检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

中药冰片在动物体内转化为樟脑的研究

世界科学技术-中医药现代化 2008年第3期10卷 27-36页

作者：姜晓飞邹佳丽袁月梅姚美村 francis c.p.law 乔延江中山大学药学院广州510080 Department of Biological Sciences Simon Fraser UniversityBurnabyB.C.Canada VSA 1S6 北京中医药大学中药学院北京100106

目的:给小鼠等动物灌服冰片后,对冰片在其体内转化为樟脑的情况进行初步的定性研究。方法:将天然冰片、冰片(合成龙脑)和异龙脑配成混悬液后,给小鼠灌服,30min后处死小鼠,取肝脏和血浆,经过(肝脏匀浆、)萃取、离心等处理后,取上清液注入... 详细信息

目的:给小鼠等动物灌服冰片后,对冰片在其体内转化为樟脑的情况进行初步的定性研究。方法:将天然冰片、冰片(合成龙脑)和异龙脑配成混悬液后,给小鼠灌服,30min后处死小鼠,取肝脏和血浆,经过(肝脏匀浆、)萃取、离心等处理后,取上清液注入Gc-MS进行定性分析;给小鼠、大鼠、家兔灌服天然冰片后,在不同时间点取样,经处理后对樟脑进行分析。结果:Gc-MS法可很好的分离和定性龙脑、异龙脑和樟脑等成分;小鼠灌服天然冰片、冰片(合成龙脑)和异龙脑后30min,小鼠体内均检测到樟脑色谱峰;灌服天然冰片后在不同动物体内樟脑的含量基本都随着时间的延长而呈一定规律性的变化。结论:冰片(天然冰片、冰片(合成龙脑))和异龙脑在小鼠、大鼠、家兔体内有转化为樟脑的趋势,动物体内的樟脑含量随时间而呈规律性变化。

关键词：天然冰片冰片(合成龙脑) 异龙脑樟脑 Gc-MS分析

Doped low-density parity-check codes

在线全文

学校读者我要写书评

暂无评论

Digital communications and Networks 2024年第1期10卷 217-226页

作者： Yong Li Rui Liu Xianlong Jiao Youqiang Hu Zhen Luo francis c.M.Lau college of computer Science Chongqing UniversityChongqing400044China School of Automation Chongqing UniversityChongqing400044China college of Electronic and Information Engineering Southwest UniversityChongqing400715China Future Wireless Networks and IoT Focusing Area Department of Electronic and Information EngineeringHong Kong Polytechnic UniversityHong KongChina

In this paper,we propose a doping approach to lower the error floor of Low-Density parity-check(LDpc)*** doping component is a short block code in which the information bits are selected from the coded bits of the dominant trapping sets of the LDpc ***,an algorithm for selecting the information bits of the short code is proposed,and a specific two-stage decoding algorithm is *** results demonstrate that the proposed doped LDpc code achieves up to 2.0 dB gain compared with the original LDpc code at a frame error rate of 10^(-6)Furthermore,the proposed design can lower the error floor of original LDpc codes.

关键词： LDpc codes Doped LDpc codes Tanner graph Quadratic residue codes Trapping sets

Synthesis of nanostructured zinc oxide and its composite with carbon dots for DSScs applications using flexible electrode

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Materials Reports(Energy) 2024年第3期4卷 77-83页

作者： Habtamu Fekadu Etefa francis Birhanu Dejene Department of physics Walter Sisulu UniversityPrivate Bag X-1Mthatha5117South Africa

ZnO nanowires(ZnO NWs),ZnO nanoparticles(ZnO Nps)and carbon dots(c-dots)were synthesized by hydrothermal,sol-gel and hydrothermal methods *** were also characterized and applied for dye sensitized solar cells(DSScs).The effects of c-dots on ZnO NWs and ZnO Nps have been *** c-dots were used at a mole ratio of citric acid(cA)to ethylene diamine(EDA)of 1:*** c-dots were found to enhance the performance of the flexible electrode *** the addition of c-dots,the power conversion efficiency(pcE)of ZnO Nps was boosted to be two times higher than that of ZnO Nps DSScs without ***,the ultraviolet(UV)-band revealed a blue shift,resulting in a lower band gap and a reduced charge transfer resistance,which can enhance the pcE of *** loaded quantity on the flexible electrode substrate made of polyethylene terephthalate(pET)was optimized(50 mg).For DSScs,the pET flexible electrode conductive polymer has produced positive *** ZnO NWs and ZnO NWs@c-dots,the pcE values were 1.45%and 4.25%;while for ZnO Nps and ZnO Nps@c-dots,they were 2.34%and 5.81%,*** work achieved remarkable and competitive performance when compared to solid(indium tin oxides/glass)-based substrate.

关键词： ZnO NWs@c-dots ZnO Nps@c-dots pET DSScs Flexible electrode

Hybrid ionic/electronic interphase enabling uniform nucleation and fast diffusion kinetics for stable lithium metal anode

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

chinese chemical Letters 2024年第2期35卷 626-633页

作者： Lun Li pengxia Ji Meng Huang Zixin Zhang Hong Wang francis Verpoort Jinlong Yang Daping He State Key Laboratory of Advanced Technology for Materials Synthesis and processing School of Materials Science and EngineeringWuhan University of TechnologyWuhan 430070China Guangdong Research center for Interfacial Engineering of Functional Materials College of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China Sanya Science and Education Innovation park of Wuhan University of Technology Sanya 572000China Hubei Engineering Research center of RF-Microwave Technology and Application Wuhan University of TechnologyWuhan 430070China State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China

Lithium(Li)dendrite issue,which is usually caused by inhomogeneous Li nucleation and fragile solid electrolyte interphase(SEI),impedes the further development of high-energy Li metal ***,the integrated construction of a high-stable SEI layer that can regulate uniform nucleation and facilitate fast Li-ion diffusion kinetics for Li metal anode still falls ***,we designed an artificial SEI with hybrid ionic/electronic interphase to regulate Li deposition by in-situ constructing metal co clusters embedded in LiF *** generated co and LiF both enable fast Li-ion diffusion kinetics,meanwhile,the lithiophilic properties of co clusters can serve as Li-ion nucleation sites,thereby contributing to uniform Li nucleation and non-dendritic *** a result,a dendrite-free Li deposition with a low overpotential(16.1 mV)is achieved,which enables an extended lifespan over 750 h under strict *** full cells with high-mass-loading LiFepO_(4)(11.5 mg/cm^(2))as cathodes exhibit a remarkable rate capacity of 84.1 mAh/g at 5 c and an improved cycling performance with a capacity retention of 96.4%after undergoing 180 cycles.

关键词： Lithium metal anode Hybrid ionic/electronic interphase Solid electrolyte interphase Fast diffusion kinetics Dendritic growth of lithium

Beta-HcG Levels and Ovarian Ultrasonography Results among Non-pregnant Women of Reproductive Age in port Harcourt, Nigeria: A cross-Sectional Study

在线全文

学校读者我要写书评

暂无评论

Journal of Biosciences and Medicines 2024年第5期12卷 233-241页

作者： celine c. Agonsi francis Anacletus Joel Aluko chinemerem Eleke Joy c. Samuel African centre of public Health and Toxicological Research (AcE-pUTOR) University of Port Harcourt Choba Nigeria Department of Nursing Science University of Port Harcourt Choba Nigeria

Background: certain ovarian cancers that were previously common in postmenopausal women are now increasingly observed in women of reproductive age. The research on using β-HcG as a diagnostic biomarker for ovarian cancer in women of reproductive age is ongoing. Aim: This study assessed the level of serum β-HcG in non-pregnant women of reproductive age and determined its potential association with suspicious ovarian ultrasonography results. Methods: The study was conducted in port Harcourt, Nigeria. This study adopted a cross-sectional design on a quota sample of 224 case notes of women aged 18 - 40 years obtained from eight diagnostic centres. A data extraction form was used for data collection. Data analysis employed descriptive statistics, chi-square, Fisher’s exact test, and Odds Ratio at 95% confidence and 5% significance levels. Results: About 5.8% of the participants exhibited detectable levels of serum β-HcG above 5 IU/L (World Health Organization reference) at a mean concentration of 5.87 (±1.75) IU/L. About 4.0% of the participants had suspicious ovarian lesions identified through ultrasonography. participants with elevated serum β-HcG levels above the WHO reference were 59 times more likely to have suspicious ovarian lesions (Odds ratio: 59.4, 95%cI: 12.3 - 287.8, p β-HcG level and age (p = 0.041) as well as parity (p conclusion: Serum β-HcG levels above the WHO reference in non-pregnant women were associated with suspicious ovarian lesions. More rigorous primary research, systematic reviews, and meta-analyses are needed to confirm the findings of this study.

关键词： Biomarkers Ovarian cancer pregnancy Ultrasonography

Understanding the catalysis of chromium trioxide added magnesium hydride for hydrogen storage and Li ion battery applications

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 Magnesium and Alloys 2024年第3期12卷 1117-1130页

作者： D.pukazhselvan IhsanÇaha catarina de Lemos Sergey M.Mikhalev francis Leonard Deepak Duncan paul Fagg Department of Mechanical Engineering TEMA-Centre for Mechanical Technology and AutomationUniversity of AveiroAveiro 3810-193Portugal LASI-Intelligent Systems Associate Laboratory Guimarães 4800-058Portugal Nanostructured Materials Group International Iberian Nanotechnology Laboratory(INL)Avenida Mestre Jose VeigaBraga 4715-330Portugal

This study explores how the chemical interaction between magnesium hydride(MgH_(2))and the additive crO_(3) influences the hydrogen/lithium storage characteristics of MgH_(2).We have observed that a 5 wt.%crO_(3) additive reduces the dehydrogenation activation energy of MgH_(2) by 68 kJ/mol and lowers the required dehydrogenation temperature by 80℃.crO_(3) added MgH_(2) was also tested as an anode in an Li ion battery,and it is possible to deliver over 90%of the total theoretical capacity(2038 mAh/g).Evidence for improved reversibility in the battery reaction is found only after the incorporation of additives with MgH_(2).In depth characterization study by X-ray diffraction(XRD)technique provides convincing evidence that the crO_(3) additive interacts with MgH_(2) and produces cr/MgO *** free energy analyses confirm the thermodynamic feasibility of conversion from MgH_(2)/crO_(3) to MgO/cr,which is well supported by the identification of cr(0)in the powder by X ray photoelectron spectroscopy(XpS)*** high resolution transmission electron microscopy(HRTEM)and energy dispersive spectroscopy(EDS)we found evidence for the presence of 5 nm size cr nanocrystals on the surface of MgO rock salt *** is also convincing ground to consider that MgO rock salt accommodates cr in the *** observations support the argument that creation of active metal–metal dissolved rock salt oxide interface may be vital for improving the reactivity of MgH_(2),both for the improved storage of hydrogen and lithium.

关键词： Hydrogen storage Rechargeable batteries Binary hydrides Metal oxides catalytic mechanism.

Hierarchical cobalt-molybdenum layered double hydroxide arrays power efficient oxygen evolution reaction

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第6期17卷 5080-5086页

作者： Xinyi Zhu Jiahui Lyu Shanshan Wang Xingchuan Li Xiaoyu Wei cheng chen Wanida Kooamornpattana francis Verpoort Jinsong Wu Zongkui Kou State Key Laboratory of Advanced Technology for Materials Synthesis and processing Wuhan University of TechnologyWuhan 430070China Sanya Science and Education Innovation park of Wuhan University of Technology Sanya 572000China Nanostructure Research center Wuhan University of TechnologyWuhan 430070China Department of chemical Engineering Faculty of EngineeringMahidol UniversityNakhon Pathom 73170Thailand

Transition metal-based layered double hydroxides(LDHs)have been capable of working efficiently as catalysts in the basic oxygen evolution reaction(OER)for sustaining hydrogen production of alkaline water ***,exploring new LDH-based electrocatalysts featuring both remarkable activity and good stability is still in high demand,which is pivotal for comprehensive understanding and impressive improvement of the sluggish OER ***,a series of bimetallic(co and Mo)LDH arrays were designed and fabricated via a facile and controlled strategy by incorporating a Mo source into presynthesized co-based metal-organic framework(MOF)arrays on carbon cloth(cc),named as ZIF-67/cc *** found that tuning the Mo content resulted in gradual differences in the structural properties,surface morphology,and chemical states of the resulting catalysts,namely coMox-LDH/cc(x representing the added weight of the Mo source).Gratifyingly,the best-performing coMo_(0.20)-LDH/cc electrocatalyst demonstrates a low overpotential of only 226 mV and high stability at a current density of 10 mA·cm^(−2),which is superior to most LDH-based OER catalysts reported ***,it only required 1.611 V voltage to drive the overall water splitting device at the current density of 10 mA·cm^(−2).The present study represents a significant advancement in the development and applications of new OER catalysts.

关键词： layered double hydroxides(LDHs) metal-organic frameworks(MOFs) array catalysts Mo modification electrocatalytic oxygen evolution reaction(OER)

Artificial Neural Network and Fuzzy Logic Based Techniques for Numerical Modeling and prediction of Aluminum-5%Magnesium Alloy Doped with REM Neodymium

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 Nonferrous Metallurgy 2024年第1期11卷 1-19页

作者： Anukwonke Maxwell chukwuma chibueze Ikechukwu Godwills cynthia c. Nwaeju Osakwe francis Onyemachi Department of Metallurgical and Materials Engineering Nnamdi Azikiwe University Awka Nigeria Department of Mechanical Engineering Nigeria Martine University Okerenkoko Nigeria

In this study, the mechanical properties of aluminum-5%magnesium doped with rare earth metal neodymium were evaluated. Fuzzy logic (FL) and artificial neural network (ANN) were used to model the mechanical properties of aluminum-5%magnesium (0-0.9 wt%) neodymium. The single input (SI) to the fuzzy logic and artificial neural network models was the percentage weight of neodymium, while the multiple outputs (MO) were average grain size, ultimate tensile strength, yield strength elongation and hardness. The fuzzy logic-based model showed more accurate prediction than the artificial neutral network-based model in terms of the correlation coefficient values (R).

关键词： Al-5%Mg Alloy Neodymium Artificial Neural Network Fuzzy Logic Average Grain Size and Mechanical properties

Enhanced detection of freeze‒thaw induced landslides in Zhidoi county(Tibetan plateau,china)with Google Earth Engine and image fusion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in climate change Research 2024年第3期15卷 476-489页

作者： Jia-Hui YANG Yan-chen GAO Lang JIA Wen-Juan WANG Qing-Bai WU francis ZVOMUYA Miles DYcK Hai-Long HE college of Natural Resources and Environment Northwest A&F UniversityYangling 712100China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Department of Soil Science University of Manitob1Winnipeg MB R3T 2N2Canada Department of Renewable Resources University of Albert1Edmonton AB T6G 2H1Canad

Freeze‒thaw induced landslides(FTILs)in grasslands on the Tibetan plateau are a geological disaster leading to soil *** landslides reduce biodiversity and intensify landscape fragmentation,which in turn are strengthen by the persistent climate change and increased anthropogenic ***,conventional techniques for mapping FTILs on a regional scale are impractical due to their labor-intensive,costly,and time-consuming *** study focuses on improving FTILs detection by implementing image fusion-based Google Earth Engine(GEE)and a random forest *** of multiple data sources,including texture features,index features,spectral features,slope,and vertical‒vertical polarization data,allow automatic detection of the spatial distribution characteristics of FTILs in Zhidoi county,which is located within the Qinghai‒Tibet Engineering corridor(QTEc).We employed statistical techniques to elucidate the mechanisms influencing FTILs *** enhanced method identifies two schemes that achieve high accuracy using a smaller training sample(scheme A:94.1%;scheme D:94.5%)compared to other methods(scheme B:50.0%;scheme c:95.8%).This methodology is effective in generating accurate results using only~10%of the training sample size necessitated by other *** spatial distribution patterns of FTILs generated for 2021 are similar to those obtained using various other training sample sources,with a primary concentration observed along the central region traversed by the *** results highlight the slope as the most crucial feature in the fusion images,accounting for 93%of FTILs occurring on gentle slopes ranging from 0°to 14°.This study provides a theoretical framework and technological reference for the identification,monitoring,prevention and control of FTILs in *** developments hold the potential to benefit the management of grassland ecosystem,reduce economic losses,and promote grassland sustainability.

关键词： permafrost degradation Random forest Thaw slump Spatial distribution Tibetan plateau