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| 1 | Estimation of tree transpiration and response of tree conductance to meteorological variables in desert-oasis system of Northwest China显示文摘Transpirations of three dominated tree species, namely Mongol Scotch Pine (Pinus sylvestris var. mongolica Litvin), White elm (Ulmus pumila) and Gansu Poplar (Populus gansuensis Wang et Yang) in oasis shelter forest (Linze site) and of two dominated tree species,namely Euphrates Poplar (Populus euphratica Oliv.) and Russia olive (Elaeagnus angustifolia Linn.) in lowland desert (Erjinaqi site) have been estimated using measured sapflow in summer,autumn and winter, 2002 and in spring, 2003. An ENVIS System was used for each site to measure microclimate variables, soil moisture and sapflow every half an hour, and the study time scale is one day. In the 104 days of observation during the growing season at the Linze site, the average daily sapflow of Gansu Poplar is 9.93L·d-1,and the average transpiration per unit leaf area is 1.99mm·d-1.For White elm tree,the daily average sapflow is 4.08L·d-1,while the daily average transpiration per unit leaf area is 0.49mm·d-1.The values for Mongol Scotch Pine are 3.91L·d-1 and 0.25mm·d-1,respectively.In the total 73 days of observation during the growing season at the Erjinaqi site, the daily average sapflows of Russia olive and Euphrates Poplar are 12.1 and 20.97L·d-1,respectively,and the average transpirations per unit leaf area are 0.22 amd 0.31mm·d-1,respectively.In the observation period of the growing season,tree conductances of Mongol Scotch Pine, White elm, Gansu Poplar or Russia olive show an exponential relationship with the daily average air temperature or vapour pressure deficit, but the relationship is not so obvious between tree conductance and global radiation. The transpiration process of each tree species is affected by all the observed four environmental variables. The response of tree conductance to different climatic factors changes with tree species. The effect of the same factor to the same tree species is also variable in different growing stages. The sapflow of every tree species is relatively large in later spring to early summer, and low in summer, and then reaches its largest value in later September. In the mid-November, the sapflow is relatively large, especially the deciduous tree species. This may be characteristic of the tree species in Arid Regions of Northwest China. | CHEN Rensheng KANG Ersi ZHANG Zhihui ZHAO Wenzhi SONG Kechao ZHANG Jishi LAN Yongchao | 2004 | Science China Earth Sciences2004，47，z1： | 5 |
| 2 | CO2 methanation and co-methanation of CO and CO2 over Mn-promoted Ni/Al2O3 catalysts显示文摘一系列支持 Mn 15 wt-% Ni/Al 2 O 3 催化剂被一个早期的湿受精方法准备。在 Ni/Al 2 为公司 2 methanation 和在一个改正床反应堆的公司和公司 2 的 comethanation 的 O 3 催化剂被调查。催化剂被 N2 physisorption 描绘,氢规划温度的减小和解吸附作用,二氧化碳规划温度的解吸附作用, X 光检查衍射和 highresolution 传播电子显微镜学。Mn 的存在增加了公司 2 吸附地点的数字并且由于改进 Ni 分散禁止了 Ni 粒子凝块并且削弱了在镍种类和支持之间的相互作用。支持 Mn 15 wt-% Ni/Al 2 O 3 催化剂特别在低温度改进了公司 2 methanation 活动(250 ~ 400 25 ?1, 的 mg 12.5 ?2 的 mg 并且 25 ? 导致了 32 的 3 的 mg ? B 1, 的 s 32.89?Zn, Cu, Se, Mn,我, Fe,瞬间和 Br。mea 覈 ? 覈?? | Kechao Zhao Zhenhua Li Li Bian | 2016 | Frontiers of Chemical Science and Engineering2016，10，2： | 4 |
| 3 | Ni/ZrO_2 Catalysts Synthesized via Urea Combustion Method for CO_2 Methanation显示文摘A series of Ni/ZrO_2 catalysts were synthesized by urea combustion method for CO_2 methanation.The effects of zirconium precursors and urea dosage on the structure and catalytic performance of the catalysts were tested.Results showed that the Ni/ZrO_2–O catalyst derived from zirconium oxynitrate hydrate exhibited better catalytic activity than the Ni/ZrO_2 catalyst because of its higher Ni dispersion and smaller Ni particle size.In addition,the urea dosage significantly influenced the low-temperature activity of the catalysts by affecting the metal–support interaction,Ni dispersion,and Ni particle size.The Ni/ZrO_2–O-0.4 catalyst with a urea-to-nitrate molar ratio of 0.4 exhibited the best catalytic activity owing to its moderate metal–support interaction,highest Ni dispersion,and smallest Ni particle size,achieving 69.2% CO_2 conversion and 100% CH_4 selectivity at 300℃,0.1 MPa,and a weight hour space velocity(WHSV)of 50,000 mL/(g·h).Moreover,the urea combustion method can lead to the entire phase transformation from monoclinic ZrO_2 to tetragonal ZrO_2 accompanied by the incorporation of oxygen vacancies in the ZrO_2 lattice.This phenomenon can also be related to the high catalytic activity of the as-prepared catalysts. | Zhenhua Li Lijuan Zhang Kechao Zhao Li Bian | 2018 | Transactions of Tianjin University2018，24，5： | 2 |
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