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Study on the growth of platinum nanowires as cathode catalysts in proton exchange membrane fuel cells

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Frontiers of Chemical Science and Engineering 2022年第3期16卷 364-375页

作者： Ruiqing Wang Xiaolan Cao Sheng Sui bing Li Qingfeng li Institute of Fuel Cells Shanghai Jiao Tong UniversityShanghai200240China School of Mechanical and Power Engineering East China University of Science and TechnologyShanghai200237China Department of Energy Conversion and Storage Technical University of Denmark2800LyngbyCopenhagenDenmark

The platinum nanowires have been verified to be a promising catalyst to promote the performance of proton exchange membrane fuel cells.In this paper,accurately controlled growth of nanowires in a carbon matrix is achieved for reducing Pt loading.The effects of formic acid concentration and reaction temperature on the morphology and size of the Pt nanowires,as well as their electrochemical performances in a single cell,are investigated.The results showed that the increase in the formic acid concentration results in a volcano trend with the length of Pt nanowires.With increasing reduction temperature,the diameter of Pt nanowires increases while Pt particles evolve from one-dimensional to zero-dimensional up to 40°C.A mechanism of the Pt nanowires growth is proposed.The optimized Pt nanowires electrode exhibits a power density(based on electrochemical active surface area)79%higher than conventional Pt/C one.The control strategy obtained contributes to the design and control of novel nanostructures in nano-synthesis and catalyst applications.

关键词： Pt nanowires morphology structure control in situ growth mechanism proton exchange membrane fuel cells

Effect of saline water ionic strength on phosphorus recovery from synthetic swine wastewater

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Journal of Environmental Sciences 2022年第3期34卷 81-91页

作者： Zhipeng Zhang bing Li Filicia Wicaksana Wei Yu Brent Young Department of Chemical&Materials Engineering University of AucklandAuckland 1010New Zealand

Declining worldwide phosphate rock reserves has driven a growing interest in exploration of alternative phosphate supplies. This study involved phosphorus recovery from swine wastewater through precipitation of struvite, a valuable slow-release fertiliser. The economic feasibility of this process is highly dependent on the cost of magnesium source. Two different magnesium sources were used for phosphorus recovery: pure magnesium chloride and nanofiltration(NF) saline water retentate. The paper focuses on the impact of ionic strength on phosphorus recovery performance that has not been reported elsewhere. Experimental design with five numerical variables(Mg/P molar ratio, pH, PO_(4)^(3-)-P, NH_(4)^(+)-N, and Ca^(2+) levels) and one categorical variable(type of magnesium source) was used to evaluate the effect of ionic strength on phosphorus removal and struvite purity. The experimental data were analysed using analysis of variance(ANOVA) and principal component analysis(PCA). Results indicated that a magnesium source obtained from NF retentate was as effective as MgCl_(2) for struvite precipitation. It was also revealed that ionic strength had a more positive effect on struvite purity than on phosphorus removal. Within the range of parameters studied in this research, high ionic strength, high p H and wastewater with high phosphate, high ammonium and low calcium contents were found to be the most favourable conditions for struvite precipitation. Findings from this study will be beneficial to determine the feasibility of using high ionic strength saline water, such as NF seawater retentate, as a magnesium source for phosphorus recovery from wastewater that is rich in ammoniumnitrogen and phosphate.

关键词： Phosphorus recovery Struvite Ionic strength Wastewater Nanofiltration retentate

Advances and challenges in artificial intelligence text generation

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Frontiers of Information Technology & Electronic Engineering 2024年第1期25卷 64-83页

作者： bing Li Peng YANG Yuankang SUN Zhongjian HU Meng YI School of Computer Science and Engineering Southeast UniversityNanjing 210000China Key Laboratory of Computer Network and Information Integration Ministry of EducationSoutheast UniversityNanjing 210000China

Text generation is an essential research area in artificial intelligence(AI)technology and natural language processing and provides key technical support for the rapid development of AI-generated content(AIGC).It is based on technologies such as natural language processing,machine learning,and deep learning,which enable learning language rules through training models to automatically generate text that meets grammatical and semantic requirements.In this paper,we sort and systematically summarize the main research progress in text generation and review recent text generation papers,focusing on presenting a detailed understanding of the technical models.In addition,several typical text generation application systems are presented.Finally,we address some challenges and future directions in AI text generation.We conclude that improving the quality,quantity,interactivity,and adaptability of generated text can help fundamentally advance AI text generation development.

关键词： AI text generation Natural language processing Machine learning Deep learning

Thermal Analysis by Means of Differential Scanning Calorimetry of the Characteristic Thermodynamic Temperatures of a Cu-Zr-Al Bulk Metallic Glass

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Fluid Dynamics & Materials Processing 2022年第1期18卷 71-80页

作者： Yanhong li bing Li Xinhui Fan Ke Yang Xin Wang Shaanxi Key Laboratory of Photoelectric Functional Materials and Devices School of Material and Chemical EngineeringXi’an Technological UniversityXi’an710021China

In this study a Cu_(43)Zr_(48)Al_(9)bulk metallic glass prepared by the copper mold casting method is considered.In recent years,Cu-Zr-Al systems like this have enjoyed widespread attention due to their high strength,high hardness,high corrosion resistance and low cost.Here samples of this substance are studied using DSC(Differential scanning calorimetry)to determine the effect of different test conditions(heating rate,sample mass,sample specific surface area and sample crystal phase)on the characteristic thermodynamic temperature of the bulk metallic glass.Experimental results show that almost all of the five characteristic thermodynamic temperatures(T_(g),T_(x),T_(p),T_(m),T_(l))of this substance have higher values when the heating rate is increased.The influence of the variation of sample mass,sample specific surface area and sample crystal phase on the amorphous alloy characteristic temperature is very weak.lower the heating rate,the more developed the crystalline phase in the amorphous alloy will be.

关键词： Cu-Zr-Al amorphous influence factors characteristic thermodynamic temperature DSC

Technical feasibility of salvage endoscopic full-thickness resection for a giant gastrointestinal stromal tumor located in low rectum after imatinib:a case report

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Gastroenterology Report 2023年第1期11卷 527-529页

作者： Jingyi liu bing Li Pinghong Zhou Mingyan Cai Yunshi Zhong Endoscopy Center Zhongshan Hospital of Fudan UniversityShanghaiP.R.China Endoscopy Research Institute of Fudan University ShanghaiP.R.China Shanghai Collaborative Innovation Center of Endoscopy ShanghaiP.R.China Endoscopy Center Xuhui HospitalZhongshan Hospital of Fudan UniversityShanghaiP.R.China

Introduction Gastrointestinal stromal tumors(GISTs)in adults are nearly 10%–30%with a potential malignant tendency[1].Colorectal GISTs account for 5%of all cases and have a higher progression risk with a poor prognosis[2,3].Rectal GISTs usually need radical operations such as laparoscopy to obtain tumor-free margins.Sometimes,it is difficult for surgery to preserve the anal function because of the tumor size and location.Here,we report a case of a 70-year-old female with a giant GIST located in the lower rectum,which was removed by function-preserving endoscopic minimally invasive resection after routine imatinib therapy.

关键词： rectum resection routine

Plasticity improvement of(Cu_(43)Zr_(48)Al_(9))_(98)Y_(2)bulk metallic glass composites by dispersed Ta particles

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China Foundry 2022年第3期19卷 275-280页

作者： Ke Yang bing Li Xin Wang Xin-hui Fan School of Materials Science and Chemical Engineering Xi'an Technological UniversityXi'an 710021China

(Cu_(43)Zr_(48)Al_(9))_(98)Y_(2)-based bulk metallic glass composites(BMGCs)with dispersed Ta particles(3vol.%,6vol.%,9vol.%)were successfully fabricated through suction casting.The thermal properties,microstructure,and mechanical properties of the BMGCs were systematically investigated.Ta particles are homogeneously dispersed in the amorphous matrix.Ta particle reinforced BMGCs exhibit similar thermal properties and glass-forming ability with the Cu_(43)Zr_(48)Al_(9))_(98)Y_(2)base BMG.Compression test results show that the BMGC with 9vol.%Ta particles has superior mechanical performance with up to 15.7%compressive plastic strain,2,216 MPa yield strength,and 2,260 MPa fracture strength at room temperature.These homogeneously distributed Ta particles act as discrete obstacles in the amorphous matrix,restricting the highly localized shear band.This results in the formation of multiple shear bands around the Ta-rich particles,which lowers the stress concentration,allowing the shear band to propagate further and improve plasticity.

关键词： bulk metallic glass composites Ta particles mechanical properties microstructure

A dynamic PUF anti-aging authentication system based on restrict race code

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Science China(Information Sciences) 2016年第1期59卷 149-160页

作者： bing Li Shuai CHEN Southeast University School of Integrated Circuit

This paper presents a PUF(physical unclonable functions) authentication mechanism which can combat aging based on restrict race code(RRC). PUF provide a mechanism for identifying an integrated circuit based on the intrinsic variations of physical components uniquely and provide a cheap and secure alternative to random message storage on devices. However, due to its own characteristics, the chip-level PUF circuit reliability is easily affected by environment. The effect of reversible temporal noise on PUF is well studied and has obtained good effect(e.g. temperature, voltage), but sufficient attention has not been given so far to analyze the effect of the irreversible temporal variabilities(e.g. aging on PUF). This paper proposes a dynamic PUF authentication method, which is based on the RRC with two-ring strong characteristics structure. A combination of hardware and software system is used to improve the efficiency of authentication, and in an FPGA(field-programmable gate array)-based SRAM(static random access memory) PUF are used as an experimental object to verify the feasibility of this design. And this system can enhance the authentication system safety from the CVC(characteristic value challenge) randomness test.

关键词： aging PUF dynamically maintain RRC characteristic value

Production of p-rich nuclei with Z = 20-25 based on radioactive ion beams

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Nuclear Science and Techniques 2022年第5期33卷 30-38页

作者： bing Li Na Tang Yu-Hai Zhang Feng-Shou Zhang Key Laboratory of Beam Technology of the Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of LanzhouLanzhou 730000China

Within the framework of isospin-dependent Boltzmann-Langevin model,the production cross sections of proton-rich nuclei with Z=20-25 are investigated.According to the reaction results for different isospin of projectiles^(48)Ni,^(49)Ni,and^(50)Ni,proton-rich fragments tend to be more easily produced in reactions with the protonrich projectile^(48)Ni.The production cross sections of the unknown nuclei in the vicinity of the projectile are sensitive to incident energy.It is observed that incident energy of 345 MeV/u is appropriate for producing proton-rich nuclei with Z=20-25.In projectile fragmentation reactions based on the radioactive ion beam of48Ni at 345MeV/u,several unknown proton-rich nuclei near the proton drip line are generated in the simulations.All these new nuclei are near-projectile elements near Z=28.The production cross sections of the new nuclei^(34)Ca,37,38Sc,^(38)Ti,^(40,41,42)V,^(40,41)Cr,and^(42,43,44,45)Mn are in the range of 10-2-102mb.Hence,projectile fragmentation of radioactive ion beams of Ni is a potential method for generating new proton-rich nuclei with Z=20-25.

关键词： Production cross sections Radioactive ion beams Isospin-dependent Boltzmann-Langevin model

PD-like finite time controller with simple structure for satellite attitude control

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Defence Technology（防务技术） 2023年第8期26卷 123-133页

作者： li You Ye Dong Xiao bing Xidian University Xi'an710126China Harbin Institute of Technology Harbin 150090China Northwestern Polytechnical University Xi'an710072China

A finite time controller with PD-like structure for satellite attitude control is proposed in this paper.The controller is constructed with simple structure based on standard PD controller.The fractional order term is designed hence system could both have strong robustness and finite time convergence rate,and the advantage of finite time control and PD control is combined in this paper.System convergence rate is discussed by Lyapunov method,and the constraint on control parameters is given by implementing the coupled term of angular velocity and attitude quaternion.Moreover,the accuracy at steady stage depending on control parameters is given hence system could converge to this field within finite time.System stability and performance is demonstrated by numerical simulation results.

关键词： Finite time control PD-like Simple structure Attitude control