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Stability assessment of tree ring growth of Pinus armandii Franch in response to climate change based on slope directions at the Lubanling in the Funiu Mountains,China

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Journal of Forestry Research 2024年第2期35卷 197-208页

作者： Jinkuan Li Jianfeng Peng xiaoxu wei Meng Peng Xuan Li Yameng Liu Jiaxin Li College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China Key Laboratory of Earth System Observation and Simulation of Henan Province Kaifeng 475004People’s Republic of China

Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.

关键词： Tree ring width Lubanling Pinus armandii Franch Slope direction Climate response

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Climate-growth relationships of Pinus tabuliformis along an altitudinal gradient on Baiyunshan Mountain,Central China

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Journal of Forestry Research 2024年第1期35卷 202-212页

作者： xiaoxu wei Jianfeng Peng Jinbao Li Jinkuan Li Meng Peng Xuan Li Yameng Liu Jiaxin Li College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China Key Laboratory of Earth System Observation and Simulation of He’nan Province Kaifeng 475004People’s Republic of China Department of Geography University of Hong KongPokfulamHong Kong SARPeople’s Republic of China HKU Shenzhen Institute of Research and Innovation Shenzhen 518057People’s Republic of China

A set of standard chronologies for tree-ring width(TRW),earlywood width(EWW)and latewood width(LWW)in Pinus tabuliformis Carr.along an altitudi-nal gradient(1450,1400,and 1350 m a.s.l.)on Baiyunshan Mountain,Central China to analyze the effect of varying temperature and precipitation on growth along the gradi-ent.Correlation analyses showed that at all three altitudes and the TRW and EWW chronologies generally had signifi-cant negative correlations with mean and maximum tem-peratures in the current April and May and with minimum temperatures in the prior July and August,but significant positive correlations with precipitation in the current May.Correlations were generally significantly negative between LWW chronologies and all temperatures in the prior July and August,indicating that the prior summer temperature had a strong lag effect on the growth of P.tabuliformis that increased with altitude.The correlation with the standard-ized precipitation evapotranspiration index(SPEI)confirmed that wet conditions in the current May promoted growth of TR and EW at all altitudes.Significant altitudinal differences were also found;at 1400 m,there were significant positive correlations between EWW chronologies and SPEI in the current April and significant negative correlations between LWW chronologies and SPEI in the current September,but these correlations were not significant at 1450 m.At 1350 m,there were also significant negative correlations between the TRW and the EWW chronologies and SPEI in the prior October and the current July and between LWW chronology and SPEI in the current August,but these cor-relations were not significant at 1400 m.Moving correlation results showed a stable response of EWW in relation to the SPEI in the current May at all three altitudes and of LWW to maximum temperature in the prior July-August at 1400 m from 2002 to 2018.The EWW chronology at 1400 m and the LWW chronology at 1450 m were identified as more suitable for climate reconstruction.These results provide a strong scientific basis f

关键词： Tree rings Climate response Altitudinal gradient Baiyunshan Mountain Pinus tabuliformis Carr

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Microenvironmental effects on growth response of Pinus massoniana to climate at its northern boundary in the Tongbai Mountains,Central China

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Journal of Forestry Research 2024年第1期35卷 44-57页

作者： Jianfeng Peng Jiayue Cui Jinbao Li Meng Peng Yongtao Ma xiaoxu wei Jinkuan Li Xuan Li Yamen Liu Jiaxin Li College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China Key Laboratory of Earth System Observation and Simulation of Henan Province Kaifeng 475004People’s Republic of China Department of Geography University of Hong KongHong KongSARPeople’s Republic of China HKU Shenzhen Institute of Research and Innovation Shenzhen 518057People’s Republic of China Henan Academy of Forestry Zhengzhou 450000People’s Republic of China

The Tongbai Mountains is an ecologically sensi-tive region and the northern boundary of Pinus massoniana Lamb.To analyze the effect of different microenvironments on tree growth response to climate factors,we developed standard chronologies for earlywood width(EWW),late-wood width(LWW),and total ring width(TRW)of P.massoniana at two sampling sites on slopes with different orientations,then analyzed characteristics of the chronolo-gies and their correlations with climate variables from five stations in the region and with a regional normalized differ-ence vegetation index(NDVI).Statistical results showed that the TRW/EWW/LWW chronology consistency and charac-teristics(mean sensitivity,signal to noise ratio,expressed population signal)for trees growing on the southeastern slope were much higher than for trees on the northeastern slope.Correlations indicated that temperature in current March and August has a significant positive effect on TRW/EWW/LWW formation,and the effect on the northeastern slope was weaker than on the southeastern slope.Compared to temperature,precipitation has more complicated effects on tree growth,but the effect on the northeastern slope was also generally weaker than on the southeastern slope.Step-wise linear regression analyses showed that temperature in August was the main limiting factor at the two sampling sites.Similarly,the response of tree growth on the southeast-ern slope as determined by the NDVI is better than on the northeastern slope,and the TRW/EWW/LWW chronologies for the southeastern slope explained over 50%of the total NDVI variances in June.Overall,the results indicate that the difference in the climate response of P.massoniana at two sampling sites is clearly caused by differences in the microenvironment,and such differences should be properly considered in future studies of forest dynamics and climate reconstructions.

关键词： Tree-rings Pinus massoniana lamb Microenvironment Radial growth Climate-growth response

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Stability assessment of tree ring growth of Pinus armandii Franch in response to climate change based on slope directions at the Lubanling in the Funiu Mountains, China

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Journal of Forestry Research 2024年第3期 88-99页

作者： Jinkuan Li Jianfeng Peng xiaoxu wei Meng Peng Xuan Li Yameng Liu Jiaxin Li College of Geography and Environmental Science Henan University Key Laboratory of Earth System Observation and Simulation of Henan Province

Global warming will affect growth strategies and how trees will adapt. To compare the response of tree radial growth to climate warming in different slope directions, samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains. Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July. The difference of the climate response to slopes was small but not negligible. Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures, while that of the LBL02 site was affected by maximum temperatures. With regards to moisture, radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July, while on the western slope, it was affected by the relative humidity in the previous June–August, the current May–July and the precipitation in the current May–July. With the change in climate, the effects of the main limiting factors on growth on different slopes were visible to a certain extent, but the differences in response of trees on different slopes gradually decreased, which might be caused by factors such as different slope directions and the change in diurnal temperature range. These results may provide information for forest protection and ecological construction in this region, and a scientific reference for future climate reconstruction.

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Stability assessment of tree ring growth of Pinus armandi Franch in response to climate change based on slope directions at the Lubanling in the Funiu Mountains,China

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Journal of Forestry Research 2024年第3期35卷 87-98页

作者： Jinkuan Li Jianfeng Peng xiaoxu wei Meng Peng Xuan Li Yameng Liu Jiaxin Li College of Geography and Environmental Science Henan UniversityKaifeng 475004People's Republic of China Key Laboratory of Earth System Observation and Simulation of Henan Province Kaifeng 475004People's Republic of China

Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and tree-ring chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June-August and the com-bination of temperatures and moisture in the current May-July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBLO1 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBLO2 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May-July,while on the western slope,it was affected by the relative humidity in the previous June-August,the current May-July and the precipitation in the current May-July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.

关键词： Tree ring width Lubanling Pinus armandi Franch Slope direction Climate response

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High expression circRALGPS2 in atretic follicle induces chicken granulosa cell apoptosis and autophagy via encoding a new protein

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Journal of Animal Science and Biotechnology 2024年第3期15卷 971-986页

作者： Haorong He Yuanhang wei Yuqi Chen Xiyu Zhao xiaoxu Shen Qing Zhu Huadong Yin Key Laboratory of Livestock and Poultry Multi‑Omics Ministry of Agriculture and Rural AffairsCollege of Animal Science and TechnologySichuan Agricultural UniversityChengduSichuan 611130China Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province Sichuan Agricultural UniversityChengduSichuan 611130China

Background The reproductive performance of chickens mainly depends on the development of follicles.Abnor-mal follicle development can lead to decreased reproductive performance and even ovarian disease among chick-ens.Chicken is the only non-human animal with a high incidence of spontaneous ovarian cancer.In recent years,the involvement of circRNAs in follicle development and atresia regulation has been confirmed.Results In the present study,we used healthy and atretic chicken follicles for circRNA RNC-seq.The results showed differential expression of circRALGPS2.It was then confirmed that circRALGPS2 can translate into a protein,named cir-cRALGPS2-212aa,which has IRES activity.Next,we found that circRALGPS2-212aa promotes apoptosis and autophagy in chicken granulosa cells by forming a complex with PARP1 and HMGB1.Conclusions Our results revealed that circRALGPS2 can regulate chicken granulosa cell apoptosis and autophagy through the circRALGPS2-212aa/PARP1/HMGB1 axis.

关键词： Apoptosis Autophagy Chicken CircRALGPS2 Follicle atresia PARP1 RNC-seq

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Review on piezoelectric actuators:materials,classifications,applications,and recent trends

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Frontiers of Mechanical Engineering 2024年第1期19卷 5-33页

作者： Xuyang ZHOU Shuang WU xiaoxu WANG Zhenshan WANG Qixuan ZHU Jinshuai SUN Panfeng HUANG Xuewen WANG wei HUANG Qianbo LU Institute of Flexible Electronics(IFE) Northwestern Polytechnical UniversityXi’an 710072China School of Automation Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingbo 315103China

Piezoelectric actuators are a class of actuators that precisely transfer input electric energy into displacement,force,or movement outputs efficiently via inverse piezoelectric effect-based electromechanical coupling.Various types of piezoelectric actuators have sprung up and gained widespread use in various applications in terms of compelling attributes,such as high precision,flexibility of stoke,immunity to electromagnetic interference,and structural scalability.This paper systematically reviews the piezoelectric materials,operating principles,representative schemes,characteristics,and potential applications of each mainstream type of piezoelectric actuator.Herein,we intend to provide a more scientific and nuanced perspective to classify piezoelectric actuators into direct and indirect categories with several subcategories.In addition,this review outlines the pros and cons and the future development trends for all kinds of piezoelectric actuators by exploring the relations and mechanisms behind them.The rich content and detailed comparison can help build an in-depth and holistic understanding of piezoelectric actuators and pave the way for future research and the selection of practical applications.

关键词： piezoelectric actuator piezoelectric effect amplified piezoelectric actuator ultrasonic actuator stepping actuator piezoelectric polymer

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Synergistic effects of planting density and nitrogen fertilization on chlorophyll degradation and leaf senescence after silking in maize

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The Crop Journal 2024年第2期12卷 605-613页

作者： Tianqiong Lan Lunjing Du Xinglong Wang xiaoxu Zhan Qinlin Liu Gui wei Chengcheng Lyu Fan Liu Jiaxu Gao Dongju Feng Fanlei Kong Jichao Yuan Key Laboratory of Crop Physiology Ecologyand Cultivation SouthwestMinistry of AgricultureSichuan Agricultural UniversityChengdu 611130SichuanChina Chongqing Academy of Agricultural Sciences Chongqing 401329China College of Agronomy Sichuan Agricultural UniversityChengdu 611130SichuanChina

Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield.

关键词： Density Nitrogen fertilization Leaf senescence Chlorophyll-degrading enzyme Logistic model

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Ecosystem changes revealed by land cover in the three-river headwaters region of Qinghai,China(1990–2015)

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Research in Cold and Arid Regions 2023年第2期15卷 85-91页

作者： Xuwei Sun Sen Li XiaoHui Zhai xiaoxu wei ChangZhen Yan Gansu Academy of Eco-environmental Sciences LanzhouGansu 730020China Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhouGansu 730000China College of Social Development and Public Administration Northwest Normal UniversityLanzhouGansu 730070China

The Three-River Headwaters Region(TRHR) of Qinghai Province, in the Tibetan Plateau of China, is the main source of the Yangtze, Yellow, and Lancang rivers, and is very significant to the security of freshwater resources for China and southeastern Asia. It is a critical ecological region of China for its ecological functions, and has been changed or even degraded in recent decades owing to climate change and human pressure. To effectively protect and restore the degraded ecosystems, the Chinese government initiated a series of ecological conservation projects in TRHR. It is essential to quantitatively assess ecosystem changes and their relationship to driving factors for indepth understanding of long-term changes of ecosystems and effects of ecological restoration policies and offer practical insights for ecological restoration. Here, land cover data has been interpreted with the series data of Landsat during 1990–2015. The patterns of different ecosystems and their developing process have been derived from land cover change. The results show that ecosystem types in TRHR include forest, grassland, cropland,wetland, artificial surface and barren land, accounting for 4.51%, 70.80%, 0.15%, 9.47%, 0.16% and 14.90%,respectively. Barren land converted to wetland was the significant ecosystem change from 1990 to 2015. Increases in temperature and precipitation and implementation of ecological rehabilitation helped maintain relatively stable ecosystem patterns. It is necessary to continue ecological projects to improve and/or maintain the ecosystems in TRHR because there is still a risk of land degradation under increasing climate change and human activity.

关键词： Three-river headwaters region Ecosystem change Land cover Affecting factor

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小角度燕尾型同层侧钻水平井分段控水策略

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西南石油大学学报（自然科学版） 2024年第1期46卷 97-104页

作者：唐晓旭裴柏林赵威中海石油(中国)有限公司天津分公司天津滨海新区300452 安东柏林石油科技(北京)有限公司北京昌平102200

渤海油田高含水低产低效的井逐渐增多,部分区块产量递减快。同层侧钻水平井技术搭配分段控水完井是治理高含水低产低效井的有效手段,但小角度燕尾型同层侧钻水平井应用分段控水完井后未见到控水效果。为此,通过建立理论模型分析发现此... 详细信息

渤海油田高含水低产低效的井逐渐增多,部分区块产量递减快。同层侧钻水平井技术搭配分段控水完井是治理高含水低产低效井的有效手段,但小角度燕尾型同层侧钻水平井应用分段控水完井后未见到控水效果。为此,通过建立理论模型分析发现此类井分段控水失效原理,确定了原井眼的“空腔”是分段控水技术在此类井上适应性差的主控因素。在考虑可行性及经济性等因素后,调整现阶段的钻完井思路,提出了水平段延伸与优化完井管柱配管的综合钻完井改进策略,并对该策略的有效性进行了矿场试验验证。试验井控水效果远超预期,投产164 d仍未见水,无水期累产油高达1.5×10^(4) m^(3)。该策略在目标井控水效果显著的同时,单井建井成本增幅仅为8.8%,为后续类似低产低效井治理提供思路及技术储备。

关键词：低产低效井同层侧钻技术分段控水技术水平井控水钻完井策略优化

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