Photovoltaic properties of SnCl2Pc films and SnCl2Pc/pentacene heterostructures

The optical and photovoltaic properties of dichlorotin phthalocyanine (SnCl₂Pc) films and SnCl₂Pc/pentacene (Pn) heterostructures (HS) have been studied. Weak bands at 1.35, 1.52 and 2.05 eV have been found in absorption and modulated photoreflectance spectra of SnCl₂Pc films. These bands can be caused by the formation of charge transfer states. The low concentration of recombination centers of charge carriers has been formed on a free surface of SnCl₂Pc films. This concentration essentially decreases at air evacuation before vacuum deposition of a Pn layer. Therefore, interface with an insignificant recombination rate of charge carriers is formed for SnCl₂Pc/Pn HS.     

Drug self-assembly: A phenomenon at the nanometer scale with major impact in the structure–biological properties relationship and the treatment of disease

Under water-rich conditions, small amphiphilic and hydrophobic drug molecules self-assemble into supramolecular nanostructures. Thus, substantial modifications in their interaction with cellular structures and the ability to reach intracellular targets could happen. Additionally, drug aggregates could be more toxic than the non-aggregated counterparts, or vice versa. Moreover, since self-aggregation reduces the number of effective “monomeric” molecules that interact with the target, the drug potency could be underestimated. In other cases, the activity could be ascribed to the non-aggregated molecule while it stems from its aggregates. Thus, drug self-assembly could mislead from drug throughput screening assays to advanced preclinical and clinical trials. Finally, aggregates could serve as crystallization nuclei. The impact that this phenomenon has on the biological performance of active compounds, the inconsistent and often controversial nature of the published data and the need for recommendations/guidelines as preamble of more harmonized research protocols to characterize drug self-aggregation were main motivations for this review. First, the key molecular and environmental parameters governing drug self-aggregation, the main drug families for which this phenomenon and the methods used for its characterization are described. Then, promising nanotechnology platforms investigated to prevent/control it towards a more efficient drug development process are briefly discussed.     

低功耗、高可靠性PC/104总线控制器设计

通过对PC/104总线协议的分析,提出相应总线控制器的设计方法.基于面向航空领域应用所具备的特殊要求以及SoC系统的特点,对设计的可靠性及功耗方面做出改进,包括对关键信号的去噪音处理;为从已陷入长等待的状态恢复至正常模式而加入的延时等待逻辑;门控时钟被采用以作为正常工作模式与睡眠工作模式的切换;对主要功耗部分状态机进行优化编码.使用FPGA测试结果表明,该PC/104总线控制器设计安全可靠,功耗低,可以很好地支持大部分PC/104总线设备.     

Polymer/carbon based composites as electromagnetic interference (EMI) shielding materials

The extensive development of electronic systems and telecommunications has lead to major concerns regarding electromagnetic pollution. Motivated by environmental questions and by a wide variety of applications, the quest for materials with high efficiency to mitigate electromagnetic interferences (EMI) pollution has become a mainstream field of research. This paper reviews the state-of-the-art research in the design and characterization of polymer/carbon based composites as EMI shielding materials. After a brief introduction, in Section 1, the electromagnetic theory will be briefly discussed in Section 2 setting the foundations of the strategies to be employed to design efficient EMI shielding materials. These materials will be classified in the next section by the type of carbon fillers, involving carbon black, carbon fiber, carbon nanotubes and graphene. The importance of the dispersion method into the polymer matrix (melt-blending, solution processing, etc.) on the final material properties will be discussed. The combination of carbon fillers with other constituents such as metallic nanoparticles or conductive polymers will be the topic of Section 4. The final section will address advanced complex architectures that are currently studied to improve the performances of EMI materials and, in some cases, to impart additional properties such as thermal management and mechanical resistance. In all these studies, we will discuss the efficiency of the composites/devices to absorb and/or reflect the EMI radiation.     

Enhancement of short current density in polymer solar cells with phthalocyanine tin (IV) dichloride as interfacial layer

The effect of n-type phthalocyanine tin (IV) dichloride (SnCl₂Pc) as cathode interfacial layer on the performance of poly[2-methoxy,5-(2′-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) bulk heterojunction solar cells (ITO/PEDOT:PSS/MEH-PPV:PCBM/SnCl₂Pc/LiF/Al) is investigated. Our results show that the integration of SnCl₂Pc into the solar cell not only enhances the exciton dissociation efficiency due to the formation of additional MEH-PPV/SnCl₂Pc exciton dissociation junction, but also improves the electron transport and collection due to the step-like electron injection barrier to cathode caused by SnCl₂Pc interlayer. The incorporation of 6 nm thick SnCl₂Pc interlayer leads to 15.7% improvement of the short circuit current density (J_SC), which in turn results in 15.2% improvement of power conversion efficiency (η) up to 2.49%. The results suggest that the employment of an n-type organic semiconductor like SnCl₂Pc as an interlayer is a promising strategy to improve the device performance of polymer solar cells.     

Pc5频段上电离层离子加热估值

本文利用欧洲非相干散射雷达的观测数据和地面同步测量的地磁脉动Ｐｃ５ＩＴＦＣ，ＥＳ ＥＴ ＸＷＹＧＸＭＷ ＩＨ Ｉ     

Influence of flavour absorption on oxygen permeation through LDPE, PP, PC and PET plastics food packaging

The effect of flavour absorption on the oxygen permeability of low-density polyethylene (LDPE), polypropylene (PP), polycarbonate (PC) and polyethylene terephthalate (PET) was studied using an isostatic continuous flow system. Polymer samples were exposed to a model solution containing limonene, hexyl acetate, nonanone and decanal at 40°C. After exposure, one part of each sample was analysed for absorbed flavour compounds using a Large Volume Injection GC Ultrasonic 'in vial' extraction method, and from the other part, oxygen permeability was measured in a permeation cell at 25°C. After 8h of exposure, LDPE and PP samples showed a significant linear (R² = 0.82 and 0.99) increase in oxygen permeability of 21 and 130%, respectively. Owing to swelling of the polymer samples resulting from flavour absorption, the structure of the polymeric network changed (i.e. opened) and consequently increased oxygen permeability. The oxygen permeability of exposed PC showed a significant linear (R² = 0.78) decrease of 11% after 21 days. PC obviously did not swell like LDPE or PP. Therefore, it was suggested that absorbed flavour compounds occupied or blocked 'microcavities' through which normally oxygen is transported. Absorption of flavour compounds by PET did not affect the oxygen permeability of PET significantly.     

Synthesis of phthalocyanines functionalized by 4-fluorophenoxy moieties and their linear optical properties

Four kinds of phthalocyanines with 4-fluorophenoxy group (H₂Pc, CuPc, Li₂Pc, and FePc) are synthesized by the microwave-assisted method under 15 min. The synthesized phthalocyanines have good solubility in aprotic polar solvents and do not form any new aggregation state with a concentration increase. The phthalocyanine coordinated with Li⁺ ion has a more stable and stronger absorption property in aprotic polar solvents than the phthalocyanine with Cu²⁺ or Fe²⁺ ion. The phthalocyanine coordinated with Fe²⁺ ion is more subject to H-aggregation than other phthalocyanines, especially in polar solvents.     

Simulation and fabrication of heterojunction silicon solar cells from numerical computer and hot‐wire CVD

In this paper, we will present a Pc1D numerical simulation for heterojunction (HJ) silicon solar cells, and discuss their possibilities and limitations. By means of modeling and numerical computer simulation, the influence of emitter‐layer/intrinsic‐layer/crystalline‐Si heterostructures with different thickness and crystallinity on the solar cell performance is investigated and compared with hot wire chemical vapor deposition (HWCVD) experimental results. A new technique for characterization of n‐type microcrystalline silicon (n‐µc‐Si)/intrinsic amorphous silicon (i‐a‐Si)/crystalline silicon (c‐Si) heterojunction solar cells from Pc1D is developed. Results of numerical modeling as well as experimental data obtained using HWCVD on µc‐Si (n)/a‐Si (i)/c‐Si (p) heterojunction are presented. This work improves the understanding of HJ solar cells to derive arguments for design optimization. Some simulated parameters of solar cells were obtained: the best results for J_sc = 39·4 mA/cm², V_oc = 0·64 V, FF = 83%, and η = 21% have been achieved. After optimizing the deposition parameters of the n‐layer and the H₂ pretreatment of solar cell, the single‐side HJ solar cells with J_sc = 34·6 mA/cm², V_oc = 0·615 V, FF = 71%, and an efficiency of 15·2% have been achieved. The double‐side HJ solar cell with J_sc = 34·8 mA/cm², V_oc = 0·645 V, FF = 73%, and an efficiency of 16·4% has been fabricated. Copyright © 2009 John Wiley & Sons, Ltd.     

Solution of the Skyrme HF + BCS equation on a 3D mesh

Over the years, the ev8 code has been a very useful tool for the study of nuclear mean-field theory. Its main characteristic is that it solves the Hartree-Fock plus BCS equations for Skyrme type functionals via a discretization of the individual wave-functions on a three-dimensional Cartesian mesh. This allows maximal flexibility in the determination of the nuclear shape by the variational process. For instance, the same mesh can be used to describe the oblate deformed, spherical, prolate deformed, superdeformed and fission configurations of a given nucleus. The quadrupole constraining operator yielding the deformation energy curve covering all these configurations is included in ev8. This version of the code is restricted to even-even nuclei.

Program summary

Title of program:ev8Catalogue identifier:ADWAProgram obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandProgram summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWALicensing provisions: noneComputers on which the program has been tested: HP-RX4640, Compaq-Digital Alpha GS140, has run on several other platformsComputer for which the program is designed and others on which is has been tested:Unix, LinuxOperating systems or monitors under which the program has been tested:FORTRAN-90Programming language used:depends on problem; example given requires 60 MBMemory required to execute with typical data:yesNo. of lines in distributed program, including test data, etc.:11 524No. of bytes in distributed program, including test data, etc.:89 949Distribution format:tar.gzip fileNature of the physical problem:By means of the Hartree-Fock plus BCS method using Skyrme type functionals, ev8 allows a study of the evolution of the binding energy of even-even nuclei for various shapes determined by the most general quadrupole constraint.Solution method:The program expands the single-particle wave-functions on a 3D Cartesian mesh. The nonlinear mean-field equations are solved by the imaginary time step method. A quadratic constraint is used to obtain states corresponding to given values of the quadrupole tensor.Unusual features:The pairing correlations being included with the BCS method, a physically correct solution must not have any occupied single particle state in the continuum. This requires the Fermi energy of both nucleon species to be negative and their absolute value to be typically larger than twice the pairing gap.Running time:For the test case, which starts from Nilsson wave-functions, a deformed configuration of ⁸⁴Zr is obtained with an accuracy better than 0.1 keV in 157 s on a HP-RX4640. Starting from this solution, other deformed configurations are obtained in less than 1 min.