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Assessment of Regional Myocardial Function in Patients with Hypertrophic Cardiomyopathy by Tissue Strain Imaging 被引量:2
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作者 熊润青 谢明星 +1 位作者 王新房 吕清 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2006年第3期334-337,共4页
The value of tissue strain imaging (SI) in regional myocardial systolic and diastolic func tion assessment was studied. In 18 patients with nonobstructive hypertrophic cardiomyopathy (HCM) and 20 age-matched healt... The value of tissue strain imaging (SI) in regional myocardial systolic and diastolic func tion assessment was studied. In 18 patients with nonobstructive hypertrophic cardiomyopathy (HCM) and 20 age-matched healthy subjects, regional myocardial longitudinal peak systolic strain in eject time (represented by εet) was measured at basal, mid and apical segments of septal, lateral and posterior walls of the left ventricle (LV) and compared between groups, εet had no significant difference between segments in control group (P〉0.05), which displayed a decreasing trend from basal segments to apical ones. εet in the HCM group was significantly decreased (P(0. 05) as compared with that in the healthy group. In the HCM group, εet in the midseptum was significantly less than at the basal and apical septum, and was also less than at the rest LV walls in the same group (P〉0.01). The systolic reversed εet was noticed in 35% of the hypertrophic segments in HCM group. Significantly negative correlation existed between the absolute value of εet and wall thickness in the midseptum (r= -0.83). The post-systolic strain(PSS) segment number the and amplitudes in healthy group were significantly less than those in HCM group (P〈0.05). Both regional myocardial systolic and diastolic functions were impaired in hypertrophic or non-hypertrophic segments in patients with the HCM, especially in hypertrophic segments. Strain imaging technique is a sensitive and accura tool in myocardial dysfunction assessment. 展开更多
关键词 ECHOCARDIOGRAPHY tissue strain imaging hypertrophic cardiomyopathy regional myocardial function
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Spatial Agglomeration and Diffusion of Population Based on a Regional Density Function Approach:A Case Study of Shandong Province in China
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作者 Xiaohan Zhao Yanbin Chen 《Journal of Geographical Research》 2023年第3期61-80,共20页
Population density functions have long been used to describe the spatial structure of regional population distributions.Several studies have been conducted to examine the population distribution in Shandong Province,C... Population density functions have long been used to describe the spatial structure of regional population distributions.Several studies have been conducted to examine the population distribution in Shandong Province,China,but few have applied regional density functions to the analysis.Therefore,based on the 2000,2010,and 2020 population censuses,this study used monocentric and polycentric regional density functions to study the characteristics of population agglomeration and diffusion in Shandong.This is followed by an in-depth discussion based on population growth rate data and hot-and cold-spot analyses.The results showed that the Shandong Province population was spatially unevenly distributed.Population growth rates were higher in urban centers and counties,with more significant changes in population size in the eastern coastal areas than in the inland areas.As verified in this study,the logarithmic form of the single-center regional density function R2 was greater than 0.8,which was in line with the population spatial structure of Shandong Province.During the study period,the estimated population density of the regional center and the absolute value of the regional population density gradient both increased,indicating a clear and increasing trend of centripetal agglomeration of regional centers over the study period.Overall,the R2 value of the multicenter region density function was higher than that of the single-center region density function.The polycentric regional density function showed that the population density gradient of some centers had a downward trend,which reflected the spatial development trend of outward diffusion in these centers.Meanwhile,the variation in the estimated population density and the population density gradient exhibited differences in the central population distribution patterns at different levels. 展开更多
关键词 regional density functions Population spatial structure Shandong Province
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Functional regionalization with the restriction of ecological shelter zones: A case of Zhaotong in Yunnan 被引量:6
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作者 DU Yu WANG Chuansheng ZHAO Haiying YANG Xiaoguang 《Journal of Geographical Sciences》 SCIE CSCD 2007年第3期365-374,共10页
Ecological shelter zones reconstruction is an ecosystem restoration and conservation project aimed to the ecological safety of nations, regions and basins. Reconstruction of ecological shelter zones of the upper reach... Ecological shelter zones reconstruction is an ecosystem restoration and conservation project aimed to the ecological safety of nations, regions and basins. Reconstruction of ecological shelter zones of the upper reaches of the Yangtze River became one of the most important tasks of Western Development strategy. This article, taking Zhaotong as an example, studies the functional regionalization of ecological shelter zones. The study supplies a case for functional regionalization of small and medium regions whose main tasks are environment reservation. With the guidance of theories of functional regionalization, and based on the analysis of Zhaotong's natural, ecological and socioeconomic factors, the paper suggests five principles for factors selection. These principles include: (1) reversing order evaluation; (2) selecting main factors; (3) keeping the integrality of administrative regions of towns; and (4) making the products acceptable by local government. To analyze spatial status of selected factors, LUCC data in 2002, 1:50,000 relief maps and town-unit socioeconomic statistical data in 2004 are used. RS and GIS tools are also applied to melt traditional and modern geographical methods. This would be useful to functional regionalization research in mountainous areas. As a conclusion, the leading functional regions of ecological conservation or economic development are suggested, respectively. Zhaotong city is divided into two-level functional regions. The first-level includes three leading functional regions and they will lead developing direction of sub-regions. The second-level includes eight sub-regions, which are policy implemented regions, and will supply guidance to Zhaotong's ecological shelter zones reconstruction. 展开更多
关键词 ecological shelter zones functional regionalization Zhaotong
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Major Function Oriented Zone: New Method of Spatial Regulation for Reshaping Regional Development Pattern in China 被引量:30
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作者 FAN Jie SUN Wei +1 位作者 ZHOU Kan CHEN Dong 《Chinese Geographical Science》 SCIE CSCD 2012年第2期196-209,共14页
Newest planning methods implemented by Chinese government are promoting a coordinated regional development and shaping an orderly spatial structure by applying the regulation of territorial function. This article anal... Newest planning methods implemented by Chinese government are promoting a coordinated regional development and shaping an orderly spatial structure by applying the regulation of territorial function. This article analyzes the problems of spatial planning and regional strategy caused by the wrongly-set primary goal of economic development; it states that the three-fold objective of competitiveness, sustainability, and welfare fairness shall be the principal for China to implement the spatial regulation in the new era; it discusses about theoretical thoughts and technology framework of conducting the ′Major Function Oriented Zone′ based on their different major functions that each region plays in urbanization and industrialization, ecological constructions, grain productions, and protection of natural and cultural heritages; it introduces the new concept of ′Major Function Oriented Zone′ that include the major functions category, the stereo regional equilibrium mode, the two-level zoning specification, and the territorial development intensity; it offers a zoning scheme that defines development-optimized and development-prioritized zones as regions with massive urbanization and industrialization, development-restricted zones as ecological constructing or grain producing regions, development-prohibited zones as natural and cultural heritage protecting regions; and finally it addresses the main obstacle for implementing ′Major Function Oriented Zone′, which is the institutional arrangement of the supreme goal of high GDP growth rate that is currently being implemented. 展开更多
关键词 Major function Oriented Zone (MFOZ) spatial regulation regional development China
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Speckle tracking echocardiography to assess regional ventricular function in patients with apical hypertrophic cardiomyopathy 被引量:8
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作者 María Cristina Saccheri Tomás Francisco Cianciulli +7 位作者 Luis Alberto Morita Ricardo JoséMéndez Martín Alejandro Beck Juan Enrique Guerra Alberto Cozzarin Luciana Jimena Puente Lorena Romina Balletti Jorge Alberto Lax 《World Journal of Cardiology》 CAS 2017年第4期363-370,共8页
AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patient... AIM To explore regional systolic strain of midwall and endocardial segments using speckle tracking echocardiography in patients with apical hypertrophic cardiomyopathy(HCM).METHODS We prospectively assessed 20 patients(mean age 53 ± 16 years,range:18-81 years,10 were male),with apical HCM. We measured global longitudinal peak systolic strain(GLPSS) in the midwall and endocardium of the left ventricle. RESULTS The diastolic thickness of the 4 apical segments was 16.25 ± 2.75 mm. All patients had a normal global systolicfunction with a fractional shortening of 50% ± 8%. In spite of supernormal left ventricular(LV) systolic function,midwall GLPSS was decreased in all patients,more in the apical(-7.3% ±-8.8%) than in basal segments(-15.5% ±-6.93%),while endocardial GLPPS was significantly greater and reached normal values(apical:-22.8% ±-7.8%,basal:-17.9% ±-7.5%). CONCLUSION This study shows that two-dimensional strain was decreased mainly confined to the mesocardium,while endocardium myocardial deformation was preserved in HCM and allowed to identify subclinical LV dysfunction. This transmural heterogeneity in systolic strain had not been previously described in HCM and could be explained by the distribution of myofibrillar disarray in deep myocardial areas. The clinical application of this novel finding may help further understanding of the pathophysiology of HCM. 展开更多
关键词 Apical hypertrophic cardiomyopathy Twodimensional strain Speckle tracking ENDOCARDIUM Midwall regional myocardial systolic function
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Left Ventricular Regional Systolic Function in Patient with Hypertrophic Cardiomyopathy by Quantitative Tissue Velocity Imaging 被引量:3
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作者 李秀兰 邓又斌 杨好意 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2006年第1期153-156,共4页
The left ventricular regional systolic functions in patients with hypertrophic cardiomyopathy (HCM) were assessed by using quantitative tissue velocity imaging (QTVI). Left ventricular (LV) regional myocardial v... The left ventricular regional systolic functions in patients with hypertrophic cardiomyopathy (HCM) were assessed by using quantitative tissue velocity imaging (QTVI). Left ventricular (LV) regional myocardial velocity along long- and short-axis in 31 HCM patients and 20 healthy subjects were analyzed by QTVI, and the regional myocardial systolic peak velocities (MVS) were measured. Mean MVS at each level including mitral annular, basal, middle and apical segments were calculated. The ratio of MVS along long-axis to that along short-axis (Ri) at basal and middle segments of the LV posterior wall and ventricular septum were calculated. The results showed that mean MVS was slower at each level including mitral annular, basal, middle and apical segments in the HCM patients than that in the healthy subjects (P〈0.01). There were no significant differences in mean MVS between obstructive and non-obstructive groups in HCM patients. MVS of all regional myocardial segments along long-axis in the HCM patients were significantly slower than that in the healthy subjects (P〈0.05), but there was no significant difference in MVS of all regional myocardial segments along long-axis between hypertrophied and non-hypertrophied group in the HCM patients. Ri was significantly lower in the HCM patients than that in the healthy subjects. The LV regional myocardial contractility along long-axis was impaired not only in the hypertrophied wall but also in the non-hypertrophied one in patients with HCM, suggesting that QTVI can assess accurately LV regional systolic function in patient with HCM and provides a novel means for an early diagnosis before and independent of hypertrophy. 展开更多
关键词 quantitative tissue velocity imaging hypertrophic cardiomyopathy left ventricular regional systolic function
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Ecological function regionalization of fluvial corridor landscapes and measures for ecological regeneration in the middle and lower reaches of the Tarim River, Xinjiang of China 被引量:2
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作者 Zhou, HuaRong Xia, DuNing 《Journal of Arid Land》 SCIE 2010年第2期123-132,共10页
The middle and lower reaches of the Tarim River are currently one of the main regions of ecological restoration in the arid areas of western China.Using the principles and method of landscape ecology,this study has ch... The middle and lower reaches of the Tarim River are currently one of the main regions of ecological restoration in the arid areas of western China.Using the principles and method of landscape ecology,this study has chosen the fluvial corridor landscape in the middle and lower reaches of the Tarim River,and discusses the region’s ecologically functional regionalization system and issues related to its practical classification.On this basis the corresponding regionalizing principles and standards were developed which were used to qualitatively divide the three main landscapes as the ecologically functional areas in the drainage basin.The paper has also analyzed the characteristic of the study areas,and has put forward the measures for its ecological restoration. 展开更多
关键词 fluvial corridor landscape ecological function regionalization ecological regeneration Tarim River
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Aging effects of regional activation in a spatial task A functional magnetic resonance imaging study 被引量:1
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作者 Jong-Rak Park Dae-Woon Lim +6 位作者 Mi-Hyun Choi Su-Jeong Lee Jin-Seung Choi Hyung-Sik Kim Jeong-Han Yi Gye-Rae Tack Soon-Cheol Chung 《Neural Regeneration Research》 SCIE CAS CSCD 2009年第9期663-667,共5页
BACKGROUND: An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging (fMRI). However, little is known ... BACKGROUND: An increasing number of studies have shown the effects of aging in basic cognitive processing and higher cognitive functions using functional magnetic resonance imaging (fMRI). However, little is known about the aging effects in diverse cognitive abilities, such as spatial learning and reasoning. OBJECTIVE: To investigate the effect of aging on spatial cognitive performance and regional brain activation based on fMRI. DESIGN, TIME, AND SETTING: A block design for fMRI observation. This study was performed at the fMRI Laboratory, Brain Science Research Center, Korea Advanced Institute of Science and Technology from March 2006 to May 2009. PARTICIPANTS: Eight right-handed, male, college students in their 20s (mean age 21.5 years) and six right-handed, male, adults in their 40s (mean age 45.7 years), who graduated from college, participated in the study. All subjects were healthy and had no prior history of psychiatric or neurological disorders. METHODS: A spatial task was presented while brain images were acquired using a 3T fMRI system (ISOL Technology, Korea). The spatial tasks involved selecting a shape that corresponded to a given figure using four examples, as well as selecting a development figure of a diagram. MAIN OUTCOME MEASURES: The accuracy rate (number of correct answers/total number of items x 100%) of spatial tasks was calculated. Using the subtraction procedure, the activated areas in the brain during spatial tasks were color-coded by T-score. The double subtraction method was used to analyze the effect of aging between the two age groups (20s versus 40s). RESULTS: The cerebellum, occipital lobe, parietal lobe, and frontal lobe were similarly activated in the two age groups. Increased brain activations, however, were observed in bilateral parietal and superior frontal lobes of the younger group. More activation was observed in bilateral middle frontal and right inferior frontal lobes in the older group. Compared with the older group, the younger men exhibited greater spatial performance (P = 0.012). CONCLUSION: Reduced cognitive function correlated with decreased activation areas in the parietal lobe and altered activation in the frontal lobe. 展开更多
关键词 functional magnetic resonance imaging AGING regional activation spatial task
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Altered spontaneous brain activity in patients with diabetic optic neuropathy:A resting-state functional magnetic resonance imaging study using regional homogeneity 被引量:1
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作者 Gui-Ying Guo Li-Juan Zhang +7 位作者 Biao Li Rong-Bin Liang Qian-Min Ge Hui-Ye Shu Qiu-Yu Li Yi-Cong Pan Chong-Gang Pei Yi Shao 《World Journal of Diabetes》 SCIE 2021年第3期278-291,共14页
BACKGROUND Diabetes is a common chronic disease.Given the increasing incidence of diabetes,more individuals are affected by diabetic optic neuropathy(DON),which results in decreased vision.Whether DON leads to abnorma... BACKGROUND Diabetes is a common chronic disease.Given the increasing incidence of diabetes,more individuals are affected by diabetic optic neuropathy(DON),which results in decreased vision.Whether DON leads to abnormalities of other visual systems,including the eye,the visual cortex,and other brain regions,remains unknown.AIM To investigate the local characteristics of spontaneous brain activity using regional homogeneity(ReHo)in patients with DON.METHODS We matched 22 patients with DON with 22 healthy controls(HCs).All subjects underwent resting-state functional magnetic resonance imaging.The ReHo technique was used to record spontaneous changes in brain activity.Receiver operating characteristic(ROC)curves were applied to differentiate between ReHo values for patients with DON and HCs.We also assessed the correlation between Hospital Anxiety and Depression Scale scores and ReHo values in DON patients using Pearson correlation analysis.RESULTS ReHo values of the right middle frontal gyrus(RMFG),left anterior cingulate(LAC),and superior frontal gyrus(SFG)/left frontal superior orbital gyrus(LFSO)were significantly lower in DON patients compared to HCs.Among these,the greatest difference was observed in the RMFG.The result of the ROC curves suggest that ReHo values in altered brain regions may help diagnose DON,and the RMFG and LAC ReHo values are more clinically relevant than SFG/LFSO.We also found that anxiety and depression scores of the DON group were extremely negatively correlated with the LAC ReHo values(r=-0.9336,P<0.0001 and r=-0.8453,P<0.0001,respectively).CONCLUSION Three different brain regions show ReHo changes in DON patients,and these changes could serve as diagnostic and/or prognostic biomarkers to further guide the prevention and treatment of DON patients. 展开更多
关键词 DIABETES Diabetic optic neuropathy regional homogeneity Resting state functional magnetic resonance imaging Brain activity
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Spatial Function Regionalization Based on an Ecological-economic Analysis in Wuxi City, China
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作者 SUN Wei CHEN Wen JIN Zhifeng 《Chinese Geographical Science》 SCIE CSCD 2019年第2期352-362,共11页
As a result of rapid urbanization in China, urban sprawl has increased rapidly, and land-use regulation and smart urban growth are equally important. Spatial function regionalization can provide the scientific groundw... As a result of rapid urbanization in China, urban sprawl has increased rapidly, and land-use regulation and smart urban growth are equally important. Spatial function regionalization can provide the scientific groundwork for the regulation of land use and protection. This paper probes the system of evaluation indices and applies the methods of spatial analysis and classification clustering to the calculation of the ecologically significant value and economically significant value in each evaluation unit. After use of a classification matrix integrated by the two significant values, city space can be divided into four functional types, namely, feasible development area, moderate development area, moderate conservation area and prohibited exploiting area, and these are the basis for spatial development and control. 展开更多
关键词 SPATIAL function regionalIZATION SPATIAL analysis ecologically SIGNIFICANT VALUE economically SIGNIFICANT VALUE urbanized region
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Trade-off and Synergy of Rural Functions Under County Depopulation in the Typical Black Soil Region of Northeast China 被引量:2
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作者 LI Dongmei WEN Qing +1 位作者 QI Yue ZHANG Pingyu 《Chinese Geographical Science》 SCIE CSCD 2023年第4期616-633,共18页
As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainab... As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainable development.In this study,we focused on the impacts of depopulation on the evolution and interrelationship of rural subfunctions.Based on the rural function indexes system,the TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)method,spatial analysis method,and mathematical statistics analysis method were used to summarize the spatial and temporal characteristics of rural function development,as well as the effect of population shrinkage in the typical black soil region of Northeast China.The results showed that depopulation varied in the extent and duration between the forested region and plain areas,which both impacted the trajectories of rural subfunctions evolution.For the economic development function and ecological conservation function,the effect of continuous slight depopulation was beneficial,while the effect of rapid depopulation was adverse,which was exactly opposite to the agricultural production function.All forms of population shrinkage were conducive to the development of the social security function.With the deepening population shrinkage,depopulation mainly promoted the collaborative development between subfunctions in this study,except the relationship between agricultural production and social security function.But effects of depopulation on the interrelationship of rural subfunctions varied between the forested region and plain areas in some cases.The results provided evidence for the cognition that population shrinkage had complicated effects on rural subfunctions. 展开更多
关键词 rural function depopulation trade-off and synergy typical black soil region Northeast China
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Functional magnetic resonance imaging of regional homogeneity changes in parkinsonian resting tremor
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作者 Xian Liu Bo Liu Jun Chen Zhiguang Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第11期811-815,共5页
Regional homogeneity analysis of low-frequency blood oxygenation level-dependent signals from neighboring voxels enables the analysis of local neuronal synchrony. Both structural magnetic resonance imaging and resting... Regional homogeneity analysis of low-frequency blood oxygenation level-dependent signals from neighboring voxels enables the analysis of local neuronal synchrony. Both structural magnetic resonance imaging and resting-state functional magnetic resonance imaging scans were collected from nine Parkinson's disease patients with right resting tremor, and from eight age-matched normal controls. Regional homogeneity was compared between Parkinson's disease patients and controls. The results revealed that regional homogeneity was increased in several brain regions, including the right precuneus, right superior parietal gyrus, left anterior cingulate cortex, right middle frontal gyrus and right inferior frontal gyrus. Conversely, regional homogeneity was decreased in the cerebellar vermis in Parkinson's disease patients compared with healthy controls. 展开更多
关键词 Parkinson's disease resting tremor regional homogeneity functional magnetic resonance imaging resting state brain activity
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Regional Logistics Demand Forecast Based on Least Square and Radial Basis Function
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作者 WEI Leqin ZHANG Anguo 《Journal of Donghua University(English Edition)》 EI CAS 2020年第5期446-454,共9页
Regional logistics demand forecast is the basis for government departments to make logistics planning and logistics related policies.It has the characteristics of a small amount of data and being nonlinear,so the trad... Regional logistics demand forecast is the basis for government departments to make logistics planning and logistics related policies.It has the characteristics of a small amount of data and being nonlinear,so the traditional prediction method can not guarantee the accuracy of prediction.Taking Xiamen City as an example,this paper selects the primary industry,the secondary industry,the tertiary industry,the total amount of investment in fixed assets,total import and export volume,per capita consumption expenditure,and the total retail sales of social consumer goods as the influencing factors,and uses a combining model least square and radial basis function(LS-RBF)neural network to analyze the related data from years 2000 to 2019,so as to predict the logistics demand from years 2020 to 2024.The model can well fit the training data,and the experimental results obtained from the comparison between the predicted value and the actual value in 2019 show that the error rate is very small.Therefore,the prediction results are reasonable and reliable.This method has high prediction accuracy,and it is suitable for irregular regional logistics demand forecast. 展开更多
关键词 regional logistics demand forecast least square and radial basis function(LS-RBF)
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中国城市碳排放绩效:动态分解、空间差异与影响因素 被引量:4
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作者 魏丽莉 侯宇琦 曹昊煜 《统计与信息论坛》 北大核心 2024年第2期69-83,共15页
以非径向方向距离函数为框架,构造全要素碳排放绩效指数对中国2006—2019年城市碳排放治理绩效进行测度。在此基础上从经济含义、跨期动态变化、区域均衡等层面对全要素碳排放绩效指数进行多维分解,检验中国城市碳排放绩效的影响因素。... 以非径向方向距离函数为框架,构造全要素碳排放绩效指数对中国2006—2019年城市碳排放治理绩效进行测度。在此基础上从经济含义、跨期动态变化、区域均衡等层面对全要素碳排放绩效指数进行多维分解,检验中国城市碳排放绩效的影响因素。结果表明:第一,样本期内全国城市平均全要素碳排放绩效指数总体呈波动上升态势,动态分解结果显示,中国各地的平均碳排放绩效水平不断改进,创新效应对其贡献逐年增大但赶超效应贡献不足;第二,空间分异方面,珠三角、长三角、粤闽浙沿海、长江中游等东部地区城市群不仅平均碳排放绩效水平普遍较高,且碳排放绩效的增长速度较快,中西部地区仅成渝城市群碳排放绩效表现较好,中原、京津冀等城市群近年来碳排放绩效的改善速度较快;第三,基尼系数测度及其分解显示,近年中国城市碳排放绩效指数的分异程度逐步加深,分异成因主要为城市群组间差异,城市群内部差异贡献度较低;第四,Lasso分析及双固定面板模型分析结果显示,经济发展水平、清洁能源使用、金融发展、绿色环保和科技支持能够有效改善城市层面的碳排放绩效,能源消耗强度和第二产业就业人员比重对碳排放绩效具有负面影响;最后,城市群因子探测结果显示,各城市群间的驱动因子存在一定差异。 展开更多
关键词 碳排放 时空格局 区域差异 共同前沿面 非径向方向距离函数
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粮食功能区视角下农业高质量发展水平及区域差异研究 被引量:4
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作者 杨辉 张竹 习凯杰 《生态经济》 北大核心 2024年第4期105-113,共9页
基于2016—2020年省级农业发展数据,综合运用改进后的熵值法、Dagum基尼系数等方法,测算了全国及粮食功能区农业高质量发展水平及差异程度,并进一步从一级指标入手,分析了引起区域差异产生和波动的原因。结果表明:(1)三大粮食功能区的... 基于2016—2020年省级农业发展数据,综合运用改进后的熵值法、Dagum基尼系数等方法,测算了全国及粮食功能区农业高质量发展水平及差异程度,并进一步从一级指标入手,分析了引起区域差异产生和波动的原因。结果表明:(1)三大粮食功能区的农业高质量发展水平均保持上升趋势,按水平由大到小依次为“主销区、主产区、平衡区”。(2)三大粮食功能区存在区域差异,区域间的差异是总体差异的主要来源,区域内差异也出现不同程度的变动。(3)主销区内部差异波动与产业升级指标相关,主产区内部差异波动主要受产出高效和产业升级指标影响,平衡区内部差异波动源于产业升级指标中的追赶效应。(4)区域间差异主要源自产业升级指标,成果共享指标也起到部分影响作用,三大区域各具发展短板。因此,为提升我国农业高质量发展均衡性,应坚持“因地制宜”原则,以水平最低的平衡区为发力点,以产业升级指标为抓手,以各区域发展短板为突破,采取更具针对性的发展措施。 展开更多
关键词 粮食功能区 农业高质量 区域差异 改进后的熵值法 Dagum基尼系数
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县域教育的兜底功能:社会基础与实现路径 被引量:1
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作者 杨华 《南通大学学报(社会科学版)》 北大核心 2024年第3期125-136,160,共13页
县域教育深嵌在县域社会之中,既要承担一般化的教育功能,还要回应县域社会独特的教育需求。由于县域社会主要是乡村社会,当前乡村社会从整体走向碎片、农民家庭从完整走向分割、隔代教育的社会功能不齐全、教育城镇化加剧乡村学校衰败... 县域教育深嵌在县域社会之中,既要承担一般化的教育功能,还要回应县域社会独特的教育需求。由于县域社会主要是乡村社会,当前乡村社会从整体走向碎片、农民家庭从完整走向分割、隔代教育的社会功能不齐全、教育城镇化加剧乡村学校衰败等社会变迁,使得县域教育中家庭主体、社会主体缺位,导致一些重要的教育功能无法实现,使县乡的孩子们的权利受到侵害,给其成长带来不良影响。为此,县乡学校要对县乡孩子们的教育进行权利和责任兜底。要实现教育兜底功能,县域教育就要集中力量办好乡校、县中及县域职业学校要向多中心教育目标转型,以确保县乡的孩子们有平等的机会和权利通过县域教育走出县乡,成为有知识、懂规范、人格健全、适应社会的人。 展开更多
关键词 县域教育 养成教育 城镇化 小规模学校 兜底功能
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区域土特征函数:收敛性
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作者 袁晓铭 卢坤玉 +2 位作者 李兆焱 陈卓识 吴晓阳 《岩土工程学报》 EI CAS CSCD 北大核心 2024年第1期26-34,共9页
无论从一个地区内建立N-s_(v)关系曲线的工程应用角度还是作为区域土特征理论的必要组成部分,构建科学的N-v_(s)函数所需的数组量都是重要问题,但以往研究为空白。采用实测数据的随机分析,研究不同样本数量下N-v_(s)特征函数的稳定性和... 无论从一个地区内建立N-s_(v)关系曲线的工程应用角度还是作为区域土特征理论的必要组成部分,构建科学的N-v_(s)函数所需的数组量都是重要问题,但以往研究为空白。采用实测数据的随机分析,研究不同样本数量下N-v_(s)特征函数的稳定性和收敛性,并提出构建不同精度N-v_(s)特征函数的数组阈值。实测数据来源于4个国家9个地区,共11个工况,对此分别进行随机分析的结果表明,随样本数量增加,N-v_(s)特征函数具有稳定性与收敛性。研究表明,一个地区内取N-v_(s)数组超过50,100,200和800,则可分别得到变异系数小于0.2,0.15,0.10和0.05的N-s_(v)特征函数。 展开更多
关键词 区域土 特征函数 N-v_(s)特征函数 N-v_(s)数组 收敛阈值
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旱地小麦区试品系中抗旱高产相关基因的KASP标记检测
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作者 高洁 王富延 +8 位作者 宋国琦 孔淑鑫 李玉莲 张淑娟 张荣志 李吉虎 李根英 刘鹏 李玮 《山西农业科学》 2024年第4期9-15,共7页
利用分子标记检测小麦区试品系,明确其优异等位基因组成,有利于进一步精准改良利用。分析KASP标记检测中存在的问题,有助于促进分子育种应用。以山东省2021—2022年小麦旱地区试24份参试品系为材料,利用32个抗旱高产相关基因的KASP标记... 利用分子标记检测小麦区试品系,明确其优异等位基因组成,有利于进一步精准改良利用。分析KASP标记检测中存在的问题,有助于促进分子育种应用。以山东省2021—2022年小麦旱地区试24份参试品系为材料,利用32个抗旱高产相关基因的KASP标记,分析KASP标记检测中存在的异常结果和材料的优异等位基因利用情况。结果表明,未知基因型产生的主要原因是KASP反应失败或非特异扩增。混合DNA样品检测结果为杂合的主要原因是单株间基因型不一致,次要原因是错误分型。32个KASP标记中,14个标记的优异等位基因检出率超过83%,表明这些基因在育种中已经得到有效利用;17个标记的优异等位基因检出率低于50%,其中,WRKY51-2B、AX-95025477-7B、SnRK2.4A3、TaMoc-2433和NCED15个标记的优异等位基因未检出,表明这些基因在育种中利用较少,可通过分子标记辅助选择开展遗传改良。24份材料中,HQ04携带20个优异等位基因,是数量最多的,可作为基因供体用于育种。利用KASP标记开展辅助选择定向精准提高优异等位基因在小麦育种中的利用率仍有可为。 展开更多
关键词 小麦 抗旱 功能基因 KASP标记 区试品系
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中国极地海洋微生物研究进展
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作者 张熙颖 张玉忠 《极地研究》 CAS CSCD 北大核心 2024年第3期352-360,共9页
极地海洋环境蕴含丰富的微生物资源,其独特的生命特征、特殊的极端环境适应及生态效应机制,都有着重要的科学研究意义及应用开发前景。回顾我国近10年来在极地海洋微生物领域的研究,所取得的主要进展包括:(1)揭示了南北极海洋微生物群... 极地海洋环境蕴含丰富的微生物资源,其独特的生命特征、特殊的极端环境适应及生态效应机制,都有着重要的科学研究意义及应用开发前景。回顾我国近10年来在极地海洋微生物领域的研究,所取得的主要进展包括:(1)揭示了南北极海洋微生物群落特有的结构和功能、二甲基硫/二甲基巯基丙酸内盐(DMS/DMSP)循环相关基因及可培养细菌基因组的独特生物地理学特征;(2)发现了极地海洋细菌通过代谢DMSP抵御原生动物捕食的新生态功能、温度响应新机制及新的几丁质氧化降解利用通路;(3)揭示了噬菌体对极地海洋细菌种群的调控作用;(4)阐明了极地海洋细菌产生的系列新型有机质降解酶的催化机制及其应用潜力;(5)建立了极地海洋细菌胞外多糖的制备工艺,评估了其在医学及食品等领域的应用潜力;(6)分离鉴定了系列极地海洋微生物新物种。以上研究成果先后发表在Nature Microbiology,Nature Communica-tions,Microbiome,ISME Journal等国际知名期刊上,提升了我国极地海洋微生物研究的水平、影响力和话语权。未来加强多学科交叉研究及前沿技术应用研发将进一步促进我国极地海洋微生物学研究的发展。 展开更多
关键词 海洋微生物 功能 机制 研究进展 极区
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基于改进Faster RCNN的微操作空间目标检测算法 被引量:1
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作者 陈国良 庞裕双 《传感器与微系统》 CSCD 北大核心 2024年第3期144-147,151,共5页
将Faster RCNN引入微操作系统的目标检测之中。针对微操作空间下待检测目标存在尺度变化和在显微镜放大倍数较小时,待检测目标尺度过小、特征不明显的问题,提出了一种基于改进Faster RCNN的微操作空间目标检测算法。使用在图像分类任务... 将Faster RCNN引入微操作系统的目标检测之中。针对微操作空间下待检测目标存在尺度变化和在显微镜放大倍数较小时,待检测目标尺度过小、特征不明显的问题,提出了一种基于改进Faster RCNN的微操作空间目标检测算法。使用在图像分类任务中性能优越的深度残差网络提取图像的特征。引入递归特征金字塔网络,对特征进行融合。改进区域建议网络的采样策略,对损失函数进行优化。实验结果表明:这种改进的Faster RCNN算法能有效解决由于目标尺度变化和目标尺度过小带来的问题。相比通用的目标检测算法,该算法的准确度更高,速度更快,具有实际应用价值。 展开更多
关键词 微操作空间 目标检测 特征提取 局域建议网络采样策略 损失函数优化
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