真空灭弧室的一次封排工艺

一次封排工艺是生产真空灭弧室的先进工艺，排气，封口同时进行一次完成。本文介绍了一次封排工艺的特点，及一次封排工艺的几点关键问题。     

Short Communication: Scoring of Digital Dermatitis During Milking as an Alternative to Scoring in a Hoof Trimming Chute

Digital dermatitis is a serious problem in dairy production in many countries. In many settings, it is important to evaluate the digital dermatitis status of individual cows or an entire dairy herd. Such an evaluation has traditionally been done in a hoof trimming chute. An evaluation in the milking parlor can take place without disturbing the cows to a large extent, it can be done using less labor compared with an evaluation in a hoof trimming chute, and is cheaper than using a chute. The objective was to evaluate the sensitivity and specificity of a rapid screening method for digital dermatitis in the milking parlor, without using any specialized tools and taking approximately 15 s/cow. All lactating cows in 3 commercial Danish dairy herds were included. Cows were first scored for the presence of digital dermatitis during milking and the next day all cows were scored during hoof trimming. A 6-point nominal scoring system based on a visual inspection of the digital dermatitis lesions was used. For the analysis, the scores were dichotomized (digital dermatitis positive or digital dermatitis negative). Additionally, lesions were classified as small (diameter ≤ 2 cm) or large (diameter >2 cm). Sensitivity and specificity were calculated using observations from the hoof trimming chute as the “gold standard” and observations during milking as the diagnostic test. Relatively large variation was found between herds with an overall sensitivity of 0.65 (95% confidence interval: 0.59 to 0.72) and a specificity of 0.84 (0.81 to 0.87). The sensitivity increased to 0.69 (0.62 to 0.76), when only large lesions were assessed. The method has several advantages compared with evaluation in a chute and may be a useful tool in the daily hoof health management in dairy herds.     

大花水水电站碾压混凝土拱坝快速施工技术

大花水水电站拦河大坝为碾压混凝土双曲拱坝,最大坝高134.50 m。采用快速施工技术,创造了国内碾压混凝土连续浇筑上升33.5 m的记录。重点介绍了高速胶带机水平运输技术、缓降溜管垂直运输技术以及碾压混凝土仓面工艺。     

峨口铁矿矿石主溜井加强支护技术的探讨

为保证峨口铁矿矿石主溜井的安全运行,需要对其进行加固支护。经现场调查、充分研究和工程类比等技术手段,确定了溜井支护施工工艺和参数。方案实施后效果良好,对类似工程有借鉴和指导作用。     

吉尔吉斯斯坦某锡矿中锡石回收试验研究

根据吉尔吉斯斯坦某锡矿的原矿性质,进行了该矿石中锡石回收的选矿试验研究。采用"螺旋溜槽预先抛尾—螺旋溜槽粗精矿分粒级摇床重选—重选粗精矿脱硫脱砷"工艺流程,可实现该锡矿中锡石的有效回收,获得锡精矿锡品位47.61%,锡回收率75.71%的选别指标。     

斜梁式卸煤沟的破坏机理及简化模型

采用1/10缩尺比例的钢筋混凝土模型,对卸煤沟在运行荷载和结构从开裂到破坏的全过程进行了试验.结果表明主梁的斜向布置对侧壁和底板影响较小,斜梁具有弯扭耦合的特性.在此基础上提出用带抗扭约束的简支斜梁和平面刚架分别模拟斜梁和沟槽的简化设计模型,与规范正交卸煤沟的设计方法相统一且计算结果偏于安全.     

特长隧道投料系统优化研究

针对象山隧道2号斜井混凝土运输难题,介绍了采用混凝土竖直投料孔与斜井内混凝土溜槽下放2号斜井施工混凝土的具体方法和步骤,从而解决2号斜井长距离衬砌滞后而潜在安全风险的问题,为后续施工积累了经验。     

应用摆动装车溜槽技术改造港口装车站

湛江港300号泊位装车站直通式装车溜槽使用效果不理想,存在故障频繁、粉尘大、能耗大等问题。把直通式装车溜槽改造成摆动装车溜槽后,达到了节能、环保、降低劳动强度的目的,为港口其他装车站的改造建设提供了经验。     

邻近栈桥硐室爆破的设计与施工

介绍了峨口铁矿在邻近放矿处进行硐室爆破的设计与施工，确保了放矿栈桥的安全，对同类型爆破具有参考价值。     

粉粒体慢速斜槽流的实验研究

介绍了研究粉粒体慢速斜槽流的实验装置及测量方法 ,通过测量表面速度和流层厚度 ,初步分析了斜槽倾角、流率和壁面状况对流动的影响情况