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Science China Mathematics 2024年

作者： yanqing yin Huiqin Li Zhidong Bai School of Mathematics and Statistics Chongqing University School of Mathematics and Statistics Northeast Normal University

In this paper, we focus on the test for high-dimensional covariance structures using doublenormalized observations for an elliptical population. By investigating the limiting spectral properties of the sample covariance matrix of double-normalized observations, we propose test statistics applicable for testing the diagonality of the population covariance matrix. Extensive simulations are conducted to investigate the performances of the proposed test in various situations.

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Intestinal Dopamine Receptor D2 is Required for Neuroprotection Against 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Dopaminergic Neurodegeneration

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Neuroscience Bulletin 2022年第8期38卷 871-886页

作者： Hairong Peng Shui Yu Yukai Zhang yanqing yin Jiawei Zhou Institute of Neuroscience State Key Laboratory of NeuroscienceCAS Center for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghai200031China School of Future Technology University of Chinese Academy of SciencesBeijing100049China Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology Shanghai201210China

A wealth of evidence has suggested that gastrointestinal dysfunction is associated with the onset and progression of Parkinson’s disease(PD).However,the mechanisms underlying these links remain to be ***,we investigated the impact of deregulation of intestinal dopamine D2 receptor(DRD2)signaling in response to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-induced dopaminergic ***/dopamine signaling in the mouse colon decreased with *** ablation of Drd2,but not Drd4,in the intestinal epithelium,caused a more severe loss of dopaminergic neurons in the substantia nigra following MPTP challenge,and this was accompanied by a reduced abundance of succinate-producing Alleoprevotella in the gut *** of succinate markedly attenuated dopaminergic neuronal loss in MPTP-treated mice by elevating the mitochondrial membrane *** study suggests that intestinal epithelial DRD2 activity and succinate from the gut microbiome contribute to the maintenance of nigral DA neuron *** findings provide a potential strategy targeting neuroinflammation-related neurological disorders such as PD.

关键词： Intestine DRD2 Parkinson’s disease MPTP Succinate Mitochondria

Effect of neutral polymeric bonding agent on tensile mechanical properties and damage evolution of NEPE propellant

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Defence Technology（防务技术） 2024年第2期32卷 357-367页

作者： M.Wubuliaisan yanqing Wu Xiao Hou Kun Yang Hongzheng Duan Xinmei yin State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081PR China The Fourth Institute of China Aerospace Science and Technology Corporation Xi'an710025PR China School of Aerospace Engineering Beijing Institute of TechnologyBeijing100081PR China Science and Technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechnologyHubei441003PR China

Introducing Neutral Polymeric bonding agents(NPBA) into the Nitrate Ester Plasticized Polyether(NEPE)propellant could improve the adhesion between filler/matrix interface, thereby contributing to the development of new generations of the NEPE propellant with better mechanical properties. Therefore,understanding the effects of NPBA on the deformation and damage evolution of the NEPE propellant is fundamental to material design and applications. This paper studies the uniaxial tensile and stress relaxation responses of the NEPE propellant with different amounts of NPBA. The damage evolution in terms of interface debonding is further investigated using a cohesive-zone model(CZM). Experimental results show that the initial modulus and strength of the NEPE propellant increase with the increasing amount of NPBA while the elongation decreases. Meanwhile, the relaxation rate slows down and a higher long-term equilibrium modulus is reached. Experimental and numerical analyses indicate that interface debonding and crack propagation along filler-matrix interface are the dominant damage mechanism for the samples with a low amount of NPBA, while damage localization and crack advancement through the matrix are predominant for the ones with a high amount of NPBA. Finally, crosslinking density tests and simulation results also show that the effect of the bonding agent is interfacial rather than due to the overall crosslinking density change of the binder.

关键词： Solid propellant Bonding agent Mechanical properties Damage evolution Cohesive-zone model Interface debonding

Assessment of Crop Yield in China Simulated by Thirteen Global Gridded Crop Models

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Advances in Atmospheric Sciences 2024年第3期41卷 420-434页

作者： Dezhen yin Fang LI Yaqiong LU Xiaodong ZENG Zhongda LIN yanqing ZHOU International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China

Global gridded crop models(GGCMs) have been broadly applied to assess the impacts of climate and environmental change and adaptation on agricultural production. China is a major grain producing country, but thus far only a few studies have assessed the performance of GGCMs in China, and these studies mainly focused on the average and interannual variability of national and regional yields. Here, a systematic national-and provincial-scale evaluation of the simulations by13 GGCMs [12 from the GGCM Intercomparison(GGCMI) project, phase 1, and CLM5-crop] of the yields of four crops(wheat, maize, rice, and soybean) in China during 1980–2009 was carried out through comparison with crop yield statistics collected from the National Bureau of Statistics of China. Results showed that GGCMI models generally underestimate the national yield of rice but overestimate it for the other three crops, while CLM5-crop can reproduce the national yields of wheat, maize, and rice well. Most GGCMs struggle to simulate the spatial patterns of crop yields. In terms of temporal variability, GGCMI models generally fail to capture the observed significant increases, but some can skillfully simulate the interannual variability. Conversely, CLM5-crop can represent the increases in wheat, maize, and rice, but works less well in simulating the interannual variability. At least one model can skillfully reproduce the temporal variability of yields in the top-10 producing provinces in China, albeit with a few exceptions. This study, for the first time, provides a complete picture of GGCM performance in China, which is important for GGCM development and understanding the reliability and uncertainty of national-and provincial-scale crop yield prediction in China.

关键词： global gridded crop model historical crop yield China multi-model evaluation

案例教学法联合循证医学在神经外科住院医师规范化培训中的实践成效

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中国卫生产业 2024年第3期21卷 209-212页

作者：黄梓雄李文生郑春霞林亨尹延庆李捷门东海广东医科大学附属医院广东湛江524001

目的研究分析案例教学法联合循证医学在神经外科住院医师规范化培训中的实践成效。方法选取2022年1月—2023年12月在广东医科大学附属医院神经外科进行规范化培训的200名住院医师为研究对象,按培训时间分为参考组(2022年1—12月)和研究... 详细信息

目的研究分析案例教学法联合循证医学在神经外科住院医师规范化培训中的实践成效。方法选取2022年1月—2023年12月在广东医科大学附属医院神经外科进行规范化培训的200名住院医师为研究对象,按培训时间分为参考组(2022年1—12月)和研究组(2023年1—12月),各100名。研究组采用案例教学法联合循证医学的规范化培训模式,参考组采用传统规范化培训模式。培训2个月后对两组住院医师进行理论知识水平和案例分析考核,对比两种培训模式的教学效果。结果培训结束后,研究组的理论知识考核成绩总分为(94.19±2.28)分,显著优于参考组的(83.53±5.87)分,差异有统计学意义(P<0.05)。研究组的案例分析考核成绩总分为(92.23±2.99)分,显著优于参考组的(85.34±3.69)分,差异有统计学意义(P<0.05)。结论案例教学法联合循证医学的培训模式可以改善传统培训模式中存在的一些不足,显著提升神经外科的培训质量,激发住院医师的学习兴趣,培养其临床思维能力,使神经外科的规范化培训更加高效、精准、直观,值得进一步探索。

关键词：案例教学法循证医学神经外科规范化培训实践成效

Investigation of high rate mechanical flow followed by ignition for high-energy propellant under dynamic extrusion loading

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Defence Technology（防务技术） 2024年第2期32卷 336-347页

作者： Liying Dong yanqing Wu Kun Yang Xiao Hou State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

Investigating the ignition response of nitrate ester plasticized polyether(NEPE) propellant under dynamic extrusion loading is of great significant at least for two cases. Firstly, it helps to understand the mechanism and conditions of unwanted ignition inside charged propellant under accident ***, evaluates the risk of a shell crevice in a solid rocket motor(SRM) under a falling or overturning scene. In the present study, an innovative visual crevice extrusion experiment is designed using a dropweight apparatus. The dynamic responses of NEPE propellant during extrusion loading, including compaction and compression, rapid shear flow into the crevice, stress concentration, and ignition reaction, have been firstly observed using a high-performance high-speed camera. The ignition reaction is observed in the triangular region of the NEPE propellant sample above the crevice when the drop weight velocity was 1.90 m/s. Based on the user material subroutine interface UMAT provided by finite element software LS-DYNA, a viscoelastic-plastic model and dual ignition criterion related to plastic shear dissipation are developed and applied to the local ignition response analysis under crevice extrusion conditions. The stress concentration occurs in the crevice location of the propellant sample, the shear stress is relatively large, the effective plastic work is relatively large, and the ignition reaction is easy to occur. When the sample thickness decreases from 5 mm to 2.5 mm, the shear stress increases from 22.3 MPa to 28.6 MPa, the critical value of effective plastic work required for ignition is shortened from 1280 μs to 730 μs, and the triangular area is easily triggering an ignition reaction. The propellant sample with a small thickness is more likely to stress concentration, resulting in large shear stress and effective work, triggering an ignition reaction.

关键词： NEPE propellant Crevice extrusion Shear flow Sample thickness Ignition reaction

Xuefuzhuyu injection induces neuronal differentiation of rat bone morrow mesenchymal stem cells

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Neural Regeneration Research 2011年第3期6卷 177-182页

作者： yin, yanqing Chen, Bing Ke, Junlong Mo, Wei Zou, Xinhui Liang, Yuansheng Guangdong Med Coll Affiliated Hosp Dept Neurosurg Zhanjiang 524001 Guangdong Peoples R China Guangdong Med Coll Affiliated Hosp Dept Neurol Zhanjiang 524001 Guangdong Peoples R China

The primary effective components of Xuefuzhuyu, including Rhizoma Chqanxiong, Radix Salviae Miltiorrhiae, and Radix Angelicae Sinensis, have been shown to induce the differentiation of bone marrow mesenchymal stem cells （BMMSCs） into neuronal-like cells. However, there is little available evidence on the effects of the Chinese herbal compound Xuefuzhuyu on BMMSC differentiation. The present study investigated the effects of Xuefuzhuyu on differentiation of rat BMMSCs into neuronal-like cells, and evaluated the optimal concentration for inducing differentiation. Inverted microscopy was used to observe BMMSCs induced by Xuefuzhuyu; immunocytochemistry revealed expression of the neuronal marker neuron-specific enolase surface antigen in the majority of BMMSCs following treatment with Xuefuzhuyu at concentrations of 1,3, 5 and 10 g/L. A concentration of 3 g/L resulted in highest neuron-specific enolase expression. These results suggest that BMMSCs can be induced to differentiate into neuronal-like cells with Xuefuzhuyu, and 3 g/L is the optimal inductive concentration for effective differentiation.

关键词： Xuefuzhuyu bone marrow mesenchymal stem cells neuronal-like cells neuralregeneration induction differentiation

Comparisons of Wave Force Model Effects on the Structural Responses and Fatigue Loads of a Semi-Submersible Floating Wind Turbine

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Journal of Ocean University of China 2024年第1期23卷 69-79页

作者： HAN yanqing LE Conghuan ZHANG Puyang XU Shengnan State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Hydraulic Engineering Ludong UniversityYantai 264025China School of Civil Engineering Tianjin UniversityTianjin 300072China Shandong Marine Aerospace Equipment Technological Innovation Center Yantai 264004China

The selection of wave force models will significantly impact the structural responses of floating wind *** this study,comparisons of wave force model effects on the structural responses and fatigue loads of a semi-submersible floating wind turbine(SFWT)were *** were performed by employing the Morison equation(ME)with linear or second-order wave kinematics and potential flow theory(PFT)with first-or second-order wave forces.A comparison of regular waves,irregular waves,and coupled wind/waves analyses with the experimental data showed that many of the simulation results and experimental data are relatively ***,notable discrepancies are found in the response amplitude operators for platform heave,tower base bending moment,and tension in mooring *** models give more satisfactory results of heave but more significant discrepan-cies in tower base bending moment than the ME *** irregular wave analyses,low-frequency resonances were captured by PFT models with second-order difference-frequency terms,and high-frequency resonances were captured by the ME models or PFT models with second-order sum-frequency *** force models capture the response frequencies but do not reasonably predict the response *** coupled wind/waves analyses showed more satisfactory results than the wave-only ***,an important detail to note is that this satisfactory result is based on the overprediction of wind-induced responses.

关键词： floating wind turbine wave force model potential flow theory Morison equation second-order wave forces

Peripheral Mechanism of Cancer-Induced Bone Pain

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Neuroscience Bulletin 2024年第6期40卷 815-830页

作者： Yachen Yang Wei Yang Ruofan Zhang yanqing Wang Department of Integrative Medicine and Neurobiology School of Basic Medical SciencesShanghai Medical CollegeInstitute of Acupuncture ResearchInstitutes of Integrative MedicineFudan UniversityShanghai200032China Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function Shanghai Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain ScienceInstitutes of Brain ScienceFudan UniversityShanghai200032China Zhongshan-Fudan Joint Innovation Center Zhongshan528437China

Cancer-induced bone pain(CIBP)is a type of ongoing or breakthrough pain caused by a primary bone tumor or bone *** constitutes a specific pain state with distinct characteristics;however,it shares similarities with inflammatory and neuropathic *** present,although various therapies have been developed for this condition,complete relief from CIBP in patients with cancer is yet to be ***,it is urgent to study the mechanism underlying CIBP to develop efficient analgesic ***,we focused on the peripheral mechanism associated with the initiation of CIBP,which involves tissue injury in the bone and changes in the tumor microenvironment(TME)and dorsal root *** nerve–cancer and cancer–immunocyte cross-talk in the TME creates circumstances that promote tumor growth and metastasis,ultimately leading to *** peripheral mechanism of CIBP and current treatments as well as potential therapeutic targets are discussed in this review.

关键词： Cancer-induced bone pain Peripheral mechanism Tumor microenvironment Sensory nerve Immunocytes

Shock-induced energy localization and reaction growth considering chemical-inclusions effects for crystalline explosives

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Defence Technology（防务技术） 2024年第3期33卷 278-294页

作者： Ruqin Liu yanqing Wu Xinjie Wang Fenglei Huang Xiaona Huang Yushi Wen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China School of Power and Mechanical Engineering Wuhan UniversityWuhan430072HubeiChina Institute of Chemical Materials China Academy of Engineering Physics(CAEP)Mianyang621999SichuanChina

Chemical inclusions significantly alter shock responses of crystalline explosives in macroscale gap experiments but their microscale dynamics origin remains *** shock-induced energy localization,overall physical responses,and reactions in a-1,3,5-trinitro-1,3,5-triazinane(a-RDX)crystal entrained various chemical inclusions were investigated by the multi-scale shock technique implemented in the reactive molecular dynamics *** indicated that energy localization and shock reaction were affected by the intrinsic factors within chemical inclusions,i.e.,phase states,chemical compositions,and *** atomic origin of chemical-inclusions effects on energy localization is dependent on the dynamics mechanism of interfacial molecules with free space volume,which includes homogeneous intermolecular compression,interfacial impact and shear,and void collapse and *** introducing various chemical inclusions,the initiation of those dynamics mechanisms triggers diverse decay rates of bulk RDX molecules and hereby impacts on growth speeds of final *** chemical inclusions can reduce the effectiveness of the void during the shock *** the shockwave velocity of 9 km/s,the parent RDX decay rate in RDX entrained amorphous carbon decreases the most and is about one fourth of that in RDX with a vacuum void,and solid HMX and TATB inclusions are more reactive than amorphous carbon but less reactive than dry air or acetone *** lessdense shocking system denotes the greater increases in local temperature and stress,the faster energy liberation,and the earlier final reaction into equilibrium,revealing more pronounced responses to the present intense *** quantitative models associated with the relative system density(RD_(sys))were proposed for indicating energy-localization mechanisms and evaluating initiation safety in the shocked crystalline ***_(sys)is defined by the density ratio of defective RDX to perfec

关键词： Shock responses Energy localization Crystalline explosives Chemical inclusions Reactive molecular dynamics