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131.
Chen Xing Daihui Yang Yan Zhang Tian Sun Junfei Duan Hussein A.Younus Shiguo Zhang 《绿色能源与环境(英文)》2022,7(1):43-52
Heteroatom-doped meso/micro-porous carbon materials are conventionally produced by harsh carbonization under an inert atmosphere involving specific precursors, hard/soft templates, and heteroatom-containing agents. Herein, we report a facile synthesis of N and O co-doped meso/micro-porous carbon (NOMC) by template-free carbonization of a small-molecule precursor in a semi-closed system. The semi-closed carbonizaiton process yields hydrophilic NOMCs with large surface area in a high yield. The porous structure as well as the elemental composition of NOMCs can be modulated by changing the holding time at a particular temperature. NOMCs as metal-free heterogeneous catalysts can selectively oxidize benzyl alcohol and its derivatives into aldehydes/ketones with>85%conversion in aqueous solution, which is much higher than that of the control sample obtained in tube furnace (21%conversion), mainly due to their high N content, high percentage of pyridinic N, and large surface area. The presence of O-containing moieties also helps to improve the hydrophilicity and dispersion ability of catalysts and thus facilitates the mass transfer process during aqueous oxidation. The NOMC catalysts also dispayed excellent activity for a wide range of substrates with a selectivity of>99%. 相似文献
132.
铬离子对藻类生长的影响 总被引:6,自引:0,他引:6
利用自然光照条件,在不同铬离子质量浓度下,对5种藻类的生长进行了实验研究.研究结果表明:5种藻类在不同的光波长下,其吸收光谱存在两个最强的吸收区: 420~440 nm的蓝紫光部分和660 nm 的红光部分;在不同铬离子质量浓度0~20.63 mg·L-1范围内,5种藻类生长受到不同程度的抑制,其耐受性也尽不相同,经过分析和比较后得出5种藻类对铬的耐受性大小顺序为:微囊藻(Microcystis)>水华鱼腥藻(Anabaena flos-aquae)>细长聚球藻(Synechococcus elongatus)>斜生栅藻(Scenedesmus obliquus)>蛋白核小球藻(Chlorella pyrenoidose). 相似文献
133.
Zn2+对黄瓜发芽期生理特性的影响 总被引:4,自引:0,他引:4
锌是植物必需的营养元素,同时也是一种常见的环境有毒重金属元素.以黄瓜(Cucumis sativus L.)为试验材料,设置不同Zn2 处理(0、25、50、100、200、300 mg·L-1),利用发芽和出苗试验,研究了Zn2 对黄瓜发芽期生理特性的影响.结果显示,低处理(0~25 mg·L-1)对黄瓜种子萌发和幼苗生长有促进作用,当为25 mg·L-1时最有利于黄瓜种子萌发和幼苗生长,其种子发芽率、发芽势、发芽指数、活力指数、根长、下胚轴长、下胚轴粗度和相对含水量均高于对照及其他浓度处理;幼苗相对电导率、丙二醛含量、可溶性糖含量、游离脯氨酸含量、SOD活性及POD活性均在此浓度得到最低.但从50 mg·L-1开始,随着增加,黄瓜种子萌发的各项指标开始下降,幼苗生长的各项生理指标开始上升,对黄瓜种子发芽和幼苗生长产生抑制作用,并在300 mg·L-1时抑制作用得到最大.该研究为进一步研究农业生态整治与安全高效利用提供理论基础. 相似文献
134.
135.
136.
Zhuqiu Sun Bairen Yang Marvin Yeung Jinying Xi 《Frontiers of Environmental Science & Engineering》2023,17(2):17
137.
Qingting Wang Kun Dai Jie Tang Sidi Hong Sijie Zheng Ting Sun Raymond Jianxiong Zeng Fang Zhang 《Frontiers of Environmental Science & Engineering》2023,17(3):37
138.
Xiping Kan Xia Yu Wentao Zhao Shuguang Lyu Shuying Sun Gang Yu Qian Sui 《Frontiers of Environmental Science & Engineering》2023,17(9):116
139.
140.
Ye Sun Yuan Meng Xiaoyan Guo Tianle Zhu Hongju Liu Wenpei Li 《Journal of Material Cycles and Waste Management》2016,18(4):618-624
Experiments were conducted using a bubbling reactor to investigate nitrogen oxide absorption in the calcium sulfite slurry. The effects of CaSO3 concentration, NO2/NO mole ratio and O2 concentrations on NO2 and SO2 absorption efficiencies were investigated. Five types of additives, including MgSO4, Na2SO4, FeSO4, MgSO4/Na2SO4 and FeSO4/Na2SO4, had been evaluated for enhancing NO2 absorption in CaSO3 slurry. Results showed that CaSO3 concentration had significant impact on NO2 and SO2 absorption efficiencies, and the highest absorption efficiencies of SO2 and NO2 could reach about 99.5 and 75.0 %, respectively. Furthermore, the NO2 absorption was closely related to the NO2/NO mole ratio, and the existence of NO2 in flue gas may promote NO absorption. The presence of O2 in simulated flue gas was disadvantage for NO x removal because it can oxidize sulfite to sulfate. It was worth pointing out that FeSO4/Na2SO4 was the best additive among those investigated additives, as the NO2 removal efficiency was significantly increased from 74.8 to 95.0 %. IC and in situ FTIR results suggest that the main products were NO3 ? and NO2 ? in liquid phase and N2O, N2O5 and HNO3 in gas phase during the CaSO3 absorption process. 相似文献