Safety-based availability assessment at design stage

The availability of a system or equipment is one of the crucial characteristics that measures the customer satisfaction and strongly influences his final choice decision between concurrent products. The aim of this work is to provide an approach to improve the products availability assessment by taking into account the safety criteria by considering the use situations at design stage. Our work focuses on the routine design of complex products. The availability is often simply estimated considering reliability and maintainability. Basically, the intrinsic availability is the probability that it is operating satisfactorily at any point in time when used under conditions stated by design specifications. The time considered includes operating time and active repair time. Thus, intrinsic availability excludes from consideration all other times in the product lifecycle such as: accident management time, storage time, administrative time or logistic time. But many studies show that the loss of availability performance is also due to accidents that occur in different unforeseeable utilization situations. This engenders stops of the system to ensure the users safety according to standards recommendations. In this purpose, we consider the structural product architecture and the different use cases that correspond to the operational states and downtimes due to stop events that may happen during the utilization like failures, maintenance tasks and accidents. Then, we propose a product behavioral analysis including the use cases to describe interactions between the product and users or maintenance operators. We use Markov chains to model the use cases corresponding to operating time (OT), maintenance time (MT) and preparing time after accidents (RT). Then these three parameters are considered to specify a generic approach to improve the availability assessment. Such an approach provides the traceability of the product behavior along its lifecycle. In this way, the main causes of stop can be identified and this may guide the designer for improving the availability of the product future versions. To validate our approach, an application is presented considering a printing line. The comparison of our simulation considering an industrial case study shows a good agreement about the influence of safety on the availability.     

基于AJAX技术创建的异步方法应用研究

遵循AJAX技术的基本原理,创建了一个简单的异步引用方法,并给出登录实例来说明如何实现该方法的引用,减少代码冗余。主要阐述了通过创建方法,并引用方法到不同Web应用程序中,实现了代码的优化。     

六种药剂防治向日葵白锈病试验研究

六种药剂防治向日葵白锈病田间药效试验结果表明,25%甲霜灵WP1000倍、50%安克WG2500倍的防效分别为87.6%和86.8%,显著优于64%杀毒矾WP800倍(防效75.7%),而52.5%抑快净WG1000倍、72%霜疫必克WP600倍和80%乙磷铝WP600倍的防效相当,不理想,均未达到50%。经方差分析证明处理间差异达到显著水平。     

新疆科研投入现状及问题分析

本文基于新疆2001—2013年科学与实验研究投入数据的统计,并且对新疆与全国的科研经费、科研投入强度、科研产出等方面进行差异比较分析,发现新疆科研投入存在的不足和问题,最后在此基础上提出拓展经费融资渠道、加大政府科研投入力度、保护科研人员知识产权等相关政策建议。     

垂直螺旋管道内单颗粒悬浮运动的试验

采用高速摄影方法拍摄记录垂直矩形螺旋管道内单颗粒的悬浮运动,采用捕捉试验中颗粒运动轨迹的方法,获得其运动参数,并分析颗粒受力的规律。试验结果表明:旋转水流的角速度对颗粒运动有较大的影响;颗粒在运动过程中主要是受有效重力、阻力和旋转科氏力的作用;在一定条件下,颗粒所受的旋转科氏力与离心力满足抛物线的关系,旋转科氏力比离心力大2～3个数量级;在小尺度低速度旋转流中,颗粒所受的旋转科氏力所占比例较大,在受力分析中不应被忽略。     

高寒山区气温垂直分布的估测方法研究——以玛纳斯河为例

新疆高寒山区河流主要发源于高山带冰川和永久性积雪的融冰雪水,如何确定冰雪消融的主要影响因素的变化规律,对研究新疆山区性河流的径流形成过程具有十分重要意义。本文以玛纳斯河为例,采用肯斯瓦特水文站1958-1987年逐日气温、降水、蒸发及径流等资料,借助G IS工具提取流域数字高程,运用含融雪结构的新安江模型对流域径流进行模拟,估测其山区气温垂直地带性分布规律,以期为其他资料缺乏的地区提供一定的依据。     

土石坝坝顶溢洪道带多层水平加固的泄槽底板的稳定分析

在高山峡谷河流上修建土石坝,若溢洪道布置在岸坡上,开挖工程量会很大。为节约工程造价可将溢洪道直接布置在坝体上。坝体溢洪道的泄槽一般都比较陡,为确保其稳定性现对泄槽底板进行多层水平锚筋加固。通过对泄槽底板的稳定分析得出锚筋的数量和长度与其受力的关系式,为今后工程设计提供理论依据。     

脱水过程中无核白葡萄转录组测序及膜脂降解代谢中关键基因的筛选

该研究以吐鲁番地区无核白葡萄为试验材料,在25 ℃常温和30 ℃热风干燥后,取失水25%、50%时褐变和未褐变的样品。利用转录组测序技术筛选出膜脂降解代谢相关的关键基因,并利用实时荧光定量PCR技术对其进行验证,研究结果显示,转录组测序共获得了11.63亿的clean data,当无核白失水50%时未褐变与褐变的相比,在快速脱水组筛选出718个差异表达基因,慢速脱水组2 259个。将上述基因进行GO功能富集和KEGG富集分析后,筛选出43个膜脂代谢相关的差异基因,归类于5种代谢途径。从已获得的差异基因中最终筛选出乙醛脱氢酶7B4（Aldehyde Dehydrogenase7B4,ALDH7B4）、双半乳糖甘油二酯合成酶1（Digalactose Diglycerol Synthetase1,DGD1）、脂氧合酶（Lipoxygenase,LOX）、磷脂磷酸水解酶2（Lipid Phosphate Phosphatase2,LPP2）、二酰基甘油激酶5（Diacylglycerol Kinase5,DGK5）、非特异性磷脂酶C4（Non-specific Phospholipase C4,NPC4）、磷脂酶Dα1（Phospholipase Dα1,PLDα1）7个膜脂代谢相关的关键基因,经qRT-PCR验证,基因表达趋势与转录组测序结果基本一致。结果表明,膜脂降解代谢相关基因表达量变化对无核白脱水褐变有一定影响。     

某新型灌水器流道水力性能的数值模拟

采用RNG紊流模型,对不同压力进口条件下的某新型灌水器内部流道进行了三维数值模拟,通过与实测结果进行对比,验证了所选数学模型的可靠性和正确性,并得到该新型灌水器水头损失和流量关系以及上下游压差力和流量的关系,可以为微灌灌水器的研发提供技术支撑。     

阳离子乳化沥青混凝土配合比设计的优选方法研究

采用均匀正交试验对水泥掺量、乳液用量、拌合用水量三个因素进行优选,得到阳离子乳化沥青混凝土的基础配合比参数。通过测定每组沥青混凝土试件的稳定度和流值,并采用投影寻踪回归分析法(PPR)研究了水泥掺量、乳液用量和拌合用水量对稳定度和流值的影响规律,研究发现,对于稳定度和流值影响最大的因素是水泥掺量,其次是乳液用量的影响,而拌合用水量对稳定度和流值影响较小。