Zhong Chen

Bio: Zhong Chen is an academic researcher from Nanyang Technological University. The author has contributed to research in topics: Medicine & Chemistry. The author has an hindex of 80, co-authored 1000 publications receiving 28171 citations. Previous affiliations of Zhong Chen include Institute of High Performance Computing Singapore & National Institute of Education.

Recent advances in fabricating durable superhydrophobic surfaces: a review in the aspects of structures and materials

Abstract: Extensive attention has been concentrated toward the development of superhydrophobic coatings with unique structures and properties due to their extended applications in our daily life. However, the poor durability and short service life have greatly restricted the practical applications of superhydrophobic materials. The surface rough structure and material chemistry are important factors affecting the durability of superhydrophobic coatings. Only through fully understanding the roles played by the structure and material can we combine their advantages to prepare extremely durable coatings. In this review, we discuss ways to prolong the life-time of superhydrophobic surfaces (SHSs) in two aspects, namely the surface structures and materials. The strategy of rational design of hierarchical structures with or without special shapes, and addition of supportive structural shelters can effectively enhance the resistance to damage. The use of functional materials, such as self-healing materials, fully functionalized monolithic materials, elastic materials, and strong adhesive materials is another intelligent strategy to maintain superhydrophobicity against severe mechano-chemical attacks. This review provides a systematic account of the strategies together with deep fundamental insights for the development of durable superhydrophobic surfaces towards practical applications.

Scratch resistance of brittle thin films on compliant substrates

Abstract: There has been intensive interest in studying the behavior of hard and brittle thin films on compliant substrates under scratch action. The examples include sol–gel protective coatings on plastic optical lenses, safe windows, and flexible electronic devices and displays. Hard ceramic coatings have been widely used to prolong the life of cutting tools and biomedical implants. In this work, the scratch resistance of sol–gel coatings with different amount of colloidal silica on polycarbonate substrates was tested by the pencil scratch test following the ISO 15184 standard. The scratch failure was found to be tensile trailing cracking in the coating and substrate gouging. The indentation hardness, elasticity modulus and fracture toughness of the coatings were determined and correlated to the observed pencil scratch hardness. Based on the analysis, the main factors to improve the scratch resistance are the elasticity modulus, thickness and fracture toughness of the coatings. General consideration for the improvement of scratch resistance of hard coatings on compliant substrates was also discussed.

Surfactant–Thermal Method to Synthesize a Novel Two-Dimensional Oxochalcogenide

Abstract: A new two-dimensional (2D) oxosulfide, (N2H4)2Mn3Sb4S8(μ3-OH)2 (1), has been successfully synthesized under surfactant-thermal conditions with hexadecyltributylphosphonium bromide as the surfactant. Compound 1 has a layered structure and contains a novel [Mn3(μ3-OH)2]n chain along the b-axis. The photocatalytic activity for compound 1 has been demonstrated under visible-light irradiation and continuous H2 evolution was observed. Our results indicate that surfactant-thermal synthesis could be a promising method for growing novel crystalline oxochalcogenides with interesting structures and properties.

Impact response of aluminum foam core sandwich structures

Abstract: Sandwich panels, comprised of metallic foam core and face sheets, are widely used to withstand impact and blast loadings. Based on the actual application requirements, the performance can be optimized with the proper combination of face sheets design. In this paper the impact responses of aluminum foams with various tailored face sheets, whose behavior represents elastic, elastic-ideally plastic and elastic–plastic strain work hardening, were investigated experimentally. The experiment was carried out using hemispherical indenters on blocks of aluminum foam with and without the face sheet. Competing failure modes for the initiation of failure are discussed based on comparison of energy absorption capacity. Results show that increase in thickness of foam and the use of face sheet enhances the impact energy absorption capacity. The type of face sheet not only affects the energy absorption capacity but also the failure mode for the foam blocks. Aluminum foam blocks with stainless steel sheet are strong enough to withstand the pre-designated impact loading without penetration damage. At the same time, this study also provides a comparison of the impact performance, in terms of impact energy and failure mode, among blocks with different face sheets under the low velocity impact.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Principles of Neural Science

Abstract: I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or

Graphitic Carbon Nitride (g-C3N4)-Based Photocatalysts for Artificial Photosynthesis and Environmental Remediation: Are We a Step Closer To Achieving Sustainability?

Abstract: As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and “earth-abundant” nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The constructi...