A generalized nonlinear Baker failure criterion is employed with the upper bound limit analysis to study the surrounding rock stability of underground cavities. A three-dimensional(3D) failure mode is established by e...A generalized nonlinear Baker failure criterion is employed with the upper bound limit analysis to study the surrounding rock stability of underground cavities. A three-dimensional(3D) failure mode is established by extending the two-dimensional(2D) failure mode, which offers an upper bound expression of the surrounding rock pressure. This method is validated with a series of examples before the influence of four parameters of scale parameter, curvature parameter, shift parameter and lateral pressure coefficient, on the surrounding rock pressure is analyzed. According to these results, failure ranges of the underground cavities are determined. The following conclusions are reached:(1) the proposed approach is more accurate to predict surrounding rock pressure than the Mohr-Coulomb failure criterion;(2) the surrounding rock with large scale parameter, curvature parameter, shift parameter, and lateral pressure coefficient can lead to a more stable underground cavity;(3) the failure range in 3D mode can be predicted according to the upper bound solutions.展开更多
This study focused on the evolution of growth front about AlN growth on nano-patterned sapphire substrate by metal-organic chemical vapor deposition.The substrate with concave cones was fabricated by nano-imprint lith...This study focused on the evolution of growth front about AlN growth on nano-patterned sapphire substrate by metal-organic chemical vapor deposition.The substrate with concave cones was fabricated by nano-imprint lithography and wet etching.Two samples with different epitaxy procedures were fabricated,manifesting as two-dimensional growth mode and three-dimensional growth mode,respectively.The results showed that growth temperature deeply influenced the growth modes and thus played a critical role in the coalescence of AlN.At a relatively high temperature,the AlN epilayer was progressively coalescence and the growth mode was two-dimensional.In this case,we found that the inclined semi-polar facets arising in the process of coalescence were{112^-1}type.But when decreasing the temperature,the{112^-2}semi-polar facets arose,leading to inverse pyramid morphology and obtaining the three-dimensional growth mode.The 3 D inverse pyramid AlN structure could be used for realizing 3 D semi-polar UV-LED or facet-controlled epitaxial lateral overgrowth of AlN.展开更多
<span style="font-family:Verdana;">Purpose: </span><span style="font-family:Verdana;">To discuss the effect of “1 + 3 + 3” emergency management mode to deal with COVID-19 pandem...<span style="font-family:Verdana;">Purpose: </span><span style="font-family:Verdana;">To discuss the effect of “1 + 3 + 3” emergency management mode to deal with COVID-19 pandemic in fever outpatient service of general hospitals. Method: This paper analyzes and summarizes the problems encountered by fever outpatient service in dealing with the COVID-19 pandemic from three aspects of “One Team”, “Three-Key” Control and “Three Mosts”. Results: The application of “1 + 3 + 3” emergency management mode can effectively boost the orderliness and efficiency of fever outpatient service in dealing with COVID-19 pandemic. Conclusion: The “1 + 3 + 3” emergency management mode provides a new management mode and idea for dealing with COVID-19 pandemic,</span><span style="font-family:""> </span><span style="font-family:Verdana;">so the fever outpatient service of general hospitals can better improve the national overall anti-pandemic situation.展开更多
English teaching in vocational schools is complex and challenging. The author integrated the language into students' real life and attached more importance to quality of life in language classroom. The author made...English teaching in vocational schools is complex and challenging. The author integrated the language into students' real life and attached more importance to quality of life in language classroom. The author made several innovative changes such as Exploratory Practice, 3-D mode, learner autonomy, performance evaluation and so on during the teaching course. She advocates promoting mutual understanding and common development of both teacher and students so that students can be competitive enough in the future and teachers can also acquire professional development.展开更多
Objective: To explore the clinical significance of “3H” nursing mode in improving negative emotions and insomnia in patients with enterostomy through a prospective cohort study. Methods: Adult patients who underwent...Objective: To explore the clinical significance of “3H” nursing mode in improving negative emotions and insomnia in patients with enterostomy through a prospective cohort study. Methods: Adult patients who underwent enterostomy surgery in our gastroenterology department with negative emotions and insomnia between August 2021 and August 2022 were selected as research objects and randomly divided into “3H” nursing mode group and conventional nursing management group. For the conventional nursing group, routine standard nursing mode was adopted after enterostomy, while extra systematic “3H” nursing service on the basis of conventional nursing management was applied for its counterpart. SAS and SDS scores, Pittsburgh sleep quality index, Barthel index and nursing satisfaction were compared between the two groups. Results: SAS and SDS scores, Pittsburgh sleep quality index, Barthel index and nursing satisfaction of “3H” nursing mode group were evidently better than those of conventional nursing management group, and the difference was significant (P Conclusion: The “3H” nursing mode can effectively improve negative emotions of patients with enterostomy, such as anxiety and depression, improve their sleep quality and self-care ability in daily life, and play an important role in building a harmonious relationship between doctors and patients, nurses and patients, which is worthy of clinical application.展开更多
The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In...The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In this paper, an optical motion capture system based on the virtual reality technology is proposed to meet the requirements of the power enterprise for the qualified business ability. Electric power equipment, power equipment model entitative operating environment and the human model are established by electric power simulation unit, ZigBee technology and OpenGL graphics library. The problem of missing feature points is solved by applying the human model driven algorithm and the Kalman filtering algorithm. The experimental results show that it is more accurate to use Kalman filtering algorithm to extract the feature point in tracking process of actual motion capture and real-time animation display. The average absolute error of 3D coordinates is 1.61 mm and the average relative error is 2.23%. The system can improve trainees’ sense of experience and immersion.展开更多
This paper examines China’s effort to construct an Independent Knowledge System(IKS)as part of its broader modernization strategy.Existing models such as the Triple Helix and Mode 2 knowledge production fall short of...This paper examines China’s effort to construct an Independent Knowledge System(IKS)as part of its broader modernization strategy.Existing models such as the Triple Helix and Mode 2 knowledge production fall short of explaining the state-architected,sovereignty-driven logic of China’s approach.Using Industry-Education Integration(IEI)as a case study,the paper introduces the Sovereign Knowledge Nexus(SKN)model and proposes the concept of Mode 3 knowledge pro-duction.Mode 3 is characterized by state orchestration,strategic validation,systemic fusion,and a dual circulation of knowledge,with the ultimate goal of achieving technological and theoretical sovereignty.This framework provides new insights into China’s innovation model and its implications for global knowledge governance.展开更多
Crystal morphology is known to be of great importance to the end-use properties of crystal products, and to affect down-stream processing such as filtration and drying. However, it has been previously regarded as too ...Crystal morphology is known to be of great importance to the end-use properties of crystal products, and to affect down-stream processing such as filtration and drying. However, it has been previously regarded as too challenging to achieve automatic closed-loop control. Previous work has focused on controlling the crystal size distribution, where the size of a crystal is often defined as the diameter of a sphere that has the same volume as the crystal. This paper reviews the new advances in morphological population balance models for modelling and simulating the crystal shape distribution （CShD）, measuring and estimating crystal facet growth kinetics, and two- and three-dimensional imaging for on-line characterisation of the crystal morphology and CShD. A framework is presented that integrates the various components to achieve the ultimate objective of model-based closed-loop control of the CShD. The knowledge gaps and challenges that require further research are also identified.展开更多
In the application of long series batteries,there is always the phenomenon that multiple cells in a pack are unbalanced simultaneously.In view of this situation,a modevarying cell equalizer topology based on interleav...In the application of long series batteries,there is always the phenomenon that multiple cells in a pack are unbalanced simultaneously.In view of this situation,a modevarying cell equalizer topology based on interleaved parallel multiple transformers is proposed in this paper.Every unit in this equalizer can freely switch between LLC resonance mode and 3-state LC quasi-resonance mode.The boosting effect of LLC structure is used to reduce the number of transformer’s total turns.When multiple equalizer units need to work in LLC mode simultaneously,interleaved parallel technology is used to limit secondary side equalization current ripple for long-term protection of battery life.A prototype was designed and built to validate the effect of a closed loop LLC mode control algorithm with a state-of-charge(SOC)based equalization scheme selection strategy.Experimental results including up to 88.52%efficiency in LLC mode with 90.7%efficiency in 3-state LC mode,and minute level balancing time show the proposed topology demonstrates excellent balancing performance.展开更多
We propose a low-threshold soliton fiber laser passively mode locked with two different types of film-like saturable absorbers, one of which is fabricated by mixing Bi2Te3 with de-ionized water, as well as polyvinyl a...We propose a low-threshold soliton fiber laser passively mode locked with two different types of film-like saturable absorbers, one of which is fabricated by mixing Bi2Te3 with de-ionized water, as well as polyvinyl alcohol（PVA）, and then evaporating them in a Petri dish, and the other of which is prepared by directly dropping Bi2Te3 solution on the PVA film. Both Bi2Te3–PVA films exhibit outstanding features of low loss, high flexibility, and easy synthesis. By incorporating Bi2Te3–PVA films into fiber lasers, stable single-soliton emissions are obtained at a low pump power of 13 mW. Our results suggest that the Bi2Te3 can work as a promising mode locker for ultrafast lasers,while PVA is an excellent host for fabricating high-performance film-based saturable absorbers.展开更多
Numerical analysis of three-dimensional sound propagation in soft-soft or soft-hard circular ducts with circumferential and axial modes of sound sources at the inlet has been carried out. In this paper , the numerical...Numerical analysis of three-dimensional sound propagation in soft-soft or soft-hard circular ducts with circumferential and axial modes of sound sources at the inlet has been carried out. In this paper , the numerical method and the samples are offered and the effects of circumferential and axial modes on numerical results are discussed in detail .展开更多
基金Projects(51679117,11772358,51774322,51474249,51404179,51274249)supported by the National Natural Science Foundation of China。
文摘A generalized nonlinear Baker failure criterion is employed with the upper bound limit analysis to study the surrounding rock stability of underground cavities. A three-dimensional(3D) failure mode is established by extending the two-dimensional(2D) failure mode, which offers an upper bound expression of the surrounding rock pressure. This method is validated with a series of examples before the influence of four parameters of scale parameter, curvature parameter, shift parameter and lateral pressure coefficient, on the surrounding rock pressure is analyzed. According to these results, failure ranges of the underground cavities are determined. The following conclusions are reached:(1) the proposed approach is more accurate to predict surrounding rock pressure than the Mohr-Coulomb failure criterion;(2) the surrounding rock with large scale parameter, curvature parameter, shift parameter, and lateral pressure coefficient can lead to a more stable underground cavity;(3) the failure range in 3D mode can be predicted according to the upper bound solutions.
基金supported by the National Key R&D Program of China (No. 2016YFB0400800)the National Natural Sciences Foundation of China (Grant Nos. 61875187, 61527814, 61674147, U1505253)+1 种基金Beijing Nova Program Z181100006218 007Youth Innovation Promotion Association CAS 2017157
文摘This study focused on the evolution of growth front about AlN growth on nano-patterned sapphire substrate by metal-organic chemical vapor deposition.The substrate with concave cones was fabricated by nano-imprint lithography and wet etching.Two samples with different epitaxy procedures were fabricated,manifesting as two-dimensional growth mode and three-dimensional growth mode,respectively.The results showed that growth temperature deeply influenced the growth modes and thus played a critical role in the coalescence of AlN.At a relatively high temperature,the AlN epilayer was progressively coalescence and the growth mode was two-dimensional.In this case,we found that the inclined semi-polar facets arising in the process of coalescence were{112^-1}type.But when decreasing the temperature,the{112^-2}semi-polar facets arose,leading to inverse pyramid morphology and obtaining the three-dimensional growth mode.The 3 D inverse pyramid AlN structure could be used for realizing 3 D semi-polar UV-LED or facet-controlled epitaxial lateral overgrowth of AlN.
文摘<span style="font-family:Verdana;">Purpose: </span><span style="font-family:Verdana;">To discuss the effect of “1 + 3 + 3” emergency management mode to deal with COVID-19 pandemic in fever outpatient service of general hospitals. Method: This paper analyzes and summarizes the problems encountered by fever outpatient service in dealing with the COVID-19 pandemic from three aspects of “One Team”, “Three-Key” Control and “Three Mosts”. Results: The application of “1 + 3 + 3” emergency management mode can effectively boost the orderliness and efficiency of fever outpatient service in dealing with COVID-19 pandemic. Conclusion: The “1 + 3 + 3” emergency management mode provides a new management mode and idea for dealing with COVID-19 pandemic,</span><span style="font-family:""> </span><span style="font-family:Verdana;">so the fever outpatient service of general hospitals can better improve the national overall anti-pandemic situation.
文摘English teaching in vocational schools is complex and challenging. The author integrated the language into students' real life and attached more importance to quality of life in language classroom. The author made several innovative changes such as Exploratory Practice, 3-D mode, learner autonomy, performance evaluation and so on during the teaching course. She advocates promoting mutual understanding and common development of both teacher and students so that students can be competitive enough in the future and teachers can also acquire professional development.
文摘Objective: To explore the clinical significance of “3H” nursing mode in improving negative emotions and insomnia in patients with enterostomy through a prospective cohort study. Methods: Adult patients who underwent enterostomy surgery in our gastroenterology department with negative emotions and insomnia between August 2021 and August 2022 were selected as research objects and randomly divided into “3H” nursing mode group and conventional nursing management group. For the conventional nursing group, routine standard nursing mode was adopted after enterostomy, while extra systematic “3H” nursing service on the basis of conventional nursing management was applied for its counterpart. SAS and SDS scores, Pittsburgh sleep quality index, Barthel index and nursing satisfaction were compared between the two groups. Results: SAS and SDS scores, Pittsburgh sleep quality index, Barthel index and nursing satisfaction of “3H” nursing mode group were evidently better than those of conventional nursing management group, and the difference was significant (P Conclusion: The “3H” nursing mode can effectively improve negative emotions of patients with enterostomy, such as anxiety and depression, improve their sleep quality and self-care ability in daily life, and play an important role in building a harmonious relationship between doctors and patients, nurses and patients, which is worthy of clinical application.
文摘The safety production is critical to stable development of Chinese electric power industry. With the development of electric power enterprises, the requirements of its employees are also becoming higher and higher. In this paper, an optical motion capture system based on the virtual reality technology is proposed to meet the requirements of the power enterprise for the qualified business ability. Electric power equipment, power equipment model entitative operating environment and the human model are established by electric power simulation unit, ZigBee technology and OpenGL graphics library. The problem of missing feature points is solved by applying the human model driven algorithm and the Kalman filtering algorithm. The experimental results show that it is more accurate to use Kalman filtering algorithm to extract the feature point in tracking process of actual motion capture and real-time animation display. The average absolute error of 3D coordinates is 1.61 mm and the average relative error is 2.23%. The system can improve trainees’ sense of experience and immersion.
文摘This paper examines China’s effort to construct an Independent Knowledge System(IKS)as part of its broader modernization strategy.Existing models such as the Triple Helix and Mode 2 knowledge production fall short of explaining the state-architected,sovereignty-driven logic of China’s approach.Using Industry-Education Integration(IEI)as a case study,the paper introduces the Sovereign Knowledge Nexus(SKN)model and proposes the concept of Mode 3 knowledge pro-duction.Mode 3 is characterized by state orchestration,strategic validation,systemic fusion,and a dual circulation of knowledge,with the ultimate goal of achieving technological and theoretical sovereignty.This framework provides new insights into China’s innovation model and its implications for global knowledge governance.
基金Financial support from the following projects and organisa- tions are acknowledged： the China One Thousand Talent Scheme, the National Natural Science Foundation of China （NNSFC） under its Major Research Scheme of Meso-scale Mechanism and Control in Multi-phase Reaction Processes （project reference： 91434126）, the Natural Science Foundation of Guangdong Province （project reference： 2014A030313228）, the UK Engineering and Physical Sciences Research Council （EPSRC） for the projects of Shape （EP/C009541） and StereoVision （EP/E045707）, and the Technology Strategy Board （TSB） for the project of High Value Manufacturing CGM （TP/BD059E）.
文摘Crystal morphology is known to be of great importance to the end-use properties of crystal products, and to affect down-stream processing such as filtration and drying. However, it has been previously regarded as too challenging to achieve automatic closed-loop control. Previous work has focused on controlling the crystal size distribution, where the size of a crystal is often defined as the diameter of a sphere that has the same volume as the crystal. This paper reviews the new advances in morphological population balance models for modelling and simulating the crystal shape distribution （CShD）, measuring and estimating crystal facet growth kinetics, and two- and three-dimensional imaging for on-line characterisation of the crystal morphology and CShD. A framework is presented that integrates the various components to achieve the ultimate objective of model-based closed-loop control of the CShD. The knowledge gaps and challenges that require further research are also identified.
基金supported in main part by the General Project of National Natural Science Foundation of China under Grant 61671194in part by the General Scientific Research Projects of Zhejiang Education Department under Grant Y201840464.
文摘In the application of long series batteries,there is always the phenomenon that multiple cells in a pack are unbalanced simultaneously.In view of this situation,a modevarying cell equalizer topology based on interleaved parallel multiple transformers is proposed in this paper.Every unit in this equalizer can freely switch between LLC resonance mode and 3-state LC quasi-resonance mode.The boosting effect of LLC structure is used to reduce the number of transformer’s total turns.When multiple equalizer units need to work in LLC mode simultaneously,interleaved parallel technology is used to limit secondary side equalization current ripple for long-term protection of battery life.A prototype was designed and built to validate the effect of a closed loop LLC mode control algorithm with a state-of-charge(SOC)based equalization scheme selection strategy.Experimental results including up to 88.52%efficiency in LLC mode with 90.7%efficiency in 3-state LC mode,and minute level balancing time show the proposed topology demonstrates excellent balancing performance.
基金supported by the Fundamental Research Funds for the Central Universities (Grant Nos. 3102014JCQ01101, 3102014JCQ01099, and 3102014JCQ01085)the 973 Program (Grant No. 2012CB921900)the National Natural Science Foundation of China (Grant Nos. 61405161, 11404263, and 61377035)
文摘We propose a low-threshold soliton fiber laser passively mode locked with two different types of film-like saturable absorbers, one of which is fabricated by mixing Bi2Te3 with de-ionized water, as well as polyvinyl alcohol（PVA）, and then evaporating them in a Petri dish, and the other of which is prepared by directly dropping Bi2Te3 solution on the PVA film. Both Bi2Te3–PVA films exhibit outstanding features of low loss, high flexibility, and easy synthesis. By incorporating Bi2Te3–PVA films into fiber lasers, stable single-soliton emissions are obtained at a low pump power of 13 mW. Our results suggest that the Bi2Te3 can work as a promising mode locker for ultrafast lasers,while PVA is an excellent host for fabricating high-performance film-based saturable absorbers.
基金The project is supported by National Natural Science Foundation of China and National Education Commission Foundaion of China
文摘Numerical analysis of three-dimensional sound propagation in soft-soft or soft-hard circular ducts with circumferential and axial modes of sound sources at the inlet has been carried out. In this paper , the numerical method and the samples are offered and the effects of circumferential and axial modes on numerical results are discussed in detail .
