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An Investigation into the Total Reaction Cross Section and Production Cross Section of Energetic Particles

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Chinese Physics Letters 1993年第8期10卷 464-467页

作者： ma Yugang SHEN Wenqing FENG Jun ma Yuqiang Institute of Nuclear Research Academia SinicaShanghai 201800 Department of Physics Nanjing UniversityNanjing 210008 CCAST(World Laboratory) P.O.Box 8730Beijing 100080

New calculations for the total reaction cross sections and production cross sections of the energetic particles are carried out via the nuclear transport *** ex-perimental total reaction cross sections cann be *** addition,the efects of some ingredients on the total reaction cross sections can be easily *** is found that the total reaction cross sections are sensitive to the nuclear equation of state bclow 100 MeV/u and the in-medium nicleon-ucleon cross section in the full energy range *** the π-mcson production cross sections can be also calculated..

关键词： theory cross addition

Clinical scenarios for the use of S100β as a marker of hepatic encephalopathy

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World Journal of Gastroenterology 2016年第17期22卷 4397-4402页

作者： Andrés Duarte-Rojo Astrid Ruiz-margáin Ricardo u macias-Rodriguez Francisco Javier Cubero José Estradas-Trujillo Rosa ma Munoz-Fuentes Aldo Torre university of Arkansas for Medical Sciences Little Rock AR 72205 United States Department of Gastroenterology Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran Mexico City 14000 Mexico Department of Internal Medicine III University Hospital RWTH Aachen 52074 Aachen Germany Department of Immunology Complutense University School of Medicine 28040 Madrid Spain

AIM: To evaluate the association between serum concentrations of S100β in patients with cirrhosis and the presence of low grade hepatic encephalopathy (HE).METHODS: This was a cross-sectional study. The population was categorized into four groups healthy subjects, cirrhosis without HE, cirrhosis with covert hepatic encephalopathy (CHE) and cirrhosis with overt HE. Kruskal-Wallis, mann Whitney’s u with Bonferroni adjustment Spearman correlations and area under the ROC were used as ***: A total of 61 subjects were included, 46 cirrhotic patients and 15 healthy volunteers. S100β values were different among all groups, and differences remained significant between groups 1 and 2 (P ups 2 and 3 (P = 0.016), but not between groups 3 and 4. In cirrhotic patients with HE S100β was higher than in patients without HE [0.18 (0.14-0.28) ng/mL vs 0.11 (0.06-0.14) ng/mL, P um concentrations of S100β and psychometric hepatic encephalopathy score in patients with cirrhosis without HE compared to the patients with cirrhosis with CHE (r = -0.413, P = 0.019). ROC curve analysis yielded > 0.13 ng/mL as the best cutoff value of S100β for the diagnosis of HE (sensitivity 83.3%, specificity 63.6%).CONCLuSION: Serum concentrations of S100β are higher in patients with cirrhosis than in healthy volunteers, and are further increased in the presence of hepatic encephalopathy. The results suggest that serum biomarkers such as S100β could help in the correct characterization of incipient stages of HE.

关键词： Hepatic encephalopathy S100β protein Astrocyte Psychometric hepatic encephalopathy score Critical flicker frequency

Disturbance Observer-Based Safe Tracking Control for unmanned Helicopters With Partial State Constraints and Disturbances

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IEEE/CAA Journal of Automatica Sinica 2023年第11期10卷 2056-2069页

作者： Haoxiang ma Mou Chen Qingxian Wu College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106 College of Information Engineering Henan University of Science and TechnologyLuoyang 471023China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China IEEE

In this paper, a disturbance observer-based safe tracking control scheme is proposed for a medium-scale unmanned helicopter with rotor flapping dynamics in the presence of partial state constraints and unknown external disturbances. A safety protection algorithm is proposed to keep the constrained states within the given safe-set. A second-order disturbance observer technique is utilized to estimate the external disturbances. It is shown that the desired tracking performance of the controlled unmanned helicopter can be achieved with the application of the backstepping approach, dynamic surface control technique, and Lyapunov method. Finally, the availability of the proposed control scheme has been shown by simulation results.

关键词： Disturbance observer dynamic surface control safe tracking control safety protection algorithm unmanned autonomous helicopter

An Parallel FPGA SAT Solver Based on Multi-Thread and Pipeline

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Chinese Journal of Electronics 2021年第6期30卷 1008-1016页

作者： LI Tiejun ma Kefan ZHANG Jianmin College of Computer National University of Defense Technology

The Boolean Satisfiability(SAT) problem is the key problem in computer theory and application. A parallel multi-thread SAT solver named pprob SAT+ on a configurable hardware is proposed. In the algorithm,multithreads are executed simultaneously to hide the circuit stagnate. In order to improve the working frequency and throughput of the SAT solver, the deep pipeline strategy is adopted. When all data stored in block random access memory of the field programmable gate array, the solver can achieve maximum performance. If partial data are stored in the external memory, the size of the problem instances the SAT solver can be greatly improved. The experimental results show that the speedup of three-thread SAT solver is approximately 2.4 times with single thread,and shows that the pprob SAT+ have achieved substantial improvement while a solution is found.

关键词： field programmable gate arrays configurable hardware parallel multithread SAT solver Boolean satisfiability problem deep pipeline strategy block random access memory random-access storage pprobSAT three-thread SAT solver parallel FPGA SAT solver field programmable gate array computer theory

Wavelet-Based Boundary Element Method for Calculating the Band Structures of Two-Dimensional Phononic Crystals

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Acta Mechanica Solida Sinica 2021年第5期34卷 687-705页

作者： Qi Wei Xingfu ma Jiawei Xiang College of Mechanical and Electrical Engineering Wenzhou UniversityWenzhou325035China

A wavelet-based boundary element method is employed to calculate the band structures of two-dimensional phononic crystals,which are composed of square or triangular lattices with scatterers of arbitrary cross *** the aid of structural periodicity,the boundary integral equations of both the scatterer and the matrix are discretized in a unit *** make the curve boundary compatible,the second-order scaling functions of the B-spline wavelet on the interval are used to approximate the geometric boundaries,while the boundary variables are interpolated by scaling functions of arbitrary *** any given angular frequency,an effective technique is given to yield matrix values related to the boundary ***,combining the periodic boundary conditions and interface conditions,linear eigenvalue equations related to the Bloch wave vector are *** numerical examples illustrate the superior performance of the proposed method by comparing with the conventional BEM.

关键词： Wavelet-based boundary element method B-spline wavelet on the interval Phononic crystal Band structure

Mode transition from adsorption removal to bombardment removal induced by nanoparticle-surface collisions in fluid jet polishing

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Friction 2021年第5期9卷 1127-1137页

作者： Xuechu ZHAO Liran ma Xuefeng Xu School of Technology Beijing Forestry UniversityBeijing 100083China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

The effects of impacting particles from a jet of liquid on the removal of a surface material(on the impacted workpiece)were *** observations show that the cross section of the material removed changed fromʹWʹ‐shaped toʹuʹ‐shaped as the size of abrasive particles was *** between removed material profiles and particle collision distributions indicate that the particle-surface collisions are the main reason for the material *** deduced number of atoms removed by a single collision implies that a transition occurs in the removal *** nanoscale particles,the polished surface is likely to be removed in an atom‐by‐atom manner,possibly due to the chemisorption of the impacting particles on the impacted ***,for the case of microscale particles,bulk material removal produced by particle bombardment is more likely to *** present mechanism of material removal for particle-surface collisions is further corroborated experimentally.

关键词： ultra‐smooth surface fluid jet polishing nanoparticle-surface collision material removal

Sintering behavior and thermal conductivity of Y_(2)O_(3) fully stabilized HfO_(2) ceramics

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Rare Metals 2021年第5期40卷 1255-1266页

作者： Chun Li Jian He Yue ma School of materials Science and Engineering Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBeijing 100191China Key Laboratory of High-Temperature Structural materials and Coatings Technology(Ministry of Industry and Information Technology) Beihang UniversityBeijing 100191China

A series of Y_(2)O_(3) fully stabilized HfO2 ceramics(Hf_(1-x)Y_(x)O_(2-0.5x),x=0.20,0.24,0.28,0.32,0.36 and 0.40)were synthesized by solid-state reaction at 1500℃.The phase composition,thermal conductivity and sintering behavior at 1400℃ of the ceramic bulks were *** Hf_(1-x)Y_(x)O_(2-0.5x) ceramics were comprised of pure cubic phase with disordered fluorite *** phase transformation occurred in the ceramics with Y3+doping concentration ranging from 0.24 to *** Hf_(0.64)Y_(0.36)O_(1.82) and Hf_(0.6)Y_(0.4)O_(1.8) samples revealed the lowest grain growth rate when sintered at 1400℃,indicating good resistance to ***,the Vicker’s hardness and Young’s modulus after annealed for 96 h at 1400℃ for the Hf_(0.64)Y_(0.36)O_(1.82) sample were 8.97 and 200 GPa,respectively,much lower than those of the Hf_(0.6)Y_(0.4)O_(1.8)(14.51 and 237 GPa,respectively).The thermal conductivity of Hf_(1-x)Y_(x)O_(2-0.5x) first decreased and then increased slowly as the Y3+content increased,and the associated mechanism was discussed.

关键词： Yttria fully stabilized hafnia Sintering Mechanical properties Thermal conductivity

Group-Consensus of Hierarchical Containment Control for Linear Multi-Agent Systems

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IEEE/CAA Journal of Automatica Sinica 2023年第6期10卷 1462-1474页

作者： Jingshu Sang Dazhong ma Yu Zhou the College of Information Science and Engineering Northeastern UniversityShenyang 110004China

The existing containment control has been widely developed for several years, but ignores the case for large-scale cooperation. The strong coupling of large-scale networks will increase the costs of system detection and maintenance. Therefore, this paper is concerned with an extensional containment control issue, hierarchical containment control. It aims to enable a multitude of followers achieving a novel cooperation in the convex hull shaped by multiple leaders. Firstly, by constructing the three-layer topology, large-scale networks are decoupled. Then,under the condition of directed spanning group-tree, a class of dynamic hierarchical containment control protocol is designed such that the novel group-consensus behavior in the convex hull can be realized. Moreover, the definitions of coupling strength coefficients and the group-consensus parameter in the proposed dynamic hierarchical control protocol enhance the adjustability of systems. Compared with the existing containment control strategy, the proposed hierarchical containment control strategy improves dynamic control performance. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed hierarchical control protocol.

关键词： Group-consensus behavior hierarchical containment control linear multi-agent systems three-layer topology

Towards storable and durable Zn-MnO_(2) batteries with hydrous tetraglyme electrolyte

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Journal of Energy Chemistry 2023年第5期80卷 432-441,I0010页

作者： Kaixuan ma Gongzheng Yang Chengxin Wang State Key Laboratory of Optoelectronic materials and Technologies School of Materials Science and EngineeringSun Yat-sen(Zhongshan)UniversityGuangzhou 510275GuangdongChina

Aqueous rechargeable zinc-based batteries have attracted increasing interest and been considered potential alternatives for state-of-the-art lithium-ion batteries because of the low cost and high *** cathode materials have been gradually developed and demonstrated excellent electrochemical ***,the complex electrochemistry,inevitable hydrogen release,and zinc corrosion severely hinder the practical *** most concerned Zn-MnO_(2)batteries still suffer from the Mn dissolution and formation of *** adding organic solvents to inhibit the activity of water molecules,the hydrous organic electrolytes provide a sound solution for eliminating the unfavorable *** we report a tetraethylene glycol dimethyl ether-based hydrous organic electrolyte consisting of LiClO_(4)·3H_(2)O and Zn(ClO4)2·6H2O,and a birnessite-type MnO_(2)cathode material for Zn-MnO_(2)*** Li+/Zn2+ions co-(de)insertion mechanism is ascertained by the structural and morphological *** electrostatic interaction between inserted ions and crystal structure is reduced effectively by employment of monovalent Li+ions,which ensures structural stability of cathode *** tetraglyme electrolyte inhibits the activity of water molecules and thus avoids the formation of byproduct Zn_(4)ClO_(4)(OH)7·Meanwhile,highly stable Zn plating/stripping for over 1500 h,an average coulombic efficiency of>99%in long-term cycling,and ultralong storage life(the cells can work well after stored over 1 year)are simultaneously realized in the novel *** from these aspects,the Zn-MnO_(2)batteries manifest high specific capacity of 132 ma h g^(-1),an operating voltage of 1.25 V,and a capacity retention of>98%after 1000 cycles at a current density of 200 ma g^(-1).

关键词： Energy storage Zn battery δ-MnO_(2) Hydrous tetraglyme electrolytes Long life