Charging lithium ion battery cathode materials such as LiCoO to a higher voltage may simultaneously enhance the specific capacity and average operating voltage and thus improve the energy density. However, battery cycle life is compromised in high voltage cycling due to lattice instability and undesired oxidation of electrolyte. Cathode solid-electrolyte interphase (SEI), or cathode-electrolyte interphase (CEI), in situ formed at the cathode-electrolyte interface under high voltage, is critically important in understanding the cathode degradation process and crucial in improving high voltage cycle stability. Here we present in situ atomic force microscopy (AFM) investigation of CEI on LiCoO at high voltage. The formation of CEI is only observed at the LiCoO edge plane, not at the basal plane. The thin layer of AlO coating completely suppresses the formation of CEI at the edge planes, and is shown to significantly improve coin cell high voltage cycle stability.

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A comprehensive three-dimensional (3D) numerical model is developed for simulation of entrained coal slurry gasifiers. In this model, a presumed probability density function (PDF) method is used to consider turbulent effects on gas-phase reactions in the gasifier. A realizable k-ε model is adopted to predict turbulence information. Coal slurry particles are tracked with the Lagrangian method. The coal slurry gasification process is divided into several simple subprocesses, which are droplet evaporation, boiling, devolatilization, and heterogeneous reactions of coal char particles. The particle-source-in-cell method is adopted to couple gas-particle interactions. With this methodology, simulations for GE and staged coal slurry gasifiers are completed. A comparison between the predictions and measured data shows that the proposed model correctly predicts the global performance of the coal gasification process. The mixing process in the staged gasifier is better than that in the GE gasifier because of the existence of secondary flow. The particle size has a negative effect on coal conversion. The effects of the coal slurry concentration and molar ratio of oxygen/carbon on the gasifier performance are also studied in this paper.

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The question of the objectivity of the clinical examination has been raised in relation to Western and non-Western medical systems. Western practitioners are often skeptical about Traditional Chinese Medicine (TCM), on the basis that its diagnostic variables and subcategories of disease appear subjective and not repeatable. We conducted a study investigating the reproducibility of individual diagnostic observations within three of the four diagnostic methods used in a TCM examination: inspection, palpation, and auscultation. Three TCM practitioners participated in the study, and examined 45 adults who had mild-to-moderate hypercholesterolemia but were otherwise healthy. Results indicated that while there are certain features of the TCM system that are highly objective and repeatable, such as detection of the presence of shen, character of breath sounds, and pulse speed, there are other features that are subjective and unreliable, such as color under the eyes and tongue body color. This poses a challenge for TCM practitioners to improve their clinical practice and demonstrates to Western medical practitioners that TCM does in part rest on a rigorous and objective empirical basis.

Borrowing the idea from rubber cross linking chemistry, we report the use of a vulcanization accelerator in carbon sulfurization. The resulting Li–S battery exhibits a remarkable increase in discharge capacity while maintaining its outstanding cycling stability and low self-discharge.

Studies on circulating fluidized bed (CFB) boilers have being conducted at the Tsinghua University (TH) for about two decades and much of works are done to link the fundamentals with practical application. A full set of design theory was developed and some key elements of this theory are presented in this paper. First, a classification of state of the solid-gas two-phase flow in CFB boiler is given. TH’s studies validated that a CFB boiler can be generally described as the superposition of a fast bed in the upper part with a bubbling bed or turbulent bed in the bottom part. A concept model of material balance for the open system of CFB boiler was developed and later improved as a more comprehensive 1-D model taking ash formation, particle attrition and segregation in bed into account. Some results of the models are discussed. Then the concept of State Specification of a CFB boiler is defined and discussed. The State Specification is regarded as the first step to design a CFB and a base to classify different style of CFB boiler technologies for various CFB boiler manufacturers. The State Specification adopted by major CFB boiler makers is summarized and associated importance issues are addressed. The heat transfer model originally developed by Leckner and his coworkers is adopted and improved. It is further calibrated with experimental data obtained on the commercial CFB boiler measurements. The principle, improvements and application of the model are introduced. Some special tools developed for heat transfer field test are also given. Also, combustion behaviors of char and volatile content are studied, and the combustion difference between a CFB boiler and a bubbling bed is analyzed. The influence of volatile content and size distribution is discussed. The concept of vertical distribution of combustion and heat in CFB boiler furnace is introduced and discussed as well. In the last, the suggested design theory of CFB boiler is summarized.

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