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Journal of Materials science & Technology 2021年第31期90卷 143-149页

作者： Linlin Zhang Wenxing Peng YaKun Li Rui Qin Dong Yue Chengjun Ge Jianjun Liao ey Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of hainan province School of Ecological and Environmental SciencesHainan UniversityHaikou 570228China Shandong Ocean Chemical Industry Scientiﬁc Research Institute Weifang 262737China School of Materials science and Engineering Hainan UniversityHaikou 570228China

The construction of built-in electric field is generally considered as an effective strategy to enhance photocatalytic performance due to its significant role in charge ***,a built-in electric field within g-C_(3)N_4 hollow nanospheres co-doped with sulfur and oxygen and modified in-situ Ni_(2)P is ***_(2)P/SO-HC_(3)N_4 exhibits significantly enhanced board spectrum photocatalytic properties for hydrogen precipitation(5.21 mmol h^(-1)g^(-1))and photocatalytic Cr(VI)reduction without the use of noble *** also achieves high photocatalytic sterilization activity and remarkable stability when used to completely inactivate ***(10~7)in 60 min under Vis-NIR light *** enhanced performance is attributed to the formation of a curved hollow sphere structure,which promotes the electron transfer between the inner and outer *** addition,co-doping inhibits the recombination of photogenerated carriers,and the built-in electric field recombined with Ni_(2)facilitates the electron transfer between the composite *** design strategy demonstrates an original method of devising multifunctional photocatalysts with enhanced activity and stability.

关键词： Photocatalysis Ni_(2)P g-C_(3)N_4 Hollow nanospheres Pt-free cocatalysts

Comparative Study on the Antioxidant Activity of Peptides from Pearl Oyster(Pinctada martensii) Mantle Type V Collagen and Tilapia(Oreochromis niloticus) Scale Type Ⅰ Collagen

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Journal of Ocean University of China 2017年第6期16卷 1175-1182页

作者： XIA Guanghua ZHANG Xueying DONG Zhenghua SHEN Xuanri College of Food science and Technology Hainan University Haikou 570228 P. R. China

In this study, Pearl oyster mantle type V collagen(POMC) and tilapia scale type I collagen(TSC) were extracted and hydrolyzed by various proteases in order to obtain peptides. The antioxidant activity of the peptides was investigated by DPPH, hydroxyl radical scavenging experiments and a dynamic digestion model in vitro. The results show that there are significant differences in amino acid composition between POMC and TSC. The collagen peptides obtained from pearl oyster mantle(POMCP) by treating with alkaline protease exhibited higher antioxidant activity than that from tilapia scale(TSCP) treated with papaya protease, and both of them showed greater DPPH and hydroxyl radical scavenging activity than other peptides. After being separated via Sephadex G-25 chromatography, the M1 fraction isolated from POMCP, and the S1 fraction from TSCP with which both had higher molecular weights showed the strongest antioxidant activity than other fractions, and the M1 fraction exhibited stronger antioxidant activity than the S1 fraction in scavenging free-radicals and protecting cells from the oxidation damage. Furthermore, after treating the dynamic digestion system model in vitro, the DPPH and hydroxyl radical scavenging activity of the M1 fraction increased slightly. These results suggest that POMCP exhibits stronger antioxidant activity than TSCP, which means that PMOP may be a good candidate to be a potential natural antioxidant in the food-processing industry.

关键词： tilapia scale pearl oyster mantle collagen peptide antioxidant activity

A Double Sensitive Fault Detection Filter for Positive Markovian Jump Systems With A Hybrid Event-Triggered Mechanism

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IEEE/CAA Journal of Automatica Sinica 2024年第11期11卷 2298-2315页

作者： Junfeng Zhang Baozhu Du Suhuan Zhang Shihong Ding IEEE the School of Information and Communication Engineering Hainan University the College of Electronics and Information Engineering Tongji University the School of Electrical and Information Engineering Jiangsu University

This paper is concerned with the double sensitive fault detection filter for positive Markovian jump systems. A new hybrid adaptive event-triggered mechanism is proposed by introducing a non-monotonic adaptive law. A linear adaptive event-triggered threshold is established by virtue of 1-norm *** such a triggering strategy, the original system can be transformed into an interval uncertain system. By using a stochastic copositive Lyapunov function, an asynchronous fault detection filter is designed for positive Markovian jump systems(PMJSs) in terms of linear programming. The presented filter satisfies both L_-gain(?_-gain) fault sensitivity and L_1(?_1)internal differential privacy sensitivity. The proposed approach is also extended to the discrete-time case. Finally, two examples are provided to illustrate the effectiveness of the proposed design.

关键词： Fault detection filter hybrid event-triggered mechanism positive Markovian jump systems(PMJSs) sensitivity

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Evolution of Slow Dual Steady-State Optical Solitons in a Cold Three-State Medium

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Chinese Physics Letters 2012年第7期29卷 142-145页

作者： SUN Jian-Qiang LI Hao-Chen GU Xiao-Yan Department of Mathematics College of Information Science and TechnologyHainan UniversityHaikou 570228 Department of Physics East China University of Science and TechnologyShanghai 200237

The generalized nonlinear Schr(o)dinger equation,which describes the evolution of dual steady-state optical solitons in a cold three-state medium,is written as the Hamiltonian symplectic *** symplectic method is applied to investigate evolution of dual steady-state optical *** adjusting the initial pulses,the saturation parameter variables and the distances of optical solitons,the different behaviors of dual steady-state optical solitons are analyzed.

关键词： structure solitons symplectic

Handling the Challenges of Small-Scale Labeled Data and Class Imbalances in Classifying the N and K Statuses of Rubber Leaves Using Hyperspectroscopy Techniques

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Plant Phenomics 2024年第2期6卷 281-294页

作者： Wenfeng Hu Weihao Tang Chuang Li Jinjing Wu Hong Liu Chao Wang Xiaochuan Luo Rongnian Tang School of Mechanical and Electrical Engineering Hainan UniversityHaikou 570228China School of Electrical Engineering and Automation Tianjin UniversityTianjin 300072China

The nutritional status of rubber trees(Hevea brasiliensis)is inseparable from the production of natural ***(N)and potassium(K)levels in rubber leaves are 2 crucial criteria that reflect the nutritional status of the rubber *** hyperspectral technology can evaluate N and K statuses in leaves ***,high bias and uncertain results will be generated when using a small size and imbalance dataset to train a spectral estimaion model.A typical solution of laborious long-term nutrient stress and high-intensive data collection deviates from rapid and flexible advantages of hyperspectral ***,a less intensive and streamlined method,remining information from hyperspectral image data,was assessed.

关键词： handling data ersp challenges classifying imbalances labeled leaves rubber small-scale

Effect of an eco-friendly o/w emulsion stabilized with amphiphilic sodium alginate derivatives on lambda-cyhalothrin adsorption-desorption on natural soil minerals

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Journal of Environmental sciences 2019年第4期31卷 230-238页

作者： Yang Peng Dunchao Xiao Gaobo Yu Yuhong Feng Jiacheng Li Xinyu Zhao Yiyuan Tang Longzheng Wang Quan Zhang hainan University Key Laboratory of Advanced Materials of Tropical Island Resources Ministry of EducationCollege of Materials and Chemical EngineeringHainan University

The effects of amphiphilic O/W emulsions,stabilized by the alkyl polyglycoside(APG)or cholesterol-grafted sodium alginate(CSAD)/APG systems,on lambda-cyhalothrin adsorption/desorption mechanisms on natural soil minerals(i.e.,illite and kaolinite)were *** and desorption of lambda-cyhalothrin onto soil minerals was studied via batch equilibration to give insight into the adsorption equilibrium,kinetics,and thermodynamics of lambda-cyhalothrin adsorption onto *** results indicate the following:(i)The adsorption processes for the APG system and CSAD/APG system include:rapid adsorption,slow adsorption,and adsorption *** adsorption kinetics of pesticide on illite and kaolinite are in accordance with the Ho and McKay model,and the adsorption isotherm conforms to the Freundlich *** addition,the adsorption processes of pesticide for the two systems on minerals were spontaneous and feasible(ΔG^00),and mainly involved chemical bonding(ΔH^0>60).(ii)The equilibrium adsorption percentages of the pesticide on illite for the APG system and CSAD/APG system were 42.4%and 64.8%,and the corresponding equilibrium adsorption percentages on kaolinite were 40.8%and 61.8%,***,the pesticide adsorption rate K_(2-CSAD/APG)was faster than K_(2-APG),and its adsorption capacity K_(f-CSAD/APG )was greater than K_(f-APG).Meanwhile,the pesticide desorption K_(fd)in the CSAD/APG system was smaller than that in the APG *** a result,this eco-friendly O/W emulsion based on amphiphilic sodium alginate derivatives might provide a green pesticide formulation,since it could reduce the amount of lambda-cyhalothrin entering aquatic systems to threaten non-target fish and invertebrate species.

关键词： Sodium alginate derivatives Alkyl polyglycoside Synergetic effect Green pesticide Water pollution remediation Lambda-cyhalothrin

Liquefaction of Banana Pseudo-stem and Preparation of Polyurethane Adhesive from Liquefied Products

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Journal of Wuhan University of Technology(Materials science) 2018年第6期33卷 1437-1443页

作者： ZHOU Wei ZHANG Yueang College of Materials and Chemical Engineering Hainan University

Banana pseudo-stem was liquefied in the mixture of polyhydric alcohols of polyethylene glycol(PEG400) and glycerol. Hydroxyl value of liquefied products ranged from 294.8 to 370.2 mg KOH/g and M_n was about 430. Liquefied products(LBPP) could be used as raw materials for polyurethane by reacting with 4, 4'-diphenylmethane diisocyanate(4, 4'-MDI) and PEG400 to synthesize liquefied product-based polyurethane(LBPP-PU) adhesive. To analyze in depth the creation of urethane linkage among LBPP, PEG400 and 4, 4'-MDI, factors which had effects on the residue content were all investigated. They were characterized by FT-IR and TG. The shear strength of LBPP-PU adhesive was improved when decreasing the percentage of the substitution of PEG400 by LBPP. The adhesive strength was obtained from T-peel of aspen/polyurethane adhesive joints, and the maximum lap shear strength(4.40 MPa) was obtained when 16.70% of LBPP was added to the LBPP & PEG400 system.

关键词： liquefaction banana pseudo-stem polyhydric alcohols polyurethane adhesive

Coupling interface constructions of FeOOH/NiCo_(2)S_(4)by microwave-assisted method for efficient oxygen evolution reaction

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Rare Metals 2023年第6期42卷 1847-1857页

作者： Ming-Liang Guo Zhi-Yu Wu Miao-Miao Zhang Zi-Jian Huang Ke-Xi Zhang Bing-Rong Wang Jin-Chun Tu State Key Laboratory of Marine Resource Utilization in the South China Sea College of Materials Science and EngineeringHainan UniversityHaikou570228China School of science Hainan UniversityHaikou570228China

The oxygen evolution reaction(OER) with slow kinetics is the rate-limiting step of electrochemical water splitting.A reasonable construction of interface nanostructures is the key to improving the OER efficiency and durability of non-noble metal *** this study,a FeOOH/NiCo_(2)S_(4) core-shell nanorod array with abundant heterogeneous interfaces and high density of active sites was successfully prepared by a microwave-as sis ted *** research and theoretical calculations show that the abundant strong coupling Ni/Co-S-Fe interface helps in adjusting the electronic structure of the material surface,optimizing the adsorption energy of the intermediate,and realizing an efficient catalytic *** as-synthesized FeOOH/NiCo_(2)S_(4)/NF composite electrode exhibited lower overpotential(198 mV) and Tafel slope(62 mV·dec^(-1)) at a current density of 10 mA·cm^(-2)and excellent stability(approximately 100% retention after100 h) than the NiCo_(2)S_(4)/nickel foam(NF).In conclusion,constructing heterojunctions with complementary active materials is an effective strategy to design efficient and robust OER electrocatalysts.

关键词： Transition metal sulfides FeOOH Interface structure Adsorption energy Oxygen evolution

Isolated Co Atoms Anchored on Defective Nitrogen-doped Carbon Graphene as Efficient Oxygen Reduction Reaction Electrocatalysts

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Energy & Environmental Materials 2023年第3期6卷 144-149页

作者： Peng Rao Junming Luo Daoxiong Wu Jing Li Qi Chen Peilin Deng Yijun Shen Xinlong Tian State Key Laboratory of Marine Resource Utilization in South China Sea Hainan Provincial Key Lab of Fine ChemistrySchool of Chemical Engineering and TechnologyHainan UniversityHaikou 570228China

Oxygen reduction reaction(ORR)is the heart of many new energy conversions and storage devices,such as metal-air batteries and fuel ***,ORR is currently facing the dilemma of sluggish intrinsic kinetics and the noble electrocatalysts of high price and low *** this work,isolated Co atoms anchored on defective nitrogen-doped carbon graphene single-atom catalyst(Co-SAC/NC)are synthesized via the proposed movable type printing *** prepared Co-SAC/NC catalyst demonstrates admirable ORR performance,with a high half-wave potential of 0.884 V in alkaline electrolytes and outstanding *** addition,an assembled zinc–air battery with prepared Co-SAC/NC as air-cathode catalyst displays a high-peak power density of 179 mW cm^(-2)and a high-specific capacity(757 mAh g^(-1)).Density functional theory calculations confirm that the true active sites of the prepared catalyst are Co-N_(4)moieties,and further reveal a significantly electronic structure evolution of Co sites in the ORR process,in which the project density of states and local magnetic moment of Co atom varies during its whole reaction *** work not only paves a new avenue for synthesizing SACs as robust electrocatalysts,but also provides an electronic-level insight into the evolution of the electronic structure of single-atom catalysts.

关键词： movable type printing method oxygen reduction reaction single-atom catalyst zinc-air battery

Solvent-free 1,3-Dipolar Cycloaddition of Azomethine Imines with Terminal Alkynes Promoted by Calcium Fluoride Under the Ball Milling Condition

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Chemical Research in Chinese Universities 2015年第4期31卷 543-548页

作者： CHEN Xianglong JIA Chunman CAO Li ZHANG Dela LIU Shuixiang ZHANG Qil hainan Provincial Key Lab of Fine Chem. Key Study Center of Ministry of Education for Tropical Resources Utilization Hainan University Haikou 570228 P R. China

A convenient and efficient procedure for the synthesis ofN, N-bicyclic pyrazolidinone derivatives has been developed via the reaction of azomethine imines with terminal alkynes under the ball milling condition without sol- vent, which was promoted by calcium fluoride with a catalyst of copper（I） salt. The cyclization reactions exhibited moderate to high yields.

关键词： Ball-milling 1,3-Dipolar cycloaddition Click chemistry Solvent-free reaction