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Effects of grazing on net primary productivity,evapotranspiration and water use efficiency in the grasslands of Xinjiang,China

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Journal of Arid Land 2018年第4期10卷 588-600页

作者： HUANG Xiaotao LUO Geping YE Feipeng han qifei State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China College of Resource and Environment Sciences Xinjiang UniversityUrumqi 830046China Nanjing University of Information Science&Technology Nanjing 210044China

Grazing is a main human activity in the grasslands of Xinjiang, China. It is vital to identify the effects of grazing on the sustainable utilization of local grasslands. However, the effects of grazing on net primary productivity （NPP）, evapotranspiration （ET） and water use efficiency （WUE） in this region remain unclear. Using the spatial Biome-BGC grazing model, we explored the effects of grazing on NPP, ET and WUE across the different regions and grassland types in Xinjiang during 1979-2012. NPP, ET and WUE under the grazed scenario were generally lower than those under the ungrazed scenario, and the differences showed increasing trends over time. The decreases in NPP, ET and WUE varied significantly among the regions and grassland types. NPP decreased as follows： among the regions, Northern Xinjiang （16.60 g C/（m2·a））, Tianshan Mountains （15.94 g C/（m2·a）） and Southern Xinjiang （-3.54 g C/（m2·a））; and among the grassland types, typical grasslands （25.70 g C/（m2·a））, swamp meadows （25.26 g C/（m2·a））, mid-mountain meadows （23.39 g C/（m2·a））, alpine meadows （6.33 g C/（m2·a））, desert grasslands （5.82 g C/（m2·a）） and saline meadows （2.90 g C/（me.a））. ET decreased as follows： among the regions, Tianshan Mountains （28.95 mm/a）, Northern Xinjiang （8.11 mm/a） and Southern Xinjiang （7.57 mm/a）; and among the grassland types, mid-mountain meadows （29.30 mm/a）, swamp meadows （25.07 mm·a）, typical grasslands （24.56 mm/a）, alpine meadows （20.69 mm/a）, desert grasslands （11.06 mm/a） and saline meadows （3.44 mm/a）. WUE decreased as follows： among the regions, Northern Xinjiang （0.053 g C/kg H2O）, Tianshan Mountains （0.034 g C/kg H2O） and Southern Xinjiang （0.012 g C/kg H2O）; and among the grassland types, typical grasslands （0.0609 g C/kg H2O）, swamp meadows （0.0548 g C/kg H2O）, mid-mountain meadows （0.0501 g C/kg H2O）, desert grasslands （0.0172 g C/kg H2O）, alpine meadows （0.0121 g C/kg H2O） and saline meadows （0.0067 g C/kg H2O）. In general, the decreases in NPP and WUE were m

关键词： grazing effect grassland type net primary productivity evapotranspiration water use efficiency BiomeBGC grazing model

镁合金倾斜薄壁电弧熔丝增材制造工艺与力学性能研究

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材料工程 2024年第7期52卷 57-70页

作者：郑元翾韩启飞陈斌凌郭跃岭谭醴李星辰彭司弋刘长猛北京理工大学机械与车辆学院北京100081

电弧增材制造是一种以金属丝材为填充材料,以电弧作为热源的新型制造技术,易于制造大型复杂零件。通过往复单向路径实验,发现单向路径制造的斜壁有更好的形貌,飞溅少且表面光滑,并在有限元软件中建立了往复、单向制造路径仿真模型并求解... 详细信息

电弧增材制造是一种以金属丝材为填充材料,以电弧作为热源的新型制造技术,易于制造大型复杂零件。通过往复单向路径实验,发现单向路径制造的斜壁有更好的形貌,飞溅少且表面光滑,并在有限元软件中建立了往复、单向制造路径仿真模型并求解,仿真得到单向路径沉积温度267.4℃,沉积热应力357.4 MPa,往复路径沉积温度307.0℃,沉积热应力420.4 MPa,发现单向路径的热积累和热应力更低;以单向制造路径,采用电弧增材制造技术制备AM11,AM12,AM21三种不同斜率的斜壁样件,研究其组织和力学性能。结果表明:AM11,AM12,AM21的晶粒尺寸分别为35,39,42μm;AM21薄壁晶粒中析出相β-Mg17Al12比另外两种样品多且分布均匀、拉伸断口的韧窝更大且更多;AM21与AM11显微硬度在81.5HV左右,均高于AM12的73.1HV;且AM21的斜壁样件的水平、竖直方向抗拉强度为255.7,224.4 MPa,屈服强度为103.8,96.0 MPa,伸长率达到13.1%,8.2%,抗拉强度与伸长率均大于AM11和AM12,但屈服强度接近。AM21斜率薄壁具有更好的强度和塑性,验证了镁合金电弧增材制造的斜壁越接近垂直,其强度、塑性等力学性能越好。

关键词：电弧增材制造 AZ91D镁合金薄壁件微观组织力学性能断口组织

Modeling grassland net primary productivity and water-use efficiency along an elevational gradient of the Northern Tianshan Mountains

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Journal of Arid Land 2013年第3期5卷 354-365页

作者： qifei han GePing LUO ChaoFan LI Hui YE YaoLiang CHEN State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences University of Chinese Academy of Sciences

Mountainous ecosystems are considered highly sensitive and vulnerable to natural disasters and cli- rnatic changes. Therefore, quantifying the effects of elevation on grassland productivity to understand ecosys- tem-climate interactions is vital for mountainous ecosystems. Water-use efficiency （WUE） provides a useful index for understanding the metabolism of terrestrial ecosystems as well as for evaluating the degradation of grasslands. This paper explored net primary productivity （NPP） and WUE in grasslands along an elevational gradient ranging from 400 to 3,400 m asl in the northern Tianshan Mountains-southern Junggar Basin （TMJB）, Xinjiang of China, using the Biome-BGC model. The results showed that： 1 ） the NPP increased by 0.05 g C/（m2-a） with every increase of 1-m elevation, reached the maximum at the mid-high elevation （1,600 m asl）, and then decreased by 0.06 g C/（m2.a） per 1-m increase in elevation; 2） the grassland NPP was positively correlated with temperature in alpine meadow （AM, 2,700-3,500 m asl）, mid-mountain forest meadow （MMFM, 1,650-2,700 m asl） and low-mountain dry grassland （LMDG, 650-1,650 m asl）, while positive correlations were found between NPP and annual precipitation in plain desert grassland （PDG, lower than 650 m asl）; 3） an increase （from 0.08 to 1.09 g C/（m2.a）） in mean NPP for the grassland in TMJB under a real climate change scenario was observed from 1959 to 2009; and 4） remarkable differences in WUE were found among different elevations, in general, WUE increased with decreasing elevation, because water availability is lower at lower elevations; however, at elevations lower than 540 m asl, we did observe a decreasing trend of WUE with decreasing elevation, which may be due to the sharp changes in canopy cover over this gradient. Our research suggests that the NPP simulated by Biome-BGC is consistent with field data, and the modeling provides an opportunity to further evaluate interactions between environmental factors and ecosystem

关键词： elevational gradient net primary production water-use efficiency climate

Mapping of Regional Soil Salinities in Xinjiang and Strategies for Amelioration and Management

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Chinese Geographical Science 2015年第3期25卷 321-336页

作者： WANG Fei CHEN Xi LUO Geping han qifei State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of Sciences University of Chinese Academy of Sciences

Information on the spatial distribution of soil salinity can be used as guidance in avoiding the continued degradation of land and water resources by better informing policy makers. However, most regional soil-salinity maps are produced through a conventional direct-linking method derived from historic observations. Such maps lack spatial details and are limited in describing the evolution of soil salinization in particular instances. To overcome these limitations, we employed a method that included an integrative hierarchical-sampling strategy(IHSS) and the Soil Land Inference Model(So LIM) to map soil salinity over a regional area. A fuzzy c-means(FCM) classifier is performed to generate three measures, comprising representative grade, representative area, and representative level(membership). IHSS employs these three measures to ascertain how many representative samples are appropriate. Through this synergetic assessment, representative samples are obtained and their soil-salinity values are measured. These samples are input to So LIM, which is constructed based on fuzzy logic, to calculate the soil-forming environmental similarities between representative samples and other locations. Finally, a detailed soil-salinity map is produced through an averaging function that is linearly weighted, which is used to integrate the soil salinity value and soil similarity. This case study, in the Uyghur Autonomous Region of Xinjiang of China, demonstrates that the employed method can produce soil salinity map at a higher level of spatial detail and accuracy. Twenty-three representative points are determined. The results show that 1) the prediction is appropriate in Kuqa Oasis(R2 = 0.70, RPD = 1.55, RMSE = 12.86) and Keriya Oasis(R2 = 0.75, RPD = 1.66, RMSE = 10.92), that in Fubei Oasis(R2 = 0.77, RPD = 2.01, RMSE = 6.32) perform little better than in those two oases, according to the evaluation criterion. 2) Based on all validation samples from three oases, accuracy estimatio

关键词： salinity soil mapping purposive sampling Soil Land Inference Model(So LIM) fuzzy c-means(FCM) multiple linear regression(MLR) model

Comparative Study on Wire-Arc Additive Manufacturing and Conventional Casting of Al–Si Alloys:Porosity,Microstructure and Mechanical Property

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Acta Metallurgica Sinica(English Letters) 2022年第3期35卷 475-485页

作者： Yueling Guo qifei han Jinlong Hu Xinghai Yang Pengcheng Mao Junsheng Wang Shaobo Sun Zhi He Jiping Lu Changmeng Liu School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Center for Micro and Nano Technologies Beijing Institute of TechnologyBeijing 100081China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China Beijing hangxing Machinery Manufacturing Co. Ltd.Beijing 100013China

Here,we compare the porosity,microstructure and mechanical property of 4047 Al–Si alloys prepared by wire-arc additive manufacturing(WAAM)and conventional casting.X-ray microscopy reveals that WAAM causes a higher volume fraction of gas pores in comparison with conventional *** refi nements ofα-Al dendrites,eutectic Si particles and Ferich intermetallic compounds are achieved by WAAM,resulting from its rapid solidifi cation *** ultimate tensile strength(UTS,up to 205.6 MPa)and yield stress(YS,up to 98.0 MPa)are improved by WAAM at the expense of elongation after *** mechanical property anisotropy between scanning direction and build direction is minimal for alloys via *** microstructure refi nement and strength enhancement are enabled by increasing the travel speed of welding torch from 300 to 420 mm/min.

关键词： Wire-arc additive manufacturing Al–Si alloy Porosity Microstructure Strength

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锡铁山铅锌矿X射线智能分选试验研究及应用

现代矿业 2024年第1期40卷 156-159,163页

作者：胡生操付金涛郭劲吕勃韩琪菲西部矿业股份有限公司长沙有色冶金设计研究院有限公司北京霍里思特科技有限公司西部矿业集团科技发展有限公司

锡铁山铅锌矿为了确定经济合理的抛废率,针对原矿开展了X射线智能分选试验研究。试验结果表明:锡铁山铅锌矿利用X射线预先分选,技术上可行;当原矿粒度为10~65 mm时,分选效果最佳,抛废率为41.91%时,预选尾矿中的铅、锌品位均在0.10%以内... 详细信息

锡铁山铅锌矿为了确定经济合理的抛废率,针对原矿开展了X射线智能分选试验研究。试验结果表明:锡铁山铅锌矿利用X射线预先分选,技术上可行;当原矿粒度为10~65 mm时,分选效果最佳,抛废率为41.91%时,预选尾矿中的铅、锌品位均在0.10%以内,硫品位为0.63%,铅、锌、硫精矿作业回收率分别为99.23%,99.09%,97.54%。在该试验研究的基础上,现场实施了半自磨顽石X射线预先抛废技术改造,顽石抛废率达40%以上,废石铅+锌品位在0.25%以内,选矿厂各项选矿生产指标均有所提升。

关键词： X射线分选铅锌矿顽石预选抛废

Proteomic analysis of protein expression in lipid droplet of rat RMICs

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Proteomic analysis of protein expression in lipid droplet of...

去杠杆背景下中小饲料企业财务风险管理防控措施分析

2012国际生理学学术大会

作者： Wen Su qifei han Shizheng Huang Jialin Fu Department of Physiology ＆ Pathophysiology Peking University Health Science Center

＜正＞Basically,renomedullary interstitial cells（RMICs） are full of lipid droplets（LDs）,which have been thought to be the source of *** this study,proteomic analysis had been performed to investigate the protein profile in LDs of rat *** than 300 proteins had been identified,including some enzymes controlling arachidonic metabolism such as CYP4F6,CYP2E1 and CYP2A3,suggesting that LDs in RMICs are important places for eicosanoid *** difference in the morphology and protein profile of LDs in renal medulla of SHR（spontaneously hypertensive rat） and Wistar-Kyoto（WKY） rats were further *** microscopy revealed more LDs in renal medulla of SHR than in that of WKY *** analysis revealed 15 differently expressed proteins in renal medulla of SHR when compared with WKY *** blot further confirmed that the expression of clathrin and CYP4A3 were upregulated,whereas the expression of UBXD8 was downregulated in renal medulla LDs of *** conclusion,these preliminary results have suggested that LDs in RMICs are rich in many enzymes involving lipid metabolism and blood pressure *** further study the biological function of these proteins in LDs will shed light on the understanding of the mechanisms of high blood pressure.

关键词： lipid droplets proteomics RMICs

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中国饲料 2022年第24期 89-92页

作者：韩琦霏河南工业贸易职业学院财务会计学院河南郑州450000

中小饲料企业是饲料行业的新生力量,是饲料行业经济发展的增长点。在去杠杆背景下,中小饲料企业面临融资难的问题,并且容易因融资难引发财务风险。中小饲料企业要针对财务管理现状做好对各种风险的识别工作,并通过多种措施来做好风险防... 详细信息

中小饲料企业是饲料行业的新生力量,是饲料行业经济发展的增长点。在去杠杆背景下,中小饲料企业面临融资难的问题,并且容易因融资难引发财务风险。中小饲料企业要针对财务管理现状做好对各种风险的识别工作,并通过多种措施来做好风险防控,力求破解融资难的问题,促进中小饲料企业的健康发展。

关键词：去杠杆中小饲料企业融资财务风险防控措施

基于最大熵模型的新疆主要有毒杂草分布区预测

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生态学报 2023年第12期43卷 5096-5109页

作者：姚政宇韩其飞林彬华东师范大学地理科学学院上海200241 南京信息工程大学地理科学学院南京210044 南京信息工程大学气象灾害预报预警与评估协同创新中心南京210044 山东省第七地质矿产勘查院临沂276000

近年来,在气候变化和人类放牧活动的共同作用下,新疆地区有毒杂草发展迅速,草地退化严重,影响了新疆草地生态系统及草地畜牧业的发展。了解新疆主要有毒杂草的时空分布及影响其分布的主要生态因子,对新疆畜牧业可持续发展具有重要意义... 详细信息

近年来,在气候变化和人类放牧活动的共同作用下,新疆地区有毒杂草发展迅速,草地退化严重,影响了新疆草地生态系统及草地畜牧业的发展。了解新疆主要有毒杂草的时空分布及影响其分布的主要生态因子,对新疆畜牧业可持续发展具有重要意义。使用最大熵模型(MaxEnt),预测了不同气候情景下新疆主要有毒杂草的潜在分布区。结果表明:1)使用MaxEnt最大熵模型在三种气候情景下的模拟精度值均大于0.8,处于“好”水平,表明模型模拟结果有较高的可信度;2)白喉乌头受等温性和最干月降水量的影响,主要分布在阿勒泰等地区;无叶假木贼主要受到放牧率和最干月降水量的影响,沿天山山脉以及塔里木盆地西、北部分布;影响纳里橐吾的是平均气温日较差和等温性,分布在巴音郭楞州等地;小花棘豆主要受到平均气温日较差和降水量季节性变化的影响,集中分布在新疆西北部地区;苦豆子受海拔和最冷季降水量影响,主要分布于塔里木盆地等地区;3)有毒杂草入侵概率较低的区域(非适生区)占比51.69%;入侵的高危区面积占比5.62%,主要集中在阿勒泰、塔城、昌吉自治州、五家渠、博尔塔拉州、伊犁自治州、石河子市、乌鲁木齐市、阿克苏、克孜勒苏州和喀什;4)未来气候情景下,新疆主要有毒杂草呈现进一步扩散趋势;SSP245情境下有毒杂草扩张蔓延趋势比在SSP126情境下更为明显,这说明在较高辐射强迫的气候情境下,有毒杂草表现出较高的适应能力;未来平均气温日较差变小的区域更易被有毒杂草入侵,而最干月份降水量明显增加的区域,有毒杂草入侵的可能性较小,其面积发生退缩。

关键词：有毒杂草最大熵(MaxEnt)模型生态因子时空分布