scholarly journals Doped Lead Halide White Phosphors for Very High Efficiency and Ultra‐High Color Rendering

2020 ◽  
Vol 132 (7) ◽  
pp. 2824-2829 ◽  
Author(s):  
Hailong Yuan ◽  
Florian Massuyeau ◽  
Nicolas Gautier ◽  
Antoine Blaise Kama ◽  
Eric Faulques ◽  
...  
2020 ◽  
Vol 59 (7) ◽  
pp. 2802-2807 ◽  
Author(s):  
Hailong Yuan ◽  
Florian Massuyeau ◽  
Nicolas Gautier ◽  
Antoine Blaise Kama ◽  
Eric Faulques ◽  
...  

2018 ◽  
Vol 8 (10) ◽  
pp. 3208 ◽  
Author(s):  
Nengquan Li ◽  
Yu Zhang ◽  
Yiwu Quan ◽  
Le Li ◽  
Shanghui Ye ◽  
...  

2011 ◽  
Vol 21 (46) ◽  
pp. 18523 ◽  
Author(s):  
Jwo-Huei Jou ◽  
Yi-Chieh Chou ◽  
Shih-Ming Shen ◽  
Ming-Hsuan Wu ◽  
Po-Shian Wu ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingfeng Yang ◽  
Hanze Ying ◽  
Zhixia Li ◽  
Jiang Wang ◽  
Yingying Chen ◽  
...  

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.


1991 ◽  
Author(s):  
A. Weber ◽  
W. Steinert ◽  
H. Starken

Efforts to reduce the specific fuel consumption of a modern aero engine focus in particular on increasing the by-pass ratio beyond the current level of around 5. One concept is the counterrotating shrouded propfan operating at low overall pressure ratio and having only very few fan blades of extremely high pitch/chord ratios. The relative inlet Mach numbers cover a range from 0.7 at the hub to 1.1 at the tip section of the first rotor. A propfan cascade was designed by taking into account two characteristic features of a propfan blade-blade section: • a very high pitch/chord ratio of s/c = 2.25 • an inlet Mach number of M1 = 0.90 which leads to transonic flow conditions inside the blade passage In the design process a profile generator and a quasi-3D Euler solver were used iteratively to optimize the profile Mach number distribution. Boundary layer behavior was checked with an integral boundary layer code. The cascade design was verified experimentally in the transonic cascade wind tunnel of DLR at Cologne. The extensive experimental results confirm the design goal of roughly 5 degree flow turning. A total pressure loss coefficient of less than 1.5% was measured at design conditions. This validates the very high efficiency level the propfan concept is calling for. A 2D Navier-Stokes flow analysis code yields good results in comparison to the experimental ones.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3223
Author(s):  
Gabriel Ekemb ◽  
Fouad Slaoui-Hasnaoui ◽  
Joseph Song-Manguelle ◽  
P. M. Lingom ◽  
Issouf Fofana

This paper proposes time-domain analytical expressions of the instantaneous pulsating torque components in a synchronous machine air gap when supplied by a load-commutated-inverter (LCI) system. The LCI technology is one of the most used variable frequency drives when very high power and low speed are required in applications such as pipeline recompression and decompression, as well as liquefied natural gas compression. In such applications, synchronous motors are used because of their high efficiency resulting from a separated supply of the current to their rotor through the excitation circuit. These applications usually have long and flexible shafts, which are very sensitive to torsional vibration excitation when their natural frequencies interact with any external torque applied to the shaft. A torsional analysis is required by international standards to assess the survivability of the shaft through the overall speed range of the motor. Therefore, the magnitude and frequencies of the motor air-gap torque are needed for such evaluation. The proposed developments are supported by numerical simulations of LCI systems in a large range of operation range. From the simulation results, torque harmonic families are derived and expressed in a parametric form, which confirm the accuracy of the proposed relationships.


2021 ◽  
Author(s):  
Qiangwen Fan ◽  
Longwei Zhu ◽  
Xuhuai Li ◽  
Huijun Ren ◽  
Haibo Zhu ◽  
...  

Using readily accessible and high-efficiency photocatalyst for inducing chemical transformations is highly desirable. All inorganic lead halide perovskites (APbX3, X=Cl, Br, I) utilized intensively in photovoltaics on the benefit of...


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