The plastic cement belongs to a sort of polymer material, the chemical composition is very complex, and the plastic cement work-piece is generally manufactured by die press forming. Aimed at being difficult to control...The plastic cement belongs to a sort of polymer material, the chemical composition is very complex, and the plastic cement work-piece is generally manufactured by die press forming. Aimed at being difficult to control in parameters of forming process, the paper explored the humanoid based intelligence control strategy. In the paper, it made the anatomy in control puzzle resulted in uncertainty such as chemical component of plastic cement etc., summarized up the characteristic of cybernetics in forming process, researched on the humanoid based intelligence control strategy, and constructed the control algorithm of forming process in plastic cement work-piece. Taking the process experiment of temperature and pressure control as an example, it validated the good dynamic and static control quality through simulation of control algorithm constructed in this paper. The experimental results show that the control algorithm explored in this paper is reasonably available.展开更多
The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigate...The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigated. Observed from the optical and electron microscopes, the as-sprayed V4 steel had the finer microstructure of uniform and equiaxial grains ,while after hot rolling for densification and spheroidized annealing, the V4 steel obtained an excellent spheroidized structure that is favorable to subsequent quenching and tempering treatment. The spheroidized structure and level of annealed hardness of the V4 steel are almost the same as expensive imported powder metallurgy the V4 steel. It is difficult to produce V4 steel with the conventional ingot metallurgical technique, so the multi-step and high-cost powder metallurgy method is generally used at present. Compared to the powder metallurgy technique, using the spray forming technique to produce the V4 steel has obvious advantages and potential market competitiveness in reducing production costs, simplifying working process, and shortening the production cycle.展开更多
The Bueckner work conjugate integrals are studied for cracks in anisotropic clastic solids.The difficulties in separating Lekhnitskii's two complex arguments involved in the integrals are overcome and explicit fun...The Bueckner work conjugate integrals are studied for cracks in anisotropic clastic solids.The difficulties in separating Lekhnitskii's two complex arguments involved in the integrals are overcome and explicit functional representa- tions of the integrals are given for several typical cases.It is found that the pseudo- orthogonal property of the eigenfunction expansion forms presented previously for isotropic cases,isotropic bimaterials,and orthotropic cases,are proved to be also valid in the present case of anisotropic material.Finally,Some useful path-independent in- tegrals and weight functions are proposed.展开更多
目的探究轮班对地铁职工健康相关生命质量的影响,为提高该职业人群的健康素养提供科学依据。方法2019年对武汉市地铁集团职工进行研究,使用调查问卷收集人口学特征和职业史等信息。用生活质量评价量表(the Mos 36-item Short Form Healt...目的探究轮班对地铁职工健康相关生命质量的影响,为提高该职业人群的健康素养提供科学依据。方法2019年对武汉市地铁集团职工进行研究,使用调查问卷收集人口学特征和职业史等信息。用生活质量评价量表(the Mos 36-item Short Form Health Survey,SF-36)测定其健康相关生命质量;按照性别分层,采用单因素和多因素Logistic回归模型分析轮班对该职业人群量表各维度得分的影响。结果9960名职工中有68.6%从事轮班工作。不同性别、工种、被动吸烟状况、锻炼习惯、睡眠状况、个人疾病史亚组人群的SF-36量表得分有显著差异(P<0.05)。与不轮班者相比,不同轮班制职工的一般健康状况、健康变化和社会功能等维度得分为差的风险均较高。并且随着轮班年限的增加,轮班者在身体机能、生理职能、一般健康状况、健康变化、精力、社会功能和精神健康维度得分为差的风险呈现为先升高再趋于平缓甚至下降的趋势。在男职工中,轮班制影响其SF-36量表各维度得分,但在女职工中未见此影响。结论轮班工作可能是影响地铁职工健康相关生命质量的重要危险因素之一,尤以男职工为甚。展开更多
文摘The plastic cement belongs to a sort of polymer material, the chemical composition is very complex, and the plastic cement work-piece is generally manufactured by die press forming. Aimed at being difficult to control in parameters of forming process, the paper explored the humanoid based intelligence control strategy. In the paper, it made the anatomy in control puzzle resulted in uncertainty such as chemical component of plastic cement etc., summarized up the characteristic of cybernetics in forming process, researched on the humanoid based intelligence control strategy, and constructed the control algorithm of forming process in plastic cement work-piece. Taking the process experiment of temperature and pressure control as an example, it validated the good dynamic and static control quality through simulation of control algorithm constructed in this paper. The experimental results show that the control algorithm explored in this paper is reasonably available.
文摘The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigated. Observed from the optical and electron microscopes, the as-sprayed V4 steel had the finer microstructure of uniform and equiaxial grains ,while after hot rolling for densification and spheroidized annealing, the V4 steel obtained an excellent spheroidized structure that is favorable to subsequent quenching and tempering treatment. The spheroidized structure and level of annealed hardness of the V4 steel are almost the same as expensive imported powder metallurgy the V4 steel. It is difficult to produce V4 steel with the conventional ingot metallurgical technique, so the multi-step and high-cost powder metallurgy method is generally used at present. Compared to the powder metallurgy technique, using the spray forming technique to produce the V4 steel has obvious advantages and potential market competitiveness in reducing production costs, simplifying working process, and shortening the production cycle.
基金The project supported by the National Natural Science Foundation of China(19891180)Doctorate Foundation of Xi'an Jiaotong University
文摘The Bueckner work conjugate integrals are studied for cracks in anisotropic clastic solids.The difficulties in separating Lekhnitskii's two complex arguments involved in the integrals are overcome and explicit functional representa- tions of the integrals are given for several typical cases.It is found that the pseudo- orthogonal property of the eigenfunction expansion forms presented previously for isotropic cases,isotropic bimaterials,and orthotropic cases,are proved to be also valid in the present case of anisotropic material.Finally,Some useful path-independent in- tegrals and weight functions are proposed.
文摘目的探究轮班对地铁职工健康相关生命质量的影响,为提高该职业人群的健康素养提供科学依据。方法2019年对武汉市地铁集团职工进行研究,使用调查问卷收集人口学特征和职业史等信息。用生活质量评价量表(the Mos 36-item Short Form Health Survey,SF-36)测定其健康相关生命质量;按照性别分层,采用单因素和多因素Logistic回归模型分析轮班对该职业人群量表各维度得分的影响。结果9960名职工中有68.6%从事轮班工作。不同性别、工种、被动吸烟状况、锻炼习惯、睡眠状况、个人疾病史亚组人群的SF-36量表得分有显著差异(P<0.05)。与不轮班者相比,不同轮班制职工的一般健康状况、健康变化和社会功能等维度得分为差的风险均较高。并且随着轮班年限的增加,轮班者在身体机能、生理职能、一般健康状况、健康变化、精力、社会功能和精神健康维度得分为差的风险呈现为先升高再趋于平缓甚至下降的趋势。在男职工中,轮班制影响其SF-36量表各维度得分,但在女职工中未见此影响。结论轮班工作可能是影响地铁职工健康相关生命质量的重要危险因素之一,尤以男职工为甚。
