In order to improve the destruction efficiency of dioxins and also for developing new dioxin control technology, the destruction mechanisms of 2,3,7,8-tetrachlorodihenzo-p-dioxin (2,3,7,8-TCDD) by O3 and NO3, were i...In order to improve the destruction efficiency of dioxins and also for developing new dioxin control technology, the destruction mechanisms of 2,3,7,8-tetrachlorodihenzo-p-dioxin (2,3,7,8-TCDD) by O3 and NO3, were investigated employing quantum chemical calculations. For involved reactions, the microcosmic reaction processes were analyzed and depicted in detail based on geometry optimizations made by the B3LYP/6-31G(d) method. At the same time, the reaction activation energies were also calculated at the MP2/6- 311G(d,p)//B3LYP/6-31G(d) level. Configuration analysis indicated that 2,3,7,8-TCDD could be destroyed by 03 and NO3 in two different ways. The destruction of 2,3,7,8-TCDD by 03 proceeded via the addition of 03 and the cleavage of C=C while the destruction of 2,3,7,8-TCDD by NO3 proceeded via the substitution of chlorine by NO3. Calculated results show that, the activation energy of the destruction reaction of 2,3,7,8-TCDD by NO3 (267.48 kJ/mol) is much larger than that of the destruction reaction of 2,3,7,8-TCDD by O3 (51.20 kJ/mol). This indicated that the destruction of 2,3,7,8-TCDD by 03 is much more efficient than that of 2,3,7,8-TCDD by NO3. The reason why the activation energy for the destruction reaction of 2,3,7,8-TCDD by NO3 is so large, is also discussed.展开更多
In this paper, coordinated control of multiple robot manipulators holding a rigid object is discussed. In consideration of inaccuracy of the dynamic model of a multiple manipulator system, the error equations on obje...In this paper, coordinated control of multiple robot manipulators holding a rigid object is discussed. In consideration of inaccuracy of the dynamic model of a multiple manipulator system, the error equations on object position and internal force are derived. Then a hybrid position/force coordinated learning control scheme is presented and its convergence is proved. The scheme can improve the system performance by modifying the control input of the system after each iterative learning. Simulation results of two planar robot manipulators holding an object show the effectiveness of this control scheme.展开更多
Wavelet network, a class of neural network consisting of wavelets, is proposed to solve the inverse kinematics problem in robotic manipulator. A wavelet network suitable for dealing with multi-input and multi-output s...Wavelet network, a class of neural network consisting of wavelets, is proposed to solve the inverse kinematics problem in robotic manipulator. A wavelet network suitable for dealing with multi-input and multi-output system is constructed. The network is optimized by reducing the number of wavelets handling large dimension problem according to the sample data. The algorithms for sparseness analysis of input data and fitting wavelets to the output data with orthogonal method are introduced. Then Levenberg-Marquardt algorithm is used to train the network. Simulation results showed that this method is capable of solving the inverse kinematics problem for PUMA560.展开更多
A mathematical model was developed combining the dynamics of an Euler-Bernoulli beam, described by the assumed-mode method and hydraulic circuit dynamics. Only one matrix, termed drive Jacobian, was needed in the mode...A mathematical model was developed combining the dynamics of an Euler-Bernoulli beam, described by the assumed-mode method and hydraulic circuit dynamics. Only one matrix, termed drive Jacobian, was needed in the modeling of interaction between hydraulic circuit and flexible manipulator mechanism. Furthermore, a new robust controller based on mentioned above dynamic model was also considered to regulate both flexural vibrations and rigid body motion. The proposed controller combined sliding mode and backstepping techniques to deal with the nonlinear system with uncertainties. The sliding mode control was used to achieve an asymptotic joint angle and vibration regulation by providing a virtual force while the backstepping technique was used to regulate the spool position of a hydraulic valve to provide the required control force. Simulation results are presented to show the stabilizing effect and robustness of this control strategy.展开更多
In the underwater environment, many visual sensors don’t work, and many sensors which work well for robots working in space or on land can not be used underwater. Therefore, an optical fiber slide tactile sensor was ...In the underwater environment, many visual sensors don’t work, and many sensors which work well for robots working in space or on land can not be used underwater. Therefore, an optical fiber slide tactile sensor was designed based on the inner modulation mechanism of optical fibers. The principles and structure of the sensor are explained in detail. Its static and dynamic characteristics were analyzed theoretically and then simulated. A dynamic characteristic model was built and the simulation made using the GA based neural network. In order to improve sensor response, the recognition model of the sensor was designed based on the ‘inverse solution’ principle of neural networks, increasing the control precision and the sensitivity of the manipulator.展开更多
This study aims to explore the effectiveness of the emerging m-learning in the form of smart phones in English grammar teaching. The research mainly traces revision process of 100 sophomore students using traditional ...This study aims to explore the effectiveness of the emerging m-learning in the form of smart phones in English grammar teaching. The research mainly traces revision process of 100 sophomore students using traditional paperwork practice and smart-phone-based revision methods during half semester of grammar learning. During the research, students' learning performances, as well as their self-report reflections, are recorded, compared, and analyzed. Statistics from the research show that students in general prefer the m-learning revision methods than the traditional paper ones. Besides, the modem methods do play an essential role in motivating students' learning initiatives, and thus resulting in better learning outcomes. However, on the other hand, some of the students surveyed also demonstrate their negative impression on the m-learning methods, in that they believe this modem technology can inevitably distract them from learning and there are also some technical problems to be worked out.展开更多
Objective To design a WeChat mini program called Chinese Syndrome Differentiation Learning Platform(CSDLP)on smartphone to improve health literacy.Methods The developer tools of WeChat(Version:v1.01.170925)were used f...Objective To design a WeChat mini program called Chinese Syndrome Differentiation Learning Platform(CSDLP)on smartphone to improve health literacy.Methods The developer tools of WeChat(Version:v1.01.170925)were used for designing and debugging the mini program.SPSS17.0 was used for statistical purposes.“View container”“Basic content”“Form component”“Navigation”and“Media components”were used for the development of the WeChat mini program.The detailed method was referred to https://mp.weixin.qq.com/debug/wxadoc/dev/.Results A WeChat mini program called CSDLP was developed.This program has three major functions which are WeChat reading,WeChat class and WeChat syndrome differentiation.The official test report showed that there were no functionality errors for the seven android smartphones(referred to as A,B,C,D,E,F and G)that CSDLP was tested on.Statistical analysis results showed that the average memory in D,E,F and G was lower than in A,B and C.Average ratio was the highest in F and the lowest in G.The average loading time was the same for all smartphones.The audio database for diagnostics using traditional Chinese medicine(TCM)and a lecture video database were based on diagnostic textbook.Our team built a syndrome differentiation database which included 51 diseases.Conclusion CSDLP can improve knowledge visualization,studying process,and information sharing in terms of the training and development of new techniques for syndrome differentiation and treatment in TCM,and it can provide a better illustration for people to understand TCM.展开更多
The development of text messaging in cell phones has influenced punctuation variations in written language. In order to determine how text messaging has resulted in paradigm shift in the traditional uses of punctuatio...The development of text messaging in cell phones has influenced punctuation variations in written language. In order to determine how text messaging has resulted in paradigm shift in the traditional uses of punctuation marks, this paper explores how punctuation marks vary with language, location, register and time, and how they are constantly evolving. The discussion in this paper is structured around Coupland's sociolinguistic theory. The findings reveal that new technology has impacted on the traditional uses of punctuation marks. Thus, the results show that the use of punctuation markers in Short Message Service (SMS) texts is complex. Moreover, the use of punctuation marks in Kenyan text messages reveals personal stylistic choices. However, it is apparent that Kenyan text messages are shaped by social variables.展开更多
The dexterous hand is equiped with the flexible fiber as the optic sensor for recognition and identification of objects structured and non-structured environment.This simple and inexpensive method for object recogniti...The dexterous hand is equiped with the flexible fiber as the optic sensor for recognition and identification of objects structured and non-structured environment.This simple and inexpensive method for object recognition based on the optical fiber is presented in this paper.展开更多
Objective To investigate the clinical features and management of bronchogenic cyst in the adults. Methods We retrospectively reviewed 50 patients admitted to our hospital with histopathologically proved bronchogenic c...Objective To investigate the clinical features and management of bronchogenic cyst in the adults. Methods We retrospectively reviewed 50 patients admitted to our hospital with histopathologically proved bronchogenic cyst from January 1983 to December 2007. Of all the patients, 28 were male and 22 were female, with an average age of 36.9 (range, 18 to 64) years. The symptoms, location of the cysts, imaging evaluation, surgical treatment manner, and outcome of these patients were analyzed. Results Symptoms were present in 33 of the 50 patients, and cough was the most common symptom. Thirteen patients presented with complications: hemoptysis, infected cyst, dysphagia, paralysis, and hoarseness. The locations of the cysts included the mediastinum (28 cases), pulmonary parenchyma (12 cases), hilar area (3 cases), visceral pleura (1 case), and some rare locations including the intestinal mesentery (1 case), retroperitoneum (1 case), adrenal gland (1 case), neck (2 cases), and dura matter of the cervical verte-brae (1 case). Chest X-ray was performed in 36 patients and computed tomography (CT) was performed in 41 patients. The bronchogenic cyst in CT was characterized as a round, well circumscribed, unilocular mass, with density ranging from that of water to high density (0-50 Hu). As for treatment, complete resection of the bronchogenic cyst was performed in 47 (94%) patients, subtotal resection was performed in 3 (6%) patients. Open surgery was performed in 45 (90%) patients, and thoracoscopy (video-assisted thoracic surgery) was performed in 5 (10%) paitients. Of the 12 patients with intrapulmonary cyst, 11 patients underwent lobectomy and 1 patient underwent wedge resection. Postoperative sequelae occurred in 2 patients, 1 with persistent air leakage and 1 with hoarseness. All patients were proved with bronchogenic cyst pathologically. The average follow-up period was 6.5 years (range, 4 months to 10 years), and no late sequelae or recurrence of the cyst occurred. Conclusions The clinical and imaging presentations of bronchogenic cyst in adults are variable. Surgical resection is the best way for diagnosis and treatment. Both open surgery and thoracoscopy are appropriate for the selected candidates.展开更多
Simple, portable analytical devices are entering our daily lives for personal care, clinical analysis, allergen detection in food, and environmental monitoring. Smart- phones, as the most popular state-of-art mobile d...Simple, portable analytical devices are entering our daily lives for personal care, clinical analysis, allergen detection in food, and environmental monitoring. Smart- phones, as the most popular state-of-art mobile device, have remarkable potential for sensing applications. A growing set of physical-co-chemical sensors have been embedded; these include accelerometers, microphones, cameras, gyroscopes, and GPS units to access and perform data analysis. In this review, we discuss recent work focusing on smartphone sensing including representative electromag- netic, audio frequency, optical, and electrochemical sen- sors. The development of these capabilities will lead to more compact, lightweight, cost-effective, flexible, and durable devices in terms of their performances.展开更多
To eliminate anomalies and improve the performance of a space station remote manipulator(SSRM) used in a dynamically changeable thermal environment, we analyze the thermodynamic behavior of an SSRM that considers an i...To eliminate anomalies and improve the performance of a space station remote manipulator(SSRM) used in a dynamically changeable thermal environment, we analyze the thermodynamic behavior of an SSRM that considers an integrated thermal protection system(ITPS). Solar radiative heat gain and loss become equally significant as conductive heat transfers through the interior of the SSRM on orbit. A thermodynamic model of the SSRM with a sandwich ITPS structure is established on the coupling between harmonic drive and changeable thermal environment. A motion precision is proposed to evaluate thermodynamic behavior under continuously changeable thermal circumstances. Simulation results indicate that the ITPS with a corrugated sandwich structure reduces the maximum amplitude of angular position errors to 41.6%, which helps improve the motion precision of the SSRM. The feasible regions for the SSRM in the Low Earth Orbit(LEO) and Geostationary Earth Orbit(GEO) are analyzed, which shows that the proportion of feasible region in LEO is significantly larger than that in GEO.展开更多
Off-statistics input data sets are common in axial-flow fans design and may easily result in some violation of the requirements of a good aerodynamic blade design.In order to circumvent this problem,in the present pap...Off-statistics input data sets are common in axial-flow fans design and may easily result in some violation of the requirements of a good aerodynamic blade design.In order to circumvent this problem,in the present paper,a solution to the radial equilibrium equation is found which minimizes the outlet kinetic energy and fulfills the aerodynamic constraints,thus ensuring that the resulting blade has acceptable aerodynamic performance.The presented method is based on the optimization of a three-parameters vortex law and of the meridional channel size.The aerodynamic quantities to be employed as constraints are individuated and their suitable ranges of variation are proposed.The method is validated by means of a design with critical input data values and CFD analysis.Then,by means of systematic computations with different input data sets,some correlations and charts are obtained which are analogous to classic correlations based on statistical investigations on existing machines.Such new correlations help size a fan of given characteristics as well as study the feasibility of a given design.展开更多
文摘In order to improve the destruction efficiency of dioxins and also for developing new dioxin control technology, the destruction mechanisms of 2,3,7,8-tetrachlorodihenzo-p-dioxin (2,3,7,8-TCDD) by O3 and NO3, were investigated employing quantum chemical calculations. For involved reactions, the microcosmic reaction processes were analyzed and depicted in detail based on geometry optimizations made by the B3LYP/6-31G(d) method. At the same time, the reaction activation energies were also calculated at the MP2/6- 311G(d,p)//B3LYP/6-31G(d) level. Configuration analysis indicated that 2,3,7,8-TCDD could be destroyed by 03 and NO3 in two different ways. The destruction of 2,3,7,8-TCDD by 03 proceeded via the addition of 03 and the cleavage of C=C while the destruction of 2,3,7,8-TCDD by NO3 proceeded via the substitution of chlorine by NO3. Calculated results show that, the activation energy of the destruction reaction of 2,3,7,8-TCDD by NO3 (267.48 kJ/mol) is much larger than that of the destruction reaction of 2,3,7,8-TCDD by O3 (51.20 kJ/mol). This indicated that the destruction of 2,3,7,8-TCDD by 03 is much more efficient than that of 2,3,7,8-TCDD by NO3. The reason why the activation energy for the destruction reaction of 2,3,7,8-TCDD by NO3 is so large, is also discussed.
文摘In this paper, coordinated control of multiple robot manipulators holding a rigid object is discussed. In consideration of inaccuracy of the dynamic model of a multiple manipulator system, the error equations on object position and internal force are derived. Then a hybrid position/force coordinated learning control scheme is presented and its convergence is proved. The scheme can improve the system performance by modifying the control input of the system after each iterative learning. Simulation results of two planar robot manipulators holding an object show the effectiveness of this control scheme.
文摘Wavelet network, a class of neural network consisting of wavelets, is proposed to solve the inverse kinematics problem in robotic manipulator. A wavelet network suitable for dealing with multi-input and multi-output system is constructed. The network is optimized by reducing the number of wavelets handling large dimension problem according to the sample data. The algorithms for sparseness analysis of input data and fitting wavelets to the output data with orthogonal method are introduced. Then Levenberg-Marquardt algorithm is used to train the network. Simulation results showed that this method is capable of solving the inverse kinematics problem for PUMA560.
文摘A mathematical model was developed combining the dynamics of an Euler-Bernoulli beam, described by the assumed-mode method and hydraulic circuit dynamics. Only one matrix, termed drive Jacobian, was needed in the modeling of interaction between hydraulic circuit and flexible manipulator mechanism. Furthermore, a new robust controller based on mentioned above dynamic model was also considered to regulate both flexural vibrations and rigid body motion. The proposed controller combined sliding mode and backstepping techniques to deal with the nonlinear system with uncertainties. The sliding mode control was used to achieve an asymptotic joint angle and vibration regulation by providing a virtual force while the backstepping technique was used to regulate the spool position of a hydraulic valve to provide the required control force. Simulation results are presented to show the stabilizing effect and robustness of this control strategy.
文摘In the underwater environment, many visual sensors don’t work, and many sensors which work well for robots working in space or on land can not be used underwater. Therefore, an optical fiber slide tactile sensor was designed based on the inner modulation mechanism of optical fibers. The principles and structure of the sensor are explained in detail. Its static and dynamic characteristics were analyzed theoretically and then simulated. A dynamic characteristic model was built and the simulation made using the GA based neural network. In order to improve sensor response, the recognition model of the sensor was designed based on the ‘inverse solution’ principle of neural networks, increasing the control precision and the sensitivity of the manipulator.
文摘This study aims to explore the effectiveness of the emerging m-learning in the form of smart phones in English grammar teaching. The research mainly traces revision process of 100 sophomore students using traditional paperwork practice and smart-phone-based revision methods during half semester of grammar learning. During the research, students' learning performances, as well as their self-report reflections, are recorded, compared, and analyzed. Statistics from the research show that students in general prefer the m-learning revision methods than the traditional paper ones. Besides, the modem methods do play an essential role in motivating students' learning initiatives, and thus resulting in better learning outcomes. However, on the other hand, some of the students surveyed also demonstrate their negative impression on the m-learning methods, in that they believe this modem technology can inevitably distract them from learning and there are also some technical problems to be worked out.
基金funding support from the National Natural Science Foundation of China (No.81373551)2016 Hunan Provincial Postgraduate Research Innovation Project (No.CX2016B367)
文摘Objective To design a WeChat mini program called Chinese Syndrome Differentiation Learning Platform(CSDLP)on smartphone to improve health literacy.Methods The developer tools of WeChat(Version:v1.01.170925)were used for designing and debugging the mini program.SPSS17.0 was used for statistical purposes.“View container”“Basic content”“Form component”“Navigation”and“Media components”were used for the development of the WeChat mini program.The detailed method was referred to https://mp.weixin.qq.com/debug/wxadoc/dev/.Results A WeChat mini program called CSDLP was developed.This program has three major functions which are WeChat reading,WeChat class and WeChat syndrome differentiation.The official test report showed that there were no functionality errors for the seven android smartphones(referred to as A,B,C,D,E,F and G)that CSDLP was tested on.Statistical analysis results showed that the average memory in D,E,F and G was lower than in A,B and C.Average ratio was the highest in F and the lowest in G.The average loading time was the same for all smartphones.The audio database for diagnostics using traditional Chinese medicine(TCM)and a lecture video database were based on diagnostic textbook.Our team built a syndrome differentiation database which included 51 diseases.Conclusion CSDLP can improve knowledge visualization,studying process,and information sharing in terms of the training and development of new techniques for syndrome differentiation and treatment in TCM,and it can provide a better illustration for people to understand TCM.
文摘The development of text messaging in cell phones has influenced punctuation variations in written language. In order to determine how text messaging has resulted in paradigm shift in the traditional uses of punctuation marks, this paper explores how punctuation marks vary with language, location, register and time, and how they are constantly evolving. The discussion in this paper is structured around Coupland's sociolinguistic theory. The findings reveal that new technology has impacted on the traditional uses of punctuation marks. Thus, the results show that the use of punctuation markers in Short Message Service (SMS) texts is complex. Moreover, the use of punctuation marks in Kenyan text messages reveals personal stylistic choices. However, it is apparent that Kenyan text messages are shaped by social variables.
文摘The dexterous hand is equiped with the flexible fiber as the optic sensor for recognition and identification of objects structured and non-structured environment.This simple and inexpensive method for object recognition based on the optical fiber is presented in this paper.
文摘Objective To investigate the clinical features and management of bronchogenic cyst in the adults. Methods We retrospectively reviewed 50 patients admitted to our hospital with histopathologically proved bronchogenic cyst from January 1983 to December 2007. Of all the patients, 28 were male and 22 were female, with an average age of 36.9 (range, 18 to 64) years. The symptoms, location of the cysts, imaging evaluation, surgical treatment manner, and outcome of these patients were analyzed. Results Symptoms were present in 33 of the 50 patients, and cough was the most common symptom. Thirteen patients presented with complications: hemoptysis, infected cyst, dysphagia, paralysis, and hoarseness. The locations of the cysts included the mediastinum (28 cases), pulmonary parenchyma (12 cases), hilar area (3 cases), visceral pleura (1 case), and some rare locations including the intestinal mesentery (1 case), retroperitoneum (1 case), adrenal gland (1 case), neck (2 cases), and dura matter of the cervical verte-brae (1 case). Chest X-ray was performed in 36 patients and computed tomography (CT) was performed in 41 patients. The bronchogenic cyst in CT was characterized as a round, well circumscribed, unilocular mass, with density ranging from that of water to high density (0-50 Hu). As for treatment, complete resection of the bronchogenic cyst was performed in 47 (94%) patients, subtotal resection was performed in 3 (6%) patients. Open surgery was performed in 45 (90%) patients, and thoracoscopy (video-assisted thoracic surgery) was performed in 5 (10%) paitients. Of the 12 patients with intrapulmonary cyst, 11 patients underwent lobectomy and 1 patient underwent wedge resection. Postoperative sequelae occurred in 2 patients, 1 with persistent air leakage and 1 with hoarseness. All patients were proved with bronchogenic cyst pathologically. The average follow-up period was 6.5 years (range, 4 months to 10 years), and no late sequelae or recurrence of the cyst occurred. Conclusions The clinical and imaging presentations of bronchogenic cyst in adults are variable. Surgical resection is the best way for diagnosis and treatment. Both open surgery and thoracoscopy are appropriate for the selected candidates.
文摘Simple, portable analytical devices are entering our daily lives for personal care, clinical analysis, allergen detection in food, and environmental monitoring. Smart- phones, as the most popular state-of-art mobile device, have remarkable potential for sensing applications. A growing set of physical-co-chemical sensors have been embedded; these include accelerometers, microphones, cameras, gyroscopes, and GPS units to access and perform data analysis. In this review, we discuss recent work focusing on smartphone sensing including representative electromag- netic, audio frequency, optical, and electrochemical sen- sors. The development of these capabilities will lead to more compact, lightweight, cost-effective, flexible, and durable devices in terms of their performances.
基金supported by the National Natural Science Foundation of China(Grant No.11272171)Education Ministry Doctoral Fund of China(Grant No.20120002110070)
文摘To eliminate anomalies and improve the performance of a space station remote manipulator(SSRM) used in a dynamically changeable thermal environment, we analyze the thermodynamic behavior of an SSRM that considers an integrated thermal protection system(ITPS). Solar radiative heat gain and loss become equally significant as conductive heat transfers through the interior of the SSRM on orbit. A thermodynamic model of the SSRM with a sandwich ITPS structure is established on the coupling between harmonic drive and changeable thermal environment. A motion precision is proposed to evaluate thermodynamic behavior under continuously changeable thermal circumstances. Simulation results indicate that the ITPS with a corrugated sandwich structure reduces the maximum amplitude of angular position errors to 41.6%, which helps improve the motion precision of the SSRM. The feasible regions for the SSRM in the Low Earth Orbit(LEO) and Geostationary Earth Orbit(GEO) are analyzed, which shows that the proportion of feasible region in LEO is significantly larger than that in GEO.
文摘Off-statistics input data sets are common in axial-flow fans design and may easily result in some violation of the requirements of a good aerodynamic blade design.In order to circumvent this problem,in the present paper,a solution to the radial equilibrium equation is found which minimizes the outlet kinetic energy and fulfills the aerodynamic constraints,thus ensuring that the resulting blade has acceptable aerodynamic performance.The presented method is based on the optimization of a three-parameters vortex law and of the meridional channel size.The aerodynamic quantities to be employed as constraints are individuated and their suitable ranges of variation are proposed.The method is validated by means of a design with critical input data values and CFD analysis.Then,by means of systematic computations with different input data sets,some correlations and charts are obtained which are analogous to classic correlations based on statistical investigations on existing machines.Such new correlations help size a fan of given characteristics as well as study the feasibility of a given design.