检索结果-南通市图书馆

Soil tillage methods by years interaction for dry matter of plant yield of maize (Zea mays L.)using additive main effects and multiplicative interaction model

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2018年第12期17卷 2836-2839页

作者： Jan Bocianowski piotr szulc Kamila Nowosad Department of Mathematical and Statistical Methods Poznan University of Life SciencesWojska Polskiego 28Poznan 60-637 Poland Poznan University of Life Sciences Department of AgronomyDojazd 11Poznan 60-632Poland Wroctaw University of Environmental and Life Sciences Department of GeneticsPlant Breeding and Seed Production Grunwaldzki 24AWroctaw 53-363Poland

The objective of this study was to assess soil tillage methods by years interaction for dry matter of plant yield of maize(Zea mays L.) grown in West Poland by the additive main effects and multiplicative interaction model. The study comprised four soil tillage methods, analysed in 12 years through field trials arranged in a randomized complete block design, with four replicates. Dry matter of plant yield of the tested soil tillage methods varied from 86.7 dt ha(for no-plough tillage in 2005) to 246.4 dt ha(for complete conventional tillage in 2012), with an average of 146.6 dt ha. In the variance analysis, 49.07% of the total dry matter of plant yield variation was explained by years, 12.69% by differences between soil tillage methods, and 10.53% by soil tillage methods by years interaction. Dry matter of plant yield is highly influenced by soil tillage methods by years factors.

关键词： AMMI model biplot Zea mays L. dry matter of plant yield stability

The influence of potassium to mineral fertilizers on the maize health

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2016年第6期15卷 1286-1292页

作者： Jan Bocianowski piotr szulc Anna Tratwal Kamila Nowosad Dariusz Piesik Department of Mathematical and Statistical Methods Poznań University of Life Sciences Department of Agronomy Poznań University of Life Sciences Department of Pests Methods Forecasting and Plant Protection Economy Institute of Plant Protection–National Research Institute Department of Genetics Plant Breeding and Seed Production Wroclaw University of Environmental and Life Sciences Department of Entomology and Molecular Phytopathology UTP University of Science and Technology

Field experiments （2009-2011） were conducted at the Department of Agronomy at Poznar~ University of Life Sciences on the fields of the Research Institute in Swadzim. We evaluated the health of maize plants of two types, depending on the variations in mineral fertilization. The conducted research recorded the occurrence of pests such as oscinella frit （Oscinella frit L.） and the European corn borer （Pyrausta nubilalis Hbn.）. Diseases recorded during the research included two patho- genes： Fusarium （Fusarium ssp.） and corn smut （Ustilago maydis Corda）. It was shown that the meteorological conditions during the maize vegetation had a significant influence on the occurrence of pests. Adding potassium to mineral fertilizers increased the maize resistance to Fusarium. Cultivation of ＂stay-green＂ cultivar shall be considered as an element of in- tegrated maize protection. The occurrence of oscineUa flit was correlated with the occurrence of Fusarium as well as the occurrence of the European corn borer for both examined cultivars.

关键词： cultivars maize diseases mineral fertilization pests

Shock Wave Strength Reduction by Passive Control Using Perforated Plates

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2007年第2期16卷 97-104页

作者： piotr Doerffer Oskar szulc Institute of Fluid-Flow Machinery Polish Academy of SciencesFiszera 1480-952 GdaskPoland

Strong, normal shock wave, terminating a local supersonic area on an airfoil, not only limits aerodynamic performance but also becomes a source of a high-speed impulsive helicopter noise. The application of a passive control system （a cavity covered by a perforated plate） on a rotor blade should reduce the noise created by a moving shock. This article covers the numerical implementation of the Bohning/Doerffer transpiration law into the SPARC code and includes an extended validation against the experimental data for relatively simple geometries of transonic nozzles. It is a first step towards a full simulation of a helicopter rotor equipped with a noise reducing passive control device in hover and in forward flight conditions.

关键词： transonic flows shock wave - boundary layer interaction passive control.

Shock Wave Smearing by Passive Control

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2006年第1期15卷 43-47,42页

作者： piotr DOERFFER Oskar szulc Rainer BOHNING IMP PAN Fiszera 14 PL-80 952 Gdansk Poland ISL Universitat Karlsruhe Karlsruhe Germany

Normal shock wave, terminating a local supersonic area on an airfoil, limits its performance and becomes a source of high speed impulsive noise. It is proposed to use passive control to disintegrate the shock wave. Details of the flow structure obtained by this method are studied numerically. A new boundary condition has been developed and the results of its application are verified against experiments in a nozzle flow. The method of shock wave disintegration has been confirmed and detailed analysis of the flow details is presented. The substitution of a shock wave by a gradual compression changes completely the source of the high speed impulsive noise and bears potential of its reduction.

关键词： transonic flows shock wave boundary layer interaction passive control.

Shock Wave-Boundary Layer Interaction in Forced Shock Oscillations

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2003年第1期12卷 10-15页

作者： piotr Doerffer Oskar szulc Franco Magagnato Institute of Fluid-Flow Machinery Polish Academy of Sciences Fiszera 14Institute of Fluid-Flow Machinery Polish Academy of Sciences Fiszera 14Institute fur Stromungslehre Universitat Karlsruhe Kaiserstr. 12 80-952 Gdansk Poland 80-952 Gdansk Poland D-76128 Karlsruhe Germany

The flow in transonic diffusers as well as in supersonic air intakes becomes often unsteady due to shock wave boundary layer interaction. The oscillations may be induced by natural separation unsteadiness or may be forced by boundary conditions. Significant improvement of CFD tools, increase of computer resources as well as development of experimental methods have *** the attention of researchers to this topic. To investigate the problem forced oscillations of transonic turbulent flow in asymmetric two-dimensional Laval nozzle were considered. A viscous, perfect gas flow, was numerically simulated using the Reynolds-averaged compressible Navier-Stokes solver SPARC, employing a two-equation, eddy viscosity, turbulence closure in the URANS *** time-dependent and stationary flow simulations, Mach numbers upstream of the shock between 1.2 and 1.4 were considered. Comparison of computed and experimental data for steady states generally gave acceptable agreement. In the case of forced oscillations, a harmonic pressure variation was prescribed at the exit plane resulting in shock wave motion. Excitation frequencies between 0 Hz and 1024 Hz were investigated at the same pressure *** main result of the work carried out is the relation between the amplitude of the shock wave motion and the excitation frequency in the investigated range. Increasing excitation frequency resulted in decreasing amplitude of the shock movement. At high frequencies a natural mode of shock oscillation (of small amplitude) was observed which is not sensitive to forced excitement.

关键词： unsteady transonic flow shock wave nozzle flow.

The Influence of Poly(Vinyl Alcohol)on Oil Release Behavior of Polylactide-Based Composites Filled with Linseed Cake

在线全文

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2020年第4期8卷 347-363页

作者： Olga Mysiukiewicz Mateusz Barczewski Joanna szulc Division of Polymer Processing Institute of Material TechnologyPoznan University of TechnologyPoznan61-138Poland Departament of Food Industry Technology and Engineering Faculty of Chemical Technology and EngineeringUTP University of Science and TechnologyBydgoszcz85-326Poland

In order to limit the negative impact of industry on natural environment,ecological alternatives to conventional polymers are being *** of the most popular“green”polymers is polylactide,which can also be successfully applied as a matrix of *** application of ground linseed cake as a filler for polylactide-based composites is in line with the idea of Circular Economy,and moreover it provides a modifying effect on the polymer by increasing its crystallinity and reducing its *** effect is caused by the presence of linseed oil which can be released to the polymeric matrix in a non-controlled *** order to control the miscibility of the oil and the polymer,we modified the filler particles with poly(vinyl alcohol)before introducing it to the *** concluded that poly(vinyl alcohol),which does not mix with oil,encapsulated the active ingredients inside the filler *** evaluated the mechanical properties of the composites containing 5,10,20 and 30 wt%of the filler in a static tensile stress and by means of dynamic mechanical thermal *** and thermal properties were tested using differential scanning calorimetry as well as thermogravimetric ***’microstructure was evaluated by Scanning Electron *** was found that modifying the oil-rich filler with poly(vinyl alcohol)helps to reduce its release to the matrix and thus limits the plasticizing effect of linseed *** result was in accordance with our hypothesis.

关键词： Polylactide poly(vinyl alcohol) waste filler oil release

Numerical Simulation of the Tip Aerodynamics and Acoustics Test

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

Journal of Thermal Science 2016年第2期25卷 153-160页

作者： F Tejero E P Doerffer O szulc J L Cross The Szwalski Institute of Fluid-Flow Machinery Polish Academy of Sciences. Fiszera 14 80-231 Gdansk Poland NASA Ames Research Center (retired) Moffett Field CA USA

The application of an efficient flow control system on helicopter rotor blades may lead to improved aerodynamic performance. Recently, our invention of Rod Vortex Generators(RVGs) has been analyzed for helicopter rotor blades in hover with success. As a step forward, the study has been extended to forward flight conditions. For this reason, a validation of the numerical modelling for a reference helicopter rotor(without flow control) is needed. The article presents a study of the flow-field of the AH-1G helicopter rotor in low-, medium- and high-speed forward flight. The CFD code FLOWer from DLR has proven to be a suitable tool for the aerodynamic analysis of the two-bladed rotor without any artificial wake modelling. It solves the URANS equations with LEA(Linear Explicit Algebraic stress) k-ω model using the chimera overlapping grids technique. Validation of the numerical model uses comparison with the detailed flight test data gathered by Cross J. L. and Watts M. E. during the Tip Aerodynamics and Acoustics Test(TAAT) conducted at NASA in 1981. Satisfactory agreements for all speed regimes and a presence of significant flow separation in high-speed forward flight suggest a possible benefit from the future implementation of RVGs. The numerical results based on the URANS approach are presented not only for a popular, low-speed case commonly used in rotorcraft community for CFD codes validation but preferably for medium- and high-speed test conditions that have not been published to date.

关键词： AH-1G TAAT helicopter rotor forward flight chimera overlapping grid

The Middle Jurassic Siderite Iron Ore Deposits in Southern Poland

在线全文

学校读者我要写书评

暂无评论

矿物学报 2013年第S1期33卷 5-5页

作者： Aleksandra Kozowska Marta Kuberska Anna Feldman-Olszewska Katarzyna Jarmo owicz-szulc Anna Maliszewska Polish Geological Institute - Polish Research Institute Rakowiecka 400-975 WarsawPoland

The beginning of iron ore mining in southern Poland dates back to very ancient times. The largest underground iron ore mine from Roman times was discovered in the northern margin of the Holy Cross Mountains, near Nowa S upia. In the seventeenth century the intensive development of iron mining occurred in this area. The iron ore mines from the Cz stochowa-Wieluń area started in the fourteenth century. Several iron ore mines in both areas worked in the 20-ies and 30-ies of the twentieth century. Since the beginning of the 70's the ore mining has been under reduction in connection with the decision of liquidation of the iron ore mining industry in Poland. The stage of the mine closure finished in 1982, when last mines closed down in the Cz stochowa-Wieluń area.

关键词： microbiological metanogenesis chemical composition sideroplesite southern poland