几种混播绿化组合对高等级公路边坡防护效益的研究

试验将3种混播组合对高等级公路边坡的防护效益进行了初步研究.结果表明:混播组合方案1(红豆草60%+无芒雀麦20%+多年生黑麦草20%)的防护效果最好,减少径流82.6%,减少冲刷90.1%;其次是混播组合方案3(多年生黑麦草40%+草地早熟禾20%+匍匐翦股颖20%+紫羊茅20%),减少径流80.9%,减少冲刷80.9%;而以混播组合方案2(小冠花70%+多年生黑麦草30%)的防护效果最差,减少径流76.4%,减少冲刷73.5%.     

Seed Emulsion Coating for Preventing the Weathering of Stone Sculpture Along Hills

The polysiloxane polyacrylate seed emulsion coating was prepared to prevent the weathering of Stone Sculpture Along Hills.The experiments show that the coating is low viscous,high penetrating,and not contaminating the stone.It maintains a very nice air and moisture permeability with the stone.     

道家“归根曰静”理念在机械工程专业硕士培养中的应用

在丰富多彩和纷繁喧哗的社会大环境下,如何高质量地培养专业硕士是各高校时常思考的问题。"归根曰静"的道家哲学思想认为,世界在纷繁变化的成长历程中,万物纷纷芸芸,各自返回它们的本源。或许应该说,静是一种返璞归真的境界。将道家"归根曰静"的思想内涵应用在机械工程领域专业硕士培养中,可以在专业硕士的自身定位、如何选题、研究心态和研究方法等方面得到具体体现。高校培养的机械工程领域专业硕士是复合型应用人才,应遵循"守静笃"的研究心态,从工程项目或新命题、新理论、新方法、新结论的应用中提取研究问题,对前人研究方法进行时代性分析,在深下浅上的方向上,获得研究厚度。道家"归根曰静"的理念也能对专业硕士的研究思路和方法上产生积极的启发作用。     

Effects of KNO3 pretreatment and temperature on seed germination of Sorbus pohuashanensis

We characterized the effects of KNO3 pretreatment and germination temperature on dormancy breaking and germination of mature mountain ash seeds. Seeds treated with KNO3 and germinated at 25 ℃ followed by 5 ℃ had significantly higher germination percentages and germination potentials (51% and 49%, respectively), compared with controls. These treated seeds also exhibited reduced germination initiation times (minimum of 48 days), and elevated germination rate indices (up to 97). The germination of seeds subjected to long-term cold storage (2 years at 0-5 ℃) was also significantly improved by 3 days of 4% KNO3 pretreatment before germinating under a variable temperature regimen (5 ℃ followed by 25 ℃, and followed by 5 ℃). Germination percentages and germination potentials for these cold-stored seeds reached 67% and 54%, respectively, and the germination rate index increased to 126.99. Pretreatment of mountain ash seeds with KNO3 represents a practical, effective, and pollution-free method for improving germination, and can be implemented easily within a variety of nursery settings.     

Genetic analysis of growth and wood variations in Leucaena leucocephala (Lam.) de Wit.

We selected 28 populations of Leucaena leucocephala from different geographical locations in the states of Andhra Pradesh, Tamil Nadu and Orissa of India on the basis of height and girth at breast height (GBH). We evaluated fiber length, optical density, wall thickness, vessel element length, vessel element diameter, specific gravity and lignin of these populations of L. leucocephala in different sites. Populations had significant variations for all growth, wood and paper parameters. Girth at breast height (GBH) and specific gravity were the most important parameters for heritability and genetic gain, respectively. The minimum heritability was reported for vessel element length and genetic gain for fiber length. The populations were grouped into six clusters, cluster II had maximum number of populations (14) and clusters IV and VI had one population each. GBH contributed maximum of 34.39 % towards total divergence followed by specific gravity (14.02%). An economic technique to produce quality seed by establishing seed orchards with genetically divergent parents was suggested. The hybridization among the populations selected from diverse clusters could produce greater heterosis needed for higher growth and suitable wood and paper manufacturing parameters.     

聚丙烯酰胺型共聚物对砖红壤上菜心生长状况的影响

运用不同剂量的聚丙烯酰胺型共聚物处理菜心,研究其对菜心生长和水分利用率的影响,为海南省砖红壤蔬菜栽培使用共聚物提供参考依据。结果表明,施用共聚物后各处理菜心的生长状况均优于对照（未施共聚物）,其中每667 m2用量为4 kg的处理表现最佳;当每667 m2共聚物用量在1~4 kg范围内,菜心的根重尧地上部鲜重大致随着共聚物用量的增加表现越好,但每667 m2用量为5 kg 的菜心表现不如用量为4 kg 和3 kg 的处理曰共聚物用量在每667 m2 1~5 kg 的处理在水分利用率方面分别比对照高出14.95%、27.80%、35.22%、43.52%、18.05%。     

25-OH-D3对42~63日龄黄羽肉鸡屠宰性能、肉品质和维生素D代谢产物的影响

以低钙、磷水平为基础设计日粮,研究日粮中添加25-OH-D3对42~63日龄黄羽肉鸡屠宰性能、肉品质和VD代谢产物的影响。试验选用42日龄黄羽肉公鸡1200只,随机分成4组,每组5个重复,每个重复60只鸡。处理组1~4中25-OH-D3的添加水平分别 为0、50、70和90μg/kg。结果表明,相对于对照组,饲粮中添加不同水平的25-OH-D3对42~63日龄黄羽肉鸡的屠宰性能影响不显著;可提高内脏器官指数袁促进内脏器官发育,但90μg/kg剂量对外周免疫器官发育有抑制趋势;25-OH-D3对黄羽肉鸡肉色、系水力和嫩度具有一定的改善作用,对pH值影响不显著;血清和肾脏1,25-(OH)2-D3显著升高,且与25-OH-D3添加量成正相关性,肝脏25-OH-D3含量变化不显著。结果显示,降低日粮钙磷水平,日粮中添加25-OH-D3对后期黄羽肉鸡内脏器官发育和肉品质具有一定改善作用,其中70μg/kg25-OH-D3添加量的效果最佳。     

四种变温层积对老山芹种子胚发育及生理特性的影响

针对老山芹种子休眠特性及其生产上存在的种子发芽率低、出苗不整齐及育苗周期长等问题,设计四种变温层积处理,定期取样,观察种胚发育情况,测定种子形态及生理生化指标,分析两类指标动态变化规律及与种子后熟关系。结果表明,经变温层积处理后老山芹种胚逐渐生长发育,由心形胚后期经鱼雷形胚后进入子叶期胚时期,完成形态后熟。变温层积过程中4℃低温阶段持续时间对种胚发育进程影响最大,时间越长越利于种胚发育。四种变温层积处理相比较,处理三模式(20℃,10 d→4℃,90 d→20℃,5 d)更利于老山芹种胚形态后熟完成,胚长和胚率增长最快,最早进入子叶期胚,是有效的种子处理方法。老山芹种胚发育过程伴随营养物质变化,不同变温层积处理营养物质变化具体过程不同,但总体趋势基本一致,其中可溶性糖含量表现为先降后升再降趋势,可溶性蛋白质、淀粉和粗脂肪含量总体呈下降趋势。研究为揭示老山芹种子休眠机理、打破种子休眠、发展老山芹产业、调整林区经济结构提供理论依据和技术支撑。     

不同播种因素对扁穗冰草生产性能的影响

在青海省铁卜加高寒地区,在不施肥、不灌溉和人工清除杂草的条件下,通过田间试验研究不同行距(20,30,40cm)和播种量(67.5,101.1和135kg/hm2)对野生扁穗冰草生长、种子产量和干草产量的影响,以确定最佳的扁穗冰草田建植条件。结果表明:不同播种因素处理对鲜重、株高、茎叶比及生长速度的影响不明显。但对草产量和种子产量的影响较大。其中,行距20cm,播种量67.5kg/hm2处理下的干草产量和种子产量均最大,分别为6 065.35和1 610.33kg/hm2。     

Effects of harvesting method and date on yield loss and seed quality of rapeseed

China is one of the major rapeseed production countries in the world,but harvesting mechanization was still backward,and high harvest loss was a key inhibiting factor for rapeseed production.To obtain optimum harvesting date for winter rape in the Yangtze River Valley of China,artificial simulated combine harvesting and artificial two-stage harvesting were adopted to find correlations between harvesting date,rape variety,seed oil content,protein content,grain moisture rate,rapeseed straw moisture content,rapeseed unthreshing rate,grain drop loss rate,thousand seeds weight(TSW),and harvesting economic coefficient(HEC).Analysis of variance showed that rapeseed oil content,protein content and TSW were correlated with rape variety;HEC was correlated with harvesting method and rape variety.Rape variety was the dominant factor of rapeseed oil content,protein content,TSW and HEC.Grain moisture rate,un-threshing rate,grain drop loss rate and straw moisture content were correlated with harvesting method and date.Harvesting date was the dominant factor of rapeseed moisture rate,un-threshing rate,grain drop loss rate and straw moisture rate.Single factor tests further proved that harvesting date had less impact on rapeseed oil content,protein content,TSW and HEC.It showed little correlation with rapeseed quality except grain moisture rate.The optimum harvesting date could be known by change in straw moisture content.The combined harvesting should be carried out during the grain moisture content of 15%-20%with TSW stabilized in the highest level.The twostage harvesting cutting should be carried out at the grain moisture content of 35%-40%.This research offered a reference to harvesting method and date for rape cultivated in the Yangtze River Valley.