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941.
Ali Khalaj Morteza Pirali Hogatollah Matloubi Reza Dowlatabadi 《Monatshefte für Chemie / Chemical Monthly》2001,132(6):747-752
Summary. Several novel N-(2,3-dihydro-2-oxo-5-phenyl-1H-1,4-benzodiazepin-3-yl)-2-carboxamides were prepared by acyl coupling of 2-aminobenzophenones with α-(benzotriazol-1-yl)-N-acylglycines
followed by displacement of the benzotriazole ring with ammonia and cyclization of the resulting monoacyl aminals. In addition
to high yields and shorter reaction sequences due to avoiding deprotection and acylation of the protected 3-amino-1,4-benzodiazepin-2-one
intermediates, the present approach did not involve the use of toxic and odoriferous materials as is the case with other methods.
Received September 20, 2000. Accepted (revised) November 29, 2000 相似文献
942.
By considering the null space of incidence matrices of trivial designs over GF(2) (the space of 1- (v,k) trades overGF(2)) we obtain families of codes which are optimal for some v and k. Moreover, by generalizing the concept of bond space, the weight enumerator polynomials for these codes are obtained. 相似文献
943.
Shadpour E. Mallakpour Abdol‐Reza Hajipour Mohammad Reza Zamanlou 《Journal of polymer science. Part A, Polymer chemistry》2001,39(1):177-186
3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (4,4′‐carbonyldiphathalic anhydride) was reacted with L ‐leucine in a mixture of acetic acid and pyridine (3 : 2), and the resulting imide‐acid [N,N′‐(4,4′‐carbonyldiphthaloyl)‐bis‐L ‐leucine diacid] was obtained in quantitative yield. The compound was converted to the N,N′‐(4,4′‐carbonyldiphthaloyl)‐bis‐L ‐leucine diacid chloride by reaction with thionyl chloride. A new facile and rapid polycondensation reaction of this diacid chloride with several aromatic diamines such as 4,4′‐diaminodiphenyl methane, 2,4‐diaminotoluene, 4,4′‐sulfonyldianiline, p‐phenylenedi‐amine, 4,4′‐diaminodiphenylether, and m‐phenylenediamine was developed by using a domestic microwave oven in the presence of a small amount of a polar organic medium such as O‐cresol. The polymerization reactions proceeded rapidly compared with the conventional solution polycondensation and were completed within 6 min, producing a series of optically active poly(amide‐imide)s with a high yield and an inherent viscosity of 0.37–0.57 dL/g. All of the above polymers were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these optically active poly(amide‐imide)s are reported. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 177–186, 2001 相似文献
944.
945.
Oveisi Ali Reza Karimi Pouya Delarami Hojat Samareh Daliran Saba Khorramabadi-zad Ahmad Khajeh Mostafa Sanchooli Esmael Ghaffari-Moghaddam Mansour 《Molecular diversity》2020,24(2):335-344
Molecular Diversity - New trans-A2B2-porphyrins substituted at phenyl positions were synthesized from 4-methylphthalic acid as a starting material through sequential multistep reactions. These... 相似文献
946.
Size-effects on yield surfaces for micro reinforced composites 总被引:1,自引:0,他引:1
Reza Azizi Christian F. Niordson Brian Nyvang Legarth 《International Journal of Plasticity》2011,27(11):1817-1832
Size effects in heterogeneous materials are studied using a rate independent higher order strain gradient plasticity theory, where strain gradient effects are incorporated in the free energy of the material. Numerical studies are carried out using a finite element method, where the components of the plastic strain tensor appear as free variables in addition to the displacement variables. Non-conventional boundary conditions are applied at material interfaces to model a constraint on plastic flow due to dislocation blocking. Unit cell calculations are carried out under generalized plane strain conditions. The homogenized response of a material with cylindrical reinforcing fibers is analyzed for different values of the internal material length scale and homogenized yield surfaces are presented. While the main focus is on initial yield surfaces, subsequent yield surfaces are also presented. The center of the yield surface is tracked under uniaxial loading both in the transverse and longitudinal directions and an anisotropic Bauschinger effect is shown to depend on the size of the fibers. Results are compared to conventional predictions, and size-effects on the kinematic hardening are accentuated. 相似文献
947.
Application of graphene nanoplatelets silica composite,prepared by sol–gel technology,as a novel sorbent in two microextraction techniques
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Mahmoud Heidari Abdolrahman Bahrami Ali Reza Ghiasvand Farshid Ghorbani Shahna Ali Reza Soltanian Maryam Rafieiemam 《Journal of separation science》2015,38(24):4225-4232
In this study, the application of a novel nanomaterial composite was investigated in two microextraction techniques of solid‐phase microextraction and a needle trap device in a variety of sampling conditions. The optimum sampling temperature and relative humidity were 10°C and 20%, respectively, for both techniques with two sorbents of graphene/silica composite and polydimethyl siloxane. The two microextraction techniques with the proposed sorbent showed recoveries of 95.2 and 94.6% after 7 days. For the needle trap device the optimums desorption time and temperature were 3 min at 290°C and for SPME these measures were 1 and 1.5 min at 240–250°C for the graphene/silica composite and polydimethyl siloxane, respectively. The relative standard division obtained in inter‐ and intra‐day comparative studies were 3.3–14.3 and 5.1–25.4, respectively. For four sample the limit of detection was 0.021–0.25 ng/mL, and the limit of quantitation was 0.08–0.75 ng/mL. The results show that the graphene/silica composite is an appropriate extraction media for both techniques. Combining an appropriate sorbent with microextraction techniques, and using these in conjunction with a sensitive analytical instrument can introduce a strong method for sampling and analysis of occupational and environmental pollutants in air. 相似文献
948.
Hossein Reza Darabi Marjan Azimzadeh Arani Mohsen Tafazzoli Mina Ghiasi 《Monatshefte für Chemie / Chemical Monthly》2008,139(10):1185-1189
The existence of a short C–H ⋯ π (alkyl–alkyne) interaction in the structure of a strained and relatively rigid tolanophane
is expected to hinder the rotation about the C–C sp3 single bond. Variable-temperature NMR experiments (performed in three solvents, CDCl3, THF-d8, and acetone-d6) and ab initio density functional calculations were carried out to investigate its dynamic nature. An energy barrier of 48.6 kJ/mol is determined
at coalescence (210 K) with acetone-d6 which is in good agreement with calculation result (54 kJ/mol).
Correspondence: Hossein Reza Darabi, Chemistry and Chemical Engineering Research Center of Iran, Pajoohesh Blvd., km 17, Karaj
Hwy, 14968-13151 Tehran, Iran. 相似文献
949.
Reza Saadati S. Mansour Vaezpour 《Journal of Mathematical Analysis and Applications》2008,346(2):446-450
In this paper, we consider strongly bounded linear operators on a finite dimensional probabilistic normed space and define the topological isomorphism between probabilistic normed spaces. Then we prove that every finite dimensional probabilistic normed space which is a topological vector space is complete. 相似文献
950.