Roughness-induced emission from ocean surfaces is one of the main issues that affects the retrieval accuracy of sea surface salinity remote sensing.In previous studies,the correction of roughness effect mainly depende...Roughness-induced emission from ocean surfaces is one of the main issues that affects the retrieval accuracy of sea surface salinity remote sensing.In previous studies,the correction of roughness effect mainly depended on wind speeds retrieved from scatterometers or those provided by other means,which necessitates a high requirement for accuracy and synchronicity of wind-speed measurements.The aim of this study is to develop a novel roughness correction model of ocean emissivity for the salinity retrieval application.The combined active/passive observations of normalized radar cross-sections(NRCSs)and emissivities from ocean surfaces given by the L-band Aquarius/SAC-D mission,and the auxiliary wind directions collocated from the National Centers for Environmental Prediction(NCEP)dataset are used for model development.The model is validated against the observations and the Aquarius standard algorithms of roughness-induced emissivity correction.Comparisons between model computations and measurements indicate that the model has better accuracy in computing wind-induced brightness temperature in the upwind/downwind directions or for the surfaces with smaller NRCSs,which can be better than 0.3 K.However,for crosswind directions and larger NRCSs,the model accuracy is relatively low.A model using HH-polarized NRCSs yields better accuracy than that using VV-polarized ones.For a fair comparison to the Aquarius standard algorithms using wind speeds retrieved from multi-source data,the maximum likelihood estimation is employed to produce results combining our model calculations and those using other sources.Numerical simulations show that combined results basically have higher accuracy than the standard algorithms.展开更多
Surge active control can expand the stable operating range of the compressor.However,the difficulty of flow measurement,dynamic uncertainty disturbance,actuator delay characteristics,hard constraints of control variab...Surge active control can expand the stable operating range of the compressor.However,the difficulty of flow measurement,dynamic uncertainty disturbance,actuator delay characteristics,hard constraints of control variable,and system security measures have not been fully considered in the existing active control system,which significantly hinders its engineering application.Therefore,a nonlinear model predictive surge active control method is first presented based on flow estimator designed by using a continuous-time Kalman filter for dealing with the hard constraint of control variable and the impact of actuator delay of compression system with dynamic uncertainty.Then,a high-safety active/surge passive hybrid control strategy is designed,dominated by the surge active control and supplemented by the surge passive control,to ensure the compression system’s safe and stable operation.Lastly,the simulation results suggest that the flow estimator accurately estimates the compressor flow.When considering the delay impact of the actuators and sensors and measurement noise on the system,the proposed method exhibits stronger robustness than the existing meth-ods.The active/surge passive hybrid control strategy can successfully ensure the compression system’s safe and stable operation.This paper is of high practical significance for the engineering application of future compressor surge active control technologies.展开更多
Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion pro...Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion protection due to its stable properties and eco-friendliness(0 g/L volatile organic compounds).Nevertheless,several intrinsic deficiencies require improvement,such as fragile mechanical properties and defects(macro and micro),resulting in the continuous deterioration of comprehensive coating performances.In this work,a novel nanocomposite coating with mechanical enhancement,intelligent self-reporting,and active protection is fabricated by integrating the functionalized and compatible graphene oxide/cerium based metal-organic framework multiscale structure(GO-CeMOF-P/M).Notably,the homogenous dispersion of GO-CeMOF-P/M and its chemical interaction with the polymer matrix effectively reduces the defects resulting from solution volatilizing and enhances the compactness,which boosts the tensile strength(32.1 MPa/8.5%)and dry adhesion force(5.8 MPa)of the coating.Additionally,the controllable responsiveness and release of multiscale nanocomposite within external environments endow intelligent active protection and self-reporting characteristics for the GO-CeMOF-P/M-EP coating,making it especially suitable for a variety of practical marine applications.Furthermore,following immersion of 80 d in the aggressive environment,Zf=0.01 Hz value of GO-CeMOF-P/M-EP coating is 1.2×10^(10)Ωcm^(2),which is 164.4 times larger than that of EP coating(7.3×10^(7)Ωcm^(2)),demonstrating remarkably strengthened anti-corrosion ability.Consequently,by offering an intriguing design strategy,the current work anticipates addressing the inherent deficiencies of EP coating and facilitating its practicality and feasibility in real sea environments.展开更多
This article provides a comprehensive review of various approaches to targeted drug delivery for liver cancer, an area of significant need due to the limited effectiveness of current treatments. The article begins by ...This article provides a comprehensive review of various approaches to targeted drug delivery for liver cancer, an area of significant need due to the limited effectiveness of current treatments. The article begins by highlighting the role of the liver in metabolism and discusses the high mortality associated with hepatocellular carcinoma (HCC). The shortcomings of traditional chemotherapy, such as multidrug resistance and off-target effects, necessitate the exploration of novel therapeutic strategies, with a focus on targeted approaches. The review details both passive and active targeting strategies. Passive targeting leverages the enhanced permeability and retention (EPR) effect and unique features of the tumor microenvironment, while active targeting employs specific ligands, such as peptides, antibodies, and proteins, to bind to overexpressed receptors on liver and tumor cells. The article further details many examples of active targeting using the asialoglycoprotein receptor (ASGPR), glycyrrhetinic acid (GA), transferrin receptor (TfR), and folate receptor (FR) on hepatocytes and tumor cells, demonstrating that there has been significant research effort put into this field. The importance of non-parenchymal cells in the liver is also discussed, and the article examines methods of targeting Kupffer cells, sinusoidal endothelial cells, and hepatic stellate cells for therapeutic benefit. The review goes on to cover the emerging field of subcellular targeting, including specific strategies to target the nucleus, mitochondria, and the endoplasmic reticulum/Golgi apparatus, noting that although there has been some progress, further research is needed in this area. The text finishes with a summary which acknowledges that while targeted therapies, including enzyme-activated prodrugs, such as Pradefovir, and other novel methods for drug delivery have shown significant promise, challenges remain in translating these therapies into clinical use due to limitations in understanding the sequential transport and the mechanisms of action. Ultimately, the article emphasizes the need for in-depth research to fully realize the potential of precision cancer therapies for liver cancer.展开更多
Biodegradable magnesium(Mg)-based medical devices have revolutionized medical implants by uniquely combining biocompatibility and mechanical strength.Fully degradable Mg-based implants have been developed to provide t...Biodegradable magnesium(Mg)-based medical devices have revolutionized medical implants by uniquely combining biocompatibility and mechanical strength.Fully degradable Mg-based implants have been developed to provide temporary structural support and serve as a dynamic scaffold for tissue repair and restructuring.Additionally,Mg-based devices can respond to physiological signals,and their integration with electrical currents or pulses has been explored to enhance tissue healing and functional recovery.This review provides a comprehensive overview of the development and application of Mg-based medical devices,highlighting their evolution from traditional orthopedic,vascular,and dental uses to advanced systems that actively modulate physiological processes—a shift from passive support to active modulation.The application range of Mg-based devices has expanded from early vascular sutures,bone screws,and stents to multiple clinical fields including porous bone repair scaffolds,anastomotic staples,bioactive devices,and electro-active systems.Bioactive Mg devices demonstrate therapeutic properties including antibacterial,anti-inflammatory,anti-tumor,and osteogenic functions through their degradation products,while electro-active devices utilize the electrical properties of Mg for sensing,monitoring,and therapeutic stimulation.Finally,this review highlights current challenges,including maintaining mechanical support performance,optimizing control of biochemical reactions,and balancing electroregulatory functions,and identifies future research directions aimed at enhancing the clinical application of biodegradable Mg-based implants,thereby contributing to the significant advancement in the biomedical field.展开更多
Optical clocks with thermal atoms are characterized by compact size,simple structure,reduced weight,and low power consumption and have the potential for broad out-of-the-lab and commercial applications.Here,we demonst...Optical clocks with thermal atoms are characterized by compact size,simple structure,reduced weight,and low power consumption and have the potential for broad out-of-the-lab and commercial applications.Here,we demonstrate a 459 nm optical clock based on the 6S_(1/2)-7P_(1/2)transition in thermal^(133)Cs atoms.Two methods,modulation transfer spectroscopy(MTS)and frequency modulation spectroscopy(FMS),are employed to stabilize the frequency of a 459 nm commercial laser to the atomic transition.The MTS-MTS and MTS-FMS beat-note measurements show short-term frequency stabilities of 3.7×10^(-13)/√t and 6.4×10^(-13)/√t,respectively,at the averaging time t.The 459 nm passive optical clock further serves as the pump for an active 1470 nm optical clock based on the cavityless lasing.The resultant 1470 nm output power reaches over 10μW and the pump-beam-induced light shift is estimated to be 2π×11 Hz with a fractional uncertainty of 2.4×10^(-18).These results demonstrate the feasibility of hybridizing passive and active optical clocks,providing a promising route toward compact multi-wavelength optical frequency standards.展开更多
Passive seismic data contain large amounts of low-frequency information. To effectively extract and compensate active seismic data that lack low frequencies, we propose a multitaper spectral reconstruction method base...Passive seismic data contain large amounts of low-frequency information. To effectively extract and compensate active seismic data that lack low frequencies, we propose a multitaper spectral reconstruction method based on multiple sinusoidal tapers and derive equations for multisource and multitrace conditions. Compared to conventional cross correlation and deconvolution reconstruction methods, the proposed method can more accurately reconstruct the relative amplitude of recordings. Multidomain iterative denoising improves the SNR of retrieved data. By analyzing the spectral characteristics of passive data before and after reconstruction, we found that the data are expressed more clearly after reconstruction and denoising. To compensate for the low-frequency information in active data using passive seismic data, we match the power spectrum, supplement it, and then smooth it in the frequency domain. Finally, we use numerical simulation to verify the proposed method and conduct prestack depth migration using data after low-frequency compensation. The proposed power-matching method adds the losing low frequency information in the active seismic data using the low-frequency information of passive- source seismic data. The imaging of compensated data gives a more detailed information of deep structures.展开更多
Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these...Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface electromyography.In this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury.Eleven patients with chronic complete thoracic spinal cord injury were recruited.Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol.The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation.Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically significant.These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.展开更多
Objective Stroke is the third leading cause of death worldwide,with the highest incidence in Asia,particularly in China,where smoking remains a major risk factor.The smoking prevalence in China is similar to that in A...Objective Stroke is the third leading cause of death worldwide,with the highest incidence in Asia,particularly in China,where smoking remains a major risk factor.The smoking prevalence in China is similar to that in Asia.Whether the risk estimates for smoking-related stroke in China and all Asian countries are still unknown which is worth evaluating.Thus,this study aims to compare the Relative Risk(RR)of smoking-attributed stroke among the Chinese and Asian populations.Methods A literature search was conducted from the inception to September 10,2022.Studies meeting the criteria were included.The articles were screened,and related information was extracted.Pooled RRs stratified by smoking status and sex were analyzed,including subgroup analyses for China,other Asian countries,and Asia overall.Finally,publication bias and sensitivity analyses were conducted.Results Thirty-seven articles on the Chinese population and 15 on other Asian populations were included,with a mean Newcastle-Ottawa scale(NOS)score of 7.25.About ever smokers,there had no statistical difference existed in both sexes and females between China and other Asian countries,while the RR of males in other Asian countries[2.31(1.38,3.86)]was higher than that in China[1.21(1.15,1.26)];further subgroup analysis indicated that other Asian countries had higher RR[3.76(3.02,4.67)]in the morbidity subgroup.The RRs of both sexes,males and females,between China and the whole of Asia were not statistically different.As for current and former smokers,no meaningful statistical difference was observed in the pooled RRs of both sexes,males and females,in China,other Asian countries,and all of Asia.Conclusion The RR of males ever smokers in China was smaller than that in other Asian countries due to the few articles of morbidity subgroup,but had no statistical difference with the whole of Asia;other groups of ever smokers,current smokers,and former smokers were not statistically significant with other Asian countries or the whole of Asia.展开更多
Fiber-structured ion sensors have gained traction in health monitoring and medical diagnostics owing to their structural flexibility,enhanced sensitivity,and suitability for integration into wearable devices.This stud...Fiber-structured ion sensors have gained traction in health monitoring and medical diagnostics owing to their structural flexibility,enhanced sensitivity,and suitability for integration into wearable devices.This study employed a simple and efficient solutionbased process to fabricate nanofibers containing aggregation-induced emission(AIE)dyes.The resulting AIE nanofibers exhibited stable and intense fluorescence,nanosecond fluorescence lifetime,and low-loss light transport when functioning as active waveguides.Additionally,crossed nanofiber intersections exhibited diffraction-limited emission spots.The AIE nanofibers demonstrate efficient and ionspecific fluorescence quenching in response to Ag^(+).These results support the development of sensing units capable of operating in liquid environments or in direct contact with skin or tissues,facilitating real-time monitoring of ion concentrations for personalized healthcare management.展开更多
Population aging is one of the common challenges in the current world.As people age,the body’s tissues including cells,and molecules inevitably degrade,and their functions gradually decline,causing various age-relate...Population aging is one of the common challenges in the current world.As people age,the body’s tissues including cells,and molecules inevitably degrade,and their functions gradually decline,causing various age-related diseases like Alzheimer’s disease,osteoporosis,low immunity,glucose and lipid metabolism disorders,and cardiovascular diseases.With the continuous increase of the elderly population,the pressure on the medical industry is increasing.To lower the burden on the medical industry and increase the average age of the elderly,it is vital to explore effective anti-aging materials.Ginseng Radix et Rhizoma(Renshen),as a traditional and precious Chinese medicinal herb,is known as the“king of all herbs”.It is famous for its effects of“tonifying Qi,restoring pulse”(helping with the generation of Qi(the fundamental,vital energy that continuously flows within the body)and the circulation of blood)and strengthening the body,nourishing the spleen and lungs,generating fluids and nourishing blood,calming the mind and improving intelligence.Recently,its anti-aging effect has received increasing attention from modern scientific research.This study summarizes the pharmacological effects of the main active ingredients of Renshen(ginsenosides,polysaccharides,etc.)on resisting aging,including preventing neuroaging,suppressing skin aging,mitigating ovarian aging,inhibiting osteoporosis and arthritis,enhancing the immune system of the elderly,protecting the cardiovascular system,resisting aging-induced fatigue and exerting the anti-tumor effects.Through network pharmacology and molecular docking,the anti-aging active ingredients of Renshen were screened,and the key targets and pathways of anti-aging active ingredients in Renshen were determined.Using network pharmacology,totally 106 drug targets and 3,479 disease targets were screened,and 79 common targets between aging and Renshen were identified.Three core targets were identified in the PPI network,including TNF,AKT1,and IL-1β.Molecular docking was used to obtain further verification.This study emphasizes the potential of Renshen as a source of anti-aging activity,which can be developed into a novel drug for the treatment of age-related diseases.展开更多
BACKGROUND:Hemiplegia,a prevalent stroke-related condition,is often studied for motor dysfunction;however,spasticity remains under-researched.Abnormal muscle tone significantly hinders hemiplegic patients’walking rec...BACKGROUND:Hemiplegia,a prevalent stroke-related condition,is often studied for motor dysfunction;however,spasticity remains under-researched.Abnormal muscle tone significantly hinders hemiplegic patients’walking recovery.OBJECTIVE:To determine whether early suspension-protected training with a personal assistant machine for stroke patients enhances walking ability and prevents muscle spasms.METHODS:Thirty-two early-stage stroke patients from Shenzhen University General Hospital and the China Rehabilitation Research Center were randomly assigned to the experimental group(n=16)and the control group(n=16).Both groups underwent 4 weeks of gait training under the suspension protection system for 30 minutes daily,5 days a week.The experimental group used the personal assistant machine during training.Three-dimensional gait analysis(using the Cortex motion capture system),Brunnstrom staging,Fugl-Meyer Assessment for lower limb motor function,Fugl-Meyer balance function,and the modified Ashworth Scale were evaluated within 1 week before the intervention and after 4 weeks of intervention.RESULTS AND CONCLUSION:After the 4-week intervention,all outcome measures showed significant changes in each group.The experimental group had a small but significant increase in the modified Ashworth Scale score(P<0.05,d=|0.15|),while the control group had a large significant increase(P<0.05,d=|1.48|).The experimental group demonstrated greater improvements in walking speed(16.5 to 38.44 cm/s,P<0.05,d=|4.01|),step frequency(46.44 to 64.94 steps/min,P<0.05,d=|2.32|),stride length(15.50 to 29.81 cm,P<0.05,d=|3.44|),and peak hip and knee flexion(d=|1.82|to|2.17|).After treatment,the experimental group showed significantly greater improvements than the control group in walking speed(38.44 vs.26.63 cm/s,P<0.05,d=|2.75|),stride length,peak hip and knee flexion(d=|1.31|to|1.45|),step frequency(64.94 vs.59.38 steps/min,P<0.05,d=|0.85|),and a reduced support phase(bilateral:24.31%vs.28.38%,P<0.05,d=|0.88|;non-paretic:66.19%vs.70.13%,P<0.05,d=|0.94|).For early hemiplegia,personal assistant machine-assisted gait training under the suspension protection system helps establish a correct gait pattern,prevents muscle spasms,and improves motor function.展开更多
HPR1000 is an advanced nuclear power plant(NPP)with the significant feature of an active and passive safety design philosophy,developed by the China National Nuclear Corporation.On one hand,it is an evolutionary desig...HPR1000 is an advanced nuclear power plant(NPP)with the significant feature of an active and passive safety design philosophy,developed by the China National Nuclear Corporation.On one hand,it is an evolutionary design based on proven technology of the existing pressurized water reactor NPP;on the other hand,it incorporates advanced design features including a 177-fuel-assembly core loaded with CF3 fuel assemblies,active and passive safety systems,comprehensive severe accident prevention and mitigation measures,enhanced protection against external events,and improved emergency response capability.Extensive verification experiments and tests have been performed for critical innovative improvements on passive systems,the reactor core,and the main equipment.The design of HPR1000fulfills the international utility requirements for advanced light water reactors and the latest nuclear safety requirements,and addresses the safety issues relevant to the Fukushima accident.Along with its outstanding safety and economy,HPR1000 provides an excellent and practicable solution for both domestic and international nuclear power markets.展开更多
A new synergy tracking method of infrared and radar is presented. To improve tracking accuracy, the unscented Kalman filter （UKF）, which has better nonlinear approximation ability, is adopted. In addition, to reduce...A new synergy tracking method of infrared and radar is presented. To improve tracking accuracy, the unscented Kalman filter （UKF）, which has better nonlinear approximation ability, is adopted. In addition, to reduce the possibility of radar being locked-on by adverse electronic support measure （ESM）, radar is under the intermittent-working state. After radar is turned off, the possible target position is estimated by a set of time polynomials, which is constructed based on the sufficient observations done before radar is turned off, the estimated values from time polynomials are compared with the current observation values from infrared to determine the time when radar is turned on. Simulation results show the method has a good tracking accuracy and effectively reduces the possibility of radar being locked-on by adverse ESM.展开更多
Stroke patients always spontaneously do some learning and training of motor functions; however, learning and training are not prompt and right, while patients do not have enough activity amounts. Active and passive mo...Stroke patients always spontaneously do some learning and training of motor functions; however, learning and training are not prompt and right, while patients do not have enough activity amounts. Active and passive motor training apparatus is aimed directly at lower limb training so as to stimulate nerve function through stimulating muscular movement. Based on motor mileage, motor time, various power supplies and velocity of active and passive training apparatus, we can understand the training condition and adjust training program. OBJECTIVE： To observe the effects of grade-III rehabilitation training combining with active and passive training apparatus on lower limb function, muscle strength and activity of daily living （ADL） in stroke patients during recovery period. DESIGN： Contrast observation. SETTING： Department of Rehabilitation, Jilin Academic Institute of Traditional Chinese Medicine. PARTICIPANTS： A total of 80 patients with stroke-induced hemiplegia after stabilizing vital signs for 2 weeks were selected from Department of Rehabilitation, Jilin Academic Institute of Traditional Chinese Medicine from January to June 2007. There were 47 males and 33 females, and their ages ranged from 41 to 75 years. All patients met the diagnostic criteria of the Fourth National Cerebrovascular Disease Academic Meeting in 1995 and were diagnosed as cerebral hemorrhage or cerebral infarction through CT or MRI examinations in clinic. Patients and their parents provided the confirmed consent. Based on therapeutic orders of hospitalization, patients were randomly divided into treatment group and control group with 40 patients in each group. METHODS： Patients in the control group received physical therapy and occupational therapy combining with rehabilitative treatment based on grade-III rehabilitative treatment program, which was set by the National Cerebrovascular Disease Topic Group. In addition, patients in the treatment group were trained with active and passive motor training apparatus based on therapeutic procedures in the control group. The active and passive motor training apparatus was designed as the therapeutic style of nervous system; otherwise, the treatment was performed once a day, 30 minutes once and 6 times per week. Four weeks were regarded as a course. MAIN OUTCOME MEASURES： Before treatment, at 2 weeks after treatment and after the first course, bare-handed muscle strength examination was used to check muscle strength and muscular tension; in addition, simple Fugl-Meyer assessment （FMA） and diagnostic criteria which were set by the Fourth National Cerebrovascular Disease Academic Meeting were used to evaluate motor function of limbs and total ADL. RESULTS： All 80 stroke patients were involved in the final analysis. ① Muscle strength of lower limbs was improved in both treatment group and control group. After the first course, muscle strength in the treatment group was obviously superior to that in the control group （ x^2=6.64, P 〈 0.05）. ② After the first course, Fugl-Meyer scores in the treatment group were higher than those in the control group, and there was significant difference （t =2.82, P 〈 0.05）. ③ Muscular tension of lower limbs was not changed in both treatment group and control group after treatment （P 〉 0.05）. ④ After the first course, ADL in the treatment group was superior to that in the control group （P 〈 0.05）. Among patients in the treatment group, 24 cases （60%） had obvious progress, 16 （40%） had progress, and 0 （0%） did not have any changes. On the other hand, among patients in the control group, 13 cases （32.5%） had obvious progress, 26 （65%） had progress, and 1 （2.5%） did not have any changes. CONCLUSION： Rehabilitation training combining with active and passive motor training apparatus can promote the recovery of lower limb disorder, increase muscle strength, control spasm, improve ADL and cause satisfactorily clinical effects in stroke patients during recovery period.展开更多
InGaAs/InP avalanche photodiodes （APD） are rarely used in a free-running regime for near-infrared single photon detection. In order to overcome the detrimental afterpulsing, we demonstrate a passive quenching active...InGaAs/InP avalanche photodiodes （APD） are rarely used in a free-running regime for near-infrared single photon detection. In order to overcome the detrimental afterpulsing, we demonstrate a passive quenching active reset integrated circuit. Taking advantage of the inherent fast passive quenching process and active reset to reduce reset time, the integrated circuit is useful for reducing afterpulses and is also area-efficient. We investigate the free-running single photon detector＇s afterpulsing effect, de-trapping time, dark count rate, and photon detection efficiency, and also compare with gated regime operation. After correction for deadtime and afterpulse, we find that the passive quenching active reset free-running single photon detector＇s performance is consistent with gated operation.展开更多
In this paper,a hybrid passive/active vibration(HPAV)controller of a loosely connected spacecraft consisting of a servicing satellite,a target and an X-shape structure isolator is first proposed to suppress vibrations...In this paper,a hybrid passive/active vibration(HPAV)controller of a loosely connected spacecraft consisting of a servicing satellite,a target and an X-shape structure isolator is first proposed to suppress vibrations of the system when subjected to the impulsive external excitations during the on-orbit missions.The passive dynamic response of the combined system can be adjusted appropriately to achieve the desired vibration isolation performance by tuning the structural parameters of the bio-inspired X-shape structure.Moreover,the adaptive control design through dynamic scaling technique is selected as the active component to maintain high vibration isolation performance in the presence of parameter uncertainties such as mass of the satellite platform,the damping and rotation friction coefficients of the X-shape structure.Compared with the pure passive system and the traditional spring-mass-damper(SMD)isolator,the HPAV strategy witnesses lower transmissibility,smaller vibration amplitude and higher convergence rate when subjected to the post-capture impact.Numerical simulations demonstrate the feasibility and validity of the proposed hybrid control scheme in suppressing vibrations of the free-floating spacecraft.展开更多
Purpose: Muscle stretching is frequently prescribed in physical therapy to manage lower back and neck pain. However, there is no clear evidence regarding the differences in effectiveness of active and passive stretchi...Purpose: Muscle stretching is frequently prescribed in physical therapy to manage lower back and neck pain. However, there is no clear evidence regarding the differences in effectiveness of active and passive stretching. Therefore, we aimed to evaluate the relative effectiveness of a 12-week program of active and passive stretching on selected physical and mental stress variables of sedentary men with lower back and neck pain. Methods: A cohort of 28 sedentary men, 30 - 49 years old, were divided into two intervention groups: the passive stretching group (PSG, n = 15) and the active stretching group (ASG, n = 13). A trainer assisted with static passive stretching, while participants in the ASG were provided with an instructional video. The following outcomes were measured at the start and end of the first and twelfth week of the stretching program: physical measures (visual analogue scale score of lower back and neck pain;finger-to-floor distance, gravimetric assessment of pelvic tilt, muscle hardness of the biceps femoris, and straight-leg raising) and mental stress measures (α-amylase and cortisol levels in saliva samples). Results: Although both active and passive stretching produced acute changes in lower back and neck pain, only passive stretching yielded long-term improvement in pain, finger-to-floor distance, pelvic tilt, hardness of biceps femoris muscle and cortisol levels (p Conclusion: Passive stretching is superior to active stretching in reducing pain, increasing muscle extensibility and correcting posture among a group of sedentary men with lower back and neck pain.展开更多
Ultrasonic surface rolling process(USRP)is one of the effective mechanical surface enhancement techniques.During the USRP,unstable static force will easily do harm to the surface quality.In order to achieve a higher s...Ultrasonic surface rolling process(USRP)is one of the effective mechanical surface enhancement techniques.During the USRP,unstable static force will easily do harm to the surface quality.In order to achieve a higher surface quality on the part with a curved surface,an active and passive compliant USRP system has been developed.The compliant USRP tool can produce the natural obedience deformation along the part surface.Force control based on the fuzzy Proportional-integral-derivative(PID)method is then designed to maintain the static force during the USRP.Experiments have been performed on a real aero-engine blade with curved surface.It is proved that the deigned active and passive compliant USRP system can significantly reduce the force variation from 42.2 N to 4.2 N,and achieve a uniform surface quality after processing.展开更多
In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed： （1） active control can provide significant...In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed： （1） active control can provide significantly superior supplemental damping to a building, but causes a small frequency shift; （2） the linear quadratic regulator （LQR）-based control force is composed of an elastic restoring force component and a damping force component, where the damping force is almost identical to the total control force, however, the elastic restoring force is very small; and （3） the active control forces prevent mction most of the time during the entire control process. These three characteristics imply that active control systems connected to adjacent levels of a building behave like passive damping devices with adjustable parameters, namely damping characteristics in an active control, which is the mechanism used by semi-active control devices to reach similar performance as active control systems. Two indices are defined to quantify the damping characteristics of control forces in active control systems. These two indices can also be used to quantify the capacity of semi-active control to achieve the perfonrlance of active control. Based on the above observations, two principles are founded for optimization of parameters of semi-active control devices and passive dampers. The first is that the maximum output force of a semi-active or passive device to be designed is identical to an active device, called ＂design principle＂. The other is the response equivalent principle, which states that the response of a building with semi-active or passive devices is the same as with active devices when the same maximum output force is applied. The design procedure for semi-active control devices and passive dampers is described in detail. Finally, numerical simulations of two benchmark problems is conducted to demonstrate the damping characteristics of active control and investigate the capacity of semi-active control to achieve the same performance as active control.展开更多
基金The National Key R&D Program of China under contract Nos 2018YFA0605403 and 2016YFB0500204the Hainan Provincial Natural Science Foundation of China under contract No.418QN301the National Natural Science Foundation of China under contract No.41801238。
文摘Roughness-induced emission from ocean surfaces is one of the main issues that affects the retrieval accuracy of sea surface salinity remote sensing.In previous studies,the correction of roughness effect mainly depended on wind speeds retrieved from scatterometers or those provided by other means,which necessitates a high requirement for accuracy and synchronicity of wind-speed measurements.The aim of this study is to develop a novel roughness correction model of ocean emissivity for the salinity retrieval application.The combined active/passive observations of normalized radar cross-sections(NRCSs)and emissivities from ocean surfaces given by the L-band Aquarius/SAC-D mission,and the auxiliary wind directions collocated from the National Centers for Environmental Prediction(NCEP)dataset are used for model development.The model is validated against the observations and the Aquarius standard algorithms of roughness-induced emissivity correction.Comparisons between model computations and measurements indicate that the model has better accuracy in computing wind-induced brightness temperature in the upwind/downwind directions or for the surfaces with smaller NRCSs,which can be better than 0.3 K.However,for crosswind directions and larger NRCSs,the model accuracy is relatively low.A model using HH-polarized NRCSs yields better accuracy than that using VV-polarized ones.For a fair comparison to the Aquarius standard algorithms using wind speeds retrieved from multi-source data,the maximum likelihood estimation is employed to produce results combining our model calculations and those using other sources.Numerical simulations show that combined results basically have higher accuracy than the standard algorithms.
基金supported by the National Natural Science Foundation of China(Nos.51906103,52176009).
文摘Surge active control can expand the stable operating range of the compressor.However,the difficulty of flow measurement,dynamic uncertainty disturbance,actuator delay characteristics,hard constraints of control variable,and system security measures have not been fully considered in the existing active control system,which significantly hinders its engineering application.Therefore,a nonlinear model predictive surge active control method is first presented based on flow estimator designed by using a continuous-time Kalman filter for dealing with the hard constraint of control variable and the impact of actuator delay of compression system with dynamic uncertainty.Then,a high-safety active/surge passive hybrid control strategy is designed,dominated by the surge active control and supplemented by the surge passive control,to ensure the compression system’s safe and stable operation.Lastly,the simulation results suggest that the flow estimator accurately estimates the compressor flow.When considering the delay impact of the actuators and sensors and measurement noise on the system,the proposed method exhibits stronger robustness than the existing meth-ods.The active/surge passive hybrid control strategy can successfully ensure the compression system’s safe and stable operation.This paper is of high practical significance for the engineering application of future compressor surge active control technologies.
基金financially supported by the National Natural Science Foundation of China(Nos.52371088,52071347,and U20A20233)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515240007)Shenzhen Science and Technology Program(No.KJZD20230923114819041).
文摘Corrosion activities and related accidents are significant issues for marine facilities,leading to considerable economic losses.Waterborne epoxy(EP)coating has been seen as one of the optimal options for corrosion protection due to its stable properties and eco-friendliness(0 g/L volatile organic compounds).Nevertheless,several intrinsic deficiencies require improvement,such as fragile mechanical properties and defects(macro and micro),resulting in the continuous deterioration of comprehensive coating performances.In this work,a novel nanocomposite coating with mechanical enhancement,intelligent self-reporting,and active protection is fabricated by integrating the functionalized and compatible graphene oxide/cerium based metal-organic framework multiscale structure(GO-CeMOF-P/M).Notably,the homogenous dispersion of GO-CeMOF-P/M and its chemical interaction with the polymer matrix effectively reduces the defects resulting from solution volatilizing and enhances the compactness,which boosts the tensile strength(32.1 MPa/8.5%)and dry adhesion force(5.8 MPa)of the coating.Additionally,the controllable responsiveness and release of multiscale nanocomposite within external environments endow intelligent active protection and self-reporting characteristics for the GO-CeMOF-P/M-EP coating,making it especially suitable for a variety of practical marine applications.Furthermore,following immersion of 80 d in the aggressive environment,Zf=0.01 Hz value of GO-CeMOF-P/M-EP coating is 1.2×10^(10)Ωcm^(2),which is 164.4 times larger than that of EP coating(7.3×10^(7)Ωcm^(2)),demonstrating remarkably strengthened anti-corrosion ability.Consequently,by offering an intriguing design strategy,the current work anticipates addressing the inherent deficiencies of EP coating and facilitating its practicality and feasibility in real sea environments.
文摘This article provides a comprehensive review of various approaches to targeted drug delivery for liver cancer, an area of significant need due to the limited effectiveness of current treatments. The article begins by highlighting the role of the liver in metabolism and discusses the high mortality associated with hepatocellular carcinoma (HCC). The shortcomings of traditional chemotherapy, such as multidrug resistance and off-target effects, necessitate the exploration of novel therapeutic strategies, with a focus on targeted approaches. The review details both passive and active targeting strategies. Passive targeting leverages the enhanced permeability and retention (EPR) effect and unique features of the tumor microenvironment, while active targeting employs specific ligands, such as peptides, antibodies, and proteins, to bind to overexpressed receptors on liver and tumor cells. The article further details many examples of active targeting using the asialoglycoprotein receptor (ASGPR), glycyrrhetinic acid (GA), transferrin receptor (TfR), and folate receptor (FR) on hepatocytes and tumor cells, demonstrating that there has been significant research effort put into this field. The importance of non-parenchymal cells in the liver is also discussed, and the article examines methods of targeting Kupffer cells, sinusoidal endothelial cells, and hepatic stellate cells for therapeutic benefit. The review goes on to cover the emerging field of subcellular targeting, including specific strategies to target the nucleus, mitochondria, and the endoplasmic reticulum/Golgi apparatus, noting that although there has been some progress, further research is needed in this area. The text finishes with a summary which acknowledges that while targeted therapies, including enzyme-activated prodrugs, such as Pradefovir, and other novel methods for drug delivery have shown significant promise, challenges remain in translating these therapies into clinical use due to limitations in understanding the sequential transport and the mechanisms of action. Ultimately, the article emphasizes the need for in-depth research to fully realize the potential of precision cancer therapies for liver cancer.
文摘Biodegradable magnesium(Mg)-based medical devices have revolutionized medical implants by uniquely combining biocompatibility and mechanical strength.Fully degradable Mg-based implants have been developed to provide temporary structural support and serve as a dynamic scaffold for tissue repair and restructuring.Additionally,Mg-based devices can respond to physiological signals,and their integration with electrical currents or pulses has been explored to enhance tissue healing and functional recovery.This review provides a comprehensive overview of the development and application of Mg-based medical devices,highlighting their evolution from traditional orthopedic,vascular,and dental uses to advanced systems that actively modulate physiological processes—a shift from passive support to active modulation.The application range of Mg-based devices has expanded from early vascular sutures,bone screws,and stents to multiple clinical fields including porous bone repair scaffolds,anastomotic staples,bioactive devices,and electro-active systems.Bioactive Mg devices demonstrate therapeutic properties including antibacterial,anti-inflammatory,anti-tumor,and osteogenic functions through their degradation products,while electro-active devices utilize the electrical properties of Mg for sensing,monitoring,and therapeutic stimulation.Finally,this review highlights current challenges,including maintaining mechanical support performance,optimizing control of biochemical reactions,and balancing electroregulatory functions,and identifies future research directions aimed at enhancing the clinical application of biodegradable Mg-based implants,thereby contributing to the significant advancement in the biomedical field.
基金provided by CAS Project for Young Scientists in Basic Research(Grant No.YSBR-085)National Time Service Center(Grant No.E239SC1101)+1 种基金the funding of Wenzhou Major Science&Technology Innovation Key Project(Grant No.ZG2023021)supported by Innovation Program for Quantum Science and Technology(Grant No.2021ZD0303200).
文摘Optical clocks with thermal atoms are characterized by compact size,simple structure,reduced weight,and low power consumption and have the potential for broad out-of-the-lab and commercial applications.Here,we demonstrate a 459 nm optical clock based on the 6S_(1/2)-7P_(1/2)transition in thermal^(133)Cs atoms.Two methods,modulation transfer spectroscopy(MTS)and frequency modulation spectroscopy(FMS),are employed to stabilize the frequency of a 459 nm commercial laser to the atomic transition.The MTS-MTS and MTS-FMS beat-note measurements show short-term frequency stabilities of 3.7×10^(-13)/√t and 6.4×10^(-13)/√t,respectively,at the averaging time t.The 459 nm passive optical clock further serves as the pump for an active 1470 nm optical clock based on the cavityless lasing.The resultant 1470 nm output power reaches over 10μW and the pump-beam-induced light shift is estimated to be 2π×11 Hz with a fractional uncertainty of 2.4×10^(-18).These results demonstrate the feasibility of hybridizing passive and active optical clocks,providing a promising route toward compact multi-wavelength optical frequency standards.
基金sponsored by the Natural Science Foundation of China(No.41374115)National High Technology Research and Development Program of China(863 project)(No.2014AA06A605)
文摘Passive seismic data contain large amounts of low-frequency information. To effectively extract and compensate active seismic data that lack low frequencies, we propose a multitaper spectral reconstruction method based on multiple sinusoidal tapers and derive equations for multisource and multitrace conditions. Compared to conventional cross correlation and deconvolution reconstruction methods, the proposed method can more accurately reconstruct the relative amplitude of recordings. Multidomain iterative denoising improves the SNR of retrieved data. By analyzing the spectral characteristics of passive data before and after reconstruction, we found that the data are expressed more clearly after reconstruction and denoising. To compensate for the low-frequency information in active data using passive seismic data, we match the power spectrum, supplement it, and then smooth it in the frequency domain. Finally, we use numerical simulation to verify the proposed method and conduct prestack depth migration using data after low-frequency compensation. The proposed power-matching method adds the losing low frequency information in the active seismic data using the low-frequency information of passive- source seismic data. The imaging of compensated data gives a more detailed information of deep structures.
基金supported by the Fundamental Research Funds for Central Public Welfare Research Institute,No.2020CZ-5(to WS and GS)the National Natural Science Foundation of China,No.31970970(to JSR)Fundamental Research Funds for the Central Universities,No.YWF-23-YG-QB-010(to JSR)。
文摘Patients with complete spinal cord injury retain the potential for volitional muscle activity in muscles located below the spinal injury level.However,because of prolonged inactivity,initial attempts to activate these muscles may not effectively engage any of the remaining neurons in the descending pathway.A previous study unexpectedly found that a brief clinical round of passive activity significantly increased volitional muscle activation,as measured by surface electromyography.In this study,we further explored the effect of passive activity on surface electromyographic signals during volitional control tasks among individuals with complete spinal cord injury.Eleven patients with chronic complete thoracic spinal cord injury were recruited.Surface electromyography data from eight major leg muscles were acquired and compared before and after the passive activity protocol.The results indicated that the passive activity led to an increased number of activated volitional muscles and an increased frequency of activation.Although the cumulative root mean square of surface electromyography amplitude for volitional control of movement showed a slight increase after passive activity,the difference was not statistically significant.These findings suggest that brief passive activity may enhance the ability to initiate volitional muscle activity during surface electromyography tasks and underscore the potential of passive activity for improving residual motor control among patients with motor complete spinal cord injury.
基金funded by the State Key Laboratory Special Fund(2060204)Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2023-I2M-2-001)Strengthen Capacity of Study and Application on the Burden of Disease in Health Care Systems in China:Establishment and Development of Chinese Burden of Disease Research and Dissemination Center(15-208)supported by the China Medical Board(CMB)。
文摘Objective Stroke is the third leading cause of death worldwide,with the highest incidence in Asia,particularly in China,where smoking remains a major risk factor.The smoking prevalence in China is similar to that in Asia.Whether the risk estimates for smoking-related stroke in China and all Asian countries are still unknown which is worth evaluating.Thus,this study aims to compare the Relative Risk(RR)of smoking-attributed stroke among the Chinese and Asian populations.Methods A literature search was conducted from the inception to September 10,2022.Studies meeting the criteria were included.The articles were screened,and related information was extracted.Pooled RRs stratified by smoking status and sex were analyzed,including subgroup analyses for China,other Asian countries,and Asia overall.Finally,publication bias and sensitivity analyses were conducted.Results Thirty-seven articles on the Chinese population and 15 on other Asian populations were included,with a mean Newcastle-Ottawa scale(NOS)score of 7.25.About ever smokers,there had no statistical difference existed in both sexes and females between China and other Asian countries,while the RR of males in other Asian countries[2.31(1.38,3.86)]was higher than that in China[1.21(1.15,1.26)];further subgroup analysis indicated that other Asian countries had higher RR[3.76(3.02,4.67)]in the morbidity subgroup.The RRs of both sexes,males and females,between China and the whole of Asia were not statistically different.As for current and former smokers,no meaningful statistical difference was observed in the pooled RRs of both sexes,males and females,in China,other Asian countries,and all of Asia.Conclusion The RR of males ever smokers in China was smaller than that in other Asian countries due to the few articles of morbidity subgroup,but had no statistical difference with the whole of Asia;other groups of ever smokers,current smokers,and former smokers were not statistically significant with other Asian countries or the whole of Asia.
基金partially supported by the National Natural Science Foundation of China(Nos.11804120,61827822,and 22275072)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515030209)+1 种基金Research Projects from Guangzhou(Nos.2023A03J0018 and 2024A04J3712)Fundamental Research Funds for the Central Universities(No.21623412).
文摘Fiber-structured ion sensors have gained traction in health monitoring and medical diagnostics owing to their structural flexibility,enhanced sensitivity,and suitability for integration into wearable devices.This study employed a simple and efficient solutionbased process to fabricate nanofibers containing aggregation-induced emission(AIE)dyes.The resulting AIE nanofibers exhibited stable and intense fluorescence,nanosecond fluorescence lifetime,and low-loss light transport when functioning as active waveguides.Additionally,crossed nanofiber intersections exhibited diffraction-limited emission spots.The AIE nanofibers demonstrate efficient and ionspecific fluorescence quenching in response to Ag^(+).These results support the development of sensing units capable of operating in liquid environments or in direct contact with skin or tissues,facilitating real-time monitoring of ion concentrations for personalized healthcare management.
基金supported by the Jilin Science and Technology Development Talent Special Project,Nos.20240601086RC,23JQ08(all to ZH)YDZJ202502CXJD077+1 种基金JLARS-2025-0802-09YDZJ202501ZYTS706.
文摘Population aging is one of the common challenges in the current world.As people age,the body’s tissues including cells,and molecules inevitably degrade,and their functions gradually decline,causing various age-related diseases like Alzheimer’s disease,osteoporosis,low immunity,glucose and lipid metabolism disorders,and cardiovascular diseases.With the continuous increase of the elderly population,the pressure on the medical industry is increasing.To lower the burden on the medical industry and increase the average age of the elderly,it is vital to explore effective anti-aging materials.Ginseng Radix et Rhizoma(Renshen),as a traditional and precious Chinese medicinal herb,is known as the“king of all herbs”.It is famous for its effects of“tonifying Qi,restoring pulse”(helping with the generation of Qi(the fundamental,vital energy that continuously flows within the body)and the circulation of blood)and strengthening the body,nourishing the spleen and lungs,generating fluids and nourishing blood,calming the mind and improving intelligence.Recently,its anti-aging effect has received increasing attention from modern scientific research.This study summarizes the pharmacological effects of the main active ingredients of Renshen(ginsenosides,polysaccharides,etc.)on resisting aging,including preventing neuroaging,suppressing skin aging,mitigating ovarian aging,inhibiting osteoporosis and arthritis,enhancing the immune system of the elderly,protecting the cardiovascular system,resisting aging-induced fatigue and exerting the anti-tumor effects.Through network pharmacology and molecular docking,the anti-aging active ingredients of Renshen were screened,and the key targets and pathways of anti-aging active ingredients in Renshen were determined.Using network pharmacology,totally 106 drug targets and 3,479 disease targets were screened,and 79 common targets between aging and Renshen were identified.Three core targets were identified in the PPI network,including TNF,AKT1,and IL-1β.Molecular docking was used to obtain further verification.This study emphasizes the potential of Renshen as a source of anti-aging activity,which can be developed into a novel drug for the treatment of age-related diseases.
文摘BACKGROUND:Hemiplegia,a prevalent stroke-related condition,is often studied for motor dysfunction;however,spasticity remains under-researched.Abnormal muscle tone significantly hinders hemiplegic patients’walking recovery.OBJECTIVE:To determine whether early suspension-protected training with a personal assistant machine for stroke patients enhances walking ability and prevents muscle spasms.METHODS:Thirty-two early-stage stroke patients from Shenzhen University General Hospital and the China Rehabilitation Research Center were randomly assigned to the experimental group(n=16)and the control group(n=16).Both groups underwent 4 weeks of gait training under the suspension protection system for 30 minutes daily,5 days a week.The experimental group used the personal assistant machine during training.Three-dimensional gait analysis(using the Cortex motion capture system),Brunnstrom staging,Fugl-Meyer Assessment for lower limb motor function,Fugl-Meyer balance function,and the modified Ashworth Scale were evaluated within 1 week before the intervention and after 4 weeks of intervention.RESULTS AND CONCLUSION:After the 4-week intervention,all outcome measures showed significant changes in each group.The experimental group had a small but significant increase in the modified Ashworth Scale score(P<0.05,d=|0.15|),while the control group had a large significant increase(P<0.05,d=|1.48|).The experimental group demonstrated greater improvements in walking speed(16.5 to 38.44 cm/s,P<0.05,d=|4.01|),step frequency(46.44 to 64.94 steps/min,P<0.05,d=|2.32|),stride length(15.50 to 29.81 cm,P<0.05,d=|3.44|),and peak hip and knee flexion(d=|1.82|to|2.17|).After treatment,the experimental group showed significantly greater improvements than the control group in walking speed(38.44 vs.26.63 cm/s,P<0.05,d=|2.75|),stride length,peak hip and knee flexion(d=|1.31|to|1.45|),step frequency(64.94 vs.59.38 steps/min,P<0.05,d=|0.85|),and a reduced support phase(bilateral:24.31%vs.28.38%,P<0.05,d=|0.88|;non-paretic:66.19%vs.70.13%,P<0.05,d=|0.94|).For early hemiplegia,personal assistant machine-assisted gait training under the suspension protection system helps establish a correct gait pattern,prevents muscle spasms,and improves motor function.
文摘HPR1000 is an advanced nuclear power plant(NPP)with the significant feature of an active and passive safety design philosophy,developed by the China National Nuclear Corporation.On one hand,it is an evolutionary design based on proven technology of the existing pressurized water reactor NPP;on the other hand,it incorporates advanced design features including a 177-fuel-assembly core loaded with CF3 fuel assemblies,active and passive safety systems,comprehensive severe accident prevention and mitigation measures,enhanced protection against external events,and improved emergency response capability.Extensive verification experiments and tests have been performed for critical innovative improvements on passive systems,the reactor core,and the main equipment.The design of HPR1000fulfills the international utility requirements for advanced light water reactors and the latest nuclear safety requirements,and addresses the safety issues relevant to the Fukushima accident.Along with its outstanding safety and economy,HPR1000 provides an excellent and practicable solution for both domestic and international nuclear power markets.
基金This project was jointly supported by the National Natural Science Foundation of China (60375008) ,the China Ph.D.Discipline Special Foundation (20020248029) and the China Aviation Science Foundation (02D57003)
文摘A new synergy tracking method of infrared and radar is presented. To improve tracking accuracy, the unscented Kalman filter （UKF）, which has better nonlinear approximation ability, is adopted. In addition, to reduce the possibility of radar being locked-on by adverse electronic support measure （ESM）, radar is under the intermittent-working state. After radar is turned off, the possible target position is estimated by a set of time polynomials, which is constructed based on the sufficient observations done before radar is turned off, the estimated values from time polynomials are compared with the current observation values from infrared to determine the time when radar is turned on. Simulation results show the method has a good tracking accuracy and effectively reduces the possibility of radar being locked-on by adverse ESM.
文摘Stroke patients always spontaneously do some learning and training of motor functions; however, learning and training are not prompt and right, while patients do not have enough activity amounts. Active and passive motor training apparatus is aimed directly at lower limb training so as to stimulate nerve function through stimulating muscular movement. Based on motor mileage, motor time, various power supplies and velocity of active and passive training apparatus, we can understand the training condition and adjust training program. OBJECTIVE： To observe the effects of grade-III rehabilitation training combining with active and passive training apparatus on lower limb function, muscle strength and activity of daily living （ADL） in stroke patients during recovery period. DESIGN： Contrast observation. SETTING： Department of Rehabilitation, Jilin Academic Institute of Traditional Chinese Medicine. PARTICIPANTS： A total of 80 patients with stroke-induced hemiplegia after stabilizing vital signs for 2 weeks were selected from Department of Rehabilitation, Jilin Academic Institute of Traditional Chinese Medicine from January to June 2007. There were 47 males and 33 females, and their ages ranged from 41 to 75 years. All patients met the diagnostic criteria of the Fourth National Cerebrovascular Disease Academic Meeting in 1995 and were diagnosed as cerebral hemorrhage or cerebral infarction through CT or MRI examinations in clinic. Patients and their parents provided the confirmed consent. Based on therapeutic orders of hospitalization, patients were randomly divided into treatment group and control group with 40 patients in each group. METHODS： Patients in the control group received physical therapy and occupational therapy combining with rehabilitative treatment based on grade-III rehabilitative treatment program, which was set by the National Cerebrovascular Disease Topic Group. In addition, patients in the treatment group were trained with active and passive motor training apparatus based on therapeutic procedures in the control group. The active and passive motor training apparatus was designed as the therapeutic style of nervous system; otherwise, the treatment was performed once a day, 30 minutes once and 6 times per week. Four weeks were regarded as a course. MAIN OUTCOME MEASURES： Before treatment, at 2 weeks after treatment and after the first course, bare-handed muscle strength examination was used to check muscle strength and muscular tension; in addition, simple Fugl-Meyer assessment （FMA） and diagnostic criteria which were set by the Fourth National Cerebrovascular Disease Academic Meeting were used to evaluate motor function of limbs and total ADL. RESULTS： All 80 stroke patients were involved in the final analysis. ① Muscle strength of lower limbs was improved in both treatment group and control group. After the first course, muscle strength in the treatment group was obviously superior to that in the control group （ x^2=6.64, P 〈 0.05）. ② After the first course, Fugl-Meyer scores in the treatment group were higher than those in the control group, and there was significant difference （t =2.82, P 〈 0.05）. ③ Muscular tension of lower limbs was not changed in both treatment group and control group after treatment （P 〉 0.05）. ④ After the first course, ADL in the treatment group was superior to that in the control group （P 〈 0.05）. Among patients in the treatment group, 24 cases （60%） had obvious progress, 16 （40%） had progress, and 0 （0%） did not have any changes. On the other hand, among patients in the control group, 13 cases （32.5%） had obvious progress, 26 （65%） had progress, and 1 （2.5%） did not have any changes. CONCLUSION： Rehabilitation training combining with active and passive motor training apparatus can promote the recovery of lower limb disorder, increase muscle strength, control spasm, improve ADL and cause satisfactorily clinical effects in stroke patients during recovery period.
基金supported by the National High Technology Research and Development Program of China(Grant No.2013AA122902)the National Key Scientific Instrument and Equipment Development Project of China(Grant No.2013YQ030595)the National Natural Science Foundation of China(Grant Nos.61274024 and 61474123)
文摘InGaAs/InP avalanche photodiodes （APD） are rarely used in a free-running regime for near-infrared single photon detection. In order to overcome the detrimental afterpulsing, we demonstrate a passive quenching active reset integrated circuit. Taking advantage of the inherent fast passive quenching process and active reset to reduce reset time, the integrated circuit is useful for reducing afterpulses and is also area-efficient. We investigate the free-running single photon detector＇s afterpulsing effect, de-trapping time, dark count rate, and photon detection efficiency, and also compare with gated regime operation. After correction for deadtime and afterpulse, we find that the passive quenching active reset free-running single photon detector＇s performance is consistent with gated operation.
文摘In this paper,a hybrid passive/active vibration(HPAV)controller of a loosely connected spacecraft consisting of a servicing satellite,a target and an X-shape structure isolator is first proposed to suppress vibrations of the system when subjected to the impulsive external excitations during the on-orbit missions.The passive dynamic response of the combined system can be adjusted appropriately to achieve the desired vibration isolation performance by tuning the structural parameters of the bio-inspired X-shape structure.Moreover,the adaptive control design through dynamic scaling technique is selected as the active component to maintain high vibration isolation performance in the presence of parameter uncertainties such as mass of the satellite platform,the damping and rotation friction coefficients of the X-shape structure.Compared with the pure passive system and the traditional spring-mass-damper(SMD)isolator,the HPAV strategy witnesses lower transmissibility,smaller vibration amplitude and higher convergence rate when subjected to the post-capture impact.Numerical simulations demonstrate the feasibility and validity of the proposed hybrid control scheme in suppressing vibrations of the free-floating spacecraft.
文摘Purpose: Muscle stretching is frequently prescribed in physical therapy to manage lower back and neck pain. However, there is no clear evidence regarding the differences in effectiveness of active and passive stretching. Therefore, we aimed to evaluate the relative effectiveness of a 12-week program of active and passive stretching on selected physical and mental stress variables of sedentary men with lower back and neck pain. Methods: A cohort of 28 sedentary men, 30 - 49 years old, were divided into two intervention groups: the passive stretching group (PSG, n = 15) and the active stretching group (ASG, n = 13). A trainer assisted with static passive stretching, while participants in the ASG were provided with an instructional video. The following outcomes were measured at the start and end of the first and twelfth week of the stretching program: physical measures (visual analogue scale score of lower back and neck pain;finger-to-floor distance, gravimetric assessment of pelvic tilt, muscle hardness of the biceps femoris, and straight-leg raising) and mental stress measures (α-amylase and cortisol levels in saliva samples). Results: Although both active and passive stretching produced acute changes in lower back and neck pain, only passive stretching yielded long-term improvement in pain, finger-to-floor distance, pelvic tilt, hardness of biceps femoris muscle and cortisol levels (p Conclusion: Passive stretching is superior to active stretching in reducing pain, increasing muscle extensibility and correcting posture among a group of sedentary men with lower back and neck pain.
基金sponsored by the National Natural Science Foundation of China(No.51725503,No.51975214)Innovation Program of Shanghai Municipal Education Commission(2019-01-07-00-02-E00068)+2 种基金support by Shanghai Technology Innovation Program of SHEITC(CXY-2015-001)Fok Ying Tung Education FoundationYoung Program of Yangtze River Scholars。
文摘Ultrasonic surface rolling process(USRP)is one of the effective mechanical surface enhancement techniques.During the USRP,unstable static force will easily do harm to the surface quality.In order to achieve a higher surface quality on the part with a curved surface,an active and passive compliant USRP system has been developed.The compliant USRP tool can produce the natural obedience deformation along the part surface.Force control based on the fuzzy Proportional-integral-derivative(PID)method is then designed to maintain the static force during the USRP.Experiments have been performed on a real aero-engine blade with curved surface.It is proved that the deigned active and passive compliant USRP system can significantly reduce the force variation from 42.2 N to 4.2 N,and achieve a uniform surface quality after processing.
基金National Fundamental Research Program (973) Under Grant No. 2007CB714204the R & D Program Under Grant No. 2006BAJ03B06NSFC Under Grant No. 90815027
文摘In this paper, the characteristics of forces in active control systems connected to adjacent levels of a building are analyzed. The following characteristics are observed： （1） active control can provide significantly superior supplemental damping to a building, but causes a small frequency shift; （2） the linear quadratic regulator （LQR）-based control force is composed of an elastic restoring force component and a damping force component, where the damping force is almost identical to the total control force, however, the elastic restoring force is very small; and （3） the active control forces prevent mction most of the time during the entire control process. These three characteristics imply that active control systems connected to adjacent levels of a building behave like passive damping devices with adjustable parameters, namely damping characteristics in an active control, which is the mechanism used by semi-active control devices to reach similar performance as active control systems. Two indices are defined to quantify the damping characteristics of control forces in active control systems. These two indices can also be used to quantify the capacity of semi-active control to achieve the perfonrlance of active control. Based on the above observations, two principles are founded for optimization of parameters of semi-active control devices and passive dampers. The first is that the maximum output force of a semi-active or passive device to be designed is identical to an active device, called ＂design principle＂. The other is the response equivalent principle, which states that the response of a building with semi-active or passive devices is the same as with active devices when the same maximum output force is applied. The design procedure for semi-active control devices and passive dampers is described in detail. Finally, numerical simulations of two benchmark problems is conducted to demonstrate the damping characteristics of active control and investigate the capacity of semi-active control to achieve the same performance as active control.
