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Integrons are mobile DNA elements that allow for acquisition and dissemination of antibiotic-resistance genes among pig farm-derived bacteria. Limited information is available on integrons of Staphylococcus aureus from pig farms. The aim of this study was to characterise and investigate the prevalence of class 1 and 2 integrons in multi-drug resistant (MDR) S. aureus isolates from pig farms.

Currently, advanced biomaterial design solutions often have more than two kinds of nanotechnology design strategies, but there is no suitable classification to describe these designs systematically. Based on the material design ideas and the modes of implementing functions, this article exemplifies and proposes a new nanotechnology classification that includes physical properties, the chemical reactions that respond to the microenvironment and bio-inspired incorporation. If two or more nanotechnology designs in the same classification are to be integrated into the same biological material, it is necessary to analyze the integration conflict between the designs. With the development of big data, this classification method may help researchers and artificial intelligence to realize automated integration of multiple designs and provide new material nanotechnology design integration solutions.

Indoor safety concerns the safety of people′s life and property. Through indoor intrusion detection, it is possible to achieve early warning and avoid loss. Different from the common intrusion detection methods, the CSI(Channel status information) of the wireless communication signal WiFi is used to correlate with human behavior, which can achieve intrusion detection. The relationship between channel impulse response, channel frequency response and CSI is studied. The association between CSI and human behavior is verified using CSI dataset EHUCOUNT and machine learning method. The results show that the accuracy of intrusion detection based on SVM(Support Vector Machine) and CNN(Convolutional Neural Network) in six typical scenarios is 93.35%～99.23% and 89.17%～99.14%, respectively. Actual tests are carried out through collecting the WiFi signal using self-made spectrum sensor nodes. Experiment results show that intrusion detection accuracy is about 98%, which indicates that the intrusion detection based on WiFi signal is applicable to real scenario.

A novel approach using two-dimensional mixed baseline based on Multi-Input Multi-Output Synthetic Aperture Radar (MIMO-SAR) has been proposed for range delay and azimuth Doppler frequency modulation used in deceptive jamming. Based on MIMO-SAR phase coding method, which makes the multichannel signal orthogonal, we propose the detection of deceptive jamming phenomenon by employing multidimensional phase information, and suppress the jamming targets via phase compensation to improve the ability of countering deceptive jamming. Moreover, we utilize radar anti-jamming improvement factor as a quantitative evaluating index. In the limited platform space, the radar anti-jamming improvement factor of the proposed method is three times greater than that of conventional single-input multi-output systems. Experimental results demonstrate the validity of our method.

Compared to silicon devices, silicon carbide (SiC) devices have much lower C(oss) and Q(g); they can switch at much higher speed, SiC power modules are thus more sensitive to stray parameters. Large stray inductance may result in high voltage spikes and cause severe electro-magnetic interference (EMI) issues; unbalanced stray inductance may contribute to uneven current sharing between parallel devices. Low and symmetrical inductance is a necessity to fully utilise the superior characteristics of SiC devices. This paper first studies the current sharing and voltage spike mechanisms of multichip power modules (MCPMs). Stray inductance distribution, current sharing as well as voltage spikes under different direct bonded copper (DBC) layout conditions are investigated using finite element modelling software. A round symmetrical DBC layout is then proposed. Compared with conventional ones, the proposed structure is symmetrical in stray inductance distribution; thus improving the consistency among chips. To reduce the total equivalent stray inductance and tackle the voltage spike problem, this study further presents an improved 3D structure on the basis of the round symmetrical DBC. The stray inductance extraction and double pulse simulation results verify the effectiveness of the improved 3D structure in current sharing as well as voltage spike reduction.

Sound speed is a critical parameter in ocean acoustic studies, as it determines the propagation and interpretation of recorded sounds. The potential for exploiting oceanic vessel noise as a sound source of opportunity to estimate ocean sound speed profile is investigated. A deep learning-based inversion scheme, relying upon the underwater radiated noise of moving vessels measured by a single hydrophone, is proposed. The dataset used for this study consists of Automatic Identification System data and acoustic recordings of maritime vessels transiting through the Santa Barbara Channel between January 2015 and December 2017. The acoustic recordings and vessel descriptors are used as predictors for regressing sound speed for each meter in the top 200 m of the water column, where sound speeds are most variable. Multiple (typically ranging between 4 and 10) transits were recorded each day; therefore, this dataset provides an opportunity to investigate whether multiple acoustic observations can be leveraged together to improve inversion estimates. The proposed single-transit and multi-transit models resulted in depth-averaged root-mean-square errors of 1.79 and 1.55 m/s, respectively, compared to the seasonal average predictions of 2.80 m/s.

The single crystal nickel-based superalloys with different dendrite spacings were prepared by using various withdrawing rates, and the influence of withdrawing rates on elements segregation and creep properties of them is investigated through creep property measurements and microstructure observation. Results show that relatively bigger withdrawing rate leads to the smaller dendrite spacing and lower segregation extent of elements between the dendrite/interdendrite regions, which further causes the better creep resistance of the alloy. Dislocations climbing over the rafted γ′ phase is deemed as the deformation mechanism of the superalloys during steady state creep. In the later stage of creep, significant amount of dislocations shear into the rafted γ′ phase, which may promote the alternative slipping of dislocations to twist the rafted γ′ phase. At the further latter stage of creep, the initiation and propagation of the cracks occuring up to creep fracture is the fracture mechanism of the superalloy.