Let D(n)be the finite dimensional non-pointed and non-semisimple Hopf algebra,which is a quotient of a prime Hopf algebras of GK-dimension one for an odd number n>1.In this paper,we investigate the structure of Yet...Let D(n)be the finite dimensional non-pointed and non-semisimple Hopf algebra,which is a quotient of a prime Hopf algebras of GK-dimension one for an odd number n>1.In this paper,we investigate the structure of Yetter-Drinfeld simple modules over D(n)and give iso-classes of them.展开更多
The interaction between the active chips mounted and the same base plate is considered as a thermoelectrical coupling effect.An approach to coupling effect analysis of a multi-chip system is presented with IGBT as a s...The interaction between the active chips mounted and the same base plate is considered as a thermoelectrical coupling effect.An approach to coupling effect analysis of a multi-chip system is presented with IGBT as a sample.Finite element method is used to evaluate the temperature distribution in power modules.The precise electrothermal model is obtained by fitting the curve of transient thermal impedance with a finite series of exponential terms,in which,the thermal-coupling effect among chips is considered as a prediction of the highest transient temperature of the chips.This model can be used in many thermal monitoring systems.Both ANSYS and PSPICE si- mulation software have been employed,and the simulation results agree with the experimental ones very well.展开更多
Let H be a commutative, noetherian, semisimple and cosemisimple Hopf algebra with a bijective antipode over a field k. Then the semisimplicity of YD（H） is considered, where YD （H） means the disjoint union of the c...Let H be a commutative, noetherian, semisimple and cosemisimple Hopf algebra with a bijective antipode over a field k. Then the semisimplicity of YD（H） is considered, where YD （H） means the disjoint union of the category of generalized Yetter-Drinfeld modules nYD^H（ α, β） for any α, β E Aut Hopf（H）. First, the fact that YD（H） is closed under Mor is proved. Secondly, based on the properties of finitely generated projective modules and semisimplicity of H, YD（H） satisfies the exact condition. Thus each object in YD（H） can be decomposed into simple ones since H is noetherian and cosemisimple. Finally, it is proved that YD （H） is a sernisimple category.展开更多
An energy-storage system comprised of lithium-ion battery modules is considered to be a core component of new energy vehicles,as it provides the main power source for the transmission system.However,manufacturing defe...An energy-storage system comprised of lithium-ion battery modules is considered to be a core component of new energy vehicles,as it provides the main power source for the transmission system.However,manufacturing defects in battery modules lead to variations in performance among the cells used in series or parallel configuration.This variation results in incomplete charge and discharge of batteries and non-uniform temperature distribution,which further lead to reduction of cycle life and battery capacity over time.To solve this problem,this work uses experimental and numerical methods to conduct a comprehensive investigation on the clustering of battery cells with similar performance in order to produce a battery module with improved electrochemical performance.Experiments were first performed by dismantling battery modules for the measurement of performance parameters.The kmeans clustering and support vector clustering(SVC)algorithms were then employed to produce battery modules composed of 12 cells each.Experimental verification of the results obtained from the clustering analysis was performed by measuring the temperature rise in the cells over a certain period,while air cooling was provided.It was found that the SVC-clustered battery module in Category 3 exhibited the best performance,with a maximum observed temperature of 32℃.By contrast,the maximum observed temperatures of the other battery modules were higher,at 40℃for Category 1(manufacturer),36℃for Category 2(manufacturer),and 35℃for Category 4(k-means-clustered battery module).展开更多
To reduce the requirement for lifting capacity and decrease the hoist cable force during the descending and laying process of a subsea production system(SPS), a buoyancy module auxiliary installation technology was pr...To reduce the requirement for lifting capacity and decrease the hoist cable force during the descending and laying process of a subsea production system(SPS), a buoyancy module auxiliary installation technology was proposed by loading buoyancy modules on the SPS to reduce the lifting weight. Two models are established, namely, the SPS lowering-down model and the buoyancy module floating-up model. The main study results are the following: 1) When the buoyancy module enters the water under wave condition, the amplitude of tension fluctuation is twice that when SPS enters water; 2) Under current condition, the displacement of SPS becomes three times larger because of the existence of the buoyancy module; 3) After being released, the velocity of the buoyancy module increases to a large speed rapidly and then reaches a balancing speed gradually. The buoyancy module floats up at a balancing speed and rushes out from the water at a pop-up distance; 4) In deep water, the floating-up velocity of the buoyancy module is related to its mass density and shape, and it is not related to water depth; 5) A drag parachute can reduce floating-up velocity and pop-up distance effectively. Good agreement was found between the simulation and experiment results.展开更多
CFD simulation of the permeation process of a 19-core tandem ceramic membrane module was established to investigate flow field and resistance and its change in permeate flux to the membrane element position and the ch...CFD simulation of the permeation process of a 19-core tandem ceramic membrane module was established to investigate flow field and resistance and its change in permeate flux to the membrane element position and the channel of each membrane element.The results show that when the volume flow rate changes from26 m3·h-1 to 89 m3·h-1,the resistance of each part of the membrane module increases gradually.The increase in resistance loss in the membrane element is faster than the plates and the bell mouths.In a single ceramic membrane module,the maximum difference in flow rate of each membrane tube is 7.23%.In a single membrane tube,the outer ring channels 3–5,3–6,3–7,3–8 are relatively slow.The maximum mass flow deviation from the mean is 2.7%.This work helps to clarify the flow mechanism within the modules,optimize the structure of the equipment and provide a reliable basis for the improvement of industrial ceramic membrane modules.展开更多
The simple modules for electrical Lie algebra of type D5 were investigated.The sufficient and necessary criteria of the simple Z-graded highest weight modules were established by means of determining the singular vect...The simple modules for electrical Lie algebra of type D5 were investigated.The sufficient and necessary criteria of the simple Z-graded highest weight modules were established by means of determining the singular vectors of the Verma modules.The simple highest weight module is isomorphic to either that for the symplectic Lie algebra sp4 or Verma module.展开更多
Over an algebraically closed field of characteristic p>2,based on the results on the representation theory of special linear Lie algebra sl(2),restricted simple modules L(λ) of the Schrodinger algebra S(1)are dete...Over an algebraically closed field of characteristic p>2,based on the results on the representation theory of special linear Lie algebra sl(2),restricted simple modules L(λ) of the Schrodinger algebra S(1)are determined,and all derivations of S(1)on L(λ)are also obtained.As an application,the first cohomology of S(1)with the coefficient in L(λ)is determined.展开更多
The present study introduced a new motion analysis method for total hip arthroplasty (THA). A motion simulation module of THA was designed and developed, which can simulate the THA’s implantation condition and motion...The present study introduced a new motion analysis method for total hip arthroplasty (THA). A motion simulation module of THA was designed and developed, which can simulate the THA’s implantation condition and motion and detect the theoretic range of motion (ROM) before the prosthetic component impingement happens.展开更多
Based on chemical thermodynamics and mass balance,countercurrently fractional chiral extraction by hollow fiber membrane was investigated.The mathematical modules for the relation of chiral extraction yield and produc...Based on chemical thermodynamics and mass balance,countercurrently fractional chiral extraction by hollow fiber membrane was investigated.The mathematical modules for the relation of chiral extraction yield and product optical purity with number of transfer units by chiral extraction with hollow fiber membrane were established,and the modules were simulated by visual basic(VB)proceduce.The results show that,the difference in free energy between two diastereomeric complexes formed by R-and S-enantiomer with chiral selector,??(?G),is the force of separation of enantiomers.It is necessary to separate enantiomers,where one of the extraction factors is above 1,and the other is below 1.Under certain phase ratio,chiral separation depends on separation factor and number of transfer units.The experimental result is in agreement with the theoretical value.展开更多
The reverse osmosis process has been applied in large industrial fields （water treatment, food industry, biotechnology, and ect.）. Despite, this progress more investigation are required to optimize the reverse osmos...The reverse osmosis process has been applied in large industrial fields （water treatment, food industry, biotechnology, and ect.）. Despite, this progress more investigation are required to optimize the reverse osmosis process. The present paper deals the modeling of mass transfer in a cavity limited by a semi-permeable membrane. Mass conservation and momentum balances are developed, dimensionless and control volume method has been applied. The velocity and concentration profiles versus the Reynolds number and Sherwood are studied. The results show that the permeability of the membrane decreases as function of the transversal （radial） component of the velocity. The axial （tangential） component of the velocity presents a good stability along the thickness of the cavity; this phenomenon can be attributed to the zero gradient of the tangential velocity. These preliminary results show that the phenomenon of the concentration polarization affects the mass transfer coefficient in a channel. Current study has considered the cavity without a promoter of the turbulence; whereas, the design of the spacer has an important role on mass transfer coefficient in the reverse osmosis module. Our next interest is the integration of the spacer in the cavity, and the study of the effect of its design on the concentration and velocity profiles and the mass transfer coefficient through the reverse osmosis membrane.展开更多
Let H be a Hopf algebra over a field with bijective antipode, and A a commutative cleft right H-comodule algebra. In this paper, we investigate the ho-mological dimensions and the semisimplicity of the category of rel...Let H be a Hopf algebra over a field with bijective antipode, and A a commutative cleft right H-comodule algebra. In this paper, we investigate the ho-mological dimensions and the semisimplicity of the category of relative Hopf modulesAMH.展开更多
In this paper,we classify the simple uniformly bounded weight modules for the vector eld Lie algebra W1 of in nite rank.It turns out that any such modules are intermediate series modules.This result is very di erent f...In this paper,we classify the simple uniformly bounded weight modules for the vector eld Lie algebra W1 of in nite rank.It turns out that any such modules are intermediate series modules.This result is very di erent from the vector eld Lie algebra Wd of nite rank.展开更多
Photovoltaic (PV) modules, as essential components of solar power generation systems, significantly influence unitpower generation costs.The service life of these modules directly affects these costs. Over time, the p...Photovoltaic (PV) modules, as essential components of solar power generation systems, significantly influence unitpower generation costs.The service life of these modules directly affects these costs. Over time, the performanceof PV modules gradually declines due to internal degradation and external environmental factors.This cumulativedegradation impacts the overall reliability of photovoltaic power generation. This study addresses the complexdegradation process of PV modules by developing a two-stage Wiener process model. This approach accountsfor the distinct phases of degradation resulting from module aging and environmental influences. A powerdegradation model based on the two-stage Wiener process is constructed to describe individual differences inmodule degradation processes. To estimate the model parameters, a combination of the Expectation-Maximization(EM) algorithm and the Bayesian method is employed. Furthermore, the Schwarz Information Criterion (SIC) isutilized to identify critical change points in PV module degradation trajectories. To validate the universality andeffectiveness of the proposed method, a comparative analysis is conducted against other established life predictiontechniques for PV modules.展开更多
Medical image classification has played an important role in the medical field, and the related method based on deep learning has become an important and powerful technique in medical image classification. In this art...Medical image classification has played an important role in the medical field, and the related method based on deep learning has become an important and powerful technique in medical image classification. In this article, we propose a simplified inception module based Hadamard attention (SI + HA) mechanism for medical image classification. Specifically, we propose a new attention mechanism: Hadamard attention mechanism. It improves the accuracy of medical image classification without greatly increasing the complexity of the model. Meanwhile, we adopt a simplified inception module to improve the utilization of parameters. We use two medical image datasets to prove the superiority of our proposed method. In the BreakHis dataset, the AUCs of our method can reach 98.74%, 98.38%, 98.61% and 97.67% under the magnification factors of 40×, 100×, 200× and 400×, respectively. The accuracies can reach 95.67%, 94.17%, 94.53% and 94.12% under the magnification factors of 40×, 100×, 200× and 400×, respectively. In the KIMIA Path 960 dataset, the AUCs and accuracy of our method can reach 99.91% and 99.03%. It is superior to the currently popular methods and can significantly improve the effectiveness of medical image classification.展开更多
Photovoltaic (PV) modules have emerged as an ideal technology of choice for <span>harvesting vastly available renewable energy resources. However, the effi</span>ciency <span>of PV modules remains si...Photovoltaic (PV) modules have emerged as an ideal technology of choice for <span>harvesting vastly available renewable energy resources. However, the effi</span>ciency <span>of PV modules remains significantly lower than that of other renewable</span> energy sources such as wind and hydro. One of the critical elements affecting a photovoltaic module’s efficiency is the variety of external climatic conditions under which it is installed. In this work, the effect of simulated snow loads was evaluated on the performance of PV modules with different <span>types of cells and numbers of busbars. According to ASTM-1830 and IEC-1215</span> standards, a load of 5400 Pa was applied to the surface of PV modules for 3 hours. An indigenously developed pneumatic airbag test setup was used for the uniform application of this load throughout the test, which was validated by load cell and pressure gauge. Electroluminescence (EL) imaging and solar flash tests were performed before and after the application of load to characterize the performance and effect of load on PV modules. Based on these tests, the maxi<span>mum power output, efficiency, fill factor and series resistance were deter</span>mined. The results show that polycrystalline modules are the most likely to withstand the snow loads as compared to monocrystalline PV modules. A maximum drop of 32.13% in the power output and a 17.6% increase in series resistance were observed in the modules having more cracks. These findings demonstrated the efficacy of the newly established test setup and the potential of snow loads for reducing the overall performance of PV module.展开更多
This work proposes a novel heating and cooling system,with incorporated thermoelectric module,that can achieve energy balance using a self-water supply heat exchange subsystem.The thermoelectric effect is used to achi...This work proposes a novel heating and cooling system,with incorporated thermoelectric module,that can achieve energy balance using a self-water supply heat exchange subsystem.The thermoelectric effect is used to achieve controlled and adjustable heating of the circulating water.Simulations were conducted to study the thermal performance of the system while it simultaneously produces hot and cold water,with different working conditions for the hot-and cold-side water outlets.The results show that the water temperature at the hot side outlet increases from 32℃to 75℃when the power increases from 4.5 to 50 W.Additionally,the use of thermoelectric modules to heat water and recover waste heat is 22%more efficient than ordinary electric water heating systems.展开更多
A novel roof tile thermoelectric generator(RT-TEG)was used to harvest electrical energy from a solar heat source.The RT-TEG was fabricated and simulated by flat and curved thermoelectric modules consisting of p-n junc...A novel roof tile thermoelectric generator(RT-TEG)was used to harvest electrical energy from a solar heat source.The RT-TEG was fabricated and simulated by flat and curved thermoelectric modules consisting of p-n junctions of p-Sb_(2)Te_(3) and n-Bi_(2)Te_(3),with an Al_(2)O_(3) substrate at the top and bottom for heat absorption and heat rejection.The RT-TEG was installed in a roof tile to act as a generator.The electrical voltage and power values of the curved thermoelectric modules were higher than those of the flat thermoelectric module by 0.44 V and 80 mW,at a temperature difference(ΔT)of 100 K.In field tests,the RT-TEG produced a maximum electrical voltage of 33.70 mV and an electrical power of 46.24μW atΔT~7 K under a load resistance of 1Ωunder good sunshine at 13.00 hours.The energy conversion efficiency of RT-TEG was found to be 2.24×10^(−4).展开更多
One of the most important parameter used for the evaluation of the energy rating of PV modules is, their spectral responsivities which are the measure of electrical performance parameters per incident solar radiation....One of the most important parameter used for the evaluation of the energy rating of PV modules is, their spectral responsivities which are the measure of electrical performance parameters per incident solar radiation. In this work, spectral responsivity measurements of a mono-crystalline, a poly-crystalline, a CIGS thin film and a bifacial module were measured using xenon-based flash type solar simulator system and a set of band pass filters. For the comprehensive characterization of parameters that may influence the spectral responsivity measurements, initially the simulator system was characterized both optically and thermally according to the IEC60904-9 and IEC60891 standard requirements. The optical characterizations in terms of spectral match, spatial non-uniformity and temporal instability indicate that the measured results (~3.0%, ~0.30% and ~0.20%) according to the IEC 60904-9 standard’s classification requirements correspond to A+A+A+ classes. Moreover, thermal characterizations in terms of the temperature uniformity show that over the 2 × 2 m area temperature uniformity of simulator system’s light distribution (1ºC) is almost two times better than the IEC 60891 standard requirements (±2ºC). Next, PV modules were electrically stabilized according to the IEC 61215-2 standard requirement’s (stability test) to reduce the fluctuations in their electrical performance parameters. Then, using the band pass filters, temperature controlled xenon-based solar simulator system and a reference PV module of the spectral responsivity of PV modules were measured from 400 nm to 1100 nm with 50 nm steps with relative uncertainty of 10<sup>-3</sup> level.展开更多
A simple ballistic movement and two of its attributes (namely, reversal in time and synchronization with external events) are formulated. A three-dimensional, three-link musculoskeletal arm is subjected to a fast ball...A simple ballistic movement and two of its attributes (namely, reversal in time and synchronization with external events) are formulated. A three-dimensional, three-link musculoskeletal arm is subjected to a fast ballistic type movement. The central components of the movement from hippocampal, cerebellar, basal ganglia and reticular formation structures that may be involved in timing are identified. The role of agonist muscles and spinal reflexes in the execution of ballistic movements (namely, in fast starts and fast stops) is discussed. The needed three time intervals are constructed in real time and can be coordinated with external events. Delaying or advancing in time, synchronization, time scaling and inverting events in time relative to the movement is formulated. Digital computer simulations are presented to test the behavior of the formulated neural and spinal processing and demonstrate the behavior of the arm under such control.展开更多
基金Supported by the Fundamental Research Program of Shanxi Province(Grant No.202303021212147)the National Natural Science Foundation of China(Grant No.12471038)。
文摘Let D(n)be the finite dimensional non-pointed and non-semisimple Hopf algebra,which is a quotient of a prime Hopf algebras of GK-dimension one for an odd number n>1.In this paper,we investigate the structure of Yetter-Drinfeld simple modules over D(n)and give iso-classes of them.
文摘The interaction between the active chips mounted and the same base plate is considered as a thermoelectrical coupling effect.An approach to coupling effect analysis of a multi-chip system is presented with IGBT as a sample.Finite element method is used to evaluate the temperature distribution in power modules.The precise electrothermal model is obtained by fitting the curve of transient thermal impedance with a finite series of exponential terms,in which,the thermal-coupling effect among chips is considered as a prediction of the highest transient temperature of the chips.This model can be used in many thermal monitoring systems.Both ANSYS and PSPICE si- mulation software have been employed,and the simulation results agree with the experimental ones very well.
基金The National Natural Science Foundation of China(No.11371088)the Fundamental Research Funds for the Central Universities(No.3207013906)the Natural Science Foundation of Jiangsu Province(No.BK2012736)
文摘Let H be a commutative, noetherian, semisimple and cosemisimple Hopf algebra with a bijective antipode over a field k. Then the semisimplicity of YD（H） is considered, where YD （H） means the disjoint union of the category of generalized Yetter-Drinfeld modules nYD^H（ α, β） for any α, β E Aut Hopf（H）. First, the fact that YD（H） is closed under Mor is proved. Secondly, based on the properties of finitely generated projective modules and semisimplicity of H, YD（H） satisfies the exact condition. Thus each object in YD（H） can be decomposed into simple ones since H is noetherian and cosemisimple. Finally, it is proved that YD （H） is a sernisimple category.
基金This work was supported by the National Natural Science Foundation of China(51675196 and 51721092)the program for HUST Academic Frontier Youth Team(2017QYTD04)+2 种基金The authors acknowledge the grant(DMETKF2018019)from the State Key Lab of Digital Manufacturing Equipment and Technology,Huazhong University of Science and Technologythe Sailing Talent Program and the Guangdong University Youth Innovation Talent Project(2016KQNCX053)supported by the Department of Education of Guangdong Provincethe Shantou University Scientific Research Funded Project(NTF16002).
文摘An energy-storage system comprised of lithium-ion battery modules is considered to be a core component of new energy vehicles,as it provides the main power source for the transmission system.However,manufacturing defects in battery modules lead to variations in performance among the cells used in series or parallel configuration.This variation results in incomplete charge and discharge of batteries and non-uniform temperature distribution,which further lead to reduction of cycle life and battery capacity over time.To solve this problem,this work uses experimental and numerical methods to conduct a comprehensive investigation on the clustering of battery cells with similar performance in order to produce a battery module with improved electrochemical performance.Experiments were first performed by dismantling battery modules for the measurement of performance parameters.The kmeans clustering and support vector clustering(SVC)algorithms were then employed to produce battery modules composed of 12 cells each.Experimental verification of the results obtained from the clustering analysis was performed by measuring the temperature rise in the cells over a certain period,while air cooling was provided.It was found that the SVC-clustered battery module in Category 3 exhibited the best performance,with a maximum observed temperature of 32℃.By contrast,the maximum observed temperatures of the other battery modules were higher,at 40℃for Category 1(manufacturer),36℃for Category 2(manufacturer),and 35℃for Category 4(k-means-clustered battery module).
基金supported by the National Natural Science Foundation of China (Nos.51479183 and 51779236)
文摘To reduce the requirement for lifting capacity and decrease the hoist cable force during the descending and laying process of a subsea production system(SPS), a buoyancy module auxiliary installation technology was proposed by loading buoyancy modules on the SPS to reduce the lifting weight. Two models are established, namely, the SPS lowering-down model and the buoyancy module floating-up model. The main study results are the following: 1) When the buoyancy module enters the water under wave condition, the amplitude of tension fluctuation is twice that when SPS enters water; 2) Under current condition, the displacement of SPS becomes three times larger because of the existence of the buoyancy module; 3) After being released, the velocity of the buoyancy module increases to a large speed rapidly and then reaches a balancing speed gradually. The buoyancy module floats up at a balancing speed and rushes out from the water at a pop-up distance; 4) In deep water, the floating-up velocity of the buoyancy module is related to its mass density and shape, and it is not related to water depth; 5) A drag parachute can reduce floating-up velocity and pop-up distance effectively. Good agreement was found between the simulation and experiment results.
基金the computational resources support from the High Performance Computing Center of Nanjing Tech UniversityNational Key R&D Program of China(2017YFD0400402)the financial support from National Natural Science Foundation of China(No.21576132)。
文摘CFD simulation of the permeation process of a 19-core tandem ceramic membrane module was established to investigate flow field and resistance and its change in permeate flux to the membrane element position and the channel of each membrane element.The results show that when the volume flow rate changes from26 m3·h-1 to 89 m3·h-1,the resistance of each part of the membrane module increases gradually.The increase in resistance loss in the membrane element is faster than the plates and the bell mouths.In a single ceramic membrane module,the maximum difference in flow rate of each membrane tube is 7.23%.In a single membrane tube,the outer ring channels 3–5,3–6,3–7,3–8 are relatively slow.The maximum mass flow deviation from the mean is 2.7%.This work helps to clarify the flow mechanism within the modules,optimize the structure of the equipment and provide a reliable basis for the improvement of industrial ceramic membrane modules.
基金Fundamental Research Funds for the Central Universities,China(No.2232021G13)。
文摘The simple modules for electrical Lie algebra of type D5 were investigated.The sufficient and necessary criteria of the simple Z-graded highest weight modules were established by means of determining the singular vectors of the Verma modules.The simple highest weight module is isomorphic to either that for the symplectic Lie algebra sp4 or Verma module.
文摘Over an algebraically closed field of characteristic p>2,based on the results on the representation theory of special linear Lie algebra sl(2),restricted simple modules L(λ) of the Schrodinger algebra S(1)are determined,and all derivations of S(1)on L(λ)are also obtained.As an application,the first cohomology of S(1)with the coefficient in L(λ)is determined.
基金supported by the National Natural Science Foundation of China(No. 30810103908)the Science Foundation of Shanghai(No.09441900300)the National Basic Research Program(973)of China(No.2011CB711000)
文摘The present study introduced a new motion analysis method for total hip arthroplasty (THA). A motion simulation module of THA was designed and developed, which can simulate the THA’s implantation condition and motion and detect the theoretic range of motion (ROM) before the prosthetic component impingement happens.
基金Project(20576029) supported by the National Natural Science Foundation of ChinaProject(2004035650) supported by the China Postdoctoral Science Foundation
文摘Based on chemical thermodynamics and mass balance,countercurrently fractional chiral extraction by hollow fiber membrane was investigated.The mathematical modules for the relation of chiral extraction yield and product optical purity with number of transfer units by chiral extraction with hollow fiber membrane were established,and the modules were simulated by visual basic(VB)proceduce.The results show that,the difference in free energy between two diastereomeric complexes formed by R-and S-enantiomer with chiral selector,??(?G),is the force of separation of enantiomers.It is necessary to separate enantiomers,where one of the extraction factors is above 1,and the other is below 1.Under certain phase ratio,chiral separation depends on separation factor and number of transfer units.The experimental result is in agreement with the theoretical value.
文摘The reverse osmosis process has been applied in large industrial fields （water treatment, food industry, biotechnology, and ect.）. Despite, this progress more investigation are required to optimize the reverse osmosis process. The present paper deals the modeling of mass transfer in a cavity limited by a semi-permeable membrane. Mass conservation and momentum balances are developed, dimensionless and control volume method has been applied. The velocity and concentration profiles versus the Reynolds number and Sherwood are studied. The results show that the permeability of the membrane decreases as function of the transversal （radial） component of the velocity. The axial （tangential） component of the velocity presents a good stability along the thickness of the cavity; this phenomenon can be attributed to the zero gradient of the tangential velocity. These preliminary results show that the phenomenon of the concentration polarization affects the mass transfer coefficient in a channel. Current study has considered the cavity without a promoter of the turbulence; whereas, the design of the spacer has an important role on mass transfer coefficient in the reverse osmosis module. Our next interest is the integration of the spacer in the cavity, and the study of the effect of its design on the concentration and velocity profiles and the mass transfer coefficient through the reverse osmosis membrane.
基金The Fundation of Key Research Program (02021029) and the NSF (2004kj352) of Anhui Province, China.
文摘Let H be a Hopf algebra over a field with bijective antipode, and A a commutative cleft right H-comodule algebra. In this paper, we investigate the ho-mological dimensions and the semisimplicity of the category of relative Hopf modulesAMH.
文摘In this paper,we classify the simple uniformly bounded weight modules for the vector eld Lie algebra W1 of in nite rank.It turns out that any such modules are intermediate series modules.This result is very di erent from the vector eld Lie algebra Wd of nite rank.
基金supported by the National Natural Science Foundation of China(51767017)the Basic Research Innovation Group Project of Gansu Province(18JR3RA133)the Industrial Support and Guidance Project of Universities in Gansu Province(2022CYZC-22).
文摘Photovoltaic (PV) modules, as essential components of solar power generation systems, significantly influence unitpower generation costs.The service life of these modules directly affects these costs. Over time, the performanceof PV modules gradually declines due to internal degradation and external environmental factors.This cumulativedegradation impacts the overall reliability of photovoltaic power generation. This study addresses the complexdegradation process of PV modules by developing a two-stage Wiener process model. This approach accountsfor the distinct phases of degradation resulting from module aging and environmental influences. A powerdegradation model based on the two-stage Wiener process is constructed to describe individual differences inmodule degradation processes. To estimate the model parameters, a combination of the Expectation-Maximization(EM) algorithm and the Bayesian method is employed. Furthermore, the Schwarz Information Criterion (SIC) isutilized to identify critical change points in PV module degradation trajectories. To validate the universality andeffectiveness of the proposed method, a comparative analysis is conducted against other established life predictiontechniques for PV modules.
文摘Medical image classification has played an important role in the medical field, and the related method based on deep learning has become an important and powerful technique in medical image classification. In this article, we propose a simplified inception module based Hadamard attention (SI + HA) mechanism for medical image classification. Specifically, we propose a new attention mechanism: Hadamard attention mechanism. It improves the accuracy of medical image classification without greatly increasing the complexity of the model. Meanwhile, we adopt a simplified inception module to improve the utilization of parameters. We use two medical image datasets to prove the superiority of our proposed method. In the BreakHis dataset, the AUCs of our method can reach 98.74%, 98.38%, 98.61% and 97.67% under the magnification factors of 40×, 100×, 200× and 400×, respectively. The accuracies can reach 95.67%, 94.17%, 94.53% and 94.12% under the magnification factors of 40×, 100×, 200× and 400×, respectively. In the KIMIA Path 960 dataset, the AUCs and accuracy of our method can reach 99.91% and 99.03%. It is superior to the currently popular methods and can significantly improve the effectiveness of medical image classification.
文摘Photovoltaic (PV) modules have emerged as an ideal technology of choice for <span>harvesting vastly available renewable energy resources. However, the effi</span>ciency <span>of PV modules remains significantly lower than that of other renewable</span> energy sources such as wind and hydro. One of the critical elements affecting a photovoltaic module’s efficiency is the variety of external climatic conditions under which it is installed. In this work, the effect of simulated snow loads was evaluated on the performance of PV modules with different <span>types of cells and numbers of busbars. According to ASTM-1830 and IEC-1215</span> standards, a load of 5400 Pa was applied to the surface of PV modules for 3 hours. An indigenously developed pneumatic airbag test setup was used for the uniform application of this load throughout the test, which was validated by load cell and pressure gauge. Electroluminescence (EL) imaging and solar flash tests were performed before and after the application of load to characterize the performance and effect of load on PV modules. Based on these tests, the maxi<span>mum power output, efficiency, fill factor and series resistance were deter</span>mined. The results show that polycrystalline modules are the most likely to withstand the snow loads as compared to monocrystalline PV modules. A maximum drop of 32.13% in the power output and a 17.6% increase in series resistance were observed in the modules having more cracks. These findings demonstrated the efficacy of the newly established test setup and the potential of snow loads for reducing the overall performance of PV module.
文摘This work proposes a novel heating and cooling system,with incorporated thermoelectric module,that can achieve energy balance using a self-water supply heat exchange subsystem.The thermoelectric effect is used to achieve controlled and adjustable heating of the circulating water.Simulations were conducted to study the thermal performance of the system while it simultaneously produces hot and cold water,with different working conditions for the hot-and cold-side water outlets.The results show that the water temperature at the hot side outlet increases from 32℃to 75℃when the power increases from 4.5 to 50 W.Additionally,the use of thermoelectric modules to heat water and recover waste heat is 22%more efficient than ordinary electric water heating systems.
基金supported by the Thailand Research Fund(TRF)Research Career Development Grant:(RSA6180070).
文摘A novel roof tile thermoelectric generator(RT-TEG)was used to harvest electrical energy from a solar heat source.The RT-TEG was fabricated and simulated by flat and curved thermoelectric modules consisting of p-n junctions of p-Sb_(2)Te_(3) and n-Bi_(2)Te_(3),with an Al_(2)O_(3) substrate at the top and bottom for heat absorption and heat rejection.The RT-TEG was installed in a roof tile to act as a generator.The electrical voltage and power values of the curved thermoelectric modules were higher than those of the flat thermoelectric module by 0.44 V and 80 mW,at a temperature difference(ΔT)of 100 K.In field tests,the RT-TEG produced a maximum electrical voltage of 33.70 mV and an electrical power of 46.24μW atΔT~7 K under a load resistance of 1Ωunder good sunshine at 13.00 hours.The energy conversion efficiency of RT-TEG was found to be 2.24×10^(−4).
文摘One of the most important parameter used for the evaluation of the energy rating of PV modules is, their spectral responsivities which are the measure of electrical performance parameters per incident solar radiation. In this work, spectral responsivity measurements of a mono-crystalline, a poly-crystalline, a CIGS thin film and a bifacial module were measured using xenon-based flash type solar simulator system and a set of band pass filters. For the comprehensive characterization of parameters that may influence the spectral responsivity measurements, initially the simulator system was characterized both optically and thermally according to the IEC60904-9 and IEC60891 standard requirements. The optical characterizations in terms of spectral match, spatial non-uniformity and temporal instability indicate that the measured results (~3.0%, ~0.30% and ~0.20%) according to the IEC 60904-9 standard’s classification requirements correspond to A+A+A+ classes. Moreover, thermal characterizations in terms of the temperature uniformity show that over the 2 × 2 m area temperature uniformity of simulator system’s light distribution (1ºC) is almost two times better than the IEC 60891 standard requirements (±2ºC). Next, PV modules were electrically stabilized according to the IEC 61215-2 standard requirement’s (stability test) to reduce the fluctuations in their electrical performance parameters. Then, using the band pass filters, temperature controlled xenon-based solar simulator system and a reference PV module of the spectral responsivity of PV modules were measured from 400 nm to 1100 nm with 50 nm steps with relative uncertainty of 10<sup>-3</sup> level.
文摘A simple ballistic movement and two of its attributes (namely, reversal in time and synchronization with external events) are formulated. A three-dimensional, three-link musculoskeletal arm is subjected to a fast ballistic type movement. The central components of the movement from hippocampal, cerebellar, basal ganglia and reticular formation structures that may be involved in timing are identified. The role of agonist muscles and spinal reflexes in the execution of ballistic movements (namely, in fast starts and fast stops) is discussed. The needed three time intervals are constructed in real time and can be coordinated with external events. Delaying or advancing in time, synchronization, time scaling and inverting events in time relative to the movement is formulated. Digital computer simulations are presented to test the behavior of the formulated neural and spinal processing and demonstrate the behavior of the arm under such control.
