Delimitation and Zoning of Natural Ecological Spatial Boundary Based on GIS

In order to improve the control of land use in China,taking Sunan Yugur Autonomous County in the Qilian Mountains area as an example,this paper explores the method of national ecological space delimitation and zoning based on ARCGIS platform. Three kinds of space division techniques are formed to unify natural resources survey data,carry out land spatial suitability evaluation,delimit three kinds of space and optimize natural ecological space division. According to existing laws in China,based on ecological protection red line,natural ecological space is divided into ecological protection red line and general ecological space. According to the regulation requirements and the functional division of various protected areas,the red line area of ecological protection is divided into core protected area,ecological restoration area,traditional utilization and recreation area with the area of 3 947. 28,3 216. 89 and 6 936. 56 km2,respectively. In view of the prominent problems in the process of delimitation and zoning of natural ecological space,some suggestions are put forward,such as unification of chassis,optimization of ecological protection red line and coordination and unification of management boundary.

水系合成δ相甲脒铅碘钙钛矿粉末

近年来,甲脒基钙钛矿太阳能电池的光电转换效率取得了显著进展,其商业化前景日益明朗.随着钙钛矿电池商业化的快速发展,对于环境友好、成本低廉的钙钛矿前驱体的需求不断增长.甲脒铅碘钙钛矿材料遇水易分解,因此传统钙钛矿粉末合成方法依赖于有机溶剂和惰性气氛手套箱,不具备成本优势.在此背景下,本文提出了一种经济高效的水系合成高纯度δ相甲脒铅碘(δ-FAPbI_(3))粉末的策略.在水溶液中加入过量氢碘酸,碘离子可使不溶性PbI_(2)转化为可溶性[PbI_(2)+n]n-络合物,将FAPbI_(3)的遇水分解转化为溶解,从而使水系合成成为可能.水系合成的甲脒铅碘粉末具有高纯度、低成本优势,可作为钙钛矿薄膜前驱体材料.与以PbI_(2)和FAI的混合物作为前驱体制备的钙钛矿薄膜相比,以水系合成的δ-FAPbI_(3)粉末为前驱体制备的钙钛矿薄膜具有良好的结晶性,降低了缺陷密度,并有效抑制了有害的离子输运和降解过程,从而增强了载流子传输性能和电池稳定性.在环境空气中以合成粉末为前驱体制备的钙钛矿太阳能电池,最高转化效率可达23.24%.

Research progress in ZnO single-crystal:growth, scientific understanding, and device applications

Zinc oxide,a wide band-gap semiconductor,has shown extensive potential applications in high-efficiency semiconductor photoelectronic devices,semiconductor photocatalysis,and diluted magnetic semiconductors.Due to the undisputed lattice integrity,ZnO single crystals are essential for the fabrication of high-quality ZnO-based photoelectronic devices,and also believed to be ideal research subjects for understanding the underlying mechanisms of semiconductor photocatalysis and diluted magnetic semiconductors.This review,which is organized in two main parts,introduces the recent progress in growth,basic characterization,and device development of ZnO single crystals,and some related works in our group.The first part begins from the growth of ZnO single crystal,and summarizes the fundamental and applied investigations based on ZnO single crystals.These works are composed of the fabrication of homoepitaxial ZnO-based photoelectronic devices,the research on the photocatalysis mechanism,and dilute magnetic mechanism.The second part describes the fabrication of highly thermostable n-type ZnO with high mobility and high electron concentration through intentional doping.More importantly,in this part,a conceptual approach for fabricating highly thermostable p-type ZnO materials with high mobility through an integrated three-step treatment is proposed on the basis of the preliminary research.

Highly efficient and selective removal of low-concentration antibiotics from aqueous solution by regenerable Mg（OH）2

The prevalent presence of fluoroquinolone antibiotics in aquatic environments has attracted considerable attention because of their harmful effects on humans and the ecological environment.Magnesium hydroxide nanocrystals were found to act as a simple and effective adsorbent to remove low-concentration ciprofloxacin(CIP)in aqueous solution.The as-prepared Mg(OH)2 nanocrystals exhibited excellent CIP adsorption performance and high selectivity toward CIP molecules compared with other antibiotics or aromatics,e.g.,norfloxacin(NOR)and eosin B(EB).The adsorbent showed pH-dependent adsorption,indicating that the adsorption process is probably dominated by an electrostatic interaction mechanism.In addition,structural analysis of the adsorbent indicated that coordination and hydrogen bonding between CIP and Mg(OH)2 nanocrystal might also be involved in the adsorption process.Moreover,the adsorbent could be easily recovered by pyrolysis and hydration without significant reduction of adsorption capacity.The superior adsorption behavior of Mg(OH)2 nanocrystal indicates that it may serve as a potential adsorbent material candidate for the selective removal of CIP from aquatic environments.

Assembly of SPS/MgSi assisted by dopamine with excellent removal performance for ciprofloxacin

In this work,magnesium silicate-based sulfonated polystyrene sphere composites(SPS/MgSi)were synthesized by one-step(SMD1)and two-step(SMD2)methods.For SMD1,MgSi particles were densely assembled on the surface of SPS,assisted by complexation between Fe^3+and hydroxyl phenol.For SMD2,SPS/SiO2 was firstly obtained by the same method as SMD1,and then SPS/SiO2 was transformed directly to SPS/MgSi under hydrothermal conditions.Therefore,MgSi obtained by the two-step method had an interwoven structure.Compared to SPS,MgSi and SMD1,SMD2 presented a larger specific surface area and more negative surface charges.Therefore,SMD2 showed superior adsorption performance toward CIP with concentrations of 5,10 and 50 mg/L,and for 50 mg/L,the equilibrium adsorption capacity could reach 329.7 mg/g.The adsorption process is fast and can be described by the pseudo-second-order kinetic model.The relationship between pH value and Zeta potential demonstrated that electrostatic interaction dominated the adsorption process.In addition,competitive adsorption showed that the effect of Na^+was negligible but the effect of Ca^2+was dependent on its concentration.Humid acid(HA)could slightly promote the absorption of CIP by SMD2.After five rounds of adsorption-desorption,the equilibrium adsorption capacity of SMD2 still remained at 288.6 mg/L for 50 mg/L CIP.Notably,SMD2 presented likewise superior adsorption capacity for CIP with concentrations of 10 and 50 mg/L in Minjiang source water.All the results indicated that this synthesis method is universal and that SMD2 has potential as an adsorbent for CIP removal from aquatic environments.

AudiWFlow:Confidential,collusion-resistant auditing of distributed workflows

We discuss the problem of accountability when multiple parties cooperate towards an end result,such as multiple companies in a supply chain or departments of a government service under different authorities.In cases where a fully trusted central point does not exist,it is difficult to obtain a trusted audit trail of a workflow when each individual participant is unaccountable to all others.We propose AudiWFlow,an auditing architecture that makes participants accountable for their contributions in a distributed workflow.Our scheme provides confidentiality in most cases,collusion detection,and availability of evidence after the workflow terminates.AudiWFlow is based on verifiable secret sharing and real-time peer-to-peer verification of records;it further supports multiple levels of assurance to meet a desired trade-off between the availability of evidence and the overhead resulting from the auditing approach.We propose and evaluate two implementation approaches for AudiWFlow.The first one is fully distributed except for a central auxiliary point that,nevertheless,needs only a low level of trust.The second one is based on smart contracts running on a public blockchain,which is able to remove the need for any central point but requires integration with a blockchain.