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Effects of thinning on the understory light environment of different stands and the photosynthetic performance and growth of the reforestation species Phoebe bournei

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Journal of Forestry Research 2024年第1期35卷 12-28页

作者： Shicheng su Nianqing Jin Xiaoli wei College of Forestry Guizhou UniversityGuiyang 550025People’s Republic of China Institute for Forest Resources and Environment of Guizhou Guizhou UniversityGuiyang 550025People’s Republic of China

Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted.

关键词： Thinning Understory light environment Phoebe bournei Photosynthetic performance Growth performance

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Particle distributions in Lamb wave based acoustofluidics

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Nanotechnology and Precision Engineering 2024年第2期7卷 60-68页

作者： Chuanchao Zhang xian Chen wei wei Xuejiao Chen Quanning Li Xuexin Duan Key Laboratory of Precision Measuring Technology and Instruments College of Precision Instrument and Optoelectronics EngineeringTianjin UniversityTianjin300072China

Acoustic streaming enabled by a Lamb wave resonator(LWR)is efficient for particle trapping and enrichment in microfluidic channels.However,because Lamb waves combine the features of bulk acoustic waves and surface acoustic waves,the resulting acoustic streaming in the LWR occurs in multiple planes,and the particle flow behavior in this acoustofluidic system is largely unknown.Reported here are numerical simulations and laboratory experiments conducted to investigate the boundary conditions for particle motion inside a microvortex induced by an LWR.Upon dynamic capture,the particles’trajectories become orbital paths within an acoustic vortex.The suspended particles encounter two distinct acoustic phenomena,i.e.,the drag force resulting from acoustic streaming and the acoustic radiation force,which exert forces in various directions on the particles.When the acoustic radiation force and the fluid drag force are dominant for large and small particles in a mixed solution,respectively,the large particles reside within the vortex while the small particles remain at its periphery.Conversely,when the acoustic radiation force is dominant for both types of particles,the distribution pattern is reversed.

关键词： Acoustoﬂuidics Lamb wave resonator Particle manipulation Microvortex

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A Geometric Based Connection between Fractional Calculus and Fractal Functions

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Acta Mathematica Sinica,English Series 2024年第2期40卷 537-567页

作者： Yong Shun LIANG wei Yi su School of Mathematics and Statistic Nanjing University of Science and TechnologyNanjing 210094P.R.China Department of Mathematics Nanjing UniversityNanjing 210023P.R.China

Establishing the accurate relationship between fractional calculus and fractals is an important research content of fractional calculus theory.In the present paper,we investigate the relationship between fractional calculus and fractal functions,based only on fractal dimension considerations.Fractal dimension of the Riemann-Liouville fractional integral of continuous functions seems no more than fractal dimension of functions themselves.Meanwhile fractal dimension of the Riemann-Liouville fractional differential of continuous functions seems no less than fractal dimension of functions themselves when they exist.After further discussion,fractal dimension of the Riemann-Liouville fractional integral is at least linearly decreasing and fractal dimension of the Riemann-Liouville fractional differential is at most linearly increasing for the Holder continuous functions.Investigation about other fractional calculus,such as the Weyl-Marchaud fractional derivative and the Weyl fractional integral has also been given elementary.This work is helpful to reveal the mechanism of fractional calculus on continuous functions.At the same time,it provides some theoretical basis for the rationality of the definition of fractional calculus.This is also helpful to reveal and explain the internal relationship between fractional calculus and fractals from the perspective of geometry.

关键词： Fractional calculus fractal functions fractal dimension fractional calculus equation relationship

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Free radicals trigger the closure of open pores in lignin-derived hard carbons toward improved sodium-storage capacity

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Journal of Energy Chemistry 2024年第7期94卷 551-559页

作者： Wen-Jun Ji Zong-Lin Yi Ming-Xin Song Xiao-Qian Guo Yi-Lin Wang Yi-Xuan Mao Fang-Yuan su Jing-Peng Chen xian-xian wei Li-Jing Xie Cheng-Meng Chen CAS Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001ShanxiChina University of Chinese Academy of Sciences Beijing 100049China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Environment and Safety Taiyuan University of Science and TechnologyTaiyuan 030001ShanxiChina

The chemical activation of various precursors is effective for creating additional closed pores in hard carbons for sodium storage.However,the formation mechanism of closed pores under the influence of pore-forming agents is not well understood.Herein,an effective chemical activation followed by a high-temperature self-healing strategy is employed to generate interconnected closed pores in lignin-derived hard carbon(HCs).By systematic experimental design combined with electron paramagnetic res-onance spectroscopy,it can be found that the content of free radicals in the carbon matrix influences the closure of open pores at high temperatures.Excessively high activation temperature(>700 C)leads to a low free radical concentration,making it difficult to achieve self-healing of open pores at high tempera-tures.By activation at 700°C,a balance between pore making and self-healing is achieved in the final hard carbon.A large number of free radicals triggers rapid growth and aggregation of carbon microcrys-tals,blocking pre-formed open micropores and creating additional interconnected closed pores in as-obtained hard carbons.As a result,the optimized carbon anode(LK-700-1300)delivers a high reversible capacity of 330.8 mA h g^(-1) at 0.03 A g^(-1),which is an increase of 86 mA h g^(-1) compared to the pristine lignin-derived carbon anode(L-700-1300),and exhibits a good rate performance(202.1 mA h g^(-1) at 1 A g^(-1)).This work provides a universal and effective guidance for tuning closed pores of hard carbons from otherprecursors.

关键词： Hard carbon Chemical activation Free radical Self-healing Closed pores Sodium ion batteries

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Incidence and risk factors of depression in patients with metabolic syndrome

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World Journal of Psychiatry 2024年第2期14卷 245-254页

作者： Li-Na Zhou xian-Cang Ma wei Wang Department of Psychiatry The First Affiliated Hospital of Xi’an Jiaotong UniversityXi’an 710061Shaanxi ProvinceChina

BACKGROUND Many studies have explored the relationship between depression and metabolic syndrome(MetS),especially in older people.China has entered an aging society.However,there are still few studies on the elderly in Chinese communities.AIM To investigate the incidence and risk factors of depression in MetS patients in China's Mainland and to construct a predictive model.METHODS Data from four waves of the China Health and Retirement Longitudinal Study were selected,and middle-aged and elderly patients with MetS(n=2533)were included based on the first wave.According to the center for epidemiological survey-depression scale(CESD),participants with MetS were divided into depression(n=938)and non-depression groups(n=1595),and factors related to depression were screened out.subsequently,the 2-,4-,and 7-year follow-up data were analyzed,and a prediction model for depression in MetS patients was constructed.REsuLTS The prevalence of depression in middle-aged and elderly patients with MetS was 37.02%.The prevalence of depression at the 2-,4-,and 7-year follow-up was 29.55%,34.53%,and 38.15%,respectively.The prediction model,constructed using baseline CESD and Physical Self-Maintenance Scale scores,average sleep duration,number of chronic diseases,age,and weight had a good predictive effect on the risk of depression in MetS patients at the 2-year follow-up(area under the curve=0.775,95%confidence interval:0.750-0.800,P<0.001),with a sensitivity of 68%and a specificity of 74%.CONCLUSION The prevalence of depression in middle-aged and elderly patients with MetS has increased over time.The early identification of and intervention for depressive symptoms requires greater attention in MetS patients.

关键词： Depression Metabolic syndrome Prevalence Risk factor

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Comprehensive analysis and mitigation strategies for safety issues of sodium-ion batteries

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Rare Metals 2024年第4期43卷 1343-1349页

作者： Tao wei Xiao-Ling xian Shi-Xue Dou wei Chen Shu-Lei Chou Institute for Carbon Neutralization College of Chemistry and Materials EngineeringWenzhou University Wenzhou Key Laboratory of Sodium-Ion Batteries Wenzhou University Technology Innovation Institute for Carbon Neutralization Zhejiang Key Laboratory of Carbon Materials College of Chemistry and Materials EngineeringWenzhou University Institute for superconducting and Electronic Materials Australian Institute for Innovative MaterialsUniversity of WollongongInnovation Campus

Sodium-ion batteries show great potential as an alternative energy storage system,but safety concerns remain a major hurdle to their mass adoption.This paper analyzes the key factors and mechanisms leading to safety issues,including thermal runaway,sodium dendrite,internal short circuits,and gas release.Several promising solutions are proposed,such as high-safety electrode materials in the cathode and anode,high-safety electrolytes,and external battery management systems.Here in also we emphasize the importance of selecting appropriate analysis methods and developing reliable failure models while suggesting advanced machine learning tools for analysis.With a comprehensive approach,this study offers valuable recommendations to optimize materials and solutions for improving the safety of sodium-ion batteries.

关键词： Sodium-ion batteries Safety issues Thermal runaway Sodium dendrites

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Nanomedicine Disrupts Stromal Barriers to Augment Drug Penetration for Improved Cancer Therapy

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Chinese Journal of Chemistry 2024年第10期42卷 1175-1189页

作者： Guo-Feng Luo wei-Hai Chen xian-Zheng Zhang state Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration Key Laboratory of Oral Biomedicine Ministry of EducationHubei KeyLaboratory of StomatologySchool&Hospital of StomatologyWuhan UniversityWuhanHubei 430079China Key Laboratoryof Biomedical Polymers of Ministry of Education&Departmentof Chemistry Wuhan UniversityWuhanHubei 430072China

Tumor stroma composing diverse extracellular matrixes(ECM)and stromal cells shapes a condensed physical barrier,which severely hampers the efficient accessibility of nanomedicine to tumor cells,especially these deep-seated in the core of tumor.such barrier significantly compromises the antitumor effects of drug-loaded nanomedicine,revealing the remarkable importance of disrupting stromal barrier for improved tumor therapy with deep penetration ability.To achieve this goal,various nanoparticle-based strategies have been developed,including direct depleting ECM components via delivering anti-fibrotic agents or targeting stromal cells to suppress ECM expression,dynamic regulation of nanoparticles’physicochemical properties(i.e.,size,surface charge,and morphology),mechanical force-driven deep penetration,natural/biomimetic self-driven nanomedicine,and transcytosis-inducing nanomedicine.All these nanostrategies were systemically summarized in this review,and the design principles for obtaining admirable nanomedicine were included.With the rapid development of nanotechnology,elaborate design of multifunctional nanomedicine provides new opportunities for overcoming the critical stromal barriers to maximize the therapeutic index of various therapies,such as chemotherapy,photodynamic therapy,and immunotherapy.

关键词： Nanomedicine Tumor stroma Deep penetration Enhanced drug perfusion Cancer therapy Drug carriers Biomaterials Nanotechnology

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Hybrid vibration isolation optimization of a flexible manipulator based on neural network agent model

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Chinese Journal of Aeronautics 2024年第5期37卷 482-505页

作者： Yongxin ZHANG Liang LI Dingguo ZHANG wei-Hsin LIAO xian GUO School of Science Nanjing University of Science and TechnologyNanjing 210094China Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong KongChina

Segmented Active Constrained Layer Damping(SACLD)is an intelligent vibration-damping structure,which could be applied to the sectors of aviation,aerospace,and transportation engineering to reduce the vibration of flexible structures.Moreover,machine learning technology is widely used in the engineering field because of its efficient multi-objective optimization.The dynamic simulation of a rotational segmental flexible manipulator system is presented,in which enhanced active constrained layer damping is carried out,and the neural network model of Genetic Algorithm-Back Propagation(GA-BP)algorithm is investigated.Vibration suppression and structural optimization of the SACLD manipulator model are studied based on vibration mode and damping prediction.The modal responses of the SACLD manipulator model at rest and rotation are obtained.In addition,the four model indices are optimized using the GA-BP neural network:axial incision size,axial incision position,circumferential incision size,and circumferential incision position.Finally,the best model for vibration suppression is obtained.

关键词： Machine learning Vibration suppression Flexible manipulator Segmented active constrained layer damping Structural optimization

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Water–solid contact electrification and catalysis adjusted by surface functional groups

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Nano Research 2024年第4期17卷 3344-3351页

作者： Yusen su Andy Berbille Zhong Lin Wang wei Tang CAS Center for Excellence in Nanoscience Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing100083China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing100049China Georgia Institute of Technology AtlantaGA 30332-0245USA

Chemical functional groups on solid surfaces greatly influence contact electrification(CE)at water–solid interfaces.Previous studies of their effects mainly swapped materials or bonded related molecules to a substrate,introducing other factors of influence.This work aims at unambiguously demonstrating the role of functional groups in water-polymer CE.We study the contribution of functional groups,by using ion coupled plasma etching to modify a high-density polyethylene(HDPE)film,a polymer with a naturally quasi-null charge transfer ability.Fluoride(HDPE–F)and hydroxyl(HDPE–OH)functional groups are generated and endowed HDPE with charge withdrawing ability.HDPE–F withdraws 2.5–2.7 times more charges than HDPE–OH.Concurrently,the surface charges accumulated generate electrostatic forces,altering the droplets motion.This phenomenon provides another approach to study CE,helping to evaluate the contribution of electrons to solid–liquid CE.Finally,employing HDPE–F to perform contact-electro-catalysis shows its activity is 2.4 times higher than that of commercial fluorinated films.

关键词： contact-electro-catalysis charge transfer solid–liquid interfaces contact electrification

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Data-Driven Modeling of Partially Observed Biological Systems

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Communications on Applied Mathematics and Computation 2024年第1期6卷 739-754页

作者： wei-Hung su Ching-Shan Chou Dongbin Xiu Department of Mathematics The Ohio State UniversityColumbusOH43221USA

We present a numerical approach for modeling unknown dynamical systems using partially observed data,with a focus on biological systems with(relatively)complex dynamical behavior.As an extension of the recently developed deep neural network(DNN)learning methods,our approach is particularly suitable for practical situations when(i)measurement data are available for only a subset of the state variables,and(ii)the system parameters cannot be observed or measured at all.We demonstrate that,with a properly designed DNN structure with memory terms,effective DNN models can be learned from such partially observed data containing hidden parameters.The learned DNN model serves as an accurate predictive tool for system analysis.Through a few representative biological problems,we demonstrate that such DNN models can capture qualitative dynamical behavior changes in the system,such as bifurcations,even when the parameters controlling such behavior changes are completely unknown throughout not only the model learning process but also the system prediction process.The learned DNN model effectively creates a“closed”model involving only the observables when such a closed-form model does not exist mathematically.

关键词： Deep neural network(DNN) Governing equation discovery Biological system Partial observation

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