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Compositional diffusion at interfaces often occurs during the synthesis of heterostructures, which poses a significant challenge to the reliability and performance of heterostructure-based electronic devices. In this study, the effect of interfacial compositional diffusion on the interfacial phonon transport in GaN/AlN heterostructures has been explored using molecular dynamics and phonon dynamics simulations. It is found the compositional diffusion results in a remarkable reduction in the interfacial thermal conductance (ITC) of the heterostructures, which can be modulated by tuning the compositional diffusion thickness. Phonon wave packet simulations further revealed that the energy transmission coefficient across the interface is strongly phonon frequency-dependent and interfacial morphology-dependent, which is consistent well with the calculated ITC of the structures. The phonon mode conversion and phonon localization are observed at the region of interfaces. Furthermore, it is found that the longitudinal acoustic phonons are more sensitive to the compositional diffusion interface than transverse-acoustic phonons do. However, it is interesting to find that the energy transmission coefficients of transverse-acoustic phonons with a high frequency (above 3.6 THz) across the compositional interface are abnormally higher than those across the sharp interface due to the stronger phonon mode conversion in the compositional diffusion region, which provides additional pathways for energy transmission. Our findings provide a deeper insight into the interfacial phonon scattering and transmission under the coupling effect of interfacial morphology and compositional diffusion.

Aiming to study the electronic structures, mechanical properties, and thermodynamic characteristics within framework of density function theory for scandium carbide (ScxCy) compounds, first-principles calculations were performed. The calculated cohesive energy and formation enthalpy indicate that the compounds have the thermodynamically stable structures. Their electronic characteristics indicate that ScC, Sc2C, Sc2C3, and Sc3C4 present metallic character but Sc4C3 presents semiconductor character. According to the stress-strain method, the elastic constants were calculated. In a framework of the Voigte-Reusse-Hill approximation, bulk modulus (B), shear modulus (G), Young’s modulus (E), Poisson’s ratio (σ), and Vickers hardness ( $${{H}_{{v}}}$$ ) were analyzed. The largest value of B, G, E are found from Sc2C3. Both ScC and Sc2C3 are ductile whereas other compounds are brittle. Mechanical anisotropy analysis indicates that Sc2C3 has the highest anisotropy because its percent anisotropy AG (0.038) is the largest one. Furthermore, the relationship of thermodynamic properties such as specific heat capacity, entropy, Helmholtz free energy and internal energy with temperature were analyzed.

Expansion microscopy (ExM) is a newly developed technology in recent years that enables nanoscale imaging under conventional microscopes. Herein, we report an aptamer-based ExM imaging strategy. A nucleus-targeting aptamer Ch4-1 was chemically labeled with a dye and an acrydite at each end to perform the functions of molecular recognition, fluorescence reporting, and gel anchoring. After binding cell nucleus, the dual labeled aptamer Ac-Ch4-1-FAM directly participated in gelation and anchored in polyacrylamide gel. After expanding the gel, high-resolution imaging was achieved by confocal microscopy. Multicolor ExM imaging was also realized by combining Ac-Ch4-1-FAM, antibodies and fluorescent dyes. This aptamer-based ExM could clearly image the chromatin morphology at different mitotic stages. The expansion process is simple and the aptamer labeling is easy. The aptamer-based ExM holds great promise in super-resolution imaging of cells and tissues.

Baseline drift occurs in various measured spectra, and the existence of a baseline signal will influence qualitative and quantitative analyses. Therefore, it is necessary to perform baseline correction or background elimination before spectral analysis. In this paper, a multiple constrained asymmetric least squares method based on the penalized least squares principle is proposed for baseline correction. The method takes both baseline and peak characteristics into account. Based on the prior knowledge that the left and right boundaries of characteristic peaks should be symmetrical, additional constraints of penalized least squares are added, which ensure the symmetry of spectra. The experimental results of the proposed method on simulated spectra are compared with existing baseline correction methods to verify the accuracy and adaptability of the proposed method. The method is also successfully applied to the baseline correction of real spectra. The results show that it can be effective for estimating the baseline. In addition, this method can also be applied to the baseline correction of other similar spectral signals.

In this work, we study the effect of grain boundary (GB) on the thermal transport of phosphorene by using molecular dynamics simulations. By exploring a total of 19 GBs with different GB defect types and densities, we find that there is a relatively high Kapitza thermal boundary resistance at these boundaries. By analyzing the spatial distributions of the heat flux, we find that this high thermal boundary resistance can be attributed to the strong phonon-boundary scattering at the GBs. With the same type of defect, the thermal boundary resistance is found to increase with the increase of the defect density along the GBs, which can be attributed to the nonuniform distribution of stress and lattice distortion. Finally, we investigate the anisotropy in the thermal conductivity of phosphorene with GBs and reveal a strikingly high anisotropy ratio of thermal conductivities, which is found to arise from the different influences of boundaries on the thermal transport along the zigzag and armchair directions. Our results highlight the importance of GBs in the transport behavior of phosphorene and the need to include their effects in the thermal management of phosphorene-based electronic devices.

A longitudinal distribution profile of the mechanical properties of the formations is important for the safe drilling, successful completion, and development of oil and gas reservoirs. However, the mechanical profile of the carbonate formations from the low-permeability gas reservoirs in the Tazhong (TZ) Block is hard to achieve due to the complex structural and lithological characteristics of the carbonates. In this paper, lab measurements are carried out to determine the physical and mechanical properties of the carbonate rocks of the Yingshan Formation in the TZ Block. Based on this, the relationships among density, the interval transit time and the mechanical parameters of the rocks in the TZ Block are constructed. The constructed relationships are then applied to the well-logging prediction of the mechanical profiles of the carbonate formations. The models are verified through the application to the two wells in the TZ Block, the results show that the relative errors in the predicted mechanical parameters are within 10% indicating the efficiency of the constructed models. The result of this study provides reasonable mechanical parameters for the exploration and development of the carbonate reservoirs in the TZ Block. Cited as : Wan, Y., Zhang, H., Liu, X., Yin, G., Xiong, J., Liang, L. Prediction of mechanical parameters for low-permeability gas reservoirs in the Tazhong Block and its applications. Advances in Geo-Energy Research, 2020, 4(2): 219-228, doi: 10.26804/ager.2020.02.10

Wellbore collapse frequently happens in the clay shale formation. To maintain wellbore stability, appropriate mud pressure is a vital factor. When clay formation is opened, drilling unloading occurs, modifying rock structure and strength at the wall of borehole, which affects the selection of mud pressure. Currently, mechanism of drilling unloading is still poorly understood which in return will bring a concern to wellbore stability. Therefore, in this study, a combination of triaxial compressive test and ultrasonic wave test has been used to simulate drilling unloading and analyze its mechanism. Results indicate that more void space is created inside the clay shale sample due to unloading. This structure change leads to a decline of strength and acoustic amplitude. Additionally, unloading influence is depended on varying drilling unloading parameters. Small unloading range and fast unloading rate are able to enhance stability. With various degrees of unloading impact, collapse pressure equivalent density has a clear modification, proving that unloading is a non-negligible influencing factor of wellbore stability. Besides, the unloading effect is much stronger in large confining pressure, implying that more attention should be given to unloading when drilling is in extreme deep or high geostress formation. Findings in this paper can offer theoretical guidance for drilling in the clay shale formation.

G-quadruplex (G4) forming sequences commonly exist in the genome and are closely related to gene regulation and expression. Development of a fluorescent probe that can specifically recognize G4 is essential for studying its structures and biological functions. Thiazole orange (TO) is an often used nucleic acid dye that is reported to have higher affinity to G4 DNA than double-stranded (ds) DNA. Here, four TO derivatives were designed and synthesized by introducing different styryl groups to obtain highly specific G4 probes. The spectroscopic studies revealed that different groups affected the G4 binding ability greatly, in which TO modified with 4-(diethylamino)styryl (

Hydrogen sulfide (H2S) in mitochondria plays important roles in many mitochondria-related physiological and pathological processes. Herein, a cyanine/naphthalimide hybrid fluorescent probe, L1, was designed for the ratiometric detection and imaging of mitochondrial H2S, in which cyanine and naphthalimide were used as the mitochondria-targeting group and H2S response group, respectively. Besides its good mitochondria-targeting ability, L1 also showed high sensitivity and good selectivity for H2S. Moreover, on the basis of the fluorescence ratio of naphthalimide to cyanine fluorophore, it was successfully applied to monitor the endogenous and exogenous mitochondrial H2S in live cells. Additionally, the endogenous mitochondrial H2S in different cell lines was measured by probe L1.

Peak detection is a crucial step in spectral signal pre-processing. The accurate locations of characteristic peaks are prerequisite for chemical identification. However, measured spectra inevitably contain both noise and baseline signals. These interference signals will generate a series of false peaks, which is a challenge for spectral analyses. For this purpose, a spectral peak detection algorithm named CWT-IS, based on continuous wavelet transform (CWT) and image segmentation (IS), is proposed. First, a wavelet coefficient matrix is obtained by CWT, then the matrix is converted to a gray image and the image is segmented by a machine vision method, an improved version of the Otsu method based on fuzzy mathematical theory. The desired threshold can be determined based on the membership grades of segmentation performance and the features of false peaks are eliminated. The fuzzy Otsu method solves the problem that the traditional Otsu method cannot effectively handle an image with a unimodal histogram, thus, this method can accurately separate peak regions from the CWT coefficient matrix and ridges representing the peaks are complete. This method has been successfully applied to the peak detection of the simulated spectra and the MALDI-TOF spectra. The experimental results show that CWT-IS can effectively eliminate the adverse effect of noise and baseline and make the features of spectral peaks become more obvious, which is conducive to determine characteristic peak positions.

Two-dimensional (2D) transition-metal dichalcogenides (TMDs) hold great potential for many important device applications, such as field effect transistors and sensors, which require a robust control of defect type, density, and distribution. However, how to control the defect type, density, and distribution in these materials is still a challenge. In this study, we explore the kinetics and dynamics of four types of grain boundaries (GBs) in monolayer MoS2, which are composed of S-polar dislocation (S5|7), Mo-polar dislocation (Mo5|7), dislocation-double S vacancy complex (S4|6), and dislocation-double S interstitial complex (S6|8), respectively. Our study shows that these four GBs in monolayer MoS2 exhibit a great disparity in their migration behavior. More specifically, the S4|6 and S6|8 GBs possess a much higher migration mobility than the S5|7 and Mo5|7 GBs under the same thermal fluctuations or temperature gradient. Interestingly, the S4|6 and S6|8 GBs follow an abnormal relationship with temperature, due to the change in defect configurations with temperature. Our study further shows that the remarkably high mobilities of the S4|6 and Mo6|8 GBs may enable the reactions of GBs, leading to the annihilation and reduction of defect density. In addition, the movement of GBs in MoS2 under a temperature gradient field can cause defect redistribution, which in turn changes the thermal conductivity. The present study not only deepens our understanding of the dynamic evolution of GBs in TMDs, but also presents new opportunities to engineer GBs for novel electronic applications.

Sulfur dioxide, an essential gas signaling molecule mainly produced in mitochondria, plays important roles in many physiological and pathological processes. Herein, a near-infrared fluorescent probe, A1, with good mitochondria targeting ability was developed for colorimetric and fluorescence detection of HSO

Cell-SELEX is an effective strategy to discover aptamers that can distinguish the molecular signatures of target cells from control cells. The molecular targets of such aptamers have the potential to be biomarkers. Here, we report target identification of aptamer wy-5a generated by cell-SELEX against a prostate cancer cell line, PC-3. This aptamer specifically binds PC-3 cells and a doxorubicin-resistant breast cell line, MCF-7R, as well as tissue sections of prostate cancer with high risk of metastasis. Prion protein was identified to be the molecular target of wy-5a by stable isotope labeling with amino acids in cell culture (SILAC)-based quantitative proteomic method. The octapeptide repeat region of prion protein was demonstrated to be the binding site of aptamer wy-5a. The expression levels of prion protein in cancer tissues were further tested by immunohistochemical staining of tissue sections from 48 prostate cancer patients and 98 breast cancer patients. The results suggest that prion protein has the potential to be one of the referenced markers of prostate and breast cancers.

The pH of mitochondria (pHm) is crucial in physiological processes. Here, we report a new mitochondria-targeted ratiometric pH-sensitive fluorescent probe for monitoring the mitochondrial pH change...

Analog-to-digital converters (ADCs) are moving toward high speed and high resolution for low-cost testing. Based on the theory of intelligent sensor network, this paper designs a low-cost test solution for high-precision ADC chips, which solves the problems related to signal integrity. It mainly includes the following: designing an appropriate circuit connection scheme, planning an appropriate PCB stack-up structure, formulating detailed layout and wiring constraints, etc., and building a high-speed ADC test platform to obtain static and dynamic performance; based on the existing instruments in the laboratory, the effects of different signal sources, different input powers, and the presence or absence of filters on the dynamic performance of high-speed ADCs are studied. In the simulation process, the HyperLynx simulation platform is used to design and simulate the signal integrity of the high-speed acquisition board. Combined with the relevant theoretical knowledge of the signal integrity of high-speed digital circuits, the signal integrity analysis and simulation of the ADC module circuit and the DDR3 high-speed memory circuit are carried out, respectively. The results show that, taking the histogram method as a reference, when the optimal 30 windows are selected, the integral nonlinearity (INL) error of the proposed method is 0.12 LSB, the highest sampling frequency is up to 5GSps, and 61440 sampling points are required. The time is reduced by about 30% compared with the excitation error identification and removal (SEIR) method, which effectively improves the low-cost test effect of the ADC chip.

Cutaneous T cell lymphoma is a generally indolent disease derived from skin-homing mature T cells. However, in advanced stages, cutaneous T cell lymphoma may manifest aggressive clinical behaviour and lead to a poor prognosis. The mechanism of disease progression in cutaneous T cell lymphoma remains unknown. This study, based on a large clinical cohort, found that IKZF2, an essential transcription factor during T cell development and differentiation, showed stage- dependent overexpression in the malignant T cells in mycosis fungoides lesions. IKZF2 is specifically over- expressed in advanced-stage mycosis fungoides lesions, and correlates with poor prognosis. Mechanistically, overexpression of IKZF2 promotes cutaneous T cell lymphoma progression via inhibiting malignant cell apoptosis and may contribute to tumour immune escape by downregulating major histocompatibility complex II molecules and up-regulating the production of anti-inflammatory cytokine interleukin-10 by malignant T cells. These results demonstrate the important role of IKZF2 in high-risk cutaneous T cell lymphoma and pave the way for future targeted therapy.

Edge termination plays a vital role in determining the properties of 2D materials. By performing compelling ab initio simulations, a lowest-energy U-edge [ZZ(U)] reconstruction is revealed in the bilayer phosphorene. Such reconstruction reduces 60% edge energy compared with the pristine one and occurs almost without an energy barrier, implying it should be the dominating edge in reality. The electronic band structure of phosphorene nanoribbon with such reconstruction resembles that of an intrinsic 2D layer, exhibiting nearly edgeless band characteristics. Although ZZ(U) changes the topology of phosphorene nanoribbons, simulated transmission electron microscope, scanning transmission electron microscope and scanning tunneling microscope images indicate it is very hard to be identified. One possible identified method is infrared/Raman analyses because the ZZ(U) edge alters vibrational modes dramatically. In addition, it also increases the thermal conductivity of PNR 1.4 and 2.3 times than the pristine and Klein edges.

Background Lung cancer has the highest mortality rate among malignant tumors, with non‐small cell lung cancer (NSCLC) being the most common type. As the main component of the human microflora, the intestinal flora interacts with the human body to affect immunity, metabolism, and the formation of diseases. Methods Forty‐five patients with advanced NSCLC who received platinum‐containing dual‐drug chemotherapy were enrolled in a prospective exploratory cohort study. The intestinal flora was dynamically collected at baseline and after two chemotherapy cycles. Next‐generation sequencing and metagenomics were then used to analyze the species and function of the intestinal flora at all levels. Results Significant differences in the intestinal flora of patients with NSCLC were found according to sex and age. At the family level, the abundances of Streptococcaceae, Lactobacillaceae, and Leuconostocaceae after platinum‐containing dual‐drug chemotherapy were significantly higher compared to those before chemotherapy. At the family level, patients with chemotherapy‐induced gastrointestinal reactions had a significantly higher abundance of Leuconostocaceae than those without gastrointestinal responses. Meanwhile, patients with gastrointestinal reactions had higher metabolism, human diseases, cellular processes, and environmental information processing than those who did not. At the genus level, responders had higher abundances of Bacteroides compared to nonresponders. Moreover, nonresponders had higher levels of the six major metabolic pathways compared to responders. Conclusions The intestinal flora of Chinese patients with advanced NSCLC differed according to sex and age. Moreover, significant differences in the intestinal flora were noted after chemotherapy, which could be associated with chemotherapy‐induced gastrointestinal reactions and the efficacy of chemotherapy., Significant differences in the intestinal flora of patients with advanced NSCLC were found according to sex and age. The abundances of Streptococcaceae, Lactobacillaceae, and Leuconostocaceae after platinum‐containing dual‐drug chemotherapy were significantly higher compared to those before chemotherapy at the family level. Advanced NSCLC patients with gastrointestinal reactions had higher metabolism, human diseases, cellular processes, and environmental information processing than those who did not. Nonresponders had higher levels of the six major metabolic pathways compared to responders.

The influence of microbiota on host health and disease has attracted adequate attention, and gut microbiota components and microbiota-derived metabolites affect host immune homeostasis locally and systematically. Some studies have found that gut dysbiosis, disturbance of the structure and function of the gut microbiome, disrupts pulmonary immune homeostasis, thus leading to increased disease susceptibility; the gut-lung axis is the primary cross-talk for this communication. Gut dysbiosis is involved in carcinogenesis and the progression of lung cancer through genotoxicity, systemic inflammation, and defective immunosurveillance. In addition, the gut microbiome harbors the potential to be a novel biomarker for predicting sensitivity and adverse reactions to immunotherapy in patients with lung cancer. Probiotics and fecal microbiota transplantation (FMT) can enhance the efficacy and depress the toxicity of immune checkpoint inhibitors by regulating the gut microbiota. Although current studies have found that gut microbiota closely participates in the development and immunotherapy of lung cancer, the mechanisms require further investigation. Therefore, this review aims to discuss the underlying mechanisms of gut microbiota influencing carcinogenesis and immunotherapy in lung cancer and to provide new strategies for governing gut microbiota to enhance the prevention and treatment of lung cancer.

General cancer-targeted ligands that can deliver drugs to cells have been given considerable attention. In this paper, a high-affinity DNA aptamer (HG1) generally binding to human tumor cells was evolved by cell-SELEX, and was further optimized to have 35 deoxynucleotides (HG1-9). Aptamer HG1-9 could be taken up by live cells, and its target protein on a cell was identified to be human transferrin receptor (TfR). As a man-made ligand of TfR, aptamer HG1-9 was demonstrated to bind at the same site of human TfR as transferrin with comparable binding affinity, and was proved to cross the epithelium barrier through transferrin receptor-mediated transcytosis. These results suggest that aptamer HG1-9 holds potential as a promising ligand to develop general cancer-targeted diagnostics and therapeutics.

Viscosity of cell microenvironment plays a significant role in maintaining the normal life activities of cells. Particularly, the abnormal viscosity in mitochondria is closely associated with lots of diseases and cellular dysfunctions. Herein, we developed a group of p-aminostyryl thiazole orange derivatives with different amino side chains. These probes showed good fluorescence response to viscosity with twisted intramolecular charge transfer mechanism, among them, the probes with diethylamino (TOB), dibutylamino (TOC) and pyrrolidin (TOE) side chains showed better response to the viscosity with 78-fold, 55-fold, and 88-fold fluorescence enhancement in 95% glycerol solution respectively. TOB, TOC, and TOE could enter live cells and mainly located in mitochondria. Treatment HeLa cells with nystatin, lipopolysaccharide or oleic acid caused significant fluorescence enhancement of these probes, suggesting the good potential for monitoring the variation of mitochondrial viscosity, as well as for investigating the related physiological process of inflammation and lipid metabolism.

A blue light activated anti-cancer prodrug, NST, was designed based on a photoactive 4-aminonaphthalimide derivative and an anticancer drug, 10-hydroxycamptothecin. NST was hard to be taken up by living cells and showed negligible dark cytotoxicity. The irradiation caused photocleavage of NST and resulted in high cytotoxicity.

The slip velocity between phases is an important parameter for evaluating the volumetric flow rate of each phase in vertical pipes. This paper presents an improved empirical correction for calculating the slip velocity of two-phase, oil-water bubble flows in large-diameter vertical pipes, based on a series of experimental tests. Water holdup data were obtained through experiments on an oil-water mixture flowing through a transparent test section in a 16-m-long vertical pipe with an inner diameter of 124 mm. The water holdup ranged from 0.58 to 1, and the observed flow pattern was bubble flow. Based on these experimental data, a modified correction was developed to improve the accuracy of the prediction of slip velocity for oil-water bubble flow systems. In addition, the proposed correction was validated against published experimental data for pipes with diameters of 2–6 in. The performance of the proposed correction against an experimental dataset (from our tests and published data) was also compared with that of six other, widely accepted corrections. The proposed correction predicted the slip velocity of two-phase, oil-water bubble flow in large-diameter vertical pipes more accurately than previous corrections did.

The molecular simulation method was used to investigate the adsorption behaviors of methane on illite. The effects of several factors on methane adsorption, free gas amounts, and the proportions of absorbed gas in the illite nanopores, including the pore size, temperature, and water content, are discussed. The results obtained show that methane adsorption in illite nanopores is due mainly to van der Waals adsorption. With an increase in the pressure or of the pore size, the free gas amounts of methane increase, whereas the free gas amounts decrease with increasing temperature or water content. With increasing pressures or decreasing pore sizes, the methane adsorption capacity of the illite pores increases. When the pressure or pore size increases, the proportion of the adsorbed gas in the pores decreases. As the temperature increases, the methane adsorption capacity of the illite pores decreases, and the proportion of adsorbed gas in the illite pores decreases slightly. The adsorbed phase density decreases with increasing pore size and temperature, whereas the adsorbed phase density increases with increasing pressure. The electrostatic forces and hydrogen bonds have a positive effect on water adsorption in the illite nanopores, while the van der Waals forces have the opposite effect, which causes the water molecules in the illite pores to exist in the form of aggregates. The water molecules occupy the areas near the pore walls in a directional manner and occupy the adsorption space and the adsorption sites of methane, resulting in a decrease in the methane adsorption capacity and a slight reduction in the proportion of adsorbed gas.

To probe Fe isotopic signatures of the Quaternary Red Clay (QRC) in subtropical southeastern China, two QRC profiles located in southern Anhui Province, Southeast China, were studied. The whole profiles were generally in a narrow range in δ 56 Fe of −0.040 ± 0.061‰—0.117 ± 0.048‰. The Yellow-brown Earth (YBE) and Uniform Red Clay (URC) of the upper profiles were similar in δ 56 Fe to the Xiashu Loess along the Yangtze River, Southeast China, and the loess, paleosols and Tertiary red clay in the Chinese Loess Plateaus, Northwest China, as well as the baseline of terrestrial igneous rocks. The slight variation of δ 56 Fe from the YBE to the URC suggests that the chemical weathering and rubification on the aerobic surface did not fractionate Fe isotopes significantly. The Reticulate Red Clay (RRC) underlying the YBE and URC fluctuated in δ 56 Fe to some extent. The white veins separated from the lower RRC were depleted of Fe oxides and heavier in Fe isotopes, and the red veins, on the contrary, were isotopically lighter in Fe. δ 56 Fe of the white veins, 0.345 ± 0.053‰ on average, was significantly higher than the bulk samples, 0.033 ± 0.044‰ on average, and the red veins, −0.021 ± 0.046‰ on average. This suggests that the reticulate textures of the RRC were formed by the reductive removal/re-precipitation of Fe due to the cyclical changes of redoxic conditions. Fe isotopic composition of the QRC was dominantly controlled by the redoxic mobility of Fe, rather than the degree of weathering. δ 56 Fe of the profiles was not correlated with the paleoclimatic events, and thus cannot be used as a paleoclimatic proxy. The fractionation of Fe isotopes in the lower RRC, however, indicated the occurrence of over-humid paleoclimate with alternations between drought and wetness in Southern China during the Pleistocene.

Road construction offers a unique lens through which to investigate tourism mobility. To date, research has focused on the socio-cultural effects of road construction, such as its influence on tourists’ movements and its hindrance to tourism development, with less use of systematic methods to analyze road construction-related conflicts. Accordingly, this study comprised a systematic analysis of road construction-related conflicts in Yubeng, China, and potential strategies to solve the underlying mobility dilemmas. A geo-historical trajectory of conflicts was examined, and road construction conflicts were categorized as involving resource competition, tourism dilemma, modern anxiety, or protection paradox. Then, formal conflict analysis and an evolutionary game model were used to analyze these different conflict categories and develop a general pattern of strategies by which the dilemmas might be resolved. The theoretical implications and practical insights of the findings for tourism development, as well as other social conflict contexts, were also investigated.

Severe PM2.5 (particulate matter with aerodynamic diameter smaller than 2.5 μm) pollution in China, with adverse impact on human health and global climate change, has raised great concern in recent years. The volatile organic compound (VOC) is suggested to be a significant precursor of PM2.5, but which VOC structure contributes the most to the aerosol particulate formation is still an open question. With large space occupation and complex structures (cyclic, linear and branched), VOCs together with inorganics may play a critical role in atmospheric new particle formation (NPF). To explore the effect of molecular structure on nucleation in NPF, a multi-component (H2SO4-HNO3-NH3-VOC) kinetic model is established based on the gas kinetic theory and graph theory. As the most common VOCs in the atmosphere, alkanes with 2–15 carbons are selected for model analysis. The results show that alkanes especially those with a cyclic structure or carbon number ≥4 results in the highest rate of NPF within the species considered in this study. The dominant size of nuclei, as well as the concentration of particles (larger than 1 nm), is enhanced by the increasing carbon number in alkanes. Taking the alkanes with same carbon number for comparison, the contribution to the nucleation by molecular structure is found to follow the order cyclic>linear>branched, and inversely proportion to branching number.

Clay shale is frequently encountered in drilling. With strong hydration capacity, when clay shale contacts with drilling fluid, rock structural and mechanical property will be affected, causing wellbore instability. Acoustic frequency spectrum is a significant parameter in geophysical logging. The influence of hydration on clay shale can be reflected in acoustic logging. Therefore, in order to identify hydration damage and have precise evaluation for hydration damage, a novel hydration damage index has been built on the basis of acoustic frequency spectrum. Meanwhile, considering the influence of hydration, hydrated constitutive model has been proposed using this new index. Results demonstrate that acoustic frequency spectrum has clear modification due to hydration damage. In the hydration evolutionary process, fracture initiation and propagation happen, decreasing acoustic amplitude and dominant frequency. The whole hydration evolutionary process exhibits S curve with clear three stages. In the initial stage, changing ranges of acoustic amplitude and frequency are small. In the middle stage, clear fracture propagation can be noticed and fracture network is formed, boosting the change of acoustic frequency spectrum. Finally, acoustic frequency spectrum becomes stable, meaning hydration damage has reached its limitation. Hydration damage degree is variable with different conditions, but the tendency still remains typical S curve. Stress‐strain curves simulated from hydrated constitutive model are in good agreement with results of uniaxial compressive test, indicating this model can be used to express shale mechanical property in hydration evolutionary process. Findings of this paper can offer theoretical reference for evaluating hydration damage and are advantageous for drilling operation in clay shale formation.

Heat conduction is a universal phenomenon in nature, and is usually described by Fourier's law. Whereas, the Fourier's law is an empirical equation concluded by experiments instead of theoretical derivation based on the physical nature. To bridge the gap between engineering and physics, studies are required to start from a more fundamental basis rather than on the macro scale (e.g., Fourier's law). Herein, a one-dimensional micro particle (MP) chain model with damped harmonic vibration is established to analyze heat conduction process. The interaction force between MPs is regarded as spring force produced by a hypothetical “spring”, and a wave equation for heat conduction is established based on wave mechanics. The derived wave equation is similar to the equation describing electromagnetic wave propagation, which demonstrates the physical consistency of heat conduction and radiation. According to the wave equation, theoretical descriptions for heat conduction in pure and impure MP chain are developed, and the theoretical thermal conductivities for atomic crystals where heat conduction is governed by MP vibration are comparable to that from experiments. Moreover, effects of impurity atoms on heat conduction in atomic crystal are theoretically analyzed.