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A highly thermally conductive heat spreader for applications in electronic devices is becoming increasingly demanding, and therefore the removal of excess heat requires an efficient heat dissipating device. Boron nitride nanosheets (BNNSs) were prepared as thermally conductive fillers using hexagonal boron nitride (h-BN) powder as raw material by a water exfoliation method. A composite film was prepared by vacuum filtration using cellulose nanofibers (CNFs) as the substrate with an in-plane thermal conductivity (TC) of 82.4 W m−1 K−1, thermal conductivity enhancement increasing by 9,486% compared to pure cellulose film. Thus, CNF/BNNS composite films are promising as effective thermal interface materials (TIMs) in electronic devices and electronic component applications.

The rapid development of chip technology has all put forward higher requirements for highly thermally conductive materials. In this work, a new type of material of Fishbone-like silicon carbide (SiC) material was used as the filler in a polyvinylidene fluoride (PVDF) matrix. The silicon carbide/polyvinylidene fluoride (SiC/PVDF) composites were successfully prepared with different loading by a simple mixing method. The thermal conductivity of SiC/PVDF composite reached 0.92 W m−1 K−1, which is 470% higher than that of pure polymer. The results show that using the filler with a new structure to construct thermal conductivity networks is an effective way to improve the thermal conductivity of PVDF. This work provides a new idea for the further application in the field of electronic packaging.

Background and Hypothesis The prognostic value of nutritional scoring tools in assessing the relationship between nutritional status and prognosis in hemodialysis patients is unclear. This multicenter retrospective cohort study compared the Prognostic Nutritional Index (PNI), Controlling Nutritional Status scores (CONUT), and Geriatric Nutritional Risk Index (GNRI) for predictive accuracy of all-cause and cardiovascular mortality, especially the impact of dynamic changes over time on prognosis.Methods Hemodialysis patients from four hospitals were included. Laboratory data and nutrition scores were collected at the initiation of dialysis, and at 6th, 12th, and 18th months after dialysis initiation. A joint model analyzed the relationship between dynamic nutritional scores and prognosis. Predictive values were assessed using the area under the curve (AUC).Results The study included 863 patients with a median follow-up of 37 months. During the follow-up, 23.8% of patients died, with 14% attributed to cardiovascular causes. Malnourished patients demonstrated higher risks for all-cause and cardiovascular mortality. Dynamic changes in PNI and GNRI scores were significantly associated with reduced all-cause and cardiovascular mortality risks. Precisely, longitudinal increases in PNI and GNRI scores corresponded to a 4% and 3% reduction in all-cause (PNI: HR, 0.96; 95% CI, 0.95–0.98; GNRI: HR, 0.97; 95% CI, 0.96–0.98) and cardiovascular mortality risk (PNI: HR, 0.96; 95% CI, 0.94–0.98; GNRI: HR, 0.97; 95% CI, 0.95–0.98) respectively, with longer dialysis duration. Changes in CONUT scores were not significantly associated with either all-cause or cardiovascular mortality. The AUCs of the three joint models indicated that the GNRI score (0.893) possessed higher predictive accuracy for all-cause mortality compared to PNI (0.832) and CONUT (0.852). Similar trends were observed for cardiovascular mortality.Conclusion Nutritional scores and their dynamic changes are intimately associated with mortality risk in hemodialysis patients. Compared to PNI and CONUT, the baseline GNRI and its post-dialysis variations demonstrate a superior predictive capability for all-cause and cardiovascular mortality in these patients.

A new pixel circuit consisting of eleven n-type IGZO transistors (TFTs) and four capacitors is proposed and applied for micro light emitting diode (MLED) displays. The circuit is driven by pulse hybrid modulation (PHM), combining pulse amplitude modulation (PAM) and pulse width modulation (PWM). In purpose, high grayscales are achieved by PAM mode and low grayscales are achieved by PWM mode, which keep the driving current of LED out of the small value range so as to avoid unstable luminance performance. It is conducted that the MLED display driven by PHM demonstrate a stable luminance at low grayscale with well suppressed luminance errors of over 30% decrease, in comparison with the display driven by PAM. Moreover, both threshold voltage (VTH) shifts of driving TFTs for PAM mode and PWM mode could be well compensated in this circuit. As revealed by simulations, the driving current variations of LED could be retained within 10% when VTH shifts in the ranges from −1 to 2 V for PAM driving TFT and from −1 to 1.5 V for PWM driving TFT, respectively. In practice, a good brightness uniformity over 90% after 240-hours aging of the MLED display could be realized.

An AMLED compensation pixel circuit, cracking the boundary that the internal compensation in addition with pulse width modulation driving approach is hard to get high-bit performance, is proposed in this work. A case study of a panel with the fresh rate of 120 Hz and resolution of 20 × 20, through adding the extinguish TFT for converting the PWM equal distribution fields to unequal segments, the bit number is greatly increased from three bits to eight bits. Moreover, the current error ratio of novel 6T1C is less than 4.6%, proving that novel 6T1C circuit is proper to increase the bit number and optimize the reliability of display panel.

This study reveals the pronounced density of oxygen vacancies (Vo) at the back channel of back-channel-etched (BCE) a-InGaZnO (a-IGZO) thin-film transistors (TFTs) results from the sputtered deposition rather than the wet etching process of the source/drain metal, and they are distributed within approximately 25 nm of the back surface. Furthermore, the existence and distribution depth of the high density of Vo defects are verified by means of XPS spectra analyses. Then, the mechanism through which the above Vo defects lead to the instability of BCE a-IGZO TFTs is elucidated. Lastly, it is demonstrated that the device instability under high-humidity conditions and negative bias temperature illumination stress can be effectively alleviated by etching and thus removing the surface layer of the back channel, which contains the high density of Vo defects. In addition, this etch method does not cause a significant deterioration in the uniformity of electrical characteristics and is quite convenient to implement in practical fabrication processes. Thus, a novel and effective solution to the device instability of BCE a-IGZO TFTs is provided.

Abstract The large‐area low‐temperature processing capability and versatile characteristics of amorphous oxide semiconductor (AOS) thin‐film transistors (TFTs) are highly expected to promote the developments of next‐generation displays, 3D integrated circuit (3DIC), flexible chips, and electronics. However, the abundant native defects in AOSs engrain an inherent trade‐off between high mobility and trustworthy stability in AOS TFTs, fundamentally limiting the performance metrics and integration scale of oxide‐based electronics. To surmount this obstacle, the bilayer AOS channel is highly expected to combine the merits of diversified AOSs, while the efficiency of such an AOS “heterojunction” is debatable. This work systematically compares the TFTs based on amorphous InGaZnO (a‐IGZO), amorphous InZnO (a‐IZO), and a‐IZO/a‐IGZO bilayer. The active cation interaction between metal‐oxide semiconductors gives rise to a mixed AOS layer rather than a heterojunction channel, corresponding to moderate performance metrics. Such a spontaneous cation interdiffusion is effectively prevented using a dense metal‐oxide dielectric interlayer, aluminum oxide (AlOx). The sharpened interface effectively forms an abrupt metal‐oxide heterojunction, while the electron can still tunnel through the ultrathin AlOx to create a quantum well of 2D electron gas (2DEG). The overall performance and reliability of multilayer AOS TFT are synergistically enhanced using the proposed abrupt metal‐oxide heterojunction architecture.

Active matrix (AM) MiniLED backlight units (BLU) on glass substrate is developed to solve severe problems of MiniLED on PCB including insufficient heat dissipation and worse swelling and shrinking performance, as well as limited zone number. However, the MiniLED on glass is observed to possess a weak ability of anti-electrostatic discharge (ESD). The MiniLEDs on glass developed by us (short for MLED) are demonstrated to have a powerful ability of anti-ESD by the means of optimization of peripheral circuit design and metal and dielectric materials, also by the improvements of surroundings of module assembly factory. Consequently, the failure ratio of reliability analysis of MLED is observed to be decreased drastically after the improvements of the ability of anti-ESD.

The work presents a novel pixel circuit which breaks the constraint that the PWM driving method combined with internal compensating is unable to achieve a high-bit display. By adding another TFT to transform the equal division of PWM to unequally divided subfields, the bit of a 240 Hz 10-row panel is improved from 3 bits to 8 bits, which is a great breakthrough for bits improving in the fields of PWM driving and internal compensating. Furthermore, simulation results of the original 6T1C circuit and revised 7T1C circuit demonstrate that the current error ratio is almost the same, indicating that this revising 7T1C circuit is suitable for bits improving without sacrificing the circuit margin.

N-channel thin film transistors (TFTs) fabricated with hydrogenated low temperature polycrystalline silicon (LTPS) were exposed to ultraviolet (UV) radiation to a cumulative dose up to 16 J/cm2. The effect of radiation on the electrical characteristics of the devices was monitored after the irradiation steps and in a prolonged period after irradiation. The main monitoring parameter was the threshold voltage ( ${V} _{\mathrm{ th}}$ ) which was found to have exponentially linear dependence on irradiation dose. This, together with obtained low fading, suggests that hydrogenated n-channel low temperature polycrystalline silicon TFTs have potential as UV radiation dosimeters. In addition, the physical mechanisms of the UV induced electrical degradation were analyzed in terms of the radiation generated traps at poly-Si grain boundary and poly-Si and gate oxide insulator (poly-Si/SiO2) interface.

At present, picking Sichuan pepper is mainly undertaken by people, which is inefficient and presents the possibility of workers getting hurt. It is necessary to develop an intelligent robot for picking Sichuan peppers in which the key technology is accurate segmentation by means of mechanical vision. In this study, we first took images of Sichuan peppers (Hanyuan variety) in an orchard under various conditions of light intensity, cluster numbers, and image occlusion by other elements such as leaves. Under these various image conditions, we compared the ability of different technologies to segment the images, examining both traditional image segmentation methods (RGB color space, HSV color space, k-means clustering algorithm) and deep learning algorithms (U-Net convolutional network, Pyramid Scene Parsing Network, DeeplabV3+ convolutional network). After the images had been segmented, we compared the effectiveness of each algorithm at identifying Sichuan peppers in the various types of image, using the Intersection Over Union(IOU) and Mean Pixel Accuracy(MPA) indexes to measure success. The results showed that the U-Net algorithm was the most effective in the case of single front-lit clusters light without occlusion, with an IOU of 87.23% and an MPA of 95.95%. In multiple front-lit clusters without occlusion, its IOU was 76.52% and its MPA was 94.33%. Based on these results, we propose applicable segmentation methods for an intelligent Sichuan pepper-picking robot which can identify the fruit in images from various growing environments. The research showed good accuracy for the recognition and segmentation of Sichuan peppers, which suggests that this method can provide technical support for the visual recognition of a pepper-picking robot in the field.

Liriomyza sativae and L. trifolii (Diptera: Agromyzidae) are two highly invasive species of leafmining flies, which have become established as pests of horticultural crops throughout the world. In certain regions where both species have been introduced, L. sativae has displaced L. trifolii, whereas the opposite has occurred in other regions. These opposing outcomes suggest that neither species is an inherently superior competitor. The regions where these displacements have been observed (southern China, Japan and western USA) are climatically different. We determined whether temperature differentially affects the reproductive success of these species and therefore if climatic differences could affect the outcome of interspecific interactions where these species are sympatric. The results of life table parameters indicate that both species can develop successfully at all tested temperatures (20, 25, 31, 33°C). L. sativae had consistently higher fecundities at all temperatures, but L. trifolii developed to reproductive age faster. Age-stage specific survival rates were higher for L. sativae at low temperatures, but these were higher for L. trifolii at higher temperatures. We then compared the net reproductive rates (R0) for both species in pure and mixed cultures maintained at the same four constant temperatures. Both species had significantly lower net reproductive rates in mixed species cultures compared with their respective pure species cultures, indicating that both species are subject to intense interspecific competition. Net reproductive rates were significantly greater for L. sativae than for L. trifolii in mixed species groups at the lower temperatures, whereas the opposite occurred at the higher temperature. Therefore, interactions between the species are temperature dependent and small differences could shift the competitive balance between the species. These temperature mediated effects may contribute to the current ongoing displacement of L. sativae by the more recent invader L. trifolii in warm climatic areas of China.