Much research has been conducted on the influence of rock burst mechanisms and temperature on the mechanical properties of hard rock while research on the effect of temperature on rock bursts is ...scarce. Therefore, this paper focuses on Rock Burst Proneness Index tests and acoustic emission (AE) tests under the action of high temperature. It was found that the Rock Burst Proneness Index and the AE energy will rise as the temperature rises. It means that the degree of rock burst is increasing instead of decreasing with rising temperature. The research results revealed the temperature effect of rock burst in long deep tunnels under a certain thermal stress condition, which is helpful for explaining the rock burst disaster in tunnels at high ground temperature.
We report on a microscopic poly(N-isopropylacrylamide) hydrogel ribbon, coated by a thin gold layer, that shows helical coiling. Confined swelling and shrinkage of the hydrogel below and above its ...characteristic volume phase transition leads to a temperature actuated reversal of the sense of the helix. The extent and the shape of the winding are controlled by the dimensions and mechanical properties of the bilayer ribbon. We focus on a cylindrical helix geometry and monitor the morphing under equilibrium and nonequilibrium conditions, that is, when the temperature changes faster than the volume (millisecond range). For slow temperature variations, the water release and uptake follow the equilibrium transition trajectory determined by the time needed for the diffusion of water into and out of the microscopic gel. Much faster variations of the temperature are accomplished by internal heating of embedded gold nanorods by IR-light irradiation. This causes elastic stresses that strongly affect the motions. This method enables well-reproducible deviations from the equilibrium transition path and allows us to control rather precisely the spatiotemporal transformation in a cyclic repetitive process. Actuation and response are sensitive to small variations of temperature and composition of the aqueous sol in which the gel is immersed. The principle as described may be used to detect specific analytes that bind either to the surface of the gold layer or within the gel and can modify the interaction between the water and the gel. The reported nonequilibrium morphing implies that the system dissipates energy and may also be able to perform work as required for a microscopic motor.
•The reaction mechanism of 2,3-DCP to generate ECH was elucidated by density functional theory (DFT) simulation.•The reaction network of 2,3-DCP with alkali to prepare ECH was simplified into a ...consecutive reaction form.•The intrinsic kinetic equation of saponification of 2,3-DCP was determined by online conductivity method.•An apparent reaction model considering mass transfer performance and intrinsic kinetics was established.
As a significant chemical raw material, epichlorohydrin (ECH) is synthesized via saponification reaction of dichloropropanol (DCP) mixture consisting of 1,3-dichloro-2-propanol (1,3-DCP) and 2,3-dichloro-1-propanol (2,3-DCP). The mechanism and intrinsic kinetics of the reaction network of 2,3-DCP to ECH remain unclear. Here, density functional theory (DFT) simulation was firstly applied to elucidate the reaction mechanism. Based on the simulation results, the reaction rate equation was initially derived and the reaction network was simplified. Then, the intrinsic kinetic equation of the main reaction of 2,3-DCP saponification was determined by on-line conductivity method as kECH=1.28×1012exp-81241RT. Moreover, an apparent reaction model considering mass transfer performance, intrinsic kinetics, presence of 1,3-DCP and consecutive side reaction was established. The effects of the mass transfer performance and kinetic differences of 1,3-DCP and 2,3-DCP on the synthesis of ECH were systematically studied, which can guide the intensification and optimization of ECH synthesis.
Methylation is one of the most common and considerable modifications in biological systems mediated by multiple enzymes. Recent studies have shown that methylation has been widely identified in ...different RNA molecules. RNA methylation modifications have various kinds, such as 5-methylcytosine (m5C). However, for individual methylation sites, their functions still remain to be elucidated. Testing of all methylation sites relies heavily on high-throughput sequencing technology, which is expensive and labor consuming. Thus, computational prediction approaches could serve as a substitute. In this study, multiple machine learning models were used to predict possible RNA m5C sites on the basis of mRNA sequences in human and mouse. Each site was represented by several features derived from k-mers of an RNA subsequence containing such site as center. The powerful max-relevance and min-redundancy (mRMR) feature selection method was employed to analyse these features. The outcome feature list was fed into incremental feature selection method, incorporating four classification algorithms, to build efficient models. Furthermore, the sites related to features used in the models were also investigated.
Messenger RNA (mRNA) and long noncoding RNA (lncRNA) are two main subgroups of RNAs participating in transcription regulation. With the development of next generation sequencing, increasing lncRNAs ...are identified. Many hidden functions of lncRNAs are also revealed. However, the differences in lncRNAs and mRNAs are still unclear. For example, we need to determine whether lncRNAs have stronger tissue specificity than mRNAs and which tissues have more lncRNAs expressed. To investigate such tissue expression difference between mRNAs and lncRNAs, we encoded 9339 lncRNAs and 14,294 mRNAs with 71 expression features, including 69 maximum expression features for 69 types of cells, one feature for the maximum expression in all cells, and one expression specificity feature that was measured as Chao-Shen-corrected Shannon's entropy. With advanced feature selection methods, such as maximum relevance minimum redundancy, incremental feature selection methods, and random forest algorithm, 13 features presented the dissimilarity of lncRNAs and mRNAs. The 11 cell subtype features indicated which cell types of the lncRNAs and mRNAs had the largest expression difference. Such cell subtypes may be the potential cell models for lncRNA identification and function investigation. The expression specificity feature suggested that the cell types to express mRNAs and lncRNAs were different. The maximum expression feature suggested that the maximum expression levels of mRNAs and lncRNAs were different. In addition, the rule learning algorithm, repeated incremental pruning to produce error reduction algorithm, was also employed to produce effective classification rules for classifying lncRNAs and mRNAs, which gave competitive results compared with random forest and could give a clearer picture of different expression patterns between lncRNAs and mRNAs. Results not only revealed the heterogeneous expression pattern of lncRNA and mRNA, but also gave rise to the development of a new tool to identify the potential biological functions of such RNA subgroups.
As the concepts of intellectual property and media marketing have gained popularity, media marketing has gradually become an integral part of intellectual property marketing, and its use has become ...more widespread. However, the field of intellectual property marketing (media marketing) has become confused and faces challenges such as loss of uniqueness and weak consumer connections. Existing research efforts have focused on marketing strategies for branded intellectual property, but have neglected the important perspective of consumer psychology and behaviour. In this study, we use the AISAS model to segment digital marketing and delve into consumer psychology and behavioural factors that influence intellectual property marketing (media marketing). This exploration covers intellectual property content at the attention stage, intellectual property value at the interest stage, emotional trust at the search stage, mental consumption at the purchase stage and fan interaction at the sharing stage. We conducted a comprehensive analysis of the data using SPSS and AMOS, and integrated a consumer attitude questionnaire. The final findings confirm that intellectual property content, value, emotional trust, spiritual consumption and fan interaction all positively influence consumer psychology and behaviour. In addition, we make consumer-centric recommendations to extend the life cycle of intellectual property and promote sustainable brand development.
The growth behavior, stability, electronic and magnetic properties of the Gd2Sin− (n = 3–12) clusters are reported, which are investigated using density functional theory calculations combined with ...the Saunders ‘Kick’ and the Artificial Bee Colony algorithm. The lowest-lying structures of Gd2Sin− (n = 3–12) are all exohedral structures with two Gd atoms face-capping the Sin frameworks. Results show that the pentagonal bipyramid (PB) shape is the basic framework for the nascent growth process of the present clusters, and forming the PB structure begins with n = 5. The Gd2Si5− is the potential magic cluster due to significantly higher average binding energies and second order difference energies, which can also be further verified by localized orbital locator and adaptive natural density partitioning methods. Moreover, the localized f-electron can be observed by natural atomic orbital analysis, implying that these electrons are not affected by the pure silicon atoms and scarcely participate in bonding. Hence, the implantation of these elements into a silicon substrate could present a potential alternative strategy for designing and synthesizing rare earth magnetic silicon-based materials.
To enhance the thermal stability of ionic liquids (ILs) and increase the latent heat, the effect of amount of hydrogen bonds for geminal dicationic ionic liquids (DILs) was investigated and compared ...to that of monocationic analogues. A series of geminal dicationic ionic liquids with alkyl chain or electronegativity functional groups in the imidazolium were synthesized. Thermal stability was determined by TGA; melting point, heat of fusion, and heat capacity were investigated by DSC for synthetic DILs. The effect of molecular structure on the heat of fusion was examined by changes alkyl side-chain, linkage chain, C2–H of imidazole ring, and functional groups. Hydrogen bonding in DILs was studied, in the case of C2(eim)2(Br)2, by single-crystal X-ray diffraction. The thermal analysis results indicate that functionalized geminal dicationic ionic liquids show excellent thermal stability. The decomposition temperatures of geminal dicationic ionic liquids can be up to 603.74 K, and the latent heat can reach 159.35 J g–1. It is increased on average by 64.5% and 212.5%, respectively, as compared to alkyl chain ionic liquid (C4mim)Br. It can be expected that these geminal dicationic ionic liquids are suitable for thermal storage applications.
The redox‐targeting (RT) process or redox‐mediated process, which provides great operation flexibility in circumventing the constraints intrinsically posed by the conventional electrochemical ...systems, is intriguing for various energy storage and conversion applications. Implementation of the RT reactions in redox‐flow cells, which involves a close‐loop electrochemical–chemical cycle between an electrolyte‐borne redox mediator and an energy storage or conversion material, not only boosts the energy density of flow battery system, but also offers a versatile research platform applied to a wide variety of chemistries for different applications. Here, the recent progress of RT‐based energy storage and conversion systems is summarized and great versatility of RT processes for various energy‐related applications is demonstrated, particularly for large‐scale energy storage, spatially decoupled water electrolysis, electrolytic N2 reduction, thermal‐to‐electrical conversion, spent battery material recycling, and more. The working principle, materials aspects, and factors dictating the operation are highlighted to reveal the critical roles of RT reactions for each application. In addition, the challenges lying ahead for deployment are stated and recommendations for addressing these constraints are provided. It is anticipated that the RT concept of energy materials will provide important implications and eventually offer a credible solution for advanced large‐scale energy storage and conversion.
The redox‐targeting process provides great operation flexibility in circumventing the constraints intrinsically posed by the conventional electrochemical systems. It involves a regenerative close‐loop electrochemical–chemical cycle between an electrolyte‐borne redox mediator and an energy storage/conversion material when implemented in redox‐flow cells, boosting the energy density, and offering an intriguing research platform applied to a variety of chemistries for different applications.
Zeolitic imidazole frameworks (ZIFs), a new adsorbent with a high chemical and thermal stability and a high adsorption capacity, are used for adsorptive removal of azo dyes. The synthesized ZIF-67 ...was characterized with Fourier transform infrared spectroscopy (FTIR), thermogravimetric–differential thermal analysis (TG–DTA) and zeta potential instrument. The adsorption of some azo dyes on ZIF-67 in the single dye systems showed that the removal efficiencies are congo red > methyl orange > methyl red > methyl blue. The highest adsorption capacity of congo red and methyl orange were 3900 and 1340 mg/g, respectively. In a binary dye system the adsorption capacity of congo red decreased, while the removal efficiency of methyl orange increased in comparison with the single systems, indicating that a competitive adsorption of congo red and methyl orange over the ZIF-67 occurred. The experimental data indicate that the electrostatic attraction between ZIF-67 and congo red is the major driving force and the
π
–
π
stacking is also responsible for dye adsorption. After 5 cycles of ZIF-67 adsorption and desorption, the congo red removal efficiency maintained more than 95%.
Graphical Abstract
The adsorption of Congo red and Methyl orange on the ZIF-67
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