Mechanistic study of cobalt catalyzed growth of carbon nanofibers in a confined space by plasma-assisted chemical vapor deposition

Carbon nanofibers (CNFs) were grown in the porous anodic aluminum oxide (AAO) thin film grown on the Si wafer by electron cyclotron resonance chemical vapor deposition using cobalt as the catalyst. A larger Co particle electrodeposited in the AAO pore channel produced vertically aligned CNFs with a tube diameter in compliance with the pore size of the AAO template. On the other hand, a smaller Co particle resulted in CNF growth with a nonuniform distribution of the tube diameter and a sparse tube density. Amorphous carbon residue produced under the plasma-assisted CNF growth condition seemed to play an essential role leading to the observation. A growth mechanism is proposed to delineate the volume effect of the electrodeposited Co catalyst on the CNF growth confined in pore channels of the AAO template.     

自动大扭矩直角分度头传动轴的分析计算

通过对初步设计后的传动轴的静力分析、模态分析、频率响应分析,检查该轴的设计计算能否满足使用要求,从而改进可能存在的缺陷,最后通过实际试验检测得到最终结论。该设计分析验证方法为经济有效的较好方法。值得推广使用。     

Synthesis of functionalized copolymer electrolytes based on polysiloxane and analysis of their conductivity

Functionalized siloxane-based solid polymer electrolytes were synthesized using a platinum-catalyzed silylation reaction. The ionic conductivities of these solid polymer electrolytes were measured as a function of the concentration of lithium bis(trifluoromethylsulfonyl)imide (LiTFSi) salt. The highest ionic conductivity and lowest activation energy of solid polymer electrolytes were observed to be 1.15 × 10⁻⁴ S cm⁻¹ (25 °C) and 3.85 kJ mol⁻¹, respectively. The interface property between electrolyte and electrode and thermal stability of the polymer electrolytes were found to enhance after they were functionalized with acrylate, and the functionalized electrolytes were observed to maintain a glass transition temperature as low as that of other siloxane compounds. Thus, modifications involving acrylate with ethylene oxide group substitution provide a route for carrier ions and enhance both the ionic conductivity and mechanical properties of the siloxane structure.     

The effects of temperature and solders on the wettability between ribbon and solar cell

Wettability between ribbons of two lead SnAgPb (SAP) and SnPb (SP) solders, and a lead-free SnAgCu (SAC) solder on two Ag paste substrates at temperature ranging from 190 to 280 °C was investigated by the sessile-drop method. The Contact angle (CA) method at high and room temperature was applied to measure the wettability of solder and Ag substrate. For the CA measurement obtained at high temperature, it is generally seen that CA values decreased with increasing soldering temperatures. On the other hand, the CA values of SAP solder were lower than those of SP and SAC solders at 220–240 °C. It is suggested that SAP has a good wettability characteristic, compared to SP and SAC solders, when soldering at 220–240 °C. For the CA measurement obtained at room temperature, the results showed that two lead solders had higher CA values as compared to that of a lead-free SAC solder. Furthermore, the CA values of lead solders were known to increase with increasing soldering temperatures, while SAC solder oppositely decreased with the raising soldering temperatures. In addition, CA values of SAP were detected to be higher at higher temperature than those at RT, suggesting that SAP has dewetting characteristics during the soldering process.     

QoE-aware Q-learning based approach to dynamic TDD uplink-downlink reconfiguration in indoor small cell networks

Wireless Networks - The continuing rise of the amount of mobile traffic is daunting, but the deploying of indoor small cells provides exciting opportunities to boost network capacity, extend cell...     

Structure-activity relationship studies of 3-aroylindoles as potent antimitotic agents

The concise synthesis and structure-activity relationship (SAR) studies of 3-aroylindoles were carried out in an effort to improve the potency and solubility of anticancer drug candidate BPR0L075 (8) by exploring structure modifications through three regimens: substitution of the B ring, at the N1 position, and of the 3-carbonyl linker. The SAR information revealed that the methoxy group of the B ring could be replaced with an electron-donating group such as methyl (in compound 9) or N,N-dimethylamino (in compound 13) while retaining both strong cytotoxic and antitubulin activities. The introduction of amide (compounds 30-33) and carbamate (compounds 34-37) functionalities at the N1 position of 8 gave analogues with potent antiproliferative activities. The cytotoxic potency of 8 was improved by replacing the carbonyl group with sulfide (compound 41) or oxygen (compound 43), indicating that the carbonyl moiety is important but not essential. The N,N-dimethylamino derivative 13 not only displayed potent cytotoxicity and antitubulin activity, but also showed a markedly improved physicochemical profile relative to the parent compound.     

Anti-influenza Drug Discovery: Identification of an Orally Bioavailable Quinoline Derivative through Activity- and Property-Guided Lead Optimization

From a high-throughput screening (HTS) hit with inhibitory activity against virus-induced cytophathic in the low micromolar range, we have developed a potent anti-influenza lead through careful optimization without compromising the drug-like properties of the compound. An orally bioavailable compound was identified as a lead agent with nanomolar activity against influenza, representing a 140-fold improvement over the initial hit.     

ZrO2-Ti系材料的热力学分析与显微结构研究

通过热力学数据的预报与计算,对ＺｒＯ_２－Ｔｉ体系的相间热力学稳定性进行了分析,并确定了材料合成的热力学条件．在此基础上常压烧结合成了不同组分配比的ＺｒＯ_２－Ｔｉ系复合材料,并采用ＸＲＤ、ＳＥＭ、ＴＥＭ等方法对材料的显微结构进行了表征．ＺｒＯ_２－Ｔｉ系均质复合材料由α－Ｔｉ相,四方ＺｒＯ_２相和少量的单斜ＺｒＯ_２相组成．ＸＲＤ和ＴＥＭ分析表明,组元Ｔｉ和ＺｒＯ_２之间没有发生明显的化学反应,具有良好的化学相容性．     

ZrO2-Ti系材料的热力学分析与显微结构研究

通过热力学数据的预报与计算,对ＺｒＯ２－Ｔｉ体系的相间热力学稳定性进行了分析,并确定了材料民折和学条件。在此基础上常压烧结合不同组分配比的ＺｒＯ２－Ｔｉ系复合材料,并采用ＸＲＤ,ＳＥＭ,ＴＥＭ等方法对材料的显微结构进行了表征,ＺｒＯ２－Ｔｉ系均质复合材料由α－Ｔｉ相,四方ＺｒＯ２相和少量的单斜ＺｒＯ２相组成,ＸＲＤ和ＴＥＭ分析表明,组元Ｔｉ、ＺｒＯ２之间没有发生明显的化学反应,上有良好的化学相窝性     

A novel and efficient water-based composite binder for LiCoO2 cathodes in lithium-ion batteries

The dispersion, adhesion strength, electrical, and electrochemical properties of LiCoO₂ cathodes in lithium-ion batteries with the addition of a new composite binder composed of two acrylic emulsions, poly(butyl acrylate)-based (PBA) and polyacrylonitrile-based (PA) latex in a ratio of 3:7, were evaluated. PBA binder has a low-glass transition temperature of 10 °C, which can improve the flexibility of the electrode. This new composite binder has a very good binding ability as same as the typical organic solvent-based binder, poly(vinylidene fluoride). The dispersions of the water-based cathode slurries with the composite binder were measured by analyzing the viscosity and sedimentation behaviors. The results show that the new composite binder can well disperse the LiCoO₂. Moreover, using the new composite binder could greatly improve the rate capabilities and the cycle stability of water-based LiCoO₂ cathodes.