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Estimation of sediment sources using selected chemical tracers in the Perry lake basin,kansas,USA

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International Journal of Sediment Research 2009年第1期24卷 108-125页

作者： k. E. JURACEk A. C. ZIEGLER Hydrologist U.S. Geological Survey 4821 Quail Crest Place Lawrence KS USA 66049

The ability to achieve meaningful decreases in sediment loads to reservoirs requires a determination of the relative importance of sediment sources within the contributing basins. In an investigation of sources of fine-grained sediment(clay and silt) within the Perry Lake Basin in northeast kansas,representative samples of channel-bank sources,surface-soil sources(cropland and grassland),and reservoir bottom sediment were collected,chemically analyzed,and compared. The samples were sieved to isolate the ke Basin,the consensus of the seven indicators was that both channel-bank and surface-soil sources were important in the Atchison County Lake and Banner Creek Reservoir subbasins,whereas channel-bank sources were dominant in the Mission Lake subbasin. On the sole basis of 137Cs activity,surface-soil sources contributed the most fine-grained sediment to Atchison County Lake,and channel-bank sources contributed the most fine-grained sediment to Banner Creek Reservoir and Mission Lake. Both the seven-indicator consensus and 137Cs indicated that channel-bank sources were dominant for Perry Lake and that channel-bank sour

关键词： Sediment Source Tracer Perry Lake kansas

EFFECT OF DEEP COLD TREATMENT ON TWO CASE HARDENING STEELS

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Acta Metallurgica Sinica(English Letters) 2008年第1期21卷 1-7页

作者： C.H.Surberg P.Stratton k.Lingenhle V-Research Center of Competence for Tribology and Technical Logistics GmbH DornbirnAustriap The Linde Group UnterschleiβheimGermany Lingenhle Technology GmbH FeldkirchAustria

Although cold treatments have been used to reduce the retained austenite in the cases of carburised steel for many years, there is little data on deep cold temperatures below -70℃ or treatment times longer than an hour or two. This study set out to determine the effects of such deep cold treatments at temperatures -150℃ for 24 h. The study investigated the effects of deep cold on the microstructure, hardness profile, residual stress and internal oxidation on two typical carburising steels, 16MnCr5 and 21NiCrMo2. The study found that for both 16MnCr5 and 21NiCrMo2 carburised to a case depth of approximately 0.8 mm, the longer and colder the deep cold treatment, the more the austenite retained in the case was converted to martensite and the harder it became. After low temperature tempering, the hardness difference was smaller, but still significant. In both steels, the case appeared more refined and homogeneous after deep cold treatment. Deep cold treatment had a negligible effect on the core properties of either steel.

关键词： Carburised steel Deep cold Retained austenite

A composite sphere assemblage model for porous oolitic rocks:Application to thermal conductivity

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第1期9卷 54-61页

作者： F. Chen A. Giraud D. Grgic k. kalo Geo Ressources Laboratory Université de Lorraine (ENSG) CNRS CREGU Vandoeuvre-lès-Nancy F-54518 France

The present work is devoted to the determination of linear effective thermal conductivity of porous rocks characterized by an assemblage of grains(oolites) coated by a matrix. Two distinct classes of pores, *** or intra oolitic pores(oolite porosity) and mesopores or inter oolitic pores(inter oolite porosity), are taken into account. The overall porosity is supposed to be connected and decomposed into oolite porosity and matrix porosity. Within the framework of Hashin composite sphere assemblage(CSA)models, a two-step homogenization method is developed. At the first homogenization step, pores are assembled into two layers by using self-consistent scheme(SCS). At the second step, the two porous layers constituting the oolites and the matrix are assembled by using generalized self-consistent scheme(GSCS) and referred to as three-phase model. Numerical results are presented for data representative of a porous oolitic limestone. It is shown that the influence of porosity on the overall thermal conductivity of such materials may be significant.

关键词： Effective thermal conductivity Three-phase model Oolitic limestone Composite sphere assemblage(CSA) model

Microstructure formation and grain refinement of Mg-based alloys by electromagnetic vibration technique

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Transactions of Nonferrous Metals Society of China 2010年第7期20卷 1192-1198页

作者： M.J.LI T.TAMURA N.OMURA k.MIWA National Institute of Advanced Industrial Science and Technology Materials Research Institute for Sustainable DevelopmentNagoya 463-8560Japan

The microstructure formation and grains refinement of two Mg-based alloys,***31 and AZ91D,were reported using an electromagnetic vibration(EMV) *** two alloys were solidified at various vibration frequencies and the microstructures were *** average size of grains was quantitatively measured as a function of vibration frequencies. Moreover,the grain size distribution was outlined versus number fraction.A novel model was proposed to account for the microstructure formation and grain refinement when considering the significant difference of the electrical resistivity properties of the solid and the liquid during EMV processing in the semisolid *** remarkable difference originates uncoupled movement between the mobile solid and the sluggish liquid,which can activate melt *** microstructure evolution can be well explained when the fluid flow intensity versus vibration frequency is taken into ***,the influence of the static magnetic field on texture formation is also considered,which plays an important role at higher vibration frequencies.

关键词：晶粒细化微观结构振动技术镁基合金电磁振动 AZ91D镁合金振动频率组织形成

Competition among the two-plasmon decay of backscattered light,filamentation of the electron-plasma wave and side stimulated Raman scattering

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High Power Laser Science and Engineering 2023年第6期11卷 87-94页

作者： k.Q.Pan Z.C.Li L.Guo T.Gong S.W.Li D.Yang C.Y.Zheng B.H.Zhang X.T.He Laser Fusion Research Center China Academy of Engineering PhysicsMianyangChina Center for Applied Physics and Technology Peking UniversityBeijingChina Institute of Applied Physics and Computational Mathematics BeijingChina

Competition among the two-plasmon decay(TPD)of backscattered light of stimulated Raman scattering(SRS),filamentation of the electron-plasma wave(EPW)and forward side SRS is investigated by two-dimensional particlein-cell *** previous work[*** et al.,*** 58,096035(2018)]showed that in a plasma with the density near 1/10 of the critical density,the backscattered light would excite the TPD,which results in suppression of the backward ***,this work further shows that when the laser intensity is so high(>10^(16)W/cm^(2))that the backward SRS cannot be totally suppressed,filamentation of the EPW and forward side SRS will be *** the TPD of the backscattered light only occurs in the early stage and is suppressed in the latter *** distribution functions further show that trapped-particle-modulation instability should be responsible for filamentation of the *** research can promote the understanding of hot-electron generation and SRS saturation in inertial confinement fusion experiments.

关键词： laser plasma instability inertial confinement fusion high energy density physics particle-in-cell simulation super-hot electrons

A Hybrid Time Frequency Response and Fuzzy Decision Tree for Non-stationary Signal Analysis and Pattern Recognition

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International Journal of Automation and computing 2019年第3期16卷 398-412页

作者： N.R.Nayak P.k.Dash R.Bisoi Multidisciplinary Research Cell Siksha O Anusandhan University Khandagiri Square

A Fourier kernel based time-frequency transform is a proven candidate for non-stationary signal analysis and pattern recognition because of its ability to predict time localized spectrum and global phase reference ***,it suffers from heavy computational overhead and large execution *** paper,therefore,uses a novel fast discrete sparse S-transform(SST)suitable for extracting time frequency response to monitor non-stationary signal parameters,which can be ultimately used for disturbance detection,and their pattern *** the sparse S-transform matrix,some relevant features have been extracted which are used to distinguish among different non-stationary signals by a fuzzy decision tree based *** algorithm is robust under noisy *** power quality as well as chirp signals have been simulated and tested with the proposed technique in noisy conditions as *** real time mechanical faulty signals have been collected to demonstrate the efficiency of the proposed *** the simulation results imply that the proposed technique is very much efficient.

关键词： Non-stationary signals sparse S-transform(SST) scaling method fuzzy decision tree pattern classification

The Receptor-Like Cytoplasmic kinase （OsRLCk） Gene Family in Rice： Organization, Phylogenetic Relationship, and Expression during Development and Stress

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Molecular Plant 2008年第5期1卷 732-750页

作者： Shubha Vij Jitender Giri Prasant kumar Dansana Sanjay kapoor Akhilesh k. Tyagi Interdisciplinary Centre for Plant Genomics and Department of Plant Molecular Biology University of Delhi South Campus Benito Juarez Road New Delhi 110021 India

Receptor-like cytoplasmic kinases （RLCks） in plants belong to the super family of receptor-like kinases （RLks）. These proteins show homology to RLks in kinase domain but lack the transmembrane domain. Some of the functionally characterized RLCks from plants have been shown to play roles in development and stress responses. Previously, 149 and 187 RLCk encoding genes were identified from Arabidopsis and rice, respectively. By using HMM-based domain structure and phylogenetic relationships, we have identified 379 OsRLCks from rice. OsRLCks are distributed on all 12 chromosomes of rice and some members are located on duplicated chromosomal segments. Several OsRLCks probably also undergo alternative splicing, some having evidence only in the form of gene models. To understand their possible functions, expression patterns during landmark stages of vegetative and reproductive development as well as abiotic and biotic stress using microarray and MPSS-based data were analyzed. Real-time PCR-based expression profiling for a selected few genes confirmed the outcome of microarray analysis. Differential expression patterns observed for majority of OsRLCks during development and stress suggest their involvement in diverse functions in rice. Majority of the stress-responsive OsRLCks were also found to be localized within mapped regions of abiotic stress QTLs. Outcome of this study would help in selecting organ/development stage specific OsRLCk genes/targets for functional validation studies.

关键词： abiotic stress biotic stress genome-wide analysis kinase rice RLCk.

Si-SiO_2 interface passivation by plasma NH_3 and atomic H

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Rare Metals 2006年第Z1期25卷 146-149页

作者： WEBER k.J. JAYAPRASAD A. SMITH P.J. BLAkERS A. Centre for Sustainable Energy Systems Faculty of Engineering and Information Technology North Road the Australian National University Canberra ACT 0200 Australia Department of Physics Faculty of Sciences University of Konstanz Germany Department of Chemistry The Australian National University Canberra ACT 0200 Australia 0200 Australia

Plasma ammonia treatment at 400 ℃ leads to de-passivation of a fully hydrogenated Si-SiO2 interface, and to passivation of a fully de-hydrogenated Si-SiO2 interface. Plasma NH3 exposure causes irreversible Si surface damage and degradation of thermal stability. Atomic hydrogen exposure, although it results in similar effects on the Si-SiO2 interface, does not introduce additional defects or a decrease of the Si surface thermal stability. The difference between plasma NH3 exposure and atomic H exposure is speculated to be due to either the nitridation of Si-SiO2 interface or radiation damage resulting from plasma NH3 exposure. EPR measurements indicate changes of the paramagnetic defect properties and an increase in the paramagnetic defect density generated by plasma NH3 exposure.

关键词： plasma NH3 atomic H SiO2 EPR

SiC_(f)/SiC与GH5188钎焊接头的界面产物及机制研究

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稀有金属 2023年第5期47卷 769-777页

作者：杨佳徐新何鹏林铁松林盼盼庄艳丽 V.Savitsky k.Shyian 哈尔滨工业大学先进焊接与连接国家重点实验室黑龙江哈尔滨150001 哈尔滨理工大学材料科学与化学工程学院黑龙江省CO_(2)资源化利用与能源催化材料重点实验室黑龙江哈尔滨150040 乌克兰国家科学院巴顿焊接研究所乌克兰基辅市03680

使用CuTi+NbB_(2)活性钎料成功实现了碳化硅纤维增强碳化硅(SiC_(f)/SiC)复合材料与GH5188钴基高温合金二者的连接,研究了钎焊温度对接头界面微观组织以及力学性能的影响,并对连接机制展开了分析。接头典型的界面结构为GH5188/Cu+(Ni,Co... 详细信息

使用CuTi+NbB_(2)活性钎料成功实现了碳化硅纤维增强碳化硅(SiC_(f)/SiC)复合材料与GH5188钴基高温合金二者的连接,研究了钎焊温度对接头界面微观组织以及力学性能的影响,并对连接机制展开了分析。接头典型的界面结构为GH5188/Cu+(Ni,Co,Cu)3Ti_(2)+(Co,Ni,Cu)Ti_(2)/Cu_(4)Ti/Cu+Cu_(3)Ti_(2)+(Ni,Co)-Si+(Ni,Co,Cu)Ti_(2)/TiC+Cr-C/SiC+Cu/SiC_(f)/SiC。由于NbB2粉末的引入,导致形核点的增加,金属间化合物倾向于以小颗粒相的形态析出并弥散分布在钎缝中。而随着温度的升高,金属的溶解情况以及元素的互扩散以及反应情况均有所加强,但温度的改变基本上不改变各层的占比;同时,陶瓷侧的补充活性元素(Co,Cr,Ni)随着温度而增多,这在一定程度上有利于陶瓷与焊缝之间的连接。因此,在1050℃/10 min的情况下,接头的室温抗剪强度最高达到72 MPa。接头均沿钎缝和SiC_(f)/SiC复合材料的反应界面断裂。

关键词：钴基高温合金碳化硅纤维增强碳化硅(SiC_(f)/SiC)复合材料活性钎焊界面组织连接机制