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Summer extreme precipitation patterns and synoptic-scale circulation precursors over the Tibetan Plateau

Science China Earth Sciences 2024年第5期67卷 1625-1638页

作者： zhiyuan ding.yao ha Zhong ZHONG College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China Key Laboratory for Virtual Geographic Environment School of Geography ScienceNanjing Normal UniversityNanjing 210023China Jiangsu Collaborative Innovation Center for Climate Change School of Atmospheric SciencesNanjing UniversityNanjing 210023China

In the context of global warming,the extreme summer precipitation over the Tibetan Plateau(TP)has changed *** this study,the summer(June–August)extreme precipitation on the TP was classified into three spatial types by applying the K-means clustering method to the Third Pole Region long time-series high-resolution(1/30°)precipitation dataset(TPHi Pr,1979–2020).The characteristics of the circulation anomalies and precursors corresponding to the extreme precipitation on the TP in summer during 1979–2020 were *** results showed that the summer extreme precipitation of the TP can be categorized into northwestern(NW),southeastern(SE),and southern Himalayan(HS)types based on extreme precipitation *** NW and SE types are mainly influenced by anomalous signals in the mid-to-high latitude regions upstream of them,whereas the HS type is controlled by the localized subtropical anomalous *** the 8th day before the onset of the NW type,an anomalous cyclone was observed in the western Atlantic Ocean(60°W,50°N),which triggered the west-to-east quasi-latitudinal propagation of Rossby *** the onset day of the NW type,the upper troposphere showed positive-negative-positive geopotential height anomalies along the latitudinal 40°N from the Caspian Sea,the western part of Xinjiang,to the northeastern *** entered from the Arabian Sea along the southeastern edge of the anomalous cyclone on the southwestern TP and converged in the northwestern *** to the NW type,the precursors of the SE type appeared at higher latitudes and were more *** the 8th day before the onset of the SE type,an anomalous cyclone occurred near Greenland(60°W,70°N)and excited Rossby waves propagating *** the onset day of the SE type,the upper troposphere showed negative-positive-negative geopotential height anomalies across Eurasia from the Ural Mountains and the Iranian Plateau to the northern TP in the northwest-southeast directi

关键词： Tibetan Plateau Summer extreme precipitation Atmospheric circulation anomaly Precursor Teleconnection wave train

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SW220/430LV在不同温度下热-力压缩行为研究和表征建模

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复合材料学报 2024年第1期41卷 521-532页

作者：陈国涛梅志远夏奕海军工程大学舰船与海洋学院武汉430033 中国人民解放军92728部队上海200040

对S2/430LV进行热-力联合作用下压缩性能试验研究,重点揭示S2/430LV在20~180℃压缩损伤失效机制及强度/模量随温度变化规律;提出一种基于ha-Springer模型的分段曲线拟合方法,并对强度/模量随温度变化规律进行预报。研究表明:在热-力联... 详细信息

对S2/430LV进行热-力联合作用下压缩性能试验研究,重点揭示S2/430LV在20~180℃压缩损伤失效机制及强度/模量随温度变化规律;提出一种基于ha-Springer模型的分段曲线拟合方法,并对强度/模量随温度变化规律进行预报。研究表明:在热-力联合作用下,压缩强度和模量随着温度升高而降低,但模量保留率高于强度;随着温度增加,试样最终失效模式发生改变,在100℃之前,试样呈整体剪切失效模式,纤维束发生扭结,并伴随纤维断裂和损伤路径出现断口;但在100℃以后,最终失效模式表现为树脂基体剪切损伤,而纤维织物形态基本不变;强度和模量随温度变化规律呈“S”形趋势,其中强度-温度曲线在20~80℃为凸曲线,80~180℃则为凹曲线;模量-温度曲线在20~100℃为凸曲线,100~180℃为凹曲线;提出了一种基于ha-Springer模型的分段曲线拟合方法,并利用Origin软件对强度/模量随温度变化规律进行预报,预报结果与试验结果高度吻合,且吻合程度优于Mahieux模型。

关键词：热-力联合压缩性能失效机制 Origin ha-Springer模型 Mahieux模型

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对比弹性支点法的狭长基坑围护结构施工优化研究

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河南科技 2024年第7期51卷 64-69页

作者：邵志远中铁二十二局集团第一工程有限公司黑龙江哈尔滨150006

【目的】弹性支点法将基坑假定为平面应变问题进行分析,即假设狭长基坑长距离一次开挖,但在实际施工中有分段开挖的现实情况,所以需要对分区段开挖对基坑围护结构的影响进行研究。【方法】结合新建哈牡客专爱民隧道出口明挖段狭长基坑,... 详细信息

【目的】弹性支点法将基坑假定为平面应变问题进行分析,即假设狭长基坑长距离一次开挖,但在实际施工中有分段开挖的现实情况,所以需要对分区段开挖对基坑围护结构的影响进行研究。【方法】结合新建哈牡客专爱民隧道出口明挖段狭长基坑,建立不同单次开挖长度工况下的三维有限元模型,研究围护结构内力及变形随单次开挖长度的变化规律。【结果】随着单次开挖长度的增加,围护桩水平位移和桩身弯矩逐渐增大并趋近于弹性支点法的计算结果,一次开挖20 m、30 m、40 m时,水平位移比开挖10 m时的水平位移分别增大8.75%、12.2%和13.6%,桩身弯矩分别增大12.1%、14.9%和16.8%;一次开挖10 m、20 m、30 m、40 m时安全系数分别为弹性支点法的1.3、1.17、1.13、1.12倍。【结论】弹性支点法安全储备过大,在实际工程中可结合不同的开挖工况,在对围护结构进行合理优化或满足条件的情况下,合理调整单次开挖长度。

关键词：狭长基坑分段开挖安全系数弹性支点法三维有限元

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EFFECTS OF SUBSTITUTION OF MINERAL NITROGEN WITH ORGANIC AMENDMENTS ON NITROGEN LOSS FROM SLOPING CROPLAND OF PURPLE SOIL

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Frontiers of Agricultural Science and Engineering 2022年第3期9卷 396-406页

作者： Bo ZHU zhiyuan yao Dongni HU hamidou BAH Key Laboratory of Mountain Surface Processes and Ecological Regulation Chinese Academy of SciencesChengdu 610041China Institute of Mountain hazards and Environment Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Science Beijing 100049China.

Nitrogen loss from purple soil can lead to large negative impacts to the environment considering the wide distribution of this soil type in the upper reaches of the Yangtze ***,nitrogen loss patterns from sloping cropland of purple soil in the Sichuan Basin with the following fertilization regimes were studied in a wheat-maize rotation system:100%organic fertilizer(OM),using pig manure to replace 30%of mineral N(OMNPK)and crop residue to replace 15%of the mineral N(CRNPK)plus standard mineral fertilization(NPK)and no fertilizer *** cumulative hydrological N loss could be as high as 45 kg·ha^(−1) *** interflow accounted for up to 90%of the total N loss followed by sediment and overland flow *** high N loss via interflow found in this study highlighting that sloping cropland of purple soil may be one of the hot spots of N *** to the NPK regime,organic substitution regimes(i.e.,OM,OMNPK and CRNPK)decreased total hydrological N loss loadings by 30%−68%.In addition,they can maintain annual crop yields and decrease yield-scaled total hydrological N losses by 18%−71%.In conclusion,long-term substitution of mineral N with organic amendments can maintain high crop productivity and reduce environmental N loss loadings,and thereby recommended as good N management practices to minimize the risk of agricultural non-point source pollution in the purple soil region of China.

关键词： improved fertilization regime interflow nitrogen forms nitrogen leaching purple soil sloping cropland

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Buttress trees in a 20-hectare tropical dipterocarp rainforest in Xishuangbanna, SW China

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Journal of Plant Ecology 2013年第2期6卷 187-192页

作者： zhiyuan He Yong Tang Xiaobao Deng Min Cao Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical Gardenthe Chinese Academy of SciencesMengla 666303China University of Chinese Academy of Sciences Beijing 100049China

Aims buttresses are prevalent and are important to many ecological processes in tropical rainforests but are overlooked in many rainforest *** on a buttress survey in a 20-hectare plot,this study aims to answer the following questions:(i)is buttress forming a fixed species characteristic?(ii)is there any phylogenetic signal for buttress forming across a broad taxonomic scale?(iii)is buttress form-ing an inherent feature or simply induced by environmental factors,and how is this relevant to the size of the tree?Methods We surveyed buttresses for all 95940 trees with diameter at breast height(DbH)≥10 mm in a 20-ha tropical dipterocarp rainforest in Xishuangbanna,sW *** occurrence of buttresses was compared across different taxa and across different tree-size classes.a phylogenetic analysis was conducted among buttressed and non-buttressed species in order to understand the evolutionary background of buttress *** Findings This preliminary study showed that buttress trees are very abundant(making up 32%of trees with≥100 mm DbH)in this 20-ha tropical rainforest situated at the northern edge of the ***-one percent of the 468 tree species in the plot had stems that produced *** trees were more likely to develop buttresses than smaller *** found that although buttress formation is not a fixed species characteristic,there is a strong phylogenetic signal for buttress formation in larger species.

关键词： buttress phylogenetic signal tropical rainforest species size Xishuangbanna

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Ionospheric disturbance analysis of the January 15,2022 Tonga eruption based on GPS data

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Science China Earth Sciences 2023年第8期66卷 1798-1813页

作者： Jiafeng LI Kejie CHEN haishan ChaI Jian LIN zhiyuan ZHOU hai ZHU Mingzhe LYU Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen 518055China Department of Ocean Science and Engineering Southern University of Science and TechnologyShenzhen 518055China

Hunga Tonga-Hunga ha’apai climactic eruption on January 15,2022,released enormous energy that affected the ionosphere over the Pacific *** analyzed ionospheric disturbance following volcanic eruptions using near-field(hat the near-field ionospheric perturbation that occurred 8–15 min after the cataclysmic eruption was mainly derived from the shock wave(~1000 m/s) generated by the blast,while the low-frequency branch with long-distance propagation characteristics over the regional and the far-field was mainly associated with atmospheric Lamb waves(~330 m/s).Moreover,the amplitude of disturbance and background total electron content(TEC) are related *** intensity of the volcanic eruption and the background ionospheric conditions determine the magnitude of ionospheric *** perturbations were invisible on the reference ***,the source location and onset time were calculated using the ray tracing technique,which confirms that the Tonga event triggered the ionospheric anomaly beyond the ***,the change in the frequency of the perturbations coincided with the arrival of the initial tsunami,implying the generation of a meteotsunami.

关键词： GPS Tonga volcano Traveling ionospheric disturbances Raytracing Meteotsunami

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聚多巴胺仿生法制备的聚己内酯螺钉羟基磷灰石涂层对兔前交叉韧带重建后骨整合的影响

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郑州大学学报（医学版） 2024年第1期59卷 40-44页

作者：任铖真毕方刚王志远王亚飞李鹏举田科郑州大学第一附属医院骨科六病区郑州450052 西安市红会医院关节外科膝关节病区西安710000

目的:利用聚多巴胺仿生法在聚己内酯(PCL)螺钉表面制备羟基磷灰石(ha)涂层,评价其对前交叉韧带重建后骨整合的影响。方法:通过3D打印设计制作多孔PCL螺钉,利用聚多巴胺仿生法制备ha涂层。选取20只成年雄性新西兰大白兔,于双侧后肢建立... 详细信息

目的:利用聚多巴胺仿生法在聚己内酯(PCL)螺钉表面制备羟基磷灰石(ha)涂层,评价其对前交叉韧带重建后骨整合的影响。方法:通过3D打印设计制作多孔PCL螺钉,利用聚多巴胺仿生法制备ha涂层。选取20只成年雄性新西兰大白兔,于双侧后肢建立前交叉韧带重建模型,左右侧随机植入含ha涂层(实验组)及不含ha涂层的(对照组)PCL螺钉,术后6、12周分别处死10只,取膝关节,制备股骨-前交叉韧带-胫骨复合物标本,通过Masson染色、Micro-CT检测、生物力学测试评价螺钉与骨组织界面的骨整合情况。结果:Masson染色结果示术后6、12周两组螺钉周围均有较多新生骨小梁形成并向螺钉孔隙内生长,但实验组新生骨小梁的量和深度均优于对照组。Micro-CT示术后6、12周两组螺钉界面骨隧道内新生骨逐渐增加,且实验组周围新生骨量多于对照组。与术后6周相比,两组术后12周骨体积分数、骨小梁数量、骨密度均升高,骨小梁分离率降低;术后6、12周,实验组以上指标均优于对照组(Pha涂层能够促进前交叉韧带重建术后骨整合,提高界面螺钉生物力学稳定性。

关键词：前交叉韧带重建术羟基磷灰石涂层聚多巴胺仿生法骨整合兔

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Response of nitrogen mineralization dynamics and biochemical properties to litter amendments to soils of a poplar plantation

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Journal of Forestry Research 2018年第4期29卷 913-922页

作者： Xiaomin Ge Shiping Deng Ling Zhu Yong Li zhiyuan Jia Ye Tian Luozhong Tang Department of Silviculture College of Forestry Nanjing Forestry University Nanjing Jiangsu 210037 People's Republic of China Department of Plant and Soil Sciences Oklahoma State University Stillwater OK 74078 USA Co-Innovation Center for Sustainable Forestry in Southern China Nanjing Jiangsu 210037 People's Republic of China

Understanding the impact of plant litters on soil nitrogen （N） dynamics could facilitate development of management strategies that promote plantation ecosystem function. Our objective was to evaluate the effects of different litter types on N mineralization and availability, microbial biomass, and activities of L-asparaginase and odiphenol oxidase （o-DPO） in soils of a poplar （Populus deltoides） plantation through 24 weeks of incubation experiments. The tested litters included foliage （F）, branch （B）, or root （R） of poplar trees, and understory vegetation （U） or a mixture of F, B, and U （M）. Litter amendments led to rapid N immobilization during the first 4 weeks of incubation, while net N mineralization was detected in all tested soils from 6 to 24 weeks of incubation, with zero-order reaction rate constants （k） ranging from 7.7 to 9.6 mg N released kg-1 soil wk-1. Moreover, litter addition led to increased （C） 49-128% and increased microbial biomass carbon MBC：MBN ratio by 5-92%, strengthened activities of L-aspaxaginase and o-DPO by 14-74%; Up to about 37 kg N ha-1 net increase in mineralized N in litter added soils during 24 weeks of incubation suggests that adequate poplar and understory litter management could lead to reduced inputs while facilitate sustainable and economic viable plantation production.

关键词： Plant litter Nitrogen mineralization Soilmicrobial biomass L-asparaginase o-diphenol oxidase

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Simulating soil erodibility in southeastern China using a sequential Gaussian algorithm

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Pedosphere 2021年第5期31卷 715-724页

作者： Xuchao ZHU Yin LIANG zhiyuan TIAN Yi ZhaNG Yugang ZhaNG Jing DU Xin WANG Yu LI Lili QU Mengmeng DAI State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) Taihu Basin Monitoring Central Station for Soil and Water Conservation Taihu Basin Authority of Ministry of Water ResourcesShanghai 200434(China) College of Advanced Agricultural Sciences University of Chinese Academy of SciencesBeijing 100190(China)

Soil erodibility(K)is a key factor of soil erosion,and its appropriate quantification and interpolation are vitally important for soil and water *** traditional point-represent-polygon approaches and common kriging method for the estimation of K,however,do not sufficiently represent the original *** objectives of this study were to simulate the spatial distribution of K using a sequential Gaussian algorithm and analyze the uncertainty in evaluating the risk of soil erodibility in southeastern *** determined 101 sampling points in the area and collected disturbed soil samples from the 0-20 cm layer at each *** properties were determined,and K was calculated using five common models:the EPIC(Erosion/Productivity Impact Calculator),approximate nomograph,Torri,Shirazi,and Wang *** the chosen models,the EPIC model performed the best at estimating K(KEPIC),which ranged from 0.019 to 0.060 t ha h(ha MJ mm)^(-1),with a mean of 0.043 t ha h(ha MJ mm)^(-1).The KEPIC was moderately spatially variable and had a limited spatial structure,increasing from south to north in our study area,and all spatial simulations using the cooperative kriging(CK)interpolation and the sequential Gaussian simulation(SGS)with 10,25,50,100,200,and 500 realizations had acceptable *** CK interpolation narrowed the range,and the SGS maintained the original characteristics of the calculated *** proportions of the risk area were 38.0% and 10.1%,when the risk probability for K was 60% and 80%,respectively,and high risk areas were mostly located in the *** results provide scientific guidance for managing the risk of soil erodibility in southeastern China.

关键词： geostatistical analysis K models kriging interpolation risk assessment soil erosion spatial simulation

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4-HMA对氧糖剥夺/复氧神经元细胞和大脑中动脉栓塞/再灌注小鼠脑组织损伤的保护作用及其机制

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精准医学杂志 2024年第4期39卷 299-303页

作者：刘文豪孙晓娜王晓榕赵志远徐锐青岛大学基础医学院山东青岛266071 青岛大学附属医院介入医学科

目的探讨4-羟基扁桃酸(4-HMA)对氧糖剥夺/复氧(OGD/R)致神经元细胞损伤以及大脑中动脉栓塞/再灌注(MCAO/R)致小鼠脑组织损伤的保护作用及其机制。方法提取原代神经元细胞,设立对照组(神经元培养基培养)、OGD/R组(OGD/R处理)及OGD/R+4-HM... 详细信息

目的探讨4-羟基扁桃酸(4-HMA)对氧糖剥夺/复氧(OGD/R)致神经元细胞损伤以及大脑中动脉栓塞/再灌注(MCAO/R)致小鼠脑组织损伤的保护作用及其机制。方法提取原代神经元细胞,设立对照组(神经元培养基培养)、OGD/R组(OGD/R处理)及OGD/R+4-HMA组(给予OGD/R处理+4-HMA干预)。在各组细胞培养6 h后,采用Western blot法检测各组神经元细胞中白蛋白激酶B(Akt)和磷酸化Akt(p-Akt)的水平,通过CCK-8实验检测各组细胞的细胞活力。将C57BL/6小鼠随机分为Sham组、MCAO/R组及MCAO/R+4-HMA组,每组6只。Sham组小鼠仅颈外动脉造口,但不阻塞其大脑中动脉;MCAO/R组和MCAO/R+4-HMA组小鼠均进行MCAO手术,栓塞大脑中动脉1.5 h恢复血流,MCAO/R+4-HMA组小鼠分别于血流恢复0、3 h时腹腔注射4-HMA,MCAO/R组小鼠不做任何处理。采用TTC染色法测定各组小鼠的脑梗死体积百分比并计算梗死区域占总脑体积百分比,并通过小鼠改良神经损伤评分(mNSS)对小鼠行为学进行评估。结果OGD/R、OGD/R+4-HMA组与对照组比较,细胞中p-Akt相对表达量、p-Akt/Akt比值显著性增高(F=10.49、8.87,t_(LSD)=3.02~3.14,P0.05)。OGD/R+4-HMA组的细胞活力明显高于OGD/R组(F=104.60,t_(LSD)=7.28,P<0.05)。相较于MCAO/R组,MCAO/R+4-HMA组小鼠的mNSS分值和脑梗死体积百分比均显著降低(F=7.20、108.00,t_(LSD)=3.32、5.41,P<0.05)。结论4-HMA能够减轻OGD/R模型致神经元细胞的损伤,降低MCAO/R小鼠的脑梗死体积百分比,其作用机制可能与提高脑神经元细胞中p-Akt水平有关。

关键词：细胞低氧再灌注损伤缺氧缺血,脑神经元神经保护抗氧化剂氧化性应激

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