调节鄱阳湖枯水位 维护江湖健康

2003年以来,鄱阳湖枯水期水位连创新低,持续时间延长,导致水质恶化、湿地生态系统遭受破坏、候鸟栖息地受到威胁;生产生活用水、农田灌溉、航运和水产捕捞受到严重影响．为了改变鄱阳湖枯水期持续处于低水位状态,确保江湖水系健康,提出了鄱阳湖枯水调节的基本原则：改善生态环境为主要目的,调枯不调洪;从整体出发,做到江湖两利;以简单工程进行调节,趋利避害;保持工程运用的灵活性,实施适应性管理．同时,规划了鄱阳湖枯水调节工程的地点、规模和运行方式．作为一个以保护和改善生态环境为主的水利工程,其具有改善水环境、保护水生态、维护水安全,保护鄱阳湖湿地的生态环境及确保候鸟越冬条件,缓解长江下游枯水期低水位状态和促进湖区经济社会发展等方面的效益．     

Phenolic compounds of Pinus laricio needles: A bioindicator of the effects of prescribed burning in function of season

Fire is a dominant ecological factor in Mediterranean-type ecosystems. Forest management includes many preventive tools, in particular for fire prevention, such as mechanical treatments and prescribed burning. Prescribed burning is a commonly used method for treating fuel loads, but fuel reduction targets for reducing wildfire hazards must be balanced against fuel retention targets in order to maintain habitat and other forest functions. This approach was used on Pinus nigra ssp laricio var. Corsicana, a pine endemic to Corsica of great ecological and economic importance. Many studies of plant phenolic compounds have been carried out concerning responses to various stresses. The aim of this study was to understand i) the effects of prescribed burning 1 to 16 months later and ii) the effects of the seasonality of burning, spring or fall, on the production of phenolic compounds in Pinus laricio. After prescribed burning conducted in spring, Pinus laricio increases the synthesis of total phenolic compounds for a period of 7 months. The increase is greater after spring-burning than fall-burning. With regard to simple phenols, only dihydroferulic acid responds about 1 year after both types of prescribed burning. The causes of these increases are discussed in this paper. Total phenolic compounds could be used as a bioindicator for the short-term response of Pinus laricio needles to prescribed burning. Simple phenols may be useful for revealing the medium-term effects of prescribed burning. The results of this study include recommending forest managers to use prescribed burning in the fall rather than spring to reduce fuel loads and have less impact on the trees.     

Effect of the pre-slaughter logistic chain on meat quality of lambs

A total of 144 lambs were sampled in a 3 × 2 × 2 factorial design, testing three residence (stay) times at a pre-slaughter classification centre (0, 7, and 28 days) and two seasons (summer and winter), with two replicates in each season. Meat from the longissimus dorsi was analysed in terms of pH, WHC, texture, colour (L*a*b*, chroma and hue) and carcass bruising. Stay time had a significant effect (p < 0.001) on meat texture, while season had a significant effect (p < 0.001) on all variables analysed. Overall, stay time had less effect on meat quality than season and the interaction between treatments was not significant. Meat from lambs slaughtered in winter had some dark-cutting characteristics, with darker colour, higher ultimate pH, tougher meat and lower press juice. In conclusion, pre-slaughter classification and season are sources of stress for lambs and affect meat quality traits.     

基于SPOT-NDVI的贺兰山植被覆盖的时空变化研究

对贺兰山区进行分区的基础上,运用SPOT\|NDVI数据对1998~2010年四季不同区的植被演变进行研究。结果表明,贺兰山植被高海拔区域的平均覆盖最高,其次为中海拔区域,低海拔区域的东坡较高,其他区域覆盖较低。研究区植被的生长季为5~10月,其中植被覆盖最好为8月。近13 a来,贺兰山植被总体表现为增长趋势,其中绝大部分区域的秋季植被增长,尤其是中高海拔区域。考虑到研究区干旱化的趋势以及对植被生长的影响,贺兰山(特别是低山地区)植被的增长趋势在未来可能难以持续。     

Influence of Sea Surface Wind Vector on Sea SurfaceBrightness Temperature Gain in Different Seasons

Based on the correlation of the sea surface wind vectors to the sea surface roughness temperature in different seasons,wind field data of the Windsat L2 U10 wind fields in the northwest Pacific in January,April,July and October from 2012 to 2016 were selected,and used sea surface roughness Semi\|empirical and theoretical algorithm,the relationship between the brightness temperature gain caused by wind speed and wind vector under different seasons was analyzed.the results showed that the contribution of wind speed to horizontal brightness temperature gain was greater than that of vertical brightness temperature; the change of horizontal brightness temperature gain was the most significant in January and the least was in July; the maximum and minimum mean values of wind speed to vertical brightness gain were 0.19 K and 0.05 K respectively,indicating that the wind speed had little effect on the vertical brightness gain.It showed that the vertical brightness temperature gain was almost independent of the seasons by the standard deviation calculation; in April and October to form larger cyclone phenomenon in high latitude regions by the Pacific and Hawaii high pressure under the influence,and with brightness gain changes,showing obvious features of the North Pacific gyre.     

The influence of climatic factors on non-specific back and neck-shoulder disease

An epidemiological study was carried out to explore the relationship between climatic factors and non-specific low-back and neck-shoulder symptoms in working populations. In a review of published literature, 27 studies were found which related climatic factors to musculoskeletal symptoms, but none of these studies specifically addressed the subject. It can be concluded that a relationship between climatic factors and musculoskeletal symptoms is considered at least plausible by both researchers, workers and patients, but that the epidemiological evidence appearing from literature is very weak. Questionnaire data which were collected on musculoskeletal symptoms, workload and perceptions of climatic conditions of 2030 workers in 24 different occupations were analysed multivariately. About one-quarter of the workers related symptoms of the low back and neck-shoulders to climatic factors. They perceived climatic factors in most cases as aggravating factors for their symptoms. No seasonal influence on prevalence rates was reported. For low-back and neck-shoulder symptoms and for sick leave due to neck-shoulder symptoms, an association was found with climatic factors, and in particular with respect to draughts in relation to neck-shoulder symptoms. In addition, neck-shoulder symptoms were negatively related to frequent outdoor work. The findings suggest a relationship between climatic factors and musculoskeletal symptoms and call for further detailed investigations.     

基于季节指数修正因子的交乘趋向预测方法

季节预测模型中的交乘趋向模型虽然能根据历史趋势的变化加大季节跳动幅度,但对于季节指数的处理只是使用了历史季节指数球平均,无法很好地提取历史数据中含有的季节特征信息。在季节交乘趋向模型中,先对季节指数做出趋势预测,然后根据季节指数的趋势和季节指数与季节指数趋势之间的比值之乘积,得到修正的季节指数,以提高季节指数中含有的季节特征信息。实验结果显示,这种预测模型在现有实验数据环境中最大相对误差为3.08%,远低于原交乘趋向模型的8.42%。     

关于主导产品销量的“趋势—季度”变动预测

通过对主导产品Φ108mm×4.5mm热轧管销量的预测,从理论上、实践上详尽阐述了“趋势—季度”变动预测模型在实际生产经营中的具体运用,同时对模型的正确性也进行了实际验证。这对当今企业生产经营工作中各种目标的定量预测,具有重要的现实意义。     

Site-related airborne biological hazard and seasonal variations in two wastewater treatment plants

Results of a study conducted to assess the degree of airborne bacterial contamination generated by two wastewater treatment plants (WWTP) with different treatment systems and evaluate the dispersion of potential pathogens, have been described. Aerosols samples were collected in summer and winter with an agar impact sampler from several plant sites. External upwind and downwind controls were also examined. Total colony-forming counts of mesophilic and thermophilic bacteria, actinomycetes and streptomycetes, Gram-negatives, coliforms and sulfite-reducers were determined. Selective media were used in order to detect pathogenic bacteria. The lowest concentrations of mesophilic and thermophilic bacteria were 8 and 28 CFU/m(3) in plants A and B respectively, the highest >40,000 CFU/m(3) in both plants. Strains of Escherichia coli, Clostridium perfringens, Staphylococcus aureus and Enterococcus spp. were isolated in some sites of the two plants. Salmonella spp., Yersinia enterocolitica and Legionella spp. were never detected. The activities involving nebulization and mechanical aeration of wastewaters and the sewage inflows have proved to be of greatest potential risk. In both plants, we found a statistically significant dependence of bacterial contamination on the season for many of the analyzed parameters but a clear seasonal trend could not be observed.