施氮量和播种量对大麦[2011(07)814]鲜叶产量和品质的影响

为了探究施氮量和播种量对新选育大麦[2011(07)814]鲜叶产量和品质的影响,采用二因素4水平裂区试验设计,研究4个施氮量（N1：150kg/hm²,N2：180kg/hm²,N3：210kg/hm²,N4：240kg/hm²）和4个播种量（S1：375万粒/hm²,S2：450万粒/hm²,S3：525万粒/hm²,S4：600万粒/hm²）对大麦孕穗期鲜叶产量、叶绿素含量（SPAD值）、旗叶面积、蛋白质和微量元素含量的影响。结果表明,施氮量、播种量及二者的互作效应对大麦孕穗期鲜叶产量、SPAD值、旗叶面积、蛋白质和微量元素含量的影响均达到显著（P<0.05）或极显著（P<0.01）水平;随施氮量和播种量的增加,大麦孕穗期鲜叶产量、旗叶面积、SPAD值、蛋白质和微量元素含量均呈先增加后降低的趋势,在N2S3或N3S2处理组合下达到峰值;N2S3处理组合鲜叶产量、SPAD值、旗叶面积和蛋白质含量较N1S1处理组合分别提高了102.70%、16.09%、86.39%和33.31%,N2S3处理组合Fe（295mg/kg）、Mn（76.59mg/kg）、Cu（8.10mg/kg）、Zn（30.94mg/kg）元素含量显著高于其他处理组合。因此,在甘肃省河西地区种植大麦[2011(07)814]获取鲜叶时,根据土壤肥力情况建议一次性施氮量180~210kg/hm²以及播种量450万~525万粒/hm²,不仅能增加大麦鲜叶产量、SPAD值和旗叶面积,而且有利于提高鲜叶蛋白质和微量元素含量。     

高强钢板热冲压模具冷却水道优化设计

利用ANSYS/LS-DYNA模块对保压淬火过程零件及模具的温度场分布进行了数值模拟,分析高强钢板热冲压模具冷却系统均布水道的不足.在此基础上通过APDL参数化编程语言,选择零阶与一阶搜索相结合的优化算法,编写优化程序,以模具冷却水道半径、相邻水道间隔尺寸和水道与模面距离等参数为优化变量,以板料温度分布均匀和保证降温速率达到临界冷却速率为优化目标建立目标函数,优化后目标函数值为26.553(优化前为64.404).对优化前后成形件的温度分布进行了比较,得到成形件最高温度下降了44.5％,最低温度下降了14.5％,实现了对冷却水道各参数的优化.最后通过实验验证了优化结果的正确性.     

基于ANSYS的本田节能赛车车架静态受力分析

汽车车架是整个汽车的安装载体,不仅要支撑固定车上各个部件,还要承受着来自道路的各种复杂载荷的作用,是整车可靠性和使用寿命的重要保证。因而,车架的强度和刚度在汽车总体设计中显得非常重要。其中,三轮车车架是一个多自由度弹性振动系统,稳定性一般比四轮车差,对车架的强度和刚度要求更高。本文以我校参加本田节能竞技大赛的三轮赛车车架为研究对象,按照一定的模型简化原则,以有限元分析方法为基础,利用ANSYS软件建立节能赛车车架有限元模型。为了在简化计算的同时获得可靠的计算结果,单元类型采用梁单元BEAM189。同时,文章中对赛车实车静止状态进行了受力分析。     

区域人水和谐评价指标体系及评价模型

为了评价区域人水和谐程度,在阐述人水和谐内涵的基础上,根据复杂系统及和谐论理论,构建了区域人水和谐评价指标体系.根据集对分析和可变模糊集理论,建立了集对分析可变模糊集模型,评价人水复合系统发展态势;以合作博弈理论为基本思想确定系统"理想发展状态",结合距离协调度模型,建立了合作博弈距离协调度模型,评价人水复合系统协调度;以发展态势和协调度为基本依据,采用乘法合成模型综合评价区域人水复合系统和谐度.将上述模型应用于陕西省人水复合系统,评价2000—2009年人水系统和谐程度,评价结果显示陕西省人水系统和谐度呈现缓慢上升趋势,但均处于第I,II等级,属于不和谐或临界和谐状态.说明陕西省人水和谐程度仍处于较低水平,比较符合陕西省目前实际现状.将此模型与模糊综合评价模型的评价结果进行对比分析,评价结果基本一致,表明该模型有效可行,结果可靠.     

橡胶树白根病病原菌的鉴定

大田橡胶树白根病病原菌的子实体檐生,无柄,大小为8.2～8.6cm×5.3～5.3cm,具担子、担孢子;菌肉白色,管孔橙黄色;培养菌丝宽度2.64～4.29μm。根据病原菌的形态特征,以及室内橡胶小苗、盆栽大苗接种和子实体培养的结果,确定海南东太农场发生的橡胶白根病与国外报道的是相同的。     

麦、瓜、棉、豆间作套种栽培技术

随着杂交棉花在我国长江流域的普及，早熟大豆品种的育成与推广，棉田套种大豆技术也在不断发展，大豆、棉花、西瓜和小麦四种作物间作套种，既能增加生产效益，也能使大豆增产。简要介绍这四种作物的间作套种技术及获得高产、高效的技术关键。     

蔬菜钵苗移栽机取苗臂凸轮机构的设计与试验

采用解析法对蔬菜钵苗移栽机取苗臂凸轮机构进行了详细设计,以解决目前机构推苗作业时间长、速度慢而影响推苗成功率的问题。根据移栽机取苗和推苗作业时取苗针的运动要求,以及取苗臂的结构尺寸,建立凸轮机构设计的数学模型,优化凸轮推程运动角,进而得到凸轮实际轮廓曲线,进行了机构的运动及压力角分析。建立取苗机构的三维实体模型,制造出其物理样机,采用ADAMS软件进行虚拟样机运动仿真,开展高速摄像运动试验。仿真结果和试验结果基本一致,表明改进设计是正确和合理的,同时比较改进设计结果和原设计结果可知,所设计的凸轮机构能够满足蔬菜钵苗移栽的要求,且试验推苗时间比原设计有效缩短了27.9%,有助于提高推苗成功率和蔬菜钵苗移栽机的工作性能。     

In situ ATR-FTIR study on the adhesion of Pseudomonas putida to Red soil colloids

Purpose

Bacterial adhesion to soil particles is fundamentally important in mineral weathering, organic matter degradation, heavy metal transformation, and fate of pollutants. However, the adhesion mechanism between bacteria and soil colloids under continuous flow systems in the natural environments remains unknown.

Materials and methods

The kinetics of Pseudomonas putida cellular adsorption and desorption on Red soil colloid films under controlled flow systems were examined using in situ attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Derjaguin–Landau–Verwey–Overbeek (DLVO) and non-DLVO interactions were employed to elucidate the cellular adsorption and desorption kinetics.

Results and discussion

In situ ATR-FTIR spectroscopy can be used effectively to investigate the kinetics of bacterial adhesion to a soil colloid deposit. Surface proteins may be involved in the bacterial adhesion to soil colloids. The adsorption followed pseudo-first-order kinetic equation. High adsorption rate constant and great saturation coverage of adsorbed bacteria were found at high ionic strengths in dynamic systems.

Conclusions

P. putida bacterial cellular adsorption on the soil colloid deposit was irreversible in a wide range of ionic strengths under controlled flow systems. The less reversible adhesion was probably attributed to the DLVO predicted deep secondary energy minima together with non-DLVO factors including polymer bridging, local charge heterogeneities, surface roughness, and Lewis acid–base interactions.     

Litter decomposition reduces either N2O or NO production in strongly acidic coniferous and broad-leaved forest soils under anaerobic conditions

Purpose

The beneficial effect to the environment of nitrate (NO₃ ^?) removal by denitrification depends on the partitioning of its end products into nitrous oxide (N₂O), nitric oxide (NO), and dinitrogen (N₂). However, in subtropical China, acidic forest mineral soils are characterized by negligible denitrification capacity and thus reactive forms of N could not be effectively converted to inert N₂, resulting in a negative environmental consequence. In this study, the influences of C input from litter decomposition on denitrification rate and its gaseous products under anoxic conditions in the acidic coniferous and broad-leaved forest soils in subtropical China were investigated using the acetylene (C₂H₂) blockage technique in the laboratory.

Materials and methods

The coniferous and broad-leaved forest soils with and without litter addition were incubated under anaerobic conditions for 244 h. There were three treatments for each forest soil including addition of 0.5 and 1% corresponding litter (gram of litter per gram of soil) and the control without addition of litter.

Results and discussion

The results showed that litter addition into the broad-leaved forest soil had no effect on average rates of denitrification (calculated as the sum of NO, N₂O, and N₂), whereas in the coniferous forest soil, the addition resulted in a significant increase in average denitrification rate. In the broad-leaved forest soil, both rates of litter addition decreased the production of NO but increased the production of N₂, and high rates of litter addition into the coniferous forest soil promoted the reduction of N₂O to N₂.

Conclusions

Increased decomposition of litter in the forest soils could effectively reduce N₂O and NO production through denitrification under anaerobic conditions.     

啤酒糟发酵产高蛋白饲料菌种的配伍

以啤酒糟为主要原料,采用多菌种混合固态发酵生产蛋白饲料,并通过菌种的配伍实验对发酵产蛋白饲料菌种的组合进行优化,试验结果表明:挑选的8株菌都能在以啤酒糟为唯一底物的平板上生长,并且菌种最佳组合为固氮菌、白地霉、绿色木霉、啤酒酵母、热带假丝酵母等5株菌,其发酵后的蛋白质含量为31.45%,粗蛋白为39.22%,无机氮转化率为56.42%。