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 …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

The chemistry of graphene oxide is discussed in this critical review Particular emphasis is directed toward the synthesis of graphene oxide, as well as its structure Graphene oxide as a substrate for a variety of chemical transformations, including its reduction to graphene-like materials, is also discussed This review will be of value to synthetic chemists interested in this emerging field of materials science, as well as those investigating applications of graphene who would find a more thorough treatment of the chemistry of graphene oxide useful in understanding the scope and limitations of current approaches which utilize this material (91 references)

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The chemistry of graphene oxide

Problems associated with large-scale pattern growth of graphene constitute one of the main obstacles to using this material in device applications. Recently, macroscopic-scale graphene films were prepared by two-dimensional assembly of graphene sheets chemically derived from graphite crystals and graphene oxides. However, the sheet resistance of these films was found to be much larger than theoretically expected values. Here we report the direct synthesis of large-scale graphene films using chemical vapour deposition on thin nickel layers, and present two different methods of patterning the films and transferring them to arbitrary substrates. The transferred graphene films show very low sheet resistance of approximately 280 Omega per square, with approximately 80 per cent optical transparency. At low temperatures, the monolayers transferred to silicon dioxide substrates show electron mobility greater than 3,700 cm(2) V(-1) s(-1) and exhibit the half-integer quantum Hall effect, implying that the quality of graphene grown by chemical vapour deposition is as high as mechanically cleaved graphene. Employing the outstanding mechanical properties of graphene, we also demonstrate the macroscopic use of these highly conducting and transparent electrodes in flexible, stretchable, foldable electronics.

Large-scale pattern growth of graphene films for stretchable transparent electrodes

The invention belongs to the technical field of electrochemical detection, and particularly relates to a porous electrode working performance integral tester and test method and application thereof. The tester comprises an electrolyte-containing electrochemical reaction pool, a porous electrode, a counter electrode, an electrochemical working station and a gas providing device. The invention creatively designs the porous electrode working performance integral tester and the test method thereof. Various performance of the porous electrode in electrocatalytic reaction can be rapidly and comprehensively evaluated in one time, the complexity of testing each performance of the porous electrode one by one is solved, a detection state of each performance shows a working condition of the porous electrode in actual application, a detection result has more practicability, and the tester has better guidance significance to actual production.

Porous electrode working performance integral tester and test method and application thereof


 Lithium–sulfur (Li–S) batteries are considered as promising candidates for future-generation energy storage systems due to their prominent theoretical energy density. However, their application is still hindered by several critical issues, e.g., low conductivity of sulfur species, the shuttling effects of soluble lithium polysulfides, volumetric expansion, sluggish redox kinetics, and uncontrollable Li dendritic formation. Considerable research efforts have been devoted to breaking through the obstacles that are preventing Li–S batteries from realizing practical application. Recently, benefiting from the no additives/binders, buffer of volume change, high sulfur loading and suppress lithium dendrites, the nanoarray structures have emerged as efficient and durable electrodes in Li–S batteries. Herein, recent advances in design, synthesis and application of nanoarray structures in Li–S batteries have been reviewed. First, the multifunctional merits and typical synthetic strategies of employing nanoarray structure electrodes for Li–S batteries are outlined. Second, the applications of nanoarray structures in Li–S batteries are discussed comprehensively. Finally, the challenge and rational design of nanoarray structure for Li–S batteries are analyzed in depth, with the aim of providing promising orientations for commercialization of high-energy-density Li–S batteries.

Rational Design of Nanoarray Structures for Lithium–Sulfur Batteries: Recent Advances and Future Prospects

Phosphorus induced activity-enhancement of Fe-N-C catalysts for high temperature polymer electrolyte membrane fuel cells

The invention relates to a method for preparing precious metal/organic functional small molecule core-shell structure nano particles. The method comprises the following steps that: the cationic radical solution of organic molecules is prepared through a silver perchlorate (AgClO4) and iodine (I2) oxidation method or a ferric chloride (FeCl3) oxidation method; after precious metal nano particles are prepared, the cationic radical solution of the organic molecules is dripped to precious metal nano-particle suspension; and organic molecular cations have displacement reaction with the precious metal nano particles, and the precious metal/organic functional small molecule core-shell structure nano particles are obtained. The method is simple and easy, the shell thicknesses of the nano particles can be regulated only by controlling the amount of the added cationic radical solution of the organic molecules, different shell thicknesses reflect different optical properties, so that good materials and methods are provided for the development of optics in biological application.

Xiaoming Sun

Papers

Porous electrode working performance integral tester and test method and application thereof

Rational Design of Nanoarray Structures for Lithium–Sulfur Batteries: Recent Advances and Future Prospects

Phosphorus induced activity-enhancement of Fe-N-C catalysts for high temperature polymer electrolyte membrane fuel cells

Method for preparing precious metal/organic functional small molecule core-shell structure nano particles

From Surfactant—Inorganic Mesostructures to Tungsten Nanowires.