Assessing development options in mining communities using stated preference techniques

In this paper, two key insights are generated about community development options using stated preference techniques. Surveys were conducted to identify how residents of a mining town in central Queensland, Australia, viewed options for the development of their township. First, residents were asked in a Choice Modelling experiment how worthwhile it would be to achieve some more attractive development options if it came at a cost to them. Second, residents were asked in a Choice Behaviour experiment how the different development options might influence their decision to stay or shift from the town in the future. The same development options were used in both experiments to facilitate comparisons between the two assessment forms.     

Phosphorus speciation in the sediment profile of Lake Erhai, southwestern China: Fractionation and 31P NMR

The distribution characteristics of phosphorus(P) forms in the sediment profile of Lake Erhai,in southwestern China has been investigated by sequential extraction and 31P nuclear magnetic resonance spectroscopy(NMR) of NaOH extracts to understand P dynamics and its potential contribution to lake eutrophication.Contents of P fractions varied in the order of NH4Cl extracted P(NH4ClP) < bicarbonate-dithionite extracted P(BD-P) < HCl-P,Residual-P < NaOH extracted P(NaOH-P).The highly available NH4Cl-P represented less than 1% of total P(TP).BD-P and NaOH extracted reactive P(NaOH-rP) averaged 39%,while the ratio of Fe/P was higher than 15,indicating low P release from the sediments under permanent oxic condition.The less bio-available HCl-P,NaOH extracted nonreactive P(NaOH-nrP) and residual-P contributed 61% of TP.Regression analysis revealed that BD-P,NaOH-rP and HCl-P were positively correlated with the contents of Fe and Mn,Al and Fe,and Ca,respectively.The investigation of P compound groups in NaOH extracts by 31 P NMR showed that ortho-P and monoester-P were the largest two constituents of the P pool,followed by diester-P,phosphonate and pyro-P.A comparison of vertical variations of P groups in the sediment profile suggested that these compounds were involved in the P recycling to different extents in Lake Erhai.In particular,the lake exhibits high potential for labile P release from the surface sediments,which should be taken into consideration even after the outsourced P runoff ceased.     

Photo-catalytic decolourisation of toxic dye with N-doped titania: A case study with Acid Blue 25

Dyes are one of the hazardous water pollutants.Toxic Acid Blue 25,an anthraquinonic dye,has been decolourised by photo-catalysing it with nitrogen doped titania in aqueous medium.The photo catalyst was prepared from 15% TiCl 3 and 25% aqueous NH 3 solution as precursor.XRD and TEM revealed the formation of well crystalline anatase phase having particle size in the nano-range.BET surface area of the sample was higher than that of pure anatase TiO 2.DRS showed higher absorption of radiation in visible range compared to pure anatase TiO 2.XPS revealed the presence of nitrogen in N-Ti-O environment.The experimental parameters,namely,photocatalyst dose,initial dye concentration as well as solution pH influence the decolourisation process.At pH 3.0,the N-TiO 2 could decolourise almost 100% Acid Blue 25 within one hour.The influence of N-TiO 2 dose,initial concentration of Acid Blue 25 and solution pH on adsorption-desorption equilibrium is also studied.The adsorption process follows Lagergren first order kinetics while the modified Langmuir-Hinselwood model is suitably fitted for photocatalytic decolourisation of Acid Blue 25.     

天然有机物对混凝效果影响机制及絮体特性分析

混凝是降低水体中天然有机物浓度的有效手段.本研究旨在了解天然有机物的存在对混凝效果及絮体特性产生的影响.实验以PACl25作为混凝剂来模拟含有一定量天然有机物的典型代表物质腐殖酸或柠檬酸配水的水处理混凝过程.分析了混凝过程中这两种有机物的存在对絮体颗粒大小、分形维数、Zeta电位和水中剩余铝浓度的影响.结果表明,在一定浓度范围内,随着溶液中腐殖酸、柠檬酸浓度的增加,絮体颗粒的大小及其成长速率、Zeta电位以及分形维数均呈现出下降的趋势(腐殖酸质量浓度从0 mg·L-1增加到10 mg·L-1、柠檬酸浓度从0μmol·L-1增加到7μmol·L-1,破碎前絮体大小分别降低34.2%、53.1%;絮体Zeta电位从10 mV左右分别下降到-10 mV及-2.5 mV左右;絮体成长速率分别下降了42.6%、77.5%;分形维数分别降低了0.08和0.094),表明有机物占据了微絮体表面从而导致絮体活性及致密性的降低;而在此有机物浓度范围内溶液中剩余铝的浓度却不因絮凝能力的下降而变化.     

基于酶化学计量法探究有机无机肥配施调控果园土壤微生物碳、磷代谢机制

土壤微生物的C、N、P养分需求和代谢限制与环境养分的有效性有着密切关系.然而,有机无机肥配施如何影响苹果园土壤微生物C、N、P代谢限制亟待进一步研究.因此,基于2008年建立的苹果园长期定位试验,应用土壤酶化学计量学理论与方法,系统研究有机无机肥配施对土壤C、N和P周转相关的酶活性（β-1,4-葡萄糖苷酶,BG;β-1,4-N-乙酰基氨基葡萄糖苷酶,NAG;L-亮氨酸氨基肽酶,LAP;碱性磷酸酶,PHOS）及其化学计量特征的影响,并分析其与环境因子和微生物碳利用率之间的关系.试验共设4个处理,分别为不施肥（CK）、单施氮磷钾化肥（NPK）、单施有机肥（M）和化肥配施有机肥（MNPK）.结果表明：①在果树各生育期,施用有机肥处理（MNPK和M）的微生物量碳（microC）含量显著高于不施有机肥处理（CK和NPK）;微生物量氮（microN）含量,在萌芽期NPK、MNPK和M处理比CK处理分别增加了89%、269%和213%（P<0.05）.②CK处理在萌芽期有较高的叶片ω（N）和ω（P）（29.8 g ·kg^-1和2.17 g ·kg^-1）,并且仅果树萌芽期的叶片P含量与土壤有效磷（AP）含量呈显著负相关.③土壤酶化学计量分析的所有数据点均在1 ：1线以上,表现为微生物群落存在较强的P限制;果树生长期,矢量长度和角度的变化范围分别为0.56~0.79和59.3°~67.7°,且研究中矢量角度均>45°,也体现了微生物存在较强的磷限制.④RDA和随机森林模型分析结果表明,有机碳和速效氮（AN）是影响矢量长度的主要理化因子,AP、AN和土壤含水量是影响矢量角度的主要理化因子;SEM分析表明,AN和可溶性有机碳（DOC）直接影响microC和microN,AP直接影响microP和microN,DOC和AP直接影响矢量长度,AP和microN直接影响矢量角度;微生物碳利用率与矢量长度呈显著正相关,与矢量角度呈显著负相关.综上所述,有机无机肥配施通过影响果树不同生育期土壤碳和磷含量,调控微生物碳、磷代谢进而影响微生物碳利用率,为有机无机肥配施提升土壤质量、维持土壤健康提供科学依据.     

Ni2P/Bi2MoO6复合材料的制备及可见光催化活性

分别制备了花状Bi₂MoO₆和片状Ni₂P,采用研磨、水热及超声的方式将两种材料复合,考察了负载方式、负载率和溶液pH值对其可见光下降解亚甲基蓝（MB）的影响;利用XRD、XPS、FTIR、SEM、PL和UV-Vis等测试手段表征了样品的微观结构、形貌和光学性质;研究表明Ni₂P作为助催化剂,可加速电子空穴对分离,显著提高Bi₂MoO₆的光催化活性,其中当Ni₂P负载率为4%时,TOC去除率为64.28%,降解速率为纯Bi₂MoO₆的2倍,且将Ni₂P/Bi₂MoO₆复合催化剂循环利用3次后,同实验条件下降解率为94%,证明复合催化剂稳定性好.     

基于Sentinel-5P卫星的中国NO2浓度遥感监测

NO₂是重要的痕量气体,对其监测有助于大气污染治理。本文基于Sentinel-5P大气污染监测卫星提供的对流层NO₂浓度数据和总NO₂浓度数据,借助谷歌地球引擎(google earth engine,GEE)分析了2018~2021年间中国大气NO₂浓度时空变化特征,使用OLS模型揭示了中国地区NO₂浓度的主要影响因子。结果表明:我国对流层NO₂浓度空间分布呈现东高西低的总体格局,东中部城市群对流层NO₂柱浓度水平明显呈现冬高夏低、春秋过渡的季节特征,西部大部分城市的四季变化不明显。北京、深圳、上海3所城市NO₂柱浓度分布呈现出较为显著的圈层结构。OLS模型结果表明,中国地区NO₂浓度变化受到社会经济和自然因素的共同影响,其中城市化程度是影响NO₂排放的重要因子。     

竹基N、P共掺杂活性炭的制备及其镧离子吸附性能

采用磷酸氢二铵为活化剂和N、P源，竹屑为碳源，通过一步热解法制备N、P共掺杂活性炭，并将其用于高效去除水溶液中的La³⁺.分析了活化温度和pH值对La³⁺吸附性能的影响，并通过TG-IR、SEM-EDX、孔隙结构、XPS以及亲水性等探究其活化和吸附机制.结果表明，磷酸氢二铵在高温下容易分解产生氨气和磷酸，对物料起到活化作用，促进活性炭比表面积和孔隙容积的提高；作为N、P源，磷酸氢二铵的添加成功实现了活性炭的N、P共掺杂，而含N、P官能团的引入是提升La³⁺吸附量的关键.其中，石墨氮可以提供La³⁺—π键间的相互作用，C—P＝O和C/P—O—P可通过络合作用和静电作用为吸附La³⁺提供活性位点.La³⁺在N、P共掺杂活性炭上的吸附是吸热和自发的，吸附过程符合Langmuir等温式和二级动力学模型.在活化温度为900℃，pH=6的工艺条件下，N、P共掺杂活性炭的吸附量高达55.18 mg·g^-1，比未掺杂样品高2.53倍，并且其在La³⁺/Na⁺和La³⁺/Ca²⁺共存体系中对La³⁺的吸附选择性分别达到93.49%和82.49%，经过5次连续的吸附-解吸循环实验去除效率仍高于54%.     

Input–output analysis in an oil-rich economy: The case of Azerbaijan

This paper aims to provide empirical research to identify the linkages between final demand–total output, final demand–total supply, value-added ratios and prices, and also to analyze total factor productivity growth using input–output framework for 25 sectors. Studying the input–output tables for 2001 and 2006, the research estimates impact and response multipliers of non-oil sectors, as well as non-oil trading sectors. The results are important from the view of development of non-oil trading sectors and diversification of the economy in order to avoid the “resource curse”.     

Assessing the P fractionation in a tropical river-estuarine system of South India

Seasonal variations in dissolved and particulate P forms were assessed in the estuarine system of Chalakudy River, Kerala, South India – a tropical river having substantial relics of riparian vegetation. The contribution of the reactive P form extended to 84–96% compared with the residual fraction. Geographical and human activities have had effects on the phosphorus-loading capacity at various locations, which reveal pronounced variability in P distribution. Not all forms of phosphate in suspended particulate matter are likely to be released, and thus the nature of the P forms within the stock is a sensitive factor that can be utilised. Ca-bound P in suspensates increases to a highly significant level in the estuarine area, whereas Fe/Al-bound P predominates at the riverine and catchment areas during both the monsoon and non-monsoon seasons. Thus, calcium compounds determine the availability of P in the alkaline estuarine environment, whereas in the riverine environment, Al and Fe control P solubility. The comparatively low P load in upstream waters indicates that, under ambient situations, vegetative riparian zones can be very important P filters.