Graphitic carbon nitride-based photocatalysts in the applications of environmental catalysis

Semiconductor photocatalytic technology has shown great prospects in converting solar energy into chemical energy to mitigate energy crisis and solve environmental pollution problems. The key issue is the development of high-efficiency photocatalysts. Various strategies in the state-of-the-art advancements, such as heterostructure construction, heteroatom doping, metal/single atom loading, and defect engineering, have been presented for the graphitic carbon nitride (g-C₃N₄)-based nanocomposite catalysts to design their surface chemical environments and internal electronic structures to make them more suitable for different photocatalytic applications. In this review, nanoarchitecture design, synthesis methods, photochemical properties, potential photocatalytic applications, and related reaction mechanisms of the modified high-efficiency carbon nitride-based photocatalysts were briefly summarized. The superior photocatalytic performance was identified to be associated with the enhanced visible-light response, fast photoinduced electron-hole separation, efficient charge migration, and increased unsaturated active sites. Moreover, the further advance of the visible-light harvesting and solar-to-energy conversions are proposed.     

云天化粉煤灰理化性能的测试及研究

利用现代分析测试技术 ,对云天化集团有限责任公司自备电厂所排粉煤灰的理化性能进行了系统的测试。这些粉煤灰的化学成分以Fe2 O3含量高为特征 ,残留碳含量较低 ;物相较简单 ,未发现高温相的莫来石 ,玻璃微珠也较少见 ;颗粒呈不规则碎屑状 ,平均粒径较细 ,需水量比值较高 ;其所含的微量元素和放射性元素种类较多 ,但与国家的相关标准相比较 ,均未超标     

酸雨的形成、危害及防治对策

我国酸雨正呈蔓延之势 ,酸雨区面积占国土面积的 30 % ,已成为继欧洲、北美之后世界第三大重酸雨区。酸雨给地球生态环境和人类社会经济都带来严重的影响和破坏。酸雨的防治 ,一靠完善的环境法规和执法力度 ;二靠先进的技术和设备。本文介绍了酸雨的成因、危害及酸雨治理的措施     

Biomass chemical looping gasification for syngas production using modified hematite as oxygen carriers

Syngas is a clean energy carrier and a major industrial feedstock. In this paper, syngas was produced via biomass chemical looping gasification(CLG) process. Hematite, the most common Fe-based oxygen carrier(OC), was modified with different metal oxides(CeO₂, CaO and MgO) by the impregnation method. The hematite modified by CeO₂, CaO and MgO was namely as CeO₂-hematite(CeO₂-H), CaO-hematite(CaO-H) and MgO-hematite(MgO-H), respectively. The introduction...     

Less is more: social learning of predator recognition requires a low demonstrator to observer ratio in Arctic charr (Salvelinus alpinus)

Reintroduction programs for conservation purposes suffer from low post-release survival of captive-bred animals, especially so with fish reintroductions. High mortality is most often due to weakened antipredator skills, which could be enhanced through direct experience with predators and social learning. As yet, the relative efficiency of these learning methods has not been tested, and the significance of the factors determining how efficiently antipredator responses are transmitted socially from experienced (demonstrator) to predator naive (observer) individuals is largely unknown. Using hatchery-bred stock of the endangered Saimaa Arctic charr (Salvelinus alpinus), we show for the first time that: (1) contrary to theoretical predictions, acquired predator recognition was only socially transmitted from predator-experienced to predator-naive fish in groups with a smaller proportion of experienced than naive individuals, and that (2) socially acquired avoidance of the predator odors was as strong as in those fish conditioned with a combination of odors and predator exposure. We conclude that using social transmission procedures in training fish for reintroduction programs may provide considerable ecological, economical and ethical advantages.Communicated by J. Krause     

氯化消毒饮用水中强致突变物MX[3-氯-4-(二氯甲基)-5-羟基-2(5H)-呋喃酮]的形成

利用一系列XAD吸附树脂及大孔阴、阳离子交换树脂,将太湖水中溶解态有机物分离为溶解态富里酸类、腐殖酸类、憎水弱酸类、憎水碱类、憎水中性物类、亲水酸类、亲水碱类七种组分,分别对不同组分的有机物进行氯化处理后,用GC/MS选择离子峰面积法测定了产物中的MX[3-氯-4-（二氯甲基）-5-羟基-2（5H）-呋喃酮]。结果表明,太湖水体中的溶解态腐殖酸类可能是生成MX的重要前驱物。     

AS法制浆废液改性减水剂实验研究

通过实验，对AS法麦草、芦苇造纸制浆废液加入Ba(OH)2溶液和吐温-80进行化学改性，制成木素磺酸盐为主要成份的混凝土减水剂，制得的减水剂的3项主要性能指标均达到以国家标准，它们在掺量3‰时净浆减水率为6%-8%，砂浆减水率为15%-16%，掺麦草、芦苇浆废液减水剂的砂浆3d抗压强度分别提高28%和30%，7d抗压强度分别提高18.6和26.4%。     

废石膏用于道路回填材料的处理工艺及性能研究

讨论了化工废石膏在矿物掺合物、粉煤灰、激发剂、外加剂等存在时，在不同配比下的力学性能、凝结时间、溶蚀率、软化系数和体积稳定性，并分析了该材料水化、硬化规律，硬化体结构及与性能的关系，试验结果表明，化工废石膏掺加量的多少将直接影响到各项性能指标，采用复合早强减水剂，对于粉煤灰活性激发，及加速胶结材料凝结水化、降低用量，有显著效果。     

有毒化学物品的污染与防治

本文就有毒化学品的生产、使用，给环境带来新的污染与危害问题，概括地阐述了国内外防治有毒化学品的污染状况；并针对当前的具体问题，提出防治和控制措施．