In order to achieve the International Air Transport Association’s (IATA) goal of achieving net-zero emissions in the aviation industry by 2050, there has been a growing emphasis globally on the technological development and practical application of sustainable aviation fuels (SAFs). Discrepancies in feedstock and production processes result in differences in composition between SAFs and traditional aviation fuels, ultimately affecting the emission performance of the two types of fuel. This paper discusses the impact of CO₂/NO_x/SO₂/CO/PM/UHC emissions from the aviation industry on the natural environment and human health by comparing the two types of fuel under the same conditions. Fuel combustion is a complex process in the combustor of an engine, which transfers chemical energy into heat energy. The completeness of combustion is related to the fuel properties, including spray, evaporation, and flammability. Therefore, engine performance is not only affected by fuel performance, but also interacts with engine structure and control laws. The CO₂ emissions of SAFs differ significantly from traditional aviation fuels from a lifecycle analysis perspective, and most SAFs can reduce CO₂ emissions by 41–89%. Compared with traditional aviation fuels, SAFs and blended fuels can significantly reduce SO₂ and PM emissions. Pure Fischer–Tropsch hydroprocessed synthesized paraffinic kerosine (FT-SPK) can reduce SO₂ and PM emissions by 92% and 70–95% respectively, owing to its extremely low sulfur and aromatic compound content. In contrast, the differences in NO_x emissions between the two types of fuel are not significant, as their generation mechanisms largely stem from thermal drive and turbulent flow in the combustor, with emissions performance being correlated to power output and flame temperature profile in engine testing. CO and UHC emissions are related to engine operating conditions and the physical/chemical properties of the SAFs, with no significant upward or downward trend. Therefore, SAFs have significant advantages over conventional aviation fuels in terms of CO₂, SO₂, and PM emissions, and can effectively reduce the hazards of aviation to the environment and human health.

Herein, we have fabricated a novel robust self-healing magnetic double-network hydrogel by multiple interactions between bondable magnetic Fe₃O₄ and chitosan–polyolefin matrix, and the hydrogel also exhibits an excellent magnetogenic effect and MR imageability. The practical potential of the magnetic double-network hydrogel is further revealed by its 3D-printing performance.

Magnesium and magnesium alloys have great application potential in the field of orthopaedics. Compared with traditional inorganic nonmetallic materials and medical polymer materials, magnesium alloys have many advantages, such as better strength, toughness, fatigue resistance, and easy processing. Its mechanical properties are suitable and controllable. It can meet the same elastic modulus, cell compatibility, and biodegradability as human cortical bone. There are also some drawbacks for biodegradability, as magnesium and its alloys, with their high degradation rate, can cause insufficient integrity of the mechanical properties. This paper summarises the research on magnesium and its magnesium alloy materials in the field of bone implantation, looking at what magnesium and its magnesium alloys are, the history of magnesium alloys in bone implant materials, the manufacturing of magnesium alloys, the mechanical properties of magnesium alloys, the bio-compatibility and clinical applications of magnesium alloys, the shortcomings, and the progress of research in recent years.

The present study examined English use anxiety, motivation, self-efficacy, use of English, and their predictive effects on top university students’ English achievements. Two hundred and twenty-three students of the Top-Notch Students of Basic Disciplines Training Program in a top Chinese university answered a battery of questionnaires, which consisted of the 8-item English Use Anxiety Questionnaire, the 5-item Motivational Self-Talk Questionnaire, the 3-item Self-Efficacy Questionnaire, the 19-item Language Learning Orientations Questionnaire, and a Background Information Questionnaire. Analyses of the data revealed the following major findings: (1) the participants had a low level of extrinsic motivation-introjected regulation, a low-to-medium level of English use anxiety, extrinsic motivation-external regulation, intrinsic motivation-knowledge, and a medium-to-high level of motivational self-talk, self-efficacy, extrinsic motivation-identified regulation, intrinsic motivation-accomplishment, and intrinsic motivation-stimulation, (2) use of English anxiety (UAE) and language learning orientation were generally significantly negatively correlated with each other, and significantly correlated with other measured variables, (3) UAE and intrinsic motivation-knowledge significantly predicted the participants English achievements, measured both by standardized test scores and self-rated overall English proficiency, and (4) use of English and self-efficacy mediated the effects of English use anxiety and language learning orientations on the participants’ English achievements. These findings further pinpoint the importance of anxiety and motivation in second/foreign language learning.

Patients who has been implanted with hip implant usually undergo revision surgery. The reason is that high stiff implants would cause non-physiological distribution loadings, which is also known as stress shielding, and finally lead to bone loss and aseptic loosening. Titanium implants are widely used in human bone tissues; however, the subsequent elastic modulus mismatch problem has become increasingly serious, and can lead to stress-shielding effects. This study aimed to develop a parametric design methodology of porous titanium alloy hip implant with gradient elastic modulus, and mitigate the stress-shielding effect. Four independent adjustable dimensions of the porous structure were parametrically designed, and the Kriging algorithm was used to establish the mapping relationship between the four adjustable dimensions and the porosity, surface-to-volume ratio, and elastic modulus. Moreover, the equivalent stress on the surface of the femur was optimized by response surface methodology, and the optimal gradient elastic modulus of the implant was obtained. Finally, through the Kriging approximation model and optimization results of the finite element method, the dimensions of each segment of the porous structure that could effectively mitigate the stress-shielding effect were determined. Experimental results demonstrated that the parameterized design method of the porous implant with gradient elastic modulus proposed in this study increased the strain value on the femoral surface by 17.1% on average. Consequently, the stress-shielding effect of the femoral tissue induced by the titanium alloy implant was effectively mitigated.