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131.
An expedient,synthetic method to fused polycyclic derivatives of isoquinoline is described via tandem reaction of isoquinoline,dialkyl acetylenedicarboxylates and dialkyl chloromalonate. 相似文献
132.
Morteza Moradi Yadollah Yamini Moslem Tayyebi Hamid Asiabi 《Analytical and bioanalytical chemistry》2013,405(12):4235-4243
Novel ultrasonically enhanced supramolecular solvent microextraction (USESSM) then high-performance liquid chromatography with ultraviolet detection have been used for extraction and determination of phthalates in water and cosmetics. Coacervates consisting of decanoic acid-based nano-structured aggregates, specifically reverse micelles, have been used the first time as solvents for ultrasound-assisted emulsification microextraction (USAEME). Sonication accelerated mass transfer of the target analytes into the nano-structured solvent from the aqueous sample, thus reducing extraction time. Several conditions affecting extraction efficiency, for example the concentrations of major components of the supramolecular solvent (tetrahydrofuran and decanoic acid), sample solution pH, salt addition, and ultrasonication time, were investigated and optimized. Under the optimum conditions, preconcentration of the analytes ranged from 176 to 412-fold and the linear range was 0.5–100 μg?L?1, with correlation coefficients (R 2)?≥?0.9984. The detection sensitivity of the method was excellent, with limits of detection (LOD, S/N?=?3) in the range 0.10–0.70 μg?L?1 and precision in the range 4.1–11.7 % (RSD, n?=?5). This method was successfully used for analysis of phthalates in water and cosmetics, with good recovery of spiked phthalates (91.0–108.5 %). 相似文献
133.
Mohammad Ebadi Zahra Mirdamadian Davood Ghanbari Leila Moradi 《Journal of Cluster Science》2014,25(2):541-548
Multi-walled carbon nanotubes (MWCNT) have been successfully functionalized with amino groups. In order to improve the thermal stability of the polymer nanocomposite, aminated-MWCNTs were added to acrylonitrile–butadiene–styrene (ABS). The influence of MWCNT and phosphorus pentoxide nanostructures on the flame retardancy of the ABS matrix was studied using UL-94 test. The results show that the MWCNT nanostructure can’t enhance the flame retardancy of the ABS matrix but synergism of MWCNT and P2O5 can effectively improve the flame retardancy of the nanocomposite. 相似文献
134.
The adsorption of a H2S molecule on the surface of an MgO nanotube was investigated using density functional theory. It was found that H2S molecule can be associatively adsorbed on the tube surface without any energy barrier or it can be dissociated into –H and –SH species overcoming energy barrier of 4.03–7.77 kcal/mol. The associative adsorption is site selective so that the molecule is oriented in such a way that the sulfur atom was linked to an Mg atom. The HOMO–LUMO energy gap of the tube has slightly changed upon associative adsorption, while they were significantly influenced by dissociation process. Especially, the highest occupied molecular orbital of the tube shifts to higher energies which can facilitate electron emission current from the tube surface. Also, energy gap of the tube dramatically decreased by about 0.93–1.05 eV which influences the electrical conductivity of the tube. 相似文献
135.
A simple and efficient synthetic protocol has been developed using a one-pot, three-component reaction involving 2-amino phenols, dialkyl acetylene dicarboxylates and nitrostyrene derivatives. Utilizing this protocol, a variety of novel pyrrolo-1,4-benzoxazine derivatives were synthesized in excellent yields. 相似文献
136.
Behrooz Maleki Saba Hemmati Reza Tayebee Sirous Salemi Yasaman Farokhzad Mehdi Baghayeri Farrokhzad Mohammadi Zonoz Elahe Akbarzadeh Rohollah Moradi Azam Entezari Mohammad Reza Abdi Samaneh Sedigh Ashrafi Fereshteh Taimazi Majid Hashemi 《Helvetica chimica acta》2013,96(11):2147-2151
A convenient synthesis of sulfonamides and sulfonyl azides from thiols is described. In situ preparation of sulfonyl chlorides from thiols was accomplished by oxidation with chloramine‐T (=N‐chlorotosylamide=N‐chloro‐4‐methylbenzenesulfonamide), tetrabutylammonium chloride (Bu4NCl), and H2O. The sulfonyl chlorides were then further allowed to react with excess amine or NaN3 in the same pot. 相似文献
137.
为了考察切向强迫气流对激光辐照下树脂基复合材料热响应的影响,基于边界层换热理论,研究了切向气流与靶面的对流换热系数和热分解气体对表面热交换的覆盖效应,并用有限差分法对激光辐照下树脂基复合材料的1维热响应模型进行数值求解。数值计算表明:高速切向气流的存在会加速靶材表面与外部环境的热交换,从而明显降低激光对靶材的加热效率;边界层换热理论给出的对流换热系数和覆盖因子是合理有效的,适用于数值模拟切向气流对激光辐照下树脂基复合材料热响应的影响;向靶材表面溢出的热分解气体对靶材表面与外部环境的热交换有一定的抑制作用,但影响较小,基本可以忽略不计。 相似文献
138.
This paper is concerned with the asymptotic behavior solutions of stochastic differential equations dy
t
=dω
t
−∇Γ(y
t
) dt, y
0=0 and d=2. Γ is a 2 &\times; 2 skew-symmetric matrix associated to a shear flow characterized by an infinite number of spatial scales
Γ12=−Γ21=h(x
1), with h(x
1)=∑
n
=0
∞γ
n
h
n
(x
1/R
n
), where h
n
are smooth functions of period 1, h
n
(0)=0, γ
n
and
R
n
grow exponentially fast with n. We can show that y
t
has an anomalous fast behavior (?[|y
t
|2]∼t
1+ν with ν > 0) and obtain quantitative estimates on the anomaly using and developing the tools of homogenization.
Received: 1 June 2001 / Accepted: 11 January 2002 相似文献
139.
In cartography, the geographic regions are usually represented using regular dense maps corresponding to heights values associated with the nodes of a regular grid of R2. The simplification of such maps is an absolute requirement in order to make storage, simulation and display possible. In this Note, we propose a new simplification method based on a measure of the local deformation of the surface. The latter allows, in particular, minimization of the approximation error during the simplification. A numerical example is provided to emphasize the efficiency of this approach. To cite this article: P.J. Frey, H. Borouchaki, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 227–232. 相似文献
140.
Roberto Pierini Shahpoor Moradi Stefano Mancini 《International Journal of Theoretical Physics》2016,55(6):3059-3078
We investigate the effects of spin on entanglement arising in Dirac field in an expanding spacetime characterized by the Robertson-Walker metric. We present a general approach that allows us to treat the case where only charge conservation is required, as well as the case where also angular momentum conservation is required. We find that in both situations entanglement originated from the vacuum and quantified by subsystem entropy behaves the same and does not qualitatively deviates from the spinless case. Differences only arise when particles and/or antiparticles are present in the input state. 相似文献