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Tree species identity and interaction determine vertical forest structure in young planted forests measured by terrestrial laser scanning

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Forest Ecosystems 2024年第3期11卷 266-275页

作者： Mengxi Wang Lander Baeten Frieke Van Coillie Kim Calders Kris Verheyen quentin Ponette Haben Blondeel Bart Muys John Armston Hans Verbeeck q-ForestLab Department of EnvironmentFaculty of Bioscience EngineeringGhent UniversityBelgium Forest&Nature Lab Department of EnvironmentFaculty of Bioscience EngineeringGhent UniversityBelgium Earth and Life Institute Université Catholique de Louvain(UCLouvain)Louvain-la-NeuveBelgium Department of Earth&Environmental Sciences KU LeuvenBelgium Department of Geographical Sciences University of MarylandCollege ParkMDUSA

Vertical forest structure is closely linked to multiple ecosystem characteristics,such as biodiversity,habitat,and *** tree species in planted forests has the potential to create diverse vertical forest structures due to the different physiological and morphological traits of the composing tree ***,the relative importance of species richness,species identity and species interactions for the variation in vertical forest structure remains unclear,mainly because traditional forest inventories do not observe vertical stand structure in *** laser scanning(TLS),however,allows to study vertical forest structure in an unprecedented ***,we used TLS single scan data from 126 plots across three experimental planted forests of a largescale tree diversity experiment in Belgium to study the drivers of vertical forest *** plots were 9–11years old young pure and mixed forests,characterized by four levels of tree species richness ranging from monocultures to four-species mixtures,across twenty composition *** generated vertical plant profiles from the TLS data and derived six stand structural *** mixed models were used to test the effect of species richness on structural *** a hierarchical diversity interaction modelling framework,we further assessed species identity effect and various species interaction effects on the six stand structural *** results showed that species richness did not significantly influence most of the stand structure variables,except for canopy height and foliage height *** identity on the other hand exhibited a significant impact on vertical forest structure across all *** interaction effects were observed to be site-dependent due to varying site conditions and species pools,and rapidly growing tree species tend to dominate these ***,our results highlighted the importance of considering both species identity an

关键词： TreeDivNet FOrBIO Stand structural complexity Terrestrial laser scanning Vertical forest structure Tree diversity Planted forests

Toeplitz Operators and Carleson Measures for Weighted Bergman Spaces Induced by regular Weights

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1345-1359页

作者： Jun Tao DU Song Xiao Hasi WULAN Department of Mathematics Guangdong University of Petrochemical TechnologyMaoming 525000P.R.China Department of Mathematics Shantou UniversityShantou 515063P.R.China

In this paper,we give a universal description of the boundedness and compactness of Toeplitz operator T_(μ)^(ω)between Bergman spaces A_(η)^(p)and A_(υ)^(q)whenμis a positive Borel measure,1qre regular *** using Khinchin’s inequality and Kahane’s inequality,we get a new characterization of the Carleson measure for Bergman spaces induced by regular weights.

关键词： Bergman space Carleson measure Toeplitz operator regular weight

Compressed Data Separation via ℓ_(q)-Split Analysis with ℓ_(∞)-Constraint

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1655-1673页

作者： Ming Yang Gu Song Li Jun Hong Lin School of Mathematical Science Zhejiang UniversityHangzhou310027P.R.China Center for Data Science Zhejiang UniversityHangzhou310027P.R.China

In this paper,we study compressed data separation(CDS)problem,i.e.,sparse data separation from a few linear random *** propose the nonconvex ℓ_(q)-split analysis with ℓ_(∞)-constraint and 0q≤*** call the algorithm ℓ_(q)-split-analysis Dantzig selector(ℓ_(q)-split-analysis DS).We show that the two distinct subcomponents that are approximately sparse in terms of two different dictionaries could be stably approximated via the ℓ_(q)-split-analysis DS,provided that the measurement matrix satisfies either a classical D-rIP(restricted Isometry Property with respect to Dictionaries and ℓ_(2) norm)or a relatively new(D,q)-rIP(rIP with respect to Dictionaries and ℓ_(q)-quasi norm)condition and the two different dictionaries satisfy a mutual coherence condition between *** the Gaussian random measurements,the measurement number needed for the(D,q)-rIP condition is far less than those needed for the D-rIP condition and the(D,1)-rIP condition when q is small enough.

关键词： Data separation ℓ_(q)-split analysis Dantzig selector frames restricted isometry property compressed sensing

Cambricon-qr:a sparse and bitwise reproducible quantized training accelerator

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High Technology Letters 2024年第1期30卷 52-60页

作者：李楠 ZHAO Yongwei ZHI Tian LIU Chang DU Zidong HU Xing LI Wei ZHANG Xishan LI Ling SUN Guangzhong School of Computer Science and Technology University of Science and Technology of ChinaHefei 230026P.R.China State Key Laboratory of Processors Institute of Computing TechnologyChinese Academy of SciencesBeijing 100086P.R.China Cambricon Tech.Ltd Beijing 100191P.R.China Institute of Software Chinese Academy of SciencesBeijing 100086P.R.China

quantized training has been proven to be a prominent method to achieve deep neural network training under limited computational *** uses low bit-width arithmetics with a proper scaling factor to achieve negligible accuracy ***-q is the ASIC design proposed to efficiently support quantized training,and achieves significant performance ***,there are still two caveats in the ***,Cambricon-q with different hardware specifications may lead to different numerical errors,resulting in non-reproducible behaviors which may become a major concern in critical ***,Cambricon-q cannot leverage data sparsity,where considerable cycles could still be squeezed *** address the caveats,the acceleration core of Cambricon-q is redesigned to support fine-grained irregular data *** new design not only enables acceleration on sparse data,but also enables performing local dynamic quantization by contiguous value ranges(which is hardware independent),instead of contiguous addresses(which is dependent on hardware factors).Experimental results show that the accuracy loss of the method still keeps negligible,and the accelerator achieves 1.61×performance improvement over Cambricon-q,with about 10%energy increase.

关键词： quantized training sparse accelerator Cambricon-qr

Differential Operator Approach to■quantum Groups and Their Oscillator representations

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1360-1374页

作者： Zhao Bing FAN Ji Cheng GENG Shao Long HAN College of Mathematical Science Harbin Engineering UniversityHarbin 150001P.R.China

For a quasi-split Satake diagram,we define a modified q-Weyl algebra,and show that there is an algebra homomorphism between it and the corresponding■quantum *** other words,we provide a differential operator approach to■quantum ***,the oscillator representations of■quantum groups are *** crystal basis of the irreducible subrepresentations of these oscillator representations are constructed.

关键词： ■quantum group differential operator oscillator representation crystal basis

Long-term changes in radial growth of seven tree species in the mixed broadleaf-Korean pine forest in Northeast China: Are deciduous trees favored by climate change?

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JOUrNAL OF FOrESTrY rESEArCH 2024年第1期35卷 1-15页

作者： Gong, Xiufang Yuan, Danyang Zhu, Liangjun Li, Zongshan Wang, Xiaochun Cent South Univ Forestry & Technol Coll Life Sci & Technol Natl Engn Lab Appl Technol Forestry & Ecol South C Changsha 410004 Peoples R China Northeast Forestry Univ Ctr Ecol Res Sch Forestry Harbin 150040 Peoples R China Northeast Forestry Univ Sch Forestry Key Lab Sustainable Forest Ecosyst Management Minist Educ Harbin 150040 Peoples R China Chinese Acad Sci Res Ctr Ecoenvironm Sci State Key Lab Urban & Reg Ecol Beijing 100085 Peoples R China

The role of the temperate mixed broadleaf-Korean pine forest (BKF) in global biogeochemical cycles will depend on how the tree species community responds to climate; however, species-specific responses and vulnerabilities of common trees in BKF to extreme climates are poorly understood. Here we used dendrochronological methods to assess radial growth of seven main tree species (Pinus koraiensis, Picea jezoensis, Abies nephrolepis, Fraxinus mandshurica, Phellodendron amurense, quercus mongolica, and Ulmus davidiana) in an old-growth BKF in response to climate changes in the Xiaoxing'an Mountains and to improve predictions of changes in the tree species composition. Temperature in most months and winter precipitation significantly negatively affected growth of P. jezoensis and A. nephrolepis, but positively impacted growth of P. koraiensis and the broadleaf species, especially F. mandshurica and U. davidiana. Precipitation and relative humidity in June significantly positively impacted the growth of most tree species. The positive effect of the temperature during the previous non-growing season (PNG) on growth of F. mandshurica and q. mongolica strengthened significantly with rapid warming around 1981, while the impact of PNG temperature on the growth of P. jezoensis and A. nephrolepis changed from significantly negative to weakly negative or positive at this time. The negative response of radial growth of P. jezoensis and A. nephrolepis to precipitation during the growing season gradually weakened, and the negative response to PNG precipitation was enhanced. Among the studied species, P. koraiensis was the most resistant to drought, and U. davidiana recovered the best after extreme drought. Ulmus davidiana, P. jezoensis and A. nephrolepis were more resistant to extreme cold than the other species. Climate warming generally exacerbated the opposite growth patterns of conifer (decline) and broadleaf (increase) species. Deciduous broadleaf tree species in the old-growth

关键词： Tree rings Extreme climate resistance and recovery Broad-leaved and Korean pine mixed forest DrOUGHT TEMPErATUrE rESPONSES KOrAIENSIS rESILIENCE DYNAMICS IMPACT XYLEM

Bi-Frobenius Algebra Structures on quantum Complete Intersections

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Acta Mathematica Sinica,English Series 2024年第6期40卷 1481-1504页

作者： Hai JIN Pu ZHANG School of Mathematical Sciences Shanghai Jiao Tong UniversityShanghai 200240P.R.China

This paper is to look for bi-Frobenius algebra structures on quantum complete intersections over field *** find a class of comultiplications,such that if√−1∈k,then a quantum complete intersection becomes a bi-Frobenius algebra with comultiplication of this form if and only if all the parameters qij=±***,it is proved that if√−1∈k then a quantum exterior algebra in two variables admits a bi-Frobenius algebra structure if and only if the parameter q=±√*** if−1/∈k,then the exterior algebra with two variables admits no bi-Frobenius algebra *** prove that the quantum complete intersections admit a bialgebra structure if and only if it admits a Hopf algebra structure,if and only if it is commutative,the characteristic of k is a prime p,and every ai a power of *** also provides a large class of examples of bi-Frobenius algebras which are not bialgebras(and hence not Hopf algebras).In commutative case,other two comultiplications on complete intersection rings are given,such that they admit non-isomorphic bi-Frobenius algebra structures.

关键词： Bi-Frobenius algebras coalgebras bialgebras Hopf algebras quantum complete intersections quantum exterior algebras

A class of natural pinus koraiensis population system with time delay and diffusion term

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International Journal of Biomathematics 2024年第2期17卷 233-262页

作者： Guo-Feng Feng Jiaqi Chen Bin Ge School of Mathematical Sciences Harbin Engineering University Harbin 150001 P.R.China

In this paper,we consider the long-term sustainability of the northeast Korean *** propose a class of natural Korean pine population system with time delay and diffusion ***,by analyzing the roots distribution of the characteristic equation,we study the stability of the model system with diffusion terms and prove the occurrence of Hopf ***,we introduce lactation time delay into a population model with a diffusion term,based on stability theory of ordinary differential equation,norm form methods and center manifold theorem,the stability of bifurcating periodic solutions and the relevant formula for the direction of Hopf bifurcation are ***,some numerical simulations are given.

关键词： Pinus koraiensis populations delay diffusion term Hopf bifurcation periodic solution

Influence of organic matter input and temperature change on soil aggregate-associated respiration and microbial carbon use efficiency in alpine agricultural soils

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SOIL ECOLOGY LETTErS 2024年第3期6卷 230220-230220页

作者： Zhang, Shuaiwen Gong, Wei Wan, Xin Li, Junya Li, Zhiguo Chen, Peng Xing, Shunlin Li, Ziyan Liu, Yi Tibet Univ Sch Ecol & Environm Lhasa 850000 Peoples R China Chinese Acad Sci Key Lab Aquat Bot & Watershed Ecol Wuhan Bot Garden Wuhan 430074 Peoples R China Northwest A&F Univ Coll Resources & Environm Yangling 712100 Peoples R China

Soil aggregates affect soil respiration and its temperature *** matter input boosts soil respiration, affected by temperature and aggregate size.q10 declines with increasing aggregate size, influenced by soil quality *** CUE drops with organic matter input, temperature and aggregate size *** the dynamics of soil respiration, microbial carbon use efficiency (CUE), and temperature sensitivity (q10) in response to exogenous organic matter (EOM) input, soil aggregate size, and incubation temperature is crucial for predicting soil carbon cycling responses to environmental changes. In this study, these interactions were investigated by 180-day incubation of soil aggregates supplemented with EOM at various temperatures (5 degrees C, 15 degrees C and 25 degrees C). The results reveal an 'L-shaped' trend in soil respiration on the time scale across all treatments, characterized by initial rapid declines followed by stability. EOM input and higher temperatures significantly enhance respiration rates. Notably, the respiratory rates of soil aggregates of different sizes exhibit distinct patterns based on the presence or absence of EOM. Under conditions without the addition of EOM, larger aggregates show relatively lower respiration rates. Conversely, in the presence of EOM, larger aggregates exhibit higher respiratory rates. Furthermore, q10 decreases with increasing aggregate size. The relationship between q10 and the substrate quality index (SqI) supports the carbon quality temperature (CqT) hypothesis, highlighting SqI's influence on q10 values, particularly during later incubation stages. Microbial CUE decreases with EOM input and rising temperatures. Meanwhile, aggregate size plays a role in microbial CUE, with smaller aggregates exhibiting higher CUE due to enhanced nutrient availability. In conclusion, the intricate interplay of EOM input, aggregate size, and temperature significantly shapes soil respiration, microbial CUE,

关键词： soil aggregates soil respiration temperature sensitivity Tibetan Plateau LONG-TErM FErTILIZATION SENSITIVITY DECOMPOSITION qUALITY AVAILABILITY INCrEASES FEEDBACK MODEL STOCK