学改革 教学评价
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1+X证书制度背景下“育训结合、能力递进、书证融通”育人模式的探索与实践 被引量:1
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作者 李雪梅 《化工管理》 2024年第16期34-37,共4页
2019年《国家职业教育改革实施方案》要求启动“学历证书+若干职业技能等级证书”制度。文章基于“1+X”证书制度下的书证融通在实施过程中存在的问题,从模块化课程体系构建、信息化资源与教材开发、平台搭建、师资队伍建设、考核评价... 2019年《国家职业教育改革实施方案》要求启动“学历证书+若干职业技能等级证书”制度。文章基于“1+X”证书制度下的书证融通在实施过程中存在的问题,从模块化课程体系构建、信息化资源与教材开发、平台搭建、师资队伍建设、考核评价体系、体制机制保障等方面开展研究,逐步构建学生、学校、行业、企业、社会多方共赢的良好局面,为实现新时代中国职业教育事业的全面优质发展奠定基础。 展开更多
关键词 职业教育 1+X证书制度 育人模式
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区域性研发投入、专利产出与经济高质量发展——基于山东省的PVAR模型研究
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作者 张伟 孙广斌 《山东工商学院学报》 2024年第1期13-21,共9页
随着我国经济由高速增长向高质量发展转变,研发投入、专利产出与经济高质量发展的关系越来越密切。在知识经济时代,如何最大化发挥研发投入、专利产出对经济高质量发展的贡献问题成为当前理论研究的重点。通过构建山东省2005—2020年面... 随着我国经济由高速增长向高质量发展转变,研发投入、专利产出与经济高质量发展的关系越来越密切。在知识经济时代,如何最大化发挥研发投入、专利产出对经济高质量发展的贡献问题成为当前理论研究的重点。通过构建山东省2005—2020年面板向量自回归(PVAR)模型,对三者关系进行实证检验。研究结果与传统理念认知以及山东省经济地位存在较大反差,即无论是从静态模型上还是动态模型上,山东省研发投入、专利产出效率均没有有效发挥出对经济高质量发展的积极推动效应。因此,山东省需要因地制宜制定并完善研发投入、专利产出及人才储备方面的配套体系策略,最大程度发挥研发投入、专利产出对地区高质量经济发展的潜力作用,为其他区域性经济发展提供经验借鉴。 展开更多
关键词 研发投入 专利产出 经济增长 pvar模型
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基于GF-1数据的耕地土壤镉(Cd)含量遥感估算方法
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作者 张龙其 郭云开 +1 位作者 董胜光 刘新良 《测绘通报》 CSCD 北大核心 2024年第3期8-12,94,共6页
本文采用多种光谱变换和回归分析方法探索了使用GF-1卫星影像监测耕地土壤镉(Cd)含量的可行性。首先针对获取的GF-1原始影像数据,在完成预处理及剔除植被信息后进行倒对数、平方根和反正弦平方根变换,生成4套光谱影像;然后分别用采样点... 本文采用多种光谱变换和回归分析方法探索了使用GF-1卫星影像监测耕地土壤镉(Cd)含量的可行性。首先针对获取的GF-1原始影像数据,在完成预处理及剔除植被信息后进行倒对数、平方根和反正弦平方根变换,生成4套光谱影像;然后分别用采样点5 m缓冲区内各套影像光谱统计值与Cd含量进行相关性分析和多种回归分析。选择模型决定系数最高(>95%)的反正弦平方根变换后的自适应重加权回归方法构建的线性回归模型作为遥感估算模型。遥感估算结果在稻田积水、边缘地带等出现了异常估算值;笔者分析原因后应用线性插值的方法得到最终估算结果。相关性分析和建模精度表明该方法是可行的,有望应用于实际土壤质量监测和土地管理中。 展开更多
关键词 耕地土壤 CD含量 GF-1 光谱特征 反演模型
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