Nonlinear vibration response of a complex aeroengine under the rubbing fault

Nonlinear Dynamics - Rolling bearing and squeeze film damper will introduce structural nonlinearity into the dynamic model of aeroengine. Rubbing will occur due to the clearance reduction design of...     

彩色照片制作技术

彩色照片由于色彩鲜艳．形象逼真，在工农业生产、科研和日常生活中得到广泛应用。本文就校正偏色与曝光谈一下自己的看法。     

锂离子电池纳米材料研究

报道了作者最近在锂离子电池纳米材料方面的研究工作 .包括纳米负极材料 (如Sb ,SnSb ,CuSn及Si) ,纳米正极材料 (如CuS)合成 ,电化学性质 ,以及纳米材料的晶体结构与形貌在充放电过程中的变化等研究 .此外还报道了具有纳米尺度阴离子的锂盐在聚合物电解质中的增塑作用以及纳米硅Raman光谱和光致发光谱受电化学锂掺杂的影响 .最后对纳米材料的本征性质与其电化学性质的关系进行了讨论 ,并对其在锂离子电池中的应用及在基础研究方面的意义给予了评述 .     

非水体系中配位吸附树脂对羟基羧酸吸附性能的研究

采用负载金属离子的配位吸附树脂在不同介质中对羟基羧酸的吸附规律进行研究.考察了吸附介质、树脂基质及所负载的金属离子不同对配位吸附的影响.结果表明,负载Fe3 的大孔磺酸型树脂在正己烷体系中对羟基羧酸类成分的吸附效果最佳,且随着羟基取代数目和位置的不同表现出一定的吸附选择性.     

Sulphur-doped ordered mesoporous carbon with enhanced electrocatalytic activity for the oxygen reduction reaction

Metal-free,heteroatom functionalized carbon-based catalysts have made remarkable progress in recent years in a wide range of applications related to energy storage and energy generation.In this study,high surface area mesoporous ordered sulphur doped carbon materials are obtained via one-pot hydrothermal synthesis of carbon/SBA-15 composite after removal of in-situ synthesized hard template Si O₂.2-thiophenecarboxy acid as sulphur source gives rise to sulphur doping level of 5.5 wt%.Comparing with pristine carbon,the sulphur doped mesoporous ordered carbon demonstrates improved electro-catalytic activity in the oxygen reduction reaction in alkaline solution.     

钛酸锂基锂离子电池的析气特性

目前商用锂离子电池主要使用碳负极材料.零应变的钛酸锂被认为是比碳更安全、寿命更长的负极材料,在混合电动汽车和风/光/电并网、智能电网等领域有独特的应用前景.但是,采用钛酸锂负极的锂离子电池在充放电及储存过程中极易发生气胀,从而导致外壳变形、电池向外析气、电池性能急剧下降等问题,这是制约钛酸锂实际应用的最大障碍.本文首先介绍了钛酸锂基锂离子电池的产业发展状况,其采用的正极材料分别为Li(Ni_xCo_yMn_1-x-y)O₂、LiMn₂O₄、LiFePO₄与LiCoO₂等四种.针对其气胀问题,从钛酸锂电极材料的界面特性、水分、电解液还原分解、负极电位、杂质等方面综述了相关的最新研究进展.同时结合本课题组的研究工作,从材料、工艺、使用等角度指出了气胀的改进措施,最后,提出钛酸锂基锂离子电池气胀方面亟待解决的问题及今后的研究重点.     

Safe,Low‐Cost,Fast‐Kinetics and Low‐Strain Inorganic‐Open‐Framework Anode for Potassium‐Ion Batteries

A key challenge for potassium‐ion batteries is to explore low‐cost electrode materials that allow fast and reversible insertion of large‐ionic‐size K⁺. Here, we report an inorganic‐open‐framework anode (KTiOPO₄), which achieves a reversible capacity of up to 102 mAh g^?1 (307 mAh cm^?3), flat voltage plateaus at a safe average potential of 0.82 V (vs. K/K⁺), a long lifespan of over 200 cycles, and K⁺‐transport kinetics ≈10 times faster than those of Na‐superionic conductors. Combined experimental analysis and first‐principles calculations reveal a charge storage mechanism involving biphasic and solid solution reactions and a cell volume change (9.5 %) even smaller than that for Li⁺‐insertion into graphite (≈10 %). KTiOPO₄ exhibits quasi‐3D lattice expansion on K⁺ intercalation, enabling the disintegration of small lattice strain and thus high structural stability. The inorganic open‐frameworks may open a new avenue for exploring low‐cost, stable and fast‐kinetic battery chemistry.     

Safe,Low‐Cost,Fast‐Kinetics and Low‐Strain Inorganic‐Open‐Framework Anode for Potassium‐Ion Batteries

A key challenge for potassium‐ion batteries is to explore low‐cost electrode materials that allow fast and reversible insertion of large‐ionic‐size K⁺. Here, we report an inorganic‐open‐framework anode (KTiOPO₄), which achieves a reversible capacity of up to 102 mAh g^?1 (307 mAh cm^?3), flat voltage plateaus at a safe average potential of 0.82 V (vs. K/K⁺), a long lifespan of over 200 cycles, and K⁺‐transport kinetics ≈10 times faster than those of Na‐superionic conductors. Combined experimental analysis and first‐principles calculations reveal a charge storage mechanism involving biphasic and solid solution reactions and a cell volume change (9.5 %) even smaller than that for Li⁺‐insertion into graphite (≈10 %). KTiOPO₄ exhibits quasi‐3D lattice expansion on K⁺ intercalation, enabling the disintegration of small lattice strain and thus high structural stability. The inorganic open‐frameworks may open a new avenue for exploring low‐cost, stable and fast‐kinetic battery chemistry.     

A fluorescent probe of N'-formyl-rhodamine B hydrazide: structure and spectral properties of protonation behaviour

The title compound is an "off-on" rhodamine probe. It exhibits strong pH dependence and responds to protons. The optimized geometries and energies calculation of the protonation were determined at the B3LYP level using DFT. The theoretical results are in good agreement with the single crystal analysis and the spectral results.