大气活性气态汞采样和分析方法

改进了利用镀KCl扩散管采集大气活性气态汞分析方法。实验证明 :在 4 5 0℃条件下加热 10min被扩散管捕获的活性气态汞会被热解出。该法最低检出限为 3pg ,具有成本低、分析方法简单。

Cu(Ⅱ),Ni(Ⅱ),Co(Ⅱ),Mn(Ⅱ),Zn(Ⅱ)和Cd(Ⅱ)的乙基3-(2-氨硫化亚肼基)-2-(羟胺基)丁烯酸酯配合物:合成、表征和细胞毒性(英文)

合成了Cu（Ⅱ）,Ni（Ⅱ）,Co（Ⅱ）,Mn（Ⅱ）,Zn（Ⅱ）和Cd（Ⅱ）的乙基3-（2-氨硫化亚肼基）-2-（羟胺基）丁烯酸酯配合物（H2L）并用元素分析,DTA热分析,IR,UV-Vis,1H-NMR,质谱,顺磁共振以及磁矩,电导率测量等对合成的配合物进行表征.摩尔电导率测量结果证明合成的配合物为非电解质.光谱数据表明配体分别表现为一元的三齿配体,一元的二齿配体,中性的二齿配体,中性的三齿配体,一元的四齿配体或二元的四齿配体通过席夫碱的氮原子,氨基硫脲中的氮原子,肟中的氮原子和硫酮中的硫原子与金属离子键合生成围绕金属离子的四面体或平面正方形构型.固态Cu（Ⅱ）（2）,（3）,（4）和（5）的配合物顺磁共振谱表明其为轴向对称,但（10～15）的配合物却为各向异性.配体和配合物（2）,（3）,（10）,（13）,（16）和（19）由于它们对乳腺癌（MCF-7细胞系）和肝癌（HePG-2细胞系）的抑制作用而表现出潜在的抗癌活性.

Luminescence intensification of lanthanide complexes by silver nanoparticles incorporated in sol-gel matrix

We present how the luminescence of europium RR-2-P-oxides complexes can be increased by interaction of electronic levels of the complex with the radiation field of silver nanoparticles （NPs）. The procedure by which silver NPs are formed in a sol-gel polyurethane matrix precursor was elaborated. The formed Ag NPs were combined with Eu complex incorporated in ormocer matrix. The emission spectra of the complexes without silver NPs were compared with spectra of the same complexes with addition of silver NPs. As the result of the interaction of the electronic levels of lanthaaide ligands with silver plasmons, dramatic increase of luminescence was observed.

Electrical Properties of Li-doped P-type ZnO Ceramics

Li-doped p-type ZnO ceramics were prepared by conventional methods according to the chemical formula Zn1-xLixO2 where x=0.5, 1.0, 1.5 and 2.0 mole fraction, respectively. The crystal structures of the prepared samples were studied by X-ray diffraction analysis. The dielectric properties （including dielectric constant ε′ and dielectric loss ε″） and dc-electrical conductivity [σ（Ω^-1.cm^-1）] were investigated. The dielectric constant ε′ was sharply decreased at the low frequency range and independent on frequency at high frequency range. Otherwise, the dielectric loss ε″ varied with frequency and showed absorption peak located from 200 Hz to 4 kHz and moved to higher frequency as the concentration of Li＋ doped increased. It was found that dcelectrical conductivity logσ varied from -9 to -5 and the energy gap width were calculated by using Arrhenius equation. The p-type conductivity of Li-doped ZnO may be attributed to the formation of a Lizn-Lii donor complex, which is limited by reducing the amount of Lii.

以脉冲萃取柱利用三异辛胺从高浓度铀溶液中回收铀（英文）

利用三异辛胺(TOA)纯化Gattar小型试验工厂的高浓度铀溶液(洗脱液的铀浓度7 g·L-1),研究了脉冲萃取柱的性能。利用实验室级脉冲萃取柱进行了实验室规模的溶剂萃取实验和后续实验。结果表明,在室温、p H=1和有机相与水相的比例(VO/VA)约为1.8∶1时,加入二(2-乙基己基)磷酸(D2EHPA)使其与TOA的比例(VD2EHPA/VTOA)为2∶3,可使萃取克服Cl-的抑制效应,提高效率。将结论用于考察试验工厂级萃取柱的流体力学和传质性能,结果表明用脉冲萃取柱萃取铀可以达到97%的萃取效率,具有可行性。

A Thermochemical Study on Complex Nickel(Ⅱ) L-α-Histidine

The formation enthalpy of complex nickel(Ⅱ) histidine(His) in water was determined by means of microcalorimetry in the temperature range of 298 15-323 15 K. The standard enthalpy of the formation of Ni(His) 2+ 2(aq) was calculated. On the basis of the experimental and the calculated results, three thermodynamic parameters(the activation enthalpy, the activation entropy and the activation free energy), the rate constants, three kinetic parameters(the apparent activation energy, the pre exponential constant and the reaction order) of the formation reaction of the title complex were obtained.

Evaluation of Al and Some of Its Alloys as Anode Materials vs γ-MnO_2 as Cathode Material and Ore Produced γ-MnO_2 vs Zn Anode in KOH Solution

In this study electrochemical performance of Al and some of its alloys （Al-Zn, Al-rvlg and Al-rvln） anodes vs MnO2 cathode were carried out in alkaline solution. The results show that the Al-Zn alloy anode has the best cell capacity among the other alloys. Cell capacity values go in the order Al-Zn〉Al-Mg〉Al〉Al-Mn. This result is probably related to the nature of passive films formed on the surface of the alloys which examined by scanning electron microscopy （SEM）. SEM morphologies of Al and its alloys showed coarse grains of passive films formed on the surface of these anode materials while Al-Mn morphology shows a needle-like structure. Electrolytic manganese dioxide （EMD） produced by electrodepositing on platinum anode from liquor resulting from reduction of low grade pyrolusite ore （β-MnO2） by sulfur slag was characterized as cathode in alkaline Zn-MnO2 batteries. Ore produced sample （EMD1） was performed well in comparison with EMD standard （EMD2） （commercial battery grade electrolytic manganese dioxide, TOSOH-Hellas GH-S）. SEM morphology of Zn anode after cell reaction was carried out and showed that Zn anode has fine grains of passive film on its surface.

Synthesis and Formation Mechanisms of Calcium Ferrite Compounds

Calcium ferrite compounds were prepared using calcium nitrate and iron nitrate with different molar ratios, 1:1, 0.5:1, and 1:0.5, respectively. The reactions of formation were investigated at different temperatures following the differential thermal analysis (DTA) results. Calcium ferrite compounds are CaFeO3, Ca2FeO3.5, Ca2Fe2O5, CaFe2O4, CaFe4O7, Ca7.2Fe0.8Fe30O53, Ca3Fe15O25, Ca4Fe14O25, and Ca4Fe9O17. Other reactive species of calcium nitrate are still present after firing at 450℃. Compounds were characterized using X-ray diffraction (XRD), DTA, TG, magnetic susceptibility, infrared spectra and scanning electron microscope (SEM). It is concluded that the formation mechanism of Ca-ferrite compounds depends mainly on the valency of iron cations which in role depends on its molar ratio and the existing atmosphere.

Plasma synthesis of various polymorphs of tungsten trioxide nanoparticles using gliding electric discharge in humid air:characterization and photocatalytic properties

A gliding electric arc(glidarc)discharge generates a low-temperature plasma at atmospheric pressure.When the discharge occurs in humid air as the feed gas,the chemistry of a glidarc plasma consists of in situ formation of HO°and NO°as the primary chemical species.Tungsten trioxide(WO_(3))nanoparticles were successfully prepared by exposure of a liquid precursor to glidarc plasma.The WO_(3)samples were calcined at three different temperatures(300℃,500℃and 800℃),resulting in different pure polymorphs:γ-WO_(3)(at 300℃),β-WO_(3)(at 500℃)andα-WO_(3)(at 800℃)according to x-ray diffraction analysis.The identification of WO_(3)compounds was also confirmed by attenuated total reflection Fourier transform infrared spectroscopy analysis.Increase in the calcination temperature of WO_(3)induced a decrease in its specific surface area according to Brunauer–Emmett–Teller nitrogen physisorption analysis.The UV-visible results showed that the absorption bands of plasma-WO_(3)samples were more intense than those of WO_(3)samples obtained by a precipitation route,a classical method used for comparison.Consequently,this parameter can improve the photocatalytic properties of WO_(3)under visible light.The photodegradation(in sunlight conditions)of gentian violet,chosen as a model pollutant,confirmed the photocatalytic properties of plasma-WO_(3)samples.This novel synthesis method has great potential to improve the efficiency of advanced tungsten trioxide-based functional material preparation,as well as in pollution-reducing and energy-saving tungsten extractive metallurgy.

Synthesis, Characterization and X-Ray Structure of a Ba(II)/Ag(I)/Cr(III)-Oxalate Salt with Water-Filled Nanochannels

A novel mixed barium(II)/silver(I)/chromium(III) oxalate salt, Ba0.5Ag2[Cr(C2O4)3]·5H2O (1), with open architecture has been synthesized in water and characterized by elemental analysis, vibrational and electronic spectra, and single crystal X-ray structure determination. Compound 1 crystallizes in a monoclinic space group C2/c, with unit cell parameters a = 18.179(3), b = 14.743(2), c = 12.278(2)Å, β = 113.821(3), V = 3010.34(90) Å3, Z = 8. The structure is characterized by a network of anionic [Cr(C2O4)3]3- units connected through the O atoms of the oxalates to Ba2+ and Ag+ sites, forming a three-dimensional coordination polymer with one-dimensional isolated nanochannels parallel to the c axis, and encapsulating hydrogen-bonded guest water molecules. The bulk structure is consolidated by O–H···O bridgings within the nanochannels and by coulombic interactions.

Images of Azurin Protein Studied by AFM

Azurins, a wild type and a genetically mutant K27 altered one, were immobilized on annealed gold surface and investigated by means of atomic force microscopy. It was found that the surface coverage and height distribution of the adsorbed protein molecules are different from each other, which is possibly the result of the different orientation on the surface. It is believed that the wild type azurin is connected to gold surface by the disulphide bridge; while the mutant, K27C, might be through the thiol groups of the cysteine residues on their surface.

Developing an Efficient Technology for Key Intermediates Production Used in Enzymatic Synthesis of Cladribine and Nelarabine

The pilot-scale process for preparing 2-amino-6-chloro-9-（2＇,3＇,5＇-tri-O-acetyl-Dq3-ribofuranosyl）-purine and 2-chloroadenosine has been developed with a total yield of the desired compounds 73% and 44.5%, respectively. These compounds are useful intermediates for enzymatic synthesis of active pharmaceutical ingredients Nelarabine and Cladribine. The starting material--commercially avaliable guanosine--was acetylated with acetic anhydride, yielding 2,3,5-tri-O-acetylguanosine, which was further deoxyhalogenated with phosphorous oxychloride in presence of tetraethylammonia chloride. Diazotization of the resulting intermediate with tert-butylnitrite leads to the corresponding ribofuranosyl-substituted 2,6-dichloropurine, which was converted to 6-chloroadenosine by reaction with methanolic ammonia.

Polymeric Structure and Solid ^(31)P, ^(113)Cd NMR Spectra of Cadmium(II) Dialkyldithiophosphate (Alkyl = n-butyl and i-butyl)

Two polymeric complexes, [Cd(BTP)2]n 1 and [Cd(i-BTP)2]n 2, were prepared and investigated by solid 31P and 113Cd NMR spectroscopies. The crystal structure of 2 was determined by X-ray diffraction.

Anionic Nanochanneled Silver-Deficient Oxalatochromate(III) Complex with Hydroxonium as Counter Ion: Synthesis, Characterization and Crystal Structure

Reaction of Ba0.50[Ag2Cr(C2O4)3]·5H2O with Ag2SO4 in an aqueous solution of sulfuric acid (pH ≈ 3) yielded the silver(I)/chromium(III) oxalate salt H0.50[Ag2.50Cr(C2O4)3]·5H2O (1). Compound 1 can be best described as an anionic silver-deficient oxalatochromate(III) complex [Ag2.50Cr(C2O4)3]0.5- with nanochannels containing hydrogen-bonded water molecules and protons. Thermal analyses show significant weight losses corresponding to the elimination of water molecules of crystallization followed by the decomposition of the network.

The Debris Flow of 1^stAugust 2012 in Kakpenyi-Tinta (Akwaya Sub Division) Southwest Cameroon—I: Event Description, Causes and Impacts

Compared to large-scale infrequent disasters like volcanic eruptions, earthquakes, and gas explosions from volcanic (maar) lakes, most small-scale everyday disasters (e.g., landslides and floods) are not well reported and documented in Cameroon, despite the fact that cumulatively, they cause the most casualties and distress to the people affected. This paper documents a debris flow that occurred on the 1st of August 2012 in Kakpenyi, a quarter found in Tinta, one of the villages of Akwaya Sub Division in Manyu Division of the Southwest Region of Cameroon. The event started from the western slope (06°14.350'N & 09°31.475'E) of a hogback in the settlement, and mobilized ca 3.47 × 106 m3 of material over a ca 1 km distance. The material was made up of a chaotic mix of mud, rock fragments, boulders, twigs, tree logs, trunks, and roots. Its distal part dammed river Kakpenyi forming a 10 m deep lake which eventually safely emptied itself. No casualties were recorded but 20 people got injured and 21 people lost farmland. The debris flow was not caused by earthquake shaking. Instead, inappropriate land use acted as a remote cause to predispose the steep slope, while heavy rainfall triggered the flow. Verbal reports talk of a similar event 40 years ago in the area. This shows that Kakpenyi is vulnerable to this kind of hazard, requiring that major infrastructural development projects like roads and bridges in the area be preceded by detailed hazard and vulnerability assessments.

Experimental and Numerical Study of Mechanical Behaviour of Fired Clay Bricks after Exposure to High Temperatures

This paper reports the modeling of residual compressive strength of fired clay bricks submitted to elevated temperature. Five formulations were used and the explored temperatures were 95˚C, 200˚C, 550˚C, 700˚C and 950˚C. The stress–strain relationships and the mechanical properties (including Young’s modulus and compressive strength) were assessed using a uniaxial compressive strength machine. A proposed model equation was established and found satisfying. The elastic modulus was evaluated and tested with one existing model together with two proposed models. The proposed model was both satisfying and even more precise than the existing one. The overall results show that the effect of temperature on the mechanical properties of clays can be accurately described through the definition of thermal damage using elastic modulus.

Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) compositions

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers(electrons-holes pairs) are of paramount significance.In the current study, we report the photocatalytic characteristics of four compositions composed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harmful dyes(Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO_(2)confirm the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. Remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)samples exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on SEM images, incorporation of Cu^(2+)and La^(3+)ions influences the surface morphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm CR dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm CR dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm MB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in terms of higher charge carriers' separation(Cu^(2+)+ e-→ Cu^(+), La^(3+)+ e-→ La^(2+)), oxygen vacancies, full anatase phase structure as well as the wide range of visible light absorption.

Hydrochar and synthetic natural gas co-production for a full circular economy implementation via hydrothermal carbonization and methanation:An economic approach

Herein we study the economic performance of hydrochar and synthetic natural gas coproduction from olive tree pruning.The process entails a combination of hydrothermal carbonization and methanation.In a previous work,we evidenced that standalone hydrochar production via HTC results unprofitable.Hence,we propose a step forward on the process design by implementing a methanation,adding value to the gas effluent in an attempt to boost the overall process techno-economic aspects.Three different plant capacities were analyzed(312.5,625 and 1250 kg/hr).The baseline scenarios showed that,under the current circumstances,our circular economy strategy in unprofitable.An analysis of the revenues shows that hydrochar selling price have a high impact on NPV and subsidies for renewable coal production could help to boost the profitability of the process.On the contrary,the analysis for natural gas prices reveals that prices 8 times higher than the current ones in Spain must be achieved to reach profitability.This seems unlikely even under the presence of a strong subsidy scheme.The costs analysis suggests that a remarkable electricity cost reduction or electricity consumption of the HTC stage could be a potential strategy to reach profitability scenarios.Furthermore,significant reduction of green hydrogen production costs is deemed instrumental to improve the economic performance of the process.These results show the formidable techno-economic challenge that our society faces in the path towards circular economy societies.

Challenges and perspectives on high and intermediate-temperature sodium batteries

Energy storage systems are selected depending on factors such as storage capacity, available power, discharge time, self-discharge, efficiency, or durability. Additional parameters to be considered are safety, cost, feasibility, and environmental aspects. Sodium-based batteries （Na-S, NaNiC12） typically require operation temperatures of 300-350 ~C. The high operating temperatures substantially increase the operating costs and raise safety issues. This updated review describes the state-of-the-art materials for high-temperature sodium batteries and the trends towards the development and optimization of intermediate and low-temperature devices. Recent advances in inorganic solid electrolytes, glass-ceramic electrolytes, and polymer solid electrolytes are of immense importance in all-solid-state sodium batteries. Systems such as Na~ super ionic conductor （NASICON, Nal^xZr2PB-~SixOl2 （0 -〈 x _〈 3））, glass-ceramic 94Na3PS4＂6Na4SiS4, and polyethylene oxide （PEO）-sodium triflate （NaCF3SO3） are also discussed. Room temperature ionic liquids （RTILs） are also included as novel electrolyte solvents. This update discusses the progress of on-going strategies to enhance the conductivity, optimize the electrolyte/electrode interface, and improve the cell design of emerging technologies. This work aims to cover the recent advances in electrode and electrolyte materials for sodium- sulfur and sodium-metal-halide （zeolite battery research Africa project （ZEBRA）） batteries for use at high and intermediate temperatures.

Relationship between surface area and crystal size of pure and doped cerium oxides

Pure and Zr, La or Pr-doped cerium oxides were characterised by transmission electron microscopy (TEM), N2 adsorption-desorption at –196 oC and X-ray diffraction (XRD). For crystal sizes calculation, the Scherrer and Williamson-Hall equations were compared, and the relationship between surface area and crystal size was critically discussed. It was demonstrated that the Williamson-Hall equation must be used instead of the Scherrer equation to calculate crystal sizes, since the latter equation underestimated ...