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Effects of baffle position in serpentine flow channel on the performance of proton exchange membrane fuel cells

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Chinese Journal of Chemical Engineering 2024年第5期69卷 250-262页

作者： guodong Xia Xiaoya Zhang Dandan Ma MOE Key Laboratory of Enhanced Heat Transfer and Energy Conservation Beijing Key Laboratory of Heat Transfer and Energy ConversionBeijing University of TechnologyBeijing 100124China

This study used a three-dimensional numerical model of a proton exchange membrane fuel cell with five types of channels:a smooth channel(Case 1);eight rectangular baffles were arranged in the upstream(Case 2),midstream(Case 3),downstream(Case 4),and the entire cathode flow channel(Case 5)to study the effects of baffle position on mass transport,power density,net power,***,the effects of back pressure and humidity on the voltage were *** showed that compared to smooth channels,the oxygen and water transport facilitation at the diffusion layer-channel interface were added 11.53%-20.60%and 7.81%-9.80%at 1.68 A·cm^(-2)by adding *** closer the baffles were to upstream,the higher the total oxygen flux,but the lower the flux uniformity the worse the water *** oxygen flux of upstream baffles was 8.14%higher than that of downstream baffles,but oxygen flux uniformity decreased by 18.96%at 1.68 A·cm^(-2).The order of water removal and voltage improvement was Case 4>Case 5>Case 3>Case 2>Case *** power of Case 4 was 9.87%higher than that of the smooth *** the Case 4,when the cell worked under low back pressure or high humidity,the voltage increments were *** potential increment for the back pressure of 0 atm was 0.9%higher than that of 2 atm(1 atm=101.325 kPa).The potential increment for the humidity of 100%was 7.89%higher than that of 50%.

关键词： Proton exchange membrane fuel cell Baffle position Mass transfer Net power Uniformity Voltage increment

Sec-Auditor:A Blockchain-Based Data Auditing Solution for Ensuring Integrity and Semantic Correctness

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Computers, Materials & Continua 2024年第8期80卷 2121-2137页

作者： guodong Han Hecheng Li College of Computer Qinghai Normal UniversityXining810008China

Currently,there is a growing trend among users to store their data in the ***,the cloud is vulnerable to persistent data corruption risks arising from equipment failures and hacker ***,when users perform file operations,the semantic integrity of the data can be *** both data integrity and semantic correctness has become a critical issue that requires *** introduce a pioneering solution called Sec-Auditor,the first of its kind with the ability to verify data integrity and semantic correctness simultaneously,while maintaining a constant communication cost independent of the audited data ***-Auditor also supports public auditing,enabling anyone with access to public information to conduct data *** feature makes Sec-Auditor highly adaptable to open data environments,such as the *** Sec-Auditor,users are assigned specific rules that are utilized to verify the accuracy of data ***,users are given the flexibility to update their own rules as *** conduct in-depth analyses of the correctness and security of *** also compare several important security attributes with existing schemes,demonstrating the superior properties of *** results demonstrate that even for time-consuming file upload operations,our solution is more efficient than the comparison one.

关键词： Provable data possession public auditing cloud storage data integrity semantic correctness

Phosphorus speciation and distribution in surface sediments of the Yellow Sea and East China Sea and potential impacts on ecosystem

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Acta Oceanologica Sinica 2015年第4期34卷 84-91页

作者： SONG guodong LIU Sumei Key Laboratory of Marine Chemistry Theory and Technology of Ministry of Education College of Chemistry and Chemical Engineering Ocean University of China Qingdao Collaborative Innovation Center of Marine Science and Technology

For better understanding the phosphorus （P） cycle and its impacts on one of the most important fishing grounds and pressures on the marine ecosystem in the Yellow Sea （YS） and East China Sea （ECS）, it is essential to distinguish the contents of different P speciation in sediments and have the knowledge of its distribution and bioavailability. In this study, the modified SEDEX procedure was employed to quantify the different forms of P in sediments. The contents of phosphorus fractions in surface sediments were 0.20–0.89μmol/g for exchangeable-P （Exch-P）, 0.37–2.86μmol/g for Fe-bound P （Fe-P）, 0.61–3.07μmol/g for authigenic Ca-P （ACa-P）, 6.39–13.73μmol/g for detrital-P （DAP） and 0.54–10.06μmol/g for organic P （OP）. The distribution of Exch-P, Fe-P and OP seemed to be similar. The concentrations of Exch-P, Fe-P and OP were slightly higher in the Yellow Sea than that in the East China Sea, and low concentrations could be observed in the middle part of the ECS and southwest off Cheju Island. The distribution of ACa-P was different from those of Exch-P, Fe-P and OP. DAP was the major fraction of sedimentary P in the research region. The sum of Exch-P, Fe-P and OP may be thought to be potentially bioavailable P in the research region. The percentage of bioavailable P in TP ranged from 13%to 61%. Bioavailable P burial flux that appeared regional differences was affected by sedimentation rates, porosity and bioavailable P content, and the distribution of bioavailable P burial flux were almost the same as that of TP burial flux.

关键词： phosphorus speciation burial flux sediment Yellow Sea East China Sea

A multi-criteria fusion feature selection algorithm for fault diagnosis of helicopter planetary gear train

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Chinese Journal of Aeronautics 2020年第5期33卷 1549-1561页

作者： Canfei SUN Youren WANG guodong SUN College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China Testing Center Aviation Key Laboratory of Science and Technology on Fault Diagnosis and Health ManagementShanghai 201601China

Planetary gear train is a prominent component of helicopter transmission system and its health is of great significance for the flight safety of the *** health condition monitoring,the selection of a fault sensitive feature subset is meaningful for fault diagnosis of helicopter planetary gear *** to actual situation,this paper proposed a multi-criteria fusion feature selection algorithm (MCFFSA) to identify an optimal feature subset from the highdimensional original feature *** MCFFSA,a fault feature set of multiple domains,including time domain,frequency domain and wavelet domain,is first extracted from the raw vibration *** targeted criteria are then fused by multi-objective evolutionary algorithm based on decomposition (MOEA/D) to find Proto-efficient subsets,wherein two criteria for measuring diagnostic performance are assessed by sparse Bayesian extreme learning machine (SBELM).Further,Fmeasure is adopted to identify the optimal feature subset,which was employed for subsequent fault *** effectiveness of MCFFSA is validated through six fault recognition datasets from a real helicopter transmission *** experimental results illustrate the superiority of combination of MOEA/D and SBELM in MCFFSA,and comparative analysis demonstrates that the optimal feature subset provided by MCFFSA can achieve a better diagnosis performance than other algorithms.

关键词： Fault detection Feature selection F-measure Helicopter planetary gear train Multi-objective evolutionary algorithm

CORRELATIONS BETWEEN OXY-HEMOGLOBIN AND RESPIRATORY EXCHANGE RATIO IN THE QUADRICEPS duRING THE EARLY PHASE OF EXERCISES

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Journal of Innovative Optical Health Sciences 2010年第2期3卷 141-146页

作者： guodong XU YANJIE YE School of Physical Education Jianghan University WuhanHubei 430056P.R.China Wuhan Institute of Physical Education Wuhan Hubei 430079P.R.China

The early stage of exercises is crucial in sports training;however,its physiological mechanism is still *** hemodynamic response was reported to be associated with respiratory ***,we aimed to explore the relationship between oxy-hemoglobin concentration change(HbO_(2))and respiratory exchange ratio(RER)during the early phase of *** athletes of middle-distance race were selected from Wuhan Institute of Physical Education to conduct intermittent exercises on MERCURY4.0 at 80%VO_(2)peak *** physiological parameters were acquired by use of a near-infrared spectroscopy muscle oxygen monitor,a Cardiopulmonary Function MAX-II and a P-Lar,including HbO_(2),RER and others.A significant correlation was found between RER and HbO_(2)in quadriceps muscle in the thigh during the early phase of ***,NIRS is capable of supervising sports training in terms of HbO_(2),which actually acted as an interpreter of RER change.

关键词： Near-infrared spectroscopy intermittent exercises respiratory exchange ratio oxyhemoglobin.

Using the Lund-Potsdam-Jena Model to Understand the Different Responses of Three Woody Plants to Land Use in China

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Advances in Atmospheric Sciences 2013年第2期30卷 515-524页

作者： SUN guodong MU Mu State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 Key Laboratory of Ocean Circulation and Wave Institute of Oceanology Chinese Academy of Sciences Qingdao 266071

In this study, the approach of conditional nonlinear optimal perturbation related to initial perturbation （CNOP-I） was employed to investigate the maximum variations in plant amount for three main woody plants （a temperate broadleaved evergreen, a temperate broadleaved summergreen, and a boreal needleleaved evergreen） in China. The investigation was conducted within a certain range of land use intensity using a state-of-the-art Lund-Potsdam-Jena dynamic global vegetation model （LPJ DGVM）. CNOP-I represents a class of deforestation and can be considered a type of land use with respect to the initial perturbation. When deforestation denoted by the CNOP-I has the same intensity for all three plants, the variation in plant amount of the boreal needleleaved evergreen in northern China is greater than the variation in plant amount of both the temperate broadleaved evergreen and temperate broadleaved summergreen in southern China. As deforestation intensity increases, the plant amount variation in the three woody plant functional types carbon changes, in a nonlinear fashion. The impact of land use on plant functional types is minor because the interaction between climate condition and land use is not considered in the LPJ model. Finally, the different impacts of deforestation on net primary production of the three plant functional types were analyzed by modeling gross primary production and autotrophic respiration. Our results suggest that the CNOP-I approach is a useful tool for exploring the nonlinear and different responses of terrestrial ecosystems to land use.

关键词： conditional nonlinear optimal perturbation initial perturbation CNOP-I terrestrial ecosys-tem land use

Personal summarization from profile networks

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Frontiers of Computer Science 2017年第6期11卷 1085-1097页

作者： Zhongqing WANG Shoushan LI guodong ZHOU Natural Language Processing Lab School of Computer Science and Technology Soochow University Suzhou 215006 China

Personal profile information on social media like *** and *** is at the core of many inter- esting applications, such as talent recommendation and con- textual advertising. However, personal profiles usually lack consistent organization confronted with the large amount of available information. Therefore, it is always a challenge for people to quickly find desired information from them. In this paper, we address the task of personal profile summarization by leveraging both textual information and social connection information in social networks from both unsupervised and supervised learning paradigms. Here, using social connec- tion information is motivated by the intuition that people with similar academic, business or social background （e.g., co- major, co-university, and co-corporation） tend to have similar experiences and should have similar summaries. For unsu- pervised learning, we propose a collective ranking approach, called SocialRank, to combine textual information in an in- dividual profile and social context information from relevant profiles in generating a personal profile summary. For super- vised learning, we propose a collective factor graph model, called CoFG, to summarize personal profiles with local tex- tual attribute functions and social connection factors. Exten- sive evaluation on a large dataset from *** demon- strates the usefulness of social connection information in per- sonal profile summarization and the effectiveness of our pro- posed unsupervised and supervised learning approaches.

关键词： natural language processing machine learning,social networks personal profile summarization

Contribution of the Kodama and 4S pathways to the dibenzothiophene biodegradation in different coastal wetlands under different C/N ratios

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Journal of Environmental Sciences 2019年第2期31卷 217-226页

作者： Lei Wang guodong Ji Siqiao Huang Key Laboratory of Water and Sediment Sciences Ministry of EducationDepartment of Environmental EngineeringPeking University

Dibenzothiophene(DBT) degradation mechanisms and the transformation of pathways during the incubation of three types of coastal sediments with C/N ratios ranging from 1 to 9 were investigated. The DBT degradation efficiencies were clearly improved with increasing C/N ratio in reed wetland sediments, tidal wetlands sediments and estuary wetland sediments. The quantitative response relationships between DBT degradation rates and related functional genes demonstrate that the Kodama pathway-related gene groups were dominant factors at low C/N ratios, while the 4S-related gene groups mainly determined the degradation rate when the C/N ratio was up to 5. Network analysis also shows that the pathway shifts from the Kodama pathway to the 4S pathway occurred through changes in the connections between functional genomes and rates. Furthermore, there were competition and collaboration between the Kodama and 4S pathways. The 4S pathway-related bacteria were more active in estuary wetland sediments compared with reed wetland sediments and tidal wetland sediments. The higher degradation efficiency in estuary wetland sediments may indicate the greater participation of the 4S pathway in the DBT biodegradation reaction. And the effects of ring cleavage of Kodama pathway caused more complete metabolizing of DBT.

关键词： Dibenzothiophene(DBT) Coastal wetlands Functional genes Degradation mechanism Quantitative response relationship Network analysis

Variations in soil moisture over the ‘Huang-Huai-Hai Plain＇ in China due to temperature change using the CNOP-P method and outputs from CMIP5

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Science China Earth Sciences 2017年第10期60卷 1838-1853页

作者： SUN guodong PENG Fei MU Mu State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Institute of Atmospheric Sciences Fudan University Shanghai 200433 China University of Chinese Academy of Sciences Beijing 100049 China Numerical Weather Prediction Center China Meteorological Administration Beijing 100081 China

In this study, the variations in surface soil liquid water(SSLW) due to future climate change are explored in the‘Huang-Huai-Hai Plain'(‘3H') region in China with the Common Land Model(CoLM). To evaluate the possible maximum response of SSLW to climate change, the combination of the conditional nonlinear optimal perturbation related to the parameter(CNOP-P) approach and projections from 10 general circulation models(GCMs) of the Coupled Model Intercomparison Project5(CMIP5) are used. The CNOP-P-type temperature change scenario, a new type of temperature change scenario, is determined by using the CNOP-P method and constrained by the temperature change projections from the 10 GCMs under a high-emission scenario(the Representative Concentration Pathway 8.5 scenario). Numerical results have shown that the response of SSLW to the CNOP-P-type temperature scenario is stronger than those to the 11 temperature scenarios derived from the 10 GCMs and from their ensemble average in the entire ‘3H' region. In the northern region, SSLW under the CNOP-P-type scenario increases to0.1773 m^3 m^(-3); however, SSLW in the scenarios from the GCMs fluctuates from 0.1671 to 0.1748 m^3 m^(-3). In the southern region,SSLW decreases, and its variation(–0.0070 m^3 m^(-3)) due to the CNOP-P-type scenario is higher than each of the variations(–0.0051 to –0.0026 m^3 m^(-3)) due to the scenarios from the GCMs.

关键词： CNOP-P Surface soil liquid water CMIP5 Climate change Seasonal and regional heterogeneity