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71.
CO2浓度升高对半干旱区春小麦光合作用及水分生理生态特性的影响 总被引:2,自引:0,他引:2
大气CO2浓度升高已成为世界范围内重要环境问题。为了解大气CO2浓度升高对春小麦光合作用及水分生理生态特性的影响,在典型半干旱区定西利用开顶式气室(OTC)试验平台,以春小麦“定西24号”为供试品种,开展了CO2浓度增加模拟试验。试验设对照(390μmol·mol?1)、480μmol·mol?1和570μmol·mol?1等3个CO2浓度(摩尔分数)梯度。结果表明:在对照和增加CO2浓度条件下,春小麦叶片净光合速率和蒸腾速率日变化均呈“双峰型”分布,出现明显的“午休”现象;胞间CO2浓度的日变化表现为斜“V”字型曲线;叶水势日变化呈现反抛物线曲线走向,在中午后出现水势曲线拐点。在不同生育时期内,净光合速率、气孔导度和胞间CO2浓度均表现为开花期最大,乳熟期最小。而蒸腾速率表现为开花期最大,拔节期最小,叶片水平水分利用效率表现为孕穗期最大,乳熟期最小。随着CO2浓度升高,春小麦叶片净光合速率、胞间CO2浓度、水分利用效率和水势提高,气孔导度和蒸腾速率降低。与对照大气CO2浓度相比,在480μmol·mol?1浓度和570μmol·mol?1浓度下,整个生育期净光合速率平均分别提高了14.68%和28.20%,气孔导度平均降低了15.29%和24.83%,胞间CO2浓度平均提高了10.38%和26.15%,蒸腾速率平均减小了6.63%和12.41%,WUE平均增加了22.9%和46.9%。随着CO2浓度升高,蒸腾失水减少,叶片水势不断增加,从而增强了春小麦对干旱胁迫的抵御能力。研究结果为我国半干旱区春小麦对全球气候变化下的敏感性及适应性提供理论参考。 相似文献
72.
Gong Weifeng Zhang Haixia Wang Chuanhui Wu Bin Yuan Yaqi Fan Shengjie 《Environmental science and pollution research international》2023,30(6):14641-14655
Environmental Science and Pollution Research - The Yellow River Basin is an energy-rich area. The low-carbon development of the Yellow River Basin is one of the ways to achieve ecological... 相似文献
73.
高层建筑竖井火灾中影响因素众多,并且各因素对高层楼梯井火灾中重要现象、关键数值等的影响大小不一,使得此类火灾中的实验或理论研究成本较高。通过建立全局敏感性分析平台,定量考察了高层楼梯井结构所涉及因素的影响大小,并能够方便地筛选掉对所考察量影响较小的因素,以降低实验或计算成本。使用数值模拟方法,通过CFD软件对包含阶梯几何框架的高层楼梯井结构火灾进行了共计60次工况计算。并且根据计算结果,使用全局参数敏感性分析方法,得出建筑尺寸、热释放速率、环境参数对高层楼梯井内烟气湍流特性及输运特性的敏感性排序。结果表明,火源热释放速率对各输出参数的影响均占38%以上。 相似文献
74.
Chen Yonglin Cui Jian Gong Yaqi Wei Shuang Wei Yuanyun Yi Lan 《Environmental science and pollution research international》2021,28(13):15584-15596
Environmental Science and Pollution Research - Ionizing radiation (IR) is a form of high energy. It poses a serious threat to organisms, but radiotherapy is a key therapeutic strategy for various... 相似文献
75.
76.
Xu Su Gong Ping Ding Wen Wu Shengchun Yu Xinwei Liang Peng 《Environmental science and pollution research international》2021,28(47):66990-66997
Environmental Science and Pollution Research - Paspalum distichum L. was tested to evaluate their phytoremediation capacity for Hg contaminated soil through analyzing the dissipation of Hg in soil... 相似文献
77.
Song Qiulai Zhu Jie Gong Zhenping Feng Yanjiang Wang Qi Sun Yu Zeng Xiannan Lai Yongcai 《Environmental science and pollution research international》2021,28(39):54792-54801
Environmental Science and Pollution Research - Inappropriate farm management practices can lead to increased agricultural inputs and changes in atmospheric greenhouse gas (GHG) emissions, impacting... 相似文献
78.
Zhong Chao Gong Jinke Wang Shaoli Tan Jiqiu Liu Junan Zhu Yun Jia Guohai 《Environmental science and pollution research international》2021,28(16):20034-20044
Environmental Science and Pollution Research - The high NO2/NOX ratio in the after-treatment system is beneficial to its performance and achieved by NO catalytic conversion in diesel oxidation... 相似文献
79.
Simultaneous removal of Cu(II) and Cr(VI) by Mg–Al–Cl layered double hydroxide and mechanism insight
Mg–Al–Cl layered double hydroxide (Cl-LDH) was prepared to simultaneously remove Cu(II) and Cr(VI) from aqueous solution. The coexisting Cu(II) (20 mg/L) and Cr(VI) (40 mg/L) were completely removed within 30 min by Cl-LDH in a dosage of 2.0 g/L; the removal rate of Cu(II) was accelerated in the presence of Cr(VI). Moreover, compared with the adsorption of single Cu(II) or Cr(VI), the adsorption capacities of Cl-LDH for Cu(II) and Cr(VI) can be improved by 81.05% and 49.56%, respectively, in the case of coexisting Cu(II) (200 mg/L) and Cr(VI) (400 mg/L). The affecting factors (such as solution initial pH, adsorbent dosage, and contact time) have been systematically investigated. Besides, the changes of pH values and the concentrations of Mg2+ and Al3+ in relevant solutions were monitored. To get the underlying mechanism, the Cl-LDH samples before and after adsorption were thoroughly characterized by X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. On the basis of these analyses, a possible mechanism was proposed. The coadsorption process involves anion exchange of Cr(VI) with Cl− in Cl-LDH interlayer, isomorphic substitution of Mg2+ with Cu2+, formation of Cu2Cl(OH)3 precipitation, and the adsorption of Cr(VI) by Cu2Cl(OH)3. This work provides a new insight into simultaneous removal of heavy metal cations and anions from wastewater by Cl-LDH. 相似文献
80.
Shixiang Li Xulan Zhang Er Bei Huihui Yue Pengfei Lin Jun Wang Xiaojian Zhang Chao Chen 《环境科学学报(英文版)》2017,29(8):331-339
N-nitrosodimethylamine(NDMA) precursors consist of a positively charged dimethylamine group and a non-polar moiety, which inspired us to develop a targeted cation exchange technology to remove NDMA precursors. In this study, we tested the removal of two representative NDMA precursors, dimethylamine(DMA) and ranitidine(RNTD), by strong acidic cation exchange resin. The results showed that pH greatly affected the exchange efficiency, with high removal(DMA 78% and RNTD 94%) observed at pH pk_a-1 when the molar ratio of exchange capacity to precursor was 4. The exchange order was obtained as follows: Ca~(2+) Mg~(2+) RNTD~+ K~+ DMA~+ NH_4~+ Na~+. The partition coefficient of DMA~+to Na~+was 1.41 ± 0.26, while that of RNTD~+to Na~+was 12.1 ± 1.9. The pseudo second-order equation fitted the cation exchange kinetics well. Bivalent inorganic cations such as Ca~(2+)were found to have a notable effect on NA precursor removal in softening column test. Besides DMA and RNTD, cation exchange process also worked well for removing other 7 model NDMA precursors. Overall, NDMA precursor removal can be an added benefit of making use of cation exchange water softening processes. 相似文献