扬州与苏州传统建筑雕饰图式构成分析

目的 阐析扬州与苏州传统建筑雕饰图式构成的异同及其原因。方法 结合大量扬州与苏州传统建筑中的木雕、石雕、砖雕等实例,并以复杂的自然类、故事类题材为标准,从图式构成角度来进行分析,综合比较两地传统建筑雕饰图式的平面、立体形式构成,设图手法与布局技巧、构图关系与物象表达等。结果 扬州与苏州传统建筑雕饰图式构成依据不同的实用目的、不同的审美要求、不同的题材内容,以及不同的材料和制作工艺条件,呈现出多种多样的地域性特征。结论 受多重地域性因素的影响,扬州与苏州传统建筑雕饰的图式构成在特征上分别往“平面化”和“立体化”的趋势演进。源于扬州的传统建筑雕饰多用平视体构图,决定了扬州传统建筑雕饰趋向“平面化”,而苏州传统建筑雕饰以立视体构图形式居多,则向“立体化”发展。     

背板互连线高速信号传输的计算机仿真

采用ABCD矩阵法对传输高速信号的背板上具有频变参数的互连线建立等效时域网络模型,并给出接插件等效传输线模型和端接的I／O缓冲器IBIS瞬态行为模型,利用这些模型对实际电路进行仿真,其结果与Ansoft公司的PNC软件仿真结果相吻合,仿真效率有明显提高。     

铝在磷酸体系中复合阳极氧化研究

在磷酸介质中加入亚微米级Ａｌ２Ｏ３难溶性粉体,对铝进行复合阳极氧化结果表明,Ａｌ２Ｏ３难溶性粉体的加入使铝阳极氧化膜厚度提高了４５％,显微硬度提高了７０％以上,耐ＮａＯＨ腐蚀性能提高了一倍以上。阴离子型表面活性剂和两性型表面活性剂对复合阳极氧化效果降低。文中对复合阳极氧化过程进行了相应的讨论。     

陶瓷轴承电主轴在高速精密磨床中的应用

高速精密磨削要求主轴达到很高的转速,同时对零件加工精度的要求也越来越高。而陶瓷轴承电主轴自身所具有的优点,满足了高速超高速精密加工主轴转速的要求。本文通过本实验室集成的开放式高速精密磨床,介绍了电主轴的PLC控制,并通过主轴振动实验说明了陶瓷电主轴在高速精密机床上应用的优越性。     

Analysis on thermophoretic deposit of fine particle on water wall of 10 MW high temperature gas-cooled reactor

The water wall is an important part of the passive natural circulation residual heat removal system in a high temperature gas-cooled reactor. The maximum temperatures of the pressure shell and the water wall are calculated using annular vertical closed cavity model. Fine particles can deposit on the water wall due to the thei‘mophoresis effect. This deposit can affect heat transfer. The thermophoretic deposit efficiency is calculated by using Batch and Shen‘s formula fitted for both laminar flow and turbulent flow. The calculated results indicate that natural convection is turbulent in the closed cavity. The transient thermophoretic deposit efficiency rises with the increase of the pressure shell‘s temperature. Its maximum value is 14%.     

用双重曲柄滑块机构范成加工高速凸轮的研究

通过对高速凸轮的设计加工问题进行研究,提出了一种新型的由双重曲柄滑块机构组成轮轮廓范成装置。对该范成凸轮的运动动力学进行了分析,并对加工刀具的误差补偿及其它主要的加工工艺进行了简要讨论。     

高速瓦楞辊啮合与纸板成型理论

通过建立移动式和摆动式统一形式下的瓦楞辊啮合运动坐标系 ,得出了统一的两辊啮合方程组与纸板成型的关系 ,应用计算机编程求解得出了齿廓全部啮合点的通解 ,并得到了运动学性能图谱     

细间距SMD焊接强度试验研究

通过对细间距SMD焊接强度试验 ,分析了影响焊接强度的诸多因素 ,找到适合SMT要求的焊膏、模板、焊膏量、温度曲线等系列工艺材料参数。     

Process simulation using finite element method — prediction of cutting forces, tool stresses and temperatures in high-speed flat end milling

End milling of die/mold steels is a highly demanding operation because of the temperatures and stresses generated on the cutting tool due to high workpiece hardness. Modeling and simulation of cutting processes have the potential for improving cutting tool designs and selecting optimum conditions, especially in advanced applications such as high-speed milling. The main objective of this study was to develop a methodology for simulating the cutting process in flat end milling operation and predicting chip flow, cutting forces, tool stresses and temperatures using finite element analysis (FEA). As an application, machining of P-20 mold steel at 30 HRC hardness using uncoated carbide tooling was investigated. Using the commercially available software DEFORM-2D™, previously developed flow stress data of the workpiece material and friction at the chip–tool contact at high deformation rates and temperatures were used. A modular representation of undeformed chip geometry was used by utilizing plane strain and axisymmetric workpiece deformation models in order to predict chip formation at the primary and secondary cutting edges of the flat end milling insert. Dry machining experiments for slot milling were conducted using single insert flat end mills with a straight cutting edge (i.e. null helix angle). Comparisons of predicted cutting forces with the measured forces showed reasonable agreement and indicate that the tool stresses and temperatures are also predicted with acceptable accuracy. The highest tool temperatures were predicted at the primary cutting edge of the flat end mill insert regardless of cutting conditions. These temperatures increase wear development at the primary cutting edge. However, the highest tool stresses were predicted at the secondary (around corner radius) cutting edge.     

某细粒贫硫金矿石选矿工艺研究

陕西某金矿石中主要为微粒和超微粒自然金，主要为粒间金和部分包裹金，为合理开发利用该金矿资源，针对该矿石性质进行了重浮联合流程选别试验，重选利用尼尔森选矿机进行试验。试验最终获得的金精矿1金品位5 250 g/t，对重选尾矿进行浮选，获得的金精矿2金品位41.17 g/t，金总回收率达95.45%，尾矿金品位0.09 g/t。相较于单一流程，联合工艺的应用有助于获得更好的选冶指标，使矿产资源得到合理的开发利用。