Making online learning more student-centred in the Department of Earth Sciences at the University of Nanjing

A major challenge for tertiary education in China today is the requirement to provide an education for progressively increasing numbers of students, with relatively static resources. Enrolments are at an all-time high and growing rapidly. In contrast, teaching staff and physical resources (such as practical rooms and lecture theatres) have not grown at a comparable rate. Educational institutions are commonly located in urban areas and tend to be concentrated in densely populated areas which reduces the access to tertiary education for people living in the more remote parts of the country. In order to deal with these two challenges, tertiary institutions in the People’s Republic of China began to utilise the advantages of online learning around five years ago. One of the useful characteristics of online learning is the ease of access – educational resources can be uploaded to the Web and then utilised by anyone with a modem and a telephone. These resources can be shared among all people. Learners can access these educational resources at any time and from any place. Online learning is a new tool that can increase our reach, so that we can communicate with a much larger audience and maximise the educational opportunities of people living in the more remote regions. This technology also has the potential to improve the quality of learning and reduce the cost of education

Generating Giant and Tunable Nonlinearity in a Macroscopic Mechanical Resonator from Chemical Bonding Force

Nonlinearity in macroscopic mechanical system plays a crucial role in a wide variety of applications, including signal transduction and processing, synchronization, and building logical devices. However, it is difficult to generate nonlinearity due to the fact that macroscopic mechanical systems follow the Hooke's law and response linearly to external force, unless strong drive is used. Here we propose and experimentally realize a record-high nonlinear response in macroscopic mechanical system by exploring the anharmonicity in deforming a single chemical bond. We then demonstrate the tunability of nonlinear response by precisely controlling the chemical bonding interaction, and realize a cubic elastic constant of \mathversion{bold}$2 \times 10^{18}~{\rm N}/{\rm m^3}$, many orders of magnitude larger in strength than reported previously. This enables us to observe vibrational bistate transitions of the resonator driven by the weak Brownian thermal noise at 6~K. This method can be flexibly applied to a variety of mechanical systems to improve nonlinear responses, and can be used, with further improvements, to explore macroscopic quantum mechanics

Omics-based interpretation of synergism in a soil-derived cellulose-degrading microbial community

Reaching a comprehensive understanding of how nature solves the problem of degrading recalcitrant biomass may eventually allow development of more efficient biorefining processes. Here we interpret genomic and proteomic information generated from a cellulolytic microbial consortium (termed F1RT) enriched from soil. Analyses of reconstructed bacterial draft genomes from all seven uncultured phylotypes in F1RT indicate that its constituent microbes cooperate in both cellulose-degrading and other important metabolic processes. Support for cellulolytic inter-species cooperation came from the discovery of F1RT microbes that encode and express complimentary enzymatic inventories that include both extracellular cellulosomes and secreted free-enzyme systems. Metabolic reconstruction of the seven F1RT phylotypes predicted a wider genomic rationale as to how this particular community functions as well as possible reasons as to why biomass conversion in nature relies on a structured and cooperative microbial community

Expired Cefalexin Loaded into Mesoporous Nanosilica for Self-Healing Epoxy Coating on 304 Stainless Steel

A self-healing epoxy coating is creatively prepared by employing expired cefalexin loaded into mesoporous silica nanomaterials (MSNs) for corrosion protection of 304 stainless steel (304SS). A series of physical characterizations, including transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectrometer, and N2 adsorption–desorption isotherms, verified that the cefalexin successfully filled porous MSN. The corrosion resistance of the epoxy (EP) coating incorporated with the cefalexin@MSNs is investigated using a Tafel polarization curve and electrochemical impedance spectra (EIS) in a 3.5 wt.% NaCl solution. It is found that the EP-Cefalexin@MSNs coating has a higher self-corrosion voltage and a lower self-corrosion current density than EP coating. Moreover, the charge transfer resistance (Rct) value of Cefalexin@MSNs coating is twice that of EP coating after immersion for 24 h, indicating that the cefalexin@MSNs significantly enhance the corrosion resistance of the coating under long-duration immersion. The improved corrosion resistance is attributed to the densified adsorption of the cefalexin inhibiting the cathode corrosion reaction, providing a self-healing long-duration corrosion protection for 304SS

Compressional salt structures of salt-bearing sedimentary basins and its significance to hydrocarbon accumulation

The compressional salt structure is an important type of salt structure formed under the action of regional compressional stress field, which plays an important role in the generation, migration and trap accumulation of oil and gas in sedimentary basins.In the past few decades, important progress has been made in the study of compressional salt structures, which effectively guides the exploration of oil and gas reservoirs in compressional salt sedimentary basins.Based on the physical characteristics of salt rocks, deformation evolution of compressional salt structure and its influence on hydrocarbon accumulation distribution, this paper discusses the deformation evolution characteristics of compressional salt structure, and analyzes the typical salt-bearing fold-and-thrust belt at home and abroad and their hydrocarbon accumulation characteristics.And by comparing the domestic and foreign salt-bearing fold-and-thrust belt and typical oil and gas reservoirs, it summarizes that the domestic and foreign typical salt gypsum layers salt-bearing fold-and-thrust belt are involved in the tectonic deformation, made from the orogenic belt to the basin in the hinterland, tectonic deformation by the strong basement involved in thrust nappe deformation gradually transition to the thin skin decollement fold deformation, and affect the distribution of hydrocarbon accumulation in the fold thrust belts.Finally, the existing problems and future research directions of salt structure in the salt-bearing fold-and-thrust belt in China are analyzed