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排序方式: 共有475条查询结果,搜索用时 31 毫秒
61.
M. Gavelle G. Sarrabayrouse E. Scheid S. Siskos M. Fragopoulou M. Zamani 《Radiation Physics and Chemistry》2011,80(12):1437-1440
A MOSFET-based low-energy neutron dosimeter has been fabricated using a 10B loaded gate electrode as (n,α) converter. The response to thermal neutrons has been studied. 相似文献
62.
Erbium(Ⅲ) PVC membrane sensor based on N-(benzyloxycarbonyloxy)succinimide as a new neutral ionophore 总被引:1,自引:1,他引:0
Hassan Ali Zamani 《中国化学快报》2011,22(3):346-349
In this study,a new Er3+ sensor based on N-(benzyloxycarbonyloxy)succinimide(BCS) as a neutral carrier has been constructed. The sensor exhibits potential linear response with a Nernstian slope of 20.5±0.4 mV/decade in the concentration range of 1.0×10-6to 1.0×10-2mol/L of Er3+.It has a very short response time(<10 s),detection limit of 6.3×10-7 mol/L and a good selectivity relative to a wide variety of other metal ions including common alkali,alkaline earth,heavy,and transition metal ions.It can be used in the pH range of 2.5-10.6 without any considerable divergence in potentials.The proposed sensor was successfully applied for the recovery of Er3+ ions spiked in tap and river water samples. 相似文献
63.
Hassan Ali Zamani Rahimi Fatemeh Naghavi‐Reyabbi Fatemeh Arvinfar Ali Imani Alihossien Reza Ganjali Mohammad Faridbod Farnoush Salavati‐Niasari Masoud 《中国化学》2011,29(7):1523-1528
A poly(vinyl chloride) (PVC) membrane sensor for holmium ions was fabricated based on N‐[(Z)‐1‐(2‐thienyl)‐ methylidene]‐N‐[4‐(4‐{[(Z)‐1‐(2‐thienyl)methylidene]amino} phenoxy)phenyl] amine (TPA) as a new ion carrier, acetophenon (AP) as plasticizing solvent mediator and sodium tetraphenyl borate (NaTPB) as an anion excluder. The electrode shows a good selectivity towards Ho3+ ions respect to other inorganic cations, including alkali, alkaline earth, transition and heavy metal ions. The constructed sensor displays a Nernstian behavior (19.5±0.3 mV/decade) over the concentration range of 1.0×10−6 to 1.0×10−2 mol·L−1 with the detection limit of the electrode being 4.6×10−7 mol·L−1 and very short response time (ca. 5 s). It has a useful working pH range of 3.2–9.8 for at least 8 weeks. The electrode was successfully applied as an indicator electrode for the potentiometric titration of a Ho3+ solution with EDTA and holmium determination in some alloys. The proposed sensor accuracy was studied by the determination of Ho3+ in mixtures of three different ions. 相似文献
64.
Hassan Ali Zamani 《中国化学快报》2011,22(6):701-704
N1,N2-Bis[1-(2-hydroxyphenyl)methylidene]ethanedihydrazide(MEH) was used as new compound which plays the role of an excellent ion carrier in the fabrication of a Ho(Ⅲ) membrane electrode.The electrode shows a good selectivity for Ho(Ⅲ) ion with respect to most common cations including alkali,alkaline earth,transition and heavy metal ions.This electrode has a wide linear dynamic range from 1.0×10-6 to 1.0×10-2 mol/L with a Nernstian slope of 19.8±0.3 mV per decade and a low detection limit of 5.8×10-7 mol/L in the pH range of 2.5-9.8,while the response time was rapid(<10 s).The suggested sensor was applied to the determination of Ho(Ⅲ) ions in tap water and river water samples. 相似文献
65.
This paper focus on the effect of nanosize (<50 nm BET) inorganic alumina (Al2O3) filler on the structural, conductivity, and thermal properties of chitosan‐based polymer electrolytes. Films of chitosan and its complexes were prepared using solution‐casting technique. Different amounts of Al2O3 viz., 3, 4.5, 6, 7.5, 9, 12, and 15 wt% were added to the highest room temperature conducting sample in the chitosan–salt system, i.e. sample containing 60 wt% chitosan–40 wt% NH4SCN. The conductivity value of the sample is 1.29 × 10?4 S cm?1. On addition of 6 wt% Al2O3 filler the ionic conductivity increased to 5.86 × 10?4 S cm?1. The amide and amino peaks in the spectrum of chitosan at 1636 and 1551 cm?1, respectively, shift to lower wavenumbers on addition of salt. The glass transition temperature Tg for the highest conducting composite is 190°C. The increase in Tg with increase in more than 6 wt% filler content is attributed to the increase in degree of crystallinity as proven from X‐ray diffraction studies. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
66.
Ghaedi M Amirabad SZ Marahel F Nasiri Kokhdan S Sahraei R Nosrati M Daneshfar A 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,83(1):46-51
In the first, Cadmium selenide Nanoparticle loaded on activated carbon (CdSe-NP-AC) has been synthesized and characterized by different techniques including XRD and SEM. Then, this new adsorbent successfully has been applied for the removal of muroxide (MO) from aqueous solution in batch studies, while the effect of various experimental parameters like initial pH (pH(0)), contact time, amount of (CdSe-NP-AC) and initial MO concentration (C(0)) on its removal percentage was examined by one at a time optimization method. It was found following optimization of variable, the adsorption of MO onto (CdSe-NP-AC) followed pseudo-second-order kinetics and show Tempkin and Langmuir models for interpretation of experimental data. It was observed that by increasing the temperature the removal percentage was improved and the positive change in entropy (ΔS°) and heat of adsorption (ΔH°) show the endothermic nature of process, while the high negative value in Gibbs free energy change (ΔG°) indicates the feasible nature of adsorption process. 相似文献
67.
Mohammad Reza Akhgar Mohammad Salari Hassan Zamani 《Journal of Solid State Electrochemistry》2011,15(4):845-853
The redox response of a modified carbon nanotube paste electrode of ferrocenedicarboxylic acid was investigated. Cyclic voltammetry,
differential pulse voltammetry, and chronoamperometry were used to investigate the electrochemical behavior of levodopa (LD)
at modified electrode. Under the optimized conditions (pH 5.0), the modified electrode showed high electrocatalytic activity
toward LD oxidation; the overpotential for the oxidation of LD was decreased by more than 190 mV, and the corresponding peak
current increased significantly. Differential pulse voltammetric peak currents of LD increased linearly with its concentrations
at the range of 0.04 to 1,100 μM, and the detection limit (3σ) was determined to be 12 nM. The diffusion coefficient ( D = 9.2 ×10 - 6cm2/s ) \left( {D = {9}.{2} \times {1}{0^{ - {6}}}{\hbox{c}}{{\hbox{m}}^2}/{\hbox{s}}} \right) and transfer coefficient (α = 0.49) of LD were also determined. Mixture of LD, NADH, and tryptophan (TRP) can be separated from one another by differential
pulse voltammetry. These conditions are sufficient to allow determination of LD, NADH, and TRP both individually and simultaneously.
The modified electrode showed good reproducibility, remarkable long-term stability, and especially good surface renewability
by simple mechanical polishing. The results showed that this electrode could be used as an electrochemical sensor for determination
of LD, NADH, and TRP in real samples such as urine and water samples. 相似文献
68.
Hanane El Hajaji Nadya Lachkar Katim Alaoui Yahya Cherrah Abdellah Farah Abdesslam Ennabili Brahim El Bali Mohammed Lachkar 《Arabian Journal of Chemistry》2011,4(3):321-324
We evaluated the in vitro antioxidant property and phytochemical constituents of the crude ethyl acetate and methanol extract of the three genders of carob tree barks (spontaneous male, spontaneous female, and grafted female). The scavenging activity on DPPH (1,1-diphenyl-2-picrylhydrazyl) was determined, as well as the phenolic contents (Folin–Ciocalteu method) of both the extracts. The highest antioxidant activity and the higher amounts of total phenols were shown in methanol crude bark extract for the three genders. Variety significantly affected the phenol content and the antioxidant activity, with the spontaneous male variety globally showed a higher polyphenol concentration and antioxidant activity than the grafted female and spontaneous female. 相似文献
69.
Hanif MA Al-Maskri AY Al-Mahruqi ZM Al-sabahi JN Al-Azkawi A Al-Maskari MY 《Natural product communications》2011,6(10):1451-1454
Three wild Omani plants, Moringa peregrina, Acacia nilotica and Rhazya stricta, were selected for the present study. Na, K and Ca contents were determined using flame photometric analysis. M. peregrina seeds (22.5 mg/g) and pods (27.7 mg/g) had higher Na contents than A. nilotica (0.33 mg/g) and R. stricta (0.30 mg/g), whereas the K and Ca contents of R. stricta were significantly higher than those of the other two plants. The protein content was lowest in R. stricta (9.8%) and highest in M peregrina seeds (21.0%). The highest total phenolic contents (TPC) were found in M. peregrina seeds (350.3 mg/g) and the lowest in A. nilotica (66.1 mg/g). The major component of M. peregrina seed oil was oleic acid (74.7%). Gas chromatographic-mass spectrometric analysis (GC-MS) revealed that octadecanal (30.9%) was the major compound in A. nilotica. The presence of various phenolics and flavonoids in M. peregrina, A. nilotica and R. stricta were confirmed by high performance liquid chromatography (HPLC). 相似文献
70.
Mohammadhassan Vasheghani Ehsan Marzbanrad Cyrus Zamani Mohamed Aminy Babak Raissi Toraj Ebadzadeh Hadi Barzegar-Bafrooei 《Heat and Mass Transfer》2011,47(11):1401-1405
Thermal conductivity of α-Al2O3 was measured using hot wire method. α-Al2O3 (20 nm in size) was synthesized by microwave method for which, the results were compared with commercially available γ-Al2O3. Thermal conductivity of nanofluids was investigated considering, it is dependency on Al2O3 phase. It was observed that by adding 3 wt% of nano γ-Al2O3 and α-Al2O3 to the engine oil, thermal conductivity increases by 37 and 31%, respectively. The corresponding viscosity increase for the
same amount of nano γ-Al2O3 and α-Al2O3 were 36 and 38%, respectively. It was concluded that the differences in thermal conductivity originate from higher specific
surface area of γ-Al2O3 compared to the α-Al2O3 which is the result of porosity difference, obtained during the synthesis process. 相似文献