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Lin Wang Bin Yang Yang Bai Xiaoqiang Lu Richard T. Corlett Yunhong Tan Xiao-Yong Chen Jianguo Zhu Yan Liu Rui-Chang Quan 《Conservation biology》2021,35(6):1797-1808
Transboundary conservation is playing an increasingly important role in maintaining ecosystem integrity and halting biodiversity loss caused by anthropogenic activities. However, lack of information on species distributions in transboundary regions and understanding of the threats in these areas impairs conservation. We developed a spatial conservation plan for the transboundary areas between Yunnan province, southwestern China, and neighboring Myanmar, Laos, and Vietnam in the Indo-Burma biodiversity hotspot. To identify priority areas for conservation and restoration, we determined species distribution patterns and recent land-use changes and examined the spatiotemporal dynamics of the connected natural forest, which supports most species. We assessed connectivity with equivalent connected area (ECA), which is the amount of reachable habitat for a species. An ECA incorporates the presence of habitat in a patch and the amount of habitat in other patches within dispersal distance. We analyzed 197,845 locality records from specimen collections and monographs for 21,004 plant and vertebrate species. The region of Yunnan immediately adjacent to the international borders had the highest species richness, with 61% of recorded species and 56% of threatened vertebrates, which suggests high conservation value. Satellite imagery showed the area of natural forest in the border zone declined by 5.2% (13,255 km2) from 1995 to 2018 and monoculture plantations increased 92.4%, shrubland 10.1%, and other cropland 6.2%. The resulting decline in connected natural forest reduced the amount of habitat, especially for forest specialists with limited dispersal abilities. The most severe decline in connectivity was along the Sino-Vietnamese border. Many priority areas straddle international boundaries, indicating demand and potential for establishing transboundary protected areas. Our results illustrate the importance of bi- and multilateral cooperation to protect biodiversity in this region and provide guidance for future conservation planning and practice. 相似文献
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Jingjing Dong Chengzhi Hu Weixiao Qi Xiaoqiang An Huijuan Liu Jiuhui Qu 《环境科学学报(英文版)》2020,32(5):35-42
Much attention has been paid to the pollutant dimethylarsenic acid(DMA),because of its high toxicity even at very low doses.Although TiO_2 photocatalytic oxidation(PCO) is one of the few effective methods for treating DMA-containing water,the efficient decomposition of DMA and simultaneous removal of toxic arsenic species remains a significant but challenging task.Here,defective mesoporous TiO_2 with mixed-phase structure was synthesized and used as both photocatalyst and adsorbent for DMA removal.Due to the reduced band-gap and enhanced separation of photogenerated charge carriers, the oxygen-deficient TiO_2 nanostructures exhibited 4.2 times higher PCO efficiency than commercial TiO_2(P25).More importantly,the high surface area of the mesoporous TiO_2 provided sufficient active sites for in-situ adsorption and reaction,resulting in the efficient removal of as-formed As(V).Combining the experimental and characterization results,the different roles of reactive species during PCO reactions were clarified.In the presence of hole(h~+) as the dominant oxidation species,DMA was demethylated and transformed into MMA.Thereafter,MMA was subsequently reduced to As(Ⅲ) by photo-generated electrons.Superoxide radicals(O_2~(·-)) played a significant role in oxidizing As(Ⅲ) into As(Ⅴ),which was finally adsorptively removed by the mesoporous TiO_2. 相似文献
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Xiaorong Meng Conghui Wang Pan Zhou Xiaoqiang Xin Lei Wang 《Frontiers of Environmental Science & Engineering》2017,11(6):9
In the present paper, a polymer inclusion membrane (PIM) containing polyvinyl chloride (PVC), and bis-(2-ethylhexyl) phosphate (D2EHPA) which was used as extracting agent was used for the recovery of In(III) ions in hydrochloric acid medium. The effects of carrier concentration, feed phase pH, strip phase HCl concentration, temperature on the transport, and the membrane’s stability and thickness were examined. And the conditions for the selective separation of In(III) and Cu(II) were optimized. The results showed that the transport of In(III) across PIM was consistent with the first order kinetics equation, and also it was controlled by both the diffusion of the metal complex in the membrane and the chemical reaction at the interface of the boundary layers. The transport flux (J 0) was inversely proportional to the membrane thickness, however, the transport stability improved as the membrane thickness increased. The transport flux of In(III) and Cu(II) was decreased by excessive acidity of feed phase and high concentration of Cl–. The selectivity separation coefficient of In(III)/Cu(II) was up to 34.33 when the original concentration of both In(III) and Cu(II) was 80 mg?L–1 as well as the pH of the feed phase and the concentration of Cl– in the adjusting context were0.6 and 0.5 mol?L–1, respectively.Within the range of pH = 1–3, the separation selectivity of In(III)/Cu(II) reached the peak in the case when the Cl– concentration was 0.7 mol?L–1. 相似文献
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利用雾化挥发发生原理制备二氧化钛气溶胶,将二氧化钛气溶胶颗粒负载在石英玻璃纤维上,制备二氧化钛-石英玻璃纤维功能性空气过滤材料。实验研究了二氧化钛气溶胶发生相关参数、石英玻璃纤维直径分布、透过率曲线、最易透过粒径,并对二氧化钛气溶胶颗粒在石英玻璃纤维上的负载过程和负载形态进行了探讨。研究结果表明,发生的二氧化钛气溶胶具有可控的粒径分布和较好的分散性;中值粒径128 nm的二氧化钛气溶胶颗粒能够稳定负载在3μm的石英玻璃纤维上;二氧化钛在石英玻璃纤维上的沉积量受沉积时间的影响,沉积过程中阻力开始变化不大,随后在沉积饱和点后阻力迅速增大,滤料填充度越高沉积饱和点出现时间越早;二氧化钛粒子在纤维表面的负载形态除颗粒、团簇外,还有三维的树枝状空间结构。 相似文献
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Guo Xiaojing Sheng Yonghong Liu Bihu Tang Peng Liu Runfeng Wu Li Chen Jiehua Huang Dongping Liu Shun Qiu Xiaoqiang 《Environmental science and pollution research international》2022,29(38):57318-57329
Environmental Science and Pollution Research - Phthalates (PAEs) are common endocrine disrupting chemicals (EDCs) that disrupt fetal development. The present study aimed to evaluate the effects of... 相似文献
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为克服综合评价模型中因子权重定量的不确定性与主观性,体现出同一地下水质因子在不同地下水水源地评价单元中存在的差异性,采用地下水质因子污染贡献率确定各地下水质因子的权重,改进了欧式距离模型,建立了农村地下水源地水质评价的变权欧式距离模型,并以阜新市典型乡镇后新秋镇、苇子沟乡、哈尔套镇3个农村地下水水源地为评价对象,将2013年阜新市农村地下水水源地水质实测数据、标准数据规范化,运用数轴模型距离尺度进行地下水水质分割。评价结果与F值法结果基本吻合,变权欧式距离模型的距离尺度能够提高地下水水质评价结果的定量灵敏度,变权欧式距离模型具备一定的环境参数评价充分性、一致性及有效性。 相似文献
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莱茵衣藻(Chlamydomonas reinhardtii)是一种重要的模式生物,其miRNA的发现相对较晚.为系统化地预测分析莱茵衣藻的miRNA,采用比较基因组和同源比对相结合的方法,根据mi Rbase中已知的莱茵衣藻miRNA序列以及前体的特点,并且基于莱茵衣藻的全基因组对其miRNA的前体序列和成熟miRNA进行系统的分析和筛选,使用unigene和JGI的莱茵衣藻相关序列数据库对预测结果进行靶基因预测和功能的分析.最终发现可能存在的miRNA 36条,其前体结构符合miRNA前体的基本特征且具有高度的同源性,两个数据库所得相匹配靶基因分别为64和32条,其中部分是与莱茵衣藻各项生命活动相关的基因.本研究表明莱茵衣藻的基因组中具有可能存在的新miRNA家族,并且部分有高度匹配的靶基因,为其后续研究提供了可靠的理论支持. 相似文献