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排序方式: 共有425条查询结果,搜索用时 15 毫秒
61.
An optimization study using response surface methods on the decolorization of Reactive Blue 19 from aqueous solution by ultrasound 总被引:1,自引:0,他引:1
The decolorization of reactive dye C.I. Reactive Blue 19 from aqueous solution was studied by using ultrasound, activated carbon and combined ultrasound/activated carbon. The combined effects of independent variables, such as ultrasound power, temperature, time, activated carbon concentration, dye concentration and initial pH were investigated on the decolorization by using the central composite design. The decolorization of RB 19 was modelled statistically and optimized by means of the Matlab computer software. The decolorization were accomplished at optimum conditions by using ultrasound, activated carbon and combined ultrasound/activated carbon as 36%, 91% and 99.9%, respectively. The application of ultrasonic irradiation was found to be beneficial for decolorization of RB 19 from aqueous solution by adsorption. 相似文献
62.
Ambujakshan KR Madhavan VS Varghese HT Panicker CY Temiz-Arpaci O Tekiner-Gulbas B Yildiz I 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,69(3):782-788
FT-IR spectra of 5-methyl-2-(p-methylaminophenyl)benzoxazole was recorded and analysed. The vibrational frequencies of the compound have been computed using the Hartree-Fock/6-31G* basis and compared with the experimental values. 相似文献
63.
In this article, convergence theorems are established for a new hybrid iteration for a finite family of I-asymptotically nonexpansive mappings. Our results extend, generalize, and unify various known results in the existing literature. 相似文献
64.
On-chip generation of microbubbles as a practical technology for manufacturing contrast agents for ultrasonic imaging 总被引:2,自引:0,他引:2
This paper presents a new manufacturing method to generate monodisperse microbubble contrast agents with polydispersity index (sigma) values of <2% through microfluidic flow-focusing. Micron-sized lipid shell-based perfluorocarbon (PFC) gas microbubbles for use as ultrasound contrast agents were produced using this method. The poly(dimethylsiloxane) (PDMS)-based devices feature expanding nozzle geometry with a 7 microm orifice width, and are robust enough for consistent production of microbubbles with runtimes lasting several hours. With high-speed imaging, we characterized relationships between channel geometry, liquid flow rate Q, and gas pressure P in controlling bubble sizes. By a simple optimization of the channel geometry and Q and P, bubbles with a mean diameter of <5 microm can be obtained, ideal for various ultrasonic imaging applications. This method demonstrates the potential of microfluidics as an efficient means for custom-designing ultrasound contrast agents with precise size distributions, different gas compositions and new shell materials for stabilization, and for future targeted imaging and therapeutic applications. 相似文献
65.
ÜMIT ÇAKIR Y. Kemal Yildiz Mahir Alkan 《Journal of inclusion phenomena and macrocyclic chemistry》1999,34(2):155-167
Liquid-liquid extractive-spectrophotometric studies of sodium ion complexes of 18-crown-6(18C6), dibenzo-18-crown-6(DB18C6), 15-crown-5(15C5), and 12-crown-4(12C4) and anionic dyes [4-(2-pyridylazo)-resorcinol monosodium salt monohydrate (PAR), Eriochrom Black T (EBT), and methyl orange (MOR)] and sodium picrate (PICRAT) as the counter ion are described. The overall extraction equilibrium constants for the 1 : 1 complexes of the above crown ethers with sodium dyes between different organic solvents and water have been determined at 25deg;C. They were conducted in various solvent-water systems maintaining an identical initial cation concentration in water, [M0+]w, and macrocyclic ligand concentration in the organic phase, [L0]org}, so that in all extractions [M0+]w : [L0]org ratios were 1 : 1, 1 : 10, 1 : 20, 1 : 50, and 1 : 62.5. An ion association complex formed between the sodium-crown ether complex ion and a dye anion was extracted into the organic solvent, and then the dye concentration of the separated aqueous phase was measured with an ultraviolet-visible spectrophotometer. PAR was the best associated dye with all crown ethers sodium-dyes and the extracted dye occurs as the ion-pair complex. Methylene chloride was found to be better than other extractive solvents used in this study. 相似文献
66.
67.
Adem Kili Saliha Bege Bekir etinkaya Tuncer Hkelek Zeynel Kili Necla Gündüz Mustafa Yildiz 《Heteroatom Chemistry》1996,7(4):249-256
Reactions of hexachlorocyclotriphosphazatriene, N3P3Cl6 1 , with sodium aryloxides have been studied. Compound 1 was found to react by the nucleophilic substitution pathway to yield monocyclophosphazenes [N3P3Cl6(OC6H2Bu13-2,4,6) 5 and N3P3Cl4(OC6H2Me-4-Bu12-2,6)2 6 ] and bi(cyclophosphazenes) ([Cl5N3P3-P3N3Cl4(OC6H3Bu12-2,6)] 7 and [N3P3(OC6H3Bu12-2,6)5]2 8 ). The unusual bi(cyclophosphazenes) 7 and 8 are the first examples of two cyclotriphosphazene rings linked by a P(SINGLE BOND)P bond [2.193 (2) Å], which have been obtained by reacting 1 with ArONa. The structures of compounds 5–8 are ascertained by elemental analyses, 1H-, 31P-13C-NMR, IR, and MS spectra. The molecular structure of monocyclic-phosphazene 5 was determined by X-ray diffraction techniques for further structural assignment. It crystallizes in the monoclinic space group P21/m with a = 6.144(2), b = 17.079(9), c = 13.181(9) Å, β = 92.79(7), and Z = 2, R = 0.074. Compound 5 is on a crystallographic mirror plane, and there is only a half molecule in the asymmetric unit. © 1996 John Wiley & Sons, Inc. 相似文献
68.
Halit Kantekin Gülsev Dilber Zekeriya B?y?kl?o?lu 《Journal of organometallic chemistry》2008,693(6):1038-1042
Tetranitrile monomer (3) was synthesized by nucleophilic aromatic substitution of 1,5,9,13-tetrathiacyclohexadecane-3,11-diol (1) onto 4-nitrophthalonitrile (2). The metal-free phthalocyanine polymer (4) was prepared by the reaction of a tetranitrile monomer with 4-({11-[3-cyano-4-(cyanomethyl)phenoxy]-1,5,9,13-tetrathiacyclohexadecan-3-yl}oxy)phthalonitrile in 2-(dimethylamino)ethanol. Ni(II), Co(II), Cu(I)-phthalocyanine polymers were prepared by the reaction of the tetranitrile compound with the chlorides of Ni(II), Co(II) and Cu(I) in DMAE. Zn(II)-phthalocyanine polymer was prepared by the reaction of the tetranitrile compound with the acetates of Zn(II) in DMAE. The new compounds were characterized by a combination of IR, 1H NMR, 13C NMR, UV-Vis, elemental analysis and MS spectral data. 相似文献
69.
Dilber Gülsev Nas Asiye Pişkin Mehmet Durmuş Mahmut 《Transition Metal Chemistry》2022,47(4-5):157-168
Transition Metal Chemistry - The syntheses of highly soluble asymmetrically substituted metal free and zinc phthalocyanine derivatives bearing three 4-(4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenoxy) and... 相似文献
70.
In the present work, 4-(4′-dodecyloxycarbonyl) phenoxy phthalonitrile was synthesized and then this phthalonitrile derivative was cyclotetramerized in dodecanol resulting a new metal-free phthalocyanine. The optical properties of this phthalocyanine were investigated. Novel metal-free phthalocyanine thin films were deposited on indium tin oxide-coated glass substrates by spinning method. Surface and microstructural properties of the films were characterized by atomic force microscopy and scanning electron microscopy. Both the transmittance and reflectance spectra of the deposited films were recorded using an NKD analyser. The optical band gap energy, the thickness of thin films, refractive index (n) and extinction coefficient (k) were calculated as 2.7 eV, 300 nm, 1.47 and 0.02, respectively. 相似文献