In recent years, hospice care in Beijing has developed rapidly. In order to further promote the development of hospice care in Beijing, this paper first analyzes the current situation of hospice care in Beijing, and t...In recent years, hospice care in Beijing has developed rapidly. In order to further promote the development of hospice care in Beijing, this paper first analyzes the current situation of hospice care in Beijing, and then analyzes the existing problems of hospice care in Beijing, such as insufficient funds, lack of medical staff, no unified public information platform and low acceptance of hospice care. In view of the existing problems, the paper puts forward relevant policy suggestions for the development of hospice care in Beijing, such as increasing financial support, strengthening the propaganda and education of hospice care, strengthening the training of professional talents, improving the voluntary service system, formulating reasonable access standards, and building a unified public information platform, so as to further promote the effective, healthy and rapid development of hospice care in Beijing development.展开更多
Dear Editor,This letter proposes a new pattern matching method based on word embedding and dynamic time warping(DTW)to identify groups of similar alarm floods.First,alarm messages are transformed into numeric values t...Dear Editor,This letter proposes a new pattern matching method based on word embedding and dynamic time warping(DTW)to identify groups of similar alarm floods.First,alarm messages are transformed into numeric values that represent alarms and also reflect the relationships between alarm occurrences.Then,similarities between numerically encoded alarm flood sequences are calculated by DTW and groups of similar floods are identified via clustering.The effectiveness of the proposed method is demonstrated by a case study with alarm&event data obtained from a public industrial simulation model.展开更多
Auxetic two-dimensional(2D)materials,known from their negative Poisson's ratios(NPRs),exhibit the unique property of expanding(contracting)longitudinally while being laterally stretched(compressed),contrary to typ...Auxetic two-dimensional(2D)materials,known from their negative Poisson's ratios(NPRs),exhibit the unique property of expanding(contracting)longitudinally while being laterally stretched(compressed),contrary to typical materials.These materials offer improved mechanical characteristics and hold great potential for applications in nanoscale devices such as sensors,electronic skins,and tissue engineering.Despite their promising attributes,the availability of 2D materials with NPRs is limited,as most 2D layered materials possess positive Poisson's ratios.In this study,we employ first-principles high-throughput calculations to systematically explore Poisson's ratios of 40 commonly used 2D monolayer materials,along with various bilayer structures.Our investigation reveals that BP,GeS and GeSe exhibit out-of-plane NPRs due to their hinge-like puckered structures.For 1T-type transition metal dichalcogenides such as M X_(2)(M=Mo,W;X=S,Se,Te)and transition metal selenides/halides the auxetic behavior stems from a combination of geometric and electronic structural factors.Notably,our findings unveil V_(2)O_(5) as a novel material with out-of-plane NPR.This behavior arises primarily from the outward movement of the outermost oxygen atoms triggered by the relaxation of strain energy under uniaxial tensile strain along one of the in-plane directions.Furthermore,our computations demonstrate that Poisson's ratio can be tuned by varying the bilayer structure with distinct stacking modes attributed to interlayer coupling disparities.These results not only furnish valuable insights into designing 2D materials with a controllable NPR but also introduce V_(2)O_(5) as an exciting addition to the realm of auxetic 2D materials,holding promise for diverse nanoscale applications.展开更多
Open framework structures(e.g.,ScF_(3),Sc_(2)W_(3O)_(12),etc.)exhibit significant potential for thermal expansion tailoring owing to their high atomic vibrational degrees of freedom and diverse connectivity between po...Open framework structures(e.g.,ScF_(3),Sc_(2)W_(3O)_(12),etc.)exhibit significant potential for thermal expansion tailoring owing to their high atomic vibrational degrees of freedom and diverse connectivity between polyhedral units,displaying positive/negative thermal expansion(PTE/NTE)coefficients at a certain temperature.Despite the proposal of several physical mechanisms to explain the origin of NTE,an accurate mapping relationship between the structural–compositional properties and thermal expansion behavior is still lacking.This deficiency impedes the rapid evaluation of thermal expansion properties and hinders the design and development of such materials.We developed an algorithm for identifying and characterizing the connection patterns of structural units in open-framework structures and constructed a descriptor set for the thermal expansion properties of this system,which is composed of connectivity and elemental information.Our developed descriptor,aided by machine learning(ML)algorithms,can effectively learn the thermal expansion behavior in small sample datasets collected from literature-reported experimental data(246 samples).The trained model can accurately distinguish the thermal expansion behavior(PTE/NTE),achieving an accuracy of 92%.Additionally,our model predicted six new thermodynamically stable NTE materials,which were validated through first-principles calculations.Our results demonstrate that developing effective descriptors closely related to thermal expansion properties enables ML models to make accurate predictions even on small sample datasets,providing a new perspective for understanding the relationship between connectivity and thermal expansion properties in the open framework structure.The datasets that were used to support these results are available on Science Data Bank,accessible via the link https://doi.org/10.57760/sciencedb.j00113.00100.展开更多
In the original version,Fig.5(f)is misused because it is identical to Fig.5(e).Figure 5 after correction is shown below:The authors apologize for any confusion.
Lithium-rich layered oxides always suffer from low initial Coulombic efficiency,poor rate capability and rapid voltage fading.Herein,engineering oxygen vacancies in hierarchically Li1.2Mn0.54Ni0.13Co0.13O2 porous micr...Lithium-rich layered oxides always suffer from low initial Coulombic efficiency,poor rate capability and rapid voltage fading.Herein,engineering oxygen vacancies in hierarchically Li1.2Mn0.54Ni0.13Co0.13O2 porous microspheres(L@S)is carried out to suppress the formation of irreversible Li20 during the initial discharge process and improve the Li+diffusion kinetics and structural stability of the cathode mateiral.As a result,the prepared L@S cathode delivers high initial Coulombic efficiency of 92.3%and large specific capacity of 292.6 mA h g^-1 at 0.1 C.More importantly,a large reversible capacity of 222 mA h g^-1 with a capacity retention of95.7%can be obtained after 100 cycles at 10 C.Even cycled at ultrahigh rate of 20 C,the L@S cathode can deliver stable reversible capacity of 153 mA h g^-1 after 100 cycles.Moreover,the full cell using L@S as cathode and Li4 Ti5 O12 as anode exhibits a relatively high reversible capacity of 141 mA h g^-1 with an outstanding voltage retention of 97%after 400 cycles at a large current density of 3 C.These results may shed light on the improvement of electrochemical performances of lithiumrich layered oxides via the multiscale coordinated design based on atomic defects,microstructure and composition.展开更多
Introduction:Tracing transmission paths and identifying infection sources have been effective in curbing the spread of coronavirus disease 2019(COVID-19).However,when facing a large-scale outbreak,this is extremely ti...Introduction:Tracing transmission paths and identifying infection sources have been effective in curbing the spread of coronavirus disease 2019(COVID-19).However,when facing a large-scale outbreak,this is extremely time-consuming and laborintensive,and resources for infection source tracing become limited.In this study,we aimed to use knowledge graph(KG)technology to automatically infer transmission paths and infection sources.Methods:We constructed a KG model to automatically extract epidemiological information and contact relationships from case reports.We then used an inference engine to identify transmission paths and infection sources.To test the model’s performance,we used data from two COVID-19 outbreaks in Beijing.Results:The KG model performed well for both outbreaks.In the first outbreak,20 infection relationships were identified manually,while 42 relationships were determined using the KG model.In the second outbreak,32 relationships were identified manually and 31 relationships were determined using the KG model.All discrepancies and omissions were reasonable.Discussion:The KG model is a promising tool for predicting and controlling future COVID-19 epidemic waves and other infectious disease pandemics.By automatically inferring the source of infection,limited resources can be used efficiently to detect potential risks,allowing for rapid outbreak control.展开更多
Two-dimensional layered materials(2DLMs)have attracted growing attention in optoelectronic devices due to their intriguing anisotropic physical properties.Different members of 2DLMs exhibit unique anisotropic electric...Two-dimensional layered materials(2DLMs)have attracted growing attention in optoelectronic devices due to their intriguing anisotropic physical properties.Different members of 2DLMs exhibit unique anisotropic electrical,optical,and thermal properties,fundamentally related to their crystal structure.Among them,directional heat transfer plays a vital role in the thermal management of electronic devices.Here,we use density functional theory calculations to investigate the thermal transport properties of representative layered materials:β-InSe,γ-InSe,MoS2,and h-BN.We found that the lattice thermal conductivities ofβ-InSe,γ-InSe,MoS_(2),and h-BN display diverse anisotropic behaviors with anisotropy ratios of 10.4,9.4,64.9,and 107.7,respectively.The analysis of the phonon modes further indicates that the phonon group velocity is responsible for the anisotropy of thermal transport.Furthermore,the low lattice thermal conductivity of the layered InSe mainly comes from low phonon group velocity and atomic masses.Our findings provide a fundamental physical understanding of the anisotropic thermal transport in layered materials.We hope this study could inspire the advancement of 2DLMs thermal management applications in next-generation integrated electronic and optoelectronic devices.展开更多
It is still a challenge to prepare a water-and polymer-based electrospun air filter film with high efficiency filtration,low pressure drop,and good mechanical properties.To address this issue,polyvinyl alcohol(PVA)was...It is still a challenge to prepare a water-and polymer-based electrospun air filter film with high efficiency filtration,low pressure drop,and good mechanical properties.To address this issue,polyvinyl alcohol(PVA)was employed as the main material,mixing polyethyleneimine(PEI),bamboo-based activated carbon(BAC)and cellulose nanocrystal(CNC)to construct the air filter film by electrostatic electrospinning.In this system,the negatively charged BAC and CNC are fixed in the system through bonding with the positively charged PEI,showing a double adsorption effect.One is the mechanical filtration of the porous network structure constructed by PVA@PEI electrospun nanofibers,and the other is the electrostatic adsorption of PM2.5 on the surface of BAC and CNC.It is significant that the resulting composite air filter displays a high filtration efficiency of 95.86%,a pressure drop of only 59 Pa,and good thermal stability.Moreover,the introduced methyltrimethoxysilane(MTMS)endows it with good water-resistance.Given these excellent performances,this system can provide theoretical and technical references for the development of water-and polymerbased electrospun air filter film.展开更多
In this Letter,we have experimentally verified a low-complexity subcarrier pairwise-averaging(SPA)-enhanced channel estimation(CE)method for small-size fast Fourier transform(FFT)non-Hermitian symmetric orthogonal fre...In this Letter,we have experimentally verified a low-complexity subcarrier pairwise-averaging(SPA)-enhanced channel estimation(CE)method for small-size fast Fourier transform(FFT)non-Hermitian symmetric orthogonal frequency-division multiplexing(NHS-OFDM)transceivers.Compared with intra-symbol frequency averaging(ISFA),more than 20% look-up tables and 10%logic power consumption can be saved.The least-square(LS),ISFA,and SPA CE methods are compared by offline and real-time digital signal processing approaches.The results show that the receiver sensitivity of the SPA NHS-OFDM transmission system with 64/128-point FFT can be improved by more than 1 dB at the bit error rate of 3.8 ×10^(-3) compared to the LS.展开更多
In recent years,superhydrophobic coatings have received extensive attention due to their functions of waterproof,antifouling,self-cleaning,etc.However,wide applications of superhydrophobic coatings are still affected ...In recent years,superhydrophobic coatings have received extensive attention due to their functions of waterproof,antifouling,self-cleaning,etc.However,wide applications of superhydrophobic coatings are still affected by their disadvantages of complex preparation,low mechanical properties,and poor ultraviolet(UV)resistance.In this study,cellulose nanocrystal containing a small amount of lignin(L-CNC)/SiO_(2)composite particles were usedas the main material,polydimethylsiloxane(PDMS)as the adhesive and perfluorooctyltrichlorosilane(FOTS)as the modifier to prepare superhydrophobic coatings by a one-step spray method.The resulted coating showed excellent superhydrophobicity(water contact angle(WCA)of 161°and slide angle(SA)of 7)and high abrasion resistance(capable of withstanding 50 abrasion cycles under the load of 50 g).Moreover,it still maintained good superhydrophobicity after 5 h of exposure to the UV light(1000 W),displaying its good UV resistance.This study provides theoretical and technical referencefor thesimple preparationof organic-inorganic composite superhydrophobic coatings with high abrasion resistance and good UV resistance,which is beneficial to improving the practicability and broadening the application scope of superhydrophobic coatings.展开更多
In response to problems of poor sampling quality,low sensitivity,and high demand for medical personnel regarding the current severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)oropharyngeal(OP)swab sampling us...In response to problems of poor sampling quality,low sensitivity,and high demand for medical personnel regarding the current severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)oropharyngeal(OP)swab sampling used in China,we aimed to evaluate the diagnostic performance and acceptability of saliva-based nucleic acid amplification tests(NAATs)in China.The results showed that,using nasopharyngeal(NP)swab results as the gold standard,the overall sensitivities for saliva specimens and OP swabs were 93.3%and 85.0%,the specificities were 92.6%and 93.8%,respectively.The results of an acceptability survey showed that the scores for saliva,OP,and NP samples were 9.46±1.69,8.11±2.42,and 4.58±3.82 out of 10,respectively,with significant differences among the three groups(P<0.05).With higher sensitivity,comparable specificity,and strong public preference,saliva-based NAATs represent a convenient and effective method for detecting SARS-CoV-2 in future epidemics.展开更多
文摘In recent years, hospice care in Beijing has developed rapidly. In order to further promote the development of hospice care in Beijing, this paper first analyzes the current situation of hospice care in Beijing, and then analyzes the existing problems of hospice care in Beijing, such as insufficient funds, lack of medical staff, no unified public information platform and low acceptance of hospice care. In view of the existing problems, the paper puts forward relevant policy suggestions for the development of hospice care in Beijing, such as increasing financial support, strengthening the propaganda and education of hospice care, strengthening the training of professional talents, improving the voluntary service system, formulating reasonable access standards, and building a unified public information platform, so as to further promote the effective, healthy and rapid development of hospice care in Beijing development.
基金supported by the National Natural Science Foundation of China (61903345)the Knowledge Innovation Program of Wuhan-Shuguang Project (2022010801020208)
文摘Dear Editor,This letter proposes a new pattern matching method based on word embedding and dynamic time warping(DTW)to identify groups of similar alarm floods.First,alarm messages are transformed into numeric values that represent alarms and also reflect the relationships between alarm occurrences.Then,similarities between numerically encoded alarm flood sequences are calculated by DTW and groups of similar floods are identified via clustering.The effectiveness of the proposed method is demonstrated by a case study with alarm&event data obtained from a public industrial simulation model.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1402500)Calculations were performed in part at High-Performance Computing Center,Jilin University。
文摘Auxetic two-dimensional(2D)materials,known from their negative Poisson's ratios(NPRs),exhibit the unique property of expanding(contracting)longitudinally while being laterally stretched(compressed),contrary to typical materials.These materials offer improved mechanical characteristics and hold great potential for applications in nanoscale devices such as sensors,electronic skins,and tissue engineering.Despite their promising attributes,the availability of 2D materials with NPRs is limited,as most 2D layered materials possess positive Poisson's ratios.In this study,we employ first-principles high-throughput calculations to systematically explore Poisson's ratios of 40 commonly used 2D monolayer materials,along with various bilayer structures.Our investigation reveals that BP,GeS and GeSe exhibit out-of-plane NPRs due to their hinge-like puckered structures.For 1T-type transition metal dichalcogenides such as M X_(2)(M=Mo,W;X=S,Se,Te)and transition metal selenides/halides the auxetic behavior stems from a combination of geometric and electronic structural factors.Notably,our findings unveil V_(2)O_(5) as a novel material with out-of-plane NPR.This behavior arises primarily from the outward movement of the outermost oxygen atoms triggered by the relaxation of strain energy under uniaxial tensile strain along one of the in-plane directions.Furthermore,our computations demonstrate that Poisson's ratio can be tuned by varying the bilayer structure with distinct stacking modes attributed to interlayer coupling disparities.These results not only furnish valuable insights into designing 2D materials with a controllable NPR but also introduce V_(2)O_(5) as an exciting addition to the realm of auxetic 2D materials,holding promise for diverse nanoscale applications.
基金the National Natural Science Foundation of China(Grant Nos.12004131,22090044,62125402,and 92061113)。
文摘Open framework structures(e.g.,ScF_(3),Sc_(2)W_(3O)_(12),etc.)exhibit significant potential for thermal expansion tailoring owing to their high atomic vibrational degrees of freedom and diverse connectivity between polyhedral units,displaying positive/negative thermal expansion(PTE/NTE)coefficients at a certain temperature.Despite the proposal of several physical mechanisms to explain the origin of NTE,an accurate mapping relationship between the structural–compositional properties and thermal expansion behavior is still lacking.This deficiency impedes the rapid evaluation of thermal expansion properties and hinders the design and development of such materials.We developed an algorithm for identifying and characterizing the connection patterns of structural units in open-framework structures and constructed a descriptor set for the thermal expansion properties of this system,which is composed of connectivity and elemental information.Our developed descriptor,aided by machine learning(ML)algorithms,can effectively learn the thermal expansion behavior in small sample datasets collected from literature-reported experimental data(246 samples).The trained model can accurately distinguish the thermal expansion behavior(PTE/NTE),achieving an accuracy of 92%.Additionally,our model predicted six new thermodynamically stable NTE materials,which were validated through first-principles calculations.Our results demonstrate that developing effective descriptors closely related to thermal expansion properties enables ML models to make accurate predictions even on small sample datasets,providing a new perspective for understanding the relationship between connectivity and thermal expansion properties in the open framework structure.The datasets that were used to support these results are available on Science Data Bank,accessible via the link https://doi.org/10.57760/sciencedb.j00113.00100.
文摘In the original version,Fig.5(f)is misused because it is identical to Fig.5(e).Figure 5 after correction is shown below:The authors apologize for any confusion.
基金support from the National Key R&D Program of China(2016YFA0202602 and2016YFA0202604)the National Natural Science Foundation of China(51701169 and 51871188)+2 种基金the Natural Science Foundation of Fujian Province(2017J05087)the Key Projects of Youth Natural Foundation for the Universities of Fujian Province of China(JZ160397)the“Double-First Class” Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University
文摘Lithium-rich layered oxides always suffer from low initial Coulombic efficiency,poor rate capability and rapid voltage fading.Herein,engineering oxygen vacancies in hierarchically Li1.2Mn0.54Ni0.13Co0.13O2 porous microspheres(L@S)is carried out to suppress the formation of irreversible Li20 during the initial discharge process and improve the Li+diffusion kinetics and structural stability of the cathode mateiral.As a result,the prepared L@S cathode delivers high initial Coulombic efficiency of 92.3%and large specific capacity of 292.6 mA h g^-1 at 0.1 C.More importantly,a large reversible capacity of 222 mA h g^-1 with a capacity retention of95.7%can be obtained after 100 cycles at 10 C.Even cycled at ultrahigh rate of 20 C,the L@S cathode can deliver stable reversible capacity of 153 mA h g^-1 after 100 cycles.Moreover,the full cell using L@S as cathode and Li4 Ti5 O12 as anode exhibits a relatively high reversible capacity of 141 mA h g^-1 with an outstanding voltage retention of 97%after 400 cycles at a large current density of 3 C.These results may shed light on the improvement of electrochemical performances of lithiumrich layered oxides via the multiscale coordinated design based on atomic defects,microstructure and composition.
基金Supported by National Key Research and Development Program of China(2021ZD0114102)Science Program of Beijing City(Z221100007922019)Beijing Natural Science Foundation(7202073).
文摘Introduction:Tracing transmission paths and identifying infection sources have been effective in curbing the spread of coronavirus disease 2019(COVID-19).However,when facing a large-scale outbreak,this is extremely time-consuming and laborintensive,and resources for infection source tracing become limited.In this study,we aimed to use knowledge graph(KG)technology to automatically infer transmission paths and infection sources.Methods:We constructed a KG model to automatically extract epidemiological information and contact relationships from case reports.We then used an inference engine to identify transmission paths and infection sources.To test the model’s performance,we used data from two COVID-19 outbreaks in Beijing.Results:The KG model performed well for both outbreaks.In the first outbreak,20 infection relationships were identified manually,while 42 relationships were determined using the KG model.In the second outbreak,32 relationships were identified manually and 31 relationships were determined using the KG model.All discrepancies and omissions were reasonable.Discussion:The KG model is a promising tool for predicting and controlling future COVID-19 epidemic waves and other infectious disease pandemics.By automatically inferring the source of infection,limited resources can be used efficiently to detect potential risks,allowing for rapid outbreak control.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1402502)the National Natural Science Foundation of China(Grant Nos.12004131,22090044,and 62125402)Calculations were performed in part at the high-performance computing center of Jilin University.
文摘Two-dimensional layered materials(2DLMs)have attracted growing attention in optoelectronic devices due to their intriguing anisotropic physical properties.Different members of 2DLMs exhibit unique anisotropic electrical,optical,and thermal properties,fundamentally related to their crystal structure.Among them,directional heat transfer plays a vital role in the thermal management of electronic devices.Here,we use density functional theory calculations to investigate the thermal transport properties of representative layered materials:β-InSe,γ-InSe,MoS2,and h-BN.We found that the lattice thermal conductivities ofβ-InSe,γ-InSe,MoS_(2),and h-BN display diverse anisotropic behaviors with anisotropy ratios of 10.4,9.4,64.9,and 107.7,respectively.The analysis of the phonon modes further indicates that the phonon group velocity is responsible for the anisotropy of thermal transport.Furthermore,the low lattice thermal conductivity of the layered InSe mainly comes from low phonon group velocity and atomic masses.Our findings provide a fundamental physical understanding of the anisotropic thermal transport in layered materials.We hope this study could inspire the advancement of 2DLMs thermal management applications in next-generation integrated electronic and optoelectronic devices.
基金the China Postdoctoral Science Foundation(No.2021M692806)the Natural Science Foundation of Zhejiang Province(No.LY21C160002)the Scientific Research Development Foundation of Zhejiang A&F University(No.2018FR054).
文摘It is still a challenge to prepare a water-and polymer-based electrospun air filter film with high efficiency filtration,low pressure drop,and good mechanical properties.To address this issue,polyvinyl alcohol(PVA)was employed as the main material,mixing polyethyleneimine(PEI),bamboo-based activated carbon(BAC)and cellulose nanocrystal(CNC)to construct the air filter film by electrostatic electrospinning.In this system,the negatively charged BAC and CNC are fixed in the system through bonding with the positively charged PEI,showing a double adsorption effect.One is the mechanical filtration of the porous network structure constructed by PVA@PEI electrospun nanofibers,and the other is the electrostatic adsorption of PM2.5 on the surface of BAC and CNC.It is significant that the resulting composite air filter displays a high filtration efficiency of 95.86%,a pressure drop of only 59 Pa,and good thermal stability.Moreover,the introduced methyltrimethoxysilane(MTMS)endows it with good water-resistance.Given these excellent performances,this system can provide theoretical and technical references for the development of water-and polymerbased electrospun air filter film.
基金This work was supported in part by the National Natural Science Foundation of China(No.61805079)the Hunan Provincial Natural Science Foundation(No.2020JJ4433)the Hunan Province College Students Research Learning and Innovative Experiment Project,China(No.S202010542058).
文摘In this Letter,we have experimentally verified a low-complexity subcarrier pairwise-averaging(SPA)-enhanced channel estimation(CE)method for small-size fast Fourier transform(FFT)non-Hermitian symmetric orthogonal frequency-division multiplexing(NHS-OFDM)transceivers.Compared with intra-symbol frequency averaging(ISFA),more than 20% look-up tables and 10%logic power consumption can be saved.The least-square(LS),ISFA,and SPA CE methods are compared by offline and real-time digital signal processing approaches.The results show that the receiver sensitivity of the SPA NHS-OFDM transmission system with 64/128-point FFT can be improved by more than 1 dB at the bit error rate of 3.8 ×10^(-3) compared to the LS.
基金supported by the National Natural Science Foundation of China(Grant No.31901246)the Natural Science Foundation of Zhejiang Province(Grant No.LY21C160002)the Scientific Research Development Foundation of Zhejiang A&F University(Grant No.2021KX0042).
文摘In recent years,superhydrophobic coatings have received extensive attention due to their functions of waterproof,antifouling,self-cleaning,etc.However,wide applications of superhydrophobic coatings are still affected by their disadvantages of complex preparation,low mechanical properties,and poor ultraviolet(UV)resistance.In this study,cellulose nanocrystal containing a small amount of lignin(L-CNC)/SiO_(2)composite particles were usedas the main material,polydimethylsiloxane(PDMS)as the adhesive and perfluorooctyltrichlorosilane(FOTS)as the modifier to prepare superhydrophobic coatings by a one-step spray method.The resulted coating showed excellent superhydrophobicity(water contact angle(WCA)of 161°and slide angle(SA)of 7)and high abrasion resistance(capable of withstanding 50 abrasion cycles under the load of 50 g).Moreover,it still maintained good superhydrophobicity after 5 h of exposure to the UV light(1000 W),displaying its good UV resistance.This study provides theoretical and technical referencefor thesimple preparationof organic-inorganic composite superhydrophobic coatings with high abrasion resistance and good UV resistance,which is beneficial to improving the practicability and broadening the application scope of superhydrophobic coatings.
基金supported by Science Program of Beijing City[grant number Z221100007922019]the High Level Public Health Technical Talent Training Plan[grant number xuekegugan-01-019]National Key Research and Development Project of China[grant number 2023YFC0872400]。
文摘In response to problems of poor sampling quality,low sensitivity,and high demand for medical personnel regarding the current severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)oropharyngeal(OP)swab sampling used in China,we aimed to evaluate the diagnostic performance and acceptability of saliva-based nucleic acid amplification tests(NAATs)in China.The results showed that,using nasopharyngeal(NP)swab results as the gold standard,the overall sensitivities for saliva specimens and OP swabs were 93.3%and 85.0%,the specificities were 92.6%and 93.8%,respectively.The results of an acceptability survey showed that the scores for saliva,OP,and NP samples were 9.46±1.69,8.11±2.42,and 4.58±3.82 out of 10,respectively,with significant differences among the three groups(P<0.05).With higher sensitivity,comparable specificity,and strong public preference,saliva-based NAATs represent a convenient and effective method for detecting SARS-CoV-2 in future epidemics.
