Impact damage patterns studied by a model simulation

A lattice model has been developed to explore impact damage patterns in brittle materials. The damage evolution was modelled as a process involving the change of strain-energy distribution by cracking. Using a cubic lattice system, a large strain energy was supplied to the system surface. Crack growth initiated by this local energy supply was followed by means of computer simulations. The damage patterns were compared for systems which have different distributions of strain energy stored prior to the local energy supply. The simulations reveal a characteristic difference in the damage pattern. Impact damage for a system with a spatially fluctuating distribution of strain energy is limited around an impact point. Impact damage for a systen with a relatively uniform distribution of strain energy penetrates deeply. The results of the simulations are discussed in connection with the material evaluation and the material resistance.     

Fabrication of blue-light emission fused-silica substrates by using Si-ion implantation and high-temperature annealing

We fabricated fused-silica substrates which emit blue light by using Si-ion implantation and high-temperature annealing. Photoluminescence peak wavelengths are around 400 nm, and the peak intensities can be remarkable after annealing above 1150 °C.     

C pm MPPAC for manufacturing quality control applied to the precision voltage reference process

The multiprocess performance analysis chart (MPPAC) based on the process capability index C_pm, called C_pm MPPAC, is developed for analysing the manufacturing quality of a group of processes in a multiple process environment. The C_pm MPPAC conveys critical information of multiple processes regarding the departure of the process and process variability from one single chart. Existing research works on MPPAC are restricted to obtaining quality information from one single sample of each process ignoring sampling errors. The information provided from existing MPPAC charts, therefore, is unreliable and misleading and results in incorrect decisions. In this paper, we consider the natural estimator of C_pm based on multiple samples. Based on the natural estimator of C_pm, we consider the sampling errors by providing an explicit formula with the Matlab program to obtain the estimation accuracy of the C_pm. We tabulate the sampling accuracy of C_pm for sample size determination so that the engineers/practitioners can use it for their in-plant applications. An example of multiple precision voltage reference (PVR) processes is presented to illustrate the applicability of C_pm MPPAC for manufacturing quality control.     

矢量图形智能判断技术的研究与应用

研究矢量图形识别是建立工程制图自动阅卷与计算机辅助教学系统的基础。由于组成二维矢量图形图元类型的多样化及图形整体位置状态的不确定性，增加了矢量图形的识别与判断难度。结合开发的《三视图智能解答》系统，研究其智能识别与判断技术。系统中引入三视图导航技术，解决了图形整体定位与识别问题。实现了对矢量图形图元素信息的分类和提取，能够对所提取的的信息与标准答案进行智能判断与评定。该方法已在AutoCAD2000环境下使用AutoLISP语言编程实现。     

石灰石分解反应的热重动力学研究

用热重分析等研究方法，对我国９个主要产地的石灰石矿样品进行了大量的实验和分析工作，并分别计算出不同产地石灰石的动力学数据。     

A far-infrared spectroscopic study of low temperature soft phonon mode in Tris-Sarcosine Calcium Chloride(TSCC)

Temperature dependences of the soft phonon frequency and the damping constant in Tris-Sarcosine Calcium Chloride (TSCC) single crystal have been investigated between 5K and 100K by using a Fourier-transform far-infrared spectrometer. It has been observed that the soft phonon frequency decreases gradually and the damping constant increases as the transition temperature is approached from below The damping constant varies from 7cm^-1 a 90K to less than 0.5cm^-1 at 5K. It has been found that the damping constant is approximately proportional to temperature below about 60K.     

RCC斜层平推铺筑法施工质量评估

RCC混凝土斜层平推铺筑法是一项新的施工工艺,本文通过芯样测试法对该工艺进行了全面细致的质量评估。     

克拉玛依原油中各组分的乳化性质

用沉淀法和色谱分离法将克拉玛依原油分离成沥青质，极性物和抽余油三组分，红外光谱分析表明，沥青质和极性物中存在一些含氧官能团的羧酸类或酚类以及含氮化合物，而抽余油则主要为烃类物质，因而沥青质和极性物的界面活性大于抽余油，沥青质具有较强的油包水（W／O）乳化能力，是造成克拉玛依原油W／O乳化的主要组分，极性物具有较强的水包油（O／W）乳化能力，是造成克拉玛依原油O／W乳化的主要组分，抽余油的乳化能力很弱。