Coal and gas outburst is a complex dynamic disaster during coal underground mining.Revealing the disaster mechanism is of great signifcance for accurate prediction and prevention of coal and gas outburst.The geo-dynam...Coal and gas outburst is a complex dynamic disaster during coal underground mining.Revealing the disaster mechanism is of great signifcance for accurate prediction and prevention of coal and gas outburst.The geo-dynamic system of coal and gas outburst is proposed.The framework of geo-dynamic system is composed of gassy coal mass,geological dynamic environment and mining disturbance.Equations of stress–damage–seepage interaction for gassy coal mass is constructed to resolve the outburst elimination process by gas extraction with boreholes through layer in foor roadway.The results show the occurrence of outburst is divided into the evolution process of gestation,formation,development and termination of geo-dynamic system.The scale range of outburst occurrence is determined,which provides a spatial basis for the prevention and control of outburst.The formation criterion and instability criterion of coal and gas outburst are established.The formation criterion F1 is defned as the scale of the geo-dynamic system,and the instability criterion F2 is defned as the scale of the outburst geo-body.According to the geo-dynamic system,the elimination mechanism of coal and gas outburst—‘unloading+depressurization’is established,and the gas extraction by boreholes through layer in foor roadway for outburst elimination is given.For the research case,when the gas extraction is 120 days,the gas pressure of the coal seam is reduced to below 0.4 MPa,and the outburst danger is eliminated efectively.展开更多
The proposed scheme is based on Discrete Fourier Transform (DFT) domain processing. The key technology of this scheme is jamming parameters' accurate estimation and jamming reconstruction. Compared with the 't...The proposed scheme is based on Discrete Fourier Transform (DFT) domain processing. The key technology of this scheme is jamming parameters' accurate estimation and jamming reconstruction. Compared with the 'threshold exciser' scheme the proposed scheme can eliminate more jamming energy on the whole frequency band with the minimum loss of useful signal energy. As shown in the research and simulation, the proposed scheme is much better than the 'threshold exciser' scheme, especially in the case of high power jamming whereas the 'threshold exciser' scheme might be invalid.展开更多
During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their el...During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.展开更多
About half the population in developing countries lack safe excreta disposal facilities. Improper wastewater disposal contaminates groundwater resulting in spread of water related diseases such as typhoid, cholera, dy...About half the population in developing countries lack safe excreta disposal facilities. Improper wastewater disposal contaminates groundwater resulting in spread of water related diseases such as typhoid, cholera, dysentery. This research experimentally tested the applicability of charcoal and saw dust packed membranes as sewage purifiers for on-site sanitation systems like, septic tanks, cesspool, pit latrines, pour-flush pit excreta systems. Tests for E. coli, COD and BOD of the influent which was raw sewerage from sewers and effluent from layered saw dust and charcoal purifying materials experimental setup were separately carried out. The layers were varied from 150 mm, 200 mm and 300 mm with 150 mm layers of gravel in between. The experimental tests showed that 300 mm charcoal layers with a 150 mm gravel middle layer, reduced E. coli from 4800×1014 CFU/100ml to 1.08×104 CFU/100ml, BOD5 from 698 mg/l to 0.5 mg/l, COD from 1492 mg/l to 3.0 mg/l against environmental standards of 1.0×104 CFU/100ml, 50 mg/l, and 100 mg/l respectively and its efficiency is directly proportional to thickness of charcoal dust layers. In conclusion, introducing a lined purification chamber with layers of charcoal dust between the on-site sanitation system and soak pit will eliminate the pollution of ground water.展开更多
In mass spectrometry(MS)analysis,carryover is a common and unavoidable problem.It causes over-estimation of analyte levels,which significantly influences accuracy and precision.Therefore,there are strict limits on car...In mass spectrometry(MS)analysis,carryover is a common and unavoidable problem.It causes over-estimation of analyte levels,which significantly influences accuracy and precision.Therefore,there are strict limits on carryover in MS-based assays.The conventional capillary-based electrospray ionization(ESI)restricts the use of MS for real-time monitoring,where a prompt response is crucial.Recently,we have developed a micro probe electrospray ionization(mPESI)coupled with MS(mPESI-MS)technology,enabling MS analysis within 40 s without a chromatographic column[1].However,the challenge of carryover arises when trying to make the micro probe reusable for resource-saving purposes.Considering that dielectric barrier discharge(DBD)plasma is effective in degrading contaminants in water and gas[2],we hypothesized the eventual use of the DBD plasma to“wash”the micro probe.Then,a DBD plasma wash tube(DBD-WT)was introduced for rapid carryover elimination in mPESI-MS analysis.展开更多
A novel method based on mid-frequency vibration is proposed to eliminate coating defects such as bubbles during electroless nickel plating.An automated control system for the plating,enabling precise and stable measur...A novel method based on mid-frequency vibration is proposed to eliminate coating defects such as bubbles during electroless nickel plating.An automated control system for the plating,enabling precise and stable measurements and adjustments of critical parameters such as plating solution temperature,pH,and nickel ion concentration,is also established,which significantly improves process efficiency and coating quality.Experimental results indicate that the system is capable of realizing stable operation over extended periods.A nonporous nickel-phosphorus coating with a thickness greater than 200μm is successfully obtained,with high phosphorus content,robust adhesion,and superior machinability.展开更多
Introduction Progress toward the global elimination of cervical cancer as a public health concern remains slow and highly uneven across countries.High-income nations such as Australia and FinlandDboth of which have ac...Introduction Progress toward the global elimination of cervical cancer as a public health concern remains slow and highly uneven across countries.High-income nations such as Australia and FinlandDboth of which have achieved high human papillomavirus(HPV)vaccination coverage and implemented quality-assured cervical cancer screening programs-have successfully decreased the incidence rates to below 8 cases per 100,000 women~1.These countries are on track to reach the elimination threshold of fewer than 4 cases per 100,000 women within the next few years,as defined by the World Health Organization(WHO).展开更多
In May 2018,the Director-General of the World Health Organization(WHO)called for global action to eliminate cervical cancer~1.This call marked the beginning of an ambitious international effort to scale up 3 key strat...In May 2018,the Director-General of the World Health Organization(WHO)called for global action to eliminate cervical cancer~1.This call marked the beginning of an ambitious international effort to scale up 3 key strategies:human papillomavirus(HPV)vaccination,cervical cancer screening,and treatment of precancerous lesions and cancer.Subsequently,the WHO and its partners developed a global strategy to accelerate the reduction of cervical cancer incidence,with an ultimate goal of achieving elimination within the next century.This Global Strategy represents a formal international commitment and is anchored in the 90-70-90 targets to be achieved by 2030.In parallel,several countries have also set national commitments,such as Sweden's pledge to achieve elimination by 2027 and Australia's target of achieving elimination by 2035.展开更多
Single-phase,non-isolated microinverters used in photovoltaic(PV)systems commonly encounter two persistent challenges:High-frequency leakage current and fluctuating power delivery.This paper presents a novel single-ph...Single-phase,non-isolated microinverters used in photovoltaic(PV)systems commonly encounter two persistent challenges:High-frequency leakage current and fluctuating power delivery.This paper presents a novel single-phase,non-isolated,multi-input microinverter topology with a common-ground structure that effectively eliminates ground leakage current without requiring additional active components.The proposed microinverter architecture integrates a dual-boost configuration and uses only four active switches.This is especially advantageous in terms of the component count,which is beneficial to enhance reliability,reduce cost,and simplify the overall system design.With one,two,or four PV inputs,it can operate without interruption under unbalanced voltage or partial shading and even if some inputs drop to zero.A tailored modulation scheme minimizes conduction losses while maintaining a stable direct-current(DC)-link voltage,and a decoupling capacitor efficiently absorbs the single-phase pulsating power,thus overcoming one major limitation in existing microinverter designs.By validating with a 1-kW GaN-based prototype,both the simulated and experimental results demonstrate its high efficiency,robustness,and practical suitability for cost-effective PV applications,with a peak efficiency value of 94.8%.展开更多
Human life quality requires both industrial/agricultural fast development and high environmental quality.However,the two aspects are conflicted as some contaminants are accidentally released into the environment,poten...Human life quality requires both industrial/agricultural fast development and high environmental quality.However,the two aspects are conflicted as some contaminants are accidentally released into the environment,potentially harmful to human health even at extra-low concentrations.展开更多
The excessive use of artificial intelligence(AI)algorithms has caused the problem of errors in AI algorithms,which has challenged the fairness of decision-making,and has intensified people’s inequality.Therefore,it i...The excessive use of artificial intelligence(AI)algorithms has caused the problem of errors in AI algorithms,which has challenged the fairness of decision-making,and has intensified people’s inequality.Therefore,it is necessary to conduct in-depth research and propose corresponding error detection and error elimination methods.This paper first proposes the root causes and threats of bias in AI algorithms,then summarizes the existing bias detection and error elimination methods,and proposes a bias processing framework in three-level dimensions of data,models,and conclusions,aiming to provide a framework for a comprehensive solution to errors in algorithms.At the same time,it also summarizes the problems and challenges in existing research and makes a prospect for future research trends.It is hoped that it will be helpful for us to build fairer AI.展开更多
Intrusion detection systems play a vital role in cyberspace security.In this study,a network intrusion detection method based on the feature selection algorithm(FSA)and a deep learning model is developed using a fusio...Intrusion detection systems play a vital role in cyberspace security.In this study,a network intrusion detection method based on the feature selection algorithm(FSA)and a deep learning model is developed using a fusion of a recursive feature elimination(RFE)algorithm and a bidirectional gated recurrent unit(BGRU).Particularly,the RFE algorithm is employed to select features from high-dimensional data to reduce weak correlations between features and remove redundant features in the numerical feature space.Then,a neural network that combines the BGRU and multilayer perceptron(MLP)is adopted to extract deep intrusion behavior features.Finally,a support vector machine(SVM)classifier is used to classify intrusion behaviors.The proposed model is verified by experiments on the NSL-KDD dataset.The results indicate that the proposed model achieves a 90.25%accuracy and a 97.51%detection rate in binary classification and outperforms other machine learning and deep learning models in intrusion classification.The proposed method can provide new insight into network intrusion detection.展开更多
China has achieved the poverty reduction goal of the United Nations 2030 Agenda for Sustainable Development 10 years ahead of schedule,contributing significantly to global poverty reduction.Despite extended efforts in...China has achieved the poverty reduction goal of the United Nations 2030 Agenda for Sustainable Development 10 years ahead of schedule,contributing significantly to global poverty reduction.Despite extended efforts in poverty elimination,there is a lack of quantitative studies categorizing and comparing poverty-elimination counties(PECs)based on their processes.This study proposes an innovative framework for analyzing PECs’development paths from the perspective of population-land-industry(PLI).We quantify the PLI matching degree of PECs in China during the critical phase of the battle against poverty through a multivariate matching model,classify PECs via K-means clustering according to the consistency in PLI matching degree evolution,and summarize the typical development patterns of PECs.Results indicate that the PLI matching degree of PECs in China increased substantially from 2015 to 2020,particularly in eastern areas,while the western region,including the Qinghai-Xizang Plateau and southwestern Xinjiang,shows untapped potential for improvement.Five types of PECs are identified,with the majority(30.1%)showing sustained moderate PLI matching and a minority(9.6%)experiencing long-term PLI mismatch.Industry is the shortfall of various PECs,and effective strategies to facilitate all types of PECs include the development of emerging businesses and the expansion of secondary and tertiary industries.Additionally,enriching rural labor force and increasing farmland use efficiency are essential for optimal PLI matching and positive interaction,ultimately ensuring poverty elimination and sustainable development.展开更多
Internal multiples are commonly present in seismic data due to variations in velocity or density of subsurface media.They can reduce the signal-to-noise ratio of seismic data and degrade the quality of the image.With ...Internal multiples are commonly present in seismic data due to variations in velocity or density of subsurface media.They can reduce the signal-to-noise ratio of seismic data and degrade the quality of the image.With the development of seismic exploration into deep and ultradeep events,especially those from complex targets in the western region of China,the internal multiple eliminations become increasingly challenging.Currently,three-dimensional(3D)seismic data are primarily used for oil and gas target recognition and drilling.Effectively eliminating internal multiples in 3D seismic data of complex structures and mitigating their adverse effects is crucial for enhancing the success rate of drilling.In this study,we propose an internal multiple prediction algorithm for 3D seismic data in complex structures using the Marchenko autofocusing theory.This method can predict the accurate internal multiples of time difference without an accurate velocity model and the implementation process mainly consists of several steps.Firstly,simulating direct waves with a 3D macroscopic velocity model.Secondly,using direct waves and 3D full seismic acquisition records to obtain the upgoing and down-going Green's functions between the virtual source point and surface.Thirdly,constructing internal multiples of the relevant layers by upgoing and downgoing Green's functions.Finally,utilizing the adaptive matching subtraction method to remove predicted internal multiples from the original data to obtain seismic records without multiples.Compared with the two-dimensional(2D)Marchenko algo-rithm,the performance of the 3D Marchenko algorithm for internal multiple prediction has been significantly enhanced,resulting in higher computational accuracy.Numerical simulation test results indicate that our proposed method can effectively eliminate internal multiples in 3D seismic data,thereby exhibiting important theoretical and industrial application value.展开更多
Internal multiple interference,affecting both seismic data processing and interpretation,has been observed for long time.Although great progress has been achieved in developing a variety of internal-multiple-eliminati...Internal multiple interference,affecting both seismic data processing and interpretation,has been observed for long time.Although great progress has been achieved in developing a variety of internal-multiple-elimination(IME)methods,how to increase accuracy and reduce cost of IME still poses a significant challenge.A new method is proposed to effectively and efficiently eliminate internal multi-ples,along with its application in internal-multiple-eliminated-migration(IMEM),addressing this issue.This method stems from two-way wave equation depth-extrapolation scheme and associated up/down wavefield separation,which can accomplish depth-extrapolation of both up-going and down-going wavefields simultaneously,and complete internal-multiple-elimination processing,adaptively and effi-ciently.The proposed method has several features:(1)input data is same as that for conventional migration:source signature(used for migration only),macro velocity model,and receiver data,without additional requirements for source/receiver sampling;(2)method is efficient,without need of iterative calculations(which are typically needed for most of IME algorithms);and(3)method is cost effective:IME is completed in the same depth-extrapolation scheme of IMEM,without need of a separate pro-cessing and additional cost.Several synthesized data models are used to test the proposed method:one-dimensional model,horizontal layered model,multi-layer model with one curved layer,and SEG/EAGE Salt model.Additionally,we perform a sensitivity analysis of velocity using smoothed models.This analysis reveals that although the accuracy of velocity measurements impacts our proposed method,it significantly reduces internal multiple false imaging compared to traditional RTM techniques.When applied to actual seismic data from a carbonate reservoir zone,our method demonstrates superior clarity in imaging results,even in the presence of high-velocity carbonate formations,outperforming conven-tional migration methods in deep strata.展开更多
Semi-supervised new intent discovery is a significant research focus in natural language understanding.To address the limitations of current semi-supervised training data and the underutilization of implicit informati...Semi-supervised new intent discovery is a significant research focus in natural language understanding.To address the limitations of current semi-supervised training data and the underutilization of implicit information,a Semi-supervised New Intent Discovery for Elastic Neighborhood Syntactic Elimination and Fusion model(SNID-ENSEF)is proposed.Syntactic elimination contrast learning leverages verb-dominant syntactic features,systematically replacing specific words to enhance data diversity.The radius of the positive sample neighborhood is elastically adjusted to eliminate invalid samples and improve training efficiency.A neighborhood sample fusion strategy,based on sample distribution patterns,dynamically adjusts neighborhood size and fuses sample vectors to reduce noise and improve implicit information utilization and discovery accuracy.Experimental results show that SNID-ENSEF achieves average improvements of 0.88%,1.27%,and 1.30%in Normalized Mutual Information(NMI),Accuracy(ACC),and Adjusted Rand Index(ARI),respectively,outperforming PTJN,DPN,MTP-CLNN,and DWG models on the Banking77,StackOverflow,and Clinc150 datasets.The code is available at https://github.com/qsdesz/SNID-ENSEF,accessed on 16 January 2025.展开更多
A series of CeO2‐MnOx‐Al2O3 mixed oxide catalysts (Ce:Mn:Al mole ratio=6:4:x, x=0.25, 0.5, 1, 2) were prepared by a simple one‐step inverse co‐precipitation method to investigate the influence of the incorpo...A series of CeO2‐MnOx‐Al2O3 mixed oxide catalysts (Ce:Mn:Al mole ratio=6:4:x, x=0.25, 0.5, 1, 2) were prepared by a simple one‐step inverse co‐precipitation method to investigate the influence of the incorporation of Al3+ into CeO2‐MnOx mixed oxides. CeO2‐MnOx, CeO2‐Al2O3, and MnOx‐Al2O3 mixed oxides, and CeO2 were prepared by the same method for comparison. The samples were characterized by XRD, Raman, N2 physisorption, H2‐TPR, XPS, and in situ DRIFTS. The catalytic re‐duction of NO by CO was chosen as a model reaction to evaluate the catalytic performance. The incorporation of a small amount of Al3+into CeO2‐MnOx mixed oxides resulted in a decrease of crys‐tallite size, with the increase of the BET specific surface area and pore volume, as well as the in‐crease of Ce3+and Mn4+. The former benefits good contact between catalyst and reactants, and the latter promotes the adsorption of CO and the desorption, conversion and dissociation of adsorbed NO. All these enhanced the catalytic performance for the NO+CO model reaction. A reaction mecha‐nism was proposed to explain the excellent catalytic performance of CeO2‐MnOx‐Al2O3 catalysts for NO reduction by CO.展开更多
[Objective] The aim was to study on in-situ elimination effect on heavy metals in soil of the mining area by ramie (Boehmeria nivea (L.) Gaud.). [Methods] Based on Xiangzhu No.3 and Zhongzhu No.1, we conducted res...[Objective] The aim was to study on in-situ elimination effect on heavy metals in soil of the mining area by ramie (Boehmeria nivea (L.) Gaud.). [Methods] Based on Xiangzhu No.3 and Zhongzhu No.1, we conducted research on heavy metals contents of plants growing in soil of Qibao Mountain orefield in Liuyang, Hunan Province, and on characteristics of enrichment and transfer of heavy metals (Cu, Pb, Cd, Zn) under influence of the two ramie species. [Result] It was concluded that trend of Cu content in different parts of ramie was as follows: rootskinleafbone; trend of Pb was rootleafskinbone; trend of Cd was rootskinboneleaf; the trend of Zn was rootskinboneleaf. In farmland A (with low content of heavy metal), for per square meter of plough horizon, effect of Zhong 1 on heavy metals transferring volume and the period for restoration of the soil into national standard one (Category Ⅲ of Environmental Quality Standard for Soil) have been concluded. Specifically, for Cu, the corresponding values were 3 404.44 mg and 8.59 y, respectively; for Pb, the values were 3 638.5 mg and 13.52 y; for Cd, the values were 720.48 mg and 1.49 y; for Zn, the values were 37 324.8 mg and 0.67 y. [Conclusion] Soil contaminated by Cu, Pb, Cd, and Zn in orefield can be rapidly restored by growing ramie.展开更多
The phenomenon of anti-symmetrical bifurcation of periodic solutionsoccurring near an integral manifold is the intrinsic cause resulting in harmonic resonanceover-voltage in power systems. Due to this discovery, the p...The phenomenon of anti-symmetrical bifurcation of periodic solutionsoccurring near an integral manifold is the intrinsic cause resulting in harmonic resonanceover-voltage in power systems. Due to this discovery, the principle of eliminating resonance byusing anti-bifurcation technique is presented, which makes that the theoretical bases of verymeasure to eliminate resonance are unified firstly from a point of view of basic theory. Ourdiscussion models depend on a class of nonlinear control model. Using the direct Lyapunov method, acomplete theoretical proof is given in accordance with the measure of eliminating resonance byconnecting nonlinear resistor in series to the neutral point of P. T., and the feedback control lawbeing applied. It comprises the action of parameters of resistor to eliminate resonance and theactual process of eliminating resonance, i.e., to go against bifurcation process which forces thebig harmonic solutions to retreat to the integral manifold gradually and disappear eventually, whichby using the nonlinear controllers. This makes it sure that the intrinsic cause of resonance iseliminated thoroughly. The obtained theory results and computing results are better than thepresented results.展开更多
This paper presents a twice-gathering information interactive system prototype of e-government based on the condition that the Intranet and the Extranet are physical isolated.Users in the Extranet can gather links of ...This paper presents a twice-gathering information interactive system prototype of e-government based on the condition that the Intranet and the Extranet are physical isolated.Users in the Extranet can gather links of the latest related information from client software which is previously collected by web alert in the Internet.Finally,through ferry-type transport devices,information is browsed by users in the Intranet,and it is transported to a storage device and synchronized with the web platform in the Intranet.During information gathering in the Extranet and data synchronization in the Intranet,it is essential to avoid repeated gathering and copying by means of comparing the extracted information fingerprints gathered from the web pages.This prototype uses HashTrie to store information fingerprints.During testing,the structure based on HashTrie is 2.28 times faster than the Darts(double array Trie)which is the fastest structure in the existing applied patent.The existing 12 types of high speed Hash functions serving for HashTrie are also implemented.When the dictionary content is larger than 5×105 words,the PJWHash or the SuperFastHush function can be adopted;when the dictionary content is 105 words, CalcStrCR32 and ELFHash functions can be adopted.展开更多
基金supported by the National Natural Science Foundation of China(52004117,52174117 and 51674132)the Postdoctoral Science Foundation of China(2021T140290 and 2020M680975)the Discipline Innovation Team of Liaoning Technical University(LNTU20TD-03 and LNTU20TD-30).
文摘Coal and gas outburst is a complex dynamic disaster during coal underground mining.Revealing the disaster mechanism is of great signifcance for accurate prediction and prevention of coal and gas outburst.The geo-dynamic system of coal and gas outburst is proposed.The framework of geo-dynamic system is composed of gassy coal mass,geological dynamic environment and mining disturbance.Equations of stress–damage–seepage interaction for gassy coal mass is constructed to resolve the outburst elimination process by gas extraction with boreholes through layer in foor roadway.The results show the occurrence of outburst is divided into the evolution process of gestation,formation,development and termination of geo-dynamic system.The scale range of outburst occurrence is determined,which provides a spatial basis for the prevention and control of outburst.The formation criterion and instability criterion of coal and gas outburst are established.The formation criterion F1 is defned as the scale of the geo-dynamic system,and the instability criterion F2 is defned as the scale of the outburst geo-body.According to the geo-dynamic system,the elimination mechanism of coal and gas outburst—‘unloading+depressurization’is established,and the gas extraction by boreholes through layer in foor roadway for outburst elimination is given.For the research case,when the gas extraction is 120 days,the gas pressure of the coal seam is reduced to below 0.4 MPa,and the outburst danger is eliminated efectively.
基金the National Natural Science Foundation of China(No.60172029)
文摘The proposed scheme is based on Discrete Fourier Transform (DFT) domain processing. The key technology of this scheme is jamming parameters' accurate estimation and jamming reconstruction. Compared with the 'threshold exciser' scheme the proposed scheme can eliminate more jamming energy on the whole frequency band with the minimum loss of useful signal energy. As shown in the research and simulation, the proposed scheme is much better than the 'threshold exciser' scheme, especially in the case of high power jamming whereas the 'threshold exciser' scheme might be invalid.
基金supported by Catalan Government,Nos.2014SGR344(to JT),2017SGR704(to JT),2021SGR01214(to MAL)MCIN/AEI/10.13039/501100011033/by“ERDF A way of making Europe,”Nos.SAF2015-67143(to JT),PID2019-106332GB-I00(to JT and MAL)and PID2022-141252NB-I00(to MAL).
文摘During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.
文摘About half the population in developing countries lack safe excreta disposal facilities. Improper wastewater disposal contaminates groundwater resulting in spread of water related diseases such as typhoid, cholera, dysentery. This research experimentally tested the applicability of charcoal and saw dust packed membranes as sewage purifiers for on-site sanitation systems like, septic tanks, cesspool, pit latrines, pour-flush pit excreta systems. Tests for E. coli, COD and BOD of the influent which was raw sewerage from sewers and effluent from layered saw dust and charcoal purifying materials experimental setup were separately carried out. The layers were varied from 150 mm, 200 mm and 300 mm with 150 mm layers of gravel in between. The experimental tests showed that 300 mm charcoal layers with a 150 mm gravel middle layer, reduced E. coli from 4800×1014 CFU/100ml to 1.08×104 CFU/100ml, BOD5 from 698 mg/l to 0.5 mg/l, COD from 1492 mg/l to 3.0 mg/l against environmental standards of 1.0×104 CFU/100ml, 50 mg/l, and 100 mg/l respectively and its efficiency is directly proportional to thickness of charcoal dust layers. In conclusion, introducing a lined purification chamber with layers of charcoal dust between the on-site sanitation system and soak pit will eliminate the pollution of ground water.
基金supports provided by the National Natural Science Foundation of China(Grant Nos.:82025034 and 81973392)the Science and Technology Project of Guizhou Province,China(Project No.:ZK[2022]General 410)+1 种基金the Social Development Technology Project of Dongguan,China(Project No.:20211800907893)the Shenzhen Science and Technology Program,China(Grant No.:KQTD20190929174023858).
文摘In mass spectrometry(MS)analysis,carryover is a common and unavoidable problem.It causes over-estimation of analyte levels,which significantly influences accuracy and precision.Therefore,there are strict limits on carryover in MS-based assays.The conventional capillary-based electrospray ionization(ESI)restricts the use of MS for real-time monitoring,where a prompt response is crucial.Recently,we have developed a micro probe electrospray ionization(mPESI)coupled with MS(mPESI-MS)technology,enabling MS analysis within 40 s without a chromatographic column[1].However,the challenge of carryover arises when trying to make the micro probe reusable for resource-saving purposes.Considering that dielectric barrier discharge(DBD)plasma is effective in degrading contaminants in water and gas[2],we hypothesized the eventual use of the DBD plasma to“wash”the micro probe.Then,a DBD plasma wash tube(DBD-WT)was introduced for rapid carryover elimination in mPESI-MS analysis.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFB3407200)the National Natural Science Foundation of China(Grant Nos.52375462 and 52035009).
文摘A novel method based on mid-frequency vibration is proposed to eliminate coating defects such as bubbles during electroless nickel plating.An automated control system for the plating,enabling precise and stable measurements and adjustments of critical parameters such as plating solution temperature,pH,and nickel ion concentration,is also established,which significantly improves process efficiency and coating quality.Experimental results indicate that the system is capable of realizing stable operation over extended periods.A nonporous nickel-phosphorus coating with a thickness greater than 200μm is successfully obtained,with high phosphorus content,robust adhesion,and superior machinability.
文摘Introduction Progress toward the global elimination of cervical cancer as a public health concern remains slow and highly uneven across countries.High-income nations such as Australia and FinlandDboth of which have achieved high human papillomavirus(HPV)vaccination coverage and implemented quality-assured cervical cancer screening programs-have successfully decreased the incidence rates to below 8 cases per 100,000 women~1.These countries are on track to reach the elimination threshold of fewer than 4 cases per 100,000 women within the next few years,as defined by the World Health Organization(WHO).
基金supported by the CAMS Innovation Fund for Medical Sciences(No.2023-I2M-3-019)National Natural Science Foundation of China(No.82404366)。
文摘In May 2018,the Director-General of the World Health Organization(WHO)called for global action to eliminate cervical cancer~1.This call marked the beginning of an ambitious international effort to scale up 3 key strategies:human papillomavirus(HPV)vaccination,cervical cancer screening,and treatment of precancerous lesions and cancer.Subsequently,the WHO and its partners developed a global strategy to accelerate the reduction of cervical cancer incidence,with an ultimate goal of achieving elimination within the next century.This Global Strategy represents a formal international commitment and is anchored in the 90-70-90 targets to be achieved by 2030.In parallel,several countries have also set national commitments,such as Sweden's pledge to achieve elimination by 2027 and Australia's target of achieving elimination by 2035.
基金supported by Libyan Cultural Affair/London,Libya under Grant No.13840.
文摘Single-phase,non-isolated microinverters used in photovoltaic(PV)systems commonly encounter two persistent challenges:High-frequency leakage current and fluctuating power delivery.This paper presents a novel single-phase,non-isolated,multi-input microinverter topology with a common-ground structure that effectively eliminates ground leakage current without requiring additional active components.The proposed microinverter architecture integrates a dual-boost configuration and uses only four active switches.This is especially advantageous in terms of the component count,which is beneficial to enhance reliability,reduce cost,and simplify the overall system design.With one,two,or four PV inputs,it can operate without interruption under unbalanced voltage or partial shading and even if some inputs drop to zero.A tailored modulation scheme minimizes conduction losses while maintaining a stable direct-current(DC)-link voltage,and a decoupling capacitor efficiently absorbs the single-phase pulsating power,thus overcoming one major limitation in existing microinverter designs.By validating with a 1-kW GaN-based prototype,both the simulated and experimental results demonstrate its high efficiency,robustness,and practical suitability for cost-effective PV applications,with a peak efficiency value of 94.8%.
基金supported by National Natural Science Foundation of China(No.U21A20290)。
文摘Human life quality requires both industrial/agricultural fast development and high environmental quality.However,the two aspects are conflicted as some contaminants are accidentally released into the environment,potentially harmful to human health even at extra-low concentrations.
文摘The excessive use of artificial intelligence(AI)algorithms has caused the problem of errors in AI algorithms,which has challenged the fairness of decision-making,and has intensified people’s inequality.Therefore,it is necessary to conduct in-depth research and propose corresponding error detection and error elimination methods.This paper first proposes the root causes and threats of bias in AI algorithms,then summarizes the existing bias detection and error elimination methods,and proposes a bias processing framework in three-level dimensions of data,models,and conclusions,aiming to provide a framework for a comprehensive solution to errors in algorithms.At the same time,it also summarizes the problems and challenges in existing research and makes a prospect for future research trends.It is hoped that it will be helpful for us to build fairer AI.
基金supported in part by the National Natural Science Foundation of China(No.62001333)the Scientific Research Project of Education Department of Hubei Province(No.D20221702).
文摘Intrusion detection systems play a vital role in cyberspace security.In this study,a network intrusion detection method based on the feature selection algorithm(FSA)and a deep learning model is developed using a fusion of a recursive feature elimination(RFE)algorithm and a bidirectional gated recurrent unit(BGRU).Particularly,the RFE algorithm is employed to select features from high-dimensional data to reduce weak correlations between features and remove redundant features in the numerical feature space.Then,a neural network that combines the BGRU and multilayer perceptron(MLP)is adopted to extract deep intrusion behavior features.Finally,a support vector machine(SVM)classifier is used to classify intrusion behaviors.The proposed model is verified by experiments on the NSL-KDD dataset.The results indicate that the proposed model achieves a 90.25%accuracy and a 97.51%detection rate in binary classification and outperforms other machine learning and deep learning models in intrusion classification.The proposed method can provide new insight into network intrusion detection.
基金supported by the National Natural Science Foundation of China(Grants No.41931293,42271279,42293271,and 41801175).
文摘China has achieved the poverty reduction goal of the United Nations 2030 Agenda for Sustainable Development 10 years ahead of schedule,contributing significantly to global poverty reduction.Despite extended efforts in poverty elimination,there is a lack of quantitative studies categorizing and comparing poverty-elimination counties(PECs)based on their processes.This study proposes an innovative framework for analyzing PECs’development paths from the perspective of population-land-industry(PLI).We quantify the PLI matching degree of PECs in China during the critical phase of the battle against poverty through a multivariate matching model,classify PECs via K-means clustering according to the consistency in PLI matching degree evolution,and summarize the typical development patterns of PECs.Results indicate that the PLI matching degree of PECs in China increased substantially from 2015 to 2020,particularly in eastern areas,while the western region,including the Qinghai-Xizang Plateau and southwestern Xinjiang,shows untapped potential for improvement.Five types of PECs are identified,with the majority(30.1%)showing sustained moderate PLI matching and a minority(9.6%)experiencing long-term PLI mismatch.Industry is the shortfall of various PECs,and effective strategies to facilitate all types of PECs include the development of emerging businesses and the expansion of secondary and tertiary industries.Additionally,enriching rural labor force and increasing farmland use efficiency are essential for optimal PLI matching and positive interaction,ultimately ensuring poverty elimination and sustainable development.
文摘Internal multiples are commonly present in seismic data due to variations in velocity or density of subsurface media.They can reduce the signal-to-noise ratio of seismic data and degrade the quality of the image.With the development of seismic exploration into deep and ultradeep events,especially those from complex targets in the western region of China,the internal multiple eliminations become increasingly challenging.Currently,three-dimensional(3D)seismic data are primarily used for oil and gas target recognition and drilling.Effectively eliminating internal multiples in 3D seismic data of complex structures and mitigating their adverse effects is crucial for enhancing the success rate of drilling.In this study,we propose an internal multiple prediction algorithm for 3D seismic data in complex structures using the Marchenko autofocusing theory.This method can predict the accurate internal multiples of time difference without an accurate velocity model and the implementation process mainly consists of several steps.Firstly,simulating direct waves with a 3D macroscopic velocity model.Secondly,using direct waves and 3D full seismic acquisition records to obtain the upgoing and down-going Green's functions between the virtual source point and surface.Thirdly,constructing internal multiples of the relevant layers by upgoing and downgoing Green's functions.Finally,utilizing the adaptive matching subtraction method to remove predicted internal multiples from the original data to obtain seismic records without multiples.Compared with the two-dimensional(2D)Marchenko algo-rithm,the performance of the 3D Marchenko algorithm for internal multiple prediction has been significantly enhanced,resulting in higher computational accuracy.Numerical simulation test results indicate that our proposed method can effectively eliminate internal multiples in 3D seismic data,thereby exhibiting important theoretical and industrial application value.
基金supported by the National Natural Science Foundation of China(Grant No.42004103)Sichuan Science and Technology Program(2023NSFSC0257)the CNPC Innovation Found(2022DQ02-0306).
文摘Internal multiple interference,affecting both seismic data processing and interpretation,has been observed for long time.Although great progress has been achieved in developing a variety of internal-multiple-elimination(IME)methods,how to increase accuracy and reduce cost of IME still poses a significant challenge.A new method is proposed to effectively and efficiently eliminate internal multi-ples,along with its application in internal-multiple-eliminated-migration(IMEM),addressing this issue.This method stems from two-way wave equation depth-extrapolation scheme and associated up/down wavefield separation,which can accomplish depth-extrapolation of both up-going and down-going wavefields simultaneously,and complete internal-multiple-elimination processing,adaptively and effi-ciently.The proposed method has several features:(1)input data is same as that for conventional migration:source signature(used for migration only),macro velocity model,and receiver data,without additional requirements for source/receiver sampling;(2)method is efficient,without need of iterative calculations(which are typically needed for most of IME algorithms);and(3)method is cost effective:IME is completed in the same depth-extrapolation scheme of IMEM,without need of a separate pro-cessing and additional cost.Several synthesized data models are used to test the proposed method:one-dimensional model,horizontal layered model,multi-layer model with one curved layer,and SEG/EAGE Salt model.Additionally,we perform a sensitivity analysis of velocity using smoothed models.This analysis reveals that although the accuracy of velocity measurements impacts our proposed method,it significantly reduces internal multiple false imaging compared to traditional RTM techniques.When applied to actual seismic data from a carbonate reservoir zone,our method demonstrates superior clarity in imaging results,even in the presence of high-velocity carbonate formations,outperforming conven-tional migration methods in deep strata.
基金supported by Research Projects of the Nature Science Foundation of Hebei Province(F2021402005).
文摘Semi-supervised new intent discovery is a significant research focus in natural language understanding.To address the limitations of current semi-supervised training data and the underutilization of implicit information,a Semi-supervised New Intent Discovery for Elastic Neighborhood Syntactic Elimination and Fusion model(SNID-ENSEF)is proposed.Syntactic elimination contrast learning leverages verb-dominant syntactic features,systematically replacing specific words to enhance data diversity.The radius of the positive sample neighborhood is elastically adjusted to eliminate invalid samples and improve training efficiency.A neighborhood sample fusion strategy,based on sample distribution patterns,dynamically adjusts neighborhood size and fuses sample vectors to reduce noise and improve implicit information utilization and discovery accuracy.Experimental results show that SNID-ENSEF achieves average improvements of 0.88%,1.27%,and 1.30%in Normalized Mutual Information(NMI),Accuracy(ACC),and Adjusted Rand Index(ARI),respectively,outperforming PTJN,DPN,MTP-CLNN,and DWG models on the Banking77,StackOverflow,and Clinc150 datasets.The code is available at https://github.com/qsdesz/SNID-ENSEF,accessed on 16 January 2025.
基金supported by the National Natural Science Foundation of China (21507130)the Open Project Program of Chongqing Key Laboratory of Environmental Materials and Remediation Technology from Chongqing University of Arts and Sciences (CEK1405)+3 种基金the Open Project Program of Beijing National Laboratory for Molecular Sciences (20140142)the Open Project Program of Jiangsu Key Laboratory of Vehicle Emissions Control (OVEC001)the Open Project Program of Chongqing Key Laboratory of Catalysis and Functional Organic Molecules from Chongqing Technology and Business University (1456029)the Chongqing Science & Technology Commission (cstc2014pt-gc20002)~~
文摘A series of CeO2‐MnOx‐Al2O3 mixed oxide catalysts (Ce:Mn:Al mole ratio=6:4:x, x=0.25, 0.5, 1, 2) were prepared by a simple one‐step inverse co‐precipitation method to investigate the influence of the incorporation of Al3+ into CeO2‐MnOx mixed oxides. CeO2‐MnOx, CeO2‐Al2O3, and MnOx‐Al2O3 mixed oxides, and CeO2 were prepared by the same method for comparison. The samples were characterized by XRD, Raman, N2 physisorption, H2‐TPR, XPS, and in situ DRIFTS. The catalytic re‐duction of NO by CO was chosen as a model reaction to evaluate the catalytic performance. The incorporation of a small amount of Al3+into CeO2‐MnOx mixed oxides resulted in a decrease of crys‐tallite size, with the increase of the BET specific surface area and pore volume, as well as the in‐crease of Ce3+and Mn4+. The former benefits good contact between catalyst and reactants, and the latter promotes the adsorption of CO and the desorption, conversion and dissociation of adsorbed NO. All these enhanced the catalytic performance for the NO+CO model reaction. A reaction mecha‐nism was proposed to explain the excellent catalytic performance of CeO2‐MnOx‐Al2O3 catalysts for NO reduction by CO.
基金Supported by National Programs for High Technology Research and Development of China(2007AA061001)Talent Introduction Project Supported by Hunan Agricultural University Project(07YT03)~~
文摘[Objective] The aim was to study on in-situ elimination effect on heavy metals in soil of the mining area by ramie (Boehmeria nivea (L.) Gaud.). [Methods] Based on Xiangzhu No.3 and Zhongzhu No.1, we conducted research on heavy metals contents of plants growing in soil of Qibao Mountain orefield in Liuyang, Hunan Province, and on characteristics of enrichment and transfer of heavy metals (Cu, Pb, Cd, Zn) under influence of the two ramie species. [Result] It was concluded that trend of Cu content in different parts of ramie was as follows: rootskinleafbone; trend of Pb was rootleafskinbone; trend of Cd was rootskinboneleaf; the trend of Zn was rootskinboneleaf. In farmland A (with low content of heavy metal), for per square meter of plough horizon, effect of Zhong 1 on heavy metals transferring volume and the period for restoration of the soil into national standard one (Category Ⅲ of Environmental Quality Standard for Soil) have been concluded. Specifically, for Cu, the corresponding values were 3 404.44 mg and 8.59 y, respectively; for Pb, the values were 3 638.5 mg and 13.52 y; for Cd, the values were 720.48 mg and 1.49 y; for Zn, the values were 37 324.8 mg and 0.67 y. [Conclusion] Soil contaminated by Cu, Pb, Cd, and Zn in orefield can be rapidly restored by growing ramie.
文摘The phenomenon of anti-symmetrical bifurcation of periodic solutionsoccurring near an integral manifold is the intrinsic cause resulting in harmonic resonanceover-voltage in power systems. Due to this discovery, the principle of eliminating resonance byusing anti-bifurcation technique is presented, which makes that the theoretical bases of verymeasure to eliminate resonance are unified firstly from a point of view of basic theory. Ourdiscussion models depend on a class of nonlinear control model. Using the direct Lyapunov method, acomplete theoretical proof is given in accordance with the measure of eliminating resonance byconnecting nonlinear resistor in series to the neutral point of P. T., and the feedback control lawbeing applied. It comprises the action of parameters of resistor to eliminate resonance and theactual process of eliminating resonance, i.e., to go against bifurcation process which forces thebig harmonic solutions to retreat to the integral manifold gradually and disappear eventually, whichby using the nonlinear controllers. This makes it sure that the intrinsic cause of resonance iseliminated thoroughly. The obtained theory results and computing results are better than thepresented results.
基金The National Basic Research Program of China(973 Program)(No.2007CB310806)
文摘This paper presents a twice-gathering information interactive system prototype of e-government based on the condition that the Intranet and the Extranet are physical isolated.Users in the Extranet can gather links of the latest related information from client software which is previously collected by web alert in the Internet.Finally,through ferry-type transport devices,information is browsed by users in the Intranet,and it is transported to a storage device and synchronized with the web platform in the Intranet.During information gathering in the Extranet and data synchronization in the Intranet,it is essential to avoid repeated gathering and copying by means of comparing the extracted information fingerprints gathered from the web pages.This prototype uses HashTrie to store information fingerprints.During testing,the structure based on HashTrie is 2.28 times faster than the Darts(double array Trie)which is the fastest structure in the existing applied patent.The existing 12 types of high speed Hash functions serving for HashTrie are also implemented.When the dictionary content is larger than 5×105 words,the PJWHash or the SuperFastHush function can be adopted;when the dictionary content is 105 words, CalcStrCR32 and ELFHash functions can be adopted.