BACKGROUND Patients with head and neck cancer often develop depressive symptoms during radiochemotherapy due to changes in saliva secretion,radiation-induced oral mucositis,and dysphagia.These symptoms significantly a...BACKGROUND Patients with head and neck cancer often develop depressive symptoms during radiochemotherapy due to changes in saliva secretion,radiation-induced oral mucositis,and dysphagia.These symptoms significantly affect quality of life.Although existing nursing interventions provide some relief,they have limitations in improving swallowing function and developing coping strategies.AIM To evaluate the effectiveness of tongue pressure resistance feedback training combined with empowerment education in improving depressive symptoms and swallowing function in patients with head and neck cancer undergoing radiochemotherapy.METHODS This study included 110 patients with head and neck cancer who exhibited depressive symptoms and underwent radiochemotherapy at the Affiliated Hospital of Jiangnan University between January 2021 and December 2023.Patients were randomly assigned to either a reference group or an experimental group,each comprising 55 patients.The reference group received routine care,whereas the experimental group received tongue pressure resistance feedback training and empowerment education.After 6 weeks of continuous intervention,comparisons were made between the two groups regarding depressive symptom scores,swallowing function,coping strategies,and quality of life,both pre-and post-intervention.RESULTS Following the intervention,both groups demonstrated decreased scores for depressive symptoms and swallowing function,with the experimental group showing a significantly greater reduction than the reference group(P<0.05).The experimental group also demonstrated higher confrontation scores and lower avoidance and submission scores for coping strategies than the reference group(P<0.05).Quality of life scores improved in both groups after the intervention,with the experimental group showing markedly higher scores than the reference group(P<0.05).CONCLUSION The combination of tongue pressure resistance feedback training and empowerment education is effective in alleviating depressive symptoms,enhancing swallowing function,optimizing coping strategies,and significantly improving the quality of life of patients with head and neck cancer undergoing radiochemotherapy.This approach shows promise for clinical applications and promotion.展开更多
Current research on pilot-operated relief valve stability is primarily conducted from the perspective of system dynamics or stability criteria,and most of the existing conclusions focus on the spool shape,damping hole...Current research on pilot-operated relief valve stability is primarily conducted from the perspective of system dynamics or stability criteria,and most of the existing conclusions focus on the spool shape,damping hole size,and pulsation frequency of the pump.However,the essential factors pertaining to the unstable vibration of relief valves remain ambiguous.In this study,the dynamic behavior of a pilot-operated relief valve is investigated using the frequency-domain method.The result suggests that the dynamic pressure feedback orifice is vital to the dynamic characteristics of the valve.A large orifice has a low flow resistance.In this case,the fluid in the main spring chamber flows freely,which is not conducive to the stability of the relief valve.However,a small orifice may create significant flow resistance,thus restricting fluid flow.In this case,the oil inside the main valve spring chamber is equivalent to a high-stiffness liquid spring.The main mass-spring vibration system has a natural frequency that differs significantly from the operating frequency of the relief valve,which is conducive to the stability of the relief valve.Good agreement is obtained between the theoretical analysis and experiments.The results indicate that designing a dynamic pressure feedback orifice of an appropriate size is beneficial to improving the stability of hydraulic pilot-operated relief valves.In addition,the dynamic pressure feedback orifice reduces the response speed of the relief valve.This study comprehensively considers the stability,rapidity,and immunity of relief valves and expands current investigations into the dynamic characteristics of relief valves from the perspective of classical control theory,thus revealing the importance of different parameters.展开更多
Recently,large and thin glass substrates are transported by air film conveyors to reduce surface damage.On the production line,the glass substrates are desired to be transported flatly on the conveyor to ensure the qu...Recently,large and thin glass substrates are transported by air film conveyors to reduce surface damage.On the production line,the glass substrates are desired to be transported flatly on the conveyor to ensure the quality inspection.A method by feedbacking film pressure to the theoretical model is proposed for estimation of the deformation of the glass sheet,and the validity of the method is theoretically and experimentally verified.First,a theoretical model including the flow behavior through a porous-walled gap is established,and the film pressure distribution can be predicted by solving the model.Then,an experimental setup that can simultaneously measure the film pressure and the flatness of the glass sheet is established,and,the validity of the model is verified experimentally.Next,with the pressure points at the grooves as the boundary and the pressure points at the flange area as the feedback,an algorithm is applied to shape the one-dimensional deformation at the centerlines in accordance with a quadratic curve.Furthermore,two-dimensional deformation of the glass sheet can then be estimated by an interpolation operation.Comparisons of the calculated results with the experimental data verify the effectiveness of the estimating method.展开更多
Compared with traditional isobaric combustion,continuous rotating detonation(CRD)has been theoretically proved to be a more efficient combustion mode with higher thermal cycle efficiency.However,the realization and st...Compared with traditional isobaric combustion,continuous rotating detonation(CRD)has been theoretically proved to be a more efficient combustion mode with higher thermal cycle efficiency.However,the realization and stable operating of liquid kerosene detonation is still a challenge.As a major component of kerosene pyrolysis products after regenerative cooling,ethylene is a transitional hydrocarbon fuel from kerosene to hydrogen and it is worth studying.In this paper,a series of 2 D numerical simulations are conducted to investigate the effects of the injection nozzle on the ethylene-air CRD.Three geometrical parameters of the nozzle are thoroughly tested including the distance between two neighboring nozzle centers,the nozzle exit width,and the slant angle of the nozzle.The results show that an ethylene-air detonation wave is realized and it propagates stably.A small distance between two neighboring nozzle centers is conducive to improving the strength of the CRD wave and leads to greater feedback pressure into the plenum.As the nozzle exit width increases,the strength of the CRD wave and the feedback pressure into the plenum both increase.The CRD wave propagation velocity is greatly improved and the feedback pressure into the plenum is significantly reduced when the slant angle of the nozzle is positive.By contrast,a sizeable reduction in velocity is found when the angle is negative.The co-rotating two-wave propagation mode is observed when the angle is 30°,and the highest CRD propagation velocity and the lowest feedback pressure are both obtained when the angle is 60°.展开更多
In this paper, the objective is to achieve a successful coupling match and stable operation between the rotating detonation combustor (RDC) and the ramjet engine isolator. The propagation characteristics of the rotati...In this paper, the objective is to achieve a successful coupling match and stable operation between the rotating detonation combustor (RDC) and the ramjet engine isolator. The propagation characteristics of the rotating detonation wave (RDW) under different outlet areas, as well as the pressure feedback behavior of the isolator, are examined through the use of a gradually expanded S-shaped isolator. Liquid aviation kerosene and air are employed as propellants, and experiments are carried out at a constant air flow rate of 2.17 kg/s and varying equivalence ratios (ERs). The typical mode, pressure, and mode distribution of RDW are analyzed. A stable single-wave mode with a dominant frequency of 1138.63 Hz is obtained at the medium area ratio. Reducing the outlet area ratio is beneficial for enhancing the intensity of the detonation wave. Simultaneously, the intensity of the detonation wave increases with the rise of the equivalence ratio, and there exists an optimal equivalence ratio within the medium area ratio, which maximizes the intensity of the detonation wave. With the increase of the outlet area ratio, the boundary of detonable equivalence ratio can be widened, although the pop-out phenomenon becomes more pronounced. The pressure feedback degree of the S-shaped isolator is evaluated by defining the percentage decays of pulsating pressure and steady-state pressure. In the rotating detonation mode, the smaller the outlet area ratio, the larger the percentage decay of pulsation pressure, indicating a greater extent of pressure feedback. At the same time, as the equivalence ratio is increased, the percentage decay of pulsation pressure shows an upward trend. Under the selected operating conditions, the suppression effects of the S-shaped isolator on the pulsating pressure feedback of the detonation wave are 71.53% and 12.07%, and the suppression effects on the steady-state pressure feedback are 14.32% and 45.55%. The experimental verification of the feasibility of the S-shaped isolator presents a novel concept for suppressing the pressure feedback of the detonation wave.展开更多
文摘BACKGROUND Patients with head and neck cancer often develop depressive symptoms during radiochemotherapy due to changes in saliva secretion,radiation-induced oral mucositis,and dysphagia.These symptoms significantly affect quality of life.Although existing nursing interventions provide some relief,they have limitations in improving swallowing function and developing coping strategies.AIM To evaluate the effectiveness of tongue pressure resistance feedback training combined with empowerment education in improving depressive symptoms and swallowing function in patients with head and neck cancer undergoing radiochemotherapy.METHODS This study included 110 patients with head and neck cancer who exhibited depressive symptoms and underwent radiochemotherapy at the Affiliated Hospital of Jiangnan University between January 2021 and December 2023.Patients were randomly assigned to either a reference group or an experimental group,each comprising 55 patients.The reference group received routine care,whereas the experimental group received tongue pressure resistance feedback training and empowerment education.After 6 weeks of continuous intervention,comparisons were made between the two groups regarding depressive symptom scores,swallowing function,coping strategies,and quality of life,both pre-and post-intervention.RESULTS Following the intervention,both groups demonstrated decreased scores for depressive symptoms and swallowing function,with the experimental group showing a significantly greater reduction than the reference group(P<0.05).The experimental group also demonstrated higher confrontation scores and lower avoidance and submission scores for coping strategies than the reference group(P<0.05).Quality of life scores improved in both groups after the intervention,with the experimental group showing markedly higher scores than the reference group(P<0.05).CONCLUSION The combination of tongue pressure resistance feedback training and empowerment education is effective in alleviating depressive symptoms,enhancing swallowing function,optimizing coping strategies,and significantly improving the quality of life of patients with head and neck cancer undergoing radiochemotherapy.This approach shows promise for clinical applications and promotion.
基金Supported by National Natural Science Foundation of China(Grant No.52175059)National Key Research and Development Program of China(Grant No.2018YFB2001100).
文摘Current research on pilot-operated relief valve stability is primarily conducted from the perspective of system dynamics or stability criteria,and most of the existing conclusions focus on the spool shape,damping hole size,and pulsation frequency of the pump.However,the essential factors pertaining to the unstable vibration of relief valves remain ambiguous.In this study,the dynamic behavior of a pilot-operated relief valve is investigated using the frequency-domain method.The result suggests that the dynamic pressure feedback orifice is vital to the dynamic characteristics of the valve.A large orifice has a low flow resistance.In this case,the fluid in the main spring chamber flows freely,which is not conducive to the stability of the relief valve.However,a small orifice may create significant flow resistance,thus restricting fluid flow.In this case,the oil inside the main valve spring chamber is equivalent to a high-stiffness liquid spring.The main mass-spring vibration system has a natural frequency that differs significantly from the operating frequency of the relief valve,which is conducive to the stability of the relief valve.Good agreement is obtained between the theoretical analysis and experiments.The results indicate that designing a dynamic pressure feedback orifice of an appropriate size is beneficial to improving the stability of hydraulic pilot-operated relief valves.In addition,the dynamic pressure feedback orifice reduces the response speed of the relief valve.This study comprehensively considers the stability,rapidity,and immunity of relief valves and expands current investigations into the dynamic characteristics of relief valves from the perspective of classical control theory,thus revealing the importance of different parameters.
基金This study was supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK20181467)the National Natural Science Foundation of China(Grant No.51675247).
文摘Recently,large and thin glass substrates are transported by air film conveyors to reduce surface damage.On the production line,the glass substrates are desired to be transported flatly on the conveyor to ensure the quality inspection.A method by feedbacking film pressure to the theoretical model is proposed for estimation of the deformation of the glass sheet,and the validity of the method is theoretically and experimentally verified.First,a theoretical model including the flow behavior through a porous-walled gap is established,and the film pressure distribution can be predicted by solving the model.Then,an experimental setup that can simultaneously measure the film pressure and the flatness of the glass sheet is established,and,the validity of the model is verified experimentally.Next,with the pressure points at the grooves as the boundary and the pressure points at the flange area as the feedback,an algorithm is applied to shape the one-dimensional deformation at the centerlines in accordance with a quadratic curve.Furthermore,two-dimensional deformation of the glass sheet can then be estimated by an interpolation operation.Comparisons of the calculated results with the experimental data verify the effectiveness of the estimating method.
基金the National Natural Science Foundation of China(Nos.51776220 and 91541103)the Postgraduate Scientific Research Innovation Project of Hunan Province,China。
文摘Compared with traditional isobaric combustion,continuous rotating detonation(CRD)has been theoretically proved to be a more efficient combustion mode with higher thermal cycle efficiency.However,the realization and stable operating of liquid kerosene detonation is still a challenge.As a major component of kerosene pyrolysis products after regenerative cooling,ethylene is a transitional hydrocarbon fuel from kerosene to hydrogen and it is worth studying.In this paper,a series of 2 D numerical simulations are conducted to investigate the effects of the injection nozzle on the ethylene-air CRD.Three geometrical parameters of the nozzle are thoroughly tested including the distance between two neighboring nozzle centers,the nozzle exit width,and the slant angle of the nozzle.The results show that an ethylene-air detonation wave is realized and it propagates stably.A small distance between two neighboring nozzle centers is conducive to improving the strength of the CRD wave and leads to greater feedback pressure into the plenum.As the nozzle exit width increases,the strength of the CRD wave and the feedback pressure into the plenum both increase.The CRD wave propagation velocity is greatly improved and the feedback pressure into the plenum is significantly reduced when the slant angle of the nozzle is positive.By contrast,a sizeable reduction in velocity is found when the angle is negative.The co-rotating two-wave propagation mode is observed when the angle is 30°,and the highest CRD propagation velocity and the lowest feedback pressure are both obtained when the angle is 60°.
基金supported by the National Natural Science Foundation of China(Grant No.52025064).
文摘In this paper, the objective is to achieve a successful coupling match and stable operation between the rotating detonation combustor (RDC) and the ramjet engine isolator. The propagation characteristics of the rotating detonation wave (RDW) under different outlet areas, as well as the pressure feedback behavior of the isolator, are examined through the use of a gradually expanded S-shaped isolator. Liquid aviation kerosene and air are employed as propellants, and experiments are carried out at a constant air flow rate of 2.17 kg/s and varying equivalence ratios (ERs). The typical mode, pressure, and mode distribution of RDW are analyzed. A stable single-wave mode with a dominant frequency of 1138.63 Hz is obtained at the medium area ratio. Reducing the outlet area ratio is beneficial for enhancing the intensity of the detonation wave. Simultaneously, the intensity of the detonation wave increases with the rise of the equivalence ratio, and there exists an optimal equivalence ratio within the medium area ratio, which maximizes the intensity of the detonation wave. With the increase of the outlet area ratio, the boundary of detonable equivalence ratio can be widened, although the pop-out phenomenon becomes more pronounced. The pressure feedback degree of the S-shaped isolator is evaluated by defining the percentage decays of pulsating pressure and steady-state pressure. In the rotating detonation mode, the smaller the outlet area ratio, the larger the percentage decay of pulsation pressure, indicating a greater extent of pressure feedback. At the same time, as the equivalence ratio is increased, the percentage decay of pulsation pressure shows an upward trend. Under the selected operating conditions, the suppression effects of the S-shaped isolator on the pulsating pressure feedback of the detonation wave are 71.53% and 12.07%, and the suppression effects on the steady-state pressure feedback are 14.32% and 45.55%. The experimental verification of the feasibility of the S-shaped isolator presents a novel concept for suppressing the pressure feedback of the detonation wave.
