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Correlation between Surface Area Ratio of Medial to Lateral Tibial Plateau and Knee Alignment in Adults
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作者 Song GONG Li-zhi HAN +3 位作者 Tian-lun GONG Yi-hu YI Ruo-yu WANG Wei-hua XU 《Current Medical Science》 SCIE CAS 2022年第3期577-583,共7页
Objective This study aimed to investigate the correlation between the surface area ratio of medial tibial plateau(MTP)to lateral tibial plateau(LTP)and the mechanical tibiofemoral angle(mTFA).Methods Lower limb comput... Objective This study aimed to investigate the correlation between the surface area ratio of medial tibial plateau(MTP)to lateral tibial plateau(LTP)and the mechanical tibiofemoral angle(mTFA).Methods Lower limb computed tomography(CT)images were collected at our hospital.Then,the original CT data were analyzed and reconstructed using medical image processing software.The proximal and distal centres of the femur and tibia were marked.The surface areas of MTP and LTP were identified using image processing software.GraphPad Prism 8.0.2 was used to perform the statistical analysis.Results The surface area ratio of MTP to LTP was significantly correlated with the mTFA in all patients(P<0.0001),male group(P<0.0001),female group(P<0.0001),varus group(P<0.0001),and valgus group(P=0.002).Furthermore,the surface area of MTP and LTP was significantly greater in the male group than in the female group(P<0.0001).There was significant difference in the surface area of the MTP between the varus and valgus groups(P<0.0001).Significant difference was also observed in the surface area ratio of MTP to LTP between the varus and valgus groups(P<0.0001).Conclusion The surface area ratio of MTP to LTP was correlated with the mTFA.Within a certain range,the smaller the mTFA,the greater the surface area ratio of MTP to LTP.For patients undergoing total knee arthroplasty,of whom the surface area of the MTP was basically equal to that of the LTP,it is recommended that the osteotomy should be performed in accordance with mechanical alignment standards,and that a symmetrical tibial plateau prosthesis should be used.For patients whose surface area of MTP is significantly greater than that of the LTP,it is recommended that the osteotomy should be performed in accordance with kinematic alignment standards,and that an anatomical tibial plateau prosthesis should be used. 展开更多
关键词 knee alignment medial tibial plateau lateral tibial plateau surface area ratio prosthesis types total knee arthroplasty
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A Study of the Correlation between the Concentration of Particulate Matter and Green Area Ratio Measured through a Portable Monitoring System: With Particular Focus on the Case of Dalseo-Gu, Daegu Metropolitan City
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作者 Kyungsu Son Sanghun Baek +1 位作者 Eungho Jung Daewuk Kim 《Journal of Environmental Protection》 2022年第1期84-96,共13页
This study analyzed the relationship between the measured concentration of particulate matter (PM) and green area, which is an important spatial factor affecting urban PM concentration and even more carbon neutral in ... This study analyzed the relationship between the measured concentration of particulate matter (PM) and green area, which is an important spatial factor affecting urban PM concentration and even more carbon neutral in cities. In order to investigate the effects of green area, the green area ratio (GAR) is used and correlated with particulate matter. As a result of analyzing the correlation between GAR and PM concentration using the measured PM data, it was found that there was a positive correlation between the two variables. Hence, the higher the GAR, the lower the PM concentration. It can be said that the introduction of spatial elements with high GAR scores, such as parks and forests in cities, is effective in reducing PM concentration. In this study, a portable PM monitoring system using a vehicle for PM measurement was also established and operated. As a result, it was found that a PM monitoring system using a light-scattering sensor is an effective PM measurement method that can be used at the local government level. It was also found that a follow-up study is needed in the future to identify the PM mitigation functions of urban green areas according to the detailed characteristics of green areas as well as various environmental factors. This study can be used in air quality improvement activities and efforts as reference data by policy decision makers and in the field of environmental planning associated with the removal of airborne particulate matter pollution in urban areas. 展开更多
关键词 Particulate Matter (PM) CORRELATION Green area ratio (GAR) Monitoring System
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Effects of smartphone icon background shapes and figure/background area ratios on visual search performance and user preferences 被引量:12
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作者 Shijian LUO Yuxiao ZHOU 《Frontiers of Computer Science》 SCIE EI CSCD 2015年第5期751-764,共14页
Smartphones are becoming increasingly popular, users are provided with various interface styles with different designed icons. Icon, as an important competent of user interface, is regarded to be more efficient and pl... Smartphones are becoming increasingly popular, users are provided with various interface styles with different designed icons. Icon, as an important competent of user interface, is regarded to be more efficient and pleasurable. However, compared with desktop computers, fewer design principles on smartphone icon were proposed. This paper investigated the effects of icon background shape and the figure/background area ratio on visual search performance and user preference. Icon figures combined with six different geometric background shapes and five different figure/ background area ratios were studied on three different screens in experiments with 40 subjects. The results of an analysis of variance (ANOVA) showed that these two inde- pendent variables (background shape and figure/background area ratio) significantly affected the visual search performance and user preference. On 3.5-in (1 in=0.025 4 m) and 4.0-in displays, unified backgroundwould be optimal, shapes such as square, circle and transitions between them (e.g., rounded square, squircle, etc.) are recommended because backgrounds in these shapes yield a better search time performance and subjective satisfaction for ease of use, search and visual preference. A 60% figure/background area ratio is the most appropriate for smartphone icon design on the 3.5-in screen, while a 50% area ratio could be a suggestion for both relatively optimized search performance and user preference on 4.0-in. In terms of the 4.7-in, icon figure is used di- rectly for its better performance and preference compared with icons with background. 展开更多
关键词 icon design background shape figure/background area ratio visual search performance user preference
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Investigation of a Centrifugal Compressor and Study of the Area Ratio and TIP Clearance Effects on Performance 被引量:2
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作者 Mahdi Nili-Ahmadabadi Ali Hajilouy-Benisi +1 位作者 Mohammad Durali Farhad Ghadak 《Journal of Thermal Science》 SCIE EI CAS CSCD 2008年第4期314-323,共10页
在这研究,一件涡轮充电器的离心压气机试验性地并且数字地被调查。压缩机的表演特征被转子速度和流动参数的大小在压缩机的入口和插头试验性地获得。在 impeller 的三个维的流动领域并且更弥漫与 SST 骚乱用一个完整的海军司烧节目数... 在这研究,一件涡轮充电器的离心压气机试验性地并且数字地被调查。压缩机的表演特征被转子速度和流动参数的大小在压缩机的入口和插头试验性地获得。在 impeller 的三个维的流动领域并且更弥漫与 SST 骚乱用一个完整的海军司烧节目数字地被分析模型。压缩机的表演特征数字地被获得,它当时与试验性的结果相比。比较显示出好同意。而且,区域比率的效果和性能参数和流动地上的尖端清理数字地被学习。impeller 区域比率被切 impeller 出口轴改变从到 5.1 公里的最后的价值的 4.1 公里的起始的价值的宽度,从 0.792 ~ 0.965 导致区域比率。为有出口的转子 4.6 公里的轴的宽度,性能为 0.0, 0.5 和 1.0 公里的尖端清理被调查。当效率在 0.878 的区域比率的更高的价值达到顶点时,在设计点的这模拟的结果证明压缩机压力比率在 0.792 的区域比率达到顶点。另外,从 0 ~ 1 公里的尖端清理的增长导致了 20% 效率减少。 展开更多
关键词 离心压缩机 涡轮增压器 调查 研究
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Floor Area Ratio Regulation in Urban Planning Administration:From Technical Rationality to Policy Attribute
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作者 SUN Feng,Registrated Planner,Shenzhen Urban Planning and Development Research Center,Shenzhen,P.R.China.SHI Ke 《China City Planning Review》 2010年第2期35-43,共9页
As the key feature of land resource allocation and the core index of micro density control,floor area ratio(FAR) regulation should simultaneously implement macro density policies,guide urban development policies and m... As the key feature of land resource allocation and the core index of micro density control,floor area ratio(FAR) regulation should simultaneously implement macro density policies,guide urban development policies and maintain social equity.This is possible because of its technical,social and property attributes.However,lacking systematic theoretical guidance,it becomes a focus of debate in planning administration.This paper analyzes the attributes of FAR in order to discuss regulation methods,countermeasures and suggestions on FAR which best fit current planning and administration. 展开更多
关键词 FLOOR area ratio TECHNICAL ratioNALITY POLICY attr
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A Study on Average Velocity Ratios(V_P/V_S) in the Hohhot-Baotou Area
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作者 Han Xiaoming Zhang Fan 《Earthquake Research in China》 2012年第1期118-127,共10页
The geological structure is complex in the Hohhot-Baotou area.Several earthquakes with MS≥6.0 have occurred in the area in history.This article selected the Hohhot-Baotou area as the study region and divided it into ... The geological structure is complex in the Hohhot-Baotou area.Several earthquakes with MS≥6.0 have occurred in the area in history.This article selected the Hohhot-Baotou area as the study region and divided it into 2 sub-regions,each with a spatial scope of 3°×2°,according to the spatial distribution of ML≥1.0 earthquakes occurring between January 2001 and April 2010,and the layout of the seismic network in the study region.Average velocity ratios of respective sub-regions were calculated,and comparative analysis was made on their temporal and spatial variations.Results show that there are slight differences between sub-regions in the variation amplitude of average velocity ratio curves over time,which mostly remains between 2.5% to 2.584%.In the Hohhot area,the average velocity ratio is 1.722,significantly lower than the average velocity ratio of 1.733 in the Baotou area.We preliminarily concluded that this was related to the distribution of fault structures and properties of underground media in the Hohhot area. 展开更多
关键词 呼和浩特地区 包头地区 速度比 平均 VP VS 区域地震 地质结构
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Application of Different Image Processing Techniques on Aster and ETM+ Images for Exploration of Hydrothermal Alteration Associated with Copper Mineralizations Mapping Kehdolan Area (Eastern Azarbaijan Province-Iran) 被引量:2
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作者 Golchin Hajibapir Mohammad Lotfi +1 位作者 Afshar Zia Zarifi Nima Nezafati 《Open Journal of Geology》 2014年第11期582-597,共16页
The Kehdolan area is located at 20 kilometers to the?south-east of Dozdozan Town (Eastern Azarbaijan Province). According to structural geology, volconic rocks are situated in Alborz-Azarbyjan zone, and faults?are?obs... The Kehdolan area is located at 20 kilometers to the?south-east of Dozdozan Town (Eastern Azarbaijan Province). According to structural geology, volconic rocks are situated in Alborz-Azarbyjan zone, and faults?are?observed?in?the?same direction to this system with SE-NW trend. The results show that kaolinite alteration trend with Argilic and propylitic veins?is the?same direction with SW-NE faults in this area. Therefore, these faults with these trends can be considered as the mineralization control for determination of the alterations. Different image processing techniques,?such as false color composite?(FCC), band ratios, color ratio composite?(CRC), principal component?analysis?(PCA), Crosta technique, supervised spectral angle mapping?(SAM), are used for?identification of the alteration zones associated with copper mineralization. In this project ASTER?data are process and spectral analysis to fit for recognizing intensity and kind of argillic, propylitic,?philic, and ETM+ data?which?are process and to fit for iron oxide and relation to metal mineralization of the area. For recognizing different alterations of the study area, some chemical and mineralogical analysis data from the samples showed that ASTER data and ETM+ data were?capable of hydrothermal alteration mapping with copper mineralization.?Copper mineralization in the region is in agreement with argillic alteration. SW-NE trending faults controlled the mineralization process. 展开更多
关键词 Kehdolan area False COLOR COMPOSITE Band ratios COLOR ratio COMPOSITE Principal Component Analysis Crosta Technique Supervised Spectral Angle MAPPING ASTER DATA ETM+ DATA Alteration
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Phase-Space Areas of the Body Motion in the Solar System Deduced from the Bohr-Sommerfeld Atomic Theory and Approximate Invariance of Their Ratios for the Pairs of Planets and Satellites
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作者 Stanislaw Olszewski Tadeusz Kwiatkowski 《Journal of Modern Physics》 2012年第9期1142-1151,共10页
Energy-time and momentum-position phase spaces defined by the electron orbits in the hydrogen-like atom exhibit special properties of equivalence. It is demonstrated that equivalence of the same kind can be obtained f... Energy-time and momentum-position phase spaces defined by the electron orbits in the hydrogen-like atom exhibit special properties of equivalence. It is demonstrated that equivalence of the same kind can be obtained for the phase-space areas defined by the orbit pairs of planets, or satellites, which compose the solar system. In the choice of the examined areas it is useful to be guided by the Bohr-Sommerfeld atomic theory. 展开更多
关键词 ratios of the PHASE-SPACE areas and THEIR INVARIANCE Planets and SATELLITES Bohr-Sommerfeld Atomic Theory
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基于拉曼光谱与色度学的彩色淡水有核珍珠研究
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作者 王子轩 杨淼 +2 位作者 柳迪文 孟彬 祖恩东 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第6期1684-1688,共5页
淡水有核珍珠因为其粒径大、圆度好、色彩丰富、光泽强等优点,在珍珠市场上占据了较大份额。目前关于彩色淡水有核珍珠的致色机理尚没有一致的结论,且关于该致色物质如何使淡水有核珍珠呈现多种颜色的研究较少。基于此研究现状,选取多... 淡水有核珍珠因为其粒径大、圆度好、色彩丰富、光泽强等优点,在珍珠市场上占据了较大份额。目前关于彩色淡水有核珍珠的致色机理尚没有一致的结论,且关于该致色物质如何使淡水有核珍珠呈现多种颜色的研究较少。基于此研究现状,选取多种颜色的淡水有核珍珠进行激光拉曼光谱与色度学研究。拉曼光谱研究发现样品具有三种不同的C—C与C C峰,且表现出对应关系:1123~1125 cm^(-1)处的C—C峰常与1506~1509 cm^(-1)处的C C峰同时出现;1132~1134 cm^(-1)处的C—C峰常与1522~1523或1525 cm^(-1)处的C C峰同时出现;1128~1131 cm^(-1)处的C—C峰常与1506~1509与1520~1523或1525 cm^(-1)的C C双重峰同时出现。依据拉曼光谱中C C键峰的差异将全部样品分为P、T、G、P+T、T+G、P+G共6种类型。结合样品的色度学参数,在同类型样品中,建立亮度L或饱和度S与其拉曼光谱中CO_(3)/C—C峰面积比的相关性,发现P型珠的亮度L与CO_(3)/C—C峰面积比有明显的正相关性,而P、T、G型珠的饱和度S都与CO_(3)/C—C峰面积比有明显的负相关性,证实三种不同的C—C与C C峰是由不同的致色物质所致。并根据拉曼谱峰将彩色淡水有核珍珠中的致色有机物归属为线性多烯类分子。线性多烯分子的拉曼峰位随着有序度的增加而红移,拉曼峰位更靠近红外区的线性多烯分子的碳骨架更长更直,这导致不同类型样品的拉曼光谱中C—C与C C的峰有所区别。此外,依据色度学参数对彩色淡水有核珍珠进行颜色系列的划分。将色调角h∈(0,15)的珍珠归为红色系列;将色调角h∈(15,45)的珍珠归为黄色系列;将色调角h∈(335,360)的珍珠归为紫色系列。 展开更多
关键词 淡水有核珍珠 拉曼光谱 色度学 峰面积比 线性多烯
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弃土场原位与弃土斜坡水分运动特征对比分析
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作者 代国发 王永奇 +2 位作者 何玉琼 张家明 董文杰 《山东农业大学学报(自然科学版)》 北大核心 2024年第2期279-287,共9页
降雨入渗会改变斜坡原有的平衡状态,为探究弃土场原位与弃土斜坡降雨入渗过程的水分运动特征。以某弃土场为研究对象重复开展染色示踪试验,对比分析原位与弃土斜坡垂直方向上土壤剖面的染色面积比和渗流前后水分运动特征的差异。结果表... 降雨入渗会改变斜坡原有的平衡状态,为探究弃土场原位与弃土斜坡降雨入渗过程的水分运动特征。以某弃土场为研究对象重复开展染色示踪试验,对比分析原位与弃土斜坡垂直方向上土壤剖面的染色面积比和渗流前后水分运动特征的差异。结果表明(1)原位斜坡水分入渗以基质流为主,少量优先流动由生物通道引发;0~50 cm深度水分垂直均匀入渗程度高,随深度增大,表现出沿容重小一侧非均匀流动;50 cm深度以下,平均染色面积比与深度呈负相关;(2)无植被发育弃土斜坡无优先流动,沿斜坡土体表层水平扩散流动程度高,平均染色面积比在20 cm深度以下保持为0,无染色特征;植被发育弃土斜坡水分沿植物根茎优先入渗,垂直入渗较活跃;(3)染色面积比及湿润带特征能很好的捕捉斜坡水分渗流的非均匀信息;同时,根系会改变土体的孔隙发育程度,形成内部交织的网状结构,降低土壤容重,增加水分入渗,有利于增强表层土壤含水率,降低水分深层渗流,增强斜坡稳定性;加强弃土场植被生态恢复有利于增加斜坡的固土保水能力及稳定性。 展开更多
关键词 弃土场 水分运动特征 染色示踪试验 染色面积比 湿润锋
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Coral Ba/Ca and Mn/Ca Ratios as Proxies of Precipitation and Terrestrial Input at the Eastern Offshore Area of Hainan Island
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作者 JIANG Qiaowen CAO Zhimin +3 位作者 WANG Daoru LI Yuanchao WU Zhongjie NI Jianyu 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第6期1072-1080,共9页
Geochemical ratios in coral reef skeletons could be used as proxies to reconstruct past climatological and environmental records in data-poor regions. Using a 103-year data set(1902 to 2005), the annual variations in ... Geochemical ratios in coral reef skeletons could be used as proxies to reconstruct past climatological and environmental records in data-poor regions. Using a 103-year data set(1902 to 2005), the annual variations in Ba/Ca and Mn/Ca ratios of Porites lutea skeletons at an eastern offshore area of Hainan Island(19?12'28.4''N, 110?37'38.8''E) were analyzed using inductively coupled plasma-optic emission spectrometry(ICP-OES). The analysis results showed that Ba/Ca ratios varied from a minimum of 3.120 μmol mol^(-1) in 1903 to a maximum of 10.064 μmol mol^(-1) in 1944, with an average of 5.256 μmol mol^(-1). Mn/Ca ratios varied from 0.206 to 5.708 μmol mol^(-1) with an annual average of 1.234 μmol mol^(-1), with peak values in 2001, 1964 and 1932, that correlated with strong rainfall events caused by typhoons. Variation in Ba/Ca and Mn/Ca ratios were compared with available river discharge and precipitation records, providing insight into past climatological events. Human activities and their indirect effects could impact the strength of the relationship between Ba/Ca and Mn/Ca ratios and observed precipitation and terrestrial input in the future. 展开更多
关键词 Porites lutea eastern offshore area of Hainan Island Ba/Ca and Mn/Ca ratios TERRIGENOUS INPUT PRECIPITATION climate proxy records
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基于图像形态学的焊缝区域提取与对比度提升技术
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作者 刘欢 刘骁佳 +3 位作者 赵耀邦 王宁 罗志强 危荃 《中国材料进展》 CAS CSCD 北大核心 2024年第2期175-180,共6页
铝板焊接后可使用X射线进行焊缝内部缺陷检测,由于X射线成像存在噪声多、对比度低、焊缝区域边缘模糊、焊缝区域与背景区域灰度分布较为相似等问题,使用传统边缘检测方法效果欠佳。提出了一种自动提取焊缝区域并提高其对比度的方法,通... 铝板焊接后可使用X射线进行焊缝内部缺陷检测,由于X射线成像存在噪声多、对比度低、焊缝区域边缘模糊、焊缝区域与背景区域灰度分布较为相似等问题,使用传统边缘检测方法效果欠佳。提出了一种自动提取焊缝区域并提高其对比度的方法,通过去噪处理、边缘检测、形态学操作等步骤,最终确定焊缝区域位置,并对焊缝区域内像素值进行线性变换,提高了焊缝区域的对比度。实验结果表明,该方法针对大批量的铝板X射线图片,都能够自动提高焊缝区域的对比度,具有良好的鲁棒性和准确性。 展开更多
关键词 图像处理 X射线 焊缝区域 梯度 对比度
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卧式套管潜热蓄热单元偏心与肋片结构优化模拟
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作者 张璐荻 周国兵 《储能科学与技术》 CAS CSCD 北大核心 2024年第3期1019-1029,共11页
利用偏心布置增强相变蓄热单元内部自然对流是提高相变蓄热系统性能的新思路,为了更深入地研究偏心布置对相变蓄热系统性能的影响,基于焓-孔隙率法建立了卧式套管相变蓄热单元的三维数学模型,并利用Fluent软件对环形空间相变材料熔化过... 利用偏心布置增强相变蓄热单元内部自然对流是提高相变蓄热系统性能的新思路,为了更深入地研究偏心布置对相变蓄热系统性能的影响,基于焓-孔隙率法建立了卧式套管相变蓄热单元的三维数学模型,并利用Fluent软件对环形空间相变材料熔化过程进行数值模拟,通过对熔化过程流场、液相率及温度云图的分析,将熔化过程划分为三个阶段:导热主导的初始阶段,随后是自然对流和导热的混合作用的阶段,以及导热再次占主导地位的最终阶段,并将相变材料环形空间划分为两个区域,据此提出新的评价参数“偏心面积比”。结果表明:硬脂酸作为相变材料时较佳的偏心面积比位于16∶1附近,熔化时间相对于同心布置缩短了45.8%,但同时会使蓄热单元㶲效率略有降低,并且预测对于其他材料,预期的最佳偏心面积比与使用材料的自然对流强度和导热能力之间的比值有直接相关。利用偏心结构与肋片结合的方法进一步强化传热,比较了螺旋肋、十字肋和X形肋三种肋片,发现X形肋具有较佳性能,与相应偏心无肋结构相比熔化时间缩短了36.7%,比螺旋肋和十字肋结构分别缩短了20.3%和7.1%。 展开更多
关键词 潜热蓄热 偏心面积比 肋片 强化传热 㶲效率
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我国乡村老龄化现状及其对粮食生产的影响与应对
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作者 黄祖辉 李懿芸 毛晓红 《西北农林科技大学学报(社会科学版)》 北大核心 2024年第2期35-42,共8页
根据2020年最新人口普查数据,我国乡村老龄化率为17.72%,先于城市步入中度老龄化社会。我国乡村老龄化整体呈现出老年抚养比增速快、低龄老人务农比例高等特征,与国际主要发达国家相比我国乡村老龄人口就业占比相对较高。分区域看,粮食... 根据2020年最新人口普查数据,我国乡村老龄化率为17.72%,先于城市步入中度老龄化社会。我国乡村老龄化整体呈现出老年抚养比增速快、低龄老人务农比例高等特征,与国际主要发达国家相比我国乡村老龄人口就业占比相对较高。分区域看,粮食主产区乡村老龄化增幅更多、老年抚养比更重、老龄就业比重更高;全国乡村老年抚养比28.13%,但粮食主产省份达31.28%。通过定性梳理乡村老龄化对农户参与粮食种植及其粮食生产行为效率等的影响,提出积极应对乡村老龄化、保障粮食安全的思路与对策建议。 展开更多
关键词 乡村老龄化 老年抚养比 粮食安全 粮食主产区 区域及城乡差异
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辽宁省农村三产融合综合评价研究
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作者 王国力 聂新月 《辽宁师范大学学报(自然科学版)》 CAS 2024年第1期110-116,共7页
农村一二三产融合是实现乡村振兴和农业农村现代化的重要手段,有利于农村经济的高质量发展.辽宁省农村一二三产融合在空间上分布不均衡,运用熵权法和秩和比综合评价法研究农村三产融合综合水平,对于辽宁省三产融合高质量发展具有理论与... 农村一二三产融合是实现乡村振兴和农业农村现代化的重要手段,有利于农村经济的高质量发展.辽宁省农村一二三产融合在空间上分布不均衡,运用熵权法和秩和比综合评价法研究农村三产融合综合水平,对于辽宁省三产融合高质量发展具有理论与现实意义.首先分析了辽宁省2012—2021年农村三产融合水平的时序变化,然后以2021年为例对辽宁省14地市农村三产融合水平的空间差异进行研究.结果表明:从时间特征来看,辽宁省2012—2021年农村一二三产融合综合水平总体呈上升趋势,受2016年中国经济呈现的放缓态势的影响,2016年融合水平出现明显下降;从空间特征来看,2021年辽宁省农村一二三产融合综合水平各地存在空间差异,其中大连排名第一,沈阳次之,抚顺、营口、辽阳排名靠后,前后存在较大差距.采用障碍度模型计算障碍因子,各地应立足自身优势,弥补不足,关注生产效率和产业链延伸的同时更要注重社会效益和绿色可持续发展,推进辽宁农村三产业融合整体发展. 展开更多
关键词 农村一二三产融合 熵权法 秩和比综合评价法 障碍度模型 辽宁省
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广州市“窄马路、密路网”街区交通规划提升实践
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作者 曾滢 张海林 +1 位作者 张晓明 林兰平 《城市交通》 2024年第2期28-36,111,共10页
实现“窄马路、密路网”街区交通规划需要从路网指标、交通组织、设施配置等多方面进行更加精细化的管控。首先,通过总结广州市20余个“窄马路、密路网”街区规划案例,梳理该类街区的空间及交通特征,总结实施过程中存在的典型问题与成因... 实现“窄马路、密路网”街区交通规划需要从路网指标、交通组织、设施配置等多方面进行更加精细化的管控。首先,通过总结广州市20余个“窄马路、密路网”街区规划案例,梳理该类街区的空间及交通特征,总结实施过程中存在的典型问题与成因,分析“窄马路、密路网”街区尺度和路网形态对交通组织、设施布局的影响,提出加强“窄马路、密路网”街区交通规划管控的必要性。其次,围绕街区交通效能和出行环境提升,研究形成三大规划提升策略:加强路网指标整体管控、优化街区人车交通组织、精准配置交通设施,并明确街区尺度、支路占比、道路面积率、路网连通性、公共汽车首末站小型化、停车库互联互通等详细管控要求。最后,以广州设计之都三期为例,基于综合评估提出交通规划提升方案。 展开更多
关键词 交通规划 窄马路、密路网 小街区 道路面积率 路网连通性 场站分离 广州市
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加权断层泥比率法(WSGR)定量判别断层封闭性——以苏北盆地高邮凹陷永安地区为例
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作者 李储华 于雯泉 丁建荣 《石油实验地质》 CAS CSCD 北大核心 2024年第1期158-165,共8页
断层封闭性评价是断块圈闭成藏条件分析的重要内容,在改进断层泥比率法基础上,提出了一种新的断层封闭性评价方法——加权断层泥比率法(WSGR)。首先,通过不同的地质模型开展断层泥比率法计算参数及影响因素分析,明确了断层断距、泥质含... 断层封闭性评价是断块圈闭成藏条件分析的重要内容,在改进断层泥比率法基础上,提出了一种新的断层封闭性评价方法——加权断层泥比率法(WSGR)。首先,通过不同的地质模型开展断层泥比率法计算参数及影响因素分析,明确了断层断距、泥质含量及泥岩分布特征是泥岩涂抹的重要影响因素;并认为断层断距范围内,滑过目标位置的对置盘所有泥质含量都具有涂抹贡献,但不同点的涂抹贡献不同,距离目标位置越近泥质含量越高的对置盘泥岩点,其涂抹贡献越大。为此引入了一个新的表征参数——距离系数,定义为断层断距与各泥岩点到目标位置距离的差与断层断距的比值,来表征泥岩分布对泥岩涂抹的影响作用;在此基础上,构建了加权断层泥比率计算方法,定义为各点的泥质含量与距离系数的乘积之和再与距离系数之和的比值。利用加权断层泥比率法对苏北盆地高邮凹陷上含油气系统已知的油水层进行封闭性验证,认为当加权断层泥比率值大于0.6时,断层具有较好的封闭性,从而确定了该方法的封闭性判别标准。在高邮凹陷永安等地区始新统戴南组断层封闭性评价中取得了较好应用效果。 展开更多
关键词 加权断层泥比率法 距离系数 断层封闭性 永安地区 高邮凹陷 苏北盆地
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不同喷雾角度对混凝土仓面环境气温影响试验研究
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作者 许新刚 庄维 +2 位作者 雷金松 王廷 黄耀英 《江淮水利科技》 2024年第2期13-17,22,I0002,I0003,共8页
喷雾是高温季节混凝土浇筑仓面重要的温控措施之一,但是喷雾角度对高温季节环境气温影响规律尚不明确。基于喷雾机不同喷雾角度(15°20°25°)采集到的试验数据,分析不同工况下雾化区域点、线、面的温度分布规律,对比不同... 喷雾是高温季节混凝土浇筑仓面重要的温控措施之一,但是喷雾角度对高温季节环境气温影响规律尚不明确。基于喷雾机不同喷雾角度(15°20°25°)采集到的试验数据,分析不同工况下雾化区域点、线、面的温度分布规律,对比不同喷雾角度下温度降幅、仓面降雨量、喷雾区低于喷雾水温区域面积占比。试验表明:喷雾开始时段雾化区域温度会快速下降,随着雾化区域水雾量饱和且蒸发量逐渐稳定,雾化区域温度也逐渐达到稳定状态;喷雾角度25°时仓面降雨量最小低于喷雾水温的区域面积占比最大,说明25°喷雾角度是相对最佳的。 展开更多
关键词 仓面喷雾 喷雾角度 温度降幅 仓面降雨量 面积占比
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Ratio of In-Sphere Volume to Polyhedron Volume of the Great Pyramid Compared to Selected Convex Polyhedral Solids 被引量:3
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作者 Hans Hermann Otto 《Journal of Applied Mathematics and Physics》 2021年第1期41-56,共16页
The architecture of the Great Pyramid at Giza is based on fascinating golden mean geometry. Recently the ratio of the in-sphere volume to the pyramid volume was calculated. One yields as result <em>R</em>&... The architecture of the Great Pyramid at Giza is based on fascinating golden mean geometry. Recently the ratio of the in-sphere volume to the pyramid volume was calculated. One yields as result <em>R</em><sub><em>V</em></sub> = π <span style="white-space:nowrap;"><span style="white-space:nowrap;">&#8901;</span></span> <em><em style="white-space:normal;">φ</em></em><sup>5</sup>, where <img src="Edit_83decbce-7252-44ed-a822-fef13e43fd2a.bmp" alt="" /> is the golden mean. It is important that the number <em>φ</em><sup>5</sup> is a fundamental constant of nature describing phase transition from microscopic to cosmic scale. In this contribution the relatively small volume ratio of the Great Pyramid was compared to that of selected convex polyhedral solids such as the <em>Platonic </em>solids respectively the face-rich truncated icosahedron (bucky ball) as one of <em>Archimedes</em>’ solids leading to effective filling of the polyhedron by its in-sphere and therefore the highest volume ratio of the selected examples. The smallest ratio was found for the Great Pyramid. A regression analysis delivers the highly reliable volume ratio relation <img src="Edit_79e766ce-5580-4ae0-a706-570e0f3f1bd8.bmp" alt="" />, where <em>nF</em> represents the number of polyhedron faces and b approximates the silver mean. For less-symmetrical solids with a unique axis (tetragonal pyramids) the in-sphere can be replaced by a biaxial ellipsoid of maximum volume to adjust the <em>R</em><sub><em>V</em></sub> relation more reliably. 展开更多
关键词 POLYHEDRON Great Pyramid Platonic Solids Volume-area ratio In-Sphere and In-Ellipsoid Polyhedral Void Space Golden and Silver Mean
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不同因素对调节级气动性能影响研究
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作者 孙旺 陈二云 《热力透平》 2024年第2期102-107,134,共7页
影响汽轮机调节级性能的因素有叶栅型线、栅距、冲角,同时,动静面积比(表征级反动度)、速比和盖度也是重要因素,研究其对气动性能的影响具有重大意义。以高参数小流量工业汽轮机调节级为研究对象,在喷嘴相对叶高分别为0.24和1.0的条件下... 影响汽轮机调节级性能的因素有叶栅型线、栅距、冲角,同时,动静面积比(表征级反动度)、速比和盖度也是重要因素,研究其对气动性能的影响具有重大意义。以高参数小流量工业汽轮机调节级为研究对象,在喷嘴相对叶高分别为0.24和1.0的条件下,采用数值方法对不同动静面积比、速比和盖度的调节级流场进行了模拟计算,分析上述3个因素对调节级气动性能的影响规律。研究表明:调节级轮周效率随动静面积比的增加而增大;喷嘴相对叶高为0.24条件下,动静面积比超过1.5之后,轮周效率增速放缓,在面积比为1.65时达到最大值;喷嘴相对叶高增大为1.0后,级轮周效率随动静面积比的变化曲线向坐标轴右上方平移;轮周效率随速比增加而增大,速比为0.6~0.75时轮周效率处于较高水平;保持其他条件不变,相对盖度约0.08时,轮周效率达到最大值。研究成果可为工业汽轮机高性能调节级的设计研发提供参考。 展开更多
关键词 调节级 气动性能 数值模拟 速比 盖度 动静面积比
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