液哨超声波增氧后水中溶氧量变化的试验研究

为了研究低溶解氧含量的水体经过液哨超声波增氧装置之后，溶解氧含量的增加量及其随时间的变化趋势，本研究进行了增氧后试验水的静置试验，并监测了水体中溶解氧含量随时间变化趋势。研究共设置了6组实验，2个变量，即添加簧片与否以及流量变化。结果表明：该装置添加簧片组增氧后试验水中的溶解氧含量在2 h内还会继续增加，2 h达到最大值；2 h后，水中溶氧量会急剧下降；6 h后，溶氧量下降速率变缓；到20 h的时候，试验水溶氧量趋于稳定状态，达到7.4mg/L左右。而未添加簧片的对照组同样在2 h达到一个峰值，2~3 h的时候，溶氧量会有小幅度下降，之后溶氧量会继续增加，最后在20 h的时候，溶氧量趋于平衡状态，达到7.15 mg/L左右。实验展示了液哨超声波装置增氧后水中含氧量的变化趋势，并得出了一套科学的、合理的水体溶解氧变化的系列特征曲线，对该装置应用于水产养殖、污水处理以及增氧灌溉领域，提供了重要的理论验证和研究价值。     

水稻根际含氧量对根系生长的影响

以多个水稻品种为材料, 采用营养液培养试验, 通过气泵增加水稻根际的含氧量, 研究水稻根际含氧量与根系生长的关系。结果表明, 在水稻生长过程中, 抽穗期根系吸收氧气的能力最强, 需氧量最大。根际含氧量对水稻根系形态与分布有影响, 增氧显著增加根长, 提高根系自根基到根尖10~20 cm、＞20 cm部分所占的生物量比例, 同时减少根数; 而在缺氧环境下生长的水稻根数增多, 根长缩短。氧溶量对水稻根系活力的影响存在品种间差异, 提高水稻根际的氧溶量, 杂交稻汕优63和国稻1号齐穗期根系的活跃吸收面积和根系活力显著增加; 根系活力较高的常规籼稻湘早籼11和甬粳18在充氧处理中的根系活力也明显提高, 但根际氧含量的增加对根系活力较低的水稻品种湘早籼24和春江06的根系活力并无明显作用; 缺氧环境下生长的水稻根系的活力降低。     

Speed Ratio Matching Strategies of Metal V-belt Type CVT System

The ratio control strategy and the relevant pulley clamping control strategy of the Metal Pushing V-belt Type CVT C Continuously Variable Transmission are key technology of CVT system matching. The engine output torque model and oil consumption model are given in numerical table by cubic spline interpolation to fit engine test result. Based on the engine speed feature, the speed ratio changing strategy of CVT in the numerical table are given to realize the optimal fuel economy and optimal performance mode within the ratio range of the CVT system.     

高大平房仓控温控湿储粮试验

对现有高大平房仓进行隔热保冷改造，夏季利用单管通风机将粮堆中、下部的冷源提升至粮仓上部空间，控制仓内上部粮堆和仓壁四周的温度和湿度，能有效抑制储粮害虫和微生物的发生，避免了化学药剂熏蒸，延缓品质变化，提高了粮食储藏的稳定性。     

ZH128粮情测控系统在粮情检控分析中的应用

ZH128计算机粮情测控系统通过近3年的应用,证明了该系统在粮食储藏管理中所具有的一些先进性能,为实现粮情自动检测,通风自动控制等提供了一些经验。     

Application of Hydraulic Torque Converter Incorporated in Mechanical Continuously Variable Transmission

Continuously Variable Transmission which is the ideal transmission for automobile can improve dynamical and economical performance and reduce pollution emission effectively. Vehicle equipped with CVT where hydraulic torque converter is acted as start clutch have better acceleration performance and its starting control is very simple. Based on performance test of hydraulic torque converter and simulation on lock-up dynamic process of torque converter clutch, matching characteristic between engine and torque converter is evaluated , and the lock-up control rule of torque converter clutch and the control strategy of standing start of vehicle equipped with Continuously Variable Transmission with torque converter is proposed. By computer simulation on start process, vehicle equipped with CVT have better acceleration performance than equipped with five-speed MT.     

Soil compaction and water table effects on soil aeration and corn growth in a greenhouse study

A greenhouse experiment was conducted to study the effects of aeration on growth of corn seedlings. Variable aeration regimes were created by a combination of 3 levels of soil compaction (1.20, 1.37 and 1.56 Mg m⁻³) and 3 water table depths (10-cm, 20-cm and 30-cm). Soil aeration was assessed by measuring the oxygen diffusion rate (ODR) and the gaseous composition of soil air. Samples of soil air were analyzed for concentrations of oxygen, carbon dioxide, ethylene and nitrous oxide.The ODR decreased with increasing soil compaction. The average ODR for the 30 cm water table was 193.5, 89.2 and 15.4 μg O₂ m⁻² s⁻¹ for the three compaction treatments of 1.2, 1.37 and 1.56 Mg m⁻³, respectively. At 40 days after planting, concentration of carbon dioxide in soil air was as high as 0.5% by volume. High concentrations of ethylene and nitrous oxide were also measured in those samples that contained high levels of carbon dioxide. The range of concentration was 2–19 ppm for ethylene and 2–20 ppm for nitrous oxide.The vegetative growth of corn seedlings, as measured by root and shoot weights and plant height, was not significantly affected by the treatments imposed. However, stomatal conductance and photosynthesis significantly differed among treatments.     

Soil Aeration under Different Soil Surface Conditions

The assessment of the importance of soil aeration for various plant characteristics and environmental conditions is necessary to evaluate the oxygen relations to the crops. The root environment as a solid-liquid matrix depends upon soil structure and moisture condition. A limited oxygen supply restricts the root development and also reduces the nitrogen fixation in peanuts. Soil surface conditions can be altered by mulching and plays a significant role in protecting the plants against deficient aeration during critical periods of growth phases. The effects of eight mulching treatments (rice husk, rice husk-incorporated, paddy straw, sawdust, water mulch, clear polyethylene, black polyethylene and control) on the soil oxygen diffusion rate (ODR) during the various growth phases of peanut crop ( Arachis hypogaea L.) were investigated on a lateritic sandy loam soil (ultisols). These experiments were conducted for two consecutive seasons. ODR values were higher in mulched plots. With the progress of growth stages and also in deeper soil depths, the differences between the values of ODR among treatments narrowed down. The influence of mulches on other physical edaphic properties like bulk density, aeration (noncapillary) porosity and soil temperature were also studied. Mulches reduced the surface crusting and thereby soil bulk density; and increased the aeration porosity and ODR. Soil temperature was higher under plastic mulches whereas vegetative mulches suppressed it.     

Brush Clearing on Hill Land Pasture with Sheep and Goats

Much hill land pasture in the Appalachians is brush infested. Reclamation procedures which are low cost and require low input are needed to provide hill land pasture owners with ways to maintain production on these lands. A field experiment was carried out to evaluate the effectiveness of grazing either sheep ( Ovis sp.) or goats ( Capra sp.) separately or in combination for brush clearing on hill land pasture. Cutting or herbicide followed by grazing with sheep or goats were also compared. The experiment was conducted on a 1.8 ha powerline right of way for five years (1986 to 1990). Goats reduced brush cover from 45% to just over 15% in one year. Sheep took 3 years to bring about the same result. Cutting and herbicide application increased animal effectiveness, primarily that of sheep, but increased costs. Three year variable costs for brush clearing with goats were estimated at $33 ha^-1, sheep cost was $262 ha^-1, while cutting costs were $133 and herbicide $593 ha^-1. Brush was cleared more cost effectively and rapidly by goats, but at the end of 5 years all treatments reduced brush cover to 2%.     

Rapid Prototype Control of Hydraulic Automatic Transmission System Based on dSPACE

dSPACE is a prototype development and real-time control testing platform which is based on MATLAB/Simulink software. By establishing mathematic model of hydraulic automatic transmission system, the shift rules are achieved. A testing platform for hydraulic automatic transmission system is developed whose control software is programmed by simulink and using the dSPACE as the centre controller. The experiment of electric throttle control and power performance matching control of hydraulic automatic transmission system is carried out. the result shows that well matching performance of hydraulic automatic transmission system can be realizedby using the control strategy proposed in this paper, it provides a fast and efficient approach for researching and developing the hydraulic automatic transmission system.     

Effect of Waterscape Structures on Nitrogen and Phosphorus Removal Efficiency in Revetment Wetland System

The effect of aeration and waterscape structures reaeration system on nitrogen and phosphorus removal efficiency in revetment wetlands was studied by laboratory simulation. The results showed that the removal efficiency of TN, TP in tranquil flow waterscape was 61% and 72%; aeration and waterscape structure system promoted nitrogen and phosphorus removal efficiency in revetment wetland through increasing the DO content in the water, compared with system without artificial oxygen, the removal efficiency of TP in waterscape structures increased by 11. 6%-19. 1%, and that of TN increased by 10.5%-16. 1%; meanwhile, disturbance brought by the waterscape structure systems enhanced the adsorption of TP and flocculation effect; in addition, nitrification was confirmed as the main control step of TN removal in revetment wetland system.     

SBBR反应器SND脱氮的影响因素分析及响应曲面优化

采用活性炭涂层改性悬浮填料,在连续曝气的条件下,考察了SBBR反应器脱氮性能。结果表明,SBBR反应器表现出良好的同步硝化反硝化(SND)脱氮性能,对NH₃-N和TN的去除率分别为80.7%和63.1%。典型周期内反应器同步硝化反硝化率可达82.7%。单因素试验发现,脱氮率随着曝气时间t的增加而增加,随着溶解氧质量浓度ρ_DO和填料投加量δ增大而先增大后减小。同时,以溶解氧质量浓度、填料投加量和曝气时间为考察因素,脱氮率为评价指标,采用响应曲面法建立了二次多元回归模型。通过模型求解得出最佳工况:溶解氧浓度为2.37 mg/L,填料投加量为40.10%,曝气时间为5.17 h,此时,脱氮率得到最大值为69.28%。验证试验表明,回归模型的预测值与实测值偏差率为1.57%。     

高水分玉米地上笼机械通风降水试验

采用机械通风对高水分玉米进行降水试验,结果表明:机械通风降水技术具有投资少,能耗小、费用低等优点,较人工晾晒和烘干节省费用,可最大限度地保持粮食品质、稳定储粮性能,各项品质指标均符合宜存要求。入仓前的粮食清理、及时调整通风方式都有助于提高通风降水的均匀性。     

增氧对水培棉花生长的影响研究

通过水培试验研究增氧对棉花生长的影响;试验设计3种增氧方式,分别为持续性增氧(Physical continuous oxygen,PCO)、间歇性增氧(Physical oxygen,PO),化学增氧(Chemical oxygen,CO),种棉花不增氧CK,不种棉花不增氧CK0;研究结果表明,不同增氧方式对营养液中溶解氧浓度都有不同程度的提高,表现为PCOPOCOCK;PCO处理对根体积、根系总吸收面积、根活性面积、根系生物量、株高、地上部生物量、氮和钾的吸收量的促进作用均达到显著水平,分别比CK增加了194.62%、261.89%、301.73%、57.15%、22.76%、38.03%、35.27%、84.78%;间歇性增氧PO处理对根系生物量、株高、地上部分生物量的促进作用显著,分别比CK高30.83%、15.65%、21.19%。通过以上结果表明,棉花对氧的需求敏感,不同增氧方式均能在一定程度上促进棉花生长,其中持续性增氧效果尤为突出,特别是对棉花生物量的积累,说明增氧可以提升棉花生长潜力。     

多功能减压管在立筒仓和浅圆仓中的应用

在立筒仓及浅圆仓中安装多功能通风熏蒸减压降碎装置,可以有效降低粮食入库破碎率,减少自动分级影响,减缓出库时粮堆整体移动产生的动载荷,保护仓内设施,延长筒仓及浅圆仓使用寿命.同时利用多功能减压管进行内环流熏蒸及通风降温降湿进一步完善了立筒仓及浅圆仓储粮性能,提高了储粮稳定性.     

连续增氧对不同基因型水稻分蘖期生长和氮代谢酶活性的影响

为明确氧对不同基因型水稻生长和氮素代谢的作用机理,以籼稻、粳稻和旱稻品种为材料,采用营养液培养,考察根际连续增氧水稻分蘖期生长和氮代谢状况。结果表明,连续增氧后,各水稻品种叶绿素含量均有所下降,国稻1号(籼稻)地上部分和根系干物质重分别降低44%和40%,巴西陆稻(旱稻)和秀水09 (粳稻)降低不显著。国稻1号和巴西陆稻的氮积累量分别降低35.8%和36.0%。各基因型水稻叶片NRA (硝酸还原酶活性)显著提高,GSA (谷酰胺合成酶活性)下降。秀水09,叶片NRA增加较少(P>0.05)。连续增氧提高了水稻根比表面积和氧化强度;但降低了叶片叶绿素含量和GSA,不利于水稻氮素吸收和干物质积累。不同基因型水稻对连续增氧的响应存在差异。     

浅谈粮情测控系统在我库的应用和维护

通过我库ZH128型粮情测控系统近7年的应用，证明了该系统在粮食储藏工作中具有先进性和可维护性。为实现粮情自动检测提供了经验。     

新型负压渗灌技术对农田土壤水分精准控制应用

针对节水微灌技术发展,研发出一种新型的负压渗灌系统。新系统将常规的环形管输水改造为直路单向输水,通过控制计量水箱结构和调压器实现了植物对水分连续自动获取,改变了传统的间歇灌溉理念,提高了灌溉精准和自动化程度,同时显著提高了水分利用效率,实现了作物自身需水情况与土壤水分平衡精准供水,促进了水分高效精准利用。负压自动补给灌溉具备节水、节能和保护农业生态环境、保护土地等农业自然资源等优点,从而实现土壤水分的精确和持续控制,使省工、省力、规模化、高效率和高科技的现代农业技术成为现实,彻底颠覆了传统滴灌方式的灌水理念,由人为机械供水改为由土壤水势实时平衡自动、实时、科学调控灌水量,具有广泛的开发前景。     

Development of Car Continuously Variable Transmission on the Basis of Personal Computer

During the process of developing the Car Continuously Variable Transmission, the Control rule of the system is so complicated that we have to adjust and modificate the control parameters often. Direct debugging and empoldering by using singlechip system will result in long empoldering period and low efficiency. The present article presents an empolder scheme based on the control of Personal Computer. In the empoldering process we will predigest the Car Transmission Control Unit of the Continuously Variable Transmission into an extension which is only used for parameter tracking and measurement, while the matching control of the system and the parameter monitor is achieved with the host computer. Serial communication is carried out in the communication between the host computer and the extension. In addition, we have developed the corresponding monitoring and debugging software with Visual C++ 6.0 also. The practice shows that the system has successfully realized the empoldering of the TCU(Transmission Control Unit) with great efficiency.     

竖管通气对覆盖栽培雷竹生长的影响

探究竖管通气对覆盖栽培条件下雷竹生长的影响,为雷竹林集约化经营提供更为科学合理的技术。本试验共设置4个处理:不覆盖不通气(CK)、不覆盖通气(A)、覆盖不通气(M)、覆盖通气(MA),分析各处理的土壤氧气浓度、土壤矿质元素以及雷竹根系活力、光合参数等指标,探究通气对集约经营雷竹林生长及立地条件的影响。与不覆盖处理(CK)相比,覆盖处理(M)显著增加了土壤表层的有机质、全氮、全磷等的含量,而覆盖加通气处理(MA)则促进了土壤有机质、全氮、全磷等物质的分解;在0～10 cm、10～20 cm、20～30 cm、30～40 cm的各土层中,覆盖通气处理(MA)下的土壤氧气含量比覆盖处理(M)分别提高了：26.19%、28.36%、30.77%、26.92%(P<0.05)。MA处理下的雷竹根系活力比M处理增加了57.16%(P<0.05),叶片净光合速率增加了49.47%(P<0.05)。竖管通气显著改善了雷竹林因长期覆盖经营而引起的土壤缺氧、雷竹根系生长不良、净光合速率降低等问题。