Seasonal Changes in Forage Nutrients and Mineral Contents in Water Resources,Forage and Yak Blood

This paper reports results of a study conducted to investigate the concentrations of seven mineral elements in yak blood, forage and water resources around the Qinghai Lake in Qinghai Province in different seasons. Meanwhile, the nutritional compositions of the forage were also surveyed. The results suggest that the mineral elements and the forage nutrients change in a seasonal pattern. In yak blood,the sodium(Na)concentration varies from 0.291 to 0.034 mg/mL,and this is lower than the normal value. In the forage,the ratio calcium(Ca)to phosphorus(P)is 4.06～7.47:1 and potassium(K)to Na 30～27:1. These results indicate that the nutrition of the yak in the area is deficient in Na but high in K. For the withered forage sampled in February,the protein content is only 31.14% of the total protein in the forage growing at puerile stage in June. The severe loss of protein by 68. 9% and decrease of effective nutrients in the wintered forage are considered to be the reasons resulting in the poor condition of yak in winter and spring seasons.     

DCAB对荷斯坦奶牛泌乳性能、血液酸碱平衡及血清矿物质含量的影响

试验选用荷斯坦泌乳早期奶牛15头,采用3X3复拉丁方试验设计,研究日粮DCAB水平分别为+367、+514、+663mmol/kgDM对奶牛生产性能、血液酸碱平衡和血清矿物质含量的影响。试验结果,不同DCAB水平日粮对奶牛奶产量差异不显著(P>0.05),高DCAB水平日粮可增加奶牛血液标准HCO-3含量(P<0.05),不同DCAB水平对奶牛各种血清常量矿物质含量没有影响(P>0.05)。试验表明,日粮DCAB水平超过+514mmol/kgDM可对奶牛奶产量产生不利影响。     

金安桥水电站初次蓄水对导流洞稳定性影响的计算分析

金安桥水电站下闸蓄水后，陡升的库水位将对导流洞结构稳定造成不利影响。为保障堵头封堵前的导流洞结构稳定性，运用三维弹塑性损伤有限元，在模拟进水口边坡及导流洞开挖支护的基础上，计算汛前下闸水位时的岩体渗流场，对导流洞围岩和衬砌在岩体渗流作用下的结构稳定性进行复核分析。分析结果表明，导流洞的围岩稳定性在蓄水后仍有保障，衬砌结构受力较小，现有环向配筋满足结构内力要求，但在进水口变截面和导流洞变截面部位沿水流方向的拉应力较大，使得衬砌出现开裂。进一步分析表明，上述区域的开裂范围有限，对整体衬砌结构影响较小。     

城市农业公园的内涵、模式及路径

城市农业公园是一种将城市元素与农业元素有机结合的融入城乡一体化发展理念的集生态、绿色、人文、产业等特征于一体的以农业为主题的城市公园。阐述了城市农业公园的内涵特征及其功能价值和城市农业公园的发展模式及其路径选择，并在此基础上，结合铜仁市的山水自然特征及其农业产业发展特色，从经验借鉴和实践研究层面对铜仁市城市农业公园的发展进行战略思考和总体设计。以铜仁市郊区的和平乡、坝黄镇、挞扒洞村以及松桃正大乡为例对以铜仁市城市农业公园建设为切入点打造铜仁生态旅游城市提出了具体的发展构想。     

Nutrient cycling and biomass flows in a low-quality forest stand improvement system in the Lesser Khingan Range of China

The material flow and bulk internal flow analyses were used to establish a material accumulation and cycling model for a low-quality forest stand improvement system and a series of processes were considered. The model was applied in a one-hectare low-quality forest plot in the Lesser Khingan Range of China. Results showed that during 1997–2007, the stands absorbed 270.19 kg of N, 74.28 kg of P, and 124.39 kg of K from soils, 51.82 kg of N and 2.38 kg of P were directly absorbed by foliage, and 16.25 kg of K was released to soils by eluviation. Until 2007, the accumulated nutrients in the stands included 236.91 kg of N, 65.28 kg of P, and 108.55 kg of K. When horizontal strip clearcutting was applied in 2007, 50% accumulated nutrients in the stands were shifted due to harvesting operations, and 212.74 kg of N, 26.97 kg of P, and 98.88 kg of K were accumulated in soils, declining by 9.47% for N, 3.68% for P, and 17.60% for K, respectively, compared with year 1997. 94.61 t per hectare of biomass was generated, of which the biomass in stands accounted for 87.36%. The felled tree biomass was 36.89 t per hectare, of which 84.90% and 10.03% of biomass were utilized in terms of logs and other means, and the rest was left on site.     

等壳水电站碾压混凝土重力坝非溢流坝段稳定渗流场有限元分析研究

通过建立等壳水电站的非溢流坝段的准三维有限元模型,模拟了坝体排水管和排水廊道、上下游防渗层、坝基灌浆帷幕、坝基排水管和排水廊道等,对正常蓄水位工况下坝体、坝基的渗流总水头、压力水头、渗透比降、坝基扬压力分布及渗流量进行了计算分析,验证了坝体和坝基的防渗排水措施的合理性。     

菊花ClERF1基因的克隆与表达分析

以甘菊叶片为试验材料,采用RT-PCR和Tail-PCR以及生物信息学的方法,研究了甘菊ClERF1及其启动子序列特征、表达模式,以及甘菊ClERF1在低温胁迫下的响应。以期为进一步研究甘菊ClERF1功能提供参考依据。结果表明:ClERF1基因序列全长1 242 bp,最大开放阅读框(ORF)618 bp,可编码206个氨基酸。经理化性质分析,ClERF1分子量23 631.35 Da,理论等电点5.19,不稳定系数53.84,脂肪指数62.04,平均亲水性-0.786,亚细胞定位在细胞核内。系统进化树表明,ClERF1与拟南芥At3g23240亲缘关系最近,属于ERF亚家族。qRT-PCR分析表明ClERF1在叶片中表达最高,其次在茎段中。该研究克隆了ClERF1启动子序列1 534 bp,主要包括低温反应和乙烯响应元件、生长素和茉莉酸甲酯反应元件等。甘菊低温处理幼苗ClERF1表达量显著高于未低温处理的幼苗,其中5℃时ClERF1相对表达量最高。     

2CZD-1型段茎式甘蔗种植机设计与试验

研制了2CZD-1型段茎式甘蔗种植机,可一次性完成甘蔗种植的开沟、施肥、自动取种、自动排种、覆土和覆膜等工序,适用于宽窄行甘蔗种植。设计了机架、取送种机构、转盘施肥机构、旋耕覆土机构、覆膜机构和液压传动系统等结构,其中取送种机构采用排冗结构实现均匀排种。利用有限元分析软件ANSYS对甘蔗种植机的机架进行模态分析,并通过田间试验获得甘蔗种植机的覆土厚度合格率、种植密度、伤芽率、漏植率及总排肥量稳定性变异系数等性能参数。模拟结果表明,当激励频率为8~80 Hz时,机架容易发生共振,且最大位移可达28.12 mm。田间试验表明,该种植机的种植密度为142325芽/hm^2,覆土厚度合格率为93.6%,伤芽率为2.8%,漏植率为4.7%,种植深度合格率为89.3%,总排肥量稳定性变异系数为5.8%,工作生产率为0.32 hm2/h,符合甘蔗种植机的设计要求,能够显著提高甘蔗种植的效率。     

日粮补充苹果渣或有机矿对鹅生产性能、蛋品质及繁殖性能的影响

本研究旨在评估日粮单独添加苹果渣或补充苹果渣和有机微量元素对鹅生产、繁殖性能及蛋品质的影响。试验将产蛋期的360只鹅随机分为3组,每组120只(30只/重复),对照组饲喂基础日粮,处理组分别饲喂苹果渣日粮和苹果渣+有机微量元素日粮,试验持续14周。结果:苹果渣补充或不补充有机矿较对照组显著提高了孵化率和仔鹅存活率(P<0.05),苹果渣+有机矿组较其他两组显著提高了蛋长度、蛋壳尖端和钝端厚度(P<0.05),但显著降低了蛋型指数、蛋壳重量和蛋黄重量(P<0.05)。日粮添加苹果渣同时补充有机矿较对对照组显著提高了鹅蛋中甘油二酯、胆固醇、胆固醇酯的含量(P<0.05),但苹果渣补充或不补充有机矿磷脂含量较对照组显著降低了13.17%和20.08%(P<0.05)。与苹果渣组相比,日粮添加苹果渣补充有机矿非酯化脂肪酸含量显著提高了31.76%(P<0.05)。结论:日粮添加苹果渣同时补充有机铜和锌可显著改善鹅的繁殖性能、蛋品质及蛋中脂肪组分。     

试验干扰下土壤中微量元素空间变异性研究

[目的]为了解烟草试验站土壤中微量元素的空间变异性,进而为大田试验布局提供依据。[方法]用地统计学方法,分析彭水试验站的耕层土壤养分的空间变异特征。[结果]该站内土壤有效铁、有效铜、有效钙的含量丰富;有效锌和有效锰为中等含量水平,有效硫和有效镁含量从低至高均有分布。各中微量元素间具有显著的相关性。所有元素均可用指数模型和球状模型进行较好拟合;有效锌、有效镁和有效硫由于受结构性因素影响而呈现强空间自相关性;其余元素的空间自相关性由结构性因素和随机因素共同作用而呈现中等空间相关性。Kriging插值显示,东部及东北部较高,中部和西南部区域含量较低;有效铁、有效钙和有效硫的空间分布的规律性差。[结论]该试验站土壤中微量元素含量存在较大的空间变异性。在安排大田试验时,要充分认识这种变异性,合理布局大田试验。