排序方式: 共有25条查询结果,搜索用时 15 毫秒
1.
Ricerche di Matematica - Let D be an integral domain. G. Picozza associated to a stable semistar operation $$\star $$ on D, a semistar operation $$\star _1$$ on the polynomial ring D[X].... 相似文献
2.
Hosni K Msaâda K Ben Taârit M Chahed T Marzouk B 《Natural product communications》2011,6(11):1731-1734
The chemical composition of the essential oils obtained by hydrodistillation from the aerial parts of the Tunisian Hypericum perforatum and H. ericoides ssp. roberti was elucidated by a combination of GC and GC-MS analyses. The main constituents of the oil of H. perforatum were alpha-pinene (11.8%), alpha-ylangene (10.4%), germacrene-D (9.5%), n-octane (6.5%) and alpha-selinene (5.9%). The oil of H. ericoides ssp. roberti exhibited a higher amount of aliphatic and branched hydrocarbons and the main constituents were n-octane (29.1%), alpha-pinene (10.9%), pulegone (7.7%) and acetophenone (7%). Both qualitative and quantitative differences were observed between the studied oils. This chemical variability seems likely to result from the genetic variability, since samples of both species were collected at the same location and processed under the same conditions. 相似文献
3.
Hamadi Jerbi Thouraya Kharrat Faouzi Omri 《Mediterranean Journal of Mathematics》2016,13(5):2507-2524
In this paper, we consider a class of bilinear systems in dimension three which can be an extension of another one in \({\mathbbm{R}^{2}}\). We prove that there exists some homogeneous feedback of degree zero stabilizing the considered class if and only if these feedbacks are constants. 相似文献
4.
β‐Keto‐amides react with 2‐dimethylaminomethylene‐1,3‐bis(dimethylimonio)propane diperchlorate salt to give the corresponding 3‐acetyl‐5‐formylpyridin‐2‐ones. The annulation reactions proceed with excellent yields. 相似文献
5.
Mehdoui T Berthet JC Thuéry P Ephritikhine M 《Chemical communications (Cambridge, England)》2005,(22):2860-2862
The capacity of NHC molecules to discriminate between trivalent lanthanide and actinide ions was revealed by competition reactions of analogous U(III) and Ce(III) compounds with C3Me4N2 and a comparison of the crystal structures of the corresponding carbene adducts. 相似文献
6.
Stephane Andrieux Amel Ben Abda Thouraya Nouri Baranger 《Comptes Rendus Mecanique》2005,333(2):171-177
We propose, in this Note, a new procedure for data completion based on the minimization of an energy like error functional. The efficiency of the proposed method is illustrated by a thermostatic application. To cite this article: S. Andrieux et al., C. R. Mecanique 333 (2005). 相似文献
7.
8.
In this paper, we study the stability and stabilization of time-varying homogeneous systems that are affine in the control using some results on differentiable manifolds. 相似文献
9.
A novel and efficient one-pot preparation of 6-substituted pyrido-[2,3-d]pyrimidines by cyclocondensation of 6-amino-1,3-dimethyluracil with symmetrical vinamidinium salts under basic conditions has been developed. Regioselectivity was observed with an unsymmetrical chloropropeniminium salt. 相似文献
10.
Ricerche di Matematica - Let D be an integral domain. We associate to a semistar operation $$\star $$ on D, a semistar operation $$*$$ on D[[X]]. We prove that if D satisfies the $$\star _f$$... 相似文献