Organic light emitting devices with enhanced outcoupling via microlenses fabricated by imprint lithography

High efficiency white organic light emitting devices (WOLEDs) with optical outcoupling enhanced by hexagonal polymethylmethacrylate microlens arrays fabricated by imprint lithography on a glass substrate are demonstrated. Monte Carlo and finite difference time domain simulations of the emitted light are used to optimize the microlens design. The measured enhancement of light outcoupling and the angular dependence of the extracted light intensity are in agreement with the simulation. Using microlens arrays, we demonstrate a fluorescent/phosphorescent WOLED with a maximum external quantum efficiency of (14.3±0.3)%(14.3±0.3)% at 900 cd/m2900cd∕m2 and power efficiency of 21.6±0.5 lm/W21.6±0.5lm∕W at 220 cd/m2220cd∕m2. The electroluminescent spectra at viewing angles from normal to the substrate plane, to 60° off normal, remain almost unchanged, giving a color rendering index of 87.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87744/2/073106_1.pd

White organic light-emitting device based on a compound fluorescent-phosphor-sensitized-fluorescent emission layer

The authors demonstrate a combination fluorescent and phosphor-sensitized-fluorescent white organic light-emitting device (WOLED), employing the conductive host material, 4,4′4,4′-bis(9-ethyl-3-carbazovinylene)-1,1′1,1′-biphenyl, doped with the phosphorescent green, and the fluorescent red and blue emitters, fac-tris(2-phenylpyridinato-N,C2′N,C2′) iridium (III), 4-(dicyanomethylene)-2-t2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H4H-pyran, and 4,4′4,4′-bis (9-ethy-3-carbazolvinylene)-1-1′1-1′-biphenyl, respectively. Although two fluorescent dopants are employed along with only a single phosphor, this simple structure can, in principle, achieve 100% internal quantum efficiency. In the prototype, the phosphor-sensitized WOLED exhibits total external quantum and power efficiencies of ηext,tot = 13.1±0.5%ηext,tot=13.1±0.5% and ηp,tot = 20.2±0.7 lm/Wηp,tot=20.2±0.7lm∕W, respectively, at a luminance of 800 cd/m2800cd∕m2 with Commission Internationale de L’Eclairage chromaticity coordinates of (x = 0.38(x=0.38, y = 0.42y=0.42) and a color rendering index of 79.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87798/2/143516_1.pd

Generic Construction of Server-Aided Revocable Hierarchical Identity-Based Encryption with Decryption Key Exposure Resistance

In this paper, we extend the notion of server-aided revocable identity-based encryption (SR-IBE) to the hierarchical IBE (HIBE) setting and propose a generic construction of server-aided revocable hierarchical IBE (SR-HIBE) schemes with decryption key exposure resistance (DKER) from any (weak) L-level revocable HIBE scheme without DKER and (L+1)-level HIBE scheme. In order to realize the server-aided revocation mechanism, we use the “double encryption” technique, and this makes our construction has short ciphertext size. Furthermore, when the maximum hierarchical depth is one, we obtain a generic construction of SR-IBE schemes with DKER from any IBE scheme and two-level HIBE scheme

On the Construction of Lightweight Orthogonal MDS Matrices

In present paper, we investigate 4 problems. Firstly, it is known that, a matrix is MDS if and only if all sub-matrices of this matrix of degree from 1 to $n$ are full rank. In this paper, we propose a theorem that an orthogonal matrix is MDS if and only if all sub-matrices of this orthogonal matrix of degree from 1 to $\lfloor\frac{n}{2}\rfloor$ are full rank. With this theorem, calculation of constructing orthogonal MDS matrices is reduced largely. Secondly, Although it has been proven that the $2^d\times2^d$ circulant orthogonal matrix does not exist over the finite field, we discover that it also does not exist over a bigger set. Thirdly, previous algorithms have to continually change entries of the matrix to construct a lot of candidates. Unfortunately, in these candidates, only very few candidates are orthogonal matrices. With the matrix polynomial residue ring and the minimum polynomials of lightweight element-matrices, we propose an extremely efficient algorithm for constructing $4\times4$ circulant orthogonal MDS matrices. In this algorithm, every candidate must be an circulant orthogonal matrix. Finally, we use this algorithm to construct a lot of lightweight results, and some of them are constructed first time

CP-consensus: a Blockchain Protocol Based on Synchronous Timestamps of Compass Satellite

Bitcoin, the first decentralized cryptocurrency, achieves great success but also encounters many challenges. In this paper, we mainly focus on Bitcoin\u27s five challenges: low network synchronization; poor throughput; high information propagation delay; vulnerabilities to fork-based attacks and consumption of a large amount of computational power to maintain the blockchain. To address these challenges, we present the CP-consensus, a blockchain protocol based on synchronous timestamps of the Compass satellite. Firstly, CP-consensus provides a quasi-synchronous network for nodes. Specifically, nodes synchronously begin or end in each phase. Secondly, the block propagation delay is significantly reduced by adopting cache-nodes. Moreover, the block verification delay is significantly reduced since it is limited only by the size of block-header. Thirdly, CP-consensus has a high throughput with a larger block size since that the block size does not influence the consistency of CP-consensus. Fourthly, CP-consensus resists fork-based attacks and consumes a small amount of computational power. Finally, parameters setting and the security of CP-consensus are discussed

Towards a comprehensive view of the herpes B virus

Herpes B virus is a biosafety level 4 pathogen and widespread in its natural host species, macaques. Although most infected monkeys show asymptomatic or mild symptoms, human infections with this virus can cause serious neurological symptoms or fatal encephalomyelitis with a high mortality rate. Herpes B virus can be latent in the sensory ganglia of monkeys and humans, often leading to missed diagnoses. Furthermore, the herpes B virus has extensive antigen crossover with HSV, SA8, and HVP-2, causing false-positive results frequently. Timely diagnosis, along with methods with sensitivity and specificity, are urgent for research on the herpes B virus. The lack of a clear understanding of the host invasion and life cycle of the herpes B virus has led to slow progress in the development of effective vaccines and drugs. This review discusses the research progress and problems of the epidemiology of herpes B virus, detection methods and therapy, hoping to inspire further investigation into important factors associated with transmission of herpes B virus in macaques and humans, and arouse the development of effective vaccines or drugs, to promote the establishment of specific pathogen-free (SPF) monkeys and protect humans to effectively avoid herpes B virus infection

The function and regulation of heat shock transcription factor in Cryptococcus

Cryptococcus species are opportunistic human fungal pathogens. Survival in a hostile environment, such as the elevated body temperatures of transmitting animals and humans, is crucial for Cryptococcus infection. Numerous intriguing investigations have shown that the Hsf family of thermotolerance transcription regulators plays a crucial role in the pathogen-host axis of Cryptococcus. Although Hsf1 is known to be a master regulator of the heat shock response through the activation of gene expression of heat shock proteins (Hsps). Hsf1 and other Hsfs are multifaceted transcription regulators that regulate the expression of genes involved in protein chaperones, metabolism, cell signal transduction, and the electron transfer chain. In Saccharomyces cerevisiae, a model organism, Hsf1’s working mechanism has been intensively examined. Nonetheless, the link between Hsfs and Cryptococcus pathogenicity remains poorly understood. This review will focus on the transcriptional regulation of Hsf function in Cryptococcus, as well as potential antifungal treatments targeting Hsf proteins

Loamit: A Blockchain-based Residual Loanable-limit Query System

Currently, the blockchain technology is experiencing an exponential growth in the academia and industry. Blockchain may provide the fault-tolerance, tamper-resistance, credibility and privacy to users. In this paper, we propose a blockchain-based residual loanable-limit query system, called Loamit. Firstly, to the best of our knowledge, it is the first work to prevent that a client, who lacks the ability to repay, borrows an un-repayable amount of money from independent banks without releasing the personal privacy of client. Specifically, if a client wants to borrow a certain amount of money from a bank, then the bank can get the client\u27s residual loanable-limit in the alliance of banks without knowing details of the client\u27s previous loans and repayments. Secondly, most of data in Loamit is verifiable. Therefore, malicious banks can be checked out. Thirdly, Loamit is fault-tolerant since it may work smoothly as long as a certain number of banks are active and honest. Finally, we deploy the Loamit system on the Ethererum private blockchain and give the corresponding performance evaluation

Comparative transcriptomic and metabolomic analyses reveal differences in flavonoid biosynthesis between PCNA and PCA persimmon fruit

The fruit of the persimmon (Diospyros kaki.) has high economic and nutritional value and is rich in flavonoids. Flavonoids are essential secondary metabolisms in plants. The association between persimmon astringency and changes in the proanthocyanidins (a flavonoid subclass) content is well-known. However, information on the relationships between different astringency types and other flavonoid subclasses and biosynthetic genes is more limited. In this study, an initial correlation analysis between total flavonoids and fruit astringency type, and KEGG analysis of metabolites showed that flavonoid-related pathways were linked to differences between mature pollination-constant non-astringent (PCNA) varieties (‘Jiro’ and ‘Yohou’) and pollination-constant astringent (PCA) fruit varieties (‘Zhongshi5’ and ‘Huojing’). Based on these findings, variations in the expression of genes and metabolites associated with flavonoid biosynthesis were investigated between typical PCNA (‘Jiro’) and PCA (‘Huojing’) persimmons during fruit development. The flavonoid concentration in ‘Huojing’ fruit was significantly higher than that of ‘Jiro’ fruit, especially, in levels of proanthocyanin precursor epicatechin and anthocyanin cyanidin derivatives. Combined WGCNA and KEGG analyses showed that genes such as PAL, C4H, CHI, CHS, F3H, F3’5’H, FLS, DFR, ANR, ANS, and UF3GT in the phenylpropanoid and flavonoid biosynthesis pathways may be significant factors impacting the proanthocyanin precursor and anthocyanin contents. Moreover, interactions between the R2R3MYB (evm.TU.contig7272.598) and WD40 (evm.TU.contig3208.5) transcription factors were found to be associated with the above structural genes. These findings provide essential information on flavonoid biosynthesis and its regulation in the persimmon and lay a foundation for further investigation into how astringency types affect flavor components in PCNA and PCA persimmons

Management of singlet and triplet excitons for efficient white organic light-emitting devices

Lighting accounts for approximately 22 per cent of the electricity consumed in buildings in the United States, with 40 per cent of that amount consumed by inefficient (similar to 15 lm W-1) incandescent lamps(1,2). This has generated increased interest in the use of white electroluminescent organic light-emitting devices, owing to their potential for significantly improved efficiency over incandescent sources combined with low-cost, high-throughput manufacturability. The most impressive characteristics of such devices reported to date have been achieved in all-phosphor-doped devices, which have the potential for 100 per cent internal quantum efficiency(2): the phosphorescent molecules harness the triplet excitons that constitute three-quarters of the bound electron-hole pairs that form during charge injection, and which (unlike the remaining singlet excitons) would otherwise recombine non-radiatively. Here we introduce a different device concept that exploits a blue fluorescent molecule in exchange for a phosphorescent dopant, in combination with green and red phosphor dopants, to yield high power efficiency and stable colour balance, while maintaining the potential for unity internal quantum efficiency. Two distinct modes of energy transfer within this device serve to channel nearly all of the triplet energy to the phosphorescent dopants, retaining the singlet energy exclusively on the blue fluorescent dopant. Additionally, eliminating the exchange energy loss to the blue fluorophore allows for roughly 20 per cent increased power efficiency compared to a fully phosphorescent device. Our device challenges incandescent sources by exhibiting total external quantum and power efficiencies that peak at 18.7 +/- 0.5 per cent and 37.6 +/- 0.6 lm W-1, respectively, decreasing to 18.4 +/- 0.5 per cent and 23.8 +/- 0.5 lm W-1 at a high luminance of 500 cd m(-2).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62889/1/nature04645.pd