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91.
建立了用铝基体火花源原子发射光谱仪现有通道硬件测定镁合金(MB1)中锰元素含量的方法.方法线性相关系数为0.967 6,RSD为1.66%.对8个未知样品进行了测试,结果与化学分析方法所得结果一致. 相似文献
92.
Far‐Red and Near‐IR AIE‐Active Fluorescent Organic Nanoprobes with Enhanced Tumor‐Targeting Efficacy: Shape‐Specific Effects 下载免费PDF全文
Andong Shao Prof. Dr. Yongshu Xie Shaojia Zhu Dr. Zhiqian Guo Shiqin Zhu Dr. Jin Guo Prof. Dr. Ping Shi Prof. Dr. Tony D. James Prof. Dr. He Tian Prof. Dr. Wei‐Hong Zhu 《Angewandte Chemie (International ed. in English)》2015,54(25):7275-7280
The rational design of high‐performance fluorescent materials for cancer targeting in vivo is still challenging. A unique molecular design strategy is presented that involves tailoring aggregation‐induced emission (AIE)‐active organic molecules to realize preferable far‐red and NIR fluorescence, well‐controlled morphology (from rod‐like to spherical), and also tumor‐targeted bioimaging. The shape‐tailored organic quinoline–malononitrile (QM) nanoprobes are biocompatible and highly desirable for cell‐tracking applications. Impressively, the spherical shape of QM‐5 nanoaggregates exhibits excellent tumor‐targeted bioimaging performance after intravenously injection into mice, but not the rod‐like aggregates of QM‐2. 相似文献
93.
White‐Light Emission Strategy of a Single Organic Compound with Aggregation‐Induced Emission and Delayed Fluorescence Properties 下载免费PDF全文
Dr. Zongliang Xie Dr. Chengjian Chen Shidang Xu Jun Li Prof. Yi Zhang Prof. Siwei Liu Prof. Jiarui Xu Prof. Zhenguo Chi 《Angewandte Chemie (International ed. in English)》2015,54(24):7181-7184
A novel white‐light‐emitting organic molecule, which consists of carbazolyl‐ and phenothiazinyl‐substituted benzophenone (OPC) and exhibits aggregation‐induced emission‐delayed fluorescence (AIE‐DF) and mechanofluorochromic properties was synthesized. The CIE color coordinates of OPC were directly measured with a non‐doped powder, which presented white‐emission coordinates (0.33, 0.33) at 244 K to 252 K and (0.35, 0.35) at 298 K. The asymmetric donor–acceptor–donor′ (D‐A‐D′) type of OPC exhibits an accurate inherited relationship from dicarbazolyl‐substituted benzophenone (O2C, D‐A‐D) and diphenothiazinyl‐substituted benzophenone (O2P, D′‐A‐D′). By purposefully selecting the two parent molecules, that is, O2C (blue) and O2P (yellow), the white‐light emission of OPC can be achieved in a single molecule. This finding provides a feasible molecular strategy to design new AIE‐DF white‐light‐emitting organic molecules. 相似文献
94.
Organic Crystals with Near‐Infrared Amplified Spontaneous Emissions Based on 2′‐Hydroxychalcone Derivatives: Subtle Structure Modification but Great Property Change 下载免费PDF全文
Xiao Cheng Kai Wang Shuo Huang Dr. Houyu Zhang Prof. Dr. Hongyu Zhang Prof. Dr. Yue Wang 《Angewandte Chemie (International ed. in English)》2015,54(29):8369-8373
A series of highly efficient deep red to near‐infrared (NIR) emissive organic crystals 1 – 3 based on the structurally simple 2′‐hydroxychalcone derivatives were synthesized through a simple one‐step condensation reaction. Crystal 1 displays the highest quantum yield (Φf) of 0.32 among the reported organic single crystals with an emission maximum (λem) over 710 nm. Comparison between the bright emissive crystals 1 – 3 and the nearly nonluminous compounds 4 – 7 clearly gives evidence that a subtle structure modification can arouse great property changes, which is instructive in designing new high‐efficiency organic luminescent materials. Notably, crystals 1 – 3 exhibit amplified spontaneous emissions (ASE) with extremely low thresholds. Thus, organic deep red to NIR emissive crystals with very high Φf have been obtained and are found to display the first example of NIR fluorescent crystal ASE. 相似文献
95.
Dr. Chun Zhang Zhen Wang Liangxiao Tan Tian‐Long Zhai Dr. Sheng Wang Prof. Bien Tan Prof. Yan‐Song Zheng Prof. Xiang‐Liang Yang Prof. Hui‐Bi Xu 《Angewandte Chemie (International ed. in English)》2015,54(32):9244-9248
A quadrangular prismatic tricyclooxacalixarene cage 1 based on tetraphenylethylene (TPE) was efficiently synthesized by a one‐pot SNAr condensation reaction. As a result of the porous internal structure in the solid state, cage 1 exhibited a good CO2 uptake capacity of 12.5 wt % and a high selectivity for CO2 over N2 adsorption of 80 (273 K, 1 bar) with a BET surface area of 432 m2 g?1. Formation of cage 1 led to the fluorescence of TPE being switched on in solution. The system was employed as a single‐molecule platform to study the mechanism of aggregation‐induced emission (AIE) by examining the restriction of intramolecular rotation (RIR). 相似文献
96.
A full field solution, based on small deformation, three-dimensional elastic–plastic finite element analysis of the centrally cracked thin disk under mode I loading has been performed. The solution for the stresses under small-scale yielding and lo!cally fully plastic state has been compared with the HRR plane stress solution. At the outside of the 3D zone, within a distance of rσo/J=18, HRR dominance is maintained in the presence of a significant amount of compressive stress along the crack flanks. Ahead of this region, the HRR field overestimate the stresses. These results demonstrate a completely reversed state of stress in the near crack front compared to that in the plane strain case. The combined effect of geometry and finite thickness of the specimen on elastic–plastic crack tip stress field has been explored. To the best of our knowledge, such an attempt in the published literature has not been made yet. For the qualitative assessment of the results some of the field parameters have been compared to the available experimental results of K, gives a fair estimate of the crack opening stress near the crack front at a distance of order 10−2 in. On the basis of this analysis, the Linear Elastic Fracture Mechanics approach has been adopted in analyzing the fatigue crack extension experiments performed in the disk (Part II). 相似文献
97.
研究压电材料双周期裂纹反平面剪切与平面电场作用的问题.运用复变函数方法,获得了该问题严格的闭合解,并由此给出了裂纹尖端应力强度因子和电位移强度因子的精确公式.数值算例显示了裂纹分布特征对材料断裂行为的重要影响.叠间小裂纹能够对主裂纹的应力和电位移场起着屏蔽作用,相反行间小裂纹却起着放大作用,至于钻石形分布裂纹的影响规律则更为复杂.对于某些特殊情形给予了解答并导出一系列有意义的结果。 相似文献
98.
IntroductionOfallthefiber_reinforcedcompositematerials,theshort_fibercompositematerialnotonlystrengthensthematrixbutavoidsdefectionsofthelong_fibercompositematerialaswell.Themicro_mechanicsaboutitsuchasfracture ,fatigueanddamageisverycomplex .Intheprevi… 相似文献
99.
The interaction of a screw dislocation with an interfacial edge crack in a two-phase piezoelectric medium is investigated.
Closed-form solutions of the elastic and electrical fields induced by the screw dislocation are derived using the conformal
mapping method in conjunction with the image principle. Based on the electroelastic fields derived, the stress and electric
displacement intensity factors, the image force acting on the dislocation are given explicitly. We find that the stress and
electric displacement intensity factors depend on the effective electroelastic material constants. In the case where one of
two phases is purely elastic, the stress intensity factor and image force are plotted to illustrate the influences of electromechanical
coupling effect, the position of the dislocation and the material properties on the interaction mechanism.
The project supported by the Doctoral Foundation of Hebei Province (B2003113) 相似文献
100.
Li-Chun Bian Zouheir Fawaz Kamran Behdinan 《Archive of Applied Mechanics (Ingenieur Archiv)》2007,77(11):809-821
The maximum energy release rate criterion, i.e., G
max
criterion, is commonly used for crack propagation analysis. This fracture criterion is based on the elastic macroscopic strength
of materials. In the present investigation, however, the G
max
criterion has been modified in order to accommodate the consideration of plastic strain energy. This modified criterion is
extended to study the fatigue crack growth characteristics of mixed-mode cracks. To predict crack propagation due to fatigue
loads, a new elasto–plastic energy model is presented. This new model includes the effects of material properties such as
strain hardening exponent n, yield strength σ
y
, and fracture toughness and stress intensity factor ranges. The results obtained are compared with those obtained using the
commonly employed crack growth law and the experimental data. 相似文献