Yi Zhang  Zhongmin Zhou  Fuxiang Ji  Zhipeng Li  Guanglei Cui  Peng Gao  Emad Oveisi  Mohammad Khaja Nazeeruddin  Shuping Pang 《Advanced materials (Deerfield Beach, Fla.)》2018,30(22)

Effective passivation and stabilization of both the inside and interface of a perovskite layer are crucial for perovskite solar cells (PSCs), in terms of efficiency, reproducibility, and stability. Here, the first formamidinium lead iodide (δ‐FAPbI₃) polymorph passivated and stabilized MAPbI₃ PSCs are reported. This novel MAPbI₃/δ‐FAPbI₃ structure is realized via treating a mixed organic cation MA _x FA_{1‐ x} PbI₃ perovskite film with methylamine (MA) gas. In addition to the morphology healing, MA gas can also induce the formation of δ‐FAPbI₃ phase within the perovskite film. The in situ formed 1D δ‐FAPbI₃ polymorph behaves like an organic scaffold that can passivate the trap state, tunnel contact, and restrict organic‐cation diffusion. As a result, the device efficiency is easily boosted to 21%. Furthermore, the stability of the MAPbI₃/δ‐FAPbI₃ film is also obviously improved. This δ‐FAPbI₃ phase passivation strategy opens up a new direction of perovskite structure modification for further improving stability without sacrificing efficiency.  相似文献   

    

Mohammad Bod  Reza Sarraf‐Shirazi  Gholamreza Moradi  Ali Kiaee  Amir Jafargholi  Pedram Mousavi 《国际射频与微波计算机辅助工程杂志》2018,28(1)

In this article, a decoupled source current reconstruction method (SRM) for noisy and reactive near‐field (NF) to far‐field (FF) transformation is introduced. It is shown that the traditional SRM for NF/FF transformation shows instability in the regions that the amounts of noise or reactive radiations are noticeable. Therefore, in these regions, equivalent currents should be determined from a Tikhonov SRM equation. However, this equation increases the computational cost of the SRM. To simplify the Tikhonov SRM equation, a Tikhonov radial field retrieval algorithm is also proposed. In this algorithm, the Tikhonov integral equation is decoupled by considering and retrieving the radial components of the electric field. Results of far‐field calculation with both the proposed Tikhonov SRM equation and Tikhonov radial field retrieval algorithm with three different antennas are presented and compared with those of the full‐wave simulation and measurements. The results show more accurate field transformation with the proposed algorithms.  相似文献   

    

Etemad  Elham  Samavi  Shadrokh  Reza Soroushmehr  S. M.  Karimi  Nader  Etemad  Mohammad  Shirani  Shahram  Najarian  Kayvan 《Multimedia Tools and Applications》2018,77(2):2033-2055

Multimedia Tools and Applications - Nowadays, due to widespread usage of the Internet, digital contents are distributed quickly and inexpensively throughout the world. Watermarking techniques can...  相似文献   

    

Hadi Azmi  Mohammad Javad Khosrowjerdi 《International Journal of Adaptive Control and Signal Processing》2017,31(12):1885-1902

This paper presents 2‐novel linear matrix inequality (LMI)‐based adaptive output feedback fault‐tolerant control strategies for the class of nonlinear Lipschitz systems in the presence of bounded matched or mismatched disturbances and simultaneous occurrence of actuator faults, including failure, loss of effectiveness, and stuck. The constructive algorithms based on LMI with creatively using Lyapunov stability theory and without the need for an explicit information about mode of actuator faults or fault detection and isolation mechanism are developed for online tuning of adaptive and fixed output‐feedback gains to stabilize the closed‐loop control system asymptotically. The proposed controllers guarantee to compensate actuator faults effects and to attenuate disturbance effects. The resulting control methods have simpler structure, as compared with most existing recent methods and more suitable for practical systems. The merits of the proposed fault‐tolerant control scheme have been verified by the simulation on nonlinear Boeing 747 lateral motion dynamic model subjected to actuator faults.  相似文献   

    

M. Mohammad ;M. Montazer ;S. Abas 《中南大学学报(英文版)》2017,24(3)

This study proposes a graphical user interface (GUI) based on an enhanced bacterial foraging optimization (EBFO) to find the optimal locations and sizing parameters of multi-type DFACTS in large-scale distribution systems. The proposed GUI based toolbox, allows the user to choose between single and multiple DFACTS allocations, followed by the type and number of them to be allocated. The EBFO is then applied to obtain optimal locations and ratings of the single and multiple DFACTS. This is found to be faster and provides more accurate results compared to the usual PSO and BFO. Results obtained with MATLAB/Simulink simulations are compared with PSO, BFO and enhanced BFO. It reveals that enhanced BFO shows quick convergence to reach the desired solution there by yielding superior solution quality. Simulation results concluded that the EBFO based multiple DFACTS allocation using DSSSC, APC and DSTATCOM is preferable to reduce power losses, improve load balancing and enhance voltage deviation index to 70%, 38% and 132% respectively and also it can improve loading factor without additional power loss.  相似文献   

    

Mohammad Ahmad‐Fouad Basha  Reham Morsi Mohamed Morsi 《应用聚合物科学杂志》2017,134(34)

Cellulose acetate thin films doped with erbium (III) chloride (ErCl₃) of different concentrations were prepared by the solution method. The prepared composite films were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis. IR spectral analysis, UV–visible absorption, a.c. conductivity, and dielectric properties were investigated. The studied ErCl₃‐doped samples showed different properties from those of their pure components. SEM micrographs showed that for small dopant concentrations, samples tend to form conducting nanostructures with negligible particle agglomeration. DSC showed a monotonic development of the glass transition temperature by increasing the concentration of dopant material. Variation in the height, shape, and position of the bands in infrared transmission spectra, as well as the glass transition temperatures, indicated a complex interaction with the polymer molecular chains. Thermal stability and thermodynamic parameters were found to be concentration dependent. The electronic transitions’ band gabs and energy tails were calculated from the optical data. The dielectric studies showed that the correlated barrier hopping model was the dominant mechanism of a.c. conductivity. We found that samples with 10% and 20% ErCl₃ exhibited high dielectric constants and have pronounced electrostriction and relaxor‐like properties. Such samples can be used in many applications like electromechanical and thermomechanical transducers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45220.  相似文献   

    

Abolfazl Shakouri  Hadi Ahmari  Mohammad Hojjat  Saeed Zeinali Heris 《乙烯基与添加剂工艺杂志》2017,23(3):234-240

In recent years, addition of nanoparticles to fluids and polymers has been used as a way of modifying rheological properties. Poly(vinyl alcohol) (PVA) and titanium dioxide (TiO₂) nanoparticles aqueous composite nanofluids were prepared through the use of ultrasonic vibration. In fact, ultrasonic vibration is an advantageous method for nanoparticle dispersion. The preparation method prevents reduction of the polymer's molecular weight. TiO₂ nanoparticles with different concentrations were employed to investigate the rheological characteristics of composite nanofluids. Rheological characteristics of base fluids and composite nanofluids were measured at different temperatures. Based on the results, all composite nanofluids, as well as base fluids, exhibited non‐Newtonian behavior and rheological characteristics of composite nanofluids, following the Herschel‐Bulkley model. In addition, model parameters are functions of temperature, PVA, and TiO₂ nanoparticle concentrations. Also, two‐way interactions among temperature, PVA, and TiO₂ nanoparticle concentrations affect flow index and consistency index of the Herschel‐Bulkley model. J. VINYL ADDIT. TECHNOL., 23:234–240, 2017. © 2015 Society of Plastics Engineers  相似文献   

    

Masoud Hasany  Soheila Yaghmaei  Mohammad Mahdi Mardanpour  Zahra Ghasemi Naraghi 《中国化学工程学报》2017,25(12):1847-1855

A successful design, previously adapted for treatment of complex wastewaters in a microbial fuel cell (MFC), was used to fabricate two MFCs, with a few changes for cost reduction and ease of construction. Performance and electrochemical characteristics of MFCs were evaluated in different environmental conditions (in complete darkness and presence of light), and different flow patterns of batch and continuous in four hydraulic retention times from 8 to 30 h. Changes in chemical oxygen demand, and nitrate and phosphate concentrations were evaluated. In contrast to the microbial fuel cell operated in darkness (D-MFC) with a stable open circuit voltage of 700 mV, presence of light led to growth of other species, and consecutively low and unsteady open circuit voltage. Although the performance of theMFC subjected to light (L-MFC)was quite lowand unsteady in dynamic state (internal resistance = 100 Ω, power density = 5.15 W·m^-3), it reached power density of 9.2 W·m^-3 which was close to performance of D-MFC (internal resistance = 50 Ω, power density = 10.3 W·m^-3). Evaluated only for D-MFC, the coulombic efficiency observed in batch mode (30%) was quite higher than the maximum acquired in continuous mode (9.6%) even at the highest hydraulic retention time. In this study, changes in phosphate and different types of nitrogen existing in dairy wastewater were investigated for the first time. At hydraulic retention time of 8 h, the orthophosphate concentration in effluent was 84% higher compared to influent. Total nitrogen and total Kjeldahl nitrogen were reduced 70% and 99% respectively at hydraulic retention time of 30 h, while nitrate and nitrite concentrations increased. The microbial electrolysis cell (MEC), revamped from D-MFC, showed the maximum gas production of 0.2 m³ H₂·m^-3·d^-1 at 700 mV applied voltage.  相似文献   

    

Mohammad Akhtaruzzaman Sarker 《Water and Environment Journal》2017,31(2):284-295

Cyclones cause significant loss of life and damage to properties, ecosystems and marine facilities. To address such issues, Royal HaskoningDHV (RHDHV) has developed regional tidal hydrodynamic and wave models covering the Northern Arabian Sea. A total of 29 major cyclones were identified in the Arabian Sea since 1945. However, as less information is available on Cyclone Nilofar (2014), this paper has concentrated on this event to illustrate the use of numerical modelling to simulate waves and surge generated by cyclones. Sample results from the modelling study are presented in this paper. The methodology described in this paper for modelling cyclone waves and surges in the Arabian Sea could be applied to simulate such natural hazards at other sites around the world.  相似文献   

  总被引：1，自引：0，他引：1  

Karim Rocky‐Salimi  Maryam Hashemi  Mohammad Safari  Maryam Mousivand 《Journal of the science of food and agriculture》2017,97(1):222-229

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