针对土壤中全硼测定存在难消解、干扰大、易挥发损失等问题,利用碱熔法、微波消解法以及微敞开石墨消解法对土壤全硼进行了测定分析,优化了消解条件,并对三种消解方式进行了验证对比。结果表明:碱熔剂种类以及用量会对碱熔法的准确性造...针对土壤中全硼测定存在难消解、干扰大、易挥发损失等问题,利用碱熔法、微波消解法以及微敞开石墨消解法对土壤全硼进行了测定分析,优化了消解条件,并对三种消解方式进行了验证对比。结果表明:碱熔剂种类以及用量会对碱熔法的准确性造成较大影响,选择KOH作为碱熔剂,并且KOH添加量为3.0 g时,可以获得更准确的结果;加酸种类以及赶酸温度的选择对微波消解法测定结果影响较大,选择加酸体系(5 mL HNO_(3)+1 mL HCl+3 mL HF+1.5 mL H_(3)PO_(4)),赶酸时温度选择170℃,测试效果较好;不同的加酸体系以及消解温度同样会引起微敞开石墨消解法测定结果出现较大误差,选择加酸体系(5 mL HNO_(3)+1 mL HClO_(4)+3 mL HF+1.5 mL H_(3)PO_(4)),消解温度设为170℃,测定结果更可靠。方法验证对比结果表明,碱熔法检出限为0.7 mg/kg,微波消解法检出限为0.9 mg/kg,微敞开石墨消解法检出限为1.0 mg/kg,均满足分析测定的要求。三种消解方式测定的准确度和精密度均符合要求,均可用于土壤全硼的测定,并且实际样品测定结果无显著性差异。三种消解方式优缺点和适用范围不同,实际测试时可以根据样品数量及样品中全硼大致含量等选择具体的消解方式。建立的方法可以为第三次全国土壤普查内业检测提供参考和借鉴。展开更多
Different fusion algorithm has its own advantages and limitations,so it is very difficult to simply evaluate the good points and bad points of the fusion algorithm. Whether an algorithm was selected to fuse object ima...Different fusion algorithm has its own advantages and limitations,so it is very difficult to simply evaluate the good points and bad points of the fusion algorithm. Whether an algorithm was selected to fuse object images was also depended upon the sensor types and special research purposes. Firstly,five fusion methods,i. e. IHS,Brovey,PCA,SFIM and Gram-Schmidt,were briefly described in the paper. And then visual judgment and quantitative statistical parameters were used to assess the five algorithms. Finally,in order to determine which one is the best suitable fusion method for land cover classification of IKONOS image,the maximum likelihood classification( MLC) was applied using the above five fusion images. The results showed that the fusion effect of SFIM transform and Gram-Schmidt transform were better than the other three image fusion methods in spatial details improvement and spectral information fidelity,and Gram-Schmidt technique was superior to SFIM transform in the aspect of expressing image details. The classification accuracy of the fused image using Gram-Schmidt and SFIM algorithms was higher than that of the other three image fusion methods,and the overall accuracy was greater than 98%. The IHS-fused image classification accuracy was the lowest,the overall accuracy and kappa coefficient were 83. 14% and 0. 76,respectively. Thus the IKONOS fusion images obtained by the Gram-Schmidt and SFIM were better for improving the land cover classification accuracy.展开更多
目的探讨Bryan人工颈椎间盘置换术与颈前路椎间融合术后颈部轴性症状(axial symptom,AS)的发生,并进行对比分析。方法2004年10月-2006年4月,对22例患者行Bryan人工颈椎间盘置换术(A组),男13例,女9例;年龄33～54岁,平均43.3岁。病程1～2...目的探讨Bryan人工颈椎间盘置换术与颈前路椎间融合术后颈部轴性症状(axial symptom,AS)的发生,并进行对比分析。方法2004年10月-2006年4月,对22例患者行Bryan人工颈椎间盘置换术(A组),男13例,女9例;年龄33～54岁,平均43.3岁。病程1～21个月,平均6个月。其中脊髓型颈椎病16例,神经根型颈椎病6例。单节段置换20例,2个节段置换2例。对同期30例患者行颈前路椎间盘切除减压植骨融合内固定术(B组),男17例,女13例;年龄35～64岁,平均50.3岁。病程1～23个月,平均7个月。其中脊髓型颈椎病19例,神经根型颈椎病11例。单节段融合26例,2个节段融合4例。观察两组患者术后随访时神经功能恢复情况,手术节段颈椎曲度、颈椎总活动度(range of motion,ROM)的变化情况及颈部AS的发生情况,并进行比较分析。结果两组患者术中、术后均无严重并发症发生。所有患者均获随访,随访时间24～42个月,平均30.6个月。A组术后无假体移位、脱落等并发症发生;B组术后6个月X线片示植骨全部达骨性融合,内固定无松动、脱落、断裂等。两组神经根型患者术后随访时临床症状均明显缓解,疗效满意。两组脊髓型患者JOA评分术后随访时均较术前有明显提高(P<0.01);两组术前及随访期末差异均无统计学意义(P>0.05)。B组术后手术节段颈椎后凸发生率明显增高,且高于A组(P<0.05)。B组ROM较术前明显减小(P<0.01),A组手术前后差异无统计学意义(P>0.05);两组术后差异有统计学意义(P<0.05)。术后颈部AS发生率A组为18.18%,B组为46.67%,两组比较差异有统计学意义(P<0.05)。结论与前路融合手术相比,Bryan人工颈椎间盘置换治疗颈椎病在取得良好临床疗效的同时能维持手术节段ROM及曲度,避免ROM的减少及术后颈部AS的发生。展开更多
升降轨PSInSAR时序分析获得的同一地区2组监测结果分别为升轨和降轨下的地表形变速率与累积变形量。针对研究区地面以下沉为主,水平方向变形极为微小的特点,将视线向(line of sight,LOS)变形转换为垂向的下沉值,以此进行升降轨模式下2...升降轨PSInSAR时序分析获得的同一地区2组监测结果分别为升轨和降轨下的地表形变速率与累积变形量。针对研究区地面以下沉为主,水平方向变形极为微小的特点,将视线向(line of sight,LOS)变形转换为垂向的下沉值,以此进行升降轨模式下2组观测值的比较与精度检验。在此基础上,将相干目标的2组观测序列数据融合以实现加密观测。研究结果表明:升降轨模式下沉降速率观测值的互检验精度优于2 mm;2组观测序列数据的融合结果进一步揭示了相干目标在时域上的非线性沉降特征。展开更多
文摘针对土壤中全硼测定存在难消解、干扰大、易挥发损失等问题,利用碱熔法、微波消解法以及微敞开石墨消解法对土壤全硼进行了测定分析,优化了消解条件,并对三种消解方式进行了验证对比。结果表明:碱熔剂种类以及用量会对碱熔法的准确性造成较大影响,选择KOH作为碱熔剂,并且KOH添加量为3.0 g时,可以获得更准确的结果;加酸种类以及赶酸温度的选择对微波消解法测定结果影响较大,选择加酸体系(5 mL HNO_(3)+1 mL HCl+3 mL HF+1.5 mL H_(3)PO_(4)),赶酸时温度选择170℃,测试效果较好;不同的加酸体系以及消解温度同样会引起微敞开石墨消解法测定结果出现较大误差,选择加酸体系(5 mL HNO_(3)+1 mL HClO_(4)+3 mL HF+1.5 mL H_(3)PO_(4)),消解温度设为170℃,测定结果更可靠。方法验证对比结果表明,碱熔法检出限为0.7 mg/kg,微波消解法检出限为0.9 mg/kg,微敞开石墨消解法检出限为1.0 mg/kg,均满足分析测定的要求。三种消解方式测定的准确度和精密度均符合要求,均可用于土壤全硼的测定,并且实际样品测定结果无显著性差异。三种消解方式优缺点和适用范围不同,实际测试时可以根据样品数量及样品中全硼大致含量等选择具体的消解方式。建立的方法可以为第三次全国土壤普查内业检测提供参考和借鉴。
基金Supported by Chinese National Natural Science Foundation(51208016)Beijing Natural Science Foundation(8122008)Beijing Education Commission Fund(KM201310005023)
文摘Different fusion algorithm has its own advantages and limitations,so it is very difficult to simply evaluate the good points and bad points of the fusion algorithm. Whether an algorithm was selected to fuse object images was also depended upon the sensor types and special research purposes. Firstly,five fusion methods,i. e. IHS,Brovey,PCA,SFIM and Gram-Schmidt,were briefly described in the paper. And then visual judgment and quantitative statistical parameters were used to assess the five algorithms. Finally,in order to determine which one is the best suitable fusion method for land cover classification of IKONOS image,the maximum likelihood classification( MLC) was applied using the above five fusion images. The results showed that the fusion effect of SFIM transform and Gram-Schmidt transform were better than the other three image fusion methods in spatial details improvement and spectral information fidelity,and Gram-Schmidt technique was superior to SFIM transform in the aspect of expressing image details. The classification accuracy of the fused image using Gram-Schmidt and SFIM algorithms was higher than that of the other three image fusion methods,and the overall accuracy was greater than 98%. The IHS-fused image classification accuracy was the lowest,the overall accuracy and kappa coefficient were 83. 14% and 0. 76,respectively. Thus the IKONOS fusion images obtained by the Gram-Schmidt and SFIM were better for improving the land cover classification accuracy.
文摘目的探讨Bryan人工颈椎间盘置换术与颈前路椎间融合术后颈部轴性症状(axial symptom,AS)的发生,并进行对比分析。方法2004年10月-2006年4月,对22例患者行Bryan人工颈椎间盘置换术(A组),男13例,女9例;年龄33～54岁,平均43.3岁。病程1～21个月,平均6个月。其中脊髓型颈椎病16例,神经根型颈椎病6例。单节段置换20例,2个节段置换2例。对同期30例患者行颈前路椎间盘切除减压植骨融合内固定术(B组),男17例,女13例;年龄35～64岁,平均50.3岁。病程1～23个月,平均7个月。其中脊髓型颈椎病19例,神经根型颈椎病11例。单节段融合26例,2个节段融合4例。观察两组患者术后随访时神经功能恢复情况,手术节段颈椎曲度、颈椎总活动度(range of motion,ROM)的变化情况及颈部AS的发生情况,并进行比较分析。结果两组患者术中、术后均无严重并发症发生。所有患者均获随访,随访时间24～42个月,平均30.6个月。A组术后无假体移位、脱落等并发症发生;B组术后6个月X线片示植骨全部达骨性融合,内固定无松动、脱落、断裂等。两组神经根型患者术后随访时临床症状均明显缓解,疗效满意。两组脊髓型患者JOA评分术后随访时均较术前有明显提高(P<0.01);两组术前及随访期末差异均无统计学意义(P>0.05)。B组术后手术节段颈椎后凸发生率明显增高,且高于A组(P<0.05)。B组ROM较术前明显减小(P<0.01),A组手术前后差异无统计学意义(P>0.05);两组术后差异有统计学意义(P<0.05)。术后颈部AS发生率A组为18.18%,B组为46.67%,两组比较差异有统计学意义(P<0.05)。结论与前路融合手术相比,Bryan人工颈椎间盘置换治疗颈椎病在取得良好临床疗效的同时能维持手术节段ROM及曲度,避免ROM的减少及术后颈部AS的发生。
文摘升降轨PSInSAR时序分析获得的同一地区2组监测结果分别为升轨和降轨下的地表形变速率与累积变形量。针对研究区地面以下沉为主,水平方向变形极为微小的特点,将视线向(line of sight,LOS)变形转换为垂向的下沉值,以此进行升降轨模式下2组观测值的比较与精度检验。在此基础上,将相干目标的2组观测序列数据融合以实现加密观测。研究结果表明:升降轨模式下沉降速率观测值的互检验精度优于2 mm;2组观测序列数据的融合结果进一步揭示了相干目标在时域上的非线性沉降特征。
