The nitrile butadiene rubber(NBR)hardness effect on the sealing characteristics of hydraulic O-ring rod seals is analyzed based on a mixed lubrication elastohydrodynamic model.Parameterized studies are conducted to re...The nitrile butadiene rubber(NBR)hardness effect on the sealing characteristics of hydraulic O-ring rod seals is analyzed based on a mixed lubrication elastohydrodynamic model.Parameterized studies are conducted to reveal the mechanism of the influence of rubber hardness on the static and dynamic behavior of seals.The optimized selections of rubber hardness are then investigated under different conditions.Results show that the low hardness seal is prone to stress concentration due to the extrusion effect under high pressure conditions;it is also more prone to leaking.A high hardness seal can better prevent leakage by reducing film thickness but it will cause large frictional power loss and increase the probability of wear failure.The choice of low hardness is recommended to reduce friction with the premise that leakage requirements are met.展开更多
As an extreme manifestation of environmental degradation,karst rock desertification is caused by soil loss and rock exposure.In some areas with serious rocky desertification,there is no soil to be eroded or leaked.The...As an extreme manifestation of environmental degradation,karst rock desertification is caused by soil loss and rock exposure.In some areas with serious rocky desertification,there is no soil to be eroded or leaked.The soil loss in these areas superimposes soil erosion and unique subsurface loss by soil leakage through fissures,pipelines,sinkholes,etc.,which directly reduce soil resources and accelerate rocky desertification.However,the factors driving soil erosion and subsurface loss by soil leakage are still unclear.Rainfall experiments were conducted on simulated slopes with surface-exposed bedrock and subsurface fissures based on field investigations in a karst rocky desertification area of Guizhou Province,China.Four factors,including rainfall intensity,slope gradient,bedrock exposure rate and subsurface fissure degree,were considered in the experiment.We found that the amount of soil surface erosion and subsurface leakage loss is driven not only by the runoff volume but also by other influential factors.Rainfall intensity is the driving factor determining the amount of surface erosion and subsurface leakage loss of soil and water and the relationship between them.The slope gradient plays a leading role only in subsurface fissure flow leakage loss.The bedrock exposure rate drives the surface soil erosion rate,shows a critical value(30%),and dominates the fissure flow leakage loss rate.Subsurface fissure density plays an important role in the surface loss of soil and water;however,an increase in the subsurface fissure density does not obviously accelerate the subsurface leakage loss of soil and water.Although this result,obtained from laboratory simulations,may differ at the field scale or larger,it could provide a foundation for systematic studies on soil erosion/leakage and insights into the relations between rocky desertification and soil erosion/leakage and their driving factors in karst rocky desertification.展开更多
SOX4 is highly expressed in gastric cancer(GC)and is associated with tumor grade,metastasis and prognosis,however the mechanism is not clear.We report herein that SOX4 was upregulated and overexpression of SOX4 was as...SOX4 is highly expressed in gastric cancer(GC)and is associated with tumor grade,metastasis and prognosis,however the mechanism is not clear.We report herein that SOX4 was upregulated and overexpression of SOX4 was associated with increased expression of the markers of Epithelialemesenchymal transition(EMT)and stemness in clinic patient samples.In vitro,overexpression of SOX4 promoted the invasion as showed by Transwell assay and stemness of GC cells as assessed by sphere formation assay,which was suppressed by silencing SOX4 with shRNA.Further studies showed that SOX4 up-regulated the expression of EMT transcription factors Twist1,snail1 and zeb1 and stemness transcription factors SOX2 and OCT4,and promoted the nuclear translocation of β-catenin.Moreover,we revealed that TGF-β treatment significantly up-regulated the expression of SOX4 and silencing SOX4 reversed TGF-β induced invasion and sphere formation ability of GC cells.Finally,we showed that SOX4 promoted the lung metastasis and tumor formation ability of gastric cancer cells in nude mice.Our results suggest that SOX4 is a target TGF-β signaling and mediates TGF-β-induced EMT and stem cell characteristics of GC cells,revealing a novel role of TGF-β/SOX4 axis in the regulation of malignant behavior of GC.展开更多
Silicon offers a high theoretical specific capacity for anodic lithium storage.However,its applications are hindered by the electrode instability caused by the sharp volume change,and the limited rate performance resu...Silicon offers a high theoretical specific capacity for anodic lithium storage.However,its applications are hindered by the electrode instability caused by the sharp volume change,and the limited rate performance resulted from the insulating property.Herein,we introduce a facile and fast method of preparing honeycomb‐like silicon‐based anodes(MXene‐Si@C)with porous structure using MXene and carbon‐coated silicon.The dual protection from both the surface coating and as‐formed interlayered vacant spaces ameliorate the volume expansion of the silicon and thus reinforce the mechanical stability of the electrode.In addition,the highly conducting MXene and the surface carbon coating form a hierarchical and consecutive electron‐conducting network with evidently reduced resistance.With this proposed composite,a high average Coulombic efficiency of 99.73%and high capacity retention of 82.4%after 300 cycles at 1 A/g can be achieved even with an areal loading around 1.5 mg/cm^(2).Coupled with an NCM523 cathode,the proof‐of‐concept full cell delivers a high capacity of 164.2mAh/g with an extremely high energy density of 574Wh/kg(based on the mass of the electrode materials)at 0.2 C and an excellent cyclability at 0.5 C of 100 cycles with decent capacity retention(80.28%).展开更多
锂金属具有氧化还原电位低、理论比容量大等优点,是下一代高比能电池极具发展前景的负极.然而,锂枝晶生长和低可逆性严重阻碍了高比能锂金属电池的发展.受启发于生物细胞膜结构,本文采用涂布法在锂金属表面成功构筑了一种具有仿生离子...锂金属具有氧化还原电位低、理论比容量大等优点,是下一代高比能电池极具发展前景的负极.然而,锂枝晶生长和低可逆性严重阻碍了高比能锂金属电池的发展.受启发于生物细胞膜结构,本文采用涂布法在锂金属表面成功构筑了一种具有仿生离子通道的人工界面固体电解质层(CAL).该CAL中大量带负电荷的离子通道可以促进锂离子均匀、快速的输运,有利于稳定、均匀地进行锂沉积/剥离.此外,在循环过程中,CAL底部与锂金属发生原位转化反应,生成了一层富含亲锂性无机组分的过渡层,促进了锂离子的扩散并抑制了锂金属与电解液的连续副反应.因此,形成的具有双面神结构的人工界面固体电解质层(CAJL)使得锂金属负极可以在10 mA cm^(-2)的高电流密度和10 mAh cm^(-2)的高面积容量下长期稳定循环.更重要的是,基于CAJL功能化锂金属负极的锂硫软包电池实现了429.2 Wh kg^(-1)的高能量密度.展开更多
We regret that an error was made in“SOX4 contributions to TGF-b-induced endothelial-mesenchymal transition and stem cell characteristics of gastric cancer cells”(Genes&Diseases(2018)5,49e61).In this manuscript,t...We regret that an error was made in“SOX4 contributions to TGF-b-induced endothelial-mesenchymal transition and stem cell characteristics of gastric cancer cells”(Genes&Diseases(2018)5,49e61).In this manuscript,the expression of SOX4 of cancer and adjacent tissues in 84 patients were detected,and 8 pairs of typical pictures were listed in Figure 1A.We note that we made an unintentional error.We confused some pictures(non-cancer tissues of NO.2 and 3)of Figure 1A due to the large number of IHC samples and pictures.展开更多
In contrast to the conventional etching that makes nanoparticles rounder and our previous sharpening etching mode that causes serrated edges,here,we developed a new boring etching mode that targets the faces of Au nan...In contrast to the conventional etching that makes nanoparticles rounder and our previous sharpening etching mode that causes serrated edges,here,we developed a new boring etching mode that targets the faces of Au nanoplates to make holes.The critical factors are the pre-incubation step with the ligand 2-mercapto-5-benzimidazolecarboxylic acid(MBIA)and the subsequent removal of excess ligands in the solution.Thus,etching is focused onto the few sites with initial loss of ligands,which cannot be quickly replaced.The choice of ligand MBIA is also of importance,as it carries negative charge and repels each other.Its inability of forming a dense layer probably plays a critical role in the site-selectivity for faces,because ligands at the higher curvature edges and corners are expected to have less repulsion.The etching results from the comproportionation reaction between Au3+and Au0 in the nanoplates,where Br-coordination to Au and the extra stabilization from cetyltrimethylammonium bromide(CTAB)are essential.We believe that the ability of boring holes is an important tool for future synthetic designs.展开更多
基金supported by the National Natural Science Foundation of China(No.52005470)the Natural Science Foundation of Zhejiang Province(No.LQ21E050020)the Fundamental Research Funds for the Provincial Universities of Zhejiang(No.2021YW17),China.
文摘The nitrile butadiene rubber(NBR)hardness effect on the sealing characteristics of hydraulic O-ring rod seals is analyzed based on a mixed lubrication elastohydrodynamic model.Parameterized studies are conducted to reveal the mechanism of the influence of rubber hardness on the static and dynamic behavior of seals.The optimized selections of rubber hardness are then investigated under different conditions.Results show that the low hardness seal is prone to stress concentration due to the extrusion effect under high pressure conditions;it is also more prone to leaking.A high hardness seal can better prevent leakage by reducing film thickness but it will cause large frictional power loss and increase the probability of wear failure.The choice of low hardness is recommended to reduce friction with the premise that leakage requirements are met.
基金the National Natural Science Foundation of China(NO.42007067,41671275,41461057,41061029)the Science and Technology Plan Project of Guizhou Province(Qian Ke He Ji Chu[2020]1Y176)+3 种基金the National Key Research and Development Program of China(2016YFC0502604)the First Class Discipline Construction Projects of Guizhou Province(GNYL[2017]007)the Young Scientific and Technological Talents Growth Project in Colleges and Universities of Guizhou Province(Qian Ke Jiao KY Zi[2021]082)the National Natural Sci Foundation training program for young teachers in Guizhou Uni-versity(Gui Da Pei Yu[2019]36)。
文摘As an extreme manifestation of environmental degradation,karst rock desertification is caused by soil loss and rock exposure.In some areas with serious rocky desertification,there is no soil to be eroded or leaked.The soil loss in these areas superimposes soil erosion and unique subsurface loss by soil leakage through fissures,pipelines,sinkholes,etc.,which directly reduce soil resources and accelerate rocky desertification.However,the factors driving soil erosion and subsurface loss by soil leakage are still unclear.Rainfall experiments were conducted on simulated slopes with surface-exposed bedrock and subsurface fissures based on field investigations in a karst rocky desertification area of Guizhou Province,China.Four factors,including rainfall intensity,slope gradient,bedrock exposure rate and subsurface fissure degree,were considered in the experiment.We found that the amount of soil surface erosion and subsurface leakage loss is driven not only by the runoff volume but also by other influential factors.Rainfall intensity is the driving factor determining the amount of surface erosion and subsurface leakage loss of soil and water and the relationship between them.The slope gradient plays a leading role only in subsurface fissure flow leakage loss.The bedrock exposure rate drives the surface soil erosion rate,shows a critical value(30%),and dominates the fissure flow leakage loss rate.Subsurface fissure density plays an important role in the surface loss of soil and water;however,an increase in the subsurface fissure density does not obviously accelerate the subsurface leakage loss of soil and water.Although this result,obtained from laboratory simulations,may differ at the field scale or larger,it could provide a foundation for systematic studies on soil erosion/leakage and insights into the relations between rocky desertification and soil erosion/leakage and their driving factors in karst rocky desertification.
基金This study was supported by National Key Clinical Specialties Construction Program of China(No.[2012]649).
文摘SOX4 is highly expressed in gastric cancer(GC)and is associated with tumor grade,metastasis and prognosis,however the mechanism is not clear.We report herein that SOX4 was upregulated and overexpression of SOX4 was associated with increased expression of the markers of Epithelialemesenchymal transition(EMT)and stemness in clinic patient samples.In vitro,overexpression of SOX4 promoted the invasion as showed by Transwell assay and stemness of GC cells as assessed by sphere formation assay,which was suppressed by silencing SOX4 with shRNA.Further studies showed that SOX4 up-regulated the expression of EMT transcription factors Twist1,snail1 and zeb1 and stemness transcription factors SOX2 and OCT4,and promoted the nuclear translocation of β-catenin.Moreover,we revealed that TGF-β treatment significantly up-regulated the expression of SOX4 and silencing SOX4 reversed TGF-β induced invasion and sphere formation ability of GC cells.Finally,we showed that SOX4 promoted the lung metastasis and tumor formation ability of gastric cancer cells in nude mice.Our results suggest that SOX4 is a target TGF-β signaling and mediates TGF-β-induced EMT and stem cell characteristics of GC cells,revealing a novel role of TGF-β/SOX4 axis in the regulation of malignant behavior of GC.
基金supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.T23‐601/17‐R).
文摘Silicon offers a high theoretical specific capacity for anodic lithium storage.However,its applications are hindered by the electrode instability caused by the sharp volume change,and the limited rate performance resulted from the insulating property.Herein,we introduce a facile and fast method of preparing honeycomb‐like silicon‐based anodes(MXene‐Si@C)with porous structure using MXene and carbon‐coated silicon.The dual protection from both the surface coating and as‐formed interlayered vacant spaces ameliorate the volume expansion of the silicon and thus reinforce the mechanical stability of the electrode.In addition,the highly conducting MXene and the surface carbon coating form a hierarchical and consecutive electron‐conducting network with evidently reduced resistance.With this proposed composite,a high average Coulombic efficiency of 99.73%and high capacity retention of 82.4%after 300 cycles at 1 A/g can be achieved even with an areal loading around 1.5 mg/cm^(2).Coupled with an NCM523 cathode,the proof‐of‐concept full cell delivers a high capacity of 164.2mAh/g with an extremely high energy density of 574Wh/kg(based on the mass of the electrode materials)at 0.2 C and an excellent cyclability at 0.5 C of 100 cycles with decent capacity retention(80.28%).
基金financially supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(T23-601/17-R)supported by the Fundamental Research Funds for the Central Universities(D5000220443)。
文摘锂金属具有氧化还原电位低、理论比容量大等优点,是下一代高比能电池极具发展前景的负极.然而,锂枝晶生长和低可逆性严重阻碍了高比能锂金属电池的发展.受启发于生物细胞膜结构,本文采用涂布法在锂金属表面成功构筑了一种具有仿生离子通道的人工界面固体电解质层(CAL).该CAL中大量带负电荷的离子通道可以促进锂离子均匀、快速的输运,有利于稳定、均匀地进行锂沉积/剥离.此外,在循环过程中,CAL底部与锂金属发生原位转化反应,生成了一层富含亲锂性无机组分的过渡层,促进了锂离子的扩散并抑制了锂金属与电解液的连续副反应.因此,形成的具有双面神结构的人工界面固体电解质层(CAJL)使得锂金属负极可以在10 mA cm^(-2)的高电流密度和10 mAh cm^(-2)的高面积容量下长期稳定循环.更重要的是,基于CAJL功能化锂金属负极的锂硫软包电池实现了429.2 Wh kg^(-1)的高能量密度.
文摘We regret that an error was made in“SOX4 contributions to TGF-b-induced endothelial-mesenchymal transition and stem cell characteristics of gastric cancer cells”(Genes&Diseases(2018)5,49e61).In this manuscript,the expression of SOX4 of cancer and adjacent tissues in 84 patients were detected,and 8 pairs of typical pictures were listed in Figure 1A.We note that we made an unintentional error.We confused some pictures(non-cancer tissues of NO.2 and 3)of Figure 1A due to the large number of IHC samples and pictures.
基金the financial support from the National Natural Science Foundation of China(Nos.91956109,92356310,and 22075137)Zhejiang Provincial Natural Science Foundation of China:Major Program(No.2022XHSJJ002)+1 种基金Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.TD2022004)Foundation of Westlake University.
文摘In contrast to the conventional etching that makes nanoparticles rounder and our previous sharpening etching mode that causes serrated edges,here,we developed a new boring etching mode that targets the faces of Au nanoplates to make holes.The critical factors are the pre-incubation step with the ligand 2-mercapto-5-benzimidazolecarboxylic acid(MBIA)and the subsequent removal of excess ligands in the solution.Thus,etching is focused onto the few sites with initial loss of ligands,which cannot be quickly replaced.The choice of ligand MBIA is also of importance,as it carries negative charge and repels each other.Its inability of forming a dense layer probably plays a critical role in the site-selectivity for faces,because ligands at the higher curvature edges and corners are expected to have less repulsion.The etching results from the comproportionation reaction between Au3+and Au0 in the nanoplates,where Br-coordination to Au and the extra stabilization from cetyltrimethylammonium bromide(CTAB)are essential.We believe that the ability of boring holes is an important tool for future synthetic designs.
