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61.
Phosphorus-doped carbon nanospheres without any metal residues were synthesized and characterized.The results revealed that the doping phosphorus atoms could significantly improve the electrocatalytic activity of graphitic carbon for the oxygen-reduction reaction(ORR) both in acidic and alkaline media,and the materials exhibited high electrocatalytic activity,long-term stability,and excellent tolerance to crossover effects especially in alkaline media.Quantum mechanics calculations with the density functional theory demonstrated that the changes in charge density and energetic characteristics of frontier orbitals for the P-doped graphene sheet could facilitate the ORR. 相似文献
62.
Ruijin Yu Hongjuan Li Hailong Ma Caifeng Wang Huan Wang Byung Kee Moon Jung Hyun Jeong 《Journal of luminescence》2012,132(10):2783-2787
A thiogallate chalcogenide phosphor CaLaGa3S7:Eu2+ was synthesized by a solid-state reaction at 950 °C in a H2S atmosphere. The photoluminescence excitation,emission spectra, concentration quenching, fluorescence lifetime, and thermal quenching process of the phosphor were investigated in detail. It was found that the synthesized phosphor emitted intense and broadband yellowish-green light with a peak at 554 nm. Thus, the proposed phosphor is suitable for the development of blue or near UV LED. The critical dopant concentration of Eu2+ (Rc=15 Å) per unit formula was found to be 0.15 mol. At room temperature, the fluorescence lifetime of Eu2+ in CaLaGa3S7 was found to be 0.216 μs. The activation energy for thermal quenching was 0.29 eV. The chromaticity coordinates of our phosphor is very close in color to Y3Al5O12:Ce3+. Therefore, CaLaGa3S7:Eu2+ can be a good alternative as a yellowish-green phosphor and can be used for white light generation in phosphor-converted LEDs. 相似文献
63.
土基模量随季节变化规律及其数值的确定 总被引:1,自引:0,他引:1
土基回弹模量作为路面设计的重要力学参数,在我国路面设计方法中选取最不利季节的土基回弹模量值作为土基的设计强度,没有考虑一年中含水量变化对土基强度的影响,本文通过分析土基回弹模量随季节含水量的变化规律,借鉴AASHTO设计方法中不同季节模量对路面造成的相对损伤思想,推导出等效回弹模量计算公式uf=0.95×107E-5d,提出用等效土基回弹模量值代替最不利季节模量值作为土基强度设计值,不仅能够提高土基自身的抗变形能力,还可以很有效的提高沥青路面结构的整体设计强度。 相似文献
64.
网络智能化的基本原理是在现有固定电话网中引入用户数据库(DB)新网元,国内网络智能化主要采用TDM汇接局访问DB和端局完全访问DB方式,通过软交换实现将更有优势,而未来融合的网络将引入IMS架构. 相似文献
65.
Xiaowei Sheng Hongjuan Zhu Zixuan Zhang Danyang Zhang Jingyang Lu Jianping Xiao 《International journal of quantum chemistry》2019,119(3):e25800
In the present article, the Tang–Toennies–Yiu (TTY) potential model is modified by introducing one adjustable parameter. Then, the van der Waals potentials of He2, Ne2, Ar2, Kr2, and Xe2 are calculated by this model with the adjustable parameter being determined by the well determined well depth De of these systems. Based on the derived potentials, the vibrational energy spacings of these systems are also calculated. It is shown that the present derived potentials and vibrational energy spacings agree well with experiment and other theoretical calculations. Finally, the normalization constant A in the asymptotic wave function of rare-gas atoms is estimated. The present derived normalization constant A is very close to the one by calculating the ratio between the Hartree–Fock function and the asymptotic wave function. The results confirm that absorbing the first-order polarization energy into the exchange energy expression is a well approximation for the present systems. 相似文献
66.
Song Qingyi Wu Hongjuan Liu Hao Han Xiaoxia Qu Hongqiang Xu Jianzhong 《Journal of Thermal Analysis and Calorimetry》2019,138(2):1259-1267
Journal of Thermal Analysis and Calorimetry - The synergistic flame-retardant and smoke suppression properties of ammonium polyphosphate (APP) and activated carbon-supported Fe2O3 (AC-Fe2O3) on... 相似文献
67.
68.
直接修改控制规则的自调整模糊控制器 总被引:7,自引:1,他引:6
文献[1]研究了模糊控制系统中参考集的选择与模糊量化问题,但未解决控制规则的自动设置。本文从控制规则表出发,提出一种直接修改控制规则的算法,这种算法可以解决模糊控制规则的自动修改和自动产生问题。仿真试验的结果表明该算法是简便可行的。 相似文献
69.
A cancer activated protein-inorganic nanoparticle was used as breast cancer cell turn-on fluorescence sensor and NIR activated attenuator. 相似文献
70.
Qingling Song Hongjuan Zhao Cuixia Zheng Ke Wang Hui Gao Qianhua Feng Hongling Zhang Zhenzhong Zhang Yun Zhang Lei Wang 《Advanced functional materials》2021,31(41):2104994
A fundamental challenge in probiotic therapy is effective delivery and rapid colonization of probiotics; however, the physiological structure of probiotic spores provides an interesting idea to address this problem. Herein, the spore coat is innovatively prepared into a type of versatile spore coat nanomaterial (CN) which is subsequently anchored to the surface of probiotics to form CN-coated probiotics. The CN retains the characteristics of high resistance and natural affinity of spore coats, which serve as the “armor” for the enhancement of the probiotics delivery. Moreover, CN is beneficial for the explosive proliferation and competitive colonization of probiotics. Notably, it is found that not only CN used solely has good anti-inflammatory effect, but also it can significantly improve the functions of probiotics such as microbiome regulation, gut barrier integrity and tumor prevention. This work provides a simple and universal strategy that may guide the development of nanomaterial and material-based microecological agents. 相似文献