Search

Cocrystallization integrates the merits of high energy and insensitivity between energetic molecules to obtain energetics with satisfying performance. However, how to obtain supramolecular synthons accurately and rapidly for predicting the structure and property of cocrystal remains a challenging problem. In this research, an efficient systematic search approach to predict CL-20/2,4-DNI cocrystal has been proposed that 2,4-DNI revolves around CL-20 with a stoichiometric ratio of 1:1 in accordance with the specified rules (hydrogen bond length: 2.2–3.0 A; search radius: 6.5 A; the number of hydrogen bond: 1–3). Eight possible supramolecular synthons were obtained by combining quantum chemistry with molecular mechanics. Crystal structure prediction indicated that there are four structures in cocrystal, namely P21/c, P212121, Pbca and Pna21, and CL-20/2,4-DNI cocrystal is likely to be P21/c and the corresponding cell parameters are Z = 4, a = 8.28 A, b = 12.17 A, c = 20.42 A, α = 90°, β = 96.94°, γ = 90°, and ρ = 1.9353 g/cm3. To further study the intermolecular interaction of CL-20/2,4-DNI cocrystal, a series of theoretical analyses were employed including intermolecular interaction energy, electrostatic potential (ESP), Density of State (DOS), Hirshfeld surface analysis. The C–H⋯O hydrogen bonds are demonstrated as the predominant driving forces in the cocrystal formation. The mechanical properties and detonation properties of CL-20/2,4-DNI cocrystal implies that the cocrystal shows better ductility and excellent detonation performances (9257 m/s, 39.27 GPa) and can serve as a promising energetic material. Cocrystal structure predicted was compared with the experimental one to verify the accuracy of systematic search approach. There is a less than 8.8% error between experiment and predict results, indicating the systematic search approach has extremely high reliability and accuracy. The systematic search approach can be a new strategy to search supramolecular synthons and identify structures effectively and does have the potential to promote the development of energetic cocrystal by theoretical design.

Outburst energy is a major factor influencing coal and gas outbursts, albeit its estimation is difficult owing to the lack of amenable means for quantification of gas desorption. In the past decades, determining the mechanism of outbursts is one of the most challenging issues in rock mechanics. In this study, a triaxial coal and gas outburst simulation system was employed to perform simulated experiments using He (to rule out the influence from gas ad-desorption), N2, and CO2. This facilitated understanding of the energy principle underlying the said outbursts and evaluation of the effects of gas desorption on outburst development. Results of this study indicate that outburst energy and energy consumption are influenced by several factors, including outburst pressure, outburst intensity, ejection distance, and particle size of ejected coal. Among these, gas desorption demonstrates the greatest influence when performing controlled tests (using He). Considering the effects of gas desorption, the total outburst energy can be increased by 1.35–2.95 times, thereby causing an enormous increase in the destructive potential of outbursts. Additionally, values of the coal crushing and transport energies can be enhanced by the order of 118.9–206.6% and 157.8–406.6%, respectively, thereby resulting in a stronger conveying capacity of outburst coal–gas flow along with severe coal fragmentation. A further analysis of the energy distribution indicated that in the development stage, gas desorbed from coal acts as the force driving coal transport, whereas free gas energy is mainly consumed during coal crushing. Findings of this study highlight the importance of quantifying contributions of coal gas towards effective interpretation of outburst-causing mechanisms.

Deep mining and drilling activities typically trigger significant deformation of coal/rock roadway and even coal/rock dynamic hazards, which has attracted considerable attention. Hence, in this article, the mechanics and failure properties of intact coal are examined through triaxial compression tests and creep tests. First of all, triaxial compression experiments demonstrated that the complete stress–strain curves of intact coal are characterised by Class-I behaviour; and the post-peak modulus is negative. Second, with increasing confining pressure, peak strength and residual strength rise linearly, whereas elasticity modulus and peak strain increase as a power function form. Thirdly, compared with conventional triaxial load, tiered cyclic load can stiffen the strength of intact coal. Moreover, the data of creep tests are successfully fitted to the Burgers model. Maxwell elasticity modulus is significantly smaller than other creep parameters; Maxwell viscosity coefficient shows a positive correlation with deviatoric stress. Contrarily, Kelvin elasticity modulus and Kelvin viscosity coefficient drop with the rise in deviatoric stress. Additionally, with increasing deviatoric stress, single-step creep strain and average creep strain rate, proposed in this study, increase in a power function form. Finally, failure characteristics of intact coal under triaxial stress could be classified into four types (mainly shear failure and multiple shear fractures). The failure-plane angle generally linearly increases with the rise in confining pressure applied.

The intrinsic exothermic reaction of coal with oxygen during low-temperature oxidation is the main heat source responsible for the self-heating and spontaneous combustion of coal. Due to the comple...

Six N-glycosyl benzofuran derivatives were synthesized by the catalysis of organic bases and condensation agents. The benzofuran derivatives were obtained by the reaction of various salicylaldehydes in acetone, and then hydrolyzed to the corresponding carboxylic acids. Finally, the target compounds were synthesized by acylation and the reaction conditions were optimized. The acetylcholinesterase (AChE) inhibitory activity of the desired compounds was tested using Ellman’s method. Most of the compounds showed acetylcholinesterase-inhibition activity; N-(2,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-3-yl)benzofuran-2-carbxamide (5a) showed the best acetylcholinesterase inhibition, with an inhibitory rate of 84%.

It is imperative to have an in-depth understanding of CO overrun at the air return corner not only for pre-warning concentrations of safety and spontaneous combustion but also for providing scienti...

A series of efficient and stable Z-scheme LaCoO3/g-C3N4 heterojunction photocatalysts with different weight contents of g-C3N4 had been first successfully fabricated by a facile one-step impregnation method. The crystal structure, surface state, element distribution and photoelectronic properties of the as-prepared samples were characterized by XRD, FT-IR, XPS, SEM, TEM, UV–Vis DRS, PL, photocurrent testing and EPR technique. The results show that Z-scheme heterostructures have formed on the interfaces between the perovskite-type oxides LaCoO3 and the flake-like g-C3N4, which enhance the visible-light absorption, separation of the photogenerated electron-hole pairs and transformation of the photogenerated electrons. Moreover, the LaCoO3/g-C3N4-60 wt% composite photocatalyst presented the highest photocatalytic activity for the degradation of phenol under visible light, whose phenol degradation rate is 85% after 5 h under visible light irradiation, which is about 5.2 and 7.5 times higher than that of bare LaCoO3 and g-C3N4, respectively. What's more, the LaCoO3/g-C3N4-60 wt% composite also shows an excellent stability. The highest photocatalytic activity can mainly attribute to high charge carrier separation efficiency as well as the improved dispersity via the Z-scheme LaCoO3/g-C3N4 heterostructure and a possible mechanism for photodegradation process over the Z-scheme LaCoO3/g-C3N4 heterojunction photocatalysts has been proposed.

The bottleneck for large-scale application of Nickel-rich layered LiNi0.6Co0.2Mn0.2O2 (NCM) cathode material for lithium-ion batteries is their severe capacity fading, especially at high voltage. Herein, we modify the NCM cathode materials by substituting the boracic polyanion to suppress capacity degradation and improve power performance. The crystal structure, morphology, elemental states and surface elemental composition of the cathode materials are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM), respectively. Compared to the bare NCM, the I(003)/I(104) ratio of the B3-NCM sample increases from 1.58 to 1.66, and the cation mixing declines from 4.65% to 3.21%, as known by XRD and Rietveld refinement. The results of electrochemical tests indicate that the B1-NCM exhibit superior rate property at the high current density (131.02 mAh g−1 at 5 C), and the higher capacity retention (76.07% after 100 cycles at 1 C). Further electrochemical impedance spectra (EIS) and galvanostatic intermittent titration technique (GITT) demonstrate that boracic polyanion doping decreases impedance value and enhances lithium ion diffusion coefficient. These consequences reveal that the boracic polyanion modified LiNi0.6Co0.2Mn0.2O2 cathode material has better electrochemical performance.

Strains M65T, M69 and JN25 were isolated from seawater of the West Pacific Ocean. Cells of the three strains were Gram-stain-negative, aerobic and rod-shaped. Cells were motile by means of flagella. On the basis of the results of 16S rRNA gene sequence analysis, strains M65T, M69 and JN25 showed the highest 16S rRNA gene sequence similarity to Henriciella algicola MCS27T (98.8 %), followed by Henriciella marina DSM 19595T (98.4 %), Henriciella barbarensis MCS23T (98.4 %), Henriciella pelagia LA220T (98.3 %), Henriciella aquimarina P38T (98.1 %) and Henriciella litoralis SD10T (97.8 %). The 16S rRNA gene sequence similarities among the isolates were 100 %. Phylogenetic analyses revealed that the isolates fell within a cluster comprising the Henriciella species and represented an independent lineage. The average nucleotide identity and in silico DNA–DNA hybridization values between strain M65T and the type strains of Henriciella species were 73.9–85.8 % and 19.9–22.4 %, respectively. The sole respiratory quinone detected in the three isolates was ubiquinone 10. The principal fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and C16 : 0. The major polar lipids were glucuronopyranosyldiglyceride, monoglycosyldiglyceride and one unidentified glycolipid. The DNA G+C content was 61.3–61.4 mol%. Phylogenetic distinctiveness, chemotaxonomic differences, together with phenotypic properties, revealed that the isolates could be differentiated from the Henriciella species with validly published names. Therefore, it is proposed that strains M65T, M69 and JN25 represent a novel species of the genus Henriciella , for which the name Henriciella mobilis sp. nov. (type strain, M65T=CGMCC 1.15927T=KCTC 52576T) is proposed.

A series of catalysts with p-LaFeO3/n-ZnO heterostructure were designed and prepared by hydrothermal method. The structure, surface topographies, optical properties and interfacial interactions of these photocatalysts were analyzed by XRD, SEM, TEM, PL, Uv-vis DRS, XPS, COD, TOC etc., indicating that p-n heterojunction formed at the interface between p-LaFeO3 and n-ZnO, which enhanced the photocatalytic activity. Among them, the 20%-p-LaFeO3/n-ZnO composite exhibits the best activity for the phenol degradation under visible light. The superior photocatalytic activity of the heterojunction photocatalyst is mainly attributed to the formation of p-n heterojunction which leads to an efficient separation of photogenerated electron-hole pairs. Besides, the 20%-p-LaFeO3/n-ZnO heterojunction photocatalyst shows the excellent photocatalytic stability after 4 cycles. And from the free radical capture experiment, the degradation of phenol is dominated by the oxidation reaction of hydroxyl radicals and direct hole oxidation. What's more, certain intermediates were detected by HPLC and 3D-EEMs. Therefore, a photocatalytic mechanism of the 20%-p-LaFeO3/n-ZnO p-n heterojunction catalyst for phenol degradation under visible light irradiation was proposed.

La/Y-codoped microporous organosilica membranes were successfully fabricated by sol-gel procedure with 1,2-bis(triethoxysilyl)ethane (BTESE) as silica precursor for efficient desalination. The rare earth elements were confirmed to be doped into silica frameworks during the sol-gel procedure by various characterizations, which would decrease particles size and size distribution of BTESE-derived sols and form hydrothermally stable Si–O–RE (RE for La and Y) bonds. It could significantly influence membrane surface morphology, microstructure properties and hydrophilcity of La/Y-codoped membranes, and then improve their desalination performance. Under the optimized preparation conditions, La25Y75-SiO2 (La:Y = 25:75, mol%) membranes exhibited the highest water flux of 10.3 kg m−2 h−1 and NaCl rejection of nearly 100% towards 3.5 wt% NaCl feed solution even at room temperature of 25 °C. It was attributed to strongest hydrophilcity, finest microstructure, and lowest mass resistance of water permeation for La25Y75-SiO2 membranes. Moreover, such these organosilica membranes demonstrated good stability for 200 h simulated seawater desalination tests without any significant changes of separation performance and promising hydrothermal durability under various salts solutions with different concentrations at 25–60 °C.

Coal and gas outbursts are small-scale geological disasters controlled by tectonic movement, and tectonic coal is widespread in outburst zones. In this study, we compare tectonic and intact coal specimens to examine the basic properties of tectonic coal. We estimate the different energies and limits of the crushing work ratio of coal from five typical outburst cases using on-site outburst data, and discuss the relationship between outbursts and tectonic coal. The results show that tectonic coal is a product of tectonic movement and its original primary structure is destroyed during the tectonic process. Compared with intact coal, tectonic coal shows low strength properties and a crushing work ratio of 22.11 J/m2. The specific surface area and total pore volume of the minipores, mesopores, and macropores of the coal strongly increase under conditions of intense tectonism, which indicates that tectonic coal has a very high capacity for rapid initial gas desorption. An adequate supply of gas is required to transport outburst coal, such that the existence of coal particles smaller than the critical diameter is important. Our calculations indicate that the crushing work ratio of coal from the five outburst case ranges from 22.19 to 78.67 J/m2. Only the crushing work ratio of tectonic coal satisfies the requirement for these cases. Therefore, the properties of the tectonic coal and crushing work ratio for the five cases indicate that the widespread occurrence of tectonic coal plays a crucial role in outbursts.

Hard carbon is the most common carbon-based material with abundant raw material resources, low cost, high reversible capacity and reliable safety performance, it is the most suitable sodium-ion batteries (SIBs) anode material for commercial production, which attracts the interest of the researchers. Unfortunately, the electrochemical performances of hard carbon are still underestimated in the previous reports. In this research, we use a simple process flow to obtain carbonized oatmeal as a kind of hard carbon. It can deliver initial reversible capacity of 272.4 mAh g−1 at 20 mA g−1, the capacity retention rate is 93.3% after 100 cycles, exhibits a good electrochemical performance. Simultaneously, the transport properties of sodium-ion in carbonized oatmeal material are also characterized by electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT). The measurement results show that the low potential platform region of the oatmeal-derived hard carbon is attributed to the insertion/extraction characteristics of sodium-ion in the graphitic microcrystallites sheets.

Investigating independent active materials is inadequate to settle the technological challenges involved in the booming lithium ion battery industry. The further development of energy-storage properties with both high energy density and superior cycling lifespan are highly dependent on the overall system optimization, which highlights the study of the interface between different components in a system. Herein, a system-level strategy of engineering MnO-based anode build on the plentiful electrolytic manganese dioxide are developed via a microwave-assisted carbothermic reduction, combined with a succeeding in-situ aggregation of polydopamine (PD) onto MnO along with chemical binding with polyacrylic acid (PAA) binder. Fourier transform IR spectra, X-ray photoelectron spectroscopy spectra validate the formation of cross-linking reaction between the PD buffer and PAA binder. Benefited from the prominent structure stability which endowed by well-connected three-dimensional porous structure, as well as two steady interfaces between MnO and PD buffer and between PD buffer and PAA binder, the cross-linked MnO anode exhibit a reversible capacity of 687 mAh g−1 at 300 mA g−1 and high Coulombic efficiency of 99% over 500 cycles and impressive rate capability of 320 mAh g−1 at 3000 mA g−1.

A series of glycosyl-substituted 1,3,4-oxadiazoles were synthesized by cyclization of glycosyl-acylthiosemicarbazides via a base-catalyzed reaction. The starting glycosyl-acylthiosemicarbazide derivatives were obtained by the reaction of glycosyl isothiocyanate with various hydrazides. The acetylcholinesterase (AChE) inhibitory activities of the products were tested by Ellman’s method. The most active compounds were subsequently evaluated for the 50% inhibitory concentration (IC50) values. N-(1,3,4,6-tetra-O-benzyl-2-deoxy-β-D-glucopyranosyl)-5-(4-fluorophenyl)-1,3,4-oxadiazole-2-amine (6i) possesses the best AChE -inhibition activity with an IC50 of 1.61±0.34 μm.

Introduction Suicide is still a major event of human mortality worldwide. Yet human suicide prediction, prevention and therapeutic systems at this moment are generally ineffective in the clinic. No diagnostic system is reliable for significantly suicidal prevention and mortality reduction. As a result, human suicide etiopathologic investigation (especially at genetic/molecular levels in the clinical settings) is quite necessary. In order to boost human suicide researches, emerging human suicide diagnostic/treatment study will be transformed from clinical symptom observations into new generations of candidate drug targets and therapeutics. To achieve this goal, associations between suicidal etiopathologic identification, genetic/bioinformatics-based diagnostics and putative drug targets must be exploited than ever before. After all, the interaction and relationships between environmental/ genetic/molecular clues and overall patient's risk prediction (environmental influences and different therapeutic targets/types) should be found out. Conclusion In the future, effective clinical suicide prediction, prevention and therapeutic systems can be established via scientific expeditions and causality discovery.

Groundwater is the dominant source of freshwater in many countries around the globe, and the deterioration in its quality by contaminants originating from anthropogenic sources raises serious concern. In this study, a scenario where groundwater is contaminated by acid mine drainage (AMD) from mining activities and/or sewage was envisaged, and the performance of a direct contact membrane distillation (DCMD) system was investigated comprehensively for different compositions of the AMD- and sewage-impacted groundwater. Regardless of the composition, MD membrane achieved 98-100% removal of metals and bulk organics, while the removal of the selected micropollutants ranged between 80 and 100%. Effective retention of contaminants by the MD led to their accumulation over time, which affected the hydraulic performance of the MD membrane by reducing the permeate flux by 29-76%. When persulfate (PS)-mediated oxidation process was integrated with the DCMD, degradation of bulk organics (50-71%) and micropollutants (50-100%) by PS reduced their accumulation. Characterisation of the fouling layer revealed the occurrence of membrane scaling that was mainly due to the deposition of iron oxide or oxyhydroxide precipitates. For an identical composition of the AMD- and sewage-impacted groundwater, flux decline was 10% less in PS-assisted DCMD as compared to that in the standalone DCMD. However, this did not prevent the formation of iron oxide scales on MD membrane during the operation of PS-assisted DCMD. This study demonstrates the long-term performance of a standalone and PS-assisted DCMD operated in continuous-flow mode to treat AMD- and sewage-impacted groundwater for the first time.

Background The genus Ligusticum consists of approximately 60 species distributed in the Northern Hemisphere. It is one of the most taxonomically difficult taxa within Apiaceae, largely due to the varied morphological characteristics. To investigate the plastome evolution and phylogenetic relationships of Ligusticum, we determined the complete plastome sequences of eight Ligusticum species using a de novo assembly approach. Results Through a comprehensive comparative analysis, we found that the eight plastomes were similar in terms of repeat sequence, SSR, codon usage, and RNA editing site. However, compared with the other seven species, L. delavayi exhibited striking differences in genome size, gene number, IR/SC borders, and sequence identity. Most of the genes remained under the purifying selection, whereas four genes showed relaxed selection, namely ccsA, rpoA, ycf1, and ycf2. Non-monophyly of Ligusticum species was inferred from the plastomes and internal transcribed spacer (ITS) sequences phylogenetic analyses. Conclusion The plastome tree and ITS tree produced incongruent tree topologies, which may be attributed to the hybridization and incomplete lineage sorting. Our study highlighted the advantage of plastome with mass informative sites in resolving phylogenetic relationships. Moreover, combined with the previous studies, we considered that the current taxonomy system of Ligusticum needs to be improved and revised. In summary, our study provides new insights into the plastome evolution, phylogeny, and taxonomy of Ligusticum species.

The mutualistic symbiosis between anthozoans and intra-gastrodermal dinoflagellates of the family Symbiodiniaceae is the functional basis of all coral reef ecosystems, with the latter providing up to 95% of their fixed photosynthate to their hosts in exchange for nutrients. However, recent studies of sponges, jellyfish, and anemones have revealed the potential for this mutualistic relationship to shift to parasitism under stressful conditions. Over a period of eight weeks, we compared the physiological conditions of both inoculated and aposymbiotic anemones (Exaiptasia pallida) that were either fed or starved. By the sixth week, both fed groups of anemones were significantly larger than their starved counterparts. Moreover, inoculated and starved anemones tended to disintegrate into “tissue balls” within eight weeks, and 25% of the samples died; in contrast, starved aposymbiotic anemones required six months to form tissue balls, and no anemones from this group died. Our results show that the dinoflagellates within inoculated anemones may have posed a fatal metabolic burden on their hosts during starvation; this may be because of the need to prioritize their own metabolism and nourishment at the expense of their hosts. Collectively, our study reveals the potential of this dynamic symbiotic association to shift away from mutualism during food-deprived conditions.

Coal burst is the violent failure of overstressed coal, and it is often accompanied by sound, coal ejection and seismic events. It is subsequently recognized as a serious safety risk of Australia after double fatalities coal burst happened at Austar Coal Mine. Considering the increasing trend of coal burst severity and frequency with mining depth, it is an urgent task to develop the coal burst risk assessment methods for Australia underground coal mines. Coal burst propensity index method is a widely used method of burst risk evaluation of coal as it is summed up from the coal burst research and practice of many countries. This paper presents the experimental and theoretical research of coal burst propensity index method for coal burst risk assessment in Australia. The definition of four indexes including elastic strain energy index (WET), bursting energy index (KE), dynamic failure time (DT) and uniaxial compression strength (RC) is introduced in the first part. Then, the standard laboratory test process and test parameter of coal burst propensity index is presented. DT test is conducted with 0.3 mm/min displacement control loading rate while other test is with 0.5 mm/min. Besides, modified data processing and risk classification method of test are proposed. Differentiate analysis of stress-strain curve is adopted in the data processing of DT and KE index. A four level risk classification form of burst risk is recommended for Australian underground coal mines. Finally, two likely improvement methods of WET test, including volumetric strain indicator method and theoretical calculation method, are discussed. Keywords: Coal burst, Coal burst propensity, Risk evaluation, Underground mining

To investigate the bedding influence on coal mechanical behaviour in underground environments such as coal or rock burst, simulations of dynamic SHPB tests of pre-stressed coal specimens with different bedding angles were carried out using a particle flow code 2-dimensional (PFC2D). Three impact velocities of 4, 8 and 12 m/s were selected to study dynamic behaviours of coal containing bedding planes under different dynamic loads. The simulation results showed that the existence of bedding planes leads to the degradation of the mechanical properties and their weakening effect significantly depends on the angle θ between the bedding planes and load direction. With θ increaseing from 0° to 90°, the strength first decreased and subsequently increased and specimens became most vulnerable when θ was 30° or 45°. Five failure modes were observed in the specimens in the context of macro-cracks. Furthermore, energy characteristics combined with ultimate failure patterns revealed that maximum accumulated energy and failure intensity have a positive relation with the strength of specimen. When bedding planes were parallel or perpendicular to loading direction, specimens absorbed more energy and experienced more violent failure with increased number of cracks. In contrast, bedding planes with θ of 30° or 45° reduced the specimens’ ability of storing strain energy to the lowest with fewer cracks observed after failure. Keywords: Static–dynamic coupled loads, SHPB, Coal bedding angle, Strain energy, PFC2D

A self-developed gas desorption and diffusion experimental system was used to conduct isothermal methane gas desorption and diffusion experiments, and the pore structure of coal samples was analyzed. A new mathematical model for gas diffusion in coal particles was established, and the diffusion coefficient was calculated using the new model. The influences of particle size and the adsorption equilibrium pressure on the methane gas diffusion rate, gas diffusion quantity, and diffusion coefficient were analyzed and discussed. The results show that under different adsorption equilibrium pressures and different particle sizes, the diffusion rate and quantity vary substantially. The larger the particle size, the slower the initial gas diffusion rate and the longer the time required to reach desorption equilibrium. The larger the adsorption pressure, the greater the initial gas diffusion rate and the larger the quantity of diffusion gas accumulated. However, the coal particle size has little influence on the amount of gas diffusion. It was found that as the particle size decreases, the diffusion coefficient in the first diffusion phase is significantly reduced, which decays with a negative exponential function over time. However, the adsorption equilibrium pressure has no obvious influence on the diffusion coefficient. In addition, the methane gas diffusion process was divided into three phases, namely, phase I, rapid diffusion phase (0–10 min); phase II, slow diffusion phase (10–100 min); and phase III, smooth diffusion phase (100 min); and the diffusion mechanism corresponding to each phase was analyzed. These research results provide a theoretical and practical reference value for gas prevention and control in coal mines.

Strata movement control during backfill mining of coal seam is dependent on the goaf filling rate, which is much related to the mechanical properties of the backfill bodies in goaf. A main roof mechanics model of the inclined backfill stope was established to investigate the factors that influence the overburden stability of an inclined coal seam during backfill mining. The proposed model was based on the results of laboratory tests on the compressive mechanical properties of crushed coal gangue and the key strata theory of ground control, which considers the nonlinear elastic mechanical properties of backfill bodies under a linearly increasing overlying strata load. The deformation characteristics of the main roof of the inclined backfill stope were analyzed in reference to the elastic thin-plate theory. The stability criterion of the main roof of the inclined backfill stope was inferred by introducing the Mohr–Coulomb yield criterion. And factors that influenced the overburden stability control of the inclined backfill stope were investigated. These factors included the elasticity modulus and thickness of the main roof, the overlying strata load, the advancement distance and workface width, the strata pitch of inclined stope, and the linear and the nonlinear foundation coefficients of the goaf backfill body. The results can provide crucial theoretical bases for determination of the sizes and filling rates of the goaf backfill body and the overburden stability control of an inclined backfill mining workface in coal seam under the actual engineering geological conditions.

This paper focused on VOCs and their source apportionment in urban Beijing. Our monitoring measured 52 VOCs in July 2014 and January 2015. The concentration of VOCs was in the range of 14.5~95.2 ppb in July and 2.1~93.1 ppb in January, with the top five compounds of toluene (10.7%), ethane (6.9%), ethylene (6.3%), n-butane (5.7%), and propane (5.6%) in July and ethylene (14.7%), n-butane (14.2%), ethane (9.6%), propylene (8.0%), toluene (7.9%), and benzene (6.9%) in January. The ratio of VOCs to CO reached 0.059 in July and 0.022 in January on average. These differences implied a potential seasonal difference in the VOC source contribution. Then, we conducted a source apportionment study based on 21 major VOCs and CO by using probabilistic matrix factorization (PMF) receptor model. According to the similarity between the PMF analysis profiles and the known source profiles, combustion sources, petrochemical industry sources, solvent utilization sources, and gasoline evaporation sources were identified. The correlation coefficient (R) between the PMF analysis profile and the source profile reached 0.68~0.87 in July and 0.53~0.92 in January. The better apportionment performance in July was mainly due to the use of intensive VOC observations at a 3-h resolution. When we conducted another PMF source apportionment for July based on 12-h resolved concentration input, the R values decreased to 0.47~0.73. Thus, the PMF model depends heavily on the sample number of concentration inputs, and intensive observation is more propitious. Our PMF apportionment results showed that combustion sources, petrochemical industry, solvent utilization, gasoline evaporation, and other sources contributed ambient VOCs in Beijing urban areas of 13.7 ppb, 5.1 ppb, 7.7 ppb, 12.8 ppb, and 3.3 ppb in July and 13.2 ppb, 2.0 ppb, 5.7 ppb, 6.6 ppb, and 1.0 ppb in January, respectively, on a monthly average. These apportionment results match well with the 2013 VOC emission inventory calculated by this study, but also presented significant seasonal differences in the petrochemical industry and gasoline evaporation, in which VOC emissions strongly respond to environmental temperature.

As the one of the most catastrophic hazards in underground mining, coal and gas outburst seriously threatens the safe mining of collieries. To understand the formation and transport mechanism of outburst coal-gas flow in roadway as well as evaluate the effects of gas desorption on its development, a new apparatus was developed to conduct simulated experiments with different gases of CO2 and N2. Results indicated that the outburst coal-gas flow was a high-speed (up to 41.02 m/s during tests) gas-solid two phases flow with extreme complexity, its transport/destructiveness characteristics were significantly influenced by a number of factors including the outburst pressure, coal sample composition, ejection distance and so on. Among these factors, the gas desorption showed the greatest impact when compared to the controlled tests which only considered the effect of free gas expansion. With the effect of gas desorption, especially the rapid gas desorption from powdered coal, the total outburst energy could be promoted by 1.30–2.43 times; the peak values of outburst shockwave could be enhanced by at least 13.67%–63.22%; the transport type of coal-gas flow could be changed from dynamic pressure pneumatic conveying to the static pressure conveying which providing higher capability for outburst coal/rock conveying; the motion of ejected coal flow could have higher speed, longer transport duration and could suffer secondary acceleration. As the result, the destructiveness of outburst coal-gas flow would be remarkably intensified. A further analysis for the energy consumption during the outburst coal-gas flow transport indicated that the free gas expansion energy was insufficient for the conveying of ejected coal (only accounting for less than half of the total energy), the difference of which was made up by the gas desorption, especially the rapid gas desorption from powdered coal (the average contribution ratio reached 56.0%, while the maximum reached 64.1%). Thus, it can be concluded that the rapid gas desorption from powdered coal played a decisive role on the promotion of outburst.

Two novel complexes [Fe2(μ-SC3H6S)(CO)5][Fc(PPh2)CHO] (3) and 5-{[Fe2(μ-SC3H6S)(CO)5](PPh2Fc)}-10, 15, 20-triphenylporphyrin (4), which contain ferrocene-based ligand to simulate the role of the active site of [FeFe]-hydrogenases (H-Cluster), are synthesized and characterized successfully. A graphene-mediated [FeFe]-hydrogenases biomimetic nanohybrid (TPP-NHCO-GO-[3Fe2S]) 6 is fabricated by linking organic photosensitizer tetraphenylporphyrin (TPP) and complex 3 to graphene oxide (GO) via the covalent bond. The new nanohybrid 6 is characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and inductively coupled plasma atomic emission spectrometry (ICP-AES). By comparing the ultraviolet-visible (UV-vis) absorption, fluorescence emission and time-resolved fluorescence, it can be found the efficiency of electron transfer has been obviously improved with the presence of GO, and the efficiency of electron transfer in intramolecular system is higher than that in intermolecular system. These results are also supported by the photo-induced H2 production experiments with corresponding catalytic systems in water. Besides, the cystine is used as the sacrificial electron donor for light catalytic reaction in aqueous solution, which improves the efficiency of photocatalytic H2 production compared with the common electron donors, such as ascorbic acid (H2A), triethanolamine (TEOA), glucose or Na2S2O3.

Global climate change is anticipated to raise overall temperatures and has the potential to increase future mortality attributable to heat. Urban areas are particularly vulnerable to heat because of high concentrations of susceptible people. As the world's largest developing country, China has experienced noticeable changes in climate, partially evidenced by frequent occurrence of extreme heat in urban areas, which could expose millions of residents to summer heat stress that may result in increased health risk, including mortality. While there is a growing literature on future impacts of extreme temperatures on public health, projecting changes in future health outcomes associated with climate warming remains challenging and underexplored, particularly in developing countries. This is an exploratory study aimed at projecting future heat-related mortality risk in major urban areas in China. We focus on the 51 largest Chinese cities that include about one third of the total population in China, and project the potential changes in heat-related mortality based on 19 different global-scale climate models and three Representative Concentration Pathways (RCPs). City-specific risk estimates for high temperature and all-cause mortality were used to estimate annual heat-related mortality over two future twenty-year time periods. We estimated that for the 20-year period in Mid-21st century (2041-2060) relative to 1970-2000, incidence of excess heat-related mortality in the 51 cities to be approximately 37,800 (95% CI: 31,300-43,500), 31,700 (95% CI: 26,200-36,600) and 25,800 (95% CI: 21,300-29,800) deaths per year under RCP8.5, RCP4.5 and RCP2.6, respectively. Slowing climate change through the most stringent emission control scenario RCP2.6, relative to RCP8.5, was estimated to avoid 12,900 (95% CI: 10,800-14,800) deaths per year in the 51 cities in the 2050s, and 35,100 (95% CI: 29,200-40,100) deaths per year in the 2070s. The highest mortality risk is primarily in cities located in the North, East and Central regions of China. Population adaptation to heat is likely to reduce excess heat mortality, but the extent of adaptation is still unclear. Future heat mortality risk attributable to exposure to elevated warm season temperature is likely to be considerable in China's urban centers, with substantial geographic variations. Climate mitigation and heat risk management are needed to reduce such risk and produce substantial public health benefits.

Gas management at longwall faces has always been a challenging issue to mine operators. Along a longwall face of an Australian colliery where CO2 is the dominant coal seam gas, frequent power trip off occurred due to the high goaf gas (CO2) emission, which significantly affected the normal longwall production and brought about safety threats to the longwall crew. CO2 fringe fluctuation changes close to tailgate (TG) was identified as a major concern. To better understand the CO2 fringe behaviour on the longwall face and develop the corresponding effective control measures, Computational Fluid Dynamics (CFD) model was developed and validated based upon field data collected from the colliery. General gas flow characteristics on the longwall face were obtained based on which parametric studies were then carried out to investigate the impact of ventilation system and gas drainage options on goaf gas fringe behaviour. The use of a back-return ventilation system was demonstrated to be an effective approach to control the CO2 fringe at TG; however, it was not practical due to the restriction of existing panel layout. As a compromise of the back-return system, a new gas drainage option using TG borehole which was more practical and cost effective was proposed and assessed by the CFD models. Model results indicated that goaf gas fringe at TG can be effectively controlled when a suction pressure between − 1500 Pa and − 2000 Pa was applied to the TG borehole. Therefore, it can be concluded from this study that gas drainage conducted through TG borehole can be an effective approach to solve the CO2 accumulation at TG on a longwall face, especially when the back-return system is not applicable on site.

Nitrocellulose is an extremely dangerous explosive substance, which will decompose at a relatively low temperature. This article studied the thermal properties transformed from thermal decompositio...

An amino acid-functionalized protic ionic liquid (IL), monoethanolamine glycinate ([MEA][GLY]), was used as a CO2 absorbent. Its performance was evaluated by a membrane gas absorption (MGA) process. Various effect factors including both absorbent aspect and operational parameters were investigated in MGA for CO2 capture. Performance of [MEA][GLY] IL was also compared with that of an amino acid salt and an amine. Liquid CO2 loading of the functional protic IL was the largest in three absorbents, presenting an order of [MEA][GLY]>PGLY>MEA. [MEA][GLY] IL obtained a high membrane flux and a low gas outlet CO2 concentration in MGA process. It could reach 3.25 × 10−4 mol m−2 s−1 of membrane flux. The IL could achieve higher initial and instantaneous membrane fluxes and the maximal membrane flux with a range of optimum concentration of 3.5–4.5 mol L−1. Change of operational parameters, especially gas CO2 mole fraction, can significantly affect and enhance the membrane flux of MGA on a limited scale. [MEA][GLY] IL is a more environmentally-friendly and efficient CO2 absorbent.

Traditional phylogenies inferred from chloroplast DNA fragments have not obtained a well‐resolved evolutionary history for the backbone of Apioideae, the largest subfamily of Apiaceae. In this study, we applied the genome skimming approach of next‐generation sequencing to address whether the lack of resolution at the tip of the Apioideae phylogenetic tree is due to limited information loci or the footprint of ancient radiation. A total of 90 complete chloroplast genomes (including 23 newly sequenced genomes and covering 20 major clades of Apioideae) were analyzed (RAxML and MrBayes) to provide a phylogenomic reconstruction of Apioideae. Dating analysis was also implemented using BEAST to estimate the origin and divergence time of the major clades. As a result, the early divergences of Apioideae have been clarified but the relationship among its distally branching clades (Group A) was only partially resolved, with short internal branches pointing to an ancient radiation scenario. Four major clades, Tordyliinae I, Pimpinelleae I, Apieae and Coriandreae, were hypothesized to have originated from chloroplast capture events induced by early hybridization according to the incongruence between chloroplast-based and nrDNA-based phylogenetic trees. Furthermore, the variable and nested distribution of junction positions of LSC (Large single copy region) and IRB (inverted repeat region B) in Group A may reflect incomplete lineage sorting within this group, which possibly contributed to the unclear phylogenetic relationships among these clades inferred from plastome data. Molecular clock analysis revealed the chloroplast capture events mainly occurred during the middle to late Miocene, providing a geological and climate context for the evolution of Apioideae.

The Jigongcun Re-rich quartz vein-type Mo deposit is located in the Gangdese porphyry Cu belt, southern Tibet, China. The stratiform and lenticular orebodies are hosted within the quartz veins and are controlled by the NW-/EW-trending faults. In this study, we have identified four hydrothermal stages, namely the (1) pre-ore stage (stage Ⅰ) characterized by the development of thick Mo-free quartz veins; (2) stage Ⅱ, mainly forming thick quartz veins with Re-rich massive molybdenite (Mo1-type; mean = 1811 ppm) and bladed molybdenite (Mo2-type; mean = 1312 ppm); (3) stage III, mainly forming quartz veins with Re-barren bladed molybdenite (Mo3-type) and abundant galena and pyrite; (4) the post-ore stage (stage Ⅳ) characterized by formation of thick ore-barren quartz–calcite veins. Both electron probe micro-analysis and in situ laser ablation–inductively coupled plasma–mass spectrometry analysis of different types of molybdenite show that high Re concentrations are due to isovalent Re substitution for Mo in molybdenite. Fluid evolution during the four stages of mineralization was constrained by a detailed fluid inclusion study. Fluid inclusions during the formation of the early pre-ore stage indicate relatively high-temperature (311–337 °C), high-pressure (1300–1600 bars), low-salinity (0.2–2.6 wt% NaCl-equiv.), and CO2-rich hydrothermal fluids. Fluid immiscibility assemblages in CO2-rich inclusions coexisting with aqueous inclusions occur in quartz–K-feldspar veins of stage Ⅱ, and likely record phase separation at a temperature of 262–300 °C and pressure of 900–1100 bars, with the precipitation of Re-rich molybdenite. The subsequent fluid mixing occurs at a temperature of 220–271 °C, with the precipitation of Re-barren molybdenite at stage III. H–O–S isotope compositions show that sulfur and ore-forming fluids are derived from a deep-seated igneous source. Re-Os dating of molybdenite samples yielded an isochron age of 22.0 ± 0.4 Ma, indicating that the Jigongcun deposit formed in the Early Miocene, which is earlier than most of the porphyry Cu deposits in the Gangdese porphyry Cu belt. Combined our new geochemical and isotopic results with previous regional investigations, we suggest that the Re-rich Mo mineralization of Jigongcun deposit may be related to the Early Miocene northward subduction of the Indian continental plate.

Cardamine macrophylla is a perennial herb with short-lived seeds. Here, the complete chloroplast genome (plastome) of C.macrophylla was obtained by Illumina sequencing technology. The plastome is 155,393 bp in length, including a large single copy (LSC) region of 84,492 bp, a small single copy (SSC) region of 17,957 bp and a pair of inverted repeats (IRs) of 26,472 bp. The genome contained 131 genes, including 85 protein-coding genes (78 PCG species), 37 tRNA genes (30 tRNA species), eight rRNA genes (four rRNA species) and one pseudogene. Among these genes, 15 genes harbored a single intron and three genes harbored two introns. Seven tRNA, five protein-coding and all four rRNA genes were completely duplicated in the IR regions. The GC content of C. macrophylla plastome is 36.4%. A total of 26,470 codons were detected in 85 protein-coding genes of C. macrophylla plastome. Phylogenetic analysis demonstrated that the all Cardamine species formed a monophyletic clade, and C. macrophylla was closely related to C. impatiens.

The definition of “residual gas” can be found in different scenarios, such as the “fast” and “slow” desorption methods of measuring gas content and the sorption hysteresis test and gas management of coal mines, however, its meaning varies a lot in different contexts. The main aim of this paper is to discuss the existence of truly undesorbable residual gas in coal seam conditions and its impacts on sorption model and gas drainage efficiency. We believe the undesorbable residual gas does exist due to the observation of the extended slow desorption test and the sorption hysteresis test. The origin of undesorbable residual gas may be because of the inaccessible (closed or semi-closed) pores. Some gas molecules produced during coalification are stored in these inaccessible pores, since the coal is relatively intact in the coal seam condition, these gas molecules cannot escape during natural desorption and then create the undesorbable residual gas. Based on the existing adsorption models, we propose the improved desorption versions by taking into consideration the role of residual gas. By numerically simulating a gas drainage case, the gas contents after different drainage times are studied to understand the influence of residual gas content on gas drainage. The results indicate that the influence starts to be obvious even when the total gas content is at a high level, and the impact becomes more and more apparent with increasing drainage time. Our study shows that the existence of residual gas will impede the gas drainage and the total amount of recoverable coal seam methane may be less than expected. Keywords: Residual gas, Inaccessible pores, Desorption model, Gas drainage

Large scale open cut coal mining operations have significant impacts to groundwater in surrounding areas in both active and post-mining phases. The prediction of water inflows into a surface mine excavation is one of the many components involved in mine design phase. Groundwater performance also reacts to mining activities from the operational, economic and safety implications perspective. Under NSW planning legislation, as part of the comprehensive risk assessment, a groundwater impact assessment has to be conducted for a coal project to predict and mitigate the impacts in consideration of the government requirements. In this paper, the groundwater assessment modelling of mine pits was discussed in predicting of groundwater inflows and reviewing analytical and numerical approaches. A methodology of groundwater impact assessment for an open cut mine in NSW with a three-dimensional groundwater flow model Modflow Surfact demonstrated its functions in simulating the project’s impacts on the groundwater regime. The key findings with mitigations are discussed and recommended in the paper to reduce impacts on groundwater and fulfil regulation requirements in NSW. Keywords: Open cut coal mine, Groundwater impact assessment, Mining exposure area, Groundwater modelling methodology

Coal exhibits different creep behaviours when filled with different amounts of gas. Creep tests of coal filled with 0 and 0.5 MPa gas were performed, and strain under different axial stress was compared. The three creep constitutive models which were analysed using the method fitting experimental data for determining which creep model can reflect the creep process of the test best. The results show that the deformation of coal filled with 0.5 MPa gas is more higher than that of coal filled with 0 MPa gas under the same axial stress. Gas plays a positive effect on the deformation of coal process and will accelerate creep process. And gas will reduce coal intensity and change coal creep properties. Compared with Nishihara Model and Extensional Nishihara Model, Burgers Model can reflect the three stages of creep process of coal filled with gas better. The research results can contribute to reveal coal and gas outburst mechanism. Keywords: Coal, Gas, Creep, Constitutive model

To further understand methane flow characteristics on a longwall face, this study focuses on the investigation of methane flow behaviour under six different operating and mining conditions, namely, the impact of ventilation in terms of both flow rate and the ventilation scheme, coal seam gas content, adjacent gas bearing strata, drum sprays and the maingate (MG) curtain. Modelling results obtained from the parametric studies were compared with the corresponding base model results, through which the impact of single parameter on the methane distribution characteristics along the longwall face was investigated. Modelling results indicate that: 1) flow rate has major impact on the methane concentration around the shearer and at the inner tailgate (TG) corner while the impact is minor at the upper TG corner; 2) methane emission from adjacent gas bearing strata significantly affects the methane distribution at the immediate goaf and at the upper TG corner of the face; 3) the use of a TG cut through behind the face is very effective in diluting the methane accumulated at the upper TG corner; 4) methane levels in the vicinity of drums and downstream is reduced greatly with the operation of drum sprays.

In the aspect of numerical methods for incompressible flow problems, there are two different algorithms: semi-implicit method for pressure-linked equations (SIMPLE) series algorithms and the pressure Poisson algorithm. This paper introduced a new discretized pressure Poisson algorithm for the steady incompressible flow based on a nonstaggered grid. Compared with the SIMPLE series algorithms, this paper did not introduce three correction variables. So, there is no need to implement the guess-and-correct procedure for the calculation of pressure and velocity. Compared with the pressure Poisson algorithm, there is no need to calculate unsteady Navier–Stokes equations for steady problems in the new discretized pressure Poisson algorithm. Meanwhile, as the finite volume method and cell-centered grid are used, the governing equation for pressure is obtained from the continuity equation and the boundary conditions for pressure are easily obtained. This new discretized pressure Poisson algorithm was teste...

In this work, the interaction between camptothecin (CPT) analogs and fat mass and obesity associated (FTO) was investigated using spectroscopy and molecular docking. From the experimental results, it was found that the CPT analogs caused the fluorescence quenching of FTO through a static quenching procedure. The binding constants and thermodynamic parameters at three different temperatures, the number of binding sites were obtained, which suggested that the hydrophobic interaction and electrostatic force played major role in the reaction between CPT analogs and FTO. Results revealed that 10-hydroxycamptothecin was the strongest quencher.

Pre-gas drainage plays a significant role in the prevention of coal and gas outburst in underground coal mines. However, difficulties of reducing the content of coal seam gas, especially localized coal seam CO 2 , to be below threshold values within a given drainage lead time have been encountered in numerous coal mines in Australia. As the proneness of nitrogen outburst is way smaller than CO 2 or methane outburst, nitrogen injection would be an attractive technology for the underground gas drainage management if it is really able to enhance the drainage efficiency. From this point of view, this paper aims at investigating the feasibility of implementing this technology in Bulli seam, Sydney Basin through numerical modelling. Four parts of work were conducted in this paper. Firstly, a binary gas transport model was developed through analysing the binary gas transport mechanism in both coal matrix and coal cleat, and also the matrix-cleat interaction due to binary gas sorption swelling. A real gas mixture viscosity was introduced and its change depends on the molar fractions of both components and their own viscosities. Secondly, the characteristics of the Bulli seam were studied to collect the parameters required by the binary gas transport model. Through laboratory experiment, field investigation and reviewing literature, the coal seam gas (methane, CO 2 ) and nitrogen adsorption and diffusion properties, in-situ seam properties such as permeability, porosity, cleat spacing and virgin pressure are either measured or estimated. Thirdly, the regular drainage effects in six scenarios with different initial permeability and coal seam gas type were examined and three of them are found to have drainage difficulties, i.e., the moderate permeability (0.5 mD) CO 2 case, the low permeability (0.005 mD) methane case and the low permeability (0.005 mD) CO 2 case. The effects of nitrogen injection on enhancing gas drainage efficiency, especially reducing the gas content, are studied for these scenarios. Results show that a satisfactory result is obtained for the moderate permeability CO 2 case, the CO 2 content can be reduced largely and an apparent increase of CO 2 production rate can be seen. However, the effect of nitrogen injection in low permeability methane scenario is even worse than the regular drainage using two boreholes, although it can increase the methane flow rate of single borehole. For low permeability CO 2 case, nitrogen injection can accelerate the reduction ratio of CO 2 content in part of the injection area and increase the total CO 2 flow rate, but the enhanced effect is limited and the CO 2 content is still high after 12 months of injection. Last but not least, the feature of the movement of coal seam gas content peak in the injection area is discussed and the reasons inducing the different injection effects between methane and CO 2 scenarios are analysed. A combination of lateral movement and drop of coal seam gas content peak is found, and permeability is believed to have great impacts on the movement speed. There is no sign indicating either diffusion or permeability change controls the different injection effects between methane and CO 2 scenarios, while the different competitive adsorption characteristics and the increase of mixture gas viscosities may have influences on this difference.

Eight nickel complexes with chelating N-substituted bis(diphenylphosphanyl)amine and 1,2-benzenedithiolate or 3,4-toluenedithiolate, [RN(PPh2)2]Ni(1,2-SC6H4S) [R = CH(CH3)2, 1; CH2CH(CH3)2, 2; CH2CH2CH2CH3, 3; CH2Ph, 4] and [RN(PPh2)2]Ni[3,4-SC6H3(CH3)S] [R = CH(CH3)2, 5; CH2CH(CH3)2, 6; CH2CH2CH2CH3, 7; CH2Ph, 8], were synthesized and structurally characterized. The measurement of the electrochemical properties revealed that complex 4 can catalyze protons to hydrogen (H2) under weak acidic conditions. Complex 4 can also be used as a molecular catalyst for light-driven H2 evolution with a proton source, a photosensitizer, and an electron donor. Furthermore, by using tetraphenylporphyrin (TPP) amide-covalently functionalized graphene oxide (GO) nanohybrid (TPP-NH-GO) as a photosensitizer, the efficiency of photocatalytic H2 production of complex 4 in aqueous ethanol solution had been astonishingly improved over than for the photocatalytic systems without GO. This result suggests that the excellent properties of GO with respect to electron transfer, surface area, adsorptivity, and hydrophilicity may promote the performance of the photocatalytic H2 production system to a certain extent.

A new guar gum derivative was synthesized though the nucleophilic substitution of sodium hydroxide-activated guar gum with n-butyl glycidyl (BGE) ether. The physicochemical properties of 2-alkenyl-3-butoxypropyl guar gum (ABPG) were characterized by attenuated total reflection Fourier transform infrared spectrometry (ATR-FTIR), X-ray diffraction (XRD) and thermal gravimetric analyses (TGA). The results showed that sodium hydroxide can be effectively substituted with BGE to form the ABPG. The steady and dynamic rheological properties of the aqueous solution and ABPG gel were determined using an RS6000 rheometer. Compared with the guar gum, ABPG enhanced the thickening property and improved the solution stability. The ABPG gel exhibited good temperature resistance and shear stability properties.

The fat mass and obesity-associated protein is a potential target for anti-obesity medicines. In the present work, the interaction between our synthesized 3-substituted 2-aminochromones and fat mass and obesity-associated protein were investigated using fluorescence spectroscopy, ultraviolet–visible spectroscopy and molecular modeling approach. Fluorescence spectroscopy showed that the fluorescence of fat mass and obesity-associated protein can be quenched by these compounds with a static quenching procedure. In addition, the thermodynamic parameters obtained from the fluorescence data showed that the hydrophobic force played a major role in stabilizing the complexes. Ultraviolet–visible spectroscopy, synchronous fluorescence spectroscopy and three-dimensional fluorescence spectroscopy indicated that these compounds can induce some conformational changes of fat mass and obesity-associated protein.

p-Toluenesulfonyl isocyanate (PTSI) is introduced as electrolyte additive in a bid to enhance the electrochemical performances of LiNi0.5Co0.2Mn0.3O2 cathode materials under high voltage. A less resistive and stable film on the cathode surface derived from PTSI oxidation which taken place prior to the carbonate solvents is formed. As a result, the discharge capacity retention of Li/LiNi0.5Co0.2Mn0.3O2 cell is elevated from 71.4% to 86.2% after 100 cycles at room temperature, and from 32.3% to 54.5% after 100 cycles at 55 °C. In addition, the Li/LiNi0.5Co0.2Mn0.3O2 half cell with PTSI exhibits superior rate capability compared to that in baseline electrolyte. The improved performance is not only ascribed to the thin protective layer originated from PTSI decomposition which prevent the successive breakdown of the electrolyte on cathode surface, but it is also attributed to the S O group in PTSI serves as the weak base site to restrain the reactivity of PF5, resulting in the suppression of LiF formation and HF generation.

Cotton is a flammable material and some cottons would decompose or even self-ignite at bad storage and transport conditions. This paper studied the spontaneous combustion of cotton from the aspect of thermal decomposition temperature (TDT) and critical ambient temperature (CAT). From Fourier transform infrared spectroscopy analysis and chromatographic and mass spectrometric analysis, significant thermal decomposition was detected at the temperature of $$210\,^\circ \hbox {C}$$ , which indicated that the TDT of cotton was around $$210\,^\circ \hbox {C}$$ . From TG analysis and small-scale CAT test, activation energy of cotton and CAT of small cotton stack were obtained. Then, CATs of the cotton stacks with different dimensions were calculated based on Frank-Kamenetskii theory. With the dimensions l increased from 0.2 to 3.2 m, the CATs of cotton decreased from 195.0 to $$137.9\,^\circ \hbox {C}$$ . The TDT of cotton was higher than these CATs, and the differences between TDT and CAT of cotton varied from almost 15– $$70\,^\circ \hbox {C}$$ (with the dimensions l increased from 0.2 to 3.2 m). As the experiments and calculation of the CATs were very complicated and time-consuming, the CATs of cotton can be estimated if the TDT was known. The result of this paper was especially meaningful for evaluating the risk of spontaneous combustion of cotton and speculating the reason of cotton fire.

Heavy metal contamination induced by cigarette smoking is a critical issue in environmental pollution and human health risk. Although a number of investigations have been performed on the detection of heavy metals in cigarette tobacco, only very limited data have been reported for the determination of these metals in other parts of cigarettes. In this study, the contents of copper, cadmium, chromium, nickel and lead in cigarette tobacco, smoke, ash and butts were quantified using high-resolution continuum source graphite furnace atomic absorption spectrometry. The LODs for Cu, Cd, Cr, Ni and Pb were 0.010 μg L−1, 0.020 μg L−1, 0.025 μg L−1, 0.030 μg L−1 and 0.012 μg L−1, respectively. Twelve cigarette samples purchased from eleven popular brands in China were used for the heavy metal measurements. Microwave digestion was employed for the preparation of the cigarette tobacco, ash and butt samples. A smoke collection apparatus, which was designed to simulate human smoking behavior by alternating suction and pause intervals, was used to capture the heavy metals in smoke. The total amounts of the determined metals were observed to be the highest in ash (55.60 to 125.99 μg g−1), followed by tobacco (11.70 to 22.34 μg g−1) and butts (4.29 to 15.22 μg g−1), and were 0.67, 0.10, 0.14, 0.16 and 0.24 μg per cigarette for Cu, Cd, Cr, Ni and Pb, respectively, in smoke. The residual rates of the heavy metals in ash, smoke and butts were measured to estimate the distribution of each element after the cigarette tobacco was fully burnt. The results indicated that the majority of the heavy metals (41.1% to 68.7%) remained in ash, with 10.0% to 28.0% condensed in butts and 6.6% to 22.9% released into the mainstream smoke. Moreover, a high variance of the five metal contents was observed in different brands of cigarettes, which might be associated with the geographical origin of the tobacco plant, cigarette production procedure, and transportation and storage of the materials and products. This study provides a reliable method for the quantitation of heavy metals in different components of cigarettes, which will be beneficial to the prevention of heavy metal hazards and the reduction of human health risks through tobacco consumption.

The temperature distribution information plays an important role in industrial applications. Owing to the advantages such as non-intrusive sensing and low cost, the ultrasonic tomography (UT) is considered to be a promising method for temperature field visualization. The ultrasonic time-of-flight (TOF) measurement and the reconstruction algorithm are crucial for practical applications of the UT measurement. In this paper, a dual-threshold measurement method is proposed to ensure a high-quality TOF measurement. In view of the inaccurate nature of the reconstruction model and TOF data, a new reconstruction method that integrates the advantages of the Tikhonov regularization method and the least squares support vector machine (LSSVM) is proposed to improve the reconstruction quality. The experimental results were compared against thermocouple measurements and the results show that the temperature distribution can be reconstructed with the error of 1.3%, which validates the feasibility and effectiveness of the proposed Tikhonov-LSSVM reconstruction algorithm.

In this paper, The binding of twelve 1,3-diazaheterocyclic compounds (1a-1 l) to the fat mass and obesity-associated (FTO) protein was investigated by fluorescence, UV-vis absorption spectroscopy and molecular modeling. Results indicated that the intrinsic fluorescence of FTO is quenched by the nine compounds (1a-1i) with a static quenching procedure. No interaction was observed between FTO protein and compounds (1j-1 l). The thermodynamic parameters obtained from the fluorescence data showed that the hydrophobic force played a major role in stabilizing the complex. The results of synchronous and three-dimensional fluorescence spectra showed that the conformation of FTO was changed. In addition, the influence of molecular structure on the quenching effect has been investigated.