采用人工方法统计烟叶或烟丝含水率,费时费力且实时性差,为此,利用Visual Basic设计了含水率标准偏差统计软件。分析了西门子WINCC监控软件及其数据归档的特点,通过ADO(ActiveX DataObjects)对WINCC(Windows Control Center)的归档数据...采用人工方法统计烟叶或烟丝含水率,费时费力且实时性差,为此,利用Visual Basic设计了含水率标准偏差统计软件。分析了西门子WINCC监控软件及其数据归档的特点,通过ADO(ActiveX DataObjects)对WINCC(Windows Control Center)的归档数据进行访问。详细介绍了该软件的主界面设计,以及数据连接和主界面程序设计的编写代码。该软件经过测试表明,能够快速准确、自动统计出含水率标准偏差,满足了卷烟生产的工艺要求,克服了人工统计费时费力等不足之处,操作简单,界面清晰合理。展开更多
This study has been conducted to evaluate the influence of flux composition on the microstructure and oxygen content of the low carbon steel weldments using developed agglomerated fluxes.Ca_F2,FeMn and NiO were added ...This study has been conducted to evaluate the influence of flux composition on the microstructure and oxygen content of the low carbon steel weldments using developed agglomerated fluxes.Ca_F2,FeMn and NiO were added to the CaO-SiO_2-Al_2O_3 base fluxes in the varying amount of 2%-8% to examine the various elements transferred to the weldments.The microstructure obtained was a mixture of pearlite and ferrite contents.This study reveals that CaF_2 and Fe Mn both are having significant effect on pearlite percentage while CaF_2 and NiO are significant for oxygen transfer in the welds.The interaction effects of CaF_2 and Fe Mn and CaF_2 and Ni O are also significant to the microstructure of the welds.The fluxes were designed using response surface methodology( RSM) and were developed by agglomeration technique.展开更多
The hybrid method composed of clustering and predicting stages is proposed to predict the endpoint phos- phorus content of molten steel in BOF （Basic Oxygen Furnace）. At the clustering stage, the weighted K-means is...The hybrid method composed of clustering and predicting stages is proposed to predict the endpoint phos- phorus content of molten steel in BOF （Basic Oxygen Furnace）. At the clustering stage, the weighted K-means is performed to generate some clusters with homogeneous data. The weights of factors influencing the target are calcu- lated using EWM （Entropy Weight Method）. At the predicting stage, one GMDH （Group Method of Data Handling） polynomial neural network is built for each cluster. And the predictive results from all the GMDH polynomial neural networks are integrated into a whole to be the result for the hybrid method. The hybrid method, GMDH polnomial neural network and BP neural network are employed for a comparison. The results show that the proposed hybrid method is effective in predicting the endpoint phosphorus content of molten steel in BOF. Furthermore, the hybrid method outperforms BP neural network and GMDH polynomial neural network.展开更多
Desulfurization performance with low binary basicity refining slag in 72 grade tire cord steel was calculated using FactSage and it is found that sulfur content in steel decreases with the increase of basicity of slag...Desulfurization performance with low binary basicity refining slag in 72 grade tire cord steel was calculated using FactSage and it is found that sulfur content in steel decreases with the increase of basicity of slag, MgO content in slag and slag/steel ratio while sulfur partition ratio between slag and steel increases gradually with the increase of basicity of slag as well as MgO content. Experiments were carried out and the results are of great agreements with theoretical calculation. Then industrial application tests were performed in a domestic plant and good results were achieved. Sulfur content in steel decreases gradually during refining process, as a result, sulfur content in the billets is controlled in the range of 0.007 1%-0.008 1%. Sulfur content in steel refined with slag basicity of 1.21 is lower than that of 1.02, while the plasticity of oxide compound inclusions is a little better controlled in low basicity heats. Using refining slag with basicity of 1.0-1.2 and MgO content of 5%-10% and reducing the slag takeover of LD are favorable for improving the desulfurization performance and the plasticity of inclusions during the industrial production.展开更多
An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the b...An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the bath-oxygen impact area, such as the cavity depth, the lance height, the number of nozzles and the nozzles diameter. In the thermal issue, the model includes the targeted carbon content and temperature. The model is numerically solved, and is validated using reported data plant. The oxygen flow rate and the lance height are varied in the numerical simulations to study their effect on the carbon content and decarburization rate.展开更多
To evaluate the influence of contraceptive methods on the basic vaginal states (BVSs) in women in fertile age, 108 women consulting for birth control (14 - 45 years) were included in a prospective study. The vaginal c...To evaluate the influence of contraceptive methods on the basic vaginal states (BVSs) in women in fertile age, 108 women consulting for birth control (14 - 45 years) were included in a prospective study. The vaginal content was sampled both before they began using the chosen contraceptive method (see below) and three months later, and then analyzed using the Balance of Vaginal Content (BAVACO) methodology. Five BVSs were defined: 1) normal microbiota;2) normal microbiota with vaginal inflammatory reaction (VIR);3) intermediate microbiota;4) bacterial vaginosis and 5) non-specific microbial vaginitis. The following contraceptive methods were considered: combined oral contraceptive pill (COCP), intrauterine device (IUD), condom (CON), the rhythm method (RHYT) and simultaneous double protection (COCP + CON). The McNemar statistical test was used. COCP (n = 71): 20 samples retained normal BVSs and two were altered;nine out of the 49 altered samples returned to normal;IUD (n = 4): two samples modified their normal BVS to III and IV;CON (n = 25): the VIR increased in 20% of the samples;RHYT (n = 6): four samples retained the normal BVS;and COCP + CON (n = 2): samples preserved their initial BVS (II). The increased frequency of BVS I in the COCP group was significant (x2 = 3.3;p = 0.04). The relative frequency of each BVS was significantly modified, attributed to the type of contraceptive method used. The intake of hormones corrects alterations and retains a normal BVS. The contraceptive methods that use an external factor of local contact either maintain or alter the microbiota and VIR.展开更多
文摘采用人工方法统计烟叶或烟丝含水率,费时费力且实时性差,为此,利用Visual Basic设计了含水率标准偏差统计软件。分析了西门子WINCC监控软件及其数据归档的特点,通过ADO(ActiveX DataObjects)对WINCC(Windows Control Center)的归档数据进行访问。详细介绍了该软件的主界面设计,以及数据连接和主界面程序设计的编写代码。该软件经过测试表明,能够快速准确、自动统计出含水率标准偏差,满足了卷烟生产的工艺要求,克服了人工统计费时费力等不足之处,操作简单,界面清晰合理。
文摘This study has been conducted to evaluate the influence of flux composition on the microstructure and oxygen content of the low carbon steel weldments using developed agglomerated fluxes.Ca_F2,FeMn and NiO were added to the CaO-SiO_2-Al_2O_3 base fluxes in the varying amount of 2%-8% to examine the various elements transferred to the weldments.The microstructure obtained was a mixture of pearlite and ferrite contents.This study reveals that CaF_2 and Fe Mn both are having significant effect on pearlite percentage while CaF_2 and NiO are significant for oxygen transfer in the welds.The interaction effects of CaF_2 and Fe Mn and CaF_2 and Ni O are also significant to the microstructure of the welds.The fluxes were designed using response surface methodology( RSM) and were developed by agglomeration technique.
基金Sponsored by National Key Technology Research and Development in 11th Five Years Plan of China(2006BAE03A07)Fundamental Research Funds for Central University of China(FRF-AS-09-006B)
文摘The hybrid method composed of clustering and predicting stages is proposed to predict the endpoint phos- phorus content of molten steel in BOF （Basic Oxygen Furnace）. At the clustering stage, the weighted K-means is performed to generate some clusters with homogeneous data. The weights of factors influencing the target are calcu- lated using EWM （Entropy Weight Method）. At the predicting stage, one GMDH （Group Method of Data Handling） polynomial neural network is built for each cluster. And the predictive results from all the GMDH polynomial neural networks are integrated into a whole to be the result for the hybrid method. The hybrid method, GMDH polnomial neural network and BP neural network are employed for a comparison. The results show that the proposed hybrid method is effective in predicting the endpoint phosphorus content of molten steel in BOF. Furthermore, the hybrid method outperforms BP neural network and GMDH polynomial neural network.
基金Item Sponsored by National Key Basic Research and Development Program of China(2010CB30806)Central South University Postdoctoral Funded Project of China(120961)
文摘Desulfurization performance with low binary basicity refining slag in 72 grade tire cord steel was calculated using FactSage and it is found that sulfur content in steel decreases with the increase of basicity of slag, MgO content in slag and slag/steel ratio while sulfur partition ratio between slag and steel increases gradually with the increase of basicity of slag as well as MgO content. Experiments were carried out and the results are of great agreements with theoretical calculation. Then industrial application tests were performed in a domestic plant and good results were achieved. Sulfur content in steel decreases gradually during refining process, as a result, sulfur content in the billets is controlled in the range of 0.007 1%-0.008 1%. Sulfur content in steel refined with slag basicity of 1.21 is lower than that of 1.02, while the plasticity of oxide compound inclusions is a little better controlled in low basicity heats. Using refining slag with basicity of 1.0-1.2 and MgO content of 5%-10% and reducing the slag takeover of LD are favorable for improving the desulfurization performance and the plasticity of inclusions during the industrial production.
文摘An improved mathematical model to describe the decarburization process in basic oxygen furnaces for steelmaking is presented in this work. This model takes into account those factors or parameters that determine the bath-oxygen impact area, such as the cavity depth, the lance height, the number of nozzles and the nozzles diameter. In the thermal issue, the model includes the targeted carbon content and temperature. The model is numerically solved, and is validated using reported data plant. The oxygen flow rate and the lance height are varied in the numerical simulations to study their effect on the carbon content and decarburization rate.
文摘To evaluate the influence of contraceptive methods on the basic vaginal states (BVSs) in women in fertile age, 108 women consulting for birth control (14 - 45 years) were included in a prospective study. The vaginal content was sampled both before they began using the chosen contraceptive method (see below) and three months later, and then analyzed using the Balance of Vaginal Content (BAVACO) methodology. Five BVSs were defined: 1) normal microbiota;2) normal microbiota with vaginal inflammatory reaction (VIR);3) intermediate microbiota;4) bacterial vaginosis and 5) non-specific microbial vaginitis. The following contraceptive methods were considered: combined oral contraceptive pill (COCP), intrauterine device (IUD), condom (CON), the rhythm method (RHYT) and simultaneous double protection (COCP + CON). The McNemar statistical test was used. COCP (n = 71): 20 samples retained normal BVSs and two were altered;nine out of the 49 altered samples returned to normal;IUD (n = 4): two samples modified their normal BVS to III and IV;CON (n = 25): the VIR increased in 20% of the samples;RHYT (n = 6): four samples retained the normal BVS;and COCP + CON (n = 2): samples preserved their initial BVS (II). The increased frequency of BVS I in the COCP group was significant (x2 = 3.3;p = 0.04). The relative frequency of each BVS was significantly modified, attributed to the type of contraceptive method used. The intake of hormones corrects alterations and retains a normal BVS. The contraceptive methods that use an external factor of local contact either maintain or alter the microbiota and VIR.
