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Redox mediators play a major role in determining the photocurrent and photovoltage in dye-sensitized solar cells (DSSCs). Copper complexes are a good option for redox mediators but suffer from elec...

Three novel dyes consisting of a 5,8,15-tris(2-ethylhexyl)-8,15-dihydro-5H-benzo[1,2-b:3,4-b':6,5-b″]tricarbazole (BTC) electron-donating group and a 4,7-bis(4-hexylthiophen-2-yl)benzo[c][1,2,5]thiadiazole (BTBT) π-bridge with an anchoring group of phenyl carboxyl acid were synthesized and applied in dye-sensitized solar cells (DSCs).The AJ202 did not contain any triple bonds, the AJ201's ethynyl group was inserted between the BTC and BTBT units, and the AJ206's ethynyl group was introduced between the BTBT moiety and the anchor group. The inclusion and position of the ethynyl linkage in the sensitizer molecules significantly altered the electrochemical properties of these dyes, which can fine-tune the energy levels of the dyes. The best performing devices contained AJ206 as a sensitizer and a Cu(I/II) redox couple, which resulted in a power conversion efficiency (PCE) up to 10.8% under the standard AM 1.5 G illumination, which obtained PCEs higher than those from the devices that contained AJ201 (9.2%) and AJ202 (9.7%) under the same conditions. The highest occupied molecular orbital and lowest unoccupied molecular orbital levels of the sensitizers were tuned to be well-suited for the Cu(I/II) redox potential and the Fermi level of TiO2. The innovative synthesis of a tricarbazole-based donor moiety in a sensitizer used in combination with a Cu(I/II) redox couple has resulted in relatively high PCEs.

To reveal the errors caused by using temperature as the reference parameter during the testing of frozen soil specific heat, the compositional evolution of frozen soil during testing was analyzed. The heating process of the soil sample is regarded as a superposition of the temperature increase in each phase and the melting of ice. On this basis, we propose the calorimetry of a multicomponent system for the analysis of frozen soil specific heat test considering the effect of latent heat. The specific heat of warm frozen soil is calculated basing on a laboratory test and the methods proposed herein. The tested values of unfrozen water content were compared with the values of unfrozen water content calculated by the inverse method of specific heat, and the tested values of specific heat were compared with the values calculated by the mass-weighted average method and the values calculated by the conventional method. The results show that the specific heat of frozen soil directly determined by the heating-temperature measurement method includes the effect of the latent heat of phase change and thus cannot be used in the scientific calculation of the temperature field. The specific heat of the frozen soil determined by considering the effect of latent heat has higher accuracy and broader applicability than the conventional method.

Two push–pull metal-free sensitizers with 5,11-dihydroindolo[3,2-b]carbazole derivatives as electron-donating groups and 4-(benzo[c][1,2,5]thiadiazol-4-ylethynyl)benzoic acid (BTZ) as electron-withdrawing unit, denoted by SK201 and SK202, were synthesized and used for fabrication of dye-sensitized solar cells (DSSCs). SK202 contains a thienyl group between the donor and acceptor, whereas in SK201 the donor and acceptor are connected directly by a single bond. Introduction of a thienyl group improved the planarity of the dye molecule, broadened the absorption spectrum, enhanced the molar extinction coefficient, increased the dye loading on TiO2, and accelerated interface electron transfer on TiO2. This fine tuning of dye structure improved the performances of DSSCs based on SK202 sensitizers and gave a power conversion efficiency (PCE) of 11.0% (Jsc 16.5 mA cm−2, Voc 932 mV, and fill factor 71.7%), compared with that of 7.2% for SK201, under standard AM1.5G solar irradiation (100 mW cm−2) with a Co(II/III) complex based redox couple.

Two dyes with dithieno[3,2-b:20,30-d] pyrrole (DTP) as the donor (An101 and An102) have been synthesized and characterized. An101 and An102 were applied to dye-sensitized solar cells (DSSCs) and power conversion efficiencies (PCEs) of 8.0% and 9.5% were achieved with the I2−/I3− redox couple, which correspond to open voltages (Voc) of 784 and 690 mV, current densities (Jsc) of 15.1 and 20.0 mA cm−2, the fill factors of 67.2% and 68.7%, respectively, under AM1.5G irradiation. It is worth noting that the different connection locations of the donors with the π-bridge result in different PCEs. An102 has a higher Jsc owing to its high molar extinction coefficient and small torsion angle, which increase the light-harvesting ability and coplanarity. An101 has a higher Voc owing to introduction of the alkoxybenzene group, which can effectively suppress recombination with the electrolyte and dye. By scanning with different bias voltages with electrochemical impedance spectroscopy, the reason for the high voltage of the An101 dye is up-shift of the TiO2 conduction-band edge and elongated electron lifetimes. However, the main reason for the relatively high PCE of the An102 dye is the coplanarity, which results in good long-term stability.

Building upon the success of TRMM launched in 1997, NASA and JAXA successfully deployed the Global Precipitation Measurement (GPM) mission on February 28, 2014. GPM started to release the new-generation global precipitation products Integrated Multi-satellite Retrievals for GPM (IMERG) since April 2014. Critical data validation over diverse topographic and climatic regions could effectively help users and algorithm developers maximize the accuracy, strengths and weaknesses of the new product. To this end, this study comprehensively evaluated and compared this newly released precipitation product (IMERG V05B) and its predecessor TRMM 3B42V7 based upon the ground-based observations under complex topographic and climatic conditions over the Hexi Region in the northwest arid region of China. The evaluation was conducted at daily, monthly, seasonal and annual scales from April 2014 to September 2017. Results indicated that: (1) compared to ground-based observations, both IMERG and 3B42V7 showed good performance with slightly overestimation (with RB values of 4.58% and 2.27%, respectively) at basin scale. While at the point-to-pixel scale, both products showed overestimation in low-elevation regions and underestimation in high-altitude mountainous areas; (2) on multiple temporal and spatial scales, IMERG correlated better with ground-based observations than 3B42V7, whereas its bias were larger than 3B42V7; (3) both IMERG and 3B42V7 showed better performance in warm seasons (summer and autumn) than in cold seasons (spring and winter); (4) Compared to 3B42V7, IMERG represented both larger hit rate (POD) and false alarm ratio (FAR), but similar correct detection rate (CSI); (5) IMERG showed poorer detection capabilities in light precipitation events (0–2 mm/day), while represented a certain advantage in detecting moderate (5–10 mm/day) and heavy (>25 mm/day) rain events. Most of precipitation estimates over Hexi region are unreliable on daily and monthly time scales. Results suggest that IMERG do not show significant improvement compared to its predecessor 3B42V7, and performed even worse in estimating precipitation amounts. Further data bias-correction is needed before IMERG can be used for climatic and hydrologic research in the Hexi region.

X1 (MeO-TPD) is an inexpensive and easily synthesized pi-conjugated molecule that has been used as a hole-transport material (HTM) in solid-state dye-sensitized solar cells (ssDSSCs), achieving rel ...

Counter electrodes (CEs) play critical roles in the reduction and regeneration of triiodide/iodide redox couple in dye-sensitized solar cells (DSSCs). Compared to commercial Pt, cost-efficient CEs with excellent electrocatalytic activity and superior electrochemical stability are highly desired. Herein, we report a facile, template- and active agents-free fabrication strategy for the synthesis of carbon nanosheets (CNSs) via annealing of small molecular precursors. This process was achieved by a combined strategy, including a low-temperature solid-phase cross-linking reaction and a subsequent high temperature annealing. When employed as metal-free CEs for DSSCs, the as-obtained CNSs demonstrated an annealing temperature-dependent electrochemical behavior. Owing to the superior electrical conductivity and electrocatalytic activity, the CNSs obtained by annealing at 1200 °C exhibit the best electrochemical performance with a power conversion efficiency of 8.71%, which is superior to that of Pt CE (7.24%), thus being attractive alternatives to precious metal Pt CEs. This study presents a simple and effective strategy to configure nanostructured carbonaceous materials for high-performance energy storage and conversion.

σ54 factor (RpoN), a type of transcriptional regulatory factor, is widely found in pathogenic bacteria. It binds to core RNA polymerase (RNAP) and regulates the transcription of many functional genes in an enhancer-binding protein (EBP)-dependent manner. σ54 has two conserved functional domains: the activator-interacting domain located at the N-terminal and the DNA-binding domain located at the C-terminal. RpoN directly binds to the highly conserved sequence, GGN10GC, at the −24/−12 position relative to the transcription start site of target genes. In general, bacteria contain one or two RpoNs but multiple EBPs. A single RpoN can bind to different EBPs in order to regulate various biological functions. Thus, the overlapping and unique regulatory pathways of two RpoNs and multiple EBP-dependent regulatory pathways form a complex regulatory network in bacteria. However, the regulatory role of RpoN and EBPs is still poorly understood in phytopathogenic bacteria, which cause economically important crop diseases and pose a serious threat to world food security. In this review, we summarize the current knowledge on the regulatory function of RpoN, including swimming motility, flagella synthesis, bacterial growth, type IV pilus (T4Ps), twitching motility, type III secretion system (T3SS), and virulence-associated phenotypes in phytopathogenic bacteria. These findings and knowledge prove the key regulatory role of RpoN in bacterial growth and pathogenesis, as well as lay the groundwork for further elucidation of the complex regulatory network of RpoN in bacteria.

Colloidal quantum dot (CQD) solar cells with a ZnO/PbS-TBAI/PbS-EDT/carbon structure were prepared using a solution processing technique. A commercially available carbon paste that was processed at low-temperatures was used as a counter electrode in place of expensive noble metals, such as Au or Ag, which are used in traditional PbS CQD solar cells. These CQD solar cells exhibited remarkable photovoltaic performance with a short circuit density (Jsc) of 25.6 mA/cm2, an open circuit voltage (Voc) of 0.45 V, a fill factor (FF) of 51.8% and a power conversion efficiency (PCE) as high as 5.9%. A reference device with an Au counter electrode had a PCE of 6.0%. The PCE of the carbon-containing CQD solar cell remained stable for 180 days when tested in ambient atmosphere, while the PCE of the Au-containing CQD solar cell lost 48.3% of its original value. Electrochemical impedance spectroscopy (EIS) demonstrated that holes within the PbS CQD were effectively transported to the carbon counter electrode.

Fluorescent nitrogen-doped carbon dots (N-CDs) are synthesized by a facile one-pot solvothermal approach from Taixi anthracite in the presence of dimethyl formamide (DMF). Benefiting from superior dispersion of light components in DMF and easy exfoliation of smaller sp2-carbon structures from the anthracite, the as-prepared N-CDs show a strong photoluminescence (PL) with a high quantum yield (QY) of 47.0% and production yield of 25.6 wt%. Besides, the N-CDs also exhibit a singlet oxygen (1O2) generation behavior with a 1O2 generation QY of 19.0%. Moreover, the as-obtained N-CDs emit blue PL under the excitation wavelength of 365 nm, and can be easily dispersed in polymethyl methacrylate (PMMA), retaining the inherent advantages of the N-CDs and the PMMA matrix. The possible mechanism involved in the formation of N-CDs is proposed and discussed in terms of the macromolecular structure of the anthracite and the solvothermal approach adopted in the study.

Spore pigmentation is very common in the fungal kingdom. The best studied pigment in fungi is melanin which coats the surface of single cell spores. What and how pigments function in a fungal species with multiple cell conidia is poorly understood. Here, we identified and deleted a polyketide synthase (PKS) gene PfmaE and showed that it is essential for multicellular conidial pigmentation and development in a plant endophytic fungus, Pestalotiopsis fici. To further characterize the melanin pathway, we utilized an advanced Aspergillus nidulans heterologous system for the expression of the PKS PfmaE and the Pfma gene cluster. By structural elucidation of the pathway metabolite scytalone in A. nidulans, we provided chemical evidence that the Pfma cluster synthesizes DHN melanin. Combining genetic deletion and combinatorial gene expression of Pfma cluster genes, we determined that the putative reductase PfmaG and the PKS are sufficient for the synthesis of scytalone. Feeding scytalone back to the P. fici ΔPfmaE mutant restored pigmentation and multicellular adherence of the conidia. These results cement a growing understanding that pigments are essential not simply for protection of spores from biotic and abiotic stresses but also for spore structural development. This article is protected by copyright. All rights reserved.

The COP9 signalosome (CSN) is a highly conserved multiprotein complex in all eukaryotes and involved in regulation of organism development. In filamentous fungi, several lines of evidence indicate that fungal development and secondary metabolism (SM) are mediated by the fifth subunit of CSN, called CsnE. Here we uncover a connection with CsnE and conidial formation as well as SM regulation in the plant endophytic fungus Pestalotiopsis fici. A homology search of the P. fici genome with CsnE, involved in sexual development and SM in Aspergillus nidulans, identified PfCsnE. Deletion of PfcsnE resulted in a mutant that stopped conidial production, but the conidia are recovered in a PfcsnE complemented strain. This indicates that PfCsnE is required for the formation of conidia. Secondary metabolite analysis demonstrated that the ΔPfcsnE strain produced more chloroisosulochrin, less ficiolide A production in comparison to wild type (WT). Transcriptome analysis of WT and ΔPfcsnE strains indicated that PfcsnE impacts the expression levels of 8.37% of 14,797 annotated genes. Specifically, nine biosynthetic gene clusters (BGCs) were up-regulated and three BGCs were down-regulated by PfCsnE. Our results suggest that PfCsnE plays major roles in SM regulation and conidial development in P. fici.

Antibiotic resistance is becoming a global public health priority. The emergence of the notorious super-bugs that can produce the New Delhi β -lactamase 1 (NDM-1) had ever pushed us on the cusp of post-antibiotic era. The expression of NDM-1 (and its variants like NDM-5) allows the gut microbiota to gain the robust resistance to both extended spectrum β -lactamases (ESBL) and carbapenems, the two types of antibiotics extensively used for treatment of the multidrug- resistant bacteria. Colistin, referred to polymyxin E, belongs to a family of cationic polypeptide antibiotics, and acts as a final line of refuge against fatal infections by gram-negative pathogens with pan-drug resistance. Unfortunately, it seems likely that this last-resort antibiotics has been defied greatly by the appearance of colistin resistance. To the best of knowledge, three types of chemical modifications of the lipid A have been associated with the bacterial colistin resistance. Generally, the lipid A anchor of lipid polysaccharide (LPS) can be modified with amine-containing substitutes including (i) addition of phosphoethanolamine to 4′-phosphate position of sugar; (ii) modification of sugar with amino-arabinose at the 4′-phosphate position; and (iii) glycine (and/or diglycine) modification at 3′-linked secondary acyl chain. Consequently, the alteration of the LPS-lipid A moiety reduces the net negative charge of the bacterial outer-membrane, which in turn attenuates the binding of the cationic antimicrobial peptide colistin to bacterial surface. Thus, it is very true that divergent metabolic mechanisms are involved into bacterial colistin resistance. Very recently, a new mobilized colistin resistance gene ( mcr-1 ) is reported by a research group in China. The transferability of the MCR-1 by gene horizontal transfer enables a variety of bacteria to be tolerant with the antibiotic polymyxin, a last line of resort against multi-drug resistant enterobacteria. The global dissemination of the MCR-1 might pose a great challenge to the public health, implying the arrival of “post-antibiotics” era. It thus seems reasonable that the emergence of the MCR-1 colistin resistance attracted promptly extensive concerns worldwide. In this brief review, we concentrate on global epidemiology of the mcr-1 gene, diversified mcr-1 -bearing plasmids, complicated genetic content of the mcr-1 , and biochemical mechanism for the MCR-1. This review might allow us to better understand the MCR-1 colistin resistance, providing a clue to design strategies against the mcr-1 -harbouring super-bug.

Two novel dyes that are similar in chemical structure, except for different donor units, AJ301and AJ303 were synthesized, characterized and applied as sensitizers in dye-sensitized solar cells (DSSCs). Both dyes exhibited a wide absorption of visible sunlight. The introduction of fused rings on the donor unit of AJ303 presented an appropriate energy level, less recombination and longer electron lifetime to achieve a power conversion efficiency (PCE) of 10.2%, far above that achieved for AJ301 of 6.2% with a [Co(bpy)3]2+/3+-based electrolyte under standard AM1.5G solar irradiation (100 mW cm−2). The DSSCs based on AJ303 and AJ301 with [Cu(tmby)2]2+/+-based electrolyte showed a lower PCE of 8.2% and 5.4%, respectively. Therefore, the results indicated that the introduction of a fused-ring in the donor group is a meaningful synthetic strategy to improve the photovoltaic performance.

// Qingjing Wang 1,* , Zhencui Li 1,* , Jingxia Lin 1 , Xiuna Wang 1,3 , Xianbo Deng 2 and Youjun Feng 1 1 Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 2 College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong, China 3 Fujian Agriculture and Forestry University, Fuzhou, Fujian, China * The authors have contributed equally to this work Correspondence to: Youjun Feng, email: // Xianbo Deng, email: // Keywords : MCR-1, diversity, sequence type (ST), Immunology and Microbiology Section, Immune response, Immunity Received : August 23, 2016 Accepted : October 07, 2016 Published : October 12, 2016 Abstract The emergence of the mobilized colistin resistance gene, representing a novel mechanism for bacterial drug resistance, challenges the last resort against the severe infections by Gram-negative bacteria with multi-drug resistances. Very recently, we showed the diversity in the mcr-1 -carrying plasmid reservoirs from the gut microbiota. Here, we reported that a similar but more complex scenario is present in the healthy swine populations, Southern China, 2016. Amongst the 1026 pieces of Escherichia coli isolates from 3 different pig farms, 302 E. coli isolates were determined to be positive for the mcr-1 gene (30%, 302/1026). Multi-locus sequence typing assigned no less than 11 kinds of sequence types including one novel Sequence Type to these mcr-1 -positive strains. PCR analyses combined with the direct DNA sequencing revealed unexpected complexity of the mcr-1 -harbouring plasmids whose backbones are at least grouped into 6 types four of which are new. Transcriptional analyses showed that the mcr-1 promoter of different origins exhibits similar activity. It seems likely that complex dissemination of the diversified mcr-1 -bearing plasmids occurs amongst the various ST E. coli inhabiting the healthy swine populations, in Southern China.

Small ubiquitin-like modifiers (SUMOs) can be reversibly attached to target proteins in a process known as SUMOylation, and this process influences several important eukaryotic cell events. However, little is known regarding SUMO or SUMOylation in Aspergillus flavus. Here, we identified a novel member of the SUMO family in A. flavus, AfSumO, and validated the existence of SUMOylation in this pathogenic filamentous fungus. We investigated the roles of AfsumO in A. flavus by determining the effects of AfsumO mutations on the growth phenotype, stress response, conidia and sclerotia production, aflatoxin biosynthesis, and pathogenicity to seeds, and we found that SUMOylation plays a role in fungal virulence and toxin attributes. Taken together, these results not only reveal potential mechanisms of fungal virulence and toxin attributes in A. flavus but also provide a novel approach for promising new control strategies of this fungal pathogen.

An improved inverse method for turbomachinery design is developed in this paper. A strict ‘no-slip’ boundary condition is imposed during the flow time marching process, and a virtual movement velocity is computed based on characteristics boundary conditions according to the difference of specified and calculated pressure loading, then the camber line of the blade is moved accordingly. A new ‘inverse’ time step calculation method is proposed to make the value of the ‘inverse’ time step case-independent, and a coupled non-uniform rational B-spline (NURBS) smoothing technique is used to improve the robustness of the solver, also guarantee the manufacturability of the obtained blade. Two-dimensional test cases, including compressor and turbine cascades, are adopted to validate the method. Then, the method is extended to three dimensions, and a high-loaded rotor of a fan stage is redesigned by the method in a stage environment. The final results indicate a fairly large performance gain, which demonstra...

Regarding targeted disruption of epigenetic regulators, histone methyltransferase and deacetylase in a plant endophytic fungus Pestalotiopsis fici have been uncovered as an unexplored chemical repertoire. Manipulation of epigenetic regulators led to the isolation of 15 new polyketides, including pestaloficiols T-W (1-3 and 5), as well as 11 macrodiolide ficiolides A-K (6-16). Ficiolide K (16) was found to contain a very rare 1,6-anhydro-pyranose moiety. Finally, the biosynthetic origin of macrodiolide was characterized by isotope-labeling experiments.

Petroleum asphalt based ultrathin hollow carbon shell (PACS) was prepared via a facile template-assisted method. As the anode material of lithium-ion batteries, PACS exhibits high reversible capacity, excellent cycling stability, and superior rate performance. A high reversible capacity of 334 mA h g −1 and 90% kept of the theoretical capacity can still be maintained in PACS at a current density of 1 A g −1 even after 1000 cycles, which is ascribed to the unique hollow structure, ultrathin porous shells (4.7 nm), the doped nitrogen atoms, and high level of disorder degree. Meanwhile, the present study paves a milestone for the high-valued utilization of petroleum asphalt and other kinds of heavy oil.

Three methods were used to prepare reduced graphene oxide (rGO) with various ratios of oxygen functional groups, such as –OOH, –OH and CO, to study their effects on the NO2 sensing properties at room temperature. It was found that the percentages of oxygen-containing species such as –OH in the rGO nanosheet, significantly affected the sensitivity of rGO to NO2 at room temperature. The –OH species can promote the sensitivity and also the recovery ability with respect to NO2. This may be because –OH has a greater attraction to NO2 and obtains electrons from it, whereas the separation of NO2 from –OH is also slightly easier, enabling a better recovery compared to other oxygen functional groups such as –OOH and CO.

As renewable energies become the main direction of global energy development in the future, Virtual Power Plant (VPP) becomes a regional multi-energy aggregation model for large-scale integration of distributed generation into the power grid. It also provides an important way for distributed energy resources (DER) to participate in electricity market transactions. Firstly, the basic concept of VPP is outlined, and various uncertainties within VPP are modeled. Secondly, using multi-agent technology and Stackelberg dynamic game theory, a double-layer nested dynamic game bidding model including VPP and its internal DERs is designed. The lower layer is a bidding game for VPP internal market including DER. VPP is the leader and each DER is a subagent that acts as a follower to maximize its profit. Each subagent uses the particle swarm algorithm (PSA) to determine the optimal offer coefficient, and VPP carries out internal market clearing with the minimum variance of unit profit according to the quoting results. Then, the subagents renew the game to update the bidding strategy based on the outcomes of the external and internal markets. The upper layer is the external market bidding game. The trading center (TC) is the leader and VPP is the agent and the follower. The game is played with the goal of maximum self-interest. The agent uses genetic algorithms to determine the optimal bid strategy, and the TC carries out market clearance with the goal of maximizing social benefits according to the quotation results. Each agent renews the game to update the bidding strategy based on the clearing result and the reporting of the subagents. The dynamic game is repeated until the optimal equilibrium solution is obtained. Finally, the effectiveness of the model is verified by taking the IEEE30-bus system as an example.

Continuous and accurate spatiotemporal precipitation data plays an important role in regional climate and hydrology research, particularly in the arid inland regions where rain gauges are sparse and unevenly distributed. The main objective of this study is to evaluate and bias-correct the Tropical Rainfall Measuring Mission (TRMM) 3B42V7 rainfall product under complex topographic and climatic conditions over the Hexi region in the northwest arid region of China with the reference of rain gauge observation data during 2009&ndash, 2015. A series of statistical indicators were adopted to quantitatively evaluate the error of 3B42V7 and its ability in detecting precipitation events. Overall, the 3B42V7 overestimates the precipitation with Bias of 11.16%, and its performance generally becomes better with the increasing of time scale. The agreements between the rain gauge data and 3B42V7 are very low in cold season, and moderate in warm season. The 3B42V7 shows better correlation with rain gauges located in the southern mountainous and central oasis areas than in the northern extreme arid regions, and is more likely to underestimate the precipitation in high-altitude mountainous areas and overestimate the precipitation in low-elevation regions. The distribution of the error on the daily scale is more related to the elevation and rainfall than in monthly and annual scale. The 3B42V7 significantly overestimates the precipitation events, and the overestimation mainly focuses on tiny amounts of rainfall (0&ndash, 1 mm/d), which is also the range of false alarm concentration. Bias correction for 3B42V7 was carried out based on the deviation of the average monthly precipitation data during 2009&ndash, 2015. The bias-corrected 3B42V7 was significantly improved compared with the original product. Results suggest that regional assessment and bias correction of 3B42V7 rainfall product are of vital importance and will provide substantive reference for regional hydrological studies.

We investigate the electronic structures and magnetism of Rh 3 Z (Z=Al, Ga, In, Si, Ge, Sn, Pb, Sb) with a DO 3 structure using the first-principle calculations. The Rh 3 Z (Z=Si, Ge, Sn, Pb) alloys have been predicted to be half-metallic ferromagnets at their equilibrium lattice parameters. The half-metallicity of Rh 3 Z (Z=Si, Ge, Sn, Pb) alloys can be kept in a quite large hydrostatic strain and tetragonal distortion. The magnetic properties are discussed. The Rh 3 Z (Z=Si, Ge, Sn, Pb) alloys do not follow the M t =Z t - 24 rule but instead of following the M t =Z t - 28 rule ( M t is the total magnetic moment per unit cell and Z t is the valence concentration). Moreover, all the alloys investigated in this paper have a negative formation energy, which implies that they are possible to be synthesized in reality.

Two organic quinoxaline dyes (WQ-1 and WQ-2) with a structure of quinoxaline-2, 3-diol as the electron withdrawing and anchoring group were synthesized and applied in the dye-sensitized solar cells. Fourier transform infrared spectroscopy and two other reference dyes (WQ-R1 and WQ-R2) without the hydroxyl groups were introduced to ascertain the adsorption properties of the dye series. The effect of the new electron acceptor and anchoring group on the performance of solar cells was investigated systematically. Under the standard light illumination (100 mW m−2), WQ-2 got an efficiency of 2.25%, with a short circuit photocurrent density of 5.51 mA cm−2, an open circuit voltage of 0.612 V and a fill factor of 66.74%.

The runoff components were identified in the headwater area of Shule River Basin, using isotopic and chemical tracing with particular focus on the temporal variations of catchment sources. A total of 95 samples, including precipitation, groundwater, and glacial meltwater, were collected and analyzed for stable water isotopes (18O and2H) and major chemical ion parameters (potassium, sodium, calcium, magnesium, sulfate, chloride, and bicarbonate). Based on the isotope and water chemistry data, we applied end member mixing analysis (EMMA) to identify and quantify the major runoff generating sources and their contributions. The contributions of groundwater, precipitation, and glacial meltwater were 66.7%, 19.9%, and 13.4%, respectively. The study indicated that groundwater dominated runoff in the headwater area of Shule River Basin. The roles of glacier meltwater should be remarkable in water resource management in this basin. The uncertainties of the EMMA method were summarized and estimated via a classical Gaussian error propagation technique. Analyses suggested that the uncertainty in the measurement method was less important than that in the temporal and spatial variations of tracer concentrations. The uncertainty was sensitive when the difference between mixing components was small. Therefore, the variation of tracers and the difference of mixing components should be considered when hydrograph separation was applied in the basin.

Aflatoxins are a potent carcinogenic mycotoxin and has become a research model of fungal secondary metabolism (SM). Via systematically investigating the APSES transcription factors (TFs), two APSES proteins were identified: AfRafA and AfStuA. These play central roles in the synthesis of mycotoxins including aflatoxin and cyclopiazonic acid, and fungal development and are consequently central to the pathogenicity of the aflatoxigenic A. flavus. Loss of AfRafA not only dramatically suppressed aflatoxin cluster expression, subsequently reducing toxin synthesis both in vitro and in vivo, but also impaired conidia and sclerotia development. More importantly, aflatoxin biosynthesis as well as conidia and sclerotia development were fully blocked in ΔAfStuA. In addition, our results supported that AfStuA regulated the aflatoxin synthesis in an AflR-dependent manner. Intriguingly, it was revealed that AfRafA and AfStuA exert an antagonistic role in the regulation of biosynthesis of cyclopiazonic acid. In summary, two global transcriptional regulators for fungal development, mycotoxin production, and seed pathogenicity of the A. flavus system have been established. The two novel regulators of mycotoxins are promising targets for future plant breeding and for the development of fungicides.

Lysine methyltransferases transfer methyl groups in specific lysine sites, which regulates a variety of important biological processes in eukaryotes. In this study, we characterized a novel homolog of the yeast methyltransferase DOT1 in A. flavus, and observed the roles of dot1 in A. flavus. Deletion of dot1 showed a significant decrease in conidiation, but an increase in sclerotia formation. A change in viability to multiple stresses was also found in the Δdot1 mutant. Additionally, aflatoxin (AF) production was found severely impaired in the Δdot1 mutant. Further analysis by qRT-PCR revealed that the transcription of AF structural genes and their regulator gene aflS were prominently suppressed in the Δdot1 mutant. Furthermore, our data revealed that Dot1 is important for colonizing maize seeds in A. flavus. Our research indicates that Dot1 is involved in fungal development, aflatoxin biosynthesis and fungal virulence in A. flavus, which might provide a potential target for controlling A. flavus with new strategies.

Spore pigmentation is very common in the fungal kingdom. The best studied pigment in fungi is melanin which coats the surface of single cell spores. What and how pigments function in a fungal species with multiple cell conidia is poorly understood. Here, we identified and deleted a polyketide synthase (PKS) gene PfmaE and showed that it is essential for multicellular conidial pigmentation and development in a plant endophytic fungus, Pestalotiopsis fici. To further characterize the melanin pathway, we utilized an advanced Aspergillus nidulans heterologous system for the expression of the PKS PfmaE and the Pfma gene cluster. By structural elucidation of the pathway metabolite scytalone in A. nidulans, we provided chemical evidence that the Pfma cluster synthesizes DHN melanin. Combining genetic deletion and combinatorial gene expression of Pfma cluster genes, we determined that the putative reductase PfmaG and the PKS are sufficient for the synthesis of scytalone. Feeding scytalone back to the P. fici ΔPfmaE mutant restored pigmentation and multicellular adherence of the conidia. These results cement a growing understanding that pigments are essential not simply for protection of spores from biotic and abiotic stresses but also for spore structural development.

Here we report a new strategy for preparation of water-soluble photoluminescent carbon quantum dots (CQDs) from petroleum coke. Petroleum coke was oxidized first in mixed concentrated H2SO4 and HNO3, and then functionalized by hydrothermal ammonia treatment. The as-made CQDs and nitrogen-doped CQDs (N-CQDs) were characterized by UV–Vis absorption spectroscope, fluorescence spectroscope, transmission electron microscope, atomic force microscope, Raman spectrometer, X-ray powder diffractometer, X-ray photoelectron spectroscope and Fourier transform infrared spectrometer. The results show that the quantum yield of CQDs increases greatly from 8.7 to 15.8%, and the fluorescent lifetime increases from 3.86 to 6.11 ns after the hydrothermal treatment in ammonia. Moreover, the fluorescent color of N-CQDs can be tuned through the amount of doped nitrogen. Both CQDs and N-CQDs are water-soluble, and have uniform particle distribution, strong luminescence, and highly fluorescent sensitivity to pH in a range of 2.0–12.0. The uniform size distribution and nitrogen-doping of N-CQDs help to lead to high yield of radiative recombination, resulting in improved fluorescence properties. This work offers a simple pathway to produce high quality and enhanced photoluminescent CQDs from petroleum coke.

Five organic dyes with pyridine-N-oxide as the anchor group and electron acceptor have been synthesized and applied in dye-sensitized solar cells (DSSCs). Benzothiadiazole was introduced in the conjugation system to increase the electron withdrawing properties, FTIR spectra showed that the coordination was between the pyridine-N-oxide and the Brønsted acid site on the TiO2 surface. The relationship between different dye structures and the performance of the DSSCs was investigated systematically. The location of the thiophene unit was studied, and the direct linkage of benzothiadiazole with pyridine-N-oxide was beneficial to broaden the absorption. The donor-acceptor-acceptor-configured dye WL307, which has 2-ethylhexyloxy chains in the donor part, showed the best efficiency of 6.08% under 100 mW cm(-2) light illumination. The dye series showed a fairly good stability during the one month test period.

The desired control of size, structure, and optical properties of fluorescent carbon dots (CDs) is critical for understanding the fluorescence mechanism and exploring their potential application. Herein, a top-down strategy to chemically tailor the inexpensive coal to fluorescent CDs by a combined method of carbonization and acidic oxidation etching is reported. The size and optical properties of the as-made CDs are tuned by controlling the structures of graphitic crystallites in the starting precursor. The coal-derived CDs exhibit two different distinctive emission modes, where the intensity of the short-wavelength emission is significantly enhanced by partial reduction treatment. The evolution of the electronic structure and the surface states analysis show that two different types of fluorescence centers, nano-sized sp(2) carbon domains and surface defects, are responsible for the observed emission characteristics. The reduced CDs are demonstrated as an effective fluorescent sensing material for label-free and selective detection of Cu(II) ions with a detection limit as low as 2.0 nM, showing a great promise for real-world sensor applications.

A D-π-A type small molecule PTZ1 and an A-π-D-π-A type small molecule PTZ2 with phenothiazine as the central building block and dicyanovinyl as the electron-withdrawing end-group have been designed and synthesized. Compared with D-π-A type donor material PTZ1, the donor material PTZ2 with A-π-D-π-A configuration shows much wider response to solar light. The donor material PTZ1 possesses more positive highest occupied molecular orbital level, and higher Voc was obtained for devices with PTZ1/PC71BM blend as the active layer. An improved efficiency of 3.25% was obtained for the PTZ2/PC71BM based solar cells.

High-resolution, long-term and accurate daily-precipitation is always difficult and rarely measured in the Qinghai-Tibet Plateau (QTP) because of the high altitude and complex terrain. The accuracy of satellite-based gridded precipitation products have been continuously improved recently which is crucial to the study of cryosphere ecology and environment. The goal of this study is to evaluate the accuracy of CHIRPS v2 (Climate Hazards Group Infrared Precipitation with Stations data, version 2) and MSWEP v2 (Multi-source weighted-Ensemble Precipitation, version 2) daily-precipitation products over the QTP during the period 1981–2015. Validation was done using a time series of daily-precipitation data obtained from 104 hydrometeorological stations distributed over the QTP. Error metrics (The correlation coefficient CC, the relative bias BIAS, and root mean square error RMSE) were used for accuracy evaluation and detectability indicators (probability of detection POD, false alarm ratio RFA, and critical success index CSI) were used for the analysis of detection capabilities of rainfall occurrence events. The results indicate that when compared to rain gauge observations, CHIRPS and MSWEP daily-precipitation products represent well the spatial and temporal distribution of the mean daily precipitation over the QTP, while both of them overestimate the daily-precipitation (0.18 mm/d for CHIRPS, 0.56 mm/d for MSWEP). MSWEP performed better than CHIRPS according to CC (MSWEP is 0.44, CHIRPS is 0.23) and RMSE (MSWEP is 4.21 mm, CHIRPS is 5.03 mm) and MSWEP showed better detection capabilities with higher POD (0.65), lower RFA (0.50) and higher CSI (0.39) in the QTP. Both products are less accurate in dry conditions (the north QTP, winter) than in moist conditions (the south QTP, summer). Light precipitation events (0–2 mm/d) are underestimated but heavy precipitation events (2–25 mm/d) are overestimated. CHIRPS and MSWEP have shown great potential to be able to be applied to the precipitation-related study of the QTP. Although the accuracy of MSWEP is higher than that of CHIRPS, the latter has higher spatial resolution (o.o5°) and is more suitable for small-scale studies.