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排序方式: 共有194条查询结果,搜索用时 484 毫秒
91.
92.
An improved, efficient, and simple method for the synthesis of nonsymmetrical diamides of fumaric acid is reported. Starting from commercially available substrates, maleic diamides are formed in two steps, and then isomerized in a focused microwave reactor in acetonitrile as the solvent in the presence of a catalytic amount of piperidine, giving the corresponding fumaramides in high yields and purity. 相似文献
93.
A. Di Vita 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,56(2):205-208
A lower bound on Hartmann number for relaxed plasmas
described by Taylor’s principle of minimum magnetic energy with fixed
magnetic helicity is found analytically starting from first principles.
Spontaneous filamentation occurs if the Hartmann number is below threshold.
Comparison with both experiments and numerical computations is presented. 相似文献
94.
Marijke WA de Backer Carlos P Fitzsimons Maike AD Brans Mieneke CM Luijendijk Keith M Garner Erno Vreugdenhil Roger AH Adan 《BMC neuroscience》2010,11(1):81
Background
This study compared the transduction efficiencies of an adeno-associated viral (AAV) vector, which was pseudotyped with an AAV1 capsid and encoded the green fluorescent protein (GFP), with a lentiviral (LV) vector, which was pseudotyped with a VSV-G envelop and encoded the discosoma red fluorescent protein (dsRed), to investigate which viral vector transduced the lateral hypothalamus or the amygdala more efficiently. The LV-dsRed and AAV1-GFP vector were mixed and injected into the lateral hypothalamus or into the amygdala of adult rats. The titers that were injected were 1 × 108 or 1 × 109 genomic copies of AAV1-GFP and 1 × 105 transducing units of LV-dsRed. 相似文献95.
Baghdasaryan H Weinstein LB Laget JM Adhikari KP Aghasyan M Amarian M Anghinolfi M Avakian H Ball J Battaglieri M Bedlinskiy I Bennett RP Berman BL Biselli AS Bookwalter C Briscoe WJ Brooks WK Bültmann S Burkert VD Carman DS Crede V D'Angelo A Daniel A Dashyan N De Vita R De Sanctis E Deur A Dey B Dickson R Djalali C Dodge GE Doughty D Dupre R Egiyan H El Alaoui A El Fassi L Eugenio P Fegan S Gabrielyan MY Gilfoyle GP Giovanetti KL Gohn W Gothe RW Griffioen KA Guidal M Guo L Gyurjyan V 《Physical review letters》2010,105(22):222501
We have measured the 3He(e,e' pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum p(tot). For pair relative momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low p(tot) and rises to approximately 0.5 at large p(tot). This shows the dominance of tensor over central correlations at this relative momentum. 相似文献
96.
Avakian H Bosted P Burkert VD Elouadrhiri L Adhikari KP Aghasyan M Amaryan M Anghinolfi M Baghdasaryan H Ball J Battaglieri M Bedlinskiy I Biselli AS Branford D Briscoe WJ Brooks W Carman DS Casey L Cole PL Collins P Crabb D Crede V D'Angelo A Daniel A Dashyan N De Vita R De Sanctis E Deur A Dey B Dhamija S Dickson R Djalali C Dodge G Doughty D Dupre R El Alaoui A Eugenio P Fegan S Fersch R Forest TA Fradi A Gabrielyan MY Gavalian G Gevorgyan N Gilfoyle GP Giovanetti KL Girod FX Gohn W Gothe RW 《Physical review letters》2010,105(26):262002
We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes ? have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q2. A significant nonzero sin2? single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton. 相似文献
97.
A. Vita 《Fresenius' Journal of Analytical Chemistry》1913,52(7-8):488-489
Ohne Zusammenfassung 相似文献
98.
99.
Enza Calvaruso Andrea Pulvirenti Gianluigi Maria Lo Dico Giovanni Lo Cascio Vita Giaccone 《Natural product research》2020,34(1):34-38
AbstractA sensitive LC–ESI-MS/MS method was developed for the determination of 165 pesticides in 50 citrus fruit samples collected in Sicily. Moreover, an evaluation of pesticides levels in the citrus layers (peel, albedo, and pulp) was carried out. The method presented acceptable trueness, precision, and linearity with LOQ of 5?μg/kg. The results obtained showed a high frequency of fungicides class pesticides in all the citrus samples examined (>95%) with the highest concentrations in the peel (4468?µg/Kg). A significant difference of concentrations was found between the layers of the citrus fruits analysed (p?<?0.05). In particular, the peel and albedo present higher pesticides significantly higher than the pulp. Our findings confirming the widespread use of these substances in citrus cultivation and suggesting the importance of pesticides analysis in all the citrus fruit layers separately, considering the different interactions between the physicochemical characteristics of the matrices and the pesticides. 相似文献
100.
In this paper we introduce and study a new sequence of positive linear operators acting on the space of Lebesgue-integrable
functions on the unit interval. These operators are defined by means of continuous selections of Borel measures and generalize
the Kantorovich operators. We investigate their approximation properties by presenting several estimates of the rate of convergence
by means of suitable moduli of smoothness. Some shape preserving properties are also shown.
Dedicated to the memory of Professor Aldo Cossu 相似文献