Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and...Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination planning.This paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the destination.The results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism networks.The macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high value.The mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of clusters.The pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four different periods has a very similar importance profile structure suggesting that the attraction network has the same construction rules and evolution mechanism,which aids in understanding the attraction network pattern at both macro and micro scales.Important approaches and practical implications for planners and managers are presented.展开更多
The pose accuracy of parallel manipulators(PMs)is a key index to measure their performance.Establishing the grav-ity-based kinetostatic model of a parallel robot provides an important basis for its error composition a...The pose accuracy of parallel manipulators(PMs)is a key index to measure their performance.Establishing the grav-ity-based kinetostatic model of a parallel robot provides an important basis for its error composition and accuracy improvement.In this paper,a kinetostatic modeling approach that takes real gravity distribution into consideration is proposed to analyze the influence of gravity on the infinitesimal twist and actuator forces of PMs.First,the duality of the twist screw and constraint wrenches are used to derive the gravity-attached constraint wrenches independent of the external load and the limb stiffness matrix corresponding to the kinematics-based constraint wrenches.Sec-ond,the gravity model of the mechanism is established based on the screw theory and the principle of virtual work.Finally,the analytical formulas of the infinitesimal twist and the actuator force of PMs are obtained,and the influences of the external load,platform gravity,and rod gravity on the stiffness of the mechanism are decoupled.The non-overconstrained 3RPS and overconstrained 2PRU-UPR PMs are taken as examples to verify the proposed method.This research proposes a methodology to analyze the infinitesimal deformation of the mechanism under the influence of gravity.展开更多
BACKGROUND Patients undergoing laparoscopic resection of liver metastases of colorectal cancer are prone to negative emotions and decrease of digestive function.Early nursing and psychological intervention are necessa...BACKGROUND Patients undergoing laparoscopic resection of liver metastases of colorectal cancer are prone to negative emotions and decrease of digestive function.Early nursing and psychological intervention are necessary.AIM To observe the effect of enhanced recovery nursing combined with mental health education on postoperative recovery and mental health of patients undergoing laparoscopic resection of liver metastases of colorectal cancer.METHODS One hundred and twenty patients who underwent laparoscopic resection of liver metastases of colorectal cancer at our hospital between March 2021 and March 2023,were selected as participants.The patients admitted from March 1,2021 to February 28,2022 were set as the control group,and they were given routine nursing combined with mental health education intervention.While the patients admitted from March 1,2022 to March 31,2023 were set as the observation group,they were given accelerated rehabilitation surgical nursing combined with mental health education intervention.The differences in postoperative recovery-related indices,complications and pain degrees,and mental health-related scores were compared between groups.The T lymphocyte subset levels of the two groups were also compared.RESULTS The postoperative exhaust,defecation,eating and drainage time of the observation group were shorter than those of the control group.The pain scores of the observation group were lower than those of the control group at 6,12,24,48,and 72 h after surgery.The cumulative complication rate of the observation group was lower than that of the control group(P<0.05).The CD4+/CD8+in the observation group was higher than that in the control group 3 d after surgery(P<0.05).After intervention,the self-rating depression scale,self-rating anxiety scale,avoidance dimension,and yielding dimension in Medical coping style(MCMQ)scores of the two groups were lower than those prior to intervention,and the scores in the observation group were lower than those in the control group(P<0.05).The face dimension score in the MCMQ score was higher than that before intervention,and that of the observation group was higher than that of the control group(P<0.05).After intervention,the total scores of the life function index scale(FLIC)and psychological well-being scores of cancer patients in the two groups,and the physical and social well-being scores in the observation group,were higher than those before intervention.The nursing satisfaction of the observation group was higher than that of the control group(P<0.05).The physical,psychological,and social well-being,and the total FLIC scores of the observation group were higher than those in the control group after surgery(P<0.05).CONCLUSION Enhanced recovery nursing combined with mental health education can promote the recovery of gastrointestinal function,improve the mental health and quality of life of patients after laparoscopic resection of colorectal cancer liver metastases,and reduce the incidence of complications.展开更多
The high-quality development of a country driven by talent necessitates comprehensive and practical STEM(Science,Technology,Engineering,and Mathematics)education.The goal of localizing STEM education is to cultivate c...The high-quality development of a country driven by talent necessitates comprehensive and practical STEM(Science,Technology,Engineering,and Mathematics)education.The goal of localizing STEM education is to cultivate comprehensive innovative technology talents that meet the needs of the new era.STEM teachers play a core role in this concept,and the quality of teacher training directly determines the development trend of STEM education and the quality of future talents in the country.Therefore,based on the current situation and existing problems in STEM teacher training,the shared commitment to“high-quality STEM teacher training”is employed as a guiding principle,highlighting the role of various elements in the STEM teacher training process.The practical path for STEM teacher training is proposed from four aspects:top-level design goal orientation,resource integration to solve supply imbalance,curriculum construction to improve the teaching system,and sustainable development to enhance professional ability.This study hopes to provide guidelines for innovative training of localized STEM teachers in China.展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.41971202)the National Natural Science Foundation of China(No.42201181)the Fundamental research funding targets for central universities(No.2412022QD002)。
文摘Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination planning.This paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the destination.The results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism networks.The macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high value.The mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of clusters.The pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four different periods has a very similar importance profile structure suggesting that the attraction network has the same construction rules and evolution mechanism,which aids in understanding the attraction network pattern at both macro and micro scales.Important approaches and practical implications for planners and managers are presented.
基金Supported by National Natural Science Foundation of China(Grant No.52275036)Key Research and Development Project of Jiaxing Science and Technology Bureau of China(Grant No.2022BZ10004).
文摘The pose accuracy of parallel manipulators(PMs)is a key index to measure their performance.Establishing the grav-ity-based kinetostatic model of a parallel robot provides an important basis for its error composition and accuracy improvement.In this paper,a kinetostatic modeling approach that takes real gravity distribution into consideration is proposed to analyze the influence of gravity on the infinitesimal twist and actuator forces of PMs.First,the duality of the twist screw and constraint wrenches are used to derive the gravity-attached constraint wrenches independent of the external load and the limb stiffness matrix corresponding to the kinematics-based constraint wrenches.Sec-ond,the gravity model of the mechanism is established based on the screw theory and the principle of virtual work.Finally,the analytical formulas of the infinitesimal twist and the actuator force of PMs are obtained,and the influences of the external load,platform gravity,and rod gravity on the stiffness of the mechanism are decoupled.The non-overconstrained 3RPS and overconstrained 2PRU-UPR PMs are taken as examples to verify the proposed method.This research proposes a methodology to analyze the infinitesimal deformation of the mechanism under the influence of gravity.
基金The study was reviewed and approved by the Institutional Review Board of The Sixth Affiliated Hospital of Sun Yat-sen University,No.2023ZSLYEC-046.
文摘BACKGROUND Patients undergoing laparoscopic resection of liver metastases of colorectal cancer are prone to negative emotions and decrease of digestive function.Early nursing and psychological intervention are necessary.AIM To observe the effect of enhanced recovery nursing combined with mental health education on postoperative recovery and mental health of patients undergoing laparoscopic resection of liver metastases of colorectal cancer.METHODS One hundred and twenty patients who underwent laparoscopic resection of liver metastases of colorectal cancer at our hospital between March 2021 and March 2023,were selected as participants.The patients admitted from March 1,2021 to February 28,2022 were set as the control group,and they were given routine nursing combined with mental health education intervention.While the patients admitted from March 1,2022 to March 31,2023 were set as the observation group,they were given accelerated rehabilitation surgical nursing combined with mental health education intervention.The differences in postoperative recovery-related indices,complications and pain degrees,and mental health-related scores were compared between groups.The T lymphocyte subset levels of the two groups were also compared.RESULTS The postoperative exhaust,defecation,eating and drainage time of the observation group were shorter than those of the control group.The pain scores of the observation group were lower than those of the control group at 6,12,24,48,and 72 h after surgery.The cumulative complication rate of the observation group was lower than that of the control group(P<0.05).The CD4+/CD8+in the observation group was higher than that in the control group 3 d after surgery(P<0.05).After intervention,the self-rating depression scale,self-rating anxiety scale,avoidance dimension,and yielding dimension in Medical coping style(MCMQ)scores of the two groups were lower than those prior to intervention,and the scores in the observation group were lower than those in the control group(P<0.05).The face dimension score in the MCMQ score was higher than that before intervention,and that of the observation group was higher than that of the control group(P<0.05).After intervention,the total scores of the life function index scale(FLIC)and psychological well-being scores of cancer patients in the two groups,and the physical and social well-being scores in the observation group,were higher than those before intervention.The nursing satisfaction of the observation group was higher than that of the control group(P<0.05).The physical,psychological,and social well-being,and the total FLIC scores of the observation group were higher than those in the control group after surgery(P<0.05).CONCLUSION Enhanced recovery nursing combined with mental health education can promote the recovery of gastrointestinal function,improve the mental health and quality of life of patients after laparoscopic resection of colorectal cancer liver metastases,and reduce the incidence of complications.
文摘The high-quality development of a country driven by talent necessitates comprehensive and practical STEM(Science,Technology,Engineering,and Mathematics)education.The goal of localizing STEM education is to cultivate comprehensive innovative technology talents that meet the needs of the new era.STEM teachers play a core role in this concept,and the quality of teacher training directly determines the development trend of STEM education and the quality of future talents in the country.Therefore,based on the current situation and existing problems in STEM teacher training,the shared commitment to“high-quality STEM teacher training”is employed as a guiding principle,highlighting the role of various elements in the STEM teacher training process.The practical path for STEM teacher training is proposed from four aspects:top-level design goal orientation,resource integration to solve supply imbalance,curriculum construction to improve the teaching system,and sustainable development to enhance professional ability.This study hopes to provide guidelines for innovative training of localized STEM teachers in China.
