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NP-TPA-Tars exhibits bright emission in various states with large Stokes and facile targeted modifications, and has improved imaging efficacy, better photostability than their commercial counterparts in imaging of targeted subcellular structures.

An acceptor-substituted squaraine, NSQ1270, with an emission peak of 1270 nm, was developed and co-assembled with BSA to form dye–protein nanocomplexes with significantly enhanced fluorescence intensity for NIR-II vascular imaging.

We present a precise peripheral design for triggering propeller-like squaraine dye with highly sensitive and wide-range piezochromism. And crystal structure analysis of two polymorphs provides direct evidence to illustrate the mechanism.

Surfactant can improve the wettability of water to coal, which is beneficial to reduce the production of coal dust in coal seam water injection. Through the measurement and calculation of contact angle and its decay rate, the wettability differences of SDS (C

Diffusion and seepage play a significant role in the mine gas extraction, while their influence degree is dynamic with the change of time or location, showing a notable dynamic stage characteristic. Therefore, it is significant to master the conversion node of gas transport for improving the gas production. However, it is difficult to determine the conversion node and master controlling roles during mine gas extraction due to the lack of judgment index. In this work, a dual-porosity model was constructed to describe the gas transport in coal seam. Then, a transfer coefficient ratio between gas diffusion and gas seepage was used to define as the conversion node. Furthermore, our model was validated by comparing with the previous model, showing that our model can better describe the evolution of gas pressure under different stress conditions. The influence of stress, initial permeability and initial diffusion coefficient on the conversion node were investigated. Results showed that the initial permeability shows the most notable influence on the conversion node, followed by the stress. The initial diffusion coefficient has the relatively complex effect on the conversion node depending on the specific reservoir conditions. Finally, the transfer coefficient ratio was used to determine the best distance of boreholes for improving the gas production. The research results are important for CBM and mine gas extraction.

High temperature causes thermal damage to coal and alters its physical and mechanical properties. In this paper, in order to study the influence of thermal damage on coal mechanical properties and pore-fracture development, uniaxial compression experiments were performed on coal samples treated under different temperatures. Meanwhile, the evolution law of coal fracture in the heating process was quantitatively studied from macroscopic and microscopic perspectives by using a CT scanning electron microscope (SEM), and evolution characteristics of coal pore structure under high temperature were tested and analyzed. In addition, the influence mechanism of thermal damage to the mine fire was discussed in combination with the characteristics of coal mine fire. The results show that the failure mode of coal sample changes from splitting failure to splitting-tensile combined failure and shear-tensile combined failure with the rise of temperature. As the temperature goes up, the number and length of fractures both grow, while the fracture rate and width increase first and then decrease. The porosity of coal exhibits an upward trend on the whole. Under the action of thermal damage, the internal micropore surfaces of coal become notably rougher. The high temperature thermal damage causes the formation of a loose area at the edge of fire area. This loose area not only affects the fracture field and airflow field of the fire area, but also further induces the fire to spread deeper. The research results can be used as a reference for on-site fire prevention work.

Sea cucumber collagen (SCC) properties affected the thermal processing of sea cucumber. SCC showed the shear-thinning and pseudo-plastic properties, and the viscosity and frequency of viscoelastic crossover were decreased gradually with the temperature from 15 to 30 °C. Differential scanning calorimetry of SCC confirmed that it was thermolabile with the increase of temperatures, acid or NaCl concentrations. As the temperature increasing, the triple helix of SCC disappeared with the decrease of the relative proportion of P2 structures by circular dichroism spectrometry and Fourier transform infrared spectroscopy, and shearing could accelerate the change. Intramolecular changes investigated by molecular dynamics simulation showed the average number of hydrogen bonds decreased from 47 (20 °C) to 42 (80 °C), indicating triple helix of SCC was triggered to uncoil within 250 ns. These results could provide a scientific basis for processing of sea cucumbers.

Joule heats which are generated by coals in an applied electric field are directly correlated with variation laws of electrical parameters of coals. Moreover, the joule heating effect is closely related with microstructural changes and relevant products of coal surface. In the present study, a self-developed applied direct current (DC) field was applied onto an experimental system of coals to investigate variation laws of electrical parameters of highly, moderately and lowly metamorphic coal samples. Moreover, breakdown voltages and breakdown field intensities of above three coal samples with different metamorphic grades were tested and calculated. Variation laws of electrical parameters of these three coal samples in 2kV and 4kV DC fields were analyzed. Results show that internal current of all coal samples increases continuously and tends to be stable gradually after reaching the “inflection point” at peak. The relationship between temperature rise effect on anthracite coal surface in an applied DC field and electrical parameters was discussed. The temperature rise process on anthracite coal surface is composed of three stages, namely, slowly warming, rapid warming and slow cooling to stabilize. The temperature rise effect on anthracite coal surface lags behind changes of currents which run through coal samples. There’s uneven temperature distribution on anthracite coal surface, which is attributed to the heterogeneity of coal samples. In the experiment, the highest temperature on anthracite coal surface 65.8℃ is far belower than the lowest temperature for pyrolysis-induced gas production of coals 200℃. This study lays foundations to study microstructural changes and relevant products on coal surface in an applied DC field.

Permeability, one of the most significant parameters for CBM, is affected by many influencing factors. In this paper, an improved fully coupled permeability model was proposed to investigate the influence of the effective stress, adsorption, diffusion and variable Klinkenberg’s effect on the evolution of permeability. Then, the permeability model is validated by comparing with the experimental data in previous paper. Then, a series of cases were carried out to analyze the influence of various factors on the permeability evolution. Results showed that when the adsorption layer thickness is considered, the effective pore radius exhibited the remarkable difference. With the rising pore pressure, the adsorption layer thickness and sorption-induced swelling deformation increase, leading to the reduction in effective pore radius and thus the depression in gas permeability. Diffusion and Klinkenberg’s effect exhibit the remarkable enhancement effect on the permeability, especially at the low pore pressure conditions. It is noticed that compared with the previous constant Klinkenberg’s factor, this work constructed a variable Klinkenberg’s factor, which is affected by the effective pore radius. Finally, we constructed a governing equation for gas transport in coal seam to reveal the pressure evolution and the contribution of different influencing factors to the total permeability.

Accurate determination of basic parameters of coal spontaneous combustion process can not only directly or indirectly characterize the spontaneous combustion of coal, but also provide a reliable theoretical basis for the accurate prediction of coal spontaneous combustion period and the proposition of prevention measures of spontaneous combustion. In this paper, based on the theory of porous medium heat transfer, the mathematical models of parameters such as oxidative heat release intensity, thermal conductivity, heat capacity and activation energy of loose coal were established by using element balance method. Then, an integrated experiment system for testing characteristic parameters of coal spontaneous combustion was designed and set up, and the characteristic parameters of loose coal spontaneous combustion were accurately tested through the spontaneous combustion heating experiment on large-volume coal. The results show that the thermal conductivities of loose coal samples all decrease with the increase of voidage and rise with the increase of metamorphic grade. The heat capacity grows with the increase of volatile content. The oxidative heat release intensities of samples were increased exponentially with the rising temperature, which first rises slowly in the temperature range of 60–70 °C and then increases rapidly after 70 °C. The sample with a lower metamorphic grade and a stronger spontaneous combustion tendency owns greater oxidative heat release intensity, which grows with the increase of dynamic absorbed oxygen. At the same temperature, the large-size sample has smaller oxidative heat release intensity. The activation energy of coal samples increases with the rise of temperature and metamorphic grade. The experimental results indicate that the test system and method are reliable and can achieve the goal of rapid test.

Permeability plays a significant role on CBM. However, the gas flow mode in nanopore and fracture is different, resulting in the confusion of gas flow mechanism. In this work, a dual-permeability model was constructed with the nanopore permeability and fracture permeability. Then, the impact of adsorption layer, elastic modulus reduction ratio, adsorption effect and stress on the evolution of pore parameters were investigated to reveal the interaction mechanism between nanopore and fracture. Finally, this model was carried out to analyze the coal mine gas drainage of Qingdong coal mine. Results show that, the adsorption layer primarily controls the effective pore radius and thus impacts the nanopore permeability and total permeability. The elastic modulus reduction coefficient can affect the fracture porosity and thus change the fracture permeability, gas mobility and equilibrium pore pressure. Then, the effective pore radius, nanopore porosity and nanopore permeability are affected. For the adsorption effect, it can notably affect the effective pore radius, nanopore porosity and fracture porosity. It is noticed that its effect focuses on the evolution process. Furthermore, the effective pore radius, nanopore porosity and fracture porosity are controlled by stress and the fracture porosity is more sensitive to the stress. Finally, the permeability model can match the field test results well, indicating that our model can be used to estimate gas drainage effect and relief zone for gas pressure. In addition, for the different reservoirs, once the coal basic parameters were determined, the gas production and gas permeability can be estimated by using this model. Therefore, it is important for guiding the gas drainage in coal mine gas prevention and control.

Collagen is the main protein of sea cucumber, and its structure and thermal properties were analyzed, which were related to the storage stability of sea cucumber. Collagen molecules (SCC) and collagen fiber from sea cucumber showed the similar amino acid composition. Fourier transform infrared (FTIR) spectra of SCC revealed amide A and I band shifted slightly when the temperature ranged from 20 °C to 100 °C, and X-ray diffraction indicated the distance between adjacent molecular chains decreased from 11.85 A to 11.07 A as the temperature increased from 20 °C to 100 °C. Thermal degradation behavior was analyzed by thermogravimetric analysis (TG) coupled with FTIR, and the degradation mechanism function of SCC could be described by G(α) = [−ln (1 − α)]2/3, and the thermal degradation activation energy was in the range of 163–173 kJ/mol. As the temperature increased, the amino acids in the SCC began to degrade. CO2, NH3, H2O, CH4, NO2 and HCN were released respectively along with various chemical reactions at different temperatures.

Permeability improvement through high-pressure CO2 displacement and outburst elimination through coal seam water injection are efficient engineering technologies in coal mine gas control. However, significant problems still exist in these technologies at present. For example, CO2 displacement is likely to cause gas enrichment, leading to outburst danger; besides, conventional coal seam water injection can hardly enter the micropores and fractures of coal, resulting in poor water injection effect. In this paper, gaseous CO2, the source of outburst danger in coal, was taken as a bridge. While weak alkaline water adsorbs gaseous CO2, it is closely integrated with coal to improve the wettability of coal. In this way, the purposes of improving permeability and eliminating outburst can be achieved. An experiment was performed to test the permeability and residual gas characteristics of coal after CO2 displacement, and then a CO2–alkaline water two-phase displacement simulation test was carried out to study CO2 ...

Qinshui coalfield is the largest coalbed methane and anthracite production base in China. In the process of mine gas prevention and control, there was a larger amount of gas that can be extracted, but even with this, the residual gas pressure is not up to standard. In this paper, in order to analyze its specific reasons, a series of experiments were carried out to investigate the pore structure, particle size distribution, and CH4 release characteristics of anthracite during the pulverization process. Results show that, compared with bituminous coal, anthracite can continuously release a certain concentration of CH4 during the pulverization process. The SEM test exhibits that anthracite possesses more secondary pores while bituminous shows more mineral pores. With the increase of total pulverizing time, the coal particle size is gradually decreased. Furthermore, compared with the pre-pulverized samples, the porosity, pore volume, and surface area of post-pulverized samples are increased, indicating that t...

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted from Pacific cod (Gadus macrocephalus) skin and preliminarily purified via salting-out. Physicochemical properties of both collagen were determined. Amino acid composition analysis indicated that the contents of proline and hydroxyproline were 157 and 159 residues/1000 residues, respectively. And the proline hydroxylation rates were 40.8% for ASC and 41.5% for PSC. Denaturation temperatures (Td) measured with Ubbelohde viscometer were 14.5 °C and 16 °C, respectively, lower than that of mammals. Moreover, the analysis results of intrinsic viscosity, SDS-PAGE, Ultraviolet (UV) absorption, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) demonstrated that ASC and PSC were triple-helical type I collagens with α chain composition of (α1)2α2. Meanwhile, the scanning electron microscopy (SEM) and the hemolysis assay in vitro indicated that collagen sponge fabricated by freeze-drying technology had uniform and porous structure and good biocompatibility. So it can be applied in biomedical materials field.

Formation water intrusion into the coal seam through cross drainage boreholes seriously affects the gas extraction efficiency. Particularly in the downward boreholes, the formation water cannot be discharged through the drain. Using the conventional seepage model to estimate the effect of gas drainage will cause that the coal seam residual gas pressure is underestimated. In this paper, we construct the gas migration models in a water-intrusion coal seam, which include the gas seepage in original coal seam and the gas diffusion in water-saturated coal seam. By comparing with the field data, the mathematical models are authenticated. Then, the influences of diffusion coefficient, permeability, Henry’s constant and the radius of water-saturated coal seam on the residual gas pressure and gas production are analyzed by numerical calculations. The results show that the gas pressure decreases with the increase of the diffusion coefficient, while increases with the increase of Henry’s constant and the radius of the water-saturated coal seam. The impact of permeability is more complex. In the high permeability coal seam, the overall pressure relief effect is better. However, in the low permeability coal seam, the pressure relief effect around the borehole is better. Finally, the influence mechanism of each factor is analyzed to revel the gas production in the water-intrusion coal seam. The results of the work are of great significance to enrich the theory of gas migration and the prevention and control of mine gas disaster.

As an important part of coal, the existence of soluble organic matters (SOMs) has its own impact on the number of active groups within coal and its pore and fracture structure, which have influence on both spontaneous combustion and inhibitory effect of coal. But some in-depth researches are still lacking on this matter. On the basis of testing the composition of SOMs and analyzing the change of coal’s pore and fracture structure, we conducted an oxidation experiment on model compounds stimulating SOMs, and coal’s spontaneous combustion inhibition experiment before and after extraction. By testing characterization parameters like oxygen consumption rate, activation energy, inhibition rate, and the crossing point temperature, we analyzed how SOMs make a difference on spontaneous combustion and inhibitory effect of coal. It shows that, after the extraction of SOMs, both the amount and rate of oxygen consumption of coal goes down, while the activation energy of coal ascends after extraction. Once bei...

Two near-infrared (NIR) pH-activated heptamethine indocyanine probes with quaternary ammonium unit were designed and synthesized. The absorption and emission titrations indicate that cationic structure improves the cyanine dye’s aqueous solubility and these two probes exhibit highly sensitive response to pH in acid condition. Their fluorescence intensities both gradually increase about 25-fold from pH 7.60 to 3.00 with pKa values of 4.72 and 4.45 respectively, which are suitable for studying acidic organelles in living cells. Moreover, their fluorescence intensities are linearly proportional to pH values in the range of 5.50–4.00. These results are probably attributed to the protonation of the indole nitrogen atoms, which are verified by 1H NMR spectra. Furthermore, these two probes can achieve real-time imaging of cellular pH and detection of pH in situ in living HeLa cells due to their excellent properties, including good reversibility, desirable photostability, high selectivity, low cytotoxicity and remarkable membrane permeability.

Analysis on the source of CO is very important for prevention of coal spontaneous combustion. In this article, a method of identifying primary CO in coal seams based on an oxygen isotope method is proposed through research. Tests on the oxygen isotopes (δ18O) of CO were generated in coal oxidization reaction and coal pyrolysis reaction. It is found that δ18O of CO will reduce with rising temperature in both reactions, with δ18O of CO being 15–20‰ in air atmosphere and that being 25–28‰ in argon atmosphere in the temperature range of 130–220°C, confirming that the sources of oxygen atoms of CO vary with different atmospheric conditions. Through collecting and testing a number of gas samples from the coal seam and roof in the coal mine, their δ18O of CO is found to be 35.2–37.3‰. The result would improve the prevention of coal spontaneous combustion.

A method based on methane solubility was proposed to determine the gas pressure of a coal seam after a borehole was invaded by formation water. First, methane transport equations in a water-saturated coal seam and a water-filled borehole were established, which considered the effect of stress, density-driven convection and solute diffusion. Numerical simulation software was used to investigate the characteristics of the methane dissolution and transport. Second, we established a set of measuring devices to test the methane concentration in the borehole water. Using the No. 10 coal seam of the Taoyuan Coal Mine as the focus area, we tested the dissolved methane concentration over time, and the results were well correlated with the numerical simulation. The coal seam gas pressure was calculated to be 0.35 MPa by testing Henry’s constant of the field water. Finally, the applicability of this method was analyzed. The results showed that the effects of stress and convection had little impact on methane transport, indicating that this method was less affected by external influences. This paper provides a new idea for gas pressure measurement in water-rich coal strata.

Magnetic 3D nitrogen doped graphene gels (MNG) were easily obtained via one-pot hydrothermal synthesis process. It was found that N doping process, reduction of graphene oxide and Fe3O4 nanoparticles (NPs) generation in situ proceeded simultaneously, accompanied by the three-dimensional self-assembly. The MNG hybrids were confirmed to be interconnected poriferous frameworks of graphene sheets with uniform dispersion of Fe3O4 NPs embedded or encapsulated in N-doped graphene layers. The catalytic performance of MNG nanocatalysts was evaluated by the reduction of 4-nitrophenol to 4-aminophenol. It was worth noting that the catalytic activity of MNG hybrids was remarkably enhanced by Fe3O4 NPs loading due to the change of N doping mode induced by the in situ synthesis of these magnetic NPs, which did not alter the C/N mass ratio in fact. Meanwhile, the reaction no longer simply followed the pseudo-zero-order kinetics in late stage, this might be attributed to the enhancement of catalytic activity. Furthermore, MNG nanocatalysts were easily recycled by virtue of their superparamagnetism and exhibited excellent stability.

Coalbed methane (CBM) plays an important role in securing world energy supply and transiting electricity generation from fossil fuel to renewables. CBM reservoirs are generally very tight and require effective stimulation to achieve economic extraction. In recent years, an increasing number of coal seam stimulation techniques were developed, but selecting the most suitable stimulation technique for a particular CBM reservoir condition is becoming increasingly challenging. Therefore, it is deemed very important to compare the effectiveness of different stimulation techniques in a meaningful way to guide future research directions in this area. In this paper, the stimulation techniques were firstly classified into different categories according to the stimulation mechanisms. Then, the associated principles, the history of advances, and challenges of different stimulation techniques were comprehensively reviewed. Two indexes were proposed to compare the stimulation effectiveness at the laboratory and field scales, respectively. Finally, the comparison and evaluation of each stimulation technique in respect to the stimulation effectiveness, influence range, duration, and environment were conducted in detail; the cryogenic liquid nitrogen stimulation technique receives the highest total score among the discussed laboratory-scale stimulation techniques. Hydraulic fracturing and gas injection stimulation techniques gain the highest total score among key field-scale stimulation techniques. Considering the time required for each stimulation method to take effect, high-voltage electric fracturing may have a greater potential in the future. This work is expected to help better select the optimal stimulation technique for reservoir specific conditions.

Herein, a series of 3D nitrogen-doped graphene gels (NG) were synthesized for the removal of dyes from wastewater. Their structures were characterized by XRD, SEM, TEM, elemental analysis, BET analysis, and XPS. It was found that the distribution of functional groups on the NG surface could be significantly affected using different nitrogen sources, which could further influence their adsorption behaviors. Among them, the hybrid prepared from hexamethylenediamine as the nitrogen source shows best adsorbability for acidic dyes, whereas the hybrid obtained from ethylenediamine displays largest adsorption capacity for basic dyes. Adsorption isotherms and kinetics were also investigated. The results indicate that the best interpretation is provided by the Langmuir isotherm equation, and the adsorption dynamic behavior is fit for the pseudo-first-order model. In addition, intra-particle diffusion kinetics manifest rate-controlling steps including external diffusion and intra-particle diffusion. Moreover, all adsorbents exhibit excellent reusability. Therefore, NG adsorbents show potential applicative value in the treatment of dye wastewater.

An efficient synthetic route for moxifloxacin chiral intermediate via five steps was established. Firstly, dehydration, N-acylation and cyclization were combined in one pot to meet the industrial requirement. Then relatively low hydrogen pressure was employed in the catalytic hydrogenation reaction with high yield. Isopropanol/water system was used in resolution which guaranteed high yield and perfect optical purity. The racemic process conducted by manganese dioxide and Pd/C successfully converted the undesired enantiomer into the racemate and hence the total yield increased remarkably. Furthermore, mild hydrogen transfer catalytic hydrogenation method was utilized in debenzylation process instead of high-pressure hydrogenation. Total yield of 39.0% was achieved which was much higher than that of 29.0% in literature.

Summary The phenomenon of linear flow of slurry in mined-out areas of working face with large inclined angle is a crucial issue that hinders grouting for fire prevention. The traditional way of grouting exerts a poor effect on inhibiting coal spontaneous combustion, so it is in urgent need of a suitable grouting technology for fire prevention in mined-out areas with large inclined angle working face. This paper brings up the consolidation grouting method for fire prevention for the first time and conducts a systematic study on the flow characteristics of slurry and sedimentation characteristics of slurry in mined-out areas with large inclined angle working face. Consolidation slurry materials and their ratio are optimized by experiments. Test platform has been established, and effectiveness of the consolidation grouting for fire prevention has been simulated. The results show that settling velocity of yellow mud increases at first and then decreases as the concentration of consolidation slurry materials ascends. The optimum mass concentration is 0.2%–0.8%. The flow speed of mud is greatly reduced by laying consolidation slurry materials (The decreasing range is approaching 50%). The retention of yellow mud in mined-out areas has significantly increased. Finally, technology in working site has been developed; meanwhile, compressed air and spray between frames have been used during the period of working face, and the consolidated way of expansion bags in wood crib to lay consolidation slurry materials has been adopted during the period of stopping work. Field application shows that CO concentration at upper corner decreases significantly and eliminates signs of spontaneous combustion. Besides, the flowing water becomes clearer, and effectiveness of the consolidation grouting is remarkable after laying consolidation slurry material band. Research results can provide theoretical guidance to technology for fire hazard prevention in mined-out areas with large inclined angle. Copyright © 2016 John Wiley & Sons, Ltd.

In this paper, a series of modern advanced analysis and measurement technologies such as X-ray Fluorescence (XRF), X-ray Diffraction (XRD), 13C Nuclear Magnetic Resonance (13C NMR), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) have been used to analyze the sample after acid treatment. The result shows that after hydrochloric acid treatment and combined treatment of hydrochloric acid/nitric acid, the water content of coal sample and fixed carbon increase to some extent while the volatile component and ash content decrease. Acid treatment has reduced the content of carbon, hydrogen and sulfur but increased the oxygen content. In addition, hydrochloric acid treatment has resulted in the increase of chlorine content in coal and nitric acid treatment increase the nitrogen content. Acid treatment will influence the microcrystalline structure of the coal and improve the aromaticity which finally makes the carbon atom arrangement more orderly. After hydrochloric acid treatment, the ratio of methyl carbon, aliphatic carbon attached to oxygen, carboxyl carbon and carbonyl carbon decreases slightly, while that of other carbon functional groups increases correspondingly. The raw coal shows large differences from coal sample after the beneficiation of hydrochloric acid and nitric acid. The content of methyl carbon and the aliphatic carbon attached to oxygen is reduced obviously, while that of methylene and carbonyl carbon is raised dramatically. After acid treatment, the ratio of C C bond and C H bond on the coal surface increases gradually, but carbon in oxidation state decreases step by step which means acid treatment will destroy the active functional groups on coal surface and reduce the ratio of oxygen-containing functional groups such as ether bond and hydroxyl group. Meanwhile, acid treatment will influence the organic sulfur such as mercaptan, thioether, sulfoxide, sulfone, and sulfonate, which will change the component of organic sulfur on coal surface and decrease its content. The coal particles have no obvious change after the beneficiation of hydrochloric acid and nitric acid but their surface morphology has changed. The edges of coal particles turn obscure and their surface becomes blurred. The combined treatment of hydrochloric acid/nitric acid has increased the specific surface area of coal sample, leading to more micropores on coal surface, and thus oxygen molecules are more easily absorbed by the coal. In general, hydrochloric acid treatment has little influence on coal characteristics, chemical construction of the organic matter, inorganic minerals, functional groups on coal surface, microstructure, etc., while nitric acid treatment has significant effect on coal quality. Therefore, the influence must be taken into consideration when using the nitric acid to pretreat the coal sample.

The characteristics of the gas flow in reservoir have a great impact on exploiting coalbed methane (CBM), so many researchers have carried out the experiments to test the coal sample permeability in the laboratory. The Klinkenberg effect is an important factor in the apparent permeability which is obtained in the laboratory, and it also be recognized as a constant value for a specific gas. From the principle of the Klinkenberg effect, the Klinkenberg coefficient is closely related to the width of the gas flowing path. The coal cleat width changes because of the compressibility and sorption-induced strain features. Therefore, the Klinkenberg coefficient can not be treated as a constant. By using the cubic conceptual model of coal, the deformation behaviors of the coal matrix and fracture are analyzed in this paper, and the influential factors of the Klinkenberg coefficient are obtained. The theoretical equation of methane’s Klinkenberg coefficient was also established. The evolution equation of the cleat width is derived by coupling the effective stress and gas sorption, and the Klinkenberg coefficient model is also rewritten. Using the parameters of the coal sample, some results are obtained. The Klinkenberg coefficient increases with the increase in the pore pressure because of the sorption-induced strain at the constant effective stress; The Klinkenberg coefficient varies with the increase in the pore pressure because of the competition between the stress–strain and sorption-induced strain at the constant mean stress; The Klinkenberg coefficient increases with the increase in the mean stress at a constant pore pressure. The results improve the understanding of the Klinkenberg effect for the gas flow in a coalbed and provide theoretical guidance for CBM exploitation.

Oxidation of air-dried coal in mined-out areas is one leading factor contributing to coal spontaneous ignition during exploitation. Although some related work has been done, there is still some space for improvement. We screened out three coal samples with different ranks of coal and immersed them in distilled water for 200 days. Afterward, we identified some changes in pore structure and oxygen consumption characteristics of coal samples after water immersion. Additionally, we analyzed the composition of dissolved substance, both organic and inorganic. The results demonstrated that some parameters of three different residual coal samples increased, including average pore size, specific surface area and pore volume. In regard to the composition of dissolved substance, we identified Na+ and Cl−, which accounted for the largest proportion, along with some organic functional groups. We found that higher rank leads to a smaller total amount of dissolved substance. Additionally, we performed some experiments concerning coal oxidation rate and the amount of CO, CO2 and C2H4 generated during oxidation. The results showed that water immersion does play a significant role, along with coal rank. Considering all results and analysis, long-term water immersion is responsible for pore structure development in coal and the degree of reduction in spontaneous-ignition-proof substance, which helps to boost coal spontaneous ignition.

A smart photochromic chitosan microcapsule, which was prepared by emulsification-chemical crosslinking technique utilizing spiropyran compound EDN as core material and chitosan as shell material, was printed onto wool fabric through screen-printing process. The photochromic microcapsule was adhered onto the surface of wool fabric via the adhering and crosslinking system. The microcapsule exhibited an approximately spherical shape with a size of 3∼4 μm, and could withstand high temperature around 300°C. The time of the color development and fading stability of the microcapsule dispersions were 4.25 s and 26.00 s, respectively, which were only 0.25 s and 4.00 s slower than that of the photochromic spiropyran dispersion, respectively. When the amount of microcapsule was 8wt% and the amount of adhesive DH-BS was 15wt%, the printed fabric had remarkable photochromic responsibility and good colorfastness. The printed wool fabric presented high fatigue resistance, and the K/S, L*, a* values of the printed wool fabric were nearly no change during 25 consecutive UV/Vis irradiation cycles.

A series of Pd/γ-Al2O3 catalysts modified by potassium salts were prepared and evaluated in the reductive cyclization of 2-nitro-2′-hydroxy-5′-methylazobenzene without additional base. These solid base-hydrogenation bifunctional catalysts were characterized and the results demonstrated that potassium salts could have an important impact on the properties and catalytic performance of Pd/γ-Al2O3.

The synthesis of 2-(2′-hydroxy-5′-methylphenyl)benzotriazole from 2-nitro-2′-hydroxy-5′-methylazobenzene over Pd/γ-Al2O3 in a fixed-bed reactor was investigated. Pd/γ-Al2O3 catalysts were prepared by two methods and characterized by XRD, TEM, H2-TPR, and N2 adsorption–desorption. Employed in the above reaction, the palladium catalyst impregnated in hydrochloric acid exhibited much better catalytic performance than that impregnated in ammonia–water, which was possibly attributed to the better dispersion of palladium crystals on γ-Al2O3. This result demonstrated that the preparation process of the catalyst was very important. Furthermore, the reaction parameters were optimized. Under the optimized conditions (toluene, NAB/triethylamine molar ratio 1:2, 60 °C, 2.5 MPa hydrogen pressure, 0.23 h–1 liquid hourly space velocity), about 90% yield of 2-(2′-hydroxy-5′-methylphenyl)benzotriazole was obtained. Finally, the time on stream performance of the catalyst was evaluated, and the reaction could proceed effect...