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New method for multibody dynamics based on unknown constraint force

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Science China(Technological Sciences) 2024年第3期67卷 791-808页

作者： tian Ying JIA YingHong ZHANG jun School of Astronautics Beihang UniversityBeijing 100191China Beijing Institute of Control Engineering Beijing 100190China National Laboratory of Space Intelligent Control Beijing 100190China

This paper presents a new method for the dynamics of multibody systems based on unknown constraint force. The method can uniformly solve multibody systems with typical configurations, including the system with rigid-flexible coupling, the system in tree topology, and the system with loop constraints. Unlike common methods, the proposed method can model the loop system without “cutting off” loop constraints, leading to the exact same modelling process as the tree-like system performs. Based on graph theory, a topological record matrix M_(rec) is proposed to capture the arbitrary system configuration. Moreover, constraint forces are selected as the key variables in semi-recursive framework. With the recursive kinematics relationship between adjacent bodies, the constraint force equation is further assembled to achieve the full-state system solution. The numerical simulations demonstrate the accuracy of the proposed method.

关键词： multibody system dynamic modelling rigid-flexible coupling unknown constraint force graph theory semi-recursive algorithm

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Mass transfer in heap leaching of weathered crust elution deposited rare earth ore with Al_(2)(SO_(4))_(3) solution

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Journal of Rare Earths 2024年第6期42卷 1175-1181,I0007页

作者： Jingqun Yin Dedong Zeng jun tian Yaqing Weng Institute of Applied Chemistry Jiangxi Academy of SciencesNanchang330096China School of Chemistry and Chemical Engineering Nanchang UniversityNanchang330031China

In order to increase efficiency and avoid NH^(4+)-N pollution in the leaching process of weathered crust elution-deposited rare earth ores,the mass transfer in heap leaching with Al_(2)(SO_(4))_(3) solution was simulated with column elution and experimentally *** results indicate that the leaching yield is also up to 99%for leaching with aluminum sulfate instead of ammonium *** optimal flow rate is 60 mL/h,the height equivalent to a theoretical plate(HETP)is 1.29 mm *** peak value position of RE^(3+)is 60 mL/h,Fe^(3+)is 100 mL/h,however,Al^(3+)is 150 mL/h,and the heap leaching process has kinetic separation effect.

关键词： Raree arths Mass transfer Process optimization Heapleaching Weathered crust elution-deposited rare earth ore

Influence of Island Scanning Strategy on Microstructures and Mechanical Properties of Direct Laser-Deposited Ti–6Al–4V Structures

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Acta Metallurgica Sinica(English Letters) 2019年第9期32卷 1173-1180页

作者： Xiao Wang Fei Lv Li-Da Shen Hui-Xin Liang De-Qiao Xie zong-jun tian College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics

To investigate the influence of island scanning on the microstructures and mechanical properties of direct laser-deposited Ti–6 Al–4 V structures,two samples are prepared using island scanning and orthogonal successive scanning,*** microstructures,relative density,and mechanical properties of the samples prepared using these two scanning strategies are *** sample exhibits columnarβ-grain morphology and basket-weave microstructure *** grains of the sample prepared using island scanning are significantly finer than that prepared by orthogonal successive scanning due to faster cooling during ***,the relative density of the sample prepared using island scanning was slightly smaller due to the concentration of lack-of-fusion pores at the overlap zone of the *** testing at room temperature indicates that the ultimate tensile strength and yield strength of the sample prepared using island scanning is enhanced due to finer grains,while the ductility of the sample is weakened due to defects.

关键词： Direct laser deposition Ti-6A1W Scanning strategies Microstructure Defects Mechanical property

Systematic study of the synthesis of heavy and superheavy nuclei in 48Ca-induced fusion-evaporation reactions

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Nuclear Science and Techniques 2024年第7期35卷 157-172页

作者： Shi-Hao Zhu tian-Liang Zhao Xiao-jun Bao Department of Physics Collaborative Innovation Center for Quantum EffectsKey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationHunan Normal UniversityChangsha410081China School of Nuclear Science and Technology Lanzhou UniversityLanzhou730000China School of Physics Xi’an Jiaotong UniversityXi’an710049China

We systematically studied the evaporation residue cross sections of ^(48)Ca-induced reactions on lanthanide and actinide target nuclei under the Dinuclear System(DNS)model framework to check the reliability and applicability of the *** produce new proton-rich Fl and Lv isotopes through hot fusion reactions in the superheavy element region with Z≥104,we utilized the reactions ^(48)Ca+^(236,238,239) Pu and ^(48)Ca+^(242,243,244,250) ***,owing to the detection limit of available equipment(0.1 pb),only 283Fl and 287−289Lv,which have the maximum evaporation residue cross section values of 0.149,0.130,9.522,and 0.309 pb,respectively,can be ***,to produce neutron-deficient isotopes of actinides near the proton drip line with Z=93−100,we attempted to generate the new isotopes(224−227Pu,228−232,237Cm)using the reactions ^(48)Ca+180,182,183 W and ^(48)Ca+^(184,186,187,192) *** maximum evaporation residue cross section values are 0.07,0.06,0.26,and 0.30 nb for the former set of reactions,and 1.96 pb,5.73 pb,12.16 pb,19.39 pb,54.79 pb,and 6.45 nb for the latter,*** results are expected to provide new information for the future synthesis of unknown neutron-deficient isotopes.

关键词： Dinuclear system(DNS)model Evaporation residue cross section Neutron-deficient isotopes

Selective adsorption of tetracycline by β-CD-immobilized sodium alginate aerogel coupled with ultrafiltration for reclaimed water

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Chinese Journal of Chemical Engineering 2024年第4期68卷 27-34页

作者： Xi Quan jun Zhang Linlin Yin Wei Zuo Yu tian State Key Laboratory of Urban Water Resource and Environment(SKLUWRE) School of EnvironmentHarbin Institute of TechnologyHarbin 150090China

In this work,a novel composite material based on β-cyclodextrin-immobilized sodium alginate aerogel(β-CD/NaAlg) was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycline antibiotics from reclaimed wastewater.A series of characterizations were utilized to confirm the successful synthesis of the adsorbent and this β-CD/NaAlg presented a three-dimensional network at the nanoscale or *** optimal conditions(pH=4,t=8 h,β-CD:NaAlg=9,adsorbent dosage = 1.5 g·L-1),the maximum removal rate of β-CD/NaAlg to tetracycline was 70%.The adsorption behavior of tetracycline on β-CD/NaAlg conformed to the Freundlich isotherm model(R2=0.9977) and the pseudo-second-order kinetic model(R^(2)=0.9993).Moreover,the adsorbent still removed 55.3% of tetracycline after five ***,the adsorbent was integrated with ultrafiltration to adsorb tetracycline antibiotics from simulated reclaimed wastewater,and the removal rate of tetracycline reached 78.9% within 2 *** existence of Cr(Ⅵ) had a negligible impact on tetracycline removal,while the presence of humic acid exhibited a promoting *** possible adsorption mechanisms were also elucidated through X-ray photoelectron spectroscopy and density functional theory *** summary,β-CD/NaAlg represents an environmentally friendly,efficient,and sustainable adsorbent for removing tetracycline antibiotics from reclaimed water.

关键词： b-CD/NaAlg aerogel Covalent grafting Tetracycline antibiotics Ultrafiltration Selective adsorption Reclaimed water

αDecay in extreme laser fields within a deformed Gamow-like model

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Nuclear Science and Techniques 2024年第2期35卷 131-144页

作者： Qiong Xiao jun-Hao Cheng Yang-Yang Xu You-tian Zou jun-Gang Deng Tong-Pu Yu Department of Physics National University of Defense TechnologyChangsha 410073China College of Science China Three Gorges UniversityYichang 443002China

In this study, the effect of extreme laser fields on the α decay process of ground-state even–even nuclei was *** the deformed Gamow-like model, we found that state-of-the-art lasers can cause a slight change in the α decay penetration probability of most nuclei. In addition, we studied the correlation between the rate of change of the α decay penetration probability and angle between the directions of the laser electric field and α particle emission for different nuclei. Based on this correlation, the average effect of extreme laser fields on the half-life of many nuclei with arbitrary α particle emission angles was calculated. The calculations show that the laser suppression and promotion effects on the α decay penetration probability of the nuclei population with completely random α particle-emission directions are not completely *** remainder led to a change in the average penetration probability of the nuclei. Furthermore, the possibility of achieving a higher average rate of change by altering the spatial shape of the laser is explored. We conclude that circularly polarized lasers may be helpful in future experiments to achieve a more significant average rate of change of the α decay half-life of the nuclei population.

关键词： αDecay Deformed Gamow-like model Half-lives Extreme laser field Penetration probability

How do the landslide and non-landslide sampling strategies impact landslide susceptibility assessment? d A catchment-scale case study from China

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 877-894页

作者： Zizheng Guo Bixia tian Yuhang Zhu jun He Taili Zhang School of Civil and Transportation Engineering Hebei University of TechnologyTianjin300401China Hebei Key Laboratory of Earthquake Disaster Prevention and Risk Assessment Sanhe065201China Faculty of Engineering China University of GeosciencesWuhan430074China Nanjing Center China Geological SurveyMinistry of Natural ResourcesNanjing210016China

The aim of this study is to investigate the impacts of the sampling strategy of landslide and non-landslide on the performance of landslide susceptibility assessment(LSA).The study area is the Feiyun catchment in Wenzhou City,Southeast *** types of landslides samples,combined with seven non-landslide sampling strategies,resulted in a total of 14 *** corresponding landslide susceptibility map(LSM)for each scenario was generated using the random forest *** receiver operating characteristic(ROC)curve and statistical indicators were calculated and used to assess the impact of the dataset sampling *** results showed that higher accuracies were achieved when using the landslide core as positive samples,combined with non-landslide sampling from the very low zone or buffer *** results reveal the influence of landslide and non-landslide sampling strategies on the accuracy of LSA,which provides a reference for subsequent researchers aiming to obtain a more reasonable LSM.

关键词： Landslide susceptibility Sampling strategy Machine learning Random forest China

Developing and validating a predictive model of delivering large-forgestational-age infants among women with gestational diabetes mellitus

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World Journal of Diabetes 2024年第6期15卷 1242-1253页

作者： Yi-tian Zhu Lan-Lan Xiang Ya-jun Chen tian-Ying Zhong jun-jun Wang Yu Zeng Department of Clinical Laboratory Jinling Clinical Medical College of Nanjing Medical UniversityNanjing 210002Jiangsu ProvinceChina Department of Clinical Laboratory Women’s Hospital of Nanjing Medical UniversityNanjing Women and Children’s Healthcare HospitalNanjing 210003Jiangsu ProvinceChina

BACKGROUND The birth of large-for-gestational-age(LGA)infants is associated with many shortterm adverse pregnancy *** has been observed that the proportion of LGA infants born to pregnant women with gestational diabetes mellitus(GDM)is significantly higher than that born to healthy pregnant ***,traditional methods for the diagnosis of LGA have ***,this study aims to establish a predictive model that can effectively identify women with GDM who are at risk of delivering LGA *** To develop and validate a nomogram prediction model of delivering LGA infants among pregnant women with GDM,and provide strategies for the effective prevention and timely intervention of *** The multivariable prediction model was developed by carrying out the following ***,the variables that were associated with LGA risk in pregnant women with GDM were screened by univariate analyses,for which the P value was<***,Least Absolute Shrinkage and Selection Operator regression was fit using ten cross-validations,and the optimal combination factors were se-lected by choosing lambda 1se as the *** final predictors were deter-mined by multiple backward stepwise logistic regression analysis,in which only the independent variables were associated with LGA risk,with a P value<***,a risk prediction model was established and subsequently evaluated by using area under the receiver operating characteristic curve,calibration curve and decision curve *** After using a multistep screening method,we establish a predictive *** risk factors for delivering an LGA infant were identified(P<0.01),including weight gain during pregnancy,parity,triglyceride-glucose index,free tetraiodothyronine level,abdominal circumference,alanine transaminase-aspartate aminotransferase ratio and weight at 24 gestational *** nomogram’s prediction ability was supported by the area under the curve(0.703,0.709,and 0.699 f

关键词： Large-for-gestational-age Gestational diabetes mellitus Predictive model Nomogram Triglyceride-glucose index

Therapeutic effect and psychological impact of aspirin plus edaravone on patients with cerebral infarction

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World Journal of Psychiatry 2024年第5期14卷 644-652页

作者： tian-Shu Wang Li-jun Jing Department of Neurology The First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052Henan ProvinceChina

BACKGROUND Cerebral infarction(CI)is characterized by a high prevalence,disability,and *** or improper treatment greatly affects patient *** To explore the drug efficacy of aspirin plus edaravone and to explore their effect on quality of life(QOL),anxiety and depression in CI *** We retrospectively analyzed the records of 124 CI patients treated between june 2019 and February 2021 who were assigned to an observation group(OG)(combination therapy of aspirin and edaravone,65 patients)or a control group(CG)(aspirin monotherapy,59 patients).The therapeutic effects,pre-and posttreatment National Institutes of Health Stroke Scale(NIHSS)scores,activities of daily living,degree of cognitive impairment,protein levels of glial fibrillary acidic protein(GFAP),neuron-specific enolase(NSE)and S-100B,occurrence of adverse reactions,and serum high-sensitivity C-reactive protein(hs-CRP),interleukin(IL)-6 and tumor necrosis factor(TNF)-αwere evaluated,detected and compared between the two ***,posttreatment QOL,anxiety,and depression were assessed by the Medical Outcomes Study 36-Item Short Form Health Survey Scale,Self-rating Depression Scale(SDS),and Self-rating Anxiety Scale(SAS),*** Compared with the CG,the OG had markedly better therapeutic effects,greater improvements in activities of daily living,and better alleviation in cognitive dysfunction after treatment,as well as lower posttreatment NIHSS scores and serum NSE,GFAP,S-100B,hs-CRP,IL-6,and TNF-αlevels;the OG was similar to the CG in terms of adverse reactions but was better than the CG in terms of posttreatment QOL;and the OG also had lower SDS and SAS scores than the CG after *** Aspirin plus edaravone had a good curative effect on *** can reverse cranial nerve damage in patients,improve neurological function and prognosis,and alleviate inflammation,anxiety,and depression;thus,it is considered safe and worthy of clinical application.

关键词： Aspirin Edaravone Cerebral infarction Efficacy Quality of life