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Journal of Computational Mathematics 2006年第1期24卷 81-90页

作者： Wen-sheng chen chen Xu Wei Lin Department of Mathematics Shenzhen University Shenzhen 518060 China Key Laboratory of Mathematics Mechanization CAS Beijing 100080 China Department of Mathematics Sun Yat-Sen University Guangzhou 510275 China

Subdivision algorithm （Stationary or Non-stationary） is one of the most active and exciting research topics in wavelet analysis and applied mathematical theory. In multidimensional non-stationary situation, its limit functions are both compactly supported and infinitely differentiable. Also, these limit functions can serve as the scaling functions to generate the multidimensional non-stationary orthogonal or biorthogonal semi-multiresolution analysis （Semi-MRAs）. The spectral approximation property of multidimensional non-stationary biorthogonal Semi-MRAs is considered in this paper. Based on nonstationary subdivision scheme and its limit scaling functions, it is shown that the multidimensional nonstationary biorthogonal Semi-MRAs have spectral approximation order r in Sobolev space H^s（R^d）, for all r ≥ s ≥ 0.

关键词： Nonstationary subdivision algorithm Biorthogonal Semi-MRAs Wavelets,Spectral approximation Sobolev space

Simulation of thermoacoustic waves by a pressure-based algorithm for compressible flows

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Acta Mechanica Sinica 2012年第3期28卷 819-824页

作者： Wei Li Qi-sheng chen Key laboratory of Microgravity Institute of MechanicsChinese Academy of Sciences15 Beisihuan West Road100190 BeijingChina

A modified SIMPLEC method which can solve compressible flows at low Mach number is introduced and used to study thermoacoustic waves induced by a rapid change of temperature at a solid wall and alternating- direction flows generated by thermoacoustic effects in a ta- pered resonator. The results indicate that the algorithm adopted in this paper can be used for calculating com- pressible flows and thermoacoustic waves. It is found that the pressure and velocity in the resonator behave as stand- ing waves, and the tapered resonator can suppress high- frequency harmonic waves as observed in a cylindrical res- onator.

关键词： Compressible flow Thermoacoustic wave Resonator. SIMPLEC

Small-Scale Spatial Variability of Soil Nutrients and Vegetation Properties in Semi-Arid Northern China

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Pedosphere 2006年第6期16卷 778-787页

作者： chen Fu-sheng ZENG De-Hui he Xing-Yuan Daqinggou Ecological Station Institute of Applied Ecology Chinese Academy of Sciences Shengyang 110016 （China） Life College Nanchang University Nanchang 330047 （China）

A field experiment was conducted at Kezuohouqi County, Inner Mongolia Autonomous Region of China, which was located on the southeastern edge of the Horqin Sandy Land, to study the spatial variability of soil nutrients for a smallscale, nutrient-poor, sandy site in a semi-arid region of northern China; to investigate whether or not there were 'islands of fertility' at the experimental site; and to determine the key nutrient elements that sustained ecosystem stability. Results obtained from geostatistical analysis indicated that the spatial distribution pattern of soil total nitrogen (STN) was far different from those of soil organic matter (SOM), total phosphorus (STP), and total potassium (STK). Compared to SOM, STP, and STK, STN had a lower structural heterogeneity ratio and a longer range, while other elements were all similar. In addition, STN had an isotropic spatial structure, whereas the others had an anisotropic spatial structure. The spatial structure patterns of herbage species, cover,and height also differed, indicating that spatial variability was subjected to different ecological factors. Differences in the spatial variability patterns among soil nutrients and vegetation properties showed that soil nutrients for a small-scale were not the primary limiting factors that influenced herbage spatial distribution patterns. Incorporating spatial distribution patterns of tree species, namely, Pinus sylvestris var. mongolica Litv. and shrub Lespedeza bicolor Turcz. in a research plot and using fractal dimension,SOM, STP, and STK were shown to contribute to the 'islands of fertility' phenomenon, however STN was not, possibly meaning that nitrogen was a key limiting element. Therefore, during restoration of similar ecosystems more attention should be given to soil nitrogen.

关键词： Pinus sylvestris war. mongolica Litv. semi-arid region soil nutrients spatial variability species richness

Pheromone-trapping the nun moth, Lymantria monacha （Lepidoptera： Lymantriidae）in Inner Mongolia, China

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Insect Science 2017年第4期24卷 631-639页

作者： Peng Wang Guo-Fa chen Jun-sheng Zhang Qi Xue Jin-Hua Zhang Chao chen Qing-he Zhang Station of Forest Pest Control and Quarantine Daxinganling Forestry Administration Yakeshi Inner Mongolia China General Station of Forest Pest control NFA Shenyang China Kuduer Forestry District Daxinganling Forestry Administration Kuduer Inner Mongolia China Wuerqihan Forestry District Daxinganling Forestry Administration Wuerqihan Inner Mongolia China Arshan Forestry District Daxinganling Forestry Administration Arshan Inner Mongolia China Sterling International Inc. Spokane Washington USA

The nun moth, Lymantria monacha L., is one of the most important defoliators of Eurasian coniferous forests. Outbreaks during 2011-2015 in the natural/planted larch, and larch-birch mixed forests of the Greater Khingan Range in Inner Mongolia, China, caused tremendous timber losses from severe defoliation and tree mortality. A series of trapping experiments were conducted in these outbreak areas to evaluate the efficacy of a synthetic species-specific pheromone lure based on the female pheromone blend of European nun moth populations. Our results clearly show that the nun moth in Inner Mongolia is highly and specifically attracted to this synthetic pheromone, with few gypsy moths （Lymantria dispar） captured. Flight activity monitoring ofL. monacha male moths using pheromone-baited Unitraps at 2 locations during the summer of 2015 indicated that the flight period started in mid-July, peaking in early August at both locations. Based on male moth captures, there was a strong diurnal rhythm of flight activity throughout the entire scotophase, peaking between 22：00 and 24：00. Unitraps and wing traps had significantly and surprisingly higher catches than the gypsy moth traps. Unitraps fastened to tree trunks 2 m above ground caught significantly more male moths than those at the ground level or at 5 m height. Male L. monacha moths can be attracted to pheromone- baited traps in open areas 150-200 m distant from the infested forest edge. Our data should allow improvement on the performance of pheromone-baited traps for monitoring or mass-trapping to combat outbreaks of this pest in northeastern China.

关键词： disparlure 2-methyl-(Z)-7-octadecene monachalure monitoring phero-mone trap

Smart CU1.75S nanocapsules with high and stable photothermal efficiency for NIR photo-triggered drug release

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Nano Research 2015年第12期8卷 4038-4047页

作者： sheng Huang Jing Liu Qian he Hongli chen Jiabin Cui Suying Xu Yuliang Zhao Chunying chen Leyu Wang State Key Laboratory of Chemical Resource Engineering Beijing Key Laboratory of Environmentally Harmful Chemical Analysis Beijing University of Chemical Technology Beijing 100029 China CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety National Center for Nanoscience and Technology of China and Institute of High Energy Physics Chinese Academy of Sciences Beijing 100190 China

Thermosensitive drug delivery systems （DDSs） face major challenges, such as remote and repeatable control of in vivo temperature, although these can increase the therapeutic efficacy of drugs. To address this issue, we coated near- infrared （NIR） photothermal Cu175S nanocrystals with pH/thermos-sensitive polymer by in situ polymerization. The doxorubicine （DOX） loading content was up to 40 wt.%, with less than 8.2 wt.% of DOX being leaked under normal physiological conditions （pH = 7.4, 37 ~C） for almost 48 h in the absence of NIR light. These nanocapsules demonstrate excellent photothermal stability by continuous long- term NIR irradiation. Based on the stable and high photothermal efficiency （55.8%）, pre-loaded drugs were released as desired using 808-nm light as a trigger. Both in vitro and in vivo antitumor therapy results demonstrated that this smart nanoplatform is an effective agent for synergistic hyperthermia-based chemotherapy of cancer, demonstratin~ remote and noninvasive control.

关键词： copper sulfides near infrared light phothermal therapy drug release

An improved nonlinear onboard adaptive model for aero-engine performance control

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Chinese Journal of Aeronautics 2023年第10期36卷 317-334页

作者： Qian chen Hanlin sheng Tianhong ZHANG Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

The onboard adaptive model can achieve the online real-time estimation of performance parameters that are difficult to measure in a real aero-engine,which is the key to realizing modelbased performance *** must possess satisfactory numerical stability and estimation ***,the positive definiteness of the state covariance matrix may be destroyed in filter estimation because of the existence of some uncertain factors,such as the accumulated measurement error,noise,and disturbance in the strongly nonlinear engine system,inevitably causing divergence of estimates of Cholesky decomposition-based Spherical Unscented Kalman Filter(SUKF).Therefore,this paper proposes an improved SUKF algorithm(iSUKF)and applies it to the performance degradation estimation of the *** to SUKF,the iSUKF mainly replaces the Cholesky decomposition with the Singular Value Decomposition(SVD),which is numerically stable without any strict requirement for the state covariance ***,a correction factor is designed to assess the measurement deviation between the real engine and the nonlinear onboard model to correct the state covariance matrix,thus maintaining better numerical stability of parameters estimated by the ***,an offline correction strategy is also proposed to eliminate the influence of the degradation of unestimated health parameters or the filter’s inadequate estimation of the coupled health *** action effectively promotes the onboard adaptive model’s estimation accuracy concerning the degradation of the engine’real health parameters and its performance ***,the simulation results show that the iSUKF can maintain the numerical stability of the filter’s estimation of health *** with the existing methods,the offline correction strategy improves the estimation accuracy of the iSUKF-based nonlinear onboard adaptive model for the performance parameters of the real engine by more than 50%.The proposed met

关键词： Aero-engine Onboard adaptive model Spherical unscented Kalman filter Parameter estimation iSUKF

Multi-coset angular sampling-based compressed sensing of blade tip-timing vibration signals under variable speeds

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Chinese Journal of Aeronautics 2021年第9期34卷 83-93页

作者： Zhongsheng chen Hao sheng Yemei XIA College of Electrical&Information Engineering Hunan University of TechnologyZhuzhou 412007China

Blade Tip-Timing(BTT)has been regarded as a promising way of on-line blade vibration *** blind multi-band BTT vibration reconstruction is a big challenge under variable speeds and *** order to deal with it,a novel Compressed Sensing(CS)method is proposed based on Multi-Coset Angular Sampling(MCAS)in this ***,multi-coset sampling scheme of BTT vibration signals is *** the CS model of BTT vibration signals is derived in order domain.A sufficient condition of the number of BTT sensors is derived for perfect reconstruction and optimal placement of BTT sensors is determined by minimizing the condition *** the end,numerical simulations are done to validate the proposed method and the performances of four reconstruction algorithms are compared,i.e.,Orthogonal Matching Pursuit(OMP),Multiple Signal Classification(MUSIC),Basis Pursuit Denoising(BPDN)and Modified Focal Underdetermined System Solver(MFOCUSS).Influences of the sensor placement,the number of BTT sensors and measurement noises on the reconstruction performances are also *** results demonstrate that the proposed method is feasible and the overall performance of the BPDN algorithm is the best among the four *** the reconstruction performance decreases with the accelerations of rotating speed.

关键词： Blade tip-timing Blind and multi-band signal reconstruction Compressed sensing Multi-coset angular sampling Vibration analysis

Monodispersed Au Pd nanoalloy: composition control synthesis and catalytic properties in the oxidative dehydrogenative coupling of aniline

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Science China Chemistry 2015年第10期58卷 1532-1536页

作者： Fangyu Fu Sen he Sha Yang chen Wang Xun Zhang Peng Li Hongting sheng Manzhou Zhu Department of Chemistry and Center for Atomic Engineering of Advanced Materials Anhui University

A series of Au Pd@C nanoalloy catalysts with tunable compositions were successfully prepared by a co-reduction method. The use of borane-tert-butylamine complex as reductant and oleylamine as both solvent and reductant was very effective for the preparation of the monodispersed nanoalloy. We evaluated the catalytic activity of these Au Pd@C nanoalloys for oxidative dehydrogenative coupling of aniline, which showed better catalytic activity than equal amounts of sole Au@C or Pd@C catalyst. The Au1Pd3@C catalyst exhibited the best performance, indicating that the conversion and selectivity were improved along with the increase of Pd composition. However, if the Pd composition was too high in the Au Pd alloy, Au1Pd7@C achieved only 81% conversion in this reaction.

关键词： Au Pd alloy catalyst oxidative coupling

Mechanisms involved in triggering debris flows,within a cohesive gravel soil mass on a slope:a case in SW China

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Journal of Mountain Science 2017年第4期14卷 611-620页

作者： chen Ning-sheng ZHU Yun-hua HUANG Qi IQBAL Javed DENG Ming-feng he Na Key Laboratory of Mountain Hazards and Surface Process Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences and Ministry of Water ResourcesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China Southwest Petroleum University Chengdu 610500China Southwest Electric Power Design Institute CO LTDChengdu 610021China Department of Earth Sciences COMSATS Institute of Information Technology22060 AbbottabadPakistan

The triggering mechanisms of debris flows were explored in the field using artificial rainfall experiments in two gullies, Dawazi Gully and Aizi Gully, in Yunnan and Sichuan Provinces, China,respectively. The soils at both sites are bare, loose and cohesive gravel-dominated. The results of a direct shear test, rheological test and back-analysis using soil mass stability calculations indicate that the mechanisms responsible for triggering debris flows involved the decreases in static and dynamic resistance of the soil. The triggering processes can be divided into 7 stages: rainfall infiltration, generation of excess runoff, high pore water pressure, surface erosion, soil creep, soil slipping, debris flow triggering and debris flow increment. In addition, two critical steps are evident:(i) During the process of the soil mass changing from a static to a mobile state, its cohesion decreased sharply(e.g., the cohesion of the soil mass in Dawazi Gully decreased from 0.520 to0.090 k Pa, a decrease of 83%). This would have reduced the soil strength and the kinetic energy during slipping, eventually triggered the debris flow.(ii) When the soil mass began to slip, the velocity and the volume increment of the debris flow fluctuated as a result of the interaction of soil resistance and the sliding force. The displaced soil mass from the source area of the slope resulted in the deposition of a volume of soil more than 7-8 times greater than that in the source area.

关键词： Debris flow Cohesive gravel soil Triggering mechanism Slip Soil erosion

Damage Layer Evolution of a Breakwater Under Seawater Attack: Testing and Modeling

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Acta Mechanica Solida Sinica 2020年第1期33卷 1-13页

作者： sheng Cang Yizhan Yang Jiankang chen Key Laboratory of Impact and Safety Engineering Ningbo UniversityNingbo 315211China Ningbo City College of Vocational Technology Ningbo 315100China

This paper presents experimental and theoretical methods to study the damage layer evolution of a breakwater made with concrete hollow squares in marine *** time was directly related to the performance degradation of the breakwater by *** thickness of damage layer was detected by means of ultrasonic ***,some samples drilled from concrete hollow squares were analyzed by SEM and XRD in order to illustrate the damage ***,a theoretical model containing wetting time ratio was established to simulate the damage layer evolution based on Fick’s second law,which could be suggested to predict the service life of concrete structures in marine environment.

关键词： Breakwater Seawater attack Damage layer.Wetting time ratio.Modeling