观赏海棠新品种“花冠”的选育

观赏海棠新品种"花冠"是由"绚丽"(‘Radiant’)开放授粉,实生选种育成。树姿直立,生长势强。成熟叶片绿色。花蕾红色,花朵粉红色,花瓣椭圆形,基部离生。每个花序的单花开放后在萼片处仍聚拢,花序似一个花束。平均花冠大小3.8cm,花期13~15d。连续开花结果能力强,果实扁圆形,果面光滑,呈黑红色,降霜后果实仍较硬,经冬不落,观赏性高。适宜于辽宁地区庭院、小区、街路、广场绿化。     

云南蔬菜产业发展的问题与思考

简述了云南省利用国家实行新一轮西部大开发机遇,推进实施绿色经济强省、民族文化强省建设和中国向西南开放的“桥头堡”战略机遇,重点发展高原特色农业,描述云南蔬菜产业发展状况的基础上,阐述了云南蔬菜产业发展出现的农药残留超标、蔬菜品质低、蔬菜净菜率低、蔬菜废弃物污染环境、蔬菜重茬导致的土壤盐碱化、蔬菜重茬导致的土传病害暴发等问题以及制约云南蔬菜产业发展的主要因素,提出云南蔬菜产业要可持续发展,必须开展提质增效研究,供读者参考。     

Simulation of the factors affecting β-glucan levels during the cultivation of oats

A Monte Carlo simulation technique was employed to simulate the factors influencing the level of β-glucan content in both hulled (HO) and naked (NO) oat cultivars during cultivation of the crop. Probability density functions were used to model the uncertainty and variability in the input factors. A scenario analysis was subsequently developed to look at the impact of different model assumptions and input parameters. The simulated mean β-glucan level in harvested oats grain was 3.50 and 4.25 g/100 g for hulled (HO) and naked (NO), respectively. A sensitivity analysis highlighted that cultivar selection was the most important input parameter compared to other inputs in determining the final β-glucan level (correlation coefficients of 0.64 and 0.79 for HO and NO, respectively). The analysis also indicated the positive effect of delayed sowing on β-glucan content (correlation coefficients of 0.32 and 0.25 for HO and NO, respectively). Germination and storage factors showed a negative impact on the final β-glucan levels. The scenario analysis shows the applicability of the proposed model for various agronomic practices. This approach establishes a quantitative scientific ranking of factors influencing β-glucan levels during the cultivation of oats.     

喷水推进泵非均匀进流研究进展

针对喷水推进泵运行过程中存在的非均匀进流,从驱动轴扰动、船舶边界层厚度以及进水流道结构等方面分析了非均匀进流的成因,探讨了进口速度比IVR和船舶航行速度对不均匀度产生的影响,总结了非均匀进流的不良效应.当进口速度比IVR以及船速增加时,进流面不均匀度也随之增加,进流品质逐渐恶化.非均匀进流下,泵进流面存在径向速度与压力梯度,导致喷水推进泵在工作过程中会出现回流、二次流、流动分离等失稳现象,内部涡旋扰动代替系统扰动催生失速,导致能量耗散.同时,叶片载荷、空泡体积分布以及压力脉动也呈现出高度不均匀性.基于近年来国内外对非均匀进流的研究现状,提出了喷水推进泵非均匀进流需要进一步深入研究的内容和方向.     

传统农业文化在云南高原蔬菜产业中的可持续应用

系统研究了传统农业文化以及现代科学技术在云南蔬菜产业中的应用现状,同时,重点阐述了现代农业的可持续发展离不开传统农业,将二者融合发展,才能产出优质蔬菜,提出云南蔬菜产业发展的根本在于突出生态走传统农业文化之路。     

Deep-Sea Coral Garden Invertebrates and Their Associated Fungi Are Genetic Resources for Chronic Disease Drug Discovery

Chronic diseases characterized by bone and cartilage loss are associated with a reduced ability of progenitor cells to regenerate new tissues in an inflammatory environment. A promising strategy to treat such diseases is based on tissue repair mediated by human mesenchymal stem cells (hMSCs), but therapeutic outcomes are hindered by the absence of small molecules to efficiently modulate cell behaviour. Here, we applied a high-throughput drug screening technology to bioprospect a large library of extracts from Irish deep-sea organisms to induce hMSC differentiation toward musculoskeletal lineages and reduce inflammation of activated macrophages. The library included extracts from deep-sea corals, sponges and filamentous fungi representing a novel source of compounds for the targeted bioactivity. A validated hit rate of 3.4% was recorded from the invertebrate library, with cold water sea pens (octocoral order Pennatulacea), such as Kophobelemnon sp. and Anthoptilum sp., showing the most promising results in influencing stem cell differentiation toward osteogenic and chondrogenic lineages. Extracts obtained from deep-sea fungi showed no effects on stem cell differentiation, but a 6.8% hit rate in reducing the inflammation of activated macrophages. Our results demonstrate the potential of deep-sea organisms to synthetize pro-differentiation and immunomodulatory compounds that may represent potential drug development candidates to treat chronic musculoskeletal diseases.     

导叶式混流泵旋转失速的研究进展

旋转失速是混流泵等旋转流体机械内部流动中普遍存在的不稳定现象,对机组性能甚至安全问题带来重要影响.从导叶式混流泵外部性能曲线、内部流动结构和压力脉动的时频特性分析了旋转失速的表现形式、失速先兆、失速的形成及传播机制,探讨了影响混流泵旋转失速形成、发展的关键因素.混流泵发生旋转失速的典型表现是外特性曲线出现不同形式的正斜率(马鞍形),内部流场出现周期性传播的漩涡结构,旋涡造成了流道的堵塞,由此导致不稳定的压力波动;轮缘泄漏涡形态结构和运动轨迹分析为混流泵失速先兆研究提供了新的思路.流量工况是导致混流泵旋转失速现象发生的最直接因素,随着流量减小,会对失速团的数量产生明显的影响.叶片数、叶轮转速和轮缘间隙也是影响失速团数量、传播速度和发展过程的重要因素.基于近年来国内外的研究现状,提出了未来混流泵旋转失速需要进一步深入研究的内容和方向.     

Management tools for optimal allocation of wood fibre to conventional log and bio-energy markets in Ireland: a case study

A set of tools are described for optimal allocation of wood fibre at an operational planning level. These were applied to a case study in Ireland. Allocation was based on optimising net value recovery (delivered price minus harvesting and transportation costs) while meeting market demands and operational constraints (mainly crew capability and productivity limits). Two new models were developed to predict harvesting costs and transportation costs for Irish forest conditions. A new model was developed to link Sitka spruce biomass expansion factors to optimal log-making algorithms so that log and bio-energy product yields could be estimated for individual harvest areas. An existing operational allocation model based on a tabu search heuristic procedure was used. The case study included 16 forest harvest areas and 12 processing plants (saw logs, pallet logs, stakes, pulp, bio-energy slash bundles, etc.). New terrestrial lidar scanning procedures were used to obtain representative stem profiles from over 4,000 trees for the 16 forests. We demonstrated that optimal allocation of bio-energy and log products, while complex, can be achieved through the use of appropriate management tools.     

离心风机涡旋结构及失稳流动特性分析

为了了解离心风机转子区域的失稳流动特性,基于SST k-ω湍流模型,探究了风机进流面非均匀流动特性与转子区域失稳流动的匹配关系,并基于涡动力学探究了转子失稳流道的涡旋尺度与结构.研究结果表明,在设计风量下,离心风机转子区域呈现明显的非均匀流动特性,可由气流速度、流动品质划分为稳流区和失稳区.同时,风机进流面流动特性与转子区域内流特性保持较好一致性,压力、速度、进流冲角皆呈现非均匀分布.进流面高速气流仅仅冲刷转子稳流区流道,而进流面低速流体在流经转子轴端后经由离心力的作用流至各个流道.通过使用进流冲角、环量、切向速度等方法,确定了额定工况下转子区域涡旋尺度、堵塞程度最为剧烈的流道,并通过湍动能及涡核分布成功捕捉堵塞流道的涡旋结构.