检索结果-南通市图书馆

First-Principles Investigation on Triazine Based Thermally Activated Delayed Fluorescence Emitters

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2016年第3期29卷 291-296,I0001页

作者：范建忠邱帅蔺丽丽王传奎山东师范大学物理与电子科学学院济南250014

Three kinds of triazine based organic molecules designed for thermally activated delayed fluorescence （TADF） emitters are investigated by first-principles calculations. An optimal Hartree-Fork （HF） method is adopted for the calculation of energy gap between the first singlet state （S1） and the first triplet state （T1）. The natural transition orbital, the electron- hole （e-h） distribution and the e-h overlap diagram indicate that the S1 states for the three systems include both charge-transfer and some localized excitation component. Further quantitative analysis of the excitation property is performed by introducing the index Ar and the integral of e-h overlap S. It is found that symmetric geometry is a necessary condition for TADF emitters, which can provide more delocalized transition orbitals and consequently a small S1-T1 energy gap. Artful inserting aromatic groups between donors and acceptors can significantly enhance the oscillator strength. Finally, the energy state structures calculated with the optimal HF method is presented, which can provide basis for the study of the dynamics of excited states.

关键词： First-principles Thermally activated delayed fluorescence Charge-transferstates

Wafer-bonding AlGaInP light emitting diodes with pyramidally patterned metal reflector

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Semiconductors 2015年第2期36卷 106-110页

作者：左致远夏伟王钢徐现刚 School of Physics and Engineering Sun Yat-Sen University INSPUR GROUP shandong Inspur Huaguang Optoelectronics Co. Ltd State Key Laboratory of Crystal Material Shandong University

We demonstrate and introduce here a pyramidally patterned metal reflector into wafer-bonding AlGaInP light emitting diodes （LEDs） to improve the light extraction efficiency by using a photo-assisted chemical etched GaP：Mg layer. The pyramid patterns were fabricated employing a HF and H202 mixed solution in combination with a 532 nm laser on a GaP：Mg surface firstly, and then a gold reflector layer was evaporated onto the patterned GaP：Mg surface. After the whole chip process, the patterned gold reflector structure was confirmed to be efficient for light extraction and a 18.55% enhancement of the electroluminescent flux has been obtained by an integrating sphere, compared to the surface textured LEDs with flat reflectors.

关键词： pyramidally patterned reflector light emitting diodes wafer-bonding light extraction efficiency

Rapid Hydrothermal Synthesis of Submillimeter Ultralong Flexible Hydroxyapatite Fiber Using Different pH Regulators

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2016年第7期29卷 609-613页

作者： Mei-li Qi Gui-yong Xiao Yu-peng Lu Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong University School of Materials Science and Engineering Shandong University

Hydroxyapatite fiber （HAF） was fabricated via a one-step hydrothermal route by using urea （CA）, acetamide （AA） and propanamide （PA） as pH regulators, respectively, and the reaction time was only 0.5 h. The HAF synthesized by CA as the pH regulator was agglomerated with irregular morphology, while using AA or PA as the pH regulator, the HAF was composed of well-dispersed fibers with lengths larger than 200 pm. Two different morphologies form mainly due to the different hydrolysis rates of the pH regulators. Most of the fibers synthesized by the three pH regulators showed curving appearance, implying their outstanding flexibility. The technique in this paper allows the rapid formation of flexible HAF and may have wider applications in the restorations and reinforcement composites.

关键词： Hydroxyapatite Fiber Hydrothermal PH regulators

Modelling Wave Transmission and Overtopping Based on Energy Balance Equation

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2018年第5期17卷 1033-1043页

作者： JI Qiaoling DONG Sheng College of Transportation Shandong University of Science and Technology College of Engineering Ocean University of China

Wave transmission and overtopping around nearshore breakwaters can have significant influence on the transmitted wave parameters,which affects wave conditions and sediment transportation and becomes the focus of design in *** objective of this paper is to present a simplified model to estimate these important wave *** paper describes the incorporation of wave transmission and overtopping module into a wave model for multi-directional random wave transformation based on energy balance equation with the consideration of wave shoaling,refraction,diffraction,reflection and ***'s frequency spectrum and non-linear dispersion relation are also included in this *** influence of wave parameters of transmitted waves through a smooth submerged breakwater has been considered in this model with an improved description of the transmitted wave spectrum of van der Meer et al.(2000) by Carevic et al.(2013).This improved wave model has been validated through available laboratory *** the verified model is applied to investigate the effect of wave transmission and overtopping on wave heights behind low-crested breakwaters in a project for nearshore *** calculations are carried out with and without consideration of the wave transmission and overtopping,and comparison of them indicates that there is a considerable difference in wave height and thus it is important to include wave transmission and overtopping in modelling nearshore wave field with the presence of low-crested ***,this model can provide a general estimate of the desired wave field parameters,which is adequate for engineers at the preliminary design stage of low-crested breakwaters.

关键词： random wave transformation energy balance equation numerical modelling Wen's spectrum diffraction transmission overtopping

Synthesis, Post-modification and Catalytic Properties of Metal-organic Framework NH2-MIL-53（Al）

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2017年第2期33卷 231-238页

作者： LIU Lili TAI Xishi ZHOU Xiaojing LIU Lijuan School of Chemistry & Chemical Engineering and Environmental Engineering Weifang University Weifang 261061 P. R. China

A postsynthetic modification method was used to prepare salicylaldehyde functionalized metal-organicframeworks through the nucleophilic addition of salicylaldehyde with the amine group present in the frameworks ofNH2-MIL-53（A1）. Hydroxyl groups were successfully grafted onto NI-I2-MIL-53（A1）, and imine groups were ***, these hydroxyl and imine groups of the resulting NH2-MIL-53（A1）-SA can be used as the anchoringgroup to stabilise Au^3＋ ions and Au^0 nanoparticles（NPs）. By doing this, Au^3＋ ions and Au^0 NPs were successfully en-capsulated in the cages of NH2-MIL-53（A1） by a simple impregnation method. The resulting gold functionalizedNH2-MIL-53（AI） showed good catalytic activities in the one-pot synthesis of structurally divergent propargylaminesby three-component coupling reactions of aldehydes, amines and alkynes. Various aromatic/aliphatic aldehydes, aro-matic alkynes, and piperidine were able to undergo three-component coupling on NH2-MIL-53（A1）-Au. In addition,the catalyst NH2-M/L-53（A/）-Au was recovered easily by centrifugation and reused up to four times. Thus, it can beused for the environmentally friendly synthesis ofpropargylamines.

关键词： Metal-organic framework Postmodification NH2-MIL-53(AI) Three-component coupling Propargyl-amine

Particle size distributions, PM2.5 concentrations and water- soluble inorganic ions in different public indoor environments： a case study in Jinan, China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2013年第1期7卷 55-65页

作者： Can DONG Lingxiao YANG Chao YAN Qi YUAN Yangchun YU Wenxing WANG Environment Research Institute Shandong University Jinan 250100 China School of Environmental Science and Engineering Shandong University Jinan 250100 China Chinese Research Academy of Environmental Sciences Beijing 100012 China

In this study, we collected particles with aerodynamic diameter≤2.5 μm (PM ) from three different public indoor places (a supermarket, a commercial office, and a university dining hall) in Jinan, a medium-sized city located in northern China. Water-soluble inorganic ions of PM and particle size distributions were also measured. Both indoor and outdoor PM levels (102.3–143.8 μg·m and 160.2–301.3 μg·m , respectively) were substantially higher than the value recommended by the World Health Organization (25 μg·m ), and outdoor sources were found to be the major contributors to indoor pollutants. Diurnal particle number size distributions were different, while the maximum volume concentrations all appeared to be approximately 300 nm in the three indoor locations. Concentrations of indoor and outdoor PM were shown to exhibit the same variation trends for the supermarket and dining hall. For the office, PM concentrations during nighttime were observed to decrease sharply. Among others, , and were found to be the dominant water-soluble ions of both indoor and outdoor particles. Concentrations of in the supermarket and office during the daytime were observed to decrease sharply, which might be attributed to the fact that the indoor temperature was much higher than the outdoor temperature. In addition, domestic activities such as cleaning, water usage, cooking, and smoking also played roles in degraded indoor air quality. However, the results obtained here might be negatively impacted by the small number of samples and short sampling durations.

关键词： indoor air quality indoor/outdoor ratios size distributions particles with aerodynamic diameter≤2.5 μm (PM2.5) water-soluble ions

A study on the catalytic performance of carbide slag in transesterification and the calculation of kinetic parameters

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第2期58卷 258-265页

作者： LIU Meng Qi NIU Sheng Li LU Chun Mei LI Hui HUO Meng Jia School of Energy and Power Engineering Shandong University

The catalytic performance of carbide slag in transesterification is investigated and the reaction kinetic parameters are calculated. After being activated at 650℃, calcium compounds of carbonate and hydroxide in the carbide slag are mainly transformed into calcium oxide. The activated carbide slag utilized as the transesterification catalyst is characterized by X-ray diffraction （XRD）, attenuated total reflectance-Fourier transform infrared spectroscopy （ATR-FTIR）, nitrogen adsorption-desorption and the Hammett indicator method. Compared with the carbide slag activated at 700 and 800℃, the largest surface area of 22.63 m2g^-1, the smallest particle size of 265.12 nm and the highest catalytic efficiency of the carbide slag activated at 650℃ guarantee its capacity in catalyzing transesterification. Then, the influences of activated temperature （Ta）, molar ratio of methanol to oil （γ）, catalyst added amount （ζ）, reaction temperature （Tr） and reaction time （τ） on the catalytic performance are investi- gated. Under the optimal transesterification condition of Ta=650℃, γ=15, ζ=3%, Tr=60℃ and τ=-110 rain, the catalytic efficiency of 92.98% can be achieved. Finally, the kinetic parameters of transesterification catalyzed by the activated carbide slag are calculated, where activation energy （E） is 68.45 kJ mol^-1 and pre-exponential factor （k0） is 1.75×10^9 min^-1. The activated carbide slag shows better reused property than calcium hydroxide.

关键词： transesterification catalyst carbide slag kinetic parameters

Precambrian Captured Zircon Ages in the Daheigou Formation, Xing’an Block

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2019年第3期93卷 758-759页

作者： SONG Wanbing CUI Fanghua YANG Hongzhi ZHANG Li WU Xinwei SHI Jianmin ZHANG Chao Shenyang Institute of Geology and Mineral Resources China Geological Survey Shenyang 110034 Liaoning China Resources and Environmental Engineering of shandong University of Technology Zibo 255049 Shandong China

The Xing'an Block (XB) is located between the ErgunaBlock (EB) and the Songnen Block (SB), whichtopographically occupies the northeastern half of the GreatXing'an Range (Liu et al., 2017). The XB wastraditionally considered to be composed of a Precambrianmetamorphic basement and post-Cambrian cover.However, the recent geochronological studies show thatthe so-called "Precambrian metamorphic rocks^^ are muchyounger in age and considered to be formed in the EarlyPaleozoic, indicating no existence of the Precambrianmetamorphic basement.

关键词： Xing'an Block Precambrian Captured Zircon Ages

Experimental detection of quantum entanglement

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2013年第4期8卷 357-374页

作者： Ming Li Ming-Jing Zhao Shao-Ming Fei Zhi-Xi Wang College of the Science China University of Petroleum Qingdao 266580 China School of Mathematical Sciences Capital Normal University Beijing 100048 China Max-Planck-Institute for Mathematics in the Sciences Leipzig 04103 Germany

In this review, we introduce some methods for detecting or measuring entanglement. Several non- linear entanglement witnesses are presented. We derive a series of Bell inequalities whose maximally violations for any multipartite qubit states can be calculated by using our formulas. Both the non- linear entanglement witnesses and the Bell inequalities can be operated experimentally. Thus they supply an effective way for detecting entanglement. We also introduce some experimental methods to measure the entanglement of formation, and the lower bound of the convex-roof extension of negativity.

关键词： quantum entanglement Bell-type inequality entanglement detection