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Clinical observation of effects of pidotimod combined with ribavirin on inflammatory factors, T lymphocyte subsets, immunoglobulin and blood biochemical markers in children with hand-foot-mouth disease
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作者 Shi-Chao Zhang Sha-Sha Wang +2 位作者 jing-feng li Na Ding Jian-Hong Ren 《Journal of Hainan Medical University》 2017年第17期87-90,共4页
Objective:To observe the effects of pidotimod combined with ribavirin on inflammatory factors, T lymphocyte subsets, immunoglobulin, lactate, D-dimer and procalcitonin in children with hand-foot-mouth disease.Methods:... Objective:To observe the effects of pidotimod combined with ribavirin on inflammatory factors, T lymphocyte subsets, immunoglobulin, lactate, D-dimer and procalcitonin in children with hand-foot-mouth disease.Methods: A total of 108 children with foot-hand-and-mouth epidemic in our hospital from Jan. 2013-Dec. 2016 were divide into the observation group and the control group, each groups has 54 cases. Two groups of children were treated with isolation, the observation group was given pidotimod combined with ribavirin, and the control group was treated with ribavirin. 5 mL venous blood of two group patients were collected at admission and after 6 d treatment, respectively, to compare inflammatory factor, T lymphocyte subsets, immunoglobulin, lactate, D-dimer and procalcitonin in two groups.Results: Before treatment, the levels of inflammatory factor, T lymphocyte subsets, immunoglobulin, lactate, D-dimer and procalcitonin of two groups were not statistically significant. Compared with groups after treatment, the levels of CRP, IL-6, TNF-α were lower than that before treatment, CRP (2.23±0.37) mg/L, IL-6 (21.24±9.81) pg/mL and TNF-α (56.97±50.36) pg/mL levels in observation group after treatment were significantly lower than those in control group, the difference was statistically significant. After treatment, the levels of CD3, CD4, CD4/CD8, IgG, IgA and IgM in control group were significantly higher than that before treatment, the difference was statistically significant;After treatment, the levels of CD3 (51.26±10.27)%, CD4 (36.36±4.09)% and CD4/CD8 (1.60±0.47), IgG (10.24±1.82) mg/L, IgA (1.30±0.31) mg/L and IgM (1.48±0.30) mg/L in observation group were significantly higher than in control group, the difference was statistically significant. After treatment, the levels of lactate, D-dimer and procalcitonin in two groups were significantly lower than that before treatment, the difference was statistically significant;After treatment, the levels of lactate (1.19±0.20) mmol/L, D-dimer (150.23±27.21) ng/mL, and procalcitonin (0.08±0.02) ng/mL in observation group were significantly higher than in control group, the difference was statistically significant. Conclusion: Pidotimod combined with ribavirin has a pronounced effect on children with hand-foot-mouth disease, which can effectively reduce the body's inflammatory response, enhance immune function, improve clinical biochemical indicators, and should be widely recommended for clinical use. 展开更多
关键词 PIDOTIMOD RIBAVIRIN Hand FOOT and MOUTH disease INFLAMMATORY factors Immune function
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Coxsackievirus A6 was the most common enterovirus serotype causing hand,foot,and mouth disease in Shiyan City,central China 被引量:4
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作者 jing-feng li Chuan-Jie Zhang +8 位作者 Ya-Wei li Chao li Shi-Chao Zhang Sha-Sha Wang Yong Jiang Xin-Bing Luo Xing-Juan liao Shou-Xin Wu ling lin 《World Journal of Clinical Cases》 SCIE 2022年第31期11358-11370,共13页
BACKGROUND Hand,foot,and mouth disease(HFMD)has become one of the most common infectious diseases in China.Before 2016,the primary causal serotypes were enterovirus A71(EV-A71)and coxsackievirus A16(CV-A16).Following ... BACKGROUND Hand,foot,and mouth disease(HFMD)has become one of the most common infectious diseases in China.Before 2016,the primary causal serotypes were enterovirus A71(EV-A71)and coxsackievirus A16(CV-A16).Following the introduction of EV-A71 vaccines in China since 2016,the situation could change.CV-A6 has recently replaced EV-A71 and CV-A16 in some areas of China.However,the epidemiological characteristics of central China remain unknown.AIM To investigate the clinical symptoms and pathogen spectrum of HFMD in Shiyan City,central China,in recent years.METHODS The epidemiological,clinical,and laboratory data from HFMD cases reported to the Shiyan Center for Disease Control and Prevention between January 2016 and December 2020 were analyzed.196 throat swab specimens were collected from hospitalized HFMD patients between January 2018 and December 2020.To detect and genotype enteroviruses,real-time reverse transcription-polymerase chain reaction and sequencing of the 5'-untranslated region were used.In Shiyan,168 laboratory-confirmed HFMD cases were studied using a logistic regression model to determine the effect of predominant enterovirus serotypes.Based on the logistic regression model,the least absolute shrinkage and selection operator model was used to analyze the correlation between CV-A6 infection and various clinical characteristics in HFMD patients in Shiyan.RESULTS From 2016 to 2020,35840 HFMD cases were reported in Shiyan.The number of cases decreased by 48.4%from 2016 to 2017.Approximately 1.58-fold increases were found in 2018 and 2019 when compared to the previous year,respectively.In 2020,a decrease of about 85.5%was reported when compared to 2019.The most common serotypes shifted from EV-A71 and CV-A16(about 60%-80%in 2016 and 2018)to others(more than 80.0%in 2017,2019,and 2020).EV-A71 lost its dominance in 2017 in Shiyan.Among 196 confirmed HFMD cases,85.7%tested positive for enterovirus,with CV-A6 being the most common serotype(121/168,72.0%).The positive rates for CV-A16 and CVA10 were 4.8%and 3.0%,respectively.There was no EV-A71 discovered.Infection with CV-A6 was linked to fever,myocardial damage,increased creatine kinase MB isoenzyme,and lactate dehydrogenase levels.CONCLUSION CV-A6 was the most common enterovirus serotype in Shiyan City,replacing EV-A71 and CV-A16 as the HFMD pathogen.Developing vaccines against CV-A6 or multiple pathogens,as well as rising CV-A6 surveillance,will help prevent HFMD in central China. 展开更多
关键词 Hand foot and mouth disease Coxsackievirus A6 ENTEROVIRUS Prevalence serotype Fever Myocardial damage
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Delineating complex ferroelectric domain structures via second harmonic generation spectral imaging
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作者 Wei li Yunpeng Ma +5 位作者 Tianyi Feng Ziwan Du Yixuan liu Sergei VKalinin jing-feng li Qian li 《Journal of Materiomics》 SCIE CSCD 2023年第2期395-402,共8页
Understanding the mechanisms and spatial correlations of crystallographic symmetry breaking in ferroelectric materials is essential to tuning their functional properties.While optical second harmonic generation(SHG)ha... Understanding the mechanisms and spatial correlations of crystallographic symmetry breaking in ferroelectric materials is essential to tuning their functional properties.While optical second harmonic generation(SHG)has long been utilized in ferroelectric studies,its capability for probing complex polar materials has yet to be fully realized.Here,we develop a SHG spectral imaging method implemented on a home-designed laser-scanning SHG microscope,and demonstrate its application for a model system of(K,Na)NbO3 single crystals.Supervised model fitting analysis produces comprehensive information about the polarization vector orientations and relative fractions of constituent domain variants as well as their thermal evolution across the polymorphic phase transitions.Multiple domains and phases are clearly delineated at different temperatures,suggesting the phase competitions in(K,Na)NbO3.Besides,we show that unsupervised matrix decomposition analysis can quickly and faithfully reveal domain configurations without a priori knowledge about specific material systems.The SHG spectral imaging method can be readily extended to other ferroelectric materials with potentials to be further enhanced. 展开更多
关键词 Second harmonic generation FERROELECTRICS Domain structure Bayes linear unmixing
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Enhanced energy storage properties and antiferroelectric stability of Mn-doped NaNbO_(3)-CaHfO_(3) lead-free ceramics:Regulating phase structure and tolerance factor
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作者 Yang Yin Jing-Ru Yu +6 位作者 Yu-Cheng Tang Ai-Zhen Song Huan liu Dong Yang jing-feng li Lei Zhao Bo-Ping Zhang 《Journal of Materiomics》 SCIE 2022年第3期611-617,共7页
NaNbO_(3)-based ceramics usually show ferroelectric-like P-E loops at room temperature due to the irreversible transformation of the antiferroelectric orthorhombic phase to ferroelectric orthorhombic phase,which is no... NaNbO_(3)-based ceramics usually show ferroelectric-like P-E loops at room temperature due to the irreversible transformation of the antiferroelectric orthorhombic phase to ferroelectric orthorhombic phase,which is not conducive to energy storage applications.Our previous work found that incorporating CaHfO_(3) into NaNbO_(3) can stabilize its antiferroelectric phase by reducing the tolerance factor(t),as indicated by the appearance of characteristic double P-E loops.Furthermore,a small amount of MnO_(2) addition effectively regulate the phase structure and tolerance factor of 0.94NaNbO_(3)-0.06CaHfO_(3)(0.94NN-0.06CH),which can further improve the stability of antiferroelectricity.The XRD and XPS results reveal that the Mn ions preferentially replace A-sites and then B-sites as increasing MnO_(2).The antiferroelectric orthorhombic phase first increases and then decreases,while the t shows the reversed trend,thus an enhanced antiferroelectricity and the energy storage density Wrec of 1.69 J/cm^(3) at 240 kV/cm are obtained for 0.94NN-0.06CH-0.5%MnO_(2)(in mass fraction).With the increase of Mn content to 1.0%from 0.5%,the efficiency increases to 81% from 45%,although the energy storage density decreases to 1.31 J/cm^(3) due to both increased tolerance factor and non-polar phase. 展开更多
关键词 NaNbO_(3) Antiferroelectric ceramic Tolerance factor Energy-storage density
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(K,Na)NbO_(3)-based lead-free ceramics with enhanced temperature-stable piezoelectricity and efficient red luminescence
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作者 Qing liU Er PAN +1 位作者 Fucai liU jing-feng li 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2023年第2期373-385,共13页
There has been a surge of research interest in the promising lead-free potassium-sodium niobate(KNN)-based ceramics,applications of which could be significantly promoted by improving thermal stability of piezoelectric... There has been a surge of research interest in the promising lead-free potassium-sodium niobate(KNN)-based ceramics,applications of which could be significantly promoted by improving thermal stability of piezoelectricity.Besides,endowing the KNN-based ceramics with photoluminescence property by rare-earth-ion doping can make them more completive lead-free counterparts in potential applications such as novel multifunctional sensing devices.Herein,a novel KNN-based ceramic material doped with Eu was elaborately designed to simultaneously obtain enhanced temperaturestable piezoelectricity and good luminescence property.By the introduction of diffused phase transition and the modulation of unit cell distortion,a large piezoelectric strain coefficient(d^(*)_(33))with a small variation(590±59 pm/V)over a wide temperature range(from room temperature to 110℃)was realized.The optimal composition also exhibited a considerable piezoelectric coefficient(d_(33))with small fluctuation(330±33 pC/N)from 20 to 80℃.In addition to the enhanced temperature-stable piezoelectricity,the luminescence of these ceramics was slightly enhanced with the elevation of BaZrO_(3)(BZ)doping contents,which could be attributed to the increased compositional disorder and the decreased unit cell distortion of the matrix material.Moreover,an optical characteristic was more prominent at ultra-low temperatures.This work unprecedentedly provides a novel paradigm for the design of multifunctional KNN-based ceramics with enhanced temperature-stable piezoelectricity and good luminescence property,revealing the great potential of the rare-earth-element-doped KNN material for future applications in the novel multifunctional devices. 展开更多
关键词 piezoelectric thermal stability RARE-EARTH LEAD-FREE potassium-sodium niobate(KNN)
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B-Site Nanoscale-Ordered Structure Enables Ultra-High Tunable Performance
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作者 Biaolin Peng Qiuping Lu +7 位作者 Yi-Chi Wang jing-feng li Qi Zhang Haitao Huang Laijun liu Chao li limei Zheng Zhong lin Wang 《Research》 EI CAS CSCD 2023年第1期413-426,共14页
Tunable devices constructed by ferroelectric thin flms are often desired to possess a low dielectric loss while maintainging a high dielectric tunability over a broad operating temperature range in applications,for ex... Tunable devices constructed by ferroelectric thin flms are often desired to possess a low dielectric loss while maintainging a high dielectric tunability over a broad operating temperature range in applications,for example,resonators,filters,or phase shifters.However,it is dificult to simultaneously achieve these characteristics by traditional strategies,such as doping and strain modifying.Here,we demonstrate that the dielectric tunability of the sol-gel-prepared Pb(Sc_(1/2)Nb_(1/2))_(0.9)(Mg_(1/3)Nb_(2/3))_(0.O3)(PSNMN)thin film can be almost doubled from~47%to~80.0%(at 10kHz)at a low electric field(~530kV/cm),and the dielectric loss can be sharply reduced by more than an order of magnitude,from~0.50 to~0.037(at 1 kHz)when the thin flm was annealed in air at 650℃ for 15h under the help of an atmosphere-compensating-block(ACB)made from the proto-PSNMN gel.Moreover,the PSNMN thin flm annealed with ACB also exhibited an extremely high thermally-stable dielectric tunability in an ultrabroad temperature range(>130 K),which could be attributed to the Maxwell-Wagner(MW)effect generated by the interface between the PSNMN disordered matrix and the B-site nanoscale-ordered structure formed during the long-term annealing process.The reduced dielectric loss is mainly benefited from the reduced concentration of oxygen vacancy and the possibie MW efects,and the enhanced dielectric tunability could be ascribed to the weaker domain-pinning effect by oxygen vacancy.The breakthrough provides a new universal strategy to achieve utrahigh tunable performance in A(B'_(1/2)B"_(1/2))O3 ferroelectric thin films with a B-site nanoscale-ordered structure,meanwhile it paves the way for ultraintergrated tunable thin-flm-devices with great phase shifter performance in practical applications. 展开更多
关键词 DIELECTRIC FERROELECTRIC BREAKTHROUGH
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(K,Na)NbO_(3)-based lead-free piezoceramics:Phase transition,sintering and property enhancement 被引量:16
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作者 Ke WANG jing-feng li 《Journal of Advanced Ceramics》 SCIE CAS 2012年第1期24-37,共14页
Most widely used piezoelectric ceramics are based on Pb(Zr,Ti)O3(PZT)composition which has adverse environmental and health effects due to its high lead content.Environmental and safety concerns with respect to the ut... Most widely used piezoelectric ceramics are based on Pb(Zr,Ti)O3(PZT)composition which has adverse environmental and health effects due to its high lead content.Environmental and safety concerns with respect to the utilization,recycling,and disposal of lead-based piezoelectric ceramics have induced a new surge in developing lead-free piezoelectric ceramics.Among all the lead-free ceramics,(K,Na)NbO3(KNN)has drawn increasing attention because of its well-balanced piezoelectric properties and better environmental compatibility.On basis of the author’s work,this review summarizes the progress that has been made in recent years on development of KNN-based piezoelectric ceramics,including crystallographic structure and phase transition analysis,pressurized solid-state sintering as well as liquid-phase-assisted sintering process,and poling treatment for property enhancement.All in all,KNN is a promising lead-free system,but more research is still required both from academic and industrial interests. 展开更多
关键词 electrical properties ferroelectric properties piezoelectric properties perovskites NIOBATES LEAD-FREE
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Cascaded electron transition in CuWO4/CdS/CDs heterostructure accelerating charge separation towards enhanced photocatalytic activity 被引量:4
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作者 Yibo Chen jing-feng li +3 位作者 Pei-Yu liao Ying-Shan Zeng Zhu Wang Zhao-Qing liu 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第6期1516-1519,共4页
CuWO4,as an n-type oxide semiconductor with a bandgap of 2.2 eV,has stimulated enormous interest as a potential broad-spectrum-active photocatalyst for environmental pollution remediations.However,rapid charge recombi... CuWO4,as an n-type oxide semiconductor with a bandgap of 2.2 eV,has stimulated enormous interest as a potential broad-spectrum-active photocatalyst for environmental pollution remediations.However,rapid charge recombination greatly hinders its practical applications.Herein,we present a cascaded electron transition pathway in a ternary heterostructure consisting of CdS quantum dots,carbon dots(CDs)and CuWO4 hollow spheres,which proves to greatly facilitate the photogenerated electron-hole separation,and eventually boosts the degradation efficiency of phenol and congo red by 100%and 46%compared to bare CuWO4.The enhanced performance of the CuWO4/CdS/CDs heterostructure mainly originates from the unidirectional electron migration from CdS to CuWO4 and then to the organics through CDs.This work elucidates the electron transfer kinetics in multi-phase system and provides a new design paradigm for optimizing the properties of CuWO4 based photocatalysts. 展开更多
关键词 Cascaded electron transition CuWO4 Hollow spheres Carbon dots PHOTOCATALYSIS
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Low-cost and environmentally benign selenides as promising thermoelectric materials 被引量:8
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作者 Tian-Ran Wei Chao-Feng Wu +1 位作者 Fu li jing-feng li 《Journal of Materiomics》 SCIE EI 2018年第4期304-320,共17页
Developing high-efficiency materials with earth-abundant and low-toxicity elements has become a popular trend in the field of thermoelectrics.Among these compounds,oxides and sulfides,the lighter,cheaper and green ana... Developing high-efficiency materials with earth-abundant and low-toxicity elements has become a popular trend in the field of thermoelectrics.Among these compounds,oxides and sulfides,the lighter,cheaper and green analogies of tellurides,have been extensively investigated and summarized as well defined classes.Nonetheless,the vast family of selenides with better electrical performance,lower thermal conductivity and higher thermoelectric efficiency have not been specially discussed.Here in this review,we present recent advances in binary and multinary selenide thermoelectric materials,covering traditional PbSe,liquid-like Cu_(2)Se,layered SnSe,diamond-like and disordered multinary compounds.The features of selenides are discussed based on both environmental concerns and from the perspective of chemical bonding,transport properties and performance.Emphasis is put on the“compositionstructure-processing-performance”relationship,and some interesting issues are addressed.Finally,challenges for thermoelectric selenides are discussed,and possible optimization strategies are also suggested. 展开更多
关键词 Thermoelectric materials SELENIDES Transport properties
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Determination of polarization states in(K,Na)NbO3 lead-free piezoelectric crystal 被引量:4
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作者 Mao-Hua ZHANG Chengpeng HU +7 位作者 Zhen ZHOU Hao TIAN Hao-Cheng THONG Yi Xuan liU Xing-Yu XU Xiao-Qing XI jing-feng li Ke WANG 《Journal of Advanced Ceramics》 SCIE CSCD 2020年第2期204-209,共6页
Polarization switching in lead-free(K0.40Na0.60)NbO3(KNN)single crystals was studied by switching spectroscopy piezoresponse force microscopy(SS-PFM).Acquisition of multiple hysteresis loops on a closely spaced square... Polarization switching in lead-free(K0.40Na0.60)NbO3(KNN)single crystals was studied by switching spectroscopy piezoresponse force microscopy(SS-PFM).Acquisition of multiple hysteresis loops on a closely spaced square grid enables polarization switching parameters to be mapped in real space.Piezoresponse amplitude and phase hysteresis loops show collective symmetric/asymmetric characteristics,affording information regarding the switching behavior of different domains.As such,the out-of-plane polarization states of the domains,including amplitudes and phases can be determined.Our results could contribute to a further understanding of the relationships between polarization switching and polarization vectors at the nanoscale,and provide a feasible method to correlate the polarization hysteresis loops in a domain under an electric field with the polarization vector states. 展开更多
关键词 PIEZOELECTRICS LEAD-FREE (K0.40Na0.60)NbO3(KNN) switching spectroscopy piezoresponse force microscopy(SS-PFM) ferroelectric domain
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Highly Textured N-Type SnSe Polycrystals with Enhanced Thermoelectric Performance 被引量:6
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作者 Peng-Peng Shang Jinfeng Dong +6 位作者 Jun Pei Fu-Hua Sun Yu Pan Huaichao Tang Bo-Ping Zhang li-Dong Zhao jing-feng li 《Research》 EI CAS 2019年第1期251-260,共10页
Thermoelectric materials,which directly convert heat into electricity based on the Seebeck effects,have long been investigated for use in semiconductor refrigeration or waste heat recovery.Among them,SnSe has attracte... Thermoelectric materials,which directly convert heat into electricity based on the Seebeck effects,have long been investigated for use in semiconductor refrigeration or waste heat recovery.Among them,SnSe has attracted significant attention due to its promising performance in both p-type and n-type crystals;in particular,a higher out-of-plane ZT value could be achieved in ntype SnSe due to its 3D charge and 2D phonon transports.In this work,the thermoelectric transport properties of n-type polycrystalline SnSe were investigated with an emphasis on the out-of-plane transport through producing textural microstructure.The textures were fabricated using mechanical alloying and repeated spark plasma sintering(SPS),as a kind of hot pressing,aimed at producing strong anisotropic transports in n-type polycrystalline SnSe as that in crystalline SnSe.Results show that the lowest thermal conductivity of 0.36 Wm^(-1) K^(-1) was obtained at 783 K in perpendicular to texture direction.Interestingly,the electrical transport properties are less anisotropic and even nearly isotropic,and the power factors reach 681.3μWm^(-1) K^(-2) at 783 K along both parallel and perpendicular directions.The combination of large isotropic power factor and low anisotropic thermal conductivity leads to a maximum ZT of 1.5 at 783 K.The high performance elucidates the outstanding electrical and thermal transport behaviors in n-type polycrystalline SnSe,and a higher thermoelectric performance can be expected with future optimizing texture in n-type polycrystalline SnSe. 展开更多
关键词 ALLOYING POLYCRYSTALLINE ANISOTROPIC
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High thermoelectric figure of merit ZT>1 in SnS polycrystals 被引量:4
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作者 Asfandiyar Bowen Cai +1 位作者 li-Dong Zhao jing-feng li 《Journal of Materiomics》 SCIE EI 2020年第1期77-85,共9页
Eco-friendly tin sulfide(SnS)has attracted increasing attention in the thermoelectric community because of its elemental abundance and analogous crystal structure to SnSe as a new thermoelectric material.However,so fa... Eco-friendly tin sulfide(SnS)has attracted increasing attention in the thermoelectric community because of its elemental abundance and analogous crystal structure to SnSe as a new thermoelectric material.However,so far no high dimensionless thermoelectric figure of merit ZT>1 was reported in SnS polycrystals.This work found an effective strategy for enhancing the thermoelectric performance of ptype polycrystalline SnS by Ag doping and vacancy engineering,leading to three orders of magnitude increase in carrier concentration and optimized effective mass and carrier mobility.As a result of the enhanced electrical conductivity,three times higher power factor ~3.85 μW/cm K^(2) at 877 K is realized in Sn_(0.995)Ag_(0.005)S sample.Interestingly,nanostructuring with Ag nano-precipitates were formed in the Agdoped SnS sample.Moreover,with introducing Sn vacancies in the crystal structure of Sn_(0.995-vac)Ag_(0.005)S,the power factor further enhanced to~4.25 μW/cm K^(2).In addition to the low-frequency phonons scattering by Ag nano-precipitates,dislocations strengthens the scattering of mid-frequency phonon,leading to an ultralow lattice thermal conductivity <0.5 W/m K above 800 K and a record high ZT up to 1.1 at 877 K in Sn_(0.99)Ag_(0.005)S polycrystals. 展开更多
关键词 Thermoelectric tin sulfide Spark plasma sintering NANOPRECIPITATION DISLOCATION
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湿化学方法掺杂Na对多晶SnS热电性能的影响(英文) 被引量:2
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作者 唐怀超 董金峰 +3 位作者 孙富华 Asfandiyar 尚鹏鹏 李敬锋 《Science China Materials》 SCIE EI CSCD 2019年第7期1005-1012,共8页
SnS作为一种与SnSe特征结构相似且元素丰度更高的热电材料,受到越来越多的关注,但是其较低的本征载流子浓度限制了热电性能的提升.本工作利用了一种改进的化学共沉淀方法调节基体中Na+含量来提高载流子浓度,进而提升了多晶SnS的热电性能... SnS作为一种与SnSe特征结构相似且元素丰度更高的热电材料,受到越来越多的关注,但是其较低的本征载流子浓度限制了热电性能的提升.本工作利用了一种改进的化学共沉淀方法调节基体中Na+含量来提高载流子浓度,进而提升了多晶SnS的热电性能.最大功率因子在873K达到362μWm^-1K^-2,高于目前关于多晶SnS的最高报道值.得益于提升的电输运性能以及较低的热导率, ZT值在873K达到0.52 .该工作为其他热电化合物的掺杂改性技术提供了新思路. 展开更多
关键词 热电性能 SNS Na+ 湿化学方法 多晶 掺杂 化学共沉淀方法 载流子浓度
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基于数值模拟的低温风洞羽流扩散过程的参数敏感性分析(英文) 被引量:2
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作者 jing-feng li Kai WANG +2 位作者 Xiao-bin ZHANG Xia ZHOU li-min QIU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2018年第10期746-757,共12页
目的:低温风洞运行时大流量低温氮气被排放到大气环境中,对周围环境造成潜在的低温、缺氧危险。本文旨在研究羽流扩散过程中各变量(环境风速、环境风温度、相对湿度和排气出口流速)对羽流沉降的影响。创新点:采用考虑相变的低温羽流扩... 目的:低温风洞运行时大流量低温氮气被排放到大气环境中,对周围环境造成潜在的低温、缺氧危险。本文旨在研究羽流扩散过程中各变量(环境风速、环境风温度、相对湿度和排气出口流速)对羽流沉降的影响。创新点:采用考虑相变的低温羽流扩散模型,通过数值模拟对影响羽流扩散的各参数进行敏感性分析。方法:1.基于Hertz-Knudsen关系修正,考虑空气中水的相变,构建低温羽流扩散的数值模型;2.对照美国National TransonicFacility的羽流扩散数据和NASA的二阶分析模型的计算结果,验证本文所采用的数值模型的准确性;3.利用数值模拟,比较不同排放条件下近地面的最低氧含量和最低温度,并对各变量进行敏感性分析。结论:1.考虑相变的羽流扩散数值模型,相比NASA的二阶分析模型拥有更好的准确性。2.对于0.3m低温风洞的羽流扩散,高环境风速有利于羽流消散;高环境温度和高相对湿度能提升近地面的最低温度,但对近地面的最低氧含量影响甚微。3.当排气速度小于2 kg/s时,排气流速增大不利于羽流消散;当羽流速度大于2 kg/s时,排气流速增大有利于羽流消散。 展开更多
关键词 低温风洞 羽流扩散 计算流体动力学 相变
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Ferroelectric domains and phase transition of sol-gel processed epitaxial Sm-doped BiFeO_(3)(001)thin films 被引量:2
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作者 Zhen Zhou Wei Sun +3 位作者 Zhenyu liao Shuai Ning Jing Zhu jing-feng li 《Journal of Materiomics》 SCIE EI 2018年第1期27-34,共8页
BiFeO_(3),a room-temperature multiferroic material,has recently been increasingly applied as a potential lead-free piezoelectric material due to its large piezoelectricity achieved by doping.In this work,12%Smdoped Bi... BiFeO_(3),a room-temperature multiferroic material,has recently been increasingly applied as a potential lead-free piezoelectric material due to its large piezoelectricity achieved by doping.In this work,12%Smdoped BiFeO_(3)epitaxial thin films were fabricated on Nb-doped SrTiO_(3)(001)single crystal substrates via sol-gel method.The epitaxy was verified by reciprocal space mapping(RSM)and transmission electron microscope(TEM).The TEM results indicated the coexistence of R3c and Pbam phases in the film.The domains and piezoelectric properties from room temperature to 200℃were characterized by piezoresponse force microscopy(PFM).Domains became active from 110℃to 170℃,and domain configurations changed obviously.A partially fading piezoresponse indicated the emergence of antiferroelectric Pbam.The in-situ domain analysis suggested that the phase transition was accompanied by domain wall motion.Switching spectroscopy PFM(SS-PFM)was further conducted to investigate the piezoresponse during the phase transition.Anomalous responses were found in both ON and OFF states at 170℃,and the film exhibits typical antiferroelectric behavior at 200℃,implying that the completion of phase transition and structure turned to the Pbam phase.This work revealed the origin of the high piezoresponse of Sm-doped BiFeO_(3)thin films at the morphotropic phase boundary(MPB). 展开更多
关键词 BiFeO_(3) Piezoresponse force microscopy Morphotropic phase boundary Phase transition ANTIFERROELECTRIC
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A sound velocity method for determining isobaric specific heat capacity 被引量:1
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作者 Jun Pei Hezhang li +8 位作者 Hua-Lu Zhuang Jinfeng Dong Bowen Cai Haihua Hu Jing-Wei li Yilin Jiang Bin Su li-Dong Zhao jing-feng li 《InfoMat》 SCIE CAS 2022年第12期103-111,共9页
Isobaric specific heat capacity(Cp)is an important parameter not only in physics but also for most materials.Its accurate measurement is particularly critical for performance evaluation of thermoelectric materials,but... Isobaric specific heat capacity(Cp)is an important parameter not only in physics but also for most materials.Its accurate measurement is particularly critical for performance evaluation of thermoelectric materials,but the experiments by differential scanning calorimetry(DSC)often lead to large uncertainties in the measurements,especially at elevated temperatures.In this study,we propose a simple method to determine Cp by measuring the sound velocity(υ)based on lattice vibration and expansion theory.The relative standard error of theυis smaller than 1%,showing good accuracy and repeatability.The calculated Cp at elevated temperature(>300 K)increases slightly with increasing temperature due to the lattice expansion,which is more reasonable than the Dulong–Petit value. 展开更多
关键词 heat capacity sound velocity THERMOELECTRIC
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A pair of SARS-CoV-2 nucleocapsid protein monoclonal antibodies shows high specificity and sensitivity for diagnosis
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作者 An-Kai Zhu Sa-Sa li +9 位作者 Shu-Pei Yu Zhao-Yong Zhang Huan li jing-feng li Shan-Shan Gao Heng Chen Jincun Zhao Run Shi Mingjian Lu Chaoyang li 《Virologica Sinica》 SCIE CAS CSCD 2022年第6期942-945,共4页
Dear Editor,Severe Acute Respiratory Syndrome Coronavirus Type 2(SARS-CoV-2) is the pathogen of the coronavirus disease 2019(COVID-19), which has spread worldwide.SARS-CoV-2 is an enveloped virus belongs to the family... Dear Editor,Severe Acute Respiratory Syndrome Coronavirus Type 2(SARS-CoV-2) is the pathogen of the coronavirus disease 2019(COVID-19), which has spread worldwide.SARS-CoV-2 is an enveloped virus belongs to the family of β-coronavirus(Xu et al., 2020). Its genome is a linear single-stranded positive-sense RNA about 30,000 nucleotides packed inside a virion with a diameter of 100 nm and a volume of about 10^(6)nm^(3)(Bar-On et al., 2020). 展开更多
关键词 al. DIAGNOSIS SPECIFICITY
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Room-temperature thermoelectric materials: Challenges and a new paradigm
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作者 Zhijia Han Jing-Wei li +4 位作者 Feng Jiang Jiating Xia Bo-Ping Zhang jing-feng li Weishu liu 《Journal of Materiomics》 SCIE 2022年第2期427-436,共10页
Room-temperature thermoelectric materials provide promising solutions for energy harvesting from the environment,and deliver a maintenance-free power supply for the internet-of-things(IoTs).The currently available Bi_... Room-temperature thermoelectric materials provide promising solutions for energy harvesting from the environment,and deliver a maintenance-free power supply for the internet-of-things(IoTs).The currently available Bi_(2)Te_(3) family discovered in the 1950s,still dominates industrial applications,however,it has serious disadvantages of brittleness and the resource shortage of tellurium(1×10^(-3) ppm in the earth's crust).The novel Mg_(3)Sb_(2) family has received increasing attention as a promising alternative for room-temperature thermoelectric materials.In this review,the development timeline and fabrication strategies of the Mg 3 Sb 2 family are depicted.Moreover,an insightful comparison between the crystal-linity and band structures of Mg_(3)Sb_(2) and Bi_(2)Te_(3) is drawn.An outlook is presented to discuss challenges and new paradigms in designing room-temperature thermoelectric materials. 展开更多
关键词 Thermoelectric materials Mg_(3)Sb_(2) Bi_(2)Te_(3) Chemical bond engineering
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Piezoelectric properties of(K_(0.5)Na_(0.5))NbO_(3)-BaTiO_(3) lead-free ceramics prepared by spark plasma sintering
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作者 Tian-Lu Men Fang-Zhou Yao +2 位作者 Zhi-Xiang Zhu Ke Wang jing-feng li 《Journal of Advanced Dielectrics》 CAS 2016年第2期79-86,共8页
(K,Na)NbO_(3)(KNN)-based lead-free piezoceramics have been the spotlight in search for practically viable candidates to replace the hazardous but dominating lead-containing counterparts.In this work,BaTiO_(3)(BT)modif... (K,Na)NbO_(3)(KNN)-based lead-free piezoceramics have been the spotlight in search for practically viable candidates to replace the hazardous but dominating lead-containing counterparts.In this work,BaTiO_(3)(BT)modified KNN ceramics were fabricated by spark plasma sintering(SPS)and the influence of BT content as well as sintering temperature on the phase structure,microstructure,and electrical properties were investigated.It was found that the 0.96(Na_(0.5)K_(0.5))NbO_(3)-0.04BaTiO_(3)(BT4)ceramics sintered at 1000℃have the optimal performance.Additionally,in-depth analysis of the electrical hysteresis revealed that the internal bias field originating from accumulation of space charges at grain boundaries is responsible for the asymmetry in the hysteresis loops. 展开更多
关键词 (K Na)NbO_(3) BaTiO_(3) piezoelectric ceramics spark plasma sintering.
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Enhanced thermoelectric performance in MnTe due to doping and insitu nanocompositing effects by Ag2S addition
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作者 Jinfeng Dong Jun Pei +5 位作者 Kei Hayashi Wataru Saito Hezhang li Bowen Cai Yuzuru Miyazaki jing-feng li 《Journal of Materiomics》 SCIE EI 2021年第3期577-584,共8页
Extremely low lattice thermal conductivity is always the pursuit of thermoelectric materials research.In this work,we reported an exceptional effect of Ag2S addition in MnTe,an emerging promising midtemperature thermo... Extremely low lattice thermal conductivity is always the pursuit of thermoelectric materials research.In this work,we reported an exceptional effect of Ag2S addition in MnTe,an emerging promising midtemperature thermoelectric material,to enable the realization of minimum lattice thermal conductivity,namely-0.4 Wm^(-1) K^(-1).Such a low lattice thermal conductivity is guaranteed by the incorporation of in-situ formed Ag rich phase(Ag2Te)with ultralow lattice thermal conductivity and further scattering of phonons from the partial doping effects induced point defects and boundaries between various phases.Apart from the dramatically decreased lattice thermal conductivity,the partial doping of Ag and S simultaneously enhance the electrical conductivity,further contributing to enhanced thermoelectric performance.Meanwhile,an inverse sign of Seebeck and Hall coefficient was observed and rationalized by the influence of highly electron-conductive Ag_(2)Te phase.Thanks to the synergetic modulation of electrical and thermal transport properties by in-situ formed composite,a high ZT value of 1.1 was achieved in MnTe based thermoelectric materials,which also demonstrates the importance of compositing approaches to design state-of-the-art thermoelectric materials. 展开更多
关键词 Manganese telluride THERMOELECTRIC Thermal conductivity Composite
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