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An Analysis of Value Differences in English and Chinese Idioms from the Perspective of Intercultural Communication
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作者 范金玲 杨雁 邹皎 《海外英语》 2018年第4期218-220,共3页
Idioms are the essence and gems of human wisdom and an important carrier of national culture. As a special form of language, they play an important role in intercultural communication. Due to the uniqueness of each cu... Idioms are the essence and gems of human wisdom and an important carrier of national culture. As a special form of language, they play an important role in intercultural communication. Due to the uniqueness of each culture, English and Chinese idioms are different in many aspects, values included. The present paper attempts to analyze the different values in English and Chinese idioms from three aspects: dependence vs independence, past-time orientation vs future-time orientation, and harmony vs competition. And the authors hope that it will be of some practical significance in people's intercultural communication. 展开更多
关键词 English and Chinese idioms value differences time orientation intercultural communication
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Theoretical research on intensity envelope function of strong ground motion
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作者 金星 瘳振鹏 《Acta Seismologica Sinica(English Edition)》 CSCD 1994年第4期637-644,共8页
After the time history of seismic motion is represented by superposition of a series of narrow frequency band wave groups, we obtain a general relation between wave group arrival time and derivative of phase spectra i... After the time history of seismic motion is represented by superposition of a series of narrow frequency band wave groups, we obtain a general relation between wave group arrival time and derivative of phase spectra in the paper. On the basis of the relation, frequency number distribution function of wave group arrival time is completely equivalent to that of phase difference spectra. Under the assumption that phase angles of seismic motionobey uniform distribution ranged from 0 to ─ 2π, a quantitative relation between intensity envelope function of seismic motion and energy distribution function with wave group arrival time has been derived in this paper. The relation illuminates inner links among Fourier amplitude spectra and derivative of phase spectra and intensity envelope function. Some examples given by the paper support the conclusions mentioned above. 展开更多
关键词 intensity envelope function phase difference spectra wave group arrival time distribution function
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Deformation Stages and Ar-Ar Age Data of the Wan-Zhe-Gan Tectonic Zone,Southeast China,and Their Tectonic Significance 被引量:10
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作者 YU Xinqi WANG De'en +3 位作者 JIANG Dazhi JIANG Laili ZHOU Xiang LI Chunlin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2011年第6期1373-1389,共17页
The major tectonic zone that passes through the border regions of the Anhui, Zhejiang, and Jiangxi Provinces in southeast China has been commonly referred to as the Wan-Zhe-Gan fault zone. Geologically, this zone cons... The major tectonic zone that passes through the border regions of the Anhui, Zhejiang, and Jiangxi Provinces in southeast China has been commonly referred to as the Wan-Zhe-Gan fault zone. Geologically, this zone consists of several regional fault belts of various ages and orientations. We have categorized the faults into four age groups based on field investigations. The Neoproterozoic faults are northeast striking. They start from the northeast Jiangxi Province and extend northeastward to Fuchuan in Anhui Province, the same location of the northeast Jiangxi-Fuchuan ophiolite belt. The faults probably acted during the Neoproterozoic as a boundary fault zone of a plate or a block suture with melange along the faults. The nearly east-west- or east-northeast-striking faults are of Silurian ages (40Ar/39Ar age 429 Ma). This group includes the Qimen-Shexian fault and the Jiangwang-Jiekou ductile shear belt. They represent a major tectonic boundary in the basement because the two sides of the fault have clear dissimilarities. The third group of faults is north-northeast striking, having formed since the early-middle Triassic with 40Ar/39Ar ages of 230-254 Ma. They form a fault belt starting from Yiyang in northern Jiangxi and connect with the Wucheng as well as the Ningguo-Jixi faults. This fault belt is a key fault-magmatic belt controlling the formation of Jurassic-Cretaceous red basins, ore distribution, magmatic activity, and mineralization. When it reactivated during the late Cretaceous, the belt behaved as a series of reverse faults from southeast to northwest and composed the fourth fault group. Therefore, classifying the Wan-Zhe-Gan fault zone into four fault groups will help in the analysis of the tectonic evolution of the eastern segment of the Jiangnan orogen since the Neoproterozoic era. 展开更多
关键词 the Wan-Zhe-Gan fault zone changes of orientations different evolution stages 40Ar/39Ar geochronology the border region of Zhejiang Jiangxi and Anhui Provinces
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On the Contrast of Interpersonal Relationship between China and America
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作者 黎畅 《海外英语》 2019年第1期180-182,共3页
With the rapid development of the globe, the world becomes smaller and smaller. The problem of interpersonal relationships attracts more concern, understanding more information about the cultural difference among coun... With the rapid development of the globe, the world becomes smaller and smaller. The problem of interpersonal relationships attracts more concern, understanding more information about the cultural difference among countries can make our communication easier and smoother, this essay is mainly about the contrast of interpersonal relationships between China and America from the factors that influence the interpersonal relationships, the contrast of types and the orientations and some strategies to deal with the intercultural relationships. To improve intercultural relationships, one must have a wealth of knowledge to reduce the degree of uncertainty and carry out a successful communication. 展开更多
关键词 inTERPERSONAL RELATIONSHIPS CULTURAL difference CONTRAST of types and the orientationS
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Three-Dimensional Sound Source Location Algorithm for Subsea Leakage Using Hydrophone 被引量:1
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作者 LI Hao-jie CAI Bao-ping +6 位作者 YUAN Xiao-bing KONG Xiang-di LIU Yong-hong Javed Akbar KHAN CHU Zheng-de YANG Chao TANG An-bang 《China Ocean Engineering》 SCIE EI CSCD 2024年第2期326-337,共12页
Leakages from subsea oil and gas equipment cause substantial economic losses and damage to marine ecosystem,so it is essential to locate the source of the leak.However,due to the complexity and variability of the mari... Leakages from subsea oil and gas equipment cause substantial economic losses and damage to marine ecosystem,so it is essential to locate the source of the leak.However,due to the complexity and variability of the marine environment,the signals collected by hydrophone contain a variety of noises,which makes it challenging to extract useful signals for localization.To solve this problem,a hydrophone denoising algorithm is proposed based on variational modal decomposition(VMD)with grey wolf optimization.First,the average envelope entropy is used as the fitness function of the grey wolf optimizer to find the optimal solution for the parameters K andα.Afterward,the VMD algorithm decomposes the original signal parameters to obtain the intrinsic mode functions(IMFs).Subsequently,the number of interrelationships between each IMF and the original signal was calculated,the threshold value was set,and the noise signal was removed to calculate the time difference using the valid signal obtained by reconstruction.Finally,the arrival time difference is used to locate the origin of the leak.The localization accuracy of the method in finding leaks is investigated experimentally by constructing a simulated leak test rig,and the effectiveness and feasibility of the method are verified. 展开更多
关键词 grey wolf optimizer variational modal decomposition mean envelope entropy correlation coefficient time difference of arrival
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COMPUTER SIMULATION OF EFFECT OF ORIENTATION DIFFERENCE ON MECHANICAL PROPERTIES OF BICRYSTALLINE SPECIMENS 被引量:1
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作者 WEI Chao QIAN Rengen LIN Shi XIAO Jimei University of Science and Technology Beijing,Beijing,China Dept.of Mathematics and Mechanics,University of Science and Technology Beijing,Bijing 100083,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1991年第1期13-16,共4页
Based on the experimental results of the work-hardening processes of single crystals,the ac- commodation processes of polycrvstal deformation and the assumption of idealized polycrystal,the stress-strain relation of e... Based on the experimental results of the work-hardening processes of single crystals,the ac- commodation processes of polycrvstal deformation and the assumption of idealized polycrystal,the stress-strain relation of elasto-plastic deformation crystal was derived.The effect of orientation difference on the mechanical properties of the bicrvstalline specimens of aluminum was simulated by means of the finite element method(FEM)of elasto-plastic crystal.The results are in good agreement with the experimental results made by Clark and Chalmers in 1954. 展开更多
关键词 BICRYSTAL orientation difference grain boundary computer simulation finite element method
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Development and Investigation of a Miniature Copper-Acetone Loop Heat Pipe with a Flat Evaporator 被引量:3
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作者 Yury F. Maydanik Vladimir G. Pastukhov Mariya A. Chernysheva 《Journal of Electronics Cooling and Thermal Control》 2015年第4期77-88,共12页
The paper presents the results of development and investigation of a copper miniature loop heat pipe (LHP) with acetone as a working fluid. The device was equipped with a flat evaporator measuring 80 × 42 × ... The paper presents the results of development and investigation of a copper miniature loop heat pipe (LHP) with acetone as a working fluid. The device was equipped with a flat evaporator measuring 80 × 42 × 7 mm and vapor and liquid lines with an outside diameter of 3 mm, whose lengths were 145 mm and 175 mm, respectively. The LHP was tested at heat loads from 5 W to 60 W, different orientations in the gravity field and heat-sink temperatures from -40°C to +50°C. It is shown that the LHP retains its efficiency at all testing conditions. It is also mentioned that at a heat-sink temperature of +50°C the device operates in the mode of constant conductivity in the whole range of heat loads, and in this case a minimum thermal resistance of the “heat source-heat sink” system equal to 0.16°C/W is achieved, which is independent of the LHP orientation in the gravity field. 展开更多
关键词 LOOP Heat Pipe FLAT EVAPORATOR Copper-Acetone Different orientation
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Transportation Infrastructure and Productivity Growth:Effects of Railway Speed-Up on Firm's TFP in China 被引量:6
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作者 施震凯 邵军 浦正宁 《China Economist》 2018年第6期17-33,共17页
Improvement of transportation infrastructure quality will lead to more sufficient market competition and promote the flow of resources with greater efficiency. This paper considers China's railway speed-up in 2007... Improvement of transportation infrastructure quality will lead to more sufficient market competition and promote the flow of resources with greater efficiency. This paper considers China's railway speed-up in 2007 as a quasi-natural experiment on China's transportation infrastructure quality improvement. With the initial operation of electric multiple units(EMUs) as the basis of grouping, this research examines the effect of railway speed-up on corporate total factor productivity(TFP) growth by the differencein-differences(DID) method. Overally, the results reveal positive effects both on firms' technological change and efficiency improvement, which lead to the increase of TFP. Based on subsamples divided by different regions and types of enterprises, further analysis indicates that the productivity of exporter, non-state and coastal firms has been mostly affected by the railway speed-up. These conclusions are verified by a placebo test. Besides, firms within "one-hour economic circle" have been shown more sensitive to the effect of railway speed increase. 展开更多
关键词 RAILWAY SPEED-UP total factor productivity(TFP) data envelopment METHOD DIFFERENCE-in-differences METHOD
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Density and temperature reconstruction of a flame-induced distorted flow field based on background-oriented schlieren(BOS) technique 被引量:2
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作者 郭广明 刘洪 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第6期203-212,共10页
An experimental system based on the background-oriented schlieren(BOS) technique is built to reconstruct the density and temperature distribution of a flame-induced distorted flow field which has a density gradient.... An experimental system based on the background-oriented schlieren(BOS) technique is built to reconstruct the density and temperature distribution of a flame-induced distorted flow field which has a density gradient. The cross-correlation algorithm with sub-pixel accuracy is introduced and used to calculate the background-element displacement of a disturbed image and a fourth-order difference scheme is also developed to solve the Poisson equation. An experiment for a disturbed flow field caused by a burning candle is performed to validate the built BOS system and the results indicate that density and temperature distribution of the disturbed flow field can be reconstructed accurately. A notable conclusion is that in order to make the reconstructed results have a satisfactory accuracy, the inquiry step length should be less than the size of the interrogation window. 展开更多
关键词 background-oriented schlieren density reconstruction finite difference methods distorted flow field
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PRELIMINARY STUDY OF INDOOR FEATURES OF TEMPERATURE AND HUMIDITY FOR ROOMS FACING NORTH-SOUTH IN WINTER IN A LOW-LATITUDE PLATEAU CITY
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作者 张一平 李佑荣 +2 位作者 王进欣 刘玉洪 马友鑫 《Journal of Tropical Meteorology》 SCIE 2002年第1期85-92,共8页
Analyzing observations of wintertime air temperature in both indoor and outdoor surroundings in Kunming,a city lying in low latitudes,characteristics of temperature and humidity have been studied for the interior of r... Analyzing observations of wintertime air temperature in both indoor and outdoor surroundings in Kunming,a city lying in low latitudes,characteristics of temperature and humidity have been studied for the interior of rooms facing north-south under differnet weather conditions ,Signicant warming effect has been identified in terms of lowest and daily-mean indoor temperature in the area of Kumming.The heating amplitude ranges from 7.7℃ to 10.0℃ and from 4.6℃ to 5.8℃ for the interior part of rooms facing the south and from 4.6℃to 7.0℃and from 1.3℃ to 4.4℃ for the interior part of rooms facing the north,respectively for the two elements,The highest air temperature is higher indoor than outdoor for rooms facing the south,but otherwise is usually true for rooms facing the north,Additional findings point out that buildings not only help maintain relatively warm indoor temperature but delay its variation.The diurnal cycle of temperature indoor is smaller and ranges by 40%-48% for south-facing rooms,and by 20%-30% for north-facing rooms,than outdoor,and the highest temperature is about 2 hours hate inside the room than outside.It shows how inertly indoor temperature varies.The work also finds that relative humidity is less indoor in southward rooms than in northward ones and difference is the largest on fine days but the smallest when it is overcast.For the diurnal variation,the indoor relative humidity is large at nighttime with small amplitude but small during daytime with large amplitude.The above-presented results can be served as scientific foundation for more research no climate in low-latitude cities and rational design of urban architectures. 展开更多
关键词 大气温度 大气湿度 房屋朝向 天气条件 冬季 城市气候
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德国高校对不同阶段教授激励策略的价值导向探究——基于德国W体系薪酬分配制度的分析
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作者 彭贤杰 阮文洁 樊秀娣 《外国教育研究》 北大核心 2024年第2期79-93,共15页
德国高校教授W体系薪酬分配制度成功实现从“注重人人有份”到“保障和激励兼顾”的转变。现已形成以“基本工资为主,多元附加浮动工资补充”的稳定结构,基本实现了“有侧重地激励不同专业发展阶段教授”的改革目标。基本工资坚持“依... 德国高校教授W体系薪酬分配制度成功实现从“注重人人有份”到“保障和激励兼顾”的转变。现已形成以“基本工资为主,多元附加浮动工资补充”的稳定结构,基本实现了“有侧重地激励不同专业发展阶段教授”的改革目标。基本工资坚持“依据资质,保障公平”、浮动工资坚持“优绩优酬,强化激励”的价值导向。具体而言,初级教授(W1阶段)面临适应和生存需求,侧重职位胜任力的提升;终身教授(W2、W3阶段),其中:普通教授(W2阶段)面临向上晋升需求,侧重教学和科研并重发展;专家教授(W3阶段)面临承担高级职位使命,侧重行政管理和对外合作等贡献。我国正处于高等学校薪酬制度的改革期,德国W体系薪酬分配制度二十余年的实践经验颇具借鉴意义。 展开更多
关键词 德国 高校 不同阶段教授 W体系薪酬分配制度 激励策略 价值导向
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虚拟环境中大尺度空间定向能力的地域差异
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作者 宋晓蕾 李宜倩 张凯歌 《心理学报》 CSCD 北大核心 2024年第1期1-14,共14页
基于空间参照系理论,本文采用虚拟现实技术探讨了大尺度空间定向能力的地域差异及其原因。实验1采用基于两种空间参照系且生态效度更高的路线重走与回溯任务以考察空间定向能力的地域差异;实验2进一步采用基于空间参照转换灵活性的定向... 基于空间参照系理论,本文采用虚拟现实技术探讨了大尺度空间定向能力的地域差异及其原因。实验1采用基于两种空间参照系且生态效度更高的路线重走与回溯任务以考察空间定向能力的地域差异;实验2进一步采用基于空间参照转换灵活性的定向接近任务以澄清该差异产生的原因;实验3通过在任务前激活环境中心参照,提高转换灵活性以改善南方被试大尺度空间定向能力。结果发现,大尺度空间定向能力存在地域差异,北方被试更擅长环境中心参照的任务,南方被试的自我中心参照在任务中有更大优势作用;说明该地域差异除与个体空间参照使用偏好有关之外,还与其空间参照转换灵活性有关;而当南方被试环境中心参照被激活,任务绩效显著提升。 展开更多
关键词 空间定向 空间参照系 地域差异 导航任务
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土地要素市场化改革能够提升企业生产效率吗?——基于工业用地市场化改革的准自然实验研究
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作者 张琳 赵翊廷 李亚轲 《大连理工大学学报(社会科学版)》 北大核心 2024年第2期24-34,共11页
深化土地要素市场化改革是提升全要素生产率、促进高质量发展的重要途径。基于微观企业视角,利用双重差分模型探究工业用地市场化改革对企业全要素生产率的影响,并从资源利用、资源配置和技术创新3个方面,探究具体的影响机制。结果表明... 深化土地要素市场化改革是提升全要素生产率、促进高质量发展的重要途径。基于微观企业视角,利用双重差分模型探究工业用地市场化改革对企业全要素生产率的影响,并从资源利用、资源配置和技术创新3个方面,探究具体的影响机制。结果表明:在研究期内,工业用地市场化改革整体上促进了企业全要素生产率提升约14%;对企业主体而言,规模越小、所属行业土地依赖程度越高,则全要素生产率的提升效果越明显;分区域来看,东北及西部地区企业生产效率的提升作用显著高于东部地区。进一步从中介效应看,该改革可以通过资源配置和技术创新来促进企业全要素生产率的提升;而资源利用机制并未发挥显著作用。综上,继续深化工业用地市场化改革,并着力优化土地资源在企业间的配置,提高企业技术创新水平,有利于企业生产率的提升。 展开更多
关键词 土地经济 市场化改革 双重差分 全要素生产率 中介效应
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低碳贝氏体钢等温淬火变体选择与特殊晶面定量化表征
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作者 杨劼 任慧平 +2 位作者 王海燕 高雪云 刘宗昌 《材料导报》 EI CAS CSCD 北大核心 2024年第9期212-219,共8页
为分析低碳贝氏体钢(15Cr12CuSiMoMn)的变体选择与特殊晶面取向差分布对其力学性能的影响,以及变体选择与晶面取向差之间的相互联系,对实验钢充分奥氏体化后在指定温度进行等温淬火热处理,随后分析并表征等温转变过程中变体选择的演变... 为分析低碳贝氏体钢(15Cr12CuSiMoMn)的变体选择与特殊晶面取向差分布对其力学性能的影响,以及变体选择与晶面取向差之间的相互联系,对实验钢充分奥氏体化后在指定温度进行等温淬火热处理,随后分析并表征等温转变过程中变体选择的演变规律与特殊晶体学面取向差分布规律。结果表明,实验钢所得{100}极图与{100}标准极图吻合,贝氏体变体与母相奥氏体的位向关系符合K-S关系,随着等温淬火温度的升高,贝氏体相变速率加快,变体选择能力降低,同时大角度晶界HAGBs(45~65°)、小角度晶界LAGBs(2~15°)界面含量减少。等温淬火60 min发现320℃时原奥氏体晶粒内同一CP组中V1/V2、V1/V3、V1/V5等变体对数量较340℃时分别增加2.4%、15%、1.1%,同一CP组中的贝氏体变体可增加大角度晶界;320℃等温淬火后实验钢具有较大的整体界面取向差、解理面(100)取向差以及滑移面(110)取向差,其整体界面取向差范围为3.2~62.5°,解理面(100)取向差范围为6.9~47.8°,滑移面(110)取向差范围为1~29.2°。通过控制贝氏体变体分布与含量进而影响其有效解理面(100)取向差与滑移面(110)取向差的分布范围,增大特殊晶面取向差范围有利于优化贝氏体组织,最终达到改善其力学性能的目的。 展开更多
关键词 贝氏体钢 取向分布 变体选择 取向差
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利用水波初至偏振方位反演海底地震仪位置及方位
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作者 刘劲松 刘健 +5 位作者 李小平 李栋青 游庆瑜 郝天珧 邱学林 王赟 《工程地球物理学报》 2024年第2期305-313,共9页
OBS(Ocean Bottom Seismometer,海底地震仪)在布放到海底之后,其方位指向通常是随机的;由于海流等因素的影响,其实际位置通常也会偏离投放位置,因此需要对其位置及方位进行重定位定向。针对目前的定位和定向方法大多基于走时计算,本文... OBS(Ocean Bottom Seismometer,海底地震仪)在布放到海底之后,其方位指向通常是随机的;由于海流等因素的影响,其实际位置通常也会偏离投放位置,因此需要对其位置及方位进行重定位定向。针对目前的定位和定向方法大多基于走时计算,本文首先讨论了利用海底地震仪的水波初至偏振方位进行海底地震仪水平位置及方位重定位定向的线性反演方法和非线性反演方法,给出了线性反演的近似公式,并分析了近似公式的误差;然后,通过大量理论模型试验对比了两种方法的误差及稳定性;最后,对我国南海某地的5台OBS实测数据进行了反演处理。理论模型试验结果表明,在一些特殊情况下,线性反演存在不收敛的情况,而非线性方法则具有较好的稳定性和较高的精度。非线性反演方法采用差分演化算法,对比了直接优化方位角残差目标函数和双差法,结果表明,对于理论模型和实际数据两种方法得到的结果几乎完全相同,但迭代收敛情况双差法明显好于前者,双差法经600余次迭代达到最优稳定状态,而前者在迭代1000多次之后才达到稳定最优状态。 展开更多
关键词 海底地震仪 定位 定向 偏振 反演 差分进化 双差
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不同地质情况下围护结构变更方案可行性研究
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作者 朱彩云 《建筑技术开发》 2024年第7期27-29,共3页
在不同地质情况下,如何有效进行围护结构的施工变更,并分析其对工程费用的影响以确定可行性方案,实际施工中提出施工变更管理策略已成为工程管理中一项重要任务。研究结合工程实例,在不同地质情况下探讨围护结构变更方案,并研究其对工... 在不同地质情况下,如何有效进行围护结构的施工变更,并分析其对工程费用的影响以确定可行性方案,实际施工中提出施工变更管理策略已成为工程管理中一项重要任务。研究结合工程实例,在不同地质情况下探讨围护结构变更方案,并研究其对工程造价和进度的影响,从而提出了此类工程变更管理研究的方向,旨在为类似项目的施工应用提供参考价值。 展开更多
关键词 不同地质 围护结构 变更方案
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技术差异视角下中国区域绿色科技创新资源配置效率测度
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作者 张兴贤 王盼盼 王仁杰 《西昌学院学报(自然科学版)》 2024年第2期17-26,共10页
绿色科技创新(green technology innovation,GTI)是推动绿色发展的重要载体,GTI资源配置效率的提升是加快实现绿色发展的重要途径。基于非期望产出超效率SBM(slack-based measure)模型来评价中国各省(市、自治区)的绿色科技创新资源配... 绿色科技创新(green technology innovation,GTI)是推动绿色发展的重要载体,GTI资源配置效率的提升是加快实现绿色发展的重要途径。基于非期望产出超效率SBM(slack-based measure)模型来评价中国各省(市、自治区)的绿色科技创新资源配置效率,并结合Meta-frontier Malmquist指数分析法,在区域技术差异视角下分析其在2010-2020年创新资源配置效率的动态变化情况。结果表明:中国GTI资源配置效率出现先缓慢上升再缓慢下降的变化趋势,且仍具有较大提升空间;同时,由于区域技术差异性的影响,中国东中西部地区的科技创新资源配置效率表现出不同的优势与不足。基于此,分别对东中西部地区从政策制定、资源投入和人才引进等方面提出相应政策建议。 展开更多
关键词 数据包络分析 绿色科技创新 资源配置 技术差异性
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基于高分一号卫星影像的水体信息提取方法初探
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作者 贾波 《经纬天地》 2024年第3期6-10,共5页
本文以山西汾河水库为研究区域,利用高分一号卫星影像,分别选择阈值分割法、归一化差异水体指数法和面向对象法对研究区水体信息进行提取,并对3种方法提取结果进行精度检查。通过试验得出如下结论:阈值分割法对水体先验知识要求低,简单... 本文以山西汾河水库为研究区域,利用高分一号卫星影像,分别选择阈值分割法、归一化差异水体指数法和面向对象法对研究区水体信息进行提取,并对3种方法提取结果进行精度检查。通过试验得出如下结论:阈值分割法对水体先验知识要求低,简单易用;归一化差异水体指数法由于未能消除阴影与水体的混淆问题,使得提取水体信息精度较低;面向对象法提取水体信息结果精度较高,但易丢失人工水塘与沟渠信息。该研究结果对利用高分一号卫星影像进行其他土地利用信息的提取具有一定借鉴意义。 展开更多
关键词 水资源信息提取 高分一号卫星 阈值分割法 归一化差异水体指数法 面向对象法
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基于熵加权的多向局部差分和方向梯度的红外小目标检测
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作者 郭亮 《智能计算机与应用》 2024年第6期240-244,F0003,共6页
复杂背景下的小目标检测一直是图像处理领域的热点和难点问题。由于背景复杂、信噪比低等因素,现有方法无法对淹没在强杂波和噪声中的目标进行鲁棒检测。本文提出了基于熵加权的多向局部差分和方向梯度方法。首先,利用熵加权的多向局部... 复杂背景下的小目标检测一直是图像处理领域的热点和难点问题。由于背景复杂、信噪比低等因素,现有方法无法对淹没在强杂波和噪声中的目标进行鲁棒检测。本文提出了基于熵加权的多向局部差分和方向梯度方法。首先,利用熵加权的多向局部差分构造目标显著图,突出小目标,同时抑制背景噪声。然后,通过方向梯度计算,精确计算小目标的边缘信息,定位小目标。最终将目标显著图和方向梯度图融合,得到红外小目标检测结果图。实验结果表明,本文所提出的方法可以抑制杂波并产生更好的结果,并且检测率和误检率都优于对比方法。 展开更多
关键词 红外小目标检测 多向局部差分 方向梯度
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基于多时相Sentinel-2遥感影像的江汉平原夏收作物提取方法 被引量:8
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作者 阴海明 王立辉 +2 位作者 董明霞 李晓冬 黄进良 《福建农林大学学报(自然科学版)》 CSCD 北大核心 2021年第1期16-22,共7页
以江汉平原潜江市为研究区,选取2017年9月至2018年7月期间12幅Sentinel-2多光谱(MSI)影像,通过分析研究区夏收作物不同生长期的光谱特征和归一化植被指数的时序变化,利用决策树算法提取2017—2018年夏收作物种植面积;将提取结果与最佳... 以江汉平原潜江市为研究区,选取2017年9月至2018年7月期间12幅Sentinel-2多光谱(MSI)影像,通过分析研究区夏收作物不同生长期的光谱特征和归一化植被指数的时序变化,利用决策树算法提取2017—2018年夏收作物种植面积;将提取结果与最佳时相的多光谱数据面向对象、随机森林算法的提取结果进行对比试验,利用实测数据计算混淆矩阵评价分类精度.结果表明,基于Sentinel-2时序NDVI的面向对象决策树方法的提取精度最高,总体精度为96.47%,Kappa系数为0.9518.基于Sentinel-2的面向对象决策树分类能够准确而有效地提取研究区农作物种植面积,并直观地反映作物的空间分布格局,为江汉平原地区调整作物种植结构提供依据,也为其他区域精细尺度作物的提取提供参考和借鉴. 展开更多
关键词 江汉平原 Sentinel-2 时序NDVI 面向对象 决策树
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