高校集中采购权力的监督与制约

高校实行集中采购,将竞争机制引入了公共支出使用过程,有利于提高资金的使用效益,但由于资金数额大,权力过于集中,为了避免在反腐败的同时产生新的问题,必须加强对采购权力的监控。     

中国股票市场综合效应与消费需求变动分析

本文首先研究股票市场影响消费需求的综合效应;在此基础上对中国股票市场促进消费需求的条件和障碍进行分析,并提出了发展股票市场促进消费需求的几条对策.     

弹药储存环境对弹药质量的影响

弹药在长期储存过程中,由于各种影响因素的作用,质量状况会逐渐变差。分析了引起弹药质量变化的因素,指出温湿度是促使弹药变质的主要因素。温度过高、过低,湿度过大、过小,或者温湿度变化过急,都会影响弹药质量;分析了温湿度对弹药各部件及不同材料的影响,并进行了分类,给出了温湿度需要控制的范围。     

轨道交通电连接器试验方法的标准分析

由于轨道交通电连接器的特殊性,不仅需要在设计和工艺上采取严格的措施进行改进,还需要进行检查试验。根据电压电流及频率对轨道交通电连接器进行分类,并结合标准NF F61-030-1992、EN 50467-2011、IEC 61984-2008、DIN 47275和EIA 364对电连接器的测试项目及条件进行分析,对轨道交通电连接器形成了系统的指导。     

部队弹药库房温湿度监测仪器选型研究

对温湿度监测仪器发展现状进行了阐述,对部队弹药库房温湿度监测的现状进行了详细分析,进而对部队弹药库房温湿度监测仪器选型进行了需求分析和方案设计,为规范弹药库房温湿度管理、确保库存弹药储存安全和促进部队弹药库房正规化建设提供了思路和借鉴。     

黄土高原地区农林牧业生态系统中主要灾害及减灾对策

农林牧业在黄土高原地区国民经济发展中占有十分重要的位置。本文根据全区的生态特点,对农业系统的生态环境恶化的几种主要形式进行了分析,同时提出了农林牧业整体建设的综合整治对策。     

吉林省畜禽养殖业的环境问题及防治技术

畜禽养殖业规模化生产带来了畜禽废弃物对环境的污染问题。2001～2002年作者的调查表明，吉林省8个主要城区畜禽存栏数已达到20184．87万头(只)，由畜禽产生的粪便尿液总量达6533．24万t，它相当于全省当年工业废弃物产生量的4．1倍，这些排泄物向环境排放BODs质量为2．7116万t，排放的CODcr质量为3．6414万t，排放的NH3-N质量为0．575万t。文章针对吉林省畜禽养殖业目前的生产规模和由此给环境带来的危害等问题，提出了相应的管理与治理措施，认为先进的饲料配方技术、清洁生产、开展国际合作以及使用生态厕所是解决问题的关键所在。     

国内外传爆药装药结构研究的发展动向

对国内和国外关于传爆药装药结构的研究现状和研究成果进行总结,分析了国内研究的一些不足,并提出了一些意见和该领域今后的研究方向.     

Long-term forest-floor litter dynamics in Canada's boreal forest: Comparison of two model formulations

Litter decomposition is a key component in ecosystem material cycling that determines (i) forest soil carbon (C) and nutrient content, (ii) release of carbon dioxide to the atmosphere, and (iii) generation and mass transfer of dissolved organic carbon from terrestrial to aquatic ecosystems. In this study, we provide simulations of long term forest-floor litter dynamics generated with both (i) an existing forest nutrient cycling and biomass growth model (ForNBM) with a single-pool formulation of forest-floor litter decomposition (Zhu et al., 2003. Ecol. Model. 169, 347-360), and (ii) a revised version of the model produced by substituting the single-pool formulation with a three-pool version of the formulation tested against data from litterbag experiments (FLDM; Zhang et al., 2010. Ecol. Model. 221, 1944-1953). This is done to determine the importance of subdividing the litter mass into categories of rates of decay (i.e., fast, slow, and very slow) on model accuracy. Forest-forest litter dynamics simulated with the two models are subsequently compared against field measurements collected at several northern jack pine (Pinus banksiana) stands along a southwest-northeast oriented transect (climate gradient) associated with the Boreal Forest Transect Case Study in northwest Canada. Initial comparison shows that the single-pool formulation underpredicts residual litter mass when forests are <65 years old, largely due to the improper treatment of the very slow decomposing litter component. This underprediction is resolved when the three-pool formulation is used. From a ecosystems-response point of view, the revised ForNBM (with the three-pool formulation) demonstrates that (i) forest-floor litter initially increases with forest growth and reaches a plateau once the forest matures; (ii) the forest floor stores more litter and C at the southern and warmer sites than at the northern sites; and (iii) in a similar climate regime, the forest floor stores more litter and C at productive than at nutrient-poor sites.     

Range‐Wide Genetic Connectivity of the Hawaiian Monk Seal and Implications for Translocation

Abstract: The Hawaiian monk seal (Monachus schauinslandi) is one of the most critically endangered marine mammals. Less than 1200 individuals remain, and the species is declining at a rate of approximately 4% per year as a result of juvenile starvation, shark predation, and entanglement in marine debris. Some of these problems may be alleviated by translocation; however, if island breeding aggregates are effectively isolated subpopulations, moving individuals may disrupt local adaptations. In these circumstances, managers must balance the pragmatic need of increasing survival with theoretical concerns about genetic viability. To assess range‐wide population structure of the Hawaiian monk seal, we examined an unprecedented, near‐complete genetic inventory of the species (n =1897 seals, sampled over 14 years) at 18 microsatellite loci. Genetic variation was not spatially partitioned (_w=?0.03, p = 1.0), and a Bayesian clustering method provided evidence of one panmictic population (K =1). Pairwise F_ST comparisons (among 7 island aggregates over 14 annual cohorts) did not reveal temporally stable, spatial reproductive isolation. Our results coupled with long‐term tag‐resight data confirm seal movement and gene flow throughout the Hawaiian Archipelago. Thus, human‐mediated translocation of seals among locations is not likely to result in genetic incompatibilities.