平整机轧制力的预报对轧制过程的优化控制有着重要意义。针对平整机轧制力预测精度不高的问题,提出采用Re LU(Rectified Linear Units)激活函数的神经网络模型来预报平整机的轧制力。在对数据进行主成分分析后,得到影响轧制力的主要因素...平整机轧制力的预报对轧制过程的优化控制有着重要意义。针对平整机轧制力预测精度不高的问题,提出采用Re LU(Rectified Linear Units)激活函数的神经网络模型来预报平整机的轧制力。在对数据进行主成分分析后,得到影响轧制力的主要因素,并将其作为神经网络的输入层,将平整机轧制力作为输出层,通过使用Python语言编程进行实验,对神经网络模型隐层的相关参数及算法进行单一变量筛选,建立了保证轧制力预报精度最高的神经网络模型。实验结果表明,通过调整隐层层数、神经元数、传播算法、正则化方法,该模型能够将预测误差控制在10%以内,且该实验方法能够对不同输入参数下的平整机轧制力进行精确预报。展开更多
本文提出了一种低剖面锥形波束漏波天线,该天线实现了宽仰角扫描范围和较低的方位面不圆度水平。通过在平行板波导表面刻蚀一系列同心圆环漏波结构,实现了导波模式向锥形辐射波束的转换。为有效拓宽俯仰面内的扫描范围,对单元格的色散...本文提出了一种低剖面锥形波束漏波天线,该天线实现了宽仰角扫描范围和较低的方位面不圆度水平。通过在平行板波导表面刻蚀一系列同心圆环漏波结构,实现了导波模式向锥形辐射波束的转换。为有效拓宽俯仰面内的扫描范围,对单元格的色散特性进行了理论分析。利用漏波结构的等效电路模型,提取了对应的集总电路元件参数。同时,评估了不同探针配置对不圆度水平的影响,并最终设计了一种基于接地共面波导的八路等功分馈电网络。实测结果表明,该天线能够工作于30.0 GHz~37.0 GHz的频率范围,相对带宽达21%,仰角扫描范围为45°。该天线具有稳定的全向辐射特性,方位面不圆度低于1.6 d B,交叉极化水平优于-22 d B。所设计的天线可满足毫米波卫星通信和引信探测等领域的应用需求。展开更多
A "leaky gut" may be the cutting edge for the passage of toxins, antigens or bacteria into the body, and may play a pathogenic role in advanced liver cirrhosis and its complications. Plasma endotoxin levels ...A "leaky gut" may be the cutting edge for the passage of toxins, antigens or bacteria into the body, and may play a pathogenic role in advanced liver cirrhosis and its complications. Plasma endotoxin levels have been admitted as a surrogate marker of bacterial translocation and close relations of endotoxemia to hyperdynamic circulation, portal hypertension, renal, cardiac, pulmonary and coagulation disturbances have been reported. Bacterial overgrowth, increased intestinal permeability, failure to inactivate endotoxin,activated innate immunity are all likely to play a role in the pathological states of bacterial translocation. Therapeutic approach by management of the gut-liver axis by antibiotics, probiotics, synbiotics, prebiotics and their combinations may improve the clinical course of cirrhotic patients. Special concern should be paid on anti-endotoxin treatment. Adequate management of the gut-liver axis may be effective for prevention of liver cirrhosis itself by inhibiting the progression of fibrosis.展开更多
Gut flora and bacterial translocation (BT) play important roles in the pathogenesis of chronic liver disease, including cirrhosis and its complications. Intestinal bacterial overgrowth and increased bacterial transloc...Gut flora and bacterial translocation (BT) play important roles in the pathogenesis of chronic liver disease, including cirrhosis and its complications. Intestinal bacterial overgrowth and increased bacterial translocation of gut flora from the intestinal lumen predispose patients to bacterial infections, major complications and also play a role in the pathogenesis of chronic liver disorders. Levels of bacterial lipopolysaccharide, a component of gram-negative bacteria, are increased in the portal and/or systemic circulation in several types of chronic liver disease. Impaired gut epithelial integrity due to alterations in tight junction proteins may be the pathological mechanism underlying bacterial translocation. Preclinical and clinical studies over the last decade have suggested a role for BT in the pathogenesis of nonalcoholic steatohepatitis (NASH). Bacterial overgrowth, immune dysfunction, alteration of the luminal factors, and altered intestinal permeability are all involved in the pathogenesis of NASH and its complications. A better understanding of the cell-specific recognition and intracellular signaling events involved in sensing gut-derived microbes will help in the development of means to achieve an optimal balance in the gut-liver axis and ameliorate liver diseases. These may suggest new targets for potential therapeutic interventions for the treatment of NASH. Here, we review some of the mechanisms connecting BT and NASH and potential therapeutic developments.展开更多
Palaeoskapha sichuanensis gen. et sp. nov. of Menispermaceae is described here for the first time based on a well preserved fossil fruit. The specimen was found in the Relu Formation of western Sichuan, West China. Th...Palaeoskapha sichuanensis gen. et sp. nov. of Menispermaceae is described here for the first time based on a well preserved fossil fruit. The specimen was found in the Relu Formation of western Sichuan, West China. The specimen, straight, boat-shaped endocarp with large ventral condyle, clearly belongs to the tribe Tinosporeae. The wide aperture of the double condyle, combined with a whole shape not deeply invaginated, indicates a genus different from what was already known to science for this tribe. This fossil widens the distribution of the tribe during Eocene from North America and Europe to Asia, where it was formerly unknown.展开更多
文摘平整机轧制力的预报对轧制过程的优化控制有着重要意义。针对平整机轧制力预测精度不高的问题,提出采用Re LU(Rectified Linear Units)激活函数的神经网络模型来预报平整机的轧制力。在对数据进行主成分分析后,得到影响轧制力的主要因素,并将其作为神经网络的输入层,将平整机轧制力作为输出层,通过使用Python语言编程进行实验,对神经网络模型隐层的相关参数及算法进行单一变量筛选,建立了保证轧制力预报精度最高的神经网络模型。实验结果表明,通过调整隐层层数、神经元数、传播算法、正则化方法,该模型能够将预测误差控制在10%以内,且该实验方法能够对不同输入参数下的平整机轧制力进行精确预报。
文摘本文提出了一种低剖面锥形波束漏波天线,该天线实现了宽仰角扫描范围和较低的方位面不圆度水平。通过在平行板波导表面刻蚀一系列同心圆环漏波结构,实现了导波模式向锥形辐射波束的转换。为有效拓宽俯仰面内的扫描范围,对单元格的色散特性进行了理论分析。利用漏波结构的等效电路模型,提取了对应的集总电路元件参数。同时,评估了不同探针配置对不圆度水平的影响,并最终设计了一种基于接地共面波导的八路等功分馈电网络。实测结果表明,该天线能够工作于30.0 GHz~37.0 GHz的频率范围,相对带宽达21%,仰角扫描范围为45°。该天线具有稳定的全向辐射特性,方位面不圆度低于1.6 d B,交叉极化水平优于-22 d B。所设计的天线可满足毫米波卫星通信和引信探测等领域的应用需求。
文摘A "leaky gut" may be the cutting edge for the passage of toxins, antigens or bacteria into the body, and may play a pathogenic role in advanced liver cirrhosis and its complications. Plasma endotoxin levels have been admitted as a surrogate marker of bacterial translocation and close relations of endotoxemia to hyperdynamic circulation, portal hypertension, renal, cardiac, pulmonary and coagulation disturbances have been reported. Bacterial overgrowth, increased intestinal permeability, failure to inactivate endotoxin,activated innate immunity are all likely to play a role in the pathological states of bacterial translocation. Therapeutic approach by management of the gut-liver axis by antibiotics, probiotics, synbiotics, prebiotics and their combinations may improve the clinical course of cirrhotic patients. Special concern should be paid on anti-endotoxin treatment. Adequate management of the gut-liver axis may be effective for prevention of liver cirrhosis itself by inhibiting the progression of fibrosis.
基金Supported by Immuron, Nasvax, Plantylight, Desert Labs,Teva Pharmaceutical and ENZO Biochem
文摘Gut flora and bacterial translocation (BT) play important roles in the pathogenesis of chronic liver disease, including cirrhosis and its complications. Intestinal bacterial overgrowth and increased bacterial translocation of gut flora from the intestinal lumen predispose patients to bacterial infections, major complications and also play a role in the pathogenesis of chronic liver disorders. Levels of bacterial lipopolysaccharide, a component of gram-negative bacteria, are increased in the portal and/or systemic circulation in several types of chronic liver disease. Impaired gut epithelial integrity due to alterations in tight junction proteins may be the pathological mechanism underlying bacterial translocation. Preclinical and clinical studies over the last decade have suggested a role for BT in the pathogenesis of nonalcoholic steatohepatitis (NASH). Bacterial overgrowth, immune dysfunction, alteration of the luminal factors, and altered intestinal permeability are all involved in the pathogenesis of NASH and its complications. A better understanding of the cell-specific recognition and intracellular signaling events involved in sensing gut-derived microbes will help in the development of means to achieve an optimal balance in the gut-liver axis and ameliorate liver diseases. These may suggest new targets for potential therapeutic interventions for the treatment of NASH. Here, we review some of the mechanisms connecting BT and NASH and potential therapeutic developments.
文摘Palaeoskapha sichuanensis gen. et sp. nov. of Menispermaceae is described here for the first time based on a well preserved fossil fruit. The specimen was found in the Relu Formation of western Sichuan, West China. The specimen, straight, boat-shaped endocarp with large ventral condyle, clearly belongs to the tribe Tinosporeae. The wide aperture of the double condyle, combined with a whole shape not deeply invaginated, indicates a genus different from what was already known to science for this tribe. This fossil widens the distribution of the tribe during Eocene from North America and Europe to Asia, where it was formerly unknown.
