The tensile properties and deformation mechanisms of the reduced activation ferritic/martensitic steel—China low activation martensitic(CLAM)steel are determined from tests carried out over a wider range of strain ra...The tensile properties and deformation mechanisms of the reduced activation ferritic/martensitic steel—China low activation martensitic(CLAM)steel are determined from tests carried out over a wider range of strain rate and temperature.During high-temperature deformation,the plastic deformation modes involve dynamic recrystallization(DRX)and dynamic recovery(DRV)processes,which govern the mechanical behaviors of CLAM steel under different loading conditions.This work systematically explored the effects of increasing strain rates and temperatures,finding that the microstructure evolution process is facilitated by nano-sized M_(23)C_(6)precipitates and the grain boundaries of the initial microstructure.Under quasi-static loading conditions,DRX grains preferentially nucleate around M_(23)C_(6) precipitates,and the dominant deformation mechanism is DRX.However,under dynamic loading conditions,the number of DRX grains decreases significantly,and the dominant deformation mechanism converts to DRV.It was concluded that the coupling effects of strain rates and temperatures strongly influence DRX and DRV processes,which ultimately determine the mechanical properties and microstructure evolution.Moreover,dynamic deformation at elevated temperatures achieves much finer grain sizes,offering a novel method for grain refinement through dynamic straining processes.展开更多
Photocatalysis is considered a promising technique for removal of pollutants from indoor air.However,the low selectivity and limited recyclability of photocatalysts in powder form currently limit their practical appli...Photocatalysis is considered a promising technique for removal of pollutants from indoor air.However,the low selectivity and limited recyclability of photocatalysts in powder form currently limit their practical application.In this work,we reported the successful preparation of a monolithic tungsten oxide(WO3)/graphene oxide(GO)aerogel photocatalyst through a cost‐effective freeze‐drying method.GO not only acts as a macroscopic support,but also increases the catalyst surface area from 46 to 57 m2/g,enhances the light absorption in the visible‐light region,and raises the separation efficiency of photogenerated electron‐hole pairs.The Obtained WO3/GO aerogel exhibited an outstanding visible‐light photocatalytic degradation rate of nitric oxide of 51%,which was 3.3 times that of pristine WO3 powder.In addition,the aerogel displayed excellent selectivity,with a generation fraction of toxic nitrogen dioxide of as low as 0.5%.This work presents a facile synthesis route to fabricate a monolithic WO3/GO aerogel photocatalyst with great promise for air purification.展开更多
Gradient nanostructure was introduced to enhance the strength and ductility via deformation incompatibility accommodated by geometrical necessary dislocations for most metallic materials recently.However,few intensive...Gradient nanostructure was introduced to enhance the strength and ductility via deformation incompatibility accommodated by geometrical necessary dislocations for most metallic materials recently.However,few intensive researches were carried out to investigate the effect of gradient structure on the deformation twin evolution and resulting performance improvements.In the present paper,we produced gradient-structured AZ31 Mg alloy with fine-grain layers,parallel twin laminates and a coarse-grain core from two upmost surfaces to the center of plate.Surprisingly,this architected Mg alloy exhibited simultaneous enhancement of strength and ductility.Subsequent microstructural observations demonstrated that abundant twin-twin interactions resulting from higher strength and multi-axial stress state could make great contributions to the increase of work-hardening capability.This was further proved by the measurement of full-field strain evolution during the plastic deformation.Such a design strategy may provide a new path for producing advanced structure materials in which the deformation twinning works as one of the dominant plasticity mechanisms.展开更多
The hypoxia-inducible factor-1α（HIF-1α） plays an important role in regulating angiogenesis, which is essential for tumor growth and metastasis. Genetic variations of HIFIA （coding HIF-1α） have been shown to inf...The hypoxia-inducible factor-1α（HIF-1α） plays an important role in regulating angiogenesis, which is essential for tumor growth and metastasis. Genetic variations of HIFIA （coding HIF-1α） have been shown to influence an individual＇s susceptibility to many human tumors; however, evidence on associations between HIFIA single-nucleotide polymorphisms （SNPs） and prostate cancer （PCa） risk is conflicting. We genotyped three potentially functional polymorphisms in HIFIA （rs11549465, rs11549467 and rs2057482） using the TaqMan method and assessed their associations with PCa risk in a case-control study of 662 PCa patients and 716 controls in a Chinese Hart population. Compared with rs 11549467 GG genotype, the variant genotypes GA ＋AA had a significantly increased PCa risk （adjusted odds ratio （OR）= 1.70; 95% confidence interval （C1）= 1.06-2.72）, particularly among older patients （0R=2.01; 95%C1 = 1.05-3.86）, smokers （0R=2.06; 95%C1 = 1.07-3.99）, never drinkers （OR=2.16; 95%C1 = 1.20-3.86） and patients without a family history of cancer （OR= 1.71; 95%C1= 1.02-2.89）. Furthermore, patients with rs11549467 variant genotypes were associated with a higher Gleason score （OR=2.14; 95%CI = 1.22-3.75）. No altered PCa risk was associated with the rs 11549465 and rs2057482 polymorphism. However, the combined variant genotypes of rs2057482 and rs 11549467 were associated with increased PCa risk （0R=2.10; 95%C1= 1.23-3.57 among subjects carrying three or more risk alleles）. These results suggest that HIFIA polymorphisms may impact PCa susceptibility and progression in the Chinese Han population.展开更多
This study was designed to evaluate whether the revised 2010 Tumour Node Metastasis （TNM） staging system could lead to a more accurate prediction of the prognosis of renal cell carcinoma （RCC） patients. A total of...This study was designed to evaluate whether the revised 2010 Tumour Node Metastasis （TNM） staging system could lead to a more accurate prediction of the prognosis of renal cell carcinoma （RCC） patients. A total of 1216 patients who had undergone radical nephrectomy or partial nephrectomy for RCC from 2003 to 2011 were enrolled. All of the patients had pathologically confirmed clear cell RCC （ccRCC）. All cases were staged by both the 2002 and 2010 TNM staging systems after pathological review, and survival data were collected. Univariate and multivariate Cox regression models were used to evaluate cancer-specific survival （CSS） and progression-free survival （PFS） after surgery. Continuous variables, such as age and tumour diameter, were calculated as mean values and standard deviations （s.d.） or as median values. Survival was calculated by the Kaplan-Meier method, and the log-rank test assessed differences between groups. Statistically significant differences in CSS and PFS were noted among patients in T3 subgroups using the new 2010 staging system. Therefore, the revised 2010 TNM staging system can lead to a more accurate prediction of the prognosis of ccRCC patients. However, when using the revised 2010 staging system, we found that more than 92% of patients （288/313） with T3 tumours were staged in the T3a subgroup, and their survival data were not significantly different from those of patients with T2b tumours. In addition, T2 subclassification failed to independently predict survival in RCC patients.展开更多
Cotton(Gossypium hirsutum L.)fibers are derived from the outer integument of ovule,while little is known about cotton ovule development.In order to identify and analyze the expression of genes associated with cotton o...Cotton(Gossypium hirsutum L.)fibers are derived from the outer integument of ovule,while little is known about cotton ovule development.In order to identify and analyze the expression of genes associated with cotton ovule development,a cDNA array approach was used to screen for genes with altered expression in cotton ovule before and after anthesis,and 25 differentially expressed genes were subsequently identified.Among them,GhlAA16 encodes a predicted polypeptide of 208 amino acids highly homologous to Arabidopsis IAA16.Molecular analysis revealed that it is a single-copy gene in cotton genome and specifically expressed in the ovule endothelium.To our knowledge,GhlAA16 is the first endothelium-specific gene isolated from cotton.Its possible function is discussed during cotton ovule formation.展开更多
The origin and spatial-temporal variation of the Earth’s magnetic field(EMF)is one of the important scientific problems that has long been unsolved.The Macao Science Satellite-1(MSS-1)under construction is China’s f...The origin and spatial-temporal variation of the Earth’s magnetic field(EMF)is one of the important scientific problems that has long been unsolved.The Macao Science Satellite-1(MSS-1)under construction is China’s first high-precision EMF measurement satellite.To satisfy the highly precise requirements of the MSS-1 orbit measurement,a light,high-precision,four-prism laser retroreflector array was designed.It weighs approximately 285 g,its effective reflection area is greater than 1.77 cm^(2),and its size is 100×100×41 mm.The laser retro-reflector array has excellent performance,and it can achieve a ranging precision at the subcentimeter level for satellite laser ranging.It will be developed and installed on the MSS-1 as a power-free load for high-precision orbit measurement and accurate orbit calibration.The MSS-1 is planned to be brought into the International Laser Ranging Service observations.More than 31satellite laser ranging stations in the International Laser Ranging Service around the world will be able to measure the MSS-1 with long arcs,which will support the scientific mission of high-precision EMF exploration.展开更多
A cDNA library was successfully constructed from Anip973,a human lung adenocarcinoma cell line with high metastatic potential.NIH3T3 cells were stably transfected using this cDNA library and screened for morphological...A cDNA library was successfully constructed from Anip973,a human lung adenocarcinoma cell line with high metastatic potential.NIH3T3 cells were stably transfected using this cDNA library and screened for morphological changes in a soft agar assay.Genomic DNA was isolated from putative clones and the integrated sequence was retrieved by PCR and sequencing.Three known genes,ribosomal protein L23,hypothetical protein FLJ22104,and serine protease inhibitor,kazal type 6 and a number of 5'-terminally truncated sequences were identified.Furthermore,cells transfected with ribosomal protein L23 was highly invasive compared with the empty vector as control(P〈0.02).These results indicate that the expression cloning of cDNA libraries in NIH3T3 cells and subsequent screening for loss of contact inhibition in soft agar is a viable tool for identifying tumor-related genes and ribosomal protein L23 gene plays a role in cell movement and metastasis.展开更多
This study examines the effects of macroscopic bending and microscopic contact loading in inhomogeneous materials using a semi-analytical model based on Eshelby’s equivalent inclusion method.The model accounts for be...This study examines the effects of macroscopic bending and microscopic contact loading in inhomogeneous materials using a semi-analytical model based on Eshelby’s equivalent inclusion method.The model accounts for bending effects through the beam theory,with bending stress included in the Eshelby’s equivalent inclusion equations.The macroscopic displacement resulting from bending effects is incorporated into the microscopic contact solver,and the final displacement is determined using the conjugate gradient method in an iterative solution.Computational efficiency can be improved by incorporating the discrete convolution and fast Fourier transform.The core scheme is validated using the finite element method,yielding accurate and efficient results for bending-contact problems in inhomogeneous materials.Simulations reveal the interplay between bending,contact loading,and inhomogeneity,as stress around the inhomogeneity alters and the stress concentration area expands under increasing bending moments.Conversely,low-magnitude negative bending moments reduce both contact pressure and stress around the inhomogeneity.The position where inhomogeneities are least affected shifts from the neutral surface depending on the coupling effect.The model provides a valuable bridge for connecting the macroscopic bending effect and microscale contact-inhomogeneity problems by visualizing stress fields and assessing pressure distributions.展开更多
Audio signal separation is an open and challenging issue in the classical“Cocktail Party Problem”.Especially in a reverberation environment,the separation of mixed signals is more difficult separated due to the infl...Audio signal separation is an open and challenging issue in the classical“Cocktail Party Problem”.Especially in a reverberation environment,the separation of mixed signals is more difficult separated due to the influence of reverberation and echo.To solve the problem,we propose a determined reverberant blind source separation algorithm.The main innovation of the algorithm focuses on the estimation of the mixing matrix.A new cost function is built to obtain the accurate demixing matrix,which shows the gap between the prediction and the actual data.Then,the update rule of the demixing matrix is derived using Newton gradient descent method.The identity matrix is employed as the initial demixing matrix for avoiding local optima problem.Through the real-time iterative update of the demixing matrix,frequency-domain sources are obtained.Then,time-domain sources can be obtained using an inverse short-time Fourier transform.Experi-mental results based on a series of source separation of speech and music mixing signals demonstrate that the proposed algorithm achieves better separation performance than the state-of-the-art methods.In particular,it has much better superiority in the highly reverberant environment.展开更多
基金financially supported by National Natural Science Foundation of China(Grant Nos.12025205 and 12141203)Natural Science Basic Research Program of Shaanxi(Program No.S2023-JC-QN-0614)Fund for Basic Research(No.2021T019)from the Analytical&Testing Center of Northwestern Polytechnical University.
文摘The tensile properties and deformation mechanisms of the reduced activation ferritic/martensitic steel—China low activation martensitic(CLAM)steel are determined from tests carried out over a wider range of strain rate and temperature.During high-temperature deformation,the plastic deformation modes involve dynamic recrystallization(DRX)and dynamic recovery(DRV)processes,which govern the mechanical behaviors of CLAM steel under different loading conditions.This work systematically explored the effects of increasing strain rates and temperatures,finding that the microstructure evolution process is facilitated by nano-sized M_(23)C_(6)precipitates and the grain boundaries of the initial microstructure.Under quasi-static loading conditions,DRX grains preferentially nucleate around M_(23)C_(6) precipitates,and the dominant deformation mechanism is DRX.However,under dynamic loading conditions,the number of DRX grains decreases significantly,and the dominant deformation mechanism converts to DRV.It was concluded that the coupling effects of strain rates and temperatures strongly influence DRX and DRV processes,which ultimately determine the mechanical properties and microstructure evolution.Moreover,dynamic deformation at elevated temperatures achieves much finer grain sizes,offering a novel method for grain refinement through dynamic straining processes.
文摘Photocatalysis is considered a promising technique for removal of pollutants from indoor air.However,the low selectivity and limited recyclability of photocatalysts in powder form currently limit their practical application.In this work,we reported the successful preparation of a monolithic tungsten oxide(WO3)/graphene oxide(GO)aerogel photocatalyst through a cost‐effective freeze‐drying method.GO not only acts as a macroscopic support,but also increases the catalyst surface area from 46 to 57 m2/g,enhances the light absorption in the visible‐light region,and raises the separation efficiency of photogenerated electron‐hole pairs.The Obtained WO3/GO aerogel exhibited an outstanding visible‐light photocatalytic degradation rate of nitric oxide of 51%,which was 3.3 times that of pristine WO3 powder.In addition,the aerogel displayed excellent selectivity,with a generation fraction of toxic nitrogen dioxide of as low as 0.5%.This work presents a facile synthesis route to fabricate a monolithic WO3/GO aerogel photocatalyst with great promise for air purification.
基金This work was financially supported by National Natural Science Foundation of China(Grant Nos.11772268 and 12025205).The authors would like to appreciate the researchers in Nanjing university of science and technology for their support in preparation of gradient structured materials.
文摘Gradient nanostructure was introduced to enhance the strength and ductility via deformation incompatibility accommodated by geometrical necessary dislocations for most metallic materials recently.However,few intensive researches were carried out to investigate the effect of gradient structure on the deformation twin evolution and resulting performance improvements.In the present paper,we produced gradient-structured AZ31 Mg alloy with fine-grain layers,parallel twin laminates and a coarse-grain core from two upmost surfaces to the center of plate.Surprisingly,this architected Mg alloy exhibited simultaneous enhancement of strength and ductility.Subsequent microstructural observations demonstrated that abundant twin-twin interactions resulting from higher strength and multi-axial stress state could make great contributions to the increase of work-hardening capability.This was further proved by the measurement of full-field strain evolution during the plastic deformation.Such a design strategy may provide a new path for producing advanced structure materials in which the deformation twinning works as one of the dominant plasticity mechanisms.
文摘The hypoxia-inducible factor-1α（HIF-1α） plays an important role in regulating angiogenesis, which is essential for tumor growth and metastasis. Genetic variations of HIFIA （coding HIF-1α） have been shown to influence an individual＇s susceptibility to many human tumors; however, evidence on associations between HIFIA single-nucleotide polymorphisms （SNPs） and prostate cancer （PCa） risk is conflicting. We genotyped three potentially functional polymorphisms in HIFIA （rs11549465, rs11549467 and rs2057482） using the TaqMan method and assessed their associations with PCa risk in a case-control study of 662 PCa patients and 716 controls in a Chinese Hart population. Compared with rs 11549467 GG genotype, the variant genotypes GA ＋AA had a significantly increased PCa risk （adjusted odds ratio （OR）= 1.70; 95% confidence interval （C1）= 1.06-2.72）, particularly among older patients （0R=2.01; 95%C1 = 1.05-3.86）, smokers （0R=2.06; 95%C1 = 1.07-3.99）, never drinkers （OR=2.16; 95%C1 = 1.20-3.86） and patients without a family history of cancer （OR= 1.71; 95%C1= 1.02-2.89）. Furthermore, patients with rs11549467 variant genotypes were associated with a higher Gleason score （OR=2.14; 95%CI = 1.22-3.75）. No altered PCa risk was associated with the rs 11549465 and rs2057482 polymorphism. However, the combined variant genotypes of rs2057482 and rs 11549467 were associated with increased PCa risk （0R=2.10; 95%C1= 1.23-3.57 among subjects carrying three or more risk alleles）. These results suggest that HIFIA polymorphisms may impact PCa susceptibility and progression in the Chinese Han population.
文摘This study was designed to evaluate whether the revised 2010 Tumour Node Metastasis （TNM） staging system could lead to a more accurate prediction of the prognosis of renal cell carcinoma （RCC） patients. A total of 1216 patients who had undergone radical nephrectomy or partial nephrectomy for RCC from 2003 to 2011 were enrolled. All of the patients had pathologically confirmed clear cell RCC （ccRCC）. All cases were staged by both the 2002 and 2010 TNM staging systems after pathological review, and survival data were collected. Univariate and multivariate Cox regression models were used to evaluate cancer-specific survival （CSS） and progression-free survival （PFS） after surgery. Continuous variables, such as age and tumour diameter, were calculated as mean values and standard deviations （s.d.） or as median values. Survival was calculated by the Kaplan-Meier method, and the log-rank test assessed differences between groups. Statistically significant differences in CSS and PFS were noted among patients in T3 subgroups using the new 2010 staging system. Therefore, the revised 2010 TNM staging system can lead to a more accurate prediction of the prognosis of ccRCC patients. However, when using the revised 2010 staging system, we found that more than 92% of patients （288/313） with T3 tumours were staged in the T3a subgroup, and their survival data were not significantly different from those of patients with T2b tumours. In addition, T2 subclassification failed to independently predict survival in RCC patients.
文摘Cotton(Gossypium hirsutum L.)fibers are derived from the outer integument of ovule,while little is known about cotton ovule development.In order to identify and analyze the expression of genes associated with cotton ovule development,a cDNA array approach was used to screen for genes with altered expression in cotton ovule before and after anthesis,and 25 differentially expressed genes were subsequently identified.Among them,GhlAA16 encodes a predicted polypeptide of 208 amino acids highly homologous to Arabidopsis IAA16.Molecular analysis revealed that it is a single-copy gene in cotton genome and specifically expressed in the ovule endothelium.To our knowledge,GhlAA16 is the first endothelium-specific gene isolated from cotton.Its possible function is discussed during cotton ovule formation.
文摘The origin and spatial-temporal variation of the Earth’s magnetic field(EMF)is one of the important scientific problems that has long been unsolved.The Macao Science Satellite-1(MSS-1)under construction is China’s first high-precision EMF measurement satellite.To satisfy the highly precise requirements of the MSS-1 orbit measurement,a light,high-precision,four-prism laser retroreflector array was designed.It weighs approximately 285 g,its effective reflection area is greater than 1.77 cm^(2),and its size is 100×100×41 mm.The laser retro-reflector array has excellent performance,and it can achieve a ranging precision at the subcentimeter level for satellite laser ranging.It will be developed and installed on the MSS-1 as a power-free load for high-precision orbit measurement and accurate orbit calibration.The MSS-1 is planned to be brought into the International Laser Ranging Service observations.More than 31satellite laser ranging stations in the International Laser Ranging Service around the world will be able to measure the MSS-1 with long arcs,which will support the scientific mission of high-precision EMF exploration.
基金This work was supported by Returning Scholars Fund of Heilongjiang Province(No.LC04C02)the Department of Education Overseas Researcher Fund of Heilongjiang Province(No.1054HZ013).
文摘A cDNA library was successfully constructed from Anip973,a human lung adenocarcinoma cell line with high metastatic potential.NIH3T3 cells were stably transfected using this cDNA library and screened for morphological changes in a soft agar assay.Genomic DNA was isolated from putative clones and the integrated sequence was retrieved by PCR and sequencing.Three known genes,ribosomal protein L23,hypothetical protein FLJ22104,and serine protease inhibitor,kazal type 6 and a number of 5'-terminally truncated sequences were identified.Furthermore,cells transfected with ribosomal protein L23 was highly invasive compared with the empty vector as control(P〈0.02).These results indicate that the expression cloning of cDNA libraries in NIH3T3 cells and subsequent screening for loss of contact inhibition in soft agar is a viable tool for identifying tumor-related genes and ribosomal protein L23 gene plays a role in cell movement and metastasis.
基金support from the National Science and Technology Major Project(no.J2019-VII-0017-0159)the National Natural Science Foundation of China(no.52205048)+1 种基金support from the National Natural Science Foundation of China(no.52205192)Jinran Li would like to thank the China Scholarship Council(CSC)for its financial support(file no.201906290129)during his studies at Northwestern University as a visiting student.
文摘This study examines the effects of macroscopic bending and microscopic contact loading in inhomogeneous materials using a semi-analytical model based on Eshelby’s equivalent inclusion method.The model accounts for bending effects through the beam theory,with bending stress included in the Eshelby’s equivalent inclusion equations.The macroscopic displacement resulting from bending effects is incorporated into the microscopic contact solver,and the final displacement is determined using the conjugate gradient method in an iterative solution.Computational efficiency can be improved by incorporating the discrete convolution and fast Fourier transform.The core scheme is validated using the finite element method,yielding accurate and efficient results for bending-contact problems in inhomogeneous materials.Simulations reveal the interplay between bending,contact loading,and inhomogeneity,as stress around the inhomogeneity alters and the stress concentration area expands under increasing bending moments.Conversely,low-magnitude negative bending moments reduce both contact pressure and stress around the inhomogeneity.The position where inhomogeneities are least affected shifts from the neutral surface depending on the coupling effect.The model provides a valuable bridge for connecting the macroscopic bending effect and microscale contact-inhomogeneity problems by visualizing stress fields and assessing pressure distributions.
基金This research was partially supported by the National Natural Science Foundation of China under Grant 52105268Natural Science Foundation of Guangdong Province under Grant 2022A1515011409+2 种基金Key Platforms and Major Scientific Research Projects of Universities in Guangdong under Grants 2019KTSCX161 and 2019KTSCX165Key Projects of Natural Science Research Projects of Shaoguan University under Grants SZ2020KJ02 and SZ2021KJ04the Science and Technology Program of Shaoguan City of China under Grants 2019sn056,200811094530423,200811094530805,and 200811094530811.
文摘Audio signal separation is an open and challenging issue in the classical“Cocktail Party Problem”.Especially in a reverberation environment,the separation of mixed signals is more difficult separated due to the influence of reverberation and echo.To solve the problem,we propose a determined reverberant blind source separation algorithm.The main innovation of the algorithm focuses on the estimation of the mixing matrix.A new cost function is built to obtain the accurate demixing matrix,which shows the gap between the prediction and the actual data.Then,the update rule of the demixing matrix is derived using Newton gradient descent method.The identity matrix is employed as the initial demixing matrix for avoiding local optima problem.Through the real-time iterative update of the demixing matrix,frequency-domain sources are obtained.Then,time-domain sources can be obtained using an inverse short-time Fourier transform.Experi-mental results based on a series of source separation of speech and music mixing signals demonstrate that the proposed algorithm achieves better separation performance than the state-of-the-art methods.In particular,it has much better superiority in the highly reverberant environment.
文摘采用硅胶、Sephadex LH-20和高效液相色谱等色谱分离技术,从黄花败酱(Patrinia scabiosaefolia)干燥根和根茎的乙酸乙酯萃取相中分离得到6个环烯醚萜类化合物。通过核磁共振、计算13C NMR和质谱等波谱学方法,将它们分别鉴定为patrinin A (1)、patrinin B (2)、loganin aglycone (3)、isovillosol (4)、1,3-dimethoxy-4,7-dimethyloctahyhro-cyclopenta[c]pyran-6,7-diol (5)和viburnshosin A (6)。其中,化合物1和2为新化合物。此外,对6个化合物进行了抗流感病毒和抗炎活性评价。
