热盐腐蚀环境对TC11钛合金高温寿命影响规律试验研究

目的 针对发动机钛合金部件在热盐环境与工作载荷下的寿命衰减问题，开展TC11钛合金热盐腐蚀疲劳与应力腐蚀试验，研究腐蚀环境下TC11的高温寿命衰减规律与失效机理。方法 利用喷盐法制备TC11钛合金试验件，研究不同温度与应力水平对TC11腐蚀疲劳以及应力腐蚀的影响规律。利用SEM等观测手段，开展腐蚀疲劳以及应力腐蚀试样断口与表面的形貌分析，分析腐蚀环境下的失效机理。结果 热盐腐蚀环境导致TC11的寿命显著降低，对比450 ℃下无腐蚀寿命，腐蚀疲劳寿命下降了2个数量级，应力腐蚀寿命下降到不足1%，且分散性较大。观察腐蚀疲劳和应力腐蚀的试样可以发现，表面有明显的腐蚀坑，腐蚀坑底发现裂纹。结论 热盐环境下，TC11腐蚀疲劳寿命和应力腐蚀寿命都会明显下降。由于腐蚀导致钛合金试样表面产生许多腐蚀坑，在腐蚀坑局部形成近似缺口，缺口部位的应力集中是导致腐蚀疲劳寿命衰减的重要因素。腐蚀疲劳的寿命低于Kt=1的无腐蚀疲劳寿命，但是要大于Kt=3的无腐蚀疲劳寿命。     

A NOTE ON SPRING WARMING IN LAKE SUPERIOR1

ABSTRACT. Temperature recorder data from central Lake Superior obtained from May through July, 1967, are used to describe the spring warming of this deep lake. Data from the 30, 91 and 150 m levels suggest that water descending in the thermal bar spreads lakeward, filling the lake with an increasingly thick layer of maximum density water. Lakeward of the thermal bar, local warming is relatively slow preceeding and following the passage of the reverse thermocline at a given level.     

我国温泉旅游资源的开发与利用

我国温泉旅游资源丰富,目前已经形成了一批成熟的温泉旅游度假区,但是当前我国对温泉旅游资源的稀缺性和脆弱性认识不足,温泉旅游项目建设存在贵族化、劣势产品"搭便车"趋向、旅游功能单一等问题.提出充分重视温泉旅游资源的价值,根据市场状况合理选择开发模式,对本地洗浴客人和外来公务游客作重点营销,保持温泉旅游产品的价格优势,开发多元化旅游产品.     

玉米育苗移栽防御低温冷害和春旱试验研究

为防御玉米低温冷害和春旱,在吉林省东部开展了玉米育苗移栽田间试验。结果表明,玉米育苗移栽是一项简便有效的防灾、减灾实用技术。利用该项技术可增加220～250℃·d积温,因此可采用较当地大田播种生育期长10～15天、所需积温多230℃·d的偏晚熟品种,以避开播种出苗期干旱;产量和产值分别提高40%和35%左右,并可提早成熟,防霜害,提高玉米品质。     

EflFect of long-term ozone fumigation on growth development and yield of spring wheat in open-top field chamber

The experimental plants were grown in open-top chamber and exposed to 0.26 ppm of ozone for six hrs. per day from seedling stage till ripening. The results showed that the height of plants, rates of earing, flowering, grain forming, ripening and the weight/1000 kernels all declined in fumigated plants in comparison with the controls. The yield lost 76.7%. The actual actions of ozone were that it caused foliar injury and chlorophyll destruction accelerating leaf senescence, reduction of assimilation products. O3 was unfavorable injurious to transport and accumulation of substances to the grains after flowering.     

A preliminary study on simplified simulation model of spring wheat growth

In the model developed in this paper, taking the characters and requirements of meteorological services into account, some conventional meteorological observations which are easy to be obtained have been ch.osen, and mathematical equations describing micro-growth processes of crops have been established on the basis of the field experiments, laboratorial analysis and computer's modelling tests with time interval of ten-days for several years (1987-1989), in accordance with the known biological and physical rules and corresponding reference literatures. It is a preliminary simplified simulation model of spring wheat growth in optimal water and nutrient conditions. The field experiments show that simulation results of this simplified model are satisfactory. The potential operational application and theoretical sense are significant in the meteorological forecast of yield and in the assessment of influences of climatic change on agriculture.     

辽宁酷热日的天气气候分析

利用统计方法对辽宁1951-2003年的酷热天气进行了分析,发现辽宁的酷热天气主要出现在辽西地区;酷热天气在5-7月均可出现,主要集中在7月;无明显的年际变化.中纬度东-西高压带是造成辽宁酷热天气的主要天气形势;其次是西风带暖高压,在850hPa温度场上,辽宁西部在24℃暖中心之内有很好的指示意义.     

青岛即墨温泉沉积物特征及其对地热资源的标识意义

文章结合多种技术手段对青岛即墨温泉盆地第四纪沉积物进行研究。通过研究发现，在即墨温泉典型沉积物（矿泥）中，含有大量石膏、岩盐等与高矿化温泉地热水密切相关的自生矿物，以直隶小旋螺为代表的腹足类陆生软体动物化石和以土星介为代表的节肢动物介形虫化石在远离温泉喷口处大量分布，而在喷口附近缺失。根据胶东地区现有温泉与温泉沉积物的渊源关系，建立温泉沉积物对隐伏地热资源的标识性特征。     

涡轴发动机燃气涡轮叶片热腐蚀机理分析与改进

目的 提高航空发动机燃气涡轮工作叶片的结构完整性、安全性和可靠性。方法 以某型涡轴发动机燃气涡轮转子叶片热腐蚀案例为研究对象,详细阐述热腐蚀下燃气涡轮转子叶片的结构破坏形式,分析发生热腐蚀部位的分布规律。通过冶金分析方法,研究燃气涡轮转子叶片的热腐蚀-疲劳失效形式。结果 燃气涡轮叶片高摩擦系数的区域在高温燃气的冲刷效应以及热盐腐蚀的作用下,发生表面涂层腐蚀剥落。涂层腐蚀剥落部分的叶片合金基体受到高温燃气的氧化与侵蚀后,形成了热腐蚀坑。腐蚀坑表面的凹凸处出现应力集中,并萌生裂纹,最终引起叶片疲劳断裂。结论 探究了典型腐蚀性物质对燃气涡轮转子叶片的耐高温涂层与镍基合金基体侵蚀与氧化的化学本质,最后针对燃气涡轮转子叶片热腐蚀问题提出了改进建议,可对防范航空涡轴发动机热腐蚀问题提供有益参考。     

A comparison of overtime patrol stops made inside and out of cluster identified hotspots

Objective: The annual rate of impaired driving crashes in the United States has remained nearly constant over the last decade. While engineers, educators, enforcement, and emergency response personnel have worked diligently in their combined efforts to reduce the loss of life, there is still significant progress to be made. One area of recent interest is the use of data driven enforcement. The basis for data driven enforcement is the use of statistical clustering to identify geographic areas that represent the location of problem identification for various criminal or traffic offenses. In the case of impaired driving fatalities, the clustering represents locations with high rates of impaired driving crashes. Law enforcement officers and supervisors may allocate resources towards more specifically and efficiently addressing problem areas.

Methods: While data driven enforcement has been proven to be an effective tool in addressing crime and traffic safety problems, it has been a slow process for agencies to adopt data driven techniques. This study aims to explore the difference in traffic stops made inside and outside of hotspot identified areas. The study uses data from the Stark County Operating a Vehicle Impaired Task Force between 2013 and 2014.

Results: The analysis determined that stop occurring in hotspot defined areas are more likely to result in impaired driving arrests and seatbelt citations. Additionally it is found that the average cost of impaired driving arrests is significantly cheaper for stops occurring inside of hotspot areas.

Conclusion: Clustering as a means of directing law enforcement efforts are a way to increase the productivity and benefits of law enforcement agencies with limited finances or personnel. From this study it is seen that traffic stops made within defined cluster or hot spot areas are more effective in resulting in OVI arrests.