硅元素

Combining the experimental results and theoretical analysis, the following work has been accomplished.(1) Reasons of the decrease of interelectrode capacitance and the increase of discharge gap caused by the powder suspended in dielectric fluid are explained. And the mechanism that surface quality of workpiece improved by powder-mixed EDM is analyzed from this viewpoint.(2) The variation regularity of the percentage of silicon on the machined surface of workpiece has been summarized according to the experiment results when silicon powder was added into the working fluid. The entropy is introduced to explain the reasons for this variation regularity by thermodynamics.(3) The dimensional accuracy is greatly influenced by the overcut resulting from discharge gap and electrode wear in practice application. Empirical formulas for the overcut in EDM and powder-mixed EDM are established based on the experimental results using the ternary linear regressive method in this paper.(4) The influence of main factors on the machined surface characteristics has been evaluated based on the orthogonal experimental design method.

通过一系列普通电火花加工与混粉电火花加工的对比实验，运用工艺实验和理论分析相结合的方法，重点做了以下工作：(1)探讨了粉末颗粒导致极间电容减小、放电间隙增大的原因，并从这个角度解释了混粉电火花加工可以改善工件表面质量的机理；(2)以混合硅粉的电火花加工为例，实验得出峰值电流和脉冲宽度对加工表面层成分中硅元素含量的影响规律，并引入熵的概念从热力学的角度对硅元素含量变化的原因寻找了理论依据；(3)在实际加工中，由于粉末的加入使放电间隙变大，这使得混粉电火花加工的尺寸精度难以控制，本文利用三元线性回归的方法，在实验数据的基础上，建立了两种电火花加工过切量的计算公式；(4)将正交试验法应用于混粉电火花加工实验研究，并通过对实验指标极差的直观分析，得出各电参数对加工指标影响的敏感程度。

Scientists and science-fiction writers have long speculated about what a silicon-based life-form would look like.

科学家和科普作品的作家曾经思索过这样一个问题，一个由硅元素组成的生命体形态究竟会是怎么样的。

It was Shockley who brought the silicon to Silicon Valley.

将硅元素带进硅谷的就是萧克利。

Cacoxenite, beryllonite, viseite, beraunite, alluaudite, rhabdophane and apatite are non-silicon channel structural minerals.

黄磷铁矿、磷钠铍石、磷方沸石、簇磷铁矿、磷锰钠石、水磷铈石和磷灰石是非硅元素的孔道结构矿物。

EDXA analysis showed that: there was little silicon, only 0.1%, and dispersively distributed in the cell wall of wood.

EDXA分析表明：未处理材硅元素很少，只有0.10%，呈星散状分布于细胞壁中。

The rabbits were sacreficed in groups 20, 40, 60, 90, 120, or 180 days after operation, and the silicon and aluminium contents in iliac bone and gluteus medius muscle on both sides were determined by inductively coupled plasma atomic emission spectrometry.

本实验在家兔骼骨处植入氧化铝材料后，分别观察骼骨和臀中肌内的铝、硅元素变化及其释放情况，报道如下。

The study results have indicated that the alloy layer thickness decreases with increase of Si addition, increases linearly with rise of bath temperature and varies parabolically with length of dip time.

结果表明：在实验研究范围内，随硅元素含量的增加，合金层厚度降低；随浸镀温度的升高，合金层厚度呈直线增加；随浸镀时间的延长，合金层厚度呈抛物线规律变化。

A brief introduction about spiro compounds including Si elements is also reviewed.

对含有硅元素的螺环化合物发光材料进行了简单介绍。

Iron-base fluxed alloy is produced by adding suitable amount of boron and silicon into iron-carbon alloy, which is usually used on the wearable and weak-acid-medium proofing accessories under 500℃. Although the performance of iron-base fluxed alloy can not match with that of the nickel or cobalt alloy, it has wide source materials and low prices, which is the great advantage for application.

铁基自熔性合金是铁——碳合金中加入一定量的硼、硅元素制成的，通常应用在常温——500℃以下耐磨损、耐弱酸腐蚀介质的机械零部件上，仅管铁基自熔性合金，综合性能不如镍、钴基合金，然而原料来源广泛，价格便宜，这是其得以普及应用的较大优势。

The effect of silicon and copper on SDAS was confirmed by the experimental results, by casting the cylinder heads of different aluminum alloys.

结果证实了合金中的硅元素和铜元素减小树枝晶尺寸的作用。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。