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A temperature prediction-correction method for estimating surface soil heat flux from soil temperature and moisture data

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Science China Earth Sciences 2008年第5期51卷 721-729页

作者： kun yang JieMin Wang Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 73000 China

Surface soil heat flux is a component of surface energy budget and its estimation is needed in land-atmosphere interaction studies. This paper develops a new simple method to estimate soil heat flux from soil temperat... 详细信息

关键词： soil heat flux thermal conductivity temperature correction heat-plate

Mechanism and numerical analysis of heat transfer enhancement in the core flow along a tube

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Science China(Technological Sciences) 2008年第8期51卷 1195-1202页

作者： LIU Wei yang kun School of Energy and Power Engineering Huazhong University of Science and TechnologyWuhan 430074China

The present study introduces the principles of enhanced heat transfer in the core flow to form an equivalent thermal boundary layer in the fully developed laminar tube flow, which consequently enlarges the temperature gradient of the fluid near the tube wall, and thereby enhances the heat transfer between the fluid and the tube wall. At the same time, the increase of flow resistance in the tube is not so obvious. Mechanism analysis and numerical calculation based on air and water have been carried out to verify the principle and method presented in this paper, which may bring positive effects to the design of heat exchanger with high heat transfer efficiency and low flow resistance.

关键词： laminar tube flow core flow boundary flow heat transfer enhancement

CR-Morph: Controllable Rigid Morphing for 2D Animation

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Journal of Computer Science & Technology 2019年第5期34卷 1109-1122页

作者： Wen-Wu yang Jing Hua kun-yang Yao School of Computer and Information Engineering Zhejiang Gongshang UniversityHangzhou 310012China Department of Computer Science Wayne State UniversityMichigan 48202U.S.A.

This paper presents a rigidity-preserving morphing technique that blends a pair of 2D shapes in a controllable manner. The morphing is controllable in two aspects: 1) motion dynamics in the interpolation sequences can be effectively enhanced through an intuitive skeleton control and 2) not only the boundaries but also the interior features of the source and target shapes are precisely aligned during the morphing. We introduce a new compatible triangulation algorithm to decompose the source and target shapes into isomorphic triangles. Moreover, a robust and motion-controllable rigiditypreserving transformation scheme is proposed to blend the compatible triangulations, ultimately leading to a morphing sequence which is appearance-preserving and with the desired motion dynamics. Our approach constitutes a powerful and easy-to-use morphing tool for two-dimensional animation. We demonstrate its versatility, effectiveness and visual accuracy through a variety of examples and comparisons to prior work.

关键词： compatible triangulation disc-based interpolation rigid morphing skeleton-based dynamics

Precipitation recycling ratio and water vapor sources on the Tibetan Plateau

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Science China Earth Sciences 2022年第3期65卷 584-588页

作者： kun yang Qiuhong TANG Hui LU Department of Earth System Science Ministry of Education Key Laboratory for Earth System ModelingInstitute for Global Change StudiesTsinghua UniversityBeijing 100084China National Tibetan Plateau Data Center State Key Laboratory of Tibetan Plateau Earth System and Resource EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Precipitation recycling ratio(i.e.,evaporation-precipitation feedback strength)and water vapor sources are two key aspects of regional water cycle,and their quantification is essential for understanding water cycle processes and their *** results of existing studies on the precipitation recycling ratio and water vapor sources for the Tibetan Plateau were highly *** article clarifies different frameworks for understanding the water *** points out that(1)the ratio of evaporation to precipitation depends mainly on climate regimes,while the precipitation recycling ratio is closely related to both the climate regimes and the scale of the region of interest,and(2)the water vapor sources depend on the traced period(precipitating or non-precipitating period)and the degree of *** the same theoretical framework,there is no fundamental conflict among the results of different studies on the water cycle in the Tibetan Plateau.

关键词： Regional water vapor balance Precipitation recycle Water vapor tracing Precipitating period

Acid-assisted hydrothermal synthesis of nanocrystalline TiO_2 from titanate nanotubes: Influence of acids on the photodegradation of gaseous toluene

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Journal of Environmental Sciences 2015年第1期27卷 232-240页

作者： kunyang Chen Lizhong Zhu kun yang Department of Environmental Science Zhejiang University Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control

In order to efficiently remove volatile organic compounds（VOCs） from indoor air, onedimensional titanate nanotubes（Ti NTs） were hydrothermally treated to prepare TiO2 nanocrystals with different crystalline phases, shapes and sizes. The influences of various acids such as CH3 COOH, HNO3, HCl, HF and H2SO4 used in the treatment were separately compared to optimize the performance of the TiO2 nanocrystals. Compared with the strong and corrosive inorganic acids, CH3COOH was not only safer and more environmentally friendly, but also more efficient in promoting the photocatalytic activity of the obtained TiO2. It was observed that the anatase TiO2 synthesized in 15 mol/L CH3COOH solution exhibited the highest photodegradation rate of gaseous toluene（94%）, exceeding that of P25（44%） by a factor of more than two. The improved photocatalytic activity was attributed to the small crystallite size and surface modification by CH3COOH. The influence of relative humidity（20%–80%） on the performance of TiO2 nanocrystals was also studied. The anatase TiO2 synthesized in 15 mol/L CH3COOH solution was more tolerant to moisture than the other TiO2 nanocrystals and P25.

关键词： Titanate nanotubes CH3COOH Ti O2nanocrystals Photocatalytic Gaseous toluene

Tricrystalline TiO_2 with enhanced photocatalytic activity and durability for removing volatile organic compounds from indoor air

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Journal of Environmental Sciences 2015年第6期27卷 189-195页

作者： kunyang Chen Lizhong Zhu kun yang Department of Environmental Science Zhejiang University Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control

It is important to develop efficient and economic techniques for removing volatile organic compounds（VOCs） in indoor air. Heterogeneous Ti O2-based semiconductors are a promising technology for achieving this goal. Anatase/brookite/rutile tricrystalline Ti O2 with mesoporous structure was synthesized by a low-temperature hydrothermal route in the presence of *** obtained samples were characterized by X-ray diffraction and N2 adsorption-desorption isotherm. The photocatalytic activity was evaluated by photocatalytic decomposition of toluene in air under UV light illumination. The results show that tricrystalline Ti O2 exhibited higher photocatalytic activity and durability toward gaseous toluene than bicrystalline Ti O2,due to the synergistic effects of high surface area, uniform mesoporous structure and junctions among mixed phases. The tricrystalline Ti O2 prepared at R HNO3= 0.8, containing80.7% anatase, 15.6% brookite and 3.7% rutile, exhibited the highest photocatalytic activity,about 3.85-fold higher than that of P25. The high activity did not significantly degrade even after five reuse cycles. In conclusion, it is expected that our study regarding gas-phase degradation of toluene over tricrystalline Ti O2 will enrich the chemistry of the Ti O2-based materials as photocatalysts for environmental remediation and stimulate further research interest on this intriguing topic.

关键词： VOC Photocatalysis Tricrystalline TiO2 Nanomaterials Mesoporous Gaseous

A Covering Lemma on the Unit Sphere and Application to the Fourier-Laplace Convergence

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Acta Mathematica Sinica,English Series 2007年第7期23卷 1327-1332页

作者： Rong HUANG kun yang WANG Department of Mathematics Tianjin Normal University School of Mathematical Sciences Beijing Normal University

A covering lemma on the unit sphere is established and then is applied to establish an almost everywhere convergence test of Marcinkiewicz type for the Fourier-Laplace series on the unit sphere which can be stated as follows：Theorem Suppose f ∈ L（En-1）, n≥ 3. If f satisfies the condition1/θ^n-1∫D（x,θ）｜f（y）-f（x）｜dy=O（1/｜logθ｜）,as θ→0＋,at every point x in a set E of positive measure in Σn-1, then the Cesàro means of critical order ,n-2/2 of the Fourier-Laplace series of f converge to f at almost every point x in E.

关键词： sphere covering lemma Fourier-Laplace series a.e. convergence

Hydraulic metal structure health diagnosis based on data mining technology

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Water Science and Engineering 2015年第2期8卷 158-163页

作者： Guang-ming yang Xiao Feng kun yang College of Energy and Electrical Engineering Hohai University Research Center for Renewable Energy Generation Engineering Ministry of Education Hohai University Dayu College Hohai University

In conjunction with association rules for data mining, the connections between testing indices and strong and weak association rules were determined, and new derivative rules were obtained by further reasoning. Association rules were used to analyze correlation and check consistency between indices. This study shows that the judgment obtained by weak association rules or non-association rules is more accurate and more credible than that obtained by strong association rules. When the testing grades of two indices in the weak association rules are inconsistent, the testing grades of indices are more likely to be erroneous, and the mistakes are often caused by human factors. Clustering data mining technology was used to analyze the reliability of a diagnosis, or to perform health diagnosis directly. Analysis showed that the clustering results are related to the indices selected, and that if the indices selected are more significant, the characteristics of clustering results are also more significant, and the analysis or diagnosis is more credible. The indices and diagnosis analysis function produced by this study provide a necessary theoretical foundation and new ideas for the development of hydraulic metal structure health diagnosis technology.

关键词： Hydraulic metal structure Health diagnosis Data mining technology Clustering model Association rule

Multi-Sinusoidal Waveform Shaping for Integrated Data and Energy Transfer in Aging Channels

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China Communications 2023年第4期20卷 243-258页

作者： Jie Hu Yaping Hou kun yang yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 313001China School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

Integrated data and energy transfer(IDET)is capable of simultaneously delivering on-demand data and energy to low-power Internet of Everything(Io E)*** propose a multi-carrier IDET transceiver relying on superposition waveforms consisting of multi-sinusoidal signals for wireless energy transfer(WET)and orthogonal-frequency-divisionmultiplexing(OFDM)signals for wireless data transfer(WDT).The outdated channel state information(CSI)in aging channels is employed by the transmitter to shape IDET *** the constraints of transmission power and WDT requirement,the amplitudes and phases of the IDET waveform at the transmitter and the power splitter at the receiver are jointly optimised for maximising the average directcurrent(DC)among a limited number of transmission frames with the existence of carrier-frequencyoffset(CFO).For the amplitude optimisation,the original non-convex problem can be transformed into a reversed geometric programming problem,then it can be effectively solved with existing *** for the phase optimisation,the artificial bee colony(ABC)algorithm is invoked in order to deal with the *** between the amplitude optimisation and phase optimisation yields our joint *** results demonstrate the advantage of our joint design for the IDET waveform shaping with the existence of the CFO and the outdated CSI.

关键词： integrated data and energy transfer(IDET) wireless energy transfer(WET) simultaneous wireless information and power transfer(SWIPT) carrier-frequency-offset(CFO) waveform aging channels outdated channel state information(CSI) orthogonal frequency division multiplexing(OFDM)