The green and environmentally friendly cardanol epoxy resin has a bright application prospect, but its insufficient thermal/mechanical properties seriously hinder its application. Adding nanoclay to ...polymer matrix is an effective method to enhance the thermal/mechanical properties of material, but the dispersion and compatibility of nanoclay in epoxy resin remain to be solved. In this work, active Girard’s reagent clay (PG-clay) and non-active Girard’s reagent clay (NG-clay) were prepared by using acethydrazide trimethylammonium chloride (Girard’s reagent) as the modifier, and cardanol epoxy resin/G-clay nanocomposites were synthesized by the “clay slurry composite method”. The results showed that both PG-clay and NG-clay were dispersed in the epoxy matrix in the form of random exfoliation/intercalation, which effectively improved the thermal/mechanical properties of the composites. Tg of the cardanol epoxy resin has raised from 19.8 °C to 38.1 °C (4 wt.% PG-clay). When the mass fraction of clay is 4%, the tensile strength of the non-reactive NG-clay increases by 128%, and the elongation at break also increases by 101%. Simultaneously, the active PG-clay can participate in the curing reaction of epoxy resin due to the amino group, forming a chemical bond between the clay layer and the resin matrix and establishing a strong interfacial force. The tensile strength of the composite is increased by 970%, and the elongation at break is also increased by 428%. This research demonstrates that the cardanol epoxy resin/G-clay nanocomposite stands as a highly promising candidate for bio-based epoxy resin materials.
Despite the growing attention paid to the research of translation technology teaching (TTT), there is still a lack of studies on students' attitudes and the motivational factors in relation to it. To ...this end, the paper reports on a questionnaire-based study that describes students' attitudes towards translation technology (in the Chinese MTI context) and explores its structural relations with translation mindsets and future work self.
Data were collected from 108 grade 2021 MTI students of three selected Chinese universities and analyzed using descriptive statistics and structural equation modeling (SEM).
The results demonstrate that Chinese MTI students' overall attitudes towards translation technology are slightly positive. So far, they perceive translation technology to be slightly effective for translation and are slightly mindful of it. They are slightly influenced by teachers and still feel inhibited when learning and using it. Furthermore, the results also indicate that growth translation mindsets positively influence students' attitudes towards the effectiveness of translation technology, teacher influence, exhibition to translation technology, and mindfulness about translation technology, whereas fixed translation mindsets only negatively predict students' teacher influence. Likewise, future work self-salience positively associates with students' attitudes towards the effectiveness of translation technology and mindfulness about translation technology, while future work self-elaboration positively relates to students' exhibition to translation technology. Among them, growth translation mindsets are the strongest predictor for all attitudes components.
Theoretical and pedagogical implications are also discussed.
The issue of employability has already become a well-delineated topic of study among interpreting educators. However, the current literature still lacks descriptive research on interpreting students' ...employability development and ignores the developmental effects of interpreter competences in this process. Moreover, the advantage of using career adaptability for measurement is also under-researched. This exploratory case study aims at taking an initial step forward, surveying interpreting students' career adaptability development and the developmental effects of different interpreter competences on major adaptability resources, and ultimately diagnosing curriculum problems and making modifications accordingly. Thirty grade 2019 interpreting students from three Chinese universities contributed to data collection, through six questionnaires in a two-wave survey. The results highlight that, throughout the Chinese MTI program, interpreting students could become more concerned and well prepared for their future (concern), more curious to explore themselves and their surroundings (curiosity), and more capable of solving problems (confidence). The results also indicate that students' knowledge and language competence serve as the major facilitators in this process, and that other interpreter competences, such as psychological competence, transfer competence, professionalism, and cross-cultural competence, are also instrumental. In order to further boost their adaptability constructs, the results suggest that students' language and knowledge competence, professionalism, and cross-cultural and mental agility still need to be improved. Five suggestions for curriculum revision have been raised accordingly. As an initial effort, the current study will hopefully inspire further studies on interpreting students' career adaptability and add more knowledge to the curriculum design from this viewpoint.
The highly cross-linked epoxy cured network suffers from the brittle nature and poor elongation, which hinders many potential applications. In this study, a biology-based cardanol NC-514S-modified ...polyether amine D230 was synthesized and used as an epoxy hardener (NC-D230). The effects of NC-514S content on the mechanical and thermal properties of the prepared samples were investigated. At the same time, we used cyclic stretching to further characterize its mechanical strength, and characterized the curing agent before and after modification through SEM and FTIR. Mechanical tests on the samples showed that the increase of NC-514S content results in lower tensile strength and Young’s modulus but an increase in elongation-at-breaks. DSC and TGA analyses showed a decreasing trend of glass transition temperature with the addition of NC-514S. Typically, the epoxy thermoset without/with 75% (by wt) NC-514S-modified D230 decreased tensile strength from 61.7 to 17.74 MPa, and Young’s modulus from 496 to 11.56 MPa. It increased elongation from 13.43% to 97.97%, and decreased glass temperature from 87.5 to 51.9 °C by DSC and 87.8 to 54.7 °C by DMA, respectively. This novel bio-based renewable cashew phenol-modified polyetheramine may provide an ideal candidate for toughening an epoxy-based thermosetting materials. At the same time, it also provides a new way for the toughening of epoxy resin.
Graphical abstract
The uniform dispersion of polysilsesquioxane (POSS) in the matrix and strong interfacial bonding polysilsesquioxane (POSS) particulate and epoxy chains are critical for achieving epoxy/POSS with ...enhanced thermal and mechanical properties. In this study, polysilsesquioxane (POSS) reinforced bio-based cardanol NC-514 s epoxy elastomeric network was prepared, and the effects of POSS content on the mechanical and thermal properties of the as-prepared sample were investigated. Polysilsesquixane (POSS) modification biobased cardanol NC-514 s epoxy elastomeric (POSS-NC) was characterized by Fourier transform infrared spectroscopy, and scanning electron microscopy, respectively. Mechanical tests showed that the tensile strength, Young's modulus, and elongation-at-break of the prepared materials increased with an increase of POSS content. DSC and TGA analyses showed the increased trend of glass transition temperature with the addition of POSS. Typically, the epoxy thermoset without/with 10% (by wt) POSS increased tensile strength from 1.18 to 3.69 MPa, and Young's modulus from 1.08 to 2.71 MPa, increased elongation from 100.85 to 122.61% and increased glass temperature from 24.2 to 48.0 ºC by DSC and 32.5 to 45.1 ºC by DMA, respectively. This novel POSS reinforced bio-based renewable cashew phenol epoxy elastomer provided an ideal candidate for toughening epoxy-based thermosetting materials, showing the potential application of bio-based epoxy-based composite materials.
Graphical abstract
Elastic migration has been widely paid attention by employing the vector processing of mul- ticomponent seismic data. Ray based elastic Kirchhoff migration has such properties as high flexibility and ...high efficiency. However, it has failed to solve many problems caused by multipath. On the other hand, elastic reverse-time migration （RTM） based on the two-way wave equation is known to be capable of dealing with these problems, but it is extremely expensive when applied in 3D cases and velocity model building. Based on the elastic Kirchhoff-Helmholtz integral, we calculate deeoupled backward-continued wavefields by introducing elastic Green functions for P- and S-waves, which is expressed by a summation of elastodynamic Gaussian beams. The PP and polarity-corrected PS images are obtained by calculating the correlation between downward and deeoupled backward-continued vector wavefields, where polarity correction is performed by analyzing the relation between the polarization direction of converted PS waves and incident angle on the interface. To a large extent, our method combines the high efficiency of ray-based migration with the high accuracy of wave-equation based reverse-time migration. Application of this method to multicomponent synthetic datasets from the fault model and Marmousi 2 model demonstrates the validity, flexibility and accuracy of the new method.
Taking insight into genetic mechanisms of coalbed methane (CBM) can provide an effective approach for evaluating the value of CBM resources. In this study, the geo-temperature and the thermal ...subsidence history were used to investigate the effect of the present geothermal field characteristic on the genetic mechanisms of CBM at the Huaibei Coalfield. The results showed that the Permian coal strata in the study areas had a relatively low geo-temperature (< 50°C), high vitrinite reflectance (R
o,max
; 0.75%-1.2%) and a coal rank typical of intermediate-high metamorphic bituminous. Comprehensive analyses of the characteristics of the present geothermal field indicate that the CBM at the Huaibei Coalfield are dominated by secondary biogenic gases. Furthermore, the genetic mechanism towards CBM was further proposed based on the tectonic evolution history: (1) Tectonic thrusting contributed to R
o,max
values ranging from 0.5% to 3.0%, with maximum geo-temperatures of 140-180°C, which resulted in the generation of thermogenic CBM. (2) An extensional regime contributed to gradual uplift of the Permian coal-bearing strata, with the gradual escape of CBM at burial depths greater than 700m. (3) A large number of faults and hydrodynamic environments greatly promoted the microbial degradation of the early thermogenic gases, resulting in generation of secondary biogenic gases.
High pressure mercury, nitrogen adsorption, nano-CT, and scanning electron microscope with energy spectrum analysis were conducted on core shale samples for studying the characteristics of Taiyuan ...formation in the eastern uplift of Liaohe depression. The research results show that the shale gas reservoir pores are mainly open pores such as the wedge-shape pores and parallel-plate pores. By a genetic type, pores mainly include organic pore, pyrite crystal particle pore, illite intragranular pore, illite-smectite mixed layer intragranular pore, and feldspar dissolved pore. The micropore and mesopore play an important role in shale gas reservoir, and their surface area and pore volume are 9.56 m2/g, 0.0414 mL/g, 97.3%, and 68.8% respectively. The pores diameter presents a bimodal distribution with two main peaks at 43 nm and 6.35 μm. Based on the nano-CT, the porosity is 4.36% and the permeability is 204 nD. The brittle minerals played a supportive and protective role for the pores and controlled their spatial distribution.
Seismic migration and inversion describe a class of closely related processes sharing common objectives and underlying physical principles. Reverse time migration (RTM) is a migration method that can ...provide high quality images for structures with steep dips and strong horizontal velocity variations. Prestack waveform inversion (PWI) is an inversion method that is a practical choice for subsurface reservoir description using the current computational resources. Although RTM and PWI provide a depth image and subsurface properties, interpreting subsurface structures from the seismic images can be challenging, especially when the geology is complex. Use of automated methods using the artificial intelligence (AI) recently became popular for interpreting such complex geology. This dissertation focuses on the applications of PWI, RTM, and AI for interpreting seismic data using three proposed methods. The first method is a new methodology and workflow for a nonlinear prestack isotropic elastic waveform inversion, which we call data driven inversion, meaning that we derive the initial model entirely from the seismic data without using any well information. The second method is a joint iterative workflow that combines RTM and PWI, where PWI is run on the common image gathers (CIGs) obtained from RTM, followed by another pass of RTM, taking the updated models from PWI as input. This method allows for automatic model updates to improve the accuracy of both depth image and subsurface elastic model. The third method is an AI based semi-supervised training workflow for salt recognition, which allows the predicted model to iteratively improve as more and more information is distilled from the unlabeled data into the model. For each iteration, the model obtained from previous iteration is used for generating pseudo labels for the unlabeled data. This automated consecutive data distillation allows the model prediction to improve with iteration, without any need for human intervention. All these methods were validated using synthetic data and then applied to real datasets.
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