大型灌区节水改造经济评价

根据所收集大型灌区节水改造相关资料,以层次分析法和模糊数学理论为基础建立了大型灌区节水改造经济评价模型.在此评价模型中,利用层次分析法建立了大型灌区节水改造投资效益分析的谱系结构,并根据模糊数学确立相应的大型灌区节水改造投资效益评价指标体系及其参数.最后利用模型对我国中、西部典型灌区--韶山灌区和青铜峡灌区节水改造进行了经济评价,并对评价结果进行了讨论,说明了模型和方法的有效性,同时说明了我国西部大开发的必要性.     

Motivations of recreational fishers involved in fish habitat management

This study profiled the motivations of recreational fishers involved in habitat management activities in Australia, USA, UK and Ireland. Fishers were surveyed using an online questionnaire. Primary motivations for involvement were social (‘putting something back’) rather than to increase fish numbers or improve fishing experience. Fishers were more likely to participate in habitat management if they were members of a club or organisation or self‐rated their knowledge of various aspects of fish ecology as very good. Most activities undertaken were relatively simple tasks such as picking up litter and contacting government or the media. Fishers that did not take part in habitat management cited lack of time as the principal reason, but organisational issues (lack of contacts, funding and ideas) were also important. There are considerable opportunities for government agencies and recreational fishing organisations to increase the participation of recreational fishers in habitat management as well as their involvement in more complex tasks through targeted programmes providing contact points, ecological information and administrative support.     

恢复生态学的研究动态

综述了恢复生态学的定义、理论基础、研究发展历史、研究概况,并分析讨论了恢复生态学研究发展趋势。     

预成型软管内衬玻璃钢修复管道

介绍了预成型复合材料软管内衬修复技术及在胜利油田胜利采油厂φ219×7输油管道上的实际应用。预成型复合材料软管内衬修复技术是管道内修复技术之一,该技术采用浸渍树脂的预成型复合软管,以压缩空气作动力沿管内壁使其翻入管道,经加温固化后,形成紧贴在管内壁上的具有防腐抗渗、强度高的“管中管”。     

Organic Carbon and Alkalinity Increase in Topsoil After Rangeland Restoration Through Atriplex nummularia Plantation

This research studied the impact of fodder shrub plantations (Atriplex nummularia Lindl.) on topsoil properties, with particular reference to organic carbon, nitrogen, and soluble salts, in the Marrakech region (central Morocco). The studied plantation interventions were carried out to rehabilitate degraded rangeland and to mitigate desertification. The field experiment was conducted by drawing seventeen 50‐m‐long transects designed according to the ecological patch–interpatch approach defined by the Landscape Function Analysis. The top soil (0–5 cm) was sampled in 134 microsites, covering the main patch and interpatch types in plantation and control plots. The following variables were determined: pH, carbonates, organic carbon, total nitrogen, electrical conductivity, and soluble ions (Na⁺, K⁺, Ca²⁺, Mg²⁺ Cl⁻, NO₃⁻, SO₄²⁻ and PO₄³⁻). Statistical analyses were carried out to analyse changes between sites and between patch types. Most of the studied properties were strongly affected by the spatial pattern defined by the plantation, particularly when the sites with higher biomass production were considered. Organic carbon increased by around 63% and 117% when the under canopy patches were compared, respectively, to the between‐plants interpatches and to the control plots, a strong positive effect considering the aridity of the study area. On the other hand, a stronger increase was detected under canopy for most soluble salts and sodium adsorption rate. On average, the latter increased by 350% and up to 450% under the best developed plants, a stronger impact than observed in previous research, highlighting the very strong plant effect on the soil surface alkalinity. Copyright © 2015 John Wiley & Sons, Ltd.     

Variations in pore distribution of reconstructed soils induced by opencast mining and land rehabilitation based on computed tomography images

Opencast coal mining is an anthropogenic activity that changes the antecedent soil profile, and it was important to understand the distribution characteristics of soil pore and then select suitable land rehabilitation measures. To better quantify the pore distribution characterization of reconstructed soils in opencast coalmine dumps, high-resolution and non-destructive computed tomography (CT) method was used to study the effect of opencast coal-mining and land rehabilitation on the soil pore distribution by scanning soils from the Antaibao Opencast Coal-mine in China. The soils were taken from the dump platforms with different rehabilitation time and an unmined site. ImangeJ 2 was used to process the scanned images and the soil pore densities and porosities of different pore sizes were used to analyze the distribution characteristics of soil pore. Opencast mining activities decreased soil pore density and soil porosity, especially in macropores. Compared to unmined soils, the total porosity of the non-rehabilitated soils reduced by 25.0%, 20.5%, 17.7% at the depths of 0–25, 25–50, 50–75 cm, respectively. Vegetation rehabilitation should be used to develop soil pore structure and improve the proportion of different pore sizes.     

北京风沙化土地生态修复现状、问题与对策——以延庆县为例

风沙危害是目前北京地区面临的最为严重的生态环境问题之一,搞好本区的生态修复工作具有重要的意义。以延庆县为例,系统分析了本区风沙化土地生态建设的制约因素以及生态修复现状中存在的问题,提出了今后生态修复的模式和4条对策:一是加强农田耕作制度的指导与管理;二是坚持生态修复与经济发展相结合;三是依靠科技,强化管理,提高防沙治沙的技术含量;四是加强法制建设,实行依法治沙。     

定西地区生态修复效果研究

生态修复期间,不同土地类型上植被响应最明显的是植被盖度和生物量;生态修复调节径流、减少土壤流失的作用非常明显,减水减沙效果以退耕草地最好,其次为灌木林地和乔木林地,荒坡草地最差;生态修复有助于土壤的正向发育,能够提高土壤有机质和氮磷含量。生态修复的重点是先要保护退耕地和林草地,其次是荒地。     

Dynamic mobilisation exercises increase cross sectional area of musculus multifidus

Reason for performing study: In human subjects with back pain, the deep spinal stabiliser m. multifidus is inhibited ipsilaterally leading to atrophy, asymmetry and intervertebral instability. Specific physiotherapeutic exercises are required to reactivate m. multifidus. This study assesses the effect of dynamic mobilisation exercises on size and symmetry of m. multifidus in the equine caudal thoracic and lumbar spine. Hypotheses: Regular performance of dynamic mobilisation exercises over a period of 3 months increases cross sectional area (CSA) and left‐right symmetry of m. multifidus muscles in the caudal thoracic and lumbar spine. Methods: Eight horses performed dynamic mobilisation exercises (3 cervical flexions, one cervical extension and 3 lateral bending exercises to the left and right sides) with 5 repetitions/exercise/day on 5 days/week for 3 months during which time they were not ridden. Left and right m. multifidus CSA was measured ultrasonographically at 6 levels from T10 to L5 at the start (initial evaluation) and end (final evaluation) of the 3 month study. Changes in CSA of the right and left m. multifidus muscles and symmetry of m. multifidus CSA on the right and left sides between the 2 evaluations were sought using analysis of variance (P<0.05). Results: Between the initial evaluation and final evaluation m. multifidus CSA increased significantly at all 6 spinal levels on both right and left sides. Asymmetries in m. multifidus CSA between the right and left sides decreased between the initial and final evaluations. Conclusions: Hypertrophy of multifidus occurred over a 3 month period during which dynamic mobilisation exercises were the only exercise performed. Potential relevance: Dynamic mobilisation exercises maybe a useful rehabilitative technique for horses in which m. multifidus has atrophied in response to back pain.