Unimodular (i.e., constant modulus) sequences with good autocorrelation properties are useful in several areas, including communications and radar. The integrated sidelobe level (ISL) of the correlation function is often used to express goodness a given sequence. In this paper, we present cyclic algorithms for local minimization ISL-related metrics. These can be initialized existing sequence such as Golomb sequence, Frank or even (pseudo)random To illustrate performance proposed algorithms,...

Searching for a clean and renewable energy system is vital to alleviate the exacerbated environmental pollution problem while addressing dilemma. With clean, high calorific value features, hydrogen has been identified as an ideal carrier change global structure accomplish conversion in future. A promising technique generate water electrolysis, but rationally designing cost-effective highly efficient catalysts facilitate their widespread industrialization still formidable challenge. In recent...

As a clean, sustainable energy source, sound can carry wealth of information and play huge role in the Internet Things era. In recent years, triboelectric acoustic sensors have received increasing attention due to advantages self-power supply high sensitivity. However, charge is susceptible ambient humidity, which reduces reliability sensor limits application scenarios significantly. this paper, highly moisture-resistant fluorinated polyimide composited with an amorphous fluoropolymer film...

In this paper, oriented hBN composites with anisotropic thermal conductivity are employed to improve electrical resistivity-temperature characteristics, thus inhibiting the occurrence of DC surface flashover under temperature gradient by directionally manipulating heat flow. The performance, resistivity, carrier mobility, and electric field distribution depending on orientation studied at different temperatures. When angle between basal plane axis electrodes is 90°, out-of-plane composite...

Abstract Through years of development, the triboelectric nanogenerator (TENG) has been demonstrated as a burgeoning efficient energy harvester. Plenty efforts have devoted to further improving electric output performance through material/surface optimization, ion implantation or external circuit. However, all these methods cannot break fundamental limitation brought by inevitable electrical breakdown effect, and thus density is restricted. Here, method for enhancing threshold TENGs proposed...

We consider a multiple-input multiple-output (MIMO) radar system where both the transmitter and receiver have multiple well-separated subarrays with each subarray containing closely spaced antennas. Because of this general antenna configuration, coherent processing gain spatial diversity can be simultaneously achieved. compare several spectral estimators, including Capon APES, for target detection parameter estimation. introduce generalized-likelihood ratio test (GLRT) conditional (cGLRT)...

Wavelet shrinkage methods are effective for de-noising of partial discharge (PD) detection. Base wavelets related to distortion PD signals de-noised by wavelet methods. This paper presents a scale dependent selection scheme The is called the energy based (EBWS) because an criterion proposed scheme. In criterion, base selected as optimal if it can generate approximation with largest among all at each scale. high-frequency simulated and ultra-high-frequency obtained experiments in laboratory...

The relationship between bonding wire liftoff and terminal voltage in insulated gate bipolar transistor (IGBT) power module is studied. Bonding failure one of the most dominant limiting factors to reliability behavior IGBT module. In this paper, order monitor type fault, effects typical degradations are considered. parasitic inductance equivalent capacitance change due liftoff, which have different impacts on external characteristics. So, two aspects characteristics investigated identify any...

This paper presents aging condition assessment of oil-paper transformer insulation based on partial discharge analysis in order to realize statistical parameters reduction. The extracted feature factors this proposed model were used identify samples with different degrees. An accelerated test was implemented using artificial an internal flat air gap. During the test, signal acquisition conducted periodically. In new model, conventional phase resolved (PRPD) patterns analyzed principal...

Wavelet shrinkage is efficient for de-noising the partial discharge (PD) detection. An improved wavelet approach PD online measurement presented. The based on a genetic adaptive threshold estimation (GATE) scheme. thresholding functions with continuous derivatives are used GATE A algorithm to obtain global optimum thresholds of GATE, and improve robustness computation speed estimation. De-noising experiments simulative high-frequency signals, actual ultra-high-frequency (UHF) field detected...

Partial discharge (PD) online monitoring is an effective tool of inspecting insulation defects and identifying potential faults in power transformers. Ultra-high-frequency (UHF) approaches have caught increasing attention recently been considered as a promising technology for PD signals. The size UHF sensor transformer critical factor practical installation inside transformer. This communication presents compact fourth order Hilbert fractal antenna with desired performance suitable easy...

Electromagnetic waves generated due to partial discharge (PD) can be captured by ultra-high-frequency (UHF) antennas. The size and frequency band of an UHF antenna for PD online monitoring are critical factors practical installation inside a transformer. This paper presents compact multi-band Hilbert fractal with wide suitable easy installation. Design criteria were proposed the was selected as appropriate candidate detection. Principle discussed fourth order optimized detecting signals....

Abstract BACKGROUND A passive planar micromixer with dislocation sub‐channels, based on the principle of asymmetric split and recombination, has been proposed for its effective mixing. Both numerical simulations experiments were used to design investigate effect parameters flowing feature mixing Reynolds numbers ranging from 1 100. The index, which is as measurement criteria, dependent upon number geometrical . RESULTS Through results experimental simulation, it evident that arrangement...

Abstract Exploring low‐cost hydrogen evolution reaction (HER) catalysts with remarkable activity over wide pH range (0–14) still remains an enormous challenge. Herein, for the first time, a novel platinum‐like, double‐deck carbon coated V 8 C 7 networks highly active (110) facet exposed as new efficient HER electrocatalyst is reported. The single‐crystal interweaved are designed and fabricated based on low crystal‐mismatch strategy confinement effect of coating. In addition, electrochemical...

Herein, a unique ganoderma-like MoS2 /NiS2 hetero-nanostructure with isolated Pt atoms anchored is reported. This novel heterostructure can not only efficiently disperse and confine the few-layer nanosheets to fully expose edge sites of , provide more opportunity capture atoms, but also tune electronic structure modify catalytic activity. Because favorable dispersibility exposed large specific surface area, single be easily on ultrahigh loading 1.8 at% (the highest 1.3 date). Owing platinum...

Nanofluids, formed by adding nanoscale particles to insulating oil, are stable and homogeneous suspensions that present advanced performance of electrical insulation heat dissipation. This study shows a comprehensive literature review based on the related results nano-modified oils (both mineral vegetable oils) analyse preparation methods, stability, dielectric spectroscopy, thermal conductivity, breakdown characteristics under AC DC voltage, aging nanofluids oil–paper interaction. Then...