喷射成形7055高强铝合金的热处理工艺优化及其应用

基于两次挤压处理后的喷射成形7055铝合金,采用SEM、光学显微镜、硬度仪和拉伸试验机等分析手段研究了试验合金在不同时效工艺下的组织和性能。结果表明,相较于单级时效工艺,经过120 ℃×6 h+160 ℃×2 h双级时效处理后,析出相呈短棒状均匀分布于基体,其沿长度方向上的平均尺寸为500 nm,宽度方向平均尺寸为10 nm,时效峰值硬度达196.4 HV0.05。采用双级时效工艺处理的试验合金在298、398、498和598 K的抗拉强度分别为855、792、688和360 MPa,断后伸长率分别为14%、11%、9%和8%。采用该双级时效处理工艺处理的喷射成形7055铝合金应用于轮毂紧固件产品的制备,并对其进行硫酸阳极氧化处理,可使得紧固件试样同时兼具高强度、高硬度以及高耐蚀性能,有望得到更广泛的应用。     

激光织构和碳基薄膜复合处理提高钛合金摩擦学性能研究

在重载滑动干摩擦条件下,对比不同织构密度的钛合金表面的摩擦学性能;在耐磨性最好的织构密度钛合金表面再制备碳基薄膜,并与直接在钛合金表面制备的碳基薄膜的摩擦学性能进行对比。结果表明：3种低织构密度条件下,TC4钛合金的摩擦因数减小、磨损率降低;随着织构密度的增大,钛合金材料的摩擦因数变化极小,磨损率有所增加;在织构密度5.95%的钛合金表面制备的碳基薄膜,因织构微凹处产生的小微湍流,减少了摩擦阻力,使得其摩擦因数相比直接在钛合金表面制备的碳基薄膜的摩擦因数有所减小。织构化碳基薄膜的磨损率比钛合金的磨损率降低了99.31%,比直接在钛合金表面制备碳基薄膜的磨损率也降低了约60%,这是因为高接触应力摩擦过程中触发石墨化转变,被磨损的石墨化颗粒碎片嵌入织构微凹中,抑制了摩擦接触界面的磨损行为。     

煤粉工业锅炉系统除尘器滤袋失效原因分析

为解决布袋除尘器在煤粉工业锅炉系统中滤料失效问题,针对2个煤粉工业锅炉系统布袋除尘器在使用一个采暖季后滤料破裂,除尘器失效的问题,通过常规性能测试、红外光谱分析、差热分析和电镜扫描等方法对失效滤袋进行分析。结果表明:滤料未采用适当材质和喷吹位置安装不当分别是造成2个滤袋失效的主要原因。从系统运行参数和设备安装方面分析,提出聚苯硫醚(PPS)材质滤料是煤粉工业锅炉系统除尘器滤料的最佳选择,喷吹管上的喷嘴与花板孔之间同心度是除尘器安装的关键,为今后工程中滤袋的选择和除尘器的安装提供了依据,从而保证了过滤效果,延长了滤袋的使用寿命,减少了不必要的损失,确保烟尘排放正常达标。     

细菌纤维素发酵条件的优化及结构的初步研究

通过单因素及正交实验探索出AcetobacterxylinumNUST4·2合成细菌纤维素的发酵条件为:葡萄糖1·5%、蔗糖1·0%、蛋白胨1·5%、醋酸0·08%、Na2HPO40·27%、MgSO40·025%,接种量8%,pH5·5,28℃静置培养7d,纤维素产量为3·348g/L培养基(干重)。接着利用活性炭柱分离和气-质联用色谱(GC-MS)鉴定了发酵产物的单体成分为葡萄糖;采用固体CP/MAS13CNMR、透射电镜(TEM)、X-射线衍射表征了发酵产物的结构,得知该产物具有典型的网状结构,纤维束尺寸为纳米级且结晶度很高。     

长江流域用水趋势及用水总量控制指标研究

用水总量控制指标是“三条红线”的重要指标,是实行最严格水资源管理制度的基础工作。通过分析80年代以来长江流域及各水资源二级区用水总量、各行业用水量、用水效率和水平的变化趋势,结合经济社会发展指标和用水定额预测了2020年和2030年长江流域用水需求,分析了各产业用水量变化趋势,提出了长江流域用水总量控制指标。有关分析研究成果可为水资源合理配置,提高水资源利用效率和效益,提供科学决策依据。     

煤矿企业生产安全监管的新视角

本文通过非对称信息动态博弈模型的分析可知，在“政企不分”的生产机制下，政府的对煤矿企业的生产安全监管是“退化”的，即强监管型的概率会弱化，弱监管型的概率会强化。在“政企分开”的生产机制下，煤矿企业的生产安全与监管者的查处存在完全信息条件下的纳什均衡或混合纳什均衡。为此，政府应主要从如下方面着手建立有效的监管方式：①树立以人为本的科学发展观。②用制度化的方式加大查处，降低额外收入的诱惑。③对监管者也建立惩罚和激励相容机制。④减小国有煤矿企业的“社会负担”。     

氧化亚铁硫杆菌发酵的研究

通过对氧化亚铁硫杆菌进行单因素发酵试验,确定其优化培养基成份为(NH4)2SO40.2%,K2HPO40.07%,MgSO4·7H2O 0.07%,KCl 0.014%,Ca(NO3)2 0.001%,FeSO4·7H2O 4.44%,pH=2～3.并对发酵过程中生成的沉淀物质进行X粉末衍射分析,得出沉淀物的主要成分是NH4Fe3(SO4)2(OH)6.     

Early failure active elimination system research for electromechanical product based on meta-action

Frequent early failures have been the key factor restricting the reliability improvement of electromechanical product, and also reducing its market competitiveness. Most of the current early failure elimination methods are passive elimination technologies after a failure. Their purpose is to quickly restore the production capacity of products, which is mainly used to improve the reliability of the products, and cannot fundamentally improve the quality of the manufactured product. To address those problems, this paper first analyzed the causes of early failures in the production stage of electromechanical product, and studied the corresponding early failure elimination mechanism; second, according to the FRACAS (Failure Report Analysis and Corrective Action System), an early failure elimination method for electromechanical product was proposed based on the meta-action unit; finally, in order to ensure the smooth implementation of early failure elimination measures, a set of early failure active elimination guarantee management system was established. In addition, this paper also introduced the specific implementation process of the proposed method. The proposed method is applied to engineering, and the results verify its correctness. The proposed method provides a theoretical basis and technical support for the elimination of electromechanical product early failure.     

A new edge detection algorithm for image corrupted by White-Gaussian noise

Because corruption of image by White-Gaussian noise is a frequently encountered problem in acquisition, transmission and processing of image, and classical edge detection operators such as Roberts, Sobel, Prewitt and LOG operator have the deficiency of being sensitive to White-Gaussian noise, this paper proposes a new edge detection algorithm for Image corrupted by White-Gaussian noise that can reasonably consider White-Gaussian noise reduction and correct location of edge, and provides its specific arithmetic process. Finally, the comparison based on principle of new edge detection algorithm and classical edge detection operator is done, the experimental results indicate that the performance of new edge detection algorithm is better than that of classical edge detection operator.     

基站等电位防雷的重要性及实现方法探讨

阐述了基站的防雷现状,结合工程实践,提出了等电位防雷在基站中的重要性,并根据基站雷电引入的途径提出了具体的实现方法.