The geology, sediment and soil studies are important due to its significant impacts on agriculture, mining, constructions materials, industries, environment, ground water percolation, air pollution, surface and ground...The geology, sediment and soil studies are important due to its significant impacts on agriculture, mining, constructions materials, industries, environment, ground water percolation, air pollution, surface and ground water pollutions, earthquakes and geo-hazards in Afghanistan. In this research, we studied petrography, Sediment, tectonic structures, soil fraction selection by using hydrometer, sieving analysis, and geological mapping. Results show different kinds of metamorphic rocks of low grade and medium grade metamorphisms, Garnete mica Schist, Garnete Schist, Quarsite, different types of minerals among rocks. Further, type of sediment consisting residual angular (Autochthonous) and rounded (Allochthonous) transported by water, among sediments consisting Garnete, Gneiss, Schist, Quarsite, Biotite and consisting different type of sizes boulders, Cobble, Granule, Sand, Silt. Hydrometer analysis shows different types of soil clayey loam, sandy loam, silty loam. Moreover, Geological mapping shows complex tectonic structures like joints, cracks, faults, folds, anticline and syncline. The obtained<i> </i><span style="font-family:Verdana;">results suggest that the petrography, sediments and soil researches can be used efficiently for catchments of the Kabul Basin and other basins in Afghanistan.</span>展开更多
The dynamic thermal process during double-sided asymmetrical TIG backing welding of large thick plates （ 1 000 mm×700 mm×50 mm） is numerically simulated using MSC. MARC. The effect of arc distance on the t...The dynamic thermal process during double-sided asymmetrical TIG backing welding of large thick plates （ 1 000 mm×700 mm×50 mm） is numerically simulated using MSC. MARC. The effect of arc distance on the thermal cycle in weld zone during double-sided asymmetrical T1G backing welding is investigated. The results show that the workpiece experiences double-peak thermal cycle in double-sided asymmetrical TIG backing welding. On the one hand, the fore arc has the pre- heating effect on the rear pass, and the pre-heating temperature depends on the distance between the double arcs, the heat input of fore arc, and the initial temperature of workpiece. On the other hand, the rear arc has the post-heating effect on the fore pass. The mutual effects of two heat sources decrease with the increase of arc distance.展开更多
In an unbound area, many methods have been proposed to design fuzzy truck backer control system. For a bound area, we consider designing fuzzy truck backer control systems using the searching in tables algorithm in ...In an unbound area, many methods have been proposed to design fuzzy truck backer control system. For a bound area, we consider designing fuzzy truck backer control systems using the searching in tables algorithm in this paper. New control rule tables are established, and experiment results show that the new control rule tables are better than the old ones.展开更多
为了扩展高频水声换能器带宽,添加背衬是方法之一,然而针对水声换能器的激励信号形式和工作状态,当前缺少针对水声换能器背衬设计的准则,本文开展了水声换能器背衬参数的作用机制研究工作。基于KLM (krimholtz leedom and matthaei)传...为了扩展高频水声换能器带宽,添加背衬是方法之一,然而针对水声换能器的激励信号形式和工作状态,当前缺少针对水声换能器背衬设计的准则,本文开展了水声换能器背衬参数的作用机制研究工作。基于KLM (krimholtz leedom and matthaei)传输线模型研究了背衬厚度、衰减系数及特征阻抗对水声换能器性能的影响。研究结果表明:背衬在水声换能器中作为谐振体的一部分参与振动并形成了若干阶纵向振动模态,其作用是增加系统阻尼,而不是吸收声波。从扩展带宽的角度出发,背衬的衰减系数应尽量大,此时,发送电压响应波动减弱且对响应幅值影响很小;背衬特征阻抗能够调节两响应峰的相对幅值,阻抗过高或者过低都不利于宽带的形成,因此选择中等特征阻抗的背衬较为适宜。最后,基于上述的背衬优化方法,制备了水声换能器样机,其测试带宽为102%,与理论吻合较好。展开更多
In this paper, a novel Home Location Register(HLR) mobility database recovery scheme is proposed. With database backing-up and signal sending as its key processes, the presented scheme is designed for the purpose of b...In this paper, a novel Home Location Register(HLR) mobility database recovery scheme is proposed. With database backing-up and signal sending as its key processes, the presented scheme is designed for the purpose of both decreasing system costs and reducing number of lost calls. In our scheme, an algorithm is developed for an HLR to identify such VLRs that there are new MSs roaming into them since the latest HLR database backing up. The identification of those VLRs is used by the HLR to send Unreliable Roaming Data Directive messages to each of them to get the correct location information of those new MSs. Additionally, two kinds of relationships, one between the number of lost calls and the database backing-up period and the other between the backing-up cost and the period, are well analyzed. Both analytical and numerical results indicate that there will be an optimal HLR database backing-up period if certain system parameters are given and the total cost can be consequently minimized.展开更多
This work investigates the proposed welding of stainless steels with no backing gas by using solid wire ER316L-Si and mixed gases （ He ＋ Ar ＋ CO2 ）. The protection mechanism was also discussed from the view of arc...This work investigates the proposed welding of stainless steels with no backing gas by using solid wire ER316L-Si and mixed gases （ He ＋ Ar ＋ CO2 ）. The protection mechanism was also discussed from the view of arc physics and the alloy elements in the solid wire. The result shows that when the proportion of helium in the above-noted mixed gases excesses 45 percent, the mechanical properties and the intergranular corrosion tendency meet corresponding Chinese standards. Further, the alloy elements in the solid wire can react with oxygen during the period of high temperature boosted by helium arc ; this result in the formation of a bed of thin slag, which can avoid the oxidation of the backing weld and eliminate the need of backing gas.展开更多
文摘The geology, sediment and soil studies are important due to its significant impacts on agriculture, mining, constructions materials, industries, environment, ground water percolation, air pollution, surface and ground water pollutions, earthquakes and geo-hazards in Afghanistan. In this research, we studied petrography, Sediment, tectonic structures, soil fraction selection by using hydrometer, sieving analysis, and geological mapping. Results show different kinds of metamorphic rocks of low grade and medium grade metamorphisms, Garnete mica Schist, Garnete Schist, Quarsite, different types of minerals among rocks. Further, type of sediment consisting residual angular (Autochthonous) and rounded (Allochthonous) transported by water, among sediments consisting Garnete, Gneiss, Schist, Quarsite, Biotite and consisting different type of sizes boulders, Cobble, Granule, Sand, Silt. Hydrometer analysis shows different types of soil clayey loam, sandy loam, silty loam. Moreover, Geological mapping shows complex tectonic structures like joints, cracks, faults, folds, anticline and syncline. The obtained<i> </i><span style="font-family:Verdana;">results suggest that the petrography, sediments and soil researches can be used efficiently for catchments of the Kabul Basin and other basins in Afghanistan.</span>
文摘The dynamic thermal process during double-sided asymmetrical TIG backing welding of large thick plates （ 1 000 mm×700 mm×50 mm） is numerically simulated using MSC. MARC. The effect of arc distance on the thermal cycle in weld zone during double-sided asymmetrical T1G backing welding is investigated. The results show that the workpiece experiences double-peak thermal cycle in double-sided asymmetrical TIG backing welding. On the one hand, the fore arc has the pre- heating effect on the rear pass, and the pre-heating temperature depends on the distance between the double arcs, the heat input of fore arc, and the initial temperature of workpiece. On the other hand, the rear arc has the post-heating effect on the fore pass. The mutual effects of two heat sources decrease with the increase of arc distance.
文摘In an unbound area, many methods have been proposed to design fuzzy truck backer control system. For a bound area, we consider designing fuzzy truck backer control systems using the searching in tables algorithm in this paper. New control rule tables are established, and experiment results show that the new control rule tables are better than the old ones.
文摘为了扩展高频水声换能器带宽,添加背衬是方法之一,然而针对水声换能器的激励信号形式和工作状态,当前缺少针对水声换能器背衬设计的准则,本文开展了水声换能器背衬参数的作用机制研究工作。基于KLM (krimholtz leedom and matthaei)传输线模型研究了背衬厚度、衰减系数及特征阻抗对水声换能器性能的影响。研究结果表明:背衬在水声换能器中作为谐振体的一部分参与振动并形成了若干阶纵向振动模态,其作用是增加系统阻尼,而不是吸收声波。从扩展带宽的角度出发,背衬的衰减系数应尽量大,此时,发送电压响应波动减弱且对响应幅值影响很小;背衬特征阻抗能够调节两响应峰的相对幅值,阻抗过高或者过低都不利于宽带的形成,因此选择中等特征阻抗的背衬较为适宜。最后,基于上述的背衬优化方法,制备了水声换能器样机,其测试带宽为102%,与理论吻合较好。
基金the National 863 Program(No.MII-C3G-02-20/863-317-03-01-02-20)
文摘In this paper, a novel Home Location Register(HLR) mobility database recovery scheme is proposed. With database backing-up and signal sending as its key processes, the presented scheme is designed for the purpose of both decreasing system costs and reducing number of lost calls. In our scheme, an algorithm is developed for an HLR to identify such VLRs that there are new MSs roaming into them since the latest HLR database backing up. The identification of those VLRs is used by the HLR to send Unreliable Roaming Data Directive messages to each of them to get the correct location information of those new MSs. Additionally, two kinds of relationships, one between the number of lost calls and the database backing-up period and the other between the backing-up cost and the period, are well analyzed. Both analytical and numerical results indicate that there will be an optimal HLR database backing-up period if certain system parameters are given and the total cost can be consequently minimized.
文摘This work investigates the proposed welding of stainless steels with no backing gas by using solid wire ER316L-Si and mixed gases （ He ＋ Ar ＋ CO2 ）. The protection mechanism was also discussed from the view of arc physics and the alloy elements in the solid wire. The result shows that when the proportion of helium in the above-noted mixed gases excesses 45 percent, the mechanical properties and the intergranular corrosion tendency meet corresponding Chinese standards. Further, the alloy elements in the solid wire can react with oxygen during the period of high temperature boosted by helium arc ; this result in the formation of a bed of thin slag, which can avoid the oxidation of the backing weld and eliminate the need of backing gas.
