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Decline in tree-ring growth of Picea mongolica and its intra-annual eco-physiological responses to drought and CO_(2) enrichment in semi-arid China

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Journal of forestry Research 2024年第4期35卷 89-101页

作者： Xiaomin Zeng Ping Ni Xiaohong liu Wenzhi Wang Yao Li Wenchao Wang School of Geography and Tourism Shaanxi Normal UniversityXi’an 710119People’s Republic of China The Key Laboratory of Mountain Environment Evolution and Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041People’s Republic of China CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016People’s Republic of China university of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Episodes of drought-induced decline in tree growth and mortality are becoming more frequent as a result of climate warming and enhanced water stress in semi-arid ***,the ecophysiological mechanisms under-lying the impact of drought on tree growth remains *** this study,earlywood and latewood tree-ring growth,δ^(13)C,andδ^(18)O chronologies of Picea mongolica from 1900 to 2013 were developed to clarify the intra-and inter-annual tree-ring growth responses to increasingly fre-quent *** results indicate that annual basal area increment residuals(BAI_(res)),which removed tree age and size effects,have significantly decreased since ***-ever,the decreasing trend of earlywood BAI_(res) was higher than that of *** response analysis suggests that the dominant parameters for earlywood and latewood proxies(BAI_(res),δ^(13)C andδ^(18)O)were drought-related climate variables(Palmer drought severity index,temperature,rela-tive humidity,and vapor pressure deficit).The most signifi-cant period of earlywood and latewood proxies’responses to climate variables were focused on June-July and July-August,***_(res),andδ^(13)C were significantly affected by temperature and moisture conditions,whereasδ^(18)O was slightly *** stomatal conduct-ance due to drought outweighed the influence of increasing CO_(2) on intrinsic water use efficiency(iWUE),and ultimately led to a decline in BAI_(res).Compared to latewood,the faster decreasing BAI_(res) and smaller increasing iWUE of early-wood suggested trees were more vulnerable to water stress in the early growing *** study provides insights into the inter-and intra-annual mechanisms of tree-ring growth in semi-arid regions under rising CO_(2) and climate change.

关键词： Tree growth Drought Water-use efficiency Seasonal differences Stable isotopes

KSKV:Key-Strategy for Key-Value Data Collection with Local Differential Privacy

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3063-3083页

作者： Dan Zhao Yang You Chuanwen Luo Ting Chen Yang liu Artificial Intelligence Development Research Center Institute of Scientific and Technical Information of ChinaBeijing100038China Industry Development Department NSFOCUS Inc.BeijingChina School of Information Science and Technology Beijing Forestry UniversityBeijing100083China School of Computer Science and Engineering University of Electronic Science and Technology of ChinaChengdu610054China Institute of Computing Technology China Academy of Railway Sciences Corporation LimitedBeijing10081China

In recent years,the research field of data collection under local differential privacy(LDP)has expanded its focus fromelementary data types to includemore complex structural data,such as set-value and graph ***,our comprehensive review of existing literature reveals that there needs to be more studies that engage with key-value data *** studies would simultaneously collect the frequencies of keys and the mean of values associated with each ***,the allocation of the privacy budget between the frequencies of keys and the means of values for each key does not yield an optimal utility *** the importance of obtaining accurate key frequencies and mean estimations for key-value data collection,this paper presents a novel framework:the Key-Strategy Framework forKey-ValueDataCollection under ***,theKey-StrategyUnary Encoding(KS-UE)strategy is proposed within non-interactive frameworks for the purpose of privacy budget allocation to achieve precise key frequencies;subsequently,the Key-Strategy Generalized Randomized Response(KS-GRR)strategy is introduced for interactive frameworks to enhance the efficiency of collecting frequent keys through group-anditeration *** strategies are adapted for scenarios in which users possess either a single or multiple key-value ***,we demonstrate that the variance of KS-UE is lower than that of existing *** claims are substantiated through extensive experimental evaluation on real-world datasets,confirming the effectiveness and efficiency of the KS-UE and KS-GRR strategies.

关键词： Key-value local differential privacy frequency estimation mean estimation data perturbation

Climate warming is significantly influenced by rising summer maximum temperatures: insights from tree-ring evidence of the Western Tianshan Mountains, China

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Journal of forestry Research 2024年第5期35卷 47-59页

作者： Meng Ren Yu liu Qiufang Cai Qiang Li Huiming Song Changfeng Sun The State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061People’s Republic of China Xi’an Institute for Innovative Earth Environment Research Xi’an 710061People’s Republic of China Institute of Desert Meteorology China Meteorological AdministrationÜrümqi 830002People’s Republic of China Center for Excellence in Quaternary Science and Global Change Chinese Academy of SciencesXi’an 710061People’s Republic of China School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China Qingdao National Laboratory for Marine Science and Technology Qingdao 266237People’s Republic of China

As one of the regions most affected by global cli-mate warming,the Tianshan mountains has experienced sev-eral ecological crises,including retreating glaciers and water *** warming in these mountains is considered mainly to be caused by increases in minimum temperatures and winter temperatures,while the influence of maximum temperatures is *** this study,a 300-year tree-ring chronology developed from the Western Tianshan Moun-tains was used to reconstruct the summer(June-August)maximum temperature(T_(max6-8))variations from 1718 to *** reconstruction explained 53.1% of the variance in the observed T_(max6-8).Over the past 300 years,the T_(max6-8)reconstruction showed clear interannual and decadal *** was a significant warming trend(0.18°C/decade)after the 1950s,which was close to the increasing rates of the minimum and mean *** increase in maximum temperature was also present over the whole Tianshan mountains and its impact on climate warming has *** T_(max6-8) variations in the Western Tianshan mountains were influenced by frequent volcanic eruptions combined with the influence of solar activity and the sum-mer North Atlantic *** study reveals that cli-mate warming is significantly influenced by the increase in maximum temperatures and clarifies possible driving mech-anisms of temperature variations in the Western Tianshan mountains which should aid climate predictions.

关键词： Tree rings Western Tianshan mountains Temperature change Climate warming

STUDY AND ANALYSIS OF CUTTING FORCES ON OBLIQUE CUTTING OF WOOD

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Journal of Northeast forestry university 1991年第1期2卷 108-114页

作者： Jin Weizhu Kong Degang Northeast forestry university Northeast forestry university China

Obilque cutting of wood is an important form of cutting wood. With the developing of woodworking industry, it is widely used in wood machinary processing such as planing, milling, sawing, drilling and so on. This paper takes oblique planing and helix milling of wood as examples. The influences of bevel angle and other factors on the cutting force have been shown. The changing rules of cutting forces have been summarized. On the basis of it, we especially carried out theoretical analysis on the changing rules of cutting forces and discussed the influence of the changing rules on practice.

关键词： Wood Oblique cutting Cutting force Study Analysis

CHARACTERISTICS OF PHYSICAL ECOLOGY AND REGULATION MEASUREMENT FOR ESTABLISHMENT OF FAST GROWING AND HIGH YIELD LARCH FOREST OF LARIX GMELINI/LARIX PRINCIPIS—RUPPRECHTII IN NORTHEAST OF CHINA

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Journal of Northeast forestry university 1992年第2期3卷 23-26页

作者： Ych-chu Wang Northeast forestry university Northeast forestry university China

On the earth surface,there is a me-dium latitudinal zone in which the evapo-ration per year is greater than the precipita-tion per *** China,the northern tem-perate belt and cold temperate belt arc lo-cated in the lat... 详细信息

关键词： temperate Larix northeast plantation stand Alnus husbandry gentle mountains wetland

A biased edge enhancement method for truss-based community search

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Frontiers of Computer Science 2024年第3期18卷 251-253页

作者： Yuqi LI Tao MENG Zhixiong HE Haiyan liu Keqin LI School of Computer and Information Engineering Central South University of Forestry and TechnologyChangsha 410082China School of Business Central South University of Forestry and TechnologyChangsha 410082China College of Information Engineering Changsha Medical UniversityChangsha 410219China Department of Computer Science State University of New YorkNew York 12561USA

1 Introduction A related study called community search,whose target is to find dense subgraphs containing the given node,has drawn a growing amount of attention recently[1].To explore the higher-order structure of complex networks,truss-based community search methods[2]have been ***,the truss-based hypergraph constructed from the original graph is frequently fragmented and consists of numerous subgraphs and isolated nodes[3],which boils down to the fact that these methods often pay only attention to the truss connections but ignore the lower-order connectivity of the original graph.

关键词： graph. truss connectivity

STUDIES ON STEPWISE STABILITY CONSTANTS OF COORDINATION COMPOUNDS FROM SULFONATED SHEOAK TANNIN WITH METAL IONS

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Journal of Northeast forestry university 1993年第1期4卷 60-63页

作者： Huang Jianling Sun Dawang Nanjing forestry university Nanjing forestry university China

The stepwise stability constants of coordination compounds from sulfonatedsheoak tannin with metal ions have been determined by pH potential method with catechol asmodel compounds at 20℃and constant ionic strength.

关键词： Sulfonatcd sheoak tannin pH potential method Stcpwisc stability constants Catechol

Method to measure tree-ring width,density,elemental composition,and stable carbon and oxygen isotopes using one sample

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Journal of forestry Research 2024年第3期35卷 167-174页

作者： Chenxi Xu Yaru Zhao Wenling An Qingyu Zhao Yucheng liu Masaki Sano Takeshi Nakatsuka Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029People's Republic of China CAS Center for Excellence in Life and Paleoenvironment Beijing 100044People's Republic of China College of Earth Sciences University of Chinese Academy of SciencesBeijing 100049People's Republic of China Graduate School of Environment Studies Nagoya UniversityNagoya 4648601Japan

Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each ***,we developed a method by which each proxy can be measured in the same ***,the sample is polished for ring width *** obtaining the ring width data,the sample is cut to form a 1-mm-thick wood *** sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray ***,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,*** density and the element content are ***,cellulose is isolated from the 1-mm wood plate by removal of lignin,and *** producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)*** on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research.

关键词： Tree-ring width Tree-ring density Tree-ring elemental composition Tree-ring stable carbon and oxygenisotopes

AN ECOLOGICAL APPROACH TO FOREST HARVESTING

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Journal of Northeast forestry university 1990年第1期1卷 99-103页

作者： Shi JiyanNortheast forestry university, Harbin, 150040, China Northeast forestry university Harbin China

This paper deals with the relationships between forest harvesting and forest *** basing annual cuts and forest operation plans on ecological *** forest re-sources are decreasing and regeneration is *** combination of forest harvesting with ccologycan be viewed as a solution to the forest harvesting dilemma in *** paper also makes sometechnical recommendations for forest operations based on ecological principles.

关键词： Harvesting Forest ecology Forest operations Logging technique Post harvest regencration