检索结果-南通市图书馆

gold and tin of fluid-magmatic systems:causes of combination-separation of concentration elements

global geology 2009年第3期12卷 134-144页

作者： I.I. Fatyanov v.g. khomich Far East geological Institute Far Eastern Branch of Russian Academy of Sciences

The aim of the investigation is to reveal possible causes of isolation and co-occurrence of the economically significant concentrations of gold and tin. Comparative analysis of the different-rank factors that influenced migration and concentration of these elements show that different geochemical properties of Au and Sn are responsible for isolation of their big concentrations giving rise to independent metallogenic provinces, zones, and ore nodes. These differences resulted in individualization of the element migration ways to the level of ore concentration within the fluid-magmatie columns. Three main factors influenced the Au and Sn migration activity： different patterns of metal connection with the meh structure, different relation with oxygen, and different relation with other strong oxidizers. By the moment when ore-bearing fluid became isolated from magmas, the metallogenic signature of the melts, contrasting in redox-potential, had already been defined that was confirmed by the fact that tin ores associate predominantly with the granitoids of ilmenite series and gold ores - with those of magnetite series. The fluid-magmatic systems with an intermediate degree of the melt reduction-oxidation may be considered the potential producers of the combined metal concentrations. In these cases, the combined con- centrating of tin and gold is plagued by an opposite direction of the oxidation-reduction reactions when their most common minerals are formed： the main migration form of Sn^＋2 must be oxidized （with cassiterite portioning） , and the forms of Au^＋ or Au^＋3 must be reduced （with native gold portioning）. Probably, because of this the combined tin and gold concentrations are dominated by one of the metals with a tendency of accumulation in different-stage mineral complexes.

关键词： gold tin migration concentrating fluid-magmatic systems redox-potential

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

Deep-seated structure and gold content of Russia and China contiguous territories

引用

global geology 2010年第1期13卷 33-40页

作者： v.g. khomich YANg Yanchen N.g. Boriskina YAN Hongquan Far East geological Institute FEB of RAS Vladivostok 690022 Russia College of Earth Sciences Jilin University Changchun 130061 China

On the contiguous territories of southeastern Russia and northeastern China,many gold-bearing areas are conjugate in space with the gradient zones of the gravity *** gold-ore districts,defining in many respects the metallogenic signature of the region,are located on the joints of differently oriented gradient *** the best-studied districts,the Precambrian protrusions,staged distribution of magmatic chambers (by vertical) above the Mohorovicic discontinuity and restriction to the peripheral parts of intrusive massifs have been ***-type gold deposits in the studied ore-placer districts and nodes are often located on the areas of joint of the granitoid massifs and subvolcanic bodies with *** of areals of metasomatic alterations of rocks,placers,and ore occurrences of precious metals on such but poorly studied areas can serve as the basis for the revision and detailed forecasting-prospecting works to develop the mineral-raw material base of the region for precious metals.

关键词： gradient zone gravity field intrusive massif gold-bearing area gold content

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

An SPH Framework for Earthquake-Induced Liquefaction Hazard Assessment of geotechnical Structures

引用

Computer Modeling in Engineering & Sciences 2025年第1期142卷 251-277页

作者： Sourabh Mhaski g.v.Ramana Department of Civil Engineering Indian Institute of Technology DelhiNew Delhi110016India

Earthquake-induced soil liquefaction poses significant risks to the stability of geotechnical structures *** understanding of the liquefaction triggering,and the post-failure large deformation behaviour is essential for designing resilient *** present study develops a Smoothed Particle Hydrodynamics(SPH)framework for earthquake-induced liquefaction hazard assessment of geotechnical *** coupled flowdeformation behaviour of soils subjected to cyclic loading is described using the PM4Sand model implemented in a three-phase,single-layer SPH framework.A staggered discretisation scheme based on the stress particle SPH approach is adopted to minimise numerical inaccuracies caused by zero-energy modes and tensile ***,non-reflecting boundary conditions for seismic analysis of semi-infinite soil domains using the SPH method are *** numerical framework is employed for the analysis of cyclic direct simple shear test,seismic analysis of a level ground site,and liquefaction-induced failure of the Lower San Fernando *** agreement for liquefaction triggering and post-failure behaviour demonstrates that the SPH framework can be utilised to assess the effect of seismic loading on field-scale geotechnical *** present study also serves as the basis for future advancements of the SPH method for applications related to earthquake geotechnical engineering.

关键词： Earthquake seismic liquefaction stress particle PM4Sand smoothed particle hydrodynamics(SPH)

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

Deep-seated geodynamics and position of Platinum-bearing basite-ultrabasite massifs of southeast Russia

引用

global geology 2012年第3期15卷 204-209页

作者： khomich v.g. Boriskina N.g. Far East geological Institute of FEB of Russian Academy of Sciences

In the southeast part of the North-Asian craton, several ring basite-uhrabasite plutons have been rec- ognized, with which the commercial placers of platinoids associate. Analysis of the known geodynamic models of the region formation and materials of seismic tomography showed that the subduction processes, that actively manifested themselves in the Asia-Pacific convergence zone in Mesozoic, were responsible for initiation of the stagnated oceanic slab. Its NE and SW boundaries appear to coincide with the transform faults. Projection of the transform fault, bordering the above mentioned slab in the NEN, coincides with the Konder-Feklistovsky metal- logenic belt distinguished earlier and its Aldan （Inaglinsky） member. Higher platinum content of ring massifs of the belt is controlled by the influence of the lower mantle derivatives on the ascending upper mantle plumes.

关键词： southeast Russia mantle plumes Platinum-bearing ring massifs

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

Semantic Segmentation of Lumbar vertebrae Using Meijering U-Net(MU-Net)on Spine Magnetic Resonance Images

引用

Computer Modeling in Engineering & Sciences 2025年第1期142卷 733-757页

作者： Lakshmi S v v Shiloah Elizabeth Darmanayagam Sunil Retmin Raj Cyril Department of Computer Science and Engineering College of Engineering GuindyAnna UniversityChennai600025India Department of Information Technology Madras Institute of TechnologyAnna UniversityChrompetChennai600044India

Lower back pain is one of the most common medical problems in the world and it is experienced by a huge percentage of people *** to its ability to produce a detailed view of the soft tissues,including the spinal cord,nerves,intervertebral discs,and vertebrae,Magnetic Resonance Imaging is thought to be the most effective method for imaging the *** semantic segmentation of vertebrae plays a major role in the diagnostic process of lumbar *** is difficult to semantically partition the vertebrae in Magnetic Resonance Images from the surrounding variety of tissues,including muscles,ligaments,and intervertebral discs.U-Net is a powerful deep-learning architecture to handle the challenges of medical image analysis tasks and achieves high segmentation *** work proposes a modified U-Net architecture namely MU-Net,consisting of the Meijering convolutional layer that incorporates the Meijering filter to perform the semantic segmentation of lumbar vertebrae L1 to L5 and sacral vertebra ***-colour mask images were generated and used as ground truth for training the *** work has been carried out on 1312 images expanded from T1-weighted mid-sagittal MRI images of 515 patients in the Lumbar Spine MRI Dataset publicly available from Mendeley *** proposed MU-Net model for the semantic segmentation of the lumbar vertebrae gives better performance with 98.79%of pixel accuracy(PA),98.66%of dice similarity coefficient(DSC),97.36%of Jaccard coefficient,and 92.55%mean Intersection over Union(mean IoU)metrics using the mentioned dataset.

关键词： Computer aided diagnosis(CAD) magnetic resonance imaging(MRI) semantic segmentation lumbar vertebrae deep learning U-Net model

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

growth of 4＂ diameter polycrystailine diamond wafers with high thermal conductivity by 915 MHz microwave plasma chemical vapor deposition

引用

Plasma Science and Technology 2017年第3期19卷 93-97页

作者： A F POPOvICH v.g.RALCHENKO v K BALLA A K MALLIK A A khomich A P BOLSHAKOv D N SOvYK E E ASHKINAZI v Yu YUROv Institute of Radio Engineering and Electronics of Russian Academy of Sciences Fryazino 141190 Russia general Physics Institute of Russian Academy of Sciences Moscow 119991 Russia Harbin Institute of Technology Harbin 150001 People's Republic of China National Research Nuclear University MEPhI Moscow 115409 Russia Central glass and Ceramic Research Institute Kolkata 700 032 India

Polycrystalline diamond（PCD） films 100 mm in diameter are grown by 915 MHz microwave plasma chemical vapor deposition（MPCvD） at different process parameters,and their thermal conductivity（TC） is evaluated by a laser flash technique（LFT） in the temperature range of230-380 *** phase purity and quality of the films are assessed by micro-Raman spectroscopy based on the diamond Raman peak width and the amorphous carbon（a-C） presence in the *** and increasing dependencies for TC with temperature are found for high and low quality samples,***,as high as 1950 ± 230 W m-1 K-1 at room temperature,is measured for the most perfect material.A linear correlation between the TC at room temperature and the fraction of the diamond component in the Raman spectrum for the films is established.

关键词： thermal conductivity polycrystalline diamond microwave plasma chemical vapordeposition Raman spectroscopy

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

Structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond films

引用

Chinese Physics B 2018年第9期27卷 426-433页

作者： Hui Xu Jian-Jun Liu Hai-Tao Ye D J Coathup A v khomich Xiao-Jun Hu College of Materials Science and Engineering Zhejiang University of Technology Hangzhou 310014 China Aston Institute of Materials Research School of Engineering and Applied Science Aston University Birmingham B4 7ET United Kingdom v. A. Kotelnikov Institute of Radio-Engineering and Electronics Russian Academy of Sciences Moscow 14l 190 Russia National Research Nuclear University MEPhI Moscow Russia

We investigate the structural and electrical properties of carbon-ion-implanted ultrananocrystalline diamond（UNCD）films. Impedance spectroscopy measurements show that the impedance of diamond grains is relatively stable, while that of grain boundaries（gBs）（Rb） significantly increases after the C~＋ implantation, and decreases with the increase in the annealing temperature（Ta） from 650℃ to 1000℃. This implies that the C~＋ implantation has a more significant impact on the conductivity of gBs. Conductive atomic force microscopy demonstrates that the number of conductive sites increases in gB regions at Ta above 900℃, owing to the formation of a nanographitic phase confirmed by high-resolution transmission electronic microscopy. visible-light Raman spectra show that resistive trans-polyacetylene oligomers desorb from gBs at Ta above 900℃, which leads to lower Rb of samples annealed at 900 and 1000℃. With the increase in Ta to 1000℃, diamond grains become smaller with longer gBs modified by a more ordered nanographitic phase, supplying more conductive sites and leading to a lower Rb.

关键词： ultrananocrystalline diamond C-ion implantation annealing electrical properties

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

Autism spectrum disorder:difficulties in diagnosis and microRNA biomarkers

引用

Neural Regeneration Research 2025年第10期20卷 2776-2786页

作者： Bridget Martinez Philip v.Peplow Department of Pharmacology University of Nevada-RenoRenoNVUSA Department of Medicine University of Nevada-RenoRenoNVUSA Department of Anatomy University of OtagoDunedinNew Zealand

We performed a PubMed search for microRNAs in autism spectrum disorder that could serve as diagnostic biomarkers in patients and selected 17 articles published from January 2008 to December 2023,of which 4 studies were performed with whole blood,4 with blood plasma,5 with blood serum,1 with serum neural cell adhesion molecule L1-captured extracellular vesicles,1 with blood cells,and 2 with peripheral blood mononuclear *** of the studies involved children and the study cohorts were largely *** of the studies had performed microRNA sequencing or quantitative polymerase chain reaction assays to measure microRNA *** five studies had used real-time polymerase chain reaction assay to validate microRNA expression in autism spectrum disorder subjects compared to *** microRNAs that were validated in these studies may be considered as potential candidate biomarkers for autism spectrum disorder and include miR-500a-5p,-197-5p,-424-5p,-664a-3p,-365a-3p,-619-5p,-664a-3p,-3135a,-328-3p,and-500a-5p in blood plasma and miR-151a-3p,-181b-5p,-320a,-328,-433,-489,-572,-663a,-101-3p,-106b-5p,-19b-3p,-195-5p,and-130a-3p in blood serum of children,and miR-15b-5p and-6126 in whole blood of *** important limitations were identified in the studies reviewed,and need to be taken into account in future *** studies are warranted with children and adults having different levels of autism spectrum disorder severity and consideration should be given to using animal models of autism spectrum disorder to investigate the effects of suppressing or overexpressing specific microRNAs as a novel therapy.

关键词： autism spectrum disorder biomarker blood cells blood plasma blood serum diagnosis microRNA peripheral blood mononuclear cells serum neural cell adhesion molecule L1-captured extracellular vesicles whole blood

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

MicroRNAs as potential diagnostic biomarkers for bipolar disorder

引用

Neural Regeneration Research 2025年第6期20卷 1681-1695页

Abnormal expression of microRNAs is connected to brain development and disease and could provide novel biomarkers for the diagnosis and prognosis of bipolar disorder. We performed a PubMed search for microRNA biomarkers in bipolar disorder and found 18 original research articles on studies performed with human patients and published from January 2011 to June 2023. These studies included microRNA profiling in bloodand brain-based materials. From the studies that had validated the preliminary findings,potential candidate biomarkers for bipolar disorder in adults could be miR-140-3p,-30d-5p,-330-5p,-378a-5p,-21-3p,-330-3p,-345-5p in whole blood, miR-19b-3p,-1180-3p,-125a-5p, let-7e-5p in blood plasma, and miR-7-5p,-23b-5p,-142-3p,-221-5p,-370-3p in the blood serum. Two of the studies had investigated the changes in microRNA expression of patients with bipolar disorder receiving treatment. One showed a significant increase in plasma miR-134 compared to baseline after 4 weeks of treatment which included typical antipsychotics, atypical antipsychotics, and benzodiazepines. The other study had assessed the effects of prescribed medications which included neurotransmitter receptorsite binders(drug class B) and sedatives, hypnotics, anticonvulsants, and analgesics(drug class C) on microRNA results. The combined effects of the two drug classes increased the significance of the results for miR-219 and-29c with miR-30e-3p and-526b* acquiring significance. MicroRNAs were tested to see if they could serve as biomarkers of bipolar disorder at different clinical states of mania, depression, and euthymia. One study showed that upregulation in whole blood of miR-9-5p,-29a-3p,-106a-5p,-106b-5p,-107,-125a-3p,-125b-5p and of miR-107,-125a-3p occurred in manic and euthymic patients compared to controls, respectively, and that upregulation of miR-106a-5p,-107 was found for manic compared to euthymic patients. In two other studies using blood plasma,downregulation of miR-134 was observed i

关键词： biomarker bipolar disorder blood leukocytes blood plasma blood plasma extracellular vesicles/exosomes blood serum brain tissue brain tissue extracellular vesicles/exosomes lymphoblastoid cell lines microRNA neural progenitor cells whole blood

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

MicroRNAs as potential biomarkers for diagnosis of post-traumatic stress disorder

引用

Neural Regeneration Research 2025年第7期20卷 1957-1970页

Post-traumatic stress disorder is a mental disorder caused by exposure to severe traumatic life ***,there are no validated biomarkers or laboratory tests that can distinguish between trauma survivors with and without post-traumatic stress *** addition,the heterogeneity of clinical presentations of post-traumatic stress disorder and the overlap of symptoms with other conditions can lead to misdiagnosis and inappropriate *** suggests that this condition is a multisystem disorder that affects many biological systems,raising the possibility that peripheral markers of disease may be used to diagnose post-traumatic stress *** performed a PubMed search for microRNAs(miRNAs)in post-traumatic stress disorder(PTSD)that could serve as diagnostic biomarkers and found 18 original research articles on studies performed with human patients and published January 2012 to December *** included four studies with whole blood,seven with peripheral blood mononuclear cells,four with plasma extracellular vesicles/exosomes,and one with serum *** of these studies had also used whole *** studies were excluded as they did not involve microRNA *** of the studies had collected samples from adult male veterans who had returned from deployment and been exposed to combat,and only two were from recently traumatized adult *** measuring miRNA expression levels,many of the studies had used microarray miRNA analysis,miRNA Seq analysis,or NanoString *** six studies had used real time polymerase chain reaction assay to determine/validate miRNA expression in PTSD subjects compared to *** miRNAs that were found/validated in these studies may be considered as potential candidate biomarkers for PTSD and include miR-3130-5p in whole blood;miR-193a-5p,-7113-5p,-125a,-181c,and-671-5p in peripheral blood mononuclear cells;miR-10b-5p,-203a-3p,-4488,-502-3p,-874-3p,-5100,and-7641 in plasma extracellular vesicles/

关键词： biomarker diagnosis microRNA peripheral blood mononuclear cells plasma extracellular vesicles/exosomes post-traumatic stress disorder serum exosomes whole blood whole plasma

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

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：