检索结果-南通市图书馆

An anti-icing scaling method for wind tunnel tests of aircraft thermal ice protection system

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第6期37卷 1-6页

作者： Yu LIU Qiang WANG xian YI Ningli CHEN Jinghao ren Weihao LI Key Laboratory of Icing and Anti/de-icing China Aerodynamics Research and Development CenterMianyang 621000China State Key Laboratory of Aerodynamics Mianyang 621000China

The efficiency of the aircraft Ice Protection Systems(IPSs)needs to be verified through icing wind tunnel ***,the scaling method for testing the IPSs has not been systematically established yet,and further research is *** the present study,a scaling method specifically designed for thermal IPSs was derived from the governing equation of thin water *** scaling parameters were adopted to address the heat and mass transfer involved in the thermal anti-icing *** method validation,icing wind tunnel tests were conducted using a jet engine nacelle model equipped with a bleed air *** non-dimensional surface temperature and runback ice closely matched for both the reference and scaled *** validation confirms that the scaling method is capable of achieving the similarity of surface temperature and the runback ice *** anti-icing scaling method can serve as an important supplement to the existing icing similarity theory.

关键词： Scaling method Ice protection system Water film Anti-icing test Icing wind tunnel

Antiviral treatment standards for hepatitis B:An urgent need for expansion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第4期30卷 418-420页

作者： Zi-Hong Bao Zhi-kun Dai Hao-xian Tang Department of Infectious Diseases The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041Guangdong ProvinceChina Medical College Shantou University Medical CollegeShantou 515041Guangdong ProvinceChina Department of Cardiology The First Affiliated Hospital of Shantou University Medical CollegeShantou 515041Guangdong ProvinceChina

The present letter to the editor is related to the review with the title“Past,present,and future of long-term treatment for hepatitis B virus.”Chronic hepatitis B(CHB)represents an important and pressing public health *** identification and effective antiviral therapy hold the potential to reduce liver-related mortality attributable to chronic infection with hepatitis B virus(HBV)***,the current global treatment rates for CHB remain conspicuously low,with the excessively stringent treatment criteria advocated by national CHB guidelines being a contributing factor to these low ***,recent strides in comprehending this malady and the emergence of novel antiviral agents prompt the imperative re-evaluation of treatment standards to extend the sphere of potential *** impending need arises for a novel paradigm for the classification of patients with CHB,the expansion of antiviral treatment eligibility for HBV-infected individuals,and even the streamlining of the diagnostic process for CHB to amplify cost-effectiveness and augment survival prospects.

关键词： Hepatitis B virus Chronic hepatitis B Antiviral treatment criteria Serum alanine aminotransferase Liver-related mortality Letter to the Editor

Dynamic mechanical characteristics of deep Jinping marble in complex stress environments

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 630-644页

作者： Chendi Lou Heping Xie Ru Zhang Hai ren Hao Luo kun Xiao Yuan Peng Qiang Tan Li ren Institute for Disaster Management and Reconstruction Sichuan UniversityChengdu610207China College of Water Resource&Hydropower Sichuan UniversityChengdu610065China MOE Key Laboratory of Deep Earth Science&Engineering Sichuan UniversityChengdu610065China Yalong River Hydropower Development Company Ltd.Chengdu610051China (Chongqing)International Engineering Technology Company Ltd.Chongqing401121China

To reveal the dynamic mechanical characteristics of deep rocks,a series of impact tests under triaxial static stress states corresponding to depths of 300-2400 m were *** results showed that both the strain rates and the stress environments in depth significantly affect the mechanical characteristics of *** sensitivity of strain rate to the dynamic strength and deformation modulus shows a negative correlation with depth,indicating that producing penetrative cracks in deep environments is more difficult when damage *** dynamic strength shows a tendency to decrease and then increase slightly,but decreases sharply *** demonstrates a similar trend as that of strength,whereas reflectivity indicates the opposite ***,two critical depths with high dynamically induced hazard possibilities based on the China Jinping Underground Laboratory(CJPL)were proposed for deep *** first critical depth is 600-900 m,beyond which the sensitivity of rock dynamic characteristics to the strain rate and restraint of circumferential stress decrease,causing instability of surrounding rocks under axial stress *** second one lies at 1500-1800 m,where the wave impedance and dynamic strength of deep surrounding rocks drop sharply,and the dissipation energy presents a negative *** suggests that the dynamic instability of deep surrounding rocks can be divided into dynamic load dominant and dynamic load induced types,depending on the second critical depth.

关键词： Rock mechanics Split-Hopkinson pressure bar Coupled static‒dynamic loading Different depths Holmquist-Johnson-Cook(HJC)model

Wheat FHB resistance assessment using hyperspectral feature band image fusion and deep learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

INTERNATIONAL JOURNAL OF AGRICULTURAL AND BIOLOGICAL ENGINEERING 2024年第2期17卷 240-249页

作者： Liang, kun ren, Zhizhou Song, Jinpeng Yuan, Rui Zhang, Qun Nanjing Agr Univ Coll Artificial Intelligence Nanjing 210031 Peoples R China Jiangsu Prov Engn Lab Modern Facil Agr Technol & E Nanjing 210031 Peoples R China 40 Dian Jiangtai Rd Nanjing 210031 Jiangsu Peoples R China

The breeding and selection of resistant varieties is an effective way to minimize wheat Fusarium head blight (FHB) hazards, so it is important to identify and evaluate resistant varieties. The traditional resistance phenotype identification is still largely dependent on time-consuming manual methods. In this paper, the method for evaluating FHB resistance in wheat ears was optimized based on the fusion feature wavelength images of the hyperspectral imaging system and the Faster R-CNN algorithm. The spectral data from 400-1000 nm were preprocessed by the multiple scattering correction (MSC) algorithm. Three feature wavelengths (553 nm, 682 nm and 714 nm) were selected by analyzing the X-loading weights (XLW) according to the absolute value of the peaks and troughs in different principal component (PC) load coefficient curves. Then, the different fusion methods of the three feature wavelengths were explored with different weight coefficients. Faster R-CNN was trained on the fusion and RGB datasets with VGG16, AlexNet, ZFNet, and ResNet-50 networks separately. Then, the other detection models SSD, YOLOv5, YOLOv7, CenterNet, and RetinaNet were used to compare with the Faster R-CNN model. As a result, the Faster R-CNN with VGG16 was best with the mAP (mean Average Precision) ranged from 97.7% to 98.8%. The model showed the best performance for the Fusion Image-1 dataset. Moreover, the Faster R-CNN model with VGG16 achieved an average detection accuracy of 99.00%, which was 23.89%, 1.21%, 0.75%, 0.62%, and 8.46% higher than SSD, YOLOv5, YOLOv7, CenterNet, and RetinaNet models. Therefore, it was demonstrated that the Faster R-CNN model based on the hyperspectral feature image fusion dataset proposed in this paper was feasible for rapid evaluation of wheat FHB resistance. This study provided an important detection method for ensuring wheat food security.

关键词： Fusarium head blight resistance evaluation hyperspectral feature band image fusion deep learning Faster R-CNN FUSARIUM HEAD BLIGHT WINTER-WHEAT DURUM-WHEAT DEOXYNIVALENOL PREDICTION MANAGEMENT

Omics for deciphering oral microecology

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Oral Science 2024年第2期16卷 197-207页

作者： Yongwang Lin Xiaoyue Liang Zhengyi Li Tao Gong Biao ren Yuqing Li xian Peng State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases West China Hospital of StomatologySichuan UniversityChengduChina

The human oral microbiome harbors one of the most diverse microbial communities in the human body,playing critical roles in oral and systemic *** technological innovations are propelling the characterization and manipulation of oral ***-throughput sequencing enables comprehensive taxonomic and functional profiling of oral *** long-read platforms improve genome assembly from complex ***-cell genomics provides insights into uncultured *** imaging modalities including fluorescence,mass spectrometry,and Raman spectroscopy have enabled the visualization of the spatial organization and interactions of oral microbes with increasing *** techniques link phylogenetic identity with *** spectrometry imaging reveals metabolic niches and activities while Raman spectroscopy generates rapid biomolecular fingerprints for *** facilitates the isolation and cultivation of novel fastidious oral taxa using high-throughput *** integration of these technologies holds the promise of transforming our understanding of oral microbiome assembly,gene expression,metabolites,microenvironments,virulence mechanisms,and microbe-host interfaces in the context of health and ***,significant knowledge gaps persist regarding community origins,developmental trajectories,homeostasis versus dysbiosis triggers,functional biomarkers,and strategies to deliberately reshape the oral microbiome for therapeutic *** convergence of sequencing,imaging,cultureomics,synthetic systems,and biomimetic models will provide unprecedented insights into the oral microbiome and offer opportunities to predict,prevent,diagnose,and treat associated oral diseases.

关键词： insight holds oral

Internal electric field modulation by copper vacancy concentration of cuprous sulfide nanosheets for enhanced selective CO_(2) photoreduction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第4期91卷 324-330页

作者： xian Shi Weidong Dai Xiaoqian Li Yang Bai Qin ren Yao Lei Xing'an Dong School of Chemistry and Environmental Engineering Sichuan University of Science&EngineeringZigong 643000SichuanChina State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation School of Oil&Natural Gas EngineeringSouthwest Petroleum UniversityChengdu 610500SichuanChina Chongqing Key Laboratory of Photo-Electric Functional Materials College of Physics and Electronic EngineeringChongqing Normal UniversityChongqing 401331SichuanChina Research Center for Environmental and Energy Catalysis Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731SichuanChina

Although the internal electric field(IEF)of photocatalysts is acknowledged as a potent driving force for photocharge separation,modulating the IEF intensity to achieve enhanced photocatalytic performances remains a ***,cuprous sulfide nanosheets with different Cu vacancy concentration were employed to study IEF modulation and corresponding direct charge *** the samples,Cu_(1.8)S nanosheets possessed intensified IEF intensity compared with those of Cu_(2)S and Cu_(1.95)S nanosheets,suggesting that an enhanced IEF intensity could be achieved by introducing more Cu *** intensified IEF of Cu_(1.8)S nanosheets induced numerous photogenerated electrons to migrate to its surface,and the dissociative electrons were then captured by Cu vacancies,resulting in efficient charge separation *** addition,the Cu vacancies on Cu_(1.8)S nanosheets accumulated electrons as active sites to lower the energy barrier of rate-determining step of CO_(2)photoreduction,leading to the selective conversion of CO_(2)to ***,the manipulation of IEF intensity through Cu vacancy concentration regulation of cuprous sulfide photocatalysts for efficient charge separation has been discussed,providing a scientific strategy to rationally improve photocata lytic performances for solar energy conversion.

关键词： Internal electric field intensity Cuprous sulfide photocatalysts Cu vacancies Charge separation Selective CO_(2) photoreduction

A novel stiffness optimization model of space telescopic boom based on locking mechanism

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2024年第3期19卷 41-59页

作者： kun XU Xinghan ZHUANG Zhou SU Qiuhong LIN Shouzhi ren Hang XIAO Xilun DING School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beijing Institute of Spacecraft System Engineering Beijing 100094China

The deployable telescopic boom,whose mass and stiffness play crucial roles,is extensively used in the design of space-deployable ***,the most existing optimal design that neglects the influence of the locking mechanisms in boom joints cannot raise the whole stiffness while reducing the boom *** tackle this challenge,a novel optimization model,which utilizes the arrangement of the locking mechanisms to achieve synchronous improvement of the stiffness and mass,is *** proposed optimization model incorporates a novel joint stiffness model developed based on an equivalent parallel mechanism that enables the consideration of multiple internal stiffness factors of the locking mechanisms and tubes,resulting in more accurate representations of the joint stiffness *** analysis shows that the proposed stiffness model achieves more than at least 11% improved accuracy compared with existing ***,case verification shows that the proposed optimization model can improve stiffness while effectively reducing mass,and it is applied in boom optimization design.

关键词： deployable telescopic boom locking mechanism stiffness model clearance error optimization model

Flotation separation of feldspar from quartz using sodium fluosilicate as a selective depressant

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第3期43卷 1288-1300页

作者： Xin Hu xian-Ping Luo Zi-Shuai Liu Yong-Bing Zhang He-Peng Zhou Zhi-Zhao Yang Xue-kun Tang Faculty of Resource and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou341000China Yichun Lithium New Energy Industry Research Institute Jiangxi University of Science and TechnologyYichun336000China

The physical and chemical properties of feldspar and quartz are highly similar,thus they cannot be easily separated *** this work,the flotation separation of feldspar from quartz using sodium fluosilicate(Na_(2)SiF_(6);SF)as a selective depressant was ***,the influence mechanism of SF on the selective flotation separation of feldspar and quartz was investigated via flotation tests,chemical analysis of flotation solution,Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and contact angle *** results of the flotation tests show that feld spar and quartz without SF treatment have good *** SF treatment,feldspar still has good floatability,whereas quartz has significantly reduced *** solution chemical analysis shows that the functional group plays an important role in depressing the quartz is[SiF_(6)]^(2-).FTIR,XPS and contact angle analysis results show that[SiF_(6)]^(2-)is adsorbed only on the surface of ***,a thin hydrophilic SiOF layer is generated on the surface,which interferes with the adsorption of the collector on the surface of the *** phenomenon leads to a significant reduction in quartz's ***,SF has a good ability to separate feldspar from quartz by flotation.

关键词： Flotation separation Depressants Sodium fluorosilicate Quartz Feldspar

Enantioselective Synthesis of Benzimidazole Atropisomers Featuring a N-N Axis

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第7期42卷 711-718页

作者： Fang-Bei Ge Qi-kun Yin Chuan-Jun Lu Xuan Xuan Jia Feng ren-Rong Liu College of Chemistry and Chemical Engineering Qingdao UniversityQingdaoShandong 266071China School of Pharmacy Key Laboratory of Molecular Pharmacology and Drug EvaluationMinistry of EducationYantai UniversityYantaiShandong 264005China

Atroposelective synthesis of N-N atropisomers is an emerging area but remains underexplored;in particular,the synthesis of N-N benzimidazole atropisomers is still ***,the first enantioselective synthesis of N-N benzimidazole atropisomers via the palladium-catalyzed de novo construction of benzimidazole skeleton is *** readily available palladium catalyst and biphosphine ligand,a broad range of nonbiaryl benzimidazole and indole-benzimidazole atropisomers were conveniently ac-cessed in high yields and with excellent ***,these N-N benzimidazole atropisomers showed great anti-tumor activity and selectivity to breast cancer MCF-7 *** simple catalytic system,broad substrate scope,high enantioselectivi-ty,and good bioactivity make this approach highly attractive.

关键词： Asymmetric synthesis Atropisomerism Palladium Benzimidazole Antitumor