A large number of runaway electrons(REs)generated during disruption can cause significant damage to next-generation large-scale tokamaks.The influence of three-dimensional(3D)helical magnetic perturbations on the supp...A large number of runaway electrons(REs)generated during disruption can cause significant damage to next-generation large-scale tokamaks.The influence of three-dimensional(3D)helical magnetic perturbations on the suppression of RE generation was explored using a set of 3D helical coils in J-TEXT tokamak,which can excite m/n=-2/2 helical magnetic perturbations.Experimental evidence shows that the-2/2 magnetic perturbations caused by the opposite coil current direct plasma toward the high-field side,simultaneously enhancing the magnetic fluctuations,which would enhance the radial loss of REs and even prevent RE generation.On the other hand,-2/2 magnetic perturbations can also reduce the cooling time during the disruption phase and generate a population of high-energy REs,which can interact with high-frequency magnetic fluctuations and in turn suppress RE generation.The critical helical coil current was found to correlate with electron density,requiring higher coil currents at higher densities.According to the statistical analysis of RE generation at different electron densities,the applied-2/2 magnetic perturbations can increase the magnetic fluctuations to the same level at lower electron densities,which can decrease the threshold electron density for RE suppression.This will be beneficial for RE mitigation in future large tokamak devices.展开更多
This paper introduces a small perturbation frequency domain thermal analysis model based on the nonlinear dynamics model.The model can be applied to study the high-precision temperature control of thermal systems unde...This paper introduces a small perturbation frequency domain thermal analysis model based on the nonlinear dynamics model.The model can be applied to study the high-precision temperature control of thermal systems under low-frequency complex perturbations.The frequency domain characteristics of the space gravitational wave detection satellite are analyzed,and a multi-channel perturbation structure is established.The effects of three kinds of heat flow perturbations,including external heat flow,power generation power,and waste heat of electronic equipment,on the temperature through five transfer paths are investigated.It has been discovered that the waste heat from electronic equipment inside the satellite has the most noticeable effect on the temperature power spectral density of temperature-sensitive optical loads,serving as the primary factor influencing thermal stability.For complex noise signals,the small perturbation analysis method can decompose the different frequency components or ranges,reducing the problem to linearized analysis and simplifying complex calculations.The results indicate that the temperature power spectral density decreases as signal frequency increases,with low-frequency signals exerting a greater influence on temperature stability.The small perturbation analysis method is a novel and effective method for temperature control of space thermal systems,with high accuracy and stability.展开更多
An experimental study was conducted with the aim of understanding behavior of asymmetric vortices flow over a chined fuselage.The tests were carried out in a wind tunnel at Reynolds number of 1.87 · 105 under the...An experimental study was conducted with the aim of understanding behavior of asymmetric vortices flow over a chined fuselage.The tests were carried out in a wind tunnel at Reynolds number of 1.87 · 105 under the conditions of high angles of attack and zero angle of sideslip.The results show that leeward vortices flow becomes asymmetric vortices flow when angle of attack increases over 20.The asymmetric vortices flow is asymmetry of two forebody vortices owing to the increase of angle of attack but not asymmetry of vortex breakdown which appears when angle of attack is above 35.Asymmetric vortices flow is sensitive to tip perturbation and is nondeterministic due to randomly distributed natural minute geometrical irregularities on the nose tip within machining tolerance.Deterministic asymmetric vortices flow can be obtained by attaching artificial tip perturbation which can trigger asymmetric vortices flow and decide asymmetric vortices flow pattern.Triggered by artificial tip perturbation, the vortex on the same side with perturbation is in a higher position, and the other vortex on the opposite side is in a lower position.Vortex suction on the lower vortex side is larger, which corresponds to a side force pointing to the lower vortex side.展开更多
Influence of random initial amplitude perturbations on the lilamentation ot prefocused femtosecond laser pulses is numerically studied. Simulations are performed for the filamentation of laser pulses with different mo...Influence of random initial amplitude perturbations on the lilamentation ot prefocused femtosecond laser pulses is numerically studied. Simulations are performed for the filamentation of laser pulses with different modulation degrees and initial geometric focusings. The transverse waist of the laser beam is 5 mm. The behavior of the filament is strongly affected by the initial non-uniformity of the laser pulse envelope for a short initial focal length （f = 1 m）. In this case, the filament and plasma channel can survive for a longer distance with a small initial amplitude perturbation. For a laser pulse focused by a lens with a long focal length （f = 4 m）, decrease in the initial perturbation does not contribute to the length of the filament and the plasma channel.展开更多
Based on the Kullback-Leibler distance and information distance, someinfluence measures for model perturbations and explanatory variablap ia reg,ressionmodels are proposed.The new influence measures can be used to ide...Based on the Kullback-Leibler distance and information distance, someinfluence measures for model perturbations and explanatory variablap ia reg,ressionmodels are proposed.The new influence measures can be used to identify influentialcases and to assess the effect of explanatory variables on the interested parametersThe method is adaptable for a variety of regression models.展开更多
For deeper understanding the process of baryonic matter evolution in the expanding Universe it is necessary to know the physical property of concrete field that represents the background of substrate type of dark ener...For deeper understanding the process of baryonic matter evolution in the expanding Universe it is necessary to know the physical property of concrete field that represents the background of substrate type of dark energy. Beside, it is necessary to explore in details the influence of such field on the continuous medium of baryonic matter. These statements were realized for the quintessence field that describes by two gravitating scalar fields. They give own contributions at the total pressure and at the total mass density of baryonic matter. It allowed show that evolution of baryonic matter’s density perturbations obeys the equation of forced oscillations and admits the resonance case, when amplitude of baryonic matter’s density perturbations gets the strong short-time splash. This splash interprets as a new macroscopic mechanism of the initial matter density perturbations appearance.展开更多
The influence of Arctic sea ice concentration (SIC) on the subseasonal prediction of the North Atlantic Oscillation (NAO) event is investigated by utilizing the Community Atmospheric Model version 4. The optimal Arcti...The influence of Arctic sea ice concentration (SIC) on the subseasonal prediction of the North Atlantic Oscillation (NAO) event is investigated by utilizing the Community Atmospheric Model version 4. The optimal Arctic SIC perturbations which exert the greatest influence on the onset of an NAO event from a lead of three pentads (15 days) are obtained with a conditional nonlinear optimal perturbation approach. Numerical results show that there are two types of optimal Arctic SIC perturbations for each NAO event, with one weakening event (marked as type-1) and another strengthening event (marked as type-2). For positive NAO events, type-1 optimal SIC perturbations mainly show positive SIC anomalies in the Greenland, Barents, and Okhotsk Seas, while type-2 perturbations mainly feature negative SIC anomalies in these regions. For negative NAO events, the optimal SIC perturbations have almost opposite patterns to those in positive events, although there are some differences among these SIC perturbations due to different atmospheric initial conditions. Further diagnosis reveals that the optimal Arctic SIC perturbations first modify the surface turbulent heat flux and the temperature in the lower troposphere via diabatic processes. Afterward, the temperature in the low troposphere is mainly affected by dynamic advection. Finally, potential vorticity advection plays a crucial role in the 500-hPa geopotential height prediction in the northern North Atlantic sector during pentad 4, which influences NAO event prediction. These results highlight the importance of Arctic SIC on NAO event prediction and the spatial characteristics of the SIC perturbations may provide scientific support for target observations of SIC in improving NAO subseasonal predictions.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
Combined with elastic network model(ENM),the perturbation response scanning(PRS)has emerged as a robust technique for pinpointing allosteric interactions within proteins.Here,we proposed the PRS analysis of drug-targe...Combined with elastic network model(ENM),the perturbation response scanning(PRS)has emerged as a robust technique for pinpointing allosteric interactions within proteins.Here,we proposed the PRS analysis of drug-target networks(DTNs),which could provide a promising avenue in network medicine.We demonstrated the utility of the method by introducing a deep learning and network perturbation-based framework,for drug repurposing of multiple sclerosis(MS).First,the MS comorbidity network was constructed by performing a random walk with restart algorithm based on shared genes between MS and other diseases as seed nodes.Then,based on topological analysis and functional annotation,the neurotransmission module was identified as the“therapeutic module”of MS.Further,perturbation scores of drugs on the module were calculated by constructing the DTN and introducing the PRS analysis,giving a list of repurposable drugs for MS.Mechanism of action analysis both at pathway and structural levels screened dihydroergocristine as a candidate drug of MS by targeting a serotonin receptor of se-rotonin 2B receptor(HTR2B).Finally,we established a cuprizone-induced chronic mouse model to evaluate the alteration of HTR2B in mouse brain regions and observed that HTR2B was significantly reduced in the cuprizone-induced mouse cortex.These findings proved that the network perturbation modeling is a promising avenue for drug repurposing of MS.As a useful systematic method,our approach can also be used to discover the new molecular mechanism and provide effective candidate drugs for other complex diseases.展开更多
BACKGROUND Identifying factors that influence non-curative resection(NCR)is critical to optimize treatment strategies and improve patient outcomes in patients with early gastric cancer(EGC).AIM To investigate the fact...BACKGROUND Identifying factors that influence non-curative resection(NCR)is critical to optimize treatment strategies and improve patient outcomes in patients with early gastric cancer(EGC).AIM To investigate the factors influencing the NCR of EGC and to evaluate the predictive value of these factors.METHODS The clinical data of 173 patients with EGC admitted between July 2020 and July 2023 were retrospectively collected.According to radical resection criteria,the patients were further divided into curative resection group(n=143)and NCR group(n=30).Clinical information was collected,including surgical method,tumor diameter,tumor site,ulcer formation,depth of invasion,pathological type,and lymph node metastasis.Logistic regression analysis was used to explore the factors affecting non-curable resection.RESULTS Multivariate logistic regression analysis showed that ulcer formation[odds ratio(OR)=3.53;95%confidence interval(CI):1.55-8.01,P=0.003],pathological type(OR=3.73;95%CI:1.60-8.74,P=0.002),tumor diameter(OR=3.15;95%CI:1.40-7.05,P=0.005),tumor location(OR=3.50;95%CI:1.16-10.58,P=0.027),lymph node metastasis(OR=4.40;95%CI:1.83-10.57,P=0.001),and depth of penetration(OR=3.75;95%CI:1.60-8.74,P=0.002)were all risk factors for NCR in EGC patients.Predictive analysis showed varying area under the curve values for factors such as tumor diameter(0.636),tumor location(0.608),ulcer formation(0.652),infiltration depth(0.658),pathological type(0.656),and lymph node metastasis(0.674).CONCLUSION The results suggest that factors such as tumor diameter,tumor location,ulcer formation,depth of invasion,pathological type,and lymph node metastasis increase the risk of NCR in EGC patients.展开更多
Zinc-based alloys are promising biodegradable materials for application in the intestinal environment due to their appropriate degradation rates and favorable biocompatibility.However,the corrosion and degradation of ...Zinc-based alloys are promising biodegradable materials for application in the intestinal environment due to their appropriate degradation rates and favorable biocompatibility.However,the corrosion and degradation of biodegradable zinc alloys in the presence of intestinal microorganisms are seldom investigated.In this study,binary Zn-Mn alloys with 0.4 and 0.8 wt.%Mn content were fabricated using the extrusion process.The corrosion behaviors of pure zinc and Zn-Mn alloys with the existence of Lactobacillus acidophilus,a representative microorganism in the intestinal tract,were systematically investigated.In comparison to pure zinc,both Zn-Mn alloys exhibited enhanced strength and ductility.L.acidophilus significantly accelerated the corrosion of both pure zinc and Zn-Mn alloys by generating acidic agents.The presence of L.acidophilus increased the icorr values for pure zinc,Zn-0.4Mn,and Zn-0.8Mn from 68.7±9.9,33.9±2.3 and 17.1±0.1µA cm^(-2) to 253.5±26.7,167.6±8.7 and 30.6±2.2µA cm^(-2),respectively.The addition of Mn mitigated corrosion by refining grains and reducing the local surface potential difference.Compared to pure zinc,the surface potential difference of Zn-0.8Mn decreased from 31.8±1.7 mV to 11.8±0.9 mV.This study points out the existence of microbiologically influenced corrosion in the intestinal environment and emphasizes its importance in the comprehensive design of biodegradable zinc alloys.展开更多
The large-scale exploitation of vanadium(Ⅴ) bearing minerals has led to a massive accumulation of Ⅴ tailings, of which Ⅴ pollution poses severe ecological risks. Although the mechanisms of Ⅴ stress to the microbia...The large-scale exploitation of vanadium(Ⅴ) bearing minerals has led to a massive accumulation of Ⅴ tailings, of which Ⅴ pollution poses severe ecological risks. Although the mechanisms of Ⅴ stress to the microbial community have been reported, the influential pathways in a multi-medium-containing system, for example, the soil-tailings-groundwater system,are unknown. The dynamic redox conditions and substance exchange within the system exhibited complex Ⅴ stress on the local microbial communities. In this study, the influence pathways of Ⅴ stress to the microbial community in the soil-tailings-groundwater system were first investigated. High Ⅴ contents were observed in groundwater(139.2 ± 0.15 μg/L) and soil(98.0–323.8 ± 0.02 mg/kg), respectively. Distinct microbial composition was observed for soil and groundwater, where soil showed the highest level of diversity and richness. Firmicutes, Proteobacteria, Actinobacteria, and Acidobacteria were dominant in soil and groundwater with a sum relative abundance of around 80 %. Based on redundancy analysis and structural equation models, Ⅴ was one of the vital driving factors affecting microbial communities. Groundwater microbial communities were influenced by Ⅴ via Cr, dissolved oxygen, and total nitrogen, while Fe, Mn, and total phosphorus were the key mediators for Ⅴ to affect soil microbial communities. Ⅴ affected the microbial community via metabolic pathways related to carbonaceous matter, which was involved in the establishment of survival strategies for metal stress. This study provides novel insights into the influence pathways of Ⅴ on the microorganisms in tailings reservoir for pollution bioremediation.展开更多
The practical predictability of hail precipitation rates is significantly influenced by initial meteorological perturbations,stemming from various uncertainty sources.This study thoroughly assessed the predictability ...The practical predictability of hail precipitation rates is significantly influenced by initial meteorological perturbations,stemming from various uncertainty sources.This study thoroughly assessed the predictability of hail precipitation rates in both climatologically and flow-dependent perturbed ensembles(CEns and FEns).These ensembles incorporated initial meteorological uncertainties derived separately from two operational ensembles.Leveraging the Weather Research and Forecasting model,we conducted cloud-resolving simulations of an idealized hailstorm.The practical predictability of hail responded comparably to both climatological and flow-dependent uncertainties,which was revealed across the entire ensemble of 50 members.However,a notable difference emerged when comparing the peak hail precipitation rates among the top 10 and bottom 10 members.From a thermodynamic perspective,the primary source of uncertainty in hail precipitation lay in the significant variations in temperature stratification,particularly at-20℃and-40℃.On the microphysical front,perturbations within CEns generated greater uncertainty in the process of rainwater collection by hail,contributing significantly to the microphysical growth mechanisms of hail.Furthermore,the findings reveal a stronger dependency of hail precipitation uncertainty on thermodynamic perturbations compared to kinematic perturbations.These insights enhance the comprehension of the practical predictability of hail and contribute significantly to the understanding of ensemble forecasting for hail events.展开更多
A direct renormalization method without spectrum theory is proposed to compute the perturbation of solitons in nearly integrable systems with multiple small parameters.The evolution equations of these parameters in un...A direct renormalization method without spectrum theory is proposed to compute the perturbation of solitons in nearly integrable systems with multiple small parameters.The evolution equations of these parameters in unperturbed solitons are obtained as the renormalization equations.Compared with routine methods,the advantages of the renormalization method are that the formulation is only based on a clear and simple mathematical theory,namely the Taylor expansion at a general point,the secular terms in perturbation series are eliminated automatically,any priori physical assumption on the form of the solution is avoided,multiple time scales arise naturally from the final naive perturbation expansion,and the Green’s function and corresponding spectrum of linear differential operators are not needed.As applications,the perturbation of solitons for KDV,MKdV and nonlinear Schrodinger equations,are obtained.展开更多
Tai-Chi(TC)is a broadly used exercise that appeared to decrease the risk of falls.However,biomechanical mechanisms underlying the reduced fall risks following TC exercise remain unclear and hinder the ability to optim...Tai-Chi(TC)is a broadly used exercise that appeared to decrease the risk of falls.However,biomechanical mechanisms underlying the reduced fall risks following TC exercise remain unclear and hinder the ability to optimize TC intervention to target specific balance deficit disorders.In addition,combining TC gait exercise with ground support perturbation may be a viable approach to further challenge balance control compared to TC gait alone.The purpose of this study was to compare dynamic stability and limb support force production during comfortable walking speed(CWS),TC gait,and TC gait with medial(MED)and lateral(LAT)ground support perturbations in older and younger adults.Ten older adults and ten younger adults performed CWS,TC gait,LAT,and MED.Conditions involving TC gait showed decreased margin of stability(MoS)(main effect of condition,p<0.01)and increased vertical force impulse compared to CWS(p<0.01).Medial ground support perturbation induced the smallest MoS among all conditions.Older adults showed increased MoS compared to younger adults(p<0.01).These findings provided insight into how key balance control characteristics are modulated during TC exercise and indicate that combining ground support perturbation with TC may further challenge dynamic stability.展开更多
In recent years,universal adversarial per-turbation(UAP)has attracted the attention of many re-searchers due to its good generalization.However,in order to generate an appropriate UAP,current methods usually require e...In recent years,universal adversarial per-turbation(UAP)has attracted the attention of many re-searchers due to its good generalization.However,in order to generate an appropriate UAP,current methods usually require either accessing the original dataset or meticulously constructing optimization functions and proxy datasets.In this paper,we aim to elimi-nate any dependency on proxy datasets and explore a method for generating Universal Adversarial Pertur-bations(UAP)on a single image.After revisiting re-search on UAP,we discovered that the key to gener-ating UAP lies in the accumulation of Individual Ad-versarial Perturbation(IAP)gradient,which prompted us to study the method of accumulating gradients from an IAP.We designed a simple and effective process to generate UAP,which only includes three steps:pre-cessing,generating an IAP and scaling the perturba-tions.Through our proposed process,any IAP gener-ated on an image can be constructed into a UAP with comparable performance,indicating that UAP can be generated free of data.Extensive experiments on var-ious classifiers and attack approaches demonstrate the superiority of our method on efficiency and aggressiveness.展开更多
The spatial-temporal distribution of charging loads for electric vehicles is influenced by multiple factors,Nowadays,the accuracy of the forecasts needs to be improved and the completeness of the modeling is relativel...The spatial-temporal distribution of charging loads for electric vehicles is influenced by multiple factors,Nowadays,the accuracy of the forecasts needs to be improved and the completeness of the modeling is relatively lacking.Therefore,this paper proposes a method for modeling the charging load of electric vehicles based on the influence of multiple factors.First,an in-depth analysis of the factors affecting the charging load of electric vehicles was conducted.Then,a model of electric vehicle electricity consumption per unit kilometer was constructed based on the influencing factors.Next,the electric vehicle,the charging station,the traffic network and the grid are modeled separately.In addition,a unified model of vehicle-station-road-network was constructed through the interaction and coupling of information between the models.Finally,the spatial-temporal distribution of electric vehicle charging loads was simulated using real data from a region.The study shows that the model is able to simulate the charging load of electric vehicles more accurately.Different traffic flows and areas have a significant impact on the charging load distribution.展开更多
Personalized nursing is a necessary means to improve the satisfaction of emergency pediatric nursing.It can enhance the responsiveness of nursing services,strengthen the emotional connection between nurses and patient...Personalized nursing is a necessary means to improve the satisfaction of emergency pediatric nursing.It can enhance the responsiveness of nursing services,strengthen the emotional connection between nurses and patients,and provide a theoretical basis for clinical practice.Therefore,in the context of the new era,it is necessary to deeply analyze the essence and connotation of personalized nursing,and analyze the existing deficiencies in current emergency pediatric personalized nursing,so as to develop effective improvement plans.Research shows that personalized nursing can significantly improve the satisfaction of emergency pediatric nursing,largely avoid nursing risks,and has strong clinical application value.This article summarizes and explores the research on the influence of personalized nursing on improving the satisfaction of emergency pediatric nursing,and puts forward corresponding views.展开更多
1 No one likes acknowledging that their thoughts and behaviors are easily influenced outside of their awareness.However,Daniel M.Wegner,author of The Illusion of Conscious Will,explains that people ignore how easily t...1 No one likes acknowledging that their thoughts and behaviors are easily influenced outside of their awareness.However,Daniel M.Wegner,author of The Illusion of Conscious Will,explains that people ignore how easily they can be manipulated(操纵)because they don't feel they are being manipulated.This is what happens:After our unconscious(无意识)mind motivates a thought or action,this urge or thought is then sent to our conscious mind.Here,we become aware of it and have the false impression of generating it independently.展开更多
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China (Nos.2018YFE0309103 and 2019YFE03010004)National Natural Science Foundation of China (Nos.12475222,12205122,and 51821005)Hubei International Science and Technology Cooperation Projects (No.2022EHB003)。
文摘A large number of runaway electrons(REs)generated during disruption can cause significant damage to next-generation large-scale tokamaks.The influence of three-dimensional(3D)helical magnetic perturbations on the suppression of RE generation was explored using a set of 3D helical coils in J-TEXT tokamak,which can excite m/n=-2/2 helical magnetic perturbations.Experimental evidence shows that the-2/2 magnetic perturbations caused by the opposite coil current direct plasma toward the high-field side,simultaneously enhancing the magnetic fluctuations,which would enhance the radial loss of REs and even prevent RE generation.On the other hand,-2/2 magnetic perturbations can also reduce the cooling time during the disruption phase and generate a population of high-energy REs,which can interact with high-frequency magnetic fluctuations and in turn suppress RE generation.The critical helical coil current was found to correlate with electron density,requiring higher coil currents at higher densities.According to the statistical analysis of RE generation at different electron densities,the applied-2/2 magnetic perturbations can increase the magnetic fluctuations to the same level at lower electron densities,which can decrease the threshold electron density for RE suppression.This will be beneficial for RE mitigation in future large tokamak devices.
基金supported by the National Key Research and Development Program of China(No.2022YFC2204400)。
文摘This paper introduces a small perturbation frequency domain thermal analysis model based on the nonlinear dynamics model.The model can be applied to study the high-precision temperature control of thermal systems under low-frequency complex perturbations.The frequency domain characteristics of the space gravitational wave detection satellite are analyzed,and a multi-channel perturbation structure is established.The effects of three kinds of heat flow perturbations,including external heat flow,power generation power,and waste heat of electronic equipment,on the temperature through five transfer paths are investigated.It has been discovered that the waste heat from electronic equipment inside the satellite has the most noticeable effect on the temperature power spectral density of temperature-sensitive optical loads,serving as the primary factor influencing thermal stability.For complex noise signals,the small perturbation analysis method can decompose the different frequency components or ranges,reducing the problem to linearized analysis and simplifying complex calculations.The results indicate that the temperature power spectral density decreases as signal frequency increases,with low-frequency signals exerting a greater influence on temperature stability.The small perturbation analysis method is a novel and effective method for temperature control of space thermal systems,with high accuracy and stability.
基金supported by the National Natural Science Foundation of China (Nos.11172030, 11102012 and 11472028)
文摘An experimental study was conducted with the aim of understanding behavior of asymmetric vortices flow over a chined fuselage.The tests were carried out in a wind tunnel at Reynolds number of 1.87 · 105 under the conditions of high angles of attack and zero angle of sideslip.The results show that leeward vortices flow becomes asymmetric vortices flow when angle of attack increases over 20.The asymmetric vortices flow is asymmetry of two forebody vortices owing to the increase of angle of attack but not asymmetry of vortex breakdown which appears when angle of attack is above 35.Asymmetric vortices flow is sensitive to tip perturbation and is nondeterministic due to randomly distributed natural minute geometrical irregularities on the nose tip within machining tolerance.Deterministic asymmetric vortices flow can be obtained by attaching artificial tip perturbation which can trigger asymmetric vortices flow and decide asymmetric vortices flow pattern.Triggered by artificial tip perturbation, the vortex on the same side with perturbation is in a higher position, and the other vortex on the opposite side is in a lower position.Vortex suction on the lower vortex side is larger, which corresponds to a side force pointing to the lower vortex side.
基金supported by National Natural Science Foundation of China(Nos.60621063,10634020,10734130 and 10521002)the National Basic Research Program of China(973 Program)(Nos.2007CB815101,2006CB806007)
文摘Influence of random initial amplitude perturbations on the lilamentation ot prefocused femtosecond laser pulses is numerically studied. Simulations are performed for the filamentation of laser pulses with different modulation degrees and initial geometric focusings. The transverse waist of the laser beam is 5 mm. The behavior of the filament is strongly affected by the initial non-uniformity of the laser pulse envelope for a short initial focal length （f = 1 m）. In this case, the filament and plasma channel can survive for a longer distance with a small initial amplitude perturbation. For a laser pulse focused by a lens with a long focal length （f = 4 m）, decrease in the initial perturbation does not contribute to the length of the filament and the plasma channel.
文摘Based on the Kullback-Leibler distance and information distance, someinfluence measures for model perturbations and explanatory variablap ia reg,ressionmodels are proposed.The new influence measures can be used to identify influentialcases and to assess the effect of explanatory variables on the interested parametersThe method is adaptable for a variety of regression models.
文摘For deeper understanding the process of baryonic matter evolution in the expanding Universe it is necessary to know the physical property of concrete field that represents the background of substrate type of dark energy. Beside, it is necessary to explore in details the influence of such field on the continuous medium of baryonic matter. These statements were realized for the quintessence field that describes by two gravitating scalar fields. They give own contributions at the total pressure and at the total mass density of baryonic matter. It allowed show that evolution of baryonic matter’s density perturbations obeys the equation of forced oscillations and admits the resonance case, when amplitude of baryonic matter’s density perturbations gets the strong short-time splash. This splash interprets as a new macroscopic mechanism of the initial matter density perturbations appearance.
基金the National Natural Science Foundation of China(Grant Nos.42288101,41790475,42005046,and 41775001).
文摘The influence of Arctic sea ice concentration (SIC) on the subseasonal prediction of the North Atlantic Oscillation (NAO) event is investigated by utilizing the Community Atmospheric Model version 4. The optimal Arctic SIC perturbations which exert the greatest influence on the onset of an NAO event from a lead of three pentads (15 days) are obtained with a conditional nonlinear optimal perturbation approach. Numerical results show that there are two types of optimal Arctic SIC perturbations for each NAO event, with one weakening event (marked as type-1) and another strengthening event (marked as type-2). For positive NAO events, type-1 optimal SIC perturbations mainly show positive SIC anomalies in the Greenland, Barents, and Okhotsk Seas, while type-2 perturbations mainly feature negative SIC anomalies in these regions. For negative NAO events, the optimal SIC perturbations have almost opposite patterns to those in positive events, although there are some differences among these SIC perturbations due to different atmospheric initial conditions. Further diagnosis reveals that the optimal Arctic SIC perturbations first modify the surface turbulent heat flux and the temperature in the lower troposphere via diabatic processes. Afterward, the temperature in the low troposphere is mainly affected by dynamic advection. Finally, potential vorticity advection plays a crucial role in the 500-hPa geopotential height prediction in the northern North Atlantic sector during pentad 4, which influences NAO event prediction. These results highlight the importance of Arctic SIC on NAO event prediction and the spatial characteristics of the SIC perturbations may provide scientific support for target observations of SIC in improving NAO subseasonal predictions.
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.
基金supported by the National Natural Science Foundation of China(Grant Nos.:32271292,31872723,32200778,and 22377089)the Jiangsu Students Innovation and Entrepre-neurship Training Program,China(Program No.:202210285081Z)+6 种基金the Project of MOE Key Laboratory of Geriatric Diseases and Immunology,China(Project No.:JYN202404)Proj-ect Funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions,Natural Science Foundation of Jiangsu Province,China(Project No.:BK20220494)Suzhou Medical and Health Technology Innovation Project,China(Grant No.:SKY2022107)the Clinical Research Center of Neuro-logical Disease in The Second Affiliated Hospital of Soochow University,China(Grant No.:ND2022A04)State Key Laboratory of Drug Research(Grant No.:SKLDR-2023-KF-05)Jiangsu Shuang-chuang Program for Doctor,Young Science Talents Promotion Project of Jiangsu Science and Technology Association(Program No.:TJ-2023-019)Young Science Talents Promotion Project of Suzhou Science and Technology Association,Suzhou International Joint Laboratory for Diagnosis and Treatment of Brain Diseases,and startup funding(Grant Nos.:NH21500221,NH21500122,and NH21500123)to Qifei Cong.
文摘Combined with elastic network model(ENM),the perturbation response scanning(PRS)has emerged as a robust technique for pinpointing allosteric interactions within proteins.Here,we proposed the PRS analysis of drug-target networks(DTNs),which could provide a promising avenue in network medicine.We demonstrated the utility of the method by introducing a deep learning and network perturbation-based framework,for drug repurposing of multiple sclerosis(MS).First,the MS comorbidity network was constructed by performing a random walk with restart algorithm based on shared genes between MS and other diseases as seed nodes.Then,based on topological analysis and functional annotation,the neurotransmission module was identified as the“therapeutic module”of MS.Further,perturbation scores of drugs on the module were calculated by constructing the DTN and introducing the PRS analysis,giving a list of repurposable drugs for MS.Mechanism of action analysis both at pathway and structural levels screened dihydroergocristine as a candidate drug of MS by targeting a serotonin receptor of se-rotonin 2B receptor(HTR2B).Finally,we established a cuprizone-induced chronic mouse model to evaluate the alteration of HTR2B in mouse brain regions and observed that HTR2B was significantly reduced in the cuprizone-induced mouse cortex.These findings proved that the network perturbation modeling is a promising avenue for drug repurposing of MS.As a useful systematic method,our approach can also be used to discover the new molecular mechanism and provide effective candidate drugs for other complex diseases.
文摘BACKGROUND Identifying factors that influence non-curative resection(NCR)is critical to optimize treatment strategies and improve patient outcomes in patients with early gastric cancer(EGC).AIM To investigate the factors influencing the NCR of EGC and to evaluate the predictive value of these factors.METHODS The clinical data of 173 patients with EGC admitted between July 2020 and July 2023 were retrospectively collected.According to radical resection criteria,the patients were further divided into curative resection group(n=143)and NCR group(n=30).Clinical information was collected,including surgical method,tumor diameter,tumor site,ulcer formation,depth of invasion,pathological type,and lymph node metastasis.Logistic regression analysis was used to explore the factors affecting non-curable resection.RESULTS Multivariate logistic regression analysis showed that ulcer formation[odds ratio(OR)=3.53;95%confidence interval(CI):1.55-8.01,P=0.003],pathological type(OR=3.73;95%CI:1.60-8.74,P=0.002),tumor diameter(OR=3.15;95%CI:1.40-7.05,P=0.005),tumor location(OR=3.50;95%CI:1.16-10.58,P=0.027),lymph node metastasis(OR=4.40;95%CI:1.83-10.57,P=0.001),and depth of penetration(OR=3.75;95%CI:1.60-8.74,P=0.002)were all risk factors for NCR in EGC patients.Predictive analysis showed varying area under the curve values for factors such as tumor diameter(0.636),tumor location(0.608),ulcer formation(0.652),infiltration depth(0.658),pathological type(0.656),and lymph node metastasis(0.674).CONCLUSION The results suggest that factors such as tumor diameter,tumor location,ulcer formation,depth of invasion,pathological type,and lymph node metastasis increase the risk of NCR in EGC patients.
基金financially supported by the National Natural Science Foundation of China(No.52231010).
文摘Zinc-based alloys are promising biodegradable materials for application in the intestinal environment due to their appropriate degradation rates and favorable biocompatibility.However,the corrosion and degradation of biodegradable zinc alloys in the presence of intestinal microorganisms are seldom investigated.In this study,binary Zn-Mn alloys with 0.4 and 0.8 wt.%Mn content were fabricated using the extrusion process.The corrosion behaviors of pure zinc and Zn-Mn alloys with the existence of Lactobacillus acidophilus,a representative microorganism in the intestinal tract,were systematically investigated.In comparison to pure zinc,both Zn-Mn alloys exhibited enhanced strength and ductility.L.acidophilus significantly accelerated the corrosion of both pure zinc and Zn-Mn alloys by generating acidic agents.The presence of L.acidophilus increased the icorr values for pure zinc,Zn-0.4Mn,and Zn-0.8Mn from 68.7±9.9,33.9±2.3 and 17.1±0.1µA cm^(-2) to 253.5±26.7,167.6±8.7 and 30.6±2.2µA cm^(-2),respectively.The addition of Mn mitigated corrosion by refining grains and reducing the local surface potential difference.Compared to pure zinc,the surface potential difference of Zn-0.8Mn decreased from 31.8±1.7 mV to 11.8±0.9 mV.This study points out the existence of microbiologically influenced corrosion in the intestinal environment and emphasizes its importance in the comprehensive design of biodegradable zinc alloys.
基金supported by the National Natural Science Foundation of China(No.42377415)the Natural Science Foundation of Sichuan Province(No.2023NSFSC0811),Sichuan Science and Technology Program(Nos.2021JDTD0013 and 2021YFQ0066)+1 种基金the Science and Technology Major Project of Xizhang Autonomous Region of China(No.XZ202201ZD0004G06)the Everest Scientific Research Program(No.80000-2023ZF11405).
文摘The large-scale exploitation of vanadium(Ⅴ) bearing minerals has led to a massive accumulation of Ⅴ tailings, of which Ⅴ pollution poses severe ecological risks. Although the mechanisms of Ⅴ stress to the microbial community have been reported, the influential pathways in a multi-medium-containing system, for example, the soil-tailings-groundwater system,are unknown. The dynamic redox conditions and substance exchange within the system exhibited complex Ⅴ stress on the local microbial communities. In this study, the influence pathways of Ⅴ stress to the microbial community in the soil-tailings-groundwater system were first investigated. High Ⅴ contents were observed in groundwater(139.2 ± 0.15 μg/L) and soil(98.0–323.8 ± 0.02 mg/kg), respectively. Distinct microbial composition was observed for soil and groundwater, where soil showed the highest level of diversity and richness. Firmicutes, Proteobacteria, Actinobacteria, and Acidobacteria were dominant in soil and groundwater with a sum relative abundance of around 80 %. Based on redundancy analysis and structural equation models, Ⅴ was one of the vital driving factors affecting microbial communities. Groundwater microbial communities were influenced by Ⅴ via Cr, dissolved oxygen, and total nitrogen, while Fe, Mn, and total phosphorus were the key mediators for Ⅴ to affect soil microbial communities. Ⅴ affected the microbial community via metabolic pathways related to carbonaceous matter, which was involved in the establishment of survival strategies for metal stress. This study provides novel insights into the influence pathways of Ⅴ on the microorganisms in tailings reservoir for pollution bioremediation.
基金supported by the National Natural Science Foundation of China(Grant Nos.42005005 and 42030607)the Science and Technology Department of Shaanxi Province(Grant No.2024JC-YBQN-0248)+2 种基金the Education Department of Shaanxi Province(Grant No.23JK0686)a Xi'an Science and Technology Project(Grant No.22GXFW0131)the Young Talent fund of the University Association for Science and Technology in Shaanxi(Grant No.20210706)。
文摘The practical predictability of hail precipitation rates is significantly influenced by initial meteorological perturbations,stemming from various uncertainty sources.This study thoroughly assessed the predictability of hail precipitation rates in both climatologically and flow-dependent perturbed ensembles(CEns and FEns).These ensembles incorporated initial meteorological uncertainties derived separately from two operational ensembles.Leveraging the Weather Research and Forecasting model,we conducted cloud-resolving simulations of an idealized hailstorm.The practical predictability of hail responded comparably to both climatological and flow-dependent uncertainties,which was revealed across the entire ensemble of 50 members.However,a notable difference emerged when comparing the peak hail precipitation rates among the top 10 and bottom 10 members.From a thermodynamic perspective,the primary source of uncertainty in hail precipitation lay in the significant variations in temperature stratification,particularly at-20℃and-40℃.On the microphysical front,perturbations within CEns generated greater uncertainty in the process of rainwater collection by hail,contributing significantly to the microphysical growth mechanisms of hail.Furthermore,the findings reveal a stronger dependency of hail precipitation uncertainty on thermodynamic perturbations compared to kinematic perturbations.These insights enhance the comprehension of the practical predictability of hail and contribute significantly to the understanding of ensemble forecasting for hail events.
基金supported by the Special Program for Ability Promotion of the Basic and Scientific Research(Grant No.2023JCYJ-01).
文摘A direct renormalization method without spectrum theory is proposed to compute the perturbation of solitons in nearly integrable systems with multiple small parameters.The evolution equations of these parameters in unperturbed solitons are obtained as the renormalization equations.Compared with routine methods,the advantages of the renormalization method are that the formulation is only based on a clear and simple mathematical theory,namely the Taylor expansion at a general point,the secular terms in perturbation series are eliminated automatically,any priori physical assumption on the form of the solution is avoided,multiple time scales arise naturally from the final naive perturbation expansion,and the Green’s function and corresponding spectrum of linear differential operators are not needed.As applications,the perturbation of solitons for KDV,MKdV and nonlinear Schrodinger equations,are obtained.
基金College of Education Small Grant Award at the University of Texas at Austin.
文摘Tai-Chi(TC)is a broadly used exercise that appeared to decrease the risk of falls.However,biomechanical mechanisms underlying the reduced fall risks following TC exercise remain unclear and hinder the ability to optimize TC intervention to target specific balance deficit disorders.In addition,combining TC gait exercise with ground support perturbation may be a viable approach to further challenge balance control compared to TC gait alone.The purpose of this study was to compare dynamic stability and limb support force production during comfortable walking speed(CWS),TC gait,and TC gait with medial(MED)and lateral(LAT)ground support perturbations in older and younger adults.Ten older adults and ten younger adults performed CWS,TC gait,LAT,and MED.Conditions involving TC gait showed decreased margin of stability(MoS)(main effect of condition,p<0.01)and increased vertical force impulse compared to CWS(p<0.01).Medial ground support perturbation induced the smallest MoS among all conditions.Older adults showed increased MoS compared to younger adults(p<0.01).These findings provided insight into how key balance control characteristics are modulated during TC exercise and indicate that combining ground support perturbation with TC may further challenge dynamic stability.
基金supported in part by the Natural Science Foundation of China under Grant 62372395in part by the Research Foundation of Education Bureau of Hunan Province under Grant No.24A0105in part by the Postgraduate Scientific Research Innovation Project of Hunan Province(Grant No.CX20230546).
文摘In recent years,universal adversarial per-turbation(UAP)has attracted the attention of many re-searchers due to its good generalization.However,in order to generate an appropriate UAP,current methods usually require either accessing the original dataset or meticulously constructing optimization functions and proxy datasets.In this paper,we aim to elimi-nate any dependency on proxy datasets and explore a method for generating Universal Adversarial Pertur-bations(UAP)on a single image.After revisiting re-search on UAP,we discovered that the key to gener-ating UAP lies in the accumulation of Individual Ad-versarial Perturbation(IAP)gradient,which prompted us to study the method of accumulating gradients from an IAP.We designed a simple and effective process to generate UAP,which only includes three steps:pre-cessing,generating an IAP and scaling the perturba-tions.Through our proposed process,any IAP gener-ated on an image can be constructed into a UAP with comparable performance,indicating that UAP can be generated free of data.Extensive experiments on var-ious classifiers and attack approaches demonstrate the superiority of our method on efficiency and aggressiveness.
基金the National Key Research and Development Program of China(No.2021YFB2501602)the National Natural Science Foundation of China(No.52077208)。
文摘The spatial-temporal distribution of charging loads for electric vehicles is influenced by multiple factors,Nowadays,the accuracy of the forecasts needs to be improved and the completeness of the modeling is relatively lacking.Therefore,this paper proposes a method for modeling the charging load of electric vehicles based on the influence of multiple factors.First,an in-depth analysis of the factors affecting the charging load of electric vehicles was conducted.Then,a model of electric vehicle electricity consumption per unit kilometer was constructed based on the influencing factors.Next,the electric vehicle,the charging station,the traffic network and the grid are modeled separately.In addition,a unified model of vehicle-station-road-network was constructed through the interaction and coupling of information between the models.Finally,the spatial-temporal distribution of electric vehicle charging loads was simulated using real data from a region.The study shows that the model is able to simulate the charging load of electric vehicles more accurately.Different traffic flows and areas have a significant impact on the charging load distribution.
文摘Personalized nursing is a necessary means to improve the satisfaction of emergency pediatric nursing.It can enhance the responsiveness of nursing services,strengthen the emotional connection between nurses and patients,and provide a theoretical basis for clinical practice.Therefore,in the context of the new era,it is necessary to deeply analyze the essence and connotation of personalized nursing,and analyze the existing deficiencies in current emergency pediatric personalized nursing,so as to develop effective improvement plans.Research shows that personalized nursing can significantly improve the satisfaction of emergency pediatric nursing,largely avoid nursing risks,and has strong clinical application value.This article summarizes and explores the research on the influence of personalized nursing on improving the satisfaction of emergency pediatric nursing,and puts forward corresponding views.
文摘1 No one likes acknowledging that their thoughts and behaviors are easily influenced outside of their awareness.However,Daniel M.Wegner,author of The Illusion of Conscious Will,explains that people ignore how easily they can be manipulated(操纵)because they don't feel they are being manipulated.This is what happens:After our unconscious(无意识)mind motivates a thought or action,this urge or thought is then sent to our conscious mind.Here,we become aware of it and have the false impression of generating it independently.
