冬枣果园土壤非交换态钾的释放动力学

为了研究长期施肥条件下冬枣果园土壤非交换态钾的释放特征,以Ca Cl2和柠檬酸溶液为浸提剂,采用连续提取的方法对枣园土壤的非交换态钾释放动力学进行研究。结果表明,枣园土壤非交换态钾在释放过程中表现出快速释放和缓慢释放2个连续的阶段。快速释放阶段(188 h)的累积释放量占到总释放量的53.6%~59.2%,而在缓慢释放阶段(188~1244 h)的释放量不及总量的一半。在相同时间内,使用柠檬酸溶液浸提时,非交换态钾的释放量明显高于使用Ca Cl2溶液时的释放量。相比之下,冬枣果园土壤非交换态钾的释放量明显高于对照土壤。在5种动力学方程中,幂函数方程是描述冬枣果园土壤非交换态钾释放的最优模型。     

ICAI Realizaltion for the K-map Simplification of Logical Function

Based on the theory of the K map simplification of logical function(KSLF),this article releases a ICAI Realization for KSLF.Providing three kinds of teaching style:commonness, teaching, practice.This product,wich supports for the K map simplification with random item,is not only helpful to the construction of the curriculum of digital circuit ,but also to the design for digital application system.Under the practice method, This product's guides,checks,and corrects the student's whole process forthe proceeding of KSLF automaticly under the teaching method.     

Review on the measurement theories of enterprise knowledge management during the past three years in China

The implement of enterprise knowledge management gives rise to extensive research on its measurement. Based on the existing measurement theories and evaluation index systems of enterprise knowledge management during the past three years in China, this paper analyzes the problems in measuring target and designing the evaluation index system in the existing research findings, and explains detailedly why measurement target of enterprise knowledge management should be "level evaluation" instead of "performance evaluation", and definitely points out the meanings of enterprise knowledge management level and significance of its evaluation. This paper also indicates that the design of the evaluation index system should be complete, reasonable, proper and operable.     

EPQ Model with Different Lost Sale Factor Relative to Inventory Level

It is important for enterprises' inventory management to find out the optimal production cycle and the length of shortage time,so that the total cost of inventory system can be reduced and the service level can be raised.Based on the classical EPQ model,this paper develops an EPQ model for deterioration items with different lost sale factor relative to the inventory level during shortage period.The existence of unique optimal solution is discussed by mathematic analysis and a numeric example.The sensitivity analysis shows that the parameter of losing sale has different impact on the costs of inventory system.The factors must be considered for the production inventory system to make management decision.     

液体射流泵空化噪声与振动试验

针对液体射流泵的空化噪声与振动进行了试验研究;运用B＆K加速度仪和水听器对射流泵各部位在不同工况下的空化噪声与振动进行了测量。结果表明：（1）射流泵空化噪声以单极子声源为主,随着流速和紊流度的增大,偶极子作用逐渐增大;（2）射流泵空化噪声与振动随空化程度加剧而更强烈,最强烈处也从喉管向扩散管转移;（3）射流泵面积比越小,达到临界空化前噪声频谱波动越强,临界空化之后噪声谱级趋于平稳,随频率增加而递减;（4）初生空化出现前后噪声在整个频域范围内都有一个较大的跃升,约5-10 dB,此跃升可作为判断初生空化的参考方法;（5）泵体3个正交方向振动并不相同,径向振动较轴向更为明显。     

The quality of service provided by the irrigation department to the users associations, Tunuyan System, Mendoza, Argentina

The quality of service provided by the provincial Irrigation Department (DGI) to the Water Users Associations (UA), and subsequently by the UA's to the related water users, is based on the provincial water law. The intended volume of water being delivered per considered period further depends on the water availability and on the (crop irrigation) water requirements. The Service Level (SL) compares the intended water supply with the water supply that would be required to supply the entire irrigable area with sufficient water. As soon as the intended water delivery pattern is set, the measured actual delivery can be assessed against the intention. Several performance indicators are used in this context. Based on the assessment of the Water Delivery Performance Ratio and the Overall Consumed Ratio recommendations are made on changes which can be made to improve water use and reduce problems of waterlogging.     

水井酸处理效果预测研究

水井酸处理效果预测一直缺乏成熟的方法。提出了根据水位恢复曲线形态和含水层裂隙特征来预测井的首次酸处理效果，经与石油界所用方法有明显不同。石油界普遍认为，只有不位恢复曲线为快速上翘型的低产碳酸盐岩井才适合酸处理（即基质酸化），但作者近年来发现，多数水位恢复曲线为直线型的低产碳酸盐岩井，即井中含水层裂隙平均宽度＜5mm的井，酸处理效果也很好，被调查3眼这类井的单位涌水量增加值平均为423％；水位恢复曲线为缓慢上翘型的井中，部分含水层裂隙被松散物充填的井，采用特殊的酸处理方法处理后，井的单位涌水量可增加100％。另外，采用适当的方法，使用足够数量的酸进行首次酸处理后，水井再进行酸处理一般效果都很差。     

黑龙江省垦区2OO3年农业机械化水平评价

根据已有的农机化评价体系,调查了黑龙江垦区2003年农机化实际值,计算出了该年垦区的农业机械化水平,并进行分析评价。这对于今后提高黑龙江垦区农业机械化的综合保障能力、农机经营效益以及农业机械化水平的进一步提高有着重要的指导意义。