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Abstract An ultraviolet-infrared (UV-IR) dual-wavelength photodetector (PD) based on a monolayer (ML) graphene/GaN heterostructure has been successfully fabricated in this work. The ML graphene was synthesized by chemical vapor deposition (CVD) and subsequently transferred onto GaN substrate using polymethylmethacrylate (PMMA). The morphological and optical properties of the as-prepared graphene and GaN were presented. The fabricated PD based on the graphene/GaN heterostructure exhibited excellent rectify behavior by measuring the current–voltage (I– V) characteristics under dark conditions, and the spectral response demonstrated that the device revealed an UV-IR dual-wavelength photoresponse. In addition, the energy band structure and absorption properties of the ML graphene/GaN heterostructure were theoretically investigated based on density functional theory (DFT) to explore the underlying physical mechanism of the two-dimensional (2D)/three-dimensional (3D) hybrid heterostructure PD device. This work paves the way for the development of innovative GaN-based dual-wavelength optoelectronic devices, offering a potential strategy for future applications in the field of advanced photodetection technology. Graphical Abstract

Highlights The main effects of deformation of flexible catalytic materials on the catalytic hydrogen evolution reaction performance are discussed, and a series of novel strategies to design highly active catalysts based on the mechanical flexibility of low-dimensional nanomaterials are summarized in detail. This review provides a strategic choice for the rational design of low-cost and high-performance industrialized electrocatalysts.

Micro-LED is considered an emerging display technology with significant potential for high resolution, brightness, and energy efficiency in display applications. However, its decreasing pixel size and complex manufacturing process create challenges for its integration with driving units. Recently, researchers have proposed various methods to achieve highly integrated micro-structures with driving unit. Researchers take advantage of the high performance of the transistors to achieve low power consumption, high current gain, and fast response frequency. This paper gives a review of recent studies on the new integration methods of micro-LEDs with different types of transistors, including the integration with BJT, HEMT, TFT, and MOSFET.

GaN-based micro light-emitting diode (LED) has gradually become one of the promising light sources for visible light communication (VLC), of which high modulation bandwidth has been demonstrated. In order to acquire high speed and high brightness for VLC application, the modulation bandwidth and optical performance of micro-LEDs were investigated in series and parallel in this work. The electrical characteristics, optical characteristics and communication characteristics of single-pixel, 2-pixel, 4-pixel series and parallel green micro-LEDs with different pixel sizes were systematically tested. High modulation bandwidth as much as 1.4 GHz was acquired by using 10 μm micro-LEDs with 4-pixel in parallel. It is found that parallel micro-LED array can achieve higher modulation bandwidth, higher brightness and higher stability as well, which can be used as the preferred mode for the development of micro-LED based VLC.

Micro-light-emitting diodes (micro-LEDs) with high modulation rates and low power consumption could attract growing attention as visible light communication (VLC) technology advances. The designed and fabricated semi-polar micro-LEDs have achieved high bandwidth at low current injection due to the reduced quantum-confined Stark effect (QCSE), which was significantly greater than that of typical c-plane at the same current injection. Semi-polar green micro-LEDs got a −3 dB bandwidth that surpasses 500 MHz and 1 GHz at low current densities of 43.8 A/cm2 and 120.6 A/cm2, while blue micro-LEDs exceed 500 MHz at low current densities of 76.6 A/cm2, respectively. Additionally, the free space VLC system has shown semi-polar blue and green micro-LED transmission data rates of 3.495 Gbps (433 A/cm2) and 3.483 Gbps (402 A/cm2) respectively. Semi-polar micro-LEDs, which can achieve low power consumption and high bandwidth, are anticipated to play a significant role in the development of energy-efficient VLC in the future.

In recent years, the rapid progress in the field of GaN-based power devices has led to a smaller chip size and increased power usage. However, this has given rise to increasing heat aggregation, which affects the reliability and stability of these devices. To address this issue, diamond substrates with nanostructures were designed and investigated in this paper. The simulation results confirmed the enhanced performance of the device with diamond nanostructures, and the fabrication of a diamond substrate with nanostructures is demonstrated herein. The diamond substrate with square nanopillars 2000 nm in height exhibited optimal heat dissipation performance. Nanostructures can effectively decrease heat accumulation, resulting in a reduction in temperature from 121 °C to 114 °C. Overall, the simulation and experimental results in this work may provide guidelines and help in the development of the advanced thermal management of GaN devices using diamond micro/nanostructured substrates.

To improve the performance of optoelectronic devices, a high performance wide angle SiO2/Ti3O5 Distributed Bragg Reflector (DBR) mirror was designed and fabricated on double polished sapphire substrate. 17-pairs gradually varied DBR structure was applied in order to acquire a broad stopband reflectivity over 95% from 400 nm to 800 nm, covering the whole visible light region. The DBR mirrors deposited at the backside of optoelectronics devices are also demonstrated to remain a high reflectivity at wide incident angles, which improves the emission efficiency of LEDs and light absorption efficiency of InGaN/GaN photoelectrochemical cell (PEC).

Semi-polar micro-LEDs have gain increasing interests due to the advantages of polarization control and quantum efficiency improvement. In this work, a novel semi-polar (20-21)-plane micro-LEDs array has been designed and manufactured. In comparison with c-plane micro-LEDs, semi-polar micro-LEDs indicate better electrical and optical performance. The relative EQE of semi-polar micro-LEDs remains at 62% under the injected current density of 775.6 A/cm2, which indicates a reduced efficiency droop due to less polarization in MQWs. It has been further proved by a significant reduction of 55% in emission peak blue-shift under the injected current density from 11.1 A/cm2 to 775.6 A/cm2. In addition, the carrier recombination dynamics and spatial light distribution of semi-polar micro-LEDs with different pixel sizes have been studied. Fast recombination lifetime in smaller size semi-polar micro-LEDs indicates a promising way to be used as a high modulation bandwidth light source. Stable and uniform light distribution in a wider range of spatial azimuths further supports for the semi-polar micro-LEDs as a strong candidate for the applications of high-resolution display and high-speed visible light communication.

As the Internet of Things (IoT) has connected large number of devices to the Internet, it is urgently needed to guarantee the low latency, security, scalable content distribution of the IoT network. The benefits of Information-Centric Networking (ICN) in terms of fast and efficient data delivery and improved reliability have raised ICN as a highly promising networking model for IoT environments. However, with the widely spread of the viruses and the explosion of kinds of network devices, the attackers can easily control the devices to form a botnet such as the Mirai. Once the devices are under control, the attackers can launch a consumer-provider collusive attack in the Information-Centric IoT context. In this attack, the malicious clients issue Interest packets that can only be satisfied by the malicious content provider, and the malicious provider replies to the clients just before exceeding the Pending Interest Table entry's expiration time, to occupy the limited resources. In this paper, we expound the model of the consumer-provider collusive attack and analyze the negative effect of the attack. Then we propose a Reputation Value based Early Detection (RVED) mechanism to relieve the impact of the collusive attack. The method aims to adjust the packet dropping rates of different interfaces based on their reputation value, thus to protect the legitimate packets from being dropped as possible. We implement the consumer-provider collusive model and evaluate our defend mechanism in the simulator, and simulation results verify the feasibility and effectiveness against the collusive attack of the RVED mechanism.

GaN-based Micro-LED has been widely regarded as the most promising candidate for next generation of revolutionary display technology due to its advantages of high efficiency, high brightness and high stability. However, the typical micro-fabrication process would leave a great number of damages on the sidewalls of LED pixels, especially for Micro-LEDs, thus reducing the light emitting efficiency. In this paper, sidewall passivation methods were optimized by using acid-base wet etching and SiO2 layer passivation. The optical and electrical characteristics of optimized Micro-LEDs were measured and analyzed. The internal quantum efficiency (IQE) of Micro-LED was increased to 85.4%, and the reverse leakage current was reduced down to 10−13 A at −5 V. Optimized sidewall passivation can significantly reduce the non-radiative recombination centers, improving the device performance and supporting the development of high-resolution Micro-LED display.

GaN-based blue micro-light-emitting diodes (μ-LEDs) with different structures were designed, of which the effect of quantum well (QW) structure on modulation bandwidth was numerically explored. By using trapezoidal QWs, the quantum-confined Stark effect (QCSE) can be reduced, leading to an enhanced electron-hole wave function overlap, thereby increasing the recombination rate and reducing the differential carrier lifetime. In addition, the improved hole transport also creates favorable conditions for shortening the differential carrier lifetime. Furthermore, by comparing with traditional μ-LEDs with different thicknesses of QW, the modulation bandwidth of μ-LEDs with trapezoidal QWs exhibits a large advantage at lower current densities of below 2 kA/cm2.

As information-centric networking (ICN) cache can effectively reduce the requests from customers to producers and improve the efficiency of content acquisition, there are many studies propose to improve system performance of the Internet of Things (IoT) by using the concept of the ICN. In the context of information-centric IoT, the addressing location based on content names and routing transport mechanisms, which presents a high demand for the statistics and prediction of the content popularity. To improve the accuracy of the content popularity prediction, in this paper, we demonstrate a particular analysis of the content popularity and propose a content popularity prediction algorithm based on auto-regressive (AR) model. The algorithm derives regression parameters based on least-squares estimates and predicts future trends of the content popularity through combining various known values in a certain period. The evaluation results show that the proposed algorithm can accurately predict the content popularity of the next time period in information-centric IoT. As a result, the algorithm can increase the cache hit rate in routers, and reduce the network traffic and service access delay effectively to improve the experience of users in various scenarios such as real-time streaming media services.

GaN-based μLEDs with superior properties have enabled outstanding achievements in emerging micro-display, high-quality illumination, and communication applications, especially white-light visible light communication (WL-VLC). WL-VLC systems can simultaneously provide white-light solid-state lighting (SSL) while realizing high-speed wireless optical communication. However, the bandwidth of conventional white-light LEDs is limited by the long-lifetime yellow yttrium aluminum garnet (YAG) phosphor, which restricts the available communication performance. In this paper, white-light GaN-μLEDs combining blue InGaN-μLEDs with green/red perovskite quantum dots (PQDs) are proposed and experimentally demonstrated. Green PQDs (G-PQDs) and red PQDs (R-PQDs) with narrow emission spectrum and short fluorescence lifetime as color converters instead of the conventional slow-response YAG phosphor are mixed with high-bandwidth blue InGaN-μLEDs to generate white light. The communication and illumination performances of the WL-VLC system based on the white-light GaN-based μLEDs are systematically investigated. The VLC properties of monochromatic light (green/red) from G-PQDs or R-PQDs are studied in order to optimize the performance of the white light. The modulation bandwidths of blue InGaN-μLEDs, G-PQDs, and R-PQDs are up to 162 MHz, 64 MHz, and 90 MHz respectively. Furthermore, the white-light bandwidth of 57.5 MHz and the Commission Internationale de L’Eclairage (CIE) of (0.3327, 0.3114) for the WL-VLC system are achieved successfully. These results demonstrate the great potential and the direction of the white-light GaN-μLEDs with PQDs as color converters to be applied for VLC and SSL simultaneously. Meanwhile, these results contribute to the implementation of full-color micro-displays based on μLEDs with high-quality PQDs as color-conversion materials.

Hybrid white light emitting diodes (LEDs) have been developed utilizing micro-LEDs radiatively pumping down-conversion phosphor materials. The cyan InGaN/GaN multiple quantum wells LEDs with 95 μm in square are fabricated into 4 × 4 pixels as one unit in 4 in wafer by photolithography and inductively coupled plasma etching techniques. The relatively low turn on voltage and low leakage of cyan micro-LEDs indicate good electrical performance. A significant reduction in the efficiency droop characteristics of cyan micro-LED has been observed in comparison with that of standard green LED. Finally, based on a systemic optimization for white emission indexes, high-quality hybrid white light emission has been demonstrated by the combination of blue and cyan micro-LEDs with two types of phosphors, which have a high color rendering index up to 87 at the correlated color temperatures of 6500 K. It also demonstrates a way to adjust the color component by modifying the output power of cyan micro-LED in hybrid LED, showing a promising candidate in a large range of applications including micro-displays, bioinstrumentation, photolithography, and lab-on-chip systems in the future.

The mechanisms of reverse leakage in InGaN/GaN multiple-quantum-wells (MQWs) blue and green light-emitting diodes (LEDs) were studied through analyzing the current-voltage (I-V) characteristics with the temperature ranging from 50 to 350 K. When the reverse bias V is below 12 V, the leakage current is dominated by the variable-range hopping conduction (T250K), respectively. As the reverse bias increases (|V|>12V), the space-charge-limited conduction mechanism is responsible for the leakage current. It is found that the leakage current is highly associated with the defects density, as well as the trapping capacity of deep level centers; therefore, the lower leakage current of blue LED is mainly attributed to higher thermal activation energy Ea due to less deep level centers within GaN/InGaN MQWs structures.

Through investigating the temperature dependent current-voltage (T-I-V) properties of GaN based blue and green LEDs in this study, we propose an asymmetric tunneling model to understand the leakage current below turn-on voltage (V < 3.2 V): At the forward bias within 1.5 V ∼ 2.1 V (region 1), the leakage current is main attributed to electrons tunneling from the conduction band of n-type GaN layer to the valence band of p-type GaN layer via defect states in space-charge region (SCR); While, at the forward bias within 2 V ∼ 2.4 V (region 2), heavy holes tunneling gradually becomes dominant at low temperature (T < 200K) as long as they can overcome the energy barrier height. The tunneling barrier for heavy holes is estimated to be lower than that for electrons, indicating the heavy holes might only tunnel to the defect states. This asymmetric tunneling model shows a novel carrier transport process, which provides better understanding of the leakage characteristics and is vital for future device improvements.

Oxygen vacancy (OV) states are the most prevalent chemical defects in metal oxides without extrinsic dopants, which govern the regime of photoelectrochemical (PEC) kinetics. So far, although tremendous strategies are developed to overcome the negative effects from OV, the threshold at which OV plays a positive role has not been specifically studied. Furthermore, the kinetics of stoichiometry changes as well as their effects on the charge transport aroused from manipulating OV distribution are still in confusion. Here, taking α-Ga2O3 nanorod arrays as the model, we show the evolution mechanism about the changes in OV distribution during vacancy engineering. Since the O diffusion flow into bulk is regulated by the surface OV-assisted migration mechanism, the surface OV concentration decreased first and recovered slightly after a period of time. This is deviated from the common sense that the longtime O2 annealing should bring about monotonical OV decrease at the surface. After PEC characterization and theory calculation, the results show that OV plays to the score in the PEC process, depending on its own spatial distribution. The optimized engineering strategy of OV spatial distribution is proposed to establish the efficient carrier separation nanoarchitectures for high-performance UV photodetection. This work provides an insight for clarifying fundamental rules for defect engineering in the PEC field. [ABSTRACT FROM AUTHOR]

Clubroot disease has spread explosively in recent years, posing a serious threat to cruciferous crop production. Take rapeseed for example, according to the statistics, until year 2022 the incidence of the clubroot has exceeded 1.33 million hectares in China. Breeding for resistant cultivars is considered as the most efficient and economical way to prevent clubroot disease spreading. However, the current CR cultivars mostly used CR loci of PbBa8.1 or CRb. Due to the complexity and diversity of Plasmodiophora brassicae from different locations, resources for resistant germplasm need to be explored. In this study, 14 clubroot-resistant Chinese cabbages were characterized using different clubroot pathogens and molecular markers for known CR loci. We found that among them, five materials, DG117, ZS105, SG01, SR06 and JQ07 did not contain CRb locus, and their disease resistance were stronger than Huashuang5R/Huayouza5R. At last, KL02 containing the CRb locus showed stronger resistance to PbXM (strain from Xinmin) than 409R, therefore it may contain other novel loci leading to better resistance. These six Chinese cabbage resources can be considerd as new resistance resources and could be utilized in future breeding work for CR Brassica napus. [ABSTRACT FROM AUTHOR]

Realizing rapid and stable hydrogen sorption at low temperature is critical for magnesium-based hydrogen storage materials. Herein, liquid channels are built in magnesium hydride by introducing lithium borohydride ion conductors as an efficient route for improving its hydrogen sorption. For instance, the 5 wt% LiBH4-doped MgH2 can release about 7.1 wt.% H2 within 40 min at 300 °C but pure MgH2 only desorbs less than 0.7 wt.% H2, and more importantly it delivers faster desorption kinetics with more than 10 times enhancement to pure MgH2. The hydrogen absorption capacity of LiBH4-doped MgH2 can still be well kept at approximately 7.2 wt.% without obvious capacity degradation even after six absorption and desorption cycles. This approach is not only through building ion transfer channels as a hydrogen carrier for kinetic enhancement but also by inhibiting the agglomeration of MgH2 particles to obtain stable cyclic performance, which brings further insights to promoting the hydrogen ab-/desorption of other metal hydrides. [ABSTRACT FROM AUTHOR]

Endothelial barrier integrity requires recycling of VE-cadherin to adherens junctions. Both p18 and Rab11a play significant roles in VE-cadherin recycling. However, the underlying mechanism and the role of p18 in activating Rab11a have yet to be elucidated. Performing in vitro and in vivo experiments, we showed that p18 protein bound to VE-cadherin before Rab11a through its VE-cadherin-binding domain (aa 1-39). Transendothelial resistance showed that overexpression of p18 promoted the circulation of VE-cadherin to adherens junctions and the recovery of the endothelial barrier. Silencing of p18 caused endothelial barrier dysfunction and prevented Rab11a-positive recycling endosome accumulation in the perinuclear recycling compartments. Furthermore, p18 knockdown in pulmonary microvessels markedly increased vascular leakage in mice challenged with lipopolysaccharide and cecal ligation puncture. This study showed that p18 regulated the pulmonary endothelial barrier function in vitro and in vivo by regulating the binding of Rab11a to VE-cadherin and the activation of Rab11a. [ABSTRACT FROM AUTHOR]

Highly ordered c-plane InGaN/GaN elliptic nanorod (NR) and nano-grating (NG) arrays were fabricated by our developed soft UV-curing nanoimprint lithography on a wafer. The polarized photoluminescence emission from these elliptic NR and NG arrays has been investigated both theoretically and experimentally. Considerable in-plane optical anisotropy, with a polarization ratio of 15% and 71% and a peak shift of 5.2 meV and 28.1 meV, was discovered from these c-plane InGaN/GaN elliptic NR and NG arrays, respectively. The k.p perturbation theory was adopted to explore this situation, simulating the transitions from conduction subbands to valence subbands and their corresponding optical momentum matrix elements at/around C point under the in-plane asymmetric strain. The good agreements of observed and simulated results demonstrate that the in-plane strain asymmetry is the essential cause of the optical polarization in this case, revealing the great potential to utilize strain effect to control the polarization of InGaN/GaN nanostructures. [ABSTRACT FROM AUTHOR]

Surface-plasmon (SP) coupled red light emitting InGaN/GaN multiple quantum well (MQW) structure is fabricated and investigated. The centre wavelength of 5-period InGaN/GaN MQW structure is about 620 nm. The intensity of photoluminescence (PL) for InGaN QW with naked Ag nano-structures (NS) is only slightly increased due to the oxidation of Ag NS as compared to that for the InGaN QW. However, InGaN QW with Ag NS/SiO2 structure can evidently enhance the emission efficiency due to the elimination of surface oxide layer of Ag NS. With increasing the laser excitation power, the PL intensity is enhanced by 25%-53% as compared to that for the SiO2 coating InGaN QW. The steady-state electric field distribution obtained by the three-dimensional finite-difference time-domain method is different for both structures. The proportion of the field distributed in the Ag NS for the GaN/Ag NS/SiO2 structure is smaller as compared to that for the GaN/naked Ag NS structure. As a result, the energy loss of localized SP modes for the GaN/naked Ag NS structure will be larger due to the absorption of Ag layer. [ABSTRACT FROM AUTHOR]

The spontaneous emission (SE) of InGaN/GaN quantum well (QW) structure with silver(Ag) coated on the n-GaN layer has been investigated by using six-by-six K-P method taking into account the electron-hole band structures, the photon density of states of surface plasmon polariton (SPP), and the evanescent fields of SPP. The SE into SPP mode can be remarkably enhanced due to the increase of electron-hole pairs near the Ag by modulating the InGaN/GaN QW structure or increasing the carrier injection. However, the ratio between the total SE rates into SPP mode and free space will approach to saturation or slightly decrease for the optimized structures with various distances between Ag film and QW layer at a high injection carrier density. Furthermore, the Ga-face QW structure has a higher SE rate than the N-face QW structure due to the overlap region of electron-hole pairs nearer to the Ag film. [ABSTRACT FROM AUTHOR]

Psoriasis is an erythrogenic skin condition identified by multi-layered scales in addition to the thick epidermis (top layer of the skin). The function of interleukin-17A (IL-17A) in the progression of psoriasis is well-known. The interactivity of IL-17A with IL-17(R)A is the main target to investigate the interaction between the two interleukins, which resulted in the amelioration of psoriasis in mice. Our study was aimed to analyze the PCA effects on the association between IL-17A and IL-17(R)A in psoriasis induced mouse model by imiquimod (IMQ). The topical use of IMQ caused psoriasis in mice, followed by oral administration of two doses of PCA (-50 and -100 mg/kg) respectively for fourteen successive days. IL-17A blocking assay was performed to analyze the relationship between IL-17A and IL-17(R)A, followed by RNA-sequencing and histopathological studies. The blocking assay of IL-17A demonstrated that PCA was able to interrelate with the IL-17A residues and therefore eliminated the binding capacity of IL-17(R)A to IL-17A. PCA, in a dose-dependent manner, changed the interrelationship between IL-17A and IL-17(R)A; diminished IMQ-caused mice's skin lesions, and also improved histopathological lesions. PCA diminished the invasion of the inflammatory cells and cytokine secretions in IMQ-treated psoriasis. Our results identified novel findings involving oral administration of protocatechuic acid as a bioactive compound that offered protection against IMQ-caused psoriasis in mice through the alteration of interaction between interleukin-17A and IL-17(R)A. [ABSTRACT FROM AUTHOR]

Obesity is recognized as a significant risk factor for diabetes and hypertension. The present study aimed to examine the associations between adults' obesity risk and childhood and parental obesity. A total of 204 children aged 6-17 years were recruited in 2002 with an average follow-up period of 13.2 years. Height and body weight were measured by trained staffs. Overweight and obesity were defined based on the Chinese standard for children and adults. T-test, analysis of variance, and Chi-square analysis were used for single factor analysis. Multiple linear and logistic regression analyses were used to perform multifactor analysis. The percentage of non-obese children who grew up to be non-obese adults was 62.6%, and that of obese children who grew up to be obese adults was 80.0%. There was a significant association between childhood body mass index (BMI) and adulthood BMI with a β regression coefficient of 3.76 [95% confidence interval (CI): 1.36-6.16], and between childhood obesity and adulthood obesity with an odds ratio of 5.76 (95% CI : 1.37-24.34). There was no statistical difference between parental obesity at baseline and children's adulthood obesity, after adjustment of confounders. Male participants and those aged 10.0-13.0 years had a higher risk of adulthood obesity with odds ratios of 2.50 (95% CI : 1.12-5.26) and 3.62 (95% CI : 1.17-11.24), respectively. Childhood obesity is an important predictor of adulthood obesity. [ABSTRACT FROM AUTHOR]

A novel and simple electrochemical immunoassay for C-reactive protein was developed using metal-organic frameworks (Au-MOFs) as signal unit. In this study, we found MOFs could be used as signal probe. And this new class of signal probe differs from traditional probe. The signal of the copper ions (Cu2+) from MOFs could be directly detected without acid dissolution and preconcentration, which would greatly simplify the detection steps and reduce the detection time. Moreover, MOFs contain large amounts of Cu2+ ions, providing high electrochemical signals. Our report represents the first example of using MOFs themselves as electrochemical signal probe for biosensors. Platinum nanoparticle modified covalent organic frameworks (Pt-COFs) with high electronic conductivity was employed as the substrate, which is the first time demonstrating the use of Pt-COFs for electrochemical immunoassay. Under the optimized experimental conditions, the proposed sensing strategy provides a linear dynamic ranging from 1 to 400 ng/mL. A detection limit of 0.2 ng/mL was obtained, indicating an improved analytical performance. With these merits, this stable, simple, low-cost, sensitive and selective electrochemical immunoassay shows promise for applications in the point-of-care diagnostics of dieses and environmental monitoring. [ABSTRACT FROM AUTHOR]

Blue InGaN/GaN nanohole light-emitting diodes have been fabricated by soft UV-curing nanoimprint lithography, filling with CdSe/ZnS core/shell nanocrystals (NCs) as color conversion mediums. The excitonic recombination dynamics of hybrid nanohole light-emitting diodes were investigated by time-resolved photoluminescence, observing a significant reduction in the decay lifetime of excitons as a result of an efficient non-radiative resonant energy transfer, which leads to the improvement of color conversion and efficiency droop in these hybrid nanohole lightemitting diodes compared to hybrid nanocrystals/standard planar light-emitting diodes. The colorconversion efficiency and effective quantum yield of hybrid nanohole light-emitting diodes were nearly twice as much as those of hybrid standard light-emitting diodes. A model on the excitonic recombination process was proposed to explore this situation, explaining the advantages of nonradiative resonant energy transfer that avoiding energy loss associated with the intermediate light emission and conversion steps and transferring energy non-radiatively and resonantly to NCs with a higher quantum yield. The efficiency droop of hybrid nanohole light-emitting diodes was validly suppressed compared to the bare ones, even better than that of hybrid standard light-emitting diodes. It mainly results from the extraction of excess carrier concentrations in InGaN/GaN multiple quantum wells via the rapid non-radiative resonant energy transfer process under the higher injection condition, revealing a great potential to realize efficient white light emitters in the future. [ABSTRACT FROM AUTHOR]

The combination of NO storage and reduction and in situ NH selective catalytic reduction (NSR-SCR) provides the benefits of simple structure, no external source of NH, low precious metal consumption and high NO reduction efficiency. The by-product ammonia is of importance in the NSR-SCR coupling system. Considering the formation of ammonia and another important side product NO during the regeneration period of NSR, detailed mechanisms of H-NO and CO-NO reactions over Pt were developed. The mechanisms of H-NO and CO-NO reaction systems, which share the same NO chemistries, are capable of reproducing experimental results from literature. Ammonia was shown highly sensitive to H/NO feed ratio. NH was formed at low temperatures and decomposed with increase of temperature. For different feed conditions, NH x related reactions showed similar influential tendency on NH generation, while the hydrogenation of NH showed much greater influence than the other two reactions. In CO-NO reaction system, the intermediate species NO formed at low temperatures and reached a maximum production at about 320 °C. NO decomposed into target product N when temperature was further increased. The results of coverage and sensitivity analysis indicated that adsorbed CO occupied most catalytic active sites over the whole temperature range of 100-500 °C investigated and showed strong adsorption energy, hindering NO adsorption process and NO dissociation. As a result, the inadequacy of N species reduced the production of N and NO. [ABSTRACT FROM AUTHOR]

The aim of this study is to provide a reliability design methodology based on experience data and theory analyses to choose bolts in terms of strength grade and surface process, therefore, to ensure safe car operation The components under investigation are some clamped joints made of aluminum alloy and used in micro car chassis to connect the lower arm to the body. The aluminum alloy is realized by three kinds of surface process: dacro, Ep.FeZn8.C2C, Ep.FeZn8.C2D and three kinds of strength grade: 8.8, 10.9, and 12.9. Some experiences have been appropriately designed with the same process of the actual components on the advanced tightening device. The mean values and standard deviations of bolt yield stress can be obtained via tightening experience whereas the mean values and standard deviations of total tensile stress can be calculated according to bolt load evaluated by means of FEM. Based on stress-strength interference theory the reliability of bolt with different strength grades and surface processes can be calculated, which is useful to choose bolts. Compared the traditional safety factor method, the reliability design method takes into account random factors influence to the preload such as the bolt manufacturing error and the dispersion of the torque coefficient, so it is a more rational approach to select fasteners and has important engineering significance to the threaded connection safe operation for the automotive industry. [ABSTRACT FROM AUTHOR]