带纵向槽筒形件拉深方法的研究

针对传境拉深带纵向槽筒形件的方法的缺点,采用一次拉深成形的方法,并通过试验和计算获得毛坯的形状和尺寸。     

《燃气红外线辐射供暖系统设计选用及施工安装》国家标准图集介绍

介绍了该国家标准图集的主要内容：设计说明、典型设计、工程实例、系统设备、燃气管道安装、液化石油气气化站、电气控制及温度检测、施工安装说明。     

用分解法编制轴类零件图程序

采用分解法编写轴类零件程序，即将具有典型结构的轴分解成若干部分，把每一部分编成通用子程序，连同尺寸标注子程序、表面粗糙度子程序、剖面线子程序、尺寸公差及形位公差子程序等一并存贮在程序库中，需要时一一调用。     

Urea briquette applicator for transplanted rice

A plunger-type, completely hand-operated applicator prototype, made of polyvinyl chloride (PVC), for deep placement of urea briquettes (UB), i.e., pillow-shaped urea supergranules with edges, in line transplanted rice has been developed for use by small-scale rice farmers. The field evaluation of the applicator was conducted in the Philippines during the 1989 dry season. The applicator consistently placed UB at proper depth (7 to 8 cm), which resulted in low concentrations of urea N (<7 ppm) in about 4 cm of floodwater 1 day after placement. These findings indicated that the prototype worked properly. Average work output of the applicator was 0.20 ha workday^–1 and may increase with practice. The yields of irrigated transplanted rice in the field trials show that agronomic efficiencies of hand-placed UB and applicator-placed UB were equal and were superior to those of split-applied prilled urea.     

拉普拉斯变换的图形分析

以单边指数函数为例，分析了拉普拉斯变换象函数F(s)在其收敛域内随σ和ω的变化规律，通过|F(s)|曲面图来观察这些规律，并解释了图中某些特定点及剖面的含义，以形象化的方式加深对拉普拉斯变换的认识。借助MATLAB的绘图功能绘制出F(s)的曲面图、剖面图及信号的频谱图，从中可以观察到频域与复频域的关系以及系统函数的零极点分布等。     

Concast连铸机自控系统简介

天津钢铁有限公司引进了瑞士Concast公司6机6流方、圆坯连铸机及相关技术，文章简要介绍了Concast连铸机的自动控制系统的特点和功能。     

Structure and processability of iodinated poly(vinyl alcohol). IV. Drawability of the films iodinated at solution before casting

The drawability of iodinated at solution before casting (IBC) polyvinyl alcohol films prepared by casting aqueous solutions of 10 wt % PVA containing 15.2, 39.8, 83.2, 117.0, and 140.1% was examined with a tensile tester at 20–60°C. The tensile behavior of IBC films showed that the yield and breaking loads were much lower, and the breaking elongation was even higher than those of the unoriented iodinated after casting (IAC) films as well as the untreated PVA films. The maximum draw ratios of the films with the weight gain of 15.2, 39.8, 83.2, 117, and 140.1% were 4.5, 5.5, 8.5, 8.0, and 7.5, respectively, which were achieved at 20°C in all. The crystallinity of all films increased by the maximum draw, regardless of crystallinity before drawing. The crystalline structure was recovered to the original PVA crystalline lattice by deiodination. Amorphous orientation and initial moduli increased with the maximum draw ratio, while the orientation of crystals was constant. The orientation and moduli increased up to the weight gain of 83.2%, whose highest draw ratio and initial modulus were 8.5 and of 7.1 GPa, respectively, and then decreased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

溜井振动放矿机的设计和使用维护

介绍了溜井振动放矿机设计时的埋设参数选择，阐述了其设计和安装的基本原则和要求，简明而系统地论述了振动放矿机使用维护的注意事项以及常见故障的处理方法。     

正确运用规范把设计质量提升到一个新的高度

就民用建筑设计部门设计图纸质量抽查中出现的问题，进行了剖析并提出了注意事项。     

AutoCAD作图技巧浅析

介绍了AutoCAD中作图的原则、步骤以及使用技巧,包括AutoCAD表格制作、在Word文档中插入AutoCAD图形、线宽修改、图形的打印技巧、选择对象的一些技巧、绘制局部放大图的方法等,对大多数AutoCAD的使用者在学习和应用中有很大帮助。