钛酸锶基粉体功能材料的合成与应用研究进展

钛酸锶作为一种典型的钙钛矿型结构物质,具有介电损耗低、热稳定性好和光催化性能优良等特点,是一种用途广泛的功能陶瓷材料。综述了近年来以钛酸锶为基体各种功能陶瓷材料的合成方法与重要应用,并探讨了其今后的主要发展方向。     

Effect of ligand passivation on morphology,optical and photoresponse properties of CdS colloidal quantum dots thin film

In the present report, cadmium sulfide (CdS) colloidal quantum dots (CQDs) with average diameter of 6 nm were synthesized by using oleylamine as ligand and solvent. The insulating oleylamine ligands form barriers around the CdS CQDs to decrease carrier mobility. In order to remove the ligands and improve the photoelectrical properties of the closed-packed film, ethanedithiol, mercaptopropionic acid and cetyltrimethylammonium bromide (CTAB) were applied for solid state ligand exchange. CTAB treated film had the fastest 3 dB bandwidth of 144.7 Hz and yielded the highest detectivity of 1.37 × 10⁸ Jones. The excellent properties of ligand passivation have important application in nanocrystals based electronic and optoelectronic devices.     

MAX197芯片在现场总线智能从站开发中的应用

介绍一种PROFIBUS-DP智能从站的设计方案,应用MAX197实现8路A／D转换。由于MAX197占用较少的CPU资源,因此,该智能从站采用此芯片作为前端的信号采集和数据处理部分。     

钙[Ca(NO3)2和CaO]对茶树氟吸收的影响

通过水培和土壤盆栽试验,研究了Ca对茶树F吸收的影响。结果显示,在含F溶液中添加Ca显著降低茶树对F的吸收。在土壤盆栽试验中也得到了类似结果,在2种土壤F含量条件下,加入Ca(NO3)2后显著降低茶树成熟叶和新梢F含量。同样土壤加入CaO后,显著降低茶树对F的吸收。土壤分析表明加入Ca(NO3)2后并没有显著改变土壤水溶性F含量,而加入CaO后还增加了土壤水溶性F含量。因此,Ca减少F吸收可能并不单纯是因为形成CaF2后降低土壤F的有效性。     

Wire-in-Wire TiO2/C Nanofibers Free-Standing Anodes for Li-Ion and K-Ion Batteries with Long Cycling Stability and High Capacity

Wearable and portable mobile phones play a critical role in the market,and one of the key technologies is the flexible electrode with high spe-cific capacity an...     

Plant Responses to Herbivory,Wounding, and Infection

Plants have various self-defense mechanisms against biotic attacks, involving both physical and chemical barriers. Physical barriers include spines, trichomes, and cuticle layers, whereas chemical barriers include secondary metabolites (SMs) and volatile organic compounds (VOCs). Complex interactions between plants and herbivores occur. Plant responses to insect herbivory begin with the perception of physical stimuli, chemical compounds (orally secreted by insects and herbivore-induced VOCs) during feeding. Plant cell membranes then generate ion fluxes that create differences in plasma membrane potential (Vm), which provokes the initiation of signal transduction, the activation of various hormones (e.g., jasmonic acid, salicylic acid, and ethylene), and the release of VOCs and SMs. This review of recent studies of plant–herbivore–infection interactions focuses on early and late plant responses, including physical barriers, signal transduction, SM production as well as epigenetic regulation, and phytohormone responses.     

高压直流输电线路对通信明线影响的仿真研究

如何评价高压直流输电线路直流谐波对附近通信明线的影响,对确保通信线路正常、安全运行,以及直流输电工程的建设有着十分重要的意义.根据强电线路对弱电线路的耦合影响理论,高压直流输电线路对通信明线的影响分为危险影响和干扰影响两部分,本文介绍了高压直流输电线路对通信明线影响的原理及计算分类,以及目前国内主要的高压直流输电线路对通信明线影响的限值,并对不同参数变化下的静电感应电压和杂音电动势变化情况进行了仿真,得出了结论,为直流工程设计提供了一些参考.最后给出了具体模型进行了计算.