Electrochemical behavior of tantalum in ethylene carbonate and aluminum chloride solvate ionic liquid

To investigate the electrochemical reduction mechanism of Ta(V) in ethylene carbonate and aluminum chloride (EC−AlCl₃) solvate ionic liquid, cyclic voltammetry experiments were conducted on a tungsten working electrode. Four reduction peaks were observed in the cyclic voltammogram of the EC−AlCl₃−TaCl₅ ionic liquid. The reduction peaks at −0.55, −0.72, and −1.12 V (vs Al) were related to the reduction of Ta(V) to tantalum metal by three stages including the formation of Ta(IV) and Ta(III) complex ions. The reduction of Ta(III) to tantalum metal was an irreversible diffusion-controlled reaction with a diffusion coefficient of 3.7×10⁻⁷ cm²/s at 323 K, and the diffusion activation energy was 77 kJ/mol. Moreover, the cathode products at 323 K were characterized by scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. The results showed that tantalum metal and tantalum oxides were obtained by potentiostatic electrodeposition at −0.8 V for 2 h.     

Concentration and separation of vanadium from alkaline media by strong alkaline anion-exchange resin 717

With strong alkaline anion-exchange resin 717 as the sorbent and NaOH solution as the eluent, a study on the sorption from alkaline solution and elution of vanadium(V), silicon(IV), and aluminium(III) was carried out. Different parameters affecting the sorption and elution process, including temperature, pH values as well as the ratio of resin to solution, were investigated. The results show that sorption degree of vanadium(V) increases with a decrease of pH values, and V(V) ions are easier sorbed than Si(IV) and Al(III) ions under the same conditions. The sorption degree of V(V), Si(IV), and Al(III) at pH 9.14 for 15 min are 90.6%, 33.5%, and 21.6%, respectively. Si(IV), Al(III), and V(V) ions sorbed on 717 resin were eluted by use of 2 mol·L⁻¹ NaOH solution; the desorption degree of V(V), Si(IV), and Al(III) for 5 min are 81.7%, 99.1%, and 99.3%, respectively.     

从含Cu,Ni,Fe和Zn离子的Sarcheshmeh铜矿合成及工业溶液中萃取和反萃Cu和Ni（英文）

以D2EHPA、LIX 984、Cyanex 302、Chemorex CP 150和Acorga 5774为萃取剂,煤油为稀释剂,对取自Sarcheshmeh铜矿含Cu(770mg/L)、Ni(3200mg/L)、Fe(800mg/L)和Zn(200mg/L)的合成及工业溶液中Cu和Ni的萃取与反萃进行全面研究。萃取阶段考虑的影响因素有混合速度和时间、萃取剂浓度、p H和温度。此外,采用不同浓度的各种无机和有机酸(硫酸、盐酸、硝酸和柠檬酸)对Cu和Ni进行反萃。结果表明,在时间为3 min、混合速度为500 r/min、温度为28℃以及A/O比为1:1的条件下,Cu和Ni的萃取率最高。此外,用10%(v/v) LIX984可有效萃取Cu,而用30%(v/v) Cyanex 302可有效萃取Ni。萃取Cu和Ni的最佳p H分别为2～3和4～5。从含Ni、Cu、Zn和Fe离子的合成及工业溶液中可选择性萃取Cu和Ni,其萃取率分别为85%、93%和77%、82%。最佳条件实验结果表明,合成及工业溶液中Ni的反萃率达96%,Cu的反萃率为93%。最后,分别用D2EHPA、LIX 984和Cy...     

麻黄碱联合丙泊酚抑制芬太尼咳嗽反射的临床研究

目的 研究麻黄碱联合丙泊酚对芬太尼咳嗽反射(fentanyl-induced cough,FIC)的抑制作用。方法 选择320例择期手术接受全麻的患者,根据计算机随机数字表随机进入4组:Ⅰ组(对照组)静脉注射 2 mL 生理盐水;Ⅱ组(麻黄碱组)静脉注射 6 mg 麻黄碱;Ⅲ组(丙泊酚组)静脉注射 0.8 mg/kg 丙泊酚;Ⅳ组(丙泊酚联合麻黄碱组)静脉注射 0.8 mg/kg 丙泊酚加 6 mg 麻黄碱。给予治疗药物 2 min 后,经外周静脉快速注射 2 μg/kg 芬太尼。观察并记录患者的血压、心率、脉博血氧饱和度等生命体征, 并由一位医师按照盲法观察注射芬太尼后 1 min 内是否出现咳嗽,记录咳嗽发生的次数,并且根据咳嗽发生次数进行严重程度分级。结果 Ⅱ组、Ⅲ组和Ⅳ组患者的FIC发生率和严重程度均较Ⅰ组明显降低,而且Ⅳ组患者的血流动力学更加平稳。结论 麻醉诱导时联合应用麻黄碱和丙泊酚对FIC的抑制效果更好,患者血流动力学更加稳定,是临床上一个简单、有效的防治FIC的办法。     

吸附EDTA活性炭的电化学再生(英文)

采用吸附饱和EDTA的活性炭作为三维电极反应器中的粒子电极,多次使用后采用电化学方法对其再生。通过对吸附饱和EDTA的活性炭和多次电解使用后的活性炭的红外光谱谱图的分析得出,EDTA被活性炭吸附后产生甘氨酸H2NCH2COOH,通过N—H键生成一种永久性占据活性炭活性点的非催化活性缔合物,导致其催化活性消失,降解效率下降。采用电解方法使活性炭再生,得出活性炭的最佳活化条件为:电流100～300mA,溶液电导率1.39mS/cm,pH值6.0～8.0,电解1h可以使活性炭恢复活性,电解后有机物的残余TOC浓度低于10mg/L(初始浓度为200mg/L)。     

含Cu-EDTA络合配离子废水的铁碳微电解处理(英文)

为了破坏冶炼废水中重金属有机螯合物,例如Cu-EDTA配离子废水,研究一种破络并预处理的新方法。该方法基于铁碳微电解反应原理,.OH在酸性有氧气存在的条件下产生,并在铁碳表面攻击吸附的有机基团导致螯合物的破坏,从而使铜离子将从有机物中剥离下来,然而EDTA将被.OH降解。研究pH值、温度、微电解反应时间、Fe/C质量比对铜离子脱除率及总有机碳(TOC)残余含量的影响,通过扫描电子显微镜分析(SEM)、能谱分析(EDS)、红外光谱分析(FTIR)研究处理前、后样品的表面官能团变化及形貌推断铁碳微电解反应的机理。并进行工业条件优化,得到最佳工艺条件:pH值为2,温度为常温,Fe/C质量比≥0.02,时间为60min,有氧气存在。在该条件下TOC浓度为200mg/L、铜离子浓度为60mg/L的废水反应完成后TOC和Cu残余浓度分别减低到40.66和1.718mg/L;羟基自由基降解反应机理合理解释了该实验现象。     

Sorption of Hg2+, Nd3+, Dy3+, and Uo 22+ ions at polysiloxane xerogels functionalized with phosphonic acid derivatives

The sorption properties of silicas with mono- and bifunctional surface layers containing the complexing fragment ≡Si(CH₂)₃NHP(S)(OC₂H₅)₂ were studied. It was found that xerogels synthesized by the solgel method (like mesoporous silicas obtained by the template method) can extract mercury(II) ions from acidified solutions (SSC up to 450 mg/g). In a nonporous xerogel with a bifunctional surface layer (≡P=S/-SH), thiol groups proved to be primary sorption sites for Hg²⁺ ions; part of the ligand groups were inaccessible to metal ions. Xerogels containing the phosphonic acid residues ≡Si(CH₂)₂P(O)(OH)₂ sorbed uranyl and lanthanide ions from their nitrate solutions. The resulting surface complexes contained two (for the UO₂²⁺ ion) or three innersphere ligand groups (for the Nd³⁺ and Dy³⁺ ions). The maximum SSCs were 340 mg/g for the uranyl ion and 120 mg/g for the lanthanide ions. Original Russian Text ? O.A. Dudarko, V.P. Goncharik, V.Ya. Semenii, Yu.L. Zub, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 2, pp. 207–212.     

Adsorption of Arsenic on Activated Charcoal

This study explores the adsorption behavior of As(III) and As(V) on activated charcoal under the various conditions of solution pH and temperature. The adsorption loading of As(III) remains constant in the pH range from 0.16 to 3.5, while that of As(V) shows a maximum value at pH2.35 when the pH varies from 0.86 to 6.33. The isosteric heat of adsorption for As(III) varies from 4 to 0.75 Kcal/mole and that for As(V), from 4 to 2 Kcal/mole with varying surface loading. The magnitude of these values suggests that the adsorption of arsenic is by physisorption and due to weak forces such as Van der Waals forces. Activated charcoal adsorbs As(V) by 2.5% of its own weight while it absorbs As(III) by 1.2% of its own weight when the equilibrium concentration of each species is 22 × 10^?2 molar. Since arsenic has appreciable adsorbability on activated charcoal, this adsorbent may be a viable candidate to be used for removing arsenic from solution. Further studies to determine more information on the selectivity of arsenic over other valuable metal ions and the ones to determine the effects of other cations such as, ferric, calcium, and magnesium ions are suggested as a next step.     

Influence of metal ions on the structure of poorly crystallized iron oxide rusts

The poorly crystallized steel rusts have been prepared by hydrolysis of aqueous solutions dissolving Fe(III) and different metal ions such as Ti(IV), Cr(III), Ni(II) and Cu(II) at varied atomic ratios in metal/(Fe+metal). The precipitates formed by the hydrolysis were frozen with liquid N₂ to inhibit crystallization and particle growth. The rusts produced were poorly crystalline and nanosized particles with sizes of 4-10 nm and the rust formed without adding metal ions was assigned to ferrihydrite. The crystallite size decreased from 1.1 to 0.7 nm with increasing the added metal ions. It was shown by extended X-ray fine structure and Mössbauer spectroscopy that the short-range structure of poorly crystalline rusts was disturbed by adding Ti(IV).     

Cloud point extraction and flame atomic absorption spectrometry analysis of palladium, platinum, and gold ions from industrial polluted soil

Cloud point extraction (CPE) with Tergitol TMN-6 was applied for the extraction of trace amounts of palladium (Pd(Ⅱ)),platinum (Pt(Ⅳ)),and gold (Au(Ⅲ)) in the soil of industrial sewage.Ammonium pyrolysine dithiocarbamate (APDC) was adopted as the chelating agent prior to CPE and then was detected by atomic absorption spectrometry (AAS).Different parameters such as the concentration of surfactants,chelating agent and salt,sample pH,equilibration temperature and time,centrifugation time and rates,and the effect of foreign ions were studied.Under optimum conditions,the low limits of detections are 1.4,2.8 and 1.2 ng.ml-1 and the enrichment factors are 21,12,and 24 for Pd(Ⅱ),Pt(Ⅳ),and Au(Ⅲ),respectively.The relative standard deviations vary from 0.6％ to 1.0％ (n=11).All correlation coefficients of the calibration curves are ＞0.9960.The proposed method was successfully applied for the determination of Pd(Ⅱ),Pt(Ⅳ),and Au(Ⅲ) in the real soil of industrial sewage samples.     

Polarographic behavior of 1,4,7-triazacycloanane-N,N'''',N"-tris (meth-ylphonic acid) (NOTP)-Bi(Ⅲ) complex

The polargraphic behavior of Bi(III)-NOTP complex has been investigated in aqueous solution. It was found thatunder the conditions of pH 3.0 and of 0.02 mol/L NH4Cl, the Bi(III)-NOTP system gives a sensitive second order derivativewave at -0.340 V(vs SCE), which is proved to be an adsorptive complex wave. The composition of the complex isBi(III):NOTP. Furthermore, the peak current is linear to the concentration of Bi(III) in the range from 3.0×10-8 to 5.0×10-6mol/L. Artificial and practical samples have been detected with high sensitivity and receptivity.     

Recovery of gold(III) ions by a chitosancoated magnetic nano-adsorbent

The monodisperse chitosan-coated Fe₃O₄ nanoparticles with a mean diameter of 13.5 nm and 4.92 wt% chitosan were used as an anionic magnetic nano-adsorbent for the recovery of Au(III) ions from aqueous solutions. It was found that Au(III) ions could be fast and efficiently adsorbed, and the adsorption capacity increased with the decrease in pH due to the protonation of the amino groups of chitosan. The adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 59.52 mg/g (1210 mg/g based on the weight of chitosan) and a Langmuir adsorption equilibrium constant of 0.066 l/mg. From the studies on the adsorption kinetics and thermodynamics of Au(III) ions, it was found that the adsorption process obeyed the pseudo-second-order kinetic model. Furthermore, the time required to reach the equilibrium was significantly shorter than those using the micro-sized adsorbents due to the large available surface area.     

Adsorption properties of Ag（Ⅰ）, Au（Ⅲ）, Pd（Ⅱ） and Pt（Ⅳ） ions on commercial 717 anion-exchange resin

The adsorption properties of the four precious metal ions (Ag(I), Au(II), Pd(III) and Pt(IV)) on the commercial Cl^?-form 717 strongly basic anion-exchange resin were studied in detail. The effects of the contact time, solution acidity, and concentrations of Cl^? and Pb²⁺ ions on the adsorption properties were studied by the batch method. Then, the column method was conducted under the optimized adsorption conditions (pH=3.0). The effects of the sample loading flow rate and the length-to-diameter ratios of the columns were investigated. The precious metal ions adsorbed could not be eluted completely after the saturated adsorption because the precious metal ions were found to be reduced to their metallic states during the adsorption process. So, it is recommended that the commercial Cl^?-form 717 strongly basic anion-exchange resin should be decomposed directly to recovery the precious metals after the saturated adsorption.     

Influences of metal ions on the formation of γ-FeOOH and magnetite rusts

To elucidate the role of anti-corroding alloying metals in weathering steels, the γ-FeOOH and Fe₃O₄ particles were prepared by air-oxidation of FeSO₄ solutions containing different amount of Ti(IV), Cr(III), Cu(II) and Ni(II). The crystallinity and particle size of γ-FeOOH were lowered by adding Cr(III), Cu(II) and Ni(II) but not influenced by Ti(IV). All the metal ions impeded the crystallization and particle growth of Fe₃O₄ in a similar manner. The results on γ-FeOOH and Fe₃O₄ were compared with those on α- and β-FeOOHs previously reported to know the comprehensive effects of metal ions on the formation of rusts.     

多巯基磁性生物竹炭纳米复合材料的化学共沉积制备及其高效去除水溶液中的As(Ⅲ)（英文）

通过简单的化学共沉淀方法制备多基团磁性生物竹炭纳米复合材料(BBC@n Fe-SH)并用于废水中As(Ⅲ)的去除。研究表明,BBC@nFe-SH的磁场强度达到83376 A/m,具有极好的磁回收性。在pH 5.0、40℃的条件下BBC@n Fe-SH对As(Ⅲ)的最大吸附容量为98.63 mg/g,且在120 min内达到反应平衡。SEM、FTIR、VSM和XPS等分析表明,As(Ⅲ)的去除机制为BBC@nFe-SH表面的含氧基团与As(Ⅲ)的络合作用。在水处理过程中BBC@n Fe-SH表现出较好的稳定性和可回收性,可以通过1mol/LNa OH淋洗实现材料的再生活化。因此,BBC@n Fe-SH在含砷废水处理方面具有极大的应用潜力。     

复方861对大鼠肝星状细胞增殖及胶原合成的影响1

目的 观察中药复方861对体外培养肝星状细胞增殖及胶原合成的影响。方法 分离培养大鼠肝星状细胞, 传一代后加入不同浓度的复方861 作用48 小时, 以MT T 比色法检测对细胞增殖的作用。传一代细胞以10 mg/ml复方861作用48小时后, 以ELISA法、斑点杂交法检测胶原蛋白分泌及相应mRNA 水平的变化。结果 1.56~100 mg/ml 复方861(经0.45 μm 滤膜过滤)可使MTT转化率下降, 细胞增殖受抑, 呈明显的剂量依赖性;10 mg/ml 复方861 可使I 、III 、IV 型胶原及转化生长因子β1(TGFβ1)mRNA 水平及相应蛋白分泌量下降。结论 复方861 抗纤维化的部分机理在于抑制活化肝星状细胞的增殖及胶原蛋白的合成, 从而减少胶原纤维在肝脏内的沉积。     

铂、钯、钴合金中钴的选择性测定

建立了EDTA络合锌盐滴定选择性测定Co的方法,考察了不同类型的酸及酸浓度对EDTA络合Co(Ⅲ)及滴定终点的影响,研究了提高方法选择性的条件.结果表明:于0.1～1.0 mol/L HNO_3、0.1～1.0 mol/L HCl、0.024～0.24 mol/L H_2SO_4和0.001～0.078 mol/L HClO_4酸浓度内,EDTA-Co络合物稳定,且滴定终点敏锐;测定5.00～20.00 mg Co(Ⅲ),相对误差-0.20%～+0.24%,样品加标回收率99.40%～100.40%;采用联合掩蔽剂能消除30余种共存元素的影响;方法准确度高,选择性好,操作简便,适用性强,已用于Pt、Pd、Co合金中质量分数为5%～75%Co的测定,结果满意.     

泡沫塑料分离富集微量银的研究

研究了用聚氨酯泡沫塑料分离富集微量银的方法,对银与邻二氮菲的配合物的吸附选择性和富集效果较佳,在EDTA存在下,其它金属离子不被吸附,银可用1m0l/L HNO_3定量洗脱。     

Corrosion of uranium and its low content Zr, Nb, and Ru alloys in aqueous solutions

Corrosion of uranium and its alloys with low content (0.5–5.0 at %) of Zr, Nb, and Ru in water and bicarbonate aqueous solutions is studied; the effect of hydrogen peroxide, the main product of radiation processes, on the corrosion rate is elucidated. The rate of the primary corrosion process U +(2 +n)H₂O=UO₂·nH₂O+ 2H₂↑ is measured by electrochemical methods in anaerobic and aerobic conditions for uranium metal and its alloys containing 0.5 to 5.0 at % of Zr, Nb, and Ru. It is shown that the corrosion rates for the alloys are lower than that of reactor-grade uranium; however, the difference is rather close to the measurement error. The corrosion mechanism is studied; U(III) is shown to be rather unstable in neutral solutions when uranium(III) hydroxide is precipitated and no significant amount of U(III) and UH₃ is present among the products of the metallic uranium corrosion in water. The kinetics of the second corrosion stage U(IV) + O₂→U(VI) is studied by spectrophotometric method. It is shown that the reaction of U(IV) oxidation by atmospheric oxygen is similar in weakly acid solutions (pH 1.5–4.0) and in bicarbonate media: in particular, it has an induction period for uranium (IV) accumulation, after which the reaction accelerates; it is formally a first-order reaction with respect to uranium. The reaction mechanisms differ in the two media: in weakly acid solutions, after the appearance of U(VI), the reproportionation reaction proceeds; thus formed U(V) interacts with O₂ faster than U(IV). In the bicarbonate medium, the acceleration of the reaction is due to the formation of a [U(IV)ΣU(VI)] complex whose reactivity is higher than that of uranium (IV). In the absence of bicarbonate, of great importance is the formation of a copolymer of U(IV) and U(VI), which at pH≥4 prevents formation of U(V). It is shown that on the introduction of hydrogen peroxide to aqueous solutions, the metallic uranium surface becomes transpassive, which increases the rate of corrosion process by at least an order of magnitude,. The introducing of oxidants and platinum mesh lowers the hydrogen accumulation at 120–150°C and, hence, the hydrogen-explosion danger of the uranium-water-corrosion-products system. Methods of deposition of metal oxide (Tc, Ru, Mo, W) films onto uranium surfaces by immersing uranium metal into Tc(VII), Ru(VI), or Mo and W heteropoly compound solutions are studied. Original Russian Text ? V.F. Peretrukhin, A.G. Maslennikov, A.Yu. Tsivadze, C.H. Delegard, A.B. Yusov, V.P. Shilov, A.A. Bessonov, K.E. German, A.M. Fedoseev, L.P. Kazanskii, N.Yu. Budanova, A.V. Kareta, A.V. Gogolev, K.N. Gedgovd, G.S. Bulato, 2008, published in Zashchita Metallov, 2008, Vol. 44, No. 3, pp. 229–251.     

酮康唑对家兔体内茶碱血药浓度及药动学参数的影响

目的 观察酮康唑对茶碱血药浓度及药动学参数的影响。方法 采用荧光偏振免疫分析法测定氨茶碱单用及与酮康唑合用后家兔体内茶碱血清浓度, 并对两组药动学参数进行统计学处理。结果 酮康唑可使氨茶碱血药浓度明显降低;合并用药组Vd 为4.70±1.48 L, AUC 为51.94±25.51 mg/(L·h), 对照组Vd 为1.39±0.61 L, AUC 为75.74±11.29 mg/(L·h), 两组相比有显著差异(P<0.01 和P<0.05), 其余药动学参数无显著变化。结论 两药合用时应调整氨茶碱的给药量, 并注意监测其血药浓度。