基于前后张驰逼近(Back and Forth Nudging,简称BFN)和集合卡尔曼滤波(En KF)方法,构建了一种新的同化方法 HBFNEn KF(Hybrid Back and Forth Nudging En KF)混合同化方法,并将此同化系统分别与通道浅水模式(shallow water model)和全...基于前后张驰逼近(Back and Forth Nudging,简称BFN)和集合卡尔曼滤波(En KF)方法,构建了一种新的同化方法 HBFNEn KF(Hybrid Back and Forth Nudging En KF)混合同化方法,并将此同化系统分别与通道浅水模式(shallow water model)和全球浅水模式对接,检验了HBFNEn KF同化方法的有效性。同时,对比了集合均方根滤波(En SRF)、HNEn KF(Hybrid Nudging En KF)、HBFNEn KF三种方法在有误差模式中的同化效果。试验结果表明:HBFNEn KF同化方法保留了HNEn KF方法的同化连续性,解决了En KF同化不连续不平滑的问题,同时还有着更快的收敛速度;当采用单变量分析试验时,HBFNEn KF方法的优势最为明显,表明HBFNEn KF能够较好地保持不同模式变量间的平衡。此外,增量场尺度分析结果表明:相比En SRF,HBFNEn KF在大尺度范围有更好的同化效果,同时能够避免在中小尺度范围内出现大量的虚假增量。展开更多
研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac i...研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac id-3β-ol对重组人DNA拓扑异构酶Ⅰ、肝癌细胞BEL-7402和胃腺癌细胞MCG-803的抑制作用,效果显著,IC50值分别为12.0×10-6、6.5×10-6、8.0×10-6g/mL。由V(石油醚)∶V(乙酸乙酯)=20∶1洗脱得到的低极性成分进行了气相色谱-质谱分析,共鉴定60个化合物,其中长链脂肪族化合物,如烷烃、饱和及不饱和羧酸(酯)含量较丰富,占36.16%,萜类和甾体类化合物分别占6.42%和9.28%。展开更多
We have reported the synthesis of compounds mentioned in this paper and the characterization of their structure and properties withspectra7]. In this Work, we made a quantum chemistry calculation of Cu(En)2DDQ2, Cu(Ph...We have reported the synthesis of compounds mentioned in this paper and the characterization of their structure and properties withspectra7]. In this Work, we made a quantum chemistry calculation of Cu(En)2DDQ2, Cu(Phen)2DDQ2 and three analogous compoundsof Zn2+ coordinated with Phen, Bipy, and En ligands in octahedral model; discussed the feature of their chemical bonds. The resultObtained shows that DDQ radical anion is a considerable electron acceptor. It also would be helpful to understand the characteristics ofIR, ESR spectra of bile compounds and their conductivity discovered in solid state or solution.展开更多
Damage detection in structures is performed via vibra-tion based structural identification. Modal information, such as fre-quencies and mode shapes, are widely used for structural dama-ge detection to indicate the hea...Damage detection in structures is performed via vibra-tion based structural identification. Modal information, such as fre-quencies and mode shapes, are widely used for structural dama-ge detection to indicate the health conditions of civil structures.The deep learning algorithm that works on a multiple layer neuralnetwork model termed as deep autoencoder is proposed to learnthe relationship between the modal information and structural stiff-ness parameters. This is achieved via dimension reduction of themodal information feature and a non-linear regression against thestructural stiffness parameters. Numerical tests on a symmetri-cal steel frame model are conducted to generate the data for thetraining and validation, and to demonstrate the efficiency of theproposed approach for vibration based structural damage detec-tion.展开更多
文摘基于前后张驰逼近(Back and Forth Nudging,简称BFN)和集合卡尔曼滤波(En KF)方法,构建了一种新的同化方法 HBFNEn KF(Hybrid Back and Forth Nudging En KF)混合同化方法,并将此同化系统分别与通道浅水模式(shallow water model)和全球浅水模式对接,检验了HBFNEn KF同化方法的有效性。同时,对比了集合均方根滤波(En SRF)、HNEn KF(Hybrid Nudging En KF)、HBFNEn KF三种方法在有误差模式中的同化效果。试验结果表明:HBFNEn KF同化方法保留了HNEn KF方法的同化连续性,解决了En KF同化不连续不平滑的问题,同时还有着更快的收敛速度;当采用单变量分析试验时,HBFNEn KF方法的优势最为明显,表明HBFNEn KF能够较好地保持不同模式变量间的平衡。此外,增量场尺度分析结果表明:相比En SRF,HBFNEn KF在大尺度范围有更好的同化效果,同时能够避免在中小尺度范围内出现大量的虚假增量。
文摘研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac id-3β-ol对重组人DNA拓扑异构酶Ⅰ、肝癌细胞BEL-7402和胃腺癌细胞MCG-803的抑制作用,效果显著,IC50值分别为12.0×10-6、6.5×10-6、8.0×10-6g/mL。由V(石油醚)∶V(乙酸乙酯)=20∶1洗脱得到的低极性成分进行了气相色谱-质谱分析,共鉴定60个化合物,其中长链脂肪族化合物,如烷烃、饱和及不饱和羧酸(酯)含量较丰富,占36.16%,萜类和甾体类化合物分别占6.42%和9.28%。
文摘We have reported the synthesis of compounds mentioned in this paper and the characterization of their structure and properties withspectra7]. In this Work, we made a quantum chemistry calculation of Cu(En)2DDQ2, Cu(Phen)2DDQ2 and three analogous compoundsof Zn2+ coordinated with Phen, Bipy, and En ligands in octahedral model; discussed the feature of their chemical bonds. The resultObtained shows that DDQ radical anion is a considerable electron acceptor. It also would be helpful to understand the characteristics ofIR, ESR spectra of bile compounds and their conductivity discovered in solid state or solution.
文摘Damage detection in structures is performed via vibra-tion based structural identification. Modal information, such as fre-quencies and mode shapes, are widely used for structural dama-ge detection to indicate the health conditions of civil structures.The deep learning algorithm that works on a multiple layer neuralnetwork model termed as deep autoencoder is proposed to learnthe relationship between the modal information and structural stiff-ness parameters. This is achieved via dimension reduction of themodal information feature and a non-linear regression against thestructural stiffness parameters. Numerical tests on a symmetri-cal steel frame model are conducted to generate the data for thetraining and validation, and to demonstrate the efficiency of theproposed approach for vibration based structural damage detec-tion.
