With the advancement of electronic countermeasures,airborne synthetic aperture radar(SAR)systems are facing increasing challenges in maintaining effective performance in hostile environments.In particular,high-power i...With the advancement of electronic countermeasures,airborne synthetic aperture radar(SAR)systems are facing increasing challenges in maintaining effective performance in hostile environments.In particular,high-power interference can severely degrade SAR imaging and signal processing,often rendering target detection impossible.This highlights the urgent need for robust anti-interference solutions in both the signal processing and image processing domains.While current methods address interference across various domains,techniques such as waveform modification and spatial filtering typically increase the system costs and complexity.To overcome these limitations,we propose a novel approach that leverages the multi-domain characteristics of interference to efficiently suppress narrowband interference and repeater modulation interference.Specifically,narrowband interference is mitigated using notch filtering,a signal processing technique that effectively filters out unwanted frequencies,while repeater modulation interference is addressed through strong signal amplitude normalization,which enhances both the signal and image processing quality.These methods were validated through tests on real SAR data,demonstrating significant improvements in the imaging performance and system robustness.Our approach offers valuable insights for advancing anti-interference technologies in SAR systems and provides a cost-effective solution to enhance their resilience in complex electronic warfare environments.展开更多
The ability to predict the anti-interference communications performance of unmanned aerial vehicle(UAV)data links is critical for intelligent route planning of UAVs in real combat scenarios.Previous research in this a...The ability to predict the anti-interference communications performance of unmanned aerial vehicle(UAV)data links is critical for intelligent route planning of UAVs in real combat scenarios.Previous research in this area has encountered several limitations:Classifiers exhibit low training efficiency,their precision is notably reduced when dealing with imbalanced samples,and they cannot be applied to the condition where the UAV’s flight altitude and the antenna bearing vary.This paper proposes the sequential Latin hypercube sampling(SLHS)-support vector machine(SVM)-AdaBoost algorithm,which enhances the training efficiency of the base classifier and circumvents local optima during the search process through SLHS optimization.Additionally,it mitigates the bottleneck of sample imbalance by adjusting the sample weight distribution using the AdaBoost algorithm.Through comparison,the modeling efficiency,prediction accuracy on the test set,and macro-averaged values of precision,recall,and F1-score for SLHS-SVM-AdaBoost are improved by 22.7%,5.7%,36.0%,25.0%,and 34.2%,respectively,compared with Grid-SVM.Additionally,these values are improved by 22.2%,2.1%,11.3%,2.8%,and 7.4%,respectively,compared with particle swarm optimization(PSO)-SVM-AdaBoost.Combining Latin hypercube sampling with the SLHS-SVM-AdaBoost algorithm,the classification prediction model of anti-interference performance of UAV data links,which took factors like three-dimensional position of UAV and antenna bearing into consideration,is established and used to assess the safety of the classical flying path and optimize the flying route.It was found that the risk of loss of communications could not be completely avoided by adjusting the flying altitude based on the classical path,whereas intelligent path planning based on the classification prediction model of anti-interference performance can realize complete avoidance of being interfered meanwhile reducing the route length by at least 2.3%,thus benefiting both safety and operation efficiency.展开更多
This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[
When signal-to-interference ratio is low, the energy of strong interference leaked from the side lobe of beam pattern will infect the detection of weak target. Therefore, the beam pattern needs to be op...When signal-to-interference ratio is low, the energy of strong interference leaked from the side lobe of beam pattern will infect the detection of weak target. Therefore, the beam pattern needs to be optimized. The existing Dolph-Chebyshev weighting method can get the lowest side lobe level under given main lobe width, but for the other non-uniform circular array and nonlinear array, the low side lobe pattern needs to be designed specially. The second order cone programming optimization （SOCP） algorithm proposed in the paper transforms the optimization of the beam pattern into a standard convex optimization problem. Thus there is a paradigm to follow for any array formation, which not only achieves the purpose of Dolph-Chebyshev weighting, but also solves the problem of the increased side lobe when the signal is at end fire direction The simulation proves that the SOCP algorithm can detect the weak target better than the conventional beam forming.展开更多
An RF transceiver composed of a zero-IF receiver and a direct up-conversion transmitter for cognitive radio applications is presented. The adjustable channel filter array in the receiver is used to suppress adjacent c...An RF transceiver composed of a zero-IF receiver and a direct up-conversion transmitter for cognitive radio applications is presented. The adjustable channel filter array in the receiver is used to suppress adjacent channel interference in televisions signal coexistence environments. The low noise amplifier （LNA） with wide dynamic range and high linearity is employed to enhance the anti-interference competence of the zero-IF receiver. Meanwhile, the high linearity power amplifier （PA） .is used to promote the adjacent channel power ratio （ACPR） characteristic of the direct up-conversion transmitter. The measured error vector magnitude （EVM） results show that the anti-interference competence of the zero-IF receiver is dramatically enhanced by employing a channel filter array. The measured ACPR of the direct up-conversion transmitter is -47. 98 dBc on the channel centered at 714 MHz when the output power is 27 dBm.展开更多
Shallow conductive heterogeneity can lead to static shifts ain the apparent resistivity sounding curve of controlled-source audio-frequency magnetotellurics(CSAMT).The static effect will shift the apparent resistivity...Shallow conductive heterogeneity can lead to static shifts ain the apparent resistivity sounding curve of controlled-source audio-frequency magnetotellurics(CSAMT).The static effect will shift the apparent resistivity curves along with axial log-log coordinates.Such an effect,if not properly processed,can distort the resistivity of rock formation and the depth of interfaces,and even make the geological structures unrecognizable.In this paper,we discuss the reasons and characteristics of the static shift and summarize the previous studies regarding static shift correction.Then,we propose the Guided Image Filtering algorithm to suppress static shifts in CSAMT.In detail,we use the multi-window superposition method to superimpose 1D signals into a 2D matrix image,which is subsequently processed with Guided Image Filtering.In the synthetic model study and field examples,the Guided Image Filtering algorithm has effectively corrected and suppressed static shifts,and finally improved the precision of data interpretation.展开更多
To suppress the interference in the ultra-wideband （AI-UWB） system is a challenging problem. An anti-interference multiband orthogonal frequency-division multiplexing ultra-wideband （AI-UWB） system, based on sprea...To suppress the interference in the ultra-wideband （AI-UWB） system is a challenging problem. An anti-interference multiband orthogonal frequency-division multiplexing ultra-wideband （AI-UWB） system, based on spreading and interleaving is addressed. It will exploit the frequency diversity across the subcarriers and provide the robustness to narrow-band interference, by spreading the coded bit streams within each sub-band and interleaving across all sub-bands. Simulating results show that the spreading and interleaving provide about 5 dB to 10 dB advantages over the conventional multiband orthogonal frequency-division multiplexing ultra-wideband system in signal-to-interference ratio. Spreading and interleaving is an effective cure for enhancing the robustness to narrowband interference.展开更多
Accurate detection of important biomarkers with ultra-low levels in complex biological matrix is one of the frontier scientific issues because of possible signal interference of potential reductive agents and protein ...Accurate detection of important biomarkers with ultra-low levels in complex biological matrix is one of the frontier scientific issues because of possible signal interference of potential reductive agents and protein molecules.Herein,a self-powered anti-interference photoelectrochemical(PEC)immunosensor was explored for sensitive and specific detection of model target of cardiac troponinⅠ(cTnI).Specifically,a novel ternary heterojunction served as the photocathode to offer a remarkable current output and a zwitterionic peptide was introduced to build a robust antifouling biointerface.CuInS(CIS)film with porous network nanostructure was first prepared and then modified in order with ZnInS(ZIS)nanocrystals and Au nanoparticles to fabricate the Au/ZIS/CIS heterojunction photocathode.After capture cTnI antibody(Ab)was immobilized,the zwitterionic peptide KAEAKAEAPPPPC was then anchored to compete the immunosensor.The elaborated PEC immunosensor exhibited high sensitivity for target cTnI antigen(Ag)detection,with good anti-interference against reductive agents and nonspecific proteins.This integration strategy of heterojunction photocathode with zwitterionic peptide provides a new sight to develop advanced PEC immunosensors applying in practical biosamples.展开更多
The performance of a strapdown inertial navigation system(SINS)largely depends on the accuracy and rapidness of the initial alignment.A novel anti-interference self-alignment algorithm by attitude optimization estimat...The performance of a strapdown inertial navigation system(SINS)largely depends on the accuracy and rapidness of the initial alignment.A novel anti-interference self-alignment algorithm by attitude optimization estimation for SINS on a rocking base is presented in this paper.The algorithm transforms the initial alignment into the initial attitude determination problem by using infinite vector observations to remove the angular motions,the SINS alignment is heuristically established as an optimiza-tion problem of finding the minimum eigenvector.In order to further improve the alignment precision,an adaptive recursive weighted least squares(ARWLS)curve fitting algorithm is used to fit the translational motion interference-contaminated reference vectors according to their time domain characteristics.Simulation studies and experimental results favorably demonstrate its rapidness,accuracy and robustness.展开更多
Automatic gauge control(AGC in the article)is the key technology of product thickness accuracy and flatness quality in modern cold rolling mill.Most traditional AGC control algorithms need stable external system condi...Automatic gauge control(AGC in the article)is the key technology of product thickness accuracy and flatness quality in modern cold rolling mill.Most traditional AGC control algorithms need stable external system conditions and hard to stabilize under complex interference that meets coverage requirements.This paper presents a new anti-interference strategy for AGC control of 20-Hi cold reversing mill.The proposed algorithm introduces a united dynamic weights algorithm of feed forward-mass flow to avoid the complex interference problem in AGC control,the relevant control strategy is provided to eliminate the adverse effects.At the same time,the D-value between feed forward-mass flow pre-computation and thickness measurement deviation is dynamic compared,the final gap position regulation is calculated by developing a set of united dynamic weights between feed forward control and mass flow control.Finally,the output of controllers is sent to actuator though a constant rate smoothing.The proposed strategy is compared with conventional AGC control on Experimental platform and project application,the results show that the proposed strategy is more stable than comparison method and majority of system uncertainty produced by mentioned interference is significantly eliminated.展开更多
Integrated circuit technology based on analog electronic and digital electronic technology is more and more widely used in secondary equipment such as microcomputer protection devices. With the development of technolo...Integrated circuit technology based on analog electronic and digital electronic technology is more and more widely used in secondary equipment such as microcomputer protection devices. With the development of technology, the complexity of anti-interference problem in the secondary loop is increasing due to the diversity of technical routes and the complexity of types of devices in the power system. In the station of new energy power plant, there are many kinds of secondary circuits, which make the anti-interference problem of the circuits especially prominent. This paper attempts to analyze and discuss the common interference sources and anti-interference measures from the common interference sources and interference ways in the secondary circuits of the new energy power plant station.展开更多
With the rapid development of internet, users demand for the performance of wireless network is getting higher and higher. Under this background, with the rise of small base stations such as micro-cellular base statio...With the rapid development of internet, users demand for the performance of wireless network is getting higher and higher. Under this background, with the rise of small base stations such as micro-cellular base stations and the appearance of low-power base stations such as micro-cellular base stations and femto-cellular base stations, wireless cellular networks are gradually transformed into emerging heterogeneous wireless networks, and the number of base stations is also greatly increased. Due to the limitation of bandwidth resources, anti-interference and handoff have become common concerns at home and abroad.展开更多
A series of CeO_(2)@MnO_(2)composites was prepared by deposition-precipitation methods.These materials were used to activate sodium persulfate(PDS)for the oxidation of tetracycline.It is found that the composites,espe...A series of CeO_(2)@MnO_(2)composites was prepared by deposition-precipitation methods.These materials were used to activate sodium persulfate(PDS)for the oxidation of tetracycline.It is found that the composites,especially the CeO_(2)@MnO_(2)-1:4 composites,exhibit better tetracycline removal rates than the pure components.X-ray diffraction(XRD),Raman and scanning electron microscopy(SEM)analyses all indicate that the composite has been successfully prepared with high purity and high crystalline.The XPS analysis shows that the strong interaction between the components promotes the electron transfer.Additionally,the kinetic rate constants of CeO_(2)@MnO_(2)-1:4 after 60 min are 3.8 and 12.7 times higher than pure CeO_(2)and MnO_(2),respectively.CeO_(2)@MnO_(2-)1:4 composite also exhibits excellent catalytic activity for individual and hybrid pollutants.The effects of wastewater matrix,pH,circulation and ion stre ngth on the degradation of tetracycline were investigated.It is found that CeO_(2)@MnO_(2)-1:4 composite has good practical application prospects.CeO_(2)@MnO_(2)composites with synergistic adsorption catalysis can activate PDS and peroxymo no sulfate(PMS)for efficient organic catalytic oxidation.This paper provides the theoretical basis and data support for the practical application of the CeO_(2)@MnO_(2)composite materials.展开更多
Atherosclerosis(AS),a chronic vascular lesion,constitutes the primary pathological basis for a variety of cardiovascular diseases that account for 85%of total cardiovascular mortality.The accurate identification of AS...Atherosclerosis(AS),a chronic vascular lesion,constitutes the primary pathological basis for a variety of cardiovascular diseases that account for 85%of total cardiovascular mortality.The accurate identification of AS is of critical significance for early clinical diagnosis and therapeutic interventions for associated diseases.Herein,we report a changeableπ-conjugated probe(ASOCl-1)capable of specific AS imaging with resistance to serum protein interference and microenvironmental perturbations.ASOCl-1 itself was non-conjugated and non-fluorescent.Upon the activation by inflammatory biomarker hypochlorite(OCl^(−)),the probe underwent a molecular rearrangement to generate a near-infrared fluorophore oxazine,with environmental-insusceptible response and anti-interference from serum protein.ASOCl-1 has been used to image OCl^(−)inside foam cells,a type of cell derived from macrophages at the AS sites.Most importantly,ASOCl-1 could achieve in vivo,ex vivo and slice imaging of AS mice.The satisfactory imaging performance and anti-interference capability of ASOCl-1 make it a potential tool for AS imaging diagnosis and disease progression monitoring.展开更多
Chemical warfare agents(CWAs)can cause significant harm to health and even death in a very short time even when inhaled in small amounts(~100 mg min/m^(3)).Detection equipment based on conventional techniques,includin...Chemical warfare agents(CWAs)can cause significant harm to health and even death in a very short time even when inhaled in small amounts(~100 mg min/m^(3)).Detection equipment based on conventional techniques,including gas chromatography-mass spectrometry,Raman spectroscopy,fluorescence spectroscopy,and ion mobility spectrometry,have the disadvantages of high cost,long detection time,and high power consumption.Rapid,portable,and convenient equipment for target CWAs detection under interference is a challenge.In this study,we propose an alarm system comprising a multitype micro sensor array and a field-programmable gate array-based readout circuit for CWAs simulants detection.Under common volatile organic compound,temperature,and water vapor interference,the proposed multitype sensor-based detection system realizes an alarm function in less than 20 s with thresholds of 1 ppm dimethyl methylphosphonate(DMMP),4.6 ppm 2,2'-dichlorodiethyl ether(DCE),and 20 ppm SO_(2).Furthermore,the proposed detection system was evaluated outside the laboratory and passed the wilderness test,demonstrating its reliability in the atmosphere.We believe that the proposed alarm system will contribute to the development of intelligent,portable,low-cost,and anti-interference CWAs detection technology.展开更多
Electronic skin(e-skin),capable of perceiving various external stimuli,has emerged as a ubiquitous technology in the field of flexible electronics,finding diverse applications in healthcare systems,prosthetics,and sof...Electronic skin(e-skin),capable of perceiving various external stimuli,has emerged as a ubiquitous technology in the field of flexible electronics,finding diverse applications in healthcare systems,prosthetics,and soft robotics.Particularly,anisotropic e-skins have garnered extensive research attention due to their unique directional properties.Nevertheless,the continuous interference from diverse stimuli and intricate environments,along with low sensitivity,have hindered the further widespread application of anisotropic e-skin.Here,we present a transparent e-skin exhibiting remarkable anisotropic strain sensing performance,along with exceptional resilience against interference from other stimuli and harsh environments.Benefiting from the synergistic coexistence of aligned silver nanowires wrinkles and cracks,the e-skin achieves outstanding anisotropy showcasing maximum strain gauge factors(GFs)difference of 2825 and 0.69 along two perpendicular directions,exceeding a difference of more than 4000 times.Furthermore,the e-skin displays superior anti-interference capability,evidenced by a resistance change of less than 6%when subjected to high pressure(663 kPa),torsion(540°),or bending(180°),and exhibits negligible performance degradation even after exposure to harsh environments.Finally,our e-skin is successfully applied to undisturbed predicting crack propagation and precise control of dual-mode soft robots,highlighting its immense potential in structural damage warning and intelligent robotics.展开更多
As modern electromagnetic environments are more and more complex,the anti-interference performance of the synchronization acquisition is becoming vital in wireless communications.With the rapid development of the digi...As modern electromagnetic environments are more and more complex,the anti-interference performance of the synchronization acquisition is becoming vital in wireless communications.With the rapid development of the digital signal processing technologies,some synchronization acquisition algorithms for hybrid direct-sequence(DS)/frequency hopping(FH)spread spectrum communications have been proposed.However,these algorithms do not focus on the analysis and the design of the synchronization acquisition under typical interferences.In this paper,a synchronization acquisition algorithm based on the frequency hopping pulses combining(FHPC)is proposed.Specifically,the proposed algorithm is composed of two modules:an adaptive interference suppression(IS)module and an adaptive combining decision module.The adaptive IS module mitigates the effect of the interfered samples in the time-domain or the frequencydomain,and the adaptive combining decision module can utilize each frequency hopping pulse to construct an anti-interference decision metric and generate an adaptive acquisition decision threshold to complete the acquisition.Theory and simulation demonstrate that the proposed algorithm significantly enhances the antiinterference and anti-noise performances of the synchronization acquisition for hybrid DS/FH communications.展开更多
Balise system is one kind of high-rate point-mode data transmission equipment.It plays an indispensable role in Chinese Train Control System(CTCS),and it has been immigrated and widely used for passenger dedicated lin...Balise system is one kind of high-rate point-mode data transmission equipment.It plays an indispensable role in Chinese Train Control System(CTCS),and it has been immigrated and widely used for passenger dedicated lines and high-speed lines.Thus,its working conditions directly affect train operation safety.However,the balise information transmission system(BITS)is based on the principle of electromagnetic induction,and the communication process is susceptible to external electromagnetic interference.Therefore,it is vital to study the influence of transient signal interference on the balise system.This paper builds the up-link model between the vehicle antena and the balise,and verifies the model’s correctness using finite-difference time-domain method and electromagnetic field theory.This paper analyzes the effect of electromagnetic pulses on the transponder’s uplink and simulates the coupled current under irradiation.The spectral distribution of the three types of pulse interference is analyzed according to relevant standards.Strong electromagnetic pulses have a strong energy distribution in the working frequency band of the up-link,which will generate in-band interference and bit errors.It will affect the balise communication and threaten the safety of train operation.As we know we are the first to analyze the effects of EMP on Chinese BITS,which will lay a foundation for the research of electromagnetic anti-interference or protection to highspeed railway.展开更多
Due to the strong electromagnetic interferences and human interference,traditional electromagnetic methods cannot obtain high quality resistivity data of mineral deposits in Chinese mines.The wide field electromagneti...Due to the strong electromagnetic interferences and human interference,traditional electromagnetic methods cannot obtain high quality resistivity data of mineral deposits in Chinese mines.The wide field electromagnetic method(WFEM),in which the pseudo-random signal is taken as the transmitter source,can extract high quality resistivity data in areas with sever interference by only measuring the electric field component.We use the WFEM to extract the resistivity information of the Dongguashan mine in southeast China.Compared with the audio magnetotelluric(AMT)method,and the controlled source audio-frequency magnetotelluric(CSAMT) method,the WFEM can obtain data with higher quality and simpler operations.The inversion results indicate that the WFEM can accurately identify the location of the main ore-body,which can be used for deep mine exploration in areas with strong interference.展开更多
Vortex street flowmeter has been used in steady flow measurement for about three decades The benefits of this type of flowmeter include high accuracy,good linearty,wide measuring range,and excellent reliability Ho...Vortex street flowmeter has been used in steady flow measurement for about three decades The benefits of this type of flowmeter include high accuracy,good linearty,wide measuring range,and excellent reliability However,in unsteady flow measurement,the pressure disturbance as well as the noise from the system or surrounding can reduce the signal to noise ratio of the flowmeter seriously Aimed to use vortex street flowmeters in unsteady flow measurement,the characteristics of the vortex shedding induced hydrodynamic vibration around the prism bluff body in a vortex street flowmeter are investigated numerically and by expriments The results show that the hydrodynamic vibrations with 180° phase shift occur at the axisymmetric points of the channel around the bluff body The most intense vibration occurs at the points on the lateral faces close to the base of the prism The results provide therefore a useful reference for developing an anti interference vortex flowmeter using the different ial sensing technique.展开更多
文摘With the advancement of electronic countermeasures,airborne synthetic aperture radar(SAR)systems are facing increasing challenges in maintaining effective performance in hostile environments.In particular,high-power interference can severely degrade SAR imaging and signal processing,often rendering target detection impossible.This highlights the urgent need for robust anti-interference solutions in both the signal processing and image processing domains.While current methods address interference across various domains,techniques such as waveform modification and spatial filtering typically increase the system costs and complexity.To overcome these limitations,we propose a novel approach that leverages the multi-domain characteristics of interference to efficiently suppress narrowband interference and repeater modulation interference.Specifically,narrowband interference is mitigated using notch filtering,a signal processing technique that effectively filters out unwanted frequencies,while repeater modulation interference is addressed through strong signal amplitude normalization,which enhances both the signal and image processing quality.These methods were validated through tests on real SAR data,demonstrating significant improvements in the imaging performance and system robustness.Our approach offers valuable insights for advancing anti-interference technologies in SAR systems and provides a cost-effective solution to enhance their resilience in complex electronic warfare environments.
文摘The ability to predict the anti-interference communications performance of unmanned aerial vehicle(UAV)data links is critical for intelligent route planning of UAVs in real combat scenarios.Previous research in this area has encountered several limitations:Classifiers exhibit low training efficiency,their precision is notably reduced when dealing with imbalanced samples,and they cannot be applied to the condition where the UAV’s flight altitude and the antenna bearing vary.This paper proposes the sequential Latin hypercube sampling(SLHS)-support vector machine(SVM)-AdaBoost algorithm,which enhances the training efficiency of the base classifier and circumvents local optima during the search process through SLHS optimization.Additionally,it mitigates the bottleneck of sample imbalance by adjusting the sample weight distribution using the AdaBoost algorithm.Through comparison,the modeling efficiency,prediction accuracy on the test set,and macro-averaged values of precision,recall,and F1-score for SLHS-SVM-AdaBoost are improved by 22.7%,5.7%,36.0%,25.0%,and 34.2%,respectively,compared with Grid-SVM.Additionally,these values are improved by 22.2%,2.1%,11.3%,2.8%,and 7.4%,respectively,compared with particle swarm optimization(PSO)-SVM-AdaBoost.Combining Latin hypercube sampling with the SLHS-SVM-AdaBoost algorithm,the classification prediction model of anti-interference performance of UAV data links,which took factors like three-dimensional position of UAV and antenna bearing into consideration,is established and used to assess the safety of the classical flying path and optimize the flying route.It was found that the risk of loss of communications could not be completely avoided by adjusting the flying altitude based on the classical path,whereas intelligent path planning based on the classification prediction model of anti-interference performance can realize complete avoidance of being interfered meanwhile reducing the route length by at least 2.3%,thus benefiting both safety and operation efficiency.
文摘This paper presents the study and application of the electronic device anti-interference techniques underhigh voltage and/or heavy current electro-magnetic circumstance in power system.[
基金Special Item of National Major Scientific Apparatus Development(No.2013YQ140431)
文摘When signal-to-interference ratio is low, the energy of strong interference leaked from the side lobe of beam pattern will infect the detection of weak target. Therefore, the beam pattern needs to be optimized. The existing Dolph-Chebyshev weighting method can get the lowest side lobe level under given main lobe width, but for the other non-uniform circular array and nonlinear array, the low side lobe pattern needs to be designed specially. The second order cone programming optimization （SOCP） algorithm proposed in the paper transforms the optimization of the beam pattern into a standard convex optimization problem. Thus there is a paradigm to follow for any array formation, which not only achieves the purpose of Dolph-Chebyshev weighting, but also solves the problem of the increased side lobe when the signal is at end fire direction The simulation proves that the SOCP algorithm can detect the weak target better than the conventional beam forming.
基金The National Natural Science Foundation of China(No.60621002)the National High Technology Research and Development Program of China(863 Program)(No.2009AA011801)
文摘An RF transceiver composed of a zero-IF receiver and a direct up-conversion transmitter for cognitive radio applications is presented. The adjustable channel filter array in the receiver is used to suppress adjacent channel interference in televisions signal coexistence environments. The low noise amplifier （LNA） with wide dynamic range and high linearity is employed to enhance the anti-interference competence of the zero-IF receiver. Meanwhile, the high linearity power amplifier （PA） .is used to promote the adjacent channel power ratio （ACPR） characteristic of the direct up-conversion transmitter. The measured error vector magnitude （EVM） results show that the anti-interference competence of the zero-IF receiver is dramatically enhanced by employing a channel filter array. The measured ACPR of the direct up-conversion transmitter is -47. 98 dBc on the channel centered at 714 MHz when the output power is 27 dBm.
基金sponsored by the Basic Science Center Project of National Natural Science Foundation of China(72088101)。
文摘Shallow conductive heterogeneity can lead to static shifts ain the apparent resistivity sounding curve of controlled-source audio-frequency magnetotellurics(CSAMT).The static effect will shift the apparent resistivity curves along with axial log-log coordinates.Such an effect,if not properly processed,can distort the resistivity of rock formation and the depth of interfaces,and even make the geological structures unrecognizable.In this paper,we discuss the reasons and characteristics of the static shift and summarize the previous studies regarding static shift correction.Then,we propose the Guided Image Filtering algorithm to suppress static shifts in CSAMT.In detail,we use the multi-window superposition method to superimpose 1D signals into a 2D matrix image,which is subsequently processed with Guided Image Filtering.In the synthetic model study and field examples,the Guided Image Filtering algorithm has effectively corrected and suppressed static shifts,and finally improved the precision of data interpretation.
基金the National "863" High Technology Research Program of China (2005AA123320)Universities Natural Science Research Project of Jiangsu Province (05KJB510101).
文摘To suppress the interference in the ultra-wideband （AI-UWB） system is a challenging problem. An anti-interference multiband orthogonal frequency-division multiplexing ultra-wideband （AI-UWB） system, based on spreading and interleaving is addressed. It will exploit the frequency diversity across the subcarriers and provide the robustness to narrow-band interference, by spreading the coded bit streams within each sub-band and interleaving across all sub-bands. Simulating results show that the spreading and interleaving provide about 5 dB to 10 dB advantages over the conventional multiband orthogonal frequency-division multiplexing ultra-wideband system in signal-to-interference ratio. Spreading and interleaving is an effective cure for enhancing the robustness to narrowband interference.
基金supported by the National Natural Science Foundation of China(Nos.22074073,21275087)the Natural Science Foundation of Shandong Province of China(No.ZR2021YQ11)the Taishan Scholar Program of Shandong Province of China(No.ts20110829)。
文摘Accurate detection of important biomarkers with ultra-low levels in complex biological matrix is one of the frontier scientific issues because of possible signal interference of potential reductive agents and protein molecules.Herein,a self-powered anti-interference photoelectrochemical(PEC)immunosensor was explored for sensitive and specific detection of model target of cardiac troponinⅠ(cTnI).Specifically,a novel ternary heterojunction served as the photocathode to offer a remarkable current output and a zwitterionic peptide was introduced to build a robust antifouling biointerface.CuInS(CIS)film with porous network nanostructure was first prepared and then modified in order with ZnInS(ZIS)nanocrystals and Au nanoparticles to fabricate the Au/ZIS/CIS heterojunction photocathode.After capture cTnI antibody(Ab)was immobilized,the zwitterionic peptide KAEAKAEAPPPPC was then anchored to compete the immunosensor.The elaborated PEC immunosensor exhibited high sensitivity for target cTnI antigen(Ag)detection,with good anti-interference against reductive agents and nonspecific proteins.This integration strategy of heterojunction photocathode with zwitterionic peptide provides a new sight to develop advanced PEC immunosensors applying in practical biosamples.
基金supported by the National Natural Science Foundation of China(41174162).
文摘The performance of a strapdown inertial navigation system(SINS)largely depends on the accuracy and rapidness of the initial alignment.A novel anti-interference self-alignment algorithm by attitude optimization estimation for SINS on a rocking base is presented in this paper.The algorithm transforms the initial alignment into the initial attitude determination problem by using infinite vector observations to remove the angular motions,the SINS alignment is heuristically established as an optimiza-tion problem of finding the minimum eigenvector.In order to further improve the alignment precision,an adaptive recursive weighted least squares(ARWLS)curve fitting algorithm is used to fit the translational motion interference-contaminated reference vectors according to their time domain characteristics.Simulation studies and experimental results favorably demonstrate its rapidness,accuracy and robustness.
文摘Automatic gauge control(AGC in the article)is the key technology of product thickness accuracy and flatness quality in modern cold rolling mill.Most traditional AGC control algorithms need stable external system conditions and hard to stabilize under complex interference that meets coverage requirements.This paper presents a new anti-interference strategy for AGC control of 20-Hi cold reversing mill.The proposed algorithm introduces a united dynamic weights algorithm of feed forward-mass flow to avoid the complex interference problem in AGC control,the relevant control strategy is provided to eliminate the adverse effects.At the same time,the D-value between feed forward-mass flow pre-computation and thickness measurement deviation is dynamic compared,the final gap position regulation is calculated by developing a set of united dynamic weights between feed forward control and mass flow control.Finally,the output of controllers is sent to actuator though a constant rate smoothing.The proposed strategy is compared with conventional AGC control on Experimental platform and project application,the results show that the proposed strategy is more stable than comparison method and majority of system uncertainty produced by mentioned interference is significantly eliminated.
文摘Integrated circuit technology based on analog electronic and digital electronic technology is more and more widely used in secondary equipment such as microcomputer protection devices. With the development of technology, the complexity of anti-interference problem in the secondary loop is increasing due to the diversity of technical routes and the complexity of types of devices in the power system. In the station of new energy power plant, there are many kinds of secondary circuits, which make the anti-interference problem of the circuits especially prominent. This paper attempts to analyze and discuss the common interference sources and anti-interference measures from the common interference sources and interference ways in the secondary circuits of the new energy power plant station.
文摘With the rapid development of internet, users demand for the performance of wireless network is getting higher and higher. Under this background, with the rise of small base stations such as micro-cellular base stations and the appearance of low-power base stations such as micro-cellular base stations and femto-cellular base stations, wireless cellular networks are gradually transformed into emerging heterogeneous wireless networks, and the number of base stations is also greatly increased. Due to the limitation of bandwidth resources, anti-interference and handoff have become common concerns at home and abroad.
基金Project supported by the Science and Technology Project of Henan Province(242102321048,242102321045,232102320211)National Natural Science Foundation of China(22206080)+2 种基金Natural Science Foundation of Jiangsu(SBK2022041070)International Science and Technology Cooperation Projects of Henan Province(232102521009)Natural Science Youth Foundation of Henan Province(232300420336)。
文摘A series of CeO_(2)@MnO_(2)composites was prepared by deposition-precipitation methods.These materials were used to activate sodium persulfate(PDS)for the oxidation of tetracycline.It is found that the composites,especially the CeO_(2)@MnO_(2)-1:4 composites,exhibit better tetracycline removal rates than the pure components.X-ray diffraction(XRD),Raman and scanning electron microscopy(SEM)analyses all indicate that the composite has been successfully prepared with high purity and high crystalline.The XPS analysis shows that the strong interaction between the components promotes the electron transfer.Additionally,the kinetic rate constants of CeO_(2)@MnO_(2)-1:4 after 60 min are 3.8 and 12.7 times higher than pure CeO_(2)and MnO_(2),respectively.CeO_(2)@MnO_(2-)1:4 composite also exhibits excellent catalytic activity for individual and hybrid pollutants.The effects of wastewater matrix,pH,circulation and ion stre ngth on the degradation of tetracycline were investigated.It is found that CeO_(2)@MnO_(2)-1:4 composite has good practical application prospects.CeO_(2)@MnO_(2)composites with synergistic adsorption catalysis can activate PDS and peroxymo no sulfate(PMS)for efficient organic catalytic oxidation.This paper provides the theoretical basis and data support for the practical application of the CeO_(2)@MnO_(2)composite materials.
基金support from the National Natural Science Foundation of China(Grant Nos.82060626,22164022,22374153)Talents of Guizhou Science and Technology Cooperation Platform([2020]4104)+2 种基金Science and Technology Innovation Team of Higher Education of Guizhou Provincial Education Department(Qianjiaoji[2023]073)Future Science and Technology Elite Talent Cultivation Project of Zunyi Medical University(ZYSE-2021-01)Zunyi Science and Technology Plan Project(Zunshi Keren Platform[2023]2).
文摘Atherosclerosis(AS),a chronic vascular lesion,constitutes the primary pathological basis for a variety of cardiovascular diseases that account for 85%of total cardiovascular mortality.The accurate identification of AS is of critical significance for early clinical diagnosis and therapeutic interventions for associated diseases.Herein,we report a changeableπ-conjugated probe(ASOCl-1)capable of specific AS imaging with resistance to serum protein interference and microenvironmental perturbations.ASOCl-1 itself was non-conjugated and non-fluorescent.Upon the activation by inflammatory biomarker hypochlorite(OCl^(−)),the probe underwent a molecular rearrangement to generate a near-infrared fluorophore oxazine,with environmental-insusceptible response and anti-interference from serum protein.ASOCl-1 has been used to image OCl^(−)inside foam cells,a type of cell derived from macrophages at the AS sites.Most importantly,ASOCl-1 could achieve in vivo,ex vivo and slice imaging of AS mice.The satisfactory imaging performance and anti-interference capability of ASOCl-1 make it a potential tool for AS imaging diagnosis and disease progression monitoring.
基金supported by the National Natural Science Foundation of China(Grant Nos.61671368,62174130)Basic Public Welfare Research Planning Project of Zhejiang Province(Grant No.LGG19F040002)+2 种基金the Science and Technology Program of Shaanxi Province(Grant No.2021GY-061)the Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences,National Defense Foundation of China(Grant Nos.2022-JCJQ-JJ-1099,2022-JCJQ-JJ-1108)the Fundamental Research Funds for the Central Universities。
文摘Chemical warfare agents(CWAs)can cause significant harm to health and even death in a very short time even when inhaled in small amounts(~100 mg min/m^(3)).Detection equipment based on conventional techniques,including gas chromatography-mass spectrometry,Raman spectroscopy,fluorescence spectroscopy,and ion mobility spectrometry,have the disadvantages of high cost,long detection time,and high power consumption.Rapid,portable,and convenient equipment for target CWAs detection under interference is a challenge.In this study,we propose an alarm system comprising a multitype micro sensor array and a field-programmable gate array-based readout circuit for CWAs simulants detection.Under common volatile organic compound,temperature,and water vapor interference,the proposed multitype sensor-based detection system realizes an alarm function in less than 20 s with thresholds of 1 ppm dimethyl methylphosphonate(DMMP),4.6 ppm 2,2'-dichlorodiethyl ether(DCE),and 20 ppm SO_(2).Furthermore,the proposed detection system was evaluated outside the laboratory and passed the wilderness test,demonstrating its reliability in the atmosphere.We believe that the proposed alarm system will contribute to the development of intelligent,portable,low-cost,and anti-interference CWAs detection technology.
基金supported by the National Natural Science Foundation of China(No.22175164)Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0450402)。
文摘Electronic skin(e-skin),capable of perceiving various external stimuli,has emerged as a ubiquitous technology in the field of flexible electronics,finding diverse applications in healthcare systems,prosthetics,and soft robotics.Particularly,anisotropic e-skins have garnered extensive research attention due to their unique directional properties.Nevertheless,the continuous interference from diverse stimuli and intricate environments,along with low sensitivity,have hindered the further widespread application of anisotropic e-skin.Here,we present a transparent e-skin exhibiting remarkable anisotropic strain sensing performance,along with exceptional resilience against interference from other stimuli and harsh environments.Benefiting from the synergistic coexistence of aligned silver nanowires wrinkles and cracks,the e-skin achieves outstanding anisotropy showcasing maximum strain gauge factors(GFs)difference of 2825 and 0.69 along two perpendicular directions,exceeding a difference of more than 4000 times.Furthermore,the e-skin displays superior anti-interference capability,evidenced by a resistance change of less than 6%when subjected to high pressure(663 kPa),torsion(540°),or bending(180°),and exhibits negligible performance degradation even after exposure to harsh environments.Finally,our e-skin is successfully applied to undisturbed predicting crack propagation and precise control of dual-mode soft robots,highlighting its immense potential in structural damage warning and intelligent robotics.
基金supported in part by the National Natural Science Foundation of China (NSFC) under Grants 62131005, 62071096in part by the Fundamental Research Funds for the Central Universities under Grant 2242022k60006+1 种基金in part by the National NSFC under Grant U19B2014in part by the Natural Science Foundation of Sichuan under Grant 2022NSFSC0495
文摘As modern electromagnetic environments are more and more complex,the anti-interference performance of the synchronization acquisition is becoming vital in wireless communications.With the rapid development of the digital signal processing technologies,some synchronization acquisition algorithms for hybrid direct-sequence(DS)/frequency hopping(FH)spread spectrum communications have been proposed.However,these algorithms do not focus on the analysis and the design of the synchronization acquisition under typical interferences.In this paper,a synchronization acquisition algorithm based on the frequency hopping pulses combining(FHPC)is proposed.Specifically,the proposed algorithm is composed of two modules:an adaptive interference suppression(IS)module and an adaptive combining decision module.The adaptive IS module mitigates the effect of the interfered samples in the time-domain or the frequencydomain,and the adaptive combining decision module can utilize each frequency hopping pulse to construct an anti-interference decision metric and generate an adaptive acquisition decision threshold to complete the acquisition.Theory and simulation demonstrate that the proposed algorithm significantly enhances the antiinterference and anti-noise performances of the synchronization acquisition for hybrid DS/FH communications.
文摘Balise system is one kind of high-rate point-mode data transmission equipment.It plays an indispensable role in Chinese Train Control System(CTCS),and it has been immigrated and widely used for passenger dedicated lines and high-speed lines.Thus,its working conditions directly affect train operation safety.However,the balise information transmission system(BITS)is based on the principle of electromagnetic induction,and the communication process is susceptible to external electromagnetic interference.Therefore,it is vital to study the influence of transient signal interference on the balise system.This paper builds the up-link model between the vehicle antena and the balise,and verifies the model’s correctness using finite-difference time-domain method and electromagnetic field theory.This paper analyzes the effect of electromagnetic pulses on the transponder’s uplink and simulates the coupled current under irradiation.The spectral distribution of the three types of pulse interference is analyzed according to relevant standards.Strong electromagnetic pulses have a strong energy distribution in the working frequency band of the up-link,which will generate in-band interference and bit errors.It will affect the balise communication and threaten the safety of train operation.As we know we are the first to analyze the effects of EMP on Chinese BITS,which will lay a foundation for the research of electromagnetic anti-interference or protection to highspeed railway.
基金Project(2018YFC0807802)supported by the National Key R&D Program of ChinaProject(41874081)supported by the National Natural Science Foundation of China
文摘Due to the strong electromagnetic interferences and human interference,traditional electromagnetic methods cannot obtain high quality resistivity data of mineral deposits in Chinese mines.The wide field electromagnetic method(WFEM),in which the pseudo-random signal is taken as the transmitter source,can extract high quality resistivity data in areas with sever interference by only measuring the electric field component.We use the WFEM to extract the resistivity information of the Dongguashan mine in southeast China.Compared with the audio magnetotelluric(AMT)method,and the controlled source audio-frequency magnetotelluric(CSAMT) method,the WFEM can obtain data with higher quality and simpler operations.The inversion results indicate that the WFEM can accurately identify the location of the main ore-body,which can be used for deep mine exploration in areas with strong interference.
基金This project is supported by National Natural Science Foundation of China(No.59835160).
文摘Vortex street flowmeter has been used in steady flow measurement for about three decades The benefits of this type of flowmeter include high accuracy,good linearty,wide measuring range,and excellent reliability However,in unsteady flow measurement,the pressure disturbance as well as the noise from the system or surrounding can reduce the signal to noise ratio of the flowmeter seriously Aimed to use vortex street flowmeters in unsteady flow measurement,the characteristics of the vortex shedding induced hydrodynamic vibration around the prism bluff body in a vortex street flowmeter are investigated numerically and by expriments The results show that the hydrodynamic vibrations with 180° phase shift occur at the axisymmetric points of the channel around the bluff body The most intense vibration occurs at the points on the lateral faces close to the base of the prism The results provide therefore a useful reference for developing an anti interference vortex flowmeter using the different ial sensing technique.
