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Spatial-temporal patterns and evolution of carbon storage in China's terrestrial ecosystems from 1980 to 2020

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Science China Earth Sciences 2024年第10期67卷 3270-3287页

作者： Shaojian WANG Shijie ZHOU Chuanglin fang School of Geography and Planning Sun Yat-sen University Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Analyzing the changes in carbon storage in terrestrial ecosystems caused by land use changes is a crucial part of exploring the carbon cycle. In addition, enhancing carbon storage in terrestrial ecosystems is an effective and environmentally friendly measure to sequester anthropogenic carbon emissions, which is significant for achieving carbon neutrality and curbing global climate change. This paper uses land use data and carbon density tables with the In VEST model to obtain a carbon storage distribution map of China. It further applies land use response elasticity coefficients, Theil index multi-stage nested decomposition, and spatial autocorrelation analysis to examine the spatial-temporal patterns, causes of changes, and evolution characteristics of carbon storage in terrestrial ecosystems from 1980 to 2020. The results show that the temporal changes in China's carbon storage generally present an inverted S-curve, with an initial rapid decline followed by a slower decrease. Spatially, it features high levels in the northeast, low levels in the northwest, and a uniform distribution in the central and southern *** disturbance of land use type changes on terrestrial ecosystem carbon storage has been effectively mitigated. The significant reduction in grassland area in the Southwest region is the main source of carbon storage loss during the study period, and the encroachment of construction land on arable land in large urban agglomerations is one of the important causes of carbon storage loss. The Theil index multi-stage nested decomposition results indicate that the overall difference in carbon storage in China has decreased, while differences among cities within provinces and among counties within cities have increased. The influence of natural factors on the distribution of carbon storage is weakening, whereas the impact of human activities is becoming more profound, enhancing its influence on the spatial distribution of carbon storage in China. From 198

关键词： Terrestrial ecosystem carbon storage Carbon density Land use change InVEST model Spatiotemporal pattern

Method to Remove Handwritten Texts Using Smart Phone

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Journal of Harbin Institute of Technology(New Series) 2024年第2期31卷 12-21页

作者： Haiquan fang School of Public Administration Zhejiang University of TechnologyHangzhou 310023China Zhejiang Xingsuan Technology Co. LtdHangzhou 310023China

To remove handwritten texts from an image of a document taken by smart phone,an intelligent removal method was proposed that combines dewarping and Fully Convolutional Network with Atrous Convolutional and Atrous Spatial Pyramid Pooling(FCN-AC-ASPP).For a picture taken by a smart phone,firstly,the image is transformed into a regular image by the dewarping ***,the FCN-AC-ASPP is used to classify printed texts and handwritten ***,handwritten texts can be removed by a simple *** show that the classification accuracy of the FCN-AC-ASPP is better than FCN,DeeplabV3+,*** handwritten texts removal effect,the method of combining dewarping and FCN-AC-ASPP is superior to FCN-AC-ASP alone.

关键词： handwritten texts printed texts classification FCN-AC-ASPP smart phone

Primary acinic cell carcinoma of the breast: A case report and review of literature

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World Journal of Clinical Cases 2024年第1期12卷 196-203页

作者： Jia-Sheng Ding Min Zhang fang-fang Zhou Department of Intensive Care Unit Lishui Central HospitalThe Fifth Affiliated Hospital of Wenzhou Medical UniversityLishui 323000Zhejiang ProvinceChina Department of Pathology Lishui Central HospitalThe Fifth Affiliated Hospital of Wenzhou Medical UniversityLishui 323000Zhejiang ProvinceChina Department of Ultrasound Lishui Central HospitalThe Fifth Affiliated Hospital of Wenzhou Medical UniversityLishui 323000Zhejiang ProvinceChina

BACKGROUND In the current World Health Organization classification,acinic cell carcinoma(AcCC)of the breast is considered a rare histological subtype of triple-negative breast *** of the few reports in the literature,data concerning clinical outcomes are ***,we report a case of AcCC of the breast in a 48-year-old woman.A 48-year-old woman with a mass in her right breast came to our hospital for further *** and an ultrasound(US)scan showed a mass in the upper inner side of the right *** then underwent surgery to resect the mass in her right *** pathological examination revealed that the tumor had abundant acinar-like structures formed by tumor cells with prominent eosinophilic granules in the cytoplasm,consistent with acinar cell *** results of immunohistochemical analysis supported the diagnosis of breast acinar cell *** months later,she underwent breast-conserving surgery and sentinel lymph node *** pTNM stage was *** surgery,the patient received 30 radiotherapy *** patient was followed up for a period of one year,and no recurrence was *** of the breast is a rare type of malignant *** it is usually asym-ptomatic and can be detected by imaging studies,routine breast US or mamm-ograms are ***,there are no characteristic diagnostic imaging findings or clinical manifestations,so immunohistochemical examination is critical for an accurate diagnosis of AcCC of the breast.

关键词： Acinic cell carcinoma Breast Malignant tumor Immunohistochemical Surgery Case report

Uniqueness on Difference Operators of Meromorphic Functions of Infinite Order

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Acta Mathematica Sinica,English Series 2024年第2期40卷 511-527页

作者： Hui LI Ming Liang fang Xiao YAO School of Science China University of Mining and TechnologyBeijing 100083P.R.China Institute of Mathematics Academy of Mathematics and System SciencesChinese Academy of SciencesBeijing 100190P.R.China School of Sciences Hangzhou Dianzi UniversityHangzhou 310012P.R.China School of Mathematical sciences and LPMC Nankai UniversityTianjin 300071P.R.China

We investigate the uniqueness problems of meromorphic functions and their difference operators by using a new *** is proved that if a non-constant meromorphic function f shares a non-zero constant and ∞ counting multiplicities with its difference operators Δcf(z) and Δ_(c)^(2)f(z), thenΔcf(z)≡Δ_(c)^(2)f(z).In particular,we give a difference analogue of a result of *** method has two distinct features:(ⅰ) It converts the relations between functions into the corresponding *** makes it possible to deal with the uniqueness problem by linear algebra and combinatorics.(ⅱ) It circumvents the obstacle of the difference logarithmic derivative lemma for meromorphic functions of infinite order,since this method does not depend on the growth of the ***,the idea in this paper can also be applied to the case for several variables.

关键词： Uniqueness meromorphic functions difference operators infinite order

Lorentz violation induces isospectrality breaking in Einstein-bumblebee gravity theory

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 87-96页

作者： Wentao Liu Xiongjun fang Jiliang Jing Jieci Wang Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China

In this study,we investigate the quasinormal modes(QNMs)of a Lorentz-violating spacetime,factoring in a cosmological constant,within the framework of Einstein-bumblebee *** findings reveal that the interaction of spacetime with an anisotropic bumblebee field imparts distinct contributions to the axial and polar sectors of the vector *** subsequently breaks the isospectrality typically observed in vector *** evidence strongly indicates isospectral breaking in the vector modes of Einstein-bumblebee black holes:a pronounced breakage in the real part of the frequencies,while the imaginary component seems less *** isospectral breaking indicates the existence of two different waveforms in the Ringdown phase of the black hole,which provides a potential signal of quantum gravity observable in current experiments.

关键词： Lorentz-violating isospectral breaking quasinormal modes

Diophantine equations and Fermat's last theorem for multivariate(skew-)polynomials

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 159-173页

作者： PAN Jie JIA Yu-ming LI fang School of Mathematical Sciences Zhejiang UniversityHangzhou 310058China Henan Experimental High School Zhengzhou 450003China

Fermat’s Last Theorem is a famous theorem in number theory which is diﬃcult to ***,it is known that the version of polynomials with one variable of Fermat’s Last Theorem over C can be proved very *** aim of this paper is to study the similar problems about Fermat’s Last Theorem for multivariate(skew)-polynomials with any characteristic.

关键词： Fermat's last theorem polynomial ring skew polynomial ring

Finite Groups with Some Bounded Codegrees

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1778-1784页

作者： Dong fang YANG Yu ZENG Heng LV School of Mathematics and Statistics Southwest UniversityChongqing400715P.R.China Department of Mathematics Changshu Institute of TechnologyChangshu215500P.R.China

For a characterχof a finite group G,the number cod(χ) := ∣G:ker(χ)∣/χ(1)is called the codegree ofχ.In this paper,we give a solvability criterion for a finite group G depending on the minimum of the ratioχ(1)^(... 详细信息

关键词： Finite group codegree degree simple group

Skill enhancement learning with knowledge distillation

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Science China(Information Sciences) 2024年第8期67卷 206-220页

作者： Naijun LIU Fuchun SUN Bin fang Huaping LIU Department of Computer Science and Technology Tsinghua University

Skill learning through reinforcement learning has significantly progressed in recent years. However, it often struggles to efficiently find optimal or near-optimal policies due to the inherent trial-and-error exploration in reinforcement learning. Although algorithms have been proposed to enhance skill learning efficacy, there is still much room for improvement in terms of skill learning performance and training stability. In this paper, we propose an algorithm called skill enhancement learning with knowledge distillation(SELKD), which integrates multiple actors and multiple critics for skill learning. SELKD employs knowledge distillation to establish a mutual learning mechanism among actors. To mitigate critic overestimation bias,we introduce a novel target value calculation method. We also perform theoretical analysis to ensure the convergence of SELKD. Finally, experiments are conducted on several continuous control tasks, illustrating the effectiveness of the proposed algorithm.

关键词： skill learning enhancement learning reinforcement learning knowledge distillation

Winter-spring minimum temperature variations inferred from tree-ring δ13C in southeastern China

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JOURNAL OF FORESTRY RESEARCH 2024年第1期35卷 1-9页

作者： Li, Wenli Zhou, Feifei Zhang, Heng fang, Keyan Fujian Normal Univ Coll Geog Sci Key Lab Humid Subtrop Ecogeog Proc MOE Fuzhou 350007 Peoples R China

Long-term temperature variations inferred from high-resolution proxies provide an important context to evaluate the intensity of current warming. However, temperature reconstructions in humid southeastern China are scarce and particularly lack long-term data, limiting us to obtain a complete picture of regional temperature evolution. In this study, we present a well-verified reconstruction of winter-spring (January-April) minimum temperatures over southeastern China based on stable carbon isotopic (delta C-13) records of tree rings from Taxus wallichiana var. mairei from 1860 to 2014. This reconstruction accounted for 56.4% of the total observed variance. Cold periods occurred during the 1860s-1910s and 1960s-1970s. Although temperatures have had an upward trend since the 1920s, most of the cold extremes were in recent decades. The El Ni & ntilde;o-Southern Oscillation (ENSO) variance acted as a key modulator of regional winter-spring minimum temperature variability. However, teleconnections between them were a nonlinear process, i.e., a reduced or enhanced ENSO variance may result in a weakened or intensified temperature-ENSO relationship.

关键词： Tree rings Carbon isotope Southeastern China Extreme coldness El nino-southern oscillation NORTHERN-HEMISPHERE TEMPERATURES 2 CENTURIES RECONSTRUCTION PRECIPITATION MILLENNIUM CELLULOSE IMPACT VARIABILITY DIFFERENCE CHRONOLOGY