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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第3期10卷 423-433页

作者： Zheng-cheng WEN Zhi-hua WANG jun-hu zhou Ke-fa CEN State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

Quantum chemical simulation was used to investigate the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process. Both NO-char and NO-Na/K reactions were considered as three-step processes in this calculation. Based on geometry optimizations made using the UB3LYP/6-31G(d) method, the activation energies of NO-char and NO-Na/K reactions were calculated using the QCISD(T)/6-311G(d, p) method; Results showed that the activation energy of the NO-Na/K reaction (107.9/82.0 kJ/mol) was much lower than that of the NO-char reaction (245.1 kJ/mol). The reactions of NaO/KO and Na2O/K2O reduced by char were also studied, and their thermodynamics were calculated using the UB3LYP/6-31G(d) method; Results showed that both Na and K can be refreshed easily and rapidly by char at high temperature during the coal reburning process. Based on the calculations and analyses, the catalytic mechanism of Na/K on NO-char het-erogeneous reactions during the coal reburning process was clarified.

关键词： Catalytic mechanism Quantum chemistry Sodium Potassium Char NO

A quantum chemistry study on reaction mechanisms of SO_2 with O_3 and H_2O_2

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第9期10卷 1327-1333页

作者： Shu-dong JIANG Zhi-hua WANG jun-hu zhou Zheng-cheng WEN Ke-fa CEN State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

Reaction mechanisms of SO2 with O3 and H2O2 were investigated using quantum chemistry ab initio methods. Structures of all reactants, products, and transition states were optimized at the B3LYP/6-311G＋（3df,2p） level, and energy calculations were made at the G2M level. SO2 reactions with O3 and H2O2 occurred by O-abstraction and OH-abstraction by SO2, respectively, at length forming SO3＋O2 （3Eg） and H2SO4. For SO2＋O3 reactions the barrier height was predicted to be 9.68 kcal/mol with a rate constant of 3.61 × 10^-23 cm^3/（molecule.s） at 300 K, which is below the experimental upper limit. The rate constant predicted for this reaction accords well with the one provided by National Institute for Standards and Technology （NIST） in 250-500 K. For SO2＋H2O2 reactions the barrier height was predicted to be 62.39 kcal/mol with a rate constant of 2.48× 10^-61 cm^3/（molecule.s） at 300 K.

关键词： Sulfur dioxide Ozone Hydrogen peroxide Reaction mechanism Rate constant Quantum chemistry

Improving slurryability, rheology,and stability of slurry fuel from blending petroleum coke with lignite

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Petroleum Science 2015年第1期12卷 157-169页

作者： jun-Hong Wu Jian-Zhong Liu Yu-Jie Yu Rui-Kun Wang jun-hu zhou Ke-Fa Cen State Key Laboratory of Clean Energy Utilization Zhejiang University

Petroleum coke and lignite are two important fossil fuels that have not been widely used in China. Petroleum coke-lignite slurry （PCLS）, a mixture of petro- leum coke, lignite, water, and additives, efficiently utilizes the two materials. In this study, we investigate the effects of the proportion （7） of petroleum coke on slurryability, rheo- logical behavior, stability, and increasing temperature characteristics of PCLSs. The results show that the fixed- viscosity solid concentration （COo） increases with increasing 7. The ~Oo of lignite-water slurry （LWS, ~ = 0） is 46.7 %, compared to 71.3 % for the petroleum coke-water slurry （PCWS, c~ --- i00 %）, while that of PCLS is in between the two values. The rheological behavior of PCLS perfectly fits the power-law model. The PCWS acts as a dilatant fluid. As decreases, the slurry behaves first as an approximate Newtonian fluid, and then turns into a pseudo-plastic fluid that exhibits shear-thinning behavior. With increasing ct, the rigid sedimentation and water separation ratio （WSR） increase, indicating a decrease in the stability of PCLS. When α is 60-70 %, the result is a high-quality slurry fuel for industrial applications, which has high slurryability （ω0 = 57-60 %）, good stability （WSR 〈 2 %）, and superior pseudo-plastic behavior （n = 0.9）.

关键词： Petroleum coke Lignite Coal-water slurry Rheological characteristics Slurry stability

Occurrence of the Bunsen side reaction in the sulfur-iodine thermochemical cycle for hydrogen production

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第4期14卷 300-306页

作者： Qiao-qiao Zhu Yan-wei ZHANG Zhi YING jun-hu zhou Zhi-hua WANG Ke-fa CEN State Key Laboratory of Clean Energy Utilization Department of Energy EngineeringZhejiang University

This study aimed to establish a closed-cycle operation technology with high thermal efficiency in the thermochemical sulfur-iodine cycle for large-scale hydrogen production.A series of experimental studies were performed to investigate the occurrence of side reactions in both the H2SO4 and HI x phases from the H2SO4/HI/I2/H2O quaternary system within a constant temperature range of 323-363 *** effects of iodine content,water content and reaction temperature on the side reactions were *** results showed that an increase in the reaction temperature promoted the side ***,they were prevented as the iodine or water content *** occurrence of side reactions was faster in kinetics and more intense in the H2SO4 phase than in the HI x *** sulfur or hydrogen sulfide formation reaction or the reverse Bunsen reaction was validated under certain conditions.

关键词： Thermochemical sulfur-iodine cycle Hydrogen production Side reaction Sulfur Hydrogen sulfide

HNCO hydrolysis performance in urea-water solution thermohydrolysis process with and without catalysts

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第11期11卷 849-856页

作者： Zhen-chao CHEN Wei-juan YANG jun-hu zhou Hong-kun LV Jian-zhong LIU Ke-fa CEN State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China

The thermolysis of urea-water solution and its product, HNCO hydrolysis is investigated in a dual-reactor system. For the thermal decomposition below about 1073 K, the main products are ammonia (NH3) and isocyanic acid (HNCO) whereas at higher temperatures the oxidation processes take effect and the products include a low concentration of nitric oxide (NO) and nitrous oxide (N2O). The gas HNCO is quite stable and a high yield of HNCO is observed. The ratio of NH3 to HNCO increases from approximately 1.2 to 1.7 with the temperature. The chemical analysis shows that H radical is in favor of HNCO hydrolysis by instigating the reaction HNCO+H·→·NH2+CO and high temperature has positive effect on H radical. The hydrolysis of HNCO over an alumina catalyst made using a sol-gel process (designated as γ-Al2O3) is investigated. The conversion of HNCO is high even at the high space velocities (6×105 h-1) and low temperatures (393–673 K) in the tests with catalysts, which enhances HNCO hydrolysis and raises the ratio of NH3 to HNCO to approximately 100. The pure γ-Al2O3 shows a better catalytic performance than CuO/γ-Al2O3. The addition of CuO not only reduces the surface area but also decreases the Lewis acid sites which are recognized to have a positive effect on the catalytic activity. The apparent activation energy of the hydrolysis reaction amounts to about 25 kJ/mol in 393–473 K while 13 kJ/mol over 473 K. The overall hydrolysis reaction rate on catalysts is mainly determined by external and internal mass-transfer limitations.

关键词： Urea-water solution Sol-gel method γ-Al2O3 HNCO hydrolysis

Recyclable Polypropylene-based Insulation Materials for HVDC Cables:Progress and Perspective

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CSEE Journal of Power and Energy Systems 2024年第5期10卷 2208-2220页

作者： Yao zhou Shixun hu Chao Yuan jun hu Qi Li Jinliang He State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Beijing Key Lab of High Voltage&EMC and State Key Lab of Alternate Electrical Power System with Renewable Energy SourcesNorth China Electric Power UniversityBeijing 102206China.

Polypropylene(PP)-based recyclable materials have attracted tremendous interest for HVDC cable insulation applications due to their superior electrical properties,e.g.,high thermal stability and superior *** with crosslinked polyethylene(XLPE),PP-based materials exhibit the advantages of not only higher working temperatures but also facile and efficient cable manufacturing with reduced costs,which are highly desirable in HVDC cable *** their promising advantages,PP-based materials have received significant attention from both academia and industry in the field of HVDC cable *** order to adopt PP as a cable insulation material,the mechanical flexibility of PP should be ***,regulations of the mechanical properties inevitably influences the electrical properties of *** extensive research has been conducted on the regulation of the mechanical and electrical properties of *** review summarizes the research progress on recyclable PP-based materials for HVDC cable insulation *** attention is placed on the electrical property regulations and material structure-property *** challenges that remain to be addressed and the opportunities for future studies on PP-based recyclable HVDC cable insulation materials are also presented.

关键词： polypropylene HVDC cable dielectric materials recyclable insulation materials

Assessing target optical camouflage effects using brain functional networks:A feasibility study

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Defence Technology（防务技术） 2024年第4期34卷 69-77页

作者： zhou Yu Li Xue Weidong Xu jun Liu Qi Jia Jianghua hu Jidong Wu National Key Laboratory of Lightning Protection and Electromagnetic Camouflage Army Engineering University Nanjing 210007JiangsuChina Unit 31608 of PLA Xiamen 361000FujianChina School of Biological Sciences&Medical Engineering Southeast UniversityNanjing 210096JiangsuChina

Brain functional networks model the brain's ability to exchange information across different regions,aiding in the understanding of the cognitive process of human visual attention during target searching,thereby contributing to the advancement of camouflage *** this study,images with various camouflage effects were presented to observers to generate electroencephalography(EEG)signals,which were then used to construct a brain functional *** topological parameters of the network were subsequently extracted and input into a machine learning model for *** results indicate that most of the classifiers achieved accuracy rates exceeding 70%.Specifically,the Logistic algorithm achieved an accuracy of 81.67%.Therefore,it is possible to predict target camouflage effectiveness with high accuracy without the need to calculate discovery *** proposed method fully considers the aspects of human visual and cognitive processes,overcomes the subjectivity of human interpretation,and achieves stable and reliable accuracy.

关键词： Camouflage effect evaluation Electroencephalography(EEG) Brain functional networks Machine learning

A gas sensing neural circuit for an olfactory neuron

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Communications in Theoretical Physics 2024年第10期76卷 26-40页

作者： Xi-Kui hu Song Zhu Juan Yang Zhao Yao Ping zhou jun Ma School of Science Chongqing University of Posts and Telecommunications School of Physics and Electronics Central South University Department of Physics Lanzhou University of Technology

A gas sensor can convert external gas concentration or species into electric voltage or current signals by physical adsorption or chemical changes. As a result, a gas sensor in a nonlinear circuit can be used as a sensitive sensor for detecting external gas signals from the olfactory system. In this paper, a gas sensor and a field-effect transistor are incorporated into a simple Fithzhugh–Nagumo neural circuit for capturing and encoding external gas signals. An improved functional neural circuit is obtained, and the effect of gas concentration, gas species and neuronal activity can be discerned as the gate voltage, threshold voltage and activation coefficient of the field-effect transistor, respectively. The gas concentration can affect the neural activities from quiescent to normal working and, finally, to saturation state in bursting, spiking, periodic and chaotic firings with different frequencies. The effects of gas species and neuronal activity on the firing state can also be achieved in this functional neural circuit. In addition, variations in the gate voltage, threshold voltage and activation coefficient can cause switching between different firing modes. These results can be helpful in designing artificial olfactory devices for bionic gas recognition and other coupled systems arising in applied sciences.

关键词： bifurcation field-effect transistor gas sensor olfactory neural circuit

模拟富氧燃烧过程中燃料在CO_2中稀释对NH_3向NO_x转化影响的研究（英文）

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2015年第10期16卷 820-829页

作者： Kun-zan QIU Ye YANG Zhuo YOU Zhi-hua WANG Zhi-jun zhou jun-hu zhou Ke-fa CEN State Key Lab of Clean Energy Utilization Zhejiang University Second Institute for Wuhan Ship Development & Design

目的:探索燃料富氧燃烧过程中不同浓度CO2的稀释作用对NOx生成的影响,为探索NOx在O2/CO2气氛中生成机理研究提供理论基础。创新点:提出一种无分支链式反应解释说明CO2在还原性粒子环境中对反应的影响。方法:通过Chemkin Pro中塞流式反... 详细信息

目的:探索燃料富氧燃烧过程中不同浓度CO2的稀释作用对NOx生成的影响,为探索NOx在O2/CO2气氛中生成机理研究提供理论基础。创新点:提出一种无分支链式反应解释说明CO2在还原性粒子环境中对反应的影响。方法:通过Chemkin Pro中塞流式反应器模块对混入NH3的CH4燃料在O2/CO2气氛中反应进行数值模拟,同时改变CO2的稀释程度来探索CO2浓度对NOx生成的影响,并比较不同反应机理下的模拟结果,探索此环境中NOx的生成机理(表1)。结论:1.无支链反应机理可用于解释CO2在还原性粒子环境中对NOx生成与还原的影响;2.随着CO2浓度的升高,无支链反应和支链反应相互竞争H,进而抑制NO的生成;3.在对NH3转化效率的影响方面,CO2浓度增加引发的无支链反应和支链反应对H的竞争,在富燃料条件下从促进转化变为抑制转化,在化学当量和贫燃料条件下从无影响变为抑制转化。

关键词： CO2 富氧燃烧 NO 燃料稀释

A Review of Contact Electrification at Diversified Interfaces and Related Applications on Triboelectric Nanogenerator

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Nano-Micro Letters 2024年第1期16卷 106-130页

作者： jun hu Mitsumasa Iwamoto Xiangyu Chen CAS Center for Excellence in Nanoscience Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100083People’s Republic of China School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing 100049People’s Republic of China Department of Physical Electronics Tokyo Institute of Technology2‑12‑1 S3‑33 O‑OkayamaMeguro‑KuTokyo 152‑8552Japan

The triboelectric nanogenerator(TENG)can effectively collect energy based on contact electrification(CE)at diverse interfaces,including solid–solid,liquid–solid,liquid–liquid,gas–solid,and gas–*** enables energy harvesting from sources such as water,wind,and *** this review,we provide an overview of the coexistence of electron and ion transfer in the CE *** elucidate the diverse dominant mechanisms observed at different interfaces and emphasize the interconnectedness and complementary nature of interface *** review also offers a comprehensive summary of the factors influencing charge transfer and the advancements in interfacial modification ***,we highlight the wide range of applications stemming from the distinctive characteristics of charge transfer at various ***,this review elucidates the future opportunities and challenges that interface CE may *** anticipate that this review can offer valuable insights for future research on interface CE and facilitate the continued development and industrialization of TENG.

关键词： Contact electrification Interfaces Triboelectric nanogenerators Diversified applications