填料对废旧聚丙烯塑料改性性能的影响

通过对废旧聚丙烯塑料进行填充改性试验 ,研究了重质碳酸钙、超细重钙、滑石粉对废旧聚丙烯塑料进行改性后的塑料试样的抗拉强度、抗弯强度、断裂伸长率以及扫描电镜图像的影响 ,为填料的选用提供试验依据     

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.     

The Response of Avian Feeding Guilds to Tropical Forest Disturbance

Abstract:  Anthropogenic habitat disturbance is a major threat to tropical forests and understanding the ecological consequences of this disturbance is crucial for the conservation of biodiversity. There have been many attempts to determine the ecological traits associated with bird species' vulnerability to disturbance, but no attempt has been made to synthesize these studies to show consensus. We analyzed data from 57 published studies (covering 1214 bird species) that investigated the response of tropical bird assemblages to moderate forest disturbance (e.g., selective logging). Our results show that the mean abundance of species from six commonly reported feeding guilds responded differently to disturbance and that species' ecological traits (body size, local population size, and geographic range size) and evolutionary relationships may influence responses in some guilds. Granivore abundance increased significantly and insectivore and frugivore abundance decreased significantly following disturbance. These general conclusions were robust to the effects of ecological traits and phylogeny. Responses of carnivores, nectarivores, and omnivores were less clear, but analyses that accounted for phylogeny indicated that these guilds declined following disturbance. In contrast to the other guilds, the reported responses of carnivores and nectarivores differed among regions (Asia vs. Neotropics) and were influenced by the sampling protocols used in different studies (e.g., time since disturbance), which may explain the difficulty in detecting general responses to disturbance in these guilds. Overall, general patterns governed the responses of species to habitat disturbance, and the differential responses of guilds suggested that disturbance affects trophic organization and thus ecosystem functioning.     

岩豆凝集素分子中色氨酸残基的化学修饰及其荧光光谱研究

从岩豆（Ｍｉｌｌｅｔｔｉａ ｄｉｅｌｓｉａｎａ Ｈａｒｍｓ ｅｘ Ｄｉｅｌｓ）种妇中分离纯化得到的岩豆凝集素（简称ＭＤＬ）经链霉蛋白酶水解,测得其分子中含有４个色氨酸（Ｔｒｐ）残基。用Ｎ－溴代丁二酰亚胺（ＮＢＳ）对ＭＤＬ分子中的色氨酸残基进行化学修饰,在无变性剂存在下有３．６个Ｔｒｐ残基被修饰,在变性条件下可修饰３．８个Ｔｒｐ残基。修饰后ＭＤＬ活性均丧失,且甘露糖对ＭＤＬ活性雎有保护作用。表明Ｔｒ     

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%。     

改性活性炭在环境保护中的应用

活性炭是一种应用广泛的吸附催化剂 ,其性能取决于它的孔隙结构和表面化学性质。为了提高其吸附效率和改善其吸附选择性及其催化性能 ,往往需要对活性炭的孔隙结构进行调整以及改变其表面化学性质。综述了活性炭的改性方法及其特点、改性活性炭在环境保护中的应用及其再生等方面的研究概况     

Modelling critical levels of ozone for the forested area of austria modifications of the aot40 concept

GOAL, SCOPE AND BACKGROUND: Ozone is the most important air pollutant in Europe for forest ecosystems and the increase in the last decades is significant. The ozone impact on forests can be calculated and mapped based on the provisional European Critical Level (AOT40 = accumulated exposure over a threshold of 40 ppb, 10,000 ppb x h for 6 months of one growing season calculated for 24 h day(-1)). For Norway spruce, the Austrian main tree species, the ozone risk was assessed in a basis approach and because the calculations do not reflect the health status of forests in Austria, the AOT40 concept was developed. METHODS: Three approaches were outlined and maps were generated for Norway spruce forests covering the entire area of Austria. The 1st approach modifies the AOT40 due to the assumption that forests have adapted to the pre-industrial levels of ozone, which increase with altitude (AOTalt). The 2nd approach modifies the AOT40 according to the ozone concentration in the sub-stomata cavity. This approach is based on such factors as light intensity and water vapour saturation deficit, which affect stomatal uptake (AOTsto). The 3rd approach combines both approaches and includes the hemeroby. The pre-industrial ozone level approach was applied for autochthonous ('natural') forest areas, the ozone-uptake approach for non-autochthonous ('altered') forest areas. RESULTS AND DISCUSSION: The provisional Critical Level (AOT40) was established to allow a uniform assessment of the ozone risk for forested areas in Europe. In Austria, where ozone risk is assessed with utmost accuracy due to the dense grid of monitoring plots of the Forest Inventory and because the continuously collected data from more than 100 air quality measuring stations, an exceedance up to the five fold of the Critical Level was found. The result could lead to a yield loss of up to 30-40% and to a severe deterioration in the forest health status. However, the data of the Austrian Forest Inventory and the Austrian Forest Damage Monitoring System do not reflect such an ozone impact. Therefore, various approaches were outlined including the tolerance and avoidance mechanisms of Norway spruce against ozone impact. Taking into consideration the adaptation of forests to the pre-industrial background level of ozone, the AOT40 exceedances are markedly reduced (1st approach). Taking into account the stomatal uptake of ozone, unrealistic high amounts of exceedances up to 10,000 ppb x h were found. The modelled risk does not correspond with the health status and the wood increment of the Austrian forests (2nd approach). Consolidating the forgoing two approaches, a final map including the hemeroby was generated. It became clear that the less natural ('altered') forested regions are highly polluted. This means, that more than half of the spruce forests are endangered by ozone impact and AOT40 values of up to 30,000 ppb x h occur (3rd approach). CONCLUSIONS: The approaches revealed that a plausible result concerning the ozone impact on spruce forests in Austria could only be reached by combining pre-industrial ozone levels, ozone flux into the spruce needles and the hemeroby of forests.     

改性粉煤灰处理含铬废水的研究

在粉煤灰中添加适量的转炉铁泥经盐酸溶解后 ,制得改性粉煤灰 ,在适宜的工艺条件下 ,对六价铬和总铬都有良好的处理效果。经多项实验证明 ,此工艺方法技术可行 ,适用于小型企业间歇排放。     

超声波有机改性凹凸棒土的苯酚吸附性能研究

采用超声波技术,对凹凸棒土进行有机改性,提高凹凸棒土的苯酚吸附能力,比较了不同的阳离子表面活性剂的改性效果,并且通过正交实验得出了超声波改性的最优化工艺条件为:十八烷基三甲基氯化铵的添加比例为35mmol/100g,超声波处理时间10min,屏极电流0·5A。在此条件下,苯酚去除率可达酸处理凹凸棒土的80倍以上,是搅拌有机改性的1.5倍。