配方施肥对花椒产量的影响

采用"3414"施肥方案,通过大田试验研究了不同N、P、K配比与用量及喷施硼肥对花椒产量的影响.结果表明:N、P、K配合施用能明显提高花椒产量,其中配方6施肥效果最好,单株产量较对照提高88.4.喷施硼肥可以增加花椒产量,较不喷肥产量平均提高4.07.根据肥料效应模型,氮(N)、磷(P2O5)、钾(K2O)施用量分别为254、176、116 g·株-1时产量最高.     

永久性贮水池在水灭火法扑救森林火灾中的运用

本文简要阐述了水灭火法灭火原理与系统组成,提出通过建立永久性贮水池促进水灭火法将成为我国林火扑救重要手段的发展设想。     

几种工程措施对黄土区陡峭边坡植被盖度的影响及其机理

陡削以兰州新区的一段陡峭边坡作为试验地点,通过分析在植被重建初期经人工整地后形成的4种微地形(大圆形坑、小圆形坑、条形坑和原状坡面)的植被盖度特征及环境因子(土壤硬度和水分、地表和空气温度、坡位、无纺布)对植被盖度的影响,探寻能有效提高植被盖度的几种工程改造措施。研究表明:①铺设了无纺布坡面的植被盖度显著大于对照坡面;陡峭边坡不同坡位的植被盖度:下坡位>中坡位>上坡位(P<0.05),这与自然坡面植被盖度分布规律一致。②3种微地形的植被盖度均显著大于陡峭坡面,其中条形坑的土壤水分和植被盖度最大,最大盖度维持的时间最长。③微地形和坡面的植被盖度均与土壤水分呈显著正相关,与空气温度、地表温度均呈显著负相关;微地形的土壤硬度(3kg·cm^-2)适宜植物生长,大于该值会对植被生长产生抑制作用;铺设无纺布有利于促进上坡位的植被生长,使坡面植被分布更均匀。研究结果表明,在陡峭边坡坡度、坡位和温度等无法改变的情况下,选择对压实的坡面进行整地翻耕处理,增加长条坑的数量并铺设无纺布等有效的工程改造措施,能显著增加植被盖度,促进植被恢复。     

氨基酸添加方式和营养液杀菌方式对生菜产量与品质的影响

研究了生菜水培过程中,用混合氨基酸替代20％硝态氮时,不同的氨基酸添加方式和营养液的杀菌方式对生菜产量和品质的影响。试验于生菜采收前12 d开始进行,试验设置4个处理:A．替代氨基酸1次全部加入;B．每3 d添加氨基酸替代总量的1／4,共添加4次;C．氨基酸分次添加(添加方式同B处理),每次添加前营养液通臭氧0．5 h杀菌; D．氨基酸分次添加(添加方式同B处理),每次添加前把营养液加热到60-70℃保持10 min进行杀菌,然后迅速把营养液温度降低到常温。结果表明,在不杀菌的情况下,1次添加的产量和品质优于分次添加,但在降低硝酸盐含量方面,分次添加优于1次添加;在分次添加的情况下,杀菌与不杀菌相比,杀菌可以明显提高生菜的产量和品质,加热杀菌对生菜产量和品质的影响优于臭氧杀菌,臭氧杀菌处理的生菜根系活力、叶绿素等指标高于加热杀菌,但2种杀菌方式之间差异不大。     

沟通技能态度量表中文版的信度和效度研究

目的 检验中文版沟通技能态度量表(the Chinese version of Communication Skills Attitude Scale,Ch-CSAS)的信度和效度.方法 采用委员会法,经前译、回译与跨文化调整形成Ch-CSAS,预试验后用于267名本科护理专业学生中,以检验其信度和效度.结果 Ch-CSAS为双因子结构,分别称为正向态度和负向态度.各因子及总表的克朗巴赫系数(α)分别为0.799、0.723、0.841,重测信度系数为0.894.结论 Ch-CSAS具有较好的测评属性,可用于对护理专业学生或护士的沟通技能态度的评价.     

A preliminary study of water use strategy of desert plants in Dunhuang,China

Water is a restrictive factor for plant growth and ecosystem stability in arid and semiarid areas. The dynamics of water availability in soils and water use by plants are consequently critical to ecosystem functions, e.g. maintaining a high resistance to the changing climate. Plant water use strategies, including water-use efficiency(WUE) and the main water source that a plant species utilizes, play an important role in the evaluation of stability and sustainability of a plantation. The water use strategies of desert plants(Tamarix chinensis, Alhagi sparsifolia, Elaeagnus angustifolia, Sophora alopecuroides, Bassia dasyphylla and Nitraria sphaerocarpa) in three different habitats(saline land, sandy land and Gobi) in Dunhuang(located in the typical arid area of northwestern China) were studied. The stable isotope of oxygen was used to determine the main water source and leaf carbon isotope discrimination was used to estimate the long-term WUE of plant species in the summer of 2010. The results suggest that: 1) the studied desert plants took up soil water below the depth of 80 cm; 2) T. chinensis in the three habitats used deeper soil water and T. chinensis in the Gobi site had higher WUE than those in the saline land and the sandy land. The results indicated that desert plants in Dunhuang depended on stable water source and maintained high WUE to survive in water limited environments.     

乳清粉含量对断奶仔猪生产性能和消化吸收能力的影响

研究不同水平的乳清粉 (5 %、10 %、2 0 % )对断奶仔猪消化吸收能力的影响 ,结果表明 :随乳清粉水平的增加 ,仔猪生产性能随着增加 ,其中各组间ADG达显著水平 (P =0 .0 2 ) ;营养物质消化率也随着乳清粉水平的提高而提高 ,特别是DM和EE的消化率各组间均达显著水平 ;乳清粉从 5 %升至 2 0 %血浆葡萄糖也随着升高 ,差异显著 (P =0 .0 2 ) ,血浆总蛋白各组间差异接近显著水平 (P =0 .0 6 ) ,以 2 0 %乳清分组最高     

金黄色葡萄球菌α-溶血素的研究进展

目的α-溶血素在金黄色葡萄球菌(金葡菌)肺炎的感染过程中起着非常重要的作用,可作为治疗金葡菌肺炎的新靶标。因此,研究百里香酚对金葡菌α-溶血素表达的影响具有重要意义。方法测定最小抑菌质量浓度(MIC)和生长曲线并进行了溶血试验、蛋白免疫印迹分析、荧光定量PCR以及细胞毒性试验。结果百里香酚对金葡菌USA300的MIC为256 μg/mL,亚抑菌质量浓度的百里香酚(32 μg/mL)可下调金葡菌hla和RNAIII的转录水平,降低α-溶血素的表达,对溶血素介导的肺癌上皮细胞A549损伤具有保护作用。结论百里香酚具有成为新型抗金葡菌感染药物的潜力。     

闽南—台湾浅滩渔场中国枪乌贼生物学特性研究

头足类是最具开发潜力的渔业种群之一,然而其资源易受环境变化影响,复杂的交互作用致使二者空间关系呈现非均一性。中国枪乌贼 (Uroteuthis chinensis) 是南海北部近海重要的经济物种,且在渔业群落结构中占据优势种地位,故正确理解与掌握该物种资源-环境关系的空间特征,有助于该资源的保护与利用。基于南海北部近海2014年夏季的渔业资源调查数据,构建了地理权重回归模型 (Geographical weighted regression, GWR),探索该海域中国枪乌贼的资源分布与海洋环境关系的空间特征,阐述主要影响因子。模型评价指标结果表明,GWR的最小赤池信息准则 (Akaike Information Criterion, AIC) 和校正决定系数 (Adjusted R-Squared, Uroteuthis chinensis is an important economic species in the offshore waters of northern South China Sea, occuping a dominant position in the fishery community structure. Therefore, understanding the spatial characteristics of the resource-environment relationship is beneficial to its development, utilization and protection. Based on the fishery resources survey data in the offshore waters of northern South China Sea in summer of 2014, we established a geographically weighted regression (GWR) model to explore the spatial characteristics of the relationship between the resource distribution of U. chinensis and the marine environment in this area, and to reveal the main influencing factors. The results of model evaluation indexes show that the minimum Akaike information criterion (AIC) and adjusted R-Square (相似文献   

Statistical Model on the Time and Time Difference Error of Arrival in TDOA Location Estimation

Additional time delay of arrival resulted from non-line of sight(NLOS)propagation and muti-path effect in(cellular) environment is the dominant factor resulting in TDOA location error,study on the statistical property of TDOA error is useful for improving the accuracy of TDOA location.Based on the exponential distribution property of NLOS propagation delay,and considering the system error resulted from the signal detection,the authors establish a statistical model of arrival time and a model of TDOA error distribution by statistics when non-light of sight and multi-path propagation exist.The models reflect the statistical property of arrival time and TDOA error in cell network,the simulation shows that the proposed models have a good accuracy and a satisfactory behavior.