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排序方式: 共有1626条查询结果,搜索用时 171 毫秒
81.
Erkan Aydin Michele De Bastiani Xinbo Yang Muhammad Sajjad Faisal Aljamaan Yury Smirnov Mohamed Nejib Hedhili Wenzhu Liu Thomas G. Allen Lujia Xu Emmanuel Van Kerschaver Monica Morales‐Masis Udo Schwingenschlgl Stefaan De Wolf 《Advanced functional materials》2019,29(25)
Parasitic absorption in transparent electrodes is one of the main roadblocks to enabling power conversion efficiencies (PCEs) for perovskite‐based tandem solar cells beyond 30%. To reduce such losses and maximize light coupling, the broadband transparency of such electrodes should be improved, especially at the front of the device. Here, the excellent properties of Zr‐doped indium oxide (IZRO) transparent electrodes for such applications, with improved near‐infrared (NIR) response, compared to conventional tin‐doped indium oxide (ITO) electrodes, are shown. Optimized IZRO films feature a very high electron mobility (up to ≈77 cm2 V?1 s?1), enabling highly infrared transparent films with a very low sheet resistance (≈18 Ω □?1 for annealed 100 nm films). For devices, this translates in a parasitic absorption of only ≈5% for IZRO within the solar spectrum (250–2500 nm range), to be compared with ≈10% for commercial ITO. Fundamentally, it is found that the high conductivity of annealed IZRO films is directly linked to promoted crystallinity of the indium oxide (In2O3) films due to Zr‐doping. Overall, on a four‐terminal perovskite/silicon tandem device level, an absolute 3.5 mA cm?2 short‐circuit current improvement in silicon bottom cells is obtained by replacing commercial ITO electrodes with IZRO, resulting in improving the PCE from 23.3% to 26.2%. 相似文献
82.
A Complete Separation of Hexane Isomers by a Functionalized Flexible Metal Organic Framework
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Patricia A. P. Mendes Patricia Horcajada Sébastien Rives Hong Ren Alírio E. Rodrigues Thomas Devic Emmanuel Magnier Philippe Trens Hervé Jobic Jacques Ollivier Guillaume Maurin Christian Serre José A. C. Silva 《Advanced functional materials》2014,24(48):7666-7673
The separation ability of branched alkane isomers (nHEX, 3MP, 22DMB) of the flexible and functionalized microporous iron(III) dicarboxylate MIL‐53(Fe)‐(CF3)2 solid is evaluated through a combination of breakthrough experiments (binary or ternary mixtures), adsorption isotherms, X‐ray diffraction temperature analysis, quasi‐elastic neutron scattering measurements and molecular dynamics simulations. A kinetically controlled molecular sieve separation between the di‐branched isomer of hexane 22DMB from a mixture of paraffins is achieved. The reported total separation between mono‐ and di‐branched alkanes which was neither predicted nor observed so far in any class of porous solids is spectacular and paves the way towards a potential unprecedented upgrading of the RON of gasoline. 相似文献
83.
84.
This paper tries to assess the relationship between disaggregate energy consumption and industrial output in South Africa by undertaking a cointegration analysis using annual data from 1980 to 2005. We also investigate the causal relationships between the various disaggregate forms of energy consumption and industrial production. Our results imply that industrial production and employment are long-run forcing variables for electricity consumption. Applying the [Toda, H.Y., Yamamoto, T., 1995. Statistical inference in vector autoregressions with possibly integrated processes. Journal of Econometrics 66, 225–250] technique to Granger-causality, we find bi-directional causality between oil consumption and industrial production. For the other forms of energy consumption, there is evidence in support of the energy neutrality hypothesis. There is also evidence of causality between employment and electricity consumption as well as coal consumption causing employment. 相似文献
85.
Mechanical systems often use springs to store energy though their axial length must sometimes be significantly reduced. This
leads to the use of conical springs as they are able to telescope. Designers of mechanical systems can call on a large number
of tools to assist them though most of these are merely validation tools requiring concomitant trial and error strategies.
Optimization strategies can be applied to provide synthesis assistance tools for which the designer simply specifies his requirement.
Thus the tool directly indicates the spring best suited to standards and requirements. Recent advances in the study of constant
pitch conical springs have provided analytical expressions of their behavior even in the non-linear phase. Considering this,
we have used optimization strategies to provide a synthesis tool for conical spring design. An example of application is presented.
The tool introduced here is thus a synthesis assistance tool that can be of considerable interest for designers who require
a conical spring in their design. 相似文献
86.
Neung‐Ju Lee Nam‐In Kang Won‐Jei Cho Seon‐Hee Kim Kyung‐Tae Kang Emmanuel A Theodorakis 《Polymer International》2001,50(9):1010-1015
A new monomer, exo‐3,6‐epoxy‐1,2,3,6‐tetrahydrophthalimidocaproic acid (ETCA), was prepared by reaction of maleimidocaproic acid and furan. The homopolymer of ETCA and its copolymers with acrylic acid (AA) or with vinyl acetate (VAc) were obtained by photopolymerizations using 2,2‐dimethoxy‐2‐phenylacetophenone as an initiator at 25 °C. The synthesized ETCA and its polymers were identified by FTIR, 1H NMR and 13C NMR spectroscopies. The apparent average molecular weights and polydispersity indices determined by gel permeation chromatography (GPC) were as follows: Mn = 9600 g mol?1, Mw = 9800 g mol?1, Mw/Mn = 1.1 for poly(ETCA); Mn = 14 300 g mol?1, Mw = 16 200 g mol?1, Mw/Mn = 1.2 for poly(ETCA‐co‐AA); Mn = 17 900 g mol?1, Mw = 18 300 g mol?1, Mw/Mn = 1.1 for poly(ETCA‐co‐VAc). The in vitro cytotoxicity of the synthesized compounds against mouse mammary carcinoma and human histiocytic lymphoma cancer cell lines decreased in the following order: 5‐fluorouracil (5‐FU) ≥ ETCA > polymers. The in vivo antitumour activity of the polymers against Balb/C mice bearing sarcoma 180 tumour cells was greater than that of 5‐FU at all doses tested. © 2001 Society of Chemical Industry 相似文献
87.
Emmanuel Osalusi Jonathan SideRobert Harris 《International Communications in Heat and Mass Transfer》2009
A broadband acoustic Doppler current profiler (ADCP) moored on the seabed at 42 m depth has been used to observe the mean and turbulent flow components in the tidally energetic Fall of Warness channel over two tidal cycles. The Reynolds stress has been estimated from the difference in variance between the along-beam velocities of opposing acoustic beams. Near bed stress at 2.63 m above seabed (mab) exceeds 7.5 Pa at the time of mean flow (speed of ~ 1.3 m s− 1) while the ebb stresses are limited to ~ 3.31 Pa during the peak ebb, mean, flow of ~ 1.3 m s− 1. The production of turbulent kinetic energy (TKE), P was found to be negative below 2 × 10− 9 W m− 3 and up to 6 × 10− 4 W m− 3 was estimated during flood flows and decreasing to 3 × 10− 4 W m− 3. The TKE dissipation rate ε was estimated by inertial dissipation method (IDM) with the greatest value of 2.43 × 10− 2 W m− 3 observed near the seabed around maximum ebb, falling to 5.75 × 10− 5 W m− 3 around slack water. The comparison between P and ε was performed by calculating individual ratios of P corresponding to ε using a bootstrap resampling technique. The study shows that the ratio ε/P averaged over whole flood and ebb were found to be ~ 0.4138 and ~ 0.4177, respectively, indicating that production exceeded dissipation. The uncertainties in Reynolds stress estimates due to instrument noise were found to be 3 × 10− 4 Pa while 4.52 × 10− 2 Pa can be attributed to the uncertainties due to the increase in the flow-related component. 相似文献
88.
Xianqin Meng Guillaume Gomard Ounsi El Daif Emmanuel Drouard Regis Orobtchouk Anne Kaminski Alain Fave Mustapha Lemiti Alexei Abramov Pere Roca i Cabarrocas Christian Seassal 《Solar Energy Materials & Solar Cells》2011
In this paper, we present the integration of an absorbing photonic crystal within a thin-film photovoltaic solar cell. Optical simulations performed on a complete solar cell revealed that patterning the hydrogenated amorphous silicon active layer as a 2D photonic crystal membrane enabled to increase its integrated absorption by 28 % between 300 and 720 nm, comparing to a similar but unpatterned stack. In order to fabricate such promising cells, we developed a high throughput process based on holographic lithography and reactive ion etching. The influences of the parameters taking part in those processes on the obtained patterns are discussed. Optical measurements performed on the resulting “photonized” solar cell structures underline the regularity of the 2D pattern and a significant absorption increase above 550 nm, similarly to what is observed on the simulated absorption spectra. Moreover, our patterned cells are found to be robust with regards to the angle of incidence of the light. 相似文献
89.
Pierre-Antoine Gédouin Emmanuel Delaleau Jean-Matthieu Bourgeot Cédric Join Shabnam Arbab Chirani Sylvain Calloch 《Control Engineering Practice》2011,19(5):433-441
Shape memory alloys (SMA) are being more frequently integrated into engineering applications. These materials with their shape memory effect enable the simplification of mechanisms and the reduction in size of actuators. SMA parts can easily be activated by Joule effect but their modeling and consequently their control remains difficult. It is principally due to their non-linear hysteretic thermomechanical behavior. Most of successful control strategies applied to SMA actuators are not often suitable for industrial applications: they are particularly heavy and use the Preisach model or neural networks to model the hysteretic behavior of these materials; this kind of model is difficult to identify and to use in real time. This paper deals with an application of the new framework of model-free control (MFC) of an SMA-spring based actuator. This control strategy relies on new results for fast derivative estimation of noisy signals. Their main advantages are: its simplicity and its robustness. Experimental results and comparisons with PI control are presented that demonstrate the efficiency of this new control strategy. 相似文献
90.
Augustine E. Ofomaja Emmanuel E. UkpeborStephen A. Uzoekwe 《Biomass & bioenergy》2011,35(10):4112-4123
Determination of the overall rate controlling step in the biosorption of Methyl violet dye onto a new biosorbent, palm kernel fiber has been determined. Pseudo-second-order model described the kinetics over the whole contact time period for the effect of initial concentration and temperature. Using the Wu’s approaching equilibrium factor, Rw, it was observed that the time for the switch from initial biosorption to intraparticle diffusion is affected by initial concentration and temperature. A comparison between the activation parameters of film diffusion, pseudo-second order ion exchange and intraparticle diffusion revealed that film diffusion is the overall slowest step in the biosorption process. Temperature increased the biosorption capacity but reduced slightly the rate of intraparticle diffusion, indicating that the biosorbent surface was activated by temperature which limited the diffusion of Methyl violet molecules into the interior of the biosorbent. A multistage process design to minimize mass and contact time was done. 相似文献