A deep foundation pit constructed for an underground transportation hub was excavated near the Yangtze River. Among the strata, there are two confined aquifers, between which lies an aquiclude that is partially missin...A deep foundation pit constructed for an underground transportation hub was excavated near the Yangtze River. Among the strata, there are two confined aquifers, between which lies an aquiclude that is partially missing. To guarantee the safety of pit excavation, the piezometric head of the upper confined aquifer, where the pit bottom is located, should be 1 m below the pit bottom, while that of the lower confined aquifer should be dewatered down to a safe water level to avoid uplift problem. The Yangtze River levee is notably close to the pit, and its deformation caused by dewatering should be controlled. A pumping test was performed to obtain the hydraulic conductivity of the upper confined aquifer. The average value of the hydraulic conductivity obtained from analytical calculation is 20.45 m/d, which is larger than the values from numerical simulation（horizontal hydraulic conductivity K_H = 16 m/d and vertical hydraulic conductivity K_V = S m/d）. The difference between K_H and K_V indicates the anisotropy of the aquifer. Two dewatering schemes were designed for the construction and simulated by the numerical models for comparison purposes. The results show that though the first scheme could meet the dewatering requirements, the largest accumulated settlement and differential settlement would be94.64 mm and 3.3‰, respectively, greatly exceeding the limited values. Meanwhile, the second scheme,in which the bottoms of the waterproof curtains in ramp B and the river side of ramp A are installed at a deeper elevation of-28 m above sea level, and 27 recharge wells are set along the levee, can control the deformation of the levee significantly.展开更多
目的应用四维自动左房定量技术(4D Auto LAQ)评价不同透析方式对尿毒症患者左房结构和功能的影响。方法选取于我院肾内科就诊的尿毒症患者80例,根据透析方式分为血液透析组39例和腹膜透析组41例,另选同期健康体检者35例作为正常对照组...目的应用四维自动左房定量技术(4D Auto LAQ)评价不同透析方式对尿毒症患者左房结构和功能的影响。方法选取于我院肾内科就诊的尿毒症患者80例,根据透析方式分为血液透析组39例和腹膜透析组41例,另选同期健康体检者35例作为正常对照组。应用常规超声心动图获取左室射血分数(LVEF)、左房内径(LAD)、左室舒张末期内径(LVEDD)、室间隔厚度(IVS)、左室后壁厚度(LVPW);4D Auto LAQ获取左房应变参数,包括左房储备期纵向应变(LASr)、左房管道期纵向应变(LAScd)、左房收缩期纵向应变(LASct)、左房储备期环形应变(LASr-c)、左房管道期环形应变(LAScd-c)、左房收缩期环形应变(LASct-c),以及左房容积参数,包括左房最大容积(LAVmax)、左房最小容积(LAVmin)、左房收缩前容积(LAVpreA)、左房射血分数(LAEF),比较各组上述参数的差异;分析LAEF与左房应变参数的相关性。结果①各组常规超声心动图参数比较:腹膜透析组和血液透析组LAD、LVEDD、IVS、LVPW均较正常对照组增大,差异均有统计学意义(均P<0.05);各组LVEF比较差异无统计学意义。②各组4D Auto LAQ左房应变参数比较:与正常对照组比较,腹膜透析组LASr、LAScd、LASr-c、LAScd-c均减小,LASct、LASct-c均增大,血液透析组LASr、LAScd、LASct、LASr-c、LAScd-c、LASct-c均减小,差异均有统计学意义(均P<0.05);除LAScd外,血液透析组LASr、LAScd、LASct、LASr-c、LAScd-c、LASct-c均较腹膜透析组减小,差异均有统计学意义(均P<0.05)。③各组4D Auto LAQ左房容积参数比较:与正常对照组比较,腹膜透析组LAVmax、LAVmin、LAVpreA均增大,LAEF减小,血液透析组LAVmax、LAVmin、LAVpreA均增大,LAEF减小,差异均有统计学意义(均P<0.05);与腹膜透析组比较,血液透析组LAVmax、LAmin、LAVpreA均增大,LAEF减小,差异均有统计学意义(均P<0.05)。④相关性分析显示,LAEF与LASr、LAScd、LASr-c、LAScd-c、LASct、LASct-c均呈正相关(r=0.531、0.522、0.705、0.686、0.306、0.376,均P<0.001)。结论4D Auto LAQ可用于评价不同透析方式对尿毒症患者左房结构和功能的影响,其中血液透析较腹膜透析对左房结构和功能影响更大。展开更多
Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-network...Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.展开更多
基金financially supported by the doctoral fund of the Ministry of Education of Chinathe Nature Science Foundation of Jiangsu Province, China (Grant Nos. 20130091110020 and BE2015675)
文摘A deep foundation pit constructed for an underground transportation hub was excavated near the Yangtze River. Among the strata, there are two confined aquifers, between which lies an aquiclude that is partially missing. To guarantee the safety of pit excavation, the piezometric head of the upper confined aquifer, where the pit bottom is located, should be 1 m below the pit bottom, while that of the lower confined aquifer should be dewatered down to a safe water level to avoid uplift problem. The Yangtze River levee is notably close to the pit, and its deformation caused by dewatering should be controlled. A pumping test was performed to obtain the hydraulic conductivity of the upper confined aquifer. The average value of the hydraulic conductivity obtained from analytical calculation is 20.45 m/d, which is larger than the values from numerical simulation（horizontal hydraulic conductivity K_H = 16 m/d and vertical hydraulic conductivity K_V = S m/d）. The difference between K_H and K_V indicates the anisotropy of the aquifer. Two dewatering schemes were designed for the construction and simulated by the numerical models for comparison purposes. The results show that though the first scheme could meet the dewatering requirements, the largest accumulated settlement and differential settlement would be94.64 mm and 3.3‰, respectively, greatly exceeding the limited values. Meanwhile, the second scheme,in which the bottoms of the waterproof curtains in ramp B and the river side of ramp A are installed at a deeper elevation of-28 m above sea level, and 27 recharge wells are set along the levee, can control the deformation of the levee significantly.
文摘目的应用四维自动左房定量技术(4D Auto LAQ)评价不同透析方式对尿毒症患者左房结构和功能的影响。方法选取于我院肾内科就诊的尿毒症患者80例,根据透析方式分为血液透析组39例和腹膜透析组41例,另选同期健康体检者35例作为正常对照组。应用常规超声心动图获取左室射血分数(LVEF)、左房内径(LAD)、左室舒张末期内径(LVEDD)、室间隔厚度(IVS)、左室后壁厚度(LVPW);4D Auto LAQ获取左房应变参数,包括左房储备期纵向应变(LASr)、左房管道期纵向应变(LAScd)、左房收缩期纵向应变(LASct)、左房储备期环形应变(LASr-c)、左房管道期环形应变(LAScd-c)、左房收缩期环形应变(LASct-c),以及左房容积参数,包括左房最大容积(LAVmax)、左房最小容积(LAVmin)、左房收缩前容积(LAVpreA)、左房射血分数(LAEF),比较各组上述参数的差异;分析LAEF与左房应变参数的相关性。结果①各组常规超声心动图参数比较:腹膜透析组和血液透析组LAD、LVEDD、IVS、LVPW均较正常对照组增大,差异均有统计学意义(均P<0.05);各组LVEF比较差异无统计学意义。②各组4D Auto LAQ左房应变参数比较:与正常对照组比较,腹膜透析组LASr、LAScd、LASr-c、LAScd-c均减小,LASct、LASct-c均增大,血液透析组LASr、LAScd、LASct、LASr-c、LAScd-c、LASct-c均减小,差异均有统计学意义(均P<0.05);除LAScd外,血液透析组LASr、LAScd、LASct、LASr-c、LAScd-c、LASct-c均较腹膜透析组减小,差异均有统计学意义(均P<0.05)。③各组4D Auto LAQ左房容积参数比较:与正常对照组比较,腹膜透析组LAVmax、LAVmin、LAVpreA均增大,LAEF减小,血液透析组LAVmax、LAVmin、LAVpreA均增大,LAEF减小,差异均有统计学意义(均P<0.05);与腹膜透析组比较,血液透析组LAVmax、LAmin、LAVpreA均增大,LAEF减小,差异均有统计学意义(均P<0.05)。④相关性分析显示,LAEF与LASr、LAScd、LASr-c、LAScd-c、LASct、LASct-c均呈正相关(r=0.531、0.522、0.705、0.686、0.306、0.376,均P<0.001)。结论4D Auto LAQ可用于评价不同透析方式对尿毒症患者左房结构和功能的影响,其中血液透析较腹膜透析对左房结构和功能影响更大。
基金financially supported by the National Natural Science Foundation of China (Nos. 52033011, 52173092 and 51973237)Natural Science Foundation of Guangdong Province(Nos. 2019B1515120038, 2020A1515011276 and 2021A1515010417)+4 种基金Science and Technology Planning Project of Guangzhou City (No. 202201011568)the Talented Program of Guizhou University (No. X2022008)Fundamental Research Funds for the Central Universities,Sun Yat-sen University (No. 23yxqntd002)GBRCE for Functional Molecular Engineering,the Youth Innovation Promotion Association,CAS(No. 2020010)Guangdong Basic and Applied Basic Research Foundation (No. 2021A1515110908)。
文摘Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.
