The study aimed at introducing the design scheme of the active tag in 2.4 GHz frequency band for pig based on RFID technology. And through the actual circuit board test, the following results were come up: communicat...The study aimed at introducing the design scheme of the active tag in 2.4 GHz frequency band for pig based on RFID technology. And through the actual circuit board test, the following results were come up: communication distance and signal strength gradually increased with the data transfer rate reducing in multiples; better communication effects were achieved in the data transfer rate of 60 kbps or 10 kbps; the active tags could be recognized accurately within 50 m, greatly improving the security of swine food safety traceability system.展开更多
In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed: (1) active control can provide significant...In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed: (1) active control can provide significantly superior supplemental damping to a building, but causes a small frequency shift; (2) the linear quadratic regulator (LQR)-based control force is composed of an elastic restoring force component and a damping force component, where the damping force is almost identical to the total control force, however, the elastic restoring force is very small; and (3) the active control forces prevent mction most of the time during the entire control process. These three characteristics imply that active control systems connected to adjacent levels of a building behave like passive damping devices with adjustable parameters, namely damping characteristics in an active control, which is the mechanism used by semi-active control devices to reach similar performance as active control systems. Two indices are defined to quantify the damping characteristics of control forces in active control systems. These two indices can also be used to quantify the capacity of semi-active control to achieve the perfonrlance of active control. Based on the above observations, two principles are founded for optimization of parameters of semi-active control devices and passive dampers. The first is that the maximum output force of a semi-active or passive device to be designed is identical to an active device, called "design principle". The other is the response equivalent principle, which states that the response of a building with semi-active or passive devices is the same as with active devices when the same maximum output force is applied. The design procedure for semi-active control devices and passive dampers is described in detail. Finally, numerical simulations of two benchmark problems is conducted to demonstrate the damping characteristics of active control and investigate the capacity of semi-active control to achieve the same performance as active control.展开更多
The variation design of complex products has such features as multivariate association, weak theory coupling and implicit knowledge iteration. However, present CAD soft wares are still restricted to making decisions o...The variation design of complex products has such features as multivariate association, weak theory coupling and implicit knowledge iteration. However, present CAD soft wares are still restricted to making decisions only according to current design status in dynamic navigation which leads to the huge drain of the knowledge hidden in design process. In this paper, a method of acquisition and active navigation of knowledge particles throughout product variation design process is put forward. The multi-objective decision information model of the variation design is established via the definition of condition attribute set and decision attribute set in finite universe. The addition and retrieval of the variation semantics is achieved through bidirectional association between the transplantable structures and variation design semantics. The mapping relationships between the topology lapping geometry elements set and constraint relations set family is built by means of geometry feature analysis. The acquisition of knowledge particles is implemented by attribute reduction based on rough set theory to make multi-objective decision of variation design. The topology lapping status of transplantable substructures is known from DOF reduction. The active navigation of knowledge particles is realized through embedded event-condition-action(ECA) rules. The independent prototype system taking Alan, Charles, Ian's system(ACIS) as kernel has been developed to verify the proposed method by applying variation design of complex mechanical products. The test results demonstrate that the navigation decision basis can be successfully extended from static isolated design status to dynamic continuous design process so that it more flexibly adapts to the different designers and various variation design steps. It is of profound significance for enhancing system intelligence as well as improving design quality and efficiency.展开更多
In order to protect quality of Baiyangdian surface water and Gaoyang groundwater,the project is applied to process printing and dyeing wastewater that contains complicated compositions,high concentrations of organics ...In order to protect quality of Baiyangdian surface water and Gaoyang groundwater,the project is applied to process printing and dyeing wastewater that contains complicated compositions,high concentrations of organics and SS,and lots of pollutants difficult to degrade by microorganism. The process and operating parameters of project are optimized and debugged,and its economic and environmental benefits are analyzed.The results show that the process of coagulation sedimentation-hydrolytic acidification with aeration tank-biological aerated filter-active sand filter is applied in Gaoyang Sewage Treatment Plant. The design scale of sewage treatment plant is 120000 m^3/d. The influent is as following: COD is 669mg/L; SS is 424mg/L; NH_3-N is 8.83mg/L; TP is 6.03mg/L. After the process,the best removal rates of COD,SS,NH_3-N and TP are 93. 5%,98. 8%,97. 1% and 96. 2%,respectively. The various indexes of effluent water complied with standard A of the first order in Pollutants Emission Standard of Urban Wastewater Treatment Plant( GB 18918-2002). The processing cost is only 0. 807 yuan/m^3. As a result,the project construction and operation not only improve the environment,but also promote regional economic development. Process design and operating parameters provide an important reference value for the printing and dyeing wastewater treatment industry.展开更多
In this research,activated carbon from mangosteen peel has been synthesized using sulfuric acid as an activator.The adsorption performance of the activated carbon was optimized using malachite green dye as absorbate.M...In this research,activated carbon from mangosteen peel has been synthesized using sulfuric acid as an activator.The adsorption performance of the activated carbon was optimized using malachite green dye as absorbate.Mala-chite green dye waste is a toxic and non-biodegradable material that damages the environment.Optimization of adsorption processes was carried out using Response Surface Methodology(RSM)with a Box-Behnken Design(BBD).The synthesized activated carbon was characterized using FTIR and SEM instruments.The FTIR spectra confirmed the presence of a sulfonate group(-SO_(3)H)in the activated carbon,indicating that the activation pro-cess using sulfuric acid was successful.SEM characterization shows that activated carbon has porous morphology.Optimization was carried out for three adsorption parameters,namely contact time(20,60,and 120 min),adsor-bent mass(0.005,0.025,and 0.05 g),and initial concentration of malachite green solution(5,50,and 100 mg·L^(-1)).The concentration of the malachite green solution was determined using a UV-Vis spectrophotometer at the max-imum wavelength of malachite green,618 nm.The optimum of malachite green adsorption using mangosteen peel activated carbon was obtained at a contact time of 80 min,an adsorbent mass of 0.032 g,and malachite green initial concentration of 25 mg·L^(-1),with a maximum removal percentage and maximum adsorption capacity of 93.66%and 19.345 mg·g^(-1),respectively.展开更多
Although computer architectures incorporate fast processing hardware resources, high performance real-time implementation of a complex control algorithm requires an efficient design and software coding of the algorith...Although computer architectures incorporate fast processing hardware resources, high performance real-time implementation of a complex control algorithm requires an efficient design and software coding of the algorithm so as to exploit special features of the hardware and avoid associated architecture shortcomings. This paper presents an investigation into the analysis and design mechanisms that will lead to reduction in the execution time in implementing real-time control algorithms. The proposed mechanisms are exemplified by means of one algorithm, which demonstrates their applicability to real-time applications. An active vibration control (AVC) algorithm for a flexible beam system simulated using the finite difference (FD) method is considered to demonstrate the effectiveness of the proposed methods. A comparative performance evaluation of the proposed design mechanisms is presented and discussed through a set of experiments.展开更多
A series of quinoxalinone-1,2,3-triazole derivatives have been synthesized and tested for antifungal activity against phytopathogenic fungus through mycelial growth inhibition in vitro,spore germination inhibition in ...A series of quinoxalinone-1,2,3-triazole derivatives have been synthesized and tested for antifungal activity against phytopathogenic fungus through mycelial growth inhibition in vitro,spore germination inhibition in vitro and control effect in vivo.The results showed that the pharmacophore quinoxalinone and 1,2,3-triazole displayed promising antifungal activity.The EC50 value against C.gloeosporioides of 6a-1 was 1.17μg/mL and the compound 6c-1 showed the good bioactivity against C.fragariae Brooks and P.oryzae Cav.,displaying EC50 values of 5.56,4.62μg/mL,respectively.The inhibitory of spore germination by 6a-1 was performed with EC50 value of 1.91μg/mL.In addition,the in vivo bioassay indicated that 6a-1 possessed effective control against Pepper Anthrax Disease in protective treatment.For given activity data of target compounds,structure-activity relationship(SAR)study was operated,hoping for optimizing the target structure to find lead compound with higher activity.展开更多
Edutainment,in the kindergarten education stage,emphasizes the game as the basic activity and combines the content of education with the form of the game,thus it also forms the educational method of gamification teach...Edutainment,in the kindergarten education stage,emphasizes the game as the basic activity and combines the content of education with the form of the game,thus it also forms the educational method of gamification teaching.Through investigation and analysis,it is found that the current kindergarten game activity design has the problem of improper combination of educational content and game form.The current kindergarten game activity design has problems such as stereotypes,children’s lack of active learning opportunities in activities,teachers’insufficient theoretical understanding,inappropriate teacher guidance methods,and so on.Embodied cognition theory attaches importance to the important role of the body in the development of cognition,provides new guidance for classroom teaching,and opens up a new path for classroom teaching reform.Based on the perspective of embodied cognition theory,the concept of body and mind integration should be adhered to in kindergarten teaching with games as the basic activity,experiential teaching situation should be created,children’s subjective experience should be respected,and games and interactions should be designed to promote children’s physical and mental participation,thus laying a foundation for the realization of children’s individual freedom,autonomy,and all-round development.Therefore,this paper aims at the existing problems in the current kindergarten gamification teaching and discusses the design strategy of children’s game activities based on embodied cognition theory.展开更多
An active design method of tooth profiles for cycloid gears based on their meshing efficiency is proposed.This method takes the meshing efficiency as one of the design variables to determine the tooth profiles.The cal...An active design method of tooth profiles for cycloid gears based on their meshing efficiency is proposed.This method takes the meshing efficiency as one of the design variables to determine the tooth profiles.The calculation method for the meshing efficiency of planetary transmission is analyzed and the equation of the meshing efficiency is deduced.Relationships between the meshing efficiency,the radius of the pin wheel and the eccentric distance are revealed.The design constraint quations and the strength constraint quations are deduced.On the basis of this,a design procedure is laid out.Some examples using different input parameters are conducted to demonstrate the feasibility of the approach.A dynamic simulation of the rigid flexible coupling of cycloid gears is also presented.The results show that the proposed design method is more flexible to control the tooth profiles by changing the input values of the transmission efficiency.展开更多
This paper presents the design and implementation of a 3 kVA three-phase active T-type neutral-point clamped (NPC) inverter with GaN power devices for low-voltage microgrids. The designed inverter is used in a battery...This paper presents the design and implementation of a 3 kVA three-phase active T-type neutral-point clamped (NPC) inverter with GaN power devices for low-voltage microgrids. The designed inverter is used in a battery-based energy system (BESS) for power conversion optimization in applications to low-voltage microgrids. A modular design method has been developed for the design and implementation of the AT-NPC inverter. Experimental verification has been carried out based on a 3-kW three-phase T-Type NPC grid-connected inverter. FPGA based digital control technique has been developed for the current control of the three-level three-phase grid inverter. A maximum efficiency of 98.49% has been achieved within a load range from 50% to 75%.展开更多
Quantum chemical calculation was used to estimate the reduction potentials of 25 organic cations and the oxidation potentials of 11 anions.This information was used to select promising cations and anions for the prepa...Quantum chemical calculation was used to estimate the reduction potentials of 25 organic cations and the oxidation potentials of 11 anions.This information was used to select promising cations and anions for the preparation of ionic liquids as green electrolytes for electrodeposition of active metals.The reasonable linear correlations between the lowest unoccupied molecular orbital(LUMO)energies and the reduction potentials of cations,and the linear relationships between the oxidation potentials and the highest occupied molecular orbital(HOMO)energies of anions were obtained.The orders of electrochemical stability for cations and anions being obtained agree well with the experimental measurements.The suitable ionic liquids with sufficiently wide electrochemical windows for electrodeposition of active metals are suggested to be[Emim]NTf2,[Bmim]NTf2,[Bmim]BF4, [Bmim]PF6,[Bmim]CTf3,[Emim]BF4,[Emim]PF6,[Emim]CTf3..展开更多
Background: Players may not acquire adequate levels of moderate-to-vigorous physical activity(MVPA) when playing commercial video games.This study's goal was to evaluate the effects of an exercise bike video game ...Background: Players may not acquire adequate levels of moderate-to-vigorous physical activity(MVPA) when playing commercial video games.This study's goal was to evaluate the effects of an exercise bike video game played by using a mobile application-based exergame that was designed exclusively to promote participants' MVPA, with additional attention paid to this game's ability to promote greater situational interest.Methods: An experimental design was used with 163 students(aged 20.31 ± 1.30, 18–26 years, 61.3% male), all of whom were randomly allocated into an experimental group and a control group. Physical activity(PA) levels were assessed with Acti Graph GT3X+(Acti Graph Inc., Fort Walton Beach, FL, USA) accelerometers. The situational interest scale was used to evaluate students' situational interest in both groups.Multivariate analysis of variance was conducted to examine the differences between sedentary behavior, PA levels, and situational interest between groups. Regression analyses were also used, with the purpose being to evaluate the strength of the relationship between PA and situational interest.Results: Results revealed that the experimental group had higher degrees of sedentary behavior, light PA, total interest, instant enjoyment,exploration intention, attention demand, novelty, and challenge, whereas the control group received higher scores for MVPA(control 95.01% vs.experimental group 89.94%). Regression analysis indicated that instant enjoyment(β = 0.49, p < 0.01), exploration intention(β = 0.18, p < 0.05),and attention demand(β = 0.17, p < 0.05) were positive predictors for total interest, explaining 43% of its variance.Conclusion: A newly designed mobile application-based exergame played via an exercise bike may enhance situational interest and provide a decent level of PA for players.展开更多
Diamidine (A) was identified in our in vitro bio-assay as a possible inhibitor of ketol-acid reductoisomerase (KARI) from the ACD database search based on the known three-dimensional crystal structure of KARI. An ...Diamidine (A) was identified in our in vitro bio-assay as a possible inhibitor of ketol-acid reductoisomerase (KARI) from the ACD database search based on the known three-dimensional crystal structure of KARI. An investigation on interaction of A on KARI active sites, led to the design and synthesis of 15 novel monoamidines. Some of those showed better biological activity than A on rice KARI (in vitro) and in greenhouse herbicidal tests (in vivo). The structure-biological activity relationship was investigated, which provides valuable information to further study of potential KARI inhibitors.展开更多
In this study,adopting uniform design method established a mathematical model to prepare multi-element active flux. GH4169 superalloy plates were welded by the Nd: YAG laser equipment with the prepared active flux. Th...In this study,adopting uniform design method established a mathematical model to prepare multi-element active flux. GH4169 superalloy plates were welded by the Nd: YAG laser equipment with the prepared active flux. The results show all kinds of fluxes increase the depth to width ratio and the multi-component systems are more significant. The largest increment of the weld depth to width ratio is 159%,obtained by using of the F12 series flux. It is proved that by using of the active flux to increase the depth to width ratio of micro laser welding is feasible.展开更多
Due to both of jamming and eavesdropping,active eavesdroppers can induce more serious security threats to unmanned aerial vehicle(UAV)-enabled communications.This paper considers a secure UAV communication system incl...Due to both of jamming and eavesdropping,active eavesdroppers can induce more serious security threats to unmanned aerial vehicle(UAV)-enabled communications.This paper considers a secure UAV communication system including both the downlink(DL)and uplink(UL)transmissions,where the confidential information is transmitted between a UAV and a ground node in the presence of an active eavesdropper.We aim to maximize the average secrecy rates of the DL and UL communications,respectively,by jointly optimizing the UAV trajectory and the UAV/ground node’s transmit power control over a given flight period.Due to the non-convexity of the formulated problems,it is difficult to obtain globally optimal solutions.However,we propose efficient iterative algorithms to obtain high-quality suboptimal solutions by applying the block coordinate descent and successive convex optimization methods.Simulation results show that the joint optimization algorithms can effectively improve the secrecy rate performance for both the DL and UL communications,as compared with other baseline schemes.The proposed schemes can be considered as special cases of UAV-assisted non-orthogonal multiple access(NOMA)networks.展开更多
Background:Cross-sectional studies provide useful insight about the associations between the built environment and physical activity(PA),particularly when reasons for neighborhood choice are considered.Our study analy...Background:Cross-sectional studies provide useful insight about the associations between the built environment and physical activity(PA),particularly when reasons for neighborhood choice are considered.Our study analyzed the relationship between levels of weekly transportation and leisure PA among 3 neighborhood designs,statistically adjusting for sociodemographic characteristics and reasons for neighborhood choice.Methods:A stratified random sample of adults(age>20 years)living in Calgary(Canada)neighborhoods with different neighborhood designs(grid,warped-grid,and curvilinear)and socioeconomic status completed a self-administered questionnaire capturing PA,sociodemographic characteristics,and reasons for neighborhood choice(response rate=10.1%;n=1023).Generalized linear models estimated associations between neighborhood design and transportation and leisure PA outcomes(participation(any vs.none)and volume(metabolic equivalent:h/week)),adjusting for neighborhood socioeconomic status,sociodemographic characteristics(gender,age,ethnicity,education,household income,marital status,children,vehicle access,dog ownership,and injury),and reasons for neighborhood choice(e.g.,proximity and quality of recreational and utilitarian destinations,proximity to work,highway access,aesthetics,and sense of community).Results:Overall,854 participants had resided in their neighborhood for at least 12 months and provided complete data.Compared with those living in curvilinear neighborhoods,grid neighborhood participants had greater odds(p<0.05)of participating in any transportation walking(odds ratio(OR)=2.17),transportation and leisure cycling(OR=2.39 and OR=1.70),active transportation(OR=2.16),and high-intensity leisure PA(≥6 metabolic equivalent;OR=1.74),respectively.There were no neighborhood differences in the volume of any transportation or leisure PA undertaken.Adjustment for neighborhood selection had minimal impact on the statistical or practical importance of model estimates.Conclusion:Neighborhood design is associated with PA patterns in adults,independent of reasons for neighborhood choice and sociodemogranhic factors.展开更多
The equations of motion governing the vibration of a cantilever beam with partially treated self-sensing active constrained layer damping treatment(SACLD) are derived by application of the extended Hamilton principle....The equations of motion governing the vibration of a cantilever beam with partially treated self-sensing active constrained layer damping treatment(SACLD) are derived by application of the extended Hamilton principle. The assumed-modes method and closed loop velocity feedback control law are used to analyze and control the flexural vibration of the beam nle influences of the bonding layer and piezoelectric layer thickness, material properties, placements of the Diezoelectric patch and feedback control parameters on the actuation ability of the vibration suppression are investigated. Some design considerations for pure passive, pure active control, and self-sensing active constrained layer damping are discussed.展开更多
By combining machine learning with the design of experiments,thereby achieving so-called active machine learning,more efficient and cheaper research can be conducted.Machine learning algorithms are more flexible and a...By combining machine learning with the design of experiments,thereby achieving so-called active machine learning,more efficient and cheaper research can be conducted.Machine learning algorithms are more flexible and are better than traditional design of experiment algorithms at investigating processes spanning all length scales of chemical engineering.While active machine learning algorithms are maturing,their applications are falling behind.In this article,three types of challenges presented by active machine learning—namely,convincing the experimental researcher,the flexibility of data creation,and the robustness of active machine learning algorithms—are identified,and ways to overcome them are discussed.A bright future lies ahead for active machine learning in chemical engineering,thanks to increasing automation and more efficient algorithms that can drive novel discoveries.展开更多
In this study, waste tire was used as raw material for the production of activated carbons through pyrolysis. 'Fire char was first produced by carbomzation at 550℃ under nitrogen. A two tactortal design was used to ...In this study, waste tire was used as raw material for the production of activated carbons through pyrolysis. 'Fire char was first produced by carbomzation at 550℃ under nitrogen. A two tactortal design was used to optimize the production of activated carbon from tire char. The effects of several factors controlling the activation process, such as temperature (.830-930℃), time (2-6h) and percentage ot carbon dioxide (70%-100%) were investigated. The production was described mathematically as a function of these three factors. First order modeling equations were developed for surface area, yield and mesopore volume. It was concluded that the yield, BET surface area and mesopore volume of activated carbon were most sensitive to activation temperature and time while percentage of carbon dioxide in the activation gas was a less significant factor.展开更多
文摘The study aimed at introducing the design scheme of the active tag in 2.4 GHz frequency band for pig based on RFID technology. And through the actual circuit board test, the following results were come up: communication distance and signal strength gradually increased with the data transfer rate reducing in multiples; better communication effects were achieved in the data transfer rate of 60 kbps or 10 kbps; the active tags could be recognized accurately within 50 m, greatly improving the security of swine food safety traceability system.
基金National Fundamental Research Program (973) Under Grant No. 2007CB714204the R & D Program Under Grant No. 2006BAJ03B06NSFC Under Grant No. 90815027
文摘In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed: (1) active control can provide significantly superior supplemental damping to a building, but causes a small frequency shift; (2) the linear quadratic regulator (LQR)-based control force is composed of an elastic restoring force component and a damping force component, where the damping force is almost identical to the total control force, however, the elastic restoring force is very small; and (3) the active control forces prevent mction most of the time during the entire control process. These three characteristics imply that active control systems connected to adjacent levels of a building behave like passive damping devices with adjustable parameters, namely damping characteristics in an active control, which is the mechanism used by semi-active control devices to reach similar performance as active control systems. Two indices are defined to quantify the damping characteristics of control forces in active control systems. These two indices can also be used to quantify the capacity of semi-active control to achieve the perfonrlance of active control. Based on the above observations, two principles are founded for optimization of parameters of semi-active control devices and passive dampers. The first is that the maximum output force of a semi-active or passive device to be designed is identical to an active device, called "design principle". The other is the response equivalent principle, which states that the response of a building with semi-active or passive devices is the same as with active devices when the same maximum output force is applied. The design procedure for semi-active control devices and passive dampers is described in detail. Finally, numerical simulations of two benchmark problems is conducted to demonstrate the damping characteristics of active control and investigate the capacity of semi-active control to achieve the same performance as active control.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2006AA04Z114) National Natural Science Foundation of China (Grant No. 50775201)
文摘The variation design of complex products has such features as multivariate association, weak theory coupling and implicit knowledge iteration. However, present CAD soft wares are still restricted to making decisions only according to current design status in dynamic navigation which leads to the huge drain of the knowledge hidden in design process. In this paper, a method of acquisition and active navigation of knowledge particles throughout product variation design process is put forward. The multi-objective decision information model of the variation design is established via the definition of condition attribute set and decision attribute set in finite universe. The addition and retrieval of the variation semantics is achieved through bidirectional association between the transplantable structures and variation design semantics. The mapping relationships between the topology lapping geometry elements set and constraint relations set family is built by means of geometry feature analysis. The acquisition of knowledge particles is implemented by attribute reduction based on rough set theory to make multi-objective decision of variation design. The topology lapping status of transplantable substructures is known from DOF reduction. The active navigation of knowledge particles is realized through embedded event-condition-action(ECA) rules. The independent prototype system taking Alan, Charles, Ian's system(ACIS) as kernel has been developed to verify the proposed method by applying variation design of complex mechanical products. The test results demonstrate that the navigation decision basis can be successfully extended from static isolated design status to dynamic continuous design process so that it more flexibly adapts to the different designers and various variation design steps. It is of profound significance for enhancing system intelligence as well as improving design quality and efficiency.
基金Supported by Key Project of National Water Pollution Control and Treatment Science and Technology(2014ZX07211-001)Demonstration Study on Integration Model of Environmental Public Utilities in Industrial Parks of Key Watershed(2014ZX07211-001-04)
文摘In order to protect quality of Baiyangdian surface water and Gaoyang groundwater,the project is applied to process printing and dyeing wastewater that contains complicated compositions,high concentrations of organics and SS,and lots of pollutants difficult to degrade by microorganism. The process and operating parameters of project are optimized and debugged,and its economic and environmental benefits are analyzed.The results show that the process of coagulation sedimentation-hydrolytic acidification with aeration tank-biological aerated filter-active sand filter is applied in Gaoyang Sewage Treatment Plant. The design scale of sewage treatment plant is 120000 m^3/d. The influent is as following: COD is 669mg/L; SS is 424mg/L; NH_3-N is 8.83mg/L; TP is 6.03mg/L. After the process,the best removal rates of COD,SS,NH_3-N and TP are 93. 5%,98. 8%,97. 1% and 96. 2%,respectively. The various indexes of effluent water complied with standard A of the first order in Pollutants Emission Standard of Urban Wastewater Treatment Plant( GB 18918-2002). The processing cost is only 0. 807 yuan/m^3. As a result,the project construction and operation not only improve the environment,but also promote regional economic development. Process design and operating parameters provide an important reference value for the printing and dyeing wastewater treatment industry.
文摘In this research,activated carbon from mangosteen peel has been synthesized using sulfuric acid as an activator.The adsorption performance of the activated carbon was optimized using malachite green dye as absorbate.Mala-chite green dye waste is a toxic and non-biodegradable material that damages the environment.Optimization of adsorption processes was carried out using Response Surface Methodology(RSM)with a Box-Behnken Design(BBD).The synthesized activated carbon was characterized using FTIR and SEM instruments.The FTIR spectra confirmed the presence of a sulfonate group(-SO_(3)H)in the activated carbon,indicating that the activation pro-cess using sulfuric acid was successful.SEM characterization shows that activated carbon has porous morphology.Optimization was carried out for three adsorption parameters,namely contact time(20,60,and 120 min),adsor-bent mass(0.005,0.025,and 0.05 g),and initial concentration of malachite green solution(5,50,and 100 mg·L^(-1)).The concentration of the malachite green solution was determined using a UV-Vis spectrophotometer at the max-imum wavelength of malachite green,618 nm.The optimum of malachite green adsorption using mangosteen peel activated carbon was obtained at a contact time of 80 min,an adsorbent mass of 0.032 g,and malachite green initial concentration of 25 mg·L^(-1),with a maximum removal percentage and maximum adsorption capacity of 93.66%and 19.345 mg·g^(-1),respectively.
文摘Although computer architectures incorporate fast processing hardware resources, high performance real-time implementation of a complex control algorithm requires an efficient design and software coding of the algorithm so as to exploit special features of the hardware and avoid associated architecture shortcomings. This paper presents an investigation into the analysis and design mechanisms that will lead to reduction in the execution time in implementing real-time control algorithms. The proposed mechanisms are exemplified by means of one algorithm, which demonstrates their applicability to real-time applications. An active vibration control (AVC) algorithm for a flexible beam system simulated using the finite difference (FD) method is considered to demonstrate the effectiveness of the proposed methods. A comparative performance evaluation of the proposed design mechanisms is presented and discussed through a set of experiments.
基金financial support by the Natural Science Foundation of Beijing(No.2232004)Research Fund for Academic Degree&Graduate Education of Beijing University of Agriculture(2023YJS021)+2 种基金Science and Technology innovation support program of Beijing University of Agriculture(BUA-HHXD2023008)R&D Program of Beijing Municipal Education Commission(No.KM202210020007)Research and Innovation Ability Improvement Project for Young Teachers of Beijing University of Agriculture(QJKC2022014).
文摘A series of quinoxalinone-1,2,3-triazole derivatives have been synthesized and tested for antifungal activity against phytopathogenic fungus through mycelial growth inhibition in vitro,spore germination inhibition in vitro and control effect in vivo.The results showed that the pharmacophore quinoxalinone and 1,2,3-triazole displayed promising antifungal activity.The EC50 value against C.gloeosporioides of 6a-1 was 1.17μg/mL and the compound 6c-1 showed the good bioactivity against C.fragariae Brooks and P.oryzae Cav.,displaying EC50 values of 5.56,4.62μg/mL,respectively.The inhibitory of spore germination by 6a-1 was performed with EC50 value of 1.91μg/mL.In addition,the in vivo bioassay indicated that 6a-1 possessed effective control against Pepper Anthrax Disease in protective treatment.For given activity data of target compounds,structure-activity relationship(SAR)study was operated,hoping for optimizing the target structure to find lead compound with higher activity.
文摘Edutainment,in the kindergarten education stage,emphasizes the game as the basic activity and combines the content of education with the form of the game,thus it also forms the educational method of gamification teaching.Through investigation and analysis,it is found that the current kindergarten game activity design has the problem of improper combination of educational content and game form.The current kindergarten game activity design has problems such as stereotypes,children’s lack of active learning opportunities in activities,teachers’insufficient theoretical understanding,inappropriate teacher guidance methods,and so on.Embodied cognition theory attaches importance to the important role of the body in the development of cognition,provides new guidance for classroom teaching,and opens up a new path for classroom teaching reform.Based on the perspective of embodied cognition theory,the concept of body and mind integration should be adhered to in kindergarten teaching with games as the basic activity,experiential teaching situation should be created,children’s subjective experience should be respected,and games and interactions should be designed to promote children’s physical and mental participation,thus laying a foundation for the realization of children’s individual freedom,autonomy,and all-round development.Therefore,this paper aims at the existing problems in the current kindergarten gamification teaching and discusses the design strategy of children’s game activities based on embodied cognition theory.
基金supported by the National Natural Science Foundation of China (Nos.51205335, 51375411)the Scientific Research for the High Level Talent of Nanjing Institute of Technology (No.YKJ201702)
文摘An active design method of tooth profiles for cycloid gears based on their meshing efficiency is proposed.This method takes the meshing efficiency as one of the design variables to determine the tooth profiles.The calculation method for the meshing efficiency of planetary transmission is analyzed and the equation of the meshing efficiency is deduced.Relationships between the meshing efficiency,the radius of the pin wheel and the eccentric distance are revealed.The design constraint quations and the strength constraint quations are deduced.On the basis of this,a design procedure is laid out.Some examples using different input parameters are conducted to demonstrate the feasibility of the approach.A dynamic simulation of the rigid flexible coupling of cycloid gears is also presented.The results show that the proposed design method is more flexible to control the tooth profiles by changing the input values of the transmission efficiency.
文摘This paper presents the design and implementation of a 3 kVA three-phase active T-type neutral-point clamped (NPC) inverter with GaN power devices for low-voltage microgrids. The designed inverter is used in a battery-based energy system (BESS) for power conversion optimization in applications to low-voltage microgrids. A modular design method has been developed for the design and implementation of the AT-NPC inverter. Experimental verification has been carried out based on a 3-kW three-phase T-Type NPC grid-connected inverter. FPGA based digital control technique has been developed for the current control of the three-level three-phase grid inverter. A maximum efficiency of 98.49% has been achieved within a load range from 50% to 75%.
基金Projects(50564006,50904031)supported by the National Natural Science Foundation of ChinaProjects(2005E0004Z,2008E0049M)supported by the Natural Science Foundation of Yunnan Province,China+1 种基金Project(07Z40082)supported by the Science Foundation of the Education Department of Yunnan Province,ChinaProject(2007-16)supported by the Science Foundation of Kunming University of Science and Technology,China
文摘Quantum chemical calculation was used to estimate the reduction potentials of 25 organic cations and the oxidation potentials of 11 anions.This information was used to select promising cations and anions for the preparation of ionic liquids as green electrolytes for electrodeposition of active metals.The reasonable linear correlations between the lowest unoccupied molecular orbital(LUMO)energies and the reduction potentials of cations,and the linear relationships between the oxidation potentials and the highest occupied molecular orbital(HOMO)energies of anions were obtained.The orders of electrochemical stability for cations and anions being obtained agree well with the experimental measurements.The suitable ionic liquids with sufficiently wide electrochemical windows for electrodeposition of active metals are suggested to be[Emim]NTf2,[Bmim]NTf2,[Bmim]BF4, [Bmim]PF6,[Bmim]CTf3,[Emim]BF4,[Emim]PF6,[Emim]CTf3..
基金funded by a grant from the Brittany House of Human Sciences(2015–2017)
文摘Background: Players may not acquire adequate levels of moderate-to-vigorous physical activity(MVPA) when playing commercial video games.This study's goal was to evaluate the effects of an exercise bike video game played by using a mobile application-based exergame that was designed exclusively to promote participants' MVPA, with additional attention paid to this game's ability to promote greater situational interest.Methods: An experimental design was used with 163 students(aged 20.31 ± 1.30, 18–26 years, 61.3% male), all of whom were randomly allocated into an experimental group and a control group. Physical activity(PA) levels were assessed with Acti Graph GT3X+(Acti Graph Inc., Fort Walton Beach, FL, USA) accelerometers. The situational interest scale was used to evaluate students' situational interest in both groups.Multivariate analysis of variance was conducted to examine the differences between sedentary behavior, PA levels, and situational interest between groups. Regression analyses were also used, with the purpose being to evaluate the strength of the relationship between PA and situational interest.Results: Results revealed that the experimental group had higher degrees of sedentary behavior, light PA, total interest, instant enjoyment,exploration intention, attention demand, novelty, and challenge, whereas the control group received higher scores for MVPA(control 95.01% vs.experimental group 89.94%). Regression analysis indicated that instant enjoyment(β = 0.49, p < 0.01), exploration intention(β = 0.18, p < 0.05),and attention demand(β = 0.17, p < 0.05) were positive predictors for total interest, explaining 43% of its variance.Conclusion: A newly designed mobile application-based exergame played via an exercise bike may enhance situational interest and provide a decent level of PA for players.
文摘Diamidine (A) was identified in our in vitro bio-assay as a possible inhibitor of ketol-acid reductoisomerase (KARI) from the ACD database search based on the known three-dimensional crystal structure of KARI. An investigation on interaction of A on KARI active sites, led to the design and synthesis of 15 novel monoamidines. Some of those showed better biological activity than A on rice KARI (in vitro) and in greenhouse herbicidal tests (in vivo). The structure-biological activity relationship was investigated, which provides valuable information to further study of potential KARI inhibitors.
基金supported by National Natural Science Foundation of China(No.51565040)Science and Technology Planning Project of Jiangxi Province(20151BBE50034,20133BBE50021)Aviation Science Funds of China(2014ZE56016)
文摘In this study,adopting uniform design method established a mathematical model to prepare multi-element active flux. GH4169 superalloy plates were welded by the Nd: YAG laser equipment with the prepared active flux. The results show all kinds of fluxes increase the depth to width ratio and the multi-component systems are more significant. The largest increment of the weld depth to width ratio is 159%,obtained by using of the F12 series flux. It is proved that by using of the active flux to increase the depth to width ratio of micro laser welding is feasible.
基金This work was partially supported by the National Natural Science Foundation of China(No.61802034)National Key Research and Development Program of China(No.2019YFC1509602)Chongqing Natural Science Foundation(cstc2019jcyj-msxmX0264).
文摘Due to both of jamming and eavesdropping,active eavesdroppers can induce more serious security threats to unmanned aerial vehicle(UAV)-enabled communications.This paper considers a secure UAV communication system including both the downlink(DL)and uplink(UL)transmissions,where the confidential information is transmitted between a UAV and a ground node in the presence of an active eavesdropper.We aim to maximize the average secrecy rates of the DL and UL communications,respectively,by jointly optimizing the UAV trajectory and the UAV/ground node’s transmit power control over a given flight period.Due to the non-convexity of the formulated problems,it is difficult to obtain globally optimal solutions.However,we propose efficient iterative algorithms to obtain high-quality suboptimal solutions by applying the block coordinate descent and successive convex optimization methods.Simulation results show that the joint optimization algorithms can effectively improve the secrecy rate performance for both the DL and UL communications,as compared with other baseline schemes.The proposed schemes can be considered as special cases of UAV-assisted non-orthogonal multiple access(NOMA)networks.
基金the Pathways to Health project funded by the Canadian Institutes of Health Research (CIHRMOP126133)+4 种基金by a CIHR Foundations Scheme Grant (FDN-154331)supported by a CIHR New Investigator Award (MSH-130162)supported by a JSPS Postdoctoral Fellowship for Research in Japan (#17716) from the Japan Society for the Promotion of Sciencesupported by the MEXTSupported Program for the Strategic Research Foundation at Private Universities (2015-2019)the Japan Ministry of Education,Culture,Sports,Science and Technology (S1511017)
文摘Background:Cross-sectional studies provide useful insight about the associations between the built environment and physical activity(PA),particularly when reasons for neighborhood choice are considered.Our study analyzed the relationship between levels of weekly transportation and leisure PA among 3 neighborhood designs,statistically adjusting for sociodemographic characteristics and reasons for neighborhood choice.Methods:A stratified random sample of adults(age>20 years)living in Calgary(Canada)neighborhoods with different neighborhood designs(grid,warped-grid,and curvilinear)and socioeconomic status completed a self-administered questionnaire capturing PA,sociodemographic characteristics,and reasons for neighborhood choice(response rate=10.1%;n=1023).Generalized linear models estimated associations between neighborhood design and transportation and leisure PA outcomes(participation(any vs.none)and volume(metabolic equivalent:h/week)),adjusting for neighborhood socioeconomic status,sociodemographic characteristics(gender,age,ethnicity,education,household income,marital status,children,vehicle access,dog ownership,and injury),and reasons for neighborhood choice(e.g.,proximity and quality of recreational and utilitarian destinations,proximity to work,highway access,aesthetics,and sense of community).Results:Overall,854 participants had resided in their neighborhood for at least 12 months and provided complete data.Compared with those living in curvilinear neighborhoods,grid neighborhood participants had greater odds(p<0.05)of participating in any transportation walking(odds ratio(OR)=2.17),transportation and leisure cycling(OR=2.39 and OR=1.70),active transportation(OR=2.16),and high-intensity leisure PA(≥6 metabolic equivalent;OR=1.74),respectively.There were no neighborhood differences in the volume of any transportation or leisure PA undertaken.Adjustment for neighborhood selection had minimal impact on the statistical or practical importance of model estimates.Conclusion:Neighborhood design is associated with PA patterns in adults,independent of reasons for neighborhood choice and sociodemogranhic factors.
基金the National Natural Science Foundation of China(No.59635140)
文摘The equations of motion governing the vibration of a cantilever beam with partially treated self-sensing active constrained layer damping treatment(SACLD) are derived by application of the extended Hamilton principle. The assumed-modes method and closed loop velocity feedback control law are used to analyze and control the flexural vibration of the beam nle influences of the bonding layer and piezoelectric layer thickness, material properties, placements of the Diezoelectric patch and feedback control parameters on the actuation ability of the vibration suppression are investigated. Some design considerations for pure passive, pure active control, and self-sensing active constrained layer damping are discussed.
基金financial support from the Fund for Scientific Research Flanders(FWO Flanders)through the doctoral fellowship grants(1185822N,1S45522N,and 3F018119)funding from the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(818607)。
文摘By combining machine learning with the design of experiments,thereby achieving so-called active machine learning,more efficient and cheaper research can be conducted.Machine learning algorithms are more flexible and are better than traditional design of experiment algorithms at investigating processes spanning all length scales of chemical engineering.While active machine learning algorithms are maturing,their applications are falling behind.In this article,three types of challenges presented by active machine learning—namely,convincing the experimental researcher,the flexibility of data creation,and the robustness of active machine learning algorithms—are identified,and ways to overcome them are discussed.A bright future lies ahead for active machine learning in chemical engineering,thanks to increasing automation and more efficient algorithms that can drive novel discoveries.
基金support of the Hong Kong University of Science and Technology through the UROP program
文摘In this study, waste tire was used as raw material for the production of activated carbons through pyrolysis. 'Fire char was first produced by carbomzation at 550℃ under nitrogen. A two tactortal design was used to optimize the production of activated carbon from tire char. The effects of several factors controlling the activation process, such as temperature (.830-930℃), time (2-6h) and percentage ot carbon dioxide (70%-100%) were investigated. The production was described mathematically as a function of these three factors. First order modeling equations were developed for surface area, yield and mesopore volume. It was concluded that the yield, BET surface area and mesopore volume of activated carbon were most sensitive to activation temperature and time while percentage of carbon dioxide in the activation gas was a less significant factor.