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排序方式: 共有560条查询结果,搜索用时 171 毫秒
71.
Khalid El Sheikh Mohammad Jakir Hossain Khan Mahar Diana Hamid Siddhartha Shrestha Brahim Si Ali G.A. Ryabov Lya A. Dolgushin Mohd Azlan Hussain Tatiana V. Bukharkina Elena A. Gorelova 《中国化学工程学报》2019,27(2):426-443
Fossil fuel combustion is one of the major means to meet the mounting global energy demand. However, the increasing NOx and N2O emissions arising from fossil fuel combustion process have hazardous effects. Thus, mitigating these gases is vital to attain a sustainable environment. Interestingly, oxy-fuel combustion in fluidized bed for carbon capture and minimized NOx emissions is strongly sustainable compare to the other approaches. It was assessed that NOx formation and fuel-N conversion have significant limitation under oxy-fluidized bed compared to air mode and the mechanism of NOx formation is still deficient and requires further development. In addition, this review paper discussed the potential of primary measure as low emission process with others supplementary techniques for feasible NOx reduction. The influences of combustion mode, operating parameters, and reduction techniques such as flue gas recirculation, oxygen staging, biomass co-firing, catalyst, influence of fluidized bed design and structure, decoupling combustion and their merges are respectively evaluated. Findings show that significant minimization of NOx emission can be achieved through combination of primary and secondary reduction techniques. 相似文献
72.
Siddhartha Shrestha Shibo Kuang Aibing Yu Zongyan Zhou 《American Institute of Chemical Engineers》2019,65(11):e16736
This article presents a CFD-DEM study on the effect of particle shape on bubble dynamics in bubbling fluidized beds. The particles used are ellipsoids, covering from disk-type to cylinder-type. The phenomena such as bubble coalescence and splitting are successfully generated, and the results are compared with literature, showing a good agreement. The results demonstrate that the bubble forming/rising regions and patterns are influenced significantly by particle shape. Ellipsoidal particles have asymmetrical bubble patterns with two or more circulation vortices while the bubbles for spherical particles form at the bed centerline and rise through the center of the bed. Hence, the vertical mass flux at the bed centerline for spheres is always positive, and ellipsoids have negative or positive vertical mass fluxes. The solid mixing estimated based on the dispersion coefficient revealed poor mixing for ellipsoids. Spherical particles have a larger bubble size and higher bubble rising velocity than ellipsoids. 相似文献
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Shrestha Bibek Alsadoon Abeer Prasad P. W. C. Al-Naymat Ghazi Al-Dala’in Thair Rashid Tarik A. Alsadoon Omar Hisham 《Multimedia Tools and Applications》2022,81(27):38945-38969
Multimedia Tools and Applications - The natural population-based prediction of type 2 diabetes is costly since it needs a high number of resources. Even though much research has used machine... 相似文献
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Magnetic Resonance Materials in Physics, Biology and Medicine - Alternative versions of echo-planar imaging (EPI) sequences with standard spin echo (SE) or stimulated echo acquisition mode (STEAM)... 相似文献
79.
Xinxing Yin Jie Zhou Zhaoning Song Zihao Dong Qinye Bao Niraj Shrestha Sandip Singh Bista Randy J. Ellingson Yanfa Yan Weihua Tang 《Advanced functional materials》2019,29(38)
Dopant‐free hole transport materials (HTMs) are essential for commercialization of perovskite solar cells (PSCs). However, power conversion efficiencies (PCEs) of the state‐of‐the‐art PSCs with small molecule dopant‐free HTMs are below 20%. Herein, a simple dithieno[3,2‐b:2′,3′‐d]pyrrol‐cored small molecule, DTP‐C6Th, is reported as a promising dopant‐free HTM. Compared with commonly used spiro‐OMeTAD, DTP‐C6Th exhibits a similar energy level, a better hole mobility of 4.18 × 10?4 cm2 V?1 s?1, and more efficient hole extraction, enabling efficient and stable PSCs with a dopant‐free HTM. With the addition of an ultrathin poly(methyl methacrylate) passivation layer and properly tuning the composition of the perovskite absorber layer, a champion PCE of 21.04% is achieved, which is the highest value for small molecule dopant‐free HTM based PSCs to date. Additionally, PSCs using the DTP‐C6Th HTM exhibit significantly improved long‐term stability compared with the conventional cells with the metal additive doped spiro‐OMeTAD HTM. Therefore, this work provides a new candidate and effective device engineering strategy for achieving high PCEs with dopant‐free HTMs. 相似文献
80.
Selective CO2 Capture and High Proton Conductivity of a Functional Star‐of‐David Catenane Metal–Organic Framework
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You‐Gui Huang Shu‐Qi Wu Wei‐Hua Deng Gang Xu Fa‐Lu Hu Jonathan P. Hill Wei Wei Sheng‐Qun Su Lok Kumar Shrestha Osamu Sato Ming‐Yan Wu Mao‐Chun Hong Katsuhiko Ariga 《Advanced materials (Deerfield Beach, Fla.)》2017,29(42)
Network structures based on Star‐of‐David catenanes with multiple superior functionalities have been so far elusive, although numerous topologically interesting networks are synthesized. Here, a metal–organic framework featuring fused Star‐of‐David catenanes is reported. Two triangular metallacycles with opposite handedness are triply intertwined forming a Star‐of‐David catenane. Each catenane fuses with its six neighbors to generate a porous twofold intercatenated gyroid framework. The compound possesses exceptional stability and exhibits multiple functionalities including highly selective CO2 capture, high proton conductivity, and coexistence of slow magnetic relaxation and long‐range ordering. 相似文献