检索结果-南通市图书馆

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

高氯酸银催化炔丙醇与酸酐反应制备烯二酮

分子催化（中英文） 2024年第2期38卷 104-111,I0001页

作者：原晔段康柴多镇卜超李卫伟 francis Verpoort 武汉理工大学材料复合新技术国家重点实验室湖北武汉430070 武汉理工大学材料科学与工程学院湖北武汉430070

烯二酮类化合物是一类重要的工业原料和多功能的有机合成中间体,在制药工程、香料加工和化学合成中有着广泛的应用.利用高氯酸银(AgClO_(4))催化炔丙醇与酸酐的反应,首次合成了几种此前从未报道过的新型烯二酮类化合物.该反应过程无需溶... 详细信息

烯二酮类化合物是一类重要的工业原料和多功能的有机合成中间体,在制药工程、香料加工和化学合成中有着广泛的应用.利用高氯酸银(AgClO_(4))催化炔丙醇与酸酐的反应,首次合成了几种此前从未报道过的新型烯二酮类化合物.该反应过程无需溶剂,且具有操作简单、条件温和、绿色环保、底物普适性广等优点,这表明了该方法在烯二酮合成领域巨大的应用潜力.

关键词：烯二酮炔丙醇高氯酸银酸酐催化

dynamics of self-hybridized exciton–polaritons in 2d halide perovskites

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

Light(Science & Applications) 2024年第1期13卷 13-22页

作者： Surendra B.Anantharaman Jason Lynch Christopher E.Stevens Christopher Munley Chentao Li Jin Hou Hao Zhang Andrew Torma Thomas darlington francis Coen Kevin Li Arka Majumdar PJames Schuck Aditya Mohite Hayk Harutyunyan Joshua R.Hendrickson deep Jariwala department of Electrical and Systems Engineering University of PennsylvaniaPhiladelphiaPA19104USA KBR Inc. BeavercreekOH45431USA Air Force Research Laboratory Sensors DirectorateWright-Patterson Air Force BaseOH45433USA department of Physics University of WashingtonSeattleWA98195USA department of Physics Emory UniversityAtlantaGA30322USA department of Chemical and Biomolecular Engineering Rice UniversityHoustonTX77005USA department of Materials Science and Nanoengineering Rice UniversityHoustonTX77005USA Applied Physics Program Smalley‐Curl InstituteRice UniversityHoustonTX77005USA department of Mechanical Engineering Columbia UniversityNew YorkNY10027USA department of Electrical and Computer Engineering University of WashingtonSeattleWA98195USA

Excitons,bound electron–hole pairs,in two-dimensional hybrid organic inorganic perovskites(2d HOIPs)are capable of forming hybrid light-matter states known as exciton-polaritons(E–Ps)when the excitonic medium is confined in an optical *** the case of 2d HOIPs,they can self-hybridize into E–Ps at specific thicknesses of the HOIP crystals that form a resonant optical cavity with the ***,the fundamental properties of these self-hybridized E–Ps in 2d HOIPs,including their role in ultrafast energy and/or charge transfer at interfaces,remain ***,we demonstrate that>0.5µm thick 2d HOIP crystals on Au substrates are capable of supporting multiple-orders of self-hybridized E–P *** E–Ps have high Q factors(>100)and modulate the optical dispersion for the crystal to enhance sub-gap absorption and *** varying excitation energy and ultrafast measurements,we also confirm energy transfer from higher energy E–Ps to lower energy E–***,we also demonstrate that E–Ps are capable of charge transport and transfer at *** findings provide new insights into charge and energy transfer in E–Ps opening new opportunities towards their manipulation for polaritonic devices.

关键词： charge polar excitation

development of a Simple Extraction Method for Tetracycline Analogues from Bovine Milk

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 Biological Chemistry 2024年第4期14卷 111-120页

作者： Oscar Cordova Thien Le Christopher Lambert devin Brodie Stephany Ramirez francis Sandoval Karno Ng department of Chemistry & Biochemistry California State University San Marcos San Marcos USA

Tetracycline and analogues are among the most used antibiotics in the dairy industry. Besides the therapeutic uses, tetracyclines are often incorporated into livestock feed as growth promoters. A considerable amount of antibiotics is released unaltered through milk from dairy animals. The presence of antibiotic residues in milk and their subsequent consumption can lead to potential health impacts, including cancer, hypersensitivity reactions, and the development of antibiotic resistance. Thus, it is important to monitor residual levels of tetracyclines in milk. The purpose of this study is to develop a quick and simple method for simultaneously extracting five tetracycline analogues from bovine milk. Specifically, five tetracycline analogues: Chlortetracycline (CTC), demeclocycline (dEM), doxycycline (dC), minocycline (MC), and tetracycline (TC) were simultaneously extracted from milk using trifluoroacetic acid. Subsequently, the extracted analogues were separated by reverse-phase high-performance liquid chromatography (RP-HPLC) and detected at 355 nm using UV/Vis. Calibration curves for all five tetracycline analogues show excellent linearity (r2 value > 0.99). Percent recovery for MC, TC, dEM, CTC, and dC were: 31.88%, 96.91%, 151.29, 99.20%, and 85.58% respectively. The developed extraction method has good precision (RSd developed method with minimal sample preparation and pretreatment has the potential to serve as an initial screening test.

关键词： Antibiotics Tetracyclines Extraction Milk HPLC

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

维普期刊数据库

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

Seasonal Sodium Percentage (%NA), Absorption Ratio (SAR) and Irrigation Water Quality Index (IWQI) determination for Irrigation Purposes Along River Ethiope, Southern Nigeria

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 Water Resource and Protection 2024年第7期16卷 523-537页

作者： Ochuko Ushurhe Famous Ozabor Wekpe Vremudia Onyeayana Obisesan Adekunle Ifuwe Chineme Christabel dibosa francis Chike department of Environmental Management and Toxicology Dennis Osadebay University Asaba Nigeria School of Environment Geography and Geosciences University of Portsmouth Portsmouth United Kingdom Mabisel Trading and Construction Company Limited Portharcourt Nigeria department of Surveying and Geo-Informatics Dennis Osadebay University Asaba Nigeria department of Urban and Regional Planning Dennis Osadebay University Anwai Asaba Nigeria

The improvement of agriculture through irrigation farming is now of great need in the country Nigeria and delta State. The country is going through a phase of famine and food insecurity caused by climate change and rain dependent agricultural practices. The aim of the study therefore, was to evaluate the quality of water from River Ethiope in Southern Nigeria for irrigation agriculture purposes using the percentage sodium (%Na), sodium-adsorption ratio (SAR) and irrigation-water quality index (IWQ1) techniques. The study deployed the experimental design and water samples were collected from different segments of the Ethiope River. A total of 144 water samples were collected and analysed for physicochemical parameters quality (EC, HCO3, Cl−, Na+, Mg2+, Ca2+ and K+) from January to december, 2022. The results showed that all the calculated values for %Na were within the classified rating of 20 d 60 ded values of IWQI were within the range of 70 - 55 and 55 - 40. This implies that the water is good to doubtful for %Na, excellent for SAR and of moderate and high restrictions for IWQI. Water was adjudged to be good for irrigation activities, and should be applicable in areas with moderate and high soil permeability. The routine testing of the water to ascertain physicochemical parameters quality regularly, in order not to affect its use for irrigation was among the recommendations. This finding herein shall be of use to Water Resources and Agriculture ministries in Nigeria.

关键词： Evaluation Irrigation-Agriculture IWQI River-Ethiope SAR %Na

Estimating the Yield Loss of Winter Wheat from drought in the United States Southern Plains Region as Influenced by El Niño-Southern Oscillation (ENSO)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2024年第9期15卷 1018-1034页

作者： Prem Woli Gerald R. Smith Charles R. Long francis M. Rouquette, Jr. Texas A&M AgriLife Research Center Overton USA

Wheat (Triticum aestivum L.) production is a major economic activity in most regional and rural areas in the Southern Plains, a semi-arid region of the United States. This region is vulnerable to drought and is projected to experience a drier climate in the future. Since the interannual variability in climate in this region is linked to an ocean-atmospheric phenomenon, called El Niño-Southern Oscillation (ENSO), droughts in this region may be associated with ENSO. droughts that occur during the critical growth phases of wheat can be extremely costly. However, the losses due to an impending drought can be minimized through mitigation measures if it is predicted in advance. Predicting the yield loss from an imminent drought is crucial for stakeholders. One of the reliable ways for such prediction is using a plant physiology-based agricultural drought index, such as Agricultural Reference Index for drought (ARId). This study developed ENSO phase-specific, ARId-based models for predicting the drought-induced yield loss for winter wheat in this region by accounting for its phenological phase-specific sensitivity to drought. The reasonable values of the drought sensitivity coefficients of the yield model for each ENSO phase (El Niño, La Niña, or Neutral) indicated that the yield models reflected reasonably well the phenomena of water stress decreasing the winter wheat yields in this region during different ENSO phases. The values of various goodness-of-fit measures used, including the Nash-Sutcliffe Index (0.54 to 0.67), the Willmott Index (0.82 to 0.89), and the percentage error (20 to 26), indicated that the yield models performed fairly well at predicting the ENSO phase-specific loss of wheat yields from drought. This yield model may be useful for predicting yield loss from drought and scheduling irrigation allocation based on the phenological phase-specific sensitivity to drought as impacted by ENSO.

关键词： ARId drought drought Index ENSO El Niño Growth-Stage Model Phenological-Phase Prediction Semi-Arid Wheat Yield Loss

Three-dimensional-printed Ni-based scaffold design accelerates bubble escape for ampere-level alkaline hydrogen evolution reaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Interdisciplinary Materials 2024年第4期3卷 595-606页

作者： Jingxuan Chen Gangwen Fu Yu Tian Xingchuan Li Mengqi Luo Xiaoyu Wei Ting Zhang Tian Gao Cheng Chen Somboon Chaemchuen Xi Xu Xing Sun Tongle Bu francis Verpoort John Wang Zongkui Kou State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhanChina Marine New Materials and Equipment Technology Center Sanya Science and Education Innovation Park of Wuhan University of TechnologySanyaChina frontiers Science Center for Flexible Electronics Institute of Flexible ElectronicsNorthwestern Polytechnical UniversityXi'anChina Key laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical UniversityNingboChina School of Astronautics Northwestern Polytechnical UniversityXi'anChina department of Materials Science and Engineering College of Design and EngineeringNational University of SingaporeSingaporeSingapore National University of Singapore(Chongqing)Research Institute Chongqing Liang Jiang New AreaChongqingChina

Alkaline hydrogen evolution reaction(HER)for scalable hydrogen production largely hinges on addressing the sluggish bubble-involved kinetics on the traditional Ni-based electrode,especially for ampere-level current densities and ***,3d-printed Ni-based sulfide(3dPNS)electrodes with varying scaffolds are designed and *** situ observations at microscopic levels demonstrate that the bubble escape velocity increases with the number of hole sides(HS)in the ***,we conduct multiphysics field simulations to illustrate that as the hole shapes transition from square,pentagon,and hexagon to circle,where a noticeable reduction in the bubble-attached HS length and the pressure balance time around the bubbles results in a decrease in bubble size and an acceleration in the rate of bubble ***,the 3dPNS electrode with circular hole configura-tions exhibits the most favorable HER performance with an overpotential of 297 mV at the current density of up to 1000 mA cm^(-2) for 120 *** present study highlights a scalable and effective electrode scaffold design that promotes low-cost and low-energy green hydrogen production through the ampere-level alkaline HER.

关键词： 3d printing alkaline hydrogen evolution reaction ampere-level current densities bubble escape hole sides

基于线粒体和初级共生菌基因序列的荻草谷网蚜6个地理种群的遗传多样性研究

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

植物保护 2022年第6期48卷 255-263,306页

作者：孙靖轩李迁谭晓玲范佳张勇 francis frédéric 陈巨莲中国农业科学院植物保护研究所植物病虫害生物学国家重点实验室北京100193 比利时列日大学让布鲁农业生物技术学院功能与进化昆虫学系让布鲁5030 黑龙江省农业科学院牡丹江分院牡丹江157000

荻草谷网蚜Sitobion miscanthi(Takahashi)(在中国长时间学名误用为麦长管蚜Sitobion avenae Fabricius)是我国小麦的主要害虫,为小麦蚜虫优势种。该蚜虫因繁殖速度快、发育历期短、适应能力强且能随着气流远距离迁飞等特性,对小麦安全... 详细信息

荻草谷网蚜Sitobion miscanthi(Takahashi)(在中国长时间学名误用为麦长管蚜Sitobion avenae Fabricius)是我国小麦的主要害虫,为小麦蚜虫优势种。该蚜虫因繁殖速度快、发育历期短、适应能力强且能随着气流远距离迁飞等特性,对小麦安全生产构成严重威胁。目前关于蚜虫种群遗传结构的研究主要基于线粒体基因开展。然而,初级共生菌布赫纳氏菌Buchnera aphidicola几乎存在于所有蚜虫中,其在研究蚜虫种群遗传结构多样性方面的潜在作用报道很少。本研究基于前期收集的荻草谷网蚜6个不同地理种群(苏州、武汉、昆明、廊坊、泰安、银川),对其线粒体COⅠ基因与初级共生菌***的两个单拷贝基因gnd与trpA进行PCR扩增、测序和群体遗传结构分析。根据对3个遗传标记基因聚类分析,荻草谷网蚜6个不同地理种群分为3组,分别为银川种群、苏州种群和其他种群(COⅠ:F_(CT)=0.3642,Pd:F_(CT)=0.4033,P<0.05;trpA:F_(CT)=0.2229,P<0.05),3组间存在显著的遗传差异。银川种群和泰安种群间有相同的稀有单倍型H8(trpA),苏州种群和武汉种群也有相同的稀有单倍型H2与H23(COⅠ),3组之间仍存在基因交流。因此我们推测在4、5月份东南季风盛行的情况下,银川种群迁入了外来虫源。蚜虫线粒体基因和初级共生菌基因的遗传结构分析结果基本一致,表明共生菌基因在研究蚜虫种群遗传结构和多样性具有潜在应用意义。综上所述,基于线粒体和共生菌基因序列的荻草谷网蚜不同地理种群的遗传结构解析可为蚜虫的迁飞提供分子证据。

关键词：荻草谷网蚜种群遗传结构线粒体基因初级共生菌基因遗传分化

Climate Optimum rejuvenates the Mediterranean marine world

维普期刊数据库博看期刊

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

Integrative Zoology 2010年第2期5卷 112-121页

作者： francis d.POR department of Evolution Systematics and Ecology the National Collections of Natural HistoryHebrew University of JerusalemJerusalemIsrael

The Mediterranean,a sea with an already eventful history,is again undergoing an extreme change.A combination of general warming of the Mediterranean Sea and contact with the Indopacific world through the Suez Canal has set the stage for massive changes in the biota that inhabit this *** over a century,tropical species of all taxa have been migrating back into the Mediterranean,suggesting a duplication or restoration of a mid-Pliocene Piacenzian or late Miocene Tortonian *** cases are presented in three major *** is not a serial invasion by individual rogue exotic and damaging species,as often wrongly assumed and *** its unique biogeographic magnitude being recognized,an opportunity to study the progress of this phenomenon is being *** is because of the changed priorities in research,the acute taxonomic impediment and to the geopolitical difficulties in ***,the limitations of the restoration process are defined and a careful future outlook is presented.

关键词： climate optimum Lessepsian migration Mediterranean biota Tethys tropical restoration