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With the development of viral metagenomics and next-generation sequencing technology, more and more novel parvoviruses have been identified in recent years, including even entirely new lineages. The Parvoviridae family includes a different group of viruses that can infect a wide variety of animals. In this study, systematic analysis was performed to identify the “dark matter” (datasets that cannot be easily attributed to known viruses) of parvoviruses and to explore their genetic diversity from wild birds’ cloacal swab samples. We have tentatively defined this parvovirus “dark matter” as a highly divergent lineage in the Parvoviridae family. All parvoviruses showed several characteristics, including 2 major protein-coding genes and similar genome lengths. Moreover, we observed that the novel parvo-like viruses share similar genome organizations to most viruses in Parvoviridae but could not clustered with the established subfamilies in phylogenetic analysis. We also found some new members associated with the Bidnaviridae family, which may be derived from parvovirus. This suggests that systematic analysis of domestic and wild animal samples is necessary to explore the genetic diversity of parvoviruses and to mine for more of this potential dark matter.

Chaos synchronization properties in a novel hierarchical tree-type optical network consisting of semiconductor lasers (SLs) are investigated numerically. In such network, each child node is asymmetrically mutually coupled with the parent node. Zero-lag synchronization is found among the nodes belonging to the same layer, while the nodes belonging to different layers are not synchronized, which is denoted as hierarchical chaos synchronization (HCS). The effects of injection strength, asymmetrical injection parameters, bias currents and frequency detuning on the performance of HCS and chaotic complexity are studied in detail. Our results show that high-quality HCS can be obtained under moderate parameters. The stability of the network is also investigated systematically. Further, we explore the robustness of HCS by considering an asymmetrical network. Finally, output bit streams are generated from each SL at a tunable rate of up to about 10 Gbps with verified randomness. These results are enlightening to the multi-user chaotic communication and the synchronization mechanism in biological neuronal networks.

Perovskite photosensitive layers play an important role in the photoelectric properties of photodetectors (PDs). Here, a precursor solution comprising of a methylammonium lead iodide (MAPbI3) single-crystal is applied to prepare a perovskite film to enlarge the grain size of the perovskite photosensitive layer and improve the detectivity of the PD device. Compared with the traditional precursor solutions composed of raw-materials (MAI + PbI2), the perovskite film derived from the MAPbI3 single-crystal precursor possess high crystalline quality with large grain sizes, enhanced light absorption intensity and long carrier lifetime. Thus, the PD device based on the perovskite photosensitive layer derived from the MAPbI3 single-crystal precursor achieves an improved responsivity of 0.633 A W−1 and an optimized detectivity of 2.502 × 1011 Jones under 660 nm illumination with a light intensity of 1.25 mW cm−2 at −0.4 V. This research highlights an innovative application of perovskite single-crystals for thin film devices.

In recent years, the Chinese government has launched a national campaign to comprehensively revise history textbook in order to “fully implant socialist core values into youngsters” and ensure their familiarity and identification with “socialism with Chinese characteristics,” specifically. Based on in-depth field interviews with teachers and students in a sample of senior high schools in Beijing, this article examines what impact this textbook reform has had on students’ identity and values. We find that the ideological content and national discourse in the new textbook has been significantly strengthened compared to the pre-2003 versions. The changes have significantly reinforced positive views of the “China model,” characterized by the country’s splendid cultural and historical tradition and centralized governance, and increased nationalist and anti-Western sentiment among the Chinese younger generation. The implications of these findings are considered in the light of Lee’s (Managing Chineseness: identity and ethnic management in Singapore. Palgrave Macmillan, London, 2017) theory of identity grafting and the impact of state intervention on Chinese identities.

Bacillus anthracis is a gram-positive, rod-shaped and endospore-forming bacterium that causes anthrax, a deadly disease to livestock and, occasionally, to humans. The spores are extremely hardy and may remain viable for many years in soil. Previous studies have identified East Qinghai and neighbouring Gansu in northwest China as a potential source of anthrax infection. This study was carried out to identify conditions and areas in the Qinghai Lake basin that are environmentally suitable for B. anthracis distribution. Anthrax occurrence data from 2005–2016 and environmental variables were spatially modeled by a maximum entropy algorithm to evaluate the contribution of the variables to the distribution of B. anthracis. Principal Component Analysis and Variance Inflation Analysis were adopted to limit the number of environmental variables and minimize multicollinearity. Model performance was evaluated using AUC (area under the curve) ROC (receiver operating characteristics) curves. The three variables that contributed most to the suitability model for B. anthracis are a relatively high annual mean temperature of -2 to 0°C, (53%), soil type classified as; cambisols and kastanozems (35%), and a high human population density of 40 individuals per km2 (12%). The resulting distribution map identifies the permanently inhabited rim of the Qinghai Lake as highly suitable for B. anthracis. Our environmental suitability map and the identified variables provide the nature reserve managers and animal health authorities readily available information to devise both surveillance strategy and control strategy (administration of vaccine to livestock) in B. anthracis suitable regions to abate future epidemics.

Background Wild birds may harbor and transmit viruses that are potentially pathogenic to humans, domestic animals, and other wildlife. Results Using the viral metagenomic approach, we investigated the virome of cloacal swab specimens collected from 3182 birds (the majority of them wild species) consisting of > 87 different species in 10 different orders within the Aves classes. The virus diversity in wild birds was higher than that in breeding birds. We acquired 707 viral genomes from 18 defined families and 4 unclassified virus groups, with 265 virus genomes sharing < 60% protein sequence identities with their best matches in GenBank comprising new virus families, genera, or species. RNA viruses containing the conserved RdRp domain with no phylogenetic affinity to currently defined virus families existed in different bird species. Genomes of the astrovirus, picornavirus, coronavirus, calicivirus, parvovirus, circovirus, retrovirus, and adenovirus families which include known avian pathogens were fully characterized. Putative cross-species transmissions were observed with viruses in wild birds showing > 95% amino acid sequence identity to previously reported viruses in domestic poultry. Genomic recombination was observed for some genomes showing discordant phylogenies based on structural and non-structural regions. Mapping the next-generation sequencing (NGS) data respectively against the 707 genomes revealed that these viruses showed distribution pattern differences among birds with different habitats (breeding or wild), orders, and sampling sites but no significant differences between birds with different behavioral features (migratory and resident). Conclusions The existence of a highly diverse virome highlights the challenges in elucidating the evolution, etiology, and ecology of viruses in wild birds.

Regulating green electroluminescence (EL) of ZnO is an important but difficult task to produce white-light sources due to its strong background green emission. We have demonstrated that the green EL from solution-processed ZnO nanocrystals (NCs) can be improved and manipulated by erbium (Er) doping. Er3+ ions can be doped and activated without any high-temperature post-annealing treatment. Incorporation of the Er3+ ions in the ZnO host induces lattice expansion primarily along the (002) direction. Er3+-related characteristic green emissions are observed at 535 and 556 nm and manipulated with increasing Er concentration under forward bias. The EL mechanism is investigated and found to be driven by the energy transfer from the deep-level defects of the ZnO NCs to the nearby Er3+ ions. Our findings have demonstrated the feasibility of producing green light-emitting diodes by solution-processable Er-doped ZnO NCs and inspired a promising way to develop white-light sources based on printable ZnO NCs simply by incorporating different rare earth ions into the ZnO NCs simultaneously.

A chaos-based public channel image encryption algorithm among three users is proposed, where the random bits (RBs) generated in a star-type chaotic laser network can be well synchronized and are used as the keys. The proposed algorithm is simple and efficient. Firstly, random bits with verified randomness are generated from the synchronized chaotic semiconductor lasers in a star-type network at a rate of 10Gb/s. Next, lower-triangular error-bits detection is employed to delete the different bits among all the parties over the public channel. Based on the synchronized RBs, the XOR operation is used to diffuse the plain image. Then the hash algorithm is used to get the control parameters matrix from the plain image, and 3D cat map is used to confuse the pixel position through the parameters matrix. Finally, the encrypted image is transmitted in the public channel. The performance tests results, such as key sensitivity, histogram, correlation, differential attack, robustness and entropy analysis, show that the suggested algorithm prevents a powerful computational eavesdropper. Besides, the running speed of this algorithm is linear with the size of plain image. These results open possibilities for multi-user secure communication application.

Efficient perovskite solar cell (PSC) with SnO2 electron selective layer (ESL) prepared by radio frequency magnetron sputtering method at room-temperature has been realized. In this work, we systematically discussed the effect of sputtering power and surface roughness of SnO2 ESL on the photoelectric performance of planar PSC. This research shows that PSC based on SnO2 ESL sputtered at the low power of 60 W exhibits the better photoelectric properties than that based on SnO2 ESL sputtered at the high power of 120 W. The lower sputtering power can decrease the surface roughness of SnO2 ESL and improve the contact interface between perovskite layer and ESL, leading to the reduced carrier recombination and enhanced charge transfer property of planar PSC. Thus, with the decreased sputtering power from 120 to 60 W, the photoelectric conversion efficiency of the corresponding PSC increased from 8.19 to 12.58%.

A novel picornavirus, named "lorikeet picornavirus 1" (LoPV-1), was detected in a fecal sample from rainbow lorikeets using viral metagenomic analysis, and its complete genome sequence was determined and analyzed. The genome of LoPV-1 is 7862 nt long, including a 617-nt 5' UTR, a type IV IRES 5'UTR with an '8-like' motif, a 7032-nt polyprotein ORF, and a 213-nt 3' UTR. Phylogenetic analysis and pairwise asequence comparisons based on the amino acid sequences of P1, P2, and P3 indicated that LoPV-1 showed the closest relationship to two picornaviruses that were isolated recently from red-crowned cranes and clustered together with members of the genus Avihepatovirus.

To investigate the codon usage patterns of all available VP1 gene sequences of the GII.2 genotype, to determine the factors that affect these patterns, and to provide comprehensive details of the characteristics and evolution of the gene. Complete 519 sequences of VP1 gene of the HuNoV GII.2 genotype with known sampling dates and geographic locations from 1971 - 2017 were retrieved from the GenBank nucleotide database of the National Center for Biotechnology Information (NCBI) and analyzed. The percentage composition of T, C, A, and G nucleotides were 24.80 ± 0.30, 26.61 ± 0.31, 25.84 ± 0.13, and 22.75 ± 0.17 %, respectively, with C and A relatively more abundant than T and G, and C the most abundant (p < 0.0001). The values of T3s (34.10 ± 0.90 %) and C3s (33.54 ± 0.90 %) were significantly higher than those of A3s (29.98 ± 0.43 %) and G3s (24.13 ± 0.51 %) (p < 0.0001). While T3s was highest among the four nucleotides, G3s was the lowest. Among the 18 most frequently employed synonymous codons, six optional codons ended with T, five ended with C, five ended with A and two ended with G. Codons ending with T were the most frequently used. The ENC ranged from 51.90 to 54.25 (mean = 52.38 ± 0.43) among the 519 VP1 gene sequences. There were significant correlations between ENC and C % and G % (p < 0.01). Codons containing CpG (1 and 2 or 2 and 3 codon positions) showed the lowest frequencies, while 30, 29, and 2 codons were above, below and on the mean line, respectively. The first four principal components accounted for 69.11 % of the total variation, with the first, second, third, and fourth principal axes contributing 37.90, 14.83, 9.61, and 6.77 %, respectively. The strains were not clustered by country of isolation or year of sampling. Gravy were significantly correlated with T3s, C3s, G3s, GC3s, and ENC (p < 0.01). Mutation pressure and natural selection contributed to the codon usage bias of the VP1 gene of the HuNoV GII.2 genotype. There was a correlation between GC12s and GC3s (R2 = 0.032; p < 0.0001). The relative neutrality was 3.20 %, while natural selection was 96.80 %. The VP1 gene exhibits low codon usage bias which is affected primarily by natural selection, followed by mutation pressure and translational selection.

The complete genome of a bear picornavirus 1 (BePV-1) in the viscera of an Asian black bear (Ursus thibetanus) from China was characterized using viral metagenomics and RT-PCR/Sanger sequencing. The genome of BePV1 is 6703 nt long, contains a type-IV IRES 5'UTR with the '8-like' motif, encodes a 2053-aa-long polyprotein showing a 3-4-4 organization pattern and two 2A genes. BePV-1 showed the highest overall genome nucleotide sequence identity of 71.7% to a picornavirus genome from an Arctic ringed seal (Phoca hispida) from Canada, classified as a member of the species Aquamavirus A, currently the only one in the genus Aquamavirus. Phylogenetic and genetic distance analyses of P1 and 3D indicated that Asian bear picornavirus (aquamavirus B) represents the second sequenced member of the genus Aquamavirus.

Introduction: Bacillus anthracis spores may remain viable for many years in soil. Previous studies have identified East Qinghai and neighbouring Gansu in northwest China as a potential source of anthrax infection. This study was carried out to identify conditions and areas in the Qinghai lake basin that are environmentally suitable for Bacillus anthracis spore survival. Materials and Methods: Anthrax occurrence data from 2005 – 2016 and environmental variables were spatially modeled by a maximum entropy algorithm to evaluate the contribution of the variables to the distribution of the spore. A Principal Component and Variance Inflation Analysis were adopted to limit the number of environmental variables and minimize multicollinearity. Results: The three variables that contributed most to the suitability model for B. anthracis spores are a relatively high annual mean temperature (53%), soil type (35%), and a high human population density (12%). The most significant soil types were cambisols and kastanozems. The resulting distribution map identifies the permanently inhabited rim of the Qinghai Lake as highly suitable for the survival and persistence of the spores. Conclusion: The highly suitable areas for spores could be considered as a risk zone for Anthrax infection by spores of the livestock and the human population. Our environmental suitability map and the identified variables provides the nature reserve managers and animal health authorities readily available information to devise a surveillance strategy in B. anthracis suitable regions to abate future epidemics.

Background: Tree peony (Paeonia suffruticasa) is an economically, medicinally ornamentally important woody flowering woody plants in East Asia and is a common also ornamental shrub in Europe and North America. It is well known and prized for their beautiful flowers in many different forms. Samen petalody has been shown to be the most effective way to modify flower forms. However, there is limited information on the molecular mechanisms of stamen petalody and flower form formation in tree peony.Results: In this study, RNA sequencing was used to assemble and annotate the unigenes in the tree peony to identify the critical genes related to flower parts formation and verify the key genes in different flower forms of tree peony cultivar. A total of 76,007 high quality unigenes were assembled and 30,505 were successfully annotated. A total of 1,833 TFs were identified in our study, among them 16 MADS-box genes were found and characterized. Six key genes were selected to verity their functions in stamen petalody. AG and SEP showed high expression level in carpals and sepals separately both in stamen petalody group and non-stamen petalody groups. PI and AP3 showed high expression levels in inter-petals in stamen petalody groups than in staments in non-stamen petalody.Conclusion: Sixteen MADS-box genes were identified for the first time in tree peony through RNA-seq method. We identified six key genes based on their differential expression levels in different flower parts. These six key genes represented all categories in the ABCDE model to verify the functions in stamen petalody. PI and AP3 were verified to likely play important roles in regulating stamen petalody in tree peony. Our study has helped establish the flower development model in tree peony, identified key molecular mechanisms in the development of different flower forms, and provided valuable information in improving genetic diversity of tree peony and many other woody plants.

A two-step synthetic method is developed for the preparation of ternary CoMoO4/CuO heterostructure on Cu foam as binder-free and high-performance supercapacitor electrode. The synthesis approach involves a simple chemical bath deposition and hydrothermal reaction. CuO nanorods are obtained on Cu foam with chemical bath deposition, and CoMoO4 nanosheets are subsequently grown on as-prepared CuO nanorods to form multi-dimensional CoMoO4/CuO heterostructure by the hydrothermal procedure. The in situ grown CoMoO4/CuO heterostructure could be used as a binder-free supercapacitor electrode. The CoMoO4/CuO heterostructure delivers a significant specific capacitance of 1176 F g−1 under the scan rate of 1 mV s−1, which is distinctly higher than that of the bare CoMoO4 electrode. The galvanostatic charge and discharge tests reveal the CoMoO4/CuO heterostructure electrode has excellent cycle stability, maintaining 95.1% capacitance retention under 2.5 A g−1 after 5000 cycles. These superior performances could be original from the unique multi-dimensional CoMoO4/CuO heterostructure which provides more active sites and additional electron transport channels. These results have promoted the potential implementation of multi-dimensional heterostructure for advanced electrochemical capacitors.

Tin oxide (SnO2) film with high mobility and good transmittance has been reported as a promising semiconductor material for high performance perovskite solar cells (PSCs). In this study, ultrathin SnO2 film synthesized by radio frequency magnetron sputtering (RFMS) method at room temperature was employed as hole blocking layer for planar PSCs. The room-temperature sputtered SnO2 film not only shows favourable energy band structure but also improves the surface topography of fluorine doped SnO2 (FTO) substrate and perovskite (CH3NH3PbI3) layer. Thus, this SnO2 hole blocking layer can efficiently promote electron transport and suppress carrier recombination. Furthermore, the best efficiency of 13.68% was obtained for planar PSC with SnO2 hole blocking layer prepared at room temperature. This research highlights the room-temperature preparation process of hole blocking layer in PSC and has a certain reference significance for the usage of flexible and low-cost substrates.

In this paper, a novel image encryption algorithm based on synchronization of physical random bit generated in a cascade-coupled semiconductor ring lasers (CCSRL) system is proposed, and the security analysis is performed. In both transmitter and receiver parts, the CCSRL system is a master-slave configuration consisting of a master semiconductor ring laser (M-SRL) with cross-feedback and a solitary SRL (S-SRL). The proposed image encryption algorithm includes image preprocessing based on conventional chaotic maps, pixel confusion based on control matrix extracted from physical random bit, and pixel diffusion based on random bit stream extracted from physical random bit. Firstly, the preprocessing method is used to eliminate the correlation between adjacent pixels. Secondly, physical random bit with verified randomness is generated based on chaos in the CCSRL system, and is used to simultaneously generate the control matrix and random bit stream. Finally, the control matrix and random bit stream are used for the encryption algorithm in order to change the position and the values of pixels, respectively. Simulation results and security analysis demonstrate that the proposed algorithm is effective and able to resist various typical attacks, and thus is an excellent candidate for secure image communication application.

With the rapid development of cloud computing, cloud storage has been accepted as a convenient service by an increasing number of organizations and individuals. However, when users lose control of their data, ensuring that the uploaded data are securely stored by the cloud becomes a critical requirement. A key research challenge associated with existing designs of data auditing protocols is the limitation of application scenarios due to low auditing efficiency. In order to address this problem, we propose a provably secure and public auditing protocol based on Bell triangle for cloud data with blockless verification and batch auditing. We introduce the associative property of Bell triangle; design an index conversion algorithm to convert the one-dimensional index to a two-dimensional index ensuring that the block signature satisfies the Bell triangle requirements, and develop a recursive association algorithm to ensure relevance between the signatures of adjacent file blocks. This protocol offers significant advantages over existing protocols in terms of auditing efficiency and security in a multi-user and high-volume environment. In addition, the security analysis and the results of the experiment indicate that the protocol is secure and efficient.

Data integrity is a core security issue in reliable cloud storage that has received widespread attention. Data auditing protocols enable verifiers to efficiently check the integrity of outsourced data without downloading the data. A key research challenge associated with the design of existing data auditing protocols is the efficiency of the auditing process. Since existing protocols tend to auditing all cloud data, in fact, some data may have just been used or will be used soon, then auditing all these data is invalid, which is a waste of resources. In this paper, we attempt to address the waste of resources due to invalid auditing in cloud data integrity checking by introducing user behavior prediction algorithms,the first in such an approach, to the best of our knowledge. More specifically, we introduce the concept of valid auditing in data integrity verification based on the concept of valid auditing. We formalize a system model and a security model for this new concept. Then, using user behavior prediction algorithms, we give methods to improve auditing efficiency and reduce invalid auditing. Finally, we develop a prototype implementation of the protocol to validate the practicality of the scheme.

Background Small ruminants are important hosts for various tick species and tick-associated organisms, many of which are zoonotic. The aim of the present study was to determine the presence of tick-borne protozoans and bacteria of public health and veterinary significance in goats and wild Siberian roe deer (Capreolus pygargus) from Heilongjiang Province, northeastern China. Methods The occurrence of piroplasms, Anaplasma phagocytophilum, A. bovis, A. marginale, A. capra, A. ovis, Ehrlichia spp. and spotted fever group rickettsiae was molecularly investigated and analyzed in 134 goats and 9 free ranging C. pygargus living in close proximity. Results Piroplasm DNA was detected in 16 (11.9%) goats and 5 C. pygargus. Sequence analysis of 18S rRNA sequences identified 3 Theileria species (T. luwenshuni, T. capreoli and T. cervi). Four Anaplasma species (A. ovis, A. phagocytophilum, A. bovis and A. capra) were identified in goats and C. pygargus. Anaplasma ovis and A. bovis were detected in 11 (8.2%) and 6 (4.5%) goats, respectively; A. phagocytophilum, A. bovis and A. capra were found in 3, 7 and 3 C. pygargus, respectively. Sequence analysis of 16S rRNA sequences revealed the presence of 5 different genetic variants of A. bovis in goats and C. pygargus, while the analysis of 16S rRNA and gltA sequence data showed that A. capra isolates identified from C. pygargus were closely related to the genotype identified from sheep and Haemaphysalis qinghaiensis, but differed with the genotype from humans. Anaplasma/Theileria mixed infection was observed in 2 (1.5%) goats and 5 C. pygargus, and co-existence involving potential zoonotic organisms (A. phagocytophilum and A. capra) was found in 2 C. pygargus. All samples were negative for A. marginale, Ehrlichia spp. and SFG rickettsiae. Conclusions These findings report the tick-borne pathogens in goats and C. pygargus, and a greater diversity of these pathogens were observed in wild animals. Three Theileria (T. luwenshuni, T. capreoli and T. cervi) and four Anaplasma species (A. ovis, A. phagocytophilum, A. bovis and A. capra) with veterinary and medical significance were identified in small domestic and wild ruminants. The contact between wild and domestic animals may increase the potential risk of spread and transmission of tick-borne diseases.

DAMPE (DArk Matter Particle Explorer) is a spaceborne high-energy cosmic ray and gamma-ray detector , successfully launched in December 2015. It is designed to probe astroparticle physics in the broad energy range from few GeV to 100 TeV. The scientific goals of DAMPE include the identification of possible signatures of Dark Matter annihilation or decay, the study of the origin and propagation mechanisms of cosmic-ray particles, and gamma-ray astronomy . DAMPE consists of four sub-detectors: a plastic scintillator strip detector, a Silicon–Tungsten tracKer–converter (STK), a BGO calorimeter and a neutron detector . The STK is composed of six double layers of single-sided silicon micro-strip detectors interleaved with three layers of tungsten for photon conversions into electron–positron pairs . The STK is a crucial component of DAMPE, allowing to determine the direction of incoming photons, to reconstruct tracks of cosmic rays and to estimate their absolute charge (Z). We present the in-flight performance of the STK based on two years of in-flight DAMPE data, which includes the noise behavior, signal response, thermal and mechanical stability, alignment and position resolution.

Direct-conversion X-ray detectors made of wide-bandgap semiconductors have many advantages and important applications. In this study, a direct-conversion X-ray detector based on Pt-MgZnO-Pt structure was fabricated by radio frequency magnetron sputtering. The X-ray detection characteristics of the device were studied. The optimized device with a structure of Pt-MgZnO-Pt exhibited a responsivity of 72.6 nC Gyair –1 cm–2, response time of ∼0.1 s (rise)/∼0.4 s (fall), and a high SNR of 206 at a bias of 30 V under a dose rate of 100 mGyair/s. The experimental results demonstrate the good application prospects of the wide-bandgap MgZnO-based X-ray detectors.

Ultraviolet (UV) light-emitting diodes (LEDs) based on zinc oxide (ZnO) materials have been the subject of many investigations because of their potential applications. In this study, ZnO/MgZnO multiple-quantum-well UV LEDs with graded-composition barriers were developed and numerically analyzed. The simulation results demonstrate that an optimized LED with a Mg composition graded from 24% to 2% in each triangular barrier exhibits the highest internal quantum efficiency (IQE) (88.0%) at 200 A/cm2, showing a 31.3% increase compared with the conventional LED with square barriers. This enhancement is attributed to the modified energy band structures that improve the symmetry in carrier transportation and increase the radiative recombination rate in each ZnO quantum well, thus enhancing the IQE of the device. Additionally, the different band-offset ratios of the MgZnO/ZnO and InGaN/GaN heterojunctions, which lead to the different carrier transport and electroluminescence properties of the ZnO- and GaN-based LEDs, were discussed here, providing researchers new insights into device design of ZnO-based LEDs.

In this paper, a thin layer of high work function CuS was introduced to the interface between the anode and hole transporting layer (HTL) to modify the indium tin oxide (ITO) anode. Modified ITO substrates possess a higher work function, a lower sheet resistance and a negligible loss in transparency. More importantly, a thin layer of CuS can also benefit for the hole transporting of the device. Polymer solar cells (PSCs) utilizing modified ITO anodes exhibit a significant enhancement in power conversion efficiency ( PCE ) and air stability compared to devices with normal ITO anodes. This anode modification strategy applies to different active layer systems. Anode-modified devices with poly (3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC 61 BM) as the active layer exhibit a PCE of 3.5%, while poly(4,8-bis(5-(2-ethyl-hexyl)-thiophene-2-yl)-benzo[l,2-b:4,5-b′] dithiophene-alt-alkylcarbonyl-thieno[3,4-b]thiophene) (PBDTTT-C-T) and [6,6]-phenyl-C71-butyric acid methyl ester (PC 71 BM) system shows a PCE of 7.4%. As a result, this work provides a good compatibility for modification of ITO by a thin layer of CuS in PSCs to achieve better performance.

Alternating-current-driven ZnO-based light-emitting diodes (LEDs) with an Au/ZnMgO/ZnO/ZnMgO/GaN/In structure have been fabricated. Both polarity-controlled electroluminescence (EL) and ultraviolet emission were achieved when driven by an alternating current (AC) under a much lower root-mean-square voltage than that of conventional inorganic AC thin-film electroluminescent devices. This ZnO-based LED can be regarded as a series incorporating a metal-insulator-semiconductor diode and a p-i-n diode. The EL mechanisms were discussed in terms of the band diagrams and carrier transport behavior with reference to the semiconductor heterojunction theory.