提高聚(3,4-乙撑二氧噻吩)∶聚苯乙烯磺酸电导率的最新研究进展

随着能源危机和环境污染问题的日益严峻,近年来热电材料的研究越来越受到人们的关注。聚(3,4-乙撑二氧噻吩)∶聚苯乙烯磺酸(PEDOT∶PSS)被认为是热电性能最好的有机热电材料之一。PEDOT∶PSS具备好的成膜性、高的透明性、优异的电导可控性以及热稳定性。系统地综述了提高PEDOT∶PSS电导率的一些物理、化学方法,探讨了其电导率增强的机理以及介绍了其目前最新的应用情况。预期未来具有高电导率和高透明性的PEDOT∶PSS薄膜材料的研究将得到突破性发展。     

光伏组件蜗牛纹现象成分研究和应对策略的现状

蜗牛纹是一种光伏组件表面银栅线变暗的变色现象,对光伏组件的外观会造成严重影响,并进一步引发业主对组件产品质量的担忧,自报道以来,蜗牛纹现象已经受到了研究机构和组件厂商的广泛关注。介绍了蜗牛纹的概况,针对蜗牛纹组成成分调研了三类研究结果——单质银、碳酸银以及乙酸银和碳酸银。最后,对改进封装材料和推广双玻组件这两种蜗牛纹解决策略进行了讨论和分析。     

温差发电用BiCuSeO基热电材料的研究进展

BiCuSeO基热电材料由于具有较低的热导率和较高的Seebeck系数,热电性能优异,且原料储藏丰富、价格低廉、安全无毒,被认为是一种具有潜在应用前景的新型热电转换材料。首先介绍了BiCuSeO基材料的晶体结构、电子结构、热电性能等基本特征,随后综述了近年来国内外关于BiCuSeO基热电材料的研究进展,评述了提高其热电性能的手段,包括Na、Ag、Mg、Ca、Sr、Ba等低价元素掺杂,铜空位,双空位,带隙调整,晶粒细化,织构化和调制掺杂等。通过电热输运特性的协同调控,可使其ZT值从未掺杂样品的0.4左右提高到1.5。最后从实际应用的角度出发提出了今后BiCuSeO基热电材料的研究方向及研究重点。     

Development of CO2 Selective Poly(Ethylene Oxide)-Based Membranes: From Laboratory to Pilot Plant Scale

Membrane gas separation is one of the most promising technologies for the separation of carbon dioxide (CO₂) from various gas streams. One application of this technology is the treatment of flue gases from combustion processes for the purpose of carbon capture and storage. For this application, poly(ethylene oxide)-containing block copolymers such as Pebax^® or PolyActive™ polymer are well suited. The thin-film composite membrane that is considered in this overview employs PolyActive™ polymer as a selective layer material. The membrane shows excellent CO₂ permeances of up to 4 m³(STP)·(m²·h·bar)⁻¹ (1 bar = 10⁵ Pa) at a carbon dioxide/nitrogen (CO₂/N₂) selectivity exceeding 55 at ambient temperature. The membrane can be manufactured reproducibly on a pilot scale and mounted into flat-sheet membrane modules of different designs. The operating performance of these modules can be accurately predicted by specifically developed simulation tools, which employ single-gas permeation data as the only experimental input. The performance of membranes and modules was investigated in different pilot plant studies, in which flue gas and biogas were used as the feed gas streams. The investigated processes showed a stable separation performance, indicating the applicability of PolyActive™ polymer as a membrane material for industrial-scale gas processing.     

基于热电原理的过冷器在家用空调中应用的实验研究

在蒸气压缩制冷系统中,增加系统的过冷度可以提高系统的制冷量及其性能系数。本文设计了一种基于热电制冷原理来增加系统过冷度的空调系统,并在最小制冷,额定制冷和最大制冷三种工况下,对运行过冷装置前后的空调系统的性能进行实验对比。结果表明:采用设计的过冷器后,冷凝器出口的过冷度分别提高了2.3℃、1.9℃和1.5℃,系统的制冷量分别提高了3.6%、3.2%和4%,系统的性能系数分别提高了3.7%、3.1%和4.2%。在下一步的实验中可通过优化热电制冷片的运行工况,进一步提高系统的性能。     

Revealing the Enhanced Thermoelectric Properties of Controllably Doped Donor-Acceptor Copolymer: The Impact of Regioregularity

Albeit considerable attention to the fast-developing organic thermoelectric (OTE) materials due to their flexibility and non-toxic features, it is still challenging to design an OTE polymer with superior thermoelectric properties. In this work, two “isomorphic” donor–acceptor (D–A) conjugated polymers are studied as the semiconductor in OTE devices, revealing for the first time the internal mechanism of regioregularity on thermoelectric performances in D–A type polymers. A higher molecular structure regularity can lead to higher crystalline order and mobility, higher doping efficiency, order of energy state, and thermoelectric (TE) performance. As a result, the regioregular P2F exhibits a maximum power factor (PF) of up to 113.27 µW m⁻¹ K⁻², more than three times that of the regiorandom PRF (35.35 µW m⁻¹ K⁻²). However, the regular backbone also implies lower miscibility with a dopant, negatively affecting TE performance. Therefore, the trade-off between doping efficiency and miscibility plays a vital role in OTE materials, and this work sheds light on the molecular design strategy of OTE polymers with state-of-the-art performances.     

Modulation of Vacancy Defects and Texture for High Performance n-Type Bi2Te3 via High Energy Refinement

The carrier concentration in n-type layered Bi₂Te₃-based thermoelectric (TE) material is significantly impacted by the donor-like effect, which would be further intensified by the nonbasal slip during grain refinement of crushing, milling, and deformation, inducing a big challenge to improve its TE performance and mechanical property simultaneously. In this work, high-energy refinement and hot-pressing are used to stabilize the carrier concentration due to the facilitated recovery of cation and anion vacancies. Based on this, combined with SbI₃ doping and hot deformation, the optimized carrier concentration and high texture degree are simultaneously realized. As a result, a peak figure of merit (zT) of 1.14 at 323 K for Bi₂Te_2.7Se_0.3 + 0.05 wt.% SbI₃ sample with the high bending strength of 100 Mpa is obtained. Furthermore, a 31-couple thermoelectric cooling device consisted of n-type Bi₂Te_2.7Se_0.3 + 0.05 wt.% SbI₃ and commercial p-type Bi_0.5Sb_1.5Te₃ legs is fabricated, which generates the large maximum temperature difference (ΔT_max) of 85 K at a hot-side temperature of 343 K. Thus, the discovery of recovery effect in high energy refinement and hot-pressing has significant implications for improving TE performance and mechanical strength of n-type Bi₂Te₃, thereby promoting its applications in harsh conditions.     

Manipulating the Interfacial Band Bending For Enhancing the Thermoelectric Properties of 1T′-MoTe2/Bi2Te3 Superlattice Films

Interfacial charge effects, such as band bending, modulation doping, and energy filtering, are critical for improving electronic transport properties of superlattice films. However, effectively manipulating interfacial band bending has proven challenging in previous studies. In this study, (1T′-MoTe₂)_x(Bi₂Te₃)_y superlattice films with symmetry-mismatch were successfully fabricated via the molecular beam epitaxy. This enables to manipulate the interfacial band bending, thereby optimizing the corresponding thermoelectric performance. These results demonstrate that the increase of Te/Bi flux ratio (R) effectively tailored interfacial band bending, resulting in a reduction of the interfacial electric potential from ≈127 meV at R = 16 to ≈73 meV at R = 8. It is further verified that a smaller interfacial electric potential is more beneficial for optimizing the electronic transport properties of (1T′-MoTe₂)_x(Bi₂Te₃)_y. Especially, the (1T′-MoTe₂)₁(Bi₂Te₃)₁₂ superlattice film displays the highest thermoelectric power factor of 2.72 mW m⁻¹ K⁻² among all films, due to the synergy of modulation doping, energy filtering, and the manipulation of band bending. Moreover, the lattice thermal conductivity of the superlattice films is significantly reduced. This work provides valuable guidance to manipulate the interfacial band bending and further enhance the thermoelectric performances of superlattice films.     

基于电子政务的公文系统功能模块分析与设计——电子公文管理系统功能研究之二

随着电子政务的发展,电子公文逐渐成为现代公文管理的新主体。本文就电子政务中的公文归档、整理、鉴定、保管、利用系统功能模块作一初步分析和设计。     

计算机排课系统的实现

计算机排课系统是计算机在学校管理工作中的一个非常重要的应用,它极大地提高了排课的效率,排课的准确性,为学校的管理工作顺利进行提供了有力的帮助。计算机排课系统的实现主要从数据准备入手,如何提供组织合理的数据至关重要,具体排课时的算法在逻辑上要做到严密、连贯,报表的格式应尽量满足用户需求。面向用户是计算机应用的基本原则,系统界面、系统操作、系统结果都应从用户的意志出发。