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Within angle‐resolved polarized Raman spectroscopy (ARPRS) experiments, ensuring accurate configurations is crucial for obtaining reliable results, especially when dealing with anisotropic materials like CrOCl with anisotropic crystal structure and phonon properties. However, comprehensive understanding of phase‐dependent ARPRS and the calibration of phase angle on anisotropic phonon modes from a crystallographic perspective are still lacking. Herein, detailed investigation on phase‐dependent ARPRS and looked into the anisotropic photo‐phonon interaction in CrOCl through in situ ARPRS is conducted. The Raman tensors and crystal orientation are acquired under two typical configurations. Phase‐dependent ARPRS are thoroughly analyzed for the calibration of analyzer deviation. The anomalous anisotropic response in phase‐dependent ARPRS is closely related to the intrinsic linear dichroism (LD) effect in CrOCl, which is further confirmed by angle‐resolved polarization absorption. Moreover, the strong localized rules for various parallel energy bands of CrOCl have generated anomalous LD conversion effect near 470 nm, which expands the potential application of CrOCl in polarization‐wavelength selected devices. This findings can offer in‐depth comprehension on the anisotropic phonon physics of CrOCl and a feasible approach to utilize phase‐dependent ARPRS for probing the undiscovered abundant photo‐induced effects in low‐symmetry 2D materials. [ABSTRACT FROM AUTHOR]

A porous microplate embedded with two nanocomposite piezoelectric layers is investigated in the current work. All three layers are functionally graded and completely attached to each other, and the microstructure lies on a bi-parameter elastic foundation that withstands shear and normal forces simultaneously. Also, an external voltage is subjected to the piezoelectric patches. The mentioned patches are reinforced with carbon nanotubes to enhance their electro-mechanical performance. A higher-order shear deformation theory and von Karman's assumptions are hired to demonstrate the kinematic relations. Next, applying Hamilton's principle and variational technique, the governing motion equations are derived with the help of the modified couple stress theory to capture the scale influence. To solve the system of differential equations, a closed-form Navier method is employed, and by ensuring the correctness of the results, then it turns to investigate the impact of different factors including porosity percentage and also pores' distribution patterns, nanotubes dispersion patterns, and other important factors on the natural frequencies of the model. Obtained results show that symmetric and uniform porosity distributions have the maximum and minimum amounts of natural frequencies. Moreover, the maximum difference between natural frequencies of three different porosity distribution occurs in e0 = 0.95 and is approximately 32%. The current study results may consider to design and produce smart structures and devices with improved performance. [ABSTRACT FROM AUTHOR]

The low-temperature joining of semiconductor chips by sintering of silver paste is emerging as an alternative lead-free solution for power electronics devices and modules working in a high-temperature environment. A promising die-attachment material that would enable the rapid implementation of the sintering process is nanoscale silver paste, which can be sintered at temperatures below 300 ^\circ\C without an external pressure. In this paper, we report our findings on the silver migration in sintered nanosilver electrode-pair patterns on an alumina substrate. The electrode pairs were biased at an electric field ranging from 10 to 100 V/mm and at a temperature between 250 ^\circ\C and 400 ^\circ\C in dry air. The leakage currents across the electrodes were measured as the silver patterns were tested in an oven. Silver dendrites formed across the electrode gap were observed under an optical microscope and analyzed using scanning electron microscopy and energy dispersive spectroscopy (EDS). The silver migration was found in the samples tested at 400 ^\circ\C, 350 ^ \circ\C, 300 ^\circ\C, and 250 ^\circ\C. The measurements on the leakage current versus time were characterized by an initial incubation period, called “lifetime,” followed by a sharp rise as the silver dendrites were shorting the electrodes. A simple phenomenological model was derived to account for the observed dependence of lifetime on the electric field and temperature. The EDS mappings revealed the significant presence of oxygen on the positive electrode but the complete absence on the negative electrode. A mechanism involving the oxidation of silver and the dissociation of silver oxide at the anode was suggested. We suggest that the migration of a sintered nanosilver die attachment can be prevented in high-temperature applications through packaging or encapsulation to reduce the partial pressure of oxygen. [ABSTRACT FROM PUBLISHER]

The article focuses on a study regarding the stability and activity of α-chymotrypsin (CT) that has been immobilized on carboxyl-functionalized magnetic nanogels. Under the study, the impact of protease and surfactants on enzyme stability and the catalytic activity of the immobilized enzyme with regard to protein substrate have been determined. Findings indicate that CT sustained activity despite immobilization. The stability of CT is associated with the structural rigidity of the enzyme.