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| 1 | Floral characteristics and pollination ecology of Manglietia ventii(Magnoliaceae),a plant species with extremely small populations(PSESP)endemic to South Yunnan of China显示文摘Manglietia ventii is a highly endangered plant species endemic to Yunnan province in China, where there are only five known small populations. Despite abundant flowering there is very low fruit and seed set,and very few seedlings in natural populations, indicating problems with reproduction. The causes of low fecundity in M. ventii are not known, largely because of insufficient knowledge of the species pollination ecology and breeding system. We conducted observations and pollination experiments, and analyzed floral scents to understand the pollinatoreplant interactions and the role of floral scent in this relationship, as well as the species breeding system. Like the majority of Magnoliaceae, M. ventii has protogynous and nocturnal flowers that emit a strong fragrance over two consecutive evenings. There is a closing period(the pre-staminate stage) during the process of anthesis of a flower, and we characterize the key flowering process as an 'open-close-reopen' flowering rhythm with five distinct floral stages observed throughout the floral period of this species: pre-pistillate, pistillate, pre-staminate, staminate,and post-staminate. Flowers are in the pistillate stage during the first night of anthesis and enter the staminate stage the next night. During anthesis, floral scent emission occurs in the pistillate and staminate stages. The effective pollinators were weevils(Sitophilus sp.) and beetles(Anomala sp.), while the role of Rove beetles(Aleochara sp.) and thrips(Thrips sp.) in pollination of M. ventii appears to be minor or absent. The major chemical compounds of the floral scents were Limonene, b-Pinene, a-Pinene, 1,8-Cineole, Methyl-2-methylbutyrate, p-Cymene, Methyl-3-methyl-2-butenoate and 2-Methoxy-2-methyl-3-buten, and the relative proportions of these compounds varied between the pistillate and staminate stages. Production of these chemicals coincided with flower visitation by weevils and beetles.The results of pollination experiments suggest that M. ventii is pollinator-dependent, and low seed set in natural populations is a result of insufficient pollen deposition. Thus, conservation of the species should focus on improving pollination service through the introduction of genetically variable individuals and increase in density of reproducing trees. | Bin Wang Gao Chen Congren Li Weibang Sun | 2017 | Plant Diversity2017，39，1： | 8 |
| 2 | Application of EDTMPS as a novel calcite depressant in scheelite flotation显示文摘In this study, the innovative use of ethylenediamine tetramethylene phosphonic sodium(EDTMPS) as a calcite depressant in scheelite flotation was investigated by flotation experiments, and its selective depression mechanism was revealed by contact angle measurement, FTIR analysis, Zeta potential test and XPS analysis. The flotation experiment results showed that scheelite and calcite could be efficiently separated under the following conditions: pulp p H=9.5, Na OL concentration of 1.5×10^(-4)mol/L, EDTMPS concentration of 3.0×10^(-5)mol/L, a scheelite concentrate with WO3grade of 65.49%, recovery of 83.29%and separation efficiency of 65.29% could be obtained from the artificially mixed minerals. The analysis results of mineral surface properties demonstrated that EDTMPS was strongly adsorbed onto the calcite surface through the reaction between the phosphonate group and the calcium ions, which hindered Na OL adsorption and increased the hydrophilicity of calcite. However, EDTMPS had weak adsorption strength on the scheelite surface, which didn’t affect further adsorption of Na OL, hence, the scheelite remained hydrophobic. Consequently, the selective adsorption of EDTMPS on the two minerals’ surfaces increased a difference in wettability and thus enabling them to be separated by flotation. Finally, the mechanism model of this flotation separation process was established. | Fen Jiao Wei Li Xu Wang Congren Yang Zhengquan Zhang Liwen Fu Wenqing Qin | 2023 | International Journal of Mining Science and Technology2023，33，5： | 1 |
| 3 | Alkyl dimethyl betaine activates the low-temperature collection capacity of sodium oleate for scheelite显示文摘The impact of alkyl dimethyl betaine (ADB) on the collection capacity of sodium oleate (NaOl) at low temperatures was evaluated using flotation tests at various scales. The low-temperature synergistic mechanism of ADB and NaOl was explored by infrared spectroscopy, X-ray photoelectron spectroscopy, surface tension measurement, foam performance test, and flotation reagent size measurement.The flotation tests revealed that the collector mixed with octadecyl dimethyl betaine (ODB) and NaOl in a mass ratio of 4:96 exhibited the highest collection capacity. The combined collector could increase the scheelite recovery by 3.48% at low temperatures of 8–12℃. This is particularly relevant in the Luanchuan area, which has the largest scheelite concentrate output in China. The results confirmed that ODB enhanced the collection capability of NaOl by improving the dispersion and foaming performance. Betaine can be introduced as an additive to NaOl to improve the recovery of scheelite at low temperatures. | Xu Wang Zhengquan Zhang Yanfang Cui Wei Li Congren Yang Hao Song Wenqing Qin Fen Jiao | 2024 | International Journal of Minerals,Metallurgy and Materials2024，31，1： | 0 |
| 4 | Uncovering the evolution of tin use in the United States and its implications显示文摘Tin is of key importance to daily life and national security;it is considered an essential industrial metal.The United States(US)is the world’s largest economy and consumer of natural resources.Therefore,the analysis of historical tin use in the US is helpful for understanding future tin use trends in the world as a whole and in developing countries.Time series analysis,regression analysis with GDP or GDP/capita,and historical data fitted with logistic and Gompertz models are employed in this study.Historical tin use in the US shows three stages-increase-constant-decrease,as GDP per capita has increased.Tin use in the US is negatively correlated with the GDP value added by the manufacturing sector,while the use of tin worldwide and in China continues to increase along with the GDP value added by the manufacturing sector.Although a sigmoid curve can fit the US tin use data well,that use is not directly related to the limited tin reserves or resources.Rather,policies,economic restructuring,substitutions,new end-use markets,etc.have played key roles in the changing tin use patterns.This work contributes to understanding future tin use at both the global and national levels:tin use will continue to increase with GDP at the global level,but use patterns of tin at the national level can be changed through human intervention. | Congren Yang Xianlai Zeng Haodong Li Zuyuan Tian Wei Liu Wenqing Qin Jinhui Li | 2021 | Frontiers of Environmental Science & Engineering2021，15，6： | 0 |
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