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Advancing electrochemical drilling process via coupling of flow field and electric field in pulsating state generated by a novel tube tool

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Chinese Journal of Aeronautics 2024年第4期37卷 542-555页

作者： Liang CHENG Xiaolei CHEN Zhisen YE yongjun zhang State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of Advanced Manufacturing Technology of Marine Energy Equipment Guangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Nontraditional Machining and Equipment Guangdong University of TechnologyGuangzhou 510006China

This paper introduces an improvement to electrochemical drilling process by coupling flow field and electric field in pulsating state. A novel tube with half-wedged shape at the end(HW-tube) is prepared, with both sidewall and wedged part of the HW-tube insulated. Only the flat part is utilized to provide electric field for electrochemical drilling. By rotating the HW-tube, both flow field and electric field in pulsating state are generated, alternating in different positions within the inter-electrode gap(IEG). The pulsating flow field enhances the mass transfer process, while pulsating electric field disperses material dissolution process and distribution of electrolytic byproducts. Both pulsating fields are coupled at the same frequency, further enhancing the electrochemical drilling process. Simulation results indicate that both flow field and electric field in pulsating state are generated. Compared to the traditional tube, the HW-tube significantly reduces the number of residual particles in IEG, and this number is further reduced by increasing the rotation speed. Experimental results reveal that the surface quality and dimensional uniformity of small hole are improved with HW-tube. With feed rate of 2.22 mm/min, a small hole with diameter of 1.52± 0.017 mm is drilled, resulting in a surface roughness of 0.331 μm.

关键词： Small holes Electrochemical drilling Tools Pulsating flow field Pulsating electric field

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Sparse representation scheme with enhanced medium pixel intensity for face recognition

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CAAI Transactions on Intelligence Technology 2024年第1期9卷 116-127页

作者： Xuexue zhang yongjun zhang Zewei Wang Wei Long Weihao Gao Bob zhang State Key Laboratory of Public Big Data Institute for Artificial IntelligenceCollege of Computer Science and TechnologyGuizhou UniversityGuiyangGuizhouChina Department of Computer and Information Science University of MacaoAvenida da UniversidadeTaipaMacaoChina

Sparse representation is an effective data classification algorithm that depends on the known training samples to categorise the test sample.It has been widely used in various image classification tasks.Sparseness in sparse representation means that only a few of instances selected from all training samples can effectively convey the essential class-specific information of the test sample,which is very important for classification.For deformable images such as human faces,pixels at the same location of different images of the same subject usually have different intensities.Therefore,extracting features and correctly classifying such deformable objects is very hard.Moreover,the lighting,attitude and occlusion cause more difficulty.Considering the problems and challenges listed above,a novel image representation and classification algorithm is proposed.First,the authors’algorithm generates virtual samples by a non-linear variation method.This method can effectively extract the low-frequency information of space-domain features of the original image,which is very useful for representing deformable objects.The combination of the original and virtual samples is more beneficial to improve the clas-sification performance and robustness of the algorithm.Thereby,the authors’algorithm calculates the expression coefficients of the original and virtual samples separately using the sparse representation principle and obtains the final score by a designed efficient score fusion scheme.The weighting coefficients in the score fusion scheme are set entirely automatically.Finally,the algorithm classifies the samples based on the final scores.The experimental results show that our method performs better classification than conventional sparse representation algorithms.

关键词： computer vision face recognition image classification image representation

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Associations of Perchlorate,Nitrate,and Thiocyanate with Sex Hormones among Children:A Nationally Representative Cross-sectional Study in U.S.

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Biomedical and Environmental Sciences 2024年第6期37卷 666-671页

作者： Yiwen Wang Guodong Ding Peipei Hu yongjun zhang Department of Pediatrics Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghai 200092China MOE-Shanghai Key Laboratory of Children’s Environmental Health Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghai 200092China

Nitrates,thiocyanates,and perchlorates are ubiquitous in the environment and can be introduced to the public through various dietary and environmental sources.Nitrates,thiocyanates,and perchlorates mainly affect health via the same mechanism.These toxins may act as endocrine disrupters and can result in decreased levels of thyroid hormones^([1]).

关键词： mechanism. sectional perchlorate

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High catalytic performance of neodymium modified Co_(3)O_(4) for toluene oxidation

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Journal of Rare Earths 2024年第1期42卷 94-101,I0004页

作者： Yanqiong Hu Luyue zhang Jianbei zhang yongjun Liu School of Architecture and Environment Sichuan UniversityChengdu610065China National Engineering Research Center for Flue Gas Desulfurization Chengdu610065China

Co-based catalysts are the most promising catalysts in catalytic oxidation of volatile organic compounds(VOCs).Precious metal doping is adopted to improve the catalytic activity of toluene on Co_(3)O_(4) catalysts,but greatly increases its cost along with it.It is found that doping a small amount of rare earth(Ce,Pr,Sm and Nd)can dramatically promote the catalytic activity of Co_(3)O_(4).Especially,the Nd-doped Co_(3)O_(4) catalyst exhibits excellent catalytic activity with a toluene removal rate of 90% at 162.1℃,which is even better than that of Pt-doped Co_(3)O_(4).Compared with other rare earth metal doping,the Nd doping leads to a higher ratio of Co^(3+)/Co^(2+) and has more oxygen vacancies.The in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)experiments show that the lattice oxygen of Nd-Co sample can be utilized at a quite low temperature,while that of pure Co_(3)O_(4) cannot engage in oxidation reaction when the temperature is below 200℃,which visually demonstrates the main reason for the improved catalytic performance of Nd-Co catalyst.

关键词： Rare earth metals Nd Co_(3)O_(4) Toluene catalytic oxidation Oxygen vacancy Lattice oxygen

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Responses of arbuscular mycorrhizal fungi to straw return and nitrogen fertilizer reduction in a rainfed maize field

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Pedosphere 2024年第2期34卷 351-360页

作者： Zhenling PENG Hao XI Lin MAO Huyuan FENG Jianjun zhang yongjun LIU State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems College of EcologyLanzhou UniversityLanzhou 730000China College of Life Sciences Northwest Normal UniversityLanzhou 730070China School of Life Sciences Lanzhou UniversityLanzhou 730000China Dryland Agriculture Institute Gansu Academy of Agricultural SciencesLanzhou 730070China

Straw return can be used to reduce fertilizer input and improve agricultural sustainability and soil health.However,how straw return and reduced fertilizer application affect beneficial soil microbes,particularly arbuscular mycorrhizal fungi(AMF),remains poorly understood.Here,we conducted a five-year field experiment in a rainfed maize field on the Loess Plateau of northwestern China.We tested four treatments with straw return combined with four nitrogen(N)application rates,i.e.,100%,80%,60%,and 0%of the common N application rate(225 kg N ha^(-1)year^(-1))in this region,and two reference treatments(full or no N application),with three replicates for each treatment.Mycorrhizal colonization was quantified and AMF communities colonizing maize roots were characterized using Illumina sequencing.Forty virtual taxa(VTs)of AMF were identified in root samples,among which VT113(related to Rhizophagus fasciculatus)and VT156(related to Dominikia gansuensis)were the predominant taxa.Both root length colonization and AMF VT richness were sensitive to N fertilization,but not to straw return;furthermore,both gradually increased with decreasing N application rate.The VT composition of the AMF community was also affected by N fertilization,but not by straw return,and the community variation could be well explained by soil available N and phosphorus concentrations.Additionally,60%,80%,and full N fertilization produced similar maize yields.Thus,our study revealed the response patterns of AMF to straw return and N fertilizer reduction and showed that straw return combined with N fertilizer reduction may be a promising practice to maintain mycorrhizal symbiosis concomitantly with crop productivity.

关键词： agricultural sustainability crop productivity mycorrhizal colonization mycorrhizal symbiosis root length colonization virtual taxon

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Reinforcement learning based edge computing in B5G

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Digital Communications and Networks 2024年第1期10卷 1-6页

作者： Jiachen Yang Yiwen Sun Yutian Lei Zhuo zhang Yang Li yongjun Bao Zhihan Lv School of Electrical and Information Engineering Tianjin UniversiyTianjin300072China Technology and Data Center ***Bejing100176China School of Data Science and Software Engineering Qingdao UniversityQingdao266101China

The development of communication technology will promote the application of Internet of Things,and Beyond 5G will become a new technology promoter.At the same time,Beyond 5G will become one of the important supports for the development of edge computing technology.This paper proposes a communication task allocation algorithm based on deep reinforcement learning for vehicle-to-pedestrian communication scenarios in edge computing.Through trial and error learning of agent,the optimal spectrum and power can be determined for transmission without global information,so as to balance the communication between vehicle-to-pedestrian and vehicle-to-infrastructure.The results show that the agent can effectively improve vehicle-to-infrastructure communication rate as well as meeting the delay constraints on the vehicle-to-pedestrian link.

关键词： Reinforcement learning Edge computing Beyond 5G Vehicle-to-pedestrian

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Association of DNA methylation/demethylation with the functional outcome of stroke in a hyperinflammatory state

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Neural Regeneration Research 2024年第10期19卷 2229-2239页

作者： Yubo Wang Ling zhang Tianjie Lyu Lu Cui Shunying Zhao Xuechun Wang Meng Wang yongjun Wang Zixiao Li Vascular Neurology Department of NeurologyBeijing Tiantan HospitalCapital Medical UniversityBeijingChina China National Clinical Research Center for Neurological Diseases Beijing Tiantan HospitalCapital Medical UniversityBeijingChina National Center for Healthcare Quality Management in Neurological Diseases Beijing Tiantan HospitalCapital Medical UniversityBeijingChina Chinese Institute for Brain Research BeijingChina Research Unit of Artificial Intelligence in Cerebrovascular Disease Chinese Academy of Medical SciencesBeijingChina Beijing Engineering Research Center of Digital Healthcare for Neurological Diseases BeijingChina

Inflammation is closely related to stroke prognosis, and high inflammation status leads to poor functional outcome in stroke. DNA methylation is involved in the pathogenesis and prognosis of stroke. However, the effect of DNA methylation on stroke at high levels of inflammation is unclear. In this study, we constructed a hyperinflammatory cerebral ischemia mouse model and investigated the effect of hypomethylation and hypermethylation on the functional outcome. We constructed a mouse model of transient middle cerebral artery occlusion and treated the mice with lipopolysaccharide to induce a hyperinflammatory state. To investigate the effect of DNA methylation on stroke, we used small molecule inhibitors to restrain the function of key DNA methylation and demethylation enzymes. 2,3,5-Triphenyltetrazolium chloride staining, neurological function scores, neurobehavioral tests, enzyme-linked immunosorbent assay, quantitative reverse transcription PCR and western blot assay were used to evaluate the effects after stroke in mice. We assessed changes in the global methylation status by measuring DNA 5-mc and DNA 5-hmc levels in peripheral blood after the use of the inhibitor. In the group treated with the DNA methylation inhibitor, brain tissue 2,3,5-triphenyltetrazolium chloride staining showed an increase in infarct volume, which was accompanied by a decrease in neurological scores and worsening of neurobehavioral performance. The levels of inflammatory factors interleukin 6 and interleukin-1 beta in ischemic brain tissue and plasma were elevated, indicating increased inflammation. Related inflammatory pathway exploration showed significant overactivation of nuclear factor kappa B. These results suggested that inhibiting DNA methylation led to poor functional outcome in mice with high inflammation following stroke. Further, the effects were reversed by inhibition of DNA demethylation. Our findings suggest that DNA methylation regulates the inflammatory response in stroke and has an important role in the functional out

关键词： DNA demethylation DNA methylation DNMT3A functional outcome hyperinflammatory state interleukin neuroinflammation stroke TET2

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A growth-regulating factor 7(GRF7)-mediated gene regulatory network promotes leaf growth and expansion in sugarcane

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The Crop Journal 2024年第2期12卷 422-431页

作者： Qiaoyu Wang Yihan Li Dadong Lin Xiaoxi Feng yongjun Wang Tianyou Wang Hongyan Ding Jisen zhang State Key Lab for Conservation and Utilization of Subtropical AgroBiological Resources and Guangxi Key Lab for Saccharum Biology Guangxi UniversityNanning 530005GuangxiChina Center for Genomics and Biotechnology/Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology/Key Laboratory of Saccharum Biology and Genetic Breeding/National Engineering Research Center for Saccharum Fujian Agriculture and Forestry UniversityFuzhou 350002FujianChina

Knowledge of the function of growth-regulating factors(GRFs)in sugarcane(Saccharum officinarum and S.spontaneum)growth and development could assist breeders in selecting desirable plant architectures.However,limited information about GRFs is available in Saccharum due to their polyploidy.In this study,22 GRFs were identified in the two species and their conserved domains,gene structures,chromosome location,and synteny were characterized.GRF7 expression varied among tissues and responded to diurnal rhythm.SsGRF7-YFP was localized preferentially in the nucleus and appears to act as a transcriptional cofactor.SsGRF7 positively regulated the size and length of rice leaves,possibly by regulating cell size and plant hormones.Of seven potential transcription factors binding to the SsGRF7 promoter in S.spontaneum,four showed positive expression patterns,and two showed negative expression patterns relative to SsGRF7.

关键词： Expression analysis Growth-regulating factor Leaf development Sugarcane Transcription factors

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A Model Predictive Control Algorithm Based on Biological Regulatory Mechanism and Operational Research

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自动化学报:英文版 2023年第11期10卷 2174-2176页

作者： Jinying Yang yongjun zhang Tanju Yildirim Jiawei zhang Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China National Institute for Materials Science Ibaraki 305-0047Japan School of Electrical and Information Engineering University of SydneySydney 2000Australia

Dear Editor,This letter presents an intelligent model predictive control algorithm inspired by biological regulatory mechanism and operational research. In terms of overall architecture, based on biological regulatory system and operational research theory, priority factor module and central coordination module are innovatively added on the basis structure of heuristic dynamic programming to carry out overall regulation of the system.

关键词： carry letter programming

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A global evaluation of the associations between long-term dynamics of seed falls and rodents

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Integrative Zoology 2023年第5期18卷 831-842页

作者： Rui LIU yongjun zhang Hongmao zhang Lin CAO Chuan YAN State Key Laboratory of Grassland Agro-ecosystems College of Ecology&School of Life SciencesLanzhou UniversityLanzhouChina Institute of Evolution and Ecology College of Life SciencesCentral China Normal UniversityWuhanChina College of Ecology and Environmental Science Yunnan UniversityKunmingChina Yunnan Key Laboratory of Plant Reproductive Adaptation and Evolutionary Ecology and Institute of Biodiversity Yunnan UniversityKunmingChina

One classic system of pulsed resource and animal population is mast seeding and population dynamics of seedeating rodents in forests.However,we still lack an understanding of the global patterns regarding the contributions of seed falls to rodent outbreaks or population dynamics.We analyzed a global dataset of coupled long-term time series of seed abundances and rodent populations from published literature,including 66 and 89 time series(156 rodent-seed pairs from 37 studies)for rodent and seed abundances,respectively.We found only half of the examined rodent populations showed statistically significant coincidence between rodent outbreak and mastseeding years.Over all the coupled time series,seed abundance was found to positively correlate with rodent abundance with a one-year lag,and the relative importance of seed abundance was much lower than that of density dependence in affecting rodent population growth rates.We also found the relative importance of seed abundance decreased,but that of rodent density dependence increased with the latitude of study.For the first time,our work provides a global pattern on the associations between seed falls and rodent population dynamics mostly in midand high-latitude forests,and highlights the necessity of more long-term studies on this subject in more forest ecosystems.

关键词： density dependence mast resource pulse rodent seed

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