聚变实验堆真空室壳体成型残余应力分析

为了了解聚变实验堆真空室壳体表面残余应力的分布以及退火工艺对残余应力的影响，通过模拟分析和实验检测两种方式对不锈钢316LN冷压曲面和热压曲面残余应力进行研究，获得退火前后曲面表面残余应力的大小，得到冷压曲面和热压曲面残余应力的分布以及退火工艺对残余应力分布的影响。研究结果为分析成型工艺提供数据支撑，对中国聚变工程实验堆真空室的研究与制造具有重要意义。     

彩虹自标定方法对混合喷雾比例的原位测量

传统彩虹测量技术标定复杂、精度可重复性差且难以适应密闭空间。一种基于多彩虹谱线自标定方法,可省去原有的标定系统装置,将标定过程内化于对彩虹信号的处理,以水为例的测量偏差仅为0.13%。将该技术应用于混合喷雾液滴组分浓度测量中,探究并优化了参与混合的两种液体组分的方案。实验采用60%乙醇-水混合喷雾,原位测量了混合喷雾场多点组分浓度,测量结果差别可以控制在0.5%以内,表明该方法技术在相关领域的应用潜力。     

Further revisions on the diterpenoid alkaloids reported in a JNP paper (2012, 75, 1145–1159)

We have corrected (Tetrahedron2013, 69, 5859–5866) the structures of diterpenoid alkaloids reported in the Journal of Natural Products2012, 75, 1145–1159. Our follow-up experiments compel us to present further revisions and clarifications on the diterpenoid alkaloids:     

Electrochemical Properties of Hollow‐Structured MnS–Carbon Nanocomposite Powders Prepared by a One‐Pot Spray Pyrolysis Process

Spherical, hollow MnS? C composite powders were prepared from a solution of manganese salt, thiourea, and sucrose by one‐pot spray pyrolysis. The MnS? C composite powders were generated by direct sulfidation of MnO with hydrogen sulfide gas generated in situ by decomposition of thiourea during spray pyrolysis. Sucrose, which is used as a carbon source material, plays a key role in the formation of the MnS? C composite powders by improving the reducing atmosphere around the powders. Dot‐mapping images of the composite powders demonstrated uniform distribution of the manganese, sulfur, and carbon components within the MnS? C composite powder. Fine crystals of MnS were uniformly mixed with carbon derived from polymerization and carbonization of sucrose. The carbon content of the MnS? C composite powders was 26 wt %. The discharge capacities of the MnS? C composite powders in the 2nd and 200th cycles were 863 and 967 mA h g^?1, respectively, at a current density of 1000 mA g^?1. The spherical and hollow morphology of the MnS? C composite powders was completely retained, even after 200 cycles. The enhanced cycling and rate performance of the MnS? C composite powders is ascribed to the structural stability of the composite powders.     

Preparation of Yolk‐Shell and Filled Co9S8 Microspheres and Comparison of their Electrochemical Properties

In this study, we report the first preparation of phase‐pure Co₉S₈ yolk–shell microspheres in a facile two‐step process and their improved electrochemical properties. Yolk–shell Co₃O₄ precursor microspheres are initially obtained by spray pyrolysis and are subsequently transformed into Co₉S₈ yolk–shell microspheres by simple sulfidation in the presence of thiourea as a sulfur source at 350 °C under a reducing atmosphere. For comparison, filled Co₉S₈ microspheres were also prepared using the same procedure but in the absence of sucrose during the spray pyrolysis. The prepared yolk–shell Co₉S₈ microspheres exhibited a Brunauer–Emmett–Teller (BET) specific surface area of 18 m² g^?1 with a mean pore size of 16 nm. The yolk–shell Co₉S₈ microspheres have initial discharge and charge capacities of 1008 and 767 mA h g^?1 at a current density of 1000 mA g^?1, respectively, while the filled Co₉S₈ microspheres have initial discharge and charge capacities of 838 and 638 mA h g^?1, respectively. After 100 cycles, the discharge capacities of the yolk–shell and filled microspheres are 634 and 434 mA h g^?1, respectively, and the corresponding capacity retentions after the first cycle are 82 % and 66 %.     

Flame Spray Pyrolysis for Finding Multicomponent Nanomaterials with Superior Electrochemical Properties in the CoOx‐FeOx System for Use in Lithium‐Ion Batteries

High‐temperature flame spray pyrolysis is employed for finding highly efficient nanomaterials for use in lithium‐ion batteries. CoO_x‐FeO_x nanopowders with various compositions are prepared by one‐pot high‐temperature flame spray pyrolysis. The Co and Fe components are uniformly distributed over the CoO_x‐FeO_x composite powders, irrespective of the Co/Fe mole ratio. The Co‐rich CoO_x‐FeO_x composite powders with Co/Fe mole ratios of 3:1 and 2:1 have mixed crystal structures with CoFe₂O₄ and Co₃O₄ phases. However, Co‐substituted magnetite composite powders prepared from spray solutions with Co and Fe components in mole ratios of 1:3, 1:2, and 1:1 have a single phase. Multicomponent CoO_x‐FeO_x powders with a Co/Fe mole ratio of 2:1 and a mixed crystal structure with Co₃O₄ and CoFe₂O₄ phases show high initial capacities and good cycling performance. The stable reversible discharge capacities of the composite powders with a Co/Fe mole ratio of 2:1 decrease from 1165 to 820 mA h g^?1 as the current density is increased from 500 to 5000 mA g^?1; however, the discharge capacity again increases to 1310 mA h g^?1 as the current density is restored to 500 mA g^?1.     

Formation of liquid cone jet dependent on rise time of driving voltage

This paper reports on transient dynamics of electrospray driven by high step voltage and its dependence on voltage rise time. Three rise times (50 ns, 1.8 μs, and 400 μs) were used to compare influence on liquid dynamics. It was found that, when the applied voltage exceeds a certain level, minute differences in voltage rise time significantly affect jet formation time. A rise time of 50 ns accelerates the jet ejection by about 20% compared with other rise times. These results indicate that optimization of rise time may enable drastic improvement of controllability of drop-on-demand electrospray.     

Desorption/ionization efficiencies of triacylglycerols and phospholipids via EASI‐MS

Knowledge of the major effects governing desorption/ionization efficiency is required for the development and application of ambient mass spectrometry. Although all triacylglycerols (TAG) have the same favorable protonation and cationization sites, their desorption/ionization efficiencies can vary dramatically during easy ambient sonic‐spray ionization because of structural differences in the carbon chain. To quantify this somewhat surprising and drastic effect, we have performed a systematic investigation of desorption/ionization efficiencies as a function of unsaturation and length for TAG as well as for diacylglycerols, monoacylglycerols and several phospholipids (PL). Affinities for Na⁺ as a function of unsaturation level have also been assayed via comprehensive metadynamics calculations to understand the influence of this phenomenon on the ionization efficiency. The results suggest that dipole–dipole interactions within a carbon chain tuned by unsaturation sites govern ionization efficiency of TAG and PL. Copyright © 2014 John Wiley & Sons, Ltd.     

Alleviation of ion suppression effect in sonic spray ionization with induced alternating current voltage

In this study, alleviation of ion suppression effect in sonic spray ionization mass spectrometry (SSI‐MS) was investigated. Ion suppression effect was firstly compared between electrospray ionization (ESI) and conventional SSI, and more severe ion suppression effect was observed with SSI. Ion suppression effect of SSI was also found difficult to be alleviated by simply optimizing major parameters. Alternatively, we found that with the assistance of an alternating current (AC) voltage with low amplitude, the ion suppression effect was greatly alleviated (comparable with conventional ESI). That AC voltage was applied outside the SSI spray tip, and no direct contact between the electrode and spray solution was necessary. Besides the alleviation of the ion suppression effect, this newly‐developed method, termed as induced electrosonic spray ionization (IESSI), appeared to preserve similar charge state distribution with SSI for protonated cytochrome c, hemoglobin, and bradykinin. IESSI could also obtain significantly improved ion intensities (~1000‐fold over conventional SSI). In addition, tolerance of concentrated salts for IESSI‐MS was investigated through the analysis of cytochrome c in the presence of concentrated sodium chloride (NaCl) or ammonium acetate (NH₄OAc). Copyright © 2014 John Wiley & Sons, Ltd.