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991.
基于IPA方法的城市滨水区旅游形象感知影响因子分析——以南京沿江地区为例 总被引:1,自引:0,他引:1
滨水区是重要的城市旅游区,对其旅游形象进行有效分析,进而抓住旅游者感知的主要影响因子,能促进旅游地形象更具针对性的建设.本文运用因子分析法从26个项目中提取了影响南京沿江地区旅游形象的6个主要公因子(包括16个项目),配对样本t检验进一步表明16个项目的重要性和满意度之间存在显著差异.在此基础上,运用IPA方法划分出南京沿江旅游形象塑造的4种类型:积极提升型、控制优化型、适度发展型和重点推进型,并进一步确定了各项目在4种类型中的定位. 相似文献
992.
闫莎 《甘肃联合大学学报(自然科学版)》2010,24(1):21-24,33
本文讨论了一个三种群食物链模型解的整体性态.首先,讨论该模型解的整体存在性和一致有界性.接着,应用线性化方法和Lyapunov函数方法证明了该模型正平衡点的局部渐近稳定性和全局渐近稳定性. 相似文献
993.
LIU Yang LIU Ming ZHANG Dongkai HUA Xuewen WANG Baolei ZHOU Sha LI Zhengming 《高等学校化学研究》2016,32(6):952-958
A series of strobilurin-1,2,4-triazole derivatives containing a furan or thiophen ring was designed and synthesized. The structures of the compounds were characterized by 1H NMR, 13C NMR and HRMS spectra. The bi-oassays indicated that the fungicidal activities of compounds 10b(EC50=14.82 mg/L) and 10c(EC50=18.72 mg/L) against Cercospora arachidicola Hori in vitro were much higher than that of Azoxystrobin as control(EC50=40.54 mg/L) and the fungicidal activities of compounds 10u(EC50=8.66 mg/L) and 10n(EC50=9.89 mg/L) against Rhizotonia cerealis in vitro were higher than that of the same control(EC50=10.86 mg/L). Compounds 10b, 10c, 10n and 10k could be considered as the leading compounds for further investigation. 相似文献
994.
995.
Direct Visual Evidence for Neutral and Charged Hexaphyrin Aromaticity with and without Keto-Defect
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Shan Zhang Peng Song Sha Wang Yu-ling Chu Yuan-zuo Li Zhong Yang Yong Ding Feng-cai Ma 《化学物理学报(中文版)》2012,25(5):563-570
We use density functional theory and time-dependent together with a set of extensive mul-tidimensional visualization techniques to characterize the influence of keto effect on charge distribution at ground state and electronic transitions for neutral and charged hexaphyrin aromaticity with and without keto-defect. It is found that the aromaticity is the key fac-tor to influence the ground state Mulliken charges distribution properties, other than the meso-aryl-substituted effect. But with the enhancement of the keto-defect, the distributionchanges of Mulliken charges on the hexaphyrin groups are larger than those on the pentaflu-orophenyl substituted groups, following with the aromaticity changes from nonaromatic toaromatic. Furthermore, through characterizing by transition density and charge difference density, direct visual evidence for neutral and charged aromaticity with and without keto-defect can be clearly derived, and the ability of charge transfer between units of monoradical (nonaromaticity) and singlet biradical (aromaticity) forms is much stronger than that of neutral forms. 相似文献
996.
997.
Novel model of a AlGaN/GaN high electron mobility transistor based on an artificial neural network
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In this paper we present a novel approach to modeling AlGaN/GaN high electron mobility transistor(HEMT) with an artificial neural network(ANN).The AlGaN/GaN HEMT device structure and its fabrication process are described.The circuit-based Neuro-space mapping(neuro-SM) technique is studied in detail.The EEHEMT model is implemented according to the measurement results of the designed device,which serves as a coarse model.An ANN is proposed to model AlGaN/GaN HEMT based on the coarse model.Its optimization is performed.The simulation results from the model are compared with the measurement results.It is shown that the simulation results obtained from the ANN model of AlGaN/GaN HEMT are more accurate than those obtained from the EEHEMT model. 相似文献
998.
A new phosphorescent labeling reagent named self-ordered ring (ESOR) of eosin Y (E) was developed. And the application of
the determination of bioactive matter by affinity adsorption solid substrate–room temperature phosphorimetry (AA-SS-RTP) based
on ESOR labeling lectin was studied. Results showed that pink and homogeneous ESOR could be formed by E on polyamide membrane
(PAM) in the presence of cetyltrimethylammonium bromide (CTAB) and ammonia water. ESOR could emit strong and stable room temperature
phosphorescence (RTP) signal of E in the presence of heavy atom perturber. Specific affinity adsorption (AA) reactions could
be carried out between the products of concanavalin agglutinin (Con A), triticum vulgaris lectin (WGA) labeled with ESOR and
alpha-fetoprotein variant (AFP-V), alkaline phosphatase (ALP), glucose (G), respectively. Not only did the products of the
affinity adsorption reactions preserve good RTP characteristic of E, but also the ΔI
p (ΔI
p = I
p2 − I
p1, I
p1 is the RTP intensity of blank reagent, I
p2 is the RTP intensity of sample) of these products was proportional to the content of AFP-V, ALP and G, respectively. According
to the facts above, a new method of AA-SS-RTP for the determination of AFP-V, ALP and G was established, based on ESOR labeling
lectin. Detection limits (LD) of this method were 0.040 fg spot−1 for AFP-V, 0.045 fg spot−1 for ALP and 0.090 fg spot−1 for G. And it has been successfully applied to the determination of AFP-V in human serum as well as the survey and forecast
of human diseases. This method had high sensitivity, good repeatability, long RTP lifetime and little background interference
with at the long wavelength area. Meanwhile, the mechanism for the determination of trace AFP-V by AA-SS-RTP based on Con A labeled
with ESOR was also discussed. 相似文献
999.
针对第一代EMERGE模块化机器人控制系统和感知能力的局限性问题,本文在第一代基础上,提出了集成分布式和集中式控制方式的、具备周围环境感知能力的第二代EMERGE模块化机器人。首先分析了第一代机器人的基本性能特征,确立了模块升级改造的方向。在此基础上,通过对模块的连接机制、控制系统的分析设计,给出了具备控制方式切换功能的分布式和集中式的控制系统,实现了控制方式的灵活切换以及模块间自由通信的能力。此外,在模块的四个连接面上设计了接近距离传感器,实现对周围环境的感知能力。最后以第二代的机器人为实验对象,进行了蠕动和迷宫运动实验。实验结果表明,第二代EMERGE模块化机器人控制系统可靠、控制方式灵活、拓展了机器人执行不同任务的能力。 相似文献
1000.
地雷在战争中应用极为广泛,已经成为阻碍部队行进的主要障碍,为了保证部队在战争中保持较高的机动性,扫雷装备的研发具有重要的现实意义。以某型扫雷辊为研究对象,首先根据其三维模型建立了有限元模型,利用任意拉格朗日-欧拉(arbitrary Lagrange-Euler, ALE)算法进行了数值仿真分析,研究了扫雷辊在8 kg三硝基甲苯(tri-nitro-toluene, TNT)爆炸环境下的损伤情况,随后对扫雷辊进行了8 kg TNT的实爆测试,将仿真结果与试验结果对比分析。结果表明:在仿真与试验中,扫雷辊结构的损伤形态基本保持一致,有限元模型的准确性高,可用于扫雷辊结构的进一步研究。 相似文献