FRACTAL DIMENSION ANALYSIS APPLIED TO THE 7 DRAINAGE BASINS AND THE FLOOD IN CHINA

Foreword　Asoneofthethreegreatdiscoveriesin 1 970s ,thefractaltheoryhasbeenwidelyappliedinmanyfieldsconcerningthesciencesofnatureandthehumanities .Atpresent ,thefractaltheoryhasbeenappliedintherelatedanalysisofwatersystemordisaster .However ,thestud iesonnatureofrelationshipbetweenthewholewatersysteminChinaanddisasterfractalanaly sisarestillintheirinitialperiod .Thepaperpresentsafractaldimensionof 7drainagebasinsandthefloodinChinaaswellastheirpossiblerelations .Itishopedthatthepaperwouldbehe…     

MODELING THE BUILDUP AND WASHOFF OF POLLUTANTS ON URBAN WATERSHEDS1

ABSTRACT: A model for urban stormwater quality was developed in this study. The basis for the model is the process by which pollutants build up on the watershed surface. For the wet climate of the study site, it was assumed that there exists an interval of time over which the pollutant buildup equals the pollutant washoff (no accumulation of pollutant). The buildup model was represented by a linear function of the antecedent dry time. The buildup function was then linked with a pollutant washoff model represented by a power function of the storm runoff volume. Various time intervals for no net accumulation were tested to calibrate the model. The model was calibrated to observed data for two small urban basins in Baton Rouge, Louisiana, and model results were used to analyze the behavior of phosphorus concentrations in storm runoff from these basins over a long period of time.     

磁变仪定向的研究

讨论了固定铁磁影响环境和无铁磁影响环境中磁变仪的定向问题，并对《地磁台站观测规范》提出了修改建议     

Thermal and mechanical properties of poly(lactic Acid) and poly(ethylene/butylene Succinate) blends

In this study, blends of poly (lactic acid) (PLA) with poly(ethylene/butylene succinate) (Bionolle) have been investigated for their thermal and mechanical properties as a function of the concentration of Bionolle. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and tensile tests were used to characterize the blends. From the results of the DMA and DSC, it was found that this blend system was not miscible within the compositions studied. DSC results showed that adding Bionolle aids in crystallization of PLA. It was observed that increasing the Bionolle concentration led to a slight increase in the strain-at-break of the blends but a decrease in the Young’s modulus and ultimate tensile strength. Biaxially oriented films showed an increase in tensile strength, modulus, and strain-at-break.     

特大型煤和瓦斯突出的地质条件及其成因

特大型煤和瓦斯突出危害极大，具有独特的发生条件，应专门研究。在全国９９ 次特大型煤和瓦斯突出详细研究的基础上，总结了特大型突出的一般特征及发生的地质和采矿条件，并给出了南桐矿区的几个临界值。对特大型突出地质条件的成因进行了较深入的探讨，提出了防止特大型突出的几点建议     

Transformational leadership and organizational commitment: mediating role of psychological empowerment and moderating role of structural distance

Using a sample of 520 staff nurses employed by a large public hospital in Singapore, we examined whether psychological empowerment mediated the effects of transformational leadership on followers' organizational commitment. We also examined how structural distance (direct and indirect leadership) between leaders and followers moderated the relationship between transformational leadership and organizational commitment. Results from HLM analyses showed that psychological empowerment mediated the relationship between transformational leadership and organizational commitment. Similarly, structural distance between the leader and follower moderated the relationship between transformational leadership and organizational commitment. Implications for research and practice of our findings are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

多相催化湿式氧化法处理高浓度难降解有机废水的研究

在高压反应釜内，采用自制颗粒贵金属催化剂催化湿式氧化法处理高浓度饲料抗氧化剂合成废水，探讨了温度、压力、进水pH等反应条件对废水处理效果的影响。在温度为220℃、总压为8MPa条件下，COD，TOC，TN和色度的去除率分别达到77．0％，66．1％，70．2％，91％；处理后的废水pH很低，催化剂显示出较好的耐酸性；随进水pH的增加，COD的去除率逐渐降低，出水pH增加。     

Atrazine sorption-desorption hysteresis by sugarcane mulch residue

Sorption and desorption kinetics are essential components for modeling the movement and retention of applied agricultural chemicals in soils and the fraction of chemicals susceptible to runoff. In this study, we investigated the retention characteristics of sugarcane (Saccharum spp. hybrid) mulch residue for atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) based on studies of sorption-desorption kinetics. A sorption kinetic batch method was used to quantify retention of the mulch residue for a wide range of atrazine concentrations and reaction times. Desorption was performed following 504 h of sorption using successive dilutions, followed by methanol extraction. Atrazine retention by the mulch residue was well described using a linear model where the partitioning coefficient (K(d)) increased with reaction time from 10.40 to 23.4 cm3 g(-1) after 2 and 504 h, respectively. Values for mulch residue K(d) were an order of magnitude higher than those found for Commerce silt loam (fine-silty, mixed, superactive, nonacid, thermic Fluvaquentic Endoaquepts) where the sugarcane crop was grown. A kinetic multireaction model was successful in describing sorption behavior with reaction time. The model was equally successful in describing observed hysteretic atrazine behavior during desorption for all input concentrations. The model was concentration independent where one set of model parameters, which was derived from all batch results, was valid for the entire atrazine concentration range. Average atrazine recovery following six successive desorption steps were 63.67 +/- 4.38% of the amount adsorbed. Moreover, a hysteresis coefficient based on the difference in the area between sorption and desorption isotherms was capable of quantifying hysteresis of desorption isotherms.     

White spruce response to co-composted hydrocarbon-contaminated drilling waste: effects of compost age and nitrogen fertilization

There are growing interests to use co-composted drilling wastes contaminated with hydrocarbons as growth media for planting in land reclamation. However, such use of the compost may have potential problems such as inherent toxicity of residual hydrocarbon and microbial N immobilization due to high compost C to N ratios. We investigated the growth, biomass production, N uptake, and foliar delta13C of white spruce (Picea glauca [Moench] Voss) seedlings in a pot experiment using 1-, 2-, 3-, and 4-yr-old composts (with different hydrocarbon concentrations and C to N ratios) and a local noncontaminated soil with (200 kg N ha(-1)) or without N fertilization. Growth and N content of seedlings (particularly N content in roots) were lower when grown in the compost media as compared with those grown in the soil. Within the compost treatments seedling growth was affected by compost age, but the magnitude of growth reduction was not linearly proportional to hydrocarbon concentrations. Plant N uptake increased with compost age, which corresponds with an increase in indigenous mineral N concentration. Effects of N fertilization on N uptake were curtailed by the presence of indigenous mineral N (e.g., in the 4-yr-old compost) and by fertilization-induced stimulation of microbial activities (e.g., in the 1-yr-old compost). The differences in foliar delta13C values between seedlings grown in compost and soil (P < 0.05) suggest that limitations on water uptake caused by the residual hydrocarbon might have been the predominant factor limiting seedling growth in the compost media. This study suggests that water stress caused by residual hydrocarbons may be a critical factor for the successful use of co-composted drilling wastes as a growth medium.