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Applied Mathematics and Mechanics(English Edition) 2018年第9期39卷 1267-1276页

作者： Yichen YAO Chunxiao xu Weixi HUANG Department of Engineering Mechanics Tsinghua University

Periodic wall oscillations in the spanwise or circumferential direction can greatly reduce the friction drag in turbulent channel and pipe flows. In a concentric annulus, the constant rotation of the inner cylinder can intensify turbulence fluctuations and enhance skin friction due to centrifugal instabilities. In the present study, the effects of the periodic oscillation of the inner wall on turbulent flows through concentric annulus are investigated by the direct numerical simulation(DNS). The radius ratio of the inner to the outer cylinders is 0.1, and the Reynolds number is 2 225 based on the bulk mean velocity Um and the half annulus gap H. The influence of oscillation period is considered. It is found that for short-period oscillations, the Stokes layer formed by the circumferential wall movement can effectively inhibit the near-wall coherent motions and lead to skin friction reduction, while for long-period oscillations, the centrifugal instability has enough time to develop and generate new vortices, resulting in the enhancement of turbulence intensity and skin friction.

关键词： turbulence drag reduction circumferential oscillation Taylor vortex

Metabolic reprogramming in cancer: the bridge that connects intracellular stresses and cancer behaviors

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National Science Review 2020年第8期7卷 1270-1273页

作者： Yi Zhou Huiyan Sun Ying xu Cancer Systems Biology Center The China-Japan Union Hospital Department of Biochemistry and Molecular Biology University of Georgia School of Artificial Intelligence Jilin University

Extensive changes in cellular metabolisms have been observed in cancer. They are probably induced by the same intracellular stressor, persistent off-balance in intracellular p H across possibly all adult cancers. It is these altered metabolisms that gives rise to a variety of cancerous behaviors such as continuous cell division, metastasis and drug resistance.

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Situation assessment for air combat based on novel semi-supervised naive Bayes

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Journal of Systems Engineering and Electronics 2018年第4期29卷 768-779页

作者： xu Ximeng YANG Rennong FU Ying Aeronautics and Astronautic Engineering College Air Force Engineering University

A method is proposed to resolve the typical problem of air combat situation assessment. Taking the one-to-one air combat as an example and on the basis of air combat data recorded by the air combat maneuvering instrument, the problem of air combat situation assessment is equivalent to the situation classification problem of air combat data. The fuzzy C-means clustering algorithm is proposed to cluster the selected air combat sample data and the situation classification of the data is determined by the data correlation analysis in combination with the clustering results and the pilots＇ description of the air combat process. On the basis of semi-supervised naive Bayes classifier, an improved algorithm is proposed based on data classification confidence, through which the situation classification of air combat data is carried out. The simulation results show that the improved algorithm can assess the air combat situation effectively and the improvement of the algorithm can promote the classification performance without significantly affecting the efficiency of the classifier.

关键词： air combat situation assessment air combat maneu-vering instrument semi-supervised naive Bayes.

Corrosion behavior of a CuCrNiAl alloy in the presence of NaCl deposit

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Rare Metals 2006年第3期25卷 210-215页

作者： xu Tao CHANG Limin LIU Jianhua Department of Applied Technology Daqing Petroleum Institute Daqing 163318 China Analysis and Measure Center Jilin Normal University Siping 136000 China Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao 066004 China

The corrosion behavior of a CuCrNiAl alloy with NaCl deposit at 700 and 900℃ was studied by means of metalloscope, XRD, SEM/EDX, and thermogravimetric analysis. The results indicated that the corrosion of the CuCrNiAl alloy beneath the NaCl deposit is severe; the corrosion production is loose and easy to scale off; the Cr phase is easier to erode than the Cu phase, and the contents of Cu and Cr decrease when the content of Ni increases in the matrix of the alloy beneath the corrosion region. The effects of distortion on the corrosion of the CuCrNiAl alloy were discussed, and the acceleration mechanisms of NaCl on the corrosion were also discussed.

关键词： CuCrNiAl alloy corrosion NaCl high temperature

Environmental Information-Aided Electromagnetic Propagation Testbed for Maritime Communication

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China Communications 2023年第3期20卷 302-315页

作者： Ting Zhou Yuzhen Wang Bilian xu Tianheng xu Xiaoming Tao Honglin Hu Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of ScienceBeijing 100049China School of Microelectronics Shanghai UniversityShanghai 200444China Department of Electronic Engineering Tsinghua UniversityBeijing 100084China

Maritime channel modeling can be affected by some key time-varying environmental *** ducting effect is one of the thorniest factors since it causes anomalous propagation enhancement and severe co-channel ***,the atmospheric attenuation is much more severe in the ocean environment,resulting in shorter coverage distance and more link *** this paper,we propose an environmental information-aided electromagnetic propagation *** is based on complex refractivity estimation and improved parabolic equation propagation model,taking into account both ducting effect and atmospheric attenuation.A large-scale temporal and spatial propagation measurement was conducted with meteorological *** consider practical path loss and ducting conditions to verify the testbed feasibility in these long-distance radio *** simulation results are in good agreement with the measured data,which further reveal the basic temporal and spatial distribution of ducting effect at 3.5 GHz band.

关键词： broadband maritime communication maritime channel ducting effect electromagnetic propagation testbed propagation measurement atmospheric attenuation path loss

Prospects for green steelmaking technology with low carbon emissions in China

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Carbon Energy 2024年第2期6卷 1-24页

作者： Zhang Fucheng Hong Lukuo xu Ying College of Metallurgy and Energy North China University of Science and TechnologyTangshanHebeiChina Hebei Iron and Steel Laboratory TangshanHebeiChina

The steel industry is a major source of CO_(2) emissions,and thus,the mitigation of carbon emissions is the most pressing challenge in this *** this paper,international environmental governance in the steel industry is reviewed,and the current state of development of low-carbon technologies is ***,low-carbon pathways for the steel industry at the current time are proposed,emphasizing prevention and treatment ***,the prospects of low-carbon technologies are explored from the perspective of transitioning the energy structure to a“carbon-electricity-hydrogen”***,steel enterprises should adopt hydrogen-rich metallurgical technologies that are compatible with current needs and process flows in the short term,based on the carbon substitution with hydrogen(prevention)and the CCU(CO_(2) capture and utilization)concepts(treatment).Additionally,the capture and utilization of CO_(2) for steelmaking,which can assist in achieving short-term emission reduction targets but is not a long-term solution,is *** conclusion,in the long term,the carbon metallurgical process should be gradually supplanted by a hydrogen-electric synergistic approach,thus transforming the energy structure of existing steelmaking processes and attaining near-zero carbon emission steelmaking technology.

关键词： carbon capture and utilization carbon emission hydrogen metallurgy low-carbon technology steel industry

Feasibility study of autonomous orbit determination using only the crosslink range measurement for a combined navigation constellation

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Chinese Journal of Aeronautics 2014年第5期27卷 1199-1210页

作者： Gao Youtao xu Bo Zhang Lei College of Astronautics Nanjing University of Aeronautics and Astronautics College of Astronomy and Space Science Nanjing University

In order to expand the coverage area of satellite navigation systems, a combined navigation constellation which is formed by a global navigation constellation and a Lagrangian navigation constellation was studied. Only the crosslink range measurement was used to achieve long-term precise autonomous orbit determination for the combined navigation constellation, and the measurement model was derived. Simulations of 180 days based on the international global navigation satellite system（GNSS） service（IGS） ephemeris showed that the mentioned autonomous orbit determination method worked well in the Earth–Moon system. Statistical results were used to analyze the accuracy of autonomous orbit determination under the influences of different Lagrangian satellite constellations.

关键词： Autonomous navigation Crosslink range Lagrange point Navigation constellation Orbit determination

鼻内镜手术联合糠酸莫米松鼻喷雾剂治疗慢性鼻窦炎伴鼻息肉疗效及对患者鼻黏膜CD4^(+)及CD8^(+)T细胞分布的影响

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陕西医学杂志 2025年第1期54卷 105-108,113页

作者：宋鹏徐杨斌宁德师范学院附属宁德市医院耳鼻咽喉头颈外科福建宁德352100

目的:探讨鼻内镜手术(FESS)联合糠酸莫米松鼻喷雾剂治疗慢性鼻窦炎伴鼻息肉(CRSwNP)的疗效及对鼻黏膜CD4^(+)及CD8^(+)T细胞分布的影响。方法:选择96例CRSwNP患者,按随机数字表法分为对照组(FESS)和观察组(FESS联合糠酸莫米松鼻喷雾剂)... 详细信息

目的:探讨鼻内镜手术(FESS)联合糠酸莫米松鼻喷雾剂治疗慢性鼻窦炎伴鼻息肉(CRSwNP)的疗效及对鼻黏膜CD4^(+)及CD8^(+)T细胞分布的影响。方法:选择96例CRSwNP患者,按随机数字表法分为对照组(FESS)和观察组(FESS联合糠酸莫米松鼻喷雾剂)各48例。比较两组临床疗效,治疗前后鼻腔通气功能、鼻黏膜CD4^(+)及CD8^(+)T细胞分布、鼻黏液纤毛清除功能及复发率。结果:对照组无效10例,总有效率79.17%,观察组无效2例,总有效率95.83%,两组比较差异有统计学意义(均P<0.05)。观察组治疗后血清肿瘤坏死因子-α(TNF-α)、超敏C反应蛋白(hs-CRP)、白细胞介素-6(IL-6)水平下降,低于对照组,鼻黏膜功能均优于对照组,CD4^(+),CD4^(+)/CD8^(+)较对照组升高,CD8^(+)较对照组下降(均P<0.05)。且观察组患者术后1年内的复发率为4.17%,明显低于对照组的22.92%(χ^(2)=7.207,P<0.05)。结论:鼻内镜手术联合糠酸莫米松鼻喷剂治疗慢性鼻窦炎伴鼻息肉效果较好,且复发率低,能够降低患者的炎性反应,促进黏膜免疫功能修复,提高黏液纤毛清除功能。

关键词：鼻内镜手术细胞免疫功能慢性鼻窦炎伴鼻息肉糠酸莫米松鼻喷雾剂复发率炎性因子

DEFORMATION　BEHAVIOUR　OF　Cu－Zn－Al　ALLOYS　AND　ITS　EFFECT　ON　TRANSFORMATION　HYSTERESIS

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中国有色金属学会会刊：英文版 1995年第4期5卷 108-113页

作者： Wang, Mingpu xu, Genyin Yin, Zhiming Central South Univ of Technology Changsha China

ＤＥＦＯＲＭＡＴＩＯＮＢＥＨＡＶＩＯＵＲＯＦＣｕ－Ｚｎ－ＡｌＡＬＬＯＹＳＡＮＤＩＴＳＥＦＦＥＣＴＯＮＴＲＡＮＳＦＯＲＭＡＴＩＯＮＨＹＳＴＥＲＥＳＩＳＷａｎｇＭｉｎｇｐｕ；ＸｕＧｅｎｙｉｎ；ＹｉｎＺｈｉｍｉｎｇ（Ｄｅｐ... 详细信息

ＤＥＦＯＲＭＡＴＩＯＮＢＥＨＡＶＩＯＵＲＯＦＣｕ－Ｚｎ－ＡｌＡＬＬＯＹＳＡＮＤＩＴＳＥＦＦＥＣＴＯＮＴＲＡＮＳＦＯＲＭＡＴＩＯＮＨＹＳＴＥＲＥＳＩＳＷａｎｇＭｉｎｇｐｕ；ＸｕＧｅｎｙｉｎ；ＹｉｎＺｈｉｍｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌ...

关键词： shape memory alloy Cu-Zn-Al alloy martensite transformation boundary movement transformation hysteresis

Improvement of decentralized random decrement technique for data processing in wireless sensor network

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Earthquake Engineering and Engineering Vibration 2016年第3期15卷 627-635页

作者： Liu Chengyin xu Chunchuan Teng Jun School of Civil and Environmental Engineering Harbin Institute of Technology Shenzhen Graduate School Underground Systems Inc. 84 Business Park DriveArmonk

The Random Decrement Technique （RDT）, based on decentralized computing approaches implemented in wireless sensor networks （WSNs）, has shown advantages for modal parameter and data aggregation identification. However, previous studies of RDT-based approaches from ambient vibration data are based on the assumption of a broad-band stochastic process input excitation. The process normally is modeled by filtered white or white noise. In addition, the choice of the triggering condition in RDT is closely related to data communication. In this project, research has been conducted to study the nonstationary white noise excitations as the input to verify the random decrement technique. A local extremum triggering condition is chosen and implemented for the purpose of minimum data communication in a RDT-based distributed computing strategy. Numerical simulation results show that the proposed technique is capable of minimizing the amount of data transmitted over the network with accuracy in modal parameters identification.

关键词： RDT decentralized computing wireless sensor networks nonstationary