智能机械通风控制系统的实现和应用

系统采用计算机网络控制技术、智能技术,自动控制粮仓通风设备启停和粮仓门窗的开关。依据《储粮机械通风技术规程》和相关智能通风策略对粮仓进行通风,达到降温通风、降水通风和调质通风等目的,有效控制粮仓的储粮环境和粮食品质,从而达到绿色安全储粮的目的。     

The mechanical roles of the clasping leaf sheath in cereals: Two case studies from oat and wheat plants

Stem lodging is a common problem in cereal crop production and a main constraint for grain yield improvement. The leaf sheath that surrounds and protects the hollow internodes of stem could provide the plants with a great physical support. However, this biomechanical function has been ignored for several decades in cereal crops. This study aimed to examine the biomechanical properties of basal stem internodes and lodging susceptibility of the whole plants with or without the clasping leaf sheath in wheat (Triticum aestivum L.) and oat (Avena sativa L.) among different genotypes and agronomic practices (including planting densities and nitrogen application rates). The main objective was to quantify the mechanical role of the leaf sheath in oat and wheat crops by a “safety factor” method. On average, the leaf sheath contributed 40%, 68% and 38% of the overall stem bending strength, flexural rigidity and safety factor, in oat, while it accounted for 11%, 24% and 10%, respectively, in wheat plants. The significant contribution of the leaf sheath is due to its vital role in enlarging the peripheral position (i.e., second moment of area) and stiffness (i.e., Young's modulus). The contribution ratios (%) were found to be higher in oat than in wheat plants, due to the greater mass density of leaf sheath and more proficient/prevailing stay-green capability in oat genotypes. This study emphasizes the important mechanical role of clasping leaf sheath on stem internodes of cereals and indicates that the stay-green trait of the leaf sheath can be exploited to design appropriate varieties with improved lodging resistance and great yield potential.     

动力机械设备的故障诊断技术

介绍了动力机械设备故障诊断技术,分析了制约其发展的主要因素,阐述了动力机械设备故障诊断技术的发展趋势。

Abstract：

The mechanical equipment diagnosis technology is introduced,the main factors restricting the development of mechanical equipment fault diagnosis technology are analyzed and the development trend of mechanical equipment fault diagnosis technology is stated     

机械组件的固有可靠寿命研究

简述机械组件的可靠度的概念,比较机械组件与电子元件在可靠度上的不同特点。机械组件可靠度数据采集难度大,应做好机械组件失效分析,以在设计附件提高可靠度。     

危害沙棘的围连环夜蛾生物学特性及防治

围连环夜蛾在我国多有分布，但看见其幼虫的还是很少，因资料中寄主不祥，笔者经室内外观察。发现其危害多种植物的叶片，更喜欢危害沙棘树的叶片，笔者经2a的室内外观察得知。其生物学特性在辽宁西部每年1代，以蛹越夏及冬。对沙棘树危害较重，对栽植的大果沙棘危害尤为严重，在5a生的沙棘树上有100多头幼虫危害，成虫善飞翔。     

中国椰子寒害及其对策研究

椰子是一种典型的热带作物，受低温天气影响椰树会出现严重的落裂果、叶片变黄甚至整株枯死的现象；大灾之后，各地采取了一系列抗灾救灾措施，并取得了明显成效。本文对受2008年初椰树寒害的区域性、品种耐寒性进行回顾，对3年来的抗寒救灾措施进行全面总结，并对今后中国椰子生产发展提出可行性建议。     

耕地损毁鉴定指标体系研究

耕地损毁主要包括以下五种类型:耕地地面硬化、耕地地面塌陷、耕地挖损、耕地压占和耕地污染,笔者在分析耕地损毁类型特征基础之上,提出了耕地损毁鉴定体系指标选取的原则:综合性原则、分类指导原则、可操作性原则和耕地破坏程度认定与耕地恢复难易程度认定相当原则,由此得到耕地损毁程度的评价指标,采用层次分析法建立耕地损毁评价指标体系,并提出了完善法律法规,依法治理损毁、分类治理利用,推进耕地复垦、引导科学种田,加强耕地保护、创新防控机制等治理对策。研究结果可为耕地损毁鉴定、复垦方案的编制、复垦措施提供现实指导意义。     

Protective effects of taurine on LPS-induced myocardial damage in rats

AIM: To investigate the effects of taurine on lipopolysaccharide (LPS)-induced myocardial damage in rats. METHODS: Healthy male SD rats (n=30) were randomly divided into control group (CON), LPS model group (LPS) and taurine treatment group (TAU). The rats in CON group and LPS group were intravenously injected with normal saline, and the rats in TAU group were injected with taurine (100 mg/kg). After 2 h, the rats in LPS group and TAU group were intraperitoneally injected with LPS at 10 mg/kg, and the rats in CON group were injected with normal saline. Six hours after injection of LPS, the blood samples were collected for determination of superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) levels. The myocardial tissues were processed for histological examination and the analysis of Western blot. RESULTS: Compared with CON group, LPS significantly reduced SOD activity in the serum and heme oxygenase 1 (HO-1) protein expression in the myocardial tissues, increased the serum content of MDA and levels of TNF-α and IL-6. LPS also significantly elevated the levels of TNF-α and IL-6, and up-regulated the cyclooxygenase-2 (COX-2) expression and phosphorylation of nuclear factor kappa B (NF-κB) in the myocardial tissues. Taurine pretreatment significantly elevated SOD activity and HO-1 protein expression level, decreased the levels of COX-2, TNF-α, IL-6 and phosphorylated NF-κB. Histological observation showed that taurine reduced inflammatory response in the myocardial tissue. CONCLUSION: Taurine attenuates LPS-induced myocardial damage in rats. The beneficial effects of taurine may be associated with its reduction of p-NF-κB/COX-2 signaling by activation of HO-1/CO.     

工程施工机械维修现状浅析

维修是恢复土石方施工机械的技术性能,排除故障及消除故障隐患,延长机械使用寿命的有效方法.施工机械维修常见技术问题切记重视,只有解决上述维修过程中存在的问题和提高维修人员的素质,加上正确的养护方法和措施,才能提高机械设备的完好率和使用率,以保证最大的经济效益.     

有机质浸染砂水泥土的力学特性及本构关系

为研究海南省海湾地区分布的有机质浸染砂水泥土的力学特性,该文首先对有机质浸染砂水泥土和标准砂水泥土进行无侧限抗压强度对比试验(采用配合比均为熟石灰掺入比7.5%、水泥掺入比20%、水灰比0.45),定量分析养护龄期对其无侧限抗压强度及试样破坏形式的影响。然后对有机质浸染砂水泥土进行单轴抗压试验,获得了水泥土材料的应力-应变全过程曲线、刚度变化规律以及改进邓肯-张本构模型。结果表明:1)有机质浸染砂水泥土试样的破坏类型为塑性剪切破坏和脆性剪切破坏;2)有机质浸染砂水泥土抗压强度随着养护龄期的增加基本呈指数形式增长,但在养护龄期14 d后,增长速度逐渐降低并趋于稳定;3)随着养护龄期增长,水泥土刚度增加。在加载初期,水泥土切线模量随着轴向应变增加而增大,呈现刚度硬化现象;4)基于单轴抗压试验得到应力-应变全过程曲线,可分为2个阶段:塑性阶段、软化阶段;5)通过对应力-应变全曲线的描述,得到了修正的邓肯-张模型,确定模型参数后,与实测数据对比发现,该修正模型可以模拟有机质浸染砂水泥土的应力-应变关系。