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Influence of initial check, information exchange, final accuracy check, reaction information nursing on the psychology of elderly with lung cancer 被引量:2
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作者 Cui Jiang Jing Ma +1 位作者 Wen He Hai-Ying Zhang 《World Journal of Clinical Cases》 SCIE 2024年第4期737-745,共9页
BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychologi... BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychological problems.AIM To investigate the effectiveness of the initial check,information exchange,final accuracy check,reaction(IIFAR)information care model on the mental health status of elderly patients with lung cancer.METHODS This study is a single-centre study.We randomly recruited 60 elderly patients with lung cancer who attended our hospital from January 2021 to January 2022.These elderly patients with lung cancer were randomly divided into two groups,with the control group taking the conventional propaganda and education and the observation group taking the IIFAR information care model based on the conventional care protocol.The differences in psychological distress,anxiety and depression,life quality,fatigue,and the locus of control in psychology were compared between these two groups,and the causes of psychological distress were analyzed.RESULTS After the intervention,Distress Thermometer,Hospital Anxiety and Depression Scale(HADS)for anxiety and the HADS for depression,Revised Piper’s Fatigue Scale,and Chance Health Locus of Control scores were lower in the observation group compared to the pre-intervention period in the same group and were significantly lower in the observation group compared to those of the control group(P<0.05).After the intervention,Quality of Life Questionnaire Core 30(QLQ-C30),Internal Health Locus of Control,and Powerful Others Health Locus of Control scores were significantly higher in the observation and the control groups compared to the pre-intervention period in their same group,and QLQ-C30 scores were significantly higher in the observation group compared to those of the control group(P<0.05).CONCLUSION The IIFAR information care model can help elderly patients with lung cancer by reducing their anxiety and depression,psychological distress,and fatigue,improving their tendencies on the locus of control in psychology,and enhancing their life qualities. 展开更多
关键词 Initial check information exchange final accuracy check reaction information care model Lung cancer Mental health
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Does the Belt and Road Initiative Promote Value Chain Connection Between China and the Silk Road Countries? 被引量:3
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作者 ZHENG Zhi LIU Weidong SONG Zhouying 《Chinese Geographical Science》 SCIE CSCD 2021年第6期979-995,共17页
The global value chains have become the core skeleton of the global economy.As a large-scale international cooperation initiative,the Belt and Road Initiative(BRI hereafter)may have a significant impact on the global ... The global value chains have become the core skeleton of the global economy.As a large-scale international cooperation initiative,the Belt and Road Initiative(BRI hereafter)may have a significant impact on the global economic landscape.In this context,the spatiotemporal pattern and evolution of the value chain connection of the Silk Road countries and whether the BRI will promote the value chain connections between China and these countries are important research questions for understanding the changing global economic landscape.This paper employs input-output analysis,network analysis and difference-in-differences based on Propensity Score Matching(PSM-DID)to conduct an in-depth quantitative study of these questions.The results show that,first,the overall value chain connection between China and the Silk Road countries has been rising since 2001.From the perspective of geographical distribution,Southeast Asia is the highest value chain connection region with China,and the growth in the central and eastern Europe is the most significant,whereas the central Asia is the lowest value connection region.From the perspective of complex network analysis,China’s position in the network of value flow among the Silk Road countries has been increasing continuously,and it has been in the lead position since 2008.Besides,the implementation of the BRI has had a significant positive influence on the overall value chain connection between China and the Silk Road countries,but this positive influence is limited to the central and eastern Europe region,whereas it is not significant in other regions.Finally,this paper suggests that to promote the development of value chain connection,the Silk Road countries need to develop more specific policies related to value chains.Policymakers need to be able to correctly identify the comparative advantages of the region and the types of value chains that are compatible with them and then find suitable partners and formulate targeted promotion policies. 展开更多
关键词 the Belt and Road Initiative global value chains input-output technique pattern evolution network analysis difference-in-differences based on Propensity Score matching(PSM-DID)
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ON USE OF LHN METHOD TO ASSIMILATE THE INTENSIFIED SURFACE PRECIPITATIONS FOR GRAPES_MESO MODEL INITIALIZATION 被引量:1
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作者 吴亚丽 陈德辉 《Journal of Tropical Meteorology》 SCIE 2016年第4期544-558,共15页
The quantitative precipitation forecast(QPF) in very-short range(0-12 hours) has been investigated in this paper by using a convective-scale(3km) GRAPES_Meso model. At first, a latent heat nudging(LHN) scheme to assim... The quantitative precipitation forecast(QPF) in very-short range(0-12 hours) has been investigated in this paper by using a convective-scale(3km) GRAPES_Meso model. At first, a latent heat nudging(LHN) scheme to assimilate the hourly intensified surface precipitation data was set up to enhance the initialization of GRAPES_Meso integration. And then based on the LHN scheme, a convective-scale prediction system was built up in considering the initial "triggering"uncertainties by means of multi-scale initial analysis(MSIA), such as the three-dimensional variational data assimilation(3DVAR), the traditional LHN method(VAR0LHN3), the cycling LHN method(CYCLING), the spatial filtering(SS) and the temporal filtering(DFI) LHN methods. Furthermore, the probability matching(PM) method was used to generate the QPF in very-short range by combining the precipitation forecasts of the five runs. The experiments for one month were carried out to validate the MSIA and PM method for QPF in very-short range.The numerical simulation results showed that:(1) in comparison with the control run, the CYCLING run could generate the smaller-scale initial moist increments and was better for reducing the spin-up time and triggering the convection in a very-short time;(2) the DFI runs could generate the initial analysis fields with relatively larger-scale initial increments and trigger the weaker convections at the beginning time(0-3h) of integration, but enhance them at latter time(6-12h);(3) by combining the five runs with different convection triggering features, the PM method could significantly improve the QPF in very-short range in comparison to any single run. Therefore, the QPF with a small size of combining members proposed here is quite prospective in operation for its lower computation cost and better performance. 展开更多
关键词 convective-scale latent heat nudging (LHN) very-short-range QPF multi-scale initial analysis (MSIA) probability matching (PM)
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The Support of Public Opinion Is Imperative for any Legislative Construction
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作者 金碚 《China Economist》 2007年第3期1-1,共1页
In the early spring of 2007,two important matters of great public concern finally bore fruition.Firstly,the National People’s Congress eventually passed the Law of Property following 13 years of&bate,revision and... In the early spring of 2007,two important matters of great public concern finally bore fruition.Firstly,the National People’s Congress eventually passed the Law of Property following 13 years of&bate,revision and deliberation.Secondly,China initiated the individual tax return filing system in which an individual earning RMB 120,000 or above per year is required to file his/her annual tax returns separately with China’s tax authorities.To date,there have been about 1.6 million Chinese nationals filing tax returns under the new system. 展开更多
关键词 returns authorities PASSED eventually initiated finally REVISION separately LESSON awareness
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Application of the Method of Students' Presentations in Foreign Language Teaching
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作者 Marija Miscancuk 《Sino-US English Teaching》 2013年第10期783-789,共7页
This paper presents the results of the research conducted at the English language course of the students of Polytechnic of Medimurje in Cakovec, Croatia. The purpose of the research was to introduce the method of stud... This paper presents the results of the research conducted at the English language course of the students of Polytechnic of Medimurje in Cakovec, Croatia. The purpose of the research was to introduce the method of students' presentations in foreign language teaching, as well as the topics related to the culture and civilization of the English-speaking countries. After the introductory lectures on how the presentation on the given topic in the English language should be prepared, and after the presentations were delivered by the students during one semester, the results of the questionnaires which the students had to solve at the beginning and the end of the semester, were compared. The goal of the research was to examine the extent in which the students acquired the contents presented to them in such a way. The obtained results are satisfactory, although they have not fully met the expectations. However, if the problems and flaws are identified and addressed, the method can be further improved and better results achieved, both regarding the foreign language competencies, as well as multicultural awareness of young people. 展开更多
关键词 English language MULTICULTURALISM MOTIVATION initial and final questionnaire students' presentations
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Diagnosis and treatment of sudden sensorineural hearing loss 被引量:1
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作者 Tsutomu Nakashima 《World Journal of Otorhinolaryngology》 2015年第2期41-43,共3页
Nationwide epidemiological surveys of idiopathic sudden sensorineural hearing loss(SSNHL) have been performed five times by the Research Committee of the Ministry of Health and Welfare or the Ministry of Health, Welfa... Nationwide epidemiological surveys of idiopathic sudden sensorineural hearing loss(SSNHL) have been performed five times by the Research Committee of the Ministry of Health and Welfare or the Ministry of Health, Welfare and Labour in Japan. These surveys included patients who had SSNHL in 1972, 1987, 1993, 2001, and 2012. Using the criteria for the grading of hearing loss in SSNHL or the criteria for grading the degree of hearing recovery after SSNHL established by the Research Committee, we compared the outcomes of SSNHL between the five nationwide surveys. The results revealed that the outcomes of SSNHL have not changed in the past 40 years. In 1972, 88% of patients received steroids, but none received prostaglandin E1(PGE1). The use of PGE1 has increased since the 1980 s, but its effect on SSNHL may not be significant. Intratympanic steroid injection has been introduced recently for the treatment of SSNHL, but it does not seem to be used widely in Japan. Intratympanic therapy that can reduce the total amount of steroids administered will be used more frequently if the true effects and indications for this therapy are known. Elucidation of the etiologies of SSNHL and development of treatments specific for these etiologies are expected. 展开更多
关键词 Sudden deafness Grading system Initial hearing level Final hearing level Treatment method Nationwide epidemiological survey
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Open Innovation and New Mechanism of Market-Based Technology Diffusion from MNCs
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作者 Zheng Feihu Cai Hongbo Zhong Xin 《China Economist》 2020年第6期84-100,共17页
The international community has blamed developing countries for the lack of intellectual property rights(IPR)protection-not least the“forced technology transfers”-in attracting foreign direct investment(FDI).This pa... The international community has blamed developing countries for the lack of intellectual property rights(IPR)protection-not least the“forced technology transfers”-in attracting foreign direct investment(FDI).This paper employs the largesample contract data of multinational companies’(MNCs)IT R&D transactions in China to discuss this controversy from a unique perspective of MNCs in the role of contractors.Our findings suggest that MNCs initially guarded their know-how before the 2000s under closed innovation,but have started to take the initiative to transfer technology to local partners as open innovation held sway.China’s structured market entities and huge demand for technology transactions have served as key drivers for MNCs to transfer technology,which has been further boosted by the new business model of open innovation.This paper’s empirical analysis not only helps unravel the“black box”of technology transfers by MNCs,but reveals how late-moving developing countries may make better use of FDI referencing China’s experience on the three dimensions of market opportunities,structured entities,and economies of scale. 展开更多
关键词 open innovation foreign direct investment(FDI) market-based technology diffusion initiative to match between supply and demand
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ANALYSIS OF FDTD TO UPML FOR MAXWELL EQUATIONS IN POLAR COORDINATES 被引量:2
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作者 方能胜 应隆安 《Acta Mathematica Scientia》 SCIE CSCD 2011年第5期2007-2032,共26页
An FDTD system associated with uniaxial perfectly matched layer(UPML) for an electromagnetic scattering problem in two-dimensional space in polar coordinates is considered.Particularly the FDTD system of an initial-... An FDTD system associated with uniaxial perfectly matched layer(UPML) for an electromagnetic scattering problem in two-dimensional space in polar coordinates is considered.Particularly the FDTD system of an initial-boundary value problems of the transverse magnetic(TM) mode to Maxwell's equations is obtained by Yee's algorithm,and the open domain of the scattering problem is truncated by a circle with a UPML.Besides,an artificial boundary condition is imposed on the outer boundary of the UPML.Afterwards,stability of the FDTD system on the truncated domain is established through energy estimates by the Gronwall inequality.Numerical experiments are designed to approve the theoretical analysis. 展开更多
关键词 Maxwell's equations uniaxial perfectly matched layer initial boundary value problem STABILITY finite difference time domain polar coordinates
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基于IIFAR微信护理结合聚焦干预在急性心肌梗死PCI术后患者中的应用 被引量:2
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作者 蔡丹霞 郭燕 +1 位作者 赵毅 陈士芳 《海南医学》 CAS 2024年第12期1803-1808,共6页
目的探讨基于初始核对-信息交流-准确性核对-反应(IIFAR)微信护理结合聚焦干预在急性心肌梗死(AMI)经皮冠脉介入治疗(PCI)后的应用效果。方法选取2023年1~4月河南科技大学第一附属医院收治的102例AMI患者纳入研究,按随机数表法分为对照... 目的探讨基于初始核对-信息交流-准确性核对-反应(IIFAR)微信护理结合聚焦干预在急性心肌梗死(AMI)经皮冠脉介入治疗(PCI)后的应用效果。方法选取2023年1~4月河南科技大学第一附属医院收治的102例AMI患者纳入研究,按随机数表法分为对照组和观察组各51例。两组患者均接受PCI术治疗,对照组采取常规干预,观察组于此基础上采取基于IIFAR微信护理与聚焦干预相结合的管理模式,干预时间共6个月。干预前和干预2个月、6个月后,比较两组患者的冠心病自我管理行为量表(CSMS)评分、运动自我效能量表(SEE)评分,术后24 h内和干预2个月、6个月后,比较两组患者的心功能[左心室射血分数(LVEF)、左心室舒张末期内径(LVEDD)、左心房内径(LAD)]和运动能力[无氧阈耗氧量(VO2AT)、峰值耗氧量(VO2peak)、6 min步行距离(6MWD)],并比较两组患者的主要不良心血管事件(MACE)发生情况。结果干预2个月和6个月后,两组患者的CSMS和SEE评分均呈逐渐升高趋势,且观察组患者的CSMS、SEE评分明显高于对照组,差异均有统计学意义(P<0.05);干预2个月和6个月后,两组患者的LVEF均呈逐渐升高趋势,而LVEDD、LAD均呈逐渐降低趋势,且观察组患者的LVEF明显高于对照组,LVEDD、LAD明显低于对照组,差异均有统计学意义(P<0.05);干预2个月和6个月后,两组患者的VO2AT、VO2peak、6 MWD均呈逐渐升高趋势,且观察组患者的VO2AT、VO2peak、6 MWD明显高于对照组,差异均有统计学意义(P<0.05);观察组患者的MACE总发生率为5.88%,略低于对照组的13.73%,但差异无统计学意义(P>0.05)。结论基于IIFAR微信护理结合聚焦干预有助于提高AMI PCI术后患者自我效能与自我管理能力,恢复心功能,提高运动能力。 展开更多
关键词 心肌梗死 初始核对-信息交流-准确性核对-反应 聚焦干预 心功能 运动能力 自我管理能力 自我效能 主要不良心血管事件
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硅酸钠改善碱激发材料力学性能与凝结机理分析
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作者 顾小娟 韩文娟 田小娟 《浙江交通职业技术学院学报》 CAS 2024年第1期25-32,共8页
为了进一步增强碱激发材料的力学性能,掌握碱激发材料的凝结规律,通过掺入不同种类与掺量硅酸钠进行增硅改性,增强矿渣碱激发材料反应活性,定期观测试件的力学性能并分析凝结规律,同时结合微观分析手段深入剖析硅酸钠的增硅增强机理。... 为了进一步增强碱激发材料的力学性能,掌握碱激发材料的凝结规律,通过掺入不同种类与掺量硅酸钠进行增硅改性,增强矿渣碱激发材料反应活性,定期观测试件的力学性能并分析凝结规律,同时结合微观分析手段深入剖析硅酸钠的增硅增强机理。结果表明,固态与液态硅酸钠均能够显著提高试件的抗压强度,明显缩短初凝与终凝时间。随固态硅酸钠掺量的提升,试件抗压强度呈先上升后下降趋势,固态硅酸钠在试件内大量结晶是导致抗压强度下降的主要原因。随液态硅酸钠掺量的提升,试件抗压强度呈先显著上升后趋于平稳的趋势,这说明其增强作用具有最大限值,液态硅酸钠的激发效果明显优于固态。 展开更多
关键词 碱激发 硅酸钠 矿渣 抗压强度 初凝 终凝
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陕南南郑方言语音特点研究
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作者 李艳 《咸阳师范学院学报》 2024年第3期26-37,共12页
南郑位于汉中盆地西南部,方言语音特点较复杂。声母方面,泥来母大多洪混细分;非晓组有的读音互换;知系混入精组。韵母方面,主要表现在果摄字和深臻曾梗通摄字的读音。声调方面,法镇、红庙、濂水、碑坝、黄官、小南海、大河坎、两河、福... 南郑位于汉中盆地西南部,方言语音特点较复杂。声母方面,泥来母大多洪混细分;非晓组有的读音互换;知系混入精组。韵母方面,主要表现在果摄字和深臻曾梗通摄字的读音。声调方面,法镇、红庙、濂水、碑坝、黄官、小南海、大河坎、两河、福成、黎坪、胡家营、牟家坝、青树、湘水等14地方言全部入声归阳平,而高台、汉山、圣水、协税、新集、阳春、梁山等7地方言次浊入归阴平,全浊入归阳平。 展开更多
关键词 南郑方言 声母特点 韵母特点 入声归派
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气候变化背景下西藏高原地区界限温度时空变化特征
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作者 杜军 黄志诚 +2 位作者 次旺顿珠 德庆卓嘎 周刊社 《中国农业气象》 CSCD 2024年第2期111-123,共13页
受全球气候变化影响,农牧业生产面临较大风险,研究界限温度时空变化对调整农业种植结构,实现农业可持续发展具有重要意义。利用近40a(1981-2020年)西藏38个气象站点逐日平均气温观测数据,采用线性倾向估计、Person系数、Mann-Kendall、... 受全球气候变化影响,农牧业生产面临较大风险,研究界限温度时空变化对调整农业种植结构,实现农业可持续发展具有重要意义。利用近40a(1981-2020年)西藏38个气象站点逐日平均气温观测数据,采用线性倾向估计、Person系数、Mann-Kendall、优势分析等方法,分析了气候变暖背景下近40a西藏≥0℃、≥5℃和≥10℃界限温度(初日、终日、持续日数和活动积温)的时空变化特征。结果表明:(1)西藏≥0℃、≥5℃和≥10℃界限温度分布总体上表现为自东南向西北初日推迟、终日提早、持续日数缩短和积温减少的特征,并具有明显的海拔垂直地带性特征。1991-2020年与1981-2010年平均值比较,西藏各站三种积温均增加,以≥10℃积温增幅较大;绝大部分站点初日偏早、终日偏晚、持续日数偏多。(2)近40a西藏≥0℃、≥5℃和≥10℃初日、终日和持续日数的变幅以≥0℃最大,平均每10a初日提早3.2d、终日推迟3.5d、持续日数延长5.4d;积温增幅以≥10℃最大,为86.1℃·d·10a^(-1)。≥0℃、≥5℃持续日数增加是由于初日明显提早造成的,而≥10℃持续日数的增加因终日显著推迟导致。(3)≥0℃界限温度的线性倾向率(LTR),低海拔地区明显大于高海拔地区;≥5℃初日、积温LTR的最大值在低海拔地区,终日、持续日数LTR的最大值在中高海拔地区(3500-4000m);≥10℃初日LTR在中高海拔地区最大,终日、持续日数和积温LTR最大值出现在海拔4000-4500m地区。(4)20世纪80年代≥0℃、≥5℃和≥10℃初日偏晚、终日偏早、持续日数偏短、积温偏低;90年代初日、终日和持续日数正常,积温仍偏低;进入21世纪后,初日偏早、终日偏晚、持续日数增加、积温明显偏高,以21世纪10年代最明显。(5)≥5℃终日突变最早,发生在20世纪90年代初;≥10℃终日突变最晚,在21世纪10年代中期;初日、积温的突变分别出现在20世纪90年代中后期和21世纪初,持续日数突变点发生在20世纪90年代后期至21世纪中前期。 展开更多
关键词 界限温度 活动积温 初日 终日 变化趋势 年代际变化 气候突变
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“一带一路”倡议对中国沿线区域入境旅游发展的政策效应评价 被引量:1
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作者 秦晓楠 王悦 韩苗苗 《地理科学》 CSSCI CSCD 北大核心 2024年第1期82-90,共9页
以2007—2019年中国31个省(区、市)面板数据,结合超效率及全局Malmquist指数与PSM-DID法实证检验“一带一路”倡议对入境旅游发展的政策效应。研究表明:①入境旅游的平均发展能力呈现为正增长,但产业空间格局差异仍未缓解,“一路”区域... 以2007—2019年中国31个省(区、市)面板数据,结合超效率及全局Malmquist指数与PSM-DID法实证检验“一带一路”倡议对入境旅游发展的政策效应。研究表明:①入境旅游的平均发展能力呈现为正增长,但产业空间格局差异仍未缓解,“一路”区域空间集聚明显,“一带”区域趋向空间极化发展;②倡议显著提高了沿线区域的入境旅游效率,但其实施效果具有滞后性,“一路”区域的政策响应优于“一带”;③倡议的政策效应具有区域异质性,经济发展水平与旅游交通条件对倡议的影响存在差异,结构红利与政策驱动效应显著,但旅游产业内核基础条件亟需提升,交通设施和资源要素优化应成为未来的提升关键。 展开更多
关键词 政策效应 入境旅游效率 "一带一路"倡议 双重差分 倾向得分匹配
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基于多复杂关键词的模板图像匹配矫正算法
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作者 张昊 刘义亭 李佩娟 《自动化应用》 2024年第20期165-167,170,共4页
针对当前智能电表示数在文字识别时图像矫正效果不佳导致识别模板无法生成、识别结果精度较低等问题,提出了一种基于多复杂关键词的模板图像匹配矫正算法。该算法通过选择合适的关键词,利用标注软件提取关键词的坐标实现智能电表的模板... 针对当前智能电表示数在文字识别时图像矫正效果不佳导致识别模板无法生成、识别结果精度较低等问题,提出了一种基于多复杂关键词的模板图像匹配矫正算法。该算法通过选择合适的关键词,利用标注软件提取关键词的坐标实现智能电表的模板图像匹配矫正,为电表后续的示数识别提供了良好的识别模板。通过后续多种智能电表识别实验,证明该算法具有简单方便、鲁棒性强、矫正效果好和矫正成功率高等特点。与基于四点定位的图像矫正算法相比,所提算法矫正成功率的提升超过20%。 展开更多
关键词 模板匹配 OCR识别 初始模板
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Urbanization under globalization:How does the Belt and Road Initiative affect urbanization levels in participating countries 被引量:1
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作者 MA Haitao 《Journal of Geographical Sciences》 SCIE CSCD 2022年第11期2170-2188,共19页
China’s Belt and Road Initiative(BRI)presents the world with a new era of inclusive globalization,which will shape urbanization patterns globally.This study considered the launch of BRI as a quasi-experiment,where we... China’s Belt and Road Initiative(BRI)presents the world with a new era of inclusive globalization,which will shape urbanization patterns globally.This study considered the launch of BRI as a quasi-experiment,where we evaluated the BRI’s impact on urbanization by way of difference-in-differences(DID)and propensity score matching(PSM)methods.The results showed that the BRI exerted a significantly negative effect on urbanization in its first three years.Its positive effect emerged from the fifth year onwards,indicating that the BRI’s positive effect on urbanization required a period of practical experience.Heterogeneous analysis and placebo test were also conducted to verify the robustness of the model.The effects in low-income countries were revealed to have been much greater than in high-income countries,meaning the BRI had been conducive to promote local urban growth in underdeveloped economies.Finally,the geographical detector model was introduced to discuss the influencing mechanism of urbanization in BRI and non-BRI countries,showing external factors were the prominent driving forces in BRI countries,whereas internal drivers played an important role in non-BRI countries.Our findings indicated that the implementation of the BRI contributed to building global economic growth and supporting a shared future. 展开更多
关键词 Belt and Road Initiative URBANIZATION GLOBALIZATION DIFFERENCE-IN-DIFFERENCES propensity score matching
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Asymptotic Behavior of Global Classical Solutions to the Cauchy Problem on a Semi-Bounded Initial Axis for Quasilinear Hyperbolic Systems 被引量:1
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作者 Wei Wei HAN1,2 1. Department of Applied Mathematics, Donghua University, Shanghai 201620, P. R. China 2. School of Mathematical Sciences, Fudan University, Shanghai 200433, P. R. China 《Journal of Mathematical Research and Exposition》 CSCD 2010年第1期41-53,共13页
In this paper we study the asymptotic behavior of global classical solutions to the Cauchy problem with initial data given on a semi-bounded axis for quasilinear hyperbolic systems. Based on the existence result on th... In this paper we study the asymptotic behavior of global classical solutions to the Cauchy problem with initial data given on a semi-bounded axis for quasilinear hyperbolic systems. Based on the existence result on the global classical solution, we prove that, when t tends to the infinity, the solution approaches a combination of C1 travelling wave solutions with the algebraic rate (1 + t)^-u, provided that the initial data decay with the rate (1 + x)^-(l+u) (resp. (1 - x)^-(1+u)) as x tends to +∞ (resp. -∞), where u is a positive constant. 展开更多
关键词 quasilinear hyperbolic system Cauchy problem on a semi-bounded initial axis global classical solution weak linear degeneracy matching condition travelling wave.
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踏面匹配与初始裂纹形态交互作用下车轮多轴疲劳裂纹扩展特性
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作者 黄奎龙 余刚 +1 位作者 方修洋 张昊楠 《材料导报》 EI CAS CSCD 北大核心 2024年第4期187-191,共5页
地铁车辆车轮裂纹常萌生于车轮踏面及亚表面,亚表面裂纹是影响车轮寿命的关键因素之一。借助有限元仿真方法,在轮轨接触三维模型亚表面处插入初始裂纹,研究了不同轮轨匹配形式、不同初始裂纹形态对亚表面疲劳裂纹扩展特性的影响。结果显... 地铁车辆车轮裂纹常萌生于车轮踏面及亚表面,亚表面裂纹是影响车轮寿命的关键因素之一。借助有限元仿真方法,在轮轨接触三维模型亚表面处插入初始裂纹,研究了不同轮轨匹配形式、不同初始裂纹形态对亚表面疲劳裂纹扩展特性的影响。结果显示,车轮亚表面3 mm处接触应力数值最大,在锥形、LM型、LMA型三种踏面类型中,采用LM型踏面时车轮亚表面等效应力最大,最容易发生疲劳破坏;裂纹扩展均呈现出多轴疲劳裂纹扩展特性,锥形踏面工况下裂纹的扩展速率高于其余两种踏面类型下的裂纹扩展速率;不同初始裂纹角度中,45°初始裂纹角度是最危险的角度;初始裂纹深度对裂纹的扩展路径基本无影响。本研究结果对车轮亚表面埋藏裂纹缺陷评判及剩余寿命预测有一定的工程及理论指导意义。 展开更多
关键词 车轮 轮轨型面匹配 初始裂纹 亚表面 疲劳裂纹扩展
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丽江纳西族汉语方言音系及音韵特点
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作者 杨春艳 《现代语文》 2024年第4期29-34,共6页
丽江纳西族汉语方言,既受到民族语的影响,又受到周边汉语方言、普通话的影响,从而形成了自己的鲜明特点,这在语音方面尤为突出。在田野调查的基础上,归纳出丽江纳西族汉语方言的音系及其音韵特点。丽江纳西族汉语方言有24个声母,它的主... 丽江纳西族汉语方言,既受到民族语的影响,又受到周边汉语方言、普通话的影响,从而形成了自己的鲜明特点,这在语音方面尤为突出。在田野调查的基础上,归纳出丽江纳西族汉语方言的音系及其音韵特点。丽江纳西族汉语方言有24个声母,它的主要特点是:古全浊声母清化,尖团不分,具有[ts、tsʰ、s、z]和[tʂ、tʂʰ、ʂ、ʐ]两套声母等。有31个韵母,它的主要特点是:韵尾简化,韵头简化,以及具体韵摄的分合等。有阴平、阳平、去声、入声4个声调,它的主要特点是:古平声字按照声母的清浊今演变为阴平和阳平,清声母、次浊声母上声字与阴平合流,全浊声母上声字今读去声,古入声字今自成一个调类。 展开更多
关键词 丽江纳西族 汉语方言 音系 声母 韵母 声调
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一类抛物型最优控制问题Crank-Nicolson格式的预处理方法
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作者 李直幸 《乐山师范学院学报》 2024年第8期1-11,共11页
针对一类抛物型偏微分方程约束的分布式最优控制问题,通过此问题的一阶最优性条件得到了一组耦合的初值和终值问题,对这组耦合的问题运用Crank-Nicolson格式进行离散,采取块三角预处理策略来求解2*2的线性系统,然后通过匹配策略和基于Kr... 针对一类抛物型偏微分方程约束的分布式最优控制问题,通过此问题的一阶最优性条件得到了一组耦合的初值和终值问题,对这组耦合的问题运用Crank-Nicolson格式进行离散,采取块三角预处理策略来求解2*2的线性系统,然后通过匹配策略和基于Kronecker积的分裂技术建立了基于Kronecker积的Schur补的近似,并由此提出了一种基于Crank-Nicolson离散格式的预处理迭代方法,最后用数值实验证明了该方法的精确性和计算效率。结果表明,由于Schur补的近似具有Kronecker积的结构形式,该方法可以有效地实现预处理条件;该方法能极大地减小迭代次数,节省运算时间,降低运算成本,具有较好的结果。研究结果在解决工程技术和社会科学领域的相关最优控制问题具有应用价值。 展开更多
关键词 预处理 CRANK-NICOLSON格式 初值和终值问题 偏微分方程约束优化
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1981—2022年西藏“一江两河”主要农区农业界限温度变化特征
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作者 郭艺楠 黄志诚 +1 位作者 杜军 徐薇 《干旱气象》 2024年第1期47-53,共7页
日平均气温≥10℃是喜温作物适宜生长的下限温度。西藏“一江两河”主要农区≥10℃积温变化是判断该地区热量资源的关键指标。基于1981—2022年该区域9个气象站点的日平均气温数据,使用线性倾向估计、Pearson相关系数、Mann-Kendall检验... 日平均气温≥10℃是喜温作物适宜生长的下限温度。西藏“一江两河”主要农区≥10℃积温变化是判断该地区热量资源的关键指标。基于1981—2022年该区域9个气象站点的日平均气温数据,使用线性倾向估计、Pearson相关系数、Mann-Kendall检验和R/S分析法,分析≥10℃界限温度的气候变化特征。结果表明:(1)随着海拔高度的升高,≥10℃界限温度出现明显垂直地带性特征,包括≥10℃初日推迟、终日提前、持续日数与积温减少。(2)近42 a来,该地区≥10℃初日普遍提前,气候倾向率为-2.53 d·(10 a)-1;终日延后,倾向率为3.33 d·(10 a)-1;持续日数和积温均明显增加,倾向率分别为5.87 d·(10 a)-1、106.19℃·d·(10 a)-1。与青藏高原其他地区相比,这种变化更为明显。(3)20世纪80年代是过去40 a≥10℃初日最迟、终日最早、持续日数最短、积温最少的10 a,与之相对的是21世纪10年代的情况截然相反。(4)≥10℃界限温度的H指数均大于0.65,表明未来≥10℃界限温度初日提前、终日推迟、持续日数延长和积温增加的变化趋势将持续存在。 展开更多
关键词 ≥10℃活动积温 初日 终日 持续日数 年际和年代际变化 突变 西藏“一江两河”
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