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.

Heat Dissipation Simulation Research of LED Downlight and Optimization of Light Source Layout

Abstract: Conference Name:2nd International Conference on Opto-Electronics Engineering and Materials Research, OEMR 2013. Conference Address: Zhengzhou, Henan, China. Time:October 19, 2013 - October 20, 2013.

Erratum: ``Spatially resolved study of quantum efficiency droop in InGaN light-emitting diodes,'' [Appl. Phys. Lett. 101, 252103 (2012)]

Abstract: Yue Lin, Yong Zhang, Zhiqiang Liu, Liqin Su, Jihong Zhang, Tongbo Wei, and Zhong Chen Citation: Applied Physics Letters 103, 119902 (2013); doi: 10.1063/1.4821196 View online: http://dx.doi.org/10.1063/1.4821196 View Table of Contents: http://scitation.aip.org/content/aip/journal/apl/103/11?ver=pdfcov Published by the AIP Publishing Articles you may be interested in Interplay of point defects, extended defects, and carrier localization in the efficiency droop of InGaN quantumwells light-emitting diodes investigated using spatially resolved electroluminescence and photoluminescence J. Appl. Phys. 115, 023103 (2014); 10.1063/1.4861150 Spatially resolved study of quantum efficiency droop in InGaN light-emitting diodes Appl. Phys. Lett. 101, 252103 (2012); 10.1063/1.4772549 Rate equation analysis of efficiency droop in InGaN light-emitting diodes Appl. Phys. Lett. 95, 081114 (2009); 10.1063/1.3216578 Reduction of efficiency droop in InGaN light emitting diodes by coupled quantum wells Appl. Phys. Lett. 93, 171113 (2008); 10.1063/1.3012388 Erratum: “Evidence of localization effects in InGaN single-quantum-well ultraviolet light-emitting diodes” [Appl.Phys. Lett. 76, 1671 (2000)] Appl. Phys. Lett. 78, 679 (2001); 10.1063/1.1343504

Pityrogramma calomelanos (L.) Link: Silver fern as a copper excluder plant

Abstract: Silver ferns, Pityrogramma calomelanos, were observed to be growing on soil highly polluted with copper (Cu), which indicated a possible Cu phytoremediation potential. In this study, the Cu accumulation pattern of P. calomelanos was determined by exposing the ferns to different Cu levels (0 to 2500 mg L) in the soil for about 3 weeks. The Cu content of the fronds analysed at 5-days interval showed that P. calomelanos exposed to Cu levels of up to 1000 mg L were able to maintain normal levels of Cu within their fronds throughout the experiment. At high level of 2500 mg L Cu soil content, P. calomelanos exhibited an initial toxicity phase with significantly higher Cu content in their green fronds, but recovery was observed within 10 days and Cu content recovered back to normal level. The bioconcentration factor (BCF) was in the range of 0.005–0.11, where the maximum copper concentration up to 2500 mg kg. The frond’s nitrogen content had showed no significant differences between control and treated plants at the end of the experiment. Hence, the P. calomelanos has been identified as a good Cu excluder species which can potentially be used for phytostabilisation of Cu-polluted soils.

Highly Efficient Determination of Complex NMR Multiplet Structures in Inhomogeneous Magnetic Fields.

Abstract: Proton-proton scalar (J) coupling plays an important role in disentangling molecular structures and spatial conformations. But it is challenging to extract J coupling networks from congested 1H NMR spectra, especially in inhomogeneous magnetic fields. Herein, we propose a general liquid NMR protocol, named HR-G-SERF, to implement highly efficient determination of individual J couplings and corresponding coupling networks via simultaneously suppressing effects of spectral congestions and magnetic field inhomogeneity. This method records full-resolved 2D absorption-mode spectra to deliver great convenience for multipet analyses on complex samples. More meaningfully, it is capable of disentangling multiplet structures of biological samples, that is, grape sarcocarp, despite of its heterogeneous semisolid state and extensive compositions. In addition, a modification, named AH-G-SERF, is developed to compress experimental acquisition and subsequently improve unit-time SNR, while maintaining satisfactory spectral performance. This accelerated variant may further boost the applicability for rapid NMR detections and afford the possibility of adopting hyperpolarized substances to enhance the overall sensitivity. Therefore, this study provides a promising tool for molecular structure elucidations and composition analyses in chemistry, biochemistry, and metabonomics among others.

Review on test vehicles for electromigration (EM) study in solder interconnects

Abstract: The reliability of electronic devices faces the challenges of potential open and short failures due to electromigration (EM) in integrated circuit This issue is becoming more severe at the background of further miniaturization in solder joint size and higher current carried by solder joint Various test vehicles have been put forward for EM study This work summarized the EM test vehicles according to the fabrication complexity and development history, and sorted into four categories: flip chip (FC) interconnect, wire-type interconnect, thin-film interconnect and liquid-phase interconnect The advantages and disadvantages of these typical test vehicles are carefully compared Due to the mature process, the test vehicles with FC interconnect can be fabricated with solder joints in uniform size However, the unique geometric asymmetry induces serious current crowding in the entrance and exit of the joint The test vehicles with wire-type interconnect are often limited in miniaturizing the dimensions due to the mechanical process in fabricating wires The thin-film interconnect can adjust the dimensions by controlling the electroplating time, wherever the time to prepare the test vehicle can be much longer A multi-lines thin-film test vehicle has been proposed to study the effect of EM on the microstructure evolution as well as the lifetime prediction The liquid phase interconnect with synchrotron radiation facility provides real-time and in-situ observation of EM effect

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...