转炉冶炼20管坯钢生产实践

介绍了20#管坯钢的生产试验工艺，采取了拉碳法脱碳、钢包底吹氩及喂丝、保护浇铸、合理控制拉速等有效措施，解决了生产中存在的质量问题，为下一步的生产提供了理论和实践依据。     

策应鄱阳湖生态经济区建设 推动吉安进位赶超绿色崛起

建设鄱阳湖生态经济区是国家从战略全局和长远发展出发作出的一项重大决策。如何主动策应鄱阳湖生态经济区建设,推动吉安进位赶超、跨越发展,是摆在我们各级政府和科技部门面前一项亟待解决的问题。为此,一是要提高认识,统一思想,切实增强策应规划的使命感和责任感;二是要结合实际,突出重点,全面对接鄱阳湖生态经济区规划;三是要加强领导,落实措施,确保吉安进位赶超、绿色崛起取得明显成效。     

Optimization of the catch bench design using a genetic algorithm

Rockfalls are one of the hazards that may be associated with open pit mining. The majority of rockfalls occur due to the existing conditions of slopes, such as back break, fractures and joints. Constructing a berm on the catch bench is a popular method for the mitigation of rockfall hazards in open pit mining.The width of the catch bench and the height of the berm play a major role in the open pit bench design.However, there is no systematic method currently available to optimize the size of these parameters. This study proposes a novel methodology which calculates the optimum catch bench width by integrating the rockfall simulation model and genetic algorithm into a Simulation-Optimization Model. The proposed methodology is useful when used to determine the minimum catch bench width, or the maximum overall slope angle, insuring that a sufficient factor of safety of the slope is included while maximizing the overall profitability of the open pit mine.     

IPv6实验网的组建和测试分析

主要介绍设计、搭建IPv6实验网，并在此基础上捕获数据包，测试协议性能。通过分析数据包的结构，验证了IPv6网络的特点：地址匹配的方便性、数据报头的简洁性。通过设计和组建IPv6／IPv4双协议栈路由器，介绍了一种通过IPv4网络转发IPv6数据包的双协议栈隧道技术。     

Laboratory evaluation of dripper performance

The catch can method is traditionally used for evaluating performance of drip systems. Two variations of this method are commonly applied in laboratory testing of drippers: the sequential and the simultaneous method. This study compared uniformity and measurement uncertainty of the two methods, with the overall aim of improving irrigation water management. The simultaneous method was found to have a lower coefficient of variation (C_v) and measurement uncertainty, indicating that it is more accurate than the sequential method. In all the tests, however, the C_v was determined to be <5%, which is acceptable as per the current reference standard.     

Surface hydrophobicity and functional properties of myofibrillar proteins of mantle from frozen-stored squid (Illex argentinus) caught either jigging machine or trawling

The surface hydrophobicity and functional properties of actomyosin from the mantle of frozen squid caught either by jigging machines (AME1) or by trawl (AME2) were investigated. Two components of 155 and 55 kDa were present in the gels at zero time of storage. Degradation of the myosin heavy chain and increase in the 155 kDa component occur earlier in AME2. Irrespective of the catch method used, no significant (P>0.05) changes in protein solubility were observed. The reduced viscosity of both AME1 and AME2 decreased up to months 3 and 5 of frozen storage, respectively. At the beginning of storage, the superficial hydrophobicity of AME2 was 30% higher than that of AME1. So 1-anilino-8-naphthalene sulfonic acid of AME2 significantly increased during 3-5 months of storage period and that of AME1 at the end of storage. The emulsion activity index (EAI) of AME2 significantly (P<0.05) increased during the first month and decreased after 3 months of storage. EAI of AME1 decreased at month 3 and remained unchanged thereafter. Emulsion stability (ES) of AME2 showed a behavior that was similar to its IAE and that of AME1 remained unchanged.     

Characterization of roadway stormwater system residuals for reuse and disposal options

The chemical characterization of sediments accumulated in catch basins and stormwater ponds provides important information for assessing risks associated with management of these residuals upon removal of accumulated deposits in stormwater systems. In this study, over a period of 15 months, more than 150 residual samples were collected from 77 catch basin units and 22 stormwater ponds from 16 municipalities throughout the state of Florida. Concentrations (mg/kg) of metals and metalloids (arsenic, barium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, and zinc) and trace organics (volatile organics, semi-volatile organics, herbicides, and pesticides) in the sediments were measured. In addition, the synthetic precipitation leaching procedure (SPLP) was utilized to evaluate pollutant leachability risk for a subset of the samples collected. Measured pollutant concentrations were compared to corresponding risk-based guidelines in Florida (i.e., Florida soil cleanup target levels) to assess potential human health risks of beneficial use of these residuals through land application. Leached concentrations were compared to risk-based water quality guidelines (i.e., Florida groundwater cleanup target levels) to examine the potential for groundwater contamination. Although several metals (arsenic, barium, chromium, copper, nickel, lead, and zinc) were routinely detected in the catch basin and stormwater pond sediments, their concentrations were generally lower than the Florida's risk-based cleanup target levels for soils. A small number of organochlorine compounds (e.g., 4,4′-DDE, 4,4′-DDT) were detected, but only in a limited number of the samples (less than 10%); leaching of trace organic pollutants above the Florida risk-based groundwater thresholds was rare. The results suggest that when land-applied or beneficially used, these residuals are not expected to pose a significant threat to human health or the environment and the results of this research will provide stormwater managers and environmental management authorities with a useful resource to examine proper disposal and beneficial use of catch basin and stormwater pond sediments.     

Nitrogen dynamics following grain legumes and subsequent catch crops and the effects on succeeding cereal crops

The effects of faba bean, lupin, pea and oat crops, with and without an undersown grass-clover mixture as a nitrogen (N) catch crop, on subsequent spring wheat followed by winter triticale crops were determined by aboveground dry matter (DM) harvests, nitrate (NO₃) leaching measurements and soil N balances. A 2½-year lysimeter experiment was carried out on a temperate sandy loam soil. Crops were not fertilized in the experimental period and the natural ¹⁵N abundance technique was used to determine grain legume N₂ fixation. Faba bean total aboveground DM production was significantly higher (1,300 g m^?2) compared to lupin (950 g m^?2), pea (850 g m^?2) and oat (1,100 g m^?2) independent of the catch crop strategy. Faba bean derived more than 90% of its N from N₂ fixation, which was unusually high as compared to lupin (70–75%) and pea (50–60%). No effect of preceding crop was observed on the subsequent spring wheat or winter triticale DM production. Nitrate leaching following grain legumes was significantly reduced with catch crops compared to without catch crops during autumn and winter before sowing subsequent spring wheat. Soil N balances were calculated from monitored N leaching from the lysimeters, and measured N-accumulation from the leguminous species, as N-fixation minus N removed in grains including total N accumulation belowground according to Mayer et al. (2003a). Negative soil N balances for pea, lupin and oat indicated soil N depletion, but a positive faba bean soil N balance (11 g N m^?2) after harvest indicated that more soil mineral N may have been available for subsequent cereals. However, the plant available N may have been taken up by the grass dominated grass-clover catch crop which together with microbial N immobilization and N losses could leave limited amounts of available N for uptake by the subsequent two cereal crops.     

The mutual influence of two buildings on their wind-driven rain exposure and comments on the obstruction factor

Wind-driven rain (WDR) deposition on a two-building configuration is studied with Computational Fluid Dynamics (CFD). The configuration consists of a high-rise building screened by a low-rise building. Validation of the wind-flow simulations is performed with Particle Image Velocimetry (PIV) measurements in a wind tunnel. Raindrop motion is simulated by Lagrangian particle tracking in the mean wind-flow pattern with a reference wind speed U₁₀=10 m/s. Horizontal rainfall intensities R_h=5 and 30 mm/h are considered. Simulations of WDR are performed for the two-building configuration and for each building separately, to analyse the mutual influence of the buildings on their WDR deposition pattern. The simulation results indicate that this influence is very pronounced and that it is to some extent opposite to what might be expected. The low-rise building influences the deposition on the high-rise building (downstream disturbance), not by partly shielding it from wind and WDR, but by increasing the strength of the standing vortex between the two buildings. This locally increases WDR intensities on the high-rise building facade by more than a factor 2 for both R_h=5 and 30 mm/h. On the other hand, the high-rise building influences deposition on the low-rise building facade (upstream disturbance) by the wind-blocking effect. This effect yields a reduction in WDR deposition on the low-rise building facade by up to about 25% for both R_h=5 and 30 mm/h. In the European standard draft for WDR assessment, the mutual influence can only be taken into account by a simplified reduction factor, called the obstruction factor. It only considers downstream disturbances, and does not consider the possibility of increased WDR deposition due to neighbouring buildings. Care should therefore be exercised when using the current version of the obstruction factor to determine WDR exposure.     

Biogas production from catch crops: Increased yield by combined harvest of catch crops and straw and preservation by ensiling

The combination of catch crop cultivation with its use for biogas production would increase renewable energy production in the form of methane, without interfering with the production of food and fodder crops. The low biomass yield of catch crops has been shown as the main limiting factor for using these crops as co-substrate in biogas plants, since the profit obtained from the sale of methane barely compensates the harvest costs. Therefore, a new agricultural strategy to harvest catch crops together with the residual straw of the main crop was investigated, in order to increase the biomass and the methane yield per hectare. Seven catch crops harvested together with stubble from the previous main crop were evaluated. The effects of stubble height, harvest time and ensiling as a storage method for the different catch crops/straw blends were studied. Biomass yields as TS ranged between 3.2 and 3.6 t ha⁻¹ y⁻¹of which the catch crop constituted around 10% of the total biomass yield. Leaving the straw on the field until harvest of the catch crop in the autumn could benefit methane production from the straw both due to increased biomass yield and an increased organic matter bioavailability of the straw taking place on the field during the autumn months. Ensiling as a storage method could be feasible in terms of energy storage and guaranteeing the feedstock availability for the whole year. This new agricultural strategy may be a good alternative for economically feasible supply of catch crops and straw for biogas production.