Superwetting Ag/α-Fe_(2)O_(3) anchored mesh with enhanced photocatalytic and antibacterial activities for efficient water purification

Superwetting materials have drawn unprecedented attention in the treatment of oily wastewater due to their preferable anti-fouling property and selective oil/water separation.However,it is still a challenge to fabricate multifunctional and environmentally friendly materials,which can be stably applied to purify the actual complicated wastewater.Here,a Ag/Ag/α-Fe_(2)O_(3) heterostructure anchored copper mesh was intentionally synthesized using a facile two-step hydrothermal method.The resultant mesh with superhydrophilicity and underwater superoleophobicity was capable of separating various oil/water mixtures with superior separation efficiency and high permeationflux driven by gravity.Benefiting from the joint effects of the smaller band gap of Ag/α-Fe_(2)O_(3) heterojunction,inherent antibacterial capacity of Ag/α-Fe_(2)O_(3) and Ag nanoparticles,favorable conductive substrate,as well as the hierarchical structure with superwettability,such mesh presented remarkably enhanced degradation capability toward organic dyes under visible light irradiation and antibacterial activity against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)compared with the pure Ag/α-Fe_(2)O_(3) coated mesh.Impressively,the mesh exhibited bifunctional water purification performance,in which organic dyes were eliminated simultaneously from water during oil/water separation in onefiltration process.More importantly,this mesh behaved exceptional chemical resistance,mechanical stability and long-term reusability.Therefore,this material with multifunctional integration may hold promising potential for steady water purification in practice.

Semi-enclosed experimental system for coal spontaneous combustion for determining regional distribution of high-temperature zone of coal fire

Temperature variation and gas generation at diferent depths and positions in the coal combustion process were studied to determine the propagation and evolution of high temperature regions in the process of coal spontaneous combustion.This study selected coal samples from Mengcun,Shaanxi Province,People’s Republic of China,and developed a semi-enclosed experimental system(furnace)for simulating coal combustion.The thermal mass loss of coal samples under various heating rates(5,10,and 15℃/min)was analyzed through thermogravimetric analysis,and the dynamic characteristics of the coal samples were analyzed;the reliability of the semi-enclosed experimental system was verifed through the equal proportional method of fuzzy response.The results reveal that the high-temperature zone is distributed nonlinearly from the middle to the front end of the furnace,and the temperatures of points in this zone decreased gradually as the layer depth increased.The apparent activation energy of the coal samples during combustion frst increased and then decreased as the conversion degree increased.Furthermore,the proportion of mass loss and the mass loss rate in the coal samples observed in the thermogravimetric experiment is consistent with that observed in the frst and second stages of the experiment conducted using the semi-enclosed system.The research fndings can provide a theoretical basis for the prevention and control of hightemperature zones in coal combustion.

Optimizing interfacial electronic coupling with metal oxide to activate inert polyaniline for superior electrocatalytic hydrogen generation

Tuning and optimization of electronic structures and related reaction energetics are critical toward the rational design of efficient electrocatalysts.Herein,experimental and theoretical calculation demonstrate the originally inert N site within polyaniline(PANI)can be activated for hydrogen evolution by proper d-πinterfacial electronic coupling with metal oxide.As a result,the assynthesized WO3 assemblies@PANI via a facile redox-induced assembly and in situ polymerization,exhibits the electrocatalytic production of hydrogen better than other control samples including W18O49@PANI and most of the reported nobel-metal-free electrocatalysts,with low overpotential of 74 mV at 10 mA·cm−2 and small Tafel slope of 46 mV·dec−1 in 0.5M H2SO4(comparable to commercial Pt/C).The general efficacy of this methodology is also validated by extension to other metal oxides such as MoO3 with similar improvements.

Apparent activation energy of mineral in open pit mine based upon the evolution of active functional groups

This study aimed to investigate the mechanism of mineral spontaneous combustion in an open pit. On the study of coal and mineral mixture in open pit mines, as well as through the specifc surface area and Search Engine Marketing (SEM) experiments, the specifc surface area and aperture characteristics of distribution of open pit coal sample and pit mineral mixture samples were analyzed. Thermal analysis experiments were used to divide the oxidation process was divided into three stages, and the thermal behavior characteristics of experimental samples were characterized. On the basis of the stage division, we explored the transfer law of the key active functional groups of the experimental samples. The apparent activation energy calculation of the key active groups, performed by combining the Achar diferential method with the Coats–Redfern integral method, microstructural and oxidation kinetic properties were revealed. The resulted showed that the mixed sample had high ash, the fxed carbon content was reduced, the specifc surface area was far lower than the raw coal, the large aperture distribution was slightly higher than the medium hole, the micropore was exceptionally low, the gas adsorption capacity was weaker than the raw coal, the pit coal sample had the exceedingly more active functional groups, easy to react with oxygen, more likely to occur naturally, and its harm was relatively large. The mixed sample contained the highest C–O–C functional group absorbance. The functional groups were mainly infuenced by the self-OH content, alkyl side chain, and fatty hydrocarbon in the sample. The main functional groups of the four-like mixture had the highest apparent activation energy, and the two reactions were higher in the low-temperature oxidation phase.

An Analysis of the Factors that Affect Collective Construction Land Transfer Price: A Case Study of Yichang City

The transfer of the rural collective construction land is increasingly accelerating,and the factors affecting transfer price are manifold. In this paper,the research area is Yichang,and we establish hedonic price model to explore and analyze the factors which affect the collective construction land transfer price. The simulation results show that in geographical factors,the higher degree of prosperity,road accessibility and soundness of infrastructure will result in higher collective construction land transfer price; in economic factors,the higher farmers' per capita net income and added value of the village's tertiary industry will lead to higher collective construction land transfer price; in ownership factors,the integrity of usufruct,disposition and possession has increasingly significant impact on collective construction land transfer price. In the process of establishing rural collective construction land circulation market,the government should gradually improve conditions of collective construction land; strengthen the construction of the rural economy,improve the economic attribute of the collective construction land; establish and improve China's rural collective construction land-related laws and regulations,make the rural collective construction land use rights clear,and give the whole rights of occupation,use,earning and disposition.

基于奇异谱分析方法的孤独症儿童脑电信号特征提取及分类

孤独症谱系障碍是一种复杂的神经发育障碍,其早期发现和精确诊断非常重要.脑电图由于其具有较高的时间分辨率,是一种常用的神经成像技术.本文提出奇异谱分析方法对脑电信号进行伪迹去除和节律提取,通过从正常儿童和孤独症儿童脑电信号中提取统一α节律AFu,求其能量并使用支持向量机方法进行分类比较结果;进一步,使用加权重心点探究个体化α峰值频率PFA及节律AFi,使用SSA方法提取AFi后重复上述进行分类比较.结果显示,未经SSA处理的脑电数据提取AFu相对能量作为特征,分类准确度为81.36%,而使用SSA预处理后,分类准确度提升至89.83%,验证了SSA方法伪迹去除的有效性;使用个体化α节律AFi相对能量作为特征,SVM分类准确率降低至81.36%,而将个体化α节律AFi相对能量和α峰值频率PAF作为共同特征可得到94.92%的分类准确率.此结果揭示孤独症儿童脑电节律异常体现为两个方面:频段分布和功率调制,即孤独症儿童α节律出现了低频偏移及相对能量的降低.本研究从方法验证及病理揭示的角度为孤独症儿童的辅助诊断提供了有力的技术手段和科学依据.

Monitoring casein kinase Ⅱ at subcellular level via bio-bar-code-based electrochemiluminescence biosensing method

A highly sensitive electrochemiluminescence(ECL) biosensing method was developed for monitoring casein kinase Ⅱ(CK2) at subcellular level via bio-bar-code assay.A bio-bar-code probe(h-DNA/AuNPs/pDNA) prepared by conjugating phosphorylated DNA(p-DNA) and hairpin DNA(h-DNA) onto gold nanoparticles(AuNPs) was used as a carrier for ECL signal reagent(Ru(phen)32+) while a specific peptide was used as a recognition substance.A gold ultramicroelectrode with a diameter of 400 nm was fabricated and then modified with the specific peptide via self-assembly technique to obtain peptide modified gold ultramicroelectrode.The peptide on gold ultramicroelectrode was phosphorylated in the presence of CK2 and adenosine 5’-triphosphate,and then the phosphorylated peptide was integrated with the h-DNA/AuNPs/p-DNA through a process mediated by zirconium cations(Zr4+),and finally Ru(phen)32+ was intercalated into h-DNA.A "signal on" ECL method was developed for the detection of CK2 in the range of 0.005-0.2 U/mL with a detection limit of 0.001 U/mL.Additionally,combined efficient subcellular phosphorylation in vivo with bio-bar-code-based ECL biosensing method,the ECL method was further applied to monitor CK2 at subcellular level without tedious subcellular fractionation.It was found that the concentration of CK2 by inserting the peptide modified gold ultramicroelectrode into the nucleus was higher than that into cytoplasm of HeLa cells.A distinct heterogeneity among CK2 concentrations in single cells was observed for cellular heterogeneity assessment.

Versatile Inorganic Oligomer-based Photochromic Spiropyrane Gels

Here we report an example of a general strategy for the immobilization of various different photochromic spiropyran molecules on eco-friendly cheap nanomatrix.The spiropyrans are encapsulated in calcium salt oligomers-based gels by centrifugation,forming an inorganic oligomer-based gelatinous photoswitchable hybrid material.Ca^(2+)is also used to regulate the optical properties of spiropyrans through chelation.The oligomer-based gel can not only provide the space required for photoisomerization,but also reduce the interference of the surrounding environment on the photochromic properties.Moreover,a practical paper-based and colloidal flexible substrate platform is constructed for the removal and naked-eye detection of liquid and gaseous hydrazine at room temperature based on the reactivity of the formyl group on spiro-pyrans loaded in Ca3(PO4)2 oligomers.This general strategy can be used for other inorganic oligomer-based molecular switches and sensing systems.

Highly selective electrochemical method for the detection of serotonin at carbon fiber microelectrode modified with gold nanoflowers and overoxidized polypyrrole

A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber microelectrode (CFME). Carbon fiber was firstly modified with gold nanoflowers using electroless deposition method, and then modified with overoxidized polypyrrole using electrochemical polymerization and overoxidization to obtain OPPy/Au NFs/CFME. The obtained OPPy/Au NFs/CFME was characterized by field emission scanning electron microscopy and electrochemical techniques. It was found that the OPPy/Au NFs/CFME showed good sensitivity for the detection of 5-HT in the range of 10 nmol/L-7.0μmol/L with detection limit of 2.3 nmol/L, and negligible interferences from ascorbic acid, 5-hydroxyindole acetic acid and uric acid. The OPPy/Au NFs/CFME was successfully applied to the detection of 5-HT in human serum samples with good recovery. The work demonstrates that the electrochemical method, incorporating signal amplification of Au NFs with higher cation selection of OPPy, provides a promising tool for the detection of 5-HT in biological systems.