Enhancing catalytic activity of multi-enzyme in vitro through substrate channeling effect is promis-ing yet challenging.Herein,conjugated microporous polymers(CMPs)-scaffolded integrated en-zyme cascade systems(I-ECSs...Enhancing catalytic activity of multi-enzyme in vitro through substrate channeling effect is promis-ing yet challenging.Herein,conjugated microporous polymers(CMPs)-scaffolded integrated en-zyme cascade systems(I-ECSs)are constructed through co-entrapping glucose oxidase(GOx)and horseradish peroxidase(HRP),in which hydrogen peroxide(H_(2)O_(2)) is the intermediate product.The interplay of low-resistance mass transfer pathway and appropriate pore wall-H_(2)O_(2) interactions facilitates the directed transfer of H_(2)O_(2),resulting in 2.4-fold and 5.0-fold elevation in catalytic activ-ity compared to free ECSs and separated ECSs,respectively.The substrate channeling effect could be regulated by altering the mass ratio of GOx to HRP.Besides,I-ECSs demonstrate excellent stabili-ties in harsh environments and multiple recycling.展开更多
A novel distributed model predictive control scheme based on dynamic integrated system optimization and parameter estimation （DISOPE） was proposed for nonlinear cascade systems under network environment. Under the d...A novel distributed model predictive control scheme based on dynamic integrated system optimization and parameter estimation （DISOPE） was proposed for nonlinear cascade systems under network environment. Under the distributed control structure, online optimization of the cascade system was composed of several cascaded agents that can cooperate and exchange information via network communication. By iterating on modified distributed linear optimal control problems on the basis of estimating parameters at every iteration the correct optimal control action of the nonlinear model predictive control problem of the cascade system could be obtained, assuming that the algorithm was convergent. This approach avoids solving the complex nonlinear optimization problem and significantly reduces the computational burden. The simulation results of the fossil fuel power unit are illustrated to verify the effectiveness and practicability of the proposed algorithm.展开更多
Detection of point mutations in driver genes is of great significance for the early diagnosis,treatment,and prognostic evaluation of cancer.However,current detection methods do not offer versatility,specificity,and ra...Detection of point mutations in driver genes is of great significance for the early diagnosis,treatment,and prognostic evaluation of cancer.However,current detection methods do not offer versatility,specificity,and rapid performance simultaneously.Thus,multiple mutation detection processes are necessary,which results in long processing times and high costs.In this study,we developed a thermodynamics-guided two-way interlocking DNA cascade system for universal multiplexed mutation detection(TTI-CS).This strategy is based on the DNA probe,which changes the thermodynamic balance of the DNA cascade by the designed bubble structure,thereby achieving a good distinction between mutant and wild-type DNA.The designed method greatly shortens the detection time through two-way intrusion.In addition,this method only changes two inexpensive trigger and bridge sequences,which replace the specific and expensive nucleic acid probes used in analyses based on traditional DNA probe methods,thereby enabling multiple detections.We performed the detection of synthetic single-stranded DNA for the five mutation points and successfully detected in endometrial cancer specimens.The detection limit of this method is0.1%,which better meets the needs of clinical low-abundance multiple mutation detection.Overall,TTI-CS is currently one of the best methods for detecting multiple mutation detections.展开更多
Tank cascade system(TCS)is a series of tanks located in a meso-catchment and has been accepted as a Globally Important Agricultural Heritage System found in Sri Lanka.Ecosystem components of the TCS play a major role ...Tank cascade system(TCS)is a series of tanks located in a meso-catchment and has been accepted as a Globally Important Agricultural Heritage System found in Sri Lanka.Ecosystem components of the TCS play a major role in purifying water within the system.This study attempted to investigate the water quality status and the farmers’willingness to rehabilitate the ecosystem components of the Thirappane TCS.Drinking and irrigation water quality parameters were tested in 34 locations and drinking and irrigation water quality indexes were calculated.Participatory rural appraisal and a questioner survey were conducted to gather social data.Water of TCS was observed to be appropriate for irrigation but not for drinking during the Maha cropping season.Based on the results of the Nitrate(as NO_(3)^(-))and Total Phosphate(as PO_(4)^(3-)),water of TCS can be categorized as eutrophic.Presence of ecosystem features of tank cascade system,annual income of the respondents,satisfaction on the quality of water for drinking,and the awareness about the tank cascade system significantly influenced the participatory decisions of the community on the rehabilitation of TCS.This study shall be an example and an eye opener to formulate sustainable tank cascade management plan.展开更多
In the present work, it is assumed that the n-components are arranged in the hierarchial order. The n-cascade system surviving with loss of m components by k number of attacks is studied;the general equation for the r...In the present work, it is assumed that the n-components are arranged in the hierarchial order. The n-cascade system surviving with loss of m components by k number of attacks is studied;the general equation for the reliability is obtained for the above said system;and the system reliability is computed numerically for 6-cascade system for 2-number of attacks.展开更多
Coal and gas outbursts constitute a critical hazard in underground mining operations,characterized by rapid transitions from localized instability to catastrophic failure.Understanding the relationship between initial...Coal and gas outbursts constitute a critical hazard in underground mining operations,characterized by rapid transitions from localized instability to catastrophic failure.Understanding the relationship between initial characteristics and final outburst scale remains a fundamental challenge in geomechanics.This study conceptualizes outbursts as deterministic cascade systems through integrated physical simulations combining high-sensitivity infrasound monitoring with energy analysis under controlled gas pressure(0.5–1.0 MPa)and confining stress(5–10 MPa)conditions.Our complementary analytical algorithms—the absolute amplitude integral and predominant period function—revealed characteristic step-wise patterns in outburst development.Quantitative analysis established a robust correlation(R2=0.91)between initial acoustic response and final outburst intensity.Energy analysis demonstrated that gas expansion dominates the outburst process(91.81%–99.09%of total energy),with desorption gas contributing 59.1%–77.7%.Time-frequency analysis showed systematic frequency migration from high(12–15 Hz)to low(4–8 Hz)bands during outburst progression,reflecting hierarchical spatial scale expansion.The concentrated energy release(>20%of total)within initial 0.2 s provides a mechanistic basis for the deterministic nature of outburst evolution.These mechanistic insights establish a quantitative framework for developing physics-based monitoring protocols and risk assessment methodologies applicable to underground coal mining operations.展开更多
The thermal conductivity of plasma-facing materials(PFM)exposed to intense radiation is a critical concern for the reliable usage of materials in fusion reactors.However,limited research has been performed regarding t...The thermal conductivity of plasma-facing materials(PFM)exposed to intense radiation is a critical concern for the reliable usage of materials in fusion reactors.However,limited research has been performed regarding the thermal conductivity of structures that rapidly change in a short time during collision cascade processes under irradiation.In this study,we employed the tight-binding(TB)method to investigate the electronic thermal conductivity(κ_(e))of tungsten-based systems during various cascading processes.We found thatκ_(e) values sharply decrease within the initial 0.3 picoseconds and then partially recover at a slow pace;this is closely linked to the evolution of defects and microstructural distortions.The increase in the initial kinetic energy of the primary knock-on atom and the presence of a high concentration of hydrogen atoms further decrease theκ_(e) values.Conversely,higher temperatures have a significant positive effect onκ_(e).Furthermore,the presence of a grain boundary∑5[001](130)substantially reducesκ_(e),whereas the absorption effect of point defects by the grain boundary has little influence onκ_(e) during cascades.Our findings provide a theoretical basis for evaluating changes in the thermal conductivity performance of PFMs during their usage in nuclear fusion reactors.展开更多
In recent years,there has been a growing demand for more efficient and robust control strategies in cooperative multi-robot systems.This paper introduces the cascade explicit tube model predictive controller(CET-MPC),...In recent years,there has been a growing demand for more efficient and robust control strategies in cooperative multi-robot systems.This paper introduces the cascade explicit tube model predictive controller(CET-MPC),a control architecture designed specifically for distributed aerial robot systems.By integrating an explicit model predictive controller(MPC)with a tube MPC,our approach significantly reduces online computational demands while enhancing robustness against disturbances such as wind and measurement noise,as well as uncertainties in inertia parameters.Further,we incorporate a cascade controller to minimize steady-state errors and improve system performance dynamically.The results of this assessment provide valuable insights into the effectiveness and reliability of the CET-MPC approach under realistic operating conditions.The simulation results of flight scenarios for multi-agent quadrotors demonstrate the controller’s stability and accurate tracking of the desired path.By addressing the complexities of quadrotors’six degrees of freedom,this controller serves as a versatile solution applicable to a wide range of multi-robot systems with varying degrees of freedom,demonstrating its adaptability and scalability beyond the quadrotor domain.展开更多
This paper focuses on the problem of leaderfollowing consensus for nonlinear cascaded multi-agent systems.The control strategies for these systems are transformed into successive control problem schemes for lower-orde...This paper focuses on the problem of leaderfollowing consensus for nonlinear cascaded multi-agent systems.The control strategies for these systems are transformed into successive control problem schemes for lower-order error subsystems.A distributed consensus analysis for the corresponding error systems is conducted by employing recursive methods and virtual controllers,accompanied by a series of Lyapunov functions devised throughout the iterative process,which solves the leaderfollowing consensus problem of a class of nonlinear cascaded multi-agent systems.Specific simulation examples illustrate the effectiveness of the proposed control algorithm.展开更多
The comprehensive status of blast furnaces was one of the most important factors affecting their economy,quality,and longev-ity.The blast furnace comprehensive status had the nature of“black box,”and it was“unpredi...The comprehensive status of blast furnaces was one of the most important factors affecting their economy,quality,and longev-ity.The blast furnace comprehensive status had the nature of“black box,”and it was“unpredictable.”In this study,a blast furnace com-prehensive status score and prediction method based on a cascade system and a combined model were proposed to address this issue.A dual cascade evaluation system was developed by integrating subjective and objective weighting methods.The analytic hierarchy process,coefficient of variation,entropy weight method,and impart combinatorial games were jointly employed to determine the optimal weight distribution across indicators.Categorized statuses(raw material,gas flow,furnace body,furnace cylinder,and iron-slag)were evaluated.Based on the five categories of the status data,the second cascade was applied to upgrade the quantitative evaluation of the comprehens-ive status.The weights of the different categories were 0.22,0.15,0.22,0.21,and 0.20,respectively.According to the data analysis,the results of the comprehensive status score closely matched the on-site production logs.Based on the blast furnace smelting period,the maximal information coefficient method was applied to the 100 parameters that were most relevant to the comprehensive status.A com-bined prediction model for a comprehensive status score was designed using bidirectional long short-term memory(BiLSTM)and categorical boosting(CatBoost).The test results indicated that the combined model reduced the mean absolute error by an average of 0.275 and increased the hit rate by an average of 5.65 percentage points compared to BiLSTM or CatBoost alone.When the er-ror range was±2.5,the combined model predicted a hit rate of 91.66%for the next hour’s comprehensive status score,and its high accur-acy was deemed satisfactory for the field.SHapley Additive exPlanations(SHAP)and regression fitting were applied to analyze the lin-ear quantitative relationship between the key variables and the comprehensive status score.When the furnace bottom center temperature was increased by 10℃,the comprehensive status score increased by 0.44.This method contributes to a more precise management and control of the comprehensive status of the blast furnace on-site.展开更多
In DC distributed power systems(DPSs),the complex impedance interactions possibly lead to DC bus voltage oscillation or collapse.In previous research,the stability analysis of DPSs is implemented based on mathematical...In DC distributed power systems(DPSs),the complex impedance interactions possibly lead to DC bus voltage oscillation or collapse.In previous research,the stability analysis of DPSs is implemented based on mathematical analysis in control theory.The specific mechanisms of the instability of the cascade system have not been intuitively clarified.In this paper,the stability analysis of DPSs based on the traditional Nyquist criterion is simplified to the resonance analysis of the seriesconnected port impedance(Z=R+jX)of source and load converters.It reveals that the essential reason for impedance instability of a DC cascade system is that the negative damping characteristic(R<0)of the port the overall impedance amplifies the internal resonance source at reactance zero-crossing frequency.The simplified stability criterion for DC cascade systems can be concluded as:in the negative damping frequency ranges(R<0),there exists no zero-crossing point of the reactance component(i.e.,X=0).According to the proposed stability criterion,the oscillation modes of cascade systems are classified.A typical one is the internal impedance instability excited by the negative damping,and the other one is that the external disturbance amplified by negativity in a low stability margin.Thus,the impedance reshaping method for stability improvement of the system can be further specified.The validity of the simplified criterion is verified theoretically and experimentally by a positive damping reshaping method.展开更多
A modular system of cascaded converters based on model predictive control(MPC)is proposed to meet the application requirements ofmultiple voltage levels and electrical isolation in renewable energy generation systems....A modular system of cascaded converters based on model predictive control(MPC)is proposed to meet the application requirements ofmultiple voltage levels and electrical isolation in renewable energy generation systems.The system consists of a Buck/Boost+CLLLC cascaded converter as a submodule,which is combined in series and parallel on the input and output sides to achieve direct-current(DC)voltage transformation,bidirectional energy flow,and electrical isolation.The CLLLC converter operates in DC transformer mode in the submodule,while the Buck/Boost converter participates in voltage regulation.This article establishes a suitable mathematical model for the proposed system topology,and uses MPC to control the system based on this mathematical model.Module parameters are designed and calculated,and simulation is built in MATLAB/Simulink to complete the simulation comparison experiment between MPC and traditional proportional integral(PI)control.Finally,a physical experimental platform is built to complete the physical comparison experiment.The simulation and physical experimental results prove that the control accuracy and response speed ofMPC are better than traditional PI control strategy.展开更多
Gastric carcinoma(GC)is a malignancy with multifactorial involvement,multicellular regulation,and multistage evolution.The classic Correa's cascade of intestinal GC specifies a trilogy of malignant transformation ...Gastric carcinoma(GC)is a malignancy with multifactorial involvement,multicellular regulation,and multistage evolution.The classic Correa's cascade of intestinal GC specifies a trilogy of malignant transformation of the gastric mucosa,in which normal gastric mucosa gradually progresses from inactive or chronic active gastritis(Phase I)to gastric precancerous lesions(Phase II)and finally to GC(Phase III).Correa's cascade highlights the evolutionary pattern of GC and the importance of early intervention to prevent malignant transformation of the gastric mucosa.Intervening in early gastric mucosal lesions,i.e.,Phases I and II,will be the key strategy to prevent and treat GC.Natural products(NPs)have been an important source for drug development due to abundant sources,tremendous safety,and multiple pharmacodynamic mechanisms.This review is the first to investigate and summarize the multi-step effects and regulatory mechanisms of NPs on the Correa's cascade in gastric carcinogenesis.In Phase I,NPs modulate Helicobacter pylori urease activity,motility,adhesion,virulence factors,and drug resistance,thereby inhibiting H.pylori-induced gastric mucosal inflammation and oxidative stress,and facilitating ulcer healing.In Phase II,NPs modulate multiple pathways and mediators regulating gastric mucosal cell cycle,apoptosis,autophagy,and angiogenesis to reverse gastric precancerous lesions.In Phase III,NPs suppress cell proliferation,migration,invasion,angiogenesis,and cancer stem cells,induce apoptosis and autophagy,and enhance chemotherapeutic drug sensitivity for the treatment of GC.In contrast to existing work,we hope to uncover NPs with sequential therapeutic effects on multiple phases of GC development,providing new ideas for gastric cancer prevention,treatment,and drug development.展开更多
Broad area quantum cascade lasers(BA QCLs)have significant applications in many areas,but suffer from demanding pulse operating conditions and poor beam quality due to heat accumulation and generation of high order mo...Broad area quantum cascade lasers(BA QCLs)have significant applications in many areas,but suffer from demanding pulse operating conditions and poor beam quality due to heat accumulation and generation of high order modes.A structure of mini-array is adopted to improve the heat dissipation capacity and beam quality of BA QCLs.The active region is etched to form a multi-emitter and the channels are filled with In P:Fe,which acts as a lateral heat dissipation channel to improve the lateral heat dissipation efficiency.A device withλ~4.8μm,a peak output power of 122 W at 1.2%duty cycle with a pulse of 1.5μs is obtained in room temperature,with far-field single-lobed distribution.This result allows BA QCLs to obtain high peak power at wider pump pulse widths and higher duty cycle conditions,promotes the application of the mid-infrared laser operating in pulsed mode in th e field of standoff photoacoustic chemical detection,space optical communication,and so on.展开更多
In the process of power scaling large-area Quantum Cascade Lasers(QCLs),challenges such as degradation of beam quality and emission of multilobed far-field modes are frequently encountered.These issues become particul...In the process of power scaling large-area Quantum Cascade Lasers(QCLs),challenges such as degradation of beam quality and emission of multilobed far-field modes are frequently encountered.These issues become particularly pronounced with an increase in ridge width,resulting in multimode problems.To tackle this,an innovative multi ridge waveguide structure based on the principle of supersymmetry(SUSY)was proposed.This structure comprises a wider main waveguide in the center and two narrower auxiliary waveguides on either side.The high-order modes of the main waveguide are coupled with the modes of the auxiliary waveguides through mode-matching design,and the optical loss of the auxiliary waveguides suppresses these modes,thereby achieving fundamental mode lasing of the wider main waveguide.This paper employs the finite difference eigenmode(FDE)method to perform detailed structural modeling and simulation optimization of the 4.6μm wavelength quantum cascade laser,successfully achieving a single transverse mode QCL with a ridge width of 10μm.In comparison to the traditional single-mode QCL(with a ridge width of about 5μm),the MRW structure has the potential to increase the gain area of the laser by 100%.This offers a novel design concept and methodology for enhancing the single-mode luminous power of mid-infrared quantum cascade lasers,which is of considerable significance.展开更多
[Objective]The construction of weirs changes the hydraulic characteristics of rivers and affects the structure of phytoplankton communities and the health of aquatic ecosystems in the river.This study aims to explore ...[Objective]The construction of weirs changes the hydraulic characteristics of rivers and affects the structure of phytoplankton communities and the health of aquatic ecosystems in the river.This study aims to explore the nonlinear response relationship between phytoplankton community structure and its driving factors in spring and autumn in Furong Creek under the construction of cascade weirs.[Methods]The structure of phytoplankton communities and related environmental factors were investigated in Furong Creek from 2023 to 2024.This study focused on the analysis of the changes of nutrient concentrations and biomass of phytoplankton in autumn and spring within the same dry season in Furong Creek.Redundancy analysis was used to identify the key factors influencing the structure of phytoplankton communities.The MIKE 11 model was employed to simulate the hydrodynamic changes in the river.Combined with total nitrogen and permanganate index,a GAM model of phytoplankton diversity index and hydrodynamic factors was developed,and the change of phytoplankton diversity after the optimized layout of the cascade weirs was fitted.[Results]The result showed that the annual average value of Shannon-Wiener diversity index of phytoplankton in Furong Creek was 2.79,which was in a state of mild pollution.A total of 239 species from 95 genera in 8 phyla were identified.Among the phytoplankton,Chlorophyta was the dominant group throughout the year in Furong Creek,followed by Bacillariophyta and Cyanophyta.The cell abundance of phytoplankton ranged from 3.11 to 20.64 mg/L and from 0.23 to 6.31 mg/L in spring and autumn,which indicated a clear seasonal succession of phytoplankton community structure.Compared with autumn,the relative abundance of Cyanophyta significantly decreased in spring across the whole river section,while Chrysophyta and Dinophyta showed significant increase at some monitoring sites,leading to water bloom phenomenon and a noticeable decline in the diversity of phytoplankton.The dominant species in the water bodies throughout the year were Cyclotella catenata,Chlorella vulgaris,Scenedesmus bijuga,Scenedesmus quadricauda,Chroomonas acuta,Cryptomonas ovata,and Cryptomonas erosa.Redundancy analysis(RDA)showed that hydrodynamic factors(v,h)and water environmental factors(TN,COD_(Mn))were the main influencing factors of phytoplankton community structure.[Conclusion]The result show that the nutrient concentration,phytoplankton biomass,and density in Furong Creek in spring are significantly higher than in autumn.The GAM model,constructed by combining hydrodynamic and environmental factors,can effectively reflect the nonlinear relationship between phytoplankton diversity index and its driving factors.In spring,with an increase in nutrient concentration,the habitat conditions of low flow speed and high water depths formed by overflow weirs will lead to a decrease in the Shannon-Wiener index of phytoplankton and an intensified risk of eutrophication.However,a reasonable layout scheme of cascade weirs will improve the diversity of phytoplankton and reduce the risk of eutrophication in the river.The findings of this study can help deepen the understanding of the ecological and environmental effects of cascade weir construction in the river.展开更多
A novel synthesis of C2-spiroindoline derivatives based on the cascade reaction of 2-aryl-3H-indoles with cyclo- propanols is presented. The formation of product involves Rh(III)-catalyzed aryl C(sp2)—H bond alkylati...A novel synthesis of C2-spiroindoline derivatives based on the cascade reaction of 2-aryl-3H-indoles with cyclo- propanols is presented. The formation of product involves Rh(III)-catalyzed aryl C(sp2)—H bond alkylation of 2-aryl- 3H-indole, which is followed by intramolecular spiroannulation. In this tandem process, cyclopropanol acts as not only an alkylating agent but also a masked nucleophile to take part in the construction of the spirocyclic scaffold. Meanwhile, air acts as an economical and sustainable oxidant to promote the regeneration of the active catalyst. By using this method, hybrid compounds containing the central scaffolds of some clinical drugs were prepared effectively. In general, this newly developed method has advantages such as easily obtainable substrates, concise synthetic procedure, excellent atom-economy, good compatibility with diverse functional groups and ready scalability.展开更多
文摘Enhancing catalytic activity of multi-enzyme in vitro through substrate channeling effect is promis-ing yet challenging.Herein,conjugated microporous polymers(CMPs)-scaffolded integrated en-zyme cascade systems(I-ECSs)are constructed through co-entrapping glucose oxidase(GOx)and horseradish peroxidase(HRP),in which hydrogen peroxide(H_(2)O_(2)) is the intermediate product.The interplay of low-resistance mass transfer pathway and appropriate pore wall-H_(2)O_(2) interactions facilitates the directed transfer of H_(2)O_(2),resulting in 2.4-fold and 5.0-fold elevation in catalytic activ-ity compared to free ECSs and separated ECSs,respectively.The substrate channeling effect could be regulated by altering the mass ratio of GOx to HRP.Besides,I-ECSs demonstrate excellent stabili-ties in harsh environments and multiple recycling.
基金This work was supportedbytheNationalNaturalScienceFoundationofChina(No.60474051),theProgramforNewCenturyExcellentTalentsinUniversityofChina(NCET),andtheSpecializedResearchFundfortheDoctoralProgramofHigherEducationofChina(No.20020248028).
文摘A novel distributed model predictive control scheme based on dynamic integrated system optimization and parameter estimation （DISOPE） was proposed for nonlinear cascade systems under network environment. Under the distributed control structure, online optimization of the cascade system was composed of several cascaded agents that can cooperate and exchange information via network communication. By iterating on modified distributed linear optimal control problems on the basis of estimating parameters at every iteration the correct optimal control action of the nonlinear model predictive control problem of the cascade system could be obtained, assuming that the algorithm was convergent. This approach avoids solving the complex nonlinear optimization problem and significantly reduces the computational burden. The simulation results of the fossil fuel power unit are illustrated to verify the effectiveness and practicability of the proposed algorithm.
基金supported by the Science and Technology Innovation Project of Hubei Province(No.2019ACA138)the National Natural Science Foundation of China(Nos.81871732 and 81974409)。
文摘Detection of point mutations in driver genes is of great significance for the early diagnosis,treatment,and prognostic evaluation of cancer.However,current detection methods do not offer versatility,specificity,and rapid performance simultaneously.Thus,multiple mutation detection processes are necessary,which results in long processing times and high costs.In this study,we developed a thermodynamics-guided two-way interlocking DNA cascade system for universal multiplexed mutation detection(TTI-CS).This strategy is based on the DNA probe,which changes the thermodynamic balance of the DNA cascade by the designed bubble structure,thereby achieving a good distinction between mutant and wild-type DNA.The designed method greatly shortens the detection time through two-way intrusion.In addition,this method only changes two inexpensive trigger and bridge sequences,which replace the specific and expensive nucleic acid probes used in analyses based on traditional DNA probe methods,thereby enabling multiple detections.We performed the detection of synthetic single-stranded DNA for the five mutation points and successfully detected in endometrial cancer specimens.The detection limit of this method is0.1%,which better meets the needs of clinical low-abundance multiple mutation detection.Overall,TTI-CS is currently one of the best methods for detecting multiple mutation detections.
文摘Tank cascade system(TCS)is a series of tanks located in a meso-catchment and has been accepted as a Globally Important Agricultural Heritage System found in Sri Lanka.Ecosystem components of the TCS play a major role in purifying water within the system.This study attempted to investigate the water quality status and the farmers’willingness to rehabilitate the ecosystem components of the Thirappane TCS.Drinking and irrigation water quality parameters were tested in 34 locations and drinking and irrigation water quality indexes were calculated.Participatory rural appraisal and a questioner survey were conducted to gather social data.Water of TCS was observed to be appropriate for irrigation but not for drinking during the Maha cropping season.Based on the results of the Nitrate(as NO_(3)^(-))and Total Phosphate(as PO_(4)^(3-)),water of TCS can be categorized as eutrophic.Presence of ecosystem features of tank cascade system,annual income of the respondents,satisfaction on the quality of water for drinking,and the awareness about the tank cascade system significantly influenced the participatory decisions of the community on the rehabilitation of TCS.This study shall be an example and an eye opener to formulate sustainable tank cascade management plan.
文摘In the present work, it is assumed that the n-components are arranged in the hierarchial order. The n-cascade system surviving with loss of m components by k number of attacks is studied;the general equation for the reliability is obtained for the above said system;and the system reliability is computed numerically for 6-cascade system for 2-number of attacks.
基金funded by the National Natural Science Foundation of China(No.52464016)the Guizhou Provincial Foundation Research Project(No.QKHJC-[2024]Youth 141)+1 种基金the Guizhou Provincial Basic Research Program(No.MS[2025]632)the Young Researcher Growth Project of Guizhou Provincial Department of Education(No.QJJ-[2024]25).
文摘Coal and gas outbursts constitute a critical hazard in underground mining operations,characterized by rapid transitions from localized instability to catastrophic failure.Understanding the relationship between initial characteristics and final outburst scale remains a fundamental challenge in geomechanics.This study conceptualizes outbursts as deterministic cascade systems through integrated physical simulations combining high-sensitivity infrasound monitoring with energy analysis under controlled gas pressure(0.5–1.0 MPa)and confining stress(5–10 MPa)conditions.Our complementary analytical algorithms—the absolute amplitude integral and predominant period function—revealed characteristic step-wise patterns in outburst development.Quantitative analysis established a robust correlation(R2=0.91)between initial acoustic response and final outburst intensity.Energy analysis demonstrated that gas expansion dominates the outburst process(91.81%–99.09%of total energy),with desorption gas contributing 59.1%–77.7%.Time-frequency analysis showed systematic frequency migration from high(12–15 Hz)to low(4–8 Hz)bands during outburst progression,reflecting hierarchical spatial scale expansion.The concentrated energy release(>20%of total)within initial 0.2 s provides a mechanistic basis for the deterministic nature of outburst evolution.These mechanistic insights establish a quantitative framework for developing physics-based monitoring protocols and risk assessment methodologies applicable to underground coal mining operations.
基金supported by the Collaborative Innovation Program of Hefei Science Center of CAS(No.2022HSC-CIP007)。
文摘The thermal conductivity of plasma-facing materials(PFM)exposed to intense radiation is a critical concern for the reliable usage of materials in fusion reactors.However,limited research has been performed regarding the thermal conductivity of structures that rapidly change in a short time during collision cascade processes under irradiation.In this study,we employed the tight-binding(TB)method to investigate the electronic thermal conductivity(κ_(e))of tungsten-based systems during various cascading processes.We found thatκ_(e) values sharply decrease within the initial 0.3 picoseconds and then partially recover at a slow pace;this is closely linked to the evolution of defects and microstructural distortions.The increase in the initial kinetic energy of the primary knock-on atom and the presence of a high concentration of hydrogen atoms further decrease theκ_(e) values.Conversely,higher temperatures have a significant positive effect onκ_(e).Furthermore,the presence of a grain boundary∑5[001](130)substantially reducesκ_(e),whereas the absorption effect of point defects by the grain boundary has little influence onκ_(e) during cascades.Our findings provide a theoretical basis for evaluating changes in the thermal conductivity performance of PFMs during their usage in nuclear fusion reactors.
文摘In recent years,there has been a growing demand for more efficient and robust control strategies in cooperative multi-robot systems.This paper introduces the cascade explicit tube model predictive controller(CET-MPC),a control architecture designed specifically for distributed aerial robot systems.By integrating an explicit model predictive controller(MPC)with a tube MPC,our approach significantly reduces online computational demands while enhancing robustness against disturbances such as wind and measurement noise,as well as uncertainties in inertia parameters.Further,we incorporate a cascade controller to minimize steady-state errors and improve system performance dynamically.The results of this assessment provide valuable insights into the effectiveness and reliability of the CET-MPC approach under realistic operating conditions.The simulation results of flight scenarios for multi-agent quadrotors demonstrate the controller’s stability and accurate tracking of the desired path.By addressing the complexities of quadrotors’six degrees of freedom,this controller serves as a versatile solution applicable to a wide range of multi-robot systems with varying degrees of freedom,demonstrating its adaptability and scalability beyond the quadrotor domain.
基金National Natural Science Foundation of China(No.12071370)。
文摘This paper focuses on the problem of leaderfollowing consensus for nonlinear cascaded multi-agent systems.The control strategies for these systems are transformed into successive control problem schemes for lower-order error subsystems.A distributed consensus analysis for the corresponding error systems is conducted by employing recursive methods and virtual controllers,accompanied by a series of Lyapunov functions devised throughout the iterative process,which solves the leaderfollowing consensus problem of a class of nonlinear cascaded multi-agent systems.Specific simulation examples illustrate the effectiveness of the proposed control algorithm.
基金supported by the Youth Program of National Natural Science Foundation of China(No.52404343)the General Program of National Natural Science Foundation of China(No.52274326)+2 种基金the Fundamental Research Funds for the Central Universities,China(No.N2425031)the Seventh Batch of Ten Thousand Talents Plan of China(No.ZX20220553)the Liaoning Province Science and Technology Plan Joint Program,China(Key Research and Development Program Project)(No.2023JH2/101800058).
文摘The comprehensive status of blast furnaces was one of the most important factors affecting their economy,quality,and longev-ity.The blast furnace comprehensive status had the nature of“black box,”and it was“unpredictable.”In this study,a blast furnace com-prehensive status score and prediction method based on a cascade system and a combined model were proposed to address this issue.A dual cascade evaluation system was developed by integrating subjective and objective weighting methods.The analytic hierarchy process,coefficient of variation,entropy weight method,and impart combinatorial games were jointly employed to determine the optimal weight distribution across indicators.Categorized statuses(raw material,gas flow,furnace body,furnace cylinder,and iron-slag)were evaluated.Based on the five categories of the status data,the second cascade was applied to upgrade the quantitative evaluation of the comprehens-ive status.The weights of the different categories were 0.22,0.15,0.22,0.21,and 0.20,respectively.According to the data analysis,the results of the comprehensive status score closely matched the on-site production logs.Based on the blast furnace smelting period,the maximal information coefficient method was applied to the 100 parameters that were most relevant to the comprehensive status.A com-bined prediction model for a comprehensive status score was designed using bidirectional long short-term memory(BiLSTM)and categorical boosting(CatBoost).The test results indicated that the combined model reduced the mean absolute error by an average of 0.275 and increased the hit rate by an average of 5.65 percentage points compared to BiLSTM or CatBoost alone.When the er-ror range was±2.5,the combined model predicted a hit rate of 91.66%for the next hour’s comprehensive status score,and its high accur-acy was deemed satisfactory for the field.SHapley Additive exPlanations(SHAP)and regression fitting were applied to analyze the lin-ear quantitative relationship between the key variables and the comprehensive status score.When the furnace bottom center temperature was increased by 10℃,the comprehensive status score increased by 0.44.This method contributes to a more precise management and control of the comprehensive status of the blast furnace on-site.
基金supported by National Key Research and Development Program of China(2018YFB0904100)Science and Technology Project of SGCC(SGHB0000KXJS1800685).
文摘In DC distributed power systems(DPSs),the complex impedance interactions possibly lead to DC bus voltage oscillation or collapse.In previous research,the stability analysis of DPSs is implemented based on mathematical analysis in control theory.The specific mechanisms of the instability of the cascade system have not been intuitively clarified.In this paper,the stability analysis of DPSs based on the traditional Nyquist criterion is simplified to the resonance analysis of the seriesconnected port impedance(Z=R+jX)of source and load converters.It reveals that the essential reason for impedance instability of a DC cascade system is that the negative damping characteristic(R<0)of the port the overall impedance amplifies the internal resonance source at reactance zero-crossing frequency.The simplified stability criterion for DC cascade systems can be concluded as:in the negative damping frequency ranges(R<0),there exists no zero-crossing point of the reactance component(i.e.,X=0).According to the proposed stability criterion,the oscillation modes of cascade systems are classified.A typical one is the internal impedance instability excited by the negative damping,and the other one is that the external disturbance amplified by negativity in a low stability margin.Thus,the impedance reshaping method for stability improvement of the system can be further specified.The validity of the simplified criterion is verified theoretically and experimentally by a positive damping reshaping method.
基金supported by the National Key Research and Development Plan,Grant/Award Number:2018YFB1503005.
文摘A modular system of cascaded converters based on model predictive control(MPC)is proposed to meet the application requirements ofmultiple voltage levels and electrical isolation in renewable energy generation systems.The system consists of a Buck/Boost+CLLLC cascaded converter as a submodule,which is combined in series and parallel on the input and output sides to achieve direct-current(DC)voltage transformation,bidirectional energy flow,and electrical isolation.The CLLLC converter operates in DC transformer mode in the submodule,while the Buck/Boost converter participates in voltage regulation.This article establishes a suitable mathematical model for the proposed system topology,and uses MPC to control the system based on this mathematical model.Module parameters are designed and calculated,and simulation is built in MATLAB/Simulink to complete the simulation comparison experiment between MPC and traditional proportional integral(PI)control.Finally,a physical experimental platform is built to complete the physical comparison experiment.The simulation and physical experimental results prove that the control accuracy and response speed ofMPC are better than traditional PI control strategy.
基金supported by the Chengdu University of Traditional Chinese Medicine"Xinglin Scholars"Program,China(Grant No.:MPRC2023014).
文摘Gastric carcinoma(GC)is a malignancy with multifactorial involvement,multicellular regulation,and multistage evolution.The classic Correa's cascade of intestinal GC specifies a trilogy of malignant transformation of the gastric mucosa,in which normal gastric mucosa gradually progresses from inactive or chronic active gastritis(Phase I)to gastric precancerous lesions(Phase II)and finally to GC(Phase III).Correa's cascade highlights the evolutionary pattern of GC and the importance of early intervention to prevent malignant transformation of the gastric mucosa.Intervening in early gastric mucosal lesions,i.e.,Phases I and II,will be the key strategy to prevent and treat GC.Natural products(NPs)have been an important source for drug development due to abundant sources,tremendous safety,and multiple pharmacodynamic mechanisms.This review is the first to investigate and summarize the multi-step effects and regulatory mechanisms of NPs on the Correa's cascade in gastric carcinogenesis.In Phase I,NPs modulate Helicobacter pylori urease activity,motility,adhesion,virulence factors,and drug resistance,thereby inhibiting H.pylori-induced gastric mucosal inflammation and oxidative stress,and facilitating ulcer healing.In Phase II,NPs modulate multiple pathways and mediators regulating gastric mucosal cell cycle,apoptosis,autophagy,and angiogenesis to reverse gastric precancerous lesions.In Phase III,NPs suppress cell proliferation,migration,invasion,angiogenesis,and cancer stem cells,induce apoptosis and autophagy,and enhance chemotherapeutic drug sensitivity for the treatment of GC.In contrast to existing work,we hope to uncover NPs with sequential therapeutic effects on multiple phases of GC development,providing new ideas for gastric cancer prevention,treatment,and drug development.
文摘Broad area quantum cascade lasers(BA QCLs)have significant applications in many areas,but suffer from demanding pulse operating conditions and poor beam quality due to heat accumulation and generation of high order modes.A structure of mini-array is adopted to improve the heat dissipation capacity and beam quality of BA QCLs.The active region is etched to form a multi-emitter and the channels are filled with In P:Fe,which acts as a lateral heat dissipation channel to improve the lateral heat dissipation efficiency.A device withλ~4.8μm,a peak output power of 122 W at 1.2%duty cycle with a pulse of 1.5μs is obtained in room temperature,with far-field single-lobed distribution.This result allows BA QCLs to obtain high peak power at wider pump pulse widths and higher duty cycle conditions,promotes the application of the mid-infrared laser operating in pulsed mode in th e field of standoff photoacoustic chemical detection,space optical communication,and so on.
基金Supported by the National Natural Science Foundation of China(62105039)。
文摘In the process of power scaling large-area Quantum Cascade Lasers(QCLs),challenges such as degradation of beam quality and emission of multilobed far-field modes are frequently encountered.These issues become particularly pronounced with an increase in ridge width,resulting in multimode problems.To tackle this,an innovative multi ridge waveguide structure based on the principle of supersymmetry(SUSY)was proposed.This structure comprises a wider main waveguide in the center and two narrower auxiliary waveguides on either side.The high-order modes of the main waveguide are coupled with the modes of the auxiliary waveguides through mode-matching design,and the optical loss of the auxiliary waveguides suppresses these modes,thereby achieving fundamental mode lasing of the wider main waveguide.This paper employs the finite difference eigenmode(FDE)method to perform detailed structural modeling and simulation optimization of the 4.6μm wavelength quantum cascade laser,successfully achieving a single transverse mode QCL with a ridge width of 10μm.In comparison to the traditional single-mode QCL(with a ridge width of about 5μm),the MRW structure has the potential to increase the gain area of the laser by 100%.This offers a novel design concept and methodology for enhancing the single-mode luminous power of mid-infrared quantum cascade lasers,which is of considerable significance.
文摘[Objective]The construction of weirs changes the hydraulic characteristics of rivers and affects the structure of phytoplankton communities and the health of aquatic ecosystems in the river.This study aims to explore the nonlinear response relationship between phytoplankton community structure and its driving factors in spring and autumn in Furong Creek under the construction of cascade weirs.[Methods]The structure of phytoplankton communities and related environmental factors were investigated in Furong Creek from 2023 to 2024.This study focused on the analysis of the changes of nutrient concentrations and biomass of phytoplankton in autumn and spring within the same dry season in Furong Creek.Redundancy analysis was used to identify the key factors influencing the structure of phytoplankton communities.The MIKE 11 model was employed to simulate the hydrodynamic changes in the river.Combined with total nitrogen and permanganate index,a GAM model of phytoplankton diversity index and hydrodynamic factors was developed,and the change of phytoplankton diversity after the optimized layout of the cascade weirs was fitted.[Results]The result showed that the annual average value of Shannon-Wiener diversity index of phytoplankton in Furong Creek was 2.79,which was in a state of mild pollution.A total of 239 species from 95 genera in 8 phyla were identified.Among the phytoplankton,Chlorophyta was the dominant group throughout the year in Furong Creek,followed by Bacillariophyta and Cyanophyta.The cell abundance of phytoplankton ranged from 3.11 to 20.64 mg/L and from 0.23 to 6.31 mg/L in spring and autumn,which indicated a clear seasonal succession of phytoplankton community structure.Compared with autumn,the relative abundance of Cyanophyta significantly decreased in spring across the whole river section,while Chrysophyta and Dinophyta showed significant increase at some monitoring sites,leading to water bloom phenomenon and a noticeable decline in the diversity of phytoplankton.The dominant species in the water bodies throughout the year were Cyclotella catenata,Chlorella vulgaris,Scenedesmus bijuga,Scenedesmus quadricauda,Chroomonas acuta,Cryptomonas ovata,and Cryptomonas erosa.Redundancy analysis(RDA)showed that hydrodynamic factors(v,h)and water environmental factors(TN,COD_(Mn))were the main influencing factors of phytoplankton community structure.[Conclusion]The result show that the nutrient concentration,phytoplankton biomass,and density in Furong Creek in spring are significantly higher than in autumn.The GAM model,constructed by combining hydrodynamic and environmental factors,can effectively reflect the nonlinear relationship between phytoplankton diversity index and its driving factors.In spring,with an increase in nutrient concentration,the habitat conditions of low flow speed and high water depths formed by overflow weirs will lead to a decrease in the Shannon-Wiener index of phytoplankton and an intensified risk of eutrophication.However,a reasonable layout scheme of cascade weirs will improve the diversity of phytoplankton and reduce the risk of eutrophication in the river.The findings of this study can help deepen the understanding of the ecological and environmental effects of cascade weir construction in the river.
文摘A novel synthesis of C2-spiroindoline derivatives based on the cascade reaction of 2-aryl-3H-indoles with cyclo- propanols is presented. The formation of product involves Rh(III)-catalyzed aryl C(sp2)—H bond alkylation of 2-aryl- 3H-indole, which is followed by intramolecular spiroannulation. In this tandem process, cyclopropanol acts as not only an alkylating agent but also a masked nucleophile to take part in the construction of the spirocyclic scaffold. Meanwhile, air acts as an economical and sustainable oxidant to promote the regeneration of the active catalyst. By using this method, hybrid compounds containing the central scaffolds of some clinical drugs were prepared effectively. In general, this newly developed method has advantages such as easily obtainable substrates, concise synthetic procedure, excellent atom-economy, good compatibility with diverse functional groups and ready scalability.
