alkaline earth metal
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2022 ◽  
Author(s):  
Huaiyu Hu ◽  
Junben Huang ◽  
Zhiyong Guo ◽  
Min Zhang ◽  
Zhihua Yang ◽  
...  

The first alkaline earth metal borate-nitrate, namely, Ba2B5O8(OH)2(NO3)·3H2O (BBNOH), has been synthesized by the hydrothermal method. BBNOH crystallizes in the space group of P21/c and exhibits two-dimensional (2D) 2∞[B5O8(OH)2]3-borate anion...


2022 ◽  
Author(s):  
Hai-Bo Li ◽  
Yanna Wang ◽  
Zhenghe Wei ◽  
Lianghong Xia ◽  
Zhimin Li ◽  
...  

To explore novel coordination complexes for promising energetic materials, alkaline metal (Na+ (1), Na+ (2), K+ (3), and Rb+ (4)) and alkaline earth metal (Mg2+ (5), Ca2+ (6), and Sr2+...


Gels ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 20
Author(s):  
Ke-Jing Lee ◽  
Yeong-Her Wang

Zr can be stabilized by the element selected, such as Mg-stabilized Zr (MSZ), thus providing MSZ thin films with potentially wide applications and outstanding properties. This work employed the element from alkaline earth metal stabilized Zr to investigate the electrical properties of sol–gel AZrOx (A = alkaline earth metal; Mg, Sr, Ba) as dielectric layer in metal-insulator–metal resistive random-access memory devices. In addition, the Hume–Rothery rule was used to calculate the different atomic radii of elements. The results show that the hydrolyzed particles, surface roughness, and density of oxygen vacancy decreased with decreased difference in atomic radius between Zr and alkaline earth metal. The MgZrOx (MZO) thin film has fewer particles, smoother surface, and less density of oxygen vacancy than the SrZrOx (SZO) and BaZrOx (BZO) thin films, leading to the lower high resistance state (HRS) current and higher ON/OFF ratio. Thus, a suitable element selection for the sol–gel AZrOx memory devices is helpful for reducing the HRS current and improving the ON/OFF ratio. These results were obtained possibly because Mg has a similar atomic radius as Zr and the MgOx-stabilized ZrOx.


Author(s):  
O. M. Iniaghe ◽  
O. Ibukun

The effects of some alkali metal ions (Na+ and K+) and alkaline earth metal ions (Mg 2+ and Ba2+) on the initial reaction rates of Congregibacter litoralis KT71 β-lactamase hydrolysis of 4-nitrophenyl myristate was investigated by varying the concentrations of the metal ions in the assay mixture which comprised of 100 µl of standard enzyme solution, 200 µl of varying concentration of metal ions, 500 µl of 50 mM sodium phosphate buffer pH 7.5 and 200 µl of 4-nitrophenyl myristate (substrate) which was added last to the assay mixture after an incubation time of 10 minutes at 44 oC. The enzyme activity was measured spectrophotometrically using a UV-780 recording spectrophotometer at a wavelength of 405 nm. The hydrolysis of 4-nitrophenyl myristate to yield 4-nitrophenol was monitored by reading the absorbance at 25 minutes. Results showed that the alkaline earth metal ions (Ba2+ and Mg2+) had higher enzyme activation effect than the alkali metal ions (K+ and Na+) Also, all metal ions except Mg2+ showed enzyme stimulatory effect at low concentrations (<2 mM) but inhibitory at higher ion concentrations (2 mM - 3 mM). Mg 2+ caused a proportionate decrease in enzyme activity from its peak (when metal ion concentration was lowest). Results from this research is of great significance to the industrialist especially where the search for novel lipases with unique characteristics suitable for the industries are inevitable.


2021 ◽  
Author(s):  
Ria Sinha Roy ◽  
Avik Ghosh ◽  
Tamalika Ash ◽  
Soumadip Banerjee ◽  
Abhijit Das

Abstract Effect of complexant number on second hyperpolarizability of a series of diffuse electron system comprising aziridine (complexant) and alkaline earth metal dopnat (i.e. Be, Mg and Ca) are explored theoretically. For this, the number of the complexant is increased upto three in a stepwise fashion. Aziridine unit, that is non-covalently linked with dopant, polarizes the ns electron of dopant. This polarizing effect results the higher second hyperpolarizability value of the complexes. . Compared to pristine aziridine moiety, the gavg of Be-aziridine complex enhances significantly.Interestingly, with increase in the complexant number, the static and dynamic second hyperpolarizability value enhances in monotonical fashion and attains the maximum value when three complexant are employed. Among the studied systems, the shamrock-shaped complex (Ca@(aziridine)3) exhibits higher non-linear refractive index as well as remarkably high second hyperpolarizability value(1.83x107 a.u.).


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