NiCoFe/C cathode electrocatalysts for direct ethanol fuel cells

A direct ethanol fuel cell (DEFC), which is less prone to ethanol crossover, is reported. The cell consists of PtRu/C catalyst as the anode, Nafion^® 117 membrane, and Ni–Co–Fe (NCF) composite catalyst as the cathode. The NCF catalyst was synthesized by mixing Ni, Co, and Fe complexes into a polymer matrix (melamine-formaldehyde resins), followed by heating the mixture at 800 °C under inert atmosphere. TEM and EDX experiments suggest that the NCF catalyst has alloy structures of Ni, Co and Fe. The catalytic activity of the NCF catalyst for the oxygen reduction reaction (ORR) was compared with that of commercially available Pt/C (CAP) catalyst at different ethanol concentrations. The decrease in open circuit voltage (V_oc) of the DEFC equipped with the NCF catalysts was less than that of CAP catalyst at higher ethanol concentrations. The NCF catalyst was less prone to ethanol oxidation at cathode even when ethanol crossover occurred through the Nafion^®117 film, which prevents voltage drop at the cathode. However, the CAP catalyst did oxidize ethanol at the cathode and caused a decrease in voltage at higher ethanol concentrations.     

Direct synthesis and catalytic performance of ultralarge pore GaSBA-15 mesoporous molecular sieves with high gallium content

Mesoporous GaSBA-15 molecular sieves with different n_Si/n_Ga ratios have been directly synthesized using Pluronic 123 triblock polymer as a structure-directing agent by pH-adjusting method. The mesoporous materials have been characterized using ICP-AES, XRD, N₂ adsorption, ⁷¹Ga-MAS NMR, SEM and TEM. ICP-AES studies show a high amount of gallium incorporation on the silica pore walls. The structural and textural properties of calcined GaSBA-15 are characterized by XRD and N₂ adsorption. ⁷¹Ga MAS NMR results demonstrate that a high amount of tetrahedral-gallium could be substituted for Si in the framework of SBA-15. TEM and FE-SEM images show the uniform pore diameter and rope-like hexagonal mesoporous structure of GaSBA-15. These GaSBA-15 materials have been used as catalysts for vapour-phase t-butylation of 1,2-dihydroxybenzene (DHB) for selective synthesis of 4-t-butylcatechol (4-TBC) under different reaction conditions. GaSBA-15(10) gave the highest 93.2% conversion of DHB and 95.7% selectivity of 4-TBC as compared with other GaSBA-15 catalysts.     

直接斜率波前复原算法的控制效果分析

建立自适应光学系统功率谱抑制函数的概念，分析了采用直接斜率波前复原算法的自适应当光学系统的控制效果，理论分析与６１单元自适应光学系统上的实验结果表明，直接斜率波前复原算法将导致控制效果下降。     

Microstructural Modelling of Nb Microalloyed Steels during Thin Slab Direct Rolling Processing

The microstructural evolution during the hot rolling of coarse grain sized austenite has been modeled considering all the microstructural mechanisms (dynamic, static and metadynamic recrystallization, strain induced precipitation) that can take place during an industrial TSDR production of three Nb microalloyed steels. Based on the results obtained from the model, processing maps have been drawn for 0.02%, 0.035% and 0.05% Nb microalloyed steels. Optimum processing conditions to exploit all the benefits of the Nb microalloying have been defined considering a final gauge thickness range between 1.5 and 12.65 mm. In addition, and facing the difficulties present in the production of thick hot strip, several alternative thermomechanical schedules are proposed, which would originate microstructures with a suitable combination of homogeneity and retained strain prior to transformation.     

Electron transport in direct methanol fuel cells

A three-dimensional (3D), two-phase, isothermal model of direct methanol fuel cells (DMFCs) was employed to investigate effects of electron transport through the backing layer and the land in bipolar plates. It was found that the electronic resistance of the backing layer, affected by backing layer electronic conductivity, backing layer thickness and flow channel width, played a relatively important role in determining the current density distribution and cell performance. In order to ignore the electron transport effect on the average current density, the minimum electronic conductivity of the backing layer has to be 1000 S m⁻¹, with the relative error in the average current density less than 5%, under the given conditions.     

Ray-cast volume rendering accelerated by incremental trilinear interpolation and cell templates

Two related ideas for improving the speed of ray-cast volume rendering are studied in this paper. The first is an incremental algorithm for trilinear interpolation, a method commonly used in ray-cast volume rendering to calculate sample values. The incremental algorithm can expedite trilinear interpolation when many samples along a ray are located in one cell. The second is an efficient hybrid volume rendering restricted to parallel projection. In the preprocessing stage, acell template is created to store the information used by the incremental trilinear interpolation. When a cell is parallel projected, the information is retrieved from the template to compute the cell contribution. Because the algorithm with only one template may cause aliasing, an antialiasing technique exploiting multiple cell templates is proposed. With our method, ray-cast volume rendering can be accelerated considerably.     

利用Visual C＋＋和Direct3D设计雷达显示器

利用Visual C＋＋和Direct3D对某雷达显示器的实现过程作了详细论述,包括数据采集、PPI型显示器、A型显示器、B型显示器、余晖显示、航迹显示等。通过试验证明,采用Direct3D绘图方式比采用GDI绘图方式效果好,更适用于数据处理量大、天线扫描速度快的雷达显示器。     

Blind estimation of the PN sequence in lower SNR DS-SS signals with residual carrier

This paper presents a method of singular value decomposition (SVD) plus digital phase lock loop (DPLL) to solve the difficult problem of blind pseudo-noise (PN) sequence estimation in low signal to noise ratios (SNR) direct sequence spread spectrum (DS-SS, DS) signals with residual carrier. Of course, the method needs to know the parameters of DS signal, such as the period and code rate of PN sequence. Firstly, the received signal is sampled and divided into non-overlapping signal vectors according to a temporal window, whose duration is two periods of PN sequence. Then, an autocorrelation matrix is computed and accumulated by the signal vectors one by one. The PN sequence with residual carrier can be estimated by the principal eigenvector of this autocorrelation matrix. Furthermore, a DPLL is used to deal with the estimated PN sequence with residual carrier, it estimates and tracks the residual carrier, removes the residual carrier in the end. Theory analysis and computer simulation results show that this method can effectively realize the PN sequence estimation from the input DS signals with residual carrier in lower SNR.     

90年代的非高炉炼铁（待续）

论述了导致非高炉炼铁技术发展的原因，简介了９０年代蓬勃兴起的，各种有发展前途的直接还原技术和熔融还原技术，本部分主要介绍Ａｒｅｘ，Ｉｒｏｎ Ｃａｒｂｉｄｅ，Ｆａｓｔｍｅｔ等直接还原技术及其优缺点。     

CCUS in a net-zero U.S. power sector: Policy design,rates, and project finance

Carbon capture utilization and storage is an important technology option to rapidly and profoundly decarbonize the power sector, but will not deploy without substantial incentives or regulation. Assessment of U.S. policy options reveals that current incentives only partially close the finance gap and are most sensitive to fuel type and ownership structure. Recent proposed legislation would in some designs attract private investment for many projects, leading to widespread deployment of CCUS in the power sector. Additional constraints and concerns (including technology options and presence of CO₂ infrastructure) could play an important secondary role. This study discusses the specific US incentive policies that can provide investors and lenders with net cash flows that are adequate to attract private capital to CCUS power projects in the US.