地埋滴灌的应用及应注意的问题

地埋滴灌是一种新型的滴灌方式，具有较好的节水性能和较大的增产潜力。本文作者根据生产实践，就地埋滴灌的应用现状、优点和缺点进行了阐述，并提出了地埋滴灌应用中应注意的问题及解决方法。     

地埋滴灌系统应用中需注意的问题

近两年,一种新型的高效节水灌溉方式——地埋滴灌在兵团又悄然兴起,但它不同于膜下滴灌,因其田间管网(除控制阀外)全部埋于地下,所以在建设安装、运行管理、越冬管理中存在诸多问题,给农业生产带来一定的影响。现就其使用中发现的问题及处理方法介绍如下,谨供参考。1　系统设计     

被征地农民留用地安置方式的特征与模式分析

被征地农民的留用地安置方式自20世纪80年代初开始探索性尝试以来,已在中国东中部地区部分经济发展较快,用地需求矛盾突出的城市中推行,在取得一定成绩的同时也产生了巨大的争议,在实施过程中面临适用范围有限、规划协调难度较大、权属复杂、管理难度大等问题。结合调研实例,在留用地安置特征提取的基础上,对中国已开展的留用地实践进行了模式划分,并就此制度的规范发展提出政策建议。     

武汉与重庆典型地质结构下的地埋管换热性能

地埋管地源热泵换热器的换热性能受到不同地质结构的影响。以武汉和重庆地区的典型地质构成为边界条件,建立了三维地埋管的单孔双U管换热模型,通过模型计算,获得了两种地质条件下的地埋管换热性能,以重庆地区的地源热泵热响应测试结果以及工程运行数据出发,对模型的计算结果进行了验证,结果表明,模型吻合度较好,可以应用于工程分析。以模型为条件,进行地质结构对换热性能的影响度分析,预测了两地地埋管地源热泵的换热性能并计算得到换热器的平均换热系数分别为武汉地区K₁=1.65（W/m·K）,重庆地区K₂=1.51（W/m·K）。     

番茄地埋滴灌与膜下滴灌的效果比较

地埋滴灌是近几年在美国、澳大利亚和以色列等国家广泛推广的一种新的滴灌技术，即滴灌毛管铺设在耕作层以下，水通过地埋管上的滴头或滴孔流出，并在毛细作用或重力作用下将农作物所需要的水肥直接扩散到作物根部，供作物吸收利用的滴灌方式。由于其灌水过程中可保持作物根层疏松通透，减少地表蒸发，具有明显的节水作用，适用于番茄、棉花、玉米、小麦、马铃薯等条播作物。     

地木耳实用价值的研究

分别从食用与医疗保健、工业生产、环境监测和农业生产等方面,对地木耳的实用价值进行了简单综述,分析了其在现代生活中的具体作用与潜在利用价值,并对其发展前景进行了讨论。     

Incorporating Fault Tree Analysis into Event Tree Analysis for Failure of City Gas pipelines

The Event tree model for failure of city gas pipeline is established in this article according to the property of city gas,the fault tree analyses are incorporated into the event tree. The fault trees are used to analyze the causes and probabilities of the initial event and subsequent events, while the event tree is used to analyze the subsequent event of gas leaking and the probabilities of the consequential events. Thus, a comprehensive analysis method for failure of city gas pipeline and its hazard has been produced.     

Kolmogorov entropy analysis of surrounding rock system in the processing of unloading for deep buried tunnels

Rock is a kind of physical nonlinear complicated medium, under deep buried condition the surrounding rock system deformation shows geometrical nonlinear characteristic, and the interaction between the two nonlinear mechanism makes the unloading of surrounding rock system evolving complexly. Based on the Lagrangian method and large deformation caculation method, both the double nonlinearity and nonlinear dynamics character of deep buried tunnel surrounding rock system under unloading are studied. The numerical model results show that the Kolmogorov entropy has been extracted from the evolution data in the unloading process of surrounding rock system. The analysis indicates that the typical chaos character has been demonstrated in the process of unloading for deep buried tunnel surrounding system and the rock mass energy dissipation is analyzed at the stage of unloading.     

带锚FRP受剪加固梁非剥离破坏模式BP网络预测

对带可靠锚固FRP受剪加固混凝土梁的非剥离剪切破坏模式做了细化分类,即包括FRP断裂控制的破坏、受压区混凝土（达到极限应力状态）压碎控制的破坏、FRP断裂与混凝土压碎同步发生的界限破坏等3种模式;利用BP神经网络建立了带锚纤维受剪加固梁破坏模式的智能预测模型,与31根非剥离破坏加固梁试验的对比结果显示：模型总体精度达到90%,说明建立的破坏模式网络预测模型适用于带锚纤维受剪加固梁非剥离剪切破坏模式的判别。     

Diagnosis approach based on failure mode importance of causality diagram

Causality diagram methodology is a probabilistic reasoning, which can be applied to fault analysis. However, it lacks analysis on the importance of failure mode. The importance of failure mode is introduced to develop causality diagram methodology, which is successfully applied in fault analysis of gas explosion in colliery. The study shows that causality diagram based on importance of failure mode is an effective qualitative and quantitative method to analyse faulty, evaluate system safety and provide feasible countermeasures to prevent accidents.     

Numerical analysis on the evolutionary features of deformation and failure modes of slopes

The failure of slope is a gradual accumulation process. Under the effect of many interior and exterior factors, some parts in the slope reach yield with the increase of stress, and sliding surface forms gradually till complete transfixion. With continuous increase of the plastic strain, overall failure happens on the slope. Traditional analysis method cannot display the mechanic conditions and the whole process of deformation, transfixion of sliding surfaces and failure. Meanwhile, FEM strength reduction can quantitatively show the deformation features and the process of occurrence and development of sliding surface. Based on the previous researches, the paper classifies slopes according to the features of rock and soil and the slope structure. Through analyzing the graphs of deformation and the nephograms of plastic strain under different reduction factors or safety factors, the researchers can directly find the deformation tendency of slopes and the whole process of the extension, transfixion and failure of sliding surface with the reduction of safety factor. So, the failure mechanism of slope can be found intuitively, which can provide effective basis for the prevention and governance of slopes.     

励磁功率单元主回路快速故障诊断策略

分析总结了发电机组励磁系统功率单元的故障类型和常见故障,通过Matlab仿真功率单元主回路故障类型,重点研究基于故障频谱分析的定量故障特征提取和故障分类,提出了一种快速针对功率单元主回路的故障诊断真值表法,最后通过实验平台验证故障类别,结果表明：该方法能够正确有效地诊断出功率单元主回路具体的故障晶闸管,为励磁系统功率单元故障诊断提供依据。     

design of an equipment condition monitoring and fault diagnosis network system for the main drive of a hot strip mill

A new distributed equipment condition monitoring and fault diagnosis network system based on an RS485 field bus and an industrial ethernet was designed for the main drive system of a hot strip mill. The system structure and composition were studied. The following problems were resolved: communication of an intelligence data acquisition module with RS485 interface; communication between a server, clients and a light emitting diode; and point to point communication between a programmable logic controller and server. Real time signals of 24 radial run out, 12 axial drifting can be synchronously acquisitioned and stored in a database. System operation is satisfactory and can be used to identify the causes of rolling mill halt and transmission slip brake, and to improve sheet metal quality.     

高烈度区斜拉桥横向约束方案优化分析

为了确定强震作用下斜拉桥合理的横向抗震约束体系,以可克达拉大桥为工程背景,采用非线性时程分析法,分析了4种横向约束体系即横向滑动体系、全限位体系、位移相关型减震体系和速度相关型减震体系对强震区大跨度桥梁地震响应的影响,重点对钢阻尼器的屈服荷载和黏滞阻尼器的位置及相关参数进行优化分析,并与其他体系的地震响应进行了对比。结果表明：在强震作用下,对于大跨度桥梁横向滑动体系和全限位体系均不是理想的抗震体系;而在墩梁、塔梁之间设置减隔震装置可以有效减少横桥向的墩梁、塔梁的相对位移及地震剪力和弯矩;然而,从桥梁正常使用的角度来看,塔梁之间布设横向钢阻尼器装置优于黏滞阻尼器装置。     

Effects of the Adaptable Distribution for Lateral Forces Considering modes Coupling on Structural Pushover Analysis

Two high and flexible RC frame structures are analyzed;the paper explains the rise in the structural damping ratio and the base mode's drifting,and the modes coupling is caused by the greatly rising damping ratio.The paper also proposes that the modes coupling need be considered in the pushover analysis of the high and flexible RC frame structures.A CQC adaptive distribution for lateral forces in considering the modes coupling at every load step is given,and is compared with the traditional SRSS one.Meanwhile,some practical engineering suggestions are given.     

Theoretical Analysis for the Performance of HVDC Grounds Electrodes and the Mathematical Modal

The performance of HVDC ground electrodes is analyzed in detail.On the basis of electromagnetic field theories and its assumptions,the mathematical model is built,the ground resistance,the distribution of potential and temperature are computed with the current field distributions of HVDC ground electrodes.