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高速高载荷变转速汽轮机扭叶片优化设计及可靠性分析

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热能动力工程 2024年第4期39卷 34-40页

作者：宋选利周志明李玮琪付学伟西安陕鼓动力股份有限公司陕西西安710075 西安交通大学能源与动力工程学院陕西西安710049

为了完成高速高载荷系列工业汽轮机的低压级扭叶片的设计和应用,以常规驱动汽轮机叶片为原型,对其末三级扭叶片组进行了全三维气动性能分析;利用自适应差分进化算法对末三级叶片的型线和积叠规律进行了优化设计;然后根据常规强度计算结... 详细信息

为了完成高速高载荷系列工业汽轮机的低压级扭叶片的设计和应用,以常规驱动汽轮机叶片为原型,对其末三级扭叶片组进行了全三维气动性能分析;利用自适应差分进化算法对末三级叶片的型线和积叠规律进行了优化设计;然后根据常规强度计算结果,选择合适的材料并选择松拉筋配枞树型叶根的结构;最后采用有限元仿真软件对其进行了强度振动和动应力及疲劳分析。结果表明:优化后末三级叶片的气动效率提升约1.61%且强度满足要求;设计末两级动叶片时,优先考虑可靠性,其余级因其强度振动问题相对容易解决,优先考虑气动效率;末级叶片材料可能需要选择钛合金,而枞树型叶根是更可靠的叶根形式;选择抗弯模量大、厚度小的叶型搭配松拉筋有利于增加叶片刚度、减小叶片重量,从而为不调频叶片的设计提供参考。

关键词：工业汽轮机 CFD分析叶片优化高速高载荷强度振动动应力

CBSC: A Crowdsensing System for Automatic Calibrating of Barometers

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Journal of Computer Science & Technology 2019年第5期34卷 1007-1019页

作者： Hai-Bo Ye xuan-song li li Sheng Kai Dong College of Computer Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100China School of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China School of Computer Science and Engineering Southeast UniversityNanjing 211189China

The mobile crowdsensing software systems can complete large-scale and complex sensing tasks with the help of the collective intelligence from large numbers of ordinary users. In this paper, we build a typical crowdsensing system, which can efficiently calibrate large numbers of smartphone barometer sensors. The barometer sensor now becomes a very common sensor on smartphones. It is very useful in many applications, such as positioning, environment sensing and activity detection. Unfortunately, most smartphone barometers today are not accurate enough, and it is rather challenging to efficiently calibrate a large number of smartphone barometers. Here, we try to achieve this goal by designing a crowdsensingbased smartphone calibration system, which is called CBSC. It makes use of low-power barometers on smartphones and needs few reference points and little human assistant. We propose a hidden Markov model for peer-to-peer calibration, and calibrate all the barometers by solving a minimum dominating set problem. The field studies show that CBSC can get an accuracy of within 0.1 hPa in 84% cases. Compared with the traditional solutions, CBSC is more practical and the accuracy is satisfying. The experience gained when building this system can also help the development of other crowdsensing-based systems.

关键词： crowdsensing system smartphone sensing barometer calibration

Preparation and combustion properties of laminated sticks of B-CuO and B-Bi_(2)O_(3)

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Defence Technology（防务技术） 2024年第8期38卷 67-74页

作者： Haoyu song Chenyang li Fubing Gao Chongwei An Shijiao li xuan Zhan Jianchen He School of Environment and Safety Engineering North University of ChinaTaiyuan 030051China Chongqing Military Agency of the Army Chongqing 400060China

To explore the composite process of B-CuO and B-Bi_(2)O_(3) two-component laminated sticks,obtain the corresponding sticks with good printing effect,and explore the energy release *** this study,boron,copper oxide,and bismuth trioxide powders were dispersed in the dispersed phase (DMF) using F_(2602) as a binder,and the construction of two-component B-CuO,B-Bi_(2)O_(3),three-component microcomposite,and three-component macro-composite sticks were realized with the help of double nozzle direct ink writing (DIW) technique *** resulting sticks were ignited by a nichrome wire energized with a direct current,and a high-speed camera system was used to record the combustion behavior of the sticks,mark the flame position,and calculate the rate of *** results showed that the B-CuO stick burning rate (42.11 mm·s^(-1)) was much higher than that of B-Bi_(2)O_(3)(17.84 mm·s^(-1)).The formulation with the highest CuO content (ω_(CuO)=58.7%) in the microscale composite of the sticks also had the fastest burning rate of 60.59 mm·s^(-1),as the CuO content decreased (ω_(CuO)=43.5%,29.3%),its burning rate decreased to 34.78 mm·s^(-1),37.97 mm·s^(-1).The stick with the highest copper oxide content(ω_(CuO)=60%) also possessed the highest burning rate (48.84 mm·s^(-1)) in the macro-composite sticks,and the burning rates of the macro-composite sticks with component spacing of 0.1 mm,0.2 mm,and 0.5 mm were 43.34 mm·s^(-1),48.84 mm·s^(-1),and 40.76 mm·s^(-1).

关键词： Boron-based thermite Direct ink writing linear burning rate Multi-component composite

Automatic velocity picking based on optimal key points tracking algorithm

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Petroleum Science 2024年第2期21卷 903-917页

作者： Yong-Hao Wang Wen-Kai Lu song-Bai Jin Yang li Yu-xuan li Xiao-Feng Gu The Institute for Artificial Intelligence(THUAI) Tsinghua UniversityBeijing100084China State Key Laboratory of Intelligent Technology and Systems Tsinghua UniversityBeijing100084China Beijing National Research Center for Information Science and Technology(BNRist) Beijing100084China The Department of Automation Tsinghua UniversityBeijing100084China

Picking velocities from semblances manually is laborious and necessitates experience. Although various methods for automatic velocity picking have been developed, there remains a challenge in efficiently incorporating information from nearby gathers to ensure picked velocity aligns with seismic horizons while also improving picking accuracy. The conventional method of velocity picking from a semblance volume is computationally demanding, highlighting a need for a more efficient strategy. In this study, we introduce a novel method for automatic velocity picking based on multi-object tracking. This dynamic tracking process across different semblance panels can integrate information from nearby gathers effectively while maintaining computational efficiency. First, we employ accelerated density clustering on the velocity spectrum to discern cluster centers without the requirement for prior knowledge regarding the number of clusters. These cluster centers embody the maximum likelihood velocities of the main subsurface structures. Second, our proposed method tracks key points within the semblance volume. Kalman filter is adopted to adjust the tracking process, followed by interpolation on these tracked points to construct the final velocity model. Our synthetic data example demonstrates that our proposed algorithm can effectively rectify the picking errors of the clustering algorithm. We further compare the performances of the clustering method(CM), the proposed tracking method(TM), and the variational method(VM) on a field dataset from the Gulf of Mexico. The results attest that our method offers superior accuracy than CM, achieves comparable accuracy with VM, and benefits from a reduced computational cost.

关键词： Velocity picking Multi-object tracking Density clustering Kalman filter

Design and Experimental Verification of a Roll Control Strategy for Large Wingspan Flapping-Wing Aerial Vehicle

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Journal of Bionic Engineering 2024年第4期21卷 1644-1661页

作者： Rui Meng Bifeng song Jianlin xuan Xiaojun Yang Dong Xue School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China Research and Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen518057China Yangtze River Delta Research Institute of Northwestern Polytechnical University Taicang215400China

Most flapping-wing aircraft wings use a single degree of freedom to generate lift and thrust by flapping up and down,while relying on the tail control surfaces to manage ***,these aircraft have certain limitations,such as poor accuracy in attitude control and inadequate roll control *** paper presents a design for an active torsional mechanism at the wing's trailing edge,which enables differential variations in the pitch angle of the left and right wings during *** simple mechanical form significantly enhances the aircraft's roll control *** experimental verification of this mechanism was conducted in a wind tunnel using the RoboEagle flapping-wing aerial vehicle that we *** study investigated the effects of the control strategy on lift,thrust,and roll moment during flapping ***,the impact of roll control on roll moment was examined under various wind speeds,flapping frequencies,angles of attack,and wing ***,several rolling maneuver flight tests were performed to evaluate the agility of RoboEagle,utilizing both the elevon control strategy and the new roll control *** results demonstrated that the new roll control strategy effectively enhances the roll control capability,thereby improving the attitude control capabilities of the flapping-wing aircraft in complex wind field *** conclusion is supported by a comparison of the control time,maximum roll angle,average roll angular velocity,and other relevant parameters between the two control strategies under identical roll control input.

关键词： Roll control Bio-inspired Roll moment Flapping wing aerial vehicle

Endochondral ossification of hindlimbs in embryonic development of Japanese Quail(Coturnix japonica)

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Avian Research 2024年第1期15卷 123-132页

作者： xuan li Yuxin Zhang Hongfeng Zhao College of life Sciences Shaanxi Normal UniversityXi’an710119China

The endochondral ossification of hindlimb is essential to a bird’s ability to stand,walk and *** hindlimb is ossified in the embryos before hatching in precocial ***,the molecular mechanisms of hindlimb ossification in birds is still ***,we tried to examine the process of hindlimb ossification and its molecular regulation by using an animal model—Japanese Quail(Coturnix japonica).We selected four critical stages(Embryo Day:E6,E8,E12 and E16) of skeletal development of embryonic quails for hindlimb skeleton staining to show the process of endochondral ossification and to examine the molecular regulation of endochondral osteogenesis by RNA-Seq *** results showed that ossification became increased with embryonic development and most hindlimb was ossified before ***-Seq analysis revealed that various signaling pathways were involved with endochondral ossification with thyroid hormone signaling and WNT signaling pathway particularly ***,the expression levels of 42 genes were continuously upregulated and 14 genes were continuously downregulated from E6 to *** present study might provide new insights into complex molecular mechanisms in regulation of endochondral ossification.

关键词： Embryos Hindlimb Ossification Precocial Transcriptomics

An ultrafast rechargeable hybrid potassium dual-ion capacitor based on carbon quantum dot@ultrathin carbon film cathode

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Rare Metals 2024年第10期43卷 5070-5081页

作者： Zhao-Meng liu Da Wang Shang-Zhuo li Qing-song Lai Dong-Run Yang Lu-Kang Zhao Jian-Jia Mu xuan-Chen Wang xuan-Wen Gao Wen-Bin Luo Institute for Energy Electrochemistry and Urban Mines Metallurgy School of MetallurgyNortheastern University Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai University

Ultrafast rechargeable hybrid potassium dualion capacitors （HPDICs） were designed by employing carbon quantum dot@ultrathin carbon film （CQD@CF） as the cathode *** designed CQD@CF is selfassembled by a simple catalytic graphitization route followed by an acid leaching *** special composite features a large adsorption interface,a remarkable anion hybrid storage capability and outstanding structure *** electrochemical performance of CQD@CF composite is fully tapped in a half-cell system at the operating voltage between 1.4 and 4.5 V,achieving an admirable specific discharge capacity of 128.5 mAh·g-1a 50 mA·g-1,an ultra-high capacity retention ratio of 97.97% after cycling 5000 times at 1000 mA·g-1and a 96.10%high capacity retention ratio after cycling 40,000 times at 5000 mA·g-1,***,with the support of ex situ TEM and XPS,the structural stability principle and anionic hybrid storage mechanism of CQD@CF electrode are investigated *** the full-cell system,HPDICs with the CQD@CF as cathode and nanographite powder as anode also present a 141.5 Wh·kg-1high energy density,a 5850 W·kg-1power density and a super-long cycle stability (90.2% capacity retention ratio after cycling 30,000 times at 5000 mA·g-1).

关键词： Anion hybrid storage mechanism Carbon quantum dots Potassium dual ion capacitor Ultrafast rechargeable Ultrathin carbon film

Robustα-Fe_(2)O_(3)/Epoxy Resin Superhydrophobic Coatings for Anti-icing Property

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 621-626页

作者：乔燕明 TAO xuan li Lei 阮敏鲁礼林 College of Chemistry and Chemical Engineering Wuhan University of Science and TechnologyWuhan 430081China Hubei Key Laboratory of Mine Environmental Pollution Control&Remediation and Hubei Engineering Research Center for Collaborative Technology of Advanced Material Manufacturing and Solid Waste Recycling Hubei Polytechnic UniversityHuangshi 435003China

α-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating was prepared withα-Fe_(2)O_(3) nanoparticles and epoxy resin by spin coating *** coating without epoxy resin has higher contact angle(CA)and lower ice adhesion strength(IAS),but the mechanical properties are ***α-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating exhibits good mechanical *** addition,compared with the bare aluminum substrate,the Ecorr of the composite coating is positive and the Jcorr is *** inhibition efficiency of the composite coating is as high as 99.98%in 3.5 wt%NaCl *** difference in the microstructure caused by the two preparation methods leads to the changes in mechanical properties and corrosion resistance of composite superhydrophobic coating.

关键词： superhydrophobic anti-corrosion anti-icing robust

Chiral thermally activated delayed fluorescence materials for circularly polarized organic light-emitting diodes

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Science China Chemistry 2024年第4期67卷 1097-1116页

作者： li Yuan Yi-Pin Zhang You-xuan Zheng State Key Laboratory of Coordination Chemistry Collaborative Innovation Center of Advanced MicrostructuresJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Chirality is an important natural characteristic of organic molecules,and chiral organic molecules have shown extensive application in areas such as pharmaceutical development and material *** from the ability to achieve circularly polarized luminescence(CPL),chiral luminescent materials have shown potential applications in anti-glare display,optical communication and,3D display,*** to the ability to harvest both singlet and triplet excitons by a fast reverse intersystem crossing process without involving noble metals,chiral thermally activated delayed fluorescence(TADF)materials with point chirality,axial chirality,planar chirality and helical chirality are regarded as the state-of-the-art materials for circularly polarized organic light-emitting diodes(CP-OLEDs).In recent years,the chiral TADF materials and CP-OLEDs have rapidly developed,but unfortunately,the dissymmetry factors(g)are far from the requirement of practical *** ideal emitters and devices should have both high efficiency and a g factor,or at least a balance between these two *** review gives an overview of recent progress in chiral TADF materials,with a particular focus on the chiral skeleton,CPL property and device ***,the molecular design concept,device structure and methods to improve the g factors of chiral materials and CP-OLEDs are also discussed.

关键词： chiral thermally activated delayed fluorescence material chiral skeleton circularly polarized luminescence circularly polarized organic light-emitting diodes dissymmetry factor