Self-oscillating systems abound in the natural world and offer substantial potential for applications in controllers,micro-motors,medical equipments,and so on.Currently,numerical methods have been widely utilized for ...Self-oscillating systems abound in the natural world and offer substantial potential for applications in controllers,micro-motors,medical equipments,and so on.Currently,numerical methods have been widely utilized for obtaining the characteristics of self-oscillation including amplitude and frequency.However,numerical methods are burdened by intricate computations and limited precision,hindering comprehensive investigations into self-oscillating systems.In this paper,the stability of a liquid crystal elastomer fiber self-oscillating system under a linear temperature field is studied,and analytical solutions for the amplitude and frequency are determined.Initially,we establish the governing equations of self-oscillation,elucidate two motion regimes,and reveal the underlying mechanism.Subsequently,we conduct a stability analysis and employ a multi-scale method to obtain the analytical solutions for the amplitude and frequency.The results show agreement between the multi-scale and numerical methods.This research contributes to the examination of diverse self-oscillating systems and advances the theoretical analysis of self-oscillating systems rooted in active materials.展开更多
The self-charging concept has drawn considerable attention due to its excellent ability to achieve environmental energy harvesting,conversion and storage without an external power supply.However,most self-charging des...The self-charging concept has drawn considerable attention due to its excellent ability to achieve environmental energy harvesting,conversion and storage without an external power supply.However,most self-charging designs assembled by multiple energy harvesting,conversion and storage materials increase the energy transfer loss;the environmental energy supply is generally limited by climate and meteorological conditions,hindering the potential application of these selfpowered devices to be available at all times.Based on aerobic autoxidation of catechol,which is similar to the electrochemical oxidation of the catechol groups on the carbon materials under an electrical charge,we proposed an air-breathing chemical self-charge concept based on the aerobic autoxidation of catechol groups on oxygen-enriched carbon materials to ortho-quinone groups.Energy harvesting,conversion and storage functions could be integrated on a single carbon material to avoid the energy transfer loss among the different materials.Moreover,the assembled Cu/oxygen-enriched carbon battery confirmed the feasibility of the air-oxidation self-charging/electrical discharging mechanism for potential applications.This air-breathing chemical self-charge concept could facilitate the exploration of high-efficiency sustainable air self-charging devices.展开更多
The Cooling Storage Ring external-target experiment(CEE)spectrometer is used to study the nuclear matter created in heavy-ion collisions at√sNN=2.1-2.4 GeV with the aim to reveal the quantum chromodynamics phase stru...The Cooling Storage Ring external-target experiment(CEE)spectrometer is used to study the nuclear matter created in heavy-ion collisions at√sNN=2.1-2.4 GeV with the aim to reveal the quantum chromodynamics phase structure in the high-baryon-density region.Collective flow is considered an effective probe for evaluating the properties of media during high-energy nuclear collisions.One of the main functions of the zero-degree calorimeter(ZDC),a subdetector system in the CEE,is to determine the reaction plane in heavy-ion collisions.This step is crucial for measuring the collective flow and other reaction-plane-related analyses.In this paper,we illustrate the procedures for event plane determination using the ZDC.Finally,isospin-dependent quantum molecular dynamics model-based predictions of the rapidity dependence of the directed and elliptical flows for p,d,t,3He,and 4He,produced in 2.1 GeV U+U collisions,are presented.展开更多
The zero-degree calorimeter(ZDC)plays a crucial role toward determining the centrality in the Cooling-Storage-Ring External-target Experiment(CEE)at the Heavy Ion Research Facility in Lanzhou.A boosted decision tree(B...The zero-degree calorimeter(ZDC)plays a crucial role toward determining the centrality in the Cooling-Storage-Ring External-target Experiment(CEE)at the Heavy Ion Research Facility in Lanzhou.A boosted decision tree(BDT)multi-classification algorithm was employed to classify the centrality of the collision events based on the raw features from ZDC such as the number of fired channels and deposited energy.The data from simulated^(238)U+^(238)U collisions at 500 MeV∕u,generated by the IQMD event generator and subsequently modeled using the GEANT4 package,were employed to train and test the BDT model.The results showed the high accuracy of the multi-classification model adopted in ZDC for centrality determination,which is robust against variations in different factors of detector geometry and response.This study demon-strates the good performance of CEE-ZDC in determining the centrality in nucleus-nucleus collisions.展开更多
Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulveriz...Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulverization during the lithiation/delithiation process.The high stress induced by the Li concentration gradient and anisotropic deformation is the main reason for the fracture of Si particles.Here we present a new stress mitigation strategy by uniformly distributing small amounts of Sn and Sb in Si micron-sized particles,which reduces the Li concentration gradient and realizes an isotropic lithiation/delithiation process.The Si8.5Sn0.5Sb microparticles(mean particle size:8.22μm)show over 6000-fold and tenfold improvements in electronic conductivity and Li diffusivity than Si particles,respectively.The discharge capacities of the Si_(8.5)Sn_(0.5)Sb microparticle anode after 100 cycles at 1.0 and 3.0 A g^(-1)are 1.62 and 1.19 Ah g^(-1),respectively,corresponding to a retention rate of 94.2%and 99.6%,respectively,relative to the capacity of the first cycle after activation.Multicomponent microparticle anodes containing Si,Sn,Sb,Ge and Ag prepared using the same method yields an ultra-low capacity decay rate of 0.02%per cycle for 1000 cycles at 1 A g^(-1),corroborating the proposed mechanism.The stress regulation mechanism enabled by the industry-compatible fabrication methods opens up enormous opportunities for low-cost and high-energy-density Li-ion batteries.展开更多
While the Bushen Yizhi Formula can treat Alzheimer’s disease(AD),the yet to be ascertained specific mechanism of action was explored in this work.Methods:Different concentrations of the Bushen Yizhi Formula and amylo...While the Bushen Yizhi Formula can treat Alzheimer’s disease(AD),the yet to be ascertained specific mechanism of action was explored in this work.Methods:Different concentrations of the Bushen Yizhi Formula and amyloid-beta peptide(Aβ)were used to treat rat pheochromocytoma cells(P12)and human neuroblastoma cells(SH-SY5Y).Cell morphological changes were observed to determine the in vitro cell damage.Cell Counting Kit(CCK)-8 assay and flow cytometry were employed to identify cell viability and apoptosis/cell cycle,respectively.Western blotting and immunohistochemistry were employed to measure the expressions of endoplasmic reticulum stress(ERS)-related proteins(GRP78 and CHOP),p-IRE1α,IRE1α,ASK1,p-JNK,JNK,Bax,Bcl-2,XBP-1,and Bim.Fura 2-acetoxymethyl ester(Fura-2/AM)was used to determine the intracellular calcium(Ca^(2+))concentration.Also,an AD model was constructed by injecting Aβinto the CA1 area of the hippocampus in Sprague Dawley rats.AD model rats were gavaged with different concentrations of Bushen Yizhi Formula for 14 consecutive days.The Morris water maze experiment was conducted to test the learning and memory of rats.Hematoxylin&Eosin(H&E)and Terminal-deoxynucleotidyl Transferase(TdT)-mediated dUTP Nick-End Labeling(TUNEL)staining were done to determine histopathological changes in the brain.Results:Bushen Yizhi Formula relieved the Aβ-induced effects including cell injury,decreased viability,increased apoptosis,G0/G1 phase cell cycle arrest,upregulation of GRP78,CHOP,p-IRE1α,p-JNK,Bax,XBP-1 and Bim,as well as down-regulation of Bcl-2.These results were also seen with IRE1αsilencing.While Aβsuppressed the learning and memory abilities of rats,the Bushen Yizhi Formula alleviated these effects of Aβ.Brain nerve cell injury induced by Aβcould also be treated with Bushen Yizhi Formula.Conclusion:Bushen Yizhi Formula could influence ERS through the IRE1αsignaling pathway to achieve its therapeutic effects on AD.展开更多
BACKGROUND Reducing or preventing postoperative morbidity in patients with gastric cancer(GC)is particularly important in perioperative treatment plans.AIM To identify risk factors for early postoperative complication...BACKGROUND Reducing or preventing postoperative morbidity in patients with gastric cancer(GC)is particularly important in perioperative treatment plans.AIM To identify risk factors for early postoperative complications of GC post-distal gastrectomy and to establish a nomogram prediction model.METHODS This retrospective study included 131 patients with GC who underwent distal gastrectomy at the Second Hospital of Shandong University between January 2019 and February 2023.The factors influencing the development of complications after distal gastrectomy in these patients were evaluated using univariate and multivariate logistic regression analysis.Based on the results obtained,a predictive nomogram was established.The nomogram was validated using internal and external(n=45)datasets.Its sensitivity and specificity were established by receiver operating characteristic curve analysis.Decision curve(DCA)analysis was used to determine its clinical benefit and ten-fold overfitting was used to establish its accuracy and stability.RESULTS Multivariate logistic regression analysis showed that hypertension,diabetes,history of abdominal surgery,and perioperative blood transfusion were independent predictors of postoperative complications of distal gastrectomy.The modeling and validation sets showed that the area under the curve was 0.843[95%confidence interval(CI):0.746-0.940]and 0.877(95%CI:0.719-1.000),the sensitivity was 0.762 and 0.778,respectively,and the specificity was 0.809 and 0.944,respectively,indicating that the model had good sensitivity and specificity.The C-indexes of the modeling and validation datasets were 0.843(95%CI:0.746-0.940)and 0.877(95%CI:0.719-1.000),respectively.The calibration curve(Hosmer Lemeshow test:χ^(2)=7.33)showed that the model had good consistency.The results of the DCA analysis indicated that this model offered good clinical benefits.The accuracy of 10-fold cross-validation was 0.878,indicating that the model had good accuracy and stability.CONCLUSION The nomogram prediction model based on independent risk factors related to postoperative complications of distal gastrectomy can facilitate perioperative intervention for high-risk populations and reduce the incidence of postoperative complications.展开更多
Objective:To analyze the effect of solution-focused approach on advanced schistosomiasis(AS).Methods:10 cases of patients with AS that were treated with a solution-focused approach were included in our study.The indic...Objective:To analyze the effect of solution-focused approach on advanced schistosomiasis(AS).Methods:10 cases of patients with AS that were treated with a solution-focused approach were included in our study.The indicators before and after the intervention were measured(knowledge mastery,prevention and treatment compliance,personal behavior,self-care ability,management satisfaction,complication rate).Results:After analyzing pre-and post-intervention indicators,statistical significance was found(P<0.05).The intervention received a satisfaction rate of 80.00%,with a complication rate of 10.00%.Conclusion:Using a solution-focused approach for ankylosing spondylitis(AS)patients can enhance their understanding and attitude toward disease prevention and treatment,improve their behaviors and self-care ability,resulting in high satisfaction and reduced complications.展开更多
Steelmaking–refining–Continuous Casting(SCC) scheduling is a worldwide problem, which is NP-hard. Effective SCC scheduling algorithms can help to enhance productivity, and thus make significant monetary savings. Thi...Steelmaking–refining–Continuous Casting(SCC) scheduling is a worldwide problem, which is NP-hard. Effective SCC scheduling algorithms can help to enhance productivity, and thus make significant monetary savings. This paper develops an Improved Artificial Bee Colony(IABC) algorithm for the SCC scheduling. In the proposed IABC, charge permutation is employed to represent the solutions. In the population initialization, several solutions with certain quality are produced by a heuristic while others are generated randomly. Two variable neighborhood search neighborhood operators are devised to generate new high-quality solutions for the employed bee and onlooker bee phases, respectively. Meanwhile, in order to enhance the exploitation ability, a control parameter is introduced to conduct the search of onlooker bee phase. Moreover, to enhance the exploration ability,the new generated solutions are accepted with a control acceptance criterion. In the scout bee phase, the solution corresponding to a scout bee is updated by performing three swap operators and three insert operators with equal probability. Computational comparisons against several recent algorithms and a state-of-the-art SCC scheduling algorithm have demonstrated the strength and superiority of the IABC.展开更多
Since the impoundment of the Three Gorges Reservoir in 2003,algal blooms have frequently been observed in it.The chlorophyll a concentration is an important parameter for evaluating algal blooms.In this study,the chlo...Since the impoundment of the Three Gorges Reservoir in 2003,algal blooms have frequently been observed in it.The chlorophyll a concentration is an important parameter for evaluating algal blooms.In this study,the chlorophyll a concentration in Xiangxi Bay,in the Three Gorges Reservoir,was predicted using HJ-1 satellite imagery.Several models were established based on a correlation analysis between in situ measurements of the chlorophyll a concentration and the values obtained from satellite images of the study area from January 2010 to December 2011.Chlorophyll a concentrations in Xiangxi Bay were predicted based on the established models.The results show that the maximum correlation is between the reflectance of the band combination of B4/(B2+B3) and in situ measurements of chlorophyll a concentration.The root mean square errors of the predicted values using the linear and quadratic models are 18.49 mg/m3 and 18.52 mg/m3,respectively,and the average relative errors are 37.79% and 36.79%,respectively.The results provide a reference for water bloom prediction in typical tributaries of the Three Gorges Reservoir and contribute to large-scale remote sensing monitoring and water quality management.展开更多
It is essential to investigate the light field camera parameters for the accurate flame temperature measurement because the sampling characteristics of the flame radiation can be varied with them. In this study, novel...It is essential to investigate the light field camera parameters for the accurate flame temperature measurement because the sampling characteristics of the flame radiation can be varied with them. In this study, novel indices of the light field camera were proposed to investigate the directional and spatial sampling characteristics of the flame radiation. Effects of light field camera parameters such as focal length and magnification of the main lens, focal length and magnification of the microlens were investigated. It was observed that the sampling characteristics of the flame are varied with the different parameters of the light field camera. The optimized parameters of the light field camera were then proposed for the flame radiation sampling. The larger sampling angle(23 times larger) is achieved by the optimized parameters compared to the commercial light field camera parameters. A non-negative least square(NNLS) algorithm was used to reconstruct the flame temperature. The reconstruction accuracy was also evaluated by the optimized parameters. The results suggested that the optimized parameters can provide higher reconstruction accuracy for axisymmetric and non-symmetric flame conditions in comparison to the commercial light field camera.展开更多
In recent years,hard carbon materials have gained significant interest as anode materials for Na-ion batteries.Biomass waste is considered one of the most interesting,renewable,available,and cost-effective precursor t...In recent years,hard carbon materials have gained significant interest as anode materials for Na-ion batteries.Biomass waste is considered one of the most interesting,renewable,available,and cost-effective precursor to obtain hard carbon(HC);however,HC properties must be finely tuned to achieve performance comparable to those provided by Li-ion batteries.In this work,three biomass wastes(coconut shells,walnut shells,and corn silk) were evaluated as potential precursors for HC preparation involving a pyrolysis process and subsequent acid washing to remove the inorganic impurities.All obtained materials exhibited low and similar specific surface areas(<10 m^(2)·g^(-1)), but they presented different structures and surface functionalities.The walnut shell HC possessed a lower amount of inorganic impurities and oxygen-based functional groups compared to the coconut shell and corn silk HCs,leading to higher initial coulombic efficiency(iCE).The structural organization was higher in the case of the walnut shell HC,while the corn silk HC revealed a heterogeneous structure combining both highly disordered carbon and localized graphitized domains.All HCs delivered high initial reversible capacities between 293 and 315 mAh g^(-1) at 50 mA g^(-1) current rate,which remained rather stable during long-term cycling.The best capacity(293 mAh g^(-1) after 100 charge/discharge cycles) and highest capacity retention(93%) was achieved in walnut HCs in half-cells,which could be associated with its higher sp2 C content,better organized structure,and fewer impurities.An "adsorption-insertion" Na storage mechanism is suggested based on several techniques.The walnut HCs exhibited an attractive energy density of 279 Wh/kg when tested in full cells.展开更多
可再生能源驱动的电催化还原CO_(2)制化学品和燃料是实现碳中和目标十分具有吸引力的技术.在电催化还原CO_(2)产物中,综合考虑产物的经济价值和还原所需能量,甲酸是最可行的产物之一.甲酸用途十分广泛,不仅可以用于生产各种高值化学品,...可再生能源驱动的电催化还原CO_(2)制化学品和燃料是实现碳中和目标十分具有吸引力的技术.在电催化还原CO_(2)产物中,综合考虑产物的经济价值和还原所需能量,甲酸是最可行的产物之一.甲酸用途十分广泛,不仅可以用于生产各种高值化学品,还可作为氢的载体用于燃料电池.目前发展的电催化还原CO_(2)制甲酸或甲酸盐的催化剂主要有Pd,Cd,Hg,Sn,In,Tl,Pb和Bi等,其中Bi基催化剂具有价廉、环境友好和选择性高等特点.此外,电解器的结构也是影响反应性能的关键因素.传统的常压H池中,由于CO_(2)溶解度低和扩散限制,反应电流密度很难超过100 mA cm^(−2).流动池和膜电极反应器体系由于使用气体扩散电极,可以避免CO_(2)溶解度低的问题,获得较高的反应电流密度,但依然存在反应器结构复杂难控等问题.高压H池操控简单,而且可以使大量的CO_(2)溶解于溶液中,已有研究证明在高压H池中可以获得超过100 mA cm^(−2)的反应电流密度.同时,有研究发现,CO_(2)的压力会显著影响铜基催化剂上产物的选择性.然而,目前对高压H池中电催化还原CO_(2)的研究较少.因此,进一步设计高压条件下电催化还原CO_(2)制甲酸的高效催化剂,并研究其独特规律,具有重要意义.本文通过简单的一步水热方法合成了BiPO_(4)纳米多面体,并在高压H池中系统研究了其电催化还原CO_(2)制甲酸盐的性能.实验发现,BiPO_(4)纳米多面体衍生的催化剂(BiPO_(4)-derived)在高压H池中具有很高的活性.在CO_(2)压力为3.0 MPa的KHCO_(3)溶液中,控制阴极电位为−0.81 V vs.RHE,电催化还原CO_(2)制甲酸盐的法拉第效率为90%,甲酸盐部分电流密度可达534 mA cm^(−2),甲酸盐生成速率为9.9 mmol h^(−1) cm^(−2).X射线衍射、扫描电子显微镜、高分辨透射电子显微镜、循环伏安等表征结果表明,BiPO_(4)纳米多面体在高压CO_(2)还原反应条件下会演变成具有丰富晶界的金属铋纳米片;而在常压或低压条件下,BiPO_(4)纳米多面体演变生成的金属铋纳米片则几乎没有晶界.对比发现,丰富晶界的BiPO_(4)-derived催化剂具有更高的电催化还原CO_(2)制甲酸盐的活性和选择性.理论计算结果表明,在金属铋的晶界表面,电荷分布会发生明显变化,从而显著促进CO_(2)的活化以及反应中间HCOO^(*)的稳定性,使得电催化还原CO_(2)制甲酸的反应路径从能量上看更加有利,从而提高了反应的选择性和活性.本文展示了在高压H池中,BiPO_(4)纳米多面体在高压下衍生的催化剂在电催化还原CO_(2)制甲酸盐反应中具有较好的活性和选择性.研究发现,在高压CO_(2)还原条件下,催化剂前驱体可以衍生成具有丰富晶界的高活性催化剂,是一种构筑高效催化剂的方法.综上,本文将为电催化还原CO_(2)领域,尤其是面向CO_(2)工业应用的高效催化剂设计制备提供一些有用的参考.展开更多
We propose an eco-service provision unit method for estimating the benefit and spatial differences of forests in controlling soil erosion.A total of 197 eco-service provision units were grouped on 1424.43 km2 of fores...We propose an eco-service provision unit method for estimating the benefit and spatial differences of forests in controlling soil erosion.A total of 197 eco-service provision units were grouped on 1424.43 km2 of forest according to differences in vegetation,slope,soil,and rainfall.The amount of soil conservation and its economic value were estimated.The forests in Anji County prevent4.08 9 105 tons of soil from eroding annually,thereby avoiding 1.36 9 104 tons of nutrient loss(on-site cost) and preventing 149 tons of nutritive elements from entering water systems(off-site cost).From an economic perspective,the soil nutrient conservation in the forests of Anji County generated an annual benefit of 43.37 million RMB(Chinese Currency,6.20 RMB = US$1).On average,each hectare of ecological forest contributed up to 436 RMB annually because of soil conservation.Ecological complexes with higher rainfall intensity,such as broadleaf forest and red soil on slope gradients [25°,contributed the highest soil conservation benefits.This study identified and quantified the dominant contributors and magnitudes of soil conservation provided by forests.This information can benefit decision making regarding differentiated ecological compensation policies.展开更多
Robust model-reference control for descriptor linear systems with structural parameter uncertainties is investigated. A sufficient condition for existing a model-reference zero-error asymptotic tracking controller is ...Robust model-reference control for descriptor linear systems with structural parameter uncertainties is investigated. A sufficient condition for existing a model-reference zero-error asymptotic tracking controller is given. It is shown that the robust model reference control problem can be decomposed into two subproblems: a robust state feedback stabilization problem for descriptor systems subject to parameter uncertainties and a robust compensation problem. The latter aims to find three coefficient matrices which satisfy four matrix equations and simultaneously minimize the effect of the uncertainties to the tracking error. Based on a complete parametric solution to a class of generalized Sylvester matrix equations, the robust compensation problem is converted into a minimization problem with quadratic cost and linear constraints. A numerical example shows the effect of the proposed approach.展开更多
基金Project supported by the National Natural Science Foundation of China (No.12172001)the Anhui Provincial Natural Science Foundation of China (No.2208085Y01)+1 种基金the University Natural Science Research Project of Anhui Province of China (No.2022AH020029)the Housing and Urban-Rural Development Science and Technology Project of Anhui Province of China (No.2023-YF129)。
文摘Self-oscillating systems abound in the natural world and offer substantial potential for applications in controllers,micro-motors,medical equipments,and so on.Currently,numerical methods have been widely utilized for obtaining the characteristics of self-oscillation including amplitude and frequency.However,numerical methods are burdened by intricate computations and limited precision,hindering comprehensive investigations into self-oscillating systems.In this paper,the stability of a liquid crystal elastomer fiber self-oscillating system under a linear temperature field is studied,and analytical solutions for the amplitude and frequency are determined.Initially,we establish the governing equations of self-oscillation,elucidate two motion regimes,and reveal the underlying mechanism.Subsequently,we conduct a stability analysis and employ a multi-scale method to obtain the analytical solutions for the amplitude and frequency.The results show agreement between the multi-scale and numerical methods.This research contributes to the examination of diverse self-oscillating systems and advances the theoretical analysis of self-oscillating systems rooted in active materials.
基金financially supported by the National Natural Science Foundation of China(51503178,52202048,52027801)National Key R&D Program of China(2017YFA0206301)+1 种基金China-Germany Collaboration Project(M-0199)Natural Science Foundation of Hebei Province(B2021203012,E2022203082)。
文摘The self-charging concept has drawn considerable attention due to its excellent ability to achieve environmental energy harvesting,conversion and storage without an external power supply.However,most self-charging designs assembled by multiple energy harvesting,conversion and storage materials increase the energy transfer loss;the environmental energy supply is generally limited by climate and meteorological conditions,hindering the potential application of these selfpowered devices to be available at all times.Based on aerobic autoxidation of catechol,which is similar to the electrochemical oxidation of the catechol groups on the carbon materials under an electrical charge,we proposed an air-breathing chemical self-charge concept based on the aerobic autoxidation of catechol groups on oxygen-enriched carbon materials to ortho-quinone groups.Energy harvesting,conversion and storage functions could be integrated on a single carbon material to avoid the energy transfer loss among the different materials.Moreover,the assembled Cu/oxygen-enriched carbon battery confirmed the feasibility of the air-oxidation self-charging/electrical discharging mechanism for potential applications.This air-breathing chemical self-charge concept could facilitate the exploration of high-efficiency sustainable air self-charging devices.
基金the National Key Research and Development Program of China(Nos.2022YFA1604900 and 2020YFE0202002)the National Natural Science Foundation of China(Nos.12175084,11890710,11890711,11927901)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB34030000)Fundamental Research Funds for Central Universities(No.CCNU220N003).
文摘The Cooling Storage Ring external-target experiment(CEE)spectrometer is used to study the nuclear matter created in heavy-ion collisions at√sNN=2.1-2.4 GeV with the aim to reveal the quantum chromodynamics phase structure in the high-baryon-density region.Collective flow is considered an effective probe for evaluating the properties of media during high-energy nuclear collisions.One of the main functions of the zero-degree calorimeter(ZDC),a subdetector system in the CEE,is to determine the reaction plane in heavy-ion collisions.This step is crucial for measuring the collective flow and other reaction-plane-related analyses.In this paper,we illustrate the procedures for event plane determination using the ZDC.Finally,isospin-dependent quantum molecular dynamics model-based predictions of the rapidity dependence of the directed and elliptical flows for p,d,t,3He,and 4He,produced in 2.1 GeV U+U collisions,are presented.
基金This work was supported in part by the National Nature Science Foundation of China(NSFC)(Nos.11927901 and 12175084)the National Key Research and Development Program of China(Nos.2020YFE0202002 and 2022YFA1604900)the Fundamental Research Funds for the Central Universities(No.CCNU22QN005).
文摘The zero-degree calorimeter(ZDC)plays a crucial role toward determining the centrality in the Cooling-Storage-Ring External-target Experiment(CEE)at the Heavy Ion Research Facility in Lanzhou.A boosted decision tree(BDT)multi-classification algorithm was employed to classify the centrality of the collision events based on the raw features from ZDC such as the number of fired channels and deposited energy.The data from simulated^(238)U+^(238)U collisions at 500 MeV∕u,generated by the IQMD event generator and subsequently modeled using the GEANT4 package,were employed to train and test the BDT model.The results showed the high accuracy of the multi-classification model adopted in ZDC for centrality determination,which is robust against variations in different factors of detector geometry and response.This study demon-strates the good performance of CEE-ZDC in determining the centrality in nucleus-nucleus collisions.
基金This work was supported by the General Research Fund scheme of the Hong Kong Research Grants Council(Project No.15227121)the Hong Kong Polytechnic University(ZVGH).
文摘Si is a promising anode material for Li ion batteries because of its high specific capacity,abundant reserve,and low cost.However,its rate performance and cycling stability are poor due to the severe particle pulverization during the lithiation/delithiation process.The high stress induced by the Li concentration gradient and anisotropic deformation is the main reason for the fracture of Si particles.Here we present a new stress mitigation strategy by uniformly distributing small amounts of Sn and Sb in Si micron-sized particles,which reduces the Li concentration gradient and realizes an isotropic lithiation/delithiation process.The Si8.5Sn0.5Sb microparticles(mean particle size:8.22μm)show over 6000-fold and tenfold improvements in electronic conductivity and Li diffusivity than Si particles,respectively.The discharge capacities of the Si_(8.5)Sn_(0.5)Sb microparticle anode after 100 cycles at 1.0 and 3.0 A g^(-1)are 1.62 and 1.19 Ah g^(-1),respectively,corresponding to a retention rate of 94.2%and 99.6%,respectively,relative to the capacity of the first cycle after activation.Multicomponent microparticle anodes containing Si,Sn,Sb,Ge and Ag prepared using the same method yields an ultra-low capacity decay rate of 0.02%per cycle for 1000 cycles at 1 A g^(-1),corroborating the proposed mechanism.The stress regulation mechanism enabled by the industry-compatible fabrication methods opens up enormous opportunities for low-cost and high-energy-density Li-ion batteries.
基金supported by the National Natural Science Foundation of China[81904266,82004309].
文摘While the Bushen Yizhi Formula can treat Alzheimer’s disease(AD),the yet to be ascertained specific mechanism of action was explored in this work.Methods:Different concentrations of the Bushen Yizhi Formula and amyloid-beta peptide(Aβ)were used to treat rat pheochromocytoma cells(P12)and human neuroblastoma cells(SH-SY5Y).Cell morphological changes were observed to determine the in vitro cell damage.Cell Counting Kit(CCK)-8 assay and flow cytometry were employed to identify cell viability and apoptosis/cell cycle,respectively.Western blotting and immunohistochemistry were employed to measure the expressions of endoplasmic reticulum stress(ERS)-related proteins(GRP78 and CHOP),p-IRE1α,IRE1α,ASK1,p-JNK,JNK,Bax,Bcl-2,XBP-1,and Bim.Fura 2-acetoxymethyl ester(Fura-2/AM)was used to determine the intracellular calcium(Ca^(2+))concentration.Also,an AD model was constructed by injecting Aβinto the CA1 area of the hippocampus in Sprague Dawley rats.AD model rats were gavaged with different concentrations of Bushen Yizhi Formula for 14 consecutive days.The Morris water maze experiment was conducted to test the learning and memory of rats.Hematoxylin&Eosin(H&E)and Terminal-deoxynucleotidyl Transferase(TdT)-mediated dUTP Nick-End Labeling(TUNEL)staining were done to determine histopathological changes in the brain.Results:Bushen Yizhi Formula relieved the Aβ-induced effects including cell injury,decreased viability,increased apoptosis,G0/G1 phase cell cycle arrest,upregulation of GRP78,CHOP,p-IRE1α,p-JNK,Bax,XBP-1 and Bim,as well as down-regulation of Bcl-2.These results were also seen with IRE1αsilencing.While Aβsuppressed the learning and memory abilities of rats,the Bushen Yizhi Formula alleviated these effects of Aβ.Brain nerve cell injury induced by Aβcould also be treated with Bushen Yizhi Formula.Conclusion:Bushen Yizhi Formula could influence ERS through the IRE1αsignaling pathway to achieve its therapeutic effects on AD.
文摘BACKGROUND Reducing or preventing postoperative morbidity in patients with gastric cancer(GC)is particularly important in perioperative treatment plans.AIM To identify risk factors for early postoperative complications of GC post-distal gastrectomy and to establish a nomogram prediction model.METHODS This retrospective study included 131 patients with GC who underwent distal gastrectomy at the Second Hospital of Shandong University between January 2019 and February 2023.The factors influencing the development of complications after distal gastrectomy in these patients were evaluated using univariate and multivariate logistic regression analysis.Based on the results obtained,a predictive nomogram was established.The nomogram was validated using internal and external(n=45)datasets.Its sensitivity and specificity were established by receiver operating characteristic curve analysis.Decision curve(DCA)analysis was used to determine its clinical benefit and ten-fold overfitting was used to establish its accuracy and stability.RESULTS Multivariate logistic regression analysis showed that hypertension,diabetes,history of abdominal surgery,and perioperative blood transfusion were independent predictors of postoperative complications of distal gastrectomy.The modeling and validation sets showed that the area under the curve was 0.843[95%confidence interval(CI):0.746-0.940]and 0.877(95%CI:0.719-1.000),the sensitivity was 0.762 and 0.778,respectively,and the specificity was 0.809 and 0.944,respectively,indicating that the model had good sensitivity and specificity.The C-indexes of the modeling and validation datasets were 0.843(95%CI:0.746-0.940)and 0.877(95%CI:0.719-1.000),respectively.The calibration curve(Hosmer Lemeshow test:χ^(2)=7.33)showed that the model had good consistency.The results of the DCA analysis indicated that this model offered good clinical benefits.The accuracy of 10-fold cross-validation was 0.878,indicating that the model had good accuracy and stability.CONCLUSION The nomogram prediction model based on independent risk factors related to postoperative complications of distal gastrectomy can facilitate perioperative intervention for high-risk populations and reduce the incidence of postoperative complications.
文摘Objective:To analyze the effect of solution-focused approach on advanced schistosomiasis(AS).Methods:10 cases of patients with AS that were treated with a solution-focused approach were included in our study.The indicators before and after the intervention were measured(knowledge mastery,prevention and treatment compliance,personal behavior,self-care ability,management satisfaction,complication rate).Results:After analyzing pre-and post-intervention indicators,statistical significance was found(P<0.05).The intervention received a satisfaction rate of 80.00%,with a complication rate of 10.00%.Conclusion:Using a solution-focused approach for ankylosing spondylitis(AS)patients can enhance their understanding and attitude toward disease prevention and treatment,improve their behaviors and self-care ability,resulting in high satisfaction and reduced complications.
基金Supported by the National Natural Science Foundation of China(51705177,51575212)the Program for New Century Excellent Talents in University(NCET-13-0106)the Program for HUST Academic Frontier Youth Team
文摘Steelmaking–refining–Continuous Casting(SCC) scheduling is a worldwide problem, which is NP-hard. Effective SCC scheduling algorithms can help to enhance productivity, and thus make significant monetary savings. This paper develops an Improved Artificial Bee Colony(IABC) algorithm for the SCC scheduling. In the proposed IABC, charge permutation is employed to represent the solutions. In the population initialization, several solutions with certain quality are produced by a heuristic while others are generated randomly. Two variable neighborhood search neighborhood operators are devised to generate new high-quality solutions for the employed bee and onlooker bee phases, respectively. Meanwhile, in order to enhance the exploitation ability, a control parameter is introduced to conduct the search of onlooker bee phase. Moreover, to enhance the exploration ability,the new generated solutions are accepted with a control acceptance criterion. In the scout bee phase, the solution corresponding to a scout bee is updated by performing three swap operators and three insert operators with equal probability. Computational comparisons against several recent algorithms and a state-of-the-art SCC scheduling algorithm have demonstrated the strength and superiority of the IABC.
基金supported by the National Natural Science Foundation of China(Grants No.51009080 and 51179095)the Research Innovation Fund for Postgraduates in China Three Gorges University(Grant No.2012CX012)
文摘Since the impoundment of the Three Gorges Reservoir in 2003,algal blooms have frequently been observed in it.The chlorophyll a concentration is an important parameter for evaluating algal blooms.In this study,the chlorophyll a concentration in Xiangxi Bay,in the Three Gorges Reservoir,was predicted using HJ-1 satellite imagery.Several models were established based on a correlation analysis between in situ measurements of the chlorophyll a concentration and the values obtained from satellite images of the study area from January 2010 to December 2011.Chlorophyll a concentrations in Xiangxi Bay were predicted based on the established models.The results show that the maximum correlation is between the reflectance of the band combination of B4/(B2+B3) and in situ measurements of chlorophyll a concentration.The root mean square errors of the predicted values using the linear and quadratic models are 18.49 mg/m3 and 18.52 mg/m3,respectively,and the average relative errors are 37.79% and 36.79%,respectively.The results provide a reference for water bloom prediction in typical tributaries of the Three Gorges Reservoir and contribute to large-scale remote sensing monitoring and water quality management.
基金supported by the National Natural Science Foundation of China(Grant Nos.51676044 and 51327803)the Social Development Project of Jiangsu Province,China(Grant No.BE20187053)+1 种基金the Postgraduate Research and Practice Innovation Program of Jiangsu Province,China(Grant No.KYCX170081)China Scholarship Council
文摘It is essential to investigate the light field camera parameters for the accurate flame temperature measurement because the sampling characteristics of the flame radiation can be varied with them. In this study, novel indices of the light field camera were proposed to investigate the directional and spatial sampling characteristics of the flame radiation. Effects of light field camera parameters such as focal length and magnification of the main lens, focal length and magnification of the microlens were investigated. It was observed that the sampling characteristics of the flame are varied with the different parameters of the light field camera. The optimized parameters of the light field camera were then proposed for the flame radiation sampling. The larger sampling angle(23 times larger) is achieved by the optimized parameters compared to the commercial light field camera parameters. A non-negative least square(NNLS) algorithm was used to reconstruct the flame temperature. The reconstruction accuracy was also evaluated by the optimized parameters. The results suggested that the optimized parameters can provide higher reconstruction accuracy for axisymmetric and non-symmetric flame conditions in comparison to the commercial light field camera.
基金financial support from the European Union’s Horizon2020 Program(project NAIADEScall:LCE10-2014,Contract no.646433)。
文摘In recent years,hard carbon materials have gained significant interest as anode materials for Na-ion batteries.Biomass waste is considered one of the most interesting,renewable,available,and cost-effective precursor to obtain hard carbon(HC);however,HC properties must be finely tuned to achieve performance comparable to those provided by Li-ion batteries.In this work,three biomass wastes(coconut shells,walnut shells,and corn silk) were evaluated as potential precursors for HC preparation involving a pyrolysis process and subsequent acid washing to remove the inorganic impurities.All obtained materials exhibited low and similar specific surface areas(<10 m^(2)·g^(-1)), but they presented different structures and surface functionalities.The walnut shell HC possessed a lower amount of inorganic impurities and oxygen-based functional groups compared to the coconut shell and corn silk HCs,leading to higher initial coulombic efficiency(iCE).The structural organization was higher in the case of the walnut shell HC,while the corn silk HC revealed a heterogeneous structure combining both highly disordered carbon and localized graphitized domains.All HCs delivered high initial reversible capacities between 293 and 315 mAh g^(-1) at 50 mA g^(-1) current rate,which remained rather stable during long-term cycling.The best capacity(293 mAh g^(-1) after 100 charge/discharge cycles) and highest capacity retention(93%) was achieved in walnut HCs in half-cells,which could be associated with its higher sp2 C content,better organized structure,and fewer impurities.An "adsorption-insertion" Na storage mechanism is suggested based on several techniques.The walnut HCs exhibited an attractive energy density of 279 Wh/kg when tested in full cells.
文摘可再生能源驱动的电催化还原CO_(2)制化学品和燃料是实现碳中和目标十分具有吸引力的技术.在电催化还原CO_(2)产物中,综合考虑产物的经济价值和还原所需能量,甲酸是最可行的产物之一.甲酸用途十分广泛,不仅可以用于生产各种高值化学品,还可作为氢的载体用于燃料电池.目前发展的电催化还原CO_(2)制甲酸或甲酸盐的催化剂主要有Pd,Cd,Hg,Sn,In,Tl,Pb和Bi等,其中Bi基催化剂具有价廉、环境友好和选择性高等特点.此外,电解器的结构也是影响反应性能的关键因素.传统的常压H池中,由于CO_(2)溶解度低和扩散限制,反应电流密度很难超过100 mA cm^(−2).流动池和膜电极反应器体系由于使用气体扩散电极,可以避免CO_(2)溶解度低的问题,获得较高的反应电流密度,但依然存在反应器结构复杂难控等问题.高压H池操控简单,而且可以使大量的CO_(2)溶解于溶液中,已有研究证明在高压H池中可以获得超过100 mA cm^(−2)的反应电流密度.同时,有研究发现,CO_(2)的压力会显著影响铜基催化剂上产物的选择性.然而,目前对高压H池中电催化还原CO_(2)的研究较少.因此,进一步设计高压条件下电催化还原CO_(2)制甲酸的高效催化剂,并研究其独特规律,具有重要意义.本文通过简单的一步水热方法合成了BiPO_(4)纳米多面体,并在高压H池中系统研究了其电催化还原CO_(2)制甲酸盐的性能.实验发现,BiPO_(4)纳米多面体衍生的催化剂(BiPO_(4)-derived)在高压H池中具有很高的活性.在CO_(2)压力为3.0 MPa的KHCO_(3)溶液中,控制阴极电位为−0.81 V vs.RHE,电催化还原CO_(2)制甲酸盐的法拉第效率为90%,甲酸盐部分电流密度可达534 mA cm^(−2),甲酸盐生成速率为9.9 mmol h^(−1) cm^(−2).X射线衍射、扫描电子显微镜、高分辨透射电子显微镜、循环伏安等表征结果表明,BiPO_(4)纳米多面体在高压CO_(2)还原反应条件下会演变成具有丰富晶界的金属铋纳米片;而在常压或低压条件下,BiPO_(4)纳米多面体演变生成的金属铋纳米片则几乎没有晶界.对比发现,丰富晶界的BiPO_(4)-derived催化剂具有更高的电催化还原CO_(2)制甲酸盐的活性和选择性.理论计算结果表明,在金属铋的晶界表面,电荷分布会发生明显变化,从而显著促进CO_(2)的活化以及反应中间HCOO^(*)的稳定性,使得电催化还原CO_(2)制甲酸的反应路径从能量上看更加有利,从而提高了反应的选择性和活性.本文展示了在高压H池中,BiPO_(4)纳米多面体在高压下衍生的催化剂在电催化还原CO_(2)制甲酸盐反应中具有较好的活性和选择性.研究发现,在高压CO_(2)还原条件下,催化剂前驱体可以衍生成具有丰富晶界的高活性催化剂,是一种构筑高效催化剂的方法.综上,本文将为电催化还原CO_(2)领域,尤其是面向CO_(2)工业应用的高效催化剂设计制备提供一些有用的参考.
基金supported by the National Natural Science Foundation (No.31200531)National Science and Technology Support Program (No.2012BAC01B08)the National Environmental Protection Public Welfare Industry Targeted Research (No.201209027)
文摘We propose an eco-service provision unit method for estimating the benefit and spatial differences of forests in controlling soil erosion.A total of 197 eco-service provision units were grouped on 1424.43 km2 of forest according to differences in vegetation,slope,soil,and rainfall.The amount of soil conservation and its economic value were estimated.The forests in Anji County prevent4.08 9 105 tons of soil from eroding annually,thereby avoiding 1.36 9 104 tons of nutrient loss(on-site cost) and preventing 149 tons of nutritive elements from entering water systems(off-site cost).From an economic perspective,the soil nutrient conservation in the forests of Anji County generated an annual benefit of 43.37 million RMB(Chinese Currency,6.20 RMB = US$1).On average,each hectare of ecological forest contributed up to 436 RMB annually because of soil conservation.Ecological complexes with higher rainfall intensity,such as broadleaf forest and red soil on slope gradients [25°,contributed the highest soil conservation benefits.This study identified and quantified the dominant contributors and magnitudes of soil conservation provided by forests.This information can benefit decision making regarding differentiated ecological compensation policies.
基金This work was supported in part by the Chinese Outstanding Youth Science Foundation (No. 69925308)supported by Program for ChangjiangScholars and Innovative Research Team in University
文摘Robust model-reference control for descriptor linear systems with structural parameter uncertainties is investigated. A sufficient condition for existing a model-reference zero-error asymptotic tracking controller is given. It is shown that the robust model reference control problem can be decomposed into two subproblems: a robust state feedback stabilization problem for descriptor systems subject to parameter uncertainties and a robust compensation problem. The latter aims to find three coefficient matrices which satisfy four matrix equations and simultaneously minimize the effect of the uncertainties to the tracking error. Based on a complete parametric solution to a class of generalized Sylvester matrix equations, the robust compensation problem is converted into a minimization problem with quadratic cost and linear constraints. A numerical example shows the effect of the proposed approach.
