Conditional Control Charts for Monitoring the Weibull Shape Parameter under Progressively Type II Censored Data

In this paper, (i) we propose new conditional Shewhart‐type control charts for monitoring the shape parameter of the Weibull distribution under a progressively type II censoring strategy, and (ii) we generalize the control charts proposed by Guo and Wang¹ for the progressively type II censoring case. We provide a comparison between these control charts in terms of the out‐of‐control average run length obtained by simulation for both the known and unknown parameter cases. A real example consisting of data from breaking stress of carbon fibers is also presented for illustration and comparison of the proposed control charts. Copyright © 2014 John Wiley & Sons, Ltd.     

Exploiting array manipulation habits to optimize garbage collection and type flow analysis

A widespread practice to implement a flexible array is to consider the storage area into two parts: the used area, which is already available for read/write operations, and the supply area, which is used in case of enlargement of the array. The main purpose of the supply area is to avoid as much as possible the reallocation of the whole storage area in case of enlargement. As the supply area is not used by the application, the main idea of the paper is to convey the information to the garbage collector, making it possible to avoid completely the marking of the supply area. We also present a simple method to analyze the types of objects, which are stored in an array as well as the possible presence of NULL values within the array. This allows us to better specialize the work of the garbage collector when marking the used area, and also, by transitivity, to improve overall results for type analysis of all expressions of the source code. After introducing several abstract data types, which represent the main arrays concerned by our technique (i.e., zero or variable indexing, circular arrays and hash maps), we measure its impact during the bootstrap of two compilers whose libraries are equipped with these abstract data types. We then measure, on various software products we have not written, the frequency of certain habits of manipulation of arrays, to assess the validity of our approach. Copyright © 2014 John Wiley & Sons, Ltd.     

转角型幕墙铝板风荷载作用下内力和变形的数值模拟

阐述了转角型铝板和加劲肋构成的铝板幕墙的内力及变形计算，采用ANSYS软件，对板块由转角型铝板与5条加劲肋组成的复合结构的内力和变形进行计算，研究了加劲肋与铝板转角处由于局部铆钉松脱由刚结点变成铰接点后，其计算模型发生改变的应力及位移计算，最后介绍实际应用。     

Flotation and adsorption of a new collector α-Bromodecanoic acid on quartz surface

A new type collector α-Bromodecanoic acid (CH₃(CH₂)₇CHBrCOOH, α-BDA) was synthesized by solvent-free method (Hell–Volhard–Zelinski reaction) in laboratory for the flotation of quartz mineral at a relatively low temperature of 16 °C. The adsorption mechanism of α-BDA collector on quartz mineral surface was established by zeta potential measurements, contact angle measurements, Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS), in conjunction with the results of quartz micro-flotation tests. The flotation results showed that the activator Ca(II) functioned as an indispensable and crucial factor on the recovery of pure quartz. When the quartz was floated with α-BDA alone at strong alkaline conditions (pH ⩾ 11.50), the recovery rate reached to only 11.9%. However, when using the activator Ca(II) at a concentration of 4 × 10⁻⁴ mol/L, the collector exhibited an excellent performance, where about 99.5% of the quartz had been floated at or above pH value 11.50 at 16 °C. The study revealed that the α-BDA collector had adsorbed on the surface of pure quartz in the forms of electrostatic interaction, hydrogen bonding and chemical adsorption based on the results of zeta potential measurements, contact angle measurements, FT-IR spectra, and XPS.     

天津钢铁炼钢厂倒罐站600t无基坑不断轨钢轨塞入式轨道称重装置的实践

本文简单介绍了由我们公司制造的安装于天钢倒罐站的600t无基坑不断轨钢轨塞入式轨道称重装置,着重介绍了对该称重装置的隔热防护措施以及停车对位联锁。     

Consideration of multi‐coil type magnetization system for magnetic particle testing of omnidirectional crack in all surfaces of 3D shape test object

Mechanical parts, plants, and cross‐linkages inspected with magnetic‐particle testing (MT) are typically complex 3D shapes. In complex 3D shape portions, because a magnetizer often cannot be configured to inspection portions and the test object cannot be appropriately magnetized, there is a possibility of overlooking a crack in such an instance. Thus, MT system development that was successfully able to detect omnidirectional cracks in 3D shape portions was considered in this study's trials. Two multi‐coil type magnetizers were hence arranged face‐to‐face, and the magnetization of omnidirectional scenarios for all surfaces of 3D shape test object was evaluated.     

延长油田X油区长8储层孔隙结构特征研究

根据岩心、薄片及压汞资料,系统分析了长8储层的孔隙结构特征,并将其分为4种类型,其中Ⅰ类孔隙类型为优质储层。     

原位合成WC-6Co复合粉末制备超细YG6硬质合金

将原位合成WC-6Co复合粉末采用干袋式冷等静压压制成型(压制压力1×10~8 Pa、保压时间15 s),将压制好的坯料采用低压烧结炉烧结(烧结温度1360℃、烧结时间40 min、加压5 MPa、保温保压时间20 min),烧结制备超细YG6硬质合金,对合金的形貌、金相组织及物理力学性能进行分析。结果表明:原位合成WC-6Co复合粉末制备的超细YG6硬质合金,晶粒异常长大,WC平均晶粒尺寸为0.8μm,硬度HV_(30)为(21500±100) MPa,较传统超细YG6X硬度高。再将WC-6Co复合粉末采用滚动湿磨、压力式喷雾干燥、掺成型剂、挤压成型、低压烧结等工序制备超细YG6硬质合金,研究不同晶粒长大抑制剂配比、球磨时间、挤压压力、烧结温度对合金性能的影响。结果表明:添加0.3%VC、0.8%Cr_3C_2(质量分数),湿磨48 h,挤压压力24 MPa,烧结温度1340℃,制备的超细YG6硬质合金WC晶粒均匀,无异常长大的WC晶粒,WC平均晶粒度尺寸0.4μm,呈多边形,外形较圆。强度、硬度最高,抗弯强度TRS为(2250±20) MPa、硬度HV30为(22600±100) MPa。断口形貌为沿晶断裂,沿WC与WC晶界断裂或WC与Co晶界断裂。     

采用顶板梳状定向钻孔瓦斯抽采技术研究

通过对顶板梳状定向钻孔瓦斯抽采技术关键原理进行理论研究,结合大阳煤矿回采工作面应用顶板梳状定向钻孔瓦斯抽采的实际情况,阐述了大阳煤矿应用梳状定向钻孔产生的效果及经济效益.通过研究,推广顶板梳状定向钻孔瓦斯抽采技术,有助于实现回采工作面在采煤的同时安全高效的抽采瓦斯.     

石英粉粒度对涂料性能影响的正交试验

在石英粉粒度对涂料性能影响的试验中,选用不同粒度的石英粉作为耐火骨料,钠基膨润土和CMC联合作为悬浮剂,淀粉水溶液和水玻璃作为粘结剂,以水为载液。首先进行单一变量试验,选出4种较为关键的性能,通过4种不同粒度的骨料搭配,按照4种不同的加入量,进行4因素4水平正交试验。采用极差法来分析各种因素对涂料性能的影响,得出综合性能最好的组合并对该组合进行性能分析。结果表明,当耐火骨料的组分:240、270、300、320号加入量比为80:80:80:20时,石英粉涂料的综合性能最好。