新型多头自动分度机构的研究与开发

针对普通分度头结构工艺的复杂性,分度定位工件的单件性,以及分度盘若干孔位的计数和定位操作步骤的繁琐,设计开发了一种基于蜗杆和非标蜗轮轴传动的多头自动分度机构。该机构操作简易,分度可靠,而且实现了多工件同时分度的效果,可使生产效率提高10倍以上。     

严寒荒漠地带大口径RPM管道的应用

RPM管道是采用高模量增强纤维和合成树脂及高质量的石英砂组合的一种复合材料管,具有寿命长、抗侵蚀性能高、适应地基变形能力好、便于运输和安装等优点.本文以北疆某供水工程倒虹吸应用大口径RPM管道为例,就工程管道选用、施工工艺和质量控制方面做了系统的介绍.工程实践证明,只要设计结构合理、质量控制措施到位,在特殊环境的大型工...     

Genome organization of the linear cytoplasmic element pPE1B from Pichia etchellsii.

The linear cytoplasmic element pPE1B from Pichia etchellsii CBS2011 (synonym Debaryomyces etchellsii) was totally sequenced. It consists of 12835 bp and has a remarkable high A+T content of 77.3%. The termini of pPE1B were found to consist of inversely orientated identical nucleotide repetitions 161 base pairs long, to which proteins are probably covalently linked at the 5' ends. Ten putative genes (open reading frames, ORFs) were identified, covering 96.5% of the total sequence. The predicted polypeptides correspond to proteins encoded by ORFs 2-11 of the linear plasmids pGKL2 of Kluyveromyces lactis and pSKL of Saccharomyces kluyveri. ORF1, existing on both latter elements, is lacking on pPE1B. An upstream conserved sequence motif (UCS) is located at the expected distance from the start codon of each of the 10 ORFs. As the arbitrarily chosen UCS6 was able to drive expression of a reporter gene in the heterologous pGKL-encoded killer system of K. lactis, extranuclear promoter function is probable. The almost congruent genome organization of pPE1B and other autonomous linear yeast plasmids sequenced so far, i.e. pGKL2 and pSKL, suggests a common, presumably viral, ancestor.     

凸轮分度工作台的结构与设计

介绍一种利用普通电机驱动的组合凸轮机构,实现双向连续、小角度分度定位的分度工作台,阐述了其结构原理与设计方法。     

Probabilistic Models of Appearance for 3-D Object Recognition

We describe how to model the appearance of a 3-D object using multiple views, learn such a model from training images, and use the model for object recognition. The model uses probability distributions to describe the range of possible variation in the object's appearance. These distributions are organized on two levels. Large variations are handled by partitioning training images into clusters corresponding to distinctly different views of the object. Within each cluster, smaller variations are represented by distributions characterizing uncertainty in the presence, position, and measurements of various discrete features of appearance. Many types of features are used, ranging in abstraction from edge segments to perceptual groupings and regions. A matching procedure uses the feature uncertainty information to guide the search for a match between model and image. Hypothesized feature pairings are used to estimate a viewpoint transformation taking account of feature uncertainty. These methods have been implemented in an object recognition system, OLIVER. Experiments show that OLIVER is capable of learning to recognize complex objects in cluttered images, while acquiring models that represent those objects using relatively few views.     

非晶态合金高频方波逆变电源输出变压器的分析和设计方法研究

对采用非晶态合金材料制作高频方波逆变电源输出变压器的分析和设计方法进行了初步探讨和研究，并利用研究的结论、设计制作了样机，同时还给出了具体的设计实例和测试结果。     

虚拟联合仿真平台下的非线性系统运动控制问题研究

本文结合机械领域的虚拟样机软件-ADAMS和当前使用最为广泛的数值计算软件-MATLAB，创建了一类典型的非线性自然不稳定系统-三级倒立摆的联合仿真平台。在此基础上，通过联合仿真研究被控对象在各种初始条件和参数条件下的运动控制问题，得到了非线性控制对象运动控制研究中的一系列结论。本文也为非线性系统的控制问题研究及控制理论验证提供了一种有效的途径。     

基于时序特征数据高效索引技术的物联网感知设备安全自动监测技术

物联网设备已经被广泛应用于各个领域,为保证物联网的安全,排除内部隐患,基于时序特征数据高效索引技术设计物联网感知设备安全自动监测方法。结合时序特征数据高效索引技术提取物联网信息特征,在报文传输过程的基础上,区分不同流量数据之间的差异、恶意攻击软件与感知设备的系统特征,计算样本数据的表征值,得到物联网感知设备的原始信息特征。对数据特征进行分类,计算其数据内的缺失值和错误值,得到特征向量的筛选优化结果,计算训练损失函数,调整实际操作的阈值,保证数据特征分类的准确性。搭建物联网感知设备监测模型,训练判别器,进行物联网的自动监测。分别对数据包、字节以及数据流量进行识别,该监测技术可以准确地区分良性数据与攻击数据,从而保证物联网感知设备的安全。     

预应力混凝土箱形倒虹吸管温度应力的有限元分析

运用ANSYS有限元热—结构耦合分析建立箱形倒虹吸管结构温度计算的模型,分析了温度应力对预应力混凝土箱形倒虹吸管的影响,得出当温度应力过大时,会造成倒虹吸管表面产生裂缝的结论,该成果对类似工程温度应力分析和温控具有一定借鉴意义。