Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao)...Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao),wheat(Xiaomai),and jujube(Dazao),it functions to nourish the heart and calm the mind,harmonize the middle burner and regulate Qi,and alleviate urgency and restlessness.As its clinical application has expanded from traditional emotional disorders to neurological,endocrine,and various psychosomatic diseases,establishing a scientifically precise quality control system and deeply elucidating its pharmacodynamic material basis and mechanism of action have become critical tasks.Modern analytical methods,typified by chromatography,spectroscopy,and their hyphenated techniques,with their high sensitivity,high resolution,and powerful substance characterization capabilities,have become the core driving force for standardizing the quality control and modernizing the clinical application research of this formula.This paper systematically reviews the progress of the aforementioned analytical techniques and chemometrics in interpreting the chemical composition,establishing fingerprint profiles,controlling process quality,and researching the pharmacodynamic material basis of Ganmai Dazao Decoction.Furthermore,it discusses integrated approaches combining analytical techniques with pharmacology and clinical medicine to reveal mechanisms of action and explore therapeutic biomarkers.Finally,it provides an outlook on future directions and challenges,including technological integration and innovation,standardization of whole-process quality control systems,and evidence-based research aimed at internationalization.展开更多
Energy storage-equipped photovoltaic(PV-storage)systems can meet frequency regulation requirements under various operating conditions,and their coordinated support for grid frequency has become a future trend.To addre...Energy storage-equipped photovoltaic(PV-storage)systems can meet frequency regulation requirements under various operating conditions,and their coordinated support for grid frequency has become a future trend.To address frequency stability issues caused by low inertia and weak damping,this paper proposes a multi-timescale frequency regulation coordinated control strategy for PV-storage integrated systems.First,a self-synchronizing control strategy for grid-connected inverters is designed based on DC voltage dynamics,enabling active inertia support while transmitting frequency variation information.Next,an energy storage inertia support control strategy is developed to enhance the frequency nadir,and an active frequency support control strategy for PV system considering a frequency regulation deadband is proposed,where the deadband value is determined based on the power regulation margin of synchronous generators,allowing the PV-storage system to adaptively switch between inertia support and primary frequency regulation under different disturbance conditions.This approach ensures system frequency stability while fully leveraging the regulation capabilities of heterogeneous resources.Finally,the real-time digital simulation results of the PV-storage integrated system demonstrate that,compared to existing control methods,the proposed strategy effectively reduces the rate of change of frequency and improves the frequency nadir under various disturbance scenarios,verifying its effectiveness.展开更多
Traditional dynamic analysis of mechanical structures,often limited to individual beams or plates,fails to fully capture their dynamic behaviors.In systems where space and mass are constrained,such as the battery supp...Traditional dynamic analysis of mechanical structures,often limited to individual beams or plates,fails to fully capture their dynamic behaviors.In systems where space and mass are constrained,such as the battery support structures in electric aircraft,conventional absorbers and isolators are insufficient for effective vibration control.This study simplifies the battery support structure of electric aircraft as an integrated composite beam consisting of three interconnected beams,and investigated its structural dynamics properties and nonlinear vibration control under thermal conditions caused by battery heat.The nonlinear vibration control is performed using the Nitinol steel wire ropes(Ni Ti-ST),with nonlinear damping properties.The natural frequencies of system are determined using the Rayleigh-Ritz technique.Theoretical results are validated through both Finite Element Method(FEM)and hammer tests.Moreover,the dynamic equations are derived using the Lagrange method and discretized via the Galerkin Truncation Method(GTM).The Harmonic Balance Method(HBM)is used to evaluate the vibration responses of the integrated model,with further verification through the Runge-Kutta Method(RKM).The experiments are conducted to corroborate the theoretical analysis.The results show that the system frequency changes in stages with the increase of the stiffness of the integrated composite beam connection.Especially in the case of varying environments,as the temperature increases,the frequency of system will first increase to a certain maximum value and then gradually decrease.Furthermore,the NiTi-ST effectively reduces vibration in the integrated composite beam,particularly under varying temperatures and external excitations.展开更多
As unmanned underwater vehicles (UUVs) are increasingly designed to perform long-duration missions in highly complex and often extreme environments, traditional design methods face significant and growing challenges^(...As unmanned underwater vehicles (UUVs) are increasingly designed to perform long-duration missions in highly complex and often extreme environments, traditional design methods face significant and growing challenges^([1,2]).展开更多
In this study,artificial neural networks(ANNs)were implemented to determine design parameters for an impressed current cathodic protection(ICCP)prototype.An ASTM A36 steel plate was tested in 3.5%NaCl solution,seawate...In this study,artificial neural networks(ANNs)were implemented to determine design parameters for an impressed current cathodic protection(ICCP)prototype.An ASTM A36 steel plate was tested in 3.5%NaCl solution,seawater,and NS4 using electrochemical impedance spectroscopy(EIS)to monitor the evolution of the substrate surface,which affects the current required to reach the protection potential(Eprot).Experimental data were collected as training datasets and analyzed using statistical methods,including box plots and correlation matrices.Subsequently,ANNs were applied to predict the current demand at different exposure times,enabling the estimation of electrochemical parameters(limiting voltage values)that can be used to optimize a self-regulating ICCP system.The obtained electrochemical parameters were then used,through Particle Swarm Optimization(PSO),to fine-tune an ANN-based proportional-integral-derivative(PID)controller for the ICCP system.展开更多
[Objective] This study aimed to screen the effective pesticide for control-ling Parathrene regalis Butler. [Method] By field trials, the effects of six kinds of commonly used pesticides on P. regalis were determined. ...[Objective] This study aimed to screen the effective pesticide for control-ling Parathrene regalis Butler. [Method] By field trials, the effects of six kinds of commonly used pesticides on P. regalis were determined. ln addition, different agri-cultural measures were employed to integrate control technologies. [Result] At the early occurrence stage of P. regalis, spraying 7.5g/hm2 5% emamectin benzoate EC, 13.5 g/hm2 2% avermectin EC and 25 g/hm2 2.5% lambda-cyhalothrin EC can ef-fectively control P. regalis. [Conclusion] This study provided reference for the pre-vention and control of P. regalis.展开更多
In this paper, the robust adaptive fuzzy tracking control problem is discussed for a class of perturbed strict-feedback nonlinear systems. The fuzzy logic systems in Mamdani type are used to approximate unknown nonlin...In this paper, the robust adaptive fuzzy tracking control problem is discussed for a class of perturbed strict-feedback nonlinear systems. The fuzzy logic systems in Mamdani type are used to approximate unknown nonlinear functions. A design scheme of the robust adaptive fuzzy controller is proposed by use of the backstepping technique. The proposed controller guarantees semi-global uniform ultimate boundedness of all the signals in the derived closed-loop system and achieves the good tracking performance. The possible controller singularity problem which may occur in some existing adaptive control schemes with feedback linearization techniques can be avoided. In addition, the number of the on-line adaptive parameters is not more than the order of the designed system. Finally, two simulation examples are used to demonstrate the effectiveness of the proposed control scheme.展开更多
An agile missile with tail fins and pulse thrusters has continuous and discontinuous control inputs.This brings certain difficulty to the autopilot design and stability analysis.Indirect robust control via Theta-D tec...An agile missile with tail fins and pulse thrusters has continuous and discontinuous control inputs.This brings certain difficulty to the autopilot design and stability analysis.Indirect robust control via Theta-D technique is employed to handle this problem.An acceleration tracking system is formulated based on the nonlinear dynamics of agile missile.Considering the dynamics of actuators,there is an error between actual input and computed input.A robust control problem is formed by treating the error as input uncertainty.The robust control is equivalent to a nonlinear quadratic optimal control of the nominal system with a modified performance index including uncertainty bound.Theta-D technique is applied to solve the nonlinear optimal control problem to obtain the final control law.Numerical results show the effectiveness and robustness of the proposed strategy.展开更多
The main disease species on poplar are introduced in this paper. The main content of the integrated control technique on poplar diseases is summarized:(1) Forecast technique based on the initial disease and provention...The main disease species on poplar are introduced in this paper. The main content of the integrated control technique on poplar diseases is summarized:(1) Forecast technique based on the initial disease and provention factors. (2) Control index is established, based on the relationship among the disease index, height of tree, diameter grade and the loss rate of volume. (3) Five fine varieties are selected according to three integrated indexes of host, such as resistance, volume growth and form ratio; They are 613 (Poulus alba ×P. berolinensis), A15 (P. xiaohei × P. euramericana CV. Polska-15A), A98 (P.xiaohei×(P. simonii×P. nigra) CV. A98), A102 (P. xiaohei) × (P. simonee × P. nigra) CV. A102), L2 (P. simonii × P nigra var. italica) in northeast Chnia. (4) Sivicultural control is known as the main protection measures, combined with chemical control and biocontrol,based on the disease forecast and control index by tracing the whole process of forest production.展开更多
The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling diges...The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling digestion status and energy consumption. Very good performances and technical and technical and economical figures for digestion process have been obtained by carefully applying these comprehensive control techniques in Pingguo alumina refinery.展开更多
Aimed at the disadvantages of secondary damage to oil layers caused by the conventional bull-heading water control technique, a thermo-sensitive temporary plugging agent for water control was synthesized by water solu...Aimed at the disadvantages of secondary damage to oil layers caused by the conventional bull-heading water control technique, a thermo-sensitive temporary plugging agent for water control was synthesized by water solution polymerization and applied in the field with a new secondary temporary plugging technique. The optimization and performance evaluation of thermo-sensitive temporary plugging agent were carried out through laboratory experiments. The optimized formula is as follows:(6%-8%) acrylamide +(0.08%-0.12%) ammonium persulfate +(1.5%-2.0%) sepiolite +(0.5%-0.8%) polyethylene glycol diacrylate. The thermo-sensitive temporary plugging agent is suitable for formation temperatures of 70-90 ?C, it has high temporary plugging strength(5-40 k Pa), controllable degradation time(1-15 d), the apparent viscosity after degradation of less than 100 m Pa?S and the permeability recovery value of simulated cores of more than 95%. Based on the research results, secondary temporary plugging technique was used in a horizontal well in the Jidong Oilfield. After treatment, the well saw a drop of water cut to 27%, and now it has a water cut of 67%, its daily increased oil production was 4.8 t, and the cumulative oil increment was 750 t, demonstrating that the technique worked well in controlling water production and increasing oil production.展开更多
[Objective] The aim was to investigate the effects of DPC chemical controlling technique on agronomic traits, yield and quality of machine-harvested cotton in the Yellow River Valley of China, and clarify the reasonab...[Objective] The aim was to investigate the effects of DPC chemical controlling technique on agronomic traits, yield and quality of machine-harvested cotton in the Yellow River Valley of China, and clarify the reasonable control period and the application amount of DPC. [Method] The new machine-harvested cotton variety Hengmian HD008 was used as the test material, and 3 different DPC treatments were set. [Result] DPC significantly reduced plant height and branch length, reduced branch angle and leaf area, so the rational control can effectively shape the ideal plant type of machine-harvested cotton. DPC had significant effects on yield and yield components, and the proper amount of DPC could increase the number of bolls during hot days, the number bolls in autumn and the total number of bolls. It increased the boll weight and seed index, but decreased lint percentage decreased, and proper amount of DPC could increase the yield. DPC significantly increased the specific breaking strength of fibers, and proper control could improve the uniformity of fibers, but other indexes had no significant influence. [Conclusion] According to the requirements of machine harvest to the agronomic traits of cotton and the growth characteristics of cotton plant, chemical control could begin after floral bud emergence in cotton about every 10 d, and the spraying amount can be controlled according to the growth amount of the main stem. The daily growth amount of plant height should be controlled at 1.5-1.8 cm, and the plant height should be within 75-90 cm.展开更多
The inverted pendulum is a classic problem in dynamics and control theory and is widely used as a benchmark for testing control algorithms. It is unstable without control. The process is non linear and unstable with o...The inverted pendulum is a classic problem in dynamics and control theory and is widely used as a benchmark for testing control algorithms. It is unstable without control. The process is non linear and unstable with one input signal and several output signals. It is hence obvious that feedback of the state of the pendulum is needed to stabilize the pendulum. The aim of the study is to stabilize the pendulum such that the position of the carriage on the track is controlled quickly and accurately. The problem involves an arm, able to move horizontally in angular motion, and a pendulum, hinged to the arm at the bottom of its length such that the pendulum can move in the same plane as the arm. The conventional PID controller can be used for virtually any process condition. This makes elimination the offset of the proportional mode possible and still provides fast response. In this paper, we have modelled the system and studied conventional controller and LQR controller. It is observed that the LQR method works better compared to conventional controller.展开更多
Coal bed methane control with low permeability is a hot issue at present. The current status of coal bed methane control in China is introduced. The government-support policies on coal bed methane control are presente...Coal bed methane control with low permeability is a hot issue at present. The current status of coal bed methane control in China is introduced. The government-support policies on coal bed methane control are presented. This paper proposes the theories of methane control in depressurized mining, including methane extraction in depressurized mining, simultaneous mining technique of coal and methane without coal pillar, and circular overlying zone for high-efficiency methane extraction in coal seams with low permeability. The techniques of methane control and related instruments and equipments in China are introduced. On this basis, the problems related to coal bed methane control are addressed and further studies are pointed out.展开更多
A CMOS active mixer based on voltage control load technique which can operate at 1.0 V supply voltage was proposed, and its operation principle, noise and linearity analysis were also presented. Contrary to the conven...A CMOS active mixer based on voltage control load technique which can operate at 1.0 V supply voltage was proposed, and its operation principle, noise and linearity analysis were also presented. Contrary to the conventional Gilbert-type mixer which is based on RF current-commutating, the load impedance in this proposed mixer is controlled by the LO signal, and it has only two stacked transistors at each branch which is suitable for low voltage applications. The mixer was designed and fabricated in 0.18 tam CMOS process for 2.4 GHz ISM band applications. With an input of 2.44 GHz RF signal and 2.442 GHz LO signal, the measurement specifications of the proposed mixer are： the conversion gain （Gc） is 5.3 dB, the input-referred third-order intercept point （PIIP3） is 4.6 dBm, the input-referred 1 dB compression point （P1dB） is --7.4 dBm, and the single-sideband noise figure （NFSSB） is 21.7 dB.展开更多
Objective: To explore the clinical therapeutic effects and the mechanism on rheumatic arthritis(RA)treated with the combination of the instruments and techniques of acupuncture and moxibusiton.Methods: A total of 60 R...Objective: To explore the clinical therapeutic effects and the mechanism on rheumatic arthritis(RA)treated with the combination of the instruments and techniques of acupuncture and moxibusiton.Methods: A total of 60 RA patients were randomized into an observation group and a control group,30 cases in each one. In the control group, diclofenac sodium sustained release tablets were prescribed for oral administration, 0.3 g each time, twice a day, methotrexate tablets(MTX) for oral administration,10 mg each time, once a week and folic acid tablets for oral administration, 5 mg each time, once a week. In the observation group, besides the treatment with western medicines, simultaneously, the specific acupoints were selected and stimulated with the triple strong-stimulation therapy, in which, the strong bloodletting technique, the strong cupping technique and the strong moxibustion technique were combined together, with different instruments of acupuncture and moxibustion adopted. The treatment was given once every 3 days, consecutively for 10 times. In 30 days of treatment, the therapeutic effects were observed in the two groups. Separately, before and after treatment, the rheumatoid factors(RF),hypersensitive-C reactive protein(hs-CRP) and erythrocyte sedimentation rate(ESR), the scores of joint symptoms and physical signs as well as the disease activity score(DAS-28) were observed in the two groups.Results: Regarding RF, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 248.01 ± 79.81 vs 31.17 ± 29.01,the control group 254.11 ± 72.16 vs 66.42 ± 37.07, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05). Regarding hs-CRP, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 26.12 ± 9.22 vs 8.98 ± 7.66, the control group 23.18 ± 7.18 vs 16.01 ± 5.02, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05). Regarding ESR, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 30.56 ± 11.38 vs 12.58 ± 5.91,the control group 35.52 ± 9.67 vs 21.47 ± 6.91, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05). Regarding DAS-28, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 8.89 ± 2.01 vs 3.01 ± 0.74, the control group 8.14 ± 1.38 vs 4.12 ± 0.96, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05). Regarding the quantitative grading score of symptom, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 7.87 士 1.69 vs 3.82 ±1.96, the control group 7.77 ± 1.68 vs 5.01 ± 11.23, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05).The total effective rate was 96.67%(29/30) in the observation group and was 80.0%(24/30) in the control group, indicating the statistical significant difference between the two groups(P < 0.01).Conclusion: Based on western medications, the triple strong-stimulation therapy of acupuncture and moxibustion at specific acupoints significantly relieves the joint symptoms, reduces the inflammatory reaction indicators and improves the clinical therapeutic effects on RA in the patients.展开更多
Objective:To observe the differences of clinical effect and influence on joint function and inflammatory markers in joint fluid between stuck-needle technique and regular acupuncture in patients with knee osteoarthrit...Objective:To observe the differences of clinical effect and influence on joint function and inflammatory markers in joint fluid between stuck-needle technique and regular acupuncture in patients with knee osteoarthritis.Methods:Seventy-two patients with knee osteoarthritis were randomly divided into a stuck-needle technique group and a regular acupuncture group,with 36 cases in each one.The selection of acupoints,retaining time of needles,and treatment course were all the same in both groups.The visual analog scale(VAS)score,Lequesne index score,and the content of related inflammatory indexes in joint fluid before and after treatment were observed,and the therapeutic effect were evaluated.Results:After treatment,the VAS scores,Lequesne index scores,interleukin-1 beta(IL-1β),and the tumor necrosis factor a(TNF-α)of the two groups were all lower than those before treatment(all P<0.05).After treatment,the VAS scores,Lequesne index scores,IL-1β,and TNF-αof the stuck-needle technique group were all lower than those of the regular acupuncture group(all P<0.05).The total effective rate of the stuck-needle technique group was 96.97%(32/33),higher than 93.75%(30/32)of the regular acupuncture group(P<0.05).Conclusion:Stuck-needle technique can effectively relieve the pain and improve the joint functions,being more effective than regular acupuncture for the treatment of knee osteoarthritis.展开更多
Kiwifruit canker disease seriously affects the yield and quality of"Guichang"kiwifruit in Xiuwen County,Guizhou Province.In order to scientifically,safely,greenly and efficiently prevent and control the dise...Kiwifruit canker disease seriously affects the yield and quality of"Guichang"kiwifruit in Xiuwen County,Guizhou Province.In order to scientifically,safely,greenly and efficiently prevent and control the disease,theory was combined with prevention and control techniques to optimize existing prevention and control techniques,so as to improve the production yield and quality of kiwifruit.Specifically,biocontrol strains targeting local kiwifruit canker disease were screened,and reduced and mixed use of agrochemicals with improved efficiency was studied;and the effects and application techniques of disease resistance inducers and bioorganic fertilizers in inducing systemic disease resistance in kiwifruit trees were explored,and finally,an integrated green prevention and control scheme for kiwifruit canker disease that is suitable for kiwifruit production areas in Guizhou Province and has strong operability was proposed.This study provides technical support for green,efficient,standardized production technical services and sustainable and healthy development of kiwifruit industry.展开更多
In conjunction with general integral control, and synthesizing Singular perturbation and Equal ratio gain techniques, this paper proposes a new control design technique, named Power ratio gain technique, and then by L...In conjunction with general integral control, and synthesizing Singular perturbation and Equal ratio gain techniques, this paper proposes a new control design technique, named Power ratio gain technique, and then by Lyapunov method, theorem to ensure regionally as well as semi-globally asymptotic stability is established in terms of some bounded information. The highlight point is that it not only inherits all the essences of Singular perturbation and Equal ratio gain techniques but also makes up for their shortcomings, and then the conservatism of control input can be improved by compromising the Power ratio coefficients. Theoretical analysis, design example and simulation results show that Power ratio gain technique is a simple, practical and powerful tool to deal with the uncertain nonlinear system.展开更多
Reversible watermarking schemes for relational database are usually classified into two groups: robust schemes and fragile schemes. The main limitation of existing reversible fragile methods is that they cannot differ...Reversible watermarking schemes for relational database are usually classified into two groups: robust schemes and fragile schemes. The main limitation of existing reversible fragile methods is that they cannot differentiate between legal and malicious modifications. In this paper, we introduce a novel lossless semi-fragile scheme based on prediction-error expansion for content protection of relational database. In the proposed method, all attributes in a database relation are first classified according to their sensitivity to legitimate updates. Then, the watermark is embedded by expanding the prediction error of the two least significant digits of securely selected attributes. At watermark extraction, the proposed method has the ability to fully restore the original data while detecting and localizing tampering. The applicability of our method is demonstrated theoretically and experimentally.展开更多
文摘Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao),wheat(Xiaomai),and jujube(Dazao),it functions to nourish the heart and calm the mind,harmonize the middle burner and regulate Qi,and alleviate urgency and restlessness.As its clinical application has expanded from traditional emotional disorders to neurological,endocrine,and various psychosomatic diseases,establishing a scientifically precise quality control system and deeply elucidating its pharmacodynamic material basis and mechanism of action have become critical tasks.Modern analytical methods,typified by chromatography,spectroscopy,and their hyphenated techniques,with their high sensitivity,high resolution,and powerful substance characterization capabilities,have become the core driving force for standardizing the quality control and modernizing the clinical application research of this formula.This paper systematically reviews the progress of the aforementioned analytical techniques and chemometrics in interpreting the chemical composition,establishing fingerprint profiles,controlling process quality,and researching the pharmacodynamic material basis of Ganmai Dazao Decoction.Furthermore,it discusses integrated approaches combining analytical techniques with pharmacology and clinical medicine to reveal mechanisms of action and explore therapeutic biomarkers.Finally,it provides an outlook on future directions and challenges,including technological integration and innovation,standardization of whole-process quality control systems,and evidence-based research aimed at internationalization.
基金supported by the State Grid Corporation of China under Grant for Science and Technology Projects(No.SGNXJYOOZWJS2500029).
文摘Energy storage-equipped photovoltaic(PV-storage)systems can meet frequency regulation requirements under various operating conditions,and their coordinated support for grid frequency has become a future trend.To address frequency stability issues caused by low inertia and weak damping,this paper proposes a multi-timescale frequency regulation coordinated control strategy for PV-storage integrated systems.First,a self-synchronizing control strategy for grid-connected inverters is designed based on DC voltage dynamics,enabling active inertia support while transmitting frequency variation information.Next,an energy storage inertia support control strategy is developed to enhance the frequency nadir,and an active frequency support control strategy for PV system considering a frequency regulation deadband is proposed,where the deadband value is determined based on the power regulation margin of synchronous generators,allowing the PV-storage system to adaptively switch between inertia support and primary frequency regulation under different disturbance conditions.This approach ensures system frequency stability while fully leveraging the regulation capabilities of heterogeneous resources.Finally,the real-time digital simulation results of the PV-storage integrated system demonstrate that,compared to existing control methods,the proposed strategy effectively reduces the rate of change of frequency and improves the frequency nadir under various disturbance scenarios,verifying its effectiveness.
基金supported by the National Natural Science Foundation of China(No.12272240)the Liaoning Revitalization Talents Program,China(No.XLYC2203197)。
文摘Traditional dynamic analysis of mechanical structures,often limited to individual beams or plates,fails to fully capture their dynamic behaviors.In systems where space and mass are constrained,such as the battery support structures in electric aircraft,conventional absorbers and isolators are insufficient for effective vibration control.This study simplifies the battery support structure of electric aircraft as an integrated composite beam consisting of three interconnected beams,and investigated its structural dynamics properties and nonlinear vibration control under thermal conditions caused by battery heat.The nonlinear vibration control is performed using the Nitinol steel wire ropes(Ni Ti-ST),with nonlinear damping properties.The natural frequencies of system are determined using the Rayleigh-Ritz technique.Theoretical results are validated through both Finite Element Method(FEM)and hammer tests.Moreover,the dynamic equations are derived using the Lagrange method and discretized via the Galerkin Truncation Method(GTM).The Harmonic Balance Method(HBM)is used to evaluate the vibration responses of the integrated model,with further verification through the Runge-Kutta Method(RKM).The experiments are conducted to corroborate the theoretical analysis.The results show that the system frequency changes in stages with the increase of the stiffness of the integrated composite beam connection.Especially in the case of varying environments,as the temperature increases,the frequency of system will first increase to a certain maximum value and then gradually decrease.Furthermore,the NiTi-ST effectively reduces vibration in the integrated composite beam,particularly under varying temperatures and external excitations.
基金supported by the National Natural Science Foundation of China (Grant No.52405033)。
文摘As unmanned underwater vehicles (UUVs) are increasingly designed to perform long-duration missions in highly complex and often extreme environments, traditional design methods face significant and growing challenges^([1,2]).
文摘In this study,artificial neural networks(ANNs)were implemented to determine design parameters for an impressed current cathodic protection(ICCP)prototype.An ASTM A36 steel plate was tested in 3.5%NaCl solution,seawater,and NS4 using electrochemical impedance spectroscopy(EIS)to monitor the evolution of the substrate surface,which affects the current required to reach the protection potential(Eprot).Experimental data were collected as training datasets and analyzed using statistical methods,including box plots and correlation matrices.Subsequently,ANNs were applied to predict the current demand at different exposure times,enabling the estimation of electrochemical parameters(limiting voltage values)that can be used to optimize a self-regulating ICCP system.The obtained electrochemical parameters were then used,through Particle Swarm Optimization(PSO),to fine-tune an ANN-based proportional-integral-derivative(PID)controller for the ICCP system.
基金Supported by National Spark Program of China([2014]No.257)~~
文摘[Objective] This study aimed to screen the effective pesticide for control-ling Parathrene regalis Butler. [Method] By field trials, the effects of six kinds of commonly used pesticides on P. regalis were determined. ln addition, different agri-cultural measures were employed to integrate control technologies. [Result] At the early occurrence stage of P. regalis, spraying 7.5g/hm2 5% emamectin benzoate EC, 13.5 g/hm2 2% avermectin EC and 25 g/hm2 2.5% lambda-cyhalothrin EC can ef-fectively control P. regalis. [Conclusion] This study provided reference for the pre-vention and control of P. regalis.
基金This work was supported by the National Natural Science Foundation of China (No.60674055)the Taishan Scholar programme and the NaturalScience Foundation of Shandong Province (No.Y2006G04)
文摘In this paper, the robust adaptive fuzzy tracking control problem is discussed for a class of perturbed strict-feedback nonlinear systems. The fuzzy logic systems in Mamdani type are used to approximate unknown nonlinear functions. A design scheme of the robust adaptive fuzzy controller is proposed by use of the backstepping technique. The proposed controller guarantees semi-global uniform ultimate boundedness of all the signals in the derived closed-loop system and achieves the good tracking performance. The possible controller singularity problem which may occur in some existing adaptive control schemes with feedback linearization techniques can be avoided. In addition, the number of the on-line adaptive parameters is not more than the order of the designed system. Finally, two simulation examples are used to demonstrate the effectiveness of the proposed control scheme.
基金supported by the National Natural Science Foundation of China(61174203)Aeronautical Science Foundation of China(20110177002)
文摘An agile missile with tail fins and pulse thrusters has continuous and discontinuous control inputs.This brings certain difficulty to the autopilot design and stability analysis.Indirect robust control via Theta-D technique is employed to handle this problem.An acceleration tracking system is formulated based on the nonlinear dynamics of agile missile.Considering the dynamics of actuators,there is an error between actual input and computed input.A robust control problem is formed by treating the error as input uncertainty.The robust control is equivalent to a nonlinear quadratic optimal control of the nominal system with a modified performance index including uncertainty bound.Theta-D technique is applied to solve the nonlinear optimal control problem to obtain the final control law.Numerical results show the effectiveness and robustness of the proposed strategy.
文摘The main disease species on poplar are introduced in this paper. The main content of the integrated control technique on poplar diseases is summarized:(1) Forecast technique based on the initial disease and provention factors. (2) Control index is established, based on the relationship among the disease index, height of tree, diameter grade and the loss rate of volume. (3) Five fine varieties are selected according to three integrated indexes of host, such as resistance, volume growth and form ratio; They are 613 (Poulus alba ×P. berolinensis), A15 (P. xiaohei × P. euramericana CV. Polska-15A), A98 (P.xiaohei×(P. simonii×P. nigra) CV. A98), A102 (P. xiaohei) × (P. simonee × P. nigra) CV. A102), L2 (P. simonii × P nigra var. italica) in northeast Chnia. (4) Sivicultural control is known as the main protection measures, combined with chemical control and biocontrol,based on the disease forecast and control index by tracing the whole process of forest production.
文摘The control techniques for indirect heating digestion in Bayer process of alumina production were researched and developed. They include controlling chemical composition of slurry to be digested and controlling digestion status and energy consumption. Very good performances and technical and technical and economical figures for digestion process have been obtained by carefully applying these comprehensive control techniques in Pingguo alumina refinery.
基金Supported by the National Key Special Science and Technology Project(2016ZX05015-002)PetroChina Key Special Science and Technology Project(2016E-0104)
文摘Aimed at the disadvantages of secondary damage to oil layers caused by the conventional bull-heading water control technique, a thermo-sensitive temporary plugging agent for water control was synthesized by water solution polymerization and applied in the field with a new secondary temporary plugging technique. The optimization and performance evaluation of thermo-sensitive temporary plugging agent were carried out through laboratory experiments. The optimized formula is as follows:(6%-8%) acrylamide +(0.08%-0.12%) ammonium persulfate +(1.5%-2.0%) sepiolite +(0.5%-0.8%) polyethylene glycol diacrylate. The thermo-sensitive temporary plugging agent is suitable for formation temperatures of 70-90 ?C, it has high temporary plugging strength(5-40 k Pa), controllable degradation time(1-15 d), the apparent viscosity after degradation of less than 100 m Pa?S and the permeability recovery value of simulated cores of more than 95%. Based on the research results, secondary temporary plugging technique was used in a horizontal well in the Jidong Oilfield. After treatment, the well saw a drop of water cut to 27%, and now it has a water cut of 67%, its daily increased oil production was 4.8 t, and the cumulative oil increment was 750 t, demonstrating that the technique worked well in controlling water production and increasing oil production.
基金Supported by the Fundamental Research Funds of the Heibei Academy of Agriculture and Forestry Sciences(A2015040201)the Cotton Industry Technology System of Hebei Province+1 种基金the Key Research and Development Planning Program of Hebei Province(16226303D)the Financial Program of Hebei Province(F17C10005)~~
文摘[Objective] The aim was to investigate the effects of DPC chemical controlling technique on agronomic traits, yield and quality of machine-harvested cotton in the Yellow River Valley of China, and clarify the reasonable control period and the application amount of DPC. [Method] The new machine-harvested cotton variety Hengmian HD008 was used as the test material, and 3 different DPC treatments were set. [Result] DPC significantly reduced plant height and branch length, reduced branch angle and leaf area, so the rational control can effectively shape the ideal plant type of machine-harvested cotton. DPC had significant effects on yield and yield components, and the proper amount of DPC could increase the number of bolls during hot days, the number bolls in autumn and the total number of bolls. It increased the boll weight and seed index, but decreased lint percentage decreased, and proper amount of DPC could increase the yield. DPC significantly increased the specific breaking strength of fibers, and proper control could improve the uniformity of fibers, but other indexes had no significant influence. [Conclusion] According to the requirements of machine harvest to the agronomic traits of cotton and the growth characteristics of cotton plant, chemical control could begin after floral bud emergence in cotton about every 10 d, and the spraying amount can be controlled according to the growth amount of the main stem. The daily growth amount of plant height should be controlled at 1.5-1.8 cm, and the plant height should be within 75-90 cm.
文摘The inverted pendulum is a classic problem in dynamics and control theory and is widely used as a benchmark for testing control algorithms. It is unstable without control. The process is non linear and unstable with one input signal and several output signals. It is hence obvious that feedback of the state of the pendulum is needed to stabilize the pendulum. The aim of the study is to stabilize the pendulum such that the position of the carriage on the track is controlled quickly and accurately. The problem involves an arm, able to move horizontally in angular motion, and a pendulum, hinged to the arm at the bottom of its length such that the pendulum can move in the same plane as the arm. The conventional PID controller can be used for virtually any process condition. This makes elimination the offset of the proportional mode possible and still provides fast response. In this paper, we have modelled the system and studied conventional controller and LQR controller. It is observed that the LQR method works better compared to conventional controller.
文摘Coal bed methane control with low permeability is a hot issue at present. The current status of coal bed methane control in China is introduced. The government-support policies on coal bed methane control are presented. This paper proposes the theories of methane control in depressurized mining, including methane extraction in depressurized mining, simultaneous mining technique of coal and methane without coal pillar, and circular overlying zone for high-efficiency methane extraction in coal seams with low permeability. The techniques of methane control and related instruments and equipments in China are introduced. On this basis, the problems related to coal bed methane control are addressed and further studies are pointed out.
基金Project(61166004) supported by the National Natural Science Foundation of ChinaProject(09ZCGHHZ00200) supported by the International Scientific and Technological Cooperation Program of Science and Technology Plan of Tianjin,ChinaProject(UF10028Y)supported by the Doctoral Scientific Research Foundation for Guilin University of Electronic Technology,China
文摘A CMOS active mixer based on voltage control load technique which can operate at 1.0 V supply voltage was proposed, and its operation principle, noise and linearity analysis were also presented. Contrary to the conventional Gilbert-type mixer which is based on RF current-commutating, the load impedance in this proposed mixer is controlled by the LO signal, and it has only two stacked transistors at each branch which is suitable for low voltage applications. The mixer was designed and fabricated in 0.18 tam CMOS process for 2.4 GHz ISM band applications. With an input of 2.44 GHz RF signal and 2.442 GHz LO signal, the measurement specifications of the proposed mixer are： the conversion gain （Gc） is 5.3 dB, the input-referred third-order intercept point （PIIP3） is 4.6 dBm, the input-referred 1 dB compression point （P1dB） is --7.4 dBm, and the single-sideband noise figure （NFSSB） is 21.7 dB.
文摘Objective: To explore the clinical therapeutic effects and the mechanism on rheumatic arthritis(RA)treated with the combination of the instruments and techniques of acupuncture and moxibusiton.Methods: A total of 60 RA patients were randomized into an observation group and a control group,30 cases in each one. In the control group, diclofenac sodium sustained release tablets were prescribed for oral administration, 0.3 g each time, twice a day, methotrexate tablets(MTX) for oral administration,10 mg each time, once a week and folic acid tablets for oral administration, 5 mg each time, once a week. In the observation group, besides the treatment with western medicines, simultaneously, the specific acupoints were selected and stimulated with the triple strong-stimulation therapy, in which, the strong bloodletting technique, the strong cupping technique and the strong moxibustion technique were combined together, with different instruments of acupuncture and moxibustion adopted. The treatment was given once every 3 days, consecutively for 10 times. In 30 days of treatment, the therapeutic effects were observed in the two groups. Separately, before and after treatment, the rheumatoid factors(RF),hypersensitive-C reactive protein(hs-CRP) and erythrocyte sedimentation rate(ESR), the scores of joint symptoms and physical signs as well as the disease activity score(DAS-28) were observed in the two groups.Results: Regarding RF, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 248.01 ± 79.81 vs 31.17 ± 29.01,the control group 254.11 ± 72.16 vs 66.42 ± 37.07, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05). Regarding hs-CRP, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 26.12 ± 9.22 vs 8.98 ± 7.66, the control group 23.18 ± 7.18 vs 16.01 ± 5.02, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05). Regarding ESR, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 30.56 ± 11.38 vs 12.58 ± 5.91,the control group 35.52 ± 9.67 vs 21.47 ± 6.91, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05). Regarding DAS-28, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 8.89 ± 2.01 vs 3.01 ± 0.74, the control group 8.14 ± 1.38 vs 4.12 ± 0.96, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05). Regarding the quantitative grading score of symptom, there were statistical significant differences before and after treatment in the observation group and the control group(the observation group 7.87 士 1.69 vs 3.82 ±1.96, the control group 7.77 ± 1.68 vs 5.01 ± 11.23, both P < 0.05). The result in the observation group was lower significantly than the control group after treatment(P < 0.05).The total effective rate was 96.67%(29/30) in the observation group and was 80.0%(24/30) in the control group, indicating the statistical significant difference between the two groups(P < 0.01).Conclusion: Based on western medications, the triple strong-stimulation therapy of acupuncture and moxibustion at specific acupoints significantly relieves the joint symptoms, reduces the inflammatory reaction indicators and improves the clinical therapeutic effects on RA in the patients.
基金Guangxi Zhuang Autonomous Region Health and Family Planning Commission Guangxi Medical and Health Appropriate Technology Development and Application Project:S2017057。
文摘Objective:To observe the differences of clinical effect and influence on joint function and inflammatory markers in joint fluid between stuck-needle technique and regular acupuncture in patients with knee osteoarthritis.Methods:Seventy-two patients with knee osteoarthritis were randomly divided into a stuck-needle technique group and a regular acupuncture group,with 36 cases in each one.The selection of acupoints,retaining time of needles,and treatment course were all the same in both groups.The visual analog scale(VAS)score,Lequesne index score,and the content of related inflammatory indexes in joint fluid before and after treatment were observed,and the therapeutic effect were evaluated.Results:After treatment,the VAS scores,Lequesne index scores,interleukin-1 beta(IL-1β),and the tumor necrosis factor a(TNF-α)of the two groups were all lower than those before treatment(all P<0.05).After treatment,the VAS scores,Lequesne index scores,IL-1β,and TNF-αof the stuck-needle technique group were all lower than those of the regular acupuncture group(all P<0.05).The total effective rate of the stuck-needle technique group was 96.97%(32/33),higher than 93.75%(30/32)of the regular acupuncture group(P<0.05).Conclusion:Stuck-needle technique can effectively relieve the pain and improve the joint functions,being more effective than regular acupuncture for the treatment of knee osteoarthritis.
基金Supported by Science and Technology Support Program of Guizhou Province(QKHZC[2020]1Y135)General Higher Education Science and Technology Top-notch Talents Project of Guizhou Province(QJH KY Z[2021]037)+5 种基金Science and Technology Program of Guizhou Province(QKHJZ-ZK[2022]ZD 025)High-level Talent Scientific Research Startup Project of Guizhou Institute of Technology(XJGC20190632)Earth Thesis Project of Guizhou Institute of Technology(KJZX20-005)High-Level Talent Initial Funding of Guizhou Industry Polytechnic College(2023-RC-01)Enterprise Commissioned Project of Guizhou Industrial Polytechnic College(2023-HX-01)Enterprise Commissioned Project of Guizhou Industrial Polytechnic College(2023-HX-02).
文摘Kiwifruit canker disease seriously affects the yield and quality of"Guichang"kiwifruit in Xiuwen County,Guizhou Province.In order to scientifically,safely,greenly and efficiently prevent and control the disease,theory was combined with prevention and control techniques to optimize existing prevention and control techniques,so as to improve the production yield and quality of kiwifruit.Specifically,biocontrol strains targeting local kiwifruit canker disease were screened,and reduced and mixed use of agrochemicals with improved efficiency was studied;and the effects and application techniques of disease resistance inducers and bioorganic fertilizers in inducing systemic disease resistance in kiwifruit trees were explored,and finally,an integrated green prevention and control scheme for kiwifruit canker disease that is suitable for kiwifruit production areas in Guizhou Province and has strong operability was proposed.This study provides technical support for green,efficient,standardized production technical services and sustainable and healthy development of kiwifruit industry.
文摘In conjunction with general integral control, and synthesizing Singular perturbation and Equal ratio gain techniques, this paper proposes a new control design technique, named Power ratio gain technique, and then by Lyapunov method, theorem to ensure regionally as well as semi-globally asymptotic stability is established in terms of some bounded information. The highlight point is that it not only inherits all the essences of Singular perturbation and Equal ratio gain techniques but also makes up for their shortcomings, and then the conservatism of control input can be improved by compromising the Power ratio coefficients. Theoretical analysis, design example and simulation results show that Power ratio gain technique is a simple, practical and powerful tool to deal with the uncertain nonlinear system.
文摘Reversible watermarking schemes for relational database are usually classified into two groups: robust schemes and fragile schemes. The main limitation of existing reversible fragile methods is that they cannot differentiate between legal and malicious modifications. In this paper, we introduce a novel lossless semi-fragile scheme based on prediction-error expansion for content protection of relational database. In the proposed method, all attributes in a database relation are first classified according to their sensitivity to legitimate updates. Then, the watermark is embedded by expanding the prediction error of the two least significant digits of securely selected attributes. At watermark extraction, the proposed method has the ability to fully restore the original data while detecting and localizing tampering. The applicability of our method is demonstrated theoretically and experimentally.
