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901.
基于柠檬酸-铕金属有机纳米配体聚合物(citrate/europium lanthanide coordination polymer nanoparticles,Cit/Eu LCP NPs)构建快速检测肉品汤煲中5’-肌苷酸(inosine-5’-monophosphate,5’-IMP)的荧光探针。研究结果表明,5’-IMP对Cit/Eu?LCP?NPs有良好的荧光猝灭作用。在最佳条件下,该荧光探针在5’-IMP?2.5~200?μg/mL的质量浓度范围内呈现出良好的线性关系,检出限为0.17?μg/mL,且具备良好的抗干扰、稳定性和重复性。为了验证方法可行性,将该方法应用于实际鸡汤样品中的5’-IMP检测,测得加标回收率为97.85%~103.95%,可为快速检测肉品汤煲中5’-IMP提供新的思路和方法。 相似文献
902.
903.
《中国稀土学报(英文版)》2023,41(7):1022-1030
In this work, V/Ce–Ti catalysts were modified with different kinds of transition metals (Cu, Fe, Co, Mn) by sol–gel and impregnation methods. The NH3 oxidation performance of them was tested to select the most active catalyst in NH3-selective catalytic oxidation (NH3–SCO). The effect of NO, SO2 and H2O was also investigated. The experimental results indicate that 1% Cu–V/Ce–Ti catalyst exhibits the most significant ability to remove slip ammonia discharged from coal-fired plants and its NH3 conversion efficiency reaches 90% at 300 °C. In addition, 97% NOx can be removed when NO is introduced in the gas. Cu–V/Ce–Ti catalyst also obtains good resistance to H2O and SO2. Based on the characterization experiment, the introduced Cu and V are highly dispersed on Ce–Ti catalyst and they can increase the redox properties and the number of acidic sites. Besides, the redox cycles among Cu, V and Ce species on Cu–V/Ce–Ti catalyst surface are conducive to generating more active oxygen and promoting the oxidation capacity of the catalyst. 相似文献
904.
Giacomo Maini Ajay K Sharman Christopher J Knowles Garry Sunderland Simon A Jackman 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2000,75(8):657-664
The electrokinetic remediation of an historically contaminated soil is described. The soil was contaminated with a range of metals including lead, zinc, manganese, copper and arsenic, polycyclic aromatic hydrocarbons (PAHs) and benzene, toluene, ethylbenzene and xylene (BTEX). A small‐scale experiment (973.2 g dry weight soil), utilising a planar electrode configuration, investigated the potential for moving metals and organics. After 23 days treatment at a current density of 3.72 A /m−2, 44% of calcium and 29% of manganese were removed from the soil at the cathode. Of the other contaminating metals, zinc and lead moved towards the cathode, but with no significant removal from the soil. Movement of PAHs was also observed, with a 94% reduction in concentration in the third of the soil closest to the anode after 23 days. A larger scale experiment (46.7 kg dry weight soil) utilised a hexagonal array of tubular anodes surrounding a central tubular cathode. Treatment for 112 days led to acidification of the soil to pH 2.59 closest to the anode in a direct line between the anode and cathode. Soil not directly in line between the electrodes was not acidified significantly. Movement of metal ions was observed, in line with the electrodes, with concentrations of lead and arsenic increasing to 162% and 171% of starting concentrations closest to the anode, respectively, and those of zinc, copper and manganese decreasing to 42%, 68% and 57%, respectively. At positions not directly in line with the electrodes, no significant metal movements were observed. Overall, there was no significant removal of contaminating metals from the soil. PAHs and BTEX compounds were moved by electroosmosis towards the cathode, with soil concentrations of PAHs reduced from 720 mgkg−1 to 4.7 mgkg−1 after 22 days. PAHS (28 mg) and benzene (9660 mg) were recovered in granular activated carbon (GAC) columns. © 2000 Society of Chemical Industry 相似文献
905.
906.
Miniplants offer enormous time and cost savings when developing an industrial process. Initial product samples and the performance of the whole process with all recycle streams is the result saving pilot scale experiments. The potential use of reactive processes in a miniplant environment is discussed on different extraction techniques (liquid‐liquid extraction, membrane extraction and solvent impregnated resins). 相似文献
907.
908.
Mitchell M. Johns Wayne E. Marshall Christopher A. Toles 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1998,71(2):131-140
Surplus, low value agricultural by-products can be made into granular activated carbons (GACs) which are used in environmental remediation. This study characterized and evaluated GACs, made from these feedstocks, as effective removers of organics and metals from water. The by-products included soft lignocellulosics such as rice straw, soybean hull, sugarcane bagasse, peanut shell, and harder materials such as pecan and walnut shells. The softer materials were combined with a binder, molasses, to produce briquettes and pellets. The precursors were CO2- or steam-activated, and subsequent treatments included oxidation to enhance metal adsorption. Many of the GACs had acceptable physical GAC attributes, such as durability, for commercial usage. GACs made from pecan and walnut shells adsorbed higher levels of benzene, toluene, methanol, acetonitrile, acetone, and 1,4-dioxane from an aqueous mixture than commercial GACs. Neither CO2 nor steam activation was particularly advantageous in enhancing metal adsorption. Oxidation using O2–N2 gas increased metal adsorption while (NH4)S2O8 solution did not. In a copper solution, oxidized GACs made from soybean hull had three to four times the Cu(II) adsorption capacity of metal-adsorbing, commercial GACs. Oxidized GACs made from soybean hull, sugarcane bagasse, peanut shell, and rice straw adsorbed from a mixture higher amounts of Pb(II), Cu(II), Ni(II), Cd(II) and Zn(II) than any commercial GACs. Commercial GACs adsorbed only Pb(II), Cu(II) and Cd(II). The GACs made from the agricultural by-products have considerable potential for adsorption of organics and metals of environmental concern. © 1998 SCI. 相似文献
909.
采用共沉淀法制备一系列Mg改性的γ-Al2O3载体,用等体积浸渍法制备10%(w)Ni基催化剂,研究助剂Mg对甲烷自热重整制氢反应的影响。结果表明:碱土金属Mg的添加提高了Ni基催化剂的活性和稳定性,在反应温度800℃,甲烷空速为4800h^-1,n(CH4)∶n(O2)∶n(H2O)=1.0∶0.5∶2.5,Ni/10%MgO-Al2O3催化剂的催化性能最好,CH4的转化率高达97.2%,H2收率达89.8%。XRD和TPR表征结果表明,Mg的添加抑制了催化剂中NiAl2O4尖晶石的形成,增强了NiO与载体之间的相互作用,提高了活性组分NiO的分散。 相似文献
910.
Karel Klíma Dan Ulmann Martin Barto Michal panko Jaroslava Dukov Radka Vrbov Jan Pinc Jií Kubsek Marek Vlk Tereza Ulmannov Ren Foltn Eitan Brizman Milan Draho Michal Beo Vladimír Macho Jaroslav apek 《International journal of molecular sciences》2021,22(24)
The increasing incidence of trauma in medicine brings with it new demands on the materials used for the surgical treatment of bone fractures. Titanium, its alloys, and steel are used worldwide in the treatment of skeletal injuries. These metallic materials, although inert, are often removed after the injured bone has healed. The second-stage procedure—the removal of the plates and screws—can overwhelm patients and overload healthcare systems. The development of suitable absorbable metallic materials would help us to overcome these issues. In this experimental study, we analyzed an extruded Zn-0.8Mg-0.2Sr (wt.%) alloy on a rabbit model. From this alloy we developed screws which were implanted into the rabbit tibia. After 120, 240, and 360 days, we tested the toxicity at the site of implantation and also within the vital organs: the liver, kidneys, and brain. The results were compared with a control group, implanted with a Ti-based screw and sacrificed after 360 days. The samples were analyzed using X-ray, micro-CT, and a scanning electron microscope. Chemical analysis revealed only small concentrations of zinc, strontium, and magnesium in the liver, kidneys, and brain. Histologically, the alloy was verified to possess very good biocompatibility after 360 days, without any signs of toxicity at the site of implantation. We did not observe raised levels of Sr, Zn, or Mg in any of the vital organs when compared with the Ti group at 360 days. The material was found to slowly degrade in vivo, forming solid corrosion products on its surface. 相似文献