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Cause analysis of expressway traffic accidents based on accident statistics of Hunan provincial expressway in 2012-2018

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Transportation Safety and Environment 2024年第1期6卷 83-92页

作者： Xinyu Liu Shengjun Huang qun chen Business school Foshan UniversityFoshan 528225GuangdongChina School of Traffic and Transportation Engineering Central South UniversityChangsha 410075HunanChina Hunan Provincial Expressway Traffic Police Station Law Enforcement DepartmentChangsha 410007HunanChina

Based on the 2012–2018 accident statistics on the Hunan Provincial Expressway in China,this paper analyses the proportion to which various factors contribute to accidents,as well as the trends over *** 2012 to 2018,the total number of general procedure handling accidents(*** accidents)increased first and then decreased,while the number of accidents and deaths per 1000 kilometres decreased year by *** total number of simple procedure handling accidents(*** accidents)increased year by year,but the number of accidents per 1000 kilometres remained relatively ***,fatigued driving,improper driving operation,failure to maintain a safe distance from the preceding vehicle and pedestrians entering the expressway are the main causes of general procedure handling *** to maintain a safe distance from the preceding vehicle as required and improper driving operation accounted for approximately 2/3 of the simple procedure handling *** view of the accidents caused by these factors,how to use law enforcement,education,science and technology and facilities construction to further reduce the occurrence of expressway traffic accidents is discussed.

关键词： expressway traffic accident cause analysis

A Comprehensive Study of a Low-Grade Heat-Driven Cooling and Power System Based on Heat Current Method

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Journal of Thermal Science 2024年第4期33卷 1523-1541页

作者： ZHAO Tian XU Ronghong XIN Yonglin HE Kelun MA Huan YUAN Mengdi chen qun School of Energy Storage Science and Engineering North China University of TechnologyBeijing100144China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing100084China

Combined cooling and power(CCP)system driven by low-grade heat is promising for improving energy *** work proposes a CCP system that integrates a regenerative organic Rankine cycle(RORC)and an absorption chiller on both driving and cooling fluid *** system is modeled by using the heat current method to fully consider nonlinear heat transfer and heat-work conversion constraints and resolve its behavior *** off-design system simulation is performed next,showing that the fluid inlet temperatures and flow rates of cooling water as well as RORC working fluid strongly affect system *** off-design operation even becomes infeasible when parameters deviate from nominal values largely due to limited heat transfer capability of components,highlighting the importance of considering heat transfer constraints via heat current *** optimization aiming to minimize the total thermal conductance is also *** efficiency increases by 7.9%and decreases by 12.4%after optimization,with the hot fluid inlet temperature increase from 373.15 to 403.15 K and mass flow rate ranges from 10 to 30 kg/s,emphasizing the necessity of balancing system cost and performance.

关键词： combined cooling and power system organic Rankine cycle absorption chiller cascade heat utilization heat current method off-design analysis

Combined Effect of Temperature and Cadmium on Molecular Responses of Hsp70 and P-gp Genes in Crassostrea gigas

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Journal of Ocean University of China 2024年第4期23卷 1115-1120页

作者： HU Fanguang SUN Ming LIU Guangbin JING Yuanyuan chen qun ZHANG Tianwen Marine Science Research Institute of Shandong Province Qingdao 266104China

To evaluate the combined effect of temperature and cadmium on the molecular responses of heat shock protein 70(hsp70)and P-glycoprotein(P-gp)in mantle,digestive gland and gills of Crassostrea gigas,oysters were exposed to combinations of five temperature levels(10,15,20,25,and 30℃)and 10μg L^(-1)cadmium for 21 *** were sampled for mRNA quantification by qPCR,and the results showed that the P-gp gene expression changed significantly after treatment at different temperatures and different treatment *** P-gp gene expression was the highest in the digestive *** with the control group,the P-gp gene expression in cadmium treatment groups at all the different temperatures were significantly higher than the control *** control oysters(kept at 10℃during the whole experiment without cadmium)expressed low levels of hsp70,but the groups treated with cadmium displayed somewhat higher *** present study demonstrated hsp70 and P-gp played an important role in the detoxification of Cd in ***,and confirmed temperature should be considered for the assessment of Cd-induced toxicity in oysters.

关键词： temperature cadmium P-gp hsp70 Crassostrea gigas

Centroid Hom-associative Algebras and Centroid Hom-Lie Algebras

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Acta Mathematica Sinica,English Series 2024年第4期40卷 935-961页

作者： Yu Xiu BAI Leonid A.BOKUT Yu qun chen Ze Rui ZHANG Department of Mathematics Teaching Guangzhou Civil Aviation CollegeGuangzhou 510403P.R.China Sobolev Institute of Mathematics Novosibirsk 630090Russia Novosibirsk State University Novosibirsk 630090Russia School of Mathematical Sciences South China Normal UniversityGuangzhou 510631P.R.China

In this article,we construct free centroid hom-associative algebras and free centroid hom-Lie *** also construct some other relatively free centroid hom-associative algebras by applying the Gr?bner-Shirshov basis theory for(unital)centroid hom-associative ***,we prove that the"Poincaré-Birkhoff-Witt theorem"holds for certain type of centroid hom-Lie algebras over a field of characteristic 0,namely,every centroid hom-Lie algebra such that the eigenvectors of the mapβlinearly generates the whole algebra can be embedded into its universal enveloping centroid hom-associative algebra,and the linear basis of the universal enveloping algebra does not depend on the multiplication table of the centroid hom-Lie algebra under consideration.

关键词： Centroid hom-Lie algebra centroid hom-associative algebra Gr?bner-Shirshov basis

Dirac-geodesics with curvature term

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Science China Mathematics 2024年

作者： qun chen Mingwei Zhang School of Mathematics and Statistics Wuhan University

Dirac-geodesics with curvature term are Dirac-harmonic maps with curvature term from onedimensional domains. In this paper, we first describe the structure of Dirac-geodesics with curvature term in surfaces and give solutions on the unit 2-sphere and the hyperbolic plane, and then we give the structure of solutions in warped product spaces. Finally, we define the heat flow of Dirac-geodesics with curvature term and prove the global existence and sub-convergence of the heat flow into any closed surfaces and space forms. Our results provide the first examples and general existence theorems of Dirac-geodesics with curvature term.

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Retinitis pigmentosa and stem cell therapy

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International Journal of Ophthalmology(English edition) 2024年第7期17卷 1363-1369页

作者： Xin-Ya Qi chen-Hui Mi De-Rui Cao Xie-qun chen Peng Zhang School of Medicine Department of Life Sciences and MedicineNorthwest UniversityXi’an 710069Shaanxi ProvinceChina The Third Hospital of Xi’an Affiliated Hospital of Northwest UniversityXi’an 710021Shaanxi ProvinceChina

Retinitis pigmentosa(RP)is a group of genetic disorders characterized by progressive degeneration of photoreceptors and retinal pigment epithelium(RPE)*** main clinical manifestations include night blindness and progressive loss of peripheral vision,making it a prevalent debilitating eye disease that significantly impacts patients’quality of *** exhibits significant phenotypic and genetic *** instance,numerous abnormal genes are implicated in RP,resulting in varying clinical presentations,disease progression rates,and pathological characteristics among different ***,gene therapy for RP poses challenges due to these ***,stem cells have garnered considerable attention in the field of RPE therapy since both RPE cells and photoreceptors can be derived from stem *** recent years,a large number of animal experiments and clinical trials based on stem cell transplantation attempts,especially cord blood mesenchymal stem cell(MSC)transplantation and bone marrow-derived MSC transplantation,have confirmed that stem cell therapy can effectively and safely improve the outer retinal function of the RP-affected ***,stem cell therapy also has certain limitations,such as the fact that RP patients may involve multiple types of retinal cytopathia,which brings great challenges to stem cell transplantation therapy,and further research is needed to solve various problems faced by this approach in the *** comprehensive analysis of the etiology and histopathological changes associated with RP,this study substantiates the efficacy and safety of stem cell therapy based on rigorous animal experimentation and clinical trials,while also highlighting the existing limitations that warrant further investigation.

关键词： retinitis pigmentosa photoreceptor stem cell therapy

Integrated Stratigraphy and Mineralogy of the Doushantuo Formation in Weng’an,South China,and Implications for Ediacaran Phosphogenesis

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Journal of Earth Science 2024年第2期35卷 476-503页

作者： Liangxuan Jiao Zhenbing She Dominic Papineau Yaguan Zhang Matthew S.Dodd Kenan Cao qun chen Guoyong chen State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan430078China School of Earth Sciences China University of GeosciencesWuhan430047China London Centre for Nanotechnology University College London17-19 Gordon StreetLondonWC1E 6BTUK Department of Earth Sciences University College LondonLondonWC1E 6BTUK Centre for Planetary Science University College London and Birkbeck CollegeLondonWC1E 7HXUK Innovation Center of Ore Resources Exploration Technology in the Region of Bedrock Ministry of Natural Resources of People’s Republic of China’Guiyang550000China Guizhou Bureau of Geology and Mineral Exploration and Development Guiyang550000China

The Ediacaran–Cambrian Phosphogenic Episode is the Earth’s first true phosphogenic event and resulted in worldwide phosphate deposits,which occurred during the processes of the Neoproterozoic Oxygenation *** Ediacaran Doushantuo Formation(ca.635–551 Ma)of Weng’an area in central Guizhou,South China,contains two economic phosphorite beds(the Lower and Upper Phosphorite Beds).This paper presents a detailed stratigraphic,sedimentological and mineralogical study of multiple outcrop and drill core sections of the Doushantuo Formation across the Weng’an area,and identified 11 lithofacies and 4 types of phosphatic *** differences in lithofacies and grain types between the upper and lower phosphate deposits are observed,indicating that the two sets of phosphate deposits are the products of two distinct phosphogenic *** Lower Phosphorite Bed mainly consists of banded and laminated phosphorites,contains micro-oncoids formed by microbially-mediated precipitation and peloids formed by in-situ chemically oscillating reactions,indicating a biochemical and chemical enrichment of phosphorus to sediments during the Early Ediacaran *** Upper Phosphorite Bed is mainly composed of carbonaceous,massive,and stromatolitic phosphorites,contains bioclasts(phosphatized spheroidal fossils),and intraclasts formed by hydrodynamic agitation,suggesting that the major accesses of phosphorus to sediments were the remineralization of organic *** of the two economic phosphorite beds was controlled by two sea-level *** differences have also been documented in contemporaneous phosphate-bearing successions in Brazil and Mangolia,indicating a significant shift in global phosphogenic mechanism during the early and middle Ediacaran,which may be due to the changes in redox conditions in seawater,associated with the Neoproterozoic Oxygenation *** regional active P-cycle processes could produce more free oxygen,which may have contributed to the up

关键词： phosphorite lithofacies phosphatic grains phosphogenic paragenesis phosphorus cycle mineralogy

Catalytic asymmetric(3+3)cycloaddition between different 2-indolylmethanols

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Science China Chemistry 2024年第8期67卷 2629-2636页

作者： Tianzhen Li Sijia Liu Shufang Wu Qi cheng qun chen Yinchun Jiao Yuchen Zhang Feng Shi School of Petrochemical Engineering School of Materials ScienceEngineeringChangzhou UniversityChangzhou 213164China Research Center of Chiral Functional Heterocycles School of Chemistry and Materials ScienceJiangsu Normal UniversityXuzhou 221116China School of Chemistry and Chemical Engineering Hunan University of Science and TechnologyXiangtan 411201China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007China

The catalytic asymmetric(3+3)cycloaddition between different 2-indolylmethanols has been established,in which a series of chiral indole-fused six-membered heterocycles were constructed in high yields with excellent *** work not only has established the first catalytic asymmetric cycloaddition between different 2-indolylmethanols but also provided a powerful strategy for constructing enantioenriched indole-fused six-membered ***,biological evaluation discovered some products with promising antitumor ***,theoretical calculations performed on the reaction pathway and activation mode provide an in-depth understanding of this catalytic asymmetric(3+3)cycloaddition among different 2-indolylmethanols,which will advance the understanding of the chemistry of indolylmethanols.

关键词： asymmetric organocatalysis chiral phosphoric acid cycloaddition enantioselectivity 2-indolylmethanol

Structural transition,electric transport,and electronic structures in the compressed trilayer nickelate La_(4)Ni_(3)O_(10)

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 9-15页

作者： Jingyuan Li Cui-qun chen Chaoxin Huang Yifeng Han Mengwu Huo Xing Huang Peiyue Ma Zhengyang Qiu Junfeng chen Xunwu Hu Lan chen Tao Xie Bing Shen Hualei Sun Dao-Xin Yao Meng Wang Center for Neutron Science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesSchool of PhysicsSun Yat-sen UniversityGuangzhou 510275China Center for Materials of the Universe School of Molecular SciencesArizona State UniversityTempe 85287USA School of Sciences Sun Yat-sen UniversityShenzhen 518107China

Atomic structure and electronic band structure are fundamental properties for understanding the mechanism of superconductivity. Motivated by the discovery of pressure-induced high-temperature superconductivity at 80 K in the bilayer Ruddlesden-Popper nickelate La_(3)Ni_(2)O_(7), the atomic structure and electronic band structure of the trilayer nickelate La_(4)Ni_(3)O_(10) under pressure up to 44.3 GPa are investigated. A structural transition from the monoclinic P2_(1)/a space group to the tetragonal I4/mmm around 12.6-13.4 GPa is identified, accompanied by a drop of resistance below 7 K. Density functional theory calculations suggest that the bonding state of Ni 3d_(z^(2)) orbital rises and crosses the Fermi level at high pressures, which may give rise to possible superconductivity observed in resistance under pressure in La_(4)Ni_(3)O_(10). The trilayer nickelate La_(4)Ni_(3)O_(10) shows some similarities with the bilayer La_(3)Ni_(2)O_(7) and has unique properties, providing a new platform to investigate the underlying mechanism of superconductivity in nickelates.

关键词： La_(4)Ni_(3)O_(10) high pressure synchrotron X-ray diffraction structural transition DFT calculations