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Acta Metallurgica Sinica(English Letters) 2021年第8期34卷 1029-1041页

作者： Shuai Zhang bao-chang liu Mei-Xuan Li Hui-Yuan Wang Yin-Long Ma Key Laboratory of Drilling and Exploitation Technology in Complex Conditions of Ministry of Land and Resources College of Construction EngineeringJilin UniversityNo.938 Ximinzhu StreetChangchun 130026China Key Laboratory of Automobile Materials of Ministry of Education School of Materials Science and EngineeringJilin UniversityNanling CampusNo.5988 Renmin StreetChangchun 130025China

The effect of textures on different surfaces of an as-extruded Mg-4 Al-1 Sn-1 Zn(ATZ411) alloy sheet on its corrosion behavior was systematically investigated. The microstructure was examined by optical/scanning electron microscopy. The texture was characterized by X-ray diffraction and electron backscatter diffraction. The corrosion performance was evaluated by immersion tests, electrochemical measurements, and corrosion morphology observation. The results showed that there were obvious differences in the corrosion morphology and corrosion resistance on different surfaces. The surface perpendicular to extrusion direction had better corrosion resistance and more uniform corrosion damage than that perpendicular to the normal direction and that perpendicular to the transverse direction in 3.5 wt% NaCl solution. The corrosion morphology was mainly determined by the distribution of the second phase and fine-grained regions. The corrosion rate was more related to the overall texture.

关键词： Corrosion behavior Micro-galvanic Magnesium alloys Texture Extrusion

Using Energy Conditions to Distinguish Brane Models and Study Brane Matter

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Communications in Theoretical Physics 2008年第8期50卷 383-386页

作者： PING Yong-Li XU Li-Xin chang bao-Rong liu Hong-Ya School of Physics and Optoelectronic Technology Dalian University of Technology Dalian 116024 China

Current universe （assumed here to be normal matter on the brahe） is pressureless from observations. In this case the energy condition is po ≥ 0 and po =O. By using this condition, brahe models can be distinguished. Then, assuming arbitrary component of matter in DGP model, we use four known energy conditions to study the matter on the brahe. If there is nonnormal matter or energy （for example dark energy with w 〈-1/3） on the brane, the universe is accelerated.

关键词： brane universe cosmology energy conditions

An Online Q-Learning Method for Linear-Quadratic Nonzero-Sum Stochastic Differential Games with Completely Unknown Dynamics

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Journal of Systems Science & Complexity 2024年第5期37卷 1907-1922页

作者： ZHANG bao-Qiang WANG Bing-chang CAO Ying School of Control Science and Engineering Shandong University

In this paper, the authors design a reinforcement learning algorithm to solve the adaptive linear-quadratic stochastic n-players non-zero sum differential game with completely unknown dynamics. For each player, a critic network is used to estimate the Q-function, and an actor network is used to estimate the control input. A model-free online Q-learning algorithm is obtained for solving this kind of problems. It is proved that under some mild conditions the system state and weight estimation errors can be uniformly ultimately bounded. A simulation with five players is given to verify the effectiveness of the algorithm.

关键词： Actor-critic algorithm model-free adaptive control nonzero-sum stochastic game reinforcement learning

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

A triboelectric nanogenerator based on a spiral rotating shaft for efficient marine energy harvesting of the hydrostatic pressure differential

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Materials Reports(Energy) 2024年第3期4卷 69-76页

作者： Xuemei Song Yuan Chao Pan chang bao Han chang Xin liu Yaxiaer Yalikun Hui Yan Yang Yang Key Laboratory of Advanced Functional Materials(Beijing University of Technology) Ministry of EducationBeijing Key Lab of Microstructure and Property of Advanced MaterialsBeijing University of TechnologyBeijing100124PR China Institute of Deep-Sea Science and Engineering Chinese Academy of SciencesSanya572000PR China Division of Materials Science Nara Institute of Science and Technology8916-5 Takayama-choIkomaNara630-0192Japan

Equipment used in underwater sensing and exploration typically relies on cables or batteries for energy supply,resulting in a limited and inconvenient energy supply and marine environmental pollution that hinder the sustainable development of distributed ocean sensing ***,we design a deep-sea differential-pressure triboelectric nanogenerator(DP-TENG)based on a spiral shaft drive using modified polymer materials to harness the hydrostatic pressure gradient energy at varying ocean depths to power underwater *** spiral shaft structure converts a single compression into multiple rotations of the TENG rotor,achieving efficient conversion of differential pressure *** multi-pair electrode design enables the DP-TENG to generate a peak current of 61.7μA,the instantaneous current density can reach 0.69μA cm^(-2),and the output performance can be improved by optimizing the spiral angle of the *** DP-TENG can charge a 33μF capacitor to 17.5 V within five working *** can also power a digital calculator and light up 116 commercial power light-emitting diodes,demonstrating excellent output *** its simple structure,low production cost,and small form factor,the DP-TENG can be seamlessly integrated with underwater *** results hold broad prospects for underwater blue energy harvesting and are expected to contribute to the development of self-powered equipment toward emerging“smart ocean”and blue economy applications.

关键词： Triboelectric nanogenerators Blue energy Energy harvesting Differential pressure energy Self-power sensor

Effect of heat treatment on microstructure and mechanical properties of selective laser-melted PH13-8Mo stainless steel

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Journal of Iron and Steel Research International 2024年第4期31卷 945-955页

作者： Yuan Zhang Xiang liu chang-jun Wang chang liu School of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093YunnanChina Central Iron&Steel Research Institute Co. Ltd.Beijing 100081China

PH13-8Mo stainless steel powder with high sphericity and well fluidity was prepared by the plasma rotating electrode *** formed parts with ultra-high purity were manufactured by selective laser *** tensile and impact mechanical properties of the printed parts under three heat treatment regimes were compared to those without heat *** microstructure,grain orientation and phase composition were characterized by electron-backscatter diffraction,X-ray diffraction and transmission electron *** characterization results reveal that the addition of heat treatment makes the grains enlarge,and after different heat treatments,the average grain size from 1.51μm in the printed state increases to 2.78,3.09 and 2.06μm,*** formed parts are mainly composed of martensite and retained ***,the NiAl and M23C precipitates form,which are the major strengthening phases of PH13-8Mo stainless *** optimal heat treatment process is 925℃×1 h water cooling(WC)+0℃×2 h air cooling(AC)+540℃×4 h *** this heat treatment process,PH13-8Mo formed parts have the optimal comprehensive mechanical properties:the tensile strength,yield strength and impact energy KU2 are 1492 MPa,1432 MPa and 63 J,*** strengthening and toughening via heat treatment are mainly attributed to dislocation strengthening,the formation of NiAl and M23Co precipitates and the change of volume fraction of the retained austenite.

关键词： High-strength stainless steel-Selective laser melting-Heat treatment Microstructure Mechanical property

Adventitial Vasa Vasorum： A Potential Therapeutic Target But Yet a Long Way to Go

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Chinese Medical Journal 2015年第15期128卷 2130-2130页

作者： Su-Rong Hua chang-Wei liu bao liu Department of Vascular Surgery Peking Union Medical College Hospital Beijing 100730 China

To the Editor： I reviewed the article Quantification ofadventitial vasa vasorum （VV） vascularization in double-injury restenotic arteries by Meng et al. with great interest, which described their experiment about adventitial VV and postangioplasty restenosis. Percutaneous transluminal angioplasty is now widely used for the treatment ofatherosclerotic lesions in various arteries. Restenosis is a major concern following angioplasty, and yet with no good solutions. Previous experimental studies suggested that there is an association between VV and atherosclerotic plaque formation and intimal hyperplasia. As occlusion of VV correlates well with neointima formation, but inhibition ofVV neovascularization correlates with reduced plaque growth, VV may play several different roles in different phases of atherosclerosis or postangioplasty restenosis. The causative mechanism is still unclear.

关键词： Adventitial Vasa Vasorum Potential Therapeutic Target

Modified procedure for prolapse and hemorrhoids: Lower recurrence, higher satisfaction

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World Journal of Clinical Cases 2021年第1期9卷 36-46页

作者： Yan-Yu Chen Yi-Fan Cheng Quan-Peng Wang Bo Ye Chong-Jie Huang Chong-Jun Zhou Mao Cai Yun-KuiYe chang-bao liu Department of Anorectal Surgery The 2^nd Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhou 325000Zhejiang ProvinceChina Department of Biostatistics School of Public HealthState University of New York at AlbanyAlbanyNY 12206United States

BACKGROUND Hemorrhoidal prolapse is a common benign disease with a high *** treatment procedure for prolapse and hemorrhoids(PPH)remains an operative method used for internal hemorrhoid *** it is related to less posoperative pain,faster recovery and shorter hospital stays,the postoperative recurrence rate is higher than that of the Milligan-Morgan hemorrhoidectomy(MMH).We have considered that recurrence could be due to shortage of the pulling-up *** issue may be overcome by using lower purse-string sutures[modified-PPH(M-PPH)].AIM To compare the therapeutic effects and the patients’satisfaction after M-PPH,PPH and *** This retrospective cohort study included 1163 patients(M-PPH,461;original PPH,321;MMH,381)with severe hemorrhoids(stage III/IV)who were admitted to The 2nd Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical University from 2012 to *** postoperative complications,efficacy,postoperative anal dysfunction and patient satisfaction were compared among the three *** criteria were used to assess short-and long-term postoperative complications.A visual analog scale was used to evaluate postoperative ***-up was conducted 5 years *** Length of hospital stay and operating time were significantly longer in the MMH group(8.05±2.50 d,19.98±4.21 min;P<0.0001)than in other *** incidence of postoperative anastomotic bleeding was significantly lower after MPPH than after PPH or MMH(1.9%,5.1%and 3.7%;n=9,16 and 14;respectively).There was a significantly higher rate of sensation of rectal tenesmus after M-PPH than after MMH or PPH(15%,8%and 10%;n=69,30 and 32;respectively).There was a significantly lower rate of recurrence after M-PPH than after PPH(8.7%and 18.8%,n=40 and 61;P<0.0001).The incidence of postoperative anal incontinence differed significantly only between the MMH and M-PPH groups(1.3%and 4.3%,n=5 and 20;P=0.04).Patient satisfaction was significant

关键词： Hemorrhoids Milligan-Morgan hemorrhoidectomy Postoperative complications Procedure for prolapse and hemorrhoids Recurrence Patient satisfaction

Inflammatory airway features and hypothalamic-pituitary- adrenal axis function in asthmatic rats combined with chronic obstructive pulmonary disease

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Chinese Medical Journal 2010年第13期123卷 1720-1726页

作者： CAI Cui ZHANG Hong-ying LE Jing-jing DONG Jing-cheng CUI Yan XU chang-qing liu bao-jun WU Jin-feng DUAN Xiao-hong CAO Yu-xue Lab of Integrative Medicine for Lung Inflammation and Cancers Huashan Hospital Fudan University Shanghai 200040 China

Background Bronchial asthma （BA） and chronic obstructive pulmonary disease （COPD） are both inflammatory airway diseases with different characteristics. However, there are many patients who suffer from both BA and COPD. This study was to evaluate changes of inflammatory airway features and hypothalamic-pituitary-adrenal （HPA） axis function in asthmatic rats combined with COPD. Methods Brown Norway （BN） rats were used to model These three models were compared and evaluated with the inflammatory airway diseases of BA, COPD and COPD＋BA. respect to clinical symptoms, pulmonary histopathology, airway hyperresponsiveness （AHR）, inflammatory cytokines and HPA axis function. Results The inflammatory airway features and HPA axis function in rats in the COPD＋BA model group were greatly influenced. Rats in this model group showed features of the inflammatory diseases BA and COPD. The expression of inflammatory cytokines in this model group might be up or downregulated when both disease processes are present. The levels of corticotrophin releasing hormone mRNA and corticosterone in this model group were both significantly decreased than those in the control group （P 〈0.05）. Conclusions BN rat can be used as an animal model of COPD＋BA. By evaluating this animal model we found that the features of inflammation in rats in this model group seem to be exaggerated. The HPA axis functions in rats in this model group have been disturbed or impaired, which is prominent at the hypothalamic level.

关键词： chronic obstructive pulmonary disease bronchial asthma inflammatory airway disease hypothalamic-pituitary-adrenal axis

Phase Patterning of Poly(oxime-ester) for Information Encryption by Photo-induced Isomerization

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Chinese Journal of Polymer Science 2024年第10期42卷 1488-1494页

作者： Yu-Fan Yang Yun Bai Yi-bao Li chang-Fei He School of Chemistry and Chemical Engineering Gannan Normal University

Crystal polymers or liquid crystal elastomers undergo a phase transition that results in a change in the corresponding optical properties, which has the potential to be applied in areas such as information encryption and anti-counterfeiting. The utilization of these materials for patterning purposes requires different phase transition temperatures. However, once prepared, altering the phase transition temperature of them presents significant challenges. Herein, a poly(oxime-ester)(POE) network is developed to achieve high-resolution and multilevel patterning by photo-induced isomerization. The as-prepared POE exhibits the ability to transition from an opaque state to a transparent state under temperature stimuli, with the transition temperature and kinetics dependent on UV light exposure time. Thus, complex patterns and information can be encrypted through different selective regional exposure time and decrypted under specific temperature or cooling time. Furthermore, we illustrate an example of temporal communication, where cooling time or temperature serves as the encoded information. This research expands the application scope of advanced encryption materials, showcasing the potential of POE in dynamic information encryption and decryption processes.

关键词： Information encryption Isomerization Phase patterning Poly(oxime-ester)