检索结果-南通市图书馆

Effect of austenitizing condition on mechanical properties,microstructure and precipitation behavior of AISI H13 steel

引用

Journal of Iron and Steel Research International 2024年第1期31卷 143-156页

作者： An-gang Ning Yang Liu Rui Gao stephen Yue Ming-bo Wang Han-jie Guo College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024ShanxiChina Department of Mining and Materials Engineering McGill UniversityMontrealQCH3A 0C5Canada ASSAB Tooling Technology(Chongqing)Co. Ltd.Chongqing401120China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing100083China

The effects of austenitizing temperature(1223,1303,and 1373 K)and holding time(1-1500 s)on the microstructure,mechanical properties,and precipitation behavior of the H13 hot work die steel were *** results indicate a softening phenomenon when H13 steel is austenitized at 1303 K beyond 900 s and 1373 K beyond 600 s,*** the sample held for 1200 s,the tensile strength is found capable of reaching up to 2.2 GPa when quenched from a temperature above 1303 ***,prior-austenite grain size increases with the increase in austenitizing *** kinetic behavior of the precipitates(mainly MC-type carbides)in H13 steel could be elaborated through the principles set forth by the Arrhenius and Avrami ***,the comprehensive strengthening of the H13 steel was discussed in *** results show that the activation energy of the transformed fraction of carbides is higher than that of the diffusion process for common alloying elements(Cr,V,Mo,and Ni)found in the *** suggests that it would be difficult for precipitates to dissolve into the matrix when H13 steel is austenitized at high *** the increasing austenitizing temperature,the precipitation fraction decreases,and the dislocation density *** dislocation strengthening is regarded as the dominant strengthening contributed to yield strength in as-quenched H13 steel.

关键词： H13 steel Austenitizing Mechanical property Precipitation behavior Comprehensive strengthening

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

The 2024 Compendium of Physical Activities and its expansion

引用

Journal of Sport and Health Science 2024年第1期13卷 1-2,F0003页

作者： stephen D.Herrmann Erik A.Willis Barbara E.Ainsworth Kansas Center for Metabolism and Obesity Research University of Kansas Medical CenterKansas CityKS 66160USA Center for Health Promotion and Disease Prevention University of North Carolina at Chapel HillChapel HillNC 27599USA School of Exercise and Health Shanghai University of SportShanghai 200438China

First developed 30 years ago,the Compendium of Physical Activities(Compendium)was created to provide a standardized way of measuring and classifying specific physical activities(PAs),allowing researchers and health professionals to assess the energy expenditure and health benefits associated with different PA.1Since its inception,the Compendium has been widely utilized and recognized as a fundamental PA and health resource.

关键词： has utilized classify

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

Novel photoactive material and fabrication techniques for solar cells application:nanocellulose-based graphene oxide CdS composite

引用

Clean Energy 2024年第2期8卷 189-216页

作者： Hassan Oriyomi Shoyiga stephen Okiemute Akpasi Joseph Akpan Ubani Oluwaseun Amune Sammy Lewis Kiambi Chemistry Department North-West UniversityMafikengSouth Africa Material Science Innovation and Modelling(MaSIM)Research Focus Area Faculty of Natural and Agricultural SciencesNorth-West University(Mafikeng Campus)MmabathoSouth Africa Green Engineering Research Group Chemical Engineering DepartmentDurban University of TechnologyDurbanSouth Africa Industrial Engineering Department Durban University of TechnologyDurbanSouth Africa Chemical Engineering Department Edo State UniversityUzairueNigeria Chemical Engineering Department Vaal University of TechnologyVanderbijlparkSouth Africa

In recent times,solar energy has become one of the largest available sources of renewable energy at our ***,the design of highly efficient solar cells is increasingly becoming crucial as there has been a surge for economically viable alternative energy sources with the lowest *** advances have been made through different routes to make photovoltaic(PV)/solar technologies economically viable,eco-friendly and consequently *** a result,cellulose nanomaterials have become one of the emerging technologies in this regard because of the advantages of high-value bio-based nanostructured materials,such as their abundance and ***-based photoactive nanocomposite materials can be made by integrating conducting photoactive and electroconductive materials with hydrophilic biocompatible *** nanoparticles,such as graphene/reduced graphene oxide cadmium sulphide quantum dots,amongst others,can be introduced into the nanocellulose matrix and can be applied either as charge transporters or photoactive materials in different types of solar ***,in this review,we highlight the optoelectronic properties of different photoactive materials,particularly nanocellulose-based graphene nanocomposites;their efficiencies and drawbacks were *** effect of doping each PV material on the PV performance is also *** is anticipated that the novel material would result in a reduction in the cost of solar cells,jointly enhancing their efficacy in generating environmentally friendly *** the fabrication techniques and equipment play a crucial role in the development of solar cells,the fabrication techniques of bulk-heterojunction(BHJ)cells containing a nanocellulose-based graphene composite and case studies of already fabricated BHJ PV cells with nanocellulose-based graphene composite are discussed.

关键词： nanocellulose-based composite bulk heterojunction graphene composite photoactive materials fabrication techniques solar energy power conversion efficiency

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

Neuropeptide cholecystokinin:a key neuromodulator for hippocampal functions

引用

Neural Regeneration Research 2025年第7期20卷 1991-1992页

作者： Fengwen Huang stephen Temitayo Bello Department of Neuroscience City University of Hong KongKowloon TongHong Kong Special Administrative RegionChina Center for Regenerative Medicine and Health Hong Kong Institute of Science&InnovationChinese Academy of SciencesHong Kong Special Administrative RegionChina

Spatial memory is crucial for survival within external surroundings and wild *** hippocampus,a critical hub for spatial learning and memory formation,has received extensive investigations on how neuromodulators shape its functions(Teixeira et al.,2018;Zhang et al.,2024).However,the landscape of neuromodulations in the hippocampal system remains poorly understood because most studies focus on classical monoamine neuromodulators,such as acetylcholine,serotonin,dopamine,and *** neuropeptides,comprising the most abundant neuromodulators in the central nervous system,play a pivotal role in neural information processing in the hippocampal ***(CCK),one of the most abundant neuropeptides,has been implicated in regulating various physiological and neurobiological statuses(Chen et al.,2019).CCK-A receptor(CCK-AR)and CCK-B receptors(CCK-BR)are two key receptors mediating the biological functions of CCK,both of which belong to class-A sevenfold transmembrane G protein-coupled receptors(Nishimura et al.,2015).CCK-AR preferentially reacts to sulfated CCK,whereas CCK-BR binds both CCK and gastrin with similar affinities(Ding et al.,2022).The expression patterns of CCK-AR and CCK-BR are distinct,implying that CCK has various functions in target *** instance,CCK-AR is widely expressed in the GI and brain subregions and is hence implicated in the control of digestive function and satiety ***,CCK-BR is abundantly and widely distributed in the central nervous system,which majorly regulates anxiety,learning,and memory(Ding et al.,2022).However,the roles of endogenous CCK and CCK receptors in regulating hippocampal function at electrophysiological and behavioral levels have received less attention.

关键词： abundant functions modulator

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

Circumscription of the East Asia clade (Apiaceae subfamily Apioideae) and the taxonomic placements of several problematic genera

引用

Plant Diversity 2024年第2期46卷 206-218页

作者： Jing Zhou Xinyue Wang Shilin Zhou Junmei Niu Jiarui Yue Zhenwen Liu stephen R.Downie School of Pharmaceutical Science and Yunnan Key Laboratory of Pharmacology for Natural Products Kunming Medical University1168 Western Chunrong RoadYuhua StreetChenggong New CityKunming 650500China Yunnan Academy of Forestry and Grassland Kunming 650201China Gaoligong Mountain Forest EcosystemObservation and Research Station of Yunnan ProvinceKunming 650201China Yunnan Key Laboratory of Biodiversity of Gaoligong Mountain Kunming 650201China Department of Plant Biology University of Illinois at Urbana-ChampaignUrbanaIL 61801USA College of Modern Biomedical Industry Kunming Medical UniversityKunming 650500China

The East Asia(or Physospermopsis) clade was recognized in previous molecular phylogenetic investigations into the higher-level relationships of Apiaceae subfamily Apioideae. The composition of this clade, the phylogenetic relationships among its constituent taxa, and the placement of species previously determined to be problematic have yet to be resolved. Herein, nr DNA ITS sequences were obtained for150 accessions of Apioideae, representing species whose distributions are in East Asia or genera having one or more species included within the East Asia clade. These data, along with published ITS sequences from other Apioideae(for 3678 accessions altogether), were subjected to maximum likelihood and Bayesian inference analyses. The results show that the East Asia clade contains representatives of 11currently recognized genera: Hansenia, Hymenolaena, Keraymonia, Sinolimprichtia, Acronema, Hymenidium, Physospermopsis, Pimpinella, Sinocarum, Tongoloa, and Trachydium. However, the latter seven genera have members falling outside of the East Asia clade, including the generic types of all except Tongoloa. Within the clade, the species comprising these seven genera are widely intermingled, greatly increasing confusion among relationships than previously realized. The problematic species Physospermopsis cuneata is confirmed as falling within the East Asia clade, whereas P. rubrinervis allies with the generic type in tribe Pleurospermeae. Physospermopsis kingdon-wardii is confirmed as a member of the genus Physospermopsis, whereas the generic attributions of P. cuneata and Tongoloa stewardii remain unclear. Two species of Sinocarum(S. filicinum and S. wolffianum) are transferred into the genus Meeboldia. This is the most comprehensive molecular phylogenetic investigation of the East Asia clade to date, and while the results increase systematic understanding of the clade, they also highlight the need for further studies of one of the most taxonomically intractable groups in Api

关键词： Physospermopsis Pimpinella Sinocarum Tongoloa Trachydium

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

Fully flexible implantable neural probes for electrophysiology recording and controlled neurochemical modulation

引用

Microsystems & Nanoengineering 2024年第3期10卷 317-333页

作者： Mohammad Hassan Malekoshoaraie Bingchen Wu Daniela DKrahe Zabir Ahmed stephen Pupa Vishal Jain Xinyan Tracy Cui Maysamreza Chamanzar Electrical and Computer Engineering Carnegie Mellon UniversityPittsburghPA 15213USA Bioengineering University of PittsburghPittsburghPA 15260USA Center for Neural Basis of Cognition University of Pittsburgh and Carnegie Mellon UniversityPittburgh 15213USA McGowan Institute for Regenerative Medicine University of PittsburghPittsburgh 15219USA Carnegie Mellon Neuroscience Institute Carnegie Mellon UniversityPittsburgh 15213USA

Targeted delivery of neurochemicals and biomolecules for neuromodulation of brain activity is a powerful technique that,in addition to electrical recording and stimulation,enables a more thorough investigation of neural circuit *** have designed a novel,flexible,implantable neural probe capable of controlled,localized chemical stimulation and electrophysiology *** neural probe was implemented using planar micromachining processes on Parylene C,a mechanically flexible,biocompatible *** probe shank features two large microelectrodes(chemical sites)for drug loading and sixteen small microelectrodes for electrophysiology recording to monitor neuronal response to drug *** reduce the impedance while keeping the size of the microelectrodes small,poly(3,4-ethylenedioxythiophene)(PEDOT)was electrochemically coated on recording *** addition,PEDOT doped with mesoporous sulfonated silica nanoparticles(SNPs)was used on chemical sites to achieve controlled,electrically-actuated drug loading and *** neurotransmitters,including glutamate(Glu)and gamma-aminobutyric acid(GABA),were incorporated into the SNPs and electrically triggered to release *** in vitro experiment was conducted to quantify the stimulated release profile by applying a sinusoidal voltage(0.5 V,2 Hz).The flexible neural probe was implanted in the barrel cortex of the wild-type Sprague Dawley *** expected,due to their excitatory and inhibitory effects,Glu and GABA release caused a significant increase and decrease in neural activity,respectively,which was recorded by the recording *** novel flexible neural probe technology,combining on-demand chemical release and high-resolution electrophysiology recording,is an important addition to the neuroscience toolset used to dissect neural circuitry and investigate neural network connectivity.

关键词： Parylene recording release

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

Orbital pacing and secular evolution of lake-level changes reconstructed by sedimentary noise modeling during the Early Jurassic icehouses-(super)greenhouses

引用

Science China Earth Sciences 2024年第1期67卷 252-267页

作者： Meng LI Xin LI stephen P.HESSELBO Mingjie LI Wenjin LIU Wei WU Jienan PAN Ruizhen GAO School of Resources and Environment Henan Polytechnic UniversityJiaozuo 454000China Camborne School of Mines and Environment and Sustainability Institute University of ExeterPenryn TR109FEUnited Kingdom Qinghai No.105 Coal Geological Exploration Team Xining 810000China

Lake-level changes can significantly affect paleoenvironmental evolution,resource occurrence,terrestrial carbon budget,and biodiversity in continental *** is one of the most critical factors controlling lake-level *** of the Early Jurassic has been evidenced by oscillating icehouses to(super)greenhouses with interrupted intermittent extreme climatic events(hyperthermal and cooling),e.g.,the Toarcian oceanic anoxic event(~183 Ma)and the late Pliensbachian cooling event(~185 Ma).Lake-level evolution and hydrologic cycling on Earth’s surface during the Early Jurassic icehouses-to-(super)greenhouses are thus far poorly understood due to a lack of continuous high-resolution nonmarine *** we present a super-long nonmarine lake level record for this pivotal interval from the early Pliensbachian to Toarcian by sedimentary noise modeling,and construct a 16.7-Myr-long astronomical time scale(174.2 Ma to 190.9 Ma)based on cyclostratigraphy analysis of rock color datasets(CIE b*)of the Qaidam *** results document lake-level oscillations on a 5-to 10-million-year(Myr)scale which shows a pronounced correlation with long-term climate variation and extreme climatic events,and 1-to 2.5-Myr-scale lake-level changes that are prominently paced by the 2.4-Myr long-eccentricity forcing and the 1.2-Myr obliquity *** the Pliensbachian Stage,the 1.2-Myr-scale lake-level changes are in phase with the coeval sealevel *** forced growth and decay of the ephemeral or permanent ice sheets in polar regions are interpreted to control the synchronous ups-and-downs of continental lake level and global sea ***,during the Toarcian ice-free greenhouses to(super)greenhouses,the 1.2-Myr-scale lake-level variations show an anti-phase relationship with global sea level,indicating a‘seesaw’interaction between continental reservoirs(lakes and groundwater)and global *** 2.4-Myr longeccentricity cycles mainly regulate variation

关键词： Milankovitch cycles Orbital forcing Sedimentary noise model Lake level Continental basins

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

Experiments in Modernizing Cob Construction

引用

Journal of Civil Engineering and Architecture 2024年第6期18卷 276-281页

作者： stephen Hren Mud Dauber School of Natural Building Silk HopeNCUSA

This paper will discuss experiments using various forming systems combined with utilizing mechanical equipment,from cement mixers to excavators and skid steers with attachments,to accelerate construction of cob homes and greatly reduce the labor *** is a colloquial term for monolithic adobe,and refers to a masonry building technique used since ancient times that uses locally-sourced clay as a binder,with various aggregates from sand to small grit or stone,woven together with straw or other fiber and built in continuous layers to form a monolithic structure.

关键词： Cob monolithic adobe earth construction formworks hempcrete mechanization slipforms

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

Regional trends and petrologic factors inhibit global interpretations of zircon trace element compositions

引用

Geoscience Frontiers 2024年第5期15卷 300-307页

作者： Nick M.W.Roberts Christopher J.Spencer stephen Puetz C.Brenhin Keller Simon Tapster Geochronology and Tracers Facility British Geological SurveyNottingham NG125GGUK Department of Geological Sciences and Geological Engineering Queen’s UniversityKingstonOntarioCanada Atkinson Dr Suite 704HonoluluHI 96814USA Department of Earth Sciences Dartmouth CollegeHanoverNew HamphireUSA

The trace element composition of zircon reveals information about the melt that they are derived from,as such,detrital zircon trace element compositions can be used to interrogate melt compositions,and thus the evolution of the continental crust in time and ***,we present a global database of detrital zircon compositions and use it to test whether average global trends for five common petrogenetic proxies truly represent secular changes in continental *** demonstrate that the secular trend is broadly comparable across continental regions for Ti-in-zircon temperatures,but for other trace element ratios interrogated,secular trends are highly variable between continental *** trace element ratios result from multiple petrologic variables,we argue that these petrogenetic proxies can be overinterpreted if projected to global geologic *** particular,we caution against the interpretation of crustal thickness from trace elements in zircon,and we argue that our results negate current hypotheses concerning secular changes in crustal thickness.

关键词： Detrital zircon Trace elements Secular change Eu anomaly Crustal thickness

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

The Ban on Illegal Mining in Ghana: Environmental and Socio-Economic Effect on Local Communities

引用

Journal of Geoscience and Environment Protection 2024年第3期12卷 153-162页

作者： stephen Twumasi Annan Department of Integrated Science Education Faculty of Science Education University of Education Winneba Ghana

The study was conducted to assess the effects of small-scale (artisanal) gold mining and its social and economic implications on the people in Amansie West District of Ghana. The artisanal gold mining communities were studied using secondary data from scholarly articles and journals, books, conference papers, research reports, policy documents, working papers, and briefs. Descriptive and systematic analyses were conducted. The result indicated that youth aged between 21 - 30 were most likely to engage in illegal mining operations in the selected study areas. The study revealed that farmland had been destroyed, making farming difficult for the inhabitants. It is evident from the review that dug-out pits from mining serve as breeding grounds for mosquitoes and death traps for humans. The study, therefore, accentuates the need for illegal small-scale gold mining to be formalised and strategic interventions and policies proposed for the protection of Ghana’s Natural resources. Furthermore, community members should be involved in policy-making and environmental protection issues to help control the menace of landscape destruction. Although the ban on illegal gold mining activity by the government has caused more people to lose their jobs leading to livelihood challenges in mining communities, it is a step in the right direction, as the ban seeks to halt and check the illegal small-scale mining sector. The study recommended alternative livelihood and income-generating projects such as beekeeping, mushroom culture, grasscutter rearing, and agroforestry technologies including the growth of economic fruit trees as alternative livelihood ventures.

关键词： Small-Scale Gold Mining Livelihood Social and Economic Implications

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

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：