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Maize is a globally valuable commodity and one of the most extensively studied genetic model organisms. However, we know surprisingly little about the extent and potential utility of the genetic variation found in wild relatives of maize. Here, we characterize a high-density genomic variation map from 744 genomes encompassing maize and all wild taxa of the genus Zea, identifying over 70 million single-nucleotide polymorphisms. The variation map reveals evidence of selection within taxa displaying novel adaptations. We focus on adaptive alleles in highland teosinte and temperate maize, highlighting the key role of flowering-time-related pathways in their adaptation. To show the utility of variants in these data, we generate mutant alleles for two flowering-time candidate genes. This work provides an extensive sampling of the genetic diversity of Zea, resolving questions on evolution and identifying adaptive variants for direct use in modern breeding.

The harnessing of heavy atom effect of chalcogen elements offers a way for boosting the thermally activated delayed fluorescence (TADF) of purely organic luminescent materials that can harvest triplet excitons. However, the conformational and electronic variations induced by the heavy and large atoms may also have adverse effects on the TADF properties. Herein, the design, synthesis, and structures of a new type of through-space charge transfer (TSCT) emitters containing benzothiazino[2,3,4-kl]phenothiazine (DPTZ) as the donor unit are reported. The influences of S atoms on the emission properties have been systematically investigated by means of theoretical simulations, electrochemical and spectroscopic studies. Although the presence of π-stacking interactions and calculated spin-orbit coupling (SOC) values are beneficial for TSCT-TADF properties, the triplet TSCT states are uplifted to above the locally excited (LE) state of the acceptor moieties. As a result, the new emitters display longer delayed fluorescence lifetimes (τ

In this study, we isolated a novel Gram-stain-positive, aerobic, motile, rod-shaped bacterium, named GX 13764T, from the rhizosphere soil of a decayed mangrove plant Kandelia candel collected from Beihai, Guangxi, PR China, and characterized using a polyphasic taxonomic approach. The strain exhibited yellow-orange, round, convex, shiny, smooth, opaque and 2–3 mm diameter colonies on marine agar 2216 media after 3 days of incubation at 30 °C and was capable of growth at 4–45 °C (optimum, 30 °C), pH 5.0–9.0 (optimum, pH 7.0) and 0–4 % NaCl (w/v; optimum, 2 %). The strain was positive for catalase and negative for the oxidase. The main cellular fatty acid was anteiso-C15:0, iso-C15:0, iso-C16:0 and iso-C14:0. The cell-wall peptidoglycan comprised meso-diaminopimelic acid and the main menaquinone was MK-7. The polar lipids included one diphosphatidylglycerol, one phosphatidylglycerol, two glycolipids, two unidentified phospholipids and three unidentified lipids. Based on 16S rRNA gene analysis, GX 13764T presented the highest sequence similarity to Metabacillus mangrovi KCTC 33872T (97.04 %). The DNA G+C content of the type strain was 44.2 mol%. The average nucleotide identity values between GX 13764T and M. mangrovi KCTC 33872T, Metabacillus idriensis DSM 19097T and Metabacillus indicus LMG 22858T were 69.39, 68.87 and 68.95 %, respectively, with digital DNA–DNA hybridization values of 19.9, 19.5 and 19.5 %, respectively. Based on the polyphasic data, strain GX 13764T should be nominated as a novel species of the genus Metabacillus , for which the name Metabacillus kandeliae sp. nov. is proposed. The type strain is GX 13764T (=MCCC 1K06654T=KCTC 43366T).

To judge the coal and gas outburst (hereinafter referred to as ‘outburst’) risk of working faces in coal roadways according to the index of drilling cuttings weight (DCW), the influence factors and critical value of DCW were investigated. The study was conducted by deducing the theoretical calculation formula for DCW and using a set of self-designed, self-machined measuring apparatus for DCW which can be used to simulate the working face in a real coal roadway. The theoretical calculation formula for DCW indicates that the DCW increases with the increase of in situ stress and gas pressure while it also increases with decreasing coal strength. Among the three factors, with the change of gas pressure, the change in DCW is the smallest. On this basis, so that the critical value of DCW for judging the outburst risk of coal masses can better indicate the outburst risk at a working face, the tests for measuring DCWs under different outburst risk levels were carried out by using a set of apparatus for outburst risk which can be used to simulate the working face in a coal roadway by taking gas pressure as a controllable factor. The test results show that, with increasing outburst risk in a simulated coal seam, the DCW linearly increases at first and then suddenly rises. It also implies that the gas pressure exerts significant influences on DCW only when the outburst risk of a coal mass increases to a certain degree. There is a linear relationship between DCW and initial expansion energy of released gas (IEERG). On this basis, according to the critical values of IEERG indicating weak outburst and strong outburst risks, the critical values of DCW for outburst risk are judged. By using discriminant analysis, it can be obtained that the critical value of DCW when a weak outburst occurred is 4.88 kg/m. The critical value can be used to distinguish data samples with measured DCWs having weak outburst risk, whose accuracy reaches 89.47%. The critical value of DCW when a strong outburst occurred is 7.55 kg/m, which can accurately (100%) distinguish between data samples from weak and strong outbursts based on the measured DCWs. The final judgement accuracy of outburst risk is 93.75%.

Organic push-pull systems featuring through-space charge transfer (TSCT) excited states have been disclosed to be capable of exhibiting thermally activated delayed fluorescence (TADF), but to realize high-efficiency long-wavelength emission still remains a challenge. Herein, we report a series of strongly emissive orange-red and red TSCT-TADF emitters having (quasi)planar and rigid donor and acceptor segments which are placed in close proximity and orientated in a cofacial manner. Emission maxima (

Germacradienol is a main precursor in the biosynthesis of geosmin-type terpenes by a variety of microbes, but its biological activities are still unknown. In the biosynthetic mechanism study of an antifungal degraded sesquiterpenoid (1β,4β,4aβ,8aα)-4,8a-dimethyloctahydronaphthalene-1,4a(2H)-diol (5) with a geosmin scaffold, the germacradienol synthase B7C62_00490 was identified. To exploit the synthetic potential of the enzyme to create germacradienol, engineered strains were constructed by introducing key synthases of farnesyl diphosphate, germacradienol synthase B7C62_00490 and glycosyltransferase UGT73C5 in Escherichia coli BL21(DE3). Germacradienol (1) and the novel glycosylated derivate germacradienyl-11-O-β-d-glucopyranoside (3) were successfully obtained from engineered strains. The cytotoxic activity against nine human cancer cell lines and antimicrobial activities against a panel of bacteria and fungi of germacradienol analogs derived from engineered strains were evaluated. Germacradienol demonstrated multiple biological activities, including broad antimicrobial activities with MIC values ranging from 12.5 to 25.0 μg/mL and cytotoxic activities with IC

Haploid induction (HI) is an important tool in crop breeding. Phospholipase A1 (ZmPLA1)/NOT LIKE DAD (NLD)/MATRILINEAL (MTL) is a key gene controlling HI in maize; however, the underlying molecular mechanism remains unclear. In this study, to dissect why loss of ZmPLA1 function could mediate HI we performed a comprehensive multiple omics analysis of zmpla1 mutant anthers by integrating transcriptome, metabolome, quantitative proteome, and protein modification data. Functional classes of significantly enriched or differentially abundant molecular entities were found to be associated with the oxidative stress response, suggesting that a reactive oxygen species (ROS) burst plays a critical role in HI. In support of this, we further discovered that a simple chemical treatment of pollen with ROS reagents could lead to HI. Moreover, we identified ZmPOD65, which encodes a sperm-specific peroxidase, as a new gene controlling HI. Taken together, our study revealed a likely mechanism of HI, discovered a new gene controlling HI, and created a new method for HI in maize, indicating the importance of ROS balance in maintaining normal reproduction and providing a potential route to accelerate crop breeding.

Myocardial infarction (MI) represents one of the leading causes of death. MI models are widely used for investigating the pathomechanisms of post-MI remodeling and evaluation of novel therapeutics. Different methods (e.g., isoproterenol treatment, cryoinjury, coronary artery ligation, etc.) have been used to induce MI. Compared with isoproterenol treatment and cryoinjury, coronary artery ligation may better reflect the ischemic response and chronic remodeling after MI. However, traditional methods for coronary ligation in mice are technically challenging and require commercially available apparatus. The current study describes a simple and efficient process for induction of MI in mice with readily available materials. The mouse chest skin was cut open under stable anesthesia with a simplified anesthesia device made of centrifuge tubes. The heart was immediately externalized through the intercostal space after blunt separation of the pectoralis major and pectoralis minor. The left anterior descending branch (LAD) was ligated with a 6-0 suture 3 mm from its origin. Following LAD ligation, staining with 2,3,5-Triphenyltetrazolium chloride (TTC) indicated successful induction of MI and temporal changes of post-MI scar size. Meanwhile, survival analysis results showed overt mortality within 7 days after MI, mainly due to cardiac rupture. Moreover, post-MI echocardiographic assessment demonstrated successful induction of contractile dysfunction and ventricular remodeling. Once mastered, an MI model can be established in mice within 2-3 min with readily available materials.

Changes in coal seam permeability induced by roadway excavation may lead to many engineering problems, such as low gas extraction concentration in in-seam boreholes, coal and gas outburst disasters, and gas emissions in the process of coal roadway excavation. To solve these problems, this paper proposed a new method to directly determine the distribution of coal seam permeability around roadways. For this purpose, method principle was analyzed, equipment was developed, and field experiments were carried out in Baiyangling coal mine. Finally, the engineering applications of the method were analyzed, and a field application effect experiment was conducted to verify the new method. The results showed that the coal seam permeability around roadways was divided into four stages. In stages I and II, permeability increased, in stage III, permeability decreased, and stage IV maintained the initial permeability of the coal seam. These test results will aid in increasing the gas extraction concentration of in-seam boreholes and will guide the design of gas control areas. Using the verification experiment, it was concluded that the new method is able to accurately determine the redistribution of coal seam permeability caused by roadway excavation and provide theoretical guidance in solving engineering problems.

Side-chain fluorination of conjugated polymers has been proved to be a highly effective approach for optimizing optical and electrical properties of the relative polymers. However, current studies on the fluorination are all based on symmetric molecular structures. In this work, two new D-A type photovoltaic polymers, namely PITPh-DTffBT and PITPhf-DTffBT, based on asymmetric indenothiophene (IT) donor units with alkoxyphenyl or fluoroalkoxyphenyl substituents were designed and synthesized. Effects of the fluorine substitution in the asymmetric IT donor units on the electronic structure, ordering structure, photovoltaic properties, and charge generation and recombination dynamics were investigated. It is found that side-chain fluorination in the asymmetric donor units of the D-A polymers endowed the relative polymer with a deeper HOMO level, higher and more balanced charge mobilites, increased charge dissociation efficiency and reduced bimolecular recombination. As a result, the bulk heterojunction solar cell based on the blend film of PITPhf-DTffBT and PC71BM demonstrated an efficiency of 7.03%, whereas the cell efficiency based on PITPh-DTffBT was only 5.68%. These results indicate that our design strategy by introducing a fluoroalkoxyphenyl unit as side chain to fabricate asymmetric IT-based polymer is efficient in improving the photovoltaic performance. We believe that the results provide new insights into the design of high-performance semiconducting photovoltaic polymers.

Viscosities of ternary mixtures of VOSO4 + H2SO4 with water were measured across the entire range of total ionic strength (IT = 1 to 11) mol·kg−1 and over a temperature range of (283.15–318.15) K. The viscosity B-coefficients of the binary aqueous were determined from Jones-Dole equation. Using the B-coefficients, the activation parameters for viscous flow of the solutes were further evaluated. On the basis of Eyring’s equation, a semi-empirical method to estimate the viscosity for concentrated and mixed electrolyte solutions was put forward. The estimated viscosity values of VOSO4 + H2SO4 + H2O are in quite good agreement with the corresponding experimental results with the average absolute relative deviation of 0.96%.

Background & aims Nonalcoholic steatohepatitis (NASH) has become a worldwide epidemic, which is a common clinical condition predisposing to advanced liver diseases. A large and growing unmet therapeutic need for this condition reflects incomplete understanding of its pathogenesis. In current study, we identified a transcription factor Zinc Fingers and Homeoboxes 2 (ZHX2) in hepatocytes as a protective factor against steatohepatitis. Approach & results We found that hepatic ZHX2 was significantly suppressed in NASH models and steatotic hepatic cells. Hepatocyte-specific ablation of ZHX2 exacerbated NASH-related phenotypes in mice, including lipid accumulation, enhanced inflammation, and hepatic fibrosis. Conversely, hepatocyte-specific overexpression of ZHX2 significantly alleviated the progression of NASH in an experimental setting. Integrated analysis of transcriptomic profiling and chromatin immunoprecipitation sequencing data demonstrated that the Phosphatase and Tensin Homologue (PTEN) was a target gene of ZHX2 in hepatocyte. ZHX2 bound to the promoter of PTEN gene and subsequently promoted the transcription of PTEN, which mediated the beneficial role of ZHX2 against NASH. Conclusion In conclusion, current findings unfolded a protective role of ZHX2 against NASH progression by transcriptionally activating PTEN. These findings shed light on the therapeutic potential of targeting ZHX2 for treating NASH and related metabolic disorders.

The law of gas initial desorption from coals is greatly important for understanding the occurrence mechanism and predicting coal and gas outburst (hereinafter referred to as ‘outburst’). However, dynamic characterization of gas initial desorption remains to be investigated. In this study, by monitoring the gas pressure and temperature of tectonically deformed (TD) coal and primary-undeformed (PU) coal, we established the evolution laws of gas key parameters during the initial desorption. The results indicate that the gas pressure drop rate, mass flow rate, initial desorption rate, and gas velocity increase with increasing gas pressure, with stronger gas dynamic effect, generating a high pressure gradient on the coal surface. Under the same gas pressure, the pressure gradient formed on the TD coal surface is greater than that formed on the surface of the PU coal, resulting in easily initiating an outburst in the TD coal. Moreover, the increased gas pressure increases temperature change rates (falling rate and rising rate) of coal mass. The minimum and final stable temperatures in the TD coal are generally lower compared to the PU coal. The releasing process of gas expansion energy can be divided into two stages exhibiting two peaks which increase as gas pressure increases. The two peak values for the TD coal both are about 2–3 times of those of the PU coal. In addition, the total gas expansion energy released by TD coal is far greater than that released by PU coal. The two peaks and the total values of gas expansion energy also prove that the damage of gas pressure to coal mass increases with the increased pressure, more likely producing pulverized coals and more prone to initiate an outburst.

Asian elephant is large herbivorous animal with elongated hindgut. To explore fecal microbial community composition with various ages, sex and diets, and their role in plant biomass degrading and nutrition conversation. We generated 119 Gb by metagenome sequencing from 10 different individual feces and identified 5.3 million non-redundant genes. The comprehensive analysis established that the Bacteroidetes, Firmicutes and Proteobacteria constituted the most dominant phyla in overall fecal samples. In different individuals, the alpha diversity of the fecal microbiota in female was lower than male, and the alpha diversity of the fecal microbiota in older was higher than younger, and the fecal microbial diversity was the most complex in wild elephant. But the predominant population compositions were similar to each other. Moreover, the newborn infant elephant feces assembled and maintained a diverse but host-specific fecal microbial population. The discovery speculated that Asian elephant maybe have start to building microbial populations before birth. Meanwhile, these results illustrated that host phylogeny, diets, ages and sex are significant factors for fecal microbial community composition. Therefore, we put forward the process of Asian elephant fecal microbial community composition that the dominant populations were built first under the guidance of phylogeny, and then shaped gradually a unique and flexible gut microbial community structure under the influences of diet, age and sex. This study found also that the Bacteroidetes were presumably the main drivers of plant fiber-degradation. A large of secondary metabolite biosynthetic gene clusters, and genes related to enediyne biosynthesis were found and showed that the Asian elephant fecal microbiome harbored a diverse and abundant genetic resource. A picture of antibiotic resistance genes (ARGs) reservoirs of fecal microbiota in Asian elephants was provided. Surprisingly, there was such wide range of ARGs in newborn infant elephant. Further strengthening our speculation that the fetus of Asian elephant has colonized prototypical fecal microbiota before birth. However, it is necessary to point out that the data give a first inside into the gut microbiota of Asian elephants but too few individuals were studied to draw general conclusions for differences among wild and captured elephants, female and male or different ages. Further studies are required. Additionally, the cultured actinomycetes from Asian elephant feces also were investigated, which the feces of Asian elephants could be an important source of actinomycetes.

Coal and gas outbursts (hereinafter, collectively referred to as ‘outbursts’) often last for just a few tens of seconds and occur mostly in gas-bearing tectonically-deformed (TD) coal. It has been proved that, in comparison to primary-undeformed (PU) coal, TD coal is more susceptible to outbursts due to its lower mechanical strength, stronger gas-adsorption capability, and faster gas-desorption rate. At the same time, the energy required for the outburst process is mainly provided by the gas. However, the characteristics of the gas-desorption behavior and gas-release energy in TD and PU coal during the first dozen seconds or so have rarely been studied. In this study, gas desorption experiments were carried out on TD and PU coal at different gas pressures using self-assembled desorption equipment. The experiments focus on roughly the first 13 s. The results show that the drop rate of gas pressure is lower with TD coal compared to PU coal, while the gas desorption rate is higher for TD coal compared to PU coal. Most of the gas is released from the two types of coal in the first few seconds. For both TD and PU coal, the time taken to release 90% of the total gas expansion energy (TGEE) is shorter than that to release 90% of the total gas energy (TGE). At the different gas pressures used, the TGEE of the two types of coal accounts for about 14–16% of the TGE. The higher the gas pressure is, the greater the TGEE released by the coal samples gets, and thus the larger the TGEE: TGE ratio becomes. Although the TGEE released from the TD coal is about 3 times that released from the PU coal, it accounts for a slightly smaller proportion of the TGE compared to that in the PU coal samples.

Coal and gas outbursts (hereinafter referred to as ‘outbursts’) result in serious damage and often occur in tectonically-deformed coal that is rich in gas. It has been demonstrated that the level of outburst risk declines with increasing coal moisture content. Moreover, an outburst generally lasts for mere tens of seconds and the required energy is mainly provided by the gas expansion energy. However, the gas desorption and energy release characteristics of tectonically deformed coal with different moisture contents during the first dozen seconds have not often been studied. In this study, a set of self-designed gas desorption equipment was used to carry out gas adsorption-desorption experiments in the first dozen seconds (about 13 s) on coal with different moisture contents. The results show that the drop rate of the gas pressure increases with an increase in coal moisture content, and the total amount of gas desorption and the mass flow rate of gas desorption reduce correspondingly in the gas desorption process. Moreover, the gas velocity also slows with increasing moisture content. Under different gas pressures, the total gas expansion energy (TGEE) and the total gas energy (TGE) released from the coal decrease with the increasing moisture content. Correspondingly, it takes a shorter time for coal to release 90% of the TGEE and the TGE. For all of the coal samples, the time taken for releasing 90% of the TGEE is shorter than that for releasing 90% of the TGE. Meanwhile, the ratio of TGEE in the TGE increases with the increasing moisture content. The TGEE accounts for 14–16% of the TGE released from coal samples of different moisture contents under different gas pressures.

Coal and gas outburst accidents occurring in underground coal mines generally cause great casualties and economic losses, especially in construction areas of coal seams where the outburst risks are not accurately evaluated. Therefore, accurately identifying the outburst risks of coal seams is necessary and critical to prevent and control outbursts. In order to improve the prediction accuracy for outbursts in working faces of coal roadways, a self-designed drilling device that can simulate the in-situ outburst prediction of coal roadways was used in this study. We used the coal samples with different coal ranks to adsorb CO 2 and N 2 with different pressures in the laboratory, so as to simulate the coal seams with different outburst risks. Finally, boreholes for predicting the outburst risk were drilled in the simulated coal seams to study the correlation between common dynamic phenomena (e.g. gas and coal being ejected from the borehole (GCEB) and drill pipe being stuck by coal mass in the borehole (DPSC)) and outburst risks. The results show that the greater the outburst risks of coal seams, the more frequent the occurrence of GCEB and DPSC is. The GCEB phenomenon for outburst prediction is attributed to small-sized coal and gas outbursts in boreholes, while the occurrence of DPSC phenomenon does not affirm that there definitely are outburst risks on working faces. The DPSC phenomenon indicating outburst risks is generally accompanied with GCEB, which form a linkage system and are triggered successively.

Two new donor-acceptor (D-A) polymers, namely PNDT-QX and PNDT-QXS, with naphtho [1,2-b:5,6-b']dithiophenes (NDT) as donor unit and quinoxaline (QX) as acceptor unit, were designed and synthesized. The difference in the structures of the two polymers is that, in PNDT-QXS the side chains on the QX acceptor units are (2-ethylhexyl) thio thienyl groups, whereas in PNDT-QX the side chains are 2-ethylhexyl thienyl groups, which allow us to systematically compare the effects of alkylthio group on optical, electrochemical, molecular packing properties and PSCs performance of polymers. Our study demonstrated that, relative to alkyl group, alkylthio substituents tune down the HOMO and LUMO energy levels, red-shift and broaden the absorption, and enhance the interchain interaction, therefore significantly affect the BHJ morphology of the copolymer with PC71BM. As a result, the polymer solar cell based on the blend of PNDT-QXS and PC71BM got a highest PCE of 5.03% without using extra post-treatment steps, whereas the PNDT-QX cell only had a 1.93% highest PCE. The results prove for the first time that introducing alkylthio side chains into acceptor moiety would also be an effective strategy for improving the photovoltaic performance of the D-A copolymers.

Coal and gas outburst (hereinafter referred to as “outburst”) is a complicated dynamic disaster formed in the temporal and spatial evolution process. To further improve our understanding of outburst mechanism and help more effective outburst prevention and control measures to be devised, a finite number of outburst simulation tests were carried out in the study. The results show that the contribution of the gas pressure to the energy required for an outburst is hundreds of times that of the in situ stress during the outburst. With increasing mining depths, the higher the in situ stress, the gas pressure, and the temperature; however, the temperature shows the lowest influence on the outburst intensity among various parameters such as gas pressure, the thickness of soft coal, and the temperature. The initial expansion energy of releasing gas (IEERG) is an index reflecting the influences of in situ stress, gas pressure, and coal strength on outburst intensity. The test results indicate that the potential amount of coal ejected can be predicted by measuring the IEERG of coal masses and the thickness of soft coal in outburst-prone zones. According to the failure characteristics of coal masses after an outburst, the larger the outburst intensity is, the smaller the volume of residual coal area relative to the outburst holes. The shapes of extrusive coal-gas flows after an outburst show that the outburst process is a chain of events occurring over multiple cycles as follows: preparation, initiation, development, and termination. The recorded video footage of an outburst also shows this.

Coal and gas outburst is a serious coal and rock dynamic disaster, and effective prediction is essential to control. The initial expansion energy of released gas (IEERG) is a new method to predict coal and gas outburst, which depends primarily on the gas pressure and degree of coal fragmentation. The IEERG reflects the effects of the ground stress, the gas pressure, and coal strength on the coal and gas outburst. On the basis of the single factor on the IEERG, three factors have been studied by orthogonal experiments, including gas pressure, coal particle size, and moisture. The results show that the influence of gas pressure, coal particle size, and water content on the IEERG decreases in turn; that gas expansion energy increases significantly as gas pressure increases; and that the greater the gas pressure, the faster the increase. The index Wp of IEERG first increases and then decreases with an increase in coal particle size and decreases with an increase in moisture content. Through this work, the main influencing factors of gas expansion energy have been defined. This method offers an important theoretical and practical significance to predict coal and gas outbursts.

The amount of initial gas release after the destruction of coal by ground stress relates closely to the outburst danger. In this paper, the following method was proposed to accurately determine the initial gas desorption law of coal. First, real-time temperature and pressure data of sealed coal sample tank after the sudden exposure of coal that had reached adsorption equilibrium within the tank were collected first via a high-precision, high-frequency response sensor. Then, the mass flow of gas passing through the pneumatic component at different times was calculated according to flow rate characteristics of pneumatic component that communicated with the atmosphere on the tank. In this process, it is determined that a convergent nozzle with a larger contraction ratio should be used as the channel for gas desorption and release. Moreover, in light of the characteristics of the testing process, the existing parameters that characterize the flow characteristics of pneumatic component were optimized and measured. Finally, the initial gas desorption laws of two coal samples with different metamorphic degrees were measured and analyzed under two pressures using three different-sized convergent nozzles.

The fracture patterns of brittle materials in different stress loading modes are different. In order to study the fracture characteristics of brittle materials under confining pressure, in this study, both uniaxial compression tests and loading confining pressure tests were conducted on three concrete samples of different strengths, respectively. Meanwhile, the failure process of the samples during the loading of confining pressure was monitored using an acoustic wave tester; finally, the failure characteristics of the concrete samples were further investigated on a mesoscopic level by carrying out numerical simulations. The test results show that different failure modes were revealed in the concrete samples subjected to uniaxial compression: The failure initially started at both ends and then gradually extended to the middle part along the longitudinal direction; eventually, splitting failure, single inclined plane shear failure and conjugated inclined plane shear failure occurred. However, as the confining pressure was loaded, the samples failed merely in a simple mode, that is, the fractures occurred around the middle parts of the samples, perpendicular to the specimens axis. According to the acoustic measurements, the local failure processes before fracturing under confining pressure were consistent with those under uniaxial compression. The simulation results suggest that the failure initially started inside the samples due to the effects of longitudinal tensile stress under confining pressure, and then, it gradually extended to both sides along the lateral direction.

Coal and gas outbursts are a rapid and powerful energy-releasing process. The damage to coal and the release of gas in the initial stage play key roles in the occurrence of outbursts. Existing studies have mainly focused on the gas desorption processes in coal under specific conditions such as particle size, specified mass and exposure time of pulverized coal. However, these studies have focused less on the gas release during the initial stage, and the quantitative relationship between the outburst risk level and the test results. Seven coal samples with different metamorphic degrees were chosen for use in outburst simulation experiments to investigate trends in gas release from pulverized coal in the presence of N 2 and CO 2 . The results demonstrate a strong correlation between the gas release capacity during the first 10 s and natural desorption gas content of the onset of coal exposure during the first 120 min. In general, the higher the gas content, the larger the released gas volume, and thus the larger the limiting amount of desorptive gas. The gas release from an outburst coal sample is larger than that from a non-outburst coal sample within the first 10 s. There is a good linear relationship between the initial volume of released gas (in the first 10 s) and the initial expansion energy of released gas (IEERG), which can reflect the risk of coal outburst. Thus, according to the outburst critical value (42.98 mJ/g) of IEERG, the critical value of initial volume of released gas could be calculated to be 1.113 cm 3 /g. The results can provide a reference for further study of the effect of gas on outbursts and the investigation of coal and gas outbursts disasters.

In this study, we propose a set of rapid prediction technologies for the outburst risk of coal uncovering in crosscuts and shafts (CUCS). These technologies are needed because of the ideal model to uncover coal in crosscuts and the law that coal seam outburst intensity increases as the initial expansion energy of released gas (IEERG) increases. Our technologies include rapid coal seam gas pressure determination under complex geological conditions, complete coal-core coring and the IEERG measurement. We successfully applied these technologies in the Panyi Coal Mine in Huainan. The field application results demonstrated that these technologies could accurately and rapidly measure coal seam gas pressure, greatly minimize human damages to coal samples in the coal coring process, and accurately predict outburst risks in CUCS.

The gas pressure of a coal seam is one of the important parameters for studying gas reserves, law of gas flows, gas emissions, predicting coal and gas outburst risks and developing gas-control measures. In this study, the effects of the depth of the borehole drilled in a coal seam on the time required to determine the gas pressure and its value were discussed. Accordingly, elastic-plastic mechanics were applied to analyze the variation in the stress around the borehole, and the effective flow radii expressions of the spherical and radial flow boreholes were derived. The COMSOL Multiphysics numerical simulation software, was used to simulate the gas-flow range of the boreholes drilled at different depths in a coal seam, which were exposed for approximately 2 h. Finally, the boreholes of different depths was used to determine the gas pressure of No. 二 2 coal seam in the Xuehu coal mine (Henan Province, China). The results show that the time required in measuring the gas pressure is longer for boreholes drilled to a greater depth in a coal seam. For the same exposure times, the determined gas-pressure value will be smaller. Furthermore, the confined water and fractures in the roof and floor of the coal seam can be sealed by injecting high-pressure slurry into the borehole, which provides a reference for determining the gas pressure of the coal seam quickly under different geological conditions in future studies.

Coal and gas outburst is a dynamic phenomenon with violent eruptions of coal and gas from the working coal seam, resulting in economic loss and casualties. It has been proved that rapid desorption within a short period is necessary for occurrence of an outburst. Due to limitation of the present test condition, gas desorption characterization for the first several seconds (0–10 s) hasn’t been researched sufficiently. In this study, initial desorption characterization of gas in coal is studied by experiments with methane and carbon dioxide. The most remarkable characteristic of the experimental setup is application of a self-developed real-time data acquisition system with time interval of about 1.6 ms, which achieves the goal of collecting enough pressure and temperature data for analysis and calculation. The data is used to study gas pressure variation and calculate initial amount of desorbed gas and initial expansion energy of released gas. From the experimental results, new proof has been found to verify that coal and carbon dioxide outburst is more dangerous than coal and methane outburst.

Before uncovering an outburst coal seam in crosscut and shaft, it is necessary to detect the effect of outburst prevention measure applied to the seam, which is a key step and the last link for ensuring the safety of coal miners. However, in the working face where outburst prevention measures have been taken, the large number of densely arranged discharge boreholes, as well as the difficulty in sealing pressure-measuring boreholes, makes it extremely hard to accurately detect the effect of the measure. In order to solve this problem, this paper studied the relationship between the initial rate of gas emission from the borehole (IRGEB) and the outburst danger through carrying out experiments on a self-designed oblong simulation device of outburst coal seam and a detection device of IRGEB. In addition, it proposed a method of testing the prevention effect using the initial volume of gas emission from the borehole (IVGEB) per unit length which actually refers to the time integral of IRGEB per meter. The experimental results show that IVGEB grows with the increase of outburst danger, but its critical value varies with the types of coal seams and gasses. As a result, it may take over 20 days to get the critical value of outburst detection of a specific coal seam. For this reason, this paper presented a simplified method of determining the critical value of IVGEB per unit length. When this method is applied, the total time taken up can be enormously reduced to shorter than 4 h just by drilling another borehole for measuring the IVGEB. The field application results indicate that the method can quickly detect whether outburst danger has been locally eliminated. Hence, it can be regarded as a very applicable method for the rapid detection of outburst prevention effect before coal uncovering in crosscut and shaft.

Aurantiadioic acids A (1) and B (2), two new furan-containing polyketides, and aurantoic acid A (3), a new natural product, were isolated from the liquid fermentation of the sika deer dung-derived actinomycete Actinocorallia aurantiaca. The structures of the new compounds were established by extensive spectroscopic methods, including 1D & 2D NMR, HRESIMS spectroscopic analysis. The absolute configuration of 3 was assigned by comparison of the specific optical rotations with the reported derivatives. Biological activity evaluations suggested that compounds 1–3 showed weak inhibition on NO production in the murine monocytic RAW 264.7 macrophages with IC50 values of 35.8, 41.8, 45.2 μM, respectively. Compound 3 showed weak inhibition on influenza A virus (A/PuertoRico/8/1934, H1N1) with an EC50 value of 35.9 μM, and a selective index higher than 13.3.

A number of additives have been proven to improve the performance of vanadium redox flow batteries (VRFBs). Polyacrylic acid (PAA) is considered to be one of the promising candidates because of its beneficial effects on the stability of batteries. This paper studied the influence of PAA on viscosity, which is one of the electrolyte transport properties. The viscosity of VOSO4 + PAA + H2O ternary solution was measured at different temperature, ionic strength, and ionic strength fractions in the temperature range of 283.15 K–318.15 K. Several thermodynamic parameters of the PAA aqueous solution were calculated, such as the viscosity B-coefficients, the apparent molar volume of infinite dilution and the free energy of activation. In addition, two different semi-empirical prediction equations were established for ternary solution viscosity on the basis of the Eyring's theory, and the better one was determined through comparison. The average relative deviation is 0.74% between the predicted and the experimental values, which indicates this function can be used to predict the viscosity of VOSO4 + PAA + H2O ternary solution.

Currently, there are many methods to predict outburst risk when uncovering coal in crosscuts. When used, these prediction methods produce inconsistent prediction results. Consequently, engineers at the mining site are often at a loss on how to proceed. In the present studies, in the hope of addressing this problem, 23 different types of coal samples from 12 mines in five coal-producing provinces in China were collected to conduct 46 outburst simulation experiments in the laboratory under carbon dioxide and nitrogen conditions. In addition, coal seams under conditions identical to the outburst simulation experiments were fabricated, and various methods to predict outburst risk when uncovering coal in crosscuts were comparatively investigated. Furthermore, the accuracy of various outburst prediction methods was determined. Finally, the cause for the erroneous predictions generated using each index was theoretically analyzed. The research results provide a basis for selecting methods to predict outburst risk when uncovering coal in crosscuts at mining sites.

Two new donor–acceptor copolymers, namely PBDT-DFQX-TTSEH and PBDT-DFQX-TTSC8, based on difluorinated quinoxaline (Qx) acceptor units and alkylthiothienyl benzo[1,2-b:4,5-b′]dithiophene (BDT) donor units with different alkylthio side chains were designed and synthesized. The two copolymers exhibit a lower-lying HOMO energy level and closer interchain packing than their analogues with alkyl side chains attributed to the more polarizable S atom inducing stronger intermolecular interactions. Of these two polymers, PBDT-DFQX-TTSC8 with linear alkylthio side chains shows closer molecular stacking with PC71BM than PBDT-DFQX-TTSEH with branched alkylthio side chains. As a result, the polymer solar cell based on the blend of PBDT-DFQX-TTSC8 and PC71BM exhibited a higher PCE of 8.51% than that based on PBDT-DFQX-TTSEH and PC71BM, which was only 7.02%. More importantly, both copolymers show higher photovoltaic performances in as-cast devices than in those treated by additive or thermal annealing because an appropriate bulk morphology was formed during the process of spin-casting due to the strong interchain interactions of the polymers, which eliminates the need for solvent additives or thermal annealing.