A sinusoidal representation of speech and a cochlear model are used to extract speech parameters in this paper, and a speech analysis/synthesis system controlled by the auditory spectrum is developed with the model. T...A sinusoidal representation of speech and a cochlear model are used to extract speech parameters in this paper, and a speech analysis/synthesis system controlled by the auditory spectrum is developed with the model. The computer simulation shows that speech can be synthesized with only 12 parameters per frame on the average. The method has the advantages of few parameters, low complexity and high performance of speech representation. The synthetic speech has high intelligibility.展开更多
Spherical harmonic analysis(SHA)and synthesis(SHS)are widely used by researchers in various fields.Both numerical integration and least-squares methods can be employed for analysis and synthesis.However,these approach...Spherical harmonic analysis(SHA)and synthesis(SHS)are widely used by researchers in various fields.Both numerical integration and least-squares methods can be employed for analysis and synthesis.However,these approaches,when calculated via summation,are computationally intensive.Although the Fast Fourier Transform(FFT)algorithm is efficient,it is traditionally limited to processing global grid points starting from zero longitude.In this paper,we derive an improved FFT algorithm for spherical harmonic analysis and synthesis.The proposed algorithm eliminates the need for grid points to start at zero longitude,thereby expanding the applicability of FFT-based methods.Numerical experiments demonstrate that the new algorithm retains the computational efficiency of conventional FFT while achieving accuracy comparable to the summation method.Consequently,it enables direct harmonic coefficient calculation from global grid data without requiring interpolation to align with zero longitude.Additionally,the algrithm can generate grid points with equi-angular spacing using the improved FFT algorithm,starting from non-zero longitudes.To address the loss of orthogonality in latitude due to discrete spherical grids,a quadrature weight factor-dependent on grid type(e.g.,regular or Gauss grid)-is incorporated,as summarized in this study.展开更多
Origami mechanisms are extensively employed in various engineering applications due to their exceptional folding performance and deformability.The key to designing origami mechanisms lies in the design of the creases....Origami mechanisms are extensively employed in various engineering applications due to their exceptional folding performance and deformability.The key to designing origami mechanisms lies in the design of the creases.The crease design is often derived from experience and inspiration,so it is crucial to have a systematic approach to crease design.In this paper,a novel synthesis approach based on graph theory is proposed,which effectively addresses the challenge of designing the creases in origami mechanisms.The essence of this method lies in the acquisition of the double symmetrical crease pattern through the directed graph product operation of two subgraphs.The crease pattern can be simplified by employing a technique that eliminates certain creases while preserving the non-isomorphism and symmetry of the pattern.An improved mixed-integer linear programming model is developed to achieve an automatic distribution of the peak_valley creases of the origami.The proposed method ultimately generates 12 unique double symmetrical crease patterns.The new method proposed in this paper,through systematic design,significantly improves the efficiency of mechanism design while opening up broad prospects for exploring new mechanism structures,thereby greatly expanding its application potential in cutting-edge fields such as aerospace engineering and intelligent robots.展开更多
The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid(IL)were investigated.The presence of impurities containing oxygen a...The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid(IL)were investigated.The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL.As the water concentration increased to 65 mg·g^(-1),the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%,and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201.When the concentration of impurities increased to a critical value,the chloroaluminate IL began to deactivate,leading to a decrease in naphthalene conversion.The critical concentrations for ethanolamine,water,methanol,ether,and diisopentyl sulfide were 33 mg·g^(-1),65 mg·g^(-1),67mg·g^(-1),87 mg·g^(-1),and 123 mg·g^(-1),respectively.Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation.The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27Al NMR spectroscopy.2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better,but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks.2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL.With the increase inwater concentration,the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid,and the Lewis acid gradually decreased,while the Brønsted acid showed a change of increasing first and then decreasing.展开更多
Derris fordii and Derris elliptica belong to the Derris genus of the Fabaceae family, distinguished by their high isoflavonoid content, particularly rotenoids, which hold significance in pharmaceuticals and agricultur...Derris fordii and Derris elliptica belong to the Derris genus of the Fabaceae family, distinguished by their high isoflavonoid content, particularly rotenoids, which hold significance in pharmaceuticals and agriculture. Rotenone, as a prominent rotenoid, has a longstanding history of use in pesticides, veterinary applications, medicine, and medical research. The accumulation of rotenoids within Derris plants adheres to species-specific and tissue-specific patterns and is also influenced by environmental factors. Current research predominantly addresses extraction techniques, pharmacological applications, and pesticide formulations, whereas investigations into the biosynthesis pathway and regulatory mechanism of rotenoids remain relatively scarce. In this study, we observed notable differences in rotenone content across the roots, stems, and leaves of D. fordii, as well as within the roots of D. elliptica. Utilizing RNA sequencing (RNA-seq), we analyzed the transcriptomes and expression profiles of unigenes from these four tissues, identifying a total of 121,576 unigenes. Differentially expressed genes (DEGs) across four comparison groups demonstrated significant enrichment in the phenylpropanoid and flavonoid biosynthesis pathways. Key unigenes implicated in the rotenoid biosynthesis pathway were identified, with PAL, C4H, CHS, CHI, IFS, and HI4OMT playing critical roles in D. fordii, while IFS and HI4OMT were determined to be essential for rotenoid biosynthesis in D. elliptica. These findings enhance our understanding of the biosynthesis mechanism of rotenoids in Derris species. The unigenes identified in this study represent promising candidates for future investigations aimed at validating their roles in rotenoid biosynthesis.展开更多
BACKGROUND Meta-analysis is a critical tool in evidence-based medicine,particularly in cardiology,where it synthesizes data from multiple studies to inform clinical decisions.This study explored the potential of using...BACKGROUND Meta-analysis is a critical tool in evidence-based medicine,particularly in cardiology,where it synthesizes data from multiple studies to inform clinical decisions.This study explored the potential of using ChatGPT to streamline and enhance the meta-analysis process.AIM To investigate the potential of ChatGPT to conduct meta-analyses in interventional cardiology by comparing the results of ChatGPT-generated analyses with those of randomly selected,human-conducted meta-analyses on the same topic.METHODS We systematically searched PubMed for meta-analyses on interventional cardiology published in 2024.Five metaanalyses were randomly chosen.ChatGPT 4.0 was used to perform meta-analyses on the extracted data.We compared the results from ChatGPT with the original meta-analyses,focusing on key effect sizes,such as risk ratios(RR),hazard ratios,and odds ratios,along with their confidence intervals(CI)and P values.RESULTS The ChatGPT results showed high concordance with those of the original meta-analyses.For most outcomes,the effect measures and P values generated by ChatGPT closely matched those of the original studies,except for the RR of stent thrombosis in the Sreenivasan et al study,where ChatGPT reported a non-significant effect size,while the original study found it to be statistically significant.While minor discrepancies were observed in specific CI and P values,these differences did not alter the overall conclusions drawn from the analyses.CONCLUSION Our findings suggest the potential of ChatGPT in conducting meta-analyses in interventional cardiology.However,further research is needed to address the limitations of transparency and potential data quality issues,ensuring that AI-generated analyses are robust and trustworthy for clinical decision-making.展开更多
Coconut(Cocos nucifera L.)is a key tropical economic tree valued for its fruit flavor,particularly 2-acetyl-1-pyrroline(2AP),a vital aroma metabolite.To enhance high-aromatic coconut breeding efforts,it is essential t...Coconut(Cocos nucifera L.)is a key tropical economic tree valued for its fruit flavor,particularly 2-acetyl-1-pyrroline(2AP),a vital aroma metabolite.To enhance high-aromatic coconut breeding efforts,it is essential to deeply understand the hereditary factors governing the production of 2AP.In this study,a genome-wide association analysis identifies 32 loci that exhibit significant associations with 2AP content based on single nucleotide polymorphism(SNP)variations from 168 aromatic coconut germplasm resources.Transcriptome analysis then pinpoints 22 candidate genes near significant loci involved in 2AP metabolism.Proteins encoded by these genes are involved in amino acid metabolism,glycolysis,and secondary metabolism.Among these,Asparagine synthetase coding gene ASN1,Gamma-glutamylcysteine synthetase coding gene GSH1,and UbiA prenyltransferase coding gene UBIA are enriched in the linkage region constructed by significant locus Chr04_61490504.In particular,the SNP mutation of CnASN1 leads to amino acid changes in the functional region of the coding protein,potentially resulting in differences in 2AP content among haplotype populations.Identifying variations in related candidate genes,particularly the gene CnASN1,provides molecular markers closely associated with 2AP synthesis for coconut breeding and offers further insights into the metabolic mechanisms of 2AP.展开更多
In this paper,based on the common soil erosion model,the Three-River Headwaters region was select for study object. GIS methods are applied to conduct Semi-quantitative assessment for different types of soil erosion,a...In this paper,based on the common soil erosion model,the Three-River Headwaters region was select for study object. GIS methods are applied to conduct Semi-quantitative assessment for different types of soil erosion,and some results are concluded. The water erosion occurs in High Mountain and extra-high mountain of Yushu,Nangqian,Banma and Jiuzhi County in the southeast and south of the Three-River Headwaters region. The degree of erosion is prone to topography,precipitation,river and human activity. The freeze-thaw erosion mainly distributes in the northwest of the Three-River Headwaters region. The area of middle and above middle erosion degree accounts for roughly 50%.展开更多
According to the principles of simultaneous equilibrium and mass equilibrium, a series of thermodynamic equilibrium equations in Ni（II）-Co（II）-C2O4^2--NH3-NH4^＋-H2O system at ambient temperature were deduced. The...According to the principles of simultaneous equilibrium and mass equilibrium, a series of thermodynamic equilibrium equations in Ni（II）-Co（II）-C2O4^2--NH3-NH4^＋-H2O system at ambient temperature were deduced. The diagrams of logarithm ion concentrations versus pH values at different solution compositions were drawn. The results show that Ni^2＋ and Co^2＋ can completely precipitate at pH less than 5.0 and the predefined Ni/Co ratios can be well kept in the precursor. The precursor morphology is granular aggregation. However, rod aggregation precursor is obtained in the pH range of 5.0-8.0, and fibre-shape precursor is got at pH value higher than 8.0. The Ni/Co ratios in the above two precursors are not reproduced as that in the feed due to the formhtion of multi-coordinated Ni（NH3）n^2＋ and Co（NH3）n^2＋ （n=1-6）. Modification of precipitation medium is favorable for the precursors to keep the predefined Ni/Co ratios of the feed in the pH range of 2.0-8.6. Meanwhile, the precursors with fibrous morphology can be obtained.展开更多
Border-associated macrophages are located at the interface between the brain and the periphery, including the perivascular spaces, choroid plexus, and meninges. Until recently, the functions of border-associated macro...Border-associated macrophages are located at the interface between the brain and the periphery, including the perivascular spaces, choroid plexus, and meninges. Until recently, the functions of border-associated macrophages have been poorly understood and largely overlooked. However, a recent study reported that border-associated macrophages participate in stroke-induced inflammation, although many details and the underlying mechanisms remain unclear. In this study, we performed a comprehensive single-cell analysis of mouse border-associated macrophages using sequencing data obtained from the Gene Expression Omnibus(GEO) database(GSE174574 and GSE225948). Differentially expressed genes were identified, and enrichment analysis was performed to identify the transcription profile of border-associated macrophages. CellChat analysis was conducted to determine the cell communication network of border-associated macrophages. Transcription factors were predicted using the ‘pySCENIC' tool. We found that, in response to hypoxia, borderassociated macrophages underwent dynamic transcriptional changes and participated in the regulation of inflammatory-related pathways. Notably, the tumor necrosis factor pathway was activated by border-associated macrophages following ischemic stroke. The pySCENIC analysis indicated that the activity of signal transducer and activator of transcription 3(Stat3) was obviously upregulated in stroke, suggesting that Stat3 inhibition may be a promising strategy for treating border-associated macrophages-induced neuroinflammation. Finally, we constructed an animal model to investigate the effects of border-associated macrophages depletion following a stroke. Treatment with liposomes containing clodronate significantly reduced infarct volume in the animals and improved neurological scores compared with untreated animals. Taken together, our results demonstrate comprehensive changes in border-associated macrophages following a stroke, providing a theoretical basis for targeting border-associated macrophages-induced neuroinflammation in stroke treatment.展开更多
Background:Receptor-interacting protein kinases(RIPKs)regulate cell death,inflammation,and immune responses,yet their roles in cancer are not fully understood.This study investigates the expression,genomic alterations...Background:Receptor-interacting protein kinases(RIPKs)regulate cell death,inflammation,and immune responses,yet their roles in cancer are not fully understood.This study investigates the expression,genomic alterations,and functional implications of RIPK family members across various cancers.Methods:We collected multi-omics data from The Cancer Genome Atlas and other public databases,including gene expression,copy number variation(CNV),mutation,methylation,tumor mutation burden(TMB),and microsatellite instability(MSI).Differential expression and survival analyses were performed using DESeq2 and Cox proportional hazards models.CNV and mutation data were analyzed with GISTIC2 and Mutect2,and methylation data with the ChAMP package.Correlations with TMB and MSI were assessed using Pearson coefficients,and gene set enrichment analysis was conducted with the MSigDB Hallmark gene sets.Results:RIPK family members show significant differential expression in various cancers,with RIPK1 and RIPK4 frequently altered.Survival analysis reveals heterogeneous impacts on overall survival.CNV and mutation analyses identify high alteration frequencies for RIPK2 and RIPK7,affecting gene expression.RIPK1 and RIPK7 are hypermethylated in several cancers,inversely correlating with RIPK3 expression.RIPK1,RIPK2,RIPK5,RIPK6,and RIPK7 correlate positively with TMB,while RIPK3 shows negative correlations in some cancers.MSI analysis indicates associations with DNA mismatch repair.G ene set enrichment analysis highlights immune-related pathway enrichment for RIPK1,RIPK2,RIPK3,and RIPK6,and cell proliferation and DNA repair pathways for RIPK4 and RIPK5.RIPK family members showed heterogeneous alterations across cancers:for example,RIPK7 was mutated in up to~15%of u terine c orpus e ndometrial c arcinoma and l ung s quamous c ell c arcinoma cases,and RIPK1 and RIPK7 exhibited frequent promoter hypermethylation in multiple tumor types.Several genes displayed context-dependent associations with overall survival and with TMB/MSI.Conclusion:This pan-cancer analysis of the RIPK family reveals their diverse roles and potential as biomarkers and therapeutic targets.The findings emphasize the importance of RIPK genes in tumorigenesis and suggest context-dependent functions across cancer types.Further studies are needed to explore their mechanisms in cancer development and clinical applications.展开更多
The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.A...The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.Accordingly,comprehensive kinetic study by employing thermalgravimetric analysis at various heating rates was presented in this paper.Two main weight loss regions were observed during heating.The initial region corresponded to the dehydration of crystal water,whereas the subsequent region with overlapping peaks involved complex decomposition reactions.The overlapping peaks were separated into two individual reaction peaks and the activation energy of each peak was calculated using isoconversional kinetics methods.The activation energy of peak 1 exhibited a continual increase as the reaction conversion progressed,while that of peak 2 steadily decreased.The optimal kinetic models,identified as belonging to the random nucleation and subsequent growth category,provided valuable insights into the mechanism of the decomposition reactions.Furthermore,the adjustment factor was introduced to reconstruct the kinetic mechanism models,and the reconstructed models described the kinetic mechanism model more accurately for the decomposition reactions.This study enhanced the understanding of the thermochemical behavior and kinetic parameters of the lepidolite sulfation product decomposition reactions,further providing theoretical basis for promoting the selective extraction of lithium.展开更多
This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for ...This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for identifying critical failure modes and their root causes,while BN introduces flexibility in probabilistic reasoning,enabling dynamic updates based on new evidence.This dual methodology overcomes the limitations of static FTA models,offering a comprehensive framework for system reliability analysis.Critical failures,including External Leakage(ELU),Failure to Start(FTS),and Overheating(OHE),were identified as key risks.By incorporating redundancy into high-risk components such as pumps and batteries,the likelihood of these failures was significantly reduced.For instance,redundant pumps reduced the probability of ELU by 31.88%,while additional batteries decreased the occurrence of FTS by 36.45%.The results underscore the practical benefits of combining FTA and BN for enhancing system reliability,particularly in maritime applications where operational safety and efficiency are critical.This research provides valuable insights for maintenance planning and highlights the importance of redundancy in critical systems,especially as the industry transitions toward more autonomous vessels.展开更多
AIM:To explore the causal relationship between several possible behavioral factors and high myopia(HM)using multivariable Mendelian randomization(MVMR)approach and to find the mediators among them with mediation analy...AIM:To explore the causal relationship between several possible behavioral factors and high myopia(HM)using multivariable Mendelian randomization(MVMR)approach and to find the mediators among them with mediation analysis.METHODS:The causal effects of several behavioral factors,including screen time,education time,time spent outdoors,and physical activity,on the risk of HM using univariable Mendelian randomization(MR)and MVMR analyses were first assessed.Genome-wide association study summary statistics of serum metabolites were also used in mediation analysis to determine the extent to which serum metabolites mediate the effects of behavioral factors on HM.RESULTS:MR analyses indicated that both increased time spent outdoors and a higher frequency of moderate physical activity significantly reduced the risk of HM.Further MVMR analysis confirmed that moderate physical activity independently contributed to a lower risk of HM.Additionally,MR analyses identified 13 serum metabolites significantly associated with HM,of which 12 were lipids and one was an amino acid derivative.Mediation analysis revealed that six lipid metabolites mediated the protective effects of moderate physical activity on HM,with the highest mediation proportion observed for 1-(1-enyl-palmitoyl)-GPC(p-16:0;30.83%).CONCLUSION:This study suggests that in addition to outdoor time,moderate physical activity habits may have an independent protective effect against HM and pointed to lipid metabolites as priority targets for the prevention due to low physical activity.These results emphasize the importance of physical activity and metabolic health in HM and underscore the need for further study of these complex associations.展开更多
AIM:To summarize publication trends in the field of strabismus over the past 30y and predict future research hotspots.METHODS:A total of 2915 English-language articles and reviews on strabismus,published between 1993 ...AIM:To summarize publication trends in the field of strabismus over the past 30y and predict future research hotspots.METHODS:A total of 2915 English-language articles and reviews on strabismus,published between 1993 and 2022,were retrieved from the Web of Science Core Collection.Bibliometric analyses were performed using VOSviewer and CiteSpace software to explore publication trends,as well as the contributions and collaborative networks of countries/regions,authors,institutions,and journals.RESULTS:The annual number of publications on strabismus showed a consistent upward trend.The United States(USA)maintained a leading position in this research field while Republic of Korea and China emerged as rapidly advancing contributors over the last decade.The University of California,Los Angeles ranked as the most productive institution,and Jonathan M.Holmes from USA was the most productive author.Journal of AAPOS was the leading journal with the most strabismus publications,whereas the two most highly cited articles were both published in Ophthalmology.Co-occurrence analysis identified pivotal keywords and burst terms,including intermittent exotropia(IXT),acute acquired comitant esotropia(AACE),functional magnetic resonance imaging(fMRI),and surgical treatment,which were confirmed as predominant and frontier topics.CONCLUSION:This study provides a comprehensive bibliometric analysis of strabismus research,revealing the evolution of research hotspots over the past 30y and outlining several cutting-edge directions for future investigation.展开更多
High-quality LDH-SO4-CO3 whiskers were synthesized via liquid precipitation method using MgSO4·7 H2 O and Al2(SO4)3·18 H2O as precursors and Na2CO3-NaHCO3 buffer solution as precipitant. The influence of buf...High-quality LDH-SO4-CO3 whiskers were synthesized via liquid precipitation method using MgSO4·7 H2 O and Al2(SO4)3·18 H2O as precursors and Na2CO3-NaHCO3 buffer solution as precipitant. The influence of buffer solution concentration on the characteristics of the samples was investigated. The asgrown whiskers were characterized by X-ray diffraction, transmission electron microscopy, and BrunauerEmmett-Teller N2 specific surface area measurements. The results show that the buffer solution concentration has significant impact on whiskers with intercalated structure. The LDH-SO4-CO3 whiskers with well-defined geometry, distinct intercalated structure, decent quality, and excellent dispersing capability can be obtained under the following conditions: buffer solution volume ratio of 45%, reaction temperature of 83°C, and reaction time of 182 h. The obtained whiskers are well-crystallized and exhibit homogeneous morphology consisting of fiber bars.展开更多
Many attentions for structural synthesis are paid to planar linkages and parallel mechanisms, while design novel pyramid deployable truss structure（PDTS） of satellite SAR mainly depends on experience of designer. To...Many attentions for structural synthesis are paid to planar linkages and parallel mechanisms, while design novel pyramid deployable truss structure（PDTS） of satellite SAR mainly depends on experience of designer. To design novel configuration of PDTS, a two-step topology structure synthesis and analysis approach is proposed. Firstly, a conceptual configuration of PDTS is synthesized. Weighted graph and weighted adjacency matrix are established to realize topological description for PDTS. Graph properties are then summarized to distinguish differentia between PDTS and other type structures. According to graph properties, a procedure for synthesis conceptual configuration of PDTS is presented. Secondly, join relationship of components in a PDTS is analyzed. Kinematic chain and corresponding incidence/adjacency matrix are employed to analyze join relationship of PDTS. Properties and simplified rules of kinematic chain are extracted to construct kinematic chain. A procedure for construction kinematic chain of PDTS is then established. Finally, with this two-step approach all 11 rectangular pyramid deployable structures whose folded state is planar are discovered and their kinematic chains are constructed. Based on synthesis results, a novel deployable support structure for satellite SAR is designed. The proposed research can be applied to obtain some novel PDTSs, which is of great importance to design some novel deployable support structures for satellite SAR antenna.展开更多
A new technique -- the direct partial oxidation of methane to synthesis gas using lattice oxygen in molten salts medium has been introduced. Using CeO2 as the oxygen carrier, thermodynamic data were calculated in the ...A new technique -- the direct partial oxidation of methane to synthesis gas using lattice oxygen in molten salts medium has been introduced. Using CeO2 as the oxygen carrier, thermodynamic data were calculated in the reaction process, and the results indicated that direct partial oxidation of methane to synthesis gas using lattice oxygen of cerium oxide is feasible in theory. In a stainless steel reactor, the effects of temperature and varying amounts of γ-Al2O3 supported CeO2 on cn4 conversion, H2 and CO selectivity, were investigated, respectively. The results show that 10% CeO2/γ-Al2O3 has the maximal reaction activity at a temperature of 865 ℃ and above, the H2/CO ratio in the gas that has been produced reaches 2 and the CH4 conversion, H2 and CO selectivity reached the following percentages： i.e. 61%, 89%, and 91% at 870 ℃, respectively. In addition, increase of reaction temperature is favorable for the partial oxidation of methane.展开更多
A μ analysis and μ synthesis method for nonlinear robust control systems was presented. The nonlinear robust contrl problem using μ method was described. By means of the nonlinear state feedback and state coordin...A μ analysis and μ synthesis method for nonlinear robust control systems was presented. The nonlinear robust contrl problem using μ method was described. By means of the nonlinear state feedback and state coordinates transformation, many uncertain nonlinear systems can be transformed as a linear fractional transformation (LFT) on the generalized plant and the uncertainty. Based on the LFT, a linear robust controller can be obtained by the DK iteration and then a corresponding nonlinear robust control law is constructed. An example was given in the paper.展开更多
The title compound N-（2-ethoxyphenyl）-3-oxobenzo[d]isothiazole-2（3H）-carboxa-mide（C16H14N2O3S,Mr = 314.35） has been synthesized and structurally characterized by IR,1H NMR and single-crystal X-ray diffraction.Th...The title compound N-（2-ethoxyphenyl）-3-oxobenzo[d]isothiazole-2（3H）-carboxa-mide（C16H14N2O3S,Mr = 314.35） has been synthesized and structurally characterized by IR,1H NMR and single-crystal X-ray diffraction.The crystal belongs to triclinic,space group P with a = 4.6395（15）,b = 8.689（3）（A°）, c=17.917（7）（A°）α=87.763（9）,β = 84.625（9）,γ = 82.344（9）°,V = 712.4（4）（A°）^3,Z = 2,Dc = 1.465 Mg·m^-3,λ（MoKa） = 0.71073,F（000） = 328,μ（MoKa） = 0.242 mm-1,the final R = 0.038 and wR = 0.089.A total of 3702 unique reflections were collected,of which 2762 with I 〉 2σ（I） were observed.X-ray analysis revealed that the benzisothiazolone ring and benzene moieties were essentially planar,and three intramolecular hydrogen bonds N（2）-H（2N）…O（1）,N（2）-H（2N）…O（3） and C（10）-H（10）…O（2） were observed.The preliminary biologi-cal test showed that the title compound had antifungal and antibacteria activities against Bacillus subtilis（CMCC63003）,Aeromonas hydrophila（ATCC7966）,Staphylococcus aureus（ATCC6538）,Escherichia coli（JM103）,Blastomyces albicans,Gloeosporium papaya P.Henn,Colletotrichum gloeosporioides Penz and Botryodiplodia theobromae.展开更多
文摘A sinusoidal representation of speech and a cochlear model are used to extract speech parameters in this paper, and a speech analysis/synthesis system controlled by the auditory spectrum is developed with the model. The computer simulation shows that speech can be synthesized with only 12 parameters per frame on the average. The method has the advantages of few parameters, low complexity and high performance of speech representation. The synthetic speech has high intelligibility.
基金supported by The National Natural Science Foundation of China(42374004).
文摘Spherical harmonic analysis(SHA)and synthesis(SHS)are widely used by researchers in various fields.Both numerical integration and least-squares methods can be employed for analysis and synthesis.However,these approaches,when calculated via summation,are computationally intensive.Although the Fast Fourier Transform(FFT)algorithm is efficient,it is traditionally limited to processing global grid points starting from zero longitude.In this paper,we derive an improved FFT algorithm for spherical harmonic analysis and synthesis.The proposed algorithm eliminates the need for grid points to start at zero longitude,thereby expanding the applicability of FFT-based methods.Numerical experiments demonstrate that the new algorithm retains the computational efficiency of conventional FFT while achieving accuracy comparable to the summation method.Consequently,it enables direct harmonic coefficient calculation from global grid data without requiring interpolation to align with zero longitude.Additionally,the algrithm can generate grid points with equi-angular spacing using the improved FFT algorithm,starting from non-zero longitudes.To address the loss of orthogonality in latitude due to discrete spherical grids,a quadrature weight factor-dependent on grid type(e.g.,regular or Gauss grid)-is incorporated,as summarized in this study.
基金Supported by National Natural Science Foundation of China(Grant Nos.52375028,52205040)Hebei Provincial Natural Science Foundation(Grant Nos.E2024203052,E2024203105)Science and Technology Project of Hebei Education Department(Grant No.QN2023206).
文摘Origami mechanisms are extensively employed in various engineering applications due to their exceptional folding performance and deformability.The key to designing origami mechanisms lies in the design of the creases.The crease design is often derived from experience and inspiration,so it is crucial to have a systematic approach to crease design.In this paper,a novel synthesis approach based on graph theory is proposed,which effectively addresses the challenge of designing the creases in origami mechanisms.The essence of this method lies in the acquisition of the double symmetrical crease pattern through the directed graph product operation of two subgraphs.The crease pattern can be simplified by employing a technique that eliminates certain creases while preserving the non-isomorphism and symmetry of the pattern.An improved mixed-integer linear programming model is developed to achieve an automatic distribution of the peak_valley creases of the origami.The proposed method ultimately generates 12 unique double symmetrical crease patterns.The new method proposed in this paper,through systematic design,significantly improves the efficiency of mechanism design while opening up broad prospects for exploring new mechanism structures,thereby greatly expanding its application potential in cutting-edge fields such as aerospace engineering and intelligent robots.
基金financial support of the Scientific Research Funds of Huaqiao University (605-50Y17073)
文摘The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid(IL)were investigated.The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL.As the water concentration increased to 65 mg·g^(-1),the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%,and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201.When the concentration of impurities increased to a critical value,the chloroaluminate IL began to deactivate,leading to a decrease in naphthalene conversion.The critical concentrations for ethanolamine,water,methanol,ether,and diisopentyl sulfide were 33 mg·g^(-1),65 mg·g^(-1),67mg·g^(-1),87 mg·g^(-1),and 123 mg·g^(-1),respectively.Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation.The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27Al NMR spectroscopy.2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better,but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks.2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL.With the increase inwater concentration,the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid,and the Lewis acid gradually decreased,while the Brønsted acid showed a change of increasing first and then decreasing.
基金Guangxi Science and Technology Base and Talent Special Fund,Project No.AD21220130Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain,Project No.20-065-7Guangxi Institute of Botany Fund,Project No.21014.
文摘Derris fordii and Derris elliptica belong to the Derris genus of the Fabaceae family, distinguished by their high isoflavonoid content, particularly rotenoids, which hold significance in pharmaceuticals and agriculture. Rotenone, as a prominent rotenoid, has a longstanding history of use in pesticides, veterinary applications, medicine, and medical research. The accumulation of rotenoids within Derris plants adheres to species-specific and tissue-specific patterns and is also influenced by environmental factors. Current research predominantly addresses extraction techniques, pharmacological applications, and pesticide formulations, whereas investigations into the biosynthesis pathway and regulatory mechanism of rotenoids remain relatively scarce. In this study, we observed notable differences in rotenone content across the roots, stems, and leaves of D. fordii, as well as within the roots of D. elliptica. Utilizing RNA sequencing (RNA-seq), we analyzed the transcriptomes and expression profiles of unigenes from these four tissues, identifying a total of 121,576 unigenes. Differentially expressed genes (DEGs) across four comparison groups demonstrated significant enrichment in the phenylpropanoid and flavonoid biosynthesis pathways. Key unigenes implicated in the rotenoid biosynthesis pathway were identified, with PAL, C4H, CHS, CHI, IFS, and HI4OMT playing critical roles in D. fordii, while IFS and HI4OMT were determined to be essential for rotenoid biosynthesis in D. elliptica. These findings enhance our understanding of the biosynthesis mechanism of rotenoids in Derris species. The unigenes identified in this study represent promising candidates for future investigations aimed at validating their roles in rotenoid biosynthesis.
文摘BACKGROUND Meta-analysis is a critical tool in evidence-based medicine,particularly in cardiology,where it synthesizes data from multiple studies to inform clinical decisions.This study explored the potential of using ChatGPT to streamline and enhance the meta-analysis process.AIM To investigate the potential of ChatGPT to conduct meta-analyses in interventional cardiology by comparing the results of ChatGPT-generated analyses with those of randomly selected,human-conducted meta-analyses on the same topic.METHODS We systematically searched PubMed for meta-analyses on interventional cardiology published in 2024.Five metaanalyses were randomly chosen.ChatGPT 4.0 was used to perform meta-analyses on the extracted data.We compared the results from ChatGPT with the original meta-analyses,focusing on key effect sizes,such as risk ratios(RR),hazard ratios,and odds ratios,along with their confidence intervals(CI)and P values.RESULTS The ChatGPT results showed high concordance with those of the original meta-analyses.For most outcomes,the effect measures and P values generated by ChatGPT closely matched those of the original studies,except for the RR of stent thrombosis in the Sreenivasan et al study,where ChatGPT reported a non-significant effect size,while the original study found it to be statistically significant.While minor discrepancies were observed in specific CI and P values,these differences did not alter the overall conclusions drawn from the analyses.CONCLUSION Our findings suggest the potential of ChatGPT in conducting meta-analyses in interventional cardiology.However,further research is needed to address the limitations of transparency and potential data quality issues,ensuring that AI-generated analyses are robust and trustworthy for clinical decision-making.
基金supported by the Major Science and Technology Project of Hainan Province(ZDKJ2021012)National Natural Science Foundation of China(32071805)the National Key Research and Development Program of China(2023YFD2200700)。
文摘Coconut(Cocos nucifera L.)is a key tropical economic tree valued for its fruit flavor,particularly 2-acetyl-1-pyrroline(2AP),a vital aroma metabolite.To enhance high-aromatic coconut breeding efforts,it is essential to deeply understand the hereditary factors governing the production of 2AP.In this study,a genome-wide association analysis identifies 32 loci that exhibit significant associations with 2AP content based on single nucleotide polymorphism(SNP)variations from 168 aromatic coconut germplasm resources.Transcriptome analysis then pinpoints 22 candidate genes near significant loci involved in 2AP metabolism.Proteins encoded by these genes are involved in amino acid metabolism,glycolysis,and secondary metabolism.Among these,Asparagine synthetase coding gene ASN1,Gamma-glutamylcysteine synthetase coding gene GSH1,and UbiA prenyltransferase coding gene UBIA are enriched in the linkage region constructed by significant locus Chr04_61490504.In particular,the SNP mutation of CnASN1 leads to amino acid changes in the functional region of the coding protein,potentially resulting in differences in 2AP content among haplotype populations.Identifying variations in related candidate genes,particularly the gene CnASN1,provides molecular markers closely associated with 2AP synthesis for coconut breeding and offers further insights into the metabolic mechanisms of 2AP.
文摘In this paper,based on the common soil erosion model,the Three-River Headwaters region was select for study object. GIS methods are applied to conduct Semi-quantitative assessment for different types of soil erosion,and some results are concluded. The water erosion occurs in High Mountain and extra-high mountain of Yushu,Nangqian,Banma and Jiuzhi County in the southeast and south of the Three-River Headwaters region. The degree of erosion is prone to topography,precipitation,river and human activity. The freeze-thaw erosion mainly distributes in the northwest of the Three-River Headwaters region. The area of middle and above middle erosion degree accounts for roughly 50%.
基金Project (20090162120080) supported by Research Fund for the Doctoral Program of Higher Education of China Project (20070410989) supported by China Postdoctoral Science Foundation+1 种基金 Project (2010FJ3012) supported by the Program of Science and Technology of Hunan Province, China Project (09JJ4028) supported by Natural Science Foundation of Hunan Province, China
文摘According to the principles of simultaneous equilibrium and mass equilibrium, a series of thermodynamic equilibrium equations in Ni（II）-Co（II）-C2O4^2--NH3-NH4^＋-H2O system at ambient temperature were deduced. The diagrams of logarithm ion concentrations versus pH values at different solution compositions were drawn. The results show that Ni^2＋ and Co^2＋ can completely precipitate at pH less than 5.0 and the predefined Ni/Co ratios can be well kept in the precursor. The precursor morphology is granular aggregation. However, rod aggregation precursor is obtained in the pH range of 5.0-8.0, and fibre-shape precursor is got at pH value higher than 8.0. The Ni/Co ratios in the above two precursors are not reproduced as that in the feed due to the formhtion of multi-coordinated Ni（NH3）n^2＋ and Co（NH3）n^2＋ （n=1-6）. Modification of precipitation medium is favorable for the precursors to keep the predefined Ni/Co ratios of the feed in the pH range of 2.0-8.6. Meanwhile, the precursors with fibrous morphology can be obtained.
基金supported by Qingdao Key Medical and Health Discipline ProjectThe Intramural Research Program of the Affiliated Hospital of Qingdao University,No. 4910Qingdao West Coast New Area Science and Technology Project,No. 2020-55 (all to SW)。
文摘Border-associated macrophages are located at the interface between the brain and the periphery, including the perivascular spaces, choroid plexus, and meninges. Until recently, the functions of border-associated macrophages have been poorly understood and largely overlooked. However, a recent study reported that border-associated macrophages participate in stroke-induced inflammation, although many details and the underlying mechanisms remain unclear. In this study, we performed a comprehensive single-cell analysis of mouse border-associated macrophages using sequencing data obtained from the Gene Expression Omnibus(GEO) database(GSE174574 and GSE225948). Differentially expressed genes were identified, and enrichment analysis was performed to identify the transcription profile of border-associated macrophages. CellChat analysis was conducted to determine the cell communication network of border-associated macrophages. Transcription factors were predicted using the ‘pySCENIC' tool. We found that, in response to hypoxia, borderassociated macrophages underwent dynamic transcriptional changes and participated in the regulation of inflammatory-related pathways. Notably, the tumor necrosis factor pathway was activated by border-associated macrophages following ischemic stroke. The pySCENIC analysis indicated that the activity of signal transducer and activator of transcription 3(Stat3) was obviously upregulated in stroke, suggesting that Stat3 inhibition may be a promising strategy for treating border-associated macrophages-induced neuroinflammation. Finally, we constructed an animal model to investigate the effects of border-associated macrophages depletion following a stroke. Treatment with liposomes containing clodronate significantly reduced infarct volume in the animals and improved neurological scores compared with untreated animals. Taken together, our results demonstrate comprehensive changes in border-associated macrophages following a stroke, providing a theoretical basis for targeting border-associated macrophages-induced neuroinflammation in stroke treatment.
基金supported by grants from the Tianjin Health Technology Project(Grant no.2022QN106).
文摘Background:Receptor-interacting protein kinases(RIPKs)regulate cell death,inflammation,and immune responses,yet their roles in cancer are not fully understood.This study investigates the expression,genomic alterations,and functional implications of RIPK family members across various cancers.Methods:We collected multi-omics data from The Cancer Genome Atlas and other public databases,including gene expression,copy number variation(CNV),mutation,methylation,tumor mutation burden(TMB),and microsatellite instability(MSI).Differential expression and survival analyses were performed using DESeq2 and Cox proportional hazards models.CNV and mutation data were analyzed with GISTIC2 and Mutect2,and methylation data with the ChAMP package.Correlations with TMB and MSI were assessed using Pearson coefficients,and gene set enrichment analysis was conducted with the MSigDB Hallmark gene sets.Results:RIPK family members show significant differential expression in various cancers,with RIPK1 and RIPK4 frequently altered.Survival analysis reveals heterogeneous impacts on overall survival.CNV and mutation analyses identify high alteration frequencies for RIPK2 and RIPK7,affecting gene expression.RIPK1 and RIPK7 are hypermethylated in several cancers,inversely correlating with RIPK3 expression.RIPK1,RIPK2,RIPK5,RIPK6,and RIPK7 correlate positively with TMB,while RIPK3 shows negative correlations in some cancers.MSI analysis indicates associations with DNA mismatch repair.G ene set enrichment analysis highlights immune-related pathway enrichment for RIPK1,RIPK2,RIPK3,and RIPK6,and cell proliferation and DNA repair pathways for RIPK4 and RIPK5.RIPK family members showed heterogeneous alterations across cancers:for example,RIPK7 was mutated in up to~15%of u terine c orpus e ndometrial c arcinoma and l ung s quamous c ell c arcinoma cases,and RIPK1 and RIPK7 exhibited frequent promoter hypermethylation in multiple tumor types.Several genes displayed context-dependent associations with overall survival and with TMB/MSI.Conclusion:This pan-cancer analysis of the RIPK family reveals their diverse roles and potential as biomarkers and therapeutic targets.The findings emphasize the importance of RIPK genes in tumorigenesis and suggest context-dependent functions across cancer types.Further studies are needed to explore their mechanisms in cancer development and clinical applications.
基金financially supported by the National Natural Science Foundation of China(Nos.52034002 and U2202254)the Fundamental Research Funds for the Central Universities,China(No.FRF-TT-19-001)。
文摘The sulfation and decomposition process has proven effective in selectively extracting lithium from lepidolite.It is essential to clarify the thermochemical behavior and kinetic parameters of decomposition reactions.Accordingly,comprehensive kinetic study by employing thermalgravimetric analysis at various heating rates was presented in this paper.Two main weight loss regions were observed during heating.The initial region corresponded to the dehydration of crystal water,whereas the subsequent region with overlapping peaks involved complex decomposition reactions.The overlapping peaks were separated into two individual reaction peaks and the activation energy of each peak was calculated using isoconversional kinetics methods.The activation energy of peak 1 exhibited a continual increase as the reaction conversion progressed,while that of peak 2 steadily decreased.The optimal kinetic models,identified as belonging to the random nucleation and subsequent growth category,provided valuable insights into the mechanism of the decomposition reactions.Furthermore,the adjustment factor was introduced to reconstruct the kinetic mechanism models,and the reconstructed models described the kinetic mechanism model more accurately for the decomposition reactions.This study enhanced the understanding of the thermochemical behavior and kinetic parameters of the lepidolite sulfation product decomposition reactions,further providing theoretical basis for promoting the selective extraction of lithium.
基金supported by Istanbul Technical University(Project No.45698)supported through the“Young Researchers’Career Development Project-training of doctoral students”of the Croatian Science Foundation.
文摘This paper investigates the reliability of internal marine combustion engines using an integrated approach that combines Fault Tree Analysis(FTA)and Bayesian Networks(BN).FTA provides a structured,top-down method for identifying critical failure modes and their root causes,while BN introduces flexibility in probabilistic reasoning,enabling dynamic updates based on new evidence.This dual methodology overcomes the limitations of static FTA models,offering a comprehensive framework for system reliability analysis.Critical failures,including External Leakage(ELU),Failure to Start(FTS),and Overheating(OHE),were identified as key risks.By incorporating redundancy into high-risk components such as pumps and batteries,the likelihood of these failures was significantly reduced.For instance,redundant pumps reduced the probability of ELU by 31.88%,while additional batteries decreased the occurrence of FTS by 36.45%.The results underscore the practical benefits of combining FTA and BN for enhancing system reliability,particularly in maritime applications where operational safety and efficiency are critical.This research provides valuable insights for maintenance planning and highlights the importance of redundancy in critical systems,especially as the industry transitions toward more autonomous vessels.
基金Supported by the Central High Level Hospital Clinical Research Funding(No.BJ-2024-089).
文摘AIM:To explore the causal relationship between several possible behavioral factors and high myopia(HM)using multivariable Mendelian randomization(MVMR)approach and to find the mediators among them with mediation analysis.METHODS:The causal effects of several behavioral factors,including screen time,education time,time spent outdoors,and physical activity,on the risk of HM using univariable Mendelian randomization(MR)and MVMR analyses were first assessed.Genome-wide association study summary statistics of serum metabolites were also used in mediation analysis to determine the extent to which serum metabolites mediate the effects of behavioral factors on HM.RESULTS:MR analyses indicated that both increased time spent outdoors and a higher frequency of moderate physical activity significantly reduced the risk of HM.Further MVMR analysis confirmed that moderate physical activity independently contributed to a lower risk of HM.Additionally,MR analyses identified 13 serum metabolites significantly associated with HM,of which 12 were lipids and one was an amino acid derivative.Mediation analysis revealed that six lipid metabolites mediated the protective effects of moderate physical activity on HM,with the highest mediation proportion observed for 1-(1-enyl-palmitoyl)-GPC(p-16:0;30.83%).CONCLUSION:This study suggests that in addition to outdoor time,moderate physical activity habits may have an independent protective effect against HM and pointed to lipid metabolites as priority targets for the prevention due to low physical activity.These results emphasize the importance of physical activity and metabolic health in HM and underscore the need for further study of these complex associations.
基金Supported by National Natural Science Foundation of China(No.82020108006,No.81730025).
文摘AIM:To summarize publication trends in the field of strabismus over the past 30y and predict future research hotspots.METHODS:A total of 2915 English-language articles and reviews on strabismus,published between 1993 and 2022,were retrieved from the Web of Science Core Collection.Bibliometric analyses were performed using VOSviewer and CiteSpace software to explore publication trends,as well as the contributions and collaborative networks of countries/regions,authors,institutions,and journals.RESULTS:The annual number of publications on strabismus showed a consistent upward trend.The United States(USA)maintained a leading position in this research field while Republic of Korea and China emerged as rapidly advancing contributors over the last decade.The University of California,Los Angeles ranked as the most productive institution,and Jonathan M.Holmes from USA was the most productive author.Journal of AAPOS was the leading journal with the most strabismus publications,whereas the two most highly cited articles were both published in Ophthalmology.Co-occurrence analysis identified pivotal keywords and burst terms,including intermittent exotropia(IXT),acute acquired comitant esotropia(AACE),functional magnetic resonance imaging(fMRI),and surgical treatment,which were confirmed as predominant and frontier topics.CONCLUSION:This study provides a comprehensive bibliometric analysis of strabismus research,revealing the evolution of research hotspots over the past 30y and outlining several cutting-edge directions for future investigation.
基金Funded by National Natural Science Foundation of China(No.51272207)Science and Technology Plan of Guangdong Province((No.2013B021100019)
文摘High-quality LDH-SO4-CO3 whiskers were synthesized via liquid precipitation method using MgSO4·7 H2 O and Al2(SO4)3·18 H2O as precursors and Na2CO3-NaHCO3 buffer solution as precipitant. The influence of buffer solution concentration on the characteristics of the samples was investigated. The asgrown whiskers were characterized by X-ray diffraction, transmission electron microscopy, and BrunauerEmmett-Teller N2 specific surface area measurements. The results show that the buffer solution concentration has significant impact on whiskers with intercalated structure. The LDH-SO4-CO3 whiskers with well-defined geometry, distinct intercalated structure, decent quality, and excellent dispersing capability can be obtained under the following conditions: buffer solution volume ratio of 45%, reaction temperature of 83°C, and reaction time of 182 h. The obtained whiskers are well-crystallized and exhibit homogeneous morphology consisting of fiber bars.
基金Supported by the College Discipline Innovation Wisdom Plan in China(Grant No.B07018)National Natural Science Foundation of China(Grant Nos.50935002,11002039)
文摘Many attentions for structural synthesis are paid to planar linkages and parallel mechanisms, while design novel pyramid deployable truss structure（PDTS） of satellite SAR mainly depends on experience of designer. To design novel configuration of PDTS, a two-step topology structure synthesis and analysis approach is proposed. Firstly, a conceptual configuration of PDTS is synthesized. Weighted graph and weighted adjacency matrix are established to realize topological description for PDTS. Graph properties are then summarized to distinguish differentia between PDTS and other type structures. According to graph properties, a procedure for synthesis conceptual configuration of PDTS is presented. Secondly, join relationship of components in a PDTS is analyzed. Kinematic chain and corresponding incidence/adjacency matrix are employed to analyze join relationship of PDTS. Properties and simplified rules of kinematic chain are extracted to construct kinematic chain. A procedure for construction kinematic chain of PDTS is then established. Finally, with this two-step approach all 11 rectangular pyramid deployable structures whose folded state is planar are discovered and their kinematic chains are constructed. Based on synthesis results, a novel deployable support structure for satellite SAR is designed. The proposed research can be applied to obtain some novel PDTSs, which is of great importance to design some novel deployable support structures for satellite SAR antenna.
基金Supported by the National Natural Science Foundation of China (No. 50574046, No. 50164002,)Science & Technology Foundation of Baoshan Iron and Steel Co. Ltd, Natural Science Foundation of Yunnan province (No. 2004E0058Q)School of High Learning Doctoral Subject Special Science and Research Foundation of Ministry of Education (No. 20040674005)
文摘A new technique -- the direct partial oxidation of methane to synthesis gas using lattice oxygen in molten salts medium has been introduced. Using CeO2 as the oxygen carrier, thermodynamic data were calculated in the reaction process, and the results indicated that direct partial oxidation of methane to synthesis gas using lattice oxygen of cerium oxide is feasible in theory. In a stainless steel reactor, the effects of temperature and varying amounts of γ-Al2O3 supported CeO2 on cn4 conversion, H2 and CO selectivity, were investigated, respectively. The results show that 10% CeO2/γ-Al2O3 has the maximal reaction activity at a temperature of 865 ℃ and above, the H2/CO ratio in the gas that has been produced reaches 2 and the CH4 conversion, H2 and CO selectivity reached the following percentages： i.e. 61%, 89%, and 91% at 870 ℃, respectively. In addition, increase of reaction temperature is favorable for the partial oxidation of methane.
文摘A μ analysis and μ synthesis method for nonlinear robust control systems was presented. The nonlinear robust contrl problem using μ method was described. By means of the nonlinear state feedback and state coordinates transformation, many uncertain nonlinear systems can be transformed as a linear fractional transformation (LFT) on the generalized plant and the uncertainty. Based on the LFT, a linear robust controller can be obtained by the DK iteration and then a corresponding nonlinear robust control law is constructed. An example was given in the paper.
基金Supported by the National Natural Science Foundation of China (No. 20962007)
文摘The title compound N-（2-ethoxyphenyl）-3-oxobenzo[d]isothiazole-2（3H）-carboxa-mide（C16H14N2O3S,Mr = 314.35） has been synthesized and structurally characterized by IR,1H NMR and single-crystal X-ray diffraction.The crystal belongs to triclinic,space group P with a = 4.6395（15）,b = 8.689（3）（A°）, c=17.917（7）（A°）α=87.763（9）,β = 84.625（9）,γ = 82.344（9）°,V = 712.4（4）（A°）^3,Z = 2,Dc = 1.465 Mg·m^-3,λ（MoKa） = 0.71073,F（000） = 328,μ（MoKa） = 0.242 mm-1,the final R = 0.038 and wR = 0.089.A total of 3702 unique reflections were collected,of which 2762 with I 〉 2σ（I） were observed.X-ray analysis revealed that the benzisothiazolone ring and benzene moieties were essentially planar,and three intramolecular hydrogen bonds N（2）-H（2N）…O（1）,N（2）-H（2N）…O（3） and C（10）-H（10）…O（2） were observed.The preliminary biologi-cal test showed that the title compound had antifungal and antibacteria activities against Bacillus subtilis（CMCC63003）,Aeromonas hydrophila（ATCC7966）,Staphylococcus aureus（ATCC6538）,Escherichia coli（JM103）,Blastomyces albicans,Gloeosporium papaya P.Henn,Colletotrichum gloeosporioides Penz and Botryodiplodia theobromae.
