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A statistical study towards high-mass BGPS clumps with the MALT90 survey

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Research in Astronomy and Astrophysics 2018年第1期18卷 31-58页

作者： Xiao-Lan Liu Jin-Long Xu chang-chun ning Chuan-Peng Zhang Xiao-Tao Liu National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China NAOC-TU Joint Center for Astrophysics Lhasa 850000 China Tibet University Lhasa 850000 China Department of Finance Central China Normal University Wuhan 430079 China

In this work,we perform a statistical investigation towards 50 high-mass clumps using data from the Bolocam Galactic Plane Survey（BGPS）and Millimetre Astronomy Legacy Team 90-GHz survey（MALT90）.Eleven dense molecular lines（N2H^＋（1–0）,HNC（1–0）,HCO^＋（1–0）,HCN（1–0）,HN^（13）C（1–0）,H^（13）CO^＋（1–0）,C2H（1–0）,HC3N（10–9）,SiO（2–1）,^（13）CS（2–1）and HNCO（4（4,0）-3（0,3）））are detected.N2H^＋ and HNC are shown to be good tracers for clumps in various evolutionary stages since they are detected in all the *** detection rates of N-bearing molecules decrease as the clumps evolve,but those of O-bearing species increase with ***,the abundance ratios[N2H^＋]/[HCO^＋]and log（[HC3N]/[HCO^＋]）decline with log（[HCO^＋]）as two linear functions,*** suggests that N^＋2H^＋ and HC3N transform to HCOas the clumps *** also find that C2H is the most abundant molecule with an order of magnitude 10^（-8）.In addition,three new infall candidates,G010.214–00.324,G011.121–00.128 and G012.215–00.118（a）,are discovered to have large-scale infall motions and infall rates with an order of magnitude 10^（-3）M⊙yr^（-1）.

关键词： stars:formation ISM:abundance ISM:molecules radio lines:ISM ISM:kinematics and dynamics

Effect of Mn content on microstructure and properties of AlCrCuFeMnx high-entropy alloy

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China Foundry 2024年第2期21卷 147-158页

作者： ning Wang Kai Ma Qiu-da Li Yu-dong Yuan Yan-chun Zhao Li Feng School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Advanced Processing and Reuse of Nonferrous Metals Lanzhou 730050China CNNC Nuclear Power Operation and Management Co. Ltd.Haiyan 314300ZhejiangChina

AlCrCuFeMnx(x=0,0.5,1,1.5,and 2)high-entropy alloys were prepared using the vacuum arc melting *** microstructure and mechanical properties of AlCrCuFeMnxwere analyzed and tested by XRD,SEM,TEM,nanoindentation,and electronic universal *** results indicate that the AlCrCuFeMnxhigh-entropy alloy exhibits a dendritic structure,consisting of dendrites with a BCC structure,interdendrite regions with an FCC structure,and precipitates with an ordered BCC structure that form within the ***(Mn)has a strong affinity for dendritic,interdendritic,and precipitate structures,allowing it to easily enter these *** an increase in Mn content,the size of the precipitated nanoparticles in the dendritic region initially increases and then ***,the area fraction initially decreases and then ***,the alloy’s strength and wear resistance decrease,while its plasticity *** Al Cr Cu Fe Mn1.5alloy boasts excellent mechanical properties,including a hardness of 360 HV and a wear rate of 2.4×10^(-5)mm^(3)·N^(-1)·mm^(-1).It also exhibits impressive yield strength,compressive strength,and deformation rates of 960 MPa,1,700 MPa,and 27.5%,respectively.

关键词： high-entropy alloys microstructure mechanical properties wear resistance strengthening mechanisms

A Novel Clutter Suppression Algorithm for Low-Slow-Small Targets Detecting Based on Sparse Adaptive Filtering

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Journal of Beijing Institute of Technology 2024年第1期33卷 54-64页

作者： Zeqi Yang Shuai Ma ning Liu Kai chang Xiaode Lyu Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China National Key Laboratory of Microwave Imaging Technology Beijing 100190China School of Electronic Electrical and Communication Engineering University of Chinese Academy of SciencesBeijing 100049China Northern Institute of Electronic Equipment Beijing 100083China

Passive detection of low-slow-small(LSS)targets is easily interfered by direct signal and multipath clutter,and the traditional clutter suppression method has the contradiction between step size and convergence *** this paper,a frequency domain clutter suppression algorithm based on sparse adaptive filtering is *** pulse compression operation between the error signal and the input reference signal is added to the cost function as a sparsity constraint,and the criterion for filter weight updating is improved to obtain a purer echo *** the same time,the step size and penalty factor are brought into the adaptive iteration process,and the input data is used to drive the adaptive changes of parameters such as step *** proposed algorithm has a small amount of calculation,which improves the robustness to parameters such as step size,reduces the weight error of the filter and has a good clutter suppression performance.

关键词： passive radar interference suppression sparse representation adaptive filtering

Electrocatalytic CO_(2)reduction to syngas

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Green Energy & Environment 2024年第7期9卷 1085-1100页

作者： Bing chang Zhaojun Min ning Liu Nan Wang Maohong Fan Jing Fan Jianji Wang School of Environment Key Laboratory of Yellow River and Huai River Water Environment and Pollution ControlMinistry of EducationHenan Normal UniversityXinxiangHenan453007China School of Chemistry and Chemical Engineering Key Laboratory of Green Chemical Media and ReactionsMinistry of EducationHenan Normal UniversityXinxiangHenan453007China College of Engineering and Physical Sciences and School of Energy ResourcesUniversity of WyomingLaramieWY82071USA College of Engineering Georgia Institute of TechnologyAtlantaGA30332USA

While carbon dioxide(CO_(2))is a major greenhouse gas,it is also an important C1 *** the trend of energy conservation and emission reduction,electrocatalytic reduction has become a very promising strategy for CO_(2)utilization because it can convert CO_(2)directly to high-valued chemicals and fuels under mild *** particular,the product CO and by-product H_(2)can be combined into syngas by an electrocatalytic CO_(2)reduction reaction(CO_(2)RR)in an aqueous *** molar ratios of CO and H_(2)may be used to produce essential bulk chemicals or liquid fuels such as methanol,alkanes,and olefins through thermochemical catalysis,Fischer-Tropsch synthesis,microbial fermentation,and other *** work discusses the latest strategies in controlling the molar ratio of CO/H_(2)and improving the yield of CO_(2)*** challenges of electrocatalytic syngas production are analyzed from an industrial application perspective,and the possible measures to overcome them are proposed in terms of new catalyst design,electrolyte innovation,flow reactor optimization,anodic reaction coupling,and operando technique application.

关键词： Electrocatalysis CO_(2)reduction Syngas Electrolyte Electrolyzer

Adverse effect of niobium and boron on hot deformation behavior of sulfur-containing steel

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Journal of Iron and Steel Research International 2024年第1期31卷 252-263页

作者： Guo-ning He Shi-qi Wan Bo Jiang Chao-lei Zhang Ya-zheng Liu chun-jing Wu School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing100083China

The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were *** compression and tenssion tests were carried out by Gleeble3800 at the austenite region from 850 to 1150℃and the adverse effects of Nb and B were analyzed by the fracture,microstructure and precipitate *** compression tests showed that the proportions of instable area in hot processing maps of 0.021%Nb and Nb-B steels were higher and the deformability of Nb free steel was *** tensile deformation experiments showed that the reduction areas of Nb free,0.021%Nb and Nb-B steels were 92%-99%,84%-98%and 67%-97%,*** addition of Nb or Nb and B inhibited the dynamic recrystallization during hot deformation,and consequently,more deformed grains were then formed in 0.021%Nb and Nb-B steels thus to obtain the microstructure with worse uniformity and then deteriorate the *** addition,the interaction between inclusions and microalloyed elements was also *** particles of 0.021%Nb and Nb-B steels dynamically precipitated during deformation and precipitated together with MnS thus to worsen the deformability,resulting in the decrease of reduction area.

关键词： Hot deformation Gear steel Processing map Dynamic recrystallization Microalloying

Copper-Free Click Chemistry-Mediated Assembly of Single Quantum Dot Nanosensor for Accurately Monitoring Locus-Specific m^(6)A in Cancer Cells

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Chinese Journal of Chemistry 2024年第5期42卷 499-504页

作者： Yue-Ying Li ning-ning Zhao Yi-Xuan Geng Qian Han Jian-Ge Qiu Bing-Hua Jiang Zi-Yue Wang chun-Yang Zhang Translational Medicine Center The First Affiliated Hospital of Zhengzhou UniversityThe Academy of Medical SciencesHenan Institute of Medical and Pharmaceutical Sciences BGI CollegeZhengzhou UniversityZhengzhouHenan450052 China College of Chemistry Chemical Engineering and Materials ScienceShandong Normal UniversityJinanShandong250014 China School of Chemistry and Chemical Engineering Southeast UniversityNanjingJiangsu211189 China

N6-methyladenosine(m^(6)A)plays an important role in embryogenesis,nuclear export,transcription splicing,and protein translation ***,we demonstrate a copper-free click chemistry-mediated assembly of single quantum dot(QD)nanosensor for accurately monitoring locus-specific m^(6)A in cancer *** m^(6)A-sensitive endoribonuclease MazF can digest the unmethylated A-RNA,and the intact m^(6)A-RNA then hybridizes with DNA probes a and b to produce a sandwich hybrid,initiating the click chemistry to generate probe a–b ligation product via first tandem ligation detection reaction(LDR)***,DNA probes c and d can hybridize with the probe a–b ligation product to generate the probe c–d ligation product via second LDR *** LDR cycles can be repeated through denaturation and annealing reaction to generate abundant biotin-/fluorophore-modified probe c–d ligation products that can easily assemble on the QD surface to induce distinct fluorescence resonance energy transfer(FRET)between QD and *** assay can be homogenously performed without the involvement of copper catalyst,m^(6)A-specific antibody,radioactive labeling,ligase enzyme,enzymatic reverse transcription,and next-generation ***,it can discriminate even 0.01% m^(6)A level in complex samples and accurately measure cellular m^(6)A-RNA expression,providing a promising avenue for clinical diagnostics and biomedical research.

关键词： RNA methylation Click chemistry Förster resonance energy transfer Biosensor Cancer

Aerodynamic Features of High-Speed Maglev Trains with Different Marshaling Lengths Running on a Viaduct under Crosswinds

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 975-996页

作者： Zun-Di Huang Zhen-Bin Zhou ning chang Zheng-Wei Chen Su-Mei Wang School of Rail Transportation Wuyi UniversityJiangmen529020China National Rail Transit Electrification and Automation Engineering Technology Research Center(Hong Kong Branch) The Hong Kong Polytechnic UniversityHong Kong999077China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong Kong999077China

The safety and stability of high-speed maglev trains traveling on viaducts in crosswinds critically depend on their aerodynamic ***,this paper uses an improved delayed detached eddy simulation(IDDES)method to investigate the aerodynamic features of high-speed maglev trains with different marshaling lengths under *** effects of marshaling lengths(varying from 3-car to 8-car groups)on the train’s aerodynamic performance,surface pressure,and the flow field surrounding the train were investigated using the three-dimensional unsteady compressible Navier-Stokes(N-S)*** results showed that the marshaling lengths had minimal influence on the aerodynamic performance of the head and middle ***,the marshaling lengths are negatively correlated with the time-average side force coefficient(CS)and time-average lift force coefficient(Cl)of the tail *** to the tail car of the 3-car groups,the CS and Cl fell by 27.77%and 18.29%,respectively,for the tail car of the 8-car *** is essential to pay more attention to the operational safety of the head car,as it exhibits the highest time average ***,the mean pressure difference between the two sides of the tail car body increased with the marshaling lengths,and the side force direction on the tail car was opposite to that of the head and middle ***,the turbulent kinetic energy of the wake structure on the windward side quickly decreased as marshaling lengths increased.

关键词： High-speed maglev train marshaling lengths crosswinds aerodynamic features

Alternative relay regulates the adenosine triphosphatase activity of Locusta migratoria striated muscle myosin

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Insect Science 2024年第2期31卷 435-447页

作者： Jie Hao chang Liu ning Zhang Jing Li Tong Ni Mingbo Qu Xiang-dong Li State Key Laboratory oflntegrated Management of lnsect Pests and Rodents Insttute of ZoologyChinese Academy of SciencesBejingChina University of Chinese Academy of Sciences BejingChina School of Bioengeering Dalian University of TechnologyDalianChina

Locust(Locusta migratoria)has a single striated muscle myosin heavy chain(Mhc)gene,which contains 5 clusters of alternative exclusive exons and 1 differently included penultimate *** alternative exons of Mhc gene encode 4 distinct regions in the myosin motor domain,that is,the N-terminal SH3-like domain,one lip of the nucleotide-binding pocket,the relay,and the ***,we investigated the role of the alternative regions on the motor function of locust muscle *** Sf9-baculovirus protein expression system,we expressed and purified 5 isoforms of the locust muscle myosin heavy meromyosin(HMM),including the major isoform in the thorax dorsal longitudinal flight muscle(FL1)and 4 isoforms expressed in the abdominal intersegmental muscle(AB1 to AB4).Among these 5 HMMs,FL1-HMM displayed the highest level of actin-activated adenosine triphosphatase(ATPase)activity(hereafter referred as ATPase activity).To identify the alternative region(s)responsible for the elevated ATPase activity of FL1-HMM,we produced a number of chimeras of FL1-HMM and *** with the relay of AB4-HMM(encoded by exon-14c)substantially decreased the ATPase activity of FL1-HMM,and conversely,the relay of FL1-HMM(encoded by exon-14a)enhanced the ATPase activity of *** showed that the exon-14a-encoded residues Gly474 and Asn509 are responsible for the elevated ATPase activity of *** results indicate that the alternative relay encoded by exon-14a/c play a key role in regulating the ATPase activity of FL1-HMM and AB4-HMM.

关键词： alternative splicing ATPase Locusta migratoria molecular motor muscle myosin

Risk assessment of oil and gas investment environment in countries along the Belt and Road Initiative

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Petroleum Science 2024年第2期21卷 1429-1443页

作者： Bao-Jun Tang chang-Jing Ji Yu-Xian Zheng Kang-ning Liu Yi-Fei Ma Jun-Yu Chen Center for Energy and Environmental Policy Research Beijing Institute of TechnologyBeijing100081China School of Management and Economics Beijing Institute of TechnologyBeijing100081China Collaborative Innovation Center of Electric Vehicles in Beijing BeijingChina Sustainable Development Research Institute for Economy and Society of Beijing BeijingChina Institute of Carbon Neutrality ShanghaiTech UniversityShanghai201210China

With the implementation of the Belt and Road Initiative, China is deepening its cooperation in oil and gas resources with countries along the Initiative. In order to better mitigate risks and enhance the safety of investments, it is of significant importance to research the oil and gas investment environment in these countries for China's overseas investment macro-layout. This paper proposes an indicator system including 27 indicators from 6 dimensions. On this basis, game theory models combined with global entropy method and analytic hierarchy process are applied to determine the combined weights, and the TOPSIS-GRA model is utilized to assess the risks of oil and gas investment in 76 countries along the Initiative from 2014 to 2021. Finally, the GM(1,1) model is employed to predict risk values for 2022-2025. In conclusion, oil and gas resources and political factors have the greatest impact on investment environment risk, and 12 countries with greater investment potential are selected through cluster analysis in conjunction with the predicted results. The research findings may provide scientific decisionmaking recommendations for the Chinese government and oil enterprises to strengthen oil and gas investment cooperation with countries along the Belt and Road Initiative.

关键词： Belt and Road Initiative Oil and Gas Investment Risk assessment