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Nitrogen deposition mediates more stochastic processes in structuring plant community than soil microbial community in the Eurasian steppe

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Science China(Life Sciences) 2024年第4期67卷 778-788页

作者： Wei yang Shuhan Zhang Ang Li junjie yang Shuang Pang Zonghao Hu Zhiping Wang Xingguo Han Ximei Zhang Key Laboratory of Dryland Agriculture Ministry of AgricultureInstitute of Environment and Sustainable Development in AgricultureChinese Academy of Agricultural SciencesBeijing 100081China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China

Anthropogenic environmental changes may affect community assembly through mediating both deterministic(e.g.,competitive exclusion and environmental filtering)and stochastic processes(e.g.,birth/death and dispersal/colonization).It is traditionally thought that environmental changes have a larger mediation effect on stochastic processes in structuring soil microbial community than aboveground plant community;however,this hypothesis remains largely untested.Here we report an unexpected pattern that nitrogen(N)deposition has a larger mediation effect on stochastic processes in structuring plant community than soil microbial community(those<2 mm in diameter,including archaea,bacteria,fungi,and protists)in the Eurasian steppe.We performed a ten-year nitrogen deposition experiment in a semiarid grassland ecosystem in Inner Mongolia,manipulating nine rates(0–50 g N m^(-2)per year)at two frequencies(nitrogen added twice or 12 times per year)under two grassland management strategies(fencing or mowing).We separated the compositional variation of plant and soil microbial communities caused by each treatment into the deterministic and stochastic components with a recently-developed method.As nitrogen addition rate increased,the relative importance of stochastic component of plant community first increased and then decreased,while that of soil microbial community first decreased and then increased.On the whole,the relative importance of stochastic component was significantly larger in plant community(0.552±0.035;mean±standard error)than in microbial community(0.427±0.035).Consistently,the proportion of compositional variation explained by the deterministic soil and community indices was smaller for plant community(0.172–0.186)than microbial community(0.240–0.767).Meanwhile,as nitrogen addition rate increased,the linkage between plant and microbial community composition first became weaker and then became stronger.The larger stochasticity in plant community relative to microbial community assembly suggested that more stochasti

关键词： deterministic process environmental change grassland restoration nitrogen deposition stochastic process

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Effect of Heat Treatment on Microstructure and Mechanical Behavior of Cu-Bearing 316L Stainless Steel Produced by Selective Laser Melting

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 169-180页

作者： Huan yang Ying Liu Jianbo Jin Kunmao Li junjie yang Lingjian Meng Chunbo Li Wencai Zhang Shengfeng Zhou Sino-German College of Intelligent Manufacturing Shenzhen Technology UniversityShenzhen518118China Institute of Advanced Wear and Corrosion Resistance and Functional Materials Jinan UniversityGuangzhou510632China Department of Orthopedics First Affiliated Hospital of Jinan UniversityGuangzhou510632China

Cu-bearing stainless steels(SSs)with high strength,excellent plasticity,and effective antimicrobial properties hold significant potential for applications in the marine industry.In this study,Cu-bearing SSs with copper ranging from 0 to 6.0 wt%were successfully prepared using selective laser melting(SLM)technology.For the Cu-bearing SSs with different copper contents,the effect of heat treatment on the microstructural and mechanical behaviors was studied systematically.Microstructural observations revealed that the subgrain size of Cu-bearing SSs increased with heat treatment at 500℃ and 700℃ for 6 h.Furthermore,the tensile strength and elongation increased after the heat treatment temperature due to the combined effect of dislocations,twins,andε-Cu precipitated phases.Notably,after heat treatment at 700℃,the SLM4.5Cu sample exhibited an abnormal rise in tensile strength and elongation.This finding suggests that the diffusion strengthening caused byε-Cu precipitates exceeded the stacking fault energy.Consequently,the tensile strength and elongation reached 693.32 MPa and 56.94%,respectively.This work provides an efficient approach for preparing Cu-bearing SSs with exceptional strength and plasticity.

关键词： Selective laser melting Cu-bearing stainless steel(SS) Heat treatment Mechanical properties

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Numerical simulation research on multiphase flow of aviation centrifugal pump based on OpenFOAM

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Chinese Journal of Aeronautics 2024年第4期37卷 256-275页

作者： Xianwei LIU Jiangfeng FU junjie yang Dewen YIN Zhenhua ZHOU Huacong LI College of Power and Energy Northwestern Polytechnical UniversityXi’an 710072China Norinco Group Testing and Research Institute Huayin 714200China AECC Xi’an Engine Control Technology Co.Ltd. Xi’an 710077China AECC Guizhou Honglin Aero Engine Control Technology Co.Ltd. Guiyang 550009China

This paper aims to tackle the calculation efficiency problem raised in the cavitation-flow simulation of the aviation centrifugal pump due to the fading-away interface resulting from the dissipation of numerics used in the phase-change control equation for unstructured-grid multiphase flow,and due to the limitation of flow time-step in whole flow regimes,the control equation of vapor–liquid two-phase flow considering cavitation mass transport is established firstly,modifying the momentum equation by introducing the surface tension,and adding the artificial convective flow to the phase equation to solve the numerical dissipation problem.Secondly,in consideration of the local time step principle and based on the multi-dimensional general limiter algorithm with explicit solutions under the OpenFOAM platform,a solution method of steady-state VOF (Volume of Fluid) model considering cavitation two-phase change is constructed,and the feasibility of this method is verified by NACA hydrofoil and NASA flat plate inducer.Finally,based on the platform developed,the cavitation performance of an aviation centrifugal pump inducer is analyzed.The research results show that the error of the calculated cavitation pressure distribution for NACA hydrofoil between the simulation test and the experimental-test is less than 5%,and the maximum error of calculated cavitation number at pump head dropping for NASA high-speed flat plate inducer between the simulation test and the experimental-test is 2.1%.The cavitation area observed in the simulation test is the same as that obtained in the high-speed photography test.Based on the OpenFOAM simulation method,the position of pump head dropping of the fuel centrifugal pump can be accurately captured.The error of the calculated cavitation number at pump head dropping between the simulation test and the experimental test is about 3.7%,showing high calculation accuracy.

关键词： Aero engine Fuel centrifugal pump Multiphase flow OpenFOAM Volume of fluid

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Filterless narrowband photodetectors enabled by controllable band modulation through ion migration: The case of halide perovskites

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InfoMat 2024年第1期6卷 123-138页

作者： Yu Li Shanshan Yu junjie yang Kai Zhang Mingyu Hu Weitao Qiu Fumin Guo Wei Qian Sean Reinecke Tao Chen Makhsud I.Saidaminov Jian Wang Shihe yang Guangdong Provincial Key Lab of Nano-Micro Materials Research School of Chemical Biology and BiotechnologyShenzhen Graduate SchoolPeking UniversityShenzhenGuangdongthe People's Republic of China Shenzhen Bay Laboratory Institute of Biomedical EngineeringShenzhenGuangdongthe People's Republic of China School of Advanced Materials Shenzhen Graduate SchoolPeking UniversityShenzhenGuangdongthe People's Republic of China Department of Chemistry The University of Hong KongHong Kong SARthe People's Republic of China Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Materials for Energy ConversionDepartment of Materials Science and EngineeringSchool of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefeiAnhuithe People's Republic of China College of Materials and Energy South China Agricultural UniversityGuangzhouGuangdongthe People's Republic of China Department of Chemistry University of VictoriaVictoriaBritish ColumbiaCanada

Narrowband photodetectors conventionally rely on optical structure design orbandpass filters to achieve the narrowband regime. Recently, a strategy forfilterless narrowband photoresponse based on the charge collection narrowing(CCN) mechanism was reported. However, the CCN strategy requires an electrically and optically “thick” photoactive layer, which poses challenges in controlling the narrowband photoresponse. Here we propose a novel strategy forconstructing narrowband photodetectors by leveraging the inherent ion migration in perovskites, which we term “band modulation narrowing” (BMN). Bymanipulating the ion migration with external stimuli such as illumination,temperature, and bias voltage, we can regulate in situ the energy-band structure of perovskite photodetectors (PPDs) and hence their spectral response.Combining the Fermi energy levels obtained by the Kelvin probe force microscopy, the internal potential profiles from solar cell capacitance simulator simulation, and the anion accumulation revealed by the transient ion-drifttechnique, we discover two critical mechanisms behind our BMN strategy: theextension of an optically active but electronically dead region proximal to the top electrode and the down-bending energy bands near the electron transportlayer. Our findings offer a case for harnessing the often-annoying ionmigration for developing advanced narrowband PPDs.

关键词： band structure ion migration narrowband detection perovskite spatial distribution of charge carriers

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Polydopamine-modified metal-organic frameworks nanoparticles enhance the corrosion resistance and bioactivity of polycaprolactone coating on high-purity magnesium

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Journal of Magnesium and Alloys 2024年第5期12卷 2070-2089页

作者： Qingyun Fu Shaojie He junjie yang Ziyu Su Ping Li Xincheng Yu Weihong Jin Shulan Xu Zhentao Yu Dingsheng Zha Center of Oral Implantology Stomatological Hospital Southern Medical University Panyu Hospital of Chinese Medicine Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan University First Affiliated Hospital of Jinan University

Biodegradable magnesium（Mg） and its alloys exhibit excellent biocompatibility and mechanical compatibility, demonstrating tremendous potential for applications in orthopedics. However, the rapid degradation rate has limited their clinical application. Polycaprolactone（PCL）is commonly employed as a polymer coating to impede the rapid degradation of Mg. Unfortunately, its long-term anti-corrosion capability and bioactivity are inadequate. To address these issues, polydopamine（PDA）-modified zeolitic imidazolate framework-8（PZIF-8） bioactive nanoparticles are fabricated and incorporated into the PCL coating. The PZIF-8 particles, featuring catechol motifs, can enhance the compactness of the PCL coating, reduce its defects, and possess biomineralization ability, thereby effectively improving its anti-corrosive and bioactive properties. Moreover, the active substances released from the degradation of the PZIF-8 particles such as Zn2+and PDA are beneficial for osteogenesis. The corrosion tests indicate that the corrosion current density of PCL-treated sample decreases by more than one order of magnitude and the amount of H2released decreases from 0.23 ± 0.12 to 0.08 ± 0.08 ml cm-2after doping with the PZIF-8. Furthermore,the improved corrosion resistance and released PDA and Zn2+from the coating can promote osteogenic differentiation by up-regulating the expression of alkaline phosphatase activity, related osteogenic genes, and proteins. In addition, in vivo implantation experiments in rabbit femur defects further offer strong evidence that the doping of PZIF-8 nanoparticles accelerates bone reconstruction of the PCL coating. In summary, this work implies a new strategy to fabricate a PCL-based coating on Mg-based implants by introducing the PZIF-8 particles for orthopedic applications.

关键词： Polydopamine ZIF-8 High-purity magnesium Polycaprolactone coating Anticorrosion Bone regeneration

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Nanoparticles for the treatment of spinal cord injury

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Neural Regeneration Research 2025年第6期20卷 1665-1680页

作者： Qiwei yang Di Lu Jiuping Wu Fuming Liang Huayi Wang junjie yang Ganggang Zhang Chen Wang Yanlian yang Ling Zhu Xinzhi Sun Department of Orthopedic Surgery The First Affiliated Hospital of Zhengzhou UniversityZhengzhouHenan ProvinceChina CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Key Laboratory for Biomedical Effects of Nanomaterials and NanosafetyCAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijingChina University of Chinese Academy of Sciences BeijingChina Department of Neurosurgery The First Affiliated Hospital of Chongqing Medical UniversityChongqingChina

Spinal cord injuries lead to significant loss of motor, sensory, and autonomic functions, presenting major challenges in neural regeneration. Achieving effective therapeutic concentrations at injury sites has been a slow process, partly due to the difficulty of delivering drugs effectively. Nanoparticles, with their targeted delivery capabilities, biocompatibility, and enhanced bioavailability over conventional drugs, are garnering attention for spinal cord injury treatment. This review explores the current mechanisms and shortcomings of existing treatments, highlighting the benefits and progress of nanoparticle-based approaches. We detail nanoparticle delivery methods for spinal cord injury, including local and intravenous injections, oral delivery, and biomaterial-assisted implantation, alongside strategies such as drug loading and surface modification. The discussion extends to how nanoparticles aid in reducing oxidative stress, dampening inflammation, fostering neural regeneration, and promoting angiogenesis. We summarize the use of various types of nanoparticles for treating spinal cord injuries, including metallic, polymeric, protein-based, inorganic non-metallic, and lipid nanoparticles. We also discuss the challenges faced, such as biosafety, effectiveness in humans, precise dosage control, standardization of production and characterization, immune responses, and targeted delivery in vivo. Additionally, we explore future directions, such as improving biosafety, standardizing manufacturing and characterization processes, and advancing human trials. Nanoparticles have shown considerable progress in targeted delivery and enhancing treatment efficacy for spinal cord injuries, presenting significant potential for clinical use and drug development.

关键词： antioxidants axon regeneration biocompatible materials drug carriers nanoparticles nerve regeneration neuroinflammatory diseases neuroprotection spinal cord injury stem cells

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Optimization via response surface methodology of the synthesis of a dust suppressant and its performance characterization for use in open cut coal mines

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Journal of Environmental Sciences 2022年第11期34卷 211-223页

作者： Hu Jin Yansong Zhang Guangan Wu junjie yang Nan Li College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China College of Safety and Environmental Engineering Shandong University of Science and TechnologyQingdao 266590China Qingdao Intelligent Control Engineering Center for Production Safety Fire Accident Qingdao 266590China

To relieve dust pollution in open cut coal mines and reduce the hazards of coal dust pollution to the environment and workers we optimized the synthesis of a dust suppressant by graft copolymerization of environmentally friendly soy protein isolate with methyl methacrylate.This dust suppressant could effectively control dust pollution in open cut coal mines. The optimized conditions for graft copolymerization in this case were determined by a response surface experiment designed with Design-Expert 10 software. Characterization by scanning electron microscopy showed a significant morphology change of the dust suppressant and the generation of a rigid and dense layer on its surface after interacting with coal dust.The layer exhibited good bonding and dust suppression performance. The analysis with Fourier-transform infrared spectroscopy revealed the appearance of new absorption peaks near 1300, 1072, and 1631 cm, demonstrating effective graft copolymerization. The proposed dust suppressant exhibited excellent wind erosion resistance, with a resistance that exceeded 90% at a wind speed of 6.5 m/sec. The successful graft copolymerization and effective bonding and curing of the dust suppressant on coal dust were experimentally verified.This is of great significance to the control of coal dust pollution.

关键词： Environmental dust control Dust suppressant Response surface method Graft copolymerization Performance characterization Single factor method

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Posture Control of Legged Locomotion Based on Virtual Pivot Point Concept

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Journal of Bionic Engineering 2023年第6期20卷 2683-2702页

作者： Hao Sun junjie yang Yinghao Jia Changhong Wang Space Control and Inertial Technology Research Center Harbin Institute of TechnologyHarbin150001China

This paper presents a novel control approach for achieving robust posture control in legged locomotion,specifically for SLIP-like bipedal running and quadrupedal bounding with trunk stabilization.The approach is based on the virtual pendulum concept observed in human and animal locomotion experiments,which redirects ground reaction forces to a virtual support point called the Virtual Pivot Point(VPP)during the stance phase.Using the hybrid averaging theorem,we prove the upright posture stability of bipedal running with a fixed VPP position and propose a VPP angle feedback controller for online VPP adjustment to improve performance and convergence speed.Additionally,we present the first application of the VPP concept to quadrupedal posture control and design a VPP position feedback control law to enhance robustness in quadrupedal bounding.We evaluate the effectiveness of the proposed VPP-based controllers through various simulations,demonstrating their effectiveness in posture control of both bipedal running and quadrupedal bounding.The performance of the VPP-based control approach is further validated through experimental validation on a quadruped robot,SCIT Dog,for stable bounding motion generation at different forward speeds.

关键词： Legged robots Bionic control Virtual pivot point Posture stability Dynamic locomotion

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Discovery of novel aporphine alkaloid derivative as potent TLR2 antagonist reversing macrophage polarization and neutrophil infiltration against acute inflammation

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药学学报:英文版 2023年第9期13卷 3782-3801页

作者： junjie yang Yue Pan Xiaoshan Zeng Shuwen Liu Zhipeng Chen Kui Cheng Guangdong Provincial Key Laboratory of New Drug Screening and NMPA Key Laboratory for Research and Evaluation of Drug Metabolism School of Pharmaceutical SciencesSouthern Medical UniversityGuangzhou 510515China Department of Musculoskeletal Oncology the Third Affiliated Hospital of Southern Medical UniversityGuangzhou 510642China

Toll-like receptor 2(TLR2)mediated macrophages regulate the protective immune response to infectious microorganisms,but the aberrant activation of macrophages often leads to pathological inflammation,including tissue damage.In this study,we identified antagonists of TLR2 by screening2100 natural products and subsequently identified Taspine,an aporphine alkaloid,as an excellent candidate.Furthermore,analysis of the 10 steps chemical synthesis route and structural optimization yielded the Taspine derivative SMU-Y6,which has higher activity,better solubility,and improved drug-feasible property.Mechanistic studies and seq-RNA analysis revealed that SMU-Y6 inhibited TLR2 over other TLRs,hindered the formation of TLR2/MyD88 complex,and blocked the downstream NF-κB and MAPK signaling pathway,thus suppressing the release of inflammatory cytokines.SMU-Y6 could stabilize TLR2 and bind to TLR2 protein with a Kdof 0.18μmol/L.Additionally,SMU-Y6 could efficiently reverse the M1 phenotype macrophage polarization,reduce the production of cytokines as well as infiltration of neutrophiles and alleviate the local inflammation in mice with acute paw edema and colitis.Collectively,we reported the first aporphine alkaloid derivative that selectively inhibits TLR2 with high binding affinity and superior drug-feasible property,thus providing an urgently-needed molecular probe and potential drug candidate for inflammatory and autoimmune disease therapy.

关键词： Taspine derivative TLR2 inhibitor MyD88 NF-κB signaling pathway Macrophage polarization Anti-acute inflammatory

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Spring-Loaded Inverted Pendulum Hopping via Hybrid Averaging and Control Lyapunov Function

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Journal of Bionic Engineering 2023年第1期20卷 291-307页

作者： Hao Sun junjie yang Yinghao Jia Qinghua Li Changhong Wang Space Control and Inertial Technology Research Center Harbin Institute of TechnologyHarbin150001China

The Spring-Loaded Inverted Pendulum(SLIP)has been regarded as a canonical model for hopping and running dynamics of legged robots.This paper presents a novel control of the actuated-SLIP hopping on unknown terrains.We propose that in the neighborhood of the desired stable hybrid limit cycle,the local dynamical behavior of a hybrid system can be expressed by a set of phase coordinates and transverse coordinates.Under some acceptable assumptions,the hybrid averaging theorem is applied on the SLIP non-integrable dynamics to simplify the controller design.Using the inherent symmetry of SLIP dynamics,a control Lyapunov function-based hybrid averaging controller is developed to ensure the exponential stability of the desired gait orbit.This results in a set of linear constraints on the control signal,which can be readily solved by a quadratic programming optimization.Furthermore,a novel method is introduced to improve the robustness against unknown disturbances through the online constraint adjustment.The proposed controller is evaluated in various simulations,demonstrating the SLIP hopping on diverse terrains,including flat,sin-wave,and unregular terrains.The performance of the approach is also validated on a quadruped robot SCIT Dog for generating dynamic gaits such as pronking.

关键词： Legged robots-Spring-Loaded Inverted Pendulum Control Lyapunov function Dynamic hopping

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