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1.
Houda Lahouar 《European Journal of Combinatorics》2003,24(8):1089-1096
Let
be the set of positive integers and
a subset of
. For
, let
denote the number of partitions of n with parts in
. In the paper J. Number Theory 73 (1998) 292, Nicolas et al. proved that, given any
and
, there is a unique set
, such that
is even for n>N. Soon after, Ben Saïd and Nicolas (Acta Arith. 106 (2003) 183) considered
, and proved that for all k≥0, the sequence
is periodic on n. In this paper, we generalise the above works for any formal power series f in
with f(0)=1, by constructing a set
such that the generating function
of
is congruent to f modulo 2, and by showing that if f=P/Q, where P and Q are in
with P(0)=Q(0)=1, then for all k≥0 the sequence
is periodic on n. 相似文献
2.
7-Arylidene-2H,6H-naphtho[1,8-bc]furan-2,6-diones 3 were prepared by a retro-Diels-Alder reaction of the corresponding dihydro 1,3-oxazines 2 or in a one pot synthesis from 6-hydroxy-2H-naphtho[1,8-bc]furan-2-one 1 . Their E configuration was established from the chemical shift's values of the vinylic proton and by 1H nmr NOE difference spectroscopy. Cycloadditions of 3b upon styrene or stilbene were catalyzed by boron trifluoride etherate. The cycloadducts were obtained with the relative trans configuration. 相似文献
3.
Houda Marouani Mohamed Rzaigui Muriel Bagieu‐Beucher 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):356-357
In hexakis(m‐toluidinium) cyclohexaphosphate, 6C7H10N+·P6O186?, the atomic arrangement is typical of a layer structure. Layers including the centrosymmetric P6O18 ring anions develop around the (100) planes at x = . The hydrogen‐bond distribution is described. 相似文献
4.
Jouini Houda Mejri Imène Rhimi Baker Mhamdi Mourad Blasco Teresa Delahay Gérard 《Research on Chemical Intermediates》2021,47(7):2901-2915
Research on Chemical Intermediates - Fe–Cu–ZSM-5 and Ce–Fe–Cu–ZSM-5 solids prepared using solid-state ion exchange method (SSIE) were tested in the NH3–SCR of NO... 相似文献
5.
R. Nishi I. Houda K. Kitano Y. Sugawara S. Morita 《Applied Physics A: Materials Science & Processing》2001,72(7):S93-S95
Noncontact imaging was successfully performed with the quartz resonator in air by using the FM detection method. A constant frequency shift mode was used. The frequency shift was about -30 mHz, which was induced by the attractive force gradient. A noncontact image of the Si(111) atomic step was obtained with vertical and lateral resolutions of 0.8 Å and 60 Å. 相似文献
6.
Zied Zarai Houda Gharsallah Adnane Hammami Hafedh Mejdoub Sofiane Bezzine Youssef-Talel Gargouri 《Applied biochemistry and biotechnology》2012,168(4):877-886
In order to report pharmacological characterization of marine snail (Hexaplex trunculus) hepatopancreatic phospholipase A2 (mSDPLA2), we have talked for the first time the antimicrobial activity against different pathogenic bacterial strains, anti-chlamydial activity as well as its cytotoxic activity against McCoy cell lines. mSDPLA2, showed a high level of activity towards Gram-positive bacteria as Staphylococcus aureus and Staphylococcus epidermidis. Whereas Gram-negative bacteria, unfortunately, exhibited a higher resistance, mSDPLA2 was also found to have a strong cytotoxic activity, causing significant morphological alterations of the McCoy cell lines surfaces and to be a hinder to the proliferation. Moreover, mSDPLA2 proved to have a very potent anti-chlamydial activity. Over 95?% inhibition of chlamydial inclusions were obtained at a concentration of 10???g/ml of mSDPLA2 after 24?h postinfection. Interestingly, at a concentration of 10???g/ml of mSDPLA2, the proliferation of McCoy cells was not affected. Approximately 50?% inhibition of cell growth was obtained with a concentration of 37???g/mL of mSDPLA2. mSDPLA2 could be considered as an excellent candidate for the development of a new anti-infective agent. This enzyme showed significant antimicrobial activities. 相似文献
7.
Zakaria Benzekri Houda Serrar Sara Sibous Ali Ouasri Ali Rhandour 《Green Chemistry Letters and Reviews》2016,9(4):223-228
An easy synthetic protocol for the synthesis of biologically active benzimidazole, benzothiazole and benzoxazole derivatives has been demonstrated using a hybrid crystal NH3(CH2)4NH3SiF6 as a mild and efficient heterogeneous catalyst. Short reaction times, solvent-free conditions, good to excellent yields, easy reusability and use of an eco-friendly catalyst are some of the significant attributes of the present method. 相似文献
8.
Yuuko Houda Misako Sasabe Xu Bo Hideki Takagi Kimiaki Yamamura 《Journal of heterocyclic chemistry》2000,37(5):1363-1365
2‐Cycloheptatrienyl‐3‐(2‐furyl)benzothiophenes, which are prepared by Stille coupling reaction of 2‐cyclo‐heptatrienyl‐3‐bromobenzothiophene with the 5‐substituted 2‐trimethylstannylfurans, react with triphenylmethyl tetrafluoroborate to give the corresponding azuleno[1,2‐b]benzothiophenic enones in excellent yields. 相似文献
9.
10.
Yamamura K Houda Y Hashimoto M Kimura T Kamezawa M Otani T 《Organic & biomolecular chemistry》2004,2(9):1413-1418
Intramolecular reaction of 2-tropylio-3-(5-substituted 2-furyl)benzothiophenes (3), prepared from the corresponding 2-cycloheptatrienyl-3-(5-substituted 2-furyl)benzothiophenes (2), afforded the beta-(azuleno[1,2-b]benzothienyl)-alpha,beta-unsaturated ketones (4), which are otherwise difficult to obtain, in moderate yields. The reaction involves a ring-opening process of the furan ring by intramolecular attack of the tropylium ion onto the 2-position of the furan ring. Similarly, beta-(azuleno[2,1-b]benzothienyl)-alpha,beta-unsaturated ketones (8) were obtained from the corresponding 3-tropylio-2-(5-substituted 2-furyl)benzothiophenes (7) albeit in lower yields. The molecular and crystal structures of the methyl ketone derivative, 8a, are discussed on the basis of X-ray structure analysis. 相似文献