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排序方式: 共有233条查询结果,搜索用时 21 毫秒
131.
Binnur Aydogan Yasemin Yuksel Durmaz Muhammet U. Kahveci Mustafa Uygun M. Atilla Tasdelen Yusuf Yagci 《Macromolecular Symposia》2011,308(1):25-34
Summary: New photoiniting systems for cationic polymerization acting at near UV and visible range are described. The applicability of acylgermanes as a new class of free radical promoters for photoinitiated cationic polymerization is demonstrated. Moreover, the use of substituted vinyl halides as source for readily oxidizable free radicals is presented. The polymerization of vinyl ethers can be initiated by the irradiation of substituted vinyl halides in the presence of Lewis acids such as zinc halide. Furthermore, possibilities for conducting cationic polymerization at visible range by using highly conjugated thiophene derivatives are demonstrated. Mechanistic aspects of all initiating systems are discussed. 相似文献
132.
Atilla Karaar Matthias Freytag Peter G. Jones Rainer Bartsch Reinhard Schmutzler 《无机化学与普通化学杂志》2002,628(3):533-544
The reaction of 1, 8‐dilithionaphthalene 2 , with 2 equivalents of rac‐Me(C6F5)PCl, gave a 6 : 1 mixture of rac‐ and meso‐1, 8‐di(methyl‐pentafluorophenylphosphino)naphthalene (dmfppn, rac‐ 3h and meso‐ 3h ), but no reaction was observed when the sterically crowded rac‐tBu(C6F5)PCl was used. In 31P NMR experiments, rac‐ 3h and mmeso‐ 3h exhibited characteristic signals (virtual quintets), which indicate that there is significant coupling through space (3JPF + 7 JPF ≈ 15 Hz). Compound rac‐ 3h was isolated by fractional crystallisation and treated with aqueous H2O2 to yield the corresponding bis‐phosphine dioxide, rac‐ 7h . In contrast to rac‐ 3h , there was no sign of through‐space coupling in rac‐ 7h , which again illustrates that the latter operates via the lone pairs at phosphorus. Platinum(II) complexes were prepared from the new, P‐chiral chelate rac‐ 3h , and the related ligand 1, 8‐di(tert‐butylphenylphosphino) naphthalene (rac‐dtbppn, rac‐ 3e ). All isolated new compounds were characterised by multinuclear NMR and IR spectroscopy, mass spectrometry, and elemental analysis. Single‐crystal X‐ray structure determinations were performed for rac‐dmfppn (rac‐ 3h ), rac‐[PtCl2(dtbppn)] (rac‐ 17e ), and rac‐[PtCl2(dmfppn)] (rac‐ 17h ). rac‐ 3h displays crystallographic twofold symmetry. In rac‐ 17h , the electron‐withdrawing effect of the C6F5 groups causes a shortening of the Pt—P bond to ca. 220 pm (cf. 223 pm in rac‐ 17e ). 相似文献
133.
Afsin Gungor Murat Ozbayoglu Cosku Kasnakoglu Atilla Biyikoglu Bekir Zuhtu Uysal 《Chemical Papers》2012,66(7):677-683
In this parametric study, the effects of coal and oxidiser type, air-to-fuel ratio, steam-to-fuel ratio, reactor temperature, and pressure on H2 and CO amounts at the gasifier output, H2/CO, and higher heating value of the syngas produced have been calculated using a coal gasification model. Model simulations have been performed to identify the optimum values which are assumed to be 100 % for both cold gas efficiency and carbon conversion efficiency in the gasification process. From this study, it may be observed that the moisture content of the coal type is of crucial importance for the air gasification process; the O2 content of similar coals (taking into consideration the moisture and H2 content) is of significant importance for the air gasification process. When compared with air gasification, air-steam gasification becomes a more effective coal gasification method. The optimum working condition for air-steam gasification is to carry out the process at one atmosphere. High gasifier temperatures are not needed for the air-steam gasification of coal. 相似文献
134.
Osmanoğlu S Aydın M Osmanoğlu YE Dicle IY Başkan MH 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,78(5):1611-1614
An EPR study has been carried out to investigate the structure and behaviour of the free radical formed γ-irradiated l-alaninamide hydrochloride, dl-glutamic acid monohydrate and N-(2-carboxyethyl) iminodiacetic acid powders at room temperature. The observed paramagnetic species have been attributed to the CH(3)?HCONH(2), HOOCCH(2)CH(2)?HCOOH and HOOCCH(2)CH(2)N?HCH(2)(COOH)(2) radicals, respectively. Some spectroscopic properties and suggestions concerning possible structure of the radicals were also discussed in this study. 相似文献
135.
A. Ayd?nB. Karasözen 《Journal of Computational and Applied Mathematics》2011,235(16):4770-4779
In this paper, we construct a second order semi-explicit multi-symplectic integrator for the strongly coupled nonlinear Schrödinger equation based on the two-stage Lobatto IIIA-IIIB partitioned Runge-Kutta method. Numerical results for different solitary wave solutions including elastic and inelastic collisions, fusion of two solitons and with periodic solutions confirm the excellent long time behavior of the multi-symplectic integrator by preserving global energy, momentum and mass. 相似文献
136.
Aydın Erbil Murat Çınarlı Murat Batı Hümeyra Çalışkan Nezihe Ataol Çiğdem Yüksektepe 《Crystallography Reports》2017,62(7):1122-1127
Crystallography Reports - A new hydrazone derivative was synthesized and characterized by IR, UV-Vis spectroscopy, elemental analysis and single-crystal X-ray diffraction. The compound was... 相似文献
137.
M. Abdur Rouf Imran Vural Erem Bilensoy Atilla Hincal Dilek Demir Erol 《Journal of inclusion phenomena and macrocyclic chemistry》2011,70(1-2):167-175
The objective of this study was to improve poor aqueous solubility and dissolution properties of anticancer drug rapamycin through formation of inclusion complexes with natural and modified cyclodextrins. Of the cyclodextrins tested, ??-cyclodextrin and hydroxypropyl-??-cyclodextrin did not complex with rapamycin. However, complexes of rapamycin with ??-cyclodextrin, methyl-??-cyclodextrin and hydroxypropyl-??-cyclodextrin were prepared and characterized by techniques such as Fourier Transform infrared spectroscopy, differential scanning calorimetry, phase solubility analysis and in vitro dissolution studies. According to the characterization data for the complexes, rapamycin water solubility was highly enhanced by all three ??-cyclodextrins with methyl-??-cyclodextrin complex resulting in particularly higher solubility enhancement. FTIR spectra and DSC thermograms supported the formation of inclusion complexes. The complexes showed highly improved dissolution rate in water. Complexation with cyclodextrin derivatives such as methyl-??-cyclodextrin and hydroxypropyl-??-cyclodextrin can provide promising alternatives for the formulation of rapamycin. 相似文献
138.
139.
Merve İçli‐Özkut Jetmire Mersini Ahmet M. Önal Atilla Cihaner 《Journal of polymer science. Part A, Polymer chemistry》2012,50(4):615-621
Electrochromic polymers called poly(3,4‐dihydro‐3,3‐bis ((naphthalen‐1‐yl)methyl)‐2H‐thieno[3,4‐b][1,4]dioxepine) (PProDOT‐Np2), poly(3,3‐dibenzyl‐3,4‐dihydro‐2H‐selenopheno[3,4‐b][1,4]dioxepine), and poly(3,3‐dibenzyl‐3,4‐dihydro‐2H‐thieno[3,4‐b][1,4]dioxepine) were synthesized electrochemically and the effect of substituents and heteroatoms on the electrochromic properties were investigated for the similar systems. All polymers show electrochromism from a colored state when neutralized to transmissive when oxidized. Although, increasing bulky size (PProDOT‐Np2) causes lower coloration efficiency (CE) as well as lower optical contrast, the replacement of S atom by Se atom resulted in a lower band gap polymer with a higher CE than its thiophene analog. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
140.
We report critical coupling of electromagnetic waves to plasmonic cavity arrays fabricated on Moiré surfaces. Dark field plasmon microscopy imaging and polarization dependent spectroscopic reflection measurements reveal the critical coupling conditions of the cavities. The critical coupling conditions depend on the superperiod of the Moiré surface, which also defines the coupling between the cavities. Complete transfer of the incident power can be achieved for traveling wave plasmonic resonators, which have a relatively short superperiod. When the superperiod of the resonators increases, the coupled resonators become isolated standing wave resonators in which complete transfer of the incident power is not possible. Analytical and finite difference time domain calculations support the experimental observations. 相似文献