Extensive spatiotemporal analyses of long-trend surface ozone in the Yangtze River Delta(YRD)region and itsmeteorology-related and emission-related have not been systematically analyzed.In this study,by using 8-year-l...Extensive spatiotemporal analyses of long-trend surface ozone in the Yangtze River Delta(YRD)region and itsmeteorology-related and emission-related have not been systematically analyzed.In this study,by using 8-year-long(2015–2022)surface ozone observation data,we attempted to reveal the variation ofmultiple timescale components using the Kolmogorov–Zurbenko filter,and the effects of meteorology and emissions were quantitatively isolated using multiple linear regression with meteorological variables.The results showed that the short-term,seasonal,and long-term components accounted for daily maximum 8-hr average O_(3)(O_(3–8)hr)concentration,46.4%,45.9%,and 1.0%,respectively.The meteorological impacts account for an average of 71.8%of O_(3–8)hr,and the YRD’s eastern and northern sections aremeteorology-sensitive areas.Based on statistical analysis technology with empirical orthogonal function,the contribution of meteorology,local emission,and transport in the long-term component of O_(3–8)hr were 0.21%,0.12%,and 0.6%,respectively.The spatiotemporal analysis indicated that a distinct decreasing spatial pattern could be observed from coastal cities towards the northwest,influenced by the monsoon and synoptic conditions.The central urban agglomeration north and south of the YRD was particularly susceptible to local pollution.Among the cities studied,Shanghai,Anqing,and Xuancheng,located at similar latitudes,were significantly impacted by atmospheric transmission—the contribution of Shanghai,the maximum accounting for 3.6%.展开更多
Trend forecasting is an important aspect in fault diagnosis and work state supervision. The principle, where Grey theory is applied in fault forecasting, is that the forecast system is considered as a Grey system; the...Trend forecasting is an important aspect in fault diagnosis and work state supervision. The principle, where Grey theory is applied in fault forecasting, is that the forecast system is considered as a Grey system; the existing known information is used to infer the unknown information's character, state and development trend in a fault pattern, and to make possible forecasting and decisions for future development. It involves the whitenization of a Grey process. But the traditional equal time interval Grey GM (1,1) model requires equal interval data and needs to bring about accumulating addition generation and reversion calculations. Its calculation is very complex. However, the non equal interval Grey GM (1,1) model decreases the condition of the primitive data when establishing a model, but its requirement is still higher and the data were pre processed. The abrasion primitive data of plant could not always satisfy these modeling requirements. Therefore, it establishes a division method suited for general data modeling and estimating parameters of GM (1,1), the standard error coefficient that was applied to judge accuracy height of the model was put forward; further, the function transform to forecast plant abrasion trend and assess GM (1,1) parameter was established. These two models need not pre process the primitive data. It is not only suited for equal interval data modeling, but also for non equal interval data modeling. Its calculation is simple and convenient to use. The oil spectrum analysis acted as an example. The two GM (1,1) models put forward in this paper and the new information model and its comprehensive usage were investigated. The example shows that the two models are simple and practical, and worth expanding and applying in plant fault diagnosis.展开更多
目的采用文献计量分析方法对全球2019—2023年乙型肝炎功能性治愈相关文献进行分析,帮助研究人员了解该领域的研究热点和趋势。方法检索2019—2023年Web of Science核心合集的科学引文索引扩展版(Science Citation Index Expanded,SCI-E...目的采用文献计量分析方法对全球2019—2023年乙型肝炎功能性治愈相关文献进行分析,帮助研究人员了解该领域的研究热点和趋势。方法检索2019—2023年Web of Science核心合集的科学引文索引扩展版(Science Citation Index Expanded,SCI-Expanded)收录的乙型肝炎功能性治愈主题相关文献。利用VOSviewer和CiteSpace可视化分析工具,从发文趋势、国际科研合作网络、关键词共现聚类和突现等角度进行深入分析,并结合相关文献的具体内容进行阐述,分析研究热点和趋势。结果共纳入600篇相关文献,关键词共现及主题聚类提示乙肝功能性治愈目前主要聚焦的研究方向为功能性治愈预测与监测的血清生物标志物、功能性治愈与免疫、核苷类似物停药、干扰素治疗、功能性治愈的远期预后。ESI高被引原始研究论文的内容与上述聚类大致符合,但更多地集中于功能性治愈的新药。关键词突现显示2019年以来,研究热点从病毒学机制和血清标志物,到核苷类似物停药和干扰素治疗,再到免疫学机制与新药的变迁。结论乙型肝炎功能性治愈的病毒学机制、血清标志物、免疫学机制、核苷类似物的停药、干扰素治疗、治愈后的远期预后是研究热点和趋势。展开更多
目的基于文献计量学探讨睡眠不足对性功能影响的研究热点和发展趋势。方法检索1990年至2023年12月24日Web of Science中相关文献,采用Co-Occurrence 13.4软件和VOSViewers 1.6.13软件对年发文量、国家、作者、关键词、演化趋势等进行可...目的基于文献计量学探讨睡眠不足对性功能影响的研究热点和发展趋势。方法检索1990年至2023年12月24日Web of Science中相关文献,采用Co-Occurrence 13.4软件和VOSViewers 1.6.13软件对年发文量、国家、作者、关键词、演化趋势等进行可视化分析。结果1990年—2023年,共有370篇睡眠不足与性功能相关的文献,总体呈现快速上升趋势。美国发文量最高(141篇),国家间合作主要分为欧洲和美洲两大区域。发文量最高的作者为Andersen(37篇),该领域形成了以Andersen、Velázquez-Moctezuma、Feng、Shigehara等为学术带头人的数个合作团队。关键词共现聚类可划分为睡眠剥夺现象观察、睡眠不足对性功能影响的研究机制、睡眠不足影响性功能使生活质量下降3个主题。2006年之前以现象观察为主要研究方向,从2007年开始以疾病机制为主,2019以后主要研究方向为身心健康。结论睡眠不足会影响男性性功能,临床应重视评估睡眠状况,将睡眠干预纳入性功能障碍防治策略。展开更多
SUN Gen nian (Shaanxi Normal University, Xi’an 710062,P.R.China) ABSTRACE:Modern inbound tourism in China has been developing for 20 years, a trend line of inbound tourists in statistical data began to show. This pap...SUN Gen nian (Shaanxi Normal University, Xi’an 710062,P.R.China) ABSTRACE:Modern inbound tourism in China has been developing for 20 years, a trend line of inbound tourists in statistical data began to show. This paper introduces the concept of tourism background trend line, and explores its two functions as a barometer in demonstrating fluctuation in the tourism economy and as a forecaster in forecasting tourism development. The tourism background trend line is a new concept, the word "background" derived from environment science, refers to the trend line" which reflects the dynamic curve or dynamic equation of tourism development without considering the impact of unexpected incidents. The introduction of this concept was inspired by Karl Marx’s comments on the relation between value and price. Tourism background trend line reflects the summary of multiple factors involving tourism resources, tourism demand, population growth, the scale and speed of economic development, and the spatial interaction between tourism origins and destimations. It demonstrates the natural and stable trend and the temporal law of tourism development in a country or region. The tourism statistical curve is at random, susceptible to disruptions and disturbances from serious political, economic and environmental happenings, but it always fluctuates around the background line. Tourism background line can reveal the potential of a country’s tourism development. Compared with the statistical line, it can be used as a barometer" indicating ups and downs of tourism industry in the past. When naturally extended, the background trend line also can be used for forecasting the trend of tourism development in future. In this paper, 4 tourism background trend lines of China’s inbound tourists, i.e. foreign tourists, Hong Kong/Macao/Taiwan tourists, overseas Chinese tourists and total tourists from abroad, were established with statistical data from 1978 to 1996. And the impacts of the Political Event in 1989(or Tiananmen Square Incident) on China’s inbound tourism were evaluated. The result shows that the impact of the Event was not limited within one year, but it stretched over 3 years. The total loss was 20 million in tourist arrivals and ＄ 1620 million in foreign currency income. The paper also studied the trend of China’s inbound tourism in the next 4 years.展开更多
基金supported by the National Natural Science Foundation of China(No.42075177)the National Key Research and Development Program of China(No.2017YFC0210003).
文摘Extensive spatiotemporal analyses of long-trend surface ozone in the Yangtze River Delta(YRD)region and itsmeteorology-related and emission-related have not been systematically analyzed.In this study,by using 8-year-long(2015–2022)surface ozone observation data,we attempted to reveal the variation ofmultiple timescale components using the Kolmogorov–Zurbenko filter,and the effects of meteorology and emissions were quantitatively isolated using multiple linear regression with meteorological variables.The results showed that the short-term,seasonal,and long-term components accounted for daily maximum 8-hr average O_(3)(O_(3–8)hr)concentration,46.4%,45.9%,and 1.0%,respectively.The meteorological impacts account for an average of 71.8%of O_(3–8)hr,and the YRD’s eastern and northern sections aremeteorology-sensitive areas.Based on statistical analysis technology with empirical orthogonal function,the contribution of meteorology,local emission,and transport in the long-term component of O_(3–8)hr were 0.21%,0.12%,and 0.6%,respectively.The spatiotemporal analysis indicated that a distinct decreasing spatial pattern could be observed from coastal cities towards the northwest,influenced by the monsoon and synoptic conditions.The central urban agglomeration north and south of the YRD was particularly susceptible to local pollution.Among the cities studied,Shanghai,Anqing,and Xuancheng,located at similar latitudes,were significantly impacted by atmospheric transmission—the contribution of Shanghai,the maximum accounting for 3.6%.
文摘Trend forecasting is an important aspect in fault diagnosis and work state supervision. The principle, where Grey theory is applied in fault forecasting, is that the forecast system is considered as a Grey system; the existing known information is used to infer the unknown information's character, state and development trend in a fault pattern, and to make possible forecasting and decisions for future development. It involves the whitenization of a Grey process. But the traditional equal time interval Grey GM (1,1) model requires equal interval data and needs to bring about accumulating addition generation and reversion calculations. Its calculation is very complex. However, the non equal interval Grey GM (1,1) model decreases the condition of the primitive data when establishing a model, but its requirement is still higher and the data were pre processed. The abrasion primitive data of plant could not always satisfy these modeling requirements. Therefore, it establishes a division method suited for general data modeling and estimating parameters of GM (1,1), the standard error coefficient that was applied to judge accuracy height of the model was put forward; further, the function transform to forecast plant abrasion trend and assess GM (1,1) parameter was established. These two models need not pre process the primitive data. It is not only suited for equal interval data modeling, but also for non equal interval data modeling. Its calculation is simple and convenient to use. The oil spectrum analysis acted as an example. The two GM (1,1) models put forward in this paper and the new information model and its comprehensive usage were investigated. The example shows that the two models are simple and practical, and worth expanding and applying in plant fault diagnosis.
文摘目的采用文献计量分析方法对全球2019—2023年乙型肝炎功能性治愈相关文献进行分析,帮助研究人员了解该领域的研究热点和趋势。方法检索2019—2023年Web of Science核心合集的科学引文索引扩展版(Science Citation Index Expanded,SCI-Expanded)收录的乙型肝炎功能性治愈主题相关文献。利用VOSviewer和CiteSpace可视化分析工具,从发文趋势、国际科研合作网络、关键词共现聚类和突现等角度进行深入分析,并结合相关文献的具体内容进行阐述,分析研究热点和趋势。结果共纳入600篇相关文献,关键词共现及主题聚类提示乙肝功能性治愈目前主要聚焦的研究方向为功能性治愈预测与监测的血清生物标志物、功能性治愈与免疫、核苷类似物停药、干扰素治疗、功能性治愈的远期预后。ESI高被引原始研究论文的内容与上述聚类大致符合,但更多地集中于功能性治愈的新药。关键词突现显示2019年以来,研究热点从病毒学机制和血清标志物,到核苷类似物停药和干扰素治疗,再到免疫学机制与新药的变迁。结论乙型肝炎功能性治愈的病毒学机制、血清标志物、免疫学机制、核苷类似物的停药、干扰素治疗、治愈后的远期预后是研究热点和趋势。
文摘目的基于文献计量学探讨睡眠不足对性功能影响的研究热点和发展趋势。方法检索1990年至2023年12月24日Web of Science中相关文献,采用Co-Occurrence 13.4软件和VOSViewers 1.6.13软件对年发文量、国家、作者、关键词、演化趋势等进行可视化分析。结果1990年—2023年,共有370篇睡眠不足与性功能相关的文献,总体呈现快速上升趋势。美国发文量最高(141篇),国家间合作主要分为欧洲和美洲两大区域。发文量最高的作者为Andersen(37篇),该领域形成了以Andersen、Velázquez-Moctezuma、Feng、Shigehara等为学术带头人的数个合作团队。关键词共现聚类可划分为睡眠剥夺现象观察、睡眠不足对性功能影响的研究机制、睡眠不足影响性功能使生活质量下降3个主题。2006年之前以现象观察为主要研究方向,从2007年开始以疾病机制为主,2019以后主要研究方向为身心健康。结论睡眠不足会影响男性性功能,临床应重视评估睡眠状况,将睡眠干预纳入性功能障碍防治策略。
基金Under the auspices of National Natural Science Foundation of China.
文摘SUN Gen nian (Shaanxi Normal University, Xi’an 710062,P.R.China) ABSTRACE:Modern inbound tourism in China has been developing for 20 years, a trend line of inbound tourists in statistical data began to show. This paper introduces the concept of tourism background trend line, and explores its two functions as a barometer in demonstrating fluctuation in the tourism economy and as a forecaster in forecasting tourism development. The tourism background trend line is a new concept, the word "background" derived from environment science, refers to the trend line" which reflects the dynamic curve or dynamic equation of tourism development without considering the impact of unexpected incidents. The introduction of this concept was inspired by Karl Marx’s comments on the relation between value and price. Tourism background trend line reflects the summary of multiple factors involving tourism resources, tourism demand, population growth, the scale and speed of economic development, and the spatial interaction between tourism origins and destimations. It demonstrates the natural and stable trend and the temporal law of tourism development in a country or region. The tourism statistical curve is at random, susceptible to disruptions and disturbances from serious political, economic and environmental happenings, but it always fluctuates around the background line. Tourism background line can reveal the potential of a country’s tourism development. Compared with the statistical line, it can be used as a barometer" indicating ups and downs of tourism industry in the past. When naturally extended, the background trend line also can be used for forecasting the trend of tourism development in future. In this paper, 4 tourism background trend lines of China’s inbound tourists, i.e. foreign tourists, Hong Kong/Macao/Taiwan tourists, overseas Chinese tourists and total tourists from abroad, were established with statistical data from 1978 to 1996. And the impacts of the Political Event in 1989(or Tiananmen Square Incident) on China’s inbound tourism were evaluated. The result shows that the impact of the Event was not limited within one year, but it stretched over 3 years. The total loss was 20 million in tourist arrivals and ＄ 1620 million in foreign currency income. The paper also studied the trend of China’s inbound tourism in the next 4 years.
