Immunoglobulin heavy chain Fd gene and K chain gene were amplified by Polymerase Chain Reaction (PCR) from total RNA of a hybridom acell line secreting anti-stomach cancer monoclonal antibody 3G9. Sequences analysis s...Immunoglobulin heavy chain Fd gene and K chain gene were amplified by Polymerase Chain Reaction (PCR) from total RNA of a hybridom acell line secreting anti-stomach cancer monoclonal antibody 3G9. Sequences analysis showed that VH, D, JH genes were derived from VH7183, DFL16. 1, and JH3, and that V. and J, from VkⅡ and Jk2.3G9 Fd and K DNA segments were cloned Into expression vector pComb3. Soluble Fab was expressed by IPTG Induction and proved by western blotting. The specific antigen binding activity of the bacterially produced 3G9 Fab was demonstrated by enzyme- linked Immunofiltration展开更多
GST-π was purified from human placenta and its antiserum was raised in rabbits. The antibody IgC was purified and degraded into Fab' fragment which was conjugated with horseradish peroxidase (HRP) using N-succini...GST-π was purified from human placenta and its antiserum was raised in rabbits. The antibody IgC was purified and degraded into Fab' fragment which was conjugated with horseradish peroxidase (HRP) using N-succinimidyl-4-(N-maleimido-methyl) cyclo-hexane-1-carboxylate (SMCC) as crosslinking reagent to produce Fab'-HRP conjugate. A sandwich ELISA was established for the microquantitative determination of GST-π. The sensitivity was 11 pg/tube, which was far more sensitive than the radioimmunoassay so far reported. Using this method, the serum GST-π of 41 cases normal adult was found to be 1.06±0.94 ng/ml. The upper limit of the normal value was 2.6 ng/ml. In 30 cases of primary hepatocarcinoma, the level of serum GST-π was 24.4± 17.4 ng/ml, which was 23 times higher than the normal average value (P<0.01). The positive rate was 90%. In contrast, serum GST-π in 25 cases of chronic hepatitis was determined to be 1.74±1.16 ng/ml, which was not significantly different from the normal value (P>0.05). The pseudo-positive rate was 12.0%.展开更多
The electrical characteristics of graphene Schottky contacts formed on undoped GaN semiconductors were investigated. Excellent rectifying behavior with a rectification ratio of -10^7 at ±2 V and a low reverse lea...The electrical characteristics of graphene Schottky contacts formed on undoped GaN semiconductors were investigated. Excellent rectifying behavior with a rectification ratio of -10^7 at ±2 V and a low reverse leakage current of 1.0 × 10^-8 A/cm^2 at -5 V were observed. The Schottky barrier heights, as determined by the thermionic emission model Richardson plots, and barrier inhomogeneity model, were 0.90, 0.72, and 1.24 ± 0.13 eV, respectively. Despite the predicted low barrier height of -0.4 eV at the graphene-GaN interface, the formation of excellent rectifying characteristics with much larger barrier heights is attributed to the presence of a large number of surface states （1.2 x 1013 states/cm2/eV） and the internal spontaneous polarization field of GaN, resulted in a significant upward surface band bending or a bare surface barrier height as high as of 2.9 eV. Using the S parameter of 0.48 （measured from the work function dependence of Schottky barrier height） and the mean barrier height of 1.24 eV, the work function of graphene in the Au/graphene/GaN stack could be approximately estimated to be as low as 3.5 eV. The obtained results indicate that graphene is a promising candidate for use as a Schottky rectifier in GaN semiconductors with n-type conductivity.展开更多
A boron-silicon film was formed from boron trichloride gas and dichlorosilane gas at about 900℃in ambient hydrogen at atmospheric pressure utilizing a slim vertical cold wall chemical vapor deposition reacto...A boron-silicon film was formed from boron trichloride gas and dichlorosilane gas at about 900℃in ambient hydrogen at atmospheric pressure utilizing a slim vertical cold wall chemical vapor deposition reactor designed for the Minimal Fab system. The gas flow rates were 80, 20 and 0.1 - 20 sccm for the hydrogen, dichlorosilane and boron trichloride gases, respectively. The gas transport condition in the reactor was shown to quickly become stable when evaluated by quartz crystal microbalances at the inlet and outlet. The boron-silicon thin film was formed by achieving the various boron concentrations of 0.16% - 80%, the depth profile of which was flat. By observing the cross-sectional TEM image, the obtained film was dense. The boron trichloride gas is expected to be useful for the quick fabrication of various materials containing boron at significantly low and high concentrations.展开更多
A dichlorosilane gas and a trichlorosilane gas in ambient hydrogen were evaluated to show their different gas flow motions in a slim vertical cold wall chemical vapor deposition reactor for the Minimal Fab system. Thi...A dichlorosilane gas and a trichlorosilane gas in ambient hydrogen were evaluated to show their different gas flow motions in a slim vertical cold wall chemical vapor deposition reactor for the Minimal Fab system. This evaluation was performed for improving and controlling the film qualities and the productivities, using two quartz crystal microbalances (QCM) installed at the </span><span style="font-family:Verdana;">inlet and exhaust of the chamber by taking into account that the QCM frequency corresponds to the real time changes in the gas properties.</span><span style="font-family:Verdana;"> Typically, the time period approaching from the inlet to the exhaust was shorter for the trichlorosilane gas than that for the dichlorosilane gas. The trichlorosilane gas was shown to move like plug flow, while the dichlorosilane gas seemed to be well mixed in the entire chamber.展开更多
Soft electronics,which require mechanical elasticity,rely on elastic materials that have both a small Young’s modulus and a large elastic strain range.These materials,however,are prone to damage when stress accumulat...Soft electronics,which require mechanical elasticity,rely on elastic materials that have both a small Young’s modulus and a large elastic strain range.These materials,however,are prone to damage when stress accumulates,presenting a significant challenge for soft electronics.To address this issue,the integration of self-healing functionality into these materials appears to be a promising solution.Dynamic covalent bond chemistry has been utilized to design high-strength polymers with controllable reversibility.Nonetheless,the temperature needed to trigger self-healing may induce thermal damage to other parts of the device.In contrast,if the self-healing temperature is reduced,the device might suffer damage when exposed to temperatures exceeding the self-healing point due to the low stability of the polymer at high temperatures.These challenges highlight the need for materials that can self-heal at low temperatures while maintaining thermal stability at high temperatures.In response to this challenge,we propose a novel approach that involves forming a microfibrous network using polycaprolactone(PCL),a material with a low melting temperature of 60°C that is widely utilized in shape memory and self-healing materials.We fabricated the conductive fiber by encapsulating a microfiber PCL network with MXene nanosheets.These MXene nanosheets were seamlessly coated on the PCL fiber’s surface to prevent shape deformation at high temperatures.Furthermore,they exhibited high thermal conductivity,facilitating rapid internal heat dissipation.Consequently,the MXene/PCL microfiber networks demonstrated self-healing capabilities at 60°C and thermal stability above 200°C.This makes them potentially suitable for stretchable,self-healing electronic devices that need to withstand high temperatures.展开更多
ELF （extremely low frequency） magnetic fields from power-line current influence the yield of CMOS foundry. The poor yield happens because of ELF magnetic fields inducing directly the measurement or process equipment...ELF （extremely low frequency） magnetic fields from power-line current influence the yield of CMOS foundry. The poor yield happens because of ELF magnetic fields inducing directly the measurement or process equipment for cutting-edge chips below 28 nm process. The equipments of electron microscopes, including SEM （scanning electron microscope）, TEM （transmission electron microscopy）, STEM （scanning transmission electron microscopy） and EBLS （electron beam lithography system） are very susceptible to ELF magnetic fields emanating from various electrical power sources outside of the building and within next generation CMOS foundry recommends a maximum of 0.3 mG. The active canceling method uses active coils with current sensing field via sensor and inducing man-made electromagnetic field to reduce the stray magnetic field. Unfortunately, the conventional system takes more time to products field because of parasitical capacitance and resistance in long coil. The longer canceling coil the system construct, the more time it takes. Besides, canceling system should spend more time on calibrating non-linear current amplifier through software design. This research designs simpler anti-electro-magnetic system instead of typical frame and develops one turn canceling coil structure to reduce delaying time. Several parallel cells generate field up to 23.81 mG controlled by MPU （micro processor unit）. This system decreases the power-line inducing filed below 0.3 mG.展开更多
人工智能时代已来,学校教育该怎样面对?人工智能教育又将如何逐渐走进学校课程?本期我们邀请到华工启明星品牌创始人韩青江,请他从行业角度谈一谈有关人工智能教育与科创教育的理念。《中国信息技术教育》:韩总,您好。首先请您介绍一下...人工智能时代已来,学校教育该怎样面对?人工智能教育又将如何逐渐走进学校课程?本期我们邀请到华工启明星品牌创始人韩青江,请他从行业角度谈一谈有关人工智能教育与科创教育的理念。《中国信息技术教育》:韩总,您好。首先请您介绍一下华工启明星。韩青江:华工启明星是国内较早一批从事青少年科创教育的科技公司,成立于2014年,公司的成立源于MIT FabLab实验室,作为秉承FabLab开源创新理念的创客群体,我们于2014年引进并成立了华中区首家FabLab实验室,即FabLab Wuhan(光谷微创新实验室)。同时,基于系统的学习和创新,我们又引进了FabLab的系统科技创新课程How to Make Almost Anything,即《创造万物》课程,并在此基础上开发出了适用于国内院校的课程体系。展开更多
Objective:We present first-phase results of a performing arts public health intervention,‘Singing and Dancing for Health,’aiming to promote healthier behaviors in Ghana’s impoverished Northern Region.We hypothesize...Objective:We present first-phase results of a performing arts public health intervention,‘Singing and Dancing for Health,’aiming to promote healthier behaviors in Ghana’s impoverished Northern Region.We hypothesize that live music and dance drama provide a powerful technology to overcome barriers such as illiteracy,lack of adequate media access,inadequate health resources,and entrenched sociocultural attitudes.Our research objective is to evaluate this claim.Methods:In this first phase,we evaluated the effectiveness of arts interventions in improv-ing knowledge and behaviors associated with reduced incidence of malaria and cholera,focusing on basic information and simple practices,such as proper hand washing.Working with the Youth Home Cultural Group,we codeveloped two‘dance dramas’delivering health messages through di-alog,lyrics,and drama,using music and dance to attract spectators,focus attention,infuse emotion,and socialize impact.We also designed knowledge,attitude,and behavior surveys as measurement instruments.Using purposive sampling,we selected three contrasting test villages in the vicinity,contrasting in size and demographics.With cooperation of chiefs,elders,elected officials,and Gha-na Health Service officers,we conducted a baseline survey in each village.Next,we performed the interventions,and subsequently conducted follow-up surveys.Using a more qualitative approach,we also tracked a select subgroup,conducted focus group studies,and collected testimonials.Sur-veys were coded and data were analyzed by Epi Info.Results:Both quantitative and qualitative methods indicated that those who attended the dance drama performances were likelier than those who did not attend to list the causal,preven-tive,and transmission factors of malaria and cholera.Also,the same attendees were likelier than nonattendees to list some activities they do to prevent malaria,cholera,and other sanitation-related diseases,proving that dance dramas were highly effective both in raising awareness and in trans-forming beha展开更多
Temperature is an important physical variable that indicates the condition of the human body and artificial systems.Advanced wearable applications require the development of temperature sensors with different form fac...Temperature is an important physical variable that indicates the condition of the human body and artificial systems.Advanced wearable applications require the development of temperature sensors with different form factors.In this study,a fiber-shaped thermoelectric temperature sensor is fabricated using a continuous graphene fiber whose two halves possess different reduction states.A seamless junction is formed by partially reducing a wet-spun graphene oxide fiber with hydroiodic acid(HI)solutions of different concentrations.One-half of the fiber is mildly reduced with 0.97 wt%HI,while the other half is highly reduced with 30.6 wt%HI.The different reduction states of the graphene composite fiber result in different Seebeck coefficients,allowing for the fabrication of a fiber-shaped graphene thermocou-ple without any laborious assembly.The flexible graphene thermocouple exhibits high sensitivity with a thermopower of 12.5μV K^(-1)in the temperature range of room temperature to∼70℃.Furthermore,it exhibits high linearity with a correlation coefficient exceeding 0.995 and fast response with a time constant of 0.24 s.Owing to its mechanical robustness and flexibility,the stand-alone graphene ther-mocouple can be knitted into a cotton fabric glove,which presents a fast response to environmental changes without any external power source.This work offers a unique fabrication method for producing a high-performance,flexible thermocouple that features a seamless and clear junction without the use of additional materials.This alternative method eliminates the complicated assembly processes typically required for conventional thermocouples.展开更多
Most advanced hydrogen evolution reaction(HER)catalysts show high activity under alkaline conditions.However,the performance deteriorates at a natural and acidic pH,which is often problematic in practical applications...Most advanced hydrogen evolution reaction(HER)catalysts show high activity under alkaline conditions.However,the performance deteriorates at a natural and acidic pH,which is often problematic in practical applications.Herein,a rhenium(Re)sulfide–transition-metal dichalcogenide heterojunc-tion catalyst with Re-rich vacancies(NiS_(2)-ReS_(2)-V)has been constructed.The optimized catalyst shows extraordinary electrocatalytic HER performance over a wide range of pH,with ultralow overpotentials of 42,85,and 122 mV under alkaline,acidic,and neutral conditions,respectively.Moreover,the two-electrode system with NiS_(2)-ReS_(2)-V1 as the cathode provides a voltage of 1.73 V at 500 mA cm^(-2),superior to industrial systems.Besides,the open-circuit voltage of a single Zn–H_(2)O cell with NiS_(2)-ReS_(2)-V1 as the cathode can reach an impressive 90.9% of the theoretical value,with a maximum power density of up to 31.6 mW cm^(-2).Moreover,it shows remarkable stability,with sustained discharge for approximately 120 h at 10 mA cm^(-2),significantly outperforming commercial Pt/C catalysts under the same conditions in all aspects.A series of systematic characterizations and theoretical calculations demonstrate that Re vacancies on the heterojunction interface would generate a stronger built-in electric field,which profoundly affects surface charge distribution and subsequently enhances HER performance.展开更多
Copper(Cu)provides a cost-effective means of producing value-added fuels through the electrochemical reduction of carbon dioxide(CO_(2)RR).However,we observed the production of hydrocarbons via CO_(2)RR on commercial ...Copper(Cu)provides a cost-effective means of producing value-added fuels through the electrochemical reduction of carbon dioxide(CO_(2)RR).However,we observed the production of hydrocarbons via CO_(2)RR on commercial Cu films is less efficient because of the surface impurities,i.e.,Fe.Carbon monoxide(CO),a reaction intermediate of CO_(2)RR to hydrocarbons,binds strongly to the Fe sites and interrupts the production of hydrocarbons,resulting in an active hydrogen evolution reaction(HER).Herein,we report a method of blocking the effect of Fe impurities on the Cu surface through the preferential growth of nano-sized metal-organic frameworks(MOFs)on Fe site.When zirconium(Zr)-based MOFs(UiO-66)forms a compensating layer on Cu film via the terephthalic acid(TPA)-Fe coordination bond,the Ui O-66 coated Cu film(UiO-66@Cu)presents significantly improved hydrocarbon Faradaic efficiency(FE)of 37.59%compared to 14.68%FE on commercial Cu film(99.9%purity)by suppressing HER.According to X-ray photoelectron spectroscopy(XPS)analysis,the UiO-66 ligand binds to entire metallic Fe site on the Cu surface,while metallic Cu is retained.Thus,UiO-66@Cu provides active sites of Cu for CO_(2)RR and leads to highly efficient and selective production of hydrocarbons.展开更多
Background:Equatorward,rear-edge tree populations are natural monitors to estimate species vulnerability to climate change.According to biogeographical theory,exposition to drought events increases with increasing ari...Background:Equatorward,rear-edge tree populations are natural monitors to estimate species vulnerability to climate change.According to biogeographical theory,exposition to drought events increases with increasing aridity towards the equator and the growth of southern tree populations will be more vulnerable to drought than in central populations.However,the ecological and biogeographical margins can mismatch due to the impact of ecological factors(topography,soils)or tree-species acclimation that can blur large-scale geographical imprints in trees responses to drought making northern populations more drought limited.Methods:We tested these ideas in six tree species,three angiosperms(Fagus sylvatica,Quercus robur,Quercus petraea)and three gymnosperms(Abies alba,Pinus sylvestris and Pinus uncinata)by comparing rear-edge tree populations subjected to different degrees of aridity.We used dendrochronology to compare the radial-growth patterns of these species in northern,intermediate,and southern tree populations at the continental rear edge.Results and conclusions:We found marked variations in growth variability between species with coherent patterns of stronger drought signals in the tree-ring series of the southern populations of F.sylvatica,P.sylvestris,and A.alba.This was also observed in species from cool-wet sites(P.uncinata and Q.robur),despite their limited responsiveness to drought.However,in the case of Q.petraea the intermediate population showed the strongest relationship to drought.For drought-sensitive species as F.sylvatica and P.sylvestris,southern populations presented more variable growth which was enhanced by cool-wet conditions from late spring to summer.We found a trend of enhanced vulnerability to drought in these two species.The response of tree growth to drought has a marked biogeographical component characterized by increased drought sensitivity in southern populations even within the species distribution rear edge.Nevertheless,the relationship between tree growth and drought varied between 展开更多
At present, the development and implementation of digital transformation are the keys to promoting high-quality industry development. The new digital fabrication method of robotic 3D printing is a research area being ...At present, the development and implementation of digital transformation are the keys to promoting high-quality industry development. The new digital fabrication method of robotic 3D printing is a research area being studied by many to tackle the issue of the declining productivity of traditional construction methods. Although many studies have been done, most of the current 3D printing projects are facing limitations in terms of scale. In order to bridge the gap, this article proposed a mass customization 3D printing framework system for large-scale projects. This article discusses how mass customization is made possible through the joint operation of the FUROBOT software and 3D printing hardware. By taking the east gate of Nanjing Happy Valley Plaza as a case study, the article demonstrates and studies the feasibility of the large-scale mass customization 3D printing framework system.展开更多
文摘Immunoglobulin heavy chain Fd gene and K chain gene were amplified by Polymerase Chain Reaction (PCR) from total RNA of a hybridom acell line secreting anti-stomach cancer monoclonal antibody 3G9. Sequences analysis showed that VH, D, JH genes were derived from VH7183, DFL16. 1, and JH3, and that V. and J, from VkⅡ and Jk2.3G9 Fd and K DNA segments were cloned Into expression vector pComb3. Soluble Fab was expressed by IPTG Induction and proved by western blotting. The specific antigen binding activity of the bacterially produced 3G9 Fab was demonstrated by enzyme- linked Immunofiltration
文摘GST-π was purified from human placenta and its antiserum was raised in rabbits. The antibody IgC was purified and degraded into Fab' fragment which was conjugated with horseradish peroxidase (HRP) using N-succinimidyl-4-(N-maleimido-methyl) cyclo-hexane-1-carboxylate (SMCC) as crosslinking reagent to produce Fab'-HRP conjugate. A sandwich ELISA was established for the microquantitative determination of GST-π. The sensitivity was 11 pg/tube, which was far more sensitive than the radioimmunoassay so far reported. Using this method, the serum GST-π of 41 cases normal adult was found to be 1.06±0.94 ng/ml. The upper limit of the normal value was 2.6 ng/ml. In 30 cases of primary hepatocarcinoma, the level of serum GST-π was 24.4± 17.4 ng/ml, which was 23 times higher than the normal average value (P<0.01). The positive rate was 90%. In contrast, serum GST-π in 25 cases of chronic hepatitis was determined to be 1.74±1.16 ng/ml, which was not significantly different from the normal value (P>0.05). The pseudo-positive rate was 12.0%.
文摘The electrical characteristics of graphene Schottky contacts formed on undoped GaN semiconductors were investigated. Excellent rectifying behavior with a rectification ratio of -10^7 at ±2 V and a low reverse leakage current of 1.0 × 10^-8 A/cm^2 at -5 V were observed. The Schottky barrier heights, as determined by the thermionic emission model Richardson plots, and barrier inhomogeneity model, were 0.90, 0.72, and 1.24 ± 0.13 eV, respectively. Despite the predicted low barrier height of -0.4 eV at the graphene-GaN interface, the formation of excellent rectifying characteristics with much larger barrier heights is attributed to the presence of a large number of surface states （1.2 x 1013 states/cm2/eV） and the internal spontaneous polarization field of GaN, resulted in a significant upward surface band bending or a bare surface barrier height as high as of 2.9 eV. Using the S parameter of 0.48 （measured from the work function dependence of Schottky barrier height） and the mean barrier height of 1.24 eV, the work function of graphene in the Au/graphene/GaN stack could be approximately estimated to be as low as 3.5 eV. The obtained results indicate that graphene is a promising candidate for use as a Schottky rectifier in GaN semiconductors with n-type conductivity.
文摘A boron-silicon film was formed from boron trichloride gas and dichlorosilane gas at about 900℃in ambient hydrogen at atmospheric pressure utilizing a slim vertical cold wall chemical vapor deposition reactor designed for the Minimal Fab system. The gas flow rates were 80, 20 and 0.1 - 20 sccm for the hydrogen, dichlorosilane and boron trichloride gases, respectively. The gas transport condition in the reactor was shown to quickly become stable when evaluated by quartz crystal microbalances at the inlet and outlet. The boron-silicon thin film was formed by achieving the various boron concentrations of 0.16% - 80%, the depth profile of which was flat. By observing the cross-sectional TEM image, the obtained film was dense. The boron trichloride gas is expected to be useful for the quick fabrication of various materials containing boron at significantly low and high concentrations.
文摘A dichlorosilane gas and a trichlorosilane gas in ambient hydrogen were evaluated to show their different gas flow motions in a slim vertical cold wall chemical vapor deposition reactor for the Minimal Fab system. This evaluation was performed for improving and controlling the film qualities and the productivities, using two quartz crystal microbalances (QCM) installed at the </span><span style="font-family:Verdana;">inlet and exhaust of the chamber by taking into account that the QCM frequency corresponds to the real time changes in the gas properties.</span><span style="font-family:Verdana;"> Typically, the time period approaching from the inlet to the exhaust was shorter for the trichlorosilane gas than that for the dichlorosilane gas. The trichlorosilane gas was shown to move like plug flow, while the dichlorosilane gas seemed to be well mixed in the entire chamber.
基金National Research Foundation of Korea(NRF)grants(Number 2020M3H4A3081895,2022R1A2C1010353 and RS-2023-00247545)the Korean government(MSIP).Further support was provided by the Industry Technology R&D program(20006511)the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘Soft electronics,which require mechanical elasticity,rely on elastic materials that have both a small Young’s modulus and a large elastic strain range.These materials,however,are prone to damage when stress accumulates,presenting a significant challenge for soft electronics.To address this issue,the integration of self-healing functionality into these materials appears to be a promising solution.Dynamic covalent bond chemistry has been utilized to design high-strength polymers with controllable reversibility.Nonetheless,the temperature needed to trigger self-healing may induce thermal damage to other parts of the device.In contrast,if the self-healing temperature is reduced,the device might suffer damage when exposed to temperatures exceeding the self-healing point due to the low stability of the polymer at high temperatures.These challenges highlight the need for materials that can self-heal at low temperatures while maintaining thermal stability at high temperatures.In response to this challenge,we propose a novel approach that involves forming a microfibrous network using polycaprolactone(PCL),a material with a low melting temperature of 60°C that is widely utilized in shape memory and self-healing materials.We fabricated the conductive fiber by encapsulating a microfiber PCL network with MXene nanosheets.These MXene nanosheets were seamlessly coated on the PCL fiber’s surface to prevent shape deformation at high temperatures.Furthermore,they exhibited high thermal conductivity,facilitating rapid internal heat dissipation.Consequently,the MXene/PCL microfiber networks demonstrated self-healing capabilities at 60°C and thermal stability above 200°C.This makes them potentially suitable for stretchable,self-healing electronic devices that need to withstand high temperatures.
文摘ELF （extremely low frequency） magnetic fields from power-line current influence the yield of CMOS foundry. The poor yield happens because of ELF magnetic fields inducing directly the measurement or process equipment for cutting-edge chips below 28 nm process. The equipments of electron microscopes, including SEM （scanning electron microscope）, TEM （transmission electron microscopy）, STEM （scanning transmission electron microscopy） and EBLS （electron beam lithography system） are very susceptible to ELF magnetic fields emanating from various electrical power sources outside of the building and within next generation CMOS foundry recommends a maximum of 0.3 mG. The active canceling method uses active coils with current sensing field via sensor and inducing man-made electromagnetic field to reduce the stray magnetic field. Unfortunately, the conventional system takes more time to products field because of parasitical capacitance and resistance in long coil. The longer canceling coil the system construct, the more time it takes. Besides, canceling system should spend more time on calibrating non-linear current amplifier through software design. This research designs simpler anti-electro-magnetic system instead of typical frame and develops one turn canceling coil structure to reduce delaying time. Several parallel cells generate field up to 23.81 mG controlled by MPU （micro processor unit）. This system decreases the power-line inducing filed below 0.3 mG.
文摘人工智能时代已来,学校教育该怎样面对?人工智能教育又将如何逐渐走进学校课程?本期我们邀请到华工启明星品牌创始人韩青江,请他从行业角度谈一谈有关人工智能教育与科创教育的理念。《中国信息技术教育》:韩总,您好。首先请您介绍一下华工启明星。韩青江:华工启明星是国内较早一批从事青少年科创教育的科技公司,成立于2014年,公司的成立源于MIT FabLab实验室,作为秉承FabLab开源创新理念的创客群体,我们于2014年引进并成立了华中区首家FabLab实验室,即FabLab Wuhan(光谷微创新实验室)。同时,基于系统的学习和创新,我们又引进了FabLab的系统科技创新课程How to Make Almost Anything,即《创造万物》课程,并在此基础上开发出了适用于国内院校的课程体系。
基金This project was enabled by a Killam Cornerstone Granttogether with additional contributions from the Faculty of Arts,the Office of Global Health in the Faculty of Medicine and Dentistry,the Centre for Health and Culture at the University of Alberta,as well as a subgrant from the Canadian Department of Foreign Affairs,Trade,and Development.
文摘Objective:We present first-phase results of a performing arts public health intervention,‘Singing and Dancing for Health,’aiming to promote healthier behaviors in Ghana’s impoverished Northern Region.We hypothesize that live music and dance drama provide a powerful technology to overcome barriers such as illiteracy,lack of adequate media access,inadequate health resources,and entrenched sociocultural attitudes.Our research objective is to evaluate this claim.Methods:In this first phase,we evaluated the effectiveness of arts interventions in improv-ing knowledge and behaviors associated with reduced incidence of malaria and cholera,focusing on basic information and simple practices,such as proper hand washing.Working with the Youth Home Cultural Group,we codeveloped two‘dance dramas’delivering health messages through di-alog,lyrics,and drama,using music and dance to attract spectators,focus attention,infuse emotion,and socialize impact.We also designed knowledge,attitude,and behavior surveys as measurement instruments.Using purposive sampling,we selected three contrasting test villages in the vicinity,contrasting in size and demographics.With cooperation of chiefs,elders,elected officials,and Gha-na Health Service officers,we conducted a baseline survey in each village.Next,we performed the interventions,and subsequently conducted follow-up surveys.Using a more qualitative approach,we also tracked a select subgroup,conducted focus group studies,and collected testimonials.Sur-veys were coded and data were analyzed by Epi Info.Results:Both quantitative and qualitative methods indicated that those who attended the dance drama performances were likelier than those who did not attend to list the causal,preven-tive,and transmission factors of malaria and cholera.Also,the same attendees were likelier than nonattendees to list some activities they do to prevent malaria,cholera,and other sanitation-related diseases,proving that dance dramas were highly effective both in raising awareness and in trans-forming beha
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Ministry of Science and ICT(Nos.2022R1A2B5B02002413,2022R1A4A1031182,and 2019R1A2C2089785)supported by the Korea Institute of Industrial Technology(kitech JA-20-0001).
文摘Temperature is an important physical variable that indicates the condition of the human body and artificial systems.Advanced wearable applications require the development of temperature sensors with different form factors.In this study,a fiber-shaped thermoelectric temperature sensor is fabricated using a continuous graphene fiber whose two halves possess different reduction states.A seamless junction is formed by partially reducing a wet-spun graphene oxide fiber with hydroiodic acid(HI)solutions of different concentrations.One-half of the fiber is mildly reduced with 0.97 wt%HI,while the other half is highly reduced with 30.6 wt%HI.The different reduction states of the graphene composite fiber result in different Seebeck coefficients,allowing for the fabrication of a fiber-shaped graphene thermocou-ple without any laborious assembly.The flexible graphene thermocouple exhibits high sensitivity with a thermopower of 12.5μV K^(-1)in the temperature range of room temperature to∼70℃.Furthermore,it exhibits high linearity with a correlation coefficient exceeding 0.995 and fast response with a time constant of 0.24 s.Owing to its mechanical robustness and flexibility,the stand-alone graphene ther-mocouple can be knitted into a cotton fabric glove,which presents a fast response to environmental changes without any external power source.This work offers a unique fabrication method for producing a high-performance,flexible thermocouple that features a seamless and clear junction without the use of additional materials.This alternative method eliminates the complicated assembly processes typically required for conventional thermocouples.
基金This study was supported by the National Research Foundation of Korea(NRF-2021R1A2C4001777,NRF-2022M3H4A1A04096482 and RS-2023-00229679),the National Natural Science Foundation of China(No.21965005,52363028)the Natural Science Foundation of Guangxi Province(2021GXNSFAA076001)the Guangxi Technology Base and Talent Subject(GUIKE AD20297039).
文摘Most advanced hydrogen evolution reaction(HER)catalysts show high activity under alkaline conditions.However,the performance deteriorates at a natural and acidic pH,which is often problematic in practical applications.Herein,a rhenium(Re)sulfide–transition-metal dichalcogenide heterojunc-tion catalyst with Re-rich vacancies(NiS_(2)-ReS_(2)-V)has been constructed.The optimized catalyst shows extraordinary electrocatalytic HER performance over a wide range of pH,with ultralow overpotentials of 42,85,and 122 mV under alkaline,acidic,and neutral conditions,respectively.Moreover,the two-electrode system with NiS_(2)-ReS_(2)-V1 as the cathode provides a voltage of 1.73 V at 500 mA cm^(-2),superior to industrial systems.Besides,the open-circuit voltage of a single Zn–H_(2)O cell with NiS_(2)-ReS_(2)-V1 as the cathode can reach an impressive 90.9% of the theoretical value,with a maximum power density of up to 31.6 mW cm^(-2).Moreover,it shows remarkable stability,with sustained discharge for approximately 120 h at 10 mA cm^(-2),significantly outperforming commercial Pt/C catalysts under the same conditions in all aspects.A series of systematic characterizations and theoretical calculations demonstrate that Re vacancies on the heterojunction interface would generate a stronger built-in electric field,which profoundly affects surface charge distribution and subsequently enhances HER performance.
基金supported by the Basic Science Research Program of the National Research Foundation of Korea(NRF2021R1A2C4001777,NRF-2021R1A2C2007823)the Carbon to X Project(NRF-2020M3H7A1098231)funded by the Ministry of Science and ICT,Republic of Koreasupported by the Technology Innovation Program(20013794,Center for Composite Materials and Concurrent Design)funded by the Ministry of Trade,Industry&Energy(MOTIE),Republic of Korea。
文摘Copper(Cu)provides a cost-effective means of producing value-added fuels through the electrochemical reduction of carbon dioxide(CO_(2)RR).However,we observed the production of hydrocarbons via CO_(2)RR on commercial Cu films is less efficient because of the surface impurities,i.e.,Fe.Carbon monoxide(CO),a reaction intermediate of CO_(2)RR to hydrocarbons,binds strongly to the Fe sites and interrupts the production of hydrocarbons,resulting in an active hydrogen evolution reaction(HER).Herein,we report a method of blocking the effect of Fe impurities on the Cu surface through the preferential growth of nano-sized metal-organic frameworks(MOFs)on Fe site.When zirconium(Zr)-based MOFs(UiO-66)forms a compensating layer on Cu film via the terephthalic acid(TPA)-Fe coordination bond,the Ui O-66 coated Cu film(UiO-66@Cu)presents significantly improved hydrocarbon Faradaic efficiency(FE)of 37.59%compared to 14.68%FE on commercial Cu film(99.9%purity)by suppressing HER.According to X-ray photoelectron spectroscopy(XPS)analysis,the UiO-66 ligand binds to entire metallic Fe site on the Cu surface,while metallic Cu is retained.Thus,UiO-66@Cu provides active sites of Cu for CO_(2)RR and leads to highly efficient and selective production of hydrocarbons.
基金funding by project RTI2018–096884-B-C31(Spanish Ministry of Science)G.S-B.is supported by a Spanish Ministry of Economy,Industry+1 种基金Competitiveness Postdoctoral grant(FJCI 2016–30121FEDER funds)。
文摘Background:Equatorward,rear-edge tree populations are natural monitors to estimate species vulnerability to climate change.According to biogeographical theory,exposition to drought events increases with increasing aridity towards the equator and the growth of southern tree populations will be more vulnerable to drought than in central populations.However,the ecological and biogeographical margins can mismatch due to the impact of ecological factors(topography,soils)or tree-species acclimation that can blur large-scale geographical imprints in trees responses to drought making northern populations more drought limited.Methods:We tested these ideas in six tree species,three angiosperms(Fagus sylvatica,Quercus robur,Quercus petraea)and three gymnosperms(Abies alba,Pinus sylvestris and Pinus uncinata)by comparing rear-edge tree populations subjected to different degrees of aridity.We used dendrochronology to compare the radial-growth patterns of these species in northern,intermediate,and southern tree populations at the continental rear edge.Results and conclusions:We found marked variations in growth variability between species with coherent patterns of stronger drought signals in the tree-ring series of the southern populations of F.sylvatica,P.sylvestris,and A.alba.This was also observed in species from cool-wet sites(P.uncinata and Q.robur),despite their limited responsiveness to drought.However,in the case of Q.petraea the intermediate population showed the strongest relationship to drought.For drought-sensitive species as F.sylvatica and P.sylvestris,southern populations presented more variable growth which was enhanced by cool-wet conditions from late spring to summer.We found a trend of enhanced vulnerability to drought in these two species.The response of tree growth to drought has a marked biogeographical component characterized by increased drought sensitivity in southern populations even within the species distribution rear edge.Nevertheless,the relationship between tree growth and drought varied between
基金supported by the Shanghai Science and Technology Committee(Grant No.21DZ1204500)National Natural Science Foundation of China(Grant No.U1913603)。
文摘At present, the development and implementation of digital transformation are the keys to promoting high-quality industry development. The new digital fabrication method of robotic 3D printing is a research area being studied by many to tackle the issue of the declining productivity of traditional construction methods. Although many studies have been done, most of the current 3D printing projects are facing limitations in terms of scale. In order to bridge the gap, this article proposed a mass customization 3D printing framework system for large-scale projects. This article discusses how mass customization is made possible through the joint operation of the FUROBOT software and 3D printing hardware. By taking the east gate of Nanjing Happy Valley Plaza as a case study, the article demonstrates and studies the feasibility of the large-scale mass customization 3D printing framework system.
