EXPERIMENTAL STUDY OF A NOVEL SYNTHESIS STRATEGY OF CORE-SHELL STRUCTURED MICRO-PARTICLES VIA CYCLIC GAS-SOLID REACTIONS

At present, coating and coating-like process act as common methods of synthesizing particles, which usually have high utility consumption thus have high cost. Besides, the waste solution from the coating or coating-like processes needs further treatment to avoid hazards emission to the environment. In this study, a novel strategy is introduced to the synthesis of core-shell particles. The new strategy employs the irreversible solid-gas reaction cycle (eg,. Reduction and oxidation of metal), inducing a solid-phase ionic diffusion of effective material to the surface of the particles gradually. Different form the coating process. This novel strategy only involves the gas-solid reaction. Thus it avoid the treatment of waste solution and is thought to be more environmental-friendly. In addition, this synthesis method does not require specified coating but use the normal gas-solid reactor. So the cost can be lower than the conventional methods. To further illustrate this new strategy, micrometer- sized particles which contain the mixture of Fe2O3 and Al2O3 powders are used. This kind of particles is conducted H2 reduction and O2 oxidation reactions for certain number of cycles at high temperature. The ionic diffusion of Fe cations is known to take place during the reaction cycles. Through SEM and EDX analysis, the formation of core-shell structure is verified. The particles maintain an Al2O3 core-Fe2O3 shell structure. A comparative study is conducted using Fe2O3 and TiO2. For particles with the cyclic reaction through the diffusion of gaseous O anions, SEM and EDX analysis fail to verify the formation of desired structure. The two sample researches indicate that solid phase ionic diffusion’s dominating role in the formation of core-shell structure. Besides the comparative research, a 2-D diffusion model is employed to simulate this novel strategy.Department of Chemical EngineeringNo embargoAcademic Major: Chemical Engineerin

The Comparative Analysis of the Morphological Features of English and Chinese Neologisms From the View of Lexicology

The development and popularization of Internet have generated a new variety of language—neologism, which received a wide publicity in modern linguistics. This thesis focuses on the morphological features of English and Chinese neologism from the perspective of lexicology. It discusses the features by employing a lot of examples from English and Chinese in five aspects: shortening, affixation, compounding, blending and conversion. Meanwhile, special mention is given to some differences and similarities found in English and Chinese neologisms. English and Chinese share those five patterns to form new words but Chinese has its own characteristics for the fact that it belongs to a different linguistic system from English. Lacking in the knowledge of the morphological features of neologisms, communication on line will result in failure. Therefore, this paper aims at revealing their distinctive features and getting netizens to communicate better. The comparative analysis can also throw light on the cross-cultural communication between Chinese and Englsih-speaking netizens

Research on Design and Application of Virtual Reality Learning Environment from Perspective of Deep Learning

How to design learning environments to promote deep learning? Current studies mostly focus on real classroom environment or online learning environment, and there are few related studies on virtual reality learning environment. This paper tries to focus on the design and application of virtual reality technology learning environment from the perspective of deep learning, discussing the necessity, feasibility, design strategies and application. In the author’s opinion, this research can promote the development and improvement of deep learning theory and learning environment design theory, and the research results can be widely used in STEAM education, popular science education, curriculum experimental teaching, vocational skills training, informal venue learning and other education or teaching fields

A Study on SPOC: In the Case of English Vocabulary Teaching

Lexical ability of word formation, lexical collocation, grammatical pattern and contextual meaning are crucial to foreign language learners, especially to the English majors of local universities. This study first reviews the previous researches about knowledge of vocabulary and proposes the four elements in depth of English vocabulary knowledge. Second, it reviews some important vocabulary teaching theories and points out that the basis of vocabulary teaching based on SPOC is Connectivism. Third, it explains blended teaching modes based on SPOC. Fourth, it describes a vocabulary teaching experiment based on blended mode of SPOC conducted in English major class of a local university, including experimental process and experimental result analysis. Finally, it concludes that the SPOC-based vocabulary teaching which is very suitable for English majors of local universities is superior to traditional ones, with its significant promoting effect on the improvement of the depth of English majors’ vocabulary knowledge

Understanding the Drivers’ Continuous Intention of Online Car Booking Service

Based upon commitment theory, this study explores the effect of organizational commitment on drivers’ continuous intention to provide online car booking service. We further investigate the antecedent factors of the drivers’ organizational commitment. Online survey is utilized to collect data from the drivers who are providing service current from various companies in China. The results show that affective commitment and normative commitment serve as the crucial determinants to affect drivers’ continuous intention. Besides, social interaction ties with company, with customers, drivers’ rewards, as well as their sense of self-value cultivate their organizational commitment perception. We then propose our theoretical and practical implications according to the findings of this study

SC-NeRF: Self-Correcting Neural Radiance Field with Sparse Views

In recent studies, the generalization of neural radiance fields for novel view synthesis task has been widely explored. However, existing methods are limited to objects and indoor scenes. In this work, we extend the generalization task to outdoor scenes, trained only on object-level datasets. This approach presents two challenges. Firstly, the significant distributional shift between training and testing scenes leads to black artifacts in rendering results. Secondly, viewpoint changes in outdoor scenes cause ghosting or missing regions in rendered images. To address these challenges, we propose a geometric correction module and an appearance correction module based on multi-head attention mechanisms. We normalize rendered depth and combine it with light direction as query in the attention mechanism. Our network effectively corrects varying scene structures and geometric features in outdoor scenes, generalizing well from object-level to unseen outdoor scenes. Additionally, we use appearance correction module to correct appearance features, preventing rendering artifacts like blank borders and ghosting due to viewpoint changes. By combining these modules, our approach successfully tackles the challenges of outdoor scene generalization, producing high-quality rendering results. When evaluated on four datasets (Blender, DTU, LLFF, Spaces), our network outperforms previous methods. Notably, compared to MVSNeRF, our network improves average PSNR from 19.369 to 25.989, SSIM from 0.838 to 0.889, and reduces LPIPS from 0.265 to 0.224 on Spaces outdoor scenes

Microfluidics Fabrication of Micrometer-Sized Hydrogels with Precisely Controlled Geometries for Biomedical Applications

Micrometer-sized hydrogels are cross-linked three-dimensional network matrices with high-water contents and dimensions ranging from several to hundreds of micrometers. Due to their excellent biocompatibility and capability to mimic physiological microenvironments in vivo, micrometer-sized hydrogels have attracted much attention in the biomedical engineering field. Their biological properties and applications are primarily influenced by their chemical compositions and geometries. However, inhomogeneous morphologies and uncontrollable geometries limit traditional micrometer-sized hydrogels obtained by bulk mixing. In contrast, microfluidic technology holds great potential for the fabrication of micrometer-sized hydrogels since their geometries, sizes, structures, compositions, and physicochemical properties can be precisely manipulated on demand based on the excellent control over fluids. Therefore, micrometer-sized hydrogels fabricated by microfluidic technology have been applied in the biomedical field, including drug encapsulation, cell encapsulation, and tissue engineering. This review introduces micrometer-sized hydrogels with various geometries synthesized by different microfluidic devices, highlighting their advantages in various biomedical applications over those from traditional approaches. Overall, emerging microfluidic technologies enrich the geometries and morphologies of hydrogels and accelerate translation for industrial production and clinical applications.Peer reviewe

Investigate the plasmonic enhanced solar photothermal effect of gold nanorod nanofilm

Gold nanospheres (Au NSs) and gold nanorods (Au NRs) are traditional noble metal plasmonic nanomaterials. Particularly, Au NRs with tunable longitudinal plasmon resonance from visible to the near infrared (NIR) range were suitable for high efficient photothermal applications due to extended light receiving range. In this work, we synthesized Au NRs and Au NSs of similar volume, and subsequently developed them into Au NR/PVDF and Au NS/PVDF nanofilm, both of which exhibited excellent solar photothermal performance evaluated by solar photothermal experiments. We found that Au NR/PVDF nanofilm showed higher solar photothermal performance than Au NS/PVDF nanofilm. Through detailed analysis, such as morphological characterization, optical measurement, and finite element method (FEM) modeling, we found that the plasmonic coupling effects inside the aggregated Au NRs nanoclusters contributed to the spectral blue-shifts and intensified photothermal performance. Compare to Au NS/PVDF nanofilms, Au NR/PVDF nanofilm exhibited higher efficient light-to-heat conversion rate, because of the extended light receiving range and high absorbance, as the result of strong plasmonic interactions inside nanoclusters, which was further validated by monochromatic laser photothermal experiments and FEM simulations. Our work proved that the Au NRs have huge potential for plasmonic solar photothermal applications, and are envisioned for novel plasmonic applications

The Spatial and Temporal Dynamics of Rabies in China

Rabies is a major problem in developing countries and responsible for more than 55,000 deaths annually. More than half of the cases occur in Asia and China has the second highest incidence of rabies after India. Human rabies cases in China decreased during the early 1990s but the virus began to re-emerge in the latter half of the decade and spread rapidly across the country with a corresponding increase in cases. To try and learn more about the epidemic, in 2006 the government implemented a trial surveillance program to sample and screen canine populations in locations where human cases were reported. In this work we selected a subset of samples (representative of the entire epidemic region) for sequencing and investigated the history and origin of the virus in China and examined the variation from a geographical perspective. Our results indicate that the epidemic is primarily composed of a younger strain with a geographical dispersion that was consistent with the recorded spread of the virus and a second older strain that corresponds to a previous epidemic. This second group exhibits a different geographical pattern, and it appears that this strain remained at low levels throughout the country and was able to re-emerge as the epidemic took hold