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Evaluation of Auto-Ignition Characteristics of Diesel Surrogate Fuels with the Same Derived Cetane Numbers at Changed Thermodynamic Environments

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Journal of Thermal Science 2024年第4期33卷 1590-1606页

作者： ZhanG Cong GUAN Yuanhang HUANG zhen han Dong Key Laboratory for Power Machinery and Engineering Ministry of EducationShanghai Jiao Tong UniversityShanghai200240China College of Smart Energy Shanghai Jiao Tong UniversityShanghai200240China Shanghai Non-carbon Energy Conversion and Utilization Institute Shanghai200240China

The ignition tendency of diesel fuels is highly sensitive to ambient conditions and fuel *** this study,the ignition characteristics of different diesel surrogate fuels with the same derived cetane numbers(DCN)were measured and compared in varied thermodynamic and oxidizing *** combustion pressures,heat release rates,ignition delays,and combustion delays of the test fuels were *** experimental results showed that the diesel surrogate fuels with the same DCNs exhibit similar ignition propensity at standard DCN test ***,for the test conditions of high cetane fuels,high ambient temperatures,and suficient oxygen concentrations,surrogate fuels with the same DCN have similar ignition behaviors,and using the DCN to evaluate fuel ignition tendency is ***,for the test conditions of low cetane fuels,low ambient temperatures,and reduced oxygen concentrations,different ignition behaviors are observed for the surrogate fuels with the same DCN,so at these conditions using DCN as the evaluation index for fuel ignition tendency may lead to higher uncertainty.

关键词： diesel fuels surrogate fuels derived cetane numbers constant volume combustion chamber

Molecular dynamics study of hydrogen-induced cracking behavior of ferrite–pearlite gas transmission pipeline steel

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Journal of Iron and Steel Research International 2024年第2期31卷 488-500页

作者： Tao-long Xu Si-han Guo Gong-zhen He Hao-yu han Petroleum Engineering School Southwest Petroleum UniversityChengdu610500SichuanChina Sichuan East Gas Transmission Sales Center of Sinopec Natural Gas Branch Wuhan430074HubeiChina

Hydrogen embrittlement of pipelines depends on the hydrogen-induced cracking behavior of the pipeline steel *** on molecular dynamics analysis,the ferrite–cementite(α-Fe/Fe3C)lamellar atomic structure with the Bagaryatskii orientation relationship was established,and stepwise relaxation of the conjugate gradient energy minimization and constant-temperature and constant-pressure relaxation were performed under NPT(the isothermal–isobaric)*** mechanical property curves of theα-Fe/Fe3C models were obtained under different cementite terminal plane structures,and the evolution of the atomic structure was analyzed in *** addition,the influence of different hydrogen concentrations,different temperatures,different strain rates,changes in voids,and different micro-degrees of freedom on the deformation and failure mechanism of the model was investigated,aiming to provide a reliable way to explore the micro-mechanism of macro-cracking behavior of pipeline steel.

关键词： Ferrite-cementite lamellar structure Pipeline steel Failure mechanism Crack propagation Molecular dynamics

Black-box membership inference attacks based on shadow model

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The Journal of China Universities of Posts and Telecommunications 2024年第4期31卷 1-16页

作者： han zhen Zhou Wen'an han Xiaoxuan Wu Jie School of Computer Science Beijing University of Posts and TelecommunicationsBeijing 100876China

Membership inference attacks on machine learning models have drawn significant *** current research primarily utilizes shadow modeling techniques,which require knowledge of the target model and training data,practical scenarios involve black-box access to the target model with no available *** training data further complicate the implementation of these *** this paper,we experimentally compare common data enhancement schemes and propose a data synthesis framework based on the variational autoencoder generative adversarial network(VAE-GAN)to extend the training data for shadow ***,this paper proposes a shadow model training algorithm based on adversarial training to improve the shadow model's ability to mimic the predicted behavior of the target model when the target model's information is *** conducting attack experiments on different models under the black-box access setting,this paper verifies the effectiveness of the VAE-GAN-based data synthesis framework for improving the accuracy of membership inference ***,we verify that the shadow model,trained by using the adversarial training approach,effectively improves the degree of mimicking the predicted behavior of the target *** with existing research methods,the method proposed in this paper achieves a 2%improvement in attack accuracy and delivers better attack performance.

关键词： machine learning membership inference attack shadow model black-box model

Improved Variable Forgetting Factor Proportionate RLS Algorithm with Sparse Penalty and Fast Implementation Using DCD Iterations

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China Communications 2024年第10期21卷 16-27页

作者： han zhen Zhang Fengrui Zhang Yu han Yanfeng Jiang Peng GNSS Research Center Wuhan UniversityWuhan 430072China School of Information Science and Technology Shijiazhuang Tiedao UniversityShijiazhuang 050043China

The proportionate recursive least squares(PRLS)algorithm has shown faster convergence and better performance than both proportionate updating(PU)mechanism based least mean squares(LMS)algorithms and RLS algorithms with a sparse regularization *** this paper,we propose a variable forgetting factor(VFF)PRLS algorithm with a sparse penalty,e.g.,l_(1)-norm,for sparse *** reduce the computation complexity of the proposed algorithm,a fast implementation method based on dichotomous coordinate descent(DCD)algorithm is also *** results indicate superior performance of the proposed algorithm.

关键词： dichotomous coordinate descent proportionate matrix RLS sparse systems variable forgetting factor

Novel intelligent reasoning system for tool wear prediction and parameter optimization in intelligent milling

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Advances in Manufacturing 2024年第1期12卷 76-93页

作者： Long-Hua Xu Chuan-zhen Huang zhen Wang han-Lian Liu Shui-Quan Huang Jun Wang School of Mechanical Engineering Yanshan UniversityQinhuangdao066004HebeiPeople’s Republic of China Center for Advanced Jet Engineering Technologies(CaJET) Key Laboratory of High-efficiency and Clean Mechanical Manufacture(Ministry of Education)National Experimental Teaching Demonstration Center for Mechanical Engineering(Shandong University)School of Mechanical EngineeringShandong UniversityJinan250061People’s Republic of China Institute of Manufacturing Technology Guangdong University of TechnologyGuangzhou510006People’s Republic of China

Accurate intelligent reasoning systems are vital for intelligent *** this study,a new intelligent reasoning system was developed for milling processes to accurately predict tool wear and dynamically optimize machining *** developed system consists of a self-learning algorithm with an improved particle swarm optimization(IPSO)learning algorithm,prediction model determined by an improved case-based reasoning(ICBR)method,and optimization model containing an improved adaptive neural fuzzy inference system(IANFIS)and *** results showed that the IPSO algorithm exhibited the best global convergence *** ICBR method was observed to have a better performance in predicting tool wear than standard CBR *** IANFIS model,in combination with IPSO,enabled the optimization of multiple objectives,thus generating optimal milling *** paper offers a practical approach to developing accurate intelligent reasoning systems for sustainable and intelligent manufacturing.

关键词： Improved particle swarm optimization(IPSO)algorithm Improved case-based reasoning(ICBR)method Adaptive neural fuzzy inference system(ANFIS)model Tool wear prediction Intelligent manufacturing

Overview of SSRF phase-Ⅱ beamlines

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Nuclear Science and Techniques 2024年第8期35卷 48-57页

作者： Ren‑Zhong tai zhen‑Tang Zhao Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

The SSRF phase-Ⅱ beamline project was launched in 2016. Its major goal was to establish a systematic state-of-the-art experimental facility for third-generation synchrotron radiation to solve problems in cutting-edge science and ***, the construction is fully completed. All 16 newly built beamlines with nearly 60 experimental methods passed acceptance testing by the Chinese Academy of Sciences and are in operation.

关键词： SSRF phase-Ⅱbeamline project Accelerator upgrade User laboratory User data center Beamline technique support

Enhancing flotation recovery of residual carbon from gasification waste by mixing hydrophobic powder with diesel as collector

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Particuology 2024年第6期89卷 211-217页

作者： Rui han Ningning Zhang Anning Zhou zhen Li Jinzhou Qu Hong Wang College of Chemistry and Chemical Engineering Xi’an University of Science and TechnologyXi’anShaanxi 710054China

Coal gasification fine slag(CGFS)is a solid waste containing residual carbon and ash generated during the coal gasification process,and the separation of the two components is the essential way to realize its environmental pollution reduction and resource value *** flotation is the preferred method for separating CGFS,but there is a barrier of low carbon recovery in this process due to the extensive adsorption of collector by the well-developed pores on residual *** this study,a sufficiently simple yet innovative collector,a mixture of hydrophobic powder and diesel,was proposed in an attempt to break the *** experiments with common diesel and this novel collector were performed respectively,and FTIR,XPS,and SEM-EDX were employed to analyze the collector action *** results revealed that the novel collector could significantly improve the residual carbon recovery;test results demonstrated that the novel collector could increase the hydrophobic functional group content on the fine slag surface,and the hydrophobic powders in this novel collector mainly appeared at the pore openings of the flotation *** essence of the mechanism is that the hydrophobic powders play a dual role of blocking pores and providing adsorption sites,thus facilitating the spreading of diesel on the carbon surface and promoting its *** study can provide creative ideas for the efficient disposal of coal gasification waste.

关键词： Coal gasification fine slag Carbon recovery Collector Fotation Hydrophobic powder

Resurgence of pertussis:reasons and coping strategies

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World Journal of Pediatrics 2024年第7期20卷 639-642页

作者： Chun-zhen Hua han-Qing He Qiang Shu Department of Infectious Diseases National Clinical Research Center for Child HealthChildren’s HospitalZhejiang University School of MedicineHangzhou310052China Department of Immunization Program Zhejiang Provincial Center for Disease Control and PreventionHangzhou310051China National Clinical Research Center for Child Health Children’s HospitalZhejiang University School of MedicineHangzhou310052China

Pertussis(whooping cough)is an acute and contagious respiratory disease caused by the pathogen Bordetella pertussis(***).*** can infect individuals of all *** with pertussis may experience severe and persistent coughing and paroxysms;for newborns and infants,pertussis may be *** development and widespread administration of the pertussis vaccine had once successfully brought pertussis under control,maintaining it at a low level for many ***,resurgence of pertussis has been reported in many countries even with high vaccination coverage *** resurgence of pertussis was first reported in the United States(USA)in 1993[1].During 2000–2016,the baseline incidence increased and the age distribution of pertussis changed in the USA[2].Other countries including Canada[3],Australia[4],European Union countries,and South Korea have also reported a rise in pertussis outbreaks[2,5].

关键词： pertussis Canada surge

Climatic impacts induced by winter wheat irrigation over North China simulated by the nonhydrostatic RegCM4.7

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Advances in Climate Change Research 2024年第2期15卷 197-210页

作者： Jia WU zhen-Yu han Xue-Jie GAO zheng-Jia LIU National Climate Centre China Meteorological AdministrationBeijing 100081China Key Laboratory for Climate Studies China Meteorological AdministrationBeijing 100081China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation *** related studies mainly focused on the impact on surface processes;however,few focused on the effects of extreme events using high-resolution nonhydrostatic regional climate ***,the 9-km-resolution nonhydrostatic RegCM4.7 was coupled with a crop irrigation scheme and an updated winter wheat irrigation dataset to better simulate irrigation *** experiments were conducted with and without winter wheat irrigation to isolate the effects of *** showed that irrigation simulation reduces the model biases in temperature,precipitation,latent heat flux,soil moisture,sensitive heat flux,and top-layer soil ***,it also reduces the bias and increases the correlation with observations obtained in irrigated areas,especially in summer,indicating better representation of irrigation *** wheat irrigation tends to cause substantial cooling of the local surface maximum,minimum,and mean air temperatures(by-1.68,-0.34,and-0.79℃,respectively)over irrigated areas of North China,with the largest changes observed in relation to maximum ***,precipitation is found to increase during spring and summer,which is strongly related to water vapor transport in the lower levels of the *** analyses indicated that the number of annual mean hot days decrease(-13.9 d),whereas the number of both comfort days(+10.2 d)and rainy days(days with total precipitation greater than 1 mm:+6.6 d)increase over irrigated areas,demonstrating beneficial feedback to human perception and ***,although the heat wave risk increases(number of annual mean heat wave days:+5.8 d),the impact is limited to small areas within irrigated ***,no notable change was found in terms of heavy rainfall events and precipitation intensity

关键词： Nonhydrostatic regional climate model Irrigation effect Extreme events North China