First described by Meredith in 1987,retinal venous beading(RVB)is an extremely rare and potentially vision-threat-ening disease,^(1)which is characterized by beading or sausage-like configuration of retinal veins.It c...First described by Meredith in 1987,retinal venous beading(RVB)is an extremely rare and potentially vision-threat-ening disease,^(1)which is characterized by beading or sausage-like configuration of retinal veins.It can present with episodes of increased vascular permeability accom-panied by lipid exudation,foveal edema,recurrent branch vein occlusion,retinal ischemia with retinal neo-vascularization,and vitreous hemorrhage,^(1)or exist solely and asymptomatically.^(2)展开更多
The extracellular vesicles show great potential as a noninvasive biomarker for the early detection of cancer.Hence,there is an urgent requirement to create biosensors that are time-saving,simple,and easily scalable in...The extracellular vesicles show great potential as a noninvasive biomarker for the early detection of cancer.Hence,there is an urgent requirement to create biosensors that are time-saving,simple,and easily scalable in order to accomplish rapid,sensitive,and quantitative detection of extracellular vesicles.In this study,we present a self-propelled DNA walker powered by endonuclease Nt.Bbv CI,which enables the development of a“signal on”sensing platform for the rapid and highly sensitive detection of extracellular vesicles.The DNA motor employed tracks made of streptavidin magnetic beads,which consisted of substrate strands labeled with fluorescein and motor strands locked by aptamers.The aptamer recognition of the target protein on extracellular vesicles unlocked the motor strand,initiating the DNA motor process.After replacing the optimal buffer solution containing the endonuclease Nt.BbvC I,the motor strands autonomously moved along the streptavidin magnetic beads track,continuously releasing fluorescent molecules and producing detectable fluorescence signals.Under optimal conditions,the detection range was from 2×10~4particles/mL to 2×10~9particles/mL,with a detection limit of 2.9×10~3particles/mL,demonstrating excellent selectivity.This method has demonstrated good selectivity in different tumorderived extracellular vesicles and performs well in complex biological samples.The ability to effectively analyze surface proteins of extracellular vesicles in a short period of time gives our DNA walker a tremendous potential for developing simple and cost-effective clinical diagnostic devices.展开更多
In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool...In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool boiling heat transfer potentially induced by combining perforated copper particles on a heated surface with a sodium dodecyl sulfate(SDS)surfactant in saturated deionized water.Experiments were conducted at standard atmospheric pressure,with heat flux ranging from 20 to 100 kW/m2.The heating surface,positioned below the layer of freely moving copper beads,allowed the particle layer to shift due to liquid convection and steam nucleation.The study reports on the influence of copper bead diameter(2,3,4,and 5 mm),particle quantity,arrangement,and SDS concentration(20,200,and 500 ppm).It is shown that the combination of 5 mm particles and a 500 ppm SDS concentration can yield a remarkable 139%improvement in heat transfer efficiency.As demonstrated by direct flow visualization,bubble formation occurs primarily in the gaps between the particles and the heated surface,with the presence of SDS reducing bubble size and accelerating bubble detachment.展开更多
BACKGROUND The objectives of this study were to assess the safety and efficacy of drug-eluting bead transarterial chemoembolization(DEB-TACE)as neoadjuvant therapy before liver transplantation(LT)for advanced-stage he...BACKGROUND The objectives of this study were to assess the safety and efficacy of drug-eluting bead transarterial chemoembolization(DEB-TACE)as neoadjuvant therapy before liver transplantation(LT)for advanced-stage hepatocellular carcinoma(HCC)and to analyze the prognostic factors.AIM To determine whether DEB-TACE before LT is superior to LT for advanced-stage HCC.METHODS A total of 99 individuals diagnosed with advanced HCC were studied retrospectively.The participants were categorized into the following two groups based on whether they had received DEB-TACE before LT:DEB-TACE group(n=45)and control group(n=54).The participants were further divided into two subgroups based on the presence or absence of segmental portal vein tumor thrombus(PVTT).The DEB-TACE group consisted of two subgroups:Group A(n=31)without PVTT and group B(n=14)with PVTT.The control group also had two subgroups:Group C(n=37)without PVTT and group D(n=17)with PVTT.Data on patient demographics,disease characteristics,therapy response,and adverse events(AEs)were collected.The overall survival(OS)and recurrence-free survival(RFS)rates were assessed using Kaplan-Meier curves.Univariate and multivariate Cox regression analyses were conducted to determine the parameters that were independently related to OS and RFS.RESULTS The DEB-TACE group exhibited an overall response rate of 86.6%.Following therapy,there was a significant decrease in the median alpha-fetoprotein(AFP)level(275.1 ng/mL vs 41.7 ng/mL,P<0.001).The main AE was post-embolization syndrome.The 2-year rates of RFS and OS were significantly higher in the DEB-TACE group than in the control group(68.9%vs 38.9%,P=0.003;86.7%vs 63.0%,P=0.008).Within the subgroups,group A had higher 2-year rates of RFS and OS compared to group C(71.0%vs 45.9%,P=0.038;83.8%vs 62.2%,P=0.047).The 2-year RFS rate of group B was markedly superior to that of group D(64.3%vs 23.5%,P=0.002).Results from multivariate analyses showed that pre-LT DEB-TACE[hazard ratio(HR)=2.73,95%confidence interval(CI):1.44-5.14,P=0.04],overall target tumor diameter≤7 cm(HR=1.98,95%CI:1.05-3.75,P=0.035),and AFP level≤400 ng/mL(HR=2.34;95%CI:1.30-4.19,P=0.009)were significant risk factors for RFS.Additionally,pre-LT DEBTACE(HR=3.15,95%CI:1.43-6.96,P=0.004)was identified as a significant risk factor for OS.CONCLUSION DEB-TACE is a safe and efficient therapy for advanced-stage HCC and also enhances patient survival after LT.展开更多
BACKGROUND The combination of transarterial chemoembolization(TACE),lenvatinib,and programmed cell death 1(PD-1)inhibitor has been widely used in the treatment of advanced hepatocellular carcinoma(HCC)and has achieved...BACKGROUND The combination of transarterial chemoembolization(TACE),lenvatinib,and programmed cell death 1(PD-1)inhibitor has been widely used in the treatment of advanced hepatocellular carcinoma(HCC)and has achieved promising results.However,there are few studies comparing whether drug-eluting beads TACE(DTACE)can bring more survival benefits to patients with large HCC compared to conventional TACE(C-TACE)in this triplet therapy.AIM To compare the efficacy and adverse events(AEs)of triple therapy comprising DTACE,PD-1 inhibitors,and lenvatinib(D-TACE-P-L)and C-TACE,PD-1 inhibitors,and lenvatinib(C-TACE-P-L)in patients with large HCC(maximum diameter≥5 cm),and analyze the prognostic factors.METHODS Following a comprehensive review of our hospital’s medical records,this retrospective study included 104 patients:50 received D-TACE-P-L,and 54 received CTACE-P-L.We employed Kaplan-Meier estimation to assess the median progression-free survival(PFS)between the two groups,utilized Cox multivariate regression analysis to identify prognostic factors,and applied theχ2 test to evaluate AEs.RESULTS The objective response rate(ORR)and median PFS were significantly higher in the D-TACE-P-L group compared to the C-TACE-P-L group(ORR:66.0%vs 44.4%,P=0.027;median PFS:6.8 months vs 5.0 months,P=0.041).Cox regression analysis identified treatment option,portal vein tumor thrombus,and hepatic vein invasion as protective factors for PFS.AEs were comparable between the two CONCLUSION D-TACE-P-L may have significantly better PFS and ORR for large HCC,while exhibiting similar AEs to C-TACE-PL.展开更多
A comprehensive three-dimensional transient computational fluid dynamics(CFD)model was developed to ana-lyze the thermophysical phenomena in the arc wire additive manufacturing(WAAM)process.The model includes droplet ...A comprehensive three-dimensional transient computational fluid dynamics(CFD)model was developed to ana-lyze the thermophysical phenomena in the arc wire additive manufacturing(WAAM)process.The model includes droplet impact,gravity,heat and mass transfer,molten metal flow,and solid-liquid phase changes.By integrating the mass,energy,momentum,and volume of fluid(VOF)equations,a layer-by-layer additive process was suc-cessfully simulated.The accuracy of the model was validated by comparing the simulation results of single-pass single-layer weld beads at three welding positions with experimental data.The established model was utilized to quantitatively investigate the effects of three crucial welding process parameters-welding direction,droplet transfer frequency,and initial temperature-on the multi-layer cladding process.These findings suggest that the use of opposite welding directions in two adjacent layers can result in a well-distributed overall morphology of the weld bead.Moreover,the high initial droplet temperature enhanced the inclination of the weld bead mor-phology while decreasing the height of each layer.However,the high droplet transfer frequency caused both the height and width of the weld to increase.This research contributes to explaining the formation mechanism of the multi-layer cladding process and offers insights for improving weld bead morphology.This provides valuable theoretical guidance for the process optimization and control of arc additive manufacturing technology.展开更多
A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calci...A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calcium ions(Ca^(2+)).The shell,composed of a chitosan/activated carbon mixture,was then coated onto the core.Fourier transform infrared spectroscopy confirmed the grafting polymerization of acrylamide onto sodium alginate.Scanning electron microscopy images showed the core-shell structure.The core exhibited a high water uptake ratio,facilitating the diffusion of methylene blue into the core.During the diffusion process,the methylene blue was first adsorbed by the shell and then further adsorbed by the core.Adsorption tests showed that the coreshell structure had a larger adsorption capacity than the core alone.The shell effectively enhanced the adsorption capacity to methylene blue compared to the single core.Methylene blue was adsorbed by activated carbon and chitosan in the shell,and the residual methylene blue diffused into the core and was further adsorbed.展开更多
Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding wire.Suppression of short-circuit current was used to reduce spatter.Ar...Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding wire.Suppression of short-circuit current was used to reduce spatter.Arc length stabilizer was used to acquire a proper and stable arc length maintained at the critical position where short circuit starts to occur.Short-arc P-GMAW with or without arc length stabilizer was compared.The droplet transfer,arc behaviors and weld bead profiles were investigated and compared based on the high-speed photography and observation of weld cross-section.When the arc length stabilizer was deactivated,the arc length was unstable and too short.The droplet transfer mode was mainly short circuit partial transfer,with only a small part of the droplet transferred into the molten pool,with the characteristics of no obvious necking,a few spatters,small droplet impact,long short circuit duration and high short-circuit current.There was also a small proportion of short circuit complete transfer with obvious necking,larger droplet impact,shorter short-circuit duration and lower short-circuit current.With arc length stabilizer,droplet transfer modes were short circuit complete transfer and spray transfer.The spray transfer had the largest droplet impact,no short circuit and no spatter.With the arc length stabilizer activated,a deep penetration,a high penetration ratio,a small reinforcement and a large reinforcement factor were acquired.This provides an innovative method to solve the difficulties of droplet transfer and molten pool spreading and eliminate the incomplete fusion in the GMAW of 9%Ni steel with nickel-based alloy welding wire.展开更多
This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact.This study focused on the implementation and development of dynamic insulation t...This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact.This study focused on the implementation and development of dynamic insulation technology for a sustainable and energy-efficient future in the region,especially in Iraq.The study assessed the energy efficiency of dynamic insulation technology by analyzing three wallmodels(static,dynamic,and modified)during thewinter season.This paper expands the analysis to include a hot,dry summer scenario,providing valuable insights into the year-round performance of dynamic walls and enabling sustainable and energy-efficient solutions for Iraq’s climate.The study evaluates the thermal efficiency of the dynamic intake and exhaust facades during the cooling season for the city of Baghdad.The finding indicated that the dynamic intake facade reduces energy consumption by 16.3%for the dynamic wall and 17.2%for the modified dynamic wall.In addition,the dynamic exhaust front reduces energy consumption by 46%during the cooling season,with the maximum permissible exhaust air level.Dynamic insulation is suitable for hot and dry climates,improving energy consumption.展开更多
A problem similar to the famous brachistochrone problem is examined in which, instead of a smooth curve, the path consists of two straight-line sections, one slant and one horizontal. The condition for minimum sliding...A problem similar to the famous brachistochrone problem is examined in which, instead of a smooth curve, the path consists of two straight-line sections, one slant and one horizontal. The condition for minimum sliding time is investigated, producing results that are both counterintuitive and interesting.展开更多
Esox reieherti Dybowsk genomic microsateUites were developed by using enrichment protocols combined with radioactive hybridization protocol. Four hundred to nine hundred base pair fragments were selected for the whole...Esox reieherti Dybowsk genomic microsateUites were developed by using enrichment protocols combined with radioactive hybridization protocol. Four hundred to nine hundred base pair fragments were selected for the whole genome. DNA PCR amplification after digestion with restriction endonuclease Sau 3A Ⅰ, and （CA）12, （GA）12 probes marked with biotin were used for microsateUite DNA enrichment. The product fragments were connected with carder pGEM-T and transferred into DH5α Escherichia coli competent cells, and radioactive isotope probes marked with γ^-32 p were used for the second hybridization. As a result, a total of 1600 bacteria were obtained in the microsatellite genomic libraries, positive clones accounted for 90.91% before hybridization and 81.25% after hybridization, amounting to 1300. One hundred and ninety-six positive clones were selected for sequencing, and 192 clones included microsateUite sequences. The microsateUite sequences obtained, mono-nucleotide, quad-nucleotide and quint-nucleotide repeat motifs were observed beside double-base-pairs CA/GT, GA/CT. Seventy primers were designed according to the flanking sequences by using software Primer Premier 5.0, and 32 primers were selected to be synthesized. After optimizing PCR reaction conditions, 28 primers were amplified and produced clear purpose bands. The aim of our research was to promote the development and utilization of E. reieherti genomic resource, and lay the foundation for optimizing E. reieherti breeding strain in order to detect the genetic diversity and construct a genetic map.展开更多
A TiO2 photocatalyst is coated on the surface of a zeolite fly ash bead（ZFAB） to improve its dispersability and exposure degree in a cement system.The application of Ag particles in TiO2/ZFAB modified cementitious m...A TiO2 photocatalyst is coated on the surface of a zeolite fly ash bead（ZFAB） to improve its dispersability and exposure degree in a cement system.The application of Ag particles in TiO2/ZFAB modified cementitious materials is to further enhance the photocatalytic performance.Various Ag@TiO2/ZFAB modified cementitious specimens with different Ag dosages are prepared and the characteristics and photocatalytic performance of the prepared samples are investigated.It is observed that the multi-level pore structure of ZFAB can improve the exposure degree of TiO2 in a cement system and is also useful to enhance the photocatalytic efficiency.With an increment of the amounts of Ag particles in the TiO2/ZFAB modified cementitious samples,the photocatalytic activities increased first and then decreased.The optimal Ag@TiO2/ZFAB modified cementitious sample reveals the maximum reaction rate constant for degrading benzene（9.91×10^-3 min^-1）,which is approximately 3 and 10 times higher than those of TiO2/ZFAB and TiO2 modified samples,respectively.This suggests that suitable Ag particles coupled with a ZFAB carrier could effectively enhance the photocatalytic effects and use of TiO2 in a cement system.Thus,ZFAB as a carrier could provide a potential method for a high efficiency engineering application of TiO2 in the construction field.展开更多
基金supported by the National Natural Science Foundation of China(No.82070975,82301213)the Shanghai Science and Technology Commission of China(No.21ZR1411400)the Shanghai Hospital Development Center Foundation(SHDC12023116).
文摘First described by Meredith in 1987,retinal venous beading(RVB)is an extremely rare and potentially vision-threat-ening disease,^(1)which is characterized by beading or sausage-like configuration of retinal veins.It can present with episodes of increased vascular permeability accom-panied by lipid exudation,foveal edema,recurrent branch vein occlusion,retinal ischemia with retinal neo-vascularization,and vitreous hemorrhage,^(1)or exist solely and asymptomatically.^(2)
基金supported financially by the National Natural Science Foundation of China(NSFC,Nos.62071119 and 62075098)the National Key Research and Development Program of China(Nos.2017YFA0205301 and 2018YFC1602905)。
文摘The extracellular vesicles show great potential as a noninvasive biomarker for the early detection of cancer.Hence,there is an urgent requirement to create biosensors that are time-saving,simple,and easily scalable in order to accomplish rapid,sensitive,and quantitative detection of extracellular vesicles.In this study,we present a self-propelled DNA walker powered by endonuclease Nt.Bbv CI,which enables the development of a“signal on”sensing platform for the rapid and highly sensitive detection of extracellular vesicles.The DNA motor employed tracks made of streptavidin magnetic beads,which consisted of substrate strands labeled with fluorescein and motor strands locked by aptamers.The aptamer recognition of the target protein on extracellular vesicles unlocked the motor strand,initiating the DNA motor process.After replacing the optimal buffer solution containing the endonuclease Nt.BbvC I,the motor strands autonomously moved along the streptavidin magnetic beads track,continuously releasing fluorescent molecules and producing detectable fluorescence signals.Under optimal conditions,the detection range was from 2×10~4particles/mL to 2×10~9particles/mL,with a detection limit of 2.9×10~3particles/mL,demonstrating excellent selectivity.This method has demonstrated good selectivity in different tumorderived extracellular vesicles and performs well in complex biological samples.The ability to effectively analyze surface proteins of extracellular vesicles in a short period of time gives our DNA walker a tremendous potential for developing simple and cost-effective clinical diagnostic devices.
基金supported by the National Natural Science Foundation of China(Project No.52166004)the National Key Research and Development Program of China(Project No.2022YFC3902000)+2 种基金the Major Science and Technology Special Project of Yunnan Province(Project Nos.202202AG050007202202AG050002)the Research on the Development of Complete Sets of Technology for Extraction of Aromatic Substances from Tobacco Waste and Its Application,Applied Research-Pyrolysis Process Technology Research(2023QT01).
文摘In modern engineering,enhancing boiling heat transfer efficiency is crucial for optimizing energy use and several industrial processes involving different types of materials.This study explores the enhancement of pool boiling heat transfer potentially induced by combining perforated copper particles on a heated surface with a sodium dodecyl sulfate(SDS)surfactant in saturated deionized water.Experiments were conducted at standard atmospheric pressure,with heat flux ranging from 20 to 100 kW/m2.The heating surface,positioned below the layer of freely moving copper beads,allowed the particle layer to shift due to liquid convection and steam nucleation.The study reports on the influence of copper bead diameter(2,3,4,and 5 mm),particle quantity,arrangement,and SDS concentration(20,200,and 500 ppm).It is shown that the combination of 5 mm particles and a 500 ppm SDS concentration can yield a remarkable 139%improvement in heat transfer efficiency.As demonstrated by direct flow visualization,bubble formation occurs primarily in the gaps between the particles and the heated surface,with the presence of SDS reducing bubble size and accelerating bubble detachment.
基金Supported by Project of Medical and Health Technology Program in Zhejiang Province,No.2020KY787.
文摘BACKGROUND The objectives of this study were to assess the safety and efficacy of drug-eluting bead transarterial chemoembolization(DEB-TACE)as neoadjuvant therapy before liver transplantation(LT)for advanced-stage hepatocellular carcinoma(HCC)and to analyze the prognostic factors.AIM To determine whether DEB-TACE before LT is superior to LT for advanced-stage HCC.METHODS A total of 99 individuals diagnosed with advanced HCC were studied retrospectively.The participants were categorized into the following two groups based on whether they had received DEB-TACE before LT:DEB-TACE group(n=45)and control group(n=54).The participants were further divided into two subgroups based on the presence or absence of segmental portal vein tumor thrombus(PVTT).The DEB-TACE group consisted of two subgroups:Group A(n=31)without PVTT and group B(n=14)with PVTT.The control group also had two subgroups:Group C(n=37)without PVTT and group D(n=17)with PVTT.Data on patient demographics,disease characteristics,therapy response,and adverse events(AEs)were collected.The overall survival(OS)and recurrence-free survival(RFS)rates were assessed using Kaplan-Meier curves.Univariate and multivariate Cox regression analyses were conducted to determine the parameters that were independently related to OS and RFS.RESULTS The DEB-TACE group exhibited an overall response rate of 86.6%.Following therapy,there was a significant decrease in the median alpha-fetoprotein(AFP)level(275.1 ng/mL vs 41.7 ng/mL,P<0.001).The main AE was post-embolization syndrome.The 2-year rates of RFS and OS were significantly higher in the DEB-TACE group than in the control group(68.9%vs 38.9%,P=0.003;86.7%vs 63.0%,P=0.008).Within the subgroups,group A had higher 2-year rates of RFS and OS compared to group C(71.0%vs 45.9%,P=0.038;83.8%vs 62.2%,P=0.047).The 2-year RFS rate of group B was markedly superior to that of group D(64.3%vs 23.5%,P=0.002).Results from multivariate analyses showed that pre-LT DEB-TACE[hazard ratio(HR)=2.73,95%confidence interval(CI):1.44-5.14,P=0.04],overall target tumor diameter≤7 cm(HR=1.98,95%CI:1.05-3.75,P=0.035),and AFP level≤400 ng/mL(HR=2.34;95%CI:1.30-4.19,P=0.009)were significant risk factors for RFS.Additionally,pre-LT DEBTACE(HR=3.15,95%CI:1.43-6.96,P=0.004)was identified as a significant risk factor for OS.CONCLUSION DEB-TACE is a safe and efficient therapy for advanced-stage HCC and also enhances patient survival after LT.
文摘BACKGROUND The combination of transarterial chemoembolization(TACE),lenvatinib,and programmed cell death 1(PD-1)inhibitor has been widely used in the treatment of advanced hepatocellular carcinoma(HCC)and has achieved promising results.However,there are few studies comparing whether drug-eluting beads TACE(DTACE)can bring more survival benefits to patients with large HCC compared to conventional TACE(C-TACE)in this triplet therapy.AIM To compare the efficacy and adverse events(AEs)of triple therapy comprising DTACE,PD-1 inhibitors,and lenvatinib(D-TACE-P-L)and C-TACE,PD-1 inhibitors,and lenvatinib(C-TACE-P-L)in patients with large HCC(maximum diameter≥5 cm),and analyze the prognostic factors.METHODS Following a comprehensive review of our hospital’s medical records,this retrospective study included 104 patients:50 received D-TACE-P-L,and 54 received CTACE-P-L.We employed Kaplan-Meier estimation to assess the median progression-free survival(PFS)between the two groups,utilized Cox multivariate regression analysis to identify prognostic factors,and applied theχ2 test to evaluate AEs.RESULTS The objective response rate(ORR)and median PFS were significantly higher in the D-TACE-P-L group compared to the C-TACE-P-L group(ORR:66.0%vs 44.4%,P=0.027;median PFS:6.8 months vs 5.0 months,P=0.041).Cox regression analysis identified treatment option,portal vein tumor thrombus,and hepatic vein invasion as protective factors for PFS.AEs were comparable between the two CONCLUSION D-TACE-P-L may have significantly better PFS and ORR for large HCC,while exhibiting similar AEs to C-TACE-PL.
基金supported by National Natural Science Foundation of China(Grant Nos.52076216,51706246).
文摘A comprehensive three-dimensional transient computational fluid dynamics(CFD)model was developed to ana-lyze the thermophysical phenomena in the arc wire additive manufacturing(WAAM)process.The model includes droplet impact,gravity,heat and mass transfer,molten metal flow,and solid-liquid phase changes.By integrating the mass,energy,momentum,and volume of fluid(VOF)equations,a layer-by-layer additive process was suc-cessfully simulated.The accuracy of the model was validated by comparing the simulation results of single-pass single-layer weld beads at three welding positions with experimental data.The established model was utilized to quantitatively investigate the effects of three crucial welding process parameters-welding direction,droplet transfer frequency,and initial temperature-on the multi-layer cladding process.These findings suggest that the use of opposite welding directions in two adjacent layers can result in a well-distributed overall morphology of the weld bead.Moreover,the high initial droplet temperature enhanced the inclination of the weld bead mor-phology while decreasing the height of each layer.However,the high droplet transfer frequency caused both the height and width of the weld to increase.This research contributes to explaining the formation mechanism of the multi-layer cladding process and offers insights for improving weld bead morphology.This provides valuable theoretical guidance for the process optimization and control of arc additive manufacturing technology.
文摘A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions.The core,made of sodium alginate-g-polyacrylamide and attapulgite nanofibers,was cross-linked by Calcium ions(Ca^(2+)).The shell,composed of a chitosan/activated carbon mixture,was then coated onto the core.Fourier transform infrared spectroscopy confirmed the grafting polymerization of acrylamide onto sodium alginate.Scanning electron microscopy images showed the core-shell structure.The core exhibited a high water uptake ratio,facilitating the diffusion of methylene blue into the core.During the diffusion process,the methylene blue was first adsorbed by the shell and then further adsorbed by the core.Adsorption tests showed that the coreshell structure had a larger adsorption capacity than the core alone.The shell effectively enhanced the adsorption capacity to methylene blue compared to the single core.Methylene blue was adsorbed by activated carbon and chitosan in the shell,and the residual methylene blue diffused into the core and was further adsorbed.
基金the MARK III Materials Research Project of Ministry of Industry and Information Technology of China。
文摘Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding wire.Suppression of short-circuit current was used to reduce spatter.Arc length stabilizer was used to acquire a proper and stable arc length maintained at the critical position where short circuit starts to occur.Short-arc P-GMAW with or without arc length stabilizer was compared.The droplet transfer,arc behaviors and weld bead profiles were investigated and compared based on the high-speed photography and observation of weld cross-section.When the arc length stabilizer was deactivated,the arc length was unstable and too short.The droplet transfer mode was mainly short circuit partial transfer,with only a small part of the droplet transferred into the molten pool,with the characteristics of no obvious necking,a few spatters,small droplet impact,long short circuit duration and high short-circuit current.There was also a small proportion of short circuit complete transfer with obvious necking,larger droplet impact,shorter short-circuit duration and lower short-circuit current.With arc length stabilizer,droplet transfer modes were short circuit complete transfer and spray transfer.The spray transfer had the largest droplet impact,no short circuit and no spatter.With the arc length stabilizer activated,a deep penetration,a high penetration ratio,a small reinforcement and a large reinforcement factor were acquired.This provides an innovative method to solve the difficulties of droplet transfer and molten pool spreading and eliminate the incomplete fusion in the GMAW of 9%Ni steel with nickel-based alloy welding wire.
文摘This paper is part of a series addressing the urgent need for effective technologies to reduce energy demand and mitigate climate impact.This study focused on the implementation and development of dynamic insulation technology for a sustainable and energy-efficient future in the region,especially in Iraq.The study assessed the energy efficiency of dynamic insulation technology by analyzing three wallmodels(static,dynamic,and modified)during thewinter season.This paper expands the analysis to include a hot,dry summer scenario,providing valuable insights into the year-round performance of dynamic walls and enabling sustainable and energy-efficient solutions for Iraq’s climate.The study evaluates the thermal efficiency of the dynamic intake and exhaust facades during the cooling season for the city of Baghdad.The finding indicated that the dynamic intake facade reduces energy consumption by 16.3%for the dynamic wall and 17.2%for the modified dynamic wall.In addition,the dynamic exhaust front reduces energy consumption by 46%during the cooling season,with the maximum permissible exhaust air level.Dynamic insulation is suitable for hot and dry climates,improving energy consumption.
文摘A problem similar to the famous brachistochrone problem is examined in which, instead of a smooth curve, the path consists of two straight-line sections, one slant and one horizontal. The condition for minimum sliding time is investigated, producing results that are both counterintuitive and interesting.
文摘Esox reieherti Dybowsk genomic microsateUites were developed by using enrichment protocols combined with radioactive hybridization protocol. Four hundred to nine hundred base pair fragments were selected for the whole genome. DNA PCR amplification after digestion with restriction endonuclease Sau 3A Ⅰ, and （CA）12, （GA）12 probes marked with biotin were used for microsateUite DNA enrichment. The product fragments were connected with carder pGEM-T and transferred into DH5α Escherichia coli competent cells, and radioactive isotope probes marked with γ^-32 p were used for the second hybridization. As a result, a total of 1600 bacteria were obtained in the microsatellite genomic libraries, positive clones accounted for 90.91% before hybridization and 81.25% after hybridization, amounting to 1300. One hundred and ninety-six positive clones were selected for sequencing, and 192 clones included microsateUite sequences. The microsateUite sequences obtained, mono-nucleotide, quad-nucleotide and quint-nucleotide repeat motifs were observed beside double-base-pairs CA/GT, GA/CT. Seventy primers were designed according to the flanking sequences by using software Primer Premier 5.0, and 32 primers were selected to be synthesized. After optimizing PCR reaction conditions, 28 primers were amplified and produced clear purpose bands. The aim of our research was to promote the development and utilization of E. reieherti genomic resource, and lay the foundation for optimizing E. reieherti breeding strain in order to detect the genetic diversity and construct a genetic map.
基金supported by the National Natural Science Foundation of China (51478370)the Engineering and Physical Sciences Research Council of UK–Natural Science Foundation of China (EPSRC-NSFC) International Joint Research Project (51461135005)~~
文摘A TiO2 photocatalyst is coated on the surface of a zeolite fly ash bead（ZFAB） to improve its dispersability and exposure degree in a cement system.The application of Ag particles in TiO2/ZFAB modified cementitious materials is to further enhance the photocatalytic performance.Various Ag@TiO2/ZFAB modified cementitious specimens with different Ag dosages are prepared and the characteristics and photocatalytic performance of the prepared samples are investigated.It is observed that the multi-level pore structure of ZFAB can improve the exposure degree of TiO2 in a cement system and is also useful to enhance the photocatalytic efficiency.With an increment of the amounts of Ag particles in the TiO2/ZFAB modified cementitious samples,the photocatalytic activities increased first and then decreased.The optimal Ag@TiO2/ZFAB modified cementitious sample reveals the maximum reaction rate constant for degrading benzene（9.91×10^-3 min^-1）,which is approximately 3 and 10 times higher than those of TiO2/ZFAB and TiO2 modified samples,respectively.This suggests that suitable Ag particles coupled with a ZFAB carrier could effectively enhance the photocatalytic effects and use of TiO2 in a cement system.Thus,ZFAB as a carrier could provide a potential method for a high efficiency engineering application of TiO2 in the construction field.
