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An uncertainty investigation for liner impedance eduction methods

Chinese Journal of Aeronautics 2024年第3期37卷 49-59页

作者： Weihao shi Xiaodong jing School of Energy and Power Engineering Beihang UniversityBeijing 100191China

Impedance eduction methods have been developed for decades to meet the increasing need for high-quality impedance data in the design and optimization of acoustic *** this end,it is important to fully investigate the uncertainty problem,to which only limited attention has been devoted so *** paper considers the possibility of acoustically-induced structural vibration as a nonnegligible uncertainty or error source in impedance eduction *** the frequency moves away from the resonant frequency,with the increase in the value of cavity reactance,the acoustic particle velocity inside liner orifices possibly decreases to the extent comparable to the vibration velocity of liner facing ***,the acoustically-induced vibration,although generally being weak except at the inherent structural frequencies,may considerably affect the impedance eduction results near the anti-resonant frequency where the liner has poor *** demonstrate the effect of structural vibration,the vibration velocity of liner facing sheet is estimated from the experimentally educed admittance of the liner samples whose orifices are sealed with ***,a three-dimensional numerical model is set up,in which normal particle velocity is introduced over the solid portion of liner facing sheet to imitate structural vibration,rather than directly solving the acoustic-structural coupling *** shown by the results,the vibration of liner facing sheet,whose velocity is as small as estimated by the experiment,can result in anomalous deviation of the educed impedance from the impedance model near the anti-resonant *** trend that the anomalous deviation varies with frequency is numerically captured.

关键词： Impedance eduction Uncertainty analysis Acoustically-induced structural vibration Anti-resonant frequency Perforated liner

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Source apportionment and suitability evaluation of seasonal VOCs contaminants in the soil around a typical refining-chemical integration park in China

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Journal of Environmental Sciences 2024年第3期137卷 651-663页

作者： Xu Zhao jing Meng Qianqian Li Guijin Su Qifan Zhang Bin shi Lingwen Dai yong Yu Key Laboratory of Environmental Nanotechnology and Health Effects State Key Laboratory of Environmental Chemistry and EcotoxicologyResearch Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China State Environmental Protection Key Laboratory of Quality Control in Environmental Monitoring China National Environmental Monitoring CenterBeijing 100012China

Accurate source apportionment of volatile organic compounds(VOCs)in soil nearby petrochemical industries prevailing globally,is critical for preventing ***,in the process,seasonal effect on contamination pathways and accumulation of soil VOCs is often ***,Yanshan Refining-Chemical Integration Park,including a carpet,refining,synthetic rubber,and two synthetic resin zones,was selected for *** variations resulted in a gradual decrease of 31 VOCs in soil from winter to summer.A method of dry deposition resistance model coupling partitioning coefficient model was created,revealing that dry deposition by gas phase was the primary pathway for VOCs to enter soil in winter and spring,with 100 times higher fux than by particle *** profiles for five zones were built by gas sampling with distinct substance indicators screened,which were used for positive matrix factorization factors *** of the five zones were 14.9%,20.8%,13.6%,22.1%,and 28.6%in winter and 33.4%,12.5%,10.7%,24.9%,and 18.5%in spring,*** variation in the soil sorption capacity of VOCs causes inter-seasonal differences in *** better correlation between dry deposition capacity and soil storage of VOCs made root mean square and mean absolute errors decrease averagely by 8.8%and 5.5%in winter compared to *** study provides new perspectives and methods for the source apportionment of soil VOCs contamination in industrial sites.

关键词： Dry deposition resistance model Positive matrix factorization model Partitioning coefficient model Contamination pathway Source profile

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Atomistic study on the microscopic mechanism of grain boundary embrittlement induced by small dense helium bubbles in iron

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Nuclear Science and Techniques 2024年第3期35卷 84-95页

作者： Lei Peng yong-Jie Sun jing-Yi shi Yi-Fei Liu Shang-Ming Chen Liu-Liu Li State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

The helium bubbles induced by 14 MeV neutron irradiation can cause intergranular fractures in reduced activation ferritic martensitic steel,which is a candidate structural material for fusion *** order to elucidate the susceptibility of different grain boundaries(GBs)to helium-induced embrittlement,the tensile fracture processes of 10 types of GBs with and without helium bubbles in body-centered cubic(bcc)iron at the relevant service temperature of 600 K were investigated via molecular dynamics *** results indicate that in the absence of helium bubbles,the GBs studied here can be classified into two distinct categories:brittle GBs and ductile *** atomic scale analysis shows that the plastic deformation of ductile GB at high temperatures originates from complex plastic deformation mechanisms,including the Bain/Burgers path phase transition and deformation twinning,in which the Bain path phase transition is the most dominant plastic deformation ***,the presence of helium bubbles severely inhibits the plastic deformation channels of the GBs,resulting in a significant decrease in elongation at *** bubble-decorated GBs,the ultimate tensile strength increases with the increase in the misorientation ***,the coherent twin boundary∑3{112}was found to maintain relatively high fracture strength and maximum failure strain under the influence of helium bubbles.

关键词： Helium bubble Grain boundary Embrittlement Reduced activation ferritic martensitic steel Molecular dynamics Bain path

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Concise extraction and characterization of the pore-throat network in unconventional hydrocarbon reservoirs: A new perspective

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Petroleum Science 2024年第3期21卷 1474-1487页

作者： Shu-Heng Du yong-Min shi State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China School of Earth and Space Sciences Peking UniversityBeijing100871China

In this study,a new image-based method for the extraction and characterization of pore-throat network for unconventional hydrocarbon storage and exploitation is proposed.“Pore-throat solidity”,which is analogous to particle solidity,and a new method for automatic identification of pores and throats in tight sandstone oil reservoirs are ***,the“pore-throat combination”and“pure pore”are defined and distinguished by drawing the cumulative probability curve of the pore-throat solidity and by selecting an appropriate cutoff *** the discrete grid set is recognized as a pore-throat combination,Legendre ellipse fitting and minimum Feret diameter are *** the pore and throat grid sets are identified as pure pores,the pore diameter can be directly *** the new method,the analytical results for the physical parameters and pore radius agree well with most prior *** results comparing the maximum ball and the new model could also prove the accuracy of the latter's in micro and nano *** new model provides a more practical theoretical basis and a new calculation method for the rapid and accurate evaluation of the complex processes of oil migration.

关键词： Hydrocarbon exploitation Pore Throat Porous media Identification

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A novel weld-pool-length monitoring method based on pixel analysis in plasma arc additive manufacturing

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Advances in Manufacturing 2024年第2期12卷 335-348页

作者： Bao-Ri Zhang yong-Hua shi Bionic Robot Research Department Ji Hua LaboratoryFoshan528200GuangdongPeople’s Republic of China Guangdong Provincial Engineering Research Center for Special Welding Technology and Equipment School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou510640People’s Republic of China

The real-time monitoring of the weld pool during deposition is important for automatic control in plasma arc additive *** obtain a high deposition accuracy,it is essential to maintain a stable weld pool *** this study,a novel passive visual method is proposed to measure the weld pool *** the proposed method,the image quality was improved by designing a special visual system that employed an endoscope and a *** also includes pixel brightness-based and gradient-based algorithms that can adaptively detect feature points at the boundary when the weld pool geometry *** algorithm can also be applied to materials with different solidification *** was performed to measure the real weld pool length in world coordinates,and outlier rejection was performed to increase the accuracy of the ***,tests were carried out on the intersection component,and the results showed that the proposed method performed well in tracking the changing weld pool length and was applicable to the real-time monitoring of different types of materials.

关键词： Plasma arc additive manufacturing(PAAM) Weld pool geometry Gradient analysis Real-time detection

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The BEL1-like transcription factor GhBLH5-A05 participates in cotton response to drought stress

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The Crop Journal 2024年第1期12卷 177-187页

作者： jing-Bo Zhang Yao Wang shi-Peng Zhang Fan Cheng yong Zheng Yang Li Xue-Bao Li Hubei Key Laboratory of Genetic Regulation and Integrative Biology School of Life SciencesCentral China Normal UniversityWuhan 430079HubeiChina College of Life Sciences Xinjiang Normal UniversityUrumqi 830017XinjiangChina

Drought stress impairs crop growth and ***1-like family transcription factors may be involved in plant response to drought stress,but little is known of the molecular mechanism by which these proteins regulate plant response and defense to drought *** we show that the BEL1-like transcription factor GhBLH5-A05 functions in cotton(Gossypium hirsutum)response and defense to drought *** of GhBLH5-A05 in cotton was induced by drought *** of GhBLH5-A05 in both Arabidopsis and cotton increased drought tolerance,whereas silencing GhBLH5-A05 in cotton resulted in elevated sensitivity to drought ***5-A05 binds to cis elements in the promoters of GhRD20-A09 and GhDREB2C-D05 to activate the expression of these ***5-A05 interacted with the KNOX transcription factor ***-expression of GhBLH5-A05 and GhKNAT6-A03 increased the transcription of GhRD20-A09 and *** conclude that GhBLH5-A05 acts as a regulatory factor with GhKNAT6-A03 functioning in cotton response to drought stress by activating the expression of the drought-responsive genes GhRD20-A09 and GhDREB2C-D05.

关键词： Cotton(Gossypium hirsutum) BEL1-like transcription factor Drought stress Transcriptional regulation Drought tolerance

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Hierarchical Privacy Protection Model in Advanced Metering Infrastructure Based on Cloud and Fog Assistance

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Computers, Materials & Continua 2024年第8期80卷 3193-3219页

作者： Linghong Kuang Wenlong shi jing Zhang School of Computer Science and Mathematics Fujian University of TechnologyFuzhou350118China Fujian Provincial Key Laboratory of Big Data Mining and Applications Fuzhou350118China

The Advanced Metering Infrastructure(AMI),as a crucial subsystem in the smart grid,is responsible for measuring user electricity consumption and plays a vital role in communication between providers and ***,with the advancement of information and communication technology,new security and privacy challenges have emerged for *** address these challenges and enhance the security and privacy of user data in the smart grid,a Hierarchical Privacy Protection Model in Advanced Metering Infrastructure based on Cloud and Fog Assistance(HPPM-AMICFA)is proposed in this *** proposed model integrates cloud and fog computing with hierarchical threshold encryption,offering a flexible and efficient privacy protection solution that significantly enhances data security in the smart *** methodology involves setting user protection levels by processing missing data and utilizing fuzzy comprehensive analysis to evaluate user importance,thereby assigning appropriate protection ***,a hierarchical threshold encryption algorithm is developed to provide differentiated protection strategies for fog nodes based on user IDs,ensuring secure aggregation and encryption of user *** results demonstrate that HPPM-AMICFA effectively resists various attack strategies while minimizing time costs,thereby safeguarding user data in the smart grid.

关键词： AMI cloud and fog assistance fuzzy comprehensive analysis hierarchical threshold encryption

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俄藏TK102、TK271文献及相关问题考论

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图书馆理论与实践 2010年第5期 101-103页

作者：景永时北方民族大学银川750021

对俄藏TK102、TK271号文献进行了考证,认为两者原本是一部佛经的不同片段,不应分成两个号登记和叙录;认为该文献名称应为《密咒圆因往生集录》,从而纠正了前人的失误。作者还据现存文献的版面分析,该文献是印刷后尚未及黏装成册的半成品。

关键词：俄藏文献考论

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西夏农田水利开发与管理制度考论

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宁夏社会科学 2005年第6期 93-95页

作者：景永时宁夏社会科学院宁夏银川750021

西夏虽然是游牧民族建立的政权,但统治者重视发展本国经济,农牧并举,尤其是对宁夏平原和河西走廊的农田水利开发,不仅具有相当的规模,而且还有比较系统完善的农田水利管理制度,诸如春开渠事、修渠草料的征集、开渠役夫的调发以及水利管... 详细信息

西夏虽然是游牧民族建立的政权,但统治者重视发展本国经济,农牧并举,尤其是对宁夏平原和河西走廊的农田水利开发,不仅具有相当的规模,而且还有比较系统完善的农田水利管理制度,诸如春开渠事、修渠草料的征集、开渠役夫的调发以及水利管理体制等。西夏大力开发农田水利,不仅使社会经济得到长足发展,客观上也为西北农田水利的发展作出了贡献。西夏的农田水利管理制度在中国历史上占有一定的地位,其继承前人、尊重客观、因地制宜的积极因素是值得借鉴的。

关键词：西夏农田水利管理制度考论

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Reoxidation of liquid steel and evolution of inclusions during protective atmosphere electroslag remelting of Ce-containing heat-resistant stainless steel

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Journal of Iron and Steel Research International 2024年第8期31卷 1923-1935页

作者： Yu Zhao Cheng-bin shi shijun Wang Peng Ren jing Li State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing(USTB)Beijing 100083China

The evolution of Ce-containing inclusions and its correlation with the reoxidation of liquid steel during protective atmosphere electroslag remelting(ESR)of heat-resistant steel were *** reoxidation of liquid steel took place during the ESR,resulting in the oxygen pickup from 0.0014 to 0.0053 wt.%.The inclusions in the consumable electrode,liquid metal pool and remelted ingot are Ce_(2)O_(2)S and Ce_(2)O,inclusions *** inclusions in the remelted ingot are originated from three ways:(I)the original inclusions from the electrode;(Il)the newly formed Ce_(2)O_(2)S and Ce_(2)O_(3) inclusions in the liquid metal pool by reoxidation remaining still in remelted ingot;(IlI)the newly generated Ce2O2S and Ce_(2)O_(3) inclusions during cooling and solidification of liquid *** relative proportions of Ce_(2)O_(3) inclusions in liquid metal pool and remelted ingot are 41% and 76.5%,*** inclusions ranging from 2 to 5μm in the remelted ingot take up 55%,followed by the inclusions smaller than 2μm(43%of total inclusions).The number proportion of the Ce_(2)0,inclusions in the liquid metal pool which were removed by floating up into slag is 1.96×10-5%.

关键词： Non-metallic inclusion Electroslag remelting Rare earth cerium Reoxidation Inclusion evolution

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