检索结果-南通市图书馆

Interpreting siliciclastic sedimentation in the upper Paleozoic Mulargia-Escalaplano Basin(Sardinia, Italy):influence of tectonics on provenance

引用

Journal of Palaeogeography 2024年第1期13卷 18-34页

作者： Luca g.costamagna Sara criniti Dipartimento di Scienze chimiche e geologiche Citadella UniversitariaBlocco A09042 Monserrato CAItaly Dipartimento di Ingegneria dell'Ambiente Universita della Calabria87036 Arcavacata di Rende CSItaly

Late to post-Variscan molassic basins of Late Pennsylvanian-Permian age are exposed in Sardinia(Italy). Here, the compositional and stratigraphic evolution of the Mulargia-Escalaplano sedimentary basin(central Sardinia) has been investigated to highlight how the tectono-magmatic processes have influenced the sedimentation. Ruditic and arenitic samples were collected along well-characterized stratigraphic sections to provide a new insight into the impact of the tectono-magmatic processes on siliciclastic sedimentation. As a result, the conglomerates are mainly clast-supported, petromictic, and thus immature, with no defined maturity trend upwards. Nevertheless, pebble composition changes in times from Variscan basement pebble-rich to volcanic rock-rich, as a consequence of the basin widening and the dismantling and reworking of the coeval volcanic activity. The sandstone composition clearly changes from quartzolithic to feldspatholithic upwards, as a response to the same change of feeding and reworking of the volcanic rocks. Occasionally, interbedded quartzolithic arenites suggest exceptional floods carrying debris from the far borders of the basin. Also, the immature sandstone composition has been interpreted as being controlled by a continuous supply of fresh debris and to a rapid burial rate. In addition, the disappearance of metaradiolarite(lydite AA) Paleozoic grains in the sandstone mineral suite could represent a distinctive marker of a progressive unroofing of the Variscan chain and a clastic supply from deeper tectonic units.

关键词： Petrography Stratigraphy Provenance Molassic basins Sardinia

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

Endotoxin-induced alterations of adipose tissue function:a pathway to bovine metabolic stress

引用

Journal of Animal Science and Biotechnology 2024年第4期15卷 1391-1407页

作者： Miguel chirivi g.Andres contreras Department of Large Animal clinical Sciences Michigan State UniversityEast LansingMIUSA

During the periparturient period, dairy cows exhibit negative energy balance due to limited appetite and increased energy requirements for lactogenesis. The delicate equilibrium between energy availability and expenditure puts cows in a state of metabolic stress characterized by excessive lipolysis in white adipose tissues(AT), increased production of reactive oxygen species, and immune cell dysfunction. Metabolic stress, especially in AT, increases the risk for metabolic and inflammatory diseases. Around parturition, cows are also susceptible to endotoxemia. Bacterial-derived toxins cause endotoxemia by promoting inflammatory processes and immune cell infiltration in different organs and systems while impacting metabolic function by altering lipolysis, mitochondrial activity, and insulin sensitivity. In dairy cows, endotoxins enter the bloodstream after overcoming the defense mechanisms of the epithelial barriers, particularly during common periparturient conditions such as mastitis, metritis, and pneumonia, or after abrupt changes in the gut microbiome. In the bovine AT, endotoxins induce a pro-inflammatory response and stimulate lipolysis in AT, leading to the release of free fatty acids into the bloodstream. When excessive and protracted, endotoxin-induced lipolysis can impair adipocyte's insulin signaling pathways and lipid synthesis. Endotoxin exposure can also induce oxidative stress in AT through the production of reactive oxygen species by inflammatory cells and other cellular components. This review provides insights into endotoxins' impact on AT function, highlighting the gaps in our knowledge of the mechanisms underlying AT dysfunction, its connection with periparturient cows' disease risk, and the need to develop effective interventions to prevent and treat endotoxemia-related inflammatory conditions in dairy cattle.

关键词： Adipose tissue dysfunction Endotoxin Inflammation Insulin resistance

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

Empirical Wavelet Transform Based Method for Identification and Analysis of Sub-synchronous Oscillation Modes Using PMU Data

引用

Journal of Modern Power Systems and clean Energy 2024年第1期12卷 34-40页

作者： Joice g.Philip Jaesung Jung Ahmet Onen the Department of Energy Systems Research Ajou UniversitySuwonSouth Korea the Department of Electrical and Electronic Engineering Abdullah Gul UniversityKayseri38080Turkey the Department of Electrical and computer Engineering College of EngineeringSultan Qaboos UniversityAl-KhoudMuscatOman

This paper proposes an empirical wavelet transform(EWT)based method for identification and analysis of sub-synchronous oscillation(SSO)modes in the power system using phasor measurement unit(PMU)*** phasors from PMUs are preprocessed to check for the presence of *** the presence is established,the signal is decomposed using EWT and the parameters of the mono-components are estimated through Yoshida *** superiority of the proposed method is tested using test signals with known parameters and simulated using actual SSO signals from the Hami Power grid in Northwest *** show the effectiveness of the proposed EWT-Yoshida method in detecting the SSO and estimating its parameters.

关键词： Empirical wavelet transform(EWT) sub-synchronous oscillation Prony-based method Yoshida algorithm variational mode decomposition phasor measurement unit(PMU)

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

马来西亚东部Setiu潟湖1970年以来沉积环境演化及其对ENSO的响应

引用

海洋学报 2024年

作者：赵周平李超骆正骅 Nicholas ng chia Wei 戴璐海洋地质国家重点实验室(同济大学)

马来半岛位于低纬热带地区，厄尔尼诺-南方涛动（El Nino-Southern Oscillation，简称ENSO）如何影响该区域的气候，尤其是降水仍然存在争议。本文以马来半岛东北部登嘉楼州Setiu潟湖钻孔NTT-3为研究对象，通过粒度、总有机碳及总氮含量... 详细信息

马来半岛位于低纬热带地区，厄尔尼诺-南方涛动（El Nino-Southern Oscillation，简称ENSO）如何影响该区域的气候，尤其是降水仍然存在争议。本文以马来半岛东北部登嘉楼州Setiu潟湖钻孔NTT-3为研究对象，通过粒度、总有机碳及总氮含量、c/N比值和XRF岩心扫描等分析，探讨该钻孔的沉积环境变化及其对ENSO的响应。研究结果显示，钻孔记录中自1970年前后（84 cm处）出现两种不同的变化趋势。1970年之前钻孔下部沉积物粒度、有机和无机地球化学特征趋势波动明显，沉积速率较低。而1970年以来，潟湖沉积环境总体稳定，沉积物中的有机组分主要来自红树林，同时伴有河流输入的淡水浮游植物的贡献。频谱分析结果显示1970年以来钻孔上部存在明显的ENSO周期变化。强El Nino现象基本对应低Zr/Rb比值和低Zr/Ti比值，而强La Nina现象基本对应高Zr/Rb比值和Zr/Ti比值。该结论不仅支持了现代观测对马来半岛东部沿海地区气候变化的认识，同时也在地质记录中发现了ENSO变化的直接证据，对全面认识和理解ENSO对亚洲气候变化的影响、区域陆海相互作用过程和环境响应等方面具有重要现实意义。

关键词： Setiu潟湖沉积记录频谱分析 ENSO

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

A toast to a zebrafish germ cell induction cocktail

引用

Science china(Life Sciences) 2024年第6期67卷 1314-1315页

作者： Mary c.Mullins Department of cell and Developmental Biology University of Pennsylvania Perelman School of MedicinePhiladelphia 19104USA

The zebrafish field is ringing in the new year with a publication from Yonghua Sun's laboratory(Wang et al.,2023)of a cocktail of germline factors that can induce all cells of the zebrafish embryo into primordial germ cells(Pgcs)at phenomenal *** major advance is not only of great interest to germ cell biologists,but it has important applications to the entire zebrafish field,as shown in Wang et al.(2023).

关键词： fish zebra field

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

Performance of evolutionary optimized machine learning for modeling total organic carbon in core samples of shale gas fields

引用

Petroleum 2024年第1期10卷 150-164页

作者： Leonardo goliatt c.M.Saporetti L.c.Oliveira E.Pereira Department of computational and Applied Mechanics Federal University of Juiz de Fora Department of computational Modeling Polytechnic Institute Rio de Janeiro State University Petrobras Department of Stratigraphy and Paleontology Rio de Janeiro State University

Rock samples' TOc content is the best indicator of the organic matter in source rocks. The origin rock samples' analysis is used to calculate it manually by specialists. This method requires time and resources because it relies on samples from many well intervals in source rocks. Therefore, research has been done to aid this effort. Machine learning algorithms can estimate total organic carbon instead of well logs and stratigraphic studies. In light of these efforts, the current work present a study on automating the total organic carbon estimation using machine learning approaches improved by an evolutionary methodology to give the model flexibility and precision. genetic algorithms, differential evolution, particle swarm optimization, grey wolf optimization, artificial bee colony, and evolution strategies were used to improve machine learning models to predict TOc. The six metaheuristics were integrated into four machine learning methods: extreme learning machine, elastic net linear model, linear support vector regression, and multivariate adaptive regression splines. core samples from the YuDong-Nan shale gas field, located in the Sichuan basin, were used to evaluate the hybrid strategy. The findings show that combining machine learning models with an evolutionary algorithms in a hybrid fashion produce flexible models that accurately predict TOc. The results show that, independent of the metaheuristic used to guide the model selection, optimized extreme learning machines attained the best performance scores according to six metrics. Such hybrid models can be used in exploratory geological research,particularly for unconventional oil and gas resources.

关键词： Total organic carbon Hybrid models Automated machine learning Evolutionary algorithms geology

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

comparative measurement of cO_(2),cH_(4)and cO at two traffic interjunctions having inflated vehicular flow in Delhi

引用

Journal of Environmental Sciences 2024年第7期141卷 314-329页

作者： Komal Daya Soni Khem Singh Shankar g.Aggarwal cSIR-National Physical Laboratory Dr.K.S.Krishnan MargNew Delhi 110012India Academy of Scientific&Innovative Research(AcSIR) Ghaziabad 201002India

Vehicular emissions are considered one of the major anthropogenic sources of greenhouse gases and poor air quality in metropolitan *** study aims to see the correlation of cO_(2),cH_(4),and cO through monitoring over a period from December 2020 to October 2021 covering three seasons’winter,summer,and monsoon at two different traffic locations of Delhi having different traffic volumes,road patterns,and traffic *** annual average morning concentration of cO_(2),cH_(4)and cO was found(533±105),(7.3±3.1),(10.7±3.0)ppm at Najafgarh and(480±70),(5.2±1.8),(7.8±2.8)ppm at Rajendra Place,respectively.A relationship between concentration of all three gases and meteorological parameters such as temperature,humidity,wind speed and wind direction has also been investigated using Pearson correlation coefficient and pollution rose diagram.A comparable pattern in concentration was observed for all three gases in spatial(location)and temporal(diurnal)*** concentration trend of cO_(2)in different seasons is winter>summer>monsoon,while in the case of cH_(4)winter=summer>monsoon but not any seasonal trend was noted in cO *** is observed that cO_(2)has a good relation with cO(a tracer for vehicular emission)in terms of diurnal variation,whereas,cH_(4)does not represent a relation with cO and cO_(2)diurnally,suggesting that vehicles are the source of cO_(2)but not much contributing to other greenhouse gases like cH_(4).

关键词： Vehicular emission greenhouse gases Harmful pollutants Meteorological parameters

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

Study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties

引用

Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 677-694页

作者： A.S.JOHN B.MAHANTHESH g.LORENZINI center for Mathematical Needs Department of MathematicsCHRIST(Deemed to be University)Karnataka 560029India School of Mathematical and Statistical Sciences The University of Texas Rio Grande ValleyTexas 78539U.S.A. Department of Engineering and Architecture University of ParmaParma 43124Italy

cone-disk systems find frequent use such as conical diffusers,medical devices,various rheometric,and viscosimetry *** this study,we investigate the three-dimensional flow of a water-based Ag-Mg O hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid *** the variable fluid properties affect the dynamics and heat transfer features is studied by Reynolds's linearized model for variable viscosity and chiam's model for variable thermal *** single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids,incorporating the experimental *** model is developed as a coupled system of convective-diffusion equations,encompassing the conservation of momentum and the conservation of thermal energy,in conjunction with an incompressibility condition.A self-similar model is developed by the Lie-group scaling transformations,and the subsequent self-similar equations are then solved *** influence of variable fluid parameters on both swirling and non-swirling flow cases is ***,the Nusselt number for the disk surface is *** is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system,while the thermal conductivity parameter has the opposite effect.

关键词： hybrid nanofluid cone-disk system laminar flow variable fluid property Nusselt number

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

The great catastrophe: causes of the Permo-Triassic marine mass extinction

引用

National Science Review 2024年第1期11卷 37-50页

作者： Paul B.Wignall David P.g.Bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South china, have resolved the crisis to a ～55 kyr interval straddling the Permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the Permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(cades) and the overwhelming evidence for rapid warming during the crisis makes this an unlikely cause. Finally, whilst the extinction is well studied in equatorial latitudes, a different history is found in northern Boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

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

A prospective cohort of men with localized prostate cancer on active surveillance protocol in Hong Kong,china:what did we learn?

引用

Asian Journal of Andrology 2024年第3期26卷 245-249页

作者： Xiaobo Wu Ivan ching-Ho Ko cindy Yeuk-Lam Hong Samuel chi-Hang Yee Jeremy Yuen-chun Teoh Samson Yun-Sang chan Ho-Man Tam chi-Kwok chan chi-Fai ng Peter Ka-Fung chiu SH Ho Urology centre Department of SurgeryFaculty of MedicineThe Chinese University of Hong KongHong KongChina

This study aimed to report the outcomes of active surveillance(AS)in the management of low-risk prostate cancer(Pca).It recruited87 men who were prospectively followed up according to the Prostate cancer Research International Active Surveillance(PRIAS)protocol with local adaptation at SH Ho Urology centre,Prince of Wales Hospital,Hong Kong,*** investigated the predictorsof disease progression and found that baseline prostate-specific antigen density(PSAD)and the presence of the highest ProstateImaging-Reporting and Data System(PI-RADS)score 5 lesion on magnetic resonance imaging(MRI)are significantly correlatedwith disease ***,men with PSAD>0.2 ng ml^(−2)or PI-RADS 4 or 5 lesions had significantly worse upgradingfree survival compared to those with PSAD≤0.2 ng ml−2 and PI-RADS 2 or 3 *** study concludes that AS is a safe andeffective management strategy for selected patients to defer radical treatment and that most disease progression can be detectedafter the first repeated *** combination of PSAD>0.2 ng ml^(−2)and PI-RADS 4 or 5 lesions may serve as a useful predictorof early disease progression and provide a guide to optimize follow-up protocols for men in different risk groups.

关键词： active surveillance cohort localized prostate cancer

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：