大连软件园数字化信息管理系统网络方案

对大连软件园数字化信息管理系统网络方案进行了详细的阐述,包括建设目标(建成完善的软件园网络系统、各管理系统软件支持平台、安全接入Internet)、设计原则、网络架构、组网方案、网络中心采用千兆以太网网络技术、系统要求(可靠性、可用性、可扩展性、安全性、可管理性、协议的标准性、数据的高质量传输、布线系统要求)等。     

矿井提升机位置与速度控制系统中的PLC控制设计

矿井提升机是煤矿企业的大型机电设备,在生产过程中主要负责提升矿物、升降人员和设备及各种材料。近年来,随着电力电子技术和现代控制理论的发展和完善,将PLC运用于矿井提升机是一种趋势。就PLC在矿井提升机位置与速度控制中的运用进行探讨。     

旋转磁偶极子式超低频发射天线辐射特性

超低频电磁波（30~300 Hz）在水和土壤中的路径损耗较小,因此在海底、矿井应急、地震预报及军事等领域具有不可替代的作用。为实现小型化和低功耗的超低频机械天线,对运动磁偶极子辐射特性进行了研究。通过控制永磁体旋转产生交变磁场,辐射超低频电磁波;将旋转永磁体等效为其表面安培电流,依据法拉第电磁感应定律,结合安培电流模型,引入永磁体参数及被测距离建立辐射功率解析模型;分析实验研究影响因素与旋转永磁体辐射功率的关系,并利用二进制数字频率信号调制进行通信实验。结果表明：旋转永磁体在空间辐射功率与永磁体剩磁的平方、永磁体体积的3次方呈正比,与测试距离的4次方呈反比;通过对转速的实时控制,以及对信号进行时频域变换,实现了超低频通信。     

挪威海格纳斯潜艇水声试验场测量设施分析

利用水声试验场对潜艇的水下辐射噪声进行测量和分析,是先进国家改善潜艇安静性的重要方法.位于挪威卑尔根附近的海格纳斯潜艇水声试验场,是德国、荷兰、丹麦、挪威等北约国家最重要的潜艇水声检测机构.本文介绍了该潜艇水声试验场的选址特点和主要测量设施,分析峡湾水域建设潜艇水声试验的利弊,分析航行试验场和静态试验场对水声试验场建设的不同作用,为我国水声试验场的建设提供参照.     

Failure Investigation on Failed Blades Used in a Locomotive Turbocharger

A failure investigation has been conducted on the turboblades used in a locomotive turbocharger. These blades are made from as-cast K418 nickel-base (Ni-base) superalloy. Fracture occurred at the mid-airfoil and tip locations. In the mid-airfoil regions, a high density of intergranular cracks and dent marks are present. The microstructure at the mid-airfoil is typical of overheat damage, such as melting of the boundary or interdendritic region and degraded interdendritic carbides and remelting of eutectic phases (γ + γ′). The fracture surfaces of the failed blades have a dendritic appearance without evidence of fatigue features. It is suggested that these fractures were formed instantaneously. Overheat damage made the strength in interdendritic region decrease so that microcracking occurred preferentially in the interdendritic region. Under the action of bending stress and the spin centrifugal tensile stress, the microcracks propagated within the interdendritic region and converged so that the transverse fracture occurred at the mid-airfoil location where the maximum stress acted. The fragments from previously fractured blades hit neighboring blades, ultimately causing damage to all the turboblades.     

热液法低温制备锐钛矿型TiO_2水溶胶

以钛酸四丁酯为原料,采用热液法在低于100℃的条件下制备了锐钛矿型TiO2水溶胶。通过差热分析、X射线衍射和高分辨透射电镜对TiO2粉体进行表征。结果表明:所制备的TiO2粉体均为锐钛矿相,颗粒大小随着热液处理温度的升高而增大,其粒径介于4.8～6.9nm之间。同时,所合成的TiO2具有较高的光催化活性。     

渗透率和孔隙度对地下水源热泵地温场演化的影响

地下水源热泵系统是利用浅层地温能的一种主要方式,而水文地质条件是决定应用地下水源热泵系统是否合理的主要因素之一,应用数值模拟的方法对地下水源热泵抽水井处地下水温度进行模拟,分析了含水层渗透率和孔隙度对地温场演化的影响。研究结果表明:在抽、灌量和生产井几何参数相同的条件下,含水层渗透率和有效孔隙度对地温场的演化影响并不显著。     

Surface modification of materials by dielectric barrier discharge deposition of fluorocarbon films

Dielectric barrier discharges have been used to deposit fluorocarbon (FC) films on various materials, such as paper, glass, and silicon substrates. The primary monomers used for plasma polymerization were difluoromethane (CH₂F₂), octafluoropropane (C₃F₈), and octafluorocyclobutane (C₄F₈). FC films were characterized using Fourier transform infrared spectroscopy, atomic force microscopy, static contact angle measurements, and scanning electron microscopy. Surface and structural properties of deposited films are strongly dependent on the plasma compositions and plasma parameters. FC films deposited on paper are to enhance its barrier properties and to achieve hydrophobic surfaces. Contact angle studies reveal that a minimum FC film thickness of about 200 nm on paper is required to completely cover surface and near-surface fibers, thereby providing the paper with long term hydrophobic character. In the C₃F₈ and C₄F₈ systems, the contact angles of the deposited films do not change appreciably with plasma parameters and are strongly dependent on the substrate roughness. Hydrogenated FC films deposited with CH₂F₂ plasmas show the relatively low contact angles due to the existence of CH_X (x = 1-3) groups.     

水表连接黄铜螺母断裂分析

居民住宅内与水表连接的黄铜螺母发生断裂,造成管路泄漏.采用宏、微观检验方法对失效螺母进行了分析.结果表明,黄铜材料中含有较多的铅,使金属基体脆化并在晶界上存在脆性共晶体网膜,加上金属中还存在孔洞、缩松等铸造缺陷,是造成螺母断裂的主要原因.     

Ni-Fe-Cr多孔泡沫合金的成分及性能研究

为了改善多孔泡沫镍合金的耐高温腐蚀性能,在其表面共沉积Ni-Fe-Cr合金镀层.采用共沉积法制备耐热多孔泡沫合金,研究工艺参数对Ni-Fe-Cr合金镀层中Cr、Fe质量分数的影响,利用能量色射谱仪、X射线衍射仪、金相显微镜及扫描电子显微镜分别对镀层成分、微观结构及其形貌进行分析,采用ICP-OES电感耦合等离子体光谱2100Dv测定合金中Cr、Fe的质量分数,同时对Ni-Fe-Cr多孔泡沫合金试样进行了抗热冲击性和耐热性能测试.结果表明:共沉积优化工艺参数为CrC13·6H2O 160 g/L,FeC12·4H2O 9 g/L,阴极电流密度24 A/dm2,镀液pH值2.0,温度30℃;在优化参数下,电镀30 min,得到Cr质量分数为21.2%、Fe质量分数为43.9%的Ni-Fe-Cr多孔泡沫合金.经测试,Ni-Fe-Cr多孔泡沫合金表面由紧密排列的球形颗粒组成,并形成了面心立方微观结构,具有良好的抗热冲击性及耐热性.