检索结果-南通市图书馆

Characterization and Modeling of Mechanical Properties of Additively Manufactured Coconut Fiber-Reinforced Polypropylene Composites

引用

Advances in Materials Physics and Chemistry 2024年第6期14卷 95-112页

作者： George Mosi Bernard W. Ikua Samuel K. Kabini james W. Mwangi Department of Mechatronic Engineering Jomo Kenyatta University of Agriculture and Technology Juja Kenya

In the face of the increased global campaign to minimize the emission of greenhouse gases and the need for sustainability in manufacturing, there is a great deal of research focusing on environmentally benign and renewable materials as a substitute for synthetic and petroleum-based products. Natural fiber-reinforced polymeric composites have recently been proposed as a viable alternative to synthetic materials. The current work investigates the suitability of coconut fiber-reinforced polypropylene as a structural material. The coconut fiber-reinforced polypropylene composites were developed. Samples of coconut fiber/polypropylene (PP) composites were prepared using Fused Filament Fabrication (FFF). Tests were then conducted on the mechanical properties of the composites for different proportions of coconut fibers. The results obtained indicate that the composites loaded with 2 wt% exhibited the highest tensile and flexural strength, while the ones loaded with 3 wt% had the highest compression strength. The ultimate tensile and flexural strength at 2 wt% were determined to be 34.13 MPa and 70.47 MPa respectively. The compression strength at 3 wt% was found to be 37.88 MPa. Compared to pure polypropylene, the addition of coconut fibers increased the tensile, flexural, and compression strength of the composite. In the study, an artificial neural network model was proposed to predict the mechanical properties of polymeric composites based on the proportion of fibers. The model was found to predict data with high accuracy.

关键词： Additive Manufacturing Artificial Neural Network Mechanical Properties Natural Fibers Polypropylene

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Toxicity of a seafood toxin， domoic acid， in the retina via modulation of the NRF2 and NF-κB pathways

引用

Food Science and Human Wellness 2024年

作者： Gabriel Mbuta Tchivelekete Yanqun Cao Mohammad Almarhoun Xinzhi Zhou Agostinho Francisco Cachapa Sebasti?o Tumitangua james Reilly Patricia E.Martin Xinhua Shu Department of Biological and Biomedical Sciences Glasgow Caledonian University Department of Marine Biology Faculty of Natural Science University of Namibe Puai Medical School Shaoyang University Department of Vision Science Glasgow Caledonian University

Domoic acid (DA)， a biotoxin， is produced by several species of marine dinoflagellate and diatom during harmful algal bloom events. DA is a neurotoxin， in humans and non-human primates， oral exposure to DA results in gastrointestinal effects， while DA at higher doses leads to neurological symptoms， seizures and memory deficiency. Exposure of humans to DA occurs mainly through consumption of contaminated seafoods containing an accumulation of the toxin. Previously， it was unclear if DA can have toxic effects on the retina. We assessed the toxicity of DA in human retinal cells (ARPE-19) and in zebrafish embryos. DA significantly lowered ARPE-19 cell viability dose-dependently， and decreased anti-oxidative capacity， increased inflammation， and promoted cell death， possibly through modulating the NRF2 and NF-κB signalling pathways. Zebrafish embryos exposed to DA for four days from one day post fertilization (dpf) had an increase in mortality and a decrease in both hatching and heartbeat rate and exhibited morphological abnormalities. DA treatment also significantly downregulated expression of antioxidant genes and upregulated expression of inflammation mediators， as well as causing photoreceptor death in zebrafish embryos. The results demonstrate that consuming seafood containing DA will have potential toxic effects in human retinas.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Recent Ventures in Interdisciplinary Arctic Research:The ARCPATH Project

引用

Advances in Atmospheric Sciences 2024年第8期41卷 1559-1568页

作者： Astrid E.J.OGILVIE Leslie A.KING Noel KEENLYSIDE François COUNILLON Brynhildur DAVIÐSDÓTTIR Níels EINARSSON Sergey GULEV Ke FAN Torben KOENIGK james R.MCGOODWIN Marianne H.RASMUSSON Shuting YANG Institute of Arctic and Alpine Research(INSTAAR) University of ColoradoBoulder CO 80303USA Stefansson Arctic Institute AkureyriÍS-600Iceland Royal Roads University BC V9B 5Y2Canada University of Bergen Bergen N-5007Norway Nansen Environmental and Remote Sensing Centre Bergen N-5007Norway University of Iceland Reykjavík 102Iceland Shirshov Institute of Oceanology Moscow 117218Russia Moscow State University Moscow 11991Russia Chinese Academy of Sciences Beijing 100045China Swedish Meteorological and Hydrological Institute SE-60176 NorrköpingSweden Danish Meteorological Institute CopenhagenØ2100Denmark Obukhov Institute of Atmospheric Physics RAS119017MoscowRussia

This paper celebrates Professor Yongqi GAO's significant achievement in the field of interdisciplinary studies within the context of his final research project Arctic Climate Predictions: Pathways to Resilient Sustainable Societies-ARCPATH(https://***/en/projects/finished-projects/arcpath). The disciplines represented in the project are related to climatology, anthropology, marine biology, economics, and the broad spectrum of social-ecological studies. Team members were drawn from the Nordic countries, Russia, China, the United States, and Canada. The project was transdisciplinary as well as interdisciplinary as it included collaboration with local knowledge holders. ARCPATH made significant contributions to Arctic research through an improved understanding of the mechanisms that drive climate variability in the Arctic. In tandem with this research, a combination of historical investigations and social, economic, and marine biological fieldwork was carried out for the project study areas of Iceland, Greenland, Norway, and the surrounding seas, with a focus on the joint use of ocean and sea-ice data as well as social-ecological drivers. ARCPATH was able to provide an improved framework for predicting the near-term variation of Arctic climate on spatial scales relevant to society, as well as evaluating possible related changes in socioeconomic realms. In summary, through the integration of information from several different disciplines and research approaches, ARCPATH served to create new and valuable knowledge on crucial issues, thus providing new pathways to action for Arctic communities.

关键词： Recent Ventures in Interdisciplinary Arctic Research:The ARCPATH Project

来源：

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

罗罗扩建大型民用发动机的全球维修能力

引用

航空维修与工程 2024年第5期 27-28页

作者： james Pozzi 赵平(编译) 不详

随着疫情后全球航空业的蓬勃发展,大型民用发动机的售后维修市场需求不断攀升。全球知名的发动机制造商罗罗公司(Rolls-Royce)正在不断加大大型民用发动机维修能力建设的投入,积极扩建其全球发动机维修网络。1罗罗售后市场需求强劲《航... 详细信息

随着疫情后全球航空业的蓬勃发展,大型民用发动机的售后维修市场需求不断攀升。全球知名的发动机制造商罗罗公司(Rolls-Royce)正在不断加大大型民用发动机维修能力建设的投入,积极扩建其全球发动机维修网络。1罗罗售后市场需求强劲《航空周刊》在2024年的商业航空机队和MRO预测中明确指出,罗罗公司将会进一步提升遄达系列发动机的维修服务能力,遄达发动机将在未来10年保持很高的市场需求,特别是在亚太地区和西欧,其中遄达XWB发动机的维修需求会出现进一步的增长。

关键词：售后维修维修能力发动机制造商发动机维修机队商业航空维修需求罗罗

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Geohydraulic Investigation of Aquifer Parameters in Abak, Southern Nigeria

引用

Journal of Geoscience and Environment Protection 2024年第5期12卷 289-301页

作者： Promise james Akpan Akaninyene Okon Akankpo Joseph Gordian Atat Johnson Cletus Ibout Emmanuel Bassey Umoren Department of Physics University of Uyo Akwa Ibom Nigeria Department of Physics University of Nigeria Nsukka Nigeria

A geophysical investigation was carried out to characterize aquifer parameters and assess the groundwater condition in Abak, southern Nigeria. Vertical electrical sounding (VES) was carried out using Schlumberger configuration in 10 locations within the area. Both manual and computer interpretation of the resistivity data reveals three to four geoelectric units (laterite topsoil, medium-grained sand, coarse-grained sand, and sandy clay sand) which agrees with the lithologic log from existing boreholes. The aquifer layer was identified along the third formation with resistivity values ranging from 1239 - 5719 Ωm and aquifer depth ranging from 30.2 - 54.8 m. The aquifer thickness ranged from 24.2 - 43.7 m. Hydraulic conductivity ranged from 0.1206 m/day - 0.5026 m/day with an average value of 0.29403 m/day. Formation factor ranged from 14.55 - 16.64. Porosity ranged from 15.98% - 22.40%, with an average value of 19.64%. The aquiferous zone falls within the medium/coarse-grained sand. The aquifer is shallow, unconfined, and prolific with a little overburden formation of 13.5 m. The area shows good prospects for groundwater development.

关键词： Electrical Resistivity Porosity Formation Factor Hydraulic Conductivity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

An Automated,Highly Selective Reaction Monitoring Instrument Using Molecular Rotational Resonance Spectroscopy

引用

Precision Chemistry 2024年第2期2卷 57-62页

作者： Ann Adele Byars Khushi R.Kompally Emily Mechnick Reilly E.Sonstrom Alexander Mikhonin Justin L.Neill Ruth Boetzel james MacGregor Courtney Talicska Jian Li Yizhou Liu BrightSpec Inc.CharlottesvilleVirginia 22903United States Pfizer R&D UK Limited Sandwich CT139NJUnited Kingdom Analytical Research and Development Pfizer Research and DevelopmentGrotonConnecticut 06340United States

Online monitoring of chemical reactions by using analytical chemistry tools is a powerful way to maximize control over these *** this paper,we demonstrate the use of molecular rotational resonance,an emerging and extraordinarily selective spectroscopic technique,to perform automated reaction monitoring *** interface using a six-port valve with a calibrated sample loop,coupled to a temperature controlled inlet for analyte volatilization,was developed and *** reactions were chosen for initial characterization:an amine-aldehyde condensation reaction to form an imine product and an isotopic exchange reaction of aβ-ketoester with keto-enol *** spectrometer was able to provide kinetic information about the reaction and determine reaction *** the future,this system can be extended to detect and quantify impurities and characterize reaction selectivity,in addition to the reaction progress.

关键词： molecular rotational resonance spectroscopy reaction monitoring reaction kinetics isotopes process analytical technology

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

海底有草原？随波摇曳现鱼虾！

引用

环球人文地理 2024年第1期 106-107页

作者：申姜 james 摄图网

说起草原，无论是苍茫无涯的碧野风光，还是“风吹草低见牛羊”的壮丽丰饶，都令人心驰神往。但你可能没注意到，海底其实也有草原。相较于陆上草原，海底草原并不热门，但依然有“一川草色青袅袅”的奇景。这一秘境的重要参与者，是成...

说起草原，无论是苍茫无涯的碧野风光，还是“风吹草低见牛羊”的壮丽丰饶，都令人心驰神往。但你可能没注意到，海底其实也有草原。相较于陆上草原，海底草原并不热门，但依然有“一川草色青袅袅”的奇景。这一秘境的重要参与者，是成片生长的海草。海草通常生长在浅海与河口水域，除寒冷南极外，

关键词：

来源：

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

富氮气调--磷化氢的可供替换技术

引用

粮油食品科技 2024年第3期32卷 55-68页

作者： Manjree AGARWAL james NEWMAN Yan-yu LI Li GU Bei-bei LI Yong-lin REN 李燕羽(译) 西澳大利亚政府化学中心澳大利亚珀斯WA 6102 CBH澳大利亚谷物有限公司澳大利亚珀斯WA 6000 默多克大学环境和生命科学学院澳大利亚珀斯WA 6150 国家粮食和物资储备局科学研究院粮食储运研究所北京100037 国家粮食和物资储备局科学研究院粮食储运研究所

在粮食储藏上利用氮气的方法已经有30多年的历史,但直到最近经济有效的变压吸附(PSA)和膜分离(MS)制氮设备的出现,才使得该技术在储粮上使用成为可能。本研究首先在25、30和35℃、99%、98%和97%氮气的环境下,对小麦、大麦、燕麦、羽扇... 详细信息

在粮食储藏上利用氮气的方法已经有30多年的历史,但直到最近经济有效的变压吸附(PSA)和膜分离(MS)制氮设备的出现,才使得该技术在储粮上使用成为可能。本研究首先在25、30和35℃、99%、98%和97%氮气的环境下,对小麦、大麦、燕麦、羽扇豆和油菜籽中的花斑皮蠹、赤拟谷盗、谷蠹和米象成虫和非成虫虫态进行了为期4、3和2周的实验室生物测定。然后在终端用户LakeGrace和CBH(Cooperative BulkHandling)谷物进出口公司Albany出口港码头开展实仓验证,测定小麦、大麦和油菜籽中不同储粮害虫虫种和油菜籽瓢虫和肖叶甲类两种田间害虫的防治效果。同时对处理后的粮食品质进行了测定。实验结果表明,害虫死亡率随着氧气浓度降低、暴露时间和温度的增加而增加,富氮低氧在低温条件下不能100%致死花斑皮蠹幼虫。氮气处理对磷化氢抗性和敏感品系储粮害虫防治效果没有差异。与其他粮种相比,在油菜籽中的防治效果更好。各种粮种的水分含量、蛋白质、含油量、淀粉和籽粒颜色品质指标均未受到影响。成功开发了富氮低氧商业规模应用模式,为磷化氢高抗性害虫治理提供了解决方案,满足市场日益增长对无害虫和无化学残留粮食的需求。

关键词：气调储藏害虫治理磷化氢抗药性粮食品质应用模式

来源：

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

用nR改良海氏法则及PALT评估药物性肝损伤研究进展

引用

中国药物警戒 2024年第1期21卷 117-120页

作者：詹姆斯·布坎南 Covilance LLC 美国加利福尼亚州贝尔蒙特市

与药物、草药和其他补充或替代疗法相关的肝毒性一直是全球安全专业人员和监管机构关注的问题。在临床开发和上市后阶段及时识别肝损伤仍是一项挑战。目前,用于识别最有可能发展为肝衰竭或死亡的肝毒性病例标准已经取得最新进展,并建立... 详细信息

与药物、草药和其他补充或替代疗法相关的肝毒性一直是全球安全专业人员和监管机构关注的问题。在临床开发和上市后阶段及时识别肝损伤仍是一项挑战。目前,用于识别最有可能发展为肝衰竭或死亡的肝毒性病例标准已经取得最新进展,并建立了可用于评估与肝损伤相关肝细胞损失程度的新方法。本文将对这些新方法及其在相关肝毒性持续监测和评估中的应用进行回顾。

关键词：药物性肝损伤(DILI) 草药补充疗法替代疗法海氏法则药物引起严重肝毒性的四象限评价图表 R值 nR值谷丙转氨酶的P值

来源：

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

地壳深熔过程中锆石的Zr同位素分馏

引用

中国科学：地球科学 2024年第8期54卷 2534-2545页

作者：朱二林夏琼霞李赵雅陈仁旭 james VAN ORMAN 中国科学技术大学地球和空间科学学院合肥230026 中国科学技术大学岩石圈演化与环境演变全国重点实验室合肥230026 行星探索与前瞻性技术前沿科学中心合肥230026 Department of Earth Environmental and Planetary SciencesCase Western Reserve UniversityCleveland OH 44106USA

锆(Zr)作为高场强元素之一,由于有限的Zr同位素数据库,地质演化过程中的Zr同位素行为仍然存在许多疑问.岩浆体系中Zr同位素常用于示踪岩浆分异过程,而对于地壳深熔过程中Zr同位素分异与锆石结晶过程之间的关系仍有待研究.本研究对采自... 详细信息

锆(Zr)作为高场强元素之一,由于有限的Zr同位素数据库,地质演化过程中的Zr同位素行为仍然存在许多疑问.岩浆体系中Zr同位素常用于示踪岩浆分异过程,而对于地壳深熔过程中Zr同位素分异与锆石结晶过程之间的关系仍有待研究.本研究对采自南拉萨和北大别两个高温变质地体的混合岩进行了锆石原位Zr同位素分析,结果显示出较大的同位素分馏,δ^(94)/^(90)ZrIPGP值(标记为δ^(94)Zr)变化范围分别为-0.30‰~+0.81‰和-0.58‰~+0.49‰.在这些锆石中,除岩浆源区的残留锆石外,发现有两类新生锆石.根据寄主岩石的类型、锆石的微量元素含量和Zr同位素值,新生锆石可以分为两类:第一类是主要赋存于原位浅色体中的转熔锆石,具有最高的铌(Nb)-钽(Ta)-铪(Hf)-铀(U)含量,其δ^(94)Zr值变化范围较大,并显著高于残留锆石δ^(94)Zr值;第二类是主要赋存于异位浅色脉体中的深熔锆石,具有较高的Nb-Ta-Hf-U含量,其δ^(94)Zr值与残留锆石相似.数值模拟计算表明,新生锆石的Zr同位素组成变化较大,主要是部分熔融过程中锆石和非锆石相的差异分解所释放的Zr同位素不同而导致的.转熔锆石的Zr主要来自于原位深熔熔体中含锆矿物相的分解(非锆石效应),而深熔锆石的Zr主要来自于演化熔体中残留锆石的溶解(锆石效应).混合岩中显著的Zr同位素分馏很好地反映了部分熔融过程中深熔熔体生成-迁移-聚集-结晶的动力学过程.因此,Zr同位素可以作为区分地壳深熔过程中转熔锆石和深熔锆石的有力工具.

关键词： Zr同位素锆石效应非锆石效应混合岩地壳深熔作用

来源：

维普期刊数据库

同方期刊数据库

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：