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Based on first-principles Density functional theory (DFT), the binding work, interface energy, electronic structure and interface bonding mechanism of WC-304 stainless steel with Fe-Cr-Ni cemented carbides were calculated. The results show that the interface between Fe (100) and WC (100) C-teminations has the lowest interface distance and the highest binding work when it is constructed with MT position. The subsitution of Fe atoms with Ni atoms results in a decrease in the interfacial distance, measured at 0.9412 Å, accompanied by a simultaneous increase the adhesion work to 9.3647 J/m2. The stability of the interface structure is significantly influenced by the bonding strength of Fe C bonds. Furthermore, the C Cr bond at the interface exhibits greater strength compared to the C W bond when the W atom is replaced by Cr atom. Therefore, the doping of Cr and Ni atoms in 304 stainless steel results in a more stable interface structure between WC and Fe. The results have important guiding significance for improving the interfacial strength and stability of WC-Fe cemented carbide. • The WC-304 cemented carbide is prepared using the vacuum sintering process. • The binding work, interface energy, eletronic structure and interface bonding mechanism of WC-304 cemented cerbides are calculated. • When replacing Ni atoms in Fe structure, the interface spacing and the adhesion work have undergone a change. • The reason of the formation of stable interface is analyzed. [ABSTRACT FROM AUTHOR]

This paper presents a high-speed, low-jitter, and high-precision clock receiver circuit (CLKRX) for time-interleaved ADCs with a sampling rate of 4 GS/s operating in the 3–5 GHz frequency range. The CLKRX circuit is composed of a continuous-time linear equalizer (CTLE) and a duty-cycle corrector (DCC). The CTLE featuring active feedback, negative Miller capacitance, and source-follower feedback is capable of enhancing the bandwidth, and improving the quality of the high-speed clock. Whereas the 3–5 GHz DCC module contains a common-mode voltage correction circuit and a wideband amplifier that corrects the input signal's duty cycle ranging from 20% to 80%. A second-order duty-cycle detection circuit is used in the feedback loop, which significantly improves the range and accuracy of duty-cycle correction and greatly reduces duty cycle jitter.The clock receiver circuit proposed in this paper was verified in a 28 nm CMOS process, and the test results show that the output duty cycle is corrected to 50 ± 0.1% within the input duty cycle range of 20–80% (3–5 GHz). [ABSTRACT FROM AUTHOR]

Various signaling techniques have been considered for I/O interconnects at 25 Gb/s or higher. However, they either suffer from high baud rate, as in the case of NRZ, or an excess signal-to-noise ratio penalty, as in the case of PAM-4. To overcome these problems, a four-phase shifted sinusoid symbol (PSS-4) signaling method is proposed that can be readily applied to high-speed I/O transceivers. By using PSS-4, the SNR penalty can be reduced from PAM-4; our theoretical analysis has revealed that the SNR performance of the PSS-4 is 6.5 dB better than that of PAM-4 with comparable bandwidth. The transistor-level simulation results have shown that PSS-4 has an average of twice larger vertical eye opening than PAM-4. In addition, the supply voltage sensitivity of PSS-4 is 55% and 20% less than that of PAM-4 and NRZ, respectively, and the power consumption of PSS-4 is 13.5% lower than that of PAM-4. [ABSTRACT FROM AUTHOR]

In this paper, an optimization method of switching sequence is proposed to compensate for the gradient errors in the current source array of the current-steering digital-to-analog converter. Combining the central symmetry method and the iterative method, the linear and the quadratic gradient errors in the current source arrays are all eliminated. Through the mathematical induction and MATLAB simulation, the proposed switching sequence shows that both the linear and quadratic gradient errors can be compensated. To verify the optimization method proposed, a 12-bit DAC was fabricated under the 55 ​nm 2.5 ​V CMOS process. The measured INL and DNL are bounded at 0.62LSB and 0.37LSB, respectively. The SFDR is more than 78 ​dB with the signal frequencies below 1 ​MHz and more than 66 ​dB in the whole Nyquist band frequency. [ABSTRACT FROM AUTHOR]

This paper presents a programmable low power and low noise analog front-end (AFE) for electrocardiogram (ECG) signal acquisition. A novel capacitor-coupled instrumentation amplifier (CCIA) features independent biasing technique and AC coupling to signal source is proposed. Independent biasing technique is capable of obtaining better noise performance and more stable static working point reducing the glitch of chopping. An AC coupling style helps suppress electrode DC offset and enhance input impedance with metal-oxide-metal capacitor array, which is symmetrical to the center to alleviate the mismatch of input capacitor enhancing system common mode rejection ratio (CMRR). The current steering technology (CST) and programmable feedback capacitors are utilized to achieve an area-efficient programmable low pass filter (PLPF) under PVT variations. Also, a charge buck after PLPF is introduced to strengthen the driving ability of AFE. To verify the proposed AFE structure, a prototype is designed in 0.13 μm standard CMOS process with a 1.2 V supply. Post-simulation results show that the input impedance reaches 1.4 GΩ under 50 Hz. The in-band white noise density and integrating noise are 48 nV/sqrt (Hz) and 0.6 μV, respectively. The obtained low pass corner of PLPF are 380 Hz, 451 Hz and 1 kHz. The CMRR and PSRR under montecarlo simulation are 93 dB and 77 dB, respectively. The power of whole AFE is 48 μW. [ABSTRACT FROM AUTHOR]

• Robust HDR imaging for wide baseline and large angle deviation. • One image per viewpoint. • MVHDR images without exposure time and ISO information. • Complex geometric alignment of non-linear cameras. • Low and backlighting. The restoration and enhancement of multiview low dynamic range (MVLDR) images captured in low lighting conditions is a great challenge. The disparity maps are hardly reliable in practical, real-world scenarios and suffers from holes and artifacts due to large baseline and angle deviation among multiple cameras in low lighting conditions. Furthermore, multiple images with some additional information (e.g., ISO/exposure time, etc.) are required for the radiance map and poses the additional challenges of deghosting to encounter motion artifacts. In this paper, we proposed a method to reconstruct multiview high dynamic range (MVHDR) images from MVLDR images without relying on disparity maps. We detect and accurately match the feature points among the involved input views and gather the brightness information from the neighboring viewpoints to optimize an image restoration function based on input exposure gain to finally generate MVHDR images. Our method is very reliable and suitable for a wide baseline among sparse cameras. The proposed method requires only one image per viewpoint without any additional information and outperforms others. [ABSTRACT FROM AUTHOR]

In-situ WC/Fe composites were prepared by spark plasma sintering, and the interfacial reaction of two phases was regulated by adjusting the atomic ratio of W-to-C. With the decrease of the atomic ratio of W-to-C, the content of Fe 3 W 3 C of the interfacial products of two phases decreased, and the hardness and wear resistance of WC/Fe composites increased. The phase composition of the composite remains relatively unchanged and the optimal wear performance is achieved when the atomic ratio of W-to-C is below 1:1.5. Meanwhile, based on the nanohardness results, the hardness distribution from WC to the substrate was determined. At a penetration depth of 300 nm, the interfacial fracture toughness of Fe 3 W 3 C was found to be 3.01 ± 0.82 MPa·m1/2. Additionally, the deformation rate of Fe 3 W 3 C was determined to be 89% based on the load-displacement curve. For the composites with W to C atomic mass ratio of 1:1.5, 1:1.76 and 1:2.02, oxidative wear may play an important role in reducing the specific wear rate, while for W to C atomic mass ratio of 1:1.3, micro-cutting wear may play a key role. Through a combination of simulation and experimentation, an analysis was conducted on the impact of the friction coefficient of composite materials on their wear resistance, as well as the stress situation of WC particles during the friction process. This analysis serves as a theoretical foundation for the results obtained in the testing process. • The interfacial reaction of WC/Fe composite was regulated by adjusting the atomic ratio of W-to-C. • The optimal wear performance is achieved when the atomic ratio of W-to-C is below 1:1.5. • Based on the nanohardness results, the interfacial fracture toughness of Fe 3 W 3 C was found to be 3.01 ± 0.82 MPa·m1/2. • The main wear mechanisms of each WC/Fe composite are different. [ABSTRACT FROM AUTHOR]

This paper presents a power and area efficient pseudo single ended switching ADC for portable biomedical signal monitoring applications. The switching method features an 8-bit binary-weighted DAC array with a novel layout method called limited bottom-plate routing (LBPR) maintaining both feasibility and symmetry, a dynamic biased comparator and dynamic control logic. As a result, the proposed ADC saves 96.7% power consumption and 87.5% area occupation compared with conventional SAR ADC. Also, a novel DAC array layout method is promoted maintaining both feasibility and symmetry. A prototyped chip including a proposed ADC is fabricated in a 0.13 μm CMOS process. On condition of 0.6 V supply voltage and 10 kS/s sampling rate, the measured signal-to-noise-distortion (SNDR) and spurious free dynamic range (SFDR) are 57.8 dB and 64.3 dB, respectively. Besides, the ADC consumes only 40 nW power and 0.053 mm2 area achieving a figure-of-merit (FoM) of 6.26 fJ/conversion-step. Low power and low area occupation make it a good candidate for biomedical signal monitoring applications. [ABSTRACT FROM AUTHOR]

The health risks associated with rice consumption may decrease if consumers use cooking practices which can reduce the bioaccessibility of metal(loid)s. The effects of cooking on the Cd and As bioaccessibility, at three contamination levels of rice, were studied. Results indicated that cooking reduced bioaccessibility of Cd and As in rice. Cooking resulted in a significant increase (p < 0.01) of Cd and As concentrations in the residual fraction. Low volume water-cooking of rice to dryness reduced total Cd by about 10% for rices A and B, while medium or high volume water-cooking had no effect on Cd bioaccessibility in all rice types. In contrast, low volume cooking did not remove As, but a significant decrease (p < 0.05) was observed when cooking with higher volumes of water. This study provides information for a better understanding of more realistic estimation of metal(loid)s exposure from rice and the possible health risks. [ABSTRACT FROM AUTHOR]

• Ultrafine RuNPs are stabilised by amino-modified polymer immobilized ionic liquid. • High activity for hydrolytic evolution of hydrogen from NaBH 4. • Kinetic studies confirm the hydrolysis is first order in catalyst and hydride. • Kinetic isotope studies with H 2 O/D 2 O and NaBH 4 /NaBD 4 support the proposed mechanism. • High activity retained over five reuses with only a minor reduction in conversion. Ruthenium nanoparticles stabilised by polymer immobilized ionic liquids catalyse the hydrolytic release of hydrogen from sodium borohydride. The composition of the polymer influences performance and ruthenium nanoparticles stabilised by an amine-decorated imidazolium-based polymer immobilised ionic liquid (RuNP@NH 2 -PIILS) was the most efficient with a maximum initial turnover frequency (TOF) of 177 mole H2.mol Ru −1.min−1, obtained at 30°C with a catalyst loading of 0.08 mol%; markedly higher than that of 69 mol H2.mol Ru −1.min−1 obtained with 5 wt% Ru/C and one of the highest to be reported for a RuNP catalyst. The apparent activation energy (Ea) of 38.9 kJ mol−1 for the hydrolysis of NaBH 4 catalysed by RuNP@NH 2 -PIILS is lower than that for the other polymer immobilized ionic liquid stabilised RuNPs, which is consistent with its efficacy. Comparison of the initial rates of hydrolysis in H 2 O and D 2 O catalysed by RuNP@NH 2 -PIILS gave a primary kinetic isotope effect (k H / k D) of 2.3 which supports a mechanism involving rate limiting oxidative addition of one of the O-H bonds in a strongly hydrogen-bonded surface-coordinated [BH 3 H−]—-H 2 O ensemble. The involvement of a surface-coordinated borohydride is further supported by an inverse kinetic isotope effect of 0.65 obtained from a comparison of the initial rates for the hydrolysis of NaBH 4 and NaBD 4 under the conditions of catalysis i.e., at a high hydride/catalyst mole ratio. Interestingly though, when the comparison of the initial rates of hydrolysis of NaBH 4 and NaBD 4 was conducted in dilute solution with a hydride/catalyst mole ratio of 1 a kinetic isotope effect (k H / k D) of 2.72 was obtained; this would be more consistent with concerted activation of both an O-H and B-H bond in the rate limiting step, possibly via a concerted oxidative addition-hydride transfer in the surface-coordinated hydrogen-bonded ensemble. Catalyst stability and reuse studies showed that RuNP@NH 2 -PIILS retained 71% of its activity over five runs; the gradual drop in the initial TOF with run number appears to be due to passivation of the catalyst by the sodium borate by-product as well as an increase in viscosity of the reaction mixture rather than leaching of the catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

The present study aimed to determine the relationship between astrocytes and recurrent non-severe hypoglycemia (RH)2 -associated cognitive decline in diabetes. RH induced cognitive impairment and neuronal cell death in the cerebral cortex of diabetic mice, accompanied by excessive activation of astrocytes. Levels of the neurotrophins BDNF and GDNF, together with BDNF and GDNF- related signaling, were downregulated by RH. In vitro , recurrent low glucose (RLG)3 impaired cell viability and induced apoptosis of high-glucose cultured astrocytes. Accumulating mitochondrial ROS and dysregulated mitochondrial functions, including abnormal morphology, decreased membrane potential, downregulated ATP levels, and disrupted bioenergetic status, were observed in these cells. SS-31 mediated protection of mitochondrial functions reversed RLG-induced cell viability defects and neurotrophin production. These findings demonstrate that RH induced astrocyte overactivation and mitochondrial dysfunction, leading to astrocyte-derived neurotrophin disturbance, which might contribute to diabetic cognitive decline. Targeting astrocyte mitochondria might represent a neuroprotective therapy for hypoglycemia-associated neurodegeneration in diabetes. • RH induced neurodegeneration and excessive activation of the cortical astrocytes. • RH disrupted neurotrophin level and the related signaling in the cerebral cortex of diabetic mice. • RLG induced mitochondrial ROS accumulation in astrocytes in high glucose culture. • RLG impaired mitochondrial function of astrocytes in high glucose culture. • RLG-induced mitochondrial dysfunction reduced astrocytic neurotrophin synthesis and secretion. [ABSTRACT FROM AUTHOR]

Magnetic biochar has been widely used in the removal of aquatic pollutants due to its strong adsorption capacity and recyclability. However, the nutrient deficiency caused by magnetic biochar reduces plant performance and limits its use. The effects of magnetic biochar (derived from either eucalyptus wood or pig manure compost) on soil Cd, Zn, and Pb bioavailability to Phragmites australis L. (reed) and soil microbial community were investigated in a pot experiment. We also examined treatments of magnetic biochar with P supplementation and unmodified biochar with Fe addition to elucidate the mechanism by which magnetic biochar affects plant growth. We found that the addition of magnetic biochar significantly reduced the concentrations of available heavy metals in soil and inhibited heavy metal uptake by reeds. It also promoted the formation of iron plaque on reed roots to inhibit metal translocation. However, compared to unmodified biochar, magnetic biochar reduced reed performance, as indicated by the reduced plant biomass and photosynthetic ability, and it also reduced the biomass of soil bacteria and fungi. This was due to the interception of P by the iron plaque and the reduced concentration of soil available P. Collectively, although magnetic biochar exhibited a strong potential for heavy metal remediation, P supplementation is recommended to maintain plant performance and soil health when applying magnetic biochar. Unlabelled Image • Recyclable magnetic biochar was useful for soil heavy metal remediation. • The use of magnetic biochar promoted the formation of iron plaque on the reed root. • The iron oxide from magnetic biochar reduced soil P availability. • Plant performance and soil microbial biomass were reduced due to P deficiency. • P supplementation should be recommended in magnetic biochar-applied soil. [ABSTRACT FROM AUTHOR]

This paper presents a second-order noise-shaping successive approximation register (NS-SAR) analog-to-digital converter (ADC) employing the error-feedback (EF) structure. With the finite impulse response (FIR) filter based on a single operational transconductance amplifier (OTA), it realizes noise transfer function (NTF) zeros optimization. The specifications of OTA are relaxed without high-gain and fast-settling. To mitigate the harmonic distortion caused by capacitor mismatch, thermometer-coded 4-bit MSBs are implemented with the data weighted averaging (DWA) technique. The overall architecture is simple and robust. It does not need additional complicated digital calibrations, and only requires minor modifications to the standard SAR ADC. Design and simulation in a 130 ​nm CMOS process, the prototype consumes 96 ​μW of power when operating at 1 ​MS/s sampling frequency. The proposed ADC achieves peak Schreier FoM of 165 ​dB with 76.95 ​dB signal to noise and distortion ratio (SNDR) and 97.34 ​dB spurious free dynamic range (SFDR) at an oversampling ratio (OSR) of 8. [ABSTRACT FROM AUTHOR]

This paper presents a very compact bandpass filter with two transmission zeros using a commercial GaAs HBT technology. The filter is constructed with two shunt LC tank to generate poles to ensure its passband characteristics, and two series LC tanks to generate zeros at lower and upper stopbands to improve the sideband rejection properties. An additional inductor and capacitor coupling network is employed to achieve good input and output matching without degeneration of the filter selectivity. The filter is designed and fabricated on a 0.35 μm GaAs HBT technology with a chip size of only 0.75 × 0.54 mm2. The test results demonstrated that, the center operation frequency of the proposed BPF is 3.45 GHz with a 500 MHz 1-dB bandwidth, the insertion loss is about 2.5 dB, and the sideband rejection is lower than −20 dB at the designed transmission zero frequencies. [ABSTRACT FROM AUTHOR]