四川西部地区地理环境复杂,滑坡空间结构多样且变形剧烈。为有效预防滑坡灾害,需要探究相关区域滑坡危险性可靠评价方法。利用G1-熵权耦合赋权逼近理想解排序法(technique for order preference by similarity to ideal solution,TOPSIS...四川西部地区地理环境复杂,滑坡空间结构多样且变形剧烈。为有效预防滑坡灾害,需要探究相关区域滑坡危险性可靠评价方法。利用G1-熵权耦合赋权逼近理想解排序法(technique for order preference by similarity to ideal solution,TOPSIS)构建滑坡灾害危险性评价模型,选取高程、降雨、地震动参数等12个评价因子,对雅砻江滑坡灾害危险性进行评价。依据贴近度将滑坡区域分为4个等级,即高危险区(0.75~1)、较高危险区(0.5~0.75)、中等危险区(0.25~0.5)和低危险区(0~0.25)。同时,对比了由差分干涉测量短基线集时序分析(small baseline subset interferometric synthetic aperture radar,SBAS-InSAR)技术得到的4个区域滑坡实测结果和本文评价模型的分析结果。利用G1-熵权耦合赋权TOPSIS得到九龙县烟袋镇桤木林村高生地滑坡、新龙县和平乡甲西村麻西滑坡、德格县年古乡政府滑坡和甘孜县扎科乡达玛滑坡的贴近度分别为0.854、0.686、0.405和0.224,由SBAS-InSAR技术得到滑坡前缘局部变形速率分别为-150、-43、-66、30 mm/a,二者之间有显著的对应关系,证明本文评价模型的准确性。应用G1-熵权耦合赋权TOPSIS法对滑坡危险性评价具有较高的准确性,该方法可为其他地区滑坡地质灾害评价提供参考。展开更多
随着5G技术的不断发展,5G蜂窝网络已被广泛应用于城市地区。然而,基于5G的机会信号定位技术中存在着测距精度不高的问题。针对此问题,提出一种改进型5G机会信号定位算法,该算法将多信号分类(multiple signal classification,MUSIC)算法...随着5G技术的不断发展,5G蜂窝网络已被广泛应用于城市地区。然而,基于5G的机会信号定位技术中存在着测距精度不高的问题。针对此问题,提出一种改进型5G机会信号定位算法,该算法将多信号分类(multiple signal classification,MUSIC)算法与改进的早-晚功率锁相环(phase-locked loop,PLL)结合,不仅简化了锁相环结构,更保证了测距精度;同时搭建了基于5G机会信号定位的原理样机,并对改进算法方法的有效性和可行性进行了验证,试验结果表明伪距均方误差为3.03 m。本文所提出的算法不仅结构简单、系统稳定,而且在测距精度上也有一定的优势。展开更多
In star formation regions,the complex organic molecules(COMs)that contain peptide bonds(-NH-C(=O)-)play a major role in the metabolic process because-NH-C(=O)-is connected to amino acids(R-CHNH_2-COOH).Over the past f...In star formation regions,the complex organic molecules(COMs)that contain peptide bonds(-NH-C(=O)-)play a major role in the metabolic process because-NH-C(=O)-is connected to amino acids(R-CHNH_2-COOH).Over the past few decades,many COMs containing peptide-like bonds have been detected in hot molecular cores(HMCs),hot corinos,and cold molecular clouds,however,their prebiotic chemistry is poorly understood.We present the first detection of the rotational emission lines of formamide(NH_2CHO)and isocyanic acid(HNCO),which contain peptide-like bonds toward the chemically rich HMC G358.93-0.03 MM1,using high-resolution and high-sensitivity Atacama Large Millimeter/submillimeter Array bands 6 and 7.We estimate that the column densities of NH_2CHO and HNCO toward G358.93-0.03 MM1 are(2.80±0.29)×10~(15)cm~(-2)and(1.80±0.42)×10~(16)cm~(-2)with excitation temperatures of 165±21 K and 170±32 K,respectively.The fractional abundances of NH_2CHO and HNCO toward G358.93-0.03 MM1 are(9.03±1.44)×10~(-10)and(5.80±2.09)×10^(-9).We compare the estimated abundances of NH_2CHO and HNCO with the existing threephase warm-up chemical model abundance values and notice that the observed and modeled abundances are very close.We conclude that NH_2CHO is produced by the reaction of NH_2and H_2CO in the gas phase toward G358.93-0.03 MM1.Likewise,HNCO is produced on the surface of grains by the reaction of NH and CO toward G358.93-0.03 MM1.We also find that NH_2CHO and HNCO are chemically linked toward G358.93-0.03 MM1.展开更多
文摘四川西部地区地理环境复杂,滑坡空间结构多样且变形剧烈。为有效预防滑坡灾害,需要探究相关区域滑坡危险性可靠评价方法。利用G1-熵权耦合赋权逼近理想解排序法(technique for order preference by similarity to ideal solution,TOPSIS)构建滑坡灾害危险性评价模型,选取高程、降雨、地震动参数等12个评价因子,对雅砻江滑坡灾害危险性进行评价。依据贴近度将滑坡区域分为4个等级,即高危险区(0.75~1)、较高危险区(0.5~0.75)、中等危险区(0.25~0.5)和低危险区(0~0.25)。同时,对比了由差分干涉测量短基线集时序分析(small baseline subset interferometric synthetic aperture radar,SBAS-InSAR)技术得到的4个区域滑坡实测结果和本文评价模型的分析结果。利用G1-熵权耦合赋权TOPSIS得到九龙县烟袋镇桤木林村高生地滑坡、新龙县和平乡甲西村麻西滑坡、德格县年古乡政府滑坡和甘孜县扎科乡达玛滑坡的贴近度分别为0.854、0.686、0.405和0.224,由SBAS-InSAR技术得到滑坡前缘局部变形速率分别为-150、-43、-66、30 mm/a,二者之间有显著的对应关系,证明本文评价模型的准确性。应用G1-熵权耦合赋权TOPSIS法对滑坡危险性评价具有较高的准确性,该方法可为其他地区滑坡地质灾害评价提供参考。
文摘随着5G技术的不断发展,5G蜂窝网络已被广泛应用于城市地区。然而,基于5G的机会信号定位技术中存在着测距精度不高的问题。针对此问题,提出一种改进型5G机会信号定位算法,该算法将多信号分类(multiple signal classification,MUSIC)算法与改进的早-晚功率锁相环(phase-locked loop,PLL)结合,不仅简化了锁相环结构,更保证了测距精度;同时搭建了基于5G机会信号定位的原理样机,并对改进算法方法的有效性和可行性进行了验证,试验结果表明伪距均方误差为3.03 m。本文所提出的算法不仅结构简单、系统稳定,而且在测距精度上也有一定的优势。
文摘In star formation regions,the complex organic molecules(COMs)that contain peptide bonds(-NH-C(=O)-)play a major role in the metabolic process because-NH-C(=O)-is connected to amino acids(R-CHNH_2-COOH).Over the past few decades,many COMs containing peptide-like bonds have been detected in hot molecular cores(HMCs),hot corinos,and cold molecular clouds,however,their prebiotic chemistry is poorly understood.We present the first detection of the rotational emission lines of formamide(NH_2CHO)and isocyanic acid(HNCO),which contain peptide-like bonds toward the chemically rich HMC G358.93-0.03 MM1,using high-resolution and high-sensitivity Atacama Large Millimeter/submillimeter Array bands 6 and 7.We estimate that the column densities of NH_2CHO and HNCO toward G358.93-0.03 MM1 are(2.80±0.29)×10~(15)cm~(-2)and(1.80±0.42)×10~(16)cm~(-2)with excitation temperatures of 165±21 K and 170±32 K,respectively.The fractional abundances of NH_2CHO and HNCO toward G358.93-0.03 MM1 are(9.03±1.44)×10~(-10)and(5.80±2.09)×10^(-9).We compare the estimated abundances of NH_2CHO and HNCO with the existing threephase warm-up chemical model abundance values and notice that the observed and modeled abundances are very close.We conclude that NH_2CHO is produced by the reaction of NH_2and H_2CO in the gas phase toward G358.93-0.03 MM1.Likewise,HNCO is produced on the surface of grains by the reaction of NH and CO toward G358.93-0.03 MM1.We also find that NH_2CHO and HNCO are chemically linked toward G358.93-0.03 MM1.
