CrWMn钢Ac1温度以上的组织超塑性

对冷作模具钢ＣｒＷＭｎ在Ａｃ１温度以上的组织超塑性进行了研究。结果表明，ＣｒＷＭｎ钢经循环淬火超细化处理后，在Ａｃ１温度以上可实现超塑性，在７８０～８１０℃及０．４～２．８×１０＾－２／ｍｉｎ条件下变形时可获得较好的超塑性，其延伸率可达３００％，流变应力小于５０ＭＰａ，应变速率敏感性指数ｍ为０．３７。     

SiCW/Zn-22Al复合材料的组织与高温变形

对低压浸渗、挤压比为10：1的热挤压以及固溶处理制备的SiCw／Zn-22Al复合材料的组织与高温变形行为进行了研究。结果表明：SiCw的复合使材料中出现了熔点为655K的低熔点共晶组织。显著提高了变形抗力，降低了塑性，并使材料丧失了在共析温度区的超塑性；在出现适量液相的共晶温度区，复合材料具有超塑性。     

喷灌用镁合金管道成形工艺

研究了镁合金挤压模具及工艺参数．根据镁合金特点设计了4孔分流挤压模具，选择MB2镁合金在1250T卧式挤压机上进行了挤压试验．通过试验得到的主要工艺参数为：镁棒预热温度为548～698K，模具预热温度530～673K，挤压筒温度573～723K，挤压速度0．067～0．083m／s及挤压比40～60，与铝合金管相比，3种规格的镁合金管具有良好的力学性能和机械性能，可完全满足喷灌工程的需要．     

旱地耕作蓄水保墒技术要点和操作规程

1 技术要点 1．1 选择适宜的作业地块：深松灭茬联合整地应选择坡度在6°以下，面积0.33 hm2以上，垄长50 m以上，地里石头少，且直径最大不超2 cm的地块，垄距在0.5～0.7m之间。……     

"俄罗斯优良"沙棘嫩枝扦插育苗试验研究

2003～2004年对“俄罗斯优良”沙棘嫩枝扦插育苗技术的几项关键技术进行了田间试验。试验表明，使用方塘水比深井水N、P、K含量分别提高3．7倍、1．3倍和0．1倍。水温提高6．0～11．2℃，苗木高度生长量增加11cm。试验还表明，基质中加入牛粪和草炭，有机质含量提高2～3倍，苗床土壤的温度提高0．1～0．9℃，苗木高生长量提高2-4cm。改变追肥肥料的配比与增加追肥次数，苗木的高生长量分别提高4cm和5cm。     

SiCW/Zn-22Al复合材料的组织与高温变形

对低压浸渗、挤压比为10∶1的热挤压以及固溶处理制备的SiCW/Zn-22Al复合材料的组织与高温变形行为进行了研究.结果表明SiCW的复合使材料中出现了熔点为655 K的低熔点共晶组织,显著提高了变形抗力,降低了塑性,并使材料丧失了在共析温度区的超塑性;在出现适量液相的共晶温度区,复合材料具有超塑性.     

马铃薯生产机械化技术（续6）

干燥。工业用滚筒干燥机由1只直径为1．5m～2m、长度3m～6m或更长的蒸汽内加热干燥滚筒、5根-6根直径0．15m～0．25m的布料滚筒、刮刀、物料输送系统、驱动以及控制系统等组成。干燥滚筒内蒸汽压力一般要求保持在98N／cm^2以上。通常滚筒干燥机每1m^2干燥表面每1h可处理薯泥70kg-80kg，得到成品14kg～15kg。干燥处理良好的雪花粉厚度约0．15mm～0．25mm、密度220kg／m^3-250kg／m^3。     

榆林市大果沙棘的引种效果

为了解决中国沙棘果实小、产量低、棘刺多等问题，榆林市林业站先后引进大果沙棘品种16个。栽培试验结果表明，大部分品种在引入后生长良好、繁殖正常，没有发现早衰现象或严重的病虫危害，同时保持了果实大、产量高、无刺或刺少等优良特性。其中，果实横径5．06mm～6．51mm、纵径7．46mm～10．33mm，向阳、齐棘1号等9个品种的果实产量达到10000kg／hm2以上，单株平均拥有克隆子株2．0～5．0株，混合种子的生活力达95％。     

农用汽车制动器活塞超塑成形的研究

农用汽车制动器活塞超塑成形的研究曾宪文任先玉李季云目前国内外在研究铝合金超塑性的工作中，为获得组织超塑性，都要经过繁杂的预处理过图１制动器活塞零件图程，因而在实际生产中受到限制。为扩大超塑性的应用范围，我们将原压铸成形的制动器活塞（零件图见图１）采用...     

增氧机的使用技术

一、增氧机的合理配置 增氧机机型要与池塘的水深和面积相配套，但主要考虑水深。3kW的叶轮式增氧机，适用于1．4～2．0m水深．5．5kW的叶轮式增氧机适用于2．1～2．4m水深．7．7kW的叶轮式增氧机适用于2．5m以上。如果在1．3m以下水深中使用叶轮式增氧机会使池底污泥泛起．导致生化耗氧增多，反而降低了池塘的溶氧。水深不足1．3m的池塘配置喷水式增氧机为宜。     

Distribution of soil water-stable aggrega-tes and organic carbon content affectedby tillage systems: a meta analysis

A better understanding of soil carbon( C) distribution within aggregate fractions is essential to evaluating the potential of no-till for sustaining productivity and protecting the environment. A metaanalysis on 744 comparisons from 34 studies was conducted to determine the effects of three different tillage treatments( conventional mouldbould ploughing tillage( CT),reduced tillage( RT) and no tillage( NT)) on water-stable aggregate size distribution,soil C concentration in aggregate fractions.The meta-analysis indicates that compared with CT treatment, NT/RT significantly( P 0. 05)increases macro-aggregate above 20 cm by 20. 9%-82. 2%( 2. 00 mm) and 5. 9%-19. 1%( 0. 25-2.00 mm),whereas NT/RT significantly reduces micro-aggregate and silt clay fractions above 20 cm.NT/RT significantly( P 0. 05) increases the SOC in macro-aggregate( 0. 25 mm) and microaggregate( 0. 25 mm) size classes above 20 cm soil depth compared with CT. The results suggest that soil sampling depth should be considered to evaluate the influence of tillage systems on the distribution of soil aggregate,and the content of aggregate-associated C content.     

Dynamics and modeling of soil water under subsurface drip irrigated onion

Subsurface drip irrigation provides water to the plants around the root zone while maintaining a dry soil surface. A problem associated with the subsurface drip irrigation is the formation of cavity at the soil surface above the water emission points. This can be resolved through matching dripper flow rates to the soil hydraulic properties. Such a matching can be obtained either by the field experiments supplemented by modeling. Simulation model (Hydrus-2D) was used and tested in onion crop (Allium cepa L.) irrigated through subsurface drip system during 2002-2003, 2003-2004 and 2004-2005. Onion was transplanted at a plant to plant and row to row spacing of 10 cm × 15 cm with 3 irrigation levels and 6 depths of placement of drip lateral. The specific objective of this study was to assess the effect of depth of placement of drip laterals on crop yield and application of Hydrus-2D model for the simulation of soil water. In sandy loam soils, it was observed that operating pressures of up to 1.0 kg cm⁻² did not lead to the formation of cavity above the subsurface dripper having drippers of 2.0 l h⁻¹ discharge at depths up to 30 cm. Wetted soil area of 60 cm wide and up to a depth of 30 cm had more than 18% soil water content, which was conducive for good growth of crop resulting in higher onion yields when drip laterals were placed either on soil surface or placed up to depths of 15 cm. In deeper placement of drip lateral (20 and 30 cm below surface), adequate soil water was found at 30, 45 and 60 cm soil depth. Maximum drainage occurred when drip lateral was placed at 30 cm depth. Maximum onion yield was recorded at 10 cm depth of drip lateral (25.7 t ha⁻¹). The application of Hydrus-2D confirmed the movement of soil water at 20 and 30 cm depth of placement of drip laterals. The model performance in simulating soil water was evaluated by comparing the measured and predicted values using three parameters namely, AE, RMSE and model efficiency. Distribution of soil water under field experiment and by model simulation at different growth stages agreed closely and the differences were statistically insignificant. The use of Hydrus-2D enabled corroborating the conclusions derived from the field experimentation made on soil water distribution at different depths of placement of drip laterals. This model helped in designing the subsurface drip system for efficient use of water with minimum drainage.     

不同含水率下花生荚果静摩擦系数测定

为研究含水率对花生荚果静摩擦系数的影响,以花生主产区主要种植品种宛花2号、大白沙171为试验物料,利用DGF30/7-IA型电热鼓风干燥箱对花生荚果进行含水率调控(10.18%、13.57%、16.28%、20.66%、25.85%);利用静力学原理构建的静摩擦系数斜面仪测定花生荚果的静摩擦系数;采用单因素试验,分别分析花生品种、接触材料、荚果含水率对花生荚果静摩擦系数的影响。试验结果表明在含水率各水平下不同品种花生荚果与Q235钢板、大孔筛、小孔筛的静摩擦系数变化趋势相同;花生荚果静摩擦系数随含水率的增大而增大,宛花2号在不同含水率下与Q235钢板、大孔筛、小孔筛的静摩擦系数变化范围分别为0.388~0.611、0.494~0.819、0.553~0.975,大白沙171在不同含水率下与Q235钢板、大孔筛、小孔筛的静摩擦系数变化范围分别为0.42~0.622、0.608~0.822、0.619~0.892。在含水率各水平下花生荚果与不同接触材料的静摩擦系数变化趋势相同,其中大白沙171的静摩擦系数小于宛花2号;大白沙171花生荚果的流动性较好;研究结果可为花生循环干燥设备仿真模拟参数设置及优化设计提供参考依据。     

Assessment of maximum daily trunk shrinkage signal intensity threshold values for deficit irrigation in lemon trees

The response of adult Fino lemon trees (Citrus limon L. Burm. fil.) on sour orange (Citrus aurantium L.) to an irrigation schedule based exclusively on maximum daily trunk shrinkage (MDS) measurements was studied during the 2005-2006 and 2006-2007 seasons. Plants irrigated above their crop water requirements (T0 treatment) were compared with plants under deficit irrigation, whereby the MDS signal intensity (actual MDS/reference MDS) threshold values were maintained at around 1.15 (T1 treatment), 1.25 (T2 treatment) and 1.35 (T3 treatment). Cumulative crop evapotranspiration (ETc) values reached 536.9 and 719.4 mm during the first and the second season, respectively, and the cumulative amounts of applied water in the deficit irrigation treatments were 662.4 mm (T1, 2006-2007 season), 396.3 mm (T2, 2005-2006 season), 554.0 mm (T2, 2006-2007 season) and 220.3 mm (T3, 2005-2006 season), which generated mild, moderate and severe water stress in T1, T2 and T3 plants, respectively. Results indicated that measurements of MDS are suitable for scheduling irrigation, except for rainy periods of low evaporative demand. Therefore, to improve the precision of irrigation management, some changes in the irrigation protocol should be introduced, for instance, using higher MDS signal intensity threshold values and/or a lower irrigation frequency. According to market demand, lemon fruits were harvested on two occasions, showing no effect of irrigation treatment on total yield and total number of fruits per tree. T2 and T3 treatments resulted in a lower yield and number of fruits per tree at the first harvest and modified fruit characteristics. In contrast, the yield at first harvest and number of fruits per tree was not affected in T1 (92% ETc) plants and fruit characteristics were hardly impaired.     

变化环境下灌区地下水动态演变趋势及驱动因素

以陕西省宝鸡峡灌区为研究区,从地下水系统与外部环境的关系出发,运用了线性趋势回归检验、Kendall秩次相关检验及Spearman秩次相关检验3种统计水文学方法,分析了近30 a(1981—2010年)灌区变化环境因素——降水量、蒸发量、地表水灌溉量及地下水开采量的变化趋势,结果表明:灌区降水量呈不显著下降趋势,平均年降水量倾斜率为-2.900 mm/a,而蒸发量呈波动上升趋势,平均年蒸发量倾斜率为3.270 mm/a,降水量和蒸发量两者具有互逆变化特征;灌区地表水灌溉水量呈显著下降趋势,而地下水开采量呈不显著下降趋势.基于GIS技术和地统计学方法,研究了灌区地下水位动态的时程演变趋势和空间分布特征,研究表明:1995—2005年,灌区西北部地区地下水位有明显下降趋势,10年间下降约7~8 m,中部乃至东南部也有小幅度的下降,下降不足1 m;2005年以后,灌区内仅在渭河北岸的武功、兴平南部及咸阳中南部有小幅度下降趋势.通过灰关联分析方法,识别了灌区地下水位动态变化的主要驱动因素,得知各影响因子的关联度都较大,均在0.5以上,且塬上灌区与塬下灌区地下水位动态变化的主要人类活动驱动因素分别为地表水灌溉和地下水开采.     

滚筛式自动除杂选果装置改进设计

前期设计的滚筛式自动除杂选果装置,在测试运行过程中发现了3个问题:一是筛网由不锈钢丝网制作,钢丝比较细,在实际处理原料时会损伤果料;二是钢丝筛网的交叉部位窄小,运行中会夹卡杂质,加之部分杂质柔软细长,长时间工作后杂质会在筛网上缠绕,造成除杂效率下降;三是运行中筛网下部用于清除筛网上搭挂杂质的圆筒状夹辊的效果较差。该文针对上述问题,对存在问题的部件进行重新设计,主要对筛网、杂质夹取器和筛网顶部结构做了较大改进。      

基于逆向工程原理的钢辊式卷捆机构反求设计

钢辊式圆捆机是我国秸秆收获的关键技术装备之一,目前尚缺乏针对该机型核心机构（钢辊式卷捆机构）的基础性设计方法。为此,基于逆向工程原理,综合运用平面几何学、材料力学、机械设计学、试验法、ANSYS分析法等,对该机构展开反求设计。运用平面几何学建立卷捆室半径、钢辊数量、钢辊半径、钢辊间隙四个特征参数间的关系函数;通过理论分析建立钢辊与累积草芯的接触模型,以此为依托运用高速摄像观测法与概率学原理确定钢辊半径对二者间接触力的影响规律;通过高速摄像观测法,确定钢辊间隙及钢辊表面凸棱与缠辊现象间的关联性;采用试验与理论计算相结合的方法实现喂入口尺寸的设计;建立钢辊的力学模型,对钢辊重要组件——长轴直径进行设计,同时利用ANSYS中的Workbench模块实现对钢辊（复合体）刚度及强度的校核。运用上述研究结果,以DN4575型圆捆机为目标机进行反求设计,设计结果如下：钢辊半径75 mm,钢辊数量10根,钢辊间隙10 mm,喂入口宽度162 mm,钢辊长轴直径20 mm,钢辊辐板数量5个。上述反求过程为钢辊式卷捆机构的关键参数提供了系统性的设计方法,该方法对钢辊式圆捆机的设计具有重要的指导意义。     

基于对数螺旋线的新型被动式微混合器的性能

为了提高微混合器的混合效果,减少能量损失,提出一种由对数螺旋线流道组成的被动式微混合器,该微混合器的流道由2条对数螺旋线构成,对数螺旋线极角的取值范围为0°-180°.采用CFD软件分析了该微混合器在不同雷诺数下的混合性能,雷诺数取值范围为0.2-100.0,选择层流模型进行数值模拟.结果显示,当雷诺数小于5.0时,微混合器的出口混合指标随雷诺数的增加逐渐减小;当雷诺数大于5.0时,出口混合指标随雷诺数的增加而增大.雷诺数为0.2时,微混合器的混合指标受对数螺旋线系数b2和宽度w的影响很小,此时混合指标在0.6-0.8;随着雷诺数的增加,对数螺旋线系数b2和宽度w对混合指标的影响逐渐变强.在雷诺数为50.0的情况下,当b2为0.35-0.50,w为0.05-0.13时,微混合器的混合指标较大,混合效果较好.     

The dynamics of groundwater table and salinity over 17 years in Khorezm

Salinization of irrigated agricultural land threatens ecological sustainability and livelihoods of people. Salinization is especially severe in the dry lowlands world-wide and in Central Asia where large amounts of salts accumulated in the soil profile, originating from shallow saline groundwater (GW). Analysis of the unique dataset of 2000 monitoring wells of GW table and salinity in lowland Khorezm region of Uzbekistan over the period of 1990 till 2006 showed shallow GW levels of 1.1-1.4 m (±0.48-0.66 m) at start of leaching periods and 0.9-1.4 (±0.43-0.63 m) in July during the annual growing seasons. While leaching efficiency is decreased, shallow GW in July is far above the optimum levels of 1.4-1.5 m. The effects of topography, soil texture, and irrigation and drainage networks were found to favor shallow GW forced by excessive water diversion. The drainage network, which is seen by many specialists as underdeveloped and its improvement necessary to arrest unacceptable GW levels, is being used under its full capacity. The solution to alleviate land degradation is not only an improved drainage, but better controlled and more flexible water management.     

扩管机液压系统设计

钢管扩管通常采用冲床或液压机来加工，但由于冲力和速度难以控制，扩管破裂率达10％以上。为此，应汽下油箱生产厂家的要求，结合牛产实际，研制了油箱加油管液压扩管机，并阐述了该机的工作原理、主要技术参数、液压系统没计与计算。