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The First Reported Case of Co-Infection with Neisseria Meningitidis and Bordetella Pertussis in the Cerebrospinal Fluid Specimen of a Normal Four-Year-Old Child
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作者 XIA Xian LI Guo Ming +7 位作者 TANG Yi WANG Si Quan HE Fei JIANG Yong Zhong YANG Hong Mei JIANG Hong Lin LYU Jing MAO Ling Feng 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第4期432-435,共4页
Pertussis is an acute and highly contagious respiratory disease caused by Bordetella pertussis(B.pertussis),which occurs in people of all ages and is most dangerous for young children,especially infants.The introducti... Pertussis is an acute and highly contagious respiratory disease caused by Bordetella pertussis(B.pertussis),which occurs in people of all ages and is most dangerous for young children,especially infants.The introduction of whole-cell pertussis vaccines(wPVs)in the 1950s dramatically reduced the incidence of pertussis worldwide[1].However,over the past two decades,many studies have reported the resurgence of pertussis in different countries[2].Epidemiological surveillance in Hubei Province over the last 3 years revealed a clear increasing trend in the incidence of pertussis during the coronavirus disease 2019(COVID-19)epidemic. 展开更多
关键词 PERTUSSIS DANGEROUS HUBEI
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Efficient Removal of Phosphate from Aqueous Solutions Using Corundum-hollow-spheres Supported Caclined Hydrotalcite Porous Thin Films
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作者 刘云才 ZHU Chen 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期44-49,共6页
Phosphate was removed from aqueous environment by corundum-hollow-spheres supported caclined hydrotalcite (cHT) thin films. Mg-Al-CO3 hydrotalcite (HT) thin films were deposited on corundumhollow-sphere substrates by ... Phosphate was removed from aqueous environment by corundum-hollow-spheres supported caclined hydrotalcite (cHT) thin films. Mg-Al-CO3 hydrotalcite (HT) thin films were deposited on corundumhollow-sphere substrates by hydrothermal homogeneous precipitation at 120℃for 30-240 min and cHT thin films were obtained by annealing of the HT thin films at 500℃for 180 min. Their crystal phase, morphology and microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM).The results show that homogeneous, well-crystallized and hierarchical flower-like thin films were deposited firmly on the surface of the corundum. The mechanism of nucleation and growth of the HT thin films was fitted well with the anion coordination polyhedron growth unit model. To determine the absorption of phosphate by this adsorbent, different bed depth (10-30 cm) and flow rate (1.0-3.0 m L/min) were examined by column experiments. The highest removal efficiency of phosphate amounted to 98.5%under optimum condition (pH=7.2). The adsorption capacity increased as the bed depth increased and decreased as the flow rate increased. 展开更多
关键词 adsorption PHOSPHATE HYDROTALCITE corundum-hollow-sphere hydrothermal homogeneous precipitation thermal anneal
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Regulatory potential of soil available carbon,nitrogen,and functional genes on N_(2)O emissions in two upland plantation systems
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作者 Peng Xu Mengdie Jiang +4 位作者 Imran Khan Muhammad Shaaban Hongtao Wu Barthelemy Harerimana Ronggui Hu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第8期2792-2806,共15页
Dynamic nitrification and denitrification processes are affected by changes in soil redox conditions,and they play a vital role in regulating soil N_(2)O emissions in rice-based cultivation.It is imperative to underst... Dynamic nitrification and denitrification processes are affected by changes in soil redox conditions,and they play a vital role in regulating soil N_(2)O emissions in rice-based cultivation.It is imperative to understand the influences of different upland crop planting systems on soil N_(2)O emissions.In this study,we focused on two representative rotation systems in Central China:rapeseed–rice(RR)and wheat–rice(WR).We examined the biotic and abiotic processes underlying the impacts of these upland plantings on soil N_(2)O emissions.The results revealed that during the rapeseed-cultivated seasons in the RR rotation system,the average N_(2)O emissions were 1.24±0.20 and 0.81±0.11 kg N ha^(–1)for the first and second seasons,respectively.These values were comparable to the N_(2)O emissions observed during the first and second wheat-cultivated seasons in the WR rotation system(0.98±0.25 and 0.70±0.04 kg N ha^(–1),respectively).This suggests that upland cultivation has minimal impacts on soil N_(2)O emissions in the two rotation systems.Strong positive correlations were found between N_(2)O fluxes and soil ammonium(NH_(4)^(+)),nitrate(NO_(3)^(–)),microbial biomass nitrogen(MBN),and the ratio of soil dissolved organic carbon(DOC)to NO_(3)^(–)in both RR and WR rotation systems.Moreover,the presence of the AOA-amoA and nirK genes were positively associated with soil N_(2)O fluxes in the RR and WR systems,respectively.This implies that these genes may have different potential roles in facilitating microbial N_(2)O production in various upland plantation models.By using a structural equation model,we found that soil moisture,mineral N,MBN,and the AOA-amoA gene accounted for over 50%of the effects on N_(2)O emissions in the RR rotation system.In the WR rotation system,soil moisture,mineral N,MBN,and the AOA-amoA and nirK genes had a combined impact of over 70%on N_(2)O emissions.These findings demonstrate the interactive effects of functional genes and soil factors,including soil physical characteristics,available carbon and nitrogen,and their ratio,on soil N_(2)O emissions during upland cultivation seasons under rice-upland rotations. 展开更多
关键词 upland-rice cultivation N_(2)O emission regulatory factors functional genes
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Parental Educational Expectations,Academic Pressure,and Adolescent Mental Health:An Empirical Study Based on CEPS Survey Data
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作者 Tao Xu Fangqiang Zuo Kai Zheng 《International Journal of Mental Health Promotion》 2024年第2期93-103,共11页
Background:This study aimed to investigate the relationship between parental educational expectations and adolescent mental health problems,with academic pressure as a moderating variable.Methods:This study was based ... Background:This study aimed to investigate the relationship between parental educational expectations and adolescent mental health problems,with academic pressure as a moderating variable.Methods:This study was based on the baseline data of the China Education Panel Survey,which was collected within one school year during 2013–2014.It included 19,958 samples from seventh and ninth graders,who ranged from 11 to 18 years old.After removing missing values and conducting relevant data processing,the effective sample size for analysis was 16344.The OLS(Ordinary Least Squares)multiple linear regression analysis was used to examine the relationship between parental educational expectations,academic pressure,and adolescents’mental health problems.In addition,we established an interaction term between parents’educational expectations and academic pressure to investigate the moderating effect of academic stress.Results:The study found that adolescents whose parents had high educational expectations reported less mental health problems.(β=−0.195;p<0.001).Additionally,adolescents who had high academic pressure reported more mental health problems.(β=0.649;p<0.001).Furthermore,the study found that academic pressure had a significant moderating effect on the relationship between parental educational expectations and adolescents’mental health problems(β=0.082;p<0.001).Conclusion:Parental educational expectations had a close relationship with adolescents’mental health problems,and academic pressure moderated this relationship.For those adolescents with high levels of academic pressure,the association between high parental educational expectations and mental health problems became stronger.On the contrary,for those adolescents with low levels of academic pressure,the association between high parental educational expectations and mental health problems became weaker.These findings shed new light on how parental educational expectations affected adolescent mental health problems and had significant implications for their healthy development. 展开更多
关键词 Parental educational expectations academic pressure adolescent mental health problems
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Reform and Development of English Teaching in Colleges and Universities with the Integration of ChatGPT Technology
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作者 Jie Cao Jing Cao Yuan Tao 《Journal of Contemporary Educational Research》 2024年第6期71-76,共6页
As an artificial intelligence-powered language generation model based on natural language processing,ChatGPT,like other artificial intelligence technologies,possesses super real-time dialogue capabilities and is consi... As an artificial intelligence-powered language generation model based on natural language processing,ChatGPT,like other artificial intelligence technologies,possesses super real-time dialogue capabilities and is considered an innovative and intelligent auxiliary teaching tool in the field of language learning.This article first analyzes the current state of development of artificial intelligence technologies such as ChatGPT.Secondly,it examines the challenges encountered in the reform and development of English teaching in colleges and universities in China.Lastly,it summarizes the applications and recommendations for using ChatGPT technology in college-level English teaching. 展开更多
关键词 ChatGPT Artificial intelligence technologies College English Reform and development
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Characteristics of dissolved organic matter in lakes with different eutrophic levels in southeastern Hubei Province,China 被引量:11
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作者 Weixiang REN Xiaodong WU +5 位作者 Xuguang GE Guiying LIN Mengdie ZHOU Zijie LONG Xinhui YU Wei TIAN 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2021年第4期1256-1276,共21页
Dissolved organic matter(DOM)plays a crucial role in both the carbon cycle and geochemical cycles of other nutrient elements,which is of importance to the management and protection of the aquatic environments.To achie... Dissolved organic matter(DOM)plays a crucial role in both the carbon cycle and geochemical cycles of other nutrient elements,which is of importance to the management and protection of the aquatic environments.To achieve a more comprehensive understanding the characteristics of DOM in the Changjiang(Yangtze)River basin,water samples from four natural lakes(Xiandao,Baoan,Daye,and Qingshan)in southeastern Hubei Province in China with different eutrophication levels were collected and analyzed.The optical characteristics were analyzed using ultraviolet-visible spectrophotometry and excitation-emission matrix spectroscopy coupled with parallel factor analysis.The results show that:(1)two humic-like components(C1 and C2)and two protein-like substances(C3 and C4)of DOM were identified in all waterbodies;(2)C3 originated primarily from the degradation of microalgae and contributed substantially to humic-like components during transformation.C4 was widely present in the Changjiang River basin and its formation was related to microbial activity,rather than algal blooms or seasons.Influenced by the water mixing,the protein-like components were more likely to be transformed by microorganism,whereas humic-like components were more easily to be photobleached;(3)the concentration of DOM and the fluorescence intensity of humic-like components gradually increased with rising lake eutrophication levels.With respect to protein-like components,only C3 showed changes along the eutrophication gradients;(4)DOM showed a high affinity with permanganate index(COD Mn)and chlorophyll a(chl a)while the relationship was variable with phosphorus.This study helps us systematically understand the DOM characteristics,microbial activities,and pollutant transformation in the Changjiang River basin and provides reference to the ecological restoration of aquatic environments. 展开更多
关键词 HUBEI eutrophic lake dissolved organic matter(DOM) excitation-emission spectra parallel factor analysis
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Common Fixed Point Theorems in Non-normal Cone Metric Spaces with Banach Algebras 被引量:2
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作者 HUANG Hua-ping XU Shao-yuan +1 位作者 LIU Qiu-hua MING Wei 《Chinese Quarterly Journal of Mathematics》 2016年第2期155-161,共7页
In this paper, we obtain a class of common fixed point theorems for generalized Lipschitz mappings in cone metric spaces with Banach algebras without the assumption of normality of cones. The results greatly generaliz... In this paper, we obtain a class of common fixed point theorems for generalized Lipschitz mappings in cone metric spaces with Banach algebras without the assumption of normality of cones. The results greatly generalize some results in the literature. Moreover,we give an example to support the main assertions. 展开更多
关键词 cone metric space with Banach algebra generalized Lispchitz constant weakly compatible
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Atomic-level insight of sulfidation-engineered Aurivillius-related Bi_(2)O_(2)SiO_(3) nanosheets enabling visible light low-concentration CO_(2) conversion 被引量:6
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作者 Kai Wang Yue Du +6 位作者 Yuan Li Xiaoyong Wu Haiyan Hu Guohong Wang Yao Xiao Shulei Chou Gaoke Zhang 《Carbon Energy》 SCIE CSCD 2023年第2期1-11,共11页
Unraveling atomic-level active sites of layered photocatalyst towards lowconcentration CO_(2) conversion is still challenging.Herein,the yield and selectivity of photocatalytic CO_(2) reduction of the Aurivillius-rela... Unraveling atomic-level active sites of layered photocatalyst towards lowconcentration CO_(2) conversion is still challenging.Herein,the yield and selectivity of photocatalytic CO_(2) reduction of the Aurivillius-related oxide semiconductor Bi_(2)O_(2)SiO_(3) nanosheet(BOSO)were largely improved using a surface sulfidation strategy.The experiment and theoretical calculation confirmed that surface sulfidation of the Bi_(2)O_(2)SiO_(3) nanosheet(S-BOSO,6.28 nm)redistributed the charge-enriched Bi sites,extended the solar spectrum absorption to the whole visible range,and considerably enhanced the charge separation,in addition to creating new reaction active sites,as compared to pristine BOSO.Subsequently,surface sulfidation played a switchable role,wherein S-BOSO showed a very high CH_(3)OH generation rate(12.78μmol g^(-1) for 4 h,78.6%selectivity)from low-concentration CO_(2)(1000 ppm)under visible light irradiation,which outperforms most of the state-of-the-art photocatalysts under similar conditions.This study presents an atomic-level modification protocol for engineering reactive sites and charge behaviors to promote solar-to-energy conversion. 展开更多
关键词 [Bi_(2)O_(2)]^(2)+layer Bi_(2)O_(2)SiO_(3) low-concentration CO_(2)reduction photocatalysis SULFIDATION
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Progress in building clinically relevant patient-derived tumor xenograft models for cancer research 被引量:2
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作者 Weijing Wang Yongshu Li +3 位作者 Kaida Lin Xiaokang Wang Yanyang Tu Zhenjian Zhuo 《Animal Models and Experimental Medicine》 CAS CSCD 2023年第5期381-398,共18页
Patient-derived tumor xenograft(PDX)models,a method involving the surgical extraction of tumor tissues from cancer patients and subsequent transplantation into immunodeficient mice,have emerged as a pivotal approach i... Patient-derived tumor xenograft(PDX)models,a method involving the surgical extraction of tumor tissues from cancer patients and subsequent transplantation into immunodeficient mice,have emerged as a pivotal approach in translational research,particularly in advancing precision medicine.As the first stage of PDX development,the patient-derived orthotopic xenograft(PDOX)models implant tumor tissue in mice in the corresponding anatomical locations of the patient.The PDOX models have several advantages,including high fidelity to the original tumor,heightened drug sensitivity,and an elevated rate of successful transplantation.However,the PDOX models present significant challenges,requiring advanced surgical techniques and resourceintensive imaging technologies,which limit its application.And then,the humanized mouse models,as well as the zebrafish models,were developed.Humanized mouse models contain a human immune environment resembling the tumor and immune system interplay.The humanized mouse models are a hot topic in PDX model research.Regarding zebrafish patient-derived tumor xenografts(zPDX)and patient-derived organoids(PDO)as promising models for studying cancer and drug discovery,zPDX models are used to transplant tumors into zebrafish as novel personalized medical animal models with the advantage of reducing patient waiting time.PDO models provide a cost-effective approach for drug testing that replicates the in vivo environment and preserves important tumor-related information for patients.The present review highlights the functional characteristics of each new phase of PDX and provides insights into the challenges and prospective developments in this rapidly evolving field. 展开更多
关键词 animal model cancer PDX precision medicine
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Hierarchical Interconnected NiMoN with Large Specific Surface Area and High Mechanical Strength for Efficient and Stable Alkaline Water/Seawater Hydrogen Evolution 被引量:1
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作者 Minghui Ning Yu Wang +7 位作者 Libo Wu Lun Yang Zhaoyang Chen Shaowei Song Yan Yao Jiming Bao Shuo Chen Zhifeng Ren 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第9期520-535,共16页
NiMo-based nanostructures are among the most active hydrogen evolution reaction(HER)catalysts under an alkaline environment due to their strong water dissociation ability.However,these nanostructures are vulnerable to... NiMo-based nanostructures are among the most active hydrogen evolution reaction(HER)catalysts under an alkaline environment due to their strong water dissociation ability.However,these nanostructures are vulnerable to the destructive effects of H_(2) production,especially at industry-standard current densities.Therefore,developing a strategy to improve their mechanical strength while maintaining or even further increasing the activity of these nanocatalysts is of great interest to both the research and industrial communities.Here,a hierarchical interconnected NiMoN(HW-NiMoN-2h)with a nanorod-nanowire morphology was synthesized based on a rational combination of hydrothermal and water bath processes.HW-NiMoN-2h is found to exhibit excellent HER activity due to the accomodation of abundant active sites on its hierarchical morphology,in which nanowires con-nect free-standing nanorods,concurrently strengthening its structural stability to withstand H_(2) production at 1 A cm^(−2).Seawater is an attractive feedstock for water electrolysis since H_(2) generation and water desalination can be addressed simultaneously in a single process.The HER performance of HW-NiMoN-2h in alkaline seawater suggests that the presence of Na+ions interferes with the reation kinetics,thus lowering its activity slightly.However,benefiting from its hierarchical and interconnected characteristics,HW-NiMoN-2h is found to deliver outstanding HER activity of 1 A cm^(−2) at 130 mV overpotential and to exhibit excellent stability at 1 A cm^(−2) over 70 h in 1 M KOH seawater. 展开更多
关键词 Hydrogen evolution reaction(HER) Nanoarchitecture NiMo catalysts Direct seawater electrolysis Nanostructural stability
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Least square method based on Haar wavelet to solve multi-dimensional stochastic Ito-Volterra integral equations
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作者 JIANG Guo KE Ting DENG Meng-ting 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2023年第4期591-603,共13页
This paper proposes a method combining blue the Haar wavelet and the least square to solve the multi-dimensional stochastic Ito-Volterra integral equation.This approach is to transform stochastic integral equations in... This paper proposes a method combining blue the Haar wavelet and the least square to solve the multi-dimensional stochastic Ito-Volterra integral equation.This approach is to transform stochastic integral equations into a system of algebraic equations.Meanwhile,the error analysis is proven.Finally,the effectiveness of the approach is verified by two numerical examples. 展开更多
关键词 least squares method Haar wavelet Ito-Volterra integral equations integration operational matrix.
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Has China-ASEAN Trade opening increased China’ s carbon emissions?
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作者 Yanchun Yi Yixin Geng Mingxin Yang 《Chinese Journal of Population,Resources and Environment》 2023年第2期52-59,共8页
This study uses carbon emission data at the provincial level in China between 1998-2018 and the proportion of the total import and export trade between provinces and the Association of Southeast Asian Nations(ASEAN)in... This study uses carbon emission data at the provincial level in China between 1998-2018 and the proportion of the total import and export trade between provinces and the Association of Southeast Asian Nations(ASEAN)in GDP to measure the level of China-ASEAN trade openness.It examines the impact of China ASEAN trade openness on carbon emissions and its transmission mechanism,and selects the RMB/USD exchange rate as an instrumental variable to address the endogeneity of China-ASEAN trade openness variables.The impact of China-ASEAN trade openness on China’s environment is estimated within a two-stage least squares framework.The results show that trade openness between China and ASEAN positively impacts China’s environment and can facilitate carbon emission reduction.The scale,structural,and technology effects brought by China-ASEAN trade liberalization jointly promote China’s carbon dioxide emission reduction.An inverted“U”relationship is found between economic growth and environmental quality in China,and some provinces and municipalities have now crossed the inflection point of the curve,in which carbon emi ssions decrease with an increase in per capita wealth. 展开更多
关键词 China-ASEAN trade opening Carbon emissions Instrumental variables Environmental Kuznets curve(EKC) Environment
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1+1>2: Learning from the interfacial modulation on single-atom electrocatalysts to design dual-atom electrocatalysts for dinitrogen reduction
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作者 Qiang Zhou Feng Gong +1 位作者 Yunlong Xie Rui Xiao 《Green Energy & Environment》 SCIE EI CAS CSCD 2023年第6期1753-1763,共11页
Developing efficient electrocatalysts for converting dinitrogen to ammonia through electrocatalysis is of significance to the decentralized ammonia production. Here, through high-throughput density functional theory c... Developing efficient electrocatalysts for converting dinitrogen to ammonia through electrocatalysis is of significance to the decentralized ammonia production. Here, through high-throughput density functional theory calculations, we demonstrated that the interfacial modulation of hexagonal boron nitride/graphene(hBN-graphene) could sufficiently improve the catalytic activity of the single transition metal atom catalysts for nitrogen reduction reaction(NRR). It was revealed that Re@hBN-graphene and Os@hBN-graphene possessed remarkable NRR catalytic activity with low limiting potentials of 0.29 V and 0.33 V, respectively. Furthermore, the mechanism of the enhanced catalytic activity was investigated based on various descriptors of the adsorption energies of intermediates, where the synergistic effect of hBN and graphene in the hybrid substrate was found to play a key role. Motivated by the synergistic effect of hybrid substrate in single-atom catalysts, a novel strategy was proposed to efficiently design dual-atom catalysts by integrating the merits of both metal components. The as-designed dual-atom catalyst Fe-Mo@hBN exhibited more excellent NRR catalytic performance with a limiting potential of 0.17 V, manifesting the solidity of the design strategy. Our findings open new avenues for the search of heterostructure substrates for single-atom catalysts and the efficient design of dualatom catalysts for NRR. 展开更多
关键词 Nitrogen reduction reaction Boron nitride Graphene High throughput DESCRIPTOR Density functional theory Single-atom catalyst Dual-atom catalyst
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Discrimination of individual seed viability by using the oxygen consumption technique and headspace-gas chromatography-ion mobility spectrometry
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作者 TU Ke-ling YIN Yu-lin +2 位作者 YANG Li-ming WANG Jian-hua SUN Qun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第3期727-737,共11页
Identifying and selecting high-quality seeds is crucial for improving crop yield.The purpose of this study was to improve the selection of crop seeds based on separating vital seeds from dead seeds,by predicting the p... Identifying and selecting high-quality seeds is crucial for improving crop yield.The purpose of this study was to improve the selection of crop seeds based on separating vital seeds from dead seeds,by predicting the potential germination ability of each seed,and thus improving seed quality.The methods of oxygen consumption (Q) of seeds and the headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS) were evaluated for identifying the viability of individual seeds.Firstly,the oxygen consumption technique showed clear differences among the values related to respiratory characteristics for seeds that were either vital or not,and the discrimination ability of final oxygen consumption(Q_(120)) was achieved not only in sweet corn seeds but also in pepper and wheat seeds.Besides,Qtwas established as a new variable to shorten the measuring process in the Q2 (oxygen sensor) procedure,which was significantly related to the viability of individual seeds.To minimize seed damage during measurement,the timing for viability evaluation was pinpointed at the 12,6 and 9 h for pepper,sweet corn,and wheat seeds based on the new variables concerning oxygen consumption (i.e.,Q_(12),Q_(6)and Q_(9),respectively).The accuracies of viability prediction were 91.9,97.7 and 96.2%,respectively.Dead seeds were identified and hence discarded,leading to an enhancement in the quality of the seed lot as indicated by an increase in germination percentage,from 86.6,90.9,and 53.8%to all at 100%.We then used the HS-GC-IMS to determine the viability of individual sweet corn seeds,noting that corn seed has a heavier weight so the volatile gas components are more likely to be detected.A total of 48 chromatographic peaks were identified,among which 38 target compounds were characterized,including alcohols,aldehydes,acids and esters.However,there were no significant differences between the vital and dead seeds,due to the trace amount volatile composition differences among the individual seeds.Furthermore,a PCA based on the signal intensities of the target volatile compounds obtained was found to lose its effectiveness,as it was unable to distinguish those two types of sweet corn seeds.These strategies can provide a reference for the rapid detection of single seed viability. 展开更多
关键词 headspace-gas chromatography-ion mobility spectrometry oxygen consumption seed respiration sweet corn TOMATO wheat
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一个2×2块矩阵的Moore-Penrose逆的显式公式
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作者 曾敏 袁永新 《Chinese Quarterly Journal of Mathematics》 2023年第4期401-409,共9页
The representation for the Moore-Penrose inverse of the matrix[AC BD]is derived by using the solvability theory of linear equations,where A∈C^(m×n),B∈C^(m×p),C∈C^(q×n)and D∈C^(q×p),with which s... The representation for the Moore-Penrose inverse of the matrix[AC BD]is derived by using the solvability theory of linear equations,where A∈C^(m×n),B∈C^(m×p),C∈C^(q×n)and D∈C^(q×p),with which some special cases are discussed. 展开更多
关键词 Block matrix Moore-Penrose inverse Linear equation
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Reform and Innovation of Education and Teaching in the Information Age--Comment on “Research on Education and Teaching Theory and Practice in the Information Age”
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作者 Kaining Liu 《Journal of Contemporary Educational Research》 2023年第8期74-79,共6页
This paper takes“Research on Education and Teaching Theory and Practice in the Information Age”as the main research object,and discusses the importance and influence of education and teaching reform and innovation i... This paper takes“Research on Education and Teaching Theory and Practice in the Information Age”as the main research object,and discusses the importance and influence of education and teaching reform and innovation in the information age.First,it introduces the background of education in the information age,including the characteristics of the information age and the development status of education.Secondly,it summarizes the main content of the book“Research on the Theory and Practice of Education and Teaching in the Information Age.”Lastly,the key points of education and teaching reform in the information age are discussed in order to provide effective guidelines and support for the practice of future education and teaching reform. 展开更多
关键词 Teaching reform INFORMATIZATION Teaching theory Information literacy Modern educational technology
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Synthesis of acetals and ketals catalyzed by tungstosilicic acid supported on active carbon 被引量:9
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作者 杨水金 杜心贤 +1 位作者 贺兰 孙聚堂 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE EI CAS CSCD 2005年第5期373-377,共5页
Catalytic activity of activated carbon supported tungstosilicic acidin synthesizing 2-methyl-2-ethoxycarbonylmethyl- 1,3-dioxolane, 2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane, cyclohexanone ethylene ketal, cycl... Catalytic activity of activated carbon supported tungstosilicic acidin synthesizing 2-methyl-2-ethoxycarbonylmethyl- 1,3-dioxolane, 2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane, cyclohexanone ethylene ketal, cyclohexanone 1,2-propa- nediol ketal, butanone ethylene ketal, butanone 1,2-propanediol ketal, 2-phenyl-1,3-dioxolane, 4-methyl-2-phenyl-1,3-dioxolane, 2-propyl-1,3-dioxolane, 4-methyl-2-propyl-1,3-dioxolane was reported. It has been demonstrated that activated carbon supported tungstosilicic acid is an excellent catalyst. Various factors involved in these reactions were investigated. The optimum conditions found were: molar ratio of aldehyde/ketone to glycol is 1/1.5, mass ratio of the catalyst used to the reactants is 1.0%, and reaction time is 1.0 h. Under these conditions, the yield of 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane is 61.5%, of 2,4-dimethyl- 2-ethoxycarbonylmethyl-1,3-dioxolane is 69.1%, of cyclohexanone ethylene ketal is 74.6%, of cyclohexanone 1,2-propanediol ketal is 80.1%, of butanone ethylene ketal is 69.5%, of butanone 1,2-propanediol ketal is 78.5%, of 2-phenyl-1,3-dioxolane is 56.7%, of 4-methyl-2-phenyl-1,3-dioxolane is 86.2%, of 2-propyl-1,3-dioxolane is 87.5%, of 4-methyl-2-propyl-1,3-dioxolane is 87.9%. 展开更多
关键词 乙酰胺 缩酮 催化反应 活性碳 钨硅酸 催化剂 合成方法
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Preparation of SO_4^(2-)/TiO_2-MoO_3 Solid Superacid and Its Catalytic Activity in Acetalation and Ketalation 被引量:7
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作者 杨水金 梁永光 +1 位作者 余协卿 孙聚堂 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2005年第1期51-55,共5页
SO4^2-/TiO2-MoO3, a novel solid superacid, has been prepared and its catalytic activity at different synthetic conditions was examined with esterification of n-butanoic acid and n-butyl alcohol as probing reaction.The... SO4^2-/TiO2-MoO3, a novel solid superacid, has been prepared and its catalytic activity at different synthetic conditions was examined with esterification of n-butanoic acid and n-butyl alcohol as probing reaction.The optimum conditions were also found, that is, the mass ratio of MoO3 used in the compound is 25%, the calcination temperature 450℃, and the soaked consistency of H2SO4 is 0.5mol.L^-1. Then it was applied in the catalytic synthesis of six similar important ketals and acetals as catalyst and revealed high catalytic activity. Under the condition that the molar ratio of aldehyde/ketone to glycol was 1:1.5, the mass ratio of the catalyst to the reactants was 0.5% and the reaction time 1.0 h, the yield of ketals and acetals reached up to 63.2%. The catalyst can be easily recovered and reused. 展开更多
关键词 SO4^2-/TiO2-MoO3 固体超强酸 化学性能 反应活性 缩酮化作用 缩醛化作用 催化作用 化学反应
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Catalytic synthesis of acetals and ketals with H3PW12O40/PAn 被引量:11
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作者 YANG Shuijin ZHANG Yijun +1 位作者 DU Xinxian Philippe G. Merle 《Rare Metals》 SCIE EI CAS CSCD 2008年第1期89-94,共6页
A new environmental friendly catalyst H3PW12O40/PAn was prepared and identified by means of FT-IR,XRD,and TG/DTA.The optimum conditions have been found;that is,the mass ratio of PAn to H3PW12O40 is 1:1.5,the volume o... A new environmental friendly catalyst H3PW12O40/PAn was prepared and identified by means of FT-IR,XRD,and TG/DTA.The optimum conditions have been found;that is,the mass ratio of PAn to H3PW12O40 is 1:1.5,the volume of methanol is 20 mL,and the reflux reaction time is 3 h.The structural identity of Keggin units is preserved after the incorporation into polyaniline matrix.Catalytic activities of H3PW12O40/PAn in synthesizing 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane,2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane,cyclohexanone ethylene ketal,cyclohexanone 1,2-propanediol ketal,butanone ethylene ketal,butanone 1,2-propanediol ketal,2-phenyl-1,3-dioxolane,4-methyl-2-phenyl-1,3-dioxolane,2-propyl-1,3-dioxolane,and 4-methyl-2-propyl-1,3-dioxolane were reported.It has been demon-strated that H3PW12O40/PAn is an excellent catalyst.Various factors concerned in these reactions were investigated.The optimum conditions are as follows:the molar ratio of aldehyde/ketone to glycol(r) is 1:1.5,the mass ratio of the catalyst used to the reactants is 0.6%,and the reaction time is 1.0 h.Under these conditions,the yield is as follows:2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane,69.0%;2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane,79.5%;cyclohexanone ethylene ketal,78.9%;cyclohexanone 1,2-propanediol ketal,85.3%;butanone ethylene ketal,56.9%;butanone 1,2-propanediol ketal,78.1%;2-phenyl-1,3-dioxolane,76.3%;4-methyl-2-phenyl-1,3-dioxolane,94.2%;2-propyl-1,3-dioxolane,70.7%;and 4-methyl-2-propyl-1,3-dioxolane,79.2%. 展开更多
关键词 phosphotungstic acid ACETAL KETAL POLYANILINE CATALYSIS
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ON THE EXPECTED DISCOUNTED PENALTY FUNCTION IN A MARKOV-DEPENDENT RISK MODEL WITH CONSTANT DIVIDEND BARRIER 被引量:7
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作者 刘娟 徐建成 胡亦钧 《Acta Mathematica Scientia》 SCIE CSCD 2010年第5期1481-1491,共11页
This article considers a Markov-dependent risk model with a constant dividend barrier. A system of integro-differential equations with boundary conditions satisfied by the expected discounted penalty function, with gi... This article considers a Markov-dependent risk model with a constant dividend barrier. A system of integro-differential equations with boundary conditions satisfied by the expected discounted penalty function, with given initial environment state, is derived and solved. Explicit formulas for the discounted penalty function are obtained when the initial surplus is zero or when all the claim amount distributions are from rational family. In two state model, numerical illustrations with exponential claim amounts are given. 展开更多
关键词 Markov-dependent risk model dividend barrier Cerber-Shiu function integro-differential equation Laplace transform
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