Treatment of [Cp*RuCl2]2, 1 , [(COD)IrCl]2, 2 or [(p-cymene)RuCl2]2, 3 (Cp*=η5-C5Me5, COD= 1,5-cyclooctadiene and p-cymene=η6-iPrC6H4Me) with heterocyclic borate ligands [Na[(H3B)L], L1 and L2 ( L1 : L=amt, L2 : L=mp; amt=2-amino-5-mercapto-1,3,4-thiadiazole, mp=2-mercaptopyridine) led to the formation of borate complexes having uncommon coordination. For example, complexes 1 and 2 on reaction with L1 and L2 afforded dihydridoborate species [LAM(μ-H)2BHL] 4 – 6 ( 4 : LA=Cp*, M=Ru, L=amt; 5 : LA=Cp*, M=Ru, L=mp; 6 : LA=COD, M=Ir, L=mp). On the other hand, treatment of 3 with L2 yielded cis- and trans-bis(dihydridoborate) species, [Ru{(μ-H)2BH(mp)}2], cis- 7 and trans- 7 . The isolation and structural characterization of fac- and mer-[Ru{(μ-H)2BH(mp)}{(μ-H)BH(mp)2}], 8 from the same reaction offered an insight into the behaviour of these dihydridoborate species in solution. Fascinatingly, despite having reduced natural charges on Ru centres both at cis-and trans- 7 , they underwent hydroboration reaction with alkynes that yielded both Markovnikov and anti-Markovnikov addition products, 10 a – d . 相似文献
This work presents the investigation of some commercially available and commonly used Si3N4 foils prepared with LPCVD technique. The density and the stoichiometry of these films were determined by Rutherford backscattering spectroscopy and profilometry, while the study of impurities was achieved with particle induced X-ray emission method. It was found that the density of the studied Si3N4 films is significantly less (~2.71 g cm?3), while the stoichiometry is close to the values of the bulk material. The results were verified by measuring the ion energy loss through the films by scanning transmission ion microscopy. 相似文献
This research intends to expand a mathematical model for studying the non-Newtonian surge of blood through a hepatic artery in the presence of steno occlusive disease post-liver transplantation. Power law liquid demonstrates the non- Newtonian character of blood. The hemodynamic conduit of the fluid is altered by the occurrence of arterial stenosis. In our study, the difficulty is resolved by applying diagnostic methods with the assistance of marginal circumstances and consequences. The outcomes are explained graphically for unusual cases for such stenosis. The study design is based on a tensorial form and converts its solution using numerical and analytical techniques. Our study outcome suitably demonstrates that the mathematical model used corroborates with the clinical scenario of the patient with hepatic disease. 相似文献
Dark sector may couple to the Standard Model via one or more mediator particles.We discuss two types of mediators:the dark photon A’and the dark scalar mediatorΦ.The total cross-sections and various differential distributions of the processes e+e-→qqA’and e+e→qqφ(q=u,d,c,s and b quarks)are discussed.We focus on the study of the invisible due to the cleaner background at future e+e-colliders.It is found that the kinematic distributions of the two-jet system could be used to identify(or exclude)the dark photon and the dark scalar mediator,as well as to distinguish between them.We further study the possibility of a search for dark photons at a future CEPC experiment with s1/2=91.2 GeV and 240 GeV.With CEPC running at s1/2=91.2 GeV,it would be possible to perform a decisive measurement of the dark photon(20 GeV相似文献
In this study, we investigate the expansion of the FRLW universe in the open, closed, and flat geometries. The universe is dominated by a scalar field (spatially homogeneous) as a source of dark energy. We consider the three different classes of scalar fields – quintessence, tachyonic, and phantom field – for our analysis. A mathematical analysis is carried out by considering these three scalar fields with exponential and power-law potentials. Both potentials give exponential expansion in the open, closed, and flat FRLW universes. It is found that quintessence, tachyonic, and phantom scalar fields are indistinguishable under the slow roll approximation. 相似文献
Journal of Inclusion Phenomena and Macrocyclic Chemistry - A simple and cost-effective method for the synthesis of sulfated β-cyclodextrin, one of the most widely used chiral mobile phase... 相似文献
Bacterial nanocellulose (BNC) is an indomitable biomaterial of utmost usage in different technological areas. Previously, the BNC production has been reported in the simplified bioreactors. Thus, pioneering bioreactor-assisted strategies are desirable for the commendable BNC production. Advanced bioreactors must be corroborated along with different bacterial strains to obtain creditable BNC yield. This study deals with BNC production in rotary disc bioreactor (RDBR) using Gluconacetobacter xylinus NCIM 2526 strain. RDBR-based production of BNC provided 189?±?14 gL?1 of wet BNC, i.e., equivalent to 6.6?±?0.3 gL?1 dry BNC yield in 10 days. However, in static cultivation mode, 56?±?12 gL?1 wet weight of BNC, corresponding to 2.4?±?0.4 gL?1 dry weight, was produced. Thus, BNC production was approximately 2.75 folds higher in RDBR than statically produced BNC from the same volume of the media. The sugar to BNC conversion yield (12.2?±?0.8%) was doubled in RDBR-based production as compared to static BNC production (6.2?±?1.4%) with efficient sugar consumption (90.0?±?3.3%). The maximum amount of BNC was produced at 7 RPM and pH 6. RDBR-based BNC showed a more hydrophilic nature than statically produced BNC. The RDBR might be appropriate for large-scale BNC production, especially for wet-end applications, as an ample amount of BNC can be produced from a single fermentation process. These BNC pellicles might have the potential for biomedical applications like wound dressings, biofacial masks, hydrogels, and tissue engineering scaffolds.
Quinazoline is a heterocyclic compound having biological activities. It is aromatic in nature having bicyclic structure containing benzene ring and pyrimidine ring. Quinazoline and its derivatives are found to have wide range of biological activities that is anticancer, analgesic, antimicrobial, antihypertensive, anticonvulsant, antimalarial, antitumor, and anti-tubercular activities. The purpose of this review is to highlight the recent researches made by researchers on various biological activities of quinazoline derivatives on different targets. 相似文献
Using quasi-steady-state and time-resolved high-field impedance techniques, the frequency-dependent dielectric permittivity of poly(vinylacetate) has been studied at electric field amplitudes as high as 400 kV/cm. The relative changes of the dielectric loss depend quadratically on the field amplitude and reach about 1 %. The magnitude and frequency-dependence of this non-linear dielectric effect and its time evolution after applying the high field are consistent with energy absorption from the field being at the source of the non-linear behavior. Based upon a phenomenological model of heterogeneous dynamics at isothermal conditions, the observed changes can be explained by locally increased configurational temperatures and the resulting accelerated dynamics. 相似文献