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Vegetation dynamics and its response to climate change during the past 2000 years in the Altai Mountains,northwestern China

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Frontiers of Earth Science 2022年第2期16卷 513-522页

作者： dongliang zhang Yunpeng YANG Min RAN Bo LAN Hongyan ZHAO Qi LIU State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Research Center for Ecology and Environment of Central Asia Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China College of Environment and Planning Henan UniversityKaifeng 475004China Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions(Ministry of Education) Henan UniversityKaifeng 475004China School of Environmental and Chemical Engineering Chongqing Three Gorges UniversityChongqing 404000China School of Earth Science Northeast Normal UniversityChangchun 130024China College of Resource and Environmental Sciences Xinjiang UniversityUrumqi 830046China

Over the past 2000 years,a high-resolution pollen record from the Yushenkule Peat(46°45′-46°57′N,90°46′-90°61′E,2374 m a.s.l.)in the south-eastern Altai Mountains of northwestern China has been used to explore the changes in vegetation and climate.The regional vegetation has been dominated by alpine meadows revealed from pollen diagrams over the past 2000 years.The pollen-based climate was warm and wet during the Roman Warm Period(0-520 AD),cold and wet during the Dark Age Cold Period(520-900 AD),warm and wet during the Medieval Warm Period(900-1300 AD),and cold and dry during the Little Ice Age(1300-1850 AD).Combined with other pollen data from the Altai Mountains,we found that the percentage of arboreal pollen showed a reduced trend along the NW-SE gradient with decreasing moisture and increasing climatic continentality of the Altai Mountains over the past 2000 years;this is consistent with modern distributions of taiga forests.We also found that the taiga(Pinus forest)have spread slightly,while the steppe(Artemisia,Poaceae and Chenopodiaceae)have recovered significantly in the Altai Mountains over the past 2000 years.In addition,the relatively warm-wet climate may promote high grassland productivity and southward expansion of steppe,which favors the formation of Mongol political and military power.

关键词： pollen analysis vegetation dynamics past 2000 years Altai mountains northwestern China

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Mechanism of phthalic acid collector in flotation separation of fluorite and rare earth

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Journal of Rare Earths 2022年第1期40卷 118-126页

作者： Sheng Chang Mei Li Kai Gao dongliang zhang Haijun Duan Linlin Ma Zheng Ruan College of Mining Inner Mongolia University of Science&TechnologyBaotou 014010China Key Laboratory of Green Extraction&Efficient Utilization of Light Rare-Earth Resources Ministry of Education Baotou 014010China Inner Mongolia Key Laboratory of Rare Earth Hydrometallurgy and Light Rare Earth Application Baotou 014010China Inner Mongolia Mining Exploitation Co. Ltd.Hohhot 010020China

The mechanism of phthalic acid,a dicarboxylic acid collector,in flotation separation of fluorite and rare earth(RE)was studied in this paper.The experimental data of flotation show that phthalic acid,as the collector,can realize highly efficient separation of fluorite and rare earth under weakly acidic conditions.The adsorption mechanism of phthalic acid on the surface of fluorite and bastnaesite was analyzed in this paper by means of the zeta potential measurement,the Fourier transform infrared(FT-IR),the X-ray photoelectron spectroscopy(XPS)and the stability constant measurement of active metal ion and phthalic acid coo rdination complex.According to the zeta potential testing results,the surfaces of fluorite adsorb the collector phthalate ion with negative charge under weakly acidic conditions which,in turn,increases its electronegativity and results in the motion of its potential.After the reaction between phthalic acid and fluorite ores under weakly acidic conditions,the peak of the fluorite ores is found to have significant changes in the FT-IR results,indicating strong chemical adsorption on the surfaces of phthalic acid and fluorite ores.According to the XPS analysis,the peak of benzene ring of phthalic acid is as high as 2%on the surface of fluorite,while no obvious characteristic peak of benzene ring is found on the surface of bastnaesite.According to the pH potentiometric titration results,the stability constant Ktotal of calcium phthalate complex within the acid range is higher than the stability constant K’total of cerium phthalate complex,indicating that the complex generated between phthalic acid and Ca^(2+)is more stable than the complex generated between phthalic acid and Ce^(3+).The possible reason is that Ca^(2+),with the highest reticular density,plays a prevailing role in the octahedron structure of fluorite amidst the acidic media.As the active point of flotation,Ca^(2+)works with the carboxyl groups of the collector phthalic acid(-C=O-)to form polycyclic calcium phthalate complex.

关键词： Fluorite Bastnaesite Carboxylic acid collector Flotation Equilibrium constants of complexes Rare earths

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Changes in the root system of the herbaceous peony and soil properties under different years of continuous planting and replanting

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Horticultural Plant Journal 2023年第4期9卷 801-810页

作者： Anqi Xie Limin Sun dongliang zhang Yang Li Zemiao Liu Xue Li Xia Sun College of Horticulture State Key Laboratory of Crop BiologyShandong Agricultural UniversityTai'anShandong 271018China College of Forestry Shandong Agricultural UniversityTai'anShandong 271018China

The herbaceous peony(Paeonia lactiflora Pall.)has high ornamental value.Replanting problems occur when seedlings are replanted into previous holes.We studied the root system and soil environment of the'Dongjingnvlang'variety under a continuous planting regime of one,four,and seven years,and a replanting regime of one and four years.Under the condition of continuous planting,with the increase of number of years,pH,ammonium nitrogen,and nitrate nitrogen decreased in the rhizosphere and non-rhizosphere soils,whereas organic matter,available phosphorus and potassium,enzyme activities,and the number of bacteria,fungi,and actinomycetes increased.Under the condition of replanting,with the increase of number of years,fungi and actinomycetes in both soils increased,while pH,organic matter,nutrients,enzyme activities,and bacterial number decreased.pH,organic matter,nutrient content,enzyme activity and the number of bacterial were lower in soil replanted for four years,whereas the abundance of fungi and actinomycetes was higher,altering the soil from“bacterial high-fertility”to“fungal low-fertility”with increasing years of replanting.The activity of antioxidant enzymes and MDA content in roots of peony in replanting were higher than those in continuous planting,while the content of osmotic regulatory substances in replanting was lower than that in continuous planting.The results showed that there were no obvious adverse factors in soil during seven years of continuous planting,and herbaceous peony could maintain normal growth and development.However,soils after four years of replanting were not suitable for herbaceous peony growth.Benzoic acid increased with years of replanting,which potentially caused replanting problems.This study provides a theoretical basis for understanding the mechanism of replanting problems in the herbaceous peony.

关键词： Herbaceous peony Replanting problems Continuous planting Soil environment Phenolic acids Paeoniflorin

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Easily fabricated and recyclable Pd&Cu@Al catalyst for gram-scale phosphine-free Heck reactions with high TON

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Science Bulletin 2017年第19期62卷 1325-1330页

作者： dongliang zhang Zheng Wei Lei Yu Institute of Pesticide School of Horticulture and Plant ProtectionYangzhou University School of Chemistry and Chemical Engineering Yangzhou University

A unique Pd&Cu@Al catalyst was easily fabricated just by immersing commercial aluminum foil in a mixed xylene solution of PdCl_2 and CuCl_2. The catalyst fabrication process led to aluminum oxide coatings in situ, which supported the metal nanoparticles and enhanced their catalytic activities for the phosphine-free Heck reaction of aryl halides and styrenes with high turnover number(TON) up to 3.9×10~5. The reaction can be scaled up to at least 100 mmol and has been applied in modification of drug Lapatinib's intermediate with low metal residue. This novel catalyst is of good application potential in industrial production because it was extremely easy to be recycled, in regardless of the generation of the insoluble impurities or tars during the reaction processes.

关键词： Heck反应新型催化剂铝箔金属纳米粒子回收制造膦铜

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A novel mutation in ROR2 led to the loss of function of ROR2 and inhibited the osteogenic differentiation capability of bone marrow mesenchymal stem cells(BMSCs)

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BIOCELL 2023年第7期47卷 1561-1569页

作者： WENQI CHEN XIAOYANG CHU YANG ZENG YOUSHENG YAN YIPENG WANG DONGLAN SUN dongliang zhang JING zhang KAI YANG Prenatal Diagnosis Center Shijiazhuang Obstetrics and Gynecology HospitalKey Laboratory of Maternal and Fetal Medicine of Hebei ProvinceShijiazhuang050011China Department of Stomatology Fifth Medical Center of Chinese PLA General HospitalBeijing100039China Institute of Hematology Fifth Medical Center of Chinese PLA General HospitalBeijing100039China Prenatal Diagnosis Center Beijing Obstetrics and Gynecology HospitalBeijing Maternal and Child Health Care HospitalCapital Medical UniversityBeijing100026China Department of Orthodontics Beijing Stomatological HospitalCapital Medical University School of StomatologyCapital Medical UniversityBeijing100050China

Receptor tyrosine kinase-like orphan receptor 2(ROR2)has a vital role in osteogenesis.However,the mechanism underlying the regulation of ROR2 in osteogenic differentiation is still poorly comprehended.A previous study by our research group showed that a novel compound heterozygous ROR2 variation accounted for the autosomal recessive Robinow syndrome(ARRS).This study attempted to explore the impact of the ROR2:c.904C>T variant specifically on the osteogenic differentiation of BMSCs.Methods:Coimmunoprecipitation(CoIP)-western blotting was carried out to identify the interaction between ROR2 and Wnt5a.Double-immunofluorescence staining was used for determining the expressions and co-localization of ROR2 and Wnt5a in bone marrow mesenchymal stem cells(BMSCs).Western blot(WB)analysis and quantitative reverse transcription polymerase chain reaction(RT-qPCR)were conducted to identify the expression levels of ROR2 in the BMSCs transfected with LV-shROR2 or LV-ROR2-c.904C>T.The alkaline phosphatase(ALP)activity was detected,and Alizarin Red S staining was done for evaluating the osteogenic differentiation of BMSCs.RT-qPCR was employed to identify the expression of the sphingomyelin synthase 1(SMS1)mRNA in the BMSCs transfected with LV-shROR2 or LV-ROR2-c.904C>T and the mRNA expression levels of Runt-related transcription factor 2(RUNX2),osteocalcin(OCN),and osteopontin(OPN).WB was performed to confirm the protein expressions of extracellular regulated protein kinases1(ERK),P-ERK,Smad family member1/5/8(Smad1/5/8),P-Smad1/5/8,P-P38,P38,RUNX2,OCN,and OPN in the BMSCs transfected with LV-shROR2/LV-ROR2-c.904C>T and sphingomyelin(SM).Results:The ROR2:c.904C>T mutant altered the subcellular localization of the ROR2 protein,which caused an impaired interaction between ROR2 and Wnt5a.The depletion of ROR2 restricted the osteogenic differentiation capability of BMSCs and downregulated the expression of SMS1.SM treatment could reverse the inhibition of osteoblastic differentiation in ROR2-depleted BMSCs.Conclusion:The findings of

关键词： Bone marrow mesenchymal stem cells ROR2 Wnt5a Osteogenic differentiation Sphingomyelin

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两种隐形正畸序列磨牙远移的有限元比较

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医用生物力学 2024年第2期39卷 326-331页

作者：李慧张栋梁北京市医用内植物工程技术研究中心北京100194 首都医科大学附属北京口腔医院北京100050

目的比较两种远中移动序列的无托槽隐形矫治在磨牙远移方面的执行效果。方法建立包含牙体、牙周膜、牙槽骨及隐形矫治器的下颌右侧7颗牙齿有限元模型,分别选用两种推磨牙远中移动对牙齿进行模拟第二磨牙远移0.5 mm的过程,采用牙槽骨重... 详细信息

目的比较两种远中移动序列的无托槽隐形矫治在磨牙远移方面的执行效果。方法建立包含牙体、牙周膜、牙槽骨及隐形矫治器的下颌右侧7颗牙齿有限元模型,分别选用两种推磨牙远中移动对牙齿进行模拟第二磨牙远移0.5 mm的过程,采用牙槽骨重建技术模拟长期牙齿移动效果。结果V型、ZC远中移动序列第二磨牙最大远中位移分别为0.27、0.34 mm,ZC远中移动执行效率增大13.34%;牙齿内倾分别矫正0.18、0.44 mm,舌侧内倾角度分别矫正1.15°、2.69°,ZC舌侧内倾矫正率提高15.01%;远端倾斜分别增大1.83°、0.84°,ZC远端倾斜角度减小54.10%。结论ZC远中移动序列方法在无托槽隐形矫治中能够更有效地实现磨牙远中移动,减少磨牙远中倾斜和矫正磨牙舌侧内倾,为无托槽隐形矫治创造前牙间隙提供有利条件。

关键词：无托槽隐形矫治牙齿移动序列下颌磨牙远移有限元分析

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基于变流器并网的新能源外送系统功率传输能力评估

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电网技术 2024年第1期48卷 171-183页

作者：万易王建南东亮张博熊小伏输配电装备及系统安全与新技术国家重点实验室(重庆大学) 重庆市沙坪坝区400044 国网新疆电力有限公司电力科学研究院新疆维吾尔自治区乌鲁木齐市830011

光伏、风电等清洁能源广泛采用并网变流器接入电网,评估变流器并网新能源外送系统的功率传输能力,对于保证电网正常及紧急运行工况下的清洁能源持续、稳定外送具有重要意义。该文首先分析无功补偿前后变流器并网系统的功率传输特性,掌... 详细信息

光伏、风电等清洁能源广泛采用并网变流器接入电网,评估变流器并网新能源外送系统的功率传输能力,对于保证电网正常及紧急运行工况下的清洁能源持续、稳定外送具有重要意义。该文首先分析无功补偿前后变流器并网系统的功率传输特性,掌握变流器并网系统的安全稳定传输边界。接着,对新能源外送通道开展动态热容量评估,挖掘传输通道潜在传输能力以促进清洁能源消纳。然后,统筹考虑保证并网系统及外送通道安全稳定运行的各类型约束,确定新能源最大外送能力。最后,对算例测试系统中的新能源场站开展最大外送能力评估,算例研究表明:配合无功补偿并同时利用设备动态热容量,可以提升新能源外送能力;不同电网连接强度和运行工况下,限制清洁能源外送能力的主导因素不同,需依据主导因素确定外送功率,才能确保电网的安全稳定运行。

关键词：新能源外送并网变流器无功补偿动态热容量功率传输能力

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Merging cobalt catalysis and electrochemistry in organic synthesis

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Chinese Chemical Letters 2021年第3期32卷 963-972页

作者： Junsong Zhong Yi Yu dongliang zhang Keyin Ye Key Laboratory of Molecule Synthesis and Function Discovery(Fujian Province University) College of ChemistryFuzhou UniversityFuzhou 350108China

There is an increasing demand of using the low-cost and sustainable cobalt to replace its noble congeners(rhodium and iridium)as reflected by the recent upsurge of cobalt catalysis in the diverse organic transformations.Since all the redox reactivity of cobalt catalysis highly relies on the capability of the interconversion between their oxidation states(most frequently+1,+2 and+3),electrochemistry perfectly meets such a require ment owing to its outstanding perfo rmance in the redox manipulation.In this review,we highlight the recent advances in the merger of cobalt catalysis and electrochemistry in organic synthesis.

关键词： Cobalt Catalysis Electrochemistry Organic synthesis Sustainable chemistry

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灾害天气下计及一二次设备耦合故障的电网短时风险评估

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电力系统保护与控制 2024年第9期52卷 16-26页

作者：王建熊张忞南东亮张路欧阳金鑫输变电装备技术全国重点实验室(重庆大学) 重庆400044 国网新疆电力有限公司电力科学研究院新疆乌鲁木齐830011

灾害天气下电网发生短时多重故障有可能超出保护系统预设的反应能力,一二次设备耦合影响将助推多重故障风险发展和蔓延。为此,提出了计及一二次设备耦合故障的短时风险评估方法。首先,分析了一次设备与二次设备之间的交互作用及其对电... 详细信息

灾害天气下电网发生短时多重故障有可能超出保护系统预设的反应能力,一二次设备耦合影响将助推多重故障风险发展和蔓延。为此,提出了计及一二次设备耦合故障的短时风险评估方法。首先,分析了一次设备与二次设备之间的交互作用及其对电网短时运行风险的影响。其次,构建了一次设备和二次设备的故障概率模型,重点分析了一二次设备耦合故障引发保护拒动的概率。然后,结合保护系统对超预期故障的反应能力,提出了灾害天气下电网短时多重故障风险评估方法。最后,采用改造的IEEE39节点系统对所提方法进行测试。算例结果表明:受外界气象环境影响,保护系统缺陷暴露导致非期望动作使得电网多重故障风险更为严重;综合考虑灾害天气对一二次设备影响下的短时运行风险,对于发现和消除保护系统薄弱环节及制定电网降风险运行策略具有一定参考价值。

关键词：电力系统灾害天气多重故障耦合故障短时风险评估

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The influence of temperature on rare earth flotation with naphthyl hydroxamic acid

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Journal of Rare Earths 2018年第1期36卷 99-107页

作者： Mei Li Kai Gao dongliang zhang Haijun Duan Linlin Ma Lan Huang School of Materials Science and Engineering Beijing University of Chemical Technology Inner Mongolia Key Laboratory of Rare Earth Hydrometallurgy and Light Rare Earth Application Inner Mongolia University of Science and Technology School of Material and Metallurgy Inner Mongolia University of Science and Technology

The influence of temperature on the complex process of Bayan Obo rare earth （RE） ore flotation with a collector of naphthyl hydroxamic acid （LF8#） was investigated. Industrial test data shows that the grade and recovery of RE increase with the temperature. However, the proportion of bastnaesite in the bulk concentrate increases as the RE grade improves. Adsorption mechanism of LF8# on the surfaces of bastnaesite and monazite were confirmed via zeta potential, UV]Vis Spectrophotometer （UV]Vis）, Fourier transform infrared （FIR）, and X-ray photoelectron spectroscopy analyses （XPS）. Although the results indicate that the total amount of the LF8# adsorption on the surface of bastnaesite and monazite de- creases with increasing the temperature, the amount of stable adsorbed predominance of characteristic bonds （-C（~O）N-] from LF8# uptake on bastnaesite surfaces increases significantly at high tempera- tures. This conclusion indicates that the adsorption stability increases with increasing the temperature. For monazite, the amount of characteristic elements C and N in LF8# does not increase as the temper- ature increases on the mineral surface, but the proportion of characteristic bonds increases, which shows that the adsorption stability of LF8# on the surface of monazite also increases, but it is not as significant as bastnaesite, which may be one of the reasons that the floatability of bastnaesite is better than those of monazite. Pulp dispersion results show that the temperature improve the dispersions of both the gangue and RE minerals. This improved the flotation selectivity so that it favored RE minerals. The calculated bubble size distribution confirms that higher temperatures generate smaller bubbles, thereby increasing the bubble-particle collision probability and the recovery of RE minerals.

关键词： BastnaesiteMonaziteFlotationHydroxamic acidAdsorptionRare earths

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