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Underground Space 2023年第3期10卷 118-136页

作者： Jingkang Shi fei wang Hongwei Huang Dongming Zhang Department of Geotechnical Engineering Tongji UniversityShanghai 200092China Shanghai Institute of Disaster Prevention and Relief Tongji UniversityShanghai 200092China Key Laboratory of Geotechnical and Underground Engineering of Minister of Education Tongji UniversityShanghai 200092China

Tunnel horizontal convergence monitoring is essential to ensure the operation ***,only a few representative tunnel sec-tions are chosen for monitoring due to the cost *** is difficult to capture the horizontal convergence of each tunnel ring with limited *** with this difficulty,the paper proposes a horizontal convergence reconstruction method based on the measurements of deployed *** tunnel horizontal convergence along the longitudinal direction is seen as a one-dimensional sta-tionary and ergodic random *** reconstruction problem is then transformed into the generation of conditional random *** Carlo simulation is adopted to generate possible realizations and the mean of realizations is considered as the maximum likeli-hood *** analysis proves the effectiveness of the proposed reconstruction *** proposed method is proved to be applicable in reconstructing the time-variant horizontal convergence and is verified by the monitoring results of the shield tunnel of Shanghai Metro Line *** effect of sensor numbers is parametrically studied,and an optimal sensor placement scheme is *** sensors placed at the deformation drastically changed location can significantly improve the performance of the proposed method.

关键词： Structural performance reconstruction Tunnel convergence monitoring Conditional random field Optimal sensor placement

Security information factor based airborne radar RF stealth

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Journal of Systems Engineering and Electronics 2015年第2期26卷 258-266页

作者： fei wang Mathini Sellathurai Weigang Liu Jiangjiang Zhou College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics School of Electronics Electrical Engineering and Computer Science Queen's University Belfast

Radar radio frequency （RF） stealth is very important in electronic war （EW）, and waveform design and selection. Existing evaluation rules of radar RF stealth include too many parameters of radar and interceptors, such as Schleher interception factor, which makes it difficult to evaluate radar RF stealth technologies if interceptor parameters are unknown. In communication, security capacity has been presented to describe the possible ability to communicate in complete security. Since the essential of the secu- rity capacity is to have the interceptor get none valued information from the emitter, this paper is proposed to study security infor- mation factors taking advantage of mutual information to evaluate radar RF stealth under some conditions. Through analyzing mutual information obtained by the radar and the interceptor, this paper defines the security information factor with and without cooperative jamming. Furthermore, this paper deduces the ratio of the match filter to the match incoherent filter and discuss mutual information received by the interceptor. Numerical simulations illustrate radar RF stealth effects based on the security information factor concept under different conditions.

关键词： mutual information radar signal stealth

A GNSS Acquisition Method with the Capability of Spoofing Detection and Mitigation

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Chinese Journal of Electronics 2018年第1期27卷 213-222页

作者： YUAN Dingbo LI Hong wang fei LU Mingquan Department of Electronic Engineering Tsinghua University

For Global navigation satellite system(GNSS), spoofing attack is extremely dangerous and destructive since it can lead GNSS receivers to generate misleading time and position information. Thus, reliable and timely spoofing detection and mitigation methods are of great importance. A new GNSS acquisition method with the capability of spoofing detection and mitigation is proposed in the paper. The proposed method can not only perform acquisition, but also detect and mitigate spoofing signals based on joint consistency detection of code and carrier Dopplers. We provide performance analysis and numerical simulation results to demonstrate the validity of the proposed method when there are one or even more spoofing signals. Successful acquisition probability of the authentic signal is compared to that achieved by traditional acquisition method. The proposed method can be easily implemented with only a little modification of current receiver acquisition module.

关键词： Global navigation satellite system(GNSS) Spoofing mitigation Acquisition Doppler Joint detection

Fast separation of intact proteins with high resolution under high sample loading using non-porous RPLC packings

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Chinese Science Bulletin 2010年第16期55卷 1604-1607页

作者： wang fei GENG XinDu Institute of Modern Separation Science Shaanxi Provincial Key Laboratory of Modern Separation Science Northwest University Xi'an 710069China

A new approach for separation of intact proteins with high resolution, high speed and high sample loading ("three highs") by non-porous packings in high performance liquid chromatography is presented.A chromatographic cake having larger diameter than its thickness is firstly employed to completely separate 1.0 and 40 μg of the mixture of 7 standard proteins within 1 min un-der conventional chromatographic ***, 0.5 mg of the mixture was almost completely separated within 1 min, accom-plishing the "three high" *** research expands the application utilized for separation of intact proteins with non-porous packings.A smaller geometric size of chromatographic cake packed with much smaller particles of non-porous packings may improve results.

关键词：高效液相色谱法蛋白质分离色谱填料快速分离高负荷采样分辨率反相高分辨率

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三维高熵合金的合成及其电解水应用研究进展

现代化工 2025年第1期45卷 17-23页

作者：王帅任李萍陈春迎王龙飞王奇陈新范金鹏陈杰中煤能源研究院有限责任公司陕西西安710054 西安交通大学化学工程与技术学院陕西西安710000

概述了三维高熵合金材料的合成方法及其在电催化分解水领域的应用研究进展。重点介绍了脱合金法和湿化学法合成三维高熵合金,以及多孔结构、凸立方型结构、介孔球的三维高熵合金在电催化分解水方面所取得的突破性进展。最后指出,三维高... 详细信息

概述了三维高熵合金材料的合成方法及其在电催化分解水领域的应用研究进展。重点介绍了脱合金法和湿化学法合成三维高熵合金,以及多孔结构、凸立方型结构、介孔球的三维高熵合金在电催化分解水方面所取得的突破性进展。最后指出,三维高熵合金的可控合成方法及其电催化水分解机制方面仍缺少系统性的梳理,在实际应用方面亟待寻找简易、高效的宏量制备方法。

关键词：高熵合金三维形貌析氢反应析氧反应协同效应

Flow structures of gaseous jets injected into water for underwater propulsion

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Acta Mechanica Sinica 2011年第4期27卷 461-472页

作者： Jia-Ning Tang Ning-fei wang Wei Shyy School of Aerospace Engineering Beijing Institute of Technology 100081 Beijing China Department of Aerospace Engineering University of Michigan Ann Arbor MI 48109 USA

Gaseous jets injected into water are typically found in underwater propulsion, and the flow is essentially unsteady and turbulent. Additionally, the high water-to-gas density ratio can result in complicated flow structures; hence measuring the flow structures numerically and experimentally remains a challenge. To investigate the performance of the underwater propulsion, this paper uses detailed NavierStokes flow computations to elucidate the gas-water interactions under the framework of the volume of fluid （VOF） model. Furthermore, these computations take the fluid compressibility, viscosity, and energy transfer into consideration. This paper compares the numerical results and experimental data, showing that phenomena including expansion, bulge, necking/breaking, and back-attack are highlighted in the jet process. The resulting analysis indicates that the pressure difference on the rear and front surfaces of the propul- sion system can generate an additional thrust. The strong and oscillatory thrust of the underwater propulsion system is caused by the intermittent pulses of the back pressure and the nozzle exit pressure. As a result, the total thrust in underwater propulsion is not only determined by the nozzle geometry but also by the flow structures and associated pressure distri- butions.

关键词： Gaseous jets - Underwater propulsion Highdensity ratio Gas-water interactions

Evaluation of formaldehyde emission from particleboard using the large chamber and desiccator method at various loading ratios

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Journal of Forestry Research 2013年第1期24卷 137-142页

作者： QUE Ze-li wang fei-bin MA Ling-fei Furuno Takeshi Nanjing Forestry University Research Institute for Sustainable Humanosphere Kyoto University College of Wood Science and Technology Zhejiang A & F University Faculty of Science and Engineering Shimane University

We studied formaldehyde emission from uncoated particleboard with 16-mm thickness using the large chamber and the desiccator method. A chamber of 28.4 m3 was installed to simulate a mobile home. The formaldehyde off-gassing properties of particleboard were evaluated using the chamber. The relationship between the concentration obtained by the chamber and the values by the desiccator test was discussed in this study under different conditions of conditioning day, air exchange, and loading ratio. These two methods were compared and discussed regarding the formaldehyde emission level. Three loading ratios, 0.429 m2/m3, 0.264 m2/m3, and 0.132 m2/m3, were chosen to represent different applications of particleboard products. There was strong correlation between emissions and air exchange rates at equal product-loading ratios in the large chamber, the related coefficient R 2 exceeded 0.90. There was also an indication of a generic correlation between the large chamber and the two-hour desiccator test with a single product designated loading ratio, air exchange rate, and climatic conditions.

关键词： formaldehyde emission particleboard large chamber desiccator

Reflection-based traveltime and waveform inversion with second-order optimization

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Petroleum Science 2022年第4期19卷 1582-1591页

作者： Teng-fei wang Jiu-Bing Cheng Jian-Hua Geng State Key Laboratory of Marine Geology Tongji UniversityShanghai200092China School of Ocean and Earth Science Tongji UniversityShanghai200092China

Reflection-based inversion that aims to reconstruct the low-to-intermediate wavenumbers of the subsurface model, can be a complementary to refraction-data-driven full-waveform inversion(FWI), especially for the deep target area where diving waves cannot be acquired at the surface. Nevertheless, as a typical nonlinear inverse problem, reflection waveform inversion may easily suffer from the cycleskipping issue and have a slow convergence rate, if gradient-based first-order optimization methods are used. To improve the accuracy and convergence rate, we introduce the Hessian operator into reflection traveltime inversion(RTI) and reflection waveform inversion(RWI) in the framework of second-order optimization. A practical two-stage workflow is proposed to build the velocity model, in which Gauss-Newton RTI is first applied to mitigate the cycle-skipping problem and then Gauss-Newton RWI is employed to enhance the model resolution. To make the Gauss-Newton iterations more efficiently and robustly for large-scale applications, we introduce proper preconditioning for the Hessian matrix and design appropriate strategies to reduce the computational costs. The example of a real dataset from East China Sea demonstrates that the cascaded Hessian-based RTI and RWI have good potential to improve velocity model building and seismic imaging, especially for the deep targets.

关键词： Reflection waveform inversion Reflection traveltime inversion Gauss-Newton Hessian

国际荒漠化协会联合主席,水土保持专家王飞先生论基于土盐-水盐双分离的旱区盐碱地水土资源管理模式

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水土保持通报 2019年第1期39卷 317-321页

作者：王飞西北农林科技大学水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室中国科学院水利部水土保持研究所

[目的]从区域资源综合利用与水土资源管理角度探讨干旱地区土壤盐碱地治理问题,旨在寻求旱区盐碱地治理与开发利用新模式,以创新旱区盐碱地治理观念与技术,为旱区农业可持续发展、生态保护和环境治理提供支撑。[方法]根据在陕西、宁夏... 详细信息

[目的]从区域资源综合利用与水土资源管理角度探讨干旱地区土壤盐碱地治理问题,旨在寻求旱区盐碱地治理与开发利用新模式,以创新旱区盐碱地治理观念与技术,为旱区农业可持续发展、生态保护和环境治理提供支撑。[方法]根据在陕西、宁夏和新疆等省区的野外调查和研究经验,结合有关水土资源高效利用研究成果,通过综合分析目前国内外盐碱地治理方法中存在的主要问题,提出了一种旱区盐碱地水土资源高效利用的管理新模式。[结果]旱区盐碱地水土资源管理新模式是通过高效水调控促进土盐—水盐分离(简称:旱区盐碱地双分离治理模式),可以综合概括为"减少区域水损失,低耗水充分洗盐,集约化水盐分离,水土资源高效利用"。其中"减少区域水损失"是旱区水资源管理与生态保障的前提,"低耗水充分洗盐"是节省洗盐的时间成本和水资源成本的基础,"集约化水盐分离"是实现水盐分离和水盐分别再利用的核心技术,"水土资源高效利用"是旱区农业发展用水的核心经济原则。[结论]旱区盐碱地双分离治理模式通过集约化水土资源管理,可以提高水盐分离效率,提升土地和水资源利用效率,其资源、环境和生态风险小,治理效益持续时间长,有助于维持和提升盐碱地治理的区域经济功能和生态系统服务价值。

关键词：干旱地区盐碱地土盐—水盐分离措施水土资源管理高效利用可持续性

Experimental investigation on aerodynamic and noise characteristics of Fenestron

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Chinese Journal of Aeronautics 2023年第12期36卷 88-101页

作者： Bo wang Wei ZHANG fei wang Qijun ZHAO Chenkai CAO Yuan GAO National Key Laboratory of Rotorcraft Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China China Helicopter Research and Development Institute Jingdezhen 333001China

It is difficult to simulate the strong interference and serious flow separation of Fenestron by the CFD method based on the widely used RANS equation,and the detailed experimental data,which could be used to validate the aerodynamic and noise numerical methods,is *** experimental investigation on the aerodynamic and noise characteristics of Fenestron is carried *** view of the complex internal flow field in duct and the relative motion between the stationary duct and the rotating rotor,a comprehensive aerodynamics and pressure measurement scheme is designed based on the bottom support *** this measurement scheme,the thrust generated by the rotating rotor can be measured by the rotating shaft balance,the thrusts from Fenestron are measured by the external balance and the pressures on duct inner wall are monitored by a pressure measuring *** fully capture the noise directionality of Fenestron,a series of noise observers located at an arc array are *** terms of the Fenestron test models,the baseline model,the performance improvement model based on the high-performance tail rotor and the noise reduction model based on the non-uniform blade distribution are designed *** the designed measurement scheme,aerodynamic forces and pressure distributions and noise were measured for the three different Fenestron *** results show that the aerodynamic thrusts of the tail rotor and duct increase greatly and the noise increases slightly for the performance improvement model because of the larger *** rotor aerodynamic performance of the noise reduction model is reduced,but the modulation effect of the tail rotor improves the forces of the *** noise radiated by the noise reduction model is reduced and a good noise reduction result is obtained in frequency domain.

关键词： Helicopter Fenestron Aeroacoustic wind tunnel Noise reduction Non-uniform rotor