Most previous investigations on interference effects of tall buildings under wind actions focused on the wind induced interference effects between two buildings,and the interference effects of three or more buildings ...Most previous investigations on interference effects of tall buildings under wind actions focused on the wind induced interference effects between two buildings,and the interference effects of three or more buildings have seldom been studied so far due to the huge workload involved in experiments and data processing.In this paper,mean and dynamic force/response interference effects and peak wind pressure interference effects of two and three tall buildings,especially the three-building configuration,are investigated through a series of wind tunnel tests on typical tall building models using high frequency force balance technique and wind pressure measurements.Furthermore,the present paper focuses on the effects of parameters,including breadth ratio and height ratio of the buildings and terrain category,on the interference factors and derives relevant regression results for the interference factors.展开更多
Under the external AC and DC electric field, the effective response of nonlinear spherical coated composites, which obey the constitutive relation of electric displaeement and electric field, is investigated in the di...Under the external AC and DC electric field, the effective response of nonlinear spherical coated composites, which obey the constitutive relation of electric displaeement and electric field, is investigated in the dilute limit by using the perturbation method. The local potentials in inclusion and host regions are derived at all harmonics. Moreover, the formulae of the effective linear and nonlinear responses are given in the dilute limit.展开更多
There are some new results about photovoltaic transient response in the new effect. We suggest a theoretical model to explain the effect reasonably. The theoretical calculation results agree with that in experiments.
The effective dielectric response of linear composites containing graded material is investigated under an applied electric field E_0.For the cylindrical inclusion with gradient dielectric function,ει(r)=b+cr,random...The effective dielectric response of linear composites containing graded material is investigated under an applied electric field E_0.For the cylindrical inclusion with gradient dielectric function,ει(r)=b+cr,randomly embedded in a host with dielectric constant εm,we have obtained the exact solution of local electric potential of the composite media regions,which obeys a linear constitutive relation D=εE,using hypergeometric function.In dilute limit,we have derived the effective dielectric response of the linear composite media.Furthermore,for larger volume fraction,the formulas of effective dielectric response of the graded composite media are given.展开更多
An effective nonlinear response of a nonlinear composite with spherical coated inclusions randomly embedded in a host medium under the action of an external AC electric field, Ea= E1 sin（wt） ＋ E3 sin（3wt）, is inv...An effective nonlinear response of a nonlinear composite with spherical coated inclusions randomly embedded in a host medium under the action of an external AC electric field, Ea= E1 sin（wt） ＋ E3 sin（3wt）, is investigated using a perturbation method. The local potentials of the composite at higher harmonics are given both in the region of local inclusion particles and in the local host region under the external AC electric field. All effective nonlinear responses of the composite and the relationship between the effective nonlinear responses at the fundamental frequency and third harmonics are also studied for spherical coated inclusion in a dilute limit.展开更多
Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhi...Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.展开更多
The perturbation method is used to study the localization of electric field distribution and the effective nonlinear response of graded composites under an external alternating-current（AC） and direct-current（DC） e...The perturbation method is used to study the localization of electric field distribution and the effective nonlinear response of graded composites under an external alternating-current（AC） and direct-current（DC） electric field E app = E 0（1 ＋ sin ωt）.The dielectric profile of the cylindrical inclusions is modeled by function ε i（r） = C k r k（r ≤ a）,where r is the radius of the cylindrical inclusion,and C k,k,a are parameters.In the dilute limit,the local potentials and the effective nonlinear responses at all harmonics are derived.Meanwhile,the general effective nonlinear responses are also derived and compared with the effective nonlinear responses at harmonics under the AC and DC external field.It is found that the effective nonlinear AC and DC responses at harmonics can be calculated by those of the general effective nonlinear of the graded composites under the external DC electric field.Moreover,the obtained local electrical fields show that the electrical field distribution in the cylindrical inclusions is controllable,and the maximum of the electric field inside the cylinder is at its center.展开更多
For higher concentration of inclusions, an effective medium approximation （EMA） method is used to investigate the bulk effective response of weakly nonlinear composites, which are subject to the constitutive relatio...For higher concentration of inclusions, an effective medium approximation （EMA） method is used to investigate the bulk effective response of weakly nonlinear composites, which are subject to the constitutive relation of electric displacement and electric field, Dα = εαE ＋Xα｜E｜^2 E. As an example of three dimensions, under the external AC and DC electric fields Eapp = Eα（1 ＋ sinωt）, we have derived the general effective nonh＇near response of composites by the EMA method for higher concentration of spherical inclusions. Furthermore, the effective nonlinear responses at harmonics are predicted.展开更多
Transformation fieM method （TFM） is developed to estimate the anisotropic dielectric properties of crystal composites having arbitrary shapes and dielectric properties of crystal inclusions, whose principal dielectr...Transformation fieM method （TFM） is developed to estimate the anisotropic dielectric properties of crystal composites having arbitrary shapes and dielectric properties of crystal inclusions, whose principal dielectric axis are different from those of anisotropic crystal matrix. The complicated boundary-value problem caused by inclusion shapes is circumvented by introducing a transformation electric field into the crystal composites regions, and the effective anisotropic dielectric responses are formulated in terms of the transformation field. Furthermore, the numerical results show that the effective anisotropie dielectric responses of crystal composites periodically vary as a function of the rotating angle between the principal dielectric axes of inclusion and matrix crystal materials. It is found that at larger inclusion volume fraction the inclusion shapes induce profound effect on the effective anisotropic dielectric responses.展开更多
Epilepsy is a neurodegenerative disease that interrupts the normal electrical activity of the brain and promotes abnormal wiring in this organ.Epileptic seizures are often associated with significant changes in the fu...Epilepsy is a neurodegenerative disease that interrupts the normal electrical activity of the brain and promotes abnormal wiring in this organ.Epileptic seizures are often associated with significant changes in the functioning of the autonomic nervous system(ANS).展开更多
This paper uses the perturbation method to study effective response of nonlinear cylindrical coated composites. Under the external AC and DC electric field Ea （1 ＋sin ωt）, the local potentials of composites at all...This paper uses the perturbation method to study effective response of nonlinear cylindrical coated composites. Under the external AC and DC electric field Ea （1 ＋sin ωt）, the local potentials of composites at all harmonic frequencies are induced. An effective nonlinear response to composite is given for the cylindrical coated inclusions in the dilute limit.展开更多
By using the perturbation method, effective nonlinear direct current （DC） and alternating current （AC） responses of nonlinear composites with spherical coated inclusions randomly embedded in a host medium are stud...By using the perturbation method, effective nonlinear direct current （DC） and alternating current （AC） responses of nonlinear composites with spherical coated inclusions randomly embedded in a host medium are studied under the action of an external electric field Ea = E0 ＋ E1 sinωt ＋ E3 sin 3ωt with different amplitudes and frequencies. The local potentials of composites at all harmonics are given in the inclusion particles and the host regions. All effective nonlinear responses to composites and the relationship between the effective nonlinear responses at all harmonics are also deduced for the spherical coated inclusions in a dilute limit.展开更多
The explicit finite element analysis method combined with the artificial transmitting boundary theory is performed to evaluate the adjacent terrain effects on ground motion,and the influence of the distance between ad...The explicit finite element analysis method combined with the artificial transmitting boundary theory is performed to evaluate the adjacent terrain effects on ground motion,and the influence of the distance between adjacent terrains on the topographical amplification effects on ground motion is studied. The results show that:( 1) Compared to the case of a single hill,the presence of adjacent hills has little effect on the shape of the spectral ratio curve,but has a significant effect on the value of spectral ratio,which is dependent on the locations of observation points.( 2) The presence of adjacent hills has a greater effect on high-frequency ground motion,and with the increase of the distance between adjacent hills,such an effect weakens gradually,and the effect of the composite topography combined with multiple hills on ground motion gradually approaches that of a single hill.展开更多
The problem of soil pollution has not only destroyed the balance of the whole nature and ecological system, but also caused danger to human safety. The state must determine the important position of the eco-environmen...The problem of soil pollution has not only destroyed the balance of the whole nature and ecological system, but also caused danger to human safety. The state must determine the important position of the eco-environmental protection inspector to ensure the efficient implementation of the states responsibility for the prevention and control of soil pollution, so as to prevent all policies, measures and systems from becoming formalistic and thus promote the process of social and economic transformation and upgrading in China. The full text elaborated the current working condition of the soil pollution control deployment, analyzed the characteristics of comprehensively implementing the land control legislation, explored the construction approach of the soil pollution control system, and discussed the countermeasures of promoting the effective implementation of the soil pollution control responsibility by the ecological environment inspector, which provided reference for the actual work.展开更多
This study presents a neural network-based model for predicting linear quadratic regulator(LQR)weighting matrices for achieving a target response reduction.Based on the expected weighting matrices,the LQR algorithm is...This study presents a neural network-based model for predicting linear quadratic regulator(LQR)weighting matrices for achieving a target response reduction.Based on the expected weighting matrices,the LQR algorithm is used to determine the various responses of the structure.The responses are determined by numerically analyzing the governing equation of motion using the state-space approach.For training a neural network,four input parameters are considered:the time history of the ground motion,the percentage reduction in lateral displacement,lateral velocity,and lateral acceleration,Output parameters are LQR weighting matrices.To study the effectiveness of an LQR-based neural network(LQRNN),the actual percentage reduction in the responses obtained from using LQRNN is compared with the target percentage reductions.Furthermore,to investigate the efficacy of an active control system using LQRNN,the controlled responses of a system are compared to the corresponding uncontrolled responses.The trained neural network effectively predicts weighting parameters that can provide a percentage reduction in displacement,velocity,and acceleration close to the target percentage reduction.Based on the simulation study,it can be concluded that significant response reductions are observed in the active-controlled system using LQRNN.Moreover,the LQRNN algorithm can replace conventional LQR control with the use of an active control system.展开更多
To clarify the function effect of spectrum and linear polarization-coupled light on locusts’induction,determine the influence factors of linearly polarized light on locusts’polartactic characteristics,construct the ...To clarify the function effect of spectrum and linear polarization-coupled light on locusts’induction,determine the influence factors of linearly polarized light on locusts’polartactic characteristics,construct the technical characteristics of locusts’polarization induction,and develop locusts’polartactic induction photo-source,this study investigated the functional influence of spectral light and linear polarization-coupled light on locust phototactic and polartactic behavior.A linearly polarized light source system was used to determine the polartactic response of locusts induced by different linearly polarized vectors under normal light conditions.The results demonstrated that,within the context of spectral and linear polarization-coupled light,the visual response sensitivity of locusts was related to the spectral light intensity,being highest in response to orange light intensity.The visual aggregation and selective sensitivities of locusts were both influenced by spectral irradiation distance,with the violet spectrum inducing the strongest sensitivity in both cases.The polartactic chord function tuning response characteristics at different angles(0°-360°)were associated with linear polarization spectrum attributes.The polartactic response of locusts was related to changes in visual sensitivity resulting from the distance from the linear polarization light source,being optimal in response to the orange spectrum,whereas the violet spectrum induced the optimal visual and polartactic aggregation sensitivities.Furthermore,the specificity of chord function tuning response characteristics with periodic vector variations in a heterogeneous spectrum showed significant changes.An orange spectrum vector mode led to the most pronounced changes in response,whereas the violet spectrum vector mode exhibited the most significant changes in chord function properties.These variations in chord function and period induced by spectrum impacted the functional effect of linear polarization vector modes and reset the sensitive vector of locust polarization vision.Specifically,under the orange spectrum,locusts exhibited the highest polartactic response sensitivity at 330°vector,whereas,under the violet spectrum,the polartactic aggregation sensitivity was most pronounced at 30°vector,and visual trend sensitivity was optimal at 120°vector.Our results provide theoretical support for the study of the specific sensitivity nature of locust phototactic and polartactic behaviors,and the construction of a mechanism for inducing the polarization spectrum in locusts.展开更多
This study investigated the effects of polarized and spectral light interactions on locust polarotaxic behavior and elucidated the regulatory mechanisms of polarized and spectral lights.Locust visual response effect w...This study investigated the effects of polarized and spectral light interactions on locust polarotaxic behavior and elucidated the regulatory mechanisms of polarized and spectral lights.Locust visual response effect was investigated using a combined light source system comprising linear detection polarization violet light with various spectrum lights and a response device to explore the interaction mechanism of polarized and spectral lights on locust visual sensitivity characteristics and the specific sensitivity of locust phototaxis and polartaxis.Results indicated that the polarized vector sensitivity of locusts was related to combined light intensity,showing high visual response sensitivity at 0°and 180°under 1000 lx,whereas under rated illumination(150 mW/cm^(2)),the coupled spectrum attributes induced changes in the locusts’sensitive vectors.UV,violet,and blue lights enhanced the sensitivity at 90°and 270°,and green and orange lights did so at 0°and 180°.Moreover,UV and violet lights enhanced the aggregation and trend sensitivity at 210°and 30°,blue,green and orange lights induced high sensitivity at 0°and 180°.Under increasing illumination,the enhanced effect of light intensity on aggregation sensitivity under blue,green,and orange spectra and on trend sensitivity under orange spectra at 90°and 270°were highly pronounced because of the interaction between heterogeneous spectrum illumination and linear detection polarization vector illumination.Meanwhile,the spectral attribute determined the locust visual response effect,which was affected by the linear detection polarization vector.When illumination increased to rated illumination,coupled light intensity induced a specific vector sensitivity related to optical distance,showing the strongest response sensitivity to 180°under orange spectra and the strongest aggregation and trend sensitivity to 210°under violet spectra due to the interplay of polarization degree,coupling light intensity,and specific vision sensitivity caused by partially polarized light.Then,the locust visual response effect was improved by utilizing the enhancement effect of polarized violet light coupled with violet light at a close range and the inductive effect of polarized violet light coupled with orange light at a long distance,which provide theoretical support for understanding locust polarotactic orientation mechanisms,facilitate the development of polarization induced light sources for attracting locusts.展开更多
This paper addresses joint wind-wave induced dynamic responses of a semi-type offshore floating wind turbine（OFWT） under normal states and fault event conditions. The analysis in this paper is conducted in time doma...This paper addresses joint wind-wave induced dynamic responses of a semi-type offshore floating wind turbine（OFWT） under normal states and fault event conditions. The analysis in this paper is conducted in time domain, using an aero-hydro-servo-elastic simulation code-FAST. Owing to the unique viscous features of the reference system, the original viscous damping model implemented in FAST is replaced with a quadratic one to gain an accurate capture of viscous effects. Simulation cases involve free-decay motion in still water, steady motions in the presence of regular waves and wind as well as dynamic response in operational sea states with and without wind. Simulations also include the cases for transient responses induced by fast blade pitching after emergency shutdown. The features of platform motions, local structural loads and a typical mooring line tension force under a variety of excitations are obtained and investigated.展开更多
In this paper, a novel magnetoelectric（ME） composite structure is proposed, and the ME response in the structure is measured at the bias magnetic field up to 2000 Oe（1 Oe = 79.5775 A·m^（-1）） and the excitat...In this paper, a novel magnetoelectric（ME） composite structure is proposed, and the ME response in the structure is measured at the bias magnetic field up to 2000 Oe（1 Oe = 79.5775 A·m^（-1）） and the excitation frequency of alternating magnetic field ranging from 1 kHz to 200 kHz. The ME voltage of each PZT layer is detected. According to the measurement results, the phase differences are observed among three channels and the multi-peak phenomenon appears in each channel. Meanwhile, the results show that the ME structure can stay a relatively high ME response within a wide bandwidth.Besides, the hysteretic loops of three PZT layers are observed. When the frequency of alternating current（AC） magnetic field changes, the maximum value of ME coefficient appears in different layers due to the multiple vibration modes of the structure. Moreover, a finite element analysis is performed to evaluate the resonant frequency of the structure, and the theoretical calculating results accord well with the experimental results. The experiment results suggest that the proposed structure may be a good candidate for designing broadband magnetic field sensors.展开更多
Tailings impoundments can potentially collapse due to damage caused by earthquakes,which has frequently occurred around the world.This study takes the proposed valley type tailings impoundment in Yunnan as the researc...Tailings impoundments can potentially collapse due to damage caused by earthquakes,which has frequently occurred around the world.This study takes the proposed valley type tailings impoundment in Yunnan as the research object to analyze the dynamic response behavior under earthquake action with both numerical simulation and physical model test(1:300).The results of both tests show that the dynamic response of the valley type tailings impoundment is characterized by"medium stiffness effect",in other words,in a certain range,the"softer"the unsaturated tailings sand is,the more energy it can dissipate,which leads the decrease of the value of the acceleration amplification factor.In addition,the peak acceleration of the monitoring points increases with the vertical elevation,which indicates that the"elevation amplification effect"exists in the tailings impoundment dynamic response.The middle part of the outer side of the raised embankment reacts more sensitive than the crest,which is similar to the slope dynamic response.The starter dam reacts sensitively under the earthquake excitation,which should be given more attention during the seismic design.The dynamic response rules reflected by the numerical simulation are consistent with the results monitored on the physical model test,although there are some differences between their values.The dynamic response rules of the valley type tailings impoundment can provide basis for the design of the similar projects in this region.展开更多
基金supported by the National Natural Science Foundation of China (90715040)
文摘Most previous investigations on interference effects of tall buildings under wind actions focused on the wind induced interference effects between two buildings,and the interference effects of three or more buildings have seldom been studied so far due to the huge workload involved in experiments and data processing.In this paper,mean and dynamic force/response interference effects and peak wind pressure interference effects of two and three tall buildings,especially the three-building configuration,are investigated through a series of wind tunnel tests on typical tall building models using high frequency force balance technique and wind pressure measurements.Furthermore,the present paper focuses on the effects of parameters,including breadth ratio and height ratio of the buildings and terrain category,on the interference factors and derives relevant regression results for the interference factors.
文摘Under the external AC and DC electric field, the effective response of nonlinear spherical coated composites, which obey the constitutive relation of electric displaeement and electric field, is investigated in the dilute limit by using the perturbation method. The local potentials in inclusion and host regions are derived at all harmonics. Moreover, the formulae of the effective linear and nonlinear responses are given in the dilute limit.
文摘There are some new results about photovoltaic transient response in the new effect. We suggest a theoretical model to explain the effect reasonably. The theoretical calculation results agree with that in experiments.
文摘The effective dielectric response of linear composites containing graded material is investigated under an applied electric field E_0.For the cylindrical inclusion with gradient dielectric function,ει(r)=b+cr,randomly embedded in a host with dielectric constant εm,we have obtained the exact solution of local electric potential of the composite media regions,which obeys a linear constitutive relation D=εE,using hypergeometric function.In dilute limit,we have derived the effective dielectric response of the linear composite media.Furthermore,for larger volume fraction,the formulas of effective dielectric response of the graded composite media are given.
基金Project supported by the Natural Science Foundation of Inner Mongolia,China (Grant No.200711020116)the Open Fund of the Key Laboratory of Ocean Circulation and Waves,Chinese Academy of Sciences (Grant No.KLOCAW0805)+1 种基金the Research Fund of Higher Education of Inner Mongolia,China (Grant No.NJ09066)the National Natural Science Foundation for Young Scientists of China (Grant No.40806008)
文摘An effective nonlinear response of a nonlinear composite with spherical coated inclusions randomly embedded in a host medium under the action of an external AC electric field, Ea= E1 sin（wt） ＋ E3 sin（3wt）, is investigated using a perturbation method. The local potentials of the composite at higher harmonics are given both in the region of local inclusion particles and in the local host region under the external AC electric field. All effective nonlinear responses of the composite and the relationship between the effective nonlinear responses at the fundamental frequency and third harmonics are also studied for spherical coated inclusion in a dilute limit.
文摘Human lymphocytes pre-exposed to 10 mGy or 50 mGy of X-rays become less sensitive to subsequent large dose irradiation, exhibited lower rate of chromosome aberration than expected. This adaptive response could be inhibited by cycloheximide, a protein synthesis inhibitor for successive 2 h period ranging from 0.5h before to 4h after the low dose exposure, indicating that the adaptive response was directly related with the protein synthesis.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.40876094 and JQ10974106)the National High Technology Research and Development Program of China(Grant Nos.2009AA09Z102 and 2008AA09A403)+1 种基金the Excellent Youth Fundation of Shandong Scientific Committee,China(Grant No.JQ201018)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2009AZ002)
文摘The perturbation method is used to study the localization of electric field distribution and the effective nonlinear response of graded composites under an external alternating-current（AC） and direct-current（DC） electric field E app = E 0（1 ＋ sin ωt）.The dielectric profile of the cylindrical inclusions is modeled by function ε i（r） = C k r k（r ≤ a）,where r is the radius of the cylindrical inclusion,and C k,k,a are parameters.In the dilute limit,the local potentials and the effective nonlinear responses at all harmonics are derived.Meanwhile,the general effective nonlinear responses are also derived and compared with the effective nonlinear responses at harmonics under the AC and DC external field.It is found that the effective nonlinear AC and DC responses at harmonics can be calculated by those of the general effective nonlinear of the graded composites under the external DC electric field.Moreover,the obtained local electrical fields show that the electrical field distribution in the cylindrical inclusions is controllable,and the maximum of the electric field inside the cylinder is at its center.
基金The project supported by National Natural Science Foundation of China under Grant Nos.40476026 and 10374026
文摘For higher concentration of inclusions, an effective medium approximation （EMA） method is used to investigate the bulk effective response of weakly nonlinear composites, which are subject to the constitutive relation of electric displacement and electric field, Dα = εαE ＋Xα｜E｜^2 E. As an example of three dimensions, under the external AC and DC electric fields Eapp = Eα（1 ＋ sinωt）, we have derived the general effective nonh＇near response of composites by the EMA method for higher concentration of spherical inclusions. Furthermore, the effective nonlinear responses at harmonics are predicted.
基金Supported by the Centre for Smart Materials of the Hong Kong Polytechnic University and a RGC grant PolyU5015/06P (internal code B-Q996) of the HKSAR, the NSFC under Grant No. 40876094National 863 Project under Grant Nos. 2009AA09Z102 and 2008AA09A403
文摘Transformation fieM method （TFM） is developed to estimate the anisotropic dielectric properties of crystal composites having arbitrary shapes and dielectric properties of crystal inclusions, whose principal dielectric axis are different from those of anisotropic crystal matrix. The complicated boundary-value problem caused by inclusion shapes is circumvented by introducing a transformation electric field into the crystal composites regions, and the effective anisotropic dielectric responses are formulated in terms of the transformation field. Furthermore, the numerical results show that the effective anisotropie dielectric responses of crystal composites periodically vary as a function of the rotating angle between the principal dielectric axes of inclusion and matrix crystal materials. It is found that at larger inclusion volume fraction the inclusion shapes induce profound effect on the effective anisotropic dielectric responses.
基金supported by the Research Fund of the Erciyes University(TSD-09-1039)
文摘Epilepsy is a neurodegenerative disease that interrupts the normal electrical activity of the brain and promotes abnormal wiring in this organ.Epileptic seizures are often associated with significant changes in the functioning of the autonomic nervous system(ANS).
文摘This paper uses the perturbation method to study effective response of nonlinear cylindrical coated composites. Under the external AC and DC electric field Ea （1 ＋sin ωt）, the local potentials of composites at all harmonic frequencies are induced. An effective nonlinear response to composite is given for the cylindrical coated inclusions in the dilute limit.
基金Project supported by the Natural Science Foundation of Inner Mongolia,China (Grant No. 2011MS0113)the Talent Foundation of Inner Mongolia (2010),China
文摘By using the perturbation method, effective nonlinear direct current （DC） and alternating current （AC） responses of nonlinear composites with spherical coated inclusions randomly embedded in a host medium are studied under the action of an external electric field Ea = E0 ＋ E1 sinωt ＋ E3 sin 3ωt with different amplitudes and frequencies. The local potentials of composites at all harmonics are given in the inclusion particles and the host regions. All effective nonlinear responses to composites and the relationship between the effective nonlinear responses at all harmonics are also deduced for the spherical coated inclusions in a dilute limit.
基金sponsored by the China National Special Fund for Earthquake Scientific Research in Public Interest(Grant No.201408002)Earthquake Science and Technology Spark Plan of China Earthquake Administration(XH14061Y)
文摘The explicit finite element analysis method combined with the artificial transmitting boundary theory is performed to evaluate the adjacent terrain effects on ground motion,and the influence of the distance between adjacent terrains on the topographical amplification effects on ground motion is studied. The results show that:( 1) Compared to the case of a single hill,the presence of adjacent hills has little effect on the shape of the spectral ratio curve,but has a significant effect on the value of spectral ratio,which is dependent on the locations of observation points.( 2) The presence of adjacent hills has a greater effect on high-frequency ground motion,and with the increase of the distance between adjacent hills,such an effect weakens gradually,and the effect of the composite topography combined with multiple hills on ground motion gradually approaches that of a single hill.
文摘The problem of soil pollution has not only destroyed the balance of the whole nature and ecological system, but also caused danger to human safety. The state must determine the important position of the eco-environmental protection inspector to ensure the efficient implementation of the states responsibility for the prevention and control of soil pollution, so as to prevent all policies, measures and systems from becoming formalistic and thus promote the process of social and economic transformation and upgrading in China. The full text elaborated the current working condition of the soil pollution control deployment, analyzed the characteristics of comprehensively implementing the land control legislation, explored the construction approach of the soil pollution control system, and discussed the countermeasures of promoting the effective implementation of the soil pollution control responsibility by the ecological environment inspector, which provided reference for the actual work.
基金Dean Research&Consultancy under Grant No.Dean (R&C)/2020-21/1155。
文摘This study presents a neural network-based model for predicting linear quadratic regulator(LQR)weighting matrices for achieving a target response reduction.Based on the expected weighting matrices,the LQR algorithm is used to determine the various responses of the structure.The responses are determined by numerically analyzing the governing equation of motion using the state-space approach.For training a neural network,four input parameters are considered:the time history of the ground motion,the percentage reduction in lateral displacement,lateral velocity,and lateral acceleration,Output parameters are LQR weighting matrices.To study the effectiveness of an LQR-based neural network(LQRNN),the actual percentage reduction in the responses obtained from using LQRNN is compared with the target percentage reductions.Furthermore,to investigate the efficacy of an active control system using LQRNN,the controlled responses of a system are compared to the corresponding uncontrolled responses.The trained neural network effectively predicts weighting parameters that can provide a percentage reduction in displacement,velocity,and acceleration close to the target percentage reduction.Based on the simulation study,it can be concluded that significant response reductions are observed in the active-controlled system using LQRNN.Moreover,the LQRNN algorithm can replace conventional LQR control with the use of an active control system.
基金supported by the Scientific and Technological Project of Henan Province,China(Grant No.242102111179,222102210116,222102320080)he Natural Science Foundation Project of Henan Province,China(Grant No.232300420024).
文摘To clarify the function effect of spectrum and linear polarization-coupled light on locusts’induction,determine the influence factors of linearly polarized light on locusts’polartactic characteristics,construct the technical characteristics of locusts’polarization induction,and develop locusts’polartactic induction photo-source,this study investigated the functional influence of spectral light and linear polarization-coupled light on locust phototactic and polartactic behavior.A linearly polarized light source system was used to determine the polartactic response of locusts induced by different linearly polarized vectors under normal light conditions.The results demonstrated that,within the context of spectral and linear polarization-coupled light,the visual response sensitivity of locusts was related to the spectral light intensity,being highest in response to orange light intensity.The visual aggregation and selective sensitivities of locusts were both influenced by spectral irradiation distance,with the violet spectrum inducing the strongest sensitivity in both cases.The polartactic chord function tuning response characteristics at different angles(0°-360°)were associated with linear polarization spectrum attributes.The polartactic response of locusts was related to changes in visual sensitivity resulting from the distance from the linear polarization light source,being optimal in response to the orange spectrum,whereas the violet spectrum induced the optimal visual and polartactic aggregation sensitivities.Furthermore,the specificity of chord function tuning response characteristics with periodic vector variations in a heterogeneous spectrum showed significant changes.An orange spectrum vector mode led to the most pronounced changes in response,whereas the violet spectrum vector mode exhibited the most significant changes in chord function properties.These variations in chord function and period induced by spectrum impacted the functional effect of linear polarization vector modes and reset the sensitive vector of locust polarization vision.Specifically,under the orange spectrum,locusts exhibited the highest polartactic response sensitivity at 330°vector,whereas,under the violet spectrum,the polartactic aggregation sensitivity was most pronounced at 30°vector,and visual trend sensitivity was optimal at 120°vector.Our results provide theoretical support for the study of the specific sensitivity nature of locust phototactic and polartactic behaviors,and the construction of a mechanism for inducing the polarization spectrum in locusts.
基金supported by the Scientific and Technological Project of Henan Province,China(Grant No.242102111179)the Natural Science Foundation Project of Henan Province,China(Grant No.232300420024).
文摘This study investigated the effects of polarized and spectral light interactions on locust polarotaxic behavior and elucidated the regulatory mechanisms of polarized and spectral lights.Locust visual response effect was investigated using a combined light source system comprising linear detection polarization violet light with various spectrum lights and a response device to explore the interaction mechanism of polarized and spectral lights on locust visual sensitivity characteristics and the specific sensitivity of locust phototaxis and polartaxis.Results indicated that the polarized vector sensitivity of locusts was related to combined light intensity,showing high visual response sensitivity at 0°and 180°under 1000 lx,whereas under rated illumination(150 mW/cm^(2)),the coupled spectrum attributes induced changes in the locusts’sensitive vectors.UV,violet,and blue lights enhanced the sensitivity at 90°and 270°,and green and orange lights did so at 0°and 180°.Moreover,UV and violet lights enhanced the aggregation and trend sensitivity at 210°and 30°,blue,green and orange lights induced high sensitivity at 0°and 180°.Under increasing illumination,the enhanced effect of light intensity on aggregation sensitivity under blue,green,and orange spectra and on trend sensitivity under orange spectra at 90°and 270°were highly pronounced because of the interaction between heterogeneous spectrum illumination and linear detection polarization vector illumination.Meanwhile,the spectral attribute determined the locust visual response effect,which was affected by the linear detection polarization vector.When illumination increased to rated illumination,coupled light intensity induced a specific vector sensitivity related to optical distance,showing the strongest response sensitivity to 180°under orange spectra and the strongest aggregation and trend sensitivity to 210°under violet spectra due to the interplay of polarization degree,coupling light intensity,and specific vision sensitivity caused by partially polarized light.Then,the locust visual response effect was improved by utilizing the enhancement effect of polarized violet light coupled with violet light at a close range and the inductive effect of polarized violet light coupled with orange light at a long distance,which provide theoretical support for understanding locust polarotactic orientation mechanisms,facilitate the development of polarization induced light sources for attracting locusts.
基金financially supported by the National Natural Science Foundation of China(Grant No.51239007)
文摘This paper addresses joint wind-wave induced dynamic responses of a semi-type offshore floating wind turbine（OFWT） under normal states and fault event conditions. The analysis in this paper is conducted in time domain, using an aero-hydro-servo-elastic simulation code-FAST. Owing to the unique viscous features of the reference system, the original viscous damping model implemented in FAST is replaced with a quadratic one to gain an accurate capture of viscous effects. Simulation cases involve free-decay motion in still water, steady motions in the presence of regular waves and wind as well as dynamic response in operational sea states with and without wind. Simulations also include the cases for transient responses induced by fast blade pitching after emergency shutdown. The features of platform motions, local structural loads and a typical mooring line tension force under a variety of excitations are obtained and investigated.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11702120,11372120,11421062,and 11572143)the Fundamental Research Funds for the Central Universities,China(Grant No.lzujbky-2016-106)
文摘In this paper, a novel magnetoelectric（ME） composite structure is proposed, and the ME response in the structure is measured at the bias magnetic field up to 2000 Oe（1 Oe = 79.5775 A·m^（-1）） and the excitation frequency of alternating magnetic field ranging from 1 kHz to 200 kHz. The ME voltage of each PZT layer is detected. According to the measurement results, the phase differences are observed among three channels and the multi-peak phenomenon appears in each channel. Meanwhile, the results show that the ME structure can stay a relatively high ME response within a wide bandwidth.Besides, the hysteretic loops of three PZT layers are observed. When the frequency of alternating current（AC） magnetic field changes, the maximum value of ME coefficient appears in different layers due to the multiple vibration modes of the structure. Moreover, a finite element analysis is performed to evaluate the resonant frequency of the structure, and the theoretical calculating results accord well with the experimental results. The experiment results suggest that the proposed structure may be a good candidate for designing broadband magnetic field sensors.
基金financially supported by project (Grant NO. U1502232, U1033601)-National Science Foundation of China-Yunnan Joint Fundproject (Grant NO. 20135314110005)-Research Fund for the Doctoral Program of Higher Education of China
文摘Tailings impoundments can potentially collapse due to damage caused by earthquakes,which has frequently occurred around the world.This study takes the proposed valley type tailings impoundment in Yunnan as the research object to analyze the dynamic response behavior under earthquake action with both numerical simulation and physical model test(1:300).The results of both tests show that the dynamic response of the valley type tailings impoundment is characterized by"medium stiffness effect",in other words,in a certain range,the"softer"the unsaturated tailings sand is,the more energy it can dissipate,which leads the decrease of the value of the acceleration amplification factor.In addition,the peak acceleration of the monitoring points increases with the vertical elevation,which indicates that the"elevation amplification effect"exists in the tailings impoundment dynamic response.The middle part of the outer side of the raised embankment reacts more sensitive than the crest,which is similar to the slope dynamic response.The starter dam reacts sensitively under the earthquake excitation,which should be given more attention during the seismic design.The dynamic response rules reflected by the numerical simulation are consistent with the results monitored on the physical model test,although there are some differences between their values.The dynamic response rules of the valley type tailings impoundment can provide basis for the design of the similar projects in this region.
