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Chinese Journal of Aeronautics 2024年第3期37卷 404-416页

作者： Huibin SUN Meng LIU Yingzhi ZHANG Chenle WEI Key Laboratory of High Performance Manufacturing for Aero engine Ministry of Industry and Information TechnologyNorthwestern Polytechnical UniversityXi’an 710072China AECC South Industry company limited Zhuzhou 412002China

Due to the excellent self-centering and load-carrying capability,curvic couplings have been widely used in advanced aero-engine ***,curvic tooth surface errors lead to poor assembly *** physical-master-gauge-based indirect tooth surface error measurement and circumferential assembly angle optimization methods have the disadvantages of high cost and weak *** unknown tooth surface fitting mechanism is a big barrier to assembly precision prediction and ***,this work puts forward a data-driven assembly simulation and optimization approach for aero-engine rotors connected by curvic *** origin of curvic tooth surface error is deeply *** 5-axis sweep scan method,a large amount of high-precision curvic tooth surface data are acquired *** on geometric models of parts,the fitting mechanism of curvic couplings is uncovered for assembly precision simulation and prediction.A circumferential assembly angle optimization model is developed to decrease axial and radial assembly *** results show that the assembly precision can be predicted accurately and improved *** uncovering the essential principle of the assembly precision formation and proposing circumferential assembly angle optimization model,this work is meaningful for assembly quality,efficiency and economy improvement of multistage aero-engine rotors connected by curvic couplings.

关键词： Curvic couplings Tooth surface error Assembly precision Axial and radial runouts Circumferential assembly angle

Durable dual-state duplex Si-HfO_(2)with excellent oxidation and cracking resistance

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Journal of Advanced Ceramics 2024年第3期13卷 388-401页

作者： Lin Chen Jing-Chuan Luo Wen-Qi Yang Chang-Jiu Li Guan-Jun Yang State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an Aerospace engine company limited in CASC Xi’an 710065China

The lifetime of Si bond coatings in environmental barrier coatings is constrained by phase-transition-induced cracking of the SiO_(2)*** this study,Si-HfO_(2)dual-state duplex composite materials are proposed to address this issue by partially forming HfSiO_(4)and minimizing the SiO_(2)*** as-prepared composite exhibited a structure comprising discrete HfO_(2)“bricks”embedded in a continuous Si“mortar”,while the oxidized state transformed into discrete HfSiO_(4)“bricks”within continuous thin SiO_(2)“mortars”.The results indicate that continuous thin SiO_(2)contributes to reducing the oxidation rate to a level comparable to that of pure Si,and discrete HfSiO_(4)particles aid in relieving phase transition-induced stress and inhibiting crack propagation,thereby enhancing oxidation and cracking resistance ***,the composite with 20 mol%HfO_(2)and a mean particle size of~500 nm at 1370℃exhibited a service lifetime 10 times greater than that of pure *** research provides valuable insights for designing Si-based bond coatings with improved service lifetime.

关键词： oxidation environmental barrier coatings(EBCs) phase transition cracking bond coatings

Realizing the excellent oxidation resistance of an environmental barrier coating through aluminum surface modification

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Journal of Advanced Ceramics 2024年第7期13卷 976-986页

作者： Lin Dong Wen-Qi Yang Lin Chen Guan-Jun Yang Chang-Jiu Li State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an Aerospace engine company limited in China Aerospace Science and Technology Corporation Xi’an 710065China

The lifetime of Si-based environmental barrier coatings(EBCs)is constrained by thermally grown SiO_(2)oxidelayer(SiO_(2)-TGO),which can cause premature cracking and *** address this issue,a new approach for surfacemodification using aluminum is *** oxidation performance was examined in a 50 vol%H_(2)O-50 vol%O_(2)environment at 1350℃for up to 300 *** results indicate that a dense ytterbium aluminum garnet(YbAG)layer wasformed after modification,decreasing the porosity by 80%.Due to the elimination of fast diffusion channels and the lowoxygen permeability of YbAG,aluminum modification significantly reduced the growth rate of SiO_(2)-TGO by nearly twoorders of ***,its thickness decreased by more than 70%after 300 h of exposure.A diffusioncontrolled oxidation mechanism indicates that the modified dense surface is equivalent to an initial SiO_(2)layer with a specificthickness,causing a shift in the oxidation time and increasing the oxidation *** research provides valuableinsights for designing Si-based EBC with improved lifetimes.

关键词： environmental barrier coating(EBC) oxidation modification diffusion cracking

Naive-LSTM enabled service identification of edge computing in power internet of things

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The Journal of China Universities of Posts and Telecommunications 2024年

作者： Bai Huifeng Huo Chao Zhang Ganghong Yin Zhibin Beijing SmartChip Microelectronics Technology company limited

Great challenges and demands are presented by increasing edge computing services for current Power Internet of Things (Power IoT) to deal with serious diversity and complexity of these services. To improve the matching degree between edge computing and complex services， the services identification function is necessary for Power IoT. This article proposes a naive long short-term memory (Naive-LSTM) based services identification scheme of edge computing devices in the Power IoT， where the Naive-LSTM model makes full use of the most simplified structure and conducts discretization of the LSTM model. Moreover， the Naive-LSTM based services identification scheme can generate the probability output result to determine the task schedule police of Power IoT. After well learning operation， these Naive-LSTM classification engine module in edge computing devices of Power IoT can perform services identification， by obtaining key characteristics from various services traffics. Testing results show that the Naive-LSTM based services identification scheme is feasible and efficient in improving the edge computing ability of the Power IoT.

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Partition method for improvement of piecewise linear model with full envelope covered

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航空动力学报 2016年第12期31卷 3042-3053页

作者： YANG Shu-bo WANG Xi LONG Yi-fu LI Zhi-peng HU Zhong-zhi YIN Kai ZHANG Rong School of Energy and Power engineering Beijing University of Aeronautics and Astronautics commercial aircraft engine company limited Aero Engine(Group)Corporation of China

Since ambient conditions vary in a wide range within the full flight envelope,the existing piecewise linear model(PLM),which is based on sea-level static condition with use of corrected parameters for other points in the flight envelope,cannot meet the accuracy for replacing the nonlinear *** obtain more accurate linear models,a method of partitioning the flight envelope over a grid of Mach number and altitude boxes was ***,a set of linear models for a given operating condition was selected by picking the nearest(Mach number,altitude)box in the flight *** the selected set of linear models,interpolating for power level based on a weighted sum of corrected rotor speeds can obtain a linear model with acceptable *** results of different points within the full flight envelope showed that the maximum error between nonlinear model and the existing PLM was more than 50%,while the maximum error between nonlinear model and the improved PLM was within 8%.It is concluded that the improved PLM performs accurately,especially under the non-standard *** addition,the improved PLM can satisfy the real-time requirement better than the existing PLM.

关键词： piecewise linear model partition full envelope parameter schedule turbofan engine

Cleaner production of 3.5 valent vanadium electrolyte from ammonium metavanadate by ammonia reduction-sulfuric acid dissolution method

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Tungsten 2024年第3期6卷 555-560页

作者： Cheng Wang Lan-Jie Li Hao Du College of Chemical engineering University of Chinese Academy of Sciences Institute of Process engineering National Engineering Research Center of Green Recycling for Strategic Metal Resources Chinese Academy of Sciences Hesteel Group company limited

The vanadium redox flow battery(VRFB) has been widely used in large-scale energy storage areas due to the advantages of long lifespan and high safety. However, the high preparation cost of vanadium electrolyte limits ... 详细信息

关键词： Ammonia

Normalized glandular dose coefficients for digital breast tomosynthesis using detailed Chinese breast models

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Nuclear Science and Techniques 2024年第5期35卷 42-59页

作者： Jia-Hao Wang Rui Qiu An-Kang Hu Ye-Qi Liu Zhen Wu Hui Zhang Jun-Li Li Department of engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging Ministry of EducationTsinghua UniversityBeijing 100084China Joint Institute of Tsinghua University Nuctech Company Limited BeijingBeijing 100084China

The rise in breast cancer diagnoses among Chinese women has necessitated the use of X-ray breast screening,which carries a radiation *** study aimed to provide a dosimetry protocol for the Chinese female population to replace the traditional standard that utilizes simplified breast models,for the accurate estimation of the mean glandular dose of a patient undergoing digital breast tomosynthesis(DBT).The first set of detailed Chinese female breast models and representative breast parameters was *** backscatter radiation and computational efficiency,we improved the combination of these models and the Chinese reference adult female whole-body voxel *** acquisition for four commercial DBT systems that are widely employed in China was simulated using the Monte Carlo method to obtain the normalized glandular dose coefficients of DBT(D_(gN)^(DBT))and the glandular depth dose(D_(g)^(dep)(z))for different breast characteristics and X-ray *** calculated a series of D_(gN)^(DBT) values for breasts with different percentage mass glandularities(5%,25%,50%,75%,and 100%)and compressed breast thicknesses(2,3,4,5,6,and 7 cm)at various tube potentials(25,28,30,32,35,and 49 kV)and target/filter combinations(W/Rh,W/Al,Mo/Mo,Rh/Rh,and Rh/Ag).The parameter dependence of the breast characteristics and beam conditions on D_(gN)^(DBT) in detailed breast models was *** D_(gN)^(DBT) results were 14.6-51.0%lower than those of the traditional dosimetry standard in *** difference in D_(gN)^(DBT) was mainly due to a decrease in the depth of the main energy deposition area caused by the glandular distribution along the depth *** results obtained in this study may be used to improve breast dosimetry in China and provide more detailed information on risk assessment during DBT.

关键词： Digital breast tomosynthesis Normalized glandular dose coefficients Detailed breast model Monte Carlo simulation

A deterministic FE contact analysis of 3D rough surfaces with textures and comparison with classic statistical contact models

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Science China(Technological Sciences) 2021年第2期64卷 297-316页

作者： ZHANG Rui MENG XiangHui LYU BuGao SUN Kai School of Mechanical engineering Shanghai Jiao Tong UniversityShanghai 200240China AECC commercial aircraft engine company limited Shanghai 200241China

Accurate contact calculations of real rough surfaces are fundamental but complicated. The model-based methods are convenient and straightforward. But these methods ignore some factors and may lead to less accurate results. This is especially true when considering multi-scale topographic features of engineering rough surfaces. Based on artificially generated rough surfaces, the deterministic contact analysis of two 3D rough surfaces is conducted by the finite element method(FEM). The calculations show that when the separation between surfaces reduces, results of classic model-based methods are quite different from those of this study, especially when the roughness distribution and textures are considered. As friction pairs are working under increasing harsh conditions, the accurate contact calculation in this paper will be of great significance.

关键词： deterministic contact analysis multi-scale topography finite element method(FEM) engineering rough surfaces

Promoted catalytic property of Cu/SSZ-13 by introducing a minority of Mn for NO removal from diesel engine exhaust

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Chinese Journal of Chemical engineering 2024年第7期71卷 172-182页

作者： Runnong Yang Wuyuan Liu Zhaoying Wang Ming Sun Guangying Fu Zihan Gao Wenjian Jiao Rui Li Lin Yu Guangdong Provincial Laboratory of Chemistry and Fine Chemical engineering Jieyang Center Jieyang 515200China Guangdong engineering Technology Research Center of Modern Fine Chemical engineering School of Chemical Engineering and Light IndustryGuangdong University of TechnologyGuangzhou 510006China Key Laboratory of Bioinorganic and Synthetic Chemistry School of ChemistrySun Yat-sen UniversityGuangzhou 510275China Testing and Certification Business Department China Automotive Technology and Research Center Company LimitedWuhan 430056China Guangdong Foran Technology company limited Foshan 528000China

The Cu-exchanged SSZ-13 with the small-pore chabazite framework is considered as a highly efficient catalyst for selective catalytic reduction of NO with NH_(3)(NH_(3)-SCR).In order to further improve the catalytic property,a series of Mn ion-assisted Cu/SSZ-13 powder catalysts were prepared by co-exchange method and stepwise exchange *** is found that the NH_(3)-SCR activity,N_(2) selectivity,hydrothermal stability and sulfur resistance of Cu/SSZ-13 are promoted by introducing a minority of Mn(0.15%to 0.23%(mass))through co-exchange *** results reveal that the Cu,Mn co-exchange enables the higher amounts of Cu^(2+)active sites,the abundant medium strong and strong acid,the optimized ratio of Lewis acid to Brønsted acid etc.,which are required for a good NH_(3)-SCR catalytic property over broad temperature range and under harsh working ***,a monolithic catalyst was prepared by impregnating a cordierite ceramic support into the coating slurry containing the optimized CuMn/SSZ-13 *** diesel engine bench tests show that Cu,Mn co-exchange gives the monolith catalyst a better catalytic property than commercial *** work provides an important guidance for the rational design of secondary-ion-assisted zeolites applied in NH_(3)-SCR.

关键词： MnCu/SSZ-13 Co-exchange Zeolite Catalysis Selective catalytic reduction

Investigation of pore structure alteration and permeability enhancement of shale matrix by supercritical water treatment after hydraulic fracturing

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Petroleum 2024年第2期10卷 265-274页

作者： Yili Kang Peisong Li Wangkun Cao Mingjun Chen Lijun You Jiang Liu Zhehan Lai State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China Institute of engineering Technology Petro China Coalbed Methane Company LimitedXi'an710082China Chemical and Petroleum engineering University of CalgaryCalgaryT2N 1N4Canada

Shale gas reservoirs are unconventional tight gas reservoirs,in which horizontal wells and hydraulic fracturing are required to achieve commercial *** fracture networks created by hydraulic fracturing can increase the drainage area extensively to enhance shale gas ***,large volumes of fracturing fluid that is difficult to flow back to the surface and remained in the shale formation,will inevitably lead to damages of the shale formations and limit the effectiveness of *** water(SCW)treatment after hydraulic fracturing is a new method to enhance shale gas recovery by using appropriate heat treatment methods to the specific formation to convert the retained fracturing fluid into a supercritical state(at temperatures in excess of 373.946°C and pressures in excess of 22.064 MPa).An experiment was conducted to simulate the reaction between shale and SCW,and the capacity of SCW treatment to enhance the permeability of the shale was evaluated by measuring the response of the shale porosity and permeability on SCW *** experimental results show that the shale porosity and permeability increase by 213.43%and 2198.37%,*** pore structure alteration and permeability enhancement of the shale matrix were determined by analyzing the changes in pore structure and mineral composition after SCW *** mechanisms that affect pore structure and mineral composition include oxidative catalysis decomposition of organic matters and reducing minerals,acid-catalyzed decomposition of carbonate minerals and feldspar minerals,hydrothermal catalysis induced fracture extension and cementation weakening induced fracture *** treatment converts harm into a benefit by reducing the intrusion of harmful substances into the shale formation,which will broaden the scope and scale of shale formation stimulation.

关键词： Shale gas Formation damage control Formation heat treatment Supercritical water