Electrochemical characteristics of silicon-metals coated graphites for anode materials of lithium secondary batteries

Four kinds of silicon-metals (Cu, Ni, Sn)-graphite composites for anode active materials of lithium secondary batteries were prepared by sequential employment of PECVD (Plasma enhance chemical vapor deposition) and RF(Radio-frequency)-magnetron sputtering method. The silicon-copper-graphite composite showed the highest reversible capacity and cyclability among the silicon-metal composite graphite samples prepared. The enhanced electrochemical performance of silicon-copper-graphite composite is attributed to the formation of copper silicide on the surface of graphite. The copper silicide plays an important role as a buffering layer against volume change of silicon during the intercalation/deintercalation due to the chemical bonding of silicon and copper, and has lower interfacial impedance than that of other silicon-metal-graphite composites which may lead to low irreversible capacity.     

汞控制技术中的吸收剂喷射工艺

向烟气中喷入像粉末状活性炭之类的吸收剂，是一种最简单和最成熟的控制燃煤锅炉汞排放的方法。在4个不同的燃烟煤和次烟煤的,tY开展的第一次吸收剂喷射实验计划，证明了活性炭喷射（ACI）在控制汞排放方面的有效性。由于具有以下优点，ACI技术尤其适合现有燃煤锅炉的汞排放控制：（1）投资成本低（〈5美元／kW）；（2）改造容易且耗时短，几乎无需机组停运；（5）不论烟煤还是次烟煤均适用；（4）当使用布袋除尘器时在较低的吸收剂喷射速率下就可达到90%以上的汞去除效率。     

Domain characteristics and chemical bonds of lithium niobate

Domain characteristics such as domain shape, domain switching, and etching rate at Z-surfaces of lithium niobate (LN) single crystals are comprehensively studied from the chemical bonding viewpoint. The present work shows that the domain characteristics are closely correlated to anisotropic bonding behaviors of constituent ions, which may be regarded as a microscopic reflection of detailed conditions of the chemical bonding geometry and strength of Li⁺ and Nb⁵⁺ cations in the LN crystallographic frame.     

燃煤炉预混-喷钙二段脱硫技术研究

文章指出煤燃烧高温脱硫3方面难点：（1）石灰石分解速率低于煤燃烧时硫析出速率；（2）脱硫产物在CaSO41200℃以上再分解；（3）CaO颗粒高温严重烧结，对此，提出二段脱硫工艺，即一部分添加剂与煤预混进行料层脱硫，另一部分喷入炉内捕捉烟气中硫，建立了10t/h链条炉二段脱硫示范装置，试验和运行结果表明锅炉除尘器前脱硫率达到70％以上，除尘器后，烟气经半干法处理可达到80－90％。     

锂离子电池中电解液与石墨类负极活性材料的相容性

选择了一种具有良好贮锂结构的人造石墨试样作为锂离子电池负极活性材料，考察了它在六种不同电解液中的恒电流充、放电性能和循环伏安特性，采用傅立叶变换红外光谱分析了不同电解液在试样颗粒表面发生还原反应时所形成的固体电解质中间相膜的成份和含量。据此得出的结论是：电解液与石墨类负极活性材料能否相容的问题，实质上就是所选定的电解液能否与其颗粒表面发生缓和的还原反应、生成薄而致密的只允许锂离子通过的固体电解质中间相膜。     

Mineralogy of clean coal combustion by-products

Coal combustion technologies are changing in order to burn coal more cleanly. Many “clean combustion“ and postcombustion technologies are developed to remove SO2 and NOx gases, particulate matter during combustion, or from the flue gases leaving the furnace. This paper focuses on three types of fly ash (flue gas desulfurization (FGD) residuals, atmospheric fluidized bed combustion (AFBC) residuals and sorbent duct injection (SDI) residuals) which produced by “the clean combustion“ and postcombustion technologies. The residuals formed by FGD are PCFA (pulverized coal fly ash) grains entrained with reacted and unreacted sorbent and have lower bulk densities than PCFA grains because it contains higher concentrations of calcium and sulfur, and lower concentrations of silicon, aluminum and iron than PCFAs. AFBC residuals consist of spent bed which is a heterogeneous mixture of coarse-grained bed material and irregularly shaped, unfused, spherical PCFAs. The main crystalline phases in AFBC residuals are anhydrite (reacted sorbent), quartz and lime (unreacted sobent), calcite, hematite, periclase, magnetite and feldspars.The residuals produced by SDI contained 65%-70% PCFA with the larger sizes material being irregularly shaped, fused or roughedged. The reaction products of sorbent (portlandite and lime) included calcium sulfate (anhydrite) and calcium sulfate. The chemical properties of these residuals are similar to those of high calcium PCFAs because of the high alkalinity and high pH of these residuals.     

夏季利用城市热电厂废热作为地铁车站空调冷源的设想

能源短缺和环境问题已经成为当今举世瞩目的焦点，地下城市轨道交通空调系统耗费了大量的电能。大量回收热电厂生产工艺过程中产生的大量废（余）热，推动了溴化锂制冷机组，对节能减排具有十分重要的意义。     

石家庄站房冷热源形式选用

以石家庄站房冷热源选择为例,对北方大型站房冷热源进行分析。分析从方案选取的可实施性、技术性、经济性入手进行分析研究,以选择合理的冷热源方案。     

Simple solution-combustion synthesis of Fe2TiO5 nanomaterials with enhanced lithium storage properties

The porous Fe₂TiO₅ particles are successfully synthesized through a facile one step solution combustion method. The Fe₂TiO₅ negative materials exhibit remarkable electrochemical performance with discharge capacities of 371.4?mAh g^?1 at the 100 th cycle, and display promising rate stability with discharge capacities 76.6?mAh·g^?1 at a high current density of 3.2?A?g^?1. In addition, the mechanism of electrochemistry reaction is illustrated by the CV, raman and EIS measurements, the irreversible capacity mainly causes from the irreversible lithium insertion at 1.8?V. The results indicate that the one step solution combustion synthesis of porous Fe₂TiO₅ is a promising strategy for developing low-cost and high-performance Ti-based negative materials.     

Nanoconfined mixed Li and Mg borohydrides as materials for solid state hydrogen storage

Several mixtures of LiBH₄ and Mg(BH₄)₂ borohydrides in different stoichiometric ratios (1:0, 2:1, 1:1, 1:2, 0:1), prepared by high energy ball milling, have been investigated with X-ray powder diffraction and thermal programmed desorption (TPD) volumetric analysis to test the dehydrogenation kinetics in correlation with the physical mixture composition. Afterwards mixed and unmixed borohydrides were dispersed on high specific surface area ball milled graphite by means of the solvent infiltration technique. BET and statistical thickness methods were used to characterize the support surface properties, and SEM micrographs gave a better understanding of the preparation techniques. It has been observed by TPD volumetric measurements that the confinement of the reactive borohydrides on the nanoporous supports leads to a lower dehydrogenation temperature compared to unsupported borohydrides. Moreover, a further decrease of the dehydrogenation temperature has been observed by increasing the specific surface area of the support and the pores volume and by using the prepared mixtures instead of pure materials. The dehydrogenation process seems to be favoured by the heterogeneous nucleation on the graphite surface of decomposition products or intermediate phases from melted liquid borohydrides.