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1

Digital control system design for bearingless permanent magnet synchronous motors

Sun X., Shi Z., Yang Z., Wang S., Su B., Chen L., Li K.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 5

687--698

EN

This study investigates a digital control system which is used in bearingless permanent magnet synchronous motors (BPMSMs). Compared with traditional permanent magnet synchronous motors, a BPMSM is characterized by higher speed and no mechanic friction. Therefore, the application value of the latter to the special area is higher than that of the former. An analysis from previous work on the BPMSM had proved its feasibility, and some performances such as suspension force, inductance and so on were also investigated. Based on this analysis, this study focuses on solving control problems in practical applications by designing a control system. The control system design includes overall schematic, hardware and software designs. Main software systems, including the force/current transform module and closed loop control module for radial displacement, are analyzed. Interface circuit for radial displacement, current feedback circuit and dead zone protection circuit are designed for the hardware system. Finally, several performance experiments have been conducted to verify the effectiveness of the designed digital control system. Experiment results indicate that the rotor has unique characteristics, such as stable suspension performance, good start-of-suspension performance, and rapid anti-disturbance features.

2

Response of energy-size reduction to the control of circulating load in vertical spindle pulverizer

Li H., He Y., Zhang Y., Ge Z., Xie W., Wang S., Li K.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 2

793--801

EN

In the vertical spindle pulverizer (VSP), the large circulation ratio and high ash and sulfur contents in circulating load would result in intensive energy consumption and low grinding efficiency. Although the control of circulating load would help increase the energy efficiency, no quantitative study has been conducted due to the high temperature and pressure in the closed VSP. In this study, response of energy-size reduction to the control of circulating load was studied by the experimental simulation method. Coal mixtures with fine/coarse ratio of 11:1, 8:1 and 6:1 were ground by a lab-scale roller mill. Energy-size reductions of the coarse coal were compared to evaluate the influence of circulating load control. Results showed that the product with the coarse coal increased by 30% when the specific breakage energy was 1.0 kWht–1 as the circulation ratio decreased from 11 to 6. Meanwhile, a breakage characteristic index of the coarse coal was two times higher due to the cushioning effect of fines. Besides, decrease of circulation ratio led to increase of the breakage rate of coarse coal, and the energy saving improved by 57%. With the same energy input of 2.0 kWht-1, the yield of –0.09 mm pulverized fuel (PF) increased from 22 to 43%. Therefore, controlling the circulating load is an effective method to improve the breakage rate of coarse coal and energy efficiency for PF generation.

3

Design and analysis of interior composite-rotor bearingless permanent magnet synchronous motors with two layer permanent magnets

Sun X., Su B., Chen L., Yang Z., Li K.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2017

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Vol. 65, nr 6

833--843

EN

In this paper, a new type of interior composite-rotor bearingless permanent magnet synchronous motors (BPMSMs) with two layer permanent magnets (PMs) is proposed. In order to reduce the torque ripple of this kind of motors, the sizes of PMs are optimized. Moreover, the magnetic field analysis of the interior composite-rotor BPMSM with two layer PMs is carried out by the finite element method (FEM). The corresponding static electronic magnetic characteristics at no load, including magnetic field, PM flux linkage and inductance, are studied in detail. In addition, electromagnetic torque characteristics and suspension force characteristics are also investigated thoroughly. The results of the analysis and simulation lay a significant foundation for further research on the interior composite-rotor BPMSMs with two layer PMs.

4

Effects of Varying Temperature on Leaf Phenology and Herbivory of Dominant Tree Species in Subtropical Evergreen Broad-Leaves Forest in Eastern China

Jing J., Li K., Liu Z.

Polish Journal of Ecology

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2016

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Vol. 64, nr 1

53--69

EN

The aim of this work was to analyse the response of dominant tree species to the changing climate in a subtropical evergreen broad-leaved forest in China. We investigated the main leaf phenology and herbivory parameters of four typical trees (i.e., Schima superba, Castanopsis fargesii, Castanopsis sclerophylla and Cyclobalanopsis sessilifolia) in spring from 2010 to 2014 in the Tiantong National Forest Research Station in eastern China. The results showed that the accumulated temperature was the principle factor which affected the leaf phenology and herbivory. All four trees got an earlier, shorter and more synchronised leaf expansion in years with higher accumulated temperature, and also they suffered more sever leaf damage in these years. However the trees responded differently to climate warming in leaf phenology and herbivory. The S. superba and Ca. sclerophylla were more sensitive to the varying accumulated temperature than the Ca. fargesii and Cy. sessilifolia both in leaf phenology and herbivory during leaf expansion. We suggest that the observed variations in leaf phenology and leaf traits to the changing accumulated temperature should be taken into consideration for pest management and community stability maintenance in forests adapting to the changing climate.

5

Short-term variation in zooplankton community from Daya Bay with outbreaks of Penilia avirostris

Li K., Yin J., Tan Y., Huang L., Song X.

Oceanologia

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2014

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No. 56 (3)

583--602

EN

The zooplankton community structure in bays fluctuates as a result of anthropogenic activities in such waters. We focused on the short-term variability of a zooplankton community and compared its differences at the outflow of a nuclear power plant (ONPP), in a marine cage-culture area (MCCA) and in unpolluted waters (UW) in the south-west part of Daya Bay from 28 April to 1 June 2001. Environmental factors and zooplankton abundance differed significantly among stations at ONPP, MCCA and UW: high temperatures and a high zooplankton abundance occurred at ONPP, while a high chlorophyll a concentration and a low zooplankton abundance prevailed in MCCA. Statistical analysis revealed that the zooplankton diversity and abundance could be reduced by the activity of the marine cage-culture in a short time. Penilia avirostris made up an important component of the zooplankton in the study area, its abundance ranging widely from 16 to 7267 indiv. m-3 from April to June and peaking at the ONPP outflow. The outbreak of P. avirostris probably resulted from the combined effects of favourable water temperature, food concentration and its parthenogenetic behaviour.

6

Design and test of a new high-current electronic current transformer with a Rogowski coil

Zhang M., Li K., He S., Wang J.

Metrology and Measurement Systems

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2014

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Vol. 21, nr 1

121--132

EN

This paper describes the design and test of a new high-current electronic current transformer based on a Rogowski coil. For better performances, electronic current transformers are used to replace conventional electro-magnetic inductive current transformers based on ferromagnetic cores and windings to measure high-current on the high voltage distribution grids. The design of a new high-current electronic current transformer is described in this paper. The principal schemes of the prototype and partial evaluation results are presented. Through relative tests it is known that the prototype has a wide dynamic range and frequency band, and it can allow high accuracy measurements.

7

An on-site calibration system for electronic instrument transformers based on LabVIEW

Zhang M., Li K., Wang J., He S.

Metrology and Measurement Systems

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2014

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Vol. 21, nr 2

257--270

EN

Electronic voltage transformers (EVT) and electronic current transformers (ECT) are important instruments in a digital substation. For simple, rapid and convenient development, the paper proposed an on-site calibration system for electronic instrument transformers based on LabVIEW. In the system, analog signal sampling precision and dynamic range are guaranteed by the Agilent 3458A digital multimeter, and data synchronization is also achieved based on a self-developed PCI synchronization card. To improve the measurement accuracy, an error correction algorithm based on the Hanning window interpolation FFT has good suppression of frequency fluctuation and inter-harmonics interference. The human-computer interface and analysis algorithm are designed based on LabVIEW, and the adaptive communication technology is designed based on IEC61850 9-1/2. The calibration system can take into account pairs of digital output and analog output of the electronic voltage/current transformer calibration. The results of system tests show that the calibration system can meet the requirements of 0.2 class calibration accuracy, and the actual type test and on-site calibration also show that the system is easy to operate with convenience and satisfactory stability.

8

Znaczenie analizy gazów rozpuszczonych w oleju (DGA) w badaniu płynów estrowych (powstawanie gazów „pasożytniczych” przy prawidłowych warunkach eksploatacyjnych)

Hanson D., Li K., Plascencia J., Luksich J., Lemm A.

Energetyka

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2014

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nr 9

550--557

PL

Wykazano istnienie związku pomiędzy mechanizmami utleniania szczegółowo opisanymi w dostępnej literaturze a obecnością etanu w elektroizolacyjnych płynach na bazie estrów. Korelacji tej dowodzi kilka właściwości: występowanie zależności od reakcji utleniania w ogólnym ujęciu, zależność od zawartości kwasu linolenowego, zależność od występowania utleniania wolnorodnikowego lub autoutleniania, oraz od utleniania tlenu singletowego włącznie z występowaniem form fotoczułych. Badania te wskazują zakres stężeń etanu, jaki może powstać w wyniku tych procesów. Z doświadczenia, jakie posiadamy na dzień dzisiejszy możemy potwierdzić, że powstawanie etanu niezwiązanego z procesami usterkowymi mieści się w granicach stężeń opisywanych w tych badaniach. Posiłkując się katalogiem danych obejmujących 2800 stosowanych próbek oleju sojowego, najwyższe odnotowane stężenie etanu z nieusterkowych procesów wynosiło 1230 ppm. W przypadku uwzględnienia 90-tego percentyla dla oznaczeń etanu powstałego z nieusterkowych procesów stężenie to wynosiło 72 ppm. Badania mogą posłużyć zainicjowaniu skutecznego wyjaśnienia powstawania gazów „pasożytniczych” w celach oceny diagnostycznej sprzętu elektrycznego, gdzie stosowane są płyny estrowe.

EN

It has been shown that there is a connection between oxidation mechanisms described in detail in available literature and the presence of ethane in electroinsulating fluids based on esters. The correlation includes several points of coincidence: the relationships to oxidation in general, to linolenic acid content, to free radical oxidation or autoxidation, and singlet oxygen oxidation including the presence of photosensitive species. Tests present the concentration level of ethane that can be produced as a result of these processes. On basis of the experience the authors have gained so far they can confirm that the production of ethane not related to the fault processes remains in the concentration bounds described in these studies. Using a data pool of 2800 in-service soybean oil samples, the highest non-fault related ethane level was 1230 ppm and after taking into consideration the 90th percentile for non-fault related ethane from these samples it equalled 72 ppm. The studies can serve the initiation of effective explanation of „stray gas” production that in turn can help the diagnostic evaluation of an ester fluids filled electrical equipment.

9

Znaczenie analizy gazów rozpuszczonych (DGA) w badaniu płynów estrowych (rozkład termiczny płynów estrowych)

Hanson D., Li K., Plascencia J., Claiborne C., Cherry D., Frimpong G.

Energetyka

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2014

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nr 11

714--719

PL

W artykule wykazano, że skład chemiczny płynów elektroizolacyjnych wpływa na ich reaktywność chemiczną podczas usterek w sprzęcie wysokonapięciowym. Występujące różnice w strukturach naturalnych płynów estrowych nasuwają pytanie: jaka może być różnica w reaktywności chemicznej? W artykule wskazano na pewne istniejące różnice, jak i podobieństwa. Reakcje powstawania kwasów, tlenków węgla i etylenu należą do tych najbardziej znaczących. Analiza próbek pochodzących z urządzeń pracujących, gdzie mogą występować różnego rodzaju usterki termiczne, udowodniły, że wyniki badań DGA znajdą zastosowanie w ocenach diagnostycznych urządzeń wykorzystujących płyny estrowe.

EN

Proved is that the chemical composition of electrical insulating fluids has an influence on their chemical reactivity during faults in high-voltage equipment. Differences occurring in structures of natural ester liquids raise a question concerning differences in chemical reactivity. Pointed out are some existing differences and the similarities amongst which reactions of acids as well as carbon and ethylene oxides formation belong to the most significant. Analyses of samples coming from the working equipment, where various thermal faults can take place, prove that results of DGA can be applied in evaluation of diagnostic equipment using ester fluids.

10

Particle swarm optimization-based Fast Relevance Victor Machine for forecasting dissolved gases content in Power transformer oil

Liang Y., Li K., Zhao B., Zhao J., Niu L.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 1b

290--293

EN

Forecasting of dissolved gases concentration in power transformer is very significant to detect incipient failures of transformer early and ensure hassle free operation of entire power system. A forecasting model based on Particle Swarm Optimization –Fast Relevance Vector Machine (PSO-FRVM) is proposed in this paper. PSO is utilized to optimize the free parameter of the Gaussian kernel function to improve the forecasting performance. The Matlab program testify the correctness and validity of the model.

PL

W artykule przedstawiono metodę prognozowania rozpływu gazów w transformatorze elektrycznym, opartą na zbudowanym modelu. W tworzeniu modelu wykorzystano Optymalizację Stadną Cząsteczek z maszyną opartą na wektorach istotnych (ang. PSO-FRVM). Metoda PSO wykorzystana została do optymalizacji doboru parametru wolnego w funkcji jądra Gaussa dla polepszenia jakości prognozowania. Weryfikację przeprowadzono w programie Matlak.

11

Day-ahead Electricity Price Prediction Based on Improved ANN Information Fusion

Li K.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 3b

78--80

EN

A novel information fusion method is proposed based on the characters of day-ahead electricity price. An improved BPNN is used for its better performance as the core algorithm of information fusion. Using the information fusion ideas, a new modelling approach is proposed to establish the prediction model. The day-ahead electricity price prediction model is tested by the real data. The experiments demonstrate that the new prediction model established by improved BPNN information fusion method has better performance.

PL

W artykule przedstawiono nową metodę fuzji danych w oparciu o charakterystyki cenowe elektryczności z dnia poprzedniego. Algorytm oparto na sieci neuronowej BPNN. Jego działanie poddano badaniom, bazując na prawdziwych danych, których wyniki wskazują na skuteczność działania proponowanego rozwiązania.

12

Improved Roberts focusing evaluation method for an autofocusing system

Yin A., Dai Z., Chen B., Li K.

Optica Applicata

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2013

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Vol. 43, nr 3

529--538

EN

In this paper, a new focusing evaluation method based on local 2/8 center windows is proposed for an autofocusing system. We have proposed an evaluation function which improved the Roberts function with eight-neighborhood or four-neighborhood. The approximate optimal criteria window is selected by a 2/8 rule. Comparative experiments implemented with other methods have shown that the 2/8 rule method not only can find the approximate optimal evaluation window quickly, but also has better generality. This evaluation function of improved Roberts’ function has higher sensitivity and better real-time performance.

13

Dft investigation of a high energy density polynitro compound, 2,2’-Bis(trinitromethyl)-5,5’-azo-1,2,3,4- tetrazole

Lin H., Zhu S. G., Chen P. Y., Li K., Li H. Z., Peng X. H.

Central European Journal of Energetic Materials

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2013

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Vol. 10, no. 3

325--338

EN

A novel polynitro compound, 2,2’-bis(trinitromethyl)-5,5’-azo- 1,2,3,4-tetrazole, was designed and investigated at the DFT-B3LYP/6-31G(d) level. Its properties, such as electronic structure, IR spectrum, heat of formation, thermodynamic properties and crystal structure, were predicted. This compound is most likely to crystallize in the P21 space group, and the corresponding cell parameters are Z = 2, a = 5.46 Å, b = 9.72 Å, c = 14.05 Å, α = 90°, β = 90°, γ = 90°. In addition, the detonation velocity and pressure were also estimated by using the empirical Kamlet-Jacobs equations, and were predicted to be 8.28 km/s and 31.61 GPa respectively. The oxygen balance of this compound is +13.79%, which indicates that it could serve as an oxidizer. Bond dissociation energy calculations show that the C(13)-N(21)O2 and C(14)-N(30)O2 bonds are the locations of thermal decomposition and that this compounds meets the thermal stability requirements as an exploitable explosive. Keywords: polynitro, electronic structure, thermodynamic properties, crystal structure, detonation performance, stability.

14

Multiple SVMs Modelling Method for Fault Diagnosis of Power Transformers

Zhang M., Li K., Tian H.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 7b

232--234

EN

For enhancing the accuracy of fault diagnosis for power transformers, a multiple SVMs scheme is proposed in this paper. In this scheme, SVM is used to establish the base classifier for its good performance and fast learning speed. Secondly, the several base classifiers based on single SVM will be combined by consulting ensemble techniques. And then a multiple SVM s method is obtained. The real gas records data from a power company is used to establish fault diagnosis system for power transformers based on the new multiple SVM s method. For comparison, the conventional methods are used to build fault diagnosis models by the same data. The experiments demonstrate the new multiple SVMs method has the best performance in both learning ability aspect and generalization ability aspect for fault diagnosis of power transformers.

PL

Zaproponowano schemat SVM (support vector machine) w celu poprawy dokładności diagnostyki transformatorów mocy. W pprównaniu do metod konwencjonalnych proponowana metoda ma możliwość uczenia się i efektywnego wykorzystania bazy danych.

15

Positive grass diversity-productivity relationships and controlling factors along an elevation gradient in Central Asian alpine grasslands

Li K., Fangmeier A., Hu Y., Lu C., Liu X.

Polish Journal of Ecology

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2012

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Vol. 60, nr 1

123-131

EN

The productivity-diversity relationship in grasslands is of great interest with regard to species loss in natural ecosystems, where species extinction is not random but directed. We carried out a three-year investigation from 2005 to 2007 along an elevation gradient in alpine grasslands of Central Asia in an area of 70 x 20 km2 at Bayinbuluk, Tianshan Mountains. We selected 9 sites (10 x10 m2) and 117 plots (1 x 1 m2) from 2460 to 3260 m a.s.l. with 100 m intervals of altitude. Species richness, productivity, soil characteristics, air temperature and relative humidity (May.August) were recorded. The relationship between plant diversity and productivity was significant and positive. We used ordination techniques such as Canonical Correspondence Analysis (CCA) to examine the relationship between vegetation and the environmental factors. The results showed that plant species composition, species richness and productivity were significantly affected by air temperature, soil pH and relative humidity across the study area.

16

An on-line phase measuring profilometry based on modulation

Wu Y., Cao Y., Lu M., Li K.

Optica Applicata

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2012

|

Vol. 42, nr 1

31-41

EN

An on-line phase measuring profilometry (PMP) based on Stoilov's algorithm which can be used for on-line 3-D shape inspection is proposed in this paper. A stationary sinusoidal grayscale fringe pattern is projected onto the object kept on the production line, and an immobile charge-coupled device (CCD) is used to capture five deformed patterns equidistantly. The phase distribution is calculated by using Stoilov's algorithm, and the height distribution of the inspected object is obtained through the relation of phase-height mapping. When inspected object moves, the positions of images in different deformed patterns change, so the pixel matching is implemented to acquire the equivalent phase-shifting which meets the requirement of Stoilov's algorithm. Modulation which represents the contour of inspected object is used as the template to perform the pixel matching for the first time in this paper. Computer simulation and experiment verified the effectiveness of the method.

17

Effect of minor Cu addition on the precipitation sequence of an as-cast Al-Mg-Si 6005 alloy

Li K., Song M., Du Y., Fang X.

Archives of Metallurgy and Materials

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2012

|

Vol. 57, iss. 2

458-466

EN

The whole precipitation sequences of two as-cast Al-Mg-Si 6005 alloys (containing no Cu or 0.1 wt.% Cu) at 150 degree Celsjus were investigated using X-ray diffraction, transmission electron microscopy and hardness examinations. The precipitation sequence of the Cu-free alloy can be expressed as: super-saturated solid solution (SSSS) → spherical G.P. zones → pre - β'' → β'' → U2 +Si + β x → Si + β β xwhile that of the Cu-containing alloy can be expressed as: SSSS → spherical G.P. zones + platelet-like G.P. zones → pre - β → β'' → Q' + β + Si → Q + β + Si. A new type of βprecipitate, namely β x here, has been discovered in the Cu-free alloy. The addition of minor Cu is found to accelerate the microstructural evolution by inducing the formation of a new type of platelet-like G.P. zone along {111} Al planes, and improve the hardening response at the over-aged stage by forming Q' and Q precipitates.

PL

Kompletna sekwencja wydzieleń dwóch odlanych stopów Al-Mg-Si 6005 (zawierąjacych 0 i 0.1%.wag Cu), w temperaturze 150 stopni Celsjusza, została zbadana przy użyciu dyfrakcji rentgenowskiej, transmisyjnej mikroskopii elektronowej i badań twardości. Sekwencja wydzieleń w stopie nie zawierającym Cu może być przedstawiona następująco: przesycony roztwór stały → sferyczne strefy Guiniera-Prestona → pre - β'' → β'' → U2 +Si + β x → Si + β β x natomiast dla stopu zawierającego Cu następująco: przesycony roztwór stały → sferyczne i płytkowe strefy Guiniera-Prestona → pre - β → β'' → Q' + β + Si → Q + β + Si. Nowy rodzaj wydzieleń β, tj. β x , został odkryty w stopie niezawierajacym Cu. Stwierdzono, że dodatek niewielkiej ilości Cu przyspiesza zmiany mikrostruktury poprzez indukowanie tworzenia nowego typu płytkowych stref Guiniera-Prestona wzdłuż płaszczyzny {111}Al. i poprawia utwardzenie poprzez tworzenie wydzieleń Q' i Q.

18

Dinosaur assemblages from the Middle Jurassic Shaximiao Formation and Chuanjie Formation in the Sichuan-Yunnan Basin, China

Li K., Yang Ch., Hu F.

Volumina Jurassica

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2011

|

Vol. 9, no. 1

21-42

EN

The Shaximiao Formation (Sichuan Basin, China), and the corresponding Chuanjie Formation of the neighboring Yunnan Basin (Sichuan-Yunnan Basin), representing continental Mesozoic strata, are distinguished from other Chinese Mesozoic units because of the large area over which they are distributed, their lithological characteristics and their abundant vertebrate fossils. This paper analyses and summarizes the dinosaur fossils from the Shaximiao Formation and compares them to other vertebrate groups of the same or similar ages, both in China and abroad. For the first time, this paper presents the viewpoint that the upper member of the Shaximiao Formation is of Middle Jurassic age (Bathonian–Callovian). Furthermore, we claim that the entire Shaximiao Formation is of Bajocian–Callovian age (middle-late part of Middle Jurassic). This conclusion is supported by the age inferred from invertebrate fossils and radiometric dating (165–178 Ma). The composition, evolution and geological age of the vertebrate fauna (particularly dinosaur fossils), as well as their comparison to the dinosaur fauna from the other parts of the Sichuan-Yunnan Basin (Chuanjie Fm.) is discussed. Middle Jurassic dinosaur assemblages from China show marked differences compared with other dinosaur assemblages in the world, and this is explained by geographical isolation.

19

Methods for large scale assessment of small mammal abundance in open habitats : plateau pika (Ochotona curzoniae) in alpine grassland

Qu J., Li W., Yang M., Li K., Zhang Y.

Polish Journal of Ecology

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2011

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Vol. 59, nr 4

829-833

EN

Quick and accurate estimation of population density in large scale is required in both scientific studies and wildlife management programs. However, effective estimation of small mammal abundance is usually difficult and timeconsuming due to the body size and wide distribution of these animals. To test the efficiency of different methods in assessing small mammal densities, population dynamics of plateau pikas (Ochotona curzoniae, Hodgson) were studied from April 2005 to August 2009 in alpine grassland (Kobresia humilis) at a height of of 3846 m a.s.l. We compared the precision of walked transects method with mark-recapture method using Efford's maximum likelihood spatial estimator (ML). Significant positive correlation was found between walked transects and Efford's ML estimator (r[^2] = 0.58, P <0.001). The densities calculated with walked transects were about twice lower than those obtained using the mark-recapture method over the study period (i.e., summer). Nevertheless, the walked transects method remains useful for relative density estimation. Hence, the walked transects method is recommended for use as an index of relative density in large-scale assessment in alpine grassland where most small mammals are active and easily detected in an open habitat.

20

Correlation between leafing phenology and traits : woody species of evergreen broad-leaved forests in subtropical China

Liu Z., Li K., Cal Y., Fang Y.

Polish Journal of Ecology

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2011

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Vol. 59, nr 3

463-473

EN

Leaf phenology has been considered to evolve to maximize plant carbon gains, and it reflects plant life history strategies. To determine the effect of leaf traits on leaf phenology, leaf emergence (such as timing of leaf emergence, leaf expansion rate, durations of leaf expansion), leaf traits (leaf mass per area - LMA and leaf size), and their relationships were investigated for 40 woody species from 13 families in an evergreen broad-leaved forest, southeast China. Compared with understorey shrubs (23 species), trees species (17 species) were significantly later in timing of leaf emergence, greater in leaf area and leaf expansion rate. This is assumed to be a strategy for large-leaved tree species to decrease damage during leaf expansion. In terms of leaf size, the small-leaved species leafed out earlier than the species with large leaves, but the largeleaved species were greater in leaf expansion rate than their counterparts. Leaf expansion rate was positively correlated with leaf area and timing of leaf emergence. Leaf herbivore rate was positively correlated with leaf area and leaf expansion period, but negatively with LMA. These results suggest that large- and small-leaved species possibly employed different strategies to minimize herbivore damage. Small-leaved species avoid defoliator damage by early leafing, while largeleaved species have shorter expansion times and thereby shorten vulnerable time to herbivores. In general, dynamics of emergence and expansion of the woody species in the study forest indicate that the leaf phenology is of significance for species. carbon gain and survival.