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Soil salinity is a major constraint adversely affecting agricultural crops including wheat worldwide. The use of plant growth promoting rhizobacteria (PGPR) to alleviate salt stress in crops has attracted the focus of many researchers due to its safe and eco-friendly nature. The current study aimed to study the genetic potential of high halophilic

The Middle Jurassic Xishanyao Formation in the central section of the southern Junggar Basin has substantial amounts of low-ranked coalbed methane (CBM) recourses and is typically characterized by multi superimposed coal seams. To establish the CBM enrichment model, a series of experimental and testing methods were adopted, including coal maceral observation, proximate analysis, low temperature nitrogen adsorption (LTNA), methane carbon isotope determination, porosity/permeability simulation caused by overburden, and gas content testing. The controlling effect of sedimentary environment, geological tectonic, and hydrogeological condition on gas content was analyzed in detail. The results demonstrate that the areas with higher gas content (an average of 8.57 m3/t) are mainly located in the Urumqi River-Santun River (eastern study area), whereas gas content (an average of 3.92 m3/t) in the Manasi River-Taxi River (western study area) is relatively low. Because of the combined effects of strata temperature and pressure, the gas content in coal seam first increases and then decreases with increasing buried depth, and the critical depth of the inflection point ranges from 600 m to 850 m. Affected by the changes in topography and water head height, the direction of groundwater migration is predicted from south to north and from west to east. Based on the gas content variation, the lower and middle parts of the Xishanyao Formation can be divided into three independent coal-bearing gas systems. Within a single gas-bearing system, there is a positive correlation between gas content and strata pressure, and the key mudstone layers separating each gas-bearing system are usually developed at the end of each highstand system tract. The new CBM accumulation model of the multi-coals mixed genetic gas shows that both biological and thermal origins are found in a buried depth interval between 600 m and 850 m, suggesting that the coals with those depths are the CBM enrichment horizons and favorable exploration regions in the middle section of the southern Junggar Basin. An in-depth discussion of the low-rank CBM enrichment model with multi-coal seams in the study region can provide a basis for the optimization of CBM well locations and favorable exploration horizons.

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Based on analyses of the lithofacies palaeogeography of the Taiyuan and the Shanxi Formations in the Qinshui Basin, the spatial variations of the coal seam thickness, coal maceral composition, coal quality, and gas content, together with the lithofacies of the surrounding rocks in each palaeogeographic unit were investigated. The results show that the thick coals of the Taiyuan Formation are mainly distributed in delta and barrier island depositional units in the Yangquan area in the northern part of the basin and the Zhangzi area in the southeastern part of the basin. The thick coals of the Shanxi Formation are located within transitional areas between delta plain and delta front depositional units in the central southern part of the basin. The Taiyuan Formation generally includes mudstone in its lower part, thick, continuous coal seams and limestones in its middle part, and thin, discontinuous coal seams and limestone and sand-mud interbeds in its top part. The Shanxi Formation consists of thick, continuous sandstones in its lower part, thick coal seams in its middle part, and thin coal seams, sandstone, and thick mudstone in its upper part. From the perspective of coal-bearing sedimentology and coalbed methane (CBM) geology, the lithology and thickness of the surrounding rocks of coal seams play more significant roles in controlling gas content variation than other factors such as coal thickness, coal macerals, and coal quality. Furthermore, it is found that the key factors influencing the gas content variation are the thicknesses of mudstone and limestone overlying a coal seam. At similar burial depths, the gas content of the Taiyuan coal seams decreases gradually in the lower delta plain, barrier-lagoon, delta front, barrier-tidal flat, and carbonate platform depositional units. The CBM enrichment areas tend to be located in zones of poorly developed limestone and well-developed mudstone. In addition, the gas content of the Shanxi Formation is higher in the coals of the delta front facies compared to those in the lower delta plain. The CBM enrichment areas tend to be associated with the thicker mudstones. Therefore, based on the lithologic distribution and thickness of the rocks overlying the coal seam in each palaeogeographic unit of the Taiyuan and Shanxi Formations, the areas with higher gas content are located in the north-central basin for the Taiyuan coals and in the southern basin for the Shanxi coals. Both of these areas should be favorable for CBM exploration in the Qinshui Basin.

Two electron transporting materials, [1,1′:3′,1′′-terphenyl]-3,3′′-diylbis(diphenylphosphine oxide) (BmPOPB) and [1,1′:3′,1′′-terphenyl]-4,4′′-diylbis(diphenylphosphine oxide) (BpPOPB), have been designed and synthesized by appending a diphenylphosphine oxide moiety to the m-terphenyl core via meta- and para-linkage topologies. The influence of different linking modes on the thermal, photophysical, electrochemical, and electron transport properties of the compounds is systematically studied. Through the meta-linkage topology and supernumerary transporting channel assisted by diphenylphosphine oxide, the harmonious compatibility of a high triplet energy level (ET) of 2.82 eV and a high electron mobility of around 10−4 cm2 V−1 s−1 for BmPOPB has been achieved. When BmPOPB was used as an electron-transport material (ETM), the Ir(ppy)3-based green device hosted by CBP exhibited excellent performance with a maximum external quantum efficiency (EQE) of 22.68%; FIrpic-based and 2CzPN-based blue OLEDs hosted by mCP displayed maximum external quantum efficiencies (EQEs) of 21.3% and 17.4%, respectively. All the device performances outperformed that of its isomer BpPOPB and the typical ETM, 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi). This contribution rationally demonstrated the significance of the harmonious compatibility in designing electron-transport materials for high-performance OLEDs.

To study the stratal stacking patterns and controls on coal accumulation in a lowland alluvial plain, coastal plain, and shallow-marine setting, the depositional facies, sequence stratigraphy, and paleogeography of the Carboniferous–Permian strata in the Anyang-Hebi (Anhe) coalfield, Henan Province, northern China were analyzed based on borehole cores. Ten facies were grouped into four facies associations, which represent alluvial plain, delta plain, delta front and prodelta, and offshore marine depositional environments. Ten sequences (S1 to S10, in ascending order) were defined on the basis of vertical facies stacking patterns. Sequences S1–S3, of Moscovian to early Asselian age, are composed mainly of offshore marine carbonate and mudstone, prodelta and delta front mudstone and sandstone, and delta plain sandstone, mudstone and coal. Sequences S4–S9, late Asselian to Wuchiapingian in age, consist of delta plain sandstone, mudstone and coal. Sequence S10, corresponding to the Changhsingian stage, is composed mainly of alluvial plain sandstone and mudstone. From S1 to S10, the Anhe coalfield experienced an environmental evolution from offshore marine, prodelta and delta front through delta plain to alluvial plain environments, an evolution from a low-accommodation to a high-accommodation setting, and a paleoclimatic change from humid to semi-arid conditions. Coal accumulation was controlled by a combination of relative sea-level fluctuation, paleoclimate and paleogeography. The cyclothemic nature of S2, including presence of parasequences, and the significant sea-level fall interpreted at the base of S4 may be related to Gondwanan ice dynamics in the late Carboniferous–early Permian. The thick coals are concentrated in the transgressive systems tracts of S2 and S4. The results of this study provide new insights into the environmental evolution of Carboniferous–Permian lowland alluvial plain, coastal plain and shallow-marine successions of the northern subtropical paleolatitudes and the controls on coal deposits in North China.

By incorporating different number of pyridine rings to the periphery of the 9,10-diphenylanthracene (DPA) core, four new pyridine-containing DPA derivatives, 3-(4-(10-phenylanthracen-9-yl)phenyl)pyridine ( AnPy ), 9,10-bis(4-(pyridin-3-yl)phenyl)anthracene ( AnDPy ), 3,3'-((2-(pyridin-3-yl)anthracene-9,10-diyl)bis(4,1-phenylene))dipyridine ( AnTPy ), 3,3'-(9,10-bis(4-(pyridin-3-yl)phenyl)anthracene-2,6-diyl)dipyridine ( AnFPy ) were designed and synthesized as electron transporters. Their photophysical properties, energy levels and electron mobilities can be readily regulated through tuning the quantity of the pyridine ring. Through optimizing electron injection/transporting properties, AnTPy exhibits not only a suitable lowest unoccupied molecular orbital (LUMO) energy level for electron injection into light-emitting layer (EML), but also a relatively high electron mobility of around 10 −3 cm 2 V −1 s −1 , which is about two orders of magnitude higher than that of the widely used material Alq 3 . As expected, the blue fluorescent OLEDs with AnPy , AnTPy and AnFPy as an electron-transporting layer (ETL) exhibited superior performance compared to that using Alq 3 , remarkably lowering the driving voltages and improving efficiencies. In particular, the device with AnTPy as an ETL showed a maximum current efficiency of 14.4 cd A −1 , a maximum power efficiency of 12.1 lm W −1 , a maximum external quantum efficiency (EQE) of 8.15% and low efficiency roll-off even at an illumination-relevant luminance of 10,000 cd m −2 . These results clearly demonstrated that tuning electron injection/transporting properties by optimizing the number of peripheral electron-withdrawing groups was an efficient strategy to achieve high-performance ETMs.

To study the possible role of base-level oscillations in the formation of thick coal seams in coastal plain (paralic) environments, the Early Permian Shanxi Formation No.21 thick coal seam was investigated in 3 cores spanning a distance of 29 km in the Anhe (Anyang-Hebi) coalfield, Henan Province using sedimentology, sequence stratigraphy, and coal petrology. The accommodation condition and origin of the peatland can be interpreted from maceral and mineral composition in the No.21 coal seam. Coals that accumulated in a low accommodation peat of ombrotrophic origin are characterized by relatively high inertinite content and relatively low mineral matter abundance. Coals accumulated in a balanced accommodation peat of rheotrophic origin are characterized by high vitrinite content and low abundances of inertinite and mineral matter. Coals with relatively high vitrinite content and relatively low inertinite content are interpreted to have accumulated in a high accommodation peat of rheotrophic origin. The No.21 coal seam was developed as part of a transgressive systems tract (TST) and displays maximum thickness in the central Anhe coalfield due to the local rapid subsidence of the formative delta plain. Six types of key stratigraphic surfaces are recognized in the coal seam, including terrestrialization (TeS), paludification (PaS), give-up transgressive (GUTS), accommodation-reversal (ARS), exposure (ES), and flooding (FS) surfaces. The No.21 coal seam consists of at least three drying-up and wetting-up cycles defined by these surfaces, with each cycle spanning from 20 ka to 30 ka. The variation of peatland type from rheotrophic through ombrotrophic and back to rheotrophic peat in the landward area implies the role of high-frequency climatic fluctuations, and the water level changes in the central and seaward areas may reflect sea-level fluctuations due to the hydrological connection to the sea and the change in rainfall to evaporation rates. These cycles arrived at a period close to that of climatic precession for Milankovitch cycles during the early Permian. The oscillating high and low summer insolation would have caused the alternating wet and dry climate periods that were then recorded as the wet-dry cycles in the coal seams. The results of this study can provide insights for research addressing hydrological conditions in ancient peatlands, and paleoclimate and sea-level fluctuations recorded in thick paralic coal seams.

The assessment of coalbed methane (CBM) reservoirs can provide insights into the evolution of the pore structure systems around the first coalification jump (FCJ). The southern Junggar Basin, a typical low-rank coal-bearing basin in northwestern China, has been of interest to scientists and policy-makers due to its abundance of CBM resources and favourable conditions for CBM enrichment. A total of 28 coal samples from the Middle Jurassic Xishanyao Formation collected from 11 sampling sites in the central segment of the southern Junggar Basin were analyzed in this study. These samples were quantitatively characterized and comprehensively evaluated using macroscopic to nanometer-scale methods including macroscopic coal description, proximate analysis, vitrinite reflectance measurements, maceral analysis, low pressure nitrogen adsorption (LPNA), scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and nuclear magnetic resonance (NMR). The results show that the Xishanyao low-rank coals are characterized by low moisture contents, low or low-medium ash yields (eastern and western parts), high volatile matter contents, moderate vitrinite contents, and high inertinite contents. The physical property of the Xishanyao coals generally displays heterogeneity, with the specific surface area, the total pore volume, the air permeability and the transverse relaxation time (T2) ranging from 0.116 to 15.983 m2/g, 0.461 × 10−3 to 13.37 × 10−3 cm3/g, 0.001 to 151.66 mD (0.987 × 10−6 to 0.149 μm2) and 1.44–174.22 ms, respectively. A new parameter, namely micropore volume proportion per unit nano-meter, is proposed. Micropore and transition pore volume per nm, specific surface area, total pore volume, DN1 and DN2 (LPNA fractal dimension) all first increase, then decrease and finally increase with rising coal rank, while the maximum and minimum values of the maximum vitrinite reflectance (Ro, max) occur at 0.58–0.59% and 0.65–0.66%. The boundary of Ro, max corresponding to the FCJ can be further defined from 0.5-0.6% to 0.58–0.59% based on the evolution of adsorption pore structures. Thus, pore structure parameters related to adsorption capacity are controlled predominantly by coal rank. In addition, tectonic deformation has a strong impact on seepage pore structure but only a slight impact on that of adsorption pore, which leads to an ambiguous correlation or a complex trend between mesopore, macropore content, DMIP (fractal dimension of MIP) and coal rank around the FCJ. This study reveals the complex variation of pore structure evolution of low-rank coals and the significant influence of the FCJ on physical properties of coalbed methane reservoirs.

A series of new blue emissive materials based on the conjugates of highly fluorescent diaryl anthracene and electron-transporting triphenylimidazole moieties: 2-(4-(anthracen-9-yl)phenyl)-1,4,5-triphenyl-1H-imidazole (ACBI), 2-(4-(10-(naphthalen-1-yl)anthracen-9-yl)phenyl)-1,4,5-triphenyl-1H-imidazole (1-NaCBI), 2-(4-(10-(naphthalen-2-yl)anthracen-9-yl)phenyl)-1,4,5-triphenyl-1H-imidazole (2-NaCBI) were designed and synthesized successfully. These materials exhibit good film-forming properties and excellent thermal stabilities. Meanwhile, the decreased π-conjugation in these compounds compared with phenanthroimidazole derivatives leads to obvious hypsochromic shift. To explore the electroluminescence properties of these materials, typical three-layer organic light-emitting devices were fabricated. With respect to the three layer device 2 using 1-NaCBI as the emitting layer, its maximum current efficiency reaches 3.06 cd A−1 with Commission Internationale del’Eclairage (CIE) coordinates of (0.149, 0.092). More interestingly, sky blue doped device 5 based on 1-NaCBI achieved a maximum current efficiency of 15.53 cd A−1 and a maximum external quantum efficiency of 8.15%, high EQE has been proved to be induced by the up-conversion of a triplet excited state.

By incorporating the pyridine ring to the different positions of the rigid phenanthroimidazole skeleton, three new pyridine-containing phenanthroimidazole derivatives, 1-phenyl-2-(4-(pyridin-3-yl)phenyl)-1H-phenanthro[9,10-d]imidazole (CPI-p3Py), 2-phenyl-1-(4-(pyridin-3-yl)phenyl)-1H-phenanthro[9,10-d]imidazole (NPI-p3Py) and 1,2-bis(4-(pyridin-3-yl)phenyl)-1H-phenanthro[9,10-d]imidazole (CNPI-p3Py), were designed and synthesized as electron-transport materials (ETMs). Their photophysical properties, energy levels and electron mobilities can be readily regulated through changing the connecting position. Through optimizing electron mobility and energy levels trade-offs, CNPI-p3Py exhibits not only lower-lying HOMO/LUMO energy levels, but also a relatively high electron mobility of around 10−3 cm2 V−1 s−1, which is 2-fold greater than that of the widely used material BPhen. More interestingly, the blue fluorescent OLEDs with CPI-p3Py or CNPI-p3Py as an electron-transporting layer (ETL) exhibited superior performance compared to that using Bphen, remarkably lowering the driving voltage and improving efficiencies. In particular, the device with CNPI-p3Py as an ETL showed a maximum current efficiency of 15.17 cd A−1, a maximum power efficiency of 10.65 lm W−1, a maximum external quantum efficiency (EQE) of 7.75% and low efficiency roll-off even at an illumination-relevant luminance of 10 000 cd m−2 by the efficient utilization of the up-conversion of a triplet excited state, which are among the most efficient ETMs and proposes a new strategy for the molecular design of high-performance ETMs.

By gradually adjusting the proportion of tetraphenylethene (TPE) and phosphine oxide (PO), the series of n-type, ambipolar, and p-type aggregation-induced emission (AIE) luminogens (E,Z)-((1,2-diphenylethene-1,2-diyl)bis(4,1-phenylene))bis(diphenylphosphine oxide) (TPEDPO), diphenyl(4-(1,2,2-triphenylvinyl)phenyl)phosphine oxide (TPEPO), phenylbis(4-(1,2,2-triphenylvinyl)phenyl)phosphine oxide (DTPEPO), and tris(4-(1,2,2-triphenylvinyl)phenyl)phosphine oxide (TTPEPO) were developed for the first time. Their optical and electronic properties and AIE characteristics were investigated carefully. Time-resolved spectra indicate that the transient fluorescence decay lifetimes of aggregation-induced blue luminogens change regularly with the aggregation degree in THF/water solution. Particularly, identical electron and hole mobilities (∼2.3 × 10 –4 cm2 V–1 s–1) can be realized when the TPE/PO ratio is 1:1. In electroluminesent (EL) devices, the sky-blue-doped device based on TPEPO was found to exhibit a low turn-...

A series of star-shaped host materials DCzPOTA, CzDPOTA and TCTA containing a central triphenylamine (TPA) core, a peripheral modification with different ratios of p-type carbazole units and n-type diphenylphosphine oxide (DPPO) units were purposefully designed and synthesized. Their electronic nature, electrochemical, thermal and morphological properties were investigated systematically. In suitable proportions of carbazole and phosphine oxide, blue PhOLEDs based on DCzPOTA exhibits a maximum power efficiency of 36.9 lm W−1 and an ideal turn-on voltage (2.7 V at 1 cd m−2). These results indicate that the electronic nature of the host material can be finely adjusted by gradually changing the donor–acceptor ratio.

Cesium pivalate ((CH3)3CCOOCs) has been synthesized and applied as an electron injection material for organic light-emitting diodes, which showed low sublimation temperature of 180 °C. Typical bilayer structure of ITO/NPB (60 nm)/Alq3 (50 nm)/EIL/Al was used to evaluate the electron injection efficacy of (CH3)3CCOOCs, the results showed (CH3)3CCOOCs/Al exhibits better electron injection than LiF/Al cathode and the power efficiency was improved by about 19% at current density of 50 mA/cm2. More interestingly, in the typical three layer OLED structure ITO/2-TNATA (60 nm)/NPB (10 nm)/Alq3:2% C545T (40 nm)/MADN (15 nm)/(CH3)3CCOOCs (2 nm)/Al, the maximum current efficiency is up to 20 cd/A with Commission Internationale d’Eclairage (CIEx,y) color coordinates of (x = 0.30, y = 0.65) at current density of 140 mA/cm2, which indicates that the non-aromatic alkali metal complex can also have good match with the chemically stable compound and exhibit good electron injection properties.

This study describes the synthesis and characterization of a series of new blue fluorescent materials, with propeller-like topology, consisting of 1,3,5-tri(9-anthracene)benzene core and various aromatic dendrons, such as naphthalene, 3,5-diphenylbenzene, carbazole, and N,N-diphenylamine. These compounds show excellent thermal and morphological stability with high glass transition temperatures (Tg) (166–231 °C) and high thermal decomposition temperatures (Td) (427–504 °C). Solution-processable double-layered OLEDs fabricated with these materials as the light-emitting layer show stable blue emission and good performance. The nondoped electronic device fabricated using compound 5c exhibits a maximum brightness of 4754 cd/m2 and maximum current efficiency of 2.0 cd/A (power efficiency, 1.71 lm/W) with Commission Internationale d’Eclairage (CIEx,y) color coordinates of (x = 0.16, y = 0.19) and the devices’ threshold voltage are only 3.4 eV. Compound 5d shows an even higher efficiency of up to 4.90 cd/A with CIEx,y color coordinates of (x = 0.17, y = 0.31) when doped with a blue fluorescent dopant, 4,4′-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi).

Highly efficient blue phosphorescent organic light-emitting diodes (PhOLEDs) with a multiple quantum well (MQW) structure were investigated. A peak external quantum efficiency (EQE) of 20.31%, current efficiency of 40.31 cd/A and power efficiency of 30.14 lm/W were achieved in the optimized device with two quantum wells (QWs). The obtained efficiencies are much higher than those of the control devices without QWs. More importantly, the MQW devices exhibit low efficiency roll-off. At a high luminance of 5000 cd/m(2), the EQE still keeps at a high value of 18.86% in the optimized MQW device, and the efficiency roll-off is only 7.14%, which is lower than that of 30.78% in the control device (reduced from 16.05% to 11.11%). Meanwhile, the maximum power efficiency of the optimized MQW device was also exhibited more than 54.80% improvement compared to the control device. The high efficiency and low efficiency roll-off are attributed to the effective confinement of charge carriers and excitons by the state-of-the-art MQWs.