穿晶的

The results show that after heat treatment, the tensile strength of the alloy increases by 49 MPa, the hardness increases from 21.6 HRC to 25 HRC, and the impact fracture toughness decreases; fracture characteristic is intercrystalline fracture in as-cast, it is intercrystalline and transcrystalline mixed fracture after heat treatment.

结果表明：热处理后合金的抗拉强度σ提高了49MPa，硬度由铸态时的21.6HRC提高到了25 HRC，但合金的冲击韧度出现了较明显的下降；铸态时合金的断裂主要呈沿晶断裂特征，热处理后合金断口里沿晶＋穿晶的混合型断裂特征。

After the addition of carbon, the microhardness in the grain boundary is about 150 MPa higher than that in the grain. The fracture type of pure Mo is intergranular fracture, the grain boundary strength of Mo-C alloy is strengthened due to the addition of carbon and the fracture type is changed to transgranular fracture, transcrystalline fracture and a large number of cleavage planes and steps are observed on the bending fracture surface. But if the carbon content is too high, the carbide precipitation will be severe at grain boundaries and is deleterioated to the ductility of the alloy.

添加碳后，合金的晶界显微硬度比合金的晶内显微硬度高150MPa左右；纯钼的断裂方式以沿晶断裂为主，添加碳后，由于合金的晶界强度得到提高，合金的断裂方式变成以穿晶断裂为主，断口上有大量的解理面，具有明显的河流状花样和解理台阶，且塑性越好的断口，撕裂岭也越多；当添加的碳含量偏高时，在晶界处产生了大颗粒的碳化物，这种大颗粒的碳化物会降低合金的塑性。

The results show that the microstructure of Fe-28Al-5Cr-0.06B alloy refines by using stainless steel mold cooling method, the tensile strength of alloy increases 29 MPa, the hardness increases slightly but the elongation decreases a little at the same condition except, the impact fracture transform intercrystalline fracture into intercrystalline and transcrystalline mixed fracture.

结果表明：采用不锈钢金属型冷却，可以细化合金的铸态组织；在其他工艺相同的条件下，合金的抗拉强度提高了29 MPa，硬度有所增加，伸长率稍有下降；合金的冲击断口由沿晶断裂向沿晶＋穿晶混合型断裂转变。

With the aid of the experiment, crack formation and its expand pattern of ZTA ceramics under ultrasonic vibration were analyzed, its fracture criterion was established and the experiment results showed that intercrystalline fracture is the main fracture pattern of ZTA ceramics under common grinding, and transcrystalline fracture is the main fracture pattern of ZTA ceramics under TDUVAG, and the finding add to evidence showing that TDUVAG has better material removal property.

基于该方法分析具有预制裂纹的ZTA纳米复相陶瓷材料在超声振动条件下裂纹扩展方式，确立其断裂判据，通过该断裂模拟试验得出：沿晶断裂是普通磨削主要的断裂模式，而穿晶断裂是二维磨削主要的断裂模式，进一步证明二维磨削具有较好的材料去除特性。

In the case of granite, observation results indicate that the extending routes of active cracks are mainly intercrystalline, transcrystalline, inter-transcrystalline, and intracrystalline. When the strain rate is low, the long intercrystalline cracks are prevailing, and with increasing of the strain rate, the short transcrystalline and intracrystalline cracks gradually increase. The statistic results show that the active crack density increases with increasing of the strain rate, and the mean length of active cracks diminishes with increasing of the strain rate, that is, the induced damage in comminuted product increases with increasing of the strain rate. For the first time this dissertation integrates macroscopic results of comminution with active crack growth under impact loading. It elucidates why the dynamic comminution strength of mineral beds increases with increasing of the strain rate through the active crack extending, and analyzes the influence of structure and constitution of minerals on their damage under impact stress. It is authenticated that both the size distribution and the damage population of comminuted product can be characterized by the fractal.

为分析料层颗粒在冲击下的细观损伤效果，采用德国生产的ASM68K半自动图象分析仪对粉碎生成物中的损伤情形进行了观测，以花岗岩为例，观测结果表明花岗岩颗粒在冲击应力下的活化裂纹扩展路径主要表现为沿晶、穿晶、沿穿晶和晶内等形式，在低应变速率下，活化裂纹以沿晶裂纹较多，随着应变速率的提高，其它裂纹形式大量繁衍，统计结果表明活化裂纹密度随着应变速率的增大而增大，活化裂纹的平均长度随着应变速率的增大而减小，综合表现为颗粒的细观损伤程度随着应变速率的增大而增大；首次将应力作用下的活化裂纹演化特征与粉碎的宏观效果相联系，并就料层动态粉碎强度随应变速率增大而提高的现象从裂纹演化特征的角度进行了解释；分析了矿岩构造结构特性对损伤产生和分布的影响。

It was found that PLZT was easily reduced and the thickness of reduced layer had a linear relationship with the reduction time; The optimal conditions for PLZT were determined to be 950℃ for 1~5 hours; Reduced PLZT was composed of reduced and unreduced layer obviously and the reduced layer was transgranularly fractured while the unreduced ceramic was intergranularly fractured; Metallic lead and refractor oxides (PbO, ZrO2, TiO2, etc.) were found in the reduced layer, however, the crystal structure of PLZT was not found.

研究表明，PLZT具有较好的还原性能，还原层厚度与时间有线性关係，理想的还原条件为：950℃保温1~1.5h；还原样品有明显的分层结构，还原层表现出穿晶断裂而未还原层则是沿晶断裂的特徵；还原层主要由金属Pb及PbO， ZrO2， TiO2等氧化物组成，原先的晶体结构已不存在。

The effects of cerium-rich mischmetal on microstructures and mechanical properties of the die-cast magnesium alloys are investigated.

结果表明：少量加入稀土能起晶粒细化和固溶强化作用；随加入量增大，稀土以晶界和穿晶条状脆性相存在，对合金强度的损伤作用大于强化作用。

Grain boundary slidings happen in this alloy at the creep temperature of 200 ℃ and the deformation of this alloy is coordinated by intragranular slip and grain boundary sliding.

结果表明：在125~200 ℃蠕变温度下，当蠕变寿命接近100 h时，2024铝合金的蠕变应力随着温度的升高明显下降；与125 ℃相比，150 ℃时合金的蠕变应力下降9.3%，在175 ℃时合金的蠕变应力下降30.3%；当蠕变温度为200 ℃时，该合金的蠕变应力下降幅度达到45.8%；在125~175 ℃下，合金在蠕变过程中的变形机制主要为位错在晶内的滑移；在200℃时，合金晶界开始发生滑移，合金变形由晶界滑移与位错在晶内的滑移协调完成；在合金蠕变断面上存在大量微孔，随着蠕变温度的升高，微孔的尺寸明显变大，当微孔尺寸超过3 μm时，微孔对合金的断裂机制有显著影响；在125和150 ℃下，合金的蠕变断口呈现韧窝型穿晶断裂特征；在175和200 ℃下，合金的蠕变断口呈现沿晶断裂特征。

For thinner films, stacking faults are preferred in the scratch process, which increase storage capacity of plastic deformation in the film, and further inhibit the stick slip amplitude in the friction oscillation process. For thicker films, dislocation loops, which glide along slip plane downward to the grain boundary, dominate over the stacking faults, and finally dissipate on the grain boundaries. Since the intergrain stacking faults are inactive in thicker films, the stick slip phenomenon is similar to that in single crystal.

摩擦过程中易在较薄的薄膜表面和薄膜晶界之间产生穿晶层错，穿晶层错的产生增加了薄膜蓄积塑性变形的能力，从而抑制材料表面摩擦力在黏滑过程中的振荡幅度；在比较厚的薄膜中不易生成穿晶层错，在摩擦过程中位错环依次向体材料发射，并与晶界反应，湮灭于晶界，黏滑动摩擦响应与单晶相似。

It is found that the electric, field improves elongations in 2090 and 2090+Ce alloys markedly, especially in 2090 alloy, but has little effect on strengths. At the same time, the electric field lessenes percentages of intergranular delamination and increases transgranular fracture and microscopic plastic deformation.

研究表明：固溶电场可显著提高2090合金及2090+Ce合金的延伸率，尤其是对2090合金，但对强度则无明显的影响；同时，固溶电场减少合金的沿晶分层断裂比例，并增加穿晶断裂及微区塑性变形；固溶电场还使合金时效后δ′相颗粒的平均尺寸减小、尺寸分布范围减小，并使PFZ的宽度减小。

Fancy gold-plated dangling earrings with facetted White Opal crystals.

花式镀金悬垂耳环与facetted白欧泊水晶。

This essay chooses the study aim from biology teachers in middle school in Shi Jiazhuang which tells us that most of the middle school biology teachers in Shi Jiazhuang have the"burnout", lower successfulness, individualize.

本文选取石家庄市初中生物教师作为研究对象，运用问卷调查的方法对石家庄市初中生物教师职业倦怠的现状进行调查，调查结果发现，石家庄市初中生物教师这一群体普遍存在职业倦怠，情感枯竭程度偏高，成就感偏低，去个性化程度最为严重。