Search

Hemorrhagic disease of grass carp, which is induced by grass carp reovirus II (GCRV-II), leads to mass mortality in grass carp culture and causes enormous economic loss. However, there is currently no quantitative analysis method for the detection of GCRV-II, which is greatly restricted the etiological and epidemiological study of the disease. In this study a reverse transcription TaqMan PCR (RT-qPCR) assay was developed for the quantitative detection of GCRV-II. The probe and primers targeted location is the segment 6 (S6) region of the GCRV-II genome which is highly conserved. Standard curves were drawn and criteria were confirmed after the determination of the optimum reaction conditions. The species-specific assay showed that the method is highly specific and has no cross reactions with other pathogens. The assay was sufficiently sensitive to detect as low as 10 copies of virus RNA. Moreover, the method has a very good repeatability for batches and inter-batches sample detection. Then the method was applied to detect the virus in tissue samples from clinically infected grass carp, compared with conventional RT-seminested PCR, the RT-qPCR represents a specific value for detection rate of positive samples. In summary, the RT-qPCR was applied and achieved high sensitivity and specificity for GCRV-II detection.

The influence of DC-biased current (I DC) on the longitudinal giant magnetoimpedance (GMI) effect in Co-based amorphous ribbon with a meander structure, taken from room temperature to 120 °C, has been investigated. The results show that I DC increases the temperature stability of the impedance of amorphous ribbon at 20 MHz. By deriving the expression of the transverse permeability according to a magnetization rotation model, we attributed the improved temperature stability to the combined effect of temperature and bias field H DC generated by I DC on the transverse permeability. It is also shown that I DC not only effectively inhibits the weakening of the GMI ratio at high temperature, but also significantly improves the GMI sensitivity. This will help to achieve sensitive low magnetic field measurement under large temperature fluctuation.

In this work, we investigate the linear relationship between domain wall creep parameters, and evaluate the effect of material parameters on magnetic domain wall creep in a series of Pt/Co/Pt multilayers with perpendicular magnetic anisotropy. The results for the samples with different magnetic layer thicknesses verify the linear relationship between the domain wall creep parameters, which is because in these samples both domain wall creep parameters are mainly affected by Co layer thickness and both of the domain wall creep parameters are proportional to the Co layer thickness. With the assistance of surface acoustic waves, the domain wall creep parameters also follow the linear relationship. This suggests a relationship between the anisotropy density K and local pinning strength f p i n : f p i n ∝ K 1 8 . The above linear relationship does not exist in annealed samples because annealing breaks the relationship between the local pinning strength and material parameters.

Controlling the magnetoacoustic wave transmission with various equivalent magnetic fields is a key technology for future hybrid surface acoustic wave (SAW) devices. In this work, we experimentally and theoretically display acoustically driven spin wave resonance in Ni films with in-plane uniaxial magnetic anisotropy at an arbitrary angle relative to the SAW vector. Our experimental results show that by adjusting the angle between the hard axis and the SAW vector, we achieve the excitation of magnetoacoustic waves in any in-plane orientation. Moreover, we clearly prove that the anisotropic effective field can be utilized to optimize the applied field configuration for driving magnetoacoustic waves and design orientation sensors due to the angle-sensitive performance of acoustic spin wave resonance.

FeRh has been extensively studied because of metamagnetic phase transitions between the antiferromagnetic (AFM) and the ferromagnetic (FM) phase observed in this material. In this work, Brillouin light scattering is used to detect magnons in metamagnetic FeRh. Appearance and disappearance of magnon scattering peaks with variation of temperature illustrate the transformation of FeRh into the FM and AFM phases, respectively. The dependence of frequency on temperature indicates significant change thus characterizing metamagnetic phase transitions in FeRh, since the temperature dependence of the magnon frequency shift mainly follows the saturation magnetization temperature dependence. In addition, a considerable increase of full width at half maximum linewidth of the Stokes peak for FeRh is explained by the enhancement of magnetic damping. It is further found that the Dzyaloshinskii–Moriya interaction (DMI) takes place in single-layer FeRh with the DMI energy D affected by the first-order phase transitions in FeRh. These results provide an insight into the magnon dynamics in metamagnetic materials as well as offering new ways toward a modulation of magnetic damping in a wide range, which will be useful in the design of multifunctional spintronic devices.

We observed an unusual double-shifted hysteresis loop in a perpendicular exchange-coupled Co/IrMn system at room temperature, which leads to an uneven exchange bias field in the positive and the negative field. With the thickness of the antiferromagnetic layer ranging from 4.8 to 10.4 nm, the negative exchange bias field is approximately 100 Oe larger than the positive exchange bias field. This result is related to the density of net spins in the antiferromagnetic layer that have pinned on the ferromagnetic layer. In addition, the exchange bias field of this unusual double-shifted hysteresis loop can be adjusted by the magnetic field annealing temperature.

We study the angle dependence of the spin wave resonance spectra in FeNi–MgO granular films fabricated by magnetron sputtering, using ferromagnetic resonance technology. Seven Portis-type spin resonances with the same magnetic field spacing are observed when the magnetic field is perpendicular to the film. By varying the field angle θH, we find that there are at least two resonance modes at θH = 14°, indicating that the critical angle θc of the ferromagnetic resonance mode is in the range of 14°–15°. Furthermore, we obtained the exchange stiffness constant and distortion parameter through the surface inhomogeneity model and the volume inhomogeneity model. Moreover, in order to figure out the types of spin wave, we also investigate the dependence of spin wave resonance spectra on temperature, which reveals an excitation of the perpendicular spin standing wave.

Dissolution kinetics of the sulfide-oxide complex inclusion and its surrounding matrix of X70 steel in deaerated acidic environment was investigated. The dissolution process can be divided into three stages including the initiation stage, galvanic corrosion stage, and the corrosion propagation stage. Chemical dissolution of CaS generates H2S and deposits, providing the condition for the formation of the galvanic couple in which the occluded micro-pits serve as anode and the surrounding matrix serves as cathode. The presence of CaS and appropriate electrolyte chemistry are indispensable for the formation of galvanic couple, of which the cathode/anode area ratio is about 50.

Surface acoustic wave (SAW) devices have become an important field of interest because of their low power consumption, low cost, and high stability. In this work, we report an experimental work of tuning the intensity of SAW assisted domain wall motion via the insertion of a nonmagnetic-metal Pd layer between [Co/Pd]2 and Py. The results indicated that the velocity of the domain wall motion assisted by SAW can be reduced by increasing the thickness of the inserted nonmagnetic-metal Pd at the fundamental frequency (183.4 MHz). Above or below the fundamental frequency, the response of the device is not obvious. Our study could provide a way for achieving adjustable and stable domain wall motion in domain-wall-based spintronic devices.

High-frequency studies, of exchange-coupled multilayer films, are the key to advance the development of fast switching spintronic devices. In this paper, we utilize the first-order reversal curve (FORC) to improve the understanding of the spin-reorientation transition process when the permalloy (Py) thickness increases. We also investigate the temperature dependence of the high-frequency properties of exchange-coupled [Co/Pd]6/Py (t nm) multilayer films during the spin-reorientation transition (SRT). The results show that the phase state of the magnetic domain changes, from the perpendicular phase to the multi-domain phase as the Py layer increases during the SRT. The temperature-dependent high frequency results indicate that the resonance linewidth ΔHres increases gradually when the temperature decreases from 300 K to 50 K. Our experimental study offers new insight into the SRT process in exchange-coupled multilayer films and can help to promote the development of fast switching spintronic devices.

Objectives: The aim of this study was to evaluate the association of miR-126 with risk and severity of coronary artery disease (CAD) as well as its correlation with inflammatory cytokines and endothelial related proteins. Methods: In total, 215 patients suspected of CAD who underwent coronary angiography were enrolled in this case control study and were divided into a CAD group (n = 119) and control group (n = 96). miR-126 relative expression was assessed by real-time polymerase chain reaction. Results: The relative expression of miR-126 decreased in CAD patients compared to controls (p < 0.001), and the receiver operating characteristic curve showed a good diagnostic value of miR-126 for CAD risk with an area under the curve of 0.801 (95% CI 0.740-0.861). Additionally, miR-126 was negatively correlated with high-sensitivity C-reactive protein levels (p < 0.001) and reversely associated with TNF-α (p = 0.008) and IL-6 (p < 0.001) levels, while it was positively correlated with the IL-10 level (p < 0.001). In addition, miR-126 was negatively associated with intercellular adhesion molecule-1 (ICAM-1) levels (p = 0.001), and no association of miR-126 with vascular endothelial growth factor was detected (p = 0.142). Meanwhile, the miR-126 relative level was negatively associated with the Gensini score (p < 0.001). Conclusions: Peripheral blood mononuclear cell miR-126 predicts risk and severity and correlates with inflammatory cytokines as well as ICAM-1 in patients with CAD.

In this work, exchange-biased Co/IrMn bilayers were fabricated by dc magnetron sputtering at room temperature. We investigated the misalignment angle between uniaxial and unidirectional anisotropies by measuring in-plane angular dependent ferromagnetic resonance. We found that the misalignment angle decreases with the ferromagnetic-layer (Co) thickness increasing. An asymmetric magnetization reversal phenomenon was also observed due to the misalignment anisotropy. By rotating the sample to a certain angle which respond to the direction of effective easy axis of uniaxial and unidirectional anisotropies, the asymmetry magnetization reversal can be effectively eliminated.

High frequency properties of exchange-coupled multilayers are important to develop future fast switching spintronic devices. Here, we report an experimental investigation of temperature-dependent high frequency properties in [Co/Pd]n/Py multilayer thin films. The results demonstrate that the linewidth varies with the number of cycles at room temperature. However, the damping slightly decreases with increasing repetitions of Co/Pd. By fitting the relationship between the linewidth and the angle (the out-of-plane azimuthal angle of the external magnetic field), we found that a similar two-magnetron scattering effect becomes stronger when the number of Co/Pd cycles increases. For the (Co/Pd)10/NiFe sample, the linewidth became larger at 9 GHz and 16 GHz with the decrease of temperature. Our findings help comprehend the high frequency properties of exchange-coupled multilayer thin films and are useful for fast switching magnetic devices.

As technology grows, semiconductor industry evolved towards tinier & thinner packages to meet market demand. To create competitiveness, chip size shrinkage at front-end wafer fabrication is essential for newer packages technology. With the tireless effort from front-end fab, die size & thickness are reduced up to 30%. There are changes on wire bond pad as well, pad opening is reduced & pad metallization is changed to NiPPdAu with barrier metal underneath. This paper will discuss in details mainly on die bonding & wire bonding challenges for shrink chip technology. Critical defects such as vertical crack die, die surface contamination & passivation crack were observed during process development stage. Several efforts were made to address them accordingly. Finally this paper will share on new failure mechanism observed during ramp up, evaluations for risk assessment & future improvement ideas to overcome mass production obstacles.