Landsat TM/ETM+ and Alos remote sensing data of the study area in 1991, 2001 and 2010 were interpreted by using object-oriented RS image extraction technology, landscape ecology theories were applied as well as GIS an...Landsat TM/ETM+ and Alos remote sensing data of the study area in 1991, 2001 and 2010 were interpreted by using object-oriented RS image extraction technology, landscape ecology theories were applied as well as GIS and FRAGSTATS4.1 to choose reasonable landscape indexes for studying temporal-spatial changes of suburban landscape layouts of Haikou City, exploring spatial features and change tendency of rural landscapes. According to the results, tropical garden landscapes have taken a dominant status in the last 2 decades; tropical farmland landscapes have had the most complicate shapes; tropical open forest landscapes have been most influenced by human interventions but had the best connectivity and high degree of concentration; tropical settlement landscapes and tropical meadow landscapes have been widely scattered with poor connectivity; landscape connectivity has been well maintained; contagion index has changed slightly, landscape equilibrium has been stable; landscape diversity has been maintained, all landscape types have been evenly distributed, landscape fragmentation has increased, and landscape heterogeneity has grown.展开更多
目的系统性分析我国维持性血液透析(maintenance hemodialysis,MHD)患者并发腹主动脉钙化(abdominal aorta calcification,AAC)的危险因素。方法通过计算机对PubMed、Embase、Web of Science、中国知网、中国生物医学文献数据库CBM、万...目的系统性分析我国维持性血液透析(maintenance hemodialysis,MHD)患者并发腹主动脉钙化(abdominal aorta calcification,AAC)的危险因素。方法通过计算机对PubMed、Embase、Web of Science、中国知网、中国生物医学文献数据库CBM、万方等数据库检索关于中国MHD患者并发AAC危险因素的文献(时限为建库至2023年5月),采用纽卡斯尔-渥太华量表(Newcastle-Ottawa scale,NOS)、美国卫生保健质量和研究机构评价标准(agency for healthcare research and quality,AHRQ)进行方法学文献质量评价。采用RevMan 5.3软件进行Meta分析。结果共纳入15篇文献,其中10篇中文文献,5篇英文文献,包含2848例研究对象。Meta分析结果显示高龄(OR=1.080,95%CI:1.050~1.110,P<0.001)、长透析龄(OR=1.020,95%CI:1.010~1.040,P=0.008)、吸烟(OR=1.900,95%CI:1.440~2.500,P<0.001)、高体质量指数(body mass index,BMI)(OR=1.200,95%CI:1.050~1.110,P=0.001)、血钙升高(OR=14.140,95%CI:7.340~27.260,P<0.001)、血磷升高(OR=6.010,95%CI:2.040~17.750,P=0.001)、甲状旁腺激素升高(OR=1.310,95%CI:1.010~1.700,P=0.040)以及血镁(OR=0.490,95%CI:0.400~0.590,P<0.001)、25羟基维生素D3降低(OR=0.760,95%CI:0.610~0.950,P=0.020)为MHD患者并发AAC的危险因素。结论维持性血液透析患者并发腹主动脉钙化的影响因素较多,应重点关注高危人群,进行针对性、个性化干预,延缓MHD患者腹主动脉钙化的进展。展开更多
光纤液位传感器信号采集系统的优劣,直接关系到系统感知的外界信息能否不失真地传回中央控制系统。考虑到光纤液位传感器对外界信息感知的高精度、低时延、低温漂、大量程的基本要求,设计一种自动转换量程的光信号采集电路。系统利用程...光纤液位传感器信号采集系统的优劣,直接关系到系统感知的外界信息能否不失真地传回中央控制系统。考虑到光纤液位传感器对外界信息感知的高精度、低时延、低温漂、大量程的基本要求,设计一种自动转换量程的光信号采集电路。系统利用程控放大器CD4051对信号进行判断,并能够智能选择量程,确定放大电路的反馈电阻。通过调理电路放大、滤波、跟随后对信号进行A/D转换,并将转换后的数字信号传递给FPGA主控芯片分析处理。测试结果表明,该光信号采集系统能够实现1 n W^10 m W范围内的光信号的采集,线性度好,误差小于±0.96%,精度高,适用于光纤传感领域。展开更多
基金Supported by Hainan Natural Science Foundation (80526, 411097)
文摘Landsat TM/ETM+ and Alos remote sensing data of the study area in 1991, 2001 and 2010 were interpreted by using object-oriented RS image extraction technology, landscape ecology theories were applied as well as GIS and FRAGSTATS4.1 to choose reasonable landscape indexes for studying temporal-spatial changes of suburban landscape layouts of Haikou City, exploring spatial features and change tendency of rural landscapes. According to the results, tropical garden landscapes have taken a dominant status in the last 2 decades; tropical farmland landscapes have had the most complicate shapes; tropical open forest landscapes have been most influenced by human interventions but had the best connectivity and high degree of concentration; tropical settlement landscapes and tropical meadow landscapes have been widely scattered with poor connectivity; landscape connectivity has been well maintained; contagion index has changed slightly, landscape equilibrium has been stable; landscape diversity has been maintained, all landscape types have been evenly distributed, landscape fragmentation has increased, and landscape heterogeneity has grown.
文摘目的系统性分析我国维持性血液透析(maintenance hemodialysis,MHD)患者并发腹主动脉钙化(abdominal aorta calcification,AAC)的危险因素。方法通过计算机对PubMed、Embase、Web of Science、中国知网、中国生物医学文献数据库CBM、万方等数据库检索关于中国MHD患者并发AAC危险因素的文献(时限为建库至2023年5月),采用纽卡斯尔-渥太华量表(Newcastle-Ottawa scale,NOS)、美国卫生保健质量和研究机构评价标准(agency for healthcare research and quality,AHRQ)进行方法学文献质量评价。采用RevMan 5.3软件进行Meta分析。结果共纳入15篇文献,其中10篇中文文献,5篇英文文献,包含2848例研究对象。Meta分析结果显示高龄(OR=1.080,95%CI:1.050~1.110,P<0.001)、长透析龄(OR=1.020,95%CI:1.010~1.040,P=0.008)、吸烟(OR=1.900,95%CI:1.440~2.500,P<0.001)、高体质量指数(body mass index,BMI)(OR=1.200,95%CI:1.050~1.110,P=0.001)、血钙升高(OR=14.140,95%CI:7.340~27.260,P<0.001)、血磷升高(OR=6.010,95%CI:2.040~17.750,P=0.001)、甲状旁腺激素升高(OR=1.310,95%CI:1.010~1.700,P=0.040)以及血镁(OR=0.490,95%CI:0.400~0.590,P<0.001)、25羟基维生素D3降低(OR=0.760,95%CI:0.610~0.950,P=0.020)为MHD患者并发AAC的危险因素。结论维持性血液透析患者并发腹主动脉钙化的影响因素较多,应重点关注高危人群,进行针对性、个性化干预,延缓MHD患者腹主动脉钙化的进展。
文摘光纤液位传感器信号采集系统的优劣,直接关系到系统感知的外界信息能否不失真地传回中央控制系统。考虑到光纤液位传感器对外界信息感知的高精度、低时延、低温漂、大量程的基本要求,设计一种自动转换量程的光信号采集电路。系统利用程控放大器CD4051对信号进行判断,并能够智能选择量程,确定放大电路的反馈电阻。通过调理电路放大、滤波、跟随后对信号进行A/D转换,并将转换后的数字信号传递给FPGA主控芯片分析处理。测试结果表明,该光信号采集系统能够实现1 n W^10 m W范围内的光信号的采集,线性度好,误差小于±0.96%,精度高,适用于光纤传感领域。
