Synthesis of carbon nanomaterials for dye‐sensitized solar cells

In this paper, it was demonstrated that Na₂O can react with CO to produce carbon nanofibers at 500 °C and carbon nanosheets at 550 °C. Furthermore, the nanosheets exhibited excellent performance as a counter electrode for a dye‐sensitized solar cell (DSSC), leading to a high power conversion efficiency of 7.57%. The efficiency is larger than that (4.72%) of a DSSC with the carbon nanofiber counter electrode and even comparable with that of an expensive Pt‐based DSSC. Copyright © 2015 John Wiley & Sons, Ltd.     

Honeycomb-like bio-based carbon framework decorated with ternary tantalum-based compounds as efficient and durable electrocatalysts for triiodide reduction reaction

Finding an inexpensive and effective clean energy electrocatalyst is highly important for the new generation of photovoltaic devices. Herein, we report a facile and universal in situ co-precipitation strategy to load three novel tantalum-based compounds (NiTa₂O₆, MnTa₂O₆, and AlTaO₄) on honeycomb-like bio-based carbon (HBC) frameworks. The HBC framework with unique honeycomb-like network structure serves as a support material in nanohybrids that can provide rich surface active sites and rapid electron transport channels for triiodide reduction reaction. The adoption of widely available and abundant biomass-derived carbon into tantalum-based compounds markedly boosts electrocatalytic properties of nanohybrids and exhibits robust corrosion resistance because nanohybrids adequately utilize the synergistic effects of different components. The photovoltaic devices fabricated with NiTa₂O₆/HBC, MnTa₂O₆/HBC, and AlTaO₄/HBC counter electrode catalysts demonstrate the brilliant power conversion efficiency (PCE) of 7.09%, 7.39%, and 7.86%, respectively, outperforming the Pt-based cells (6.80%). This work offers a strategy for the further rational design of efficient, inexpensive, and durable electrocatalysts for advanced energy technology applications.     

High-performance counter electrode based on nitrogen-doped porous carbon nanoribbons for quantum dot-sensitized solar cells

Nitrogen-doped porous carbon nanoribbons (NPCNs) are facilely prepared by carbonization of polypyrrole (PPy) nanotubes followed by a chemical activation process. NPCN counter electrodes are subsequently fabricated by depositing NPCNs onto Ti mesh for quantum dot-sensitized solar cells (QDSCs). Electrochemical tests are carried out to evaluate the electrocatalytic performance of obtained NPCN electrode. The data of electrochemical tests suggest that the NPCN electrode has a superior electrocatalytic ability towards polysulfide (S₂²⁻/S²⁻) electrolyte regeneration reaction and displays a high stability in polysulfide electrolyte. The excellent electrocatalytic performance of NPCN electrode can be ascribed to their large surface area, 2D porous nanoribbon morphology, and nitrogen atom doping, which provides abundant electrocatalytic active sites and facilitates the electrolyte diffusion. Consequently, a power conversion efficiency of 3.27% is obtained by using NPCN electrode as the counter electrode for QDSC. This efficiency is close to the QDSC assembled with commonly used PbS electrode (4.0%).     

尘埃粒子计数器校准结果及其应用探讨

本文对尘埃粒子计数器粒子浓度示值误差校准结果的计算进行了讨论,并以制药行业中尘埃粒子计数器的使用为例对尘埃粒子计数器校准结果的应用进行了探讨。     

我国西部地质环境保护中的问题与对策

我国西部地质环境的基本特征及存在的主要问题。提出西部地质环境保护的主要对策 ;立法和建立四级地法环境监测体系 ,增加投入、部门关系和落实规划措施 ;开展区域性环境地质调查 ;加强地质环境有关的数据集成及科研与地质灾害的综合整治     

带式输送机拉紧装置存在的问题及其对策

概述带式输送机拉紧装置的作用、类型以及存在的问题 ,探讨解决问题的对策。     

对旋式风机Ⅱ级动叶理论特性的研究

通过理论模型分析了对旋式风机的风压特性和功率特性，结果表明，两级动叶风压特性的差异是导致Ⅱ级电机易过载的根本原因，提出了防止电机过载的方法。     

我国建设工程质量检测行业之探讨

随着我国加入WTO,国外先进的检测机构将大量进入国内,必然给长期处于保护状态的国内检测机构带来前所未有的冲击.本文通过分析检测行业的现状,并结合该行业发展中存在的问题以及面临的挑战进行探讨,为我国检测行业的发展提出一些有益的建议和主张.     

工程建设项目反索赔及实施要点

工程建设项目建设过程中会受到各种自然及人为的因素影响,加之施工条件复杂,这给合同的履行带来很大的不确定性,也导致工程索赔和反索赔事件频繁发生。作为索赔的应对措施,反索赔的有力开展,可以减少建设项目业主方的经济损失,提高企业的经济效益。文章介绍了反索赔的概念,并提出反索赔的实施要点,这对于建设项目各个参与方维护自身合法权益,促进建设市场健康发展,有着积极的意义。     

项目开发中施工阶段的成本控制

从制定严密的合同条款、严格控制工程变更、优化施工组织和施工工艺、建立寻价体系、做好反索赔工作等方面深入探讨了施工阶段项目开发的成本控制,为开发项目的成本控制铺平道路,注入实力。