Evaluation of the influence of El Niño–Southern Oscillation on air quality in southern China from long-term historical observations

•Strong ENSO influence on AOD is found in southern China region. •Low AOD occurs in El Niño but high AOD occurs in La Niña events in southern China. •Angstrom exponent anomalies reveals the circulation pattern during each ENSO phase. •ENSO exerts large influence (70.5%) on annual variations of AOD during 2002–2020. •Change of anthropogenic emissions is the dominant driver for AOD trend (2002–2020). Previous studies demonstrated that the El Niño–Southern Oscillation (ENSO) could modulate regional climate thus influencing air quality in the low-middle latitude regions like southern China. However, such influence has not been well evaluated at a long-term historical scale. To filling the gap, this study investigated two-decade (2002 to 2020) aerosol concentration and particle size in southern China during the whole dynamic development of ENSO phases. Results suggest strong positive correlations between aerosol optical depth (AOD) and ENSO phases, as low AOD occurred during El Niño while high AOD occurred during La Niña event. Such correlations are mainly attributed to the variation of atmospheric circulation and precipitation during corresponding ENSO phase. Analysis of the angstrom exponent (AE) anomalies further confirmed the circulation pattern, as negative AE anomalies is pronounced in El Niño indicating the enhanced transport of sea salt aerosols from the South China Sea, while the La Niña event exhibits positive AE anomalies which can be attributed to the enhanced import of northern fine anthropogenic aerosols. This study further quantified the AOD variation attributed to changes in ENSO phases and anthropogenic emissions. Results suggest that the long-term AOD variation from 2002 to 2020 in southern China is mostly driven (by 64.2%) by the change of anthropogenic emissions from 2002 to 2020. However, the ENSO presents dominant influence (70.5%) on year-to-year variations of AOD during 2002–2020, implying the importance of ENSO on varying aerosol concentration in a short-term period.     

Bioinspired cellulose-based membranes in oily wastewater treatment

• Cellulose-based membrane separates oily wastewater mimicking the living things. • The three central surface mechanisms were reviewed. • Preparation, performance, and mechanism are critically evaluated. • First review of wettability based cellulose membrane as major material. • The current and future importance of the research are discussed. It is challenging to purify oily wastewater, which affects water-energy-food production. One promising method is membrane-based separation. This paper reviews the current research trend of applying cellulose as a membrane material that mimics one of three typical biostructures: superhydrophobic, underwater superoleophobic, and Janus surfaces. Nature has provided efficient and effective structures through the evolutionary process. This has inspired many researchers to create technologies that mimic nature’s structures or the fabrication process. Lotus leaves, fish scales, and Namib beetles are three representative structures with distinct functional and surface properties: superhydrophobic, underwater superoleophobic, and Janus surfaces. The characteristics of these structures have been widely studied and applied to membrane materials to improve their performance. One attractive membrane material is cellulose, which has been studied from the perspective of its biodegradability and sustainability. In this review, the principles, mechanisms, fabrication processes, and membrane performances are summarized and compared. The theory of wettability is also described to build a comprehensive understanding of the concept. Finally, future outlook is discussed to challenge the gap between laboratory and industrial applications.     

农地三权分置改革对多元主体收入的影响——来自长江中下游地区的实证经验

中国反贫重点由摆脱绝对贫困向全面实施乡村振兴、系统解决相对贫困转变。农地三权分置改革作为农村土地制度改革的重要内容,对于推进乡村振兴战略和实现共同富裕具有重要作用。根据长江中下游地区1038份入户调研数据,使用多群组结构方程模型,探讨了农地三权分置改革对多元主体收入的影响。结果表明：（1）三权分置对家庭农场和资本农场有积极影响,但对传统农户和种田能手造成了不利的影响,尤其是对种田能手。从作用路径上,传统农户和种田能手收入损失的主要原因分别是经营规模萎缩和负向直接效应,而家庭农场和资本农场收入增加依赖的路径是规模扩张。（2）三权分置对务工经商、农业雇工两类主体收入有积极影响,但对赋闲农户的作用并不乐观。从作用路径上,三权分置主要通过劳动力转移和放松流动性约束两条间接路径提高务工经商、农业雇工主体收入,但赋闲农户的间接路径未形成通路。（3）三权分置对各离农主体的收入总效应高于传统农户、种田能手,却低于家庭农场、资本农场,农业经营主体内部的收入差距要远远高于离农主体内部。研究结论对于完善相关制度政策和助力政策顺利实施、保障农户福利和推动共同富裕有指导意义。     

密度分离法提取土壤中微塑料的优化

为探究一种简单、经济和可靠的微塑料分离提取手段,设立了11种(F1~F11)具有不同体积比的饱和NaCl和饱和NaI溶液的混合溶液,将混合液作为浮选液来提取土壤中的4种类型(聚乙烯,PE;聚苯乙烯,PS;聚氯乙烯,PVC;聚对苯二甲酸乙二醇酯,PET)微塑料,同时对浮选过程进行了改进.结果表明:当单独使用NaCl溶液浮选时,微塑料的总提取率为55.83%,但随着NaI所占体积比的不断增加,微塑料的总提取率基本呈上升趋势,在NaCl:NaI=1:1时总提取率超过了90%,在只有NaI的条件下总提取率高达96.67%;在F1~F11的任意条件下,PE和PS表现为较高的提取率,均超过了86.67%;PVC和PET在单独使用NaCl溶液浮选时提取率极低,在NaCl:NaI=1:1条件下提取率分别为93.33%和90%,接近单独使用NaI溶液浮选时的提取率;F1~F11任意条件下,低密度微塑料PE和PS的提取率之和均高于高密度微塑料PVC和PET的提取率之和,但在F6~F11条件下提取率差值不大.根据提取结果并结合经济成本等多方面因素考虑,建议使用NaCl:NaI=1:1的混合溶液来分离土壤中的微塑料.     

基于应力–强度干涉模型的分离螺母可靠性分析

目的 提出一种基于应力强度干涉模型的分离螺母的分离可靠性分析方法。方法 首先,建立分离螺母机构分离动力学模型和极限状态函数。然后,在考虑工作载荷、几何尺寸和药剂燃烧参数等参数不确定性的基础上,建立分离螺母不同分离阶段的基于应力–强度干涉模型的可靠性模型。最后,对分离螺母进行可靠性和灵敏度分析,量化工作载荷、几何尺寸和火药燃烧参数对分离螺母机构分离可靠性的重要性排序。结果 影响可靠性的主要参数依次为火药力、装药密度和预紧力。结论 该方法能够准确描述不确定性因素对分离螺母分离过程可靠性的影响,提升分离螺母机构分离可靠性定量分析的精度和效率,可为分离螺母的精细化设计提供支撑。     

降水产流同位素径流分割研究进展与展望

降水产流是陆地水循环中大气降水补给地表水的重要环节。氢氧稳定同位素的指纹效应能够有效示踪径流的补给来源、路径和地理区域。同位素径流分割模型已从二元分割逐渐发展到三元乃至多元分割模型,多学科交叉也逐渐丰富了径流分割研究的方法体系。本文对同位素径流分割在降水产流中的应用进展作了总结分析,介绍了环境同位素（²H和¹⁸O）在降水产流研究中的应用现状、存在的不确定性以及处理误差的方法和应用特点。最后对环境同位素在径流分割领域的应用前景进行了论述,提出环境同位素结合GIS、InSAR、ERT等地球物理方法,将进一步深化流域水文要素时空变化的研究。     

正渗透在水处理中的研究应用进展

正渗透是指水在渗透压的作用下通过半透膜从高水化学势区域(或较低渗透压)自发地向低水化学势区域(或较高渗透压)传递的过程。与压力驱动的膜分离水处理技术(如超滤、纳滤、反渗透等)相比,正渗透具有低压、低能耗和较低的膜污染等优点。介绍了正渗透的技术原理,综述了其在水处理领域的研究和应用进展,分析了目前存在的问题,并展望其应用前景。     

化学沉淀分离-置换法提纯Al13的工艺研究

采用AlCl₃溶液和Na₂CO₃粉末在不同温度下制备了不同浓度的聚合氯化铝(PACl). 以选定的中等浓度、高Al₁₃含量的PACl为原液,研究了Al₁₃与硫酸盐沉淀反应过程中SO₄/Al摩尔比、反应体系起始总铝浓度的影响以及Al₁₃硫酸盐与Ba(NO₃)₂置换反应过程中的Ba/SO₄摩尔比、超声、温度等因素的影响. 实验结果表明,在制备温度为50℃条件下,浓度在0.4～0.6　mol/L范围的PACl含有较高的Al₁₃. 沉淀分离反应的最佳SO₄/Al摩尔比为0.6∶1;生成的 Al₁₃硫酸盐沉淀物为正四面体状晶体. 在Al₁₃硫酸盐与Ba(NO₃)₂溶液置换反应过程中,Ba/SO₄的最佳摩尔比为1∶1,反应温度及超声作用对置换反应的影响较小;提高Ba(NO₃)₂的起始浓度可以得到相应较高浓度的纯化Al₁₃溶液. 所得Al₁₃纯度的统计平均值为92.1％.     

稠油废水预处理工艺

针对稠油废水乳化严重等特点,采用"沉降除油-旋流油水分离-气浮净化"预处理工艺,并选择处理效果明显的破乳剂进行破乳。实际应用结果表明,该工艺合理,处理效果良好,运行稳定,出水水质达到设计要求,回收了80%以上的原油。     

阳离子交换树脂微柱分离测定矿石中锆的研究

建立了HD-8阳离子交换树脂微色谱柱分离富集矿石中锆的方法。研究了上柱酸度、淋洗液、洗脱液、干扰离子等对锆的吸附性能的影响。结果表明,上柱最佳酸度0.5~2 mol/L HCl、淋洗液1 mol/L HCl、洗脱液1 mol/L H2SO4,锆的吸附与洗脱效果最好。选用邻氯苯基荧光酮为显色剂,直接在硫酸介质中显色,胶束增溶光度法测定,操作简便,灵敏度高,选择性好。树脂的吸附容量为81.4 mg/g。与常规柱相比,微色谱柱吸附后,洗脱体积减少了16倍,柱效高,分离速度快,试剂用量少,灵敏度高。该方法可以用于实际矿石的分离测定,经标准值验证,测定值与标准值相近,多次平行测定后,方法的相对标准偏差为1.9%~2.7%,说明此法可用于分析实际样品。