检索结果-南通市图书馆

Journal of rare Earths 2016年第4期34卷 420-427页

作者： r.Pérez-Bustamante A.reyna-Cruz D.C.Acosta-Pena C.r.Santillán-rodríguez J.A.Matutes-Aquino F.Pérez-Bustamante M.C.Maldonado-Orozco J.Aguilar-Santillán r.Martínez-Sánchez research Center in Advanced Materials(CIMA V) National Laboratory of NanotechnologyMiguel de Cervantes No.120C.P.31109ChihuahuaChih.Mexico Faculty of Engineering Autonomous University of Chihuahua(UACH)Circuito No.1 Nuevo Campus UniversitarioC.P.31 125ChihuahuaChih.Mexico Faculty of Chemical Sciences Autonomous University of Chihuahua(UACH)Circuito No.1 Nuevo Campus UniversitarioC.P.31125ChihuahuaChih.Mexico Materials&Tools LLC 4118 E Washington CtGilbertAZUSA 85234

The effect of the Al-6Ce-3La（ACL） on the microstructural behavior of the Al7075 was investigated. Materials were synthesized by mechanical alloying with variation in the ACL content and milling time. Products were characterized and studied in the as-milled condition and mechanically evaluated after sintering. The synergetic effect of milling time and ACL content in the modified materials led to a reduction in the particle size. results from electron microscopy showed a homogeneous dispersion of Ce/La phases up to 20 wt.% of ACL content after 10 h of milling. Mechanical evaluation under compressive test showed an improved performance for those alloys reinforced with 0.2 wt.% and 0.5 wt.% of ACL.

关键词： mechanical alloying rare earths aluminum microstructure sintering

Soil Fertility Survey in Western Usambara Mountains, Northern Tanzania

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2006年第2期16卷 237-244页

作者： P. A. NDAKIDEMI J. M. r. SEMOKA Selian Agricultural research Institute P.O. Box 6024 Arusha (Tanzania) Faculty of Applied ScienceCape Peninsula University of TechnologyCape Town CampusKeizersgrachtP. O. Box 652Cape Town 8000 (South Africa) Sokoine University of Agriculture Soil Science Department P. O. Box 3008Morogoro (Tanzania)

Soil samples from thirty sites representing four agro-ecological zones in the Western Usambara Mountains (WUM) of the Lushoto District in northern Tanzania were collected and analyzed for different nutrients. The results suggested that the major soil fertility constraint was P deficiency. On the basis of critical levels established in other areas, 90% of the soils were ranked as P deficient. This was followed by N, which was ranked as inadequate in 73% of the sites. Magnesium, K, and Ca also appeared limiting with 67%, 53% and 50% of the soils falling below the established critical values, respectively. A few soils (10%) were also found to contain exchangeable Al. The metallic micronutrients (Cu, Fe, and Zn) were adequate in all soils. Two sites had excessive Mn that could lead to toxicity in crops, and one was Mn deficient.

关键词：土壤肥力山地肥力控制肥沃性

Soil Strength Characteristics Along an Arable Eroded Slope

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2005年第6期15卷 739-745页

作者： PENG Xin-Hua ZHANG Bin ZHAO Qi-Guo r. HOrN State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of SciencesNanjing 210008 （China） Institute of Plant Nutrition and Soil Science CAU Kiel Olshausenstr 40 D-24118 Kiel （Germany）

Undisturbed soil cores were taken from different slope positions (upslope, backslope and footslope) and soil depths (0-15, 20-35 and 100-115 cm) in a soil catena derived from Quaternary red clay to determine the spatial changes in soil strength along the eroded slope and to evaluate an indicator to determine soil strength during compaction. Precompression stress, as an indicator of soil strength, significantly increased from topsoil layer to subsoil layer (P r (20-35 cm), the precompression stress at the footslope position was significantly greater than at the backslope and upslope positions (P re were no significant differences at 0-15 and 100-115 cm. Precompression stress followed the spatial variation of soil clay content with soil depth and had a significant linear relationship with soil porosity (r2 = 0.40, P reased with increasing soil clay content. The precompression stress was significantly related to the applied stress corresponding to the highest change of pore water pressure (r2 = 0.69, P results suggested that soil strength induced by soil erosion and soil management varied spatially along the slope and the maximum change in pore water pressure during compaction could be an easy indicator to describe soil strength.

关键词：土壤侵蚀保水力孔隙水压土壤退化

Sensitization of Hydrothermally Grown Single Crystalline TiO2 Nanowire Array with CdSeS Nanocrystals for Photovoltaic Applications

在线全文

学校读者我要写书评

暂无评论

Nano research 2011年第12期4卷 1181-1190页

作者： Akshay Kumar Kuan-teh Li Anuj r. Madaria Chongwu Zhou Department of Electrical Engineering and Center for Energy Nanoscience and Technology University of Southern California Los AngelesCA 90089 USA

搬运 nanowires 的电子的一个面向的数组，在一个透明售票员上直接成长为有效光电的应用程序组成最佳的体系结构。另外，因为他们的悦耳的光性质，半导体 nanocrystals 能作为有效轻吸收器工作。在这份报纸，我们使用在一个透明传导性... 详细信息

搬运 nanowires 的电子的一个面向的数组，在一个透明售票员上直接成长为有效光电的应用程序组成最佳的体系结构。另外，因为他们的悦耳的光性质，半导体 nanocrystals 能作为有效轻吸收器工作。在这份报纸，我们使用在一个透明传导性的电极上直接种并且随后与胶体地成年的 CdSeS nanocrystal 量点(QD ) 敏化的 TiO2 nanowires 的一个面向的数组，用一个有效双性人连接器帮助了方法论，到表明光电的房间。在有光的刺激之上，，激子分离发生在 nanowire-nanocrystal 接口它，电子被搬运到做氟的符号的听氧化物(FTO ) 经由单人赛水晶的 TiO2 nanowire 隧道的电极。我们证明促进感受性在氧血浆上跟随的 QD 的前 situ ligand 交换在 QD 装载提高对待 TiO2 nanowires 结果，作为与相比在里面 situ ligand 交换途径。长 TiO2 nanowire 与 CdSeS nanocrystals 敏化的一连串的 1 m 与 23 mA/cm2， 0.60.7 V 的开的电路电压和 5265% 的一个 fill 因素的电线走火电流展出光电的效果，导致有多达 0.6% 的效率的设备。

关键词：半导体纳米晶体纳米线阵列 CdSeS 二氧化钛光伏电池直接生长玻璃应用

Persistent cough as a paraneoplastic presenting symptom in six patients with renal cell carcinoma

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Urology 2017年第1期4卷 10-13页

作者： Vinay r.Patel Bradley A.Morganstern Louis r.Kavoussi Department of Urology Smith Institute for UrologyNorthwell HealthNew Hyde ParkNYUSA

Objective:With today’s modern imaging modalities,patients diagnosed with renal cell carcinoma(rCC)rarely present *** some cases,however,they can develop paraneoplastic syndromes with associated *** date,only three cases of rCC presenting with chronic dry cough have been *** describe six patients who presented with cough that improved following radical ***:A retrospective review of patients undergoing partial or radical nephrectomy for renal masses between January 2015 and March 2016 was performed,and patients presenting with a cough were ***:Six patients presented with chronic cough and were discovered to have a large renal *** spontaneous resolution of cough was noted in all but one patient,in whom coughing was reduced and limited to the *** duration ranged from 3 months to just over a *** patients were treated with radical nephrectomy,which was cytoreductive in four *** tumor size was 10.9 cm(SD=2.2 cm).Five of the tumors had clear cell pathology,and every tumor was Fuhrman grade IV,unifocal,and demonstrated *** features were reported in four of the ***:Our study presents the largest series of patients with rCC who presented with a chronic cough that was significantly improved following radical *** believe the cause of cough is multifactorial and further investigation is needed to clearly elucidate the etiology.

关键词： renal cell carcinoma Paraneoplastic syndrome Cough Mass effect Cytokines renin-angiotensin system

Ceramic bodies with rock processing residues(rPr)for constructing materials

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Waste Disposal and Sustainable Energy 2020年第4期2卷 321-327页

作者： r.Vijayaragavan S.Mullainathan S.Nithiyanantham Department of Physics Arasu Engineering CollegeKumbakonamTamilnaduIndia Post Graduate and research Department of Physics Applied Energy Resource DivisionsThiru.Vi.Kalyanasundaram Govt Arts and Science College(Affiliated to Bharathidasan UniversityThiruchirapalli)ThiruvarurTamilnadu 610002India

The rock processing residue(rPr)waste is used for part of the ceramic *** present work deals with the unused waste useful for making ceramic materials and save the area and the dump *** residues are initially analyzed with the chemical and spectroscopic *** residues are mixed with clay of proportions 0-50 wt%in steps of 10%.The prepared specimens are characterized with Fourier transform infrared(FTIr),X ray fluorescence(XrF)for chemical,mechanical,and physiochemical properties,such as density,compressive strength,weight loss on ignition and porous nature,which are measured through the selective *** thermal stability of the product was tested by firing at 950℃.This says the rock residues are useful for making ceramic and related materials with high concentrations.

关键词： recycling Ceramic product Waste material rock processing residue Mechanical property

Colocated Finite Volume Schemes for Fluid Flows

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2008年第6期4卷 1-25页

作者： S.Faure J.Laminie r.Temam Laboratoire de Mathematiques Universite Paris-SudBatiment 42591405 OrsayFrance. GrIMAAG Guadeloupe Universite des Antilles et de la GuyaneCampus de FouilloleBP 59297157 Pointea Pitre CedexFrance. Institute for Scientific Computing and Applied Mathematics Indiana UniversityBloomingtonIN 47405USA.

Our aim in this article is to improve the understanding of the colocated finite volume schemes for the incompressible Navier-Stokes *** all the variables are colocated,that means here when the velocities and the pressure are computed at the same place(at the centers of the control volumes),these unknowns must be properly ***,the choice of the time discretization and the method used to interpolate the fluxes at the edges of the control volumes are *** the first and second parts of this article,two different time discretization schemes are considered with a colocated space discretization and we explain how the unknowns can be correctly *** simulations are presented in the last part of the *** paper is not a comparison between staggered grid schemes and colocated schemes(for this,see,e.g.,[15,22]).We plan,in the future,to use a colocated space discretization and the multilevel method of[4]initially applied to the two dimensional Burgers problem,in order to solve the incompressible Navier-Stokes *** advantage of colocated schemes is that all variables share the same location,hence,the possibility to use hierarchical space discretizations more easily when multilevel methods are *** this reason,we think that it is important to study this family of schemes.

关键词： Finite volumes colocated scheme.

STrUCTUrE OF 1-EPICrASSICAUDINE

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1995年第2期6卷 109-110页

作者： Wang, FP Dai, XP Wang, JZ Zhang, r W China Univ Med Sci Sch Pharm Dept Chem Med Nat Prod Chengdu 610044 Peoples R China

A new C-19-diterpenoid alkaloid. 1-epicrassicaudine, was isolated from the roots of Aconitum hemslevanum Pritz var. pengshinese. Spectral methods demonstrated that it has the structure represented by (1) an 1-epimer o...

关键词：

Lithological Discrimination of the Mafic-Ultramafic Complex, Huitongshan, Beishan, China: Using ASTEr Data

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2014年第3期25卷 529-536页

作者： Lei Liu Jun Zhou Dong Jiang Dafang Zhuang Lamin r Mansaray Key Laboratory of Western Mineral resources and Geological Engineering of Ministry of Education School of Earth Sciences and Resources Chang'an University Lanzhou AuriferouStone Mining Services Co. Ltd. Institute of Geographic Sciences and Natural resources research Chinese Academy of Sciences

The Beishan area has more than seventy mafic-ultramafic complexes sparsely distributed in the area and is of a big potential in mineral resources related to mafic-ultramafic intrusions. Many mafic-ultramafic intrusions which are mostly in small sizes have been omitted by previous works. This research takes Huitongshan as the study area, which is a major district for mafic-ultramafic occurrences in Beishan. Advanced spaceborne thermal emission and reflection radiometer（ASTEr） data have been processed and interpreted for mapping the mafic-ultramafic complex. ASTEr data were processed by different techniques that were selected based on image reflectance and laboratory emissivity spectra. The visible near-infrared（VNIr） and short wave infrared（SWIr） data were transformed using band ratios and minimum noise fraction（MNF）, while the thermal infrared（TIr） data were processed using mafic index（MI） and principal components analysis（PCA）. ASTEr band ratios（6/8, 5/4, 2/1） in rGB image and MNF（1, 2, 4） in rGB image were powerful in distinguishing the subtle differences between the various rock units. PCA applied to all five bands of ASTEr TIr imagery highlighted marked differences among the mafic rock units and was more effective than the MI in differentiating mafic-ultramafic rocks. Our results were consistent with information derived from local geological maps. Based on the remote sensing results and field inspection, eleven gabbroic intrusions and a pyroxenite occurrence were recognized for the first time. A new geologic map of the Huitongshan area was created by integrating the results of remote sensing, previous geological maps and field inspection. It is concluded that the workflow of ASTEr image processing, interpretation and ground inspection has great potential for mafic-ultramafic rocks identifying and relevant mineral targeting in the sparsely vegetated arid region of northwestern China.

关键词： mafic-ultramafic complex ASTEr data band ratio minimum noise fraction mafic index principal component analysis.

Founder effects and the evolution of asymmetrical sexual isolation in a rapidly-speciating clade

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2013年第2期59卷 230-238页

作者： Kevin r OH Gina L. CONTE Kerry L. SHAW Department of Neurobiology and Behavior Comell University Ithaca NY 14853 USA Department of Biology University of Maryland College Park MD 20742 USA

Sexual isolation resulting from differences in mate choice behaviors is a hallmark of rapidly-speciating lineages. When present, asymmetrical sexual isolation may provide insights into the mechanisms responsible for the evolutionary change in mate signaling traits. In particular, Kaneshiro’s hypothesis suggests that divergence in sexual characters between populations may arise in allopatry when ‘derived’ founding populations are subject to severe population bottlenecks, accompanied by a relaxation of sexual selection relative to ‘ancestral’ source populations. In the present study, we tested predictions of asymmetrical sexual isolation between two allopatric species of HawaiianLaupalacrickets, representing ‘ancestral’ (L. makaio) and ‘derived’ (L. nigra) taxa. While crickets in this genus are notable for rapid divergence of male courtship songs, these species share similar song types, thus suggesting that patterns of sexual isolation are likely due to other mating cues. Analysis of behavioral responses in conspecific and heterospecific ‘no-choice’ mating trials revealed pronounced asymmetrical isolation in the direction predicted by Kaneshiro’s hypothesis, wherein we observed a significant reduction in mating success for crosses involving ‘derived’ males paired with ‘ancestral’ females, compared to the reciprocal heterospecific and both conspecific pairings. Further dissection of courtship behaviors suggested this difference did not reflect male mate choice, but rather, marked reduced spermatophore acceptance rates by ‘ancestral’ females paired with ‘derived’ males. The results are discussed with respect to founder effect models of speciation and the potential role of chemosensory signals in mate choice in these species.

关键词：不对称性演变方正择偶行为信号特征交配试验生殖隔离行为反应