屈服强度

The results show that proper RRA heat treatment can improve SCC properties with retention of the high strength of T6 level. After preaging at 100℃for 24 h, retrogression at 200℃for 7 min, and reaging at 100℃for 24 h, the ultimate tensile strength, yield strength and elongation of the alloy are 795 MPa, 767 MPa and 9.1%, respectively. Meanwhile the failure time of the alloy applied to tensile strength of 210MPa in 3.0%NaCl+0.5%H2O2corrosion condition is longer than 720 h. The corresponding TEM observation shows that after retrogression for 7 min and re-aging treatment, the microstructure of grain boundary is similar to that treated in the T73 condition with coarsen and isolated distribution, and the microstructure inside grain is similar to that treated in the T6 condition with small and homogeneous distribution.

研究结果表明：在峰值时效T6状态下合金强度高，但抗应力腐蚀性能差；采用合适的RRA热处理工艺既能使合金保持T6状态下的高强度的同时，又能显著改善合金的抗应力腐蚀性能；经回归7 min RRA处理后合金的晶界类似T73态析出相聚集粗化，而晶内类似T6态析出相细小弥散分布，在拉伸应力为210 MPa和3.0%NaCl+0.5%H2O2腐蚀液中，其断裂时间大于720 h，相应的抗拉强度、屈服强度和延伸率分别为795 MPa， 767 MPa和9.1%，显示优越的综合性能。

The results show that proper RRA heat treatment can improve SCC properties with retention of the high strength of T6 level. After pre-aging at 100 ℃ for 24 h, retrogression at 200 ℃ for 7 min, and reaging at 100 ℃ for 24 h, the ultimate tensile strength, yield strength and elongation of the alloy are 795 MPa, 767 MPa and 9.1%, respectively. Meanwhile the failure time of the alloy applied to tensile strength of 210 MPa in 3.0%NaCl+0.5%H2O2 corrosion condition is longer than 720 h. The corresponding TEM observation shows that after retrogression for 7 min and re-aging treatment, the microstructure of grain boundary is similar to that treated in the T73 condition with coarsen and isolated distribution, and the microstructure inside grain is similar to that treated in the T6 condition with small and homogeneous distribution.

研究结果表明：在峰值时效T6状态下合金强度高，但抗应力腐蚀性能差；采用合适的RRA热处理工艺既能使合金保持T6状态下的高强度的同时，又能显著改善合金的抗应力腐蚀性能；经回归7 min RRA处理后合金的晶界类似T73态析出相聚集粗化，而晶内类似T6态析出相细小弥散分布，在拉伸应力为210 MPa和3.0%NaCl+0.5%H2O2腐蚀液中，其断裂时间大于720 h，相应的抗拉强度、屈服强度和延伸率分别为795 MPa， 767 MPa和9.1%，显示优越的综合性能。

The results show that proper RRA heat treatment can improve SCC properties with retention of the high strength of T6 level. After pre-aging at 100℃ for 24 h, retrogression at 200℃ for 7 min, and reaging at 100℃ for 24 h, the ultimate tensile strength, yield strength and elongation of the alloy are 795 MPa, 767 MPa and 9.1%, respectively. Meanwhile the failure time of the alloy applied to tensile strength of 210 MPa in 3.0%NaCl+0.5% H2O2 corrosion condition is longer than 720 h. The corresponding TEM observation shows that after retrogression for 7 min and re-aging treatment, the micro- structure of grain boundary is similar to that treated in the T73 condition with coarsen and isolated distribution, and the microstructure inside grain is similar to that treated in the T6 condition with small and homogeneous distribution.

研究结果表明：在峰值时效T6状态下合金强度高，但抗应力腐蚀性能差；采用合适的RRA热处理工艺既能使合金保持T6状态下的高强度的同时，又能显著改善合金的抗应力腐蚀性能；经回归7min RRA处理后合金的晶界类似T73态析出相聚集粗化，而晶内类似T6态析出相细小弥散分布，在拉伸应力为210 MPa和3.0%NaCl+0.5%H2O2腐蚀液中，其断裂时间大于720h，相应的抗拉强度、屈服强度和延伸率分别为795 MPa，767 MPa和9.1%，显示优越的综合性能。

The calculating results are compared with the test data in available literatures and FEM results. The research results show that the plastic hinge model is precise and correct, which can satisfy with the actual engineering demands. The collapse pressure of perforated liner casing decreases with phrase angle, initial ovalization and diameter-thickness ratio increasing, and increases with the yield stress. The phrase angle and initial ovalization have greatly influence on the collapse pressure. The collapse pressure of perforated liner casing is slightly changed with the diameter and density of perforation when the diameter and density are smaller than 12mm and 120 shots per meter, respectively.

计算结果表明：筛管抗挤强度的塑性铰模型具有很高的计算精度和准确度，可以满足工程实际需要；筛管抗挤强度随着射孔相位角、径厚比和初始椭圆度的增加而降低，随着屈服强度的增加而增加，相位角和椭圆度对筛管抗挤强度影响比较显著；在射孔直径小于12 mm、射孔密度小于120 孔/ m 时，筛管抗挤强度随射孔直径和射孔密度增加变化不明显。

The plastic hinge model of perforated liner casing is built up to calculate the collapse pressure according to the strength and deformation behavior of perforated liner casing subjected to external pressure. The calculation equations of collapse pressure of perforated liner casing with initial ovalization are deduced by energy method. The influences of phrase angle, diameter of perforation, shot density, initial ovalization, diameter-thickness ratio and yield stress on the collapse pressure of perforated liner casing are studied. The model and equations are used to calculate the collapse pressure of an actual perforated liner casing as example.

摘摇要：根据煤层气完井筛管受力特点建立了筛管受力的塑性铰模型，利用能量法推导出带有初始椭圆度筛管抗挤强度的计算公式，分析了相位角、射孔直径、射孔密度、初始椭圆度、径厚比和屈服强度等影响因素对筛管抗挤强度的影响规律，并对某煤矿使用的筛管抗挤强度进行了计算，与已有的实验数据和有限元计算结果进行了对比。

The plastic hinge model of perforated liner casing is built up to calculate the collapse pressure according to the strength and deformation behavior of perforated liner casing subjected to external pressure. The calculation equations of collapse pressure of perforated liner casing with initial ovalization are deduced by energy method. The influences of phrase angle, diameter of perforation, shot density, initial ovalization, diameter-thickness ratio and yield stress on the collapse pressure of perforated liner casing are studied. The model and equations are used to calculate the collapse pressure of an actual perforated liner casing as example.

根据煤层气完井筛管受力特点建立了筛管受力的塑性铰模型，利用能量法推导出带有初始椭圆度筛管抗挤强度的计算公式，分析了相位角、射孔直径、射孔密度、初始椭圆度、径厚比和屈服强度等影响因素对筛管抗挤强度的影响规律，并对某煤矿使用的筛管抗挤强度进行了计算，与已有的实验数据和有限元计算结果进行了对比。

The regularities of effect of prestrain on macro-and micro-yield strength are different.

预变形对1Cr18Ni8Ti的宏观屈服强度σ_0.2与微屈服强度σ_1~(-6具有不同的影响规律。

Results of the computation under the same welding temperature field show that the longitudinal residual stresses in the weld are as high as the yield strength of the plate in the strength and TEC evenmatched joints, lower than the yield strength of the plate in the strength evenmatched and TEC undermatched joints. It also has something to do with the strain hardening exponent of the weld metal in the strength evenmatched and TEC overmatched joints.

计算结果表明：等强等胀匹配的焊缝区纵向残余拉应力水平高达母材的屈服强度，等强低胀匹配的焊缝区纵向残余应力水平低于母材屈服强度，等强高胀匹配的焊缝区纵向残余应力水平还与焊缝应变硬化指数有关。

But for the TEC overmatching, the residual stress σ〓 in the weld center is also related with the strain hardening coefficient H W of the weld metal. The residual stress σ〓 in the weld center got to the yield strength σ〓 increases little when the H'w is lower and somewhat exceeds the σ〓 when the H'w is higher.

而高胀匹配时的焊缝中心纵向残余应力σ〓还与焊缝金属应变硬化指数H〓有关，H〓较低时，焊缝中心纵向残余应力σ〓在达到焊缝金属屈服强度σ〓后不再升高；H〓较高时，焊缝中心纵向残余应力σ〓可超过焊缝金属屈服强度σ〓。

For the aged aluminum alloys which generally contain disc/plate-shaped or rod/needle-shaped precipitates, a model has been established, from the viewpoints of thermodynamics, kinetics and strengthening theory, to relate quantitatively the yield strength to the size, volume fraction and aspect ratio of precipitates which all were analytical associated with the chemical compositions of alloys, aging temperature and aging time. This model has been experimentally proved to well predict the variation of yield strength with the evolution of disc/plate-shaped or rod/needle-shaped precipitates for present Al-4. 62wt% Cu-0.65wt% Mg alloy aged at 513K and Al-1. 12wt% Mg0.57wt% Si alloy aged at 463K, respectively, and the yield strengths simulated by this model were also found to be in well agreement with previously measured values for a series of aged Al-Cu binary alloys, AA6061 and Al-Zn-Mg alloys.

以析出热力学、长大动力学及强化理论为基础，研究了含有盘/片状、棒/针状时效析出强化相铝合金在时效过程中时效析出相尺寸、体积分数和长径比等参数的演变及其对合金时效强化效果的影响，给出了合金成分、时效变量与微观组织参数之间非线性的解析表达关系式，进而从微观结构—宏观性能相结合的角度出发建立起了具有盘/片状、棒/针状时效析出相铝合金的时效工艺—屈服强度量化模型，并将该模型应用于不同温度、连续不同时间时效下Al-Cu二元系列合金、6061铝合金和Al-Zn-Mg系列合金的屈服强度预测，得到了与前人实测值吻合良好的结果。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。