Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and ...Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and agricultural economy(CECA)is of great practical significance to measure the efficiency of cultivated land use,and thereby promote regional rural revitalization.However,few studies to date have focused on coordinated development efficiency between cultivated land use and agricultural economy in mountainous areas from the perspective of cultivated land spatial morphology.Thus,the present study explores CECA with this focus using the data envelopment analysis method,and analyzes the key influencing factors via a geographical detector model in 16 counties in western Hubei province.The results show the following:(1)CECA exhibits significant spatial heterogeneity that is high in the south of the study area and low in the north;(2)scale efficiency is the primary limiting factor for CECA;(3)the insufficient output of cultivated land use mainly restricts CECA in the south of the study area,while individual county in the north suffered from input redundancy and insufficient output;and(4)population density in the southern region has the most significant effect on CECA,and gross domestic product has the greatest impact in the northern region.The results contribute to the derivation of specific measures by which to promote cultivated land use efficiency and sustainable development of the social economy.展开更多
In order to compromise the conflicts between control accuracy and system efficiency of conventional electro-hydraulic servo systems,a novel pump-valve coordinated electro-hydraulic servo system was designed and a corr...In order to compromise the conflicts between control accuracy and system efficiency of conventional electro-hydraulic servo systems,a novel pump-valve coordinated electro-hydraulic servo system was designed and a corresponding control strategy was proposed.The system was constituted of a pumpcontrolled part and a valve-controlled part,the pump controlled part is used to adjust the flow rate of oil source and the valve controlled part is used to complete the position tracking control of the hydraulic cylinder.Based on the system characteristics,a load flow grey prediction method was adopted in the pump controlled part to reduce the system overflow losses,and an adaptive robust control method was adopted in the valve controlled part to eliminate the effect of system nonlinearity and parametric uncertainties due to variable hydraulic parameters and system loads on the control precision.The experimental results validated that the adopted control strategy increased the system efficiency obviously with guaranteed high control accuracy.展开更多
Objective: to explore the effect of nursing intervention in operating room on improving the cooperation efficiency of laparoscopic surgery. Methods: from April 2020 to April 2021, 100 cases of laparoscopic surgery pat...Objective: to explore the effect of nursing intervention in operating room on improving the cooperation efficiency of laparoscopic surgery. Methods: from April 2020 to April 2021, 100 cases of laparoscopic surgery patients in our hospital were randomly divided into two groups. The routine group was given routine nursing, while the intervention group was given nursing intervention in the operating room. The anxiety level, pain level, complication rate, exhaust time and hospitalization time before and after nursing were compared between the two groups. Results: after nursing, the anxiety and pain levels of the two groups were significantly improved, while the anxiety level of the intervention group was significantly lower than that of the conventional group, and the pain level of the intervention group was significantly lower than that of the conventional group (P < 0.05). The incidence of complications in the intervention group was lower than that in the conventional group (P < 0.05). The exhaust time and hospitalization time of the intervention group were shorter than those of the routine group (P < 0.05). Conclusion: the effect of nursing intervention in operating room for patients undergoing laparoscopic surgery is definite, which can reduce complications, accelerate postoperative recovery of patients and recovery of gastrointestinal function, and reduce anxiety and pain of patients. It is worthy of promotion.展开更多
To efficiently simulate and calculate the radar cross section(RCS) related electromagnetic problems by employing the finite-difference time-domain(FDTD) algorithm, an efficient stretched coordinate perfectly matched l...To efficiently simulate and calculate the radar cross section(RCS) related electromagnetic problems by employing the finite-difference time-domain(FDTD) algorithm, an efficient stretched coordinate perfectly matched layer(ESC-PML) based upon the exponential time differencing(ETD) method is proposed.The proposed implementation can not only reduce the number of auxiliary variables in the SC-PML regions but also maintain the ability of the original SC-PML in terms of the absorbing performance. Compared with the other existed algorithms, the ETDFDTD method shows the least memory consumption resulting in the computational efficiency. The effectiveness and efficiency of the proposed ESC-PML scheme is verified through the RCS relevant problems including the perfect E conductor(PEC) sphere model and the patch antenna model. The results indicate that the proposed scheme has the advantages of the ETD-FDTD method and ESC-PML scheme in terms of high computational efficiency and considerable computational accuracy.展开更多
基金National Natural Science Foundation of China,No.71804168。
文摘Suitable spatial morphology of cultivated land is a basic requirement for sustaining agricultural economic development in mountainous areas.Coordinated development efficiency of cultivated land spatial morphology and agricultural economy(CECA)is of great practical significance to measure the efficiency of cultivated land use,and thereby promote regional rural revitalization.However,few studies to date have focused on coordinated development efficiency between cultivated land use and agricultural economy in mountainous areas from the perspective of cultivated land spatial morphology.Thus,the present study explores CECA with this focus using the data envelopment analysis method,and analyzes the key influencing factors via a geographical detector model in 16 counties in western Hubei province.The results show the following:(1)CECA exhibits significant spatial heterogeneity that is high in the south of the study area and low in the north;(2)scale efficiency is the primary limiting factor for CECA;(3)the insufficient output of cultivated land use mainly restricts CECA in the south of the study area,while individual county in the north suffered from input redundancy and insufficient output;and(4)population density in the southern region has the most significant effect on CECA,and gross domestic product has the greatest impact in the northern region.The results contribute to the derivation of specific measures by which to promote cultivated land use efficiency and sustainable development of the social economy.
基金Supported by Program for New Century Excellent Talents In University(NCET-12-0049)Beijing Natural Science Foundation(4132034)
文摘In order to compromise the conflicts between control accuracy and system efficiency of conventional electro-hydraulic servo systems,a novel pump-valve coordinated electro-hydraulic servo system was designed and a corresponding control strategy was proposed.The system was constituted of a pumpcontrolled part and a valve-controlled part,the pump controlled part is used to adjust the flow rate of oil source and the valve controlled part is used to complete the position tracking control of the hydraulic cylinder.Based on the system characteristics,a load flow grey prediction method was adopted in the pump controlled part to reduce the system overflow losses,and an adaptive robust control method was adopted in the valve controlled part to eliminate the effect of system nonlinearity and parametric uncertainties due to variable hydraulic parameters and system loads on the control precision.The experimental results validated that the adopted control strategy increased the system efficiency obviously with guaranteed high control accuracy.
文摘Objective: to explore the effect of nursing intervention in operating room on improving the cooperation efficiency of laparoscopic surgery. Methods: from April 2020 to April 2021, 100 cases of laparoscopic surgery patients in our hospital were randomly divided into two groups. The routine group was given routine nursing, while the intervention group was given nursing intervention in the operating room. The anxiety level, pain level, complication rate, exhaust time and hospitalization time before and after nursing were compared between the two groups. Results: after nursing, the anxiety and pain levels of the two groups were significantly improved, while the anxiety level of the intervention group was significantly lower than that of the conventional group, and the pain level of the intervention group was significantly lower than that of the conventional group (P < 0.05). The incidence of complications in the intervention group was lower than that in the conventional group (P < 0.05). The exhaust time and hospitalization time of the intervention group were shorter than those of the routine group (P < 0.05). Conclusion: the effect of nursing intervention in operating room for patients undergoing laparoscopic surgery is definite, which can reduce complications, accelerate postoperative recovery of patients and recovery of gastrointestinal function, and reduce anxiety and pain of patients. It is worthy of promotion.
基金supported by the National Natural Science Foundation of China(61571022611971022)。
文摘To efficiently simulate and calculate the radar cross section(RCS) related electromagnetic problems by employing the finite-difference time-domain(FDTD) algorithm, an efficient stretched coordinate perfectly matched layer(ESC-PML) based upon the exponential time differencing(ETD) method is proposed.The proposed implementation can not only reduce the number of auxiliary variables in the SC-PML regions but also maintain the ability of the original SC-PML in terms of the absorbing performance. Compared with the other existed algorithms, the ETDFDTD method shows the least memory consumption resulting in the computational efficiency. The effectiveness and efficiency of the proposed ESC-PML scheme is verified through the RCS relevant problems including the perfect E conductor(PEC) sphere model and the patch antenna model. The results indicate that the proposed scheme has the advantages of the ETD-FDTD method and ESC-PML scheme in terms of high computational efficiency and considerable computational accuracy.
