Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations.Localization based on the relative counts of different detectors has b...Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations.Localization based on the relative counts of different detectors has been widely used for all-sky gamma-ray monitors.There are two major methods for this count distribution localization:χ^(2)minimization method and the Bayesian method.Here we propose a modified Bayesian method that could take advantage of both the accuracy of the Bayesian method and the simplicity of the χ^(2)method.With comprehensive simulations,we find that our Bayesian method with Poisson likelihood is generally more applicable for various bursts than the χ^(2)method,especially for weak bursts.We further proposed a location-spectrum iteration approach based on the Bayesian inference,which could alleviate the problems caused by the spectral difference between the burst and location templates.Our method is very suitable for scenarios with limited computation resources or timesensitive applications,such as in-flight localization software,and low-latency localization for rapidly follow-up observations.展开更多
This paper aims to comprehensively analyze the influence of the principal stress angle rotation and intermediate principal stress on loess's strength and deformation characteristics. A hollow cylinder torsional sh...This paper aims to comprehensively analyze the influence of the principal stress angle rotation and intermediate principal stress on loess's strength and deformation characteristics. A hollow cylinder torsional shear apparatus was utilized to conduct tests on remolded samples under both normal and frozen conditions to investigate the mechanical properties and deformation behavior of loess under complex stress conditions. The results indicate significant differences in the internal changes of soil particles, unfrozen water, and relative positions in soil samples under normal and frozen conditions, leading to noticeable variations in strength and strain development.In frozen state, loess experiences primarily compressive failure with a slow growth of cracks, while at normal temperature, it predominantly exhibits shear failure. With the increase in the principal stress angle, the deformation patterns of the soil samples under different conditions become essentially consistent, gradually transitioning from compression to extension, accompanied by a reduction in axial strength. The gradual increase in the principal stress axis angle(α) reduces the strength of the generalized shear stress and shear strain curves.Under an increasing α, frozen soil exhibits strain-hardening characteristics, with the maximum shear strength occurring at α = 45°. The intermediate principal stress coefficient(b) also significantly impacts the strength of frozen soil, with an increasing b resulting in a gradual decrease in generalized shear stress strength. This study provides a reference for comprehensively exploring the mechanical properties of soil under traffic load and a reliable theoretical basis for the design and maintenance of roadbeds.展开更多
Catalytic hydrogenation of CO_(2) using renewable hydrogen not only reduces greenhouse gas emissions,but also provides industrial chemicals.Herein,a Co-Fe bimetallic catalyst was developed by a facile reactive ball-mi...Catalytic hydrogenation of CO_(2) using renewable hydrogen not only reduces greenhouse gas emissions,but also provides industrial chemicals.Herein,a Co-Fe bimetallic catalyst was developed by a facile reactive ball-milling method for highly active and selective hydrogenation of CO_(2) to value-added hydrocarbons.When reacted at 320℃,1.0 MPa and 9600 mL h^(-1) g_(cat)^(-1),the selectivity to light olefin(C_(2)^(=)-C_(4)^(=)) and C_(5)+ species achieves 57.3% and 22.3%,respectively,at a CO_(2) co nversion of 31.4%,which is superior to previous Fe-based catalysts.The CO_(2) activation can be promoted by the CoFe phase formed by reactive ball milling of the Fe-Co_(3)O_(4) mixture,and the in-situ Co_(2)C and Fe_(5)C_(2) formed during hydrogenation are beneficial for the C-C coupling reaction.The initial C-C coupling is related to the combination of CO species with the surface carbon of Fe/Co carbides,and the sustained C-C coupling is maintained by self-recovery of defective carbides.This new strategy contributes to the development of efficient catalysts for the hydrogenation of CO_(2) to value-added hydrocarbons.展开更多
Despite the fact that low-dimensional carbons(LDCs,1D/2D)materials are very interesting due to their intriguing electrical properties,we still attempt to enrich them by high N-content in order to enjoy their electro-a...Despite the fact that low-dimensional carbons(LDCs,1D/2D)materials are very interesting due to their intriguing electrical properties,we still attempt to enrich them by high N-content in order to enjoy their electro-applications.We here report a template-free synthesis of 1D/2D LDC with high N content(>40 at%)and tunable aspect ratios from molecular formamide(FA).The 1D/2D LDC is in polyaminoimidazole as confirmed by pair distribution function analysis,and 1D growth mode can be altered to 2D by simply adding a 2D-guiding molecule of melamine.Electrochemical properties of the LDC can befinely tuned by adjusting the solvothermal temperature and melamine dosage.It is revealed that the optimal 2D LDC delivers superior O2-to-H_(2)O_(2) yield(687.2 mmol⋅g^(-1)⋅h^(-1))and Faradic efficiency(87.5%).Considering the heavy N content and high adjustability of aspect ratio,the FAderived LDCs potentially open new synthesis routes for structural carbon materials for broad electrochemical applications.展开更多
Katok’s entropy formula is an important formula in entropy theory.It plays significant roles in large deviation theories,multifractal analysis,quantitative recurrence and so on.This paper is devoted to establishing K...Katok’s entropy formula is an important formula in entropy theory.It plays significant roles in large deviation theories,multifractal analysis,quantitative recurrence and so on.This paper is devoted to establishing Katok’s entropy formula of unstable metric entropy which is the entropy caused by the unstable part of partially hyperbolic systems.We also construct a similar formula which can be used to study the quantitative recurrence in the unstable manifold for partially hyperbolic diffeomorphisms.展开更多
Background:The widely accepted view that portal hypertension(PHT)is a con-traindication to hepatectomy for patients with hepatocellular carcinoma(HCC)is being increasingly challenged.The long-term survival outcomes an...Background:The widely accepted view that portal hypertension(PHT)is a con-traindication to hepatectomy for patients with hepatocellular carcinoma(HCC)is being increasingly challenged.The long-term survival outcomes and safety of partial hepatectomy versus interventional treatment using ablation with or without pre-ablation transarterial chemoembolization(TACE)in patients with HBV-related HCC within the Milan criteria and with clinically significant PHT were compared in this study.Methods:This open-label randomized clinical trial was conducted on consecu-tive patients with clinically PHT and hepatitis B virus(HBV)-related HCC with tumors which were within the Milan criteria.These patients were randomized 1:1 to receive either partial hepatectomy or interventional treatment between December 2012 and June 2018.The primary endpoint was overall survival(OS);secondary endpoints included recurrence-free survival(RFS)and therapeutic safety.Results:Each of the 2 groups had 80 patients.The 1-,3-and 5-year OS rates in the partial hepatectomy group and the interventional treatment group were 95.0%,86.2%,69.5%versus 93.8%,77.5%,64.9%,respectively(P=0.325).The corresponding RFS rates were 78.8%,55.0%,46.2%versus 71.3%,52.5%,45.0%,respectively(P=0.783).The partial hepatectomy group had a higher compli-cation rate compared to the interventional group(67.5%vs.20%,P<0.001).However,the differences were mainly in Clavien-Dindo Grade Ⅰ complications(P<0.001),while not significant in Grade Ⅱ/Ⅲ/Ⅳ/Ⅴ(All P>0.05).Conclusions:This study shows that partial hepatectomy treatment did not meet prespecified significance for improved OS and RFS compared to interventional treatment for patients with HBV-related HCC within the Milan criteria and with clinically significant PHT.However,partial hepatectomy is still a safe procedure and should be considered as a treatment option rather than a contraindication.展开更多
In eukaryotes,protein phosphorylation is specifically catalyzed by numerous protein kinases(PKs),faithfully orchestrates various biological processes,and reversibly determines cellular dynamics and plasticity.Here we ...In eukaryotes,protein phosphorylation is specifically catalyzed by numerous protein kinases(PKs),faithfully orchestrates various biological processes,and reversibly determines cellular dynamics and plasticity.Here we report an updated algorithm of Group-based Prediction System(GPS)5.0 to improve the performance for predicting kinase-specific phosphorylation sites(p-sites).Two novel methods,position weight determination(PWD)and scoring matrix optimization(SMO),were developed.Compared with other existing tools,GPS 5.0 exhibits a highly competitive accuracy.Besides serine/threonine or tyrosine kinases,GPS 5.0 also supports the prediction of dual-specificity kinase-specific p-sites.In the classical module of GPS 5.0,617 individual predictors were constructed for predicting p-sites of 479 human PKs.To extend the application of GPS5.0,a species-specific module was implemented to predict kinase-specific p-sites for 44,795 PKs in161 eukaryotes.The online service and local packages of GPS 5.0 are freely available for academic research at http://gps.biocuckoo.cn.展开更多
Cobalt has become a new type of barrier material with its unique advantages since the copper-interconnects in the great-large scale integrated circuits (GLSI) into 10 nm and below technical nodes, but cobalt and cop...Cobalt has become a new type of barrier material with its unique advantages since the copper-interconnects in the great-large scale integrated circuits (GLSI) into 10 nm and below technical nodes, but cobalt and copper have severe galvanic corrosion during chemical-mechanical flattening. The effect of 1,2,4-triazole on Co/Cu galvanic corrosion in alkaline slurry and the control of rate selectivity of copper and cobalt were investigated in this work. The results of electrochemical experiments and polishing experiments had indicated that a certain concentration of 1,2,4-triazole could form a layer of insoluble and dense passive film on the surface of cobalt and cop- per, which reduced the corrosion potential difference between cobalt and copper. Meantime, the removal rate of cobalt and copper could be effectively controlled according to demand during the CMP process. When the study optimized slurry was composed of 0.5 wt% colloidal silica, 0.1%vol. hydrogen peroxide, 0.05 wt% FA/O, 345 ppm 1,2,4-triazole, cobalt had higher corrosion potential than copper and the galvanic corrosion could be reduced effectively when the corrosion potential difference between them decreased to 1 mV and the galvanic corrosion current density reached 0.02 nA/cm2. Meanwhile, the removal rate of Co was 62.396 nm/min, the removal rate of Cu was 47.328 nm/min, so that the removal rate ratio of cobalt and copper was 1.32 : 1, which was a good amendment to the dishing pits. The contact potential corrosion of Co/Cu was very weak, which could be better for meeting the requirements of the barrier CMP.展开更多
Here we described the design and synthesis of a discrete 3D amphiphilic metallacage 4,in which the tetragonal prismatic frameworks act as the hydrophobic cores and the poly(ethylene glycol)(PEG)chains as the hydrophil...Here we described the design and synthesis of a discrete 3D amphiphilic metallacage 4,in which the tetragonal prismatic frameworks act as the hydrophobic cores and the poly(ethylene glycol)(PEG)chains as the hydrophilic tails.The structure of 4 was characterized by 1H NMR,31P NMR and electrospray ionization time-of-flight mass spectrometry(ESI-TOF-MS).Notably,4 with its Iong PEG tails was subsequently ordered into micelles at a low concentration(1.20×10^-6 mol/L)in water.As the concentration and cultivation time increased,the micelles can further self-assembly into nanofibers and nanoribbons.Considering the dynamic property of the coordination bond,these structures show reversible transformation under external stimuli.展开更多
This study provides the presence of carbonic anhydrase(CA) activity in waters of the Yangtze River basin, China, as well as the correlation of CA activity with HCO-3 concentration and CO2 sink flux. Different degree...This study provides the presence of carbonic anhydrase(CA) activity in waters of the Yangtze River basin, China, as well as the correlation of CA activity with HCO-3 concentration and CO2 sink flux. Different degrees of CA activity could be detected in almost all of the water samples from different geological eco-environments in all four seasons. The CA activity of water samples from karst areas was significantly higher than from non-karst areas(PP3-concentration(r = 0.672, P2 sink flux(r = 0.602, P = 0.076) in karst areas. This suggests that CA in waters might have a promoting effect on carbon sinks for atmospheric CO2 in karst river basins. In conditions of similar geological type, higher CA activity was generally detected in water samples taken from areas that exhibited better eco-environments, implying that the CA activity index of waters could be used as an indicator for monitoring ecological environments and protection of river basins. These findings suggest that the role of CA in waters in the karst carbon sink potential of river basins is worthy of further in-depth studies.展开更多
Marine microorganisms,especially marine fungi,have historically proven their value as a prolific source for structurally novel and pharmacologically active secondary metabolites(Deshmukh et al.,2018;Carroll et al.,202...Marine microorganisms,especially marine fungi,have historically proven their value as a prolific source for structurally novel and pharmacologically active secondary metabolites(Deshmukh et al.,2018;Carroll et al.,2022).The corals constitute a dominant part of reefs with the highest biodiversity,and harbor highly diverse and abundant microbial symbionts in their tissue,skeleton,and mucus layer,with species-specific core members that are spatially partitioned across coral microhabitats(Wang WQ et al.,2022).The coral-associated fungi were very recently found to be vital producers of structurally diverse compounds,terpenes,alkaloids,peptides,aromatics,lactones,and steroids.展开更多
Chemical mechanical polishing(CMP) is one of the important machining procedures of multilayered copper interconnection for GLSI, meanwhile polishing slurry is a critical factor for realizing the high polishing perfo...Chemical mechanical polishing(CMP) is one of the important machining procedures of multilayered copper interconnection for GLSI, meanwhile polishing slurry is a critical factor for realizing the high polishing performance such as high planarization efficiency, low surface roughness. The effect of slurry components such as abrasive(colloidal silica), complexing agent(glycine), inhibitor(BTA) and oxidizing agent(H_2O_2) on the stability of the novel weakly alkaline slurry of copper interconnection CMP for GLSI was investigated in this paper. First, the synergistic and competitive relationship of them in a peroxide-based weakly alkaline slurry during the copper CMP process was studied and the stability mechanism was put forward. Then 1 wt% colloidal silica, 2.5 wt% glycine,200 ppm BTA, 20 m L/L H_2O_2 had been selected as the appropriate concentration to prepare copper slurry, and using such slurry the copper blanket wafer was polished. From the variations of copper removal rate, root-mean square roughness(Sq) value with the setting time, it indicates that the working-life of the novel weakly alkaline slurry can reach more than 7 days, which satisfies the requirement of microelectronics further development.展开更多
基金supported by the National Key R&D Program of China(2021YFA0718500)support from the Strategic Priority Research Program on Space Science,the Chinese Academy of Sciences(grant Nos.XDA15360102,XDA15360300,XDA15052700 and E02212A02S)+1 种基金the National Natural Science Foundation of China(grant Nos.12173038 and U2038106)the National HEP Data Center(grant No.E029S2S1)。
文摘Fast and reliable localization of high-energy transients is crucial for characterizing the burst properties and guiding the follow-up observations.Localization based on the relative counts of different detectors has been widely used for all-sky gamma-ray monitors.There are two major methods for this count distribution localization:χ^(2)minimization method and the Bayesian method.Here we propose a modified Bayesian method that could take advantage of both the accuracy of the Bayesian method and the simplicity of the χ^(2)method.With comprehensive simulations,we find that our Bayesian method with Poisson likelihood is generally more applicable for various bursts than the χ^(2)method,especially for weak bursts.We further proposed a location-spectrum iteration approach based on the Bayesian inference,which could alleviate the problems caused by the spectral difference between the burst and location templates.Our method is very suitable for scenarios with limited computation resources or timesensitive applications,such as in-flight localization software,and low-latency localization for rapidly follow-up observations.
基金This work was supported by the National Natural Science Foundation of China(Nos.42161026&41801046)the Natural Science Foundation of Qinghai Province(No.2023-ZJ-934M)the Youth Research Foundation of Qinghai University(No.2022-QGY-5).
文摘This paper aims to comprehensively analyze the influence of the principal stress angle rotation and intermediate principal stress on loess's strength and deformation characteristics. A hollow cylinder torsional shear apparatus was utilized to conduct tests on remolded samples under both normal and frozen conditions to investigate the mechanical properties and deformation behavior of loess under complex stress conditions. The results indicate significant differences in the internal changes of soil particles, unfrozen water, and relative positions in soil samples under normal and frozen conditions, leading to noticeable variations in strength and strain development.In frozen state, loess experiences primarily compressive failure with a slow growth of cracks, while at normal temperature, it predominantly exhibits shear failure. With the increase in the principal stress angle, the deformation patterns of the soil samples under different conditions become essentially consistent, gradually transitioning from compression to extension, accompanied by a reduction in axial strength. The gradual increase in the principal stress axis angle(α) reduces the strength of the generalized shear stress and shear strain curves.Under an increasing α, frozen soil exhibits strain-hardening characteristics, with the maximum shear strength occurring at α = 45°. The intermediate principal stress coefficient(b) also significantly impacts the strength of frozen soil, with an increasing b resulting in a gradual decrease in generalized shear stress strength. This study provides a reference for comprehensively exploring the mechanical properties of soil under traffic load and a reliable theoretical basis for the design and maintenance of roadbeds.
基金supported by the National Natural Science Foundation of China (22008098, 21978156, 42002040)the Program for Innovative Research Team (in Science and Technology) in University of Henan Province (21IRTSTHN004)+1 种基金the Program for Science & Technology Innovation Talents in Universities of Henan Province (22HASTIT008)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (2022-K34)。
文摘Catalytic hydrogenation of CO_(2) using renewable hydrogen not only reduces greenhouse gas emissions,but also provides industrial chemicals.Herein,a Co-Fe bimetallic catalyst was developed by a facile reactive ball-milling method for highly active and selective hydrogenation of CO_(2) to value-added hydrocarbons.When reacted at 320℃,1.0 MPa and 9600 mL h^(-1) g_(cat)^(-1),the selectivity to light olefin(C_(2)^(=)-C_(4)^(=)) and C_(5)+ species achieves 57.3% and 22.3%,respectively,at a CO_(2) co nversion of 31.4%,which is superior to previous Fe-based catalysts.The CO_(2) activation can be promoted by the CoFe phase formed by reactive ball milling of the Fe-Co_(3)O_(4) mixture,and the in-situ Co_(2)C and Fe_(5)C_(2) formed during hydrogenation are beneficial for the C-C coupling reaction.The initial C-C coupling is related to the combination of CO species with the surface carbon of Fe/Co carbides,and the sustained C-C coupling is maintained by self-recovery of defective carbides.This new strategy contributes to the development of efficient catalysts for the hydrogenation of CO_(2) to value-added hydrocarbons.
基金supported by the National Natural Science Foundation of China(NSFC,22071137).
文摘Despite the fact that low-dimensional carbons(LDCs,1D/2D)materials are very interesting due to their intriguing electrical properties,we still attempt to enrich them by high N-content in order to enjoy their electro-applications.We here report a template-free synthesis of 1D/2D LDC with high N content(>40 at%)and tunable aspect ratios from molecular formamide(FA).The 1D/2D LDC is in polyaminoimidazole as confirmed by pair distribution function analysis,and 1D growth mode can be altered to 2D by simply adding a 2D-guiding molecule of melamine.Electrochemical properties of the LDC can befinely tuned by adjusting the solvothermal temperature and melamine dosage.It is revealed that the optimal 2D LDC delivers superior O2-to-H_(2)O_(2) yield(687.2 mmol⋅g^(-1)⋅h^(-1))and Faradic efficiency(87.5%).Considering the heavy N content and high adjustability of aspect ratio,the FAderived LDCs potentially open new synthesis routes for structural carbon materials for broad electrochemical applications.
基金supported by NNSF of China(12101446,11401581,11971236)The second author was supported by NNSF of China(11401581)+1 种基金the third author was supported by NNSF of China(11671208,11431012)At the end,we would like to express our gratitude to Tianyuan Mathematical Center in Southwest China,Sichuan University and Southwest Jiaotong University for their support and hospitality.
文摘Katok’s entropy formula is an important formula in entropy theory.It plays significant roles in large deviation theories,multifractal analysis,quantitative recurrence and so on.This paper is devoted to establishing Katok’s entropy formula of unstable metric entropy which is the entropy caused by the unstable part of partially hyperbolic systems.We also construct a similar formula which can be used to study the quantitative recurrence in the unstable manifold for partially hyperbolic diffeomorphisms.
基金supported by the grants from the Sun Yat-Sen University Clinical Research 5010 Programme(2012010)the National Natural Science Foundation of China(82272887).
文摘Background:The widely accepted view that portal hypertension(PHT)is a con-traindication to hepatectomy for patients with hepatocellular carcinoma(HCC)is being increasingly challenged.The long-term survival outcomes and safety of partial hepatectomy versus interventional treatment using ablation with or without pre-ablation transarterial chemoembolization(TACE)in patients with HBV-related HCC within the Milan criteria and with clinically significant PHT were compared in this study.Methods:This open-label randomized clinical trial was conducted on consecu-tive patients with clinically PHT and hepatitis B virus(HBV)-related HCC with tumors which were within the Milan criteria.These patients were randomized 1:1 to receive either partial hepatectomy or interventional treatment between December 2012 and June 2018.The primary endpoint was overall survival(OS);secondary endpoints included recurrence-free survival(RFS)and therapeutic safety.Results:Each of the 2 groups had 80 patients.The 1-,3-and 5-year OS rates in the partial hepatectomy group and the interventional treatment group were 95.0%,86.2%,69.5%versus 93.8%,77.5%,64.9%,respectively(P=0.325).The corresponding RFS rates were 78.8%,55.0%,46.2%versus 71.3%,52.5%,45.0%,respectively(P=0.783).The partial hepatectomy group had a higher compli-cation rate compared to the interventional group(67.5%vs.20%,P<0.001).However,the differences were mainly in Clavien-Dindo Grade Ⅰ complications(P<0.001),while not significant in Grade Ⅱ/Ⅲ/Ⅳ/Ⅴ(All P>0.05).Conclusions:This study shows that partial hepatectomy treatment did not meet prespecified significance for improved OS and RFS compared to interventional treatment for patients with HBV-related HCC within the Milan criteria and with clinically significant PHT.However,partial hepatectomy is still a safe procedure and should be considered as a treatment option rather than a contraindication.
基金Special Project on Precision Medicine under the National Key R&D Program of China(Grant Nos.2017YFC0906600 and 2018YFC0910500)National Natural Science Foundation of China(Grant Nos.31671360,81701567,and 31801095)+2 种基金National Program for Support of Top-Notch Young Professionals,Changjiang Scholars Program of Chinasupported by the program for HUST Academic Frontier Youth Team,Fundamental Research Funds for the Central Universities,China(Grant Nos.2017KFXKJC001 and 2019kfy RCPY043)China Postdoctoral Science Foundation(Grant Nos.2018M642816 and 2018M632870)
文摘In eukaryotes,protein phosphorylation is specifically catalyzed by numerous protein kinases(PKs),faithfully orchestrates various biological processes,and reversibly determines cellular dynamics and plasticity.Here we report an updated algorithm of Group-based Prediction System(GPS)5.0 to improve the performance for predicting kinase-specific phosphorylation sites(p-sites).Two novel methods,position weight determination(PWD)and scoring matrix optimization(SMO),were developed.Compared with other existing tools,GPS 5.0 exhibits a highly competitive accuracy.Besides serine/threonine or tyrosine kinases,GPS 5.0 also supports the prediction of dual-specificity kinase-specific p-sites.In the classical module of GPS 5.0,617 individual predictors were constructed for predicting p-sites of 479 human PKs.To extend the application of GPS5.0,a species-specific module was implemented to predict kinase-specific p-sites for 44,795 PKs in161 eukaryotes.The online service and local packages of GPS 5.0 are freely available for academic research at http://gps.biocuckoo.cn.
基金Project supported by the Major National Science and Technology Special Projects(No.2016ZX02301003-004-007)the Natural Science Foundation of Hebei Province,China(No.F2015202267)the Outstanding Young Science and Technology Innovation Fund of Hebei University of Technology(No.2015007)
文摘Cobalt has become a new type of barrier material with its unique advantages since the copper-interconnects in the great-large scale integrated circuits (GLSI) into 10 nm and below technical nodes, but cobalt and copper have severe galvanic corrosion during chemical-mechanical flattening. The effect of 1,2,4-triazole on Co/Cu galvanic corrosion in alkaline slurry and the control of rate selectivity of copper and cobalt were investigated in this work. The results of electrochemical experiments and polishing experiments had indicated that a certain concentration of 1,2,4-triazole could form a layer of insoluble and dense passive film on the surface of cobalt and cop- per, which reduced the corrosion potential difference between cobalt and copper. Meantime, the removal rate of cobalt and copper could be effectively controlled according to demand during the CMP process. When the study optimized slurry was composed of 0.5 wt% colloidal silica, 0.1%vol. hydrogen peroxide, 0.05 wt% FA/O, 345 ppm 1,2,4-triazole, cobalt had higher corrosion potential than copper and the galvanic corrosion could be reduced effectively when the corrosion potential difference between them decreased to 1 mV and the galvanic corrosion current density reached 0.02 nA/cm2. Meanwhile, the removal rate of Co was 62.396 nm/min, the removal rate of Cu was 47.328 nm/min, so that the removal rate ratio of cobalt and copper was 1.32 : 1, which was a good amendment to the dishing pits. The contact potential corrosion of Co/Cu was very weak, which could be better for meeting the requirements of the barrier CMP.
基金supported by the National Natural Science Foundation of China(No.21801139)Natural Science Foundation of Jiangsu Province(No.BK20180942)the Natural Science Foundation of Nantong University for High-Level Talent(No.03083004)。
文摘Here we described the design and synthesis of a discrete 3D amphiphilic metallacage 4,in which the tetragonal prismatic frameworks act as the hydrophobic cores and the poly(ethylene glycol)(PEG)chains as the hydrophilic tails.The structure of 4 was characterized by 1H NMR,31P NMR and electrospray ionization time-of-flight mass spectrometry(ESI-TOF-MS).Notably,4 with its Iong PEG tails was subsequently ordered into micelles at a low concentration(1.20×10^-6 mol/L)in water.As the concentration and cultivation time increased,the micelles can further self-assembly into nanofibers and nanoribbons.Considering the dynamic property of the coordination bond,these structures show reversible transformation under external stimuli.
基金supported by the Sub-project of Geological Survey Work Item of China Geological Survey Bureau (No. 12120113005200)the Fundamental Research Funds for the Central Universities (No. 2015QN102)
文摘This study provides the presence of carbonic anhydrase(CA) activity in waters of the Yangtze River basin, China, as well as the correlation of CA activity with HCO-3 concentration and CO2 sink flux. Different degrees of CA activity could be detected in almost all of the water samples from different geological eco-environments in all four seasons. The CA activity of water samples from karst areas was significantly higher than from non-karst areas(PP3-concentration(r = 0.672, P2 sink flux(r = 0.602, P = 0.076) in karst areas. This suggests that CA in waters might have a promoting effect on carbon sinks for atmospheric CO2 in karst river basins. In conditions of similar geological type, higher CA activity was generally detected in water samples taken from areas that exhibited better eco-environments, implying that the CA activity index of waters could be used as an indicator for monitoring ecological environments and protection of river basins. These findings suggest that the role of CA in waters in the karst carbon sink potential of river basins is worthy of further in-depth studies.
基金supported by the Guangxi Natural Science Foundation(Nos.2020GXNSFBA159001,2020GXNSF GA297002,and 2021GXNSFAA220052)the National Natural Science Foundation of China(Nos.U20A20101 and 22007019)+1 种基金the Special Fund for Bagui Scholars of Guangxi(Yonghong LIU)the Scientific Research Foundation of Guangxi University of Chinese Medicine(No.2022C038),China.
文摘Marine microorganisms,especially marine fungi,have historically proven their value as a prolific source for structurally novel and pharmacologically active secondary metabolites(Deshmukh et al.,2018;Carroll et al.,2022).The corals constitute a dominant part of reefs with the highest biodiversity,and harbor highly diverse and abundant microbial symbionts in their tissue,skeleton,and mucus layer,with species-specific core members that are spatially partitioned across coral microhabitats(Wang WQ et al.,2022).The coral-associated fungi were very recently found to be vital producers of structurally diverse compounds,terpenes,alkaloids,peptides,aromatics,lactones,and steroids.
基金supported by the Major National Science and Technology Special Projects(No.2016ZX02301003-004-007)the Professional Degree Teaching Case Foundation of Hebei Province,China(No.KCJSZ2017008)+1 种基金the Natural Science Foundation of Hebei Province,China(No.F2015202267)the Natural Science Foundation of Tianjin,China(No.16JCYBJC16100)
文摘Chemical mechanical polishing(CMP) is one of the important machining procedures of multilayered copper interconnection for GLSI, meanwhile polishing slurry is a critical factor for realizing the high polishing performance such as high planarization efficiency, low surface roughness. The effect of slurry components such as abrasive(colloidal silica), complexing agent(glycine), inhibitor(BTA) and oxidizing agent(H_2O_2) on the stability of the novel weakly alkaline slurry of copper interconnection CMP for GLSI was investigated in this paper. First, the synergistic and competitive relationship of them in a peroxide-based weakly alkaline slurry during the copper CMP process was studied and the stability mechanism was put forward. Then 1 wt% colloidal silica, 2.5 wt% glycine,200 ppm BTA, 20 m L/L H_2O_2 had been selected as the appropriate concentration to prepare copper slurry, and using such slurry the copper blanket wafer was polished. From the variations of copper removal rate, root-mean square roughness(Sq) value with the setting time, it indicates that the working-life of the novel weakly alkaline slurry can reach more than 7 days, which satisfies the requirement of microelectronics further development.