No abstract

Zeolitic imidazolate framework-8 (ZIF-8) was introduced on the surface of fibers of a non-woven fabric made of polyethylene terephthalate (PET).

Research on the impact of water projects (dams or floodgates) on river hydrology and the surrounding environment is important in river basin management. However, it is a difficult scientific issue due to its complexity. Huai River Basin is a unique region in China with high densities in both population and water projects and is experiencing a serious pollution problem.

The effect of the 2-methylimidazole (Hmim)/zinc nitrate hexahydrate (Zn) molar ratio on the physicochemical characteristics of the zeolitic imidazolate framework-8 (ZIF-8) was investigated. ZIF-8 crystals were synthesized by mixing Hmim with Zn at room temperature without any additives in methanol solution. It was found that Hmim/Zn molar ratio had significant influence on the crystallinity, yield, particle size and porosity of ZIF-8. The samples synthesized at low Hmim/Zn molar ratio showed a cubic shape, whereas at higher Hmim/Zn ratios truncated rhombic dodecahedron or rhombic dodecahedron morphologies were obtained. The particle size is decreased upon increasing the Hmim/Zn molar ratio. Besides, higher Hmim/Zn molar ratio in a certain range resulted in improving crystallinity, yield, surface area and micropore volume of ZIF-8. The ZIF-8 crystals produced at Hmim/Zn molar ratio of 8 exhibited the best characteristics. The present work provides new insights in relation to the role of Hmim/Zn molar ratio on the synthesis process of ZIF-8.

No abstract

Flow regime characteristics (magnitude, frequency, duration, seasonal timing and rates of change) play a primary role in regulating the biodiversity and ecological processes in rivers. River classification provides the foundation for comparing the hydrologic regimes of rivers and development of hydro-ecological relationships to inform environmental flow management and river restoration. This paper presents a classification of natural flow regimes and hydrologic changes due to dams and floodgates in the Huai River Basin, China, in preparation for an environmental flow assessment. The monthly natural flow regime of 45 stations in the upper and middle Huai River Basin were simulated for the period 1963-2000, based on the hydrological model SWAT (Soil and Water Assessment Tool). Six classes of flow patterns (low or high discharge, stable or variable, perennial or intermittent, predictable or unpredictable) were identified based on 80 hydrologic metrics, analysed by hierarchical clustering algorithms. The ecologically relevant climatic and geographic characteristics of these flow classes were tested for concordance with, and to strengthen, the hydro-ecological classification. The regulation of natural flow patterns by dams and floodgates changed flows at some locations within each flow class and caused some gauges to shift into another class. The research reported here is expected to provide a foundation for development of hydro-ecological relationships and environmental flow methods for wider use in China, as well as setting a new scientific direction for integrated river basin management in the Huai River Basin. Figure 4. Different hydrological metrics of six simulated natural flow regime classes. Boxes define the 25th, 50th and 75th percentile values and the vertical bars (whiskers) define the 10th and 90th percentile value. Mean values are defined by the dot symbol.

No abstract

A greenhouse pot test was conducted to study the impacts of replacing mineral fertilizer with organic fertilizers for one full growing period on soil fertility, tomato yield and quality using soils with different tomato planting history. Four types of fertilization regimes were compared: (1) conventional fertilizer with urea, (2) chicken manure compost, (3) vermicompost, and (4) no fertilizer. The effects on plant growth, yield and fruit quality and soil properties (including microbial biomass carbon and nitrogen, NH4+-N, NO3--N, soil water-soluble organic carbon, soil pH and electrical conductivity) were investigated in samples collected from the experimental soils at different tomato growth stages. The main results showed that: (1) vermicompost and chicken manure compost more effectively promoted plant growth, including stem diameter and plant height compared with other fertilizer treatments, in all three types of soil; (2) vermicompost improved fruit quality in each type of soil, and increased the sugar/acid ratio, and decreased nitrate concentration in fresh fruit compared with the CK treatment; (3) vermicompost led to greater improvements in fruit yield (74%), vitamin C (47%), and soluble sugar (71%) in soils with no tomato planting history compared with those in soils with long tomato planting history; and (4) vermicompost led to greater improvements in soil quality than chicken manure compost, including higher pH (averaged 7.37 vs. averaged 7.23) and lower soil electrical conductivity (averaged 204.1 vs. averaged 234.6 μS/cm) at the end of experiment in each type of soil. We conclude that vermicompost can be recommended as a fertilizer to improve tomato fruit quality and yield and soil quality, particularly for soils with no tomato planting history.