Predicting effects of drainage water management in Iowa's subsurface drained landscapes

Long-term hydrologic simulations are presented predicting the effects of drainage water management on subsurface drainage, surface runoff and crop production in Iowa's subsurface drained landscapes. The deterministic hydrologic model, DRAINMOD was used to simulate Webster (fine-loamy, mixed, superactive, mesic) soil in a Continuous Corn rotation (WEBS_CC) with different drain depths from 0.75 to 1.20 m and drain spacing from 10 to 50 m in a combination of free and controlled drainage over a weather record of 60 (1945-2004) years. Shallow drainage is defined as drains installed at a drain depth of 0.75 m, and controlled drainage with a drain depth of 1.20 m restricts flow at the drain outlet to maintain a water table at 0.60 m below surface level during the winter (November-March) and summer (June-August) months. These drainage design and management modifications were evaluated against conventional drainage system installed at a drain depth of 1.20 m with free drainage at the drain outlet. The simulation results indicate the potential of a tradeoff between subsurface drainage and surface runoff as a pathway to remove excess water from the system. While a reduction of subsurface drainage may occur through the use of shallow and controlled drainage, these practices may increase surface runoff in Iowa's subsurface drained landscapes. The simulations also indicate that shallow and controlled drainage might increase the excess water stress on crop production, and thereby result in slightly lower relative yields. Field experiments are needed to examine the pathways of water movement, total water balance, and crop production under shallow and controlled drainage in Iowa's subsurface drained landscapes.     

Inverse Modeling to Quantify Irrigation System Characteristics and Operational Management

Remotely sensed (RS) data is a major source to obtain spatialdata required for hydrological models. The challenge for thefuture is to obtain besides the more direct observable data(landcover, leaf area index, digital elevation model andevapotranspiration), non-visible data such as soilcharacteristics, groundwater depth and irrigation practices.In this study we have explore the option of using inversemodeling to obtain these non-RS-visible data. For a commandarea in Haryana, India, we applied for the 2000–2001 rabiseason a RS-GIS-combined inverse modeling approach to derivenon-RS-visible data required in the regional application ofhydrological models. A Genetic Algorithm loaded stochasticphysically based soil-water-atmosphere-plant model (SWAP) wasdeveloped for the inverse problem and used in the study. Theresults showed good agreement with the inventoried data suchas soil hydraulic properties, sowing dates, groundwaterdepths, irrigation practices and water quality. The deriveddata could be used to predict the state of the system at anytime in the cropping season, which can be used to evaluateoperational management strategies.     

基于粗糙集和遗传神经网络的城市日用水量预测模型

为克服日用水量主要影响因素一般采用主观判断确定的不足,利用改进粗糙集算法对影响因素进行属性约简,确定日用水量的主要影响因素。以日用水量的主要影响因素和相关日用水量为BP网络的输入,采用遗传算法优化BP网络的权阈值,建立了基于粗糙集算法和优化BP网络的日用水量预测模型。实例分析表明,与基于传统BP网络和基于遗传算法优化B...     

大棚温室作物需水量计算模型研究进展

对目前国内外大棚温室作物需水量计算模型的研究进展进行了归纳总结，在此基础上指出：基于不同气候（主要是室内外气候耦合的相关度）条件下应使用不同的计算模型，并建议对大棚温室微气候复杂的动态系统进行数值模拟及建模，有利于进一步提高计算室内作物需水量模型的精度。     

基于Pro/E的播种机零部件参数化造型

针对旱作节水播种机设计中存在的设计手段落后、设计效率低下等问题，应用基于特征的参数化造型软件Pro/E对旱作节水播种机的零部件进行参数化造型，在对该类播种机开沟器、排种器、地轮等零部件的造型设计中探讨了技术要点，提高了旱作节水播种机修改设计和系列化设计的效率。     

Expression of Jagged2/Notch3 signaling molecules in pulmonary hypertensive rats induced by monocrotaline

AIM: To study the expression of Jagged2/Notch3 signaling molecules in pulmonary vascular wall of pulmonary hypertensive rats induced by monocrotaline. METHODS: SD rats were randomly divided into normal control group (C group,n=15), solvent control group (S group,n=15) and monocrotaline model groups (M group,n=15). The model of pulmonary hypertension was established by a single subcutaneous injection of monocrotaline (50 mg/kg). The rats in S group were given a single subcutaneous injection of the same dose of solvent. After 4 weeks, the pulmonary vascular remodeling was assessed by HE staining, and the mean pulmonary artery pressure (mPAP) and right ventricular systolic pressure (RVSP) were determined by right heart catheterization. The expression of Jagged2/Notch3/Hes5 molecules in the pulmonary vascular wall was detected by immunohistochemical method and real-time PCR. RESULTS: Compared with S group and C group, the percentage of medial wall thickness of smaller arteries in model group increased significantly (P<0.01). The levels of mPAP and RVSP in M group were significantly higher than those in S group and C groups (P<0.01). The results of real-time PCR showed that the expression of Jagged2, Notch3 and Hes5 was significantly increased in M group compared with S group and C group. The data from immunohistochemical detection indicated that Jagged2 mainly expressed in the intima of small lung artery, Notch3 and Hes5 mainly expressed in the medial smooth muscle cells. Compared with S group and C group, the expression of Jagged2 and Notch3 was significantly increased in the lung small arteries of M group. CONCLUSION: The activation of Jagged2/Notch3 signaling pathway might play an important role in the formation of pulmonary hypertension.     

Egg production forecasting: Determining efficient modeling approaches

Several mathematical or statistical and artificial intelligence models were developed to compare egg production forecasts in commercial layers. Initial data for these models were collected from a comparative layer trial on commercial strains conducted at the Poultry Research Farms, Auburn University. Simulated data were produced to represent new scenarios by using means and SD of egg production of the 22 commercial strains. From the simulated data, random examples were generated for neural network training and testing for the weekly egg production prediction from wk 22 to 36. Three neural network architectures-back-propagation-3, Ward-5, and the general regression neural network-were compared for their efficiency to forecast egg production, along with other traditional models. The general regression neural network gave the best-fitting line, which almost overlapped with the commercial egg production data, with an R(2) of 0.71. The general regression neural network-predicted curve was compared with original egg production data, the average curves of white-shelled and brown-shelled strains, linear regression predictions, and the Gompertz nonlinear model. The general regression neural network was superior in all these comparisons and may be the model of choice if the initial overprediction is managed efficiently. In general, neural network models are efficient, are easy to use, require fewer data, and are practical under farm management conditions to forecast egg production.     

副猪嗜血杆菌S-核糖基高半胱氨酸酶基因序列分析与推导蛋白三维结构的分子模拟

利用PCR方法获得副猪嗜血杆菌S-核糖基高半胱氨酸酶(luxS)基因全长DNA,将PCR纯化产物与pMD18-T载体连接并转化E.coil DH5α菌株,重组阳性质粒测序并采用生物信息学软件对所推导的氨基酸序列进行三维结构分析。结果表明,该基因全长510bp,并与GenBank中登录的其他5株菌株luxS基因完整参考序列进行比较,同源性均在70%以上。用ExPAsy软件包预测了推导蛋白的特性,运用Swiss-PDB viewer软件的SWISS-Model处理器,并利用同源建模的思想建立HPS-luxS的三维结构。拉马钱德兰图证明,构建的luxS蛋白的空间结构是合理的。     

华北平原农灌咸淡水侵入界面渗透性变化机理研究

从研究应用背景、基础理论及模型、实验模拟等方面就微咸水灌溉过程,侵入界面土壤渗透性变化进行分析研究.以衡水典型研究区微咸水分布及水质矿化度分析数据为基础,应用地球化学模式PHREEQC,结合水敏性机理分析矿物迁移的存在形式及各种形式之间的转化关系.结果表明:含高价离子农灌微咸水加快粘土胶体颗粒絮凝沉降能力强于低价离子,...     

基于Master CAM和Pro/E的齿轮快速精确建模及仿真分析基于MasterCAM和Pro/E的齿轮快速精确建模及仿真分析

以外啮合直齿圆柱齿轮为例,介绍了利用Master CAM和Pro/E进行齿轮精确建模,并根据实际工况条件,采用Pro/E的Mechanica对所设计的齿轮进行仿真分析。结果表明,采用此方法可快捷、精确地完成齿轮类零件的设计。