烧结温度对煤系高岭土制备堇青石陶瓷的影响

我国的煤系高岭土具有明显的资源优势,应对其进行充分地研究和合理地应用,以缓和优质高岭土资源枯竭的燃眉之急.以鄂尔多斯煤系高岭土、鄂尔多斯滑石、工业氧化铝为原料,通过反应烧结一步合成堇青石,探讨了堇青石合成温度范围,以拓宽该煤系高岭土的应用范围.通过高温显微镜观察堇青石试样的合成温度范围为1400～1420℃.经1420℃合成的堇青石试样的吸水率为16.11;,显气孔率为28.44;,体积密度为1.77 g/cm3,径向烧成收缩为1.77;,厚度烧成收缩为4.80;,抗折强度为43.56 MPa.镁铝尖晶石是合成堇青石的重要中间产物,适当提高烧结温度可以促进镁铝尖晶石相向堇青石相转变,有利于堇青石晶粒的生长与发育.烧结温度的变化是堇青石晶粒发生变化的原因,同时导致液相量的变化,最终影响堇青石试样显微结构和烧结性能.     

Organocatalytic asymmetric chlorinative dearomatization of naphthols

An organocatalytic asymmetric chlorinative dearomatization of naphthols was realized for the first time, providing chiral naphthalenones with a Cl-containing all-substituted stereocenter in excellent yields and enantioselectivity (up to 97% yield and 96% ee). The reaction features mild reaction conditions, good tolerance of diverse functional groups and simple reaction operation.     

A post curing strategy toward the feasible covalent adaptable networks in polyacrylate latex films

The implementation of covalent adaptable networks (CANs) in general resin system is becoming attractive. In this work, we propose a simple post-curing strategy based on the core-shell structured acrylate latex for the achievement on both the improved general performance and the CANs characteristics in latex films. The building to the CANs was relied on the introduction of 4,4′-diaminophenyl disulfide as the curing agent, which cured the acetoacetoxy decorated shell polymer through the ketoamine reaction. The metathesis reaction of aromatic disulfides in the crosslinking segments enabled the thermally induced dynamic behavior of the network as revealed in the stress relaxation tests by comparison with other diamine crosslinking agents without the incorporation of disulfide. The synergism of the dynamic crosslinking of the shell polymer and static crosslinking in the core polymer contributed to the improved mechanical strength (15 MPa, strain% = 250%) and the suppressed water adsorption (~1% in 24 h of soaking) of the latex film, which exhibited above 90% of recovery in both strength and strain from a cut-off film damage within 1 h at 80°C. Moreover, the cured latex film could be recycled, and 75% of the mechanical performance was regained after three fragmentation-hot-pressing cycles. These, in addition with the feasible and environmental friendly characteristics, suggest a sustainable paradigm toward the smart thermosetting latex polymers.     

Atomic-scale simulations for lithium dendrite growth driven by strain gradient

Dendrite formation is a major obstacle, e.g., capacity loss and short circuit, to the next-generation high-energy-density lithium (Li)-metal batteries. The development of successful Li dendrite mitigation strategies is impeded by an insufficient understanding in Li dendrite growth mechanisms. The Li-plating-induced internal stress in Li-metal and its effects on dendrite growth have been widely studied, but the underlying microcosmic mechanism is elusive. In the present study, the role of the plating-induced stress in dendrite formation is analyzed through first-principles calculations and ab initio molecular dynamic (AIMD) simulations. It is shown that the deposited Li forms a stable atomic nanofilm structure on the copper (Cu) substrate, and the adsorption energy of Li atoms increases from the Li-Cu interface to the deposited Li surface, leading to more aggregated Li atoms at the interface. Compared with the pristine Li-metal, the deposited Li in the early stage becomes compacted and suffers the in-plane compressive stress. Interestingly, there is a giant strain gradient distribution from the Li-Cu interface to the deposited Li surface, making the deposited atoms adjacent to the Cu surface tend to press upwards with perturbation and causing the dendrite growth. This provides an insight into the atomicscale origin of Li dendrite growth, and may be useful for suppressing the Li dendrite in Li-metal-based rechargeable batteries.     

GZO/Al复合背电极对非晶硅太阳能电池的影响

随着能源紧缺与环境污染问题的日益严重,太阳能的开发利用越来越受到重视,其中非晶硅薄膜太阳能电池由于其制备工艺简单、价格低廉等优点被广泛地研究.为了使非晶硅薄膜太阳能电池得到更好地利用,提高其转换效率和稳定性显得尤为重要.引入复合背电极是提高非晶硅太阳能电池性能的有效手段,其中对GZO/Al复合背电极的研究还未见报道.在该工作中,利用磁控溅射法在非晶硅电池上制备了GZO/Al复合背电极,研究了复合背电极的制备条件及其对非晶硅太阳能电池性能的影响.结果显示,当GZO层的溅射功率为90 W、Al层的溅射功率为90 W时,具有复合背电极的太阳能电池表现出较好的光电转换性能,其短路电流(ISC)、开路电压(VOC)、填充因子(FF)和电池的光电转换效率(η)分别为8.92 mA、1.55 V、54.48;和7.53;.相较于单层Al背电极的太阳能电池,其光电转换效率大幅提高了47.6;(相对效率).     

用标准件对梯度磁场定标

就标准厚度卡片在霍尔传感器的定标方面的应用作了有益的探讨。在纵向测量微小长度时,霍尔片处于磁场边缘位置,其对磁场的梯度更大,即灵敏度更高,且靠中心位置的线性更好。     

NO分子宏观气体热力学性质的理论研究

采用量子统计系综理论,研究了基态NO分子宏观气体摩尔熵、摩尔内能、摩尔热容等热力学性质.首先应用课题组前期建立的变分代数法(variational algebraic method, VAM)计算获得了基态NO分子的完全振动能级,得到的VAM振动能级作为振动部分,结合欧拉-麦克劳林渐进展开公式的转动贡献,应用于经典的热力学与统计物理公式中,从而计算得到了1000-5000 K温度范围内NO宏观气体的摩尔内能、摩尔熵和摩尔热容.将不同方法计算得到的摩尔热容结果分别与实验值进行比较,结果表明基于VAM完全振动能级获得的结果优于其他方法获得的理论结果.振动部分采用谐振子模型对无限能级求和计算热力学性质的方法有一定的局限性,应当使用有限的完全振动能级进行统计求和.     

盐酸伊达比星杂质A的合成工艺优化及其高效液相分析

通过对盐酸伊达比星脱羟基杂质A的合成研究，为盐酸伊达比星的质控标准提供参考。以盐酸伊达比星为起始原料，经过4步反应得到脱羟基杂质A。本文提供了盐酸伊达比星杂质A的制备方法以及高效液相色谱分析方法，为杂质含量控制提供了依据。该工艺可以稳定、快速制备高纯度脱羟基杂质A，制备总收率为57.20%，纯度为57.20%，其结构经¹H NMR， ¹³C NMR和MS(ESI)表征。     

Comprehensive Profiling by Non-targeted Stable Isotope Tracing Capillary Electrophoresis-Mass Spectrometry: A New Tool Complementing Metabolomic Analyses of Polar Metabolites

Mass spectrometry (MS) driven metabolomics is a frequently used tool in various areas of life sciences; however, the analysis of polar metabolites is less commonly included. In general, metabolomic analyses lead to the detection of the total amount of all covered metabolites. This is currently a major limitation with respect to metabolites showing high turnover rates, but no changes in their concentration. Such metabolites and pathways could be crucial metabolic nodes (e.g., potential drug targets in cancer metabolism). A stable-isotope tracing capillary electrophoresis–mass spectrometry (CE-MS) metabolomic approach was developed to cover both polar metabolites and isotopologues in a non-targeted way. An in-house developed software enables high throughput processing of complex multidimensional data. The practicability is demonstrated analyzing [U-¹³C]-glucose exposed prostate cancer and non-cancer cells. This CE-MS-driven analytical strategy complements polar metabolite profiles through isotopologue labeling patterns, thereby improving not only the metabolomic coverage, but also the understanding of metabolism.