Impermeability of tunnel structural material after exposure to high temperature determines residual service life and security. The present study explores impermeability deterioration and water absorption change (expre...Impermeability of tunnel structural material after exposure to high temperature determines residual service life and security. The present study explores impermeability deterioration and water absorption change (expressed as w(T, t)) of tunnel structural material after exposure to 200℃, 300℃, 400℃, 500℃, and 600℃respectively. Structural cementitious material was devised according to the requirements of segment used in Yangtze River tunnel of Wuhan which has been in constructing. Effect of high temperature on impermeability is evaluated by impermeability deterioration factor (abbr. IDF) and w(T, t).Testing results indicate that impermeability of concrete decreases with the increase of temperature up to 600℃, and serious impermeability deterioration occurs at temperature above 300℃. Furthermore, concrete with higher impermeability is more sensitive to high temperature above 400℃.展开更多
The experimental study on the melting of potassic basalt and eclogite with about 2% waterat 800-1300℃ and 1.0-3.5 GPa shows that the solidi of both rocks are significantly lower thanthose obtained from the previous e...The experimental study on the melting of potassic basalt and eclogite with about 2% waterat 800-1300℃ and 1.0-3.5 GPa shows that the solidi of both rocks are significantly lower thanthose obtained from the previous experiments of the same type of rocks under dry conditions,and the former which is enriched in potassium has a lower melting point than the latter. It is con-sistent with the previous study. The melting temperature of eclogite increases with pressure,whereas potassic basalt has similar properties only at 1.5—2.5 GPa and>3.0 GPa, and at 2.5—3.0 GPa the melting temperature decreases with pressure. This can be explained as follows: (1)eclogite only has one hydrous mineral amphibole and the dehydous temperature is lower than thewet solidus of the rock. (2) Amphibole exists in potassic basalt at the pressures lower than 2.5GPa and phlogopite exists at pressures higher than 2.5 GPa, and the special compositions of bothminerals determine that amphibole has a dehydration temperature higher than or close to that ofthe wet solidus of the rocks, while phlogopite has a dehydration temperature lower than that ofthe wet solidus. On the other hand the features of the continuous solidus in the experiment ofhydrous eclogite were produced by the fact that the dehydration temperature of its amphibolelower than or close to the melting temperature of the hydrous conditions. So the melting tempera-ture lowers at higher pressures. Therefore, the composition of the rocks in the lithosphere and thetypes of hydrous minerals and their stable P-T conditions are the important factors controllingthe solidi of rocks. It can quite well explain the partial melting of rocks and the origin of the lowvelocity zone in the deep lithosphere.展开更多
High temperature（1 270–1 550 oC） and high pressure（1.0 GPa） experimental studies on Re-bearing capabilities of pyrite, galena and sphalerite from typical Pb-Zn ore deposits were performed on a six-anvil apparatus...High temperature（1 270–1 550 oC） and high pressure（1.0 GPa） experimental studies on Re-bearing capabilities of pyrite, galena and sphalerite from typical Pb-Zn ore deposits were performed on a six-anvil apparatus. We observed microstructures of the quenched sulfides using scanning electron microscope（SEM） and analyzed compositions of the run products using both energy disperse spectroscopy（EDS） and electron probe microanalyzer（EPMA）. The results show that pyrite melt can dissolve much more metallic Re than galena and sphalerite melts, forming scattered acicular ReS_2 in the quenched matrix of pyrrhotite（Fe_（1-x）S）. The quenched matrixes of Fe_（1-x）S, PbS and ZnS generally contain less than 1.0 wt.% of Re and their Re-bearing capabilities seem to range as Fe_（1-x）S〉Pb S〉Zn S. However, Re partition coefficients between them are difficult to estimate, because Re distribution is inhomogeneous in the quenched sulfide matrixes.展开更多
By using compression factors of real gas and the Vilia equations and considering the variation of the thermophysical parameters of the mois air with its temperature, this paper develops the calculating equations of th...By using compression factors of real gas and the Vilia equations and considering the variation of the thermophysical parameters of the mois air with its temperature, this paper develops the calculating equations of the thermophysical para leters of the moist air at high temperature ranging from 100℃- 200℃. It is convenient to calculate the thermophysical parameters and the thermophysical processes of the moist air at high temperature.展开更多
We report a theoretical investigation into superconductivity within the MAXH_(6) quaternary hydride system using first-principles calculations,where M and A denote alkali and alkaline earth elements,respectively,and X...We report a theoretical investigation into superconductivity within the MAXH_(6) quaternary hydride system using first-principles calculations,where M and A denote alkali and alkaline earth elements,respectively,and X represents transition metal elements.Systematic analysis of electronic band structures,phonon dispersions,and electron-phonon coupling reveals that substitution of MA binary metal combinations and X metal atoms can create favorable conditions for superconductivity.Mapping of superconducting critical temperatures,combined with dynamical stability analysis through phonon calculations,identifies ten superconducting candidates at ambient pressure.Among these,LiNaAgH_(6) exhibits nearly-free-electron behavior reminiscent of monovalent electron superconductors.It demonstrates exceptional superconducting properties with electron–phonon coupling λ=2.707,which yields a superconducting transition temperature T_(c) of 206.4 K using the Allen–Dynes formula.Its structural analogs MgNaPdH_(6),LiMgPdH_(6),LiMgAgH_(6),LiMgAuH_(6) all exhibit superconducting transition temperatures above 110 K.These findings advance our fundamental understanding of superconductivity in quaternary hydrides and provide guidance for rational design of new high-temperature superconducting materials.展开更多
It is often challenging to diagnose acute myocardial infarction(AMI)in patients with elevated high-sensitivity cardiac troponin T(hs-cTnT)before observing a significant rise and/or fall in hs-cTnT.The current study ai...It is often challenging to diagnose acute myocardial infarction(AMI)in patients with elevated high-sensitivity cardiac troponin T(hs-cTnT)before observing a significant rise and/or fall in hs-cTnT.The current study aimed to identify an optimal cut-off to rule in AMI.A total of 76411 patients with elevated hs-cTnT were included.The predictive cut-off values for diagnosing ST-segment elevation myocardial infarction(STEMI)and non-STsegment elevation myocardial infarction(NSTEMI)were assessed using the area under the receiver operating characteristic curve(AUC).Among the patients,50466(66.0%)had non-cardiac diseases,25945(34.0%)had cardiac diseases,and 15502(20.3%)had AMI,including 816(1.1%)with STEMI and 14686(19.2%)with NSTEMI.The median hs-cTnT level was 3788.0 ng/L in STEMI patients and 67.2 ng/L in NSTEMI patients.The optimal cut-off for diagnosing STEMI was 251.9 ng/L,with a sensitivity of 90.7%,specificity of 86.5%,and an AUC of 0.942;the optimal cut-off for diagnosing NSTEMI was 130.5 ng/L,with a sensitivity of 40.9%,specificity of 83.8%,and an AUC of 0.638.Collectively,optimizing the cut-off values for diagnosing STEMI and NSTEMI to 251.9 ng/L and 130.5 ng/L,respectively,demonstrated high accuracy in a large cohort of Chinese patients with elevated hs-cTnT.展开更多
目的:探讨宫颈癌患者外周血中CD4^+CD25^(+high)调节性T(regulator T cells,Tr)的表达及意义。方法:采用流式细胞术检测52例宫颈癌患者,35例健康女性外周血中CD4^+CD25^(+high)Tr、细胞毒性T细胞(cytotoxic T lymphocytes,CTL)和NK细胞...目的:探讨宫颈癌患者外周血中CD4^+CD25^(+high)调节性T(regulator T cells,Tr)的表达及意义。方法:采用流式细胞术检测52例宫颈癌患者,35例健康女性外周血中CD4^+CD25^(+high)Tr、细胞毒性T细胞(cytotoxic T lymphocytes,CTL)和NK细胞,采用ELISA检测血清中-干扰素(interferon,IFN-)的表达水平。结果:宫颈癌患者外周血CD4^+CD25^(+high)Tr占CD4^+T淋巴细胞的百分比为(7.18±2.32)%,高于健康女性组(P<0.05);宫颈癌患者外周血CD4^+CD25^(+high)Tr水平与CTL、NK细胞及IFN-水平呈负相关。结论:宫颈癌患者外周血中具免疫抑制活性的CD4^+CD25^(+high)Tr水平较高,参与宫颈癌患者的肿瘤免疫抑制。展开更多
基金Funded by National High-Tech Research and Development Program of China(No.2005AA332010)
文摘Impermeability of tunnel structural material after exposure to high temperature determines residual service life and security. The present study explores impermeability deterioration and water absorption change (expressed as w(T, t)) of tunnel structural material after exposure to 200℃, 300℃, 400℃, 500℃, and 600℃respectively. Structural cementitious material was devised according to the requirements of segment used in Yangtze River tunnel of Wuhan which has been in constructing. Effect of high temperature on impermeability is evaluated by impermeability deterioration factor (abbr. IDF) and w(T, t).Testing results indicate that impermeability of concrete decreases with the increase of temperature up to 600℃, and serious impermeability deterioration occurs at temperature above 300℃. Furthermore, concrete with higher impermeability is more sensitive to high temperature above 400℃.
基金Note:This study was supported by China National Natural Science Foundation Grant No.49070087.
文摘The experimental study on the melting of potassic basalt and eclogite with about 2% waterat 800-1300℃ and 1.0-3.5 GPa shows that the solidi of both rocks are significantly lower thanthose obtained from the previous experiments of the same type of rocks under dry conditions,and the former which is enriched in potassium has a lower melting point than the latter. It is con-sistent with the previous study. The melting temperature of eclogite increases with pressure,whereas potassic basalt has similar properties only at 1.5—2.5 GPa and>3.0 GPa, and at 2.5—3.0 GPa the melting temperature decreases with pressure. This can be explained as follows: (1)eclogite only has one hydrous mineral amphibole and the dehydous temperature is lower than thewet solidus of the rock. (2) Amphibole exists in potassic basalt at the pressures lower than 2.5GPa and phlogopite exists at pressures higher than 2.5 GPa, and the special compositions of bothminerals determine that amphibole has a dehydration temperature higher than or close to that ofthe wet solidus of the rocks, while phlogopite has a dehydration temperature lower than that ofthe wet solidus. On the other hand the features of the continuous solidus in the experiment ofhydrous eclogite were produced by the fact that the dehydration temperature of its amphibolelower than or close to the melting temperature of the hydrous conditions. So the melting tempera-ture lowers at higher pressures. Therefore, the composition of the rocks in the lithosphere and thetypes of hydrous minerals and their stable P-T conditions are the important factors controllingthe solidi of rocks. It can quite well explain the partial melting of rocks and the origin of the lowvelocity zone in the deep lithosphere.
基金supported by the National Natural Science Foundation of China (No.41430315)the National Basic Research Program of China (No.2014CB440905)
文摘High temperature（1 270–1 550 oC） and high pressure（1.0 GPa） experimental studies on Re-bearing capabilities of pyrite, galena and sphalerite from typical Pb-Zn ore deposits were performed on a six-anvil apparatus. We observed microstructures of the quenched sulfides using scanning electron microscope（SEM） and analyzed compositions of the run products using both energy disperse spectroscopy（EDS） and electron probe microanalyzer（EPMA）. The results show that pyrite melt can dissolve much more metallic Re than galena and sphalerite melts, forming scattered acicular ReS_2 in the quenched matrix of pyrrhotite（Fe_（1-x）S）. The quenched matrixes of Fe_（1-x）S, PbS and ZnS generally contain less than 1.0 wt.% of Re and their Re-bearing capabilities seem to range as Fe_（1-x）S〉Pb S〉Zn S. However, Re partition coefficients between them are difficult to estimate, because Re distribution is inhomogeneous in the quenched sulfide matrixes.
文摘By using compression factors of real gas and the Vilia equations and considering the variation of the thermophysical parameters of the mois air with its temperature, this paper develops the calculating equations of the thermophysical para leters of the moist air at high temperature ranging from 100℃- 200℃. It is convenient to calculate the thermophysical parameters and the thermophysical processes of the moist air at high temperature.
基金supported by the National Key R&D Program of China (Grant No.2022YFA1403201)the National Natural Science Foundation of China (Grant Nos.12125404,T2495231,123B2049,and 12204138)+9 种基金the Advanced MaterialsNational Science and Technology Major Project (Grant No.2024ZD0607000)the Natural Science Foundation of Jiangsu Province (Grant Nos.BK20233001 and BK20253009)the Jiangsu Funding Program for Excellent Postdoctoral Talent (Grant No.2024ZB002)the China Postdoctoral Science Foundation (Grant No.2025M773331)the Fundamental and Interdisciplinary Disciplines Breakthrough Plan of the Ministry of Education of Chinathe AI&AI for Science program of Nanjing UniversityArtificial Intelligence and Quantum physics (AIQ) program of Nanjing Universitythe Fundamental Research Funds for the Central Universitiesthe Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant Nos.NY224165,NY220038,and NY219087)the Hua Li Talents Program of Nanjing University of Posts and Telecommunications。
文摘We report a theoretical investigation into superconductivity within the MAXH_(6) quaternary hydride system using first-principles calculations,where M and A denote alkali and alkaline earth elements,respectively,and X represents transition metal elements.Systematic analysis of electronic band structures,phonon dispersions,and electron-phonon coupling reveals that substitution of MA binary metal combinations and X metal atoms can create favorable conditions for superconductivity.Mapping of superconducting critical temperatures,combined with dynamical stability analysis through phonon calculations,identifies ten superconducting candidates at ambient pressure.Among these,LiNaAgH_(6) exhibits nearly-free-electron behavior reminiscent of monovalent electron superconductors.It demonstrates exceptional superconducting properties with electron–phonon coupling λ=2.707,which yields a superconducting transition temperature T_(c) of 206.4 K using the Allen–Dynes formula.Its structural analogs MgNaPdH_(6),LiMgPdH_(6),LiMgAgH_(6),LiMgAuH_(6) all exhibit superconducting transition temperatures above 110 K.These findings advance our fundamental understanding of superconductivity in quaternary hydrides and provide guidance for rational design of new high-temperature superconducting materials.
基金funded in part by the National Key R&D Program of China(Grant No.2022YFC2402404)the National Natural Science Foundation of China(Grant Nos.82170351 and 82370342)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20222002 and BK20231145)the Clinical Capacity Enhancement Project of Jiangsu Province Hospital(the First Affiliated Hospital of Nanjing Medical University)(Grant No.J SPH-MA-2022-3)。
文摘It is often challenging to diagnose acute myocardial infarction(AMI)in patients with elevated high-sensitivity cardiac troponin T(hs-cTnT)before observing a significant rise and/or fall in hs-cTnT.The current study aimed to identify an optimal cut-off to rule in AMI.A total of 76411 patients with elevated hs-cTnT were included.The predictive cut-off values for diagnosing ST-segment elevation myocardial infarction(STEMI)and non-STsegment elevation myocardial infarction(NSTEMI)were assessed using the area under the receiver operating characteristic curve(AUC).Among the patients,50466(66.0%)had non-cardiac diseases,25945(34.0%)had cardiac diseases,and 15502(20.3%)had AMI,including 816(1.1%)with STEMI and 14686(19.2%)with NSTEMI.The median hs-cTnT level was 3788.0 ng/L in STEMI patients and 67.2 ng/L in NSTEMI patients.The optimal cut-off for diagnosing STEMI was 251.9 ng/L,with a sensitivity of 90.7%,specificity of 86.5%,and an AUC of 0.942;the optimal cut-off for diagnosing NSTEMI was 130.5 ng/L,with a sensitivity of 40.9%,specificity of 83.8%,and an AUC of 0.638.Collectively,optimizing the cut-off values for diagnosing STEMI and NSTEMI to 251.9 ng/L and 130.5 ng/L,respectively,demonstrated high accuracy in a large cohort of Chinese patients with elevated hs-cTnT.
文摘目的:探讨宫颈癌患者外周血中CD4^+CD25^(+high)调节性T(regulator T cells,Tr)的表达及意义。方法:采用流式细胞术检测52例宫颈癌患者,35例健康女性外周血中CD4^+CD25^(+high)Tr、细胞毒性T细胞(cytotoxic T lymphocytes,CTL)和NK细胞,采用ELISA检测血清中-干扰素(interferon,IFN-)的表达水平。结果:宫颈癌患者外周血CD4^+CD25^(+high)Tr占CD4^+T淋巴细胞的百分比为(7.18±2.32)%,高于健康女性组(P<0.05);宫颈癌患者外周血CD4^+CD25^(+high)Tr水平与CTL、NK细胞及IFN-水平呈负相关。结论:宫颈癌患者外周血中具免疫抑制活性的CD4^+CD25^(+high)Tr水平较高,参与宫颈癌患者的肿瘤免疫抑制。
