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Visual ***开发人员指南

Boundary layer influence on ship model tests in extremely shallow and confined water

丛书名：开发人员专业技术丛书

2002年

作者：（美）Cameron Wakefield （美）henk-evert Sonder等智慧东方工作室译

本书全面讲述了新的集成开发环境、高级***编程概念、***结构和XML Schema定义工具，以及如何创建Windows窗体等内容。

ISBN: (纸本)7111087852

本书全面讲述了新的集成开发环境、高级***编程概念、***结构和XML Schema定义工具，以及如何创建Windows窗体等内容。

关键词：互连网络 BASIC语言程序设计

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Journal of Hydrodynamics 2023年第2期35卷 365-378页

作者： evert Lataire Asif Raza Marc Vantorre Guillaume Delefortrie Maritime Technology Division Ghent UniversityGhentBelgium ANAST University of LiègeLiègeBelgium Flanders Hydraulics Research AntwerpBelgium

Ships sailing in shallow and/or confined water(when calling a harbour or other berthing areas),will experience a different behaviour due to the interaction with vertical and/or horizontal *** other hydrodynamic changes induced in confined water,the lateral ship-bank interaction force changes its sign at a critical distance between ship and bank or ***,this distance and its effects on model test results have not been quantified in the *** investigate the shallow water hydrodynamics coupled with bank effects,systematic model tests were carried out at Flanders Hydraulics Research(FHR)with different ship *** following parameters were systematically varied:water depth,lateral position,speed,and propeller *** change of the ship-bank induced lateral force from an attraction force in medium-deep and shallow water to a repulsion force in extremely shallow water conditions,can be ascribed to the interaction of the boundary layers of the ship model and the environment(tank and installed banks).In this article,a mathematical model is proposed for the critical distance in terms of boundary layer influence *** indicates the range where the model tests are influenced by the horizontal or vertical restrictions combined with the propeller’s dynamic ***,the expression has also been extended to describe the relationship between full-scale ship length and water depth with the boundary layer influence *** to lower Reynolds numbers and relatively thicker boundary layers at model scale,upscaling of the model test results,according to Froude’s law,may provide erroneous *** influence of the boundary layer initiates at a relatively higher under keel clearance(UKC)for a smaller ship model compared with a larger ship ***,the boundary layer’s influence with respect to ship model length should be considered during model testing.

关键词： Shallow water hydrodynamics bank effects boundary layer model tests mathematical model

Sedimentation in small-scale irrigation schemes in Ethiopia: Its sources and management

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International Journal of Sediment Research 2022年第5期37卷 576-588页

作者： Zerihun Anbesa Gurmu henk Ritzema Charlotte de Fraiture Mekonen Ayana Water Resources Management Group Wageningen University Arba Minch University Department of Water Science and Engineering IHE Delft Institute for Water Education Adama Science and Technology University

Numerous irrigation schemes in sub-Saharan Africa(SSA) exhibit excessive sedimentation, resulting in underperformance and high maintenance costs. In the current study, a participatory monitoring program was used to investigate sediment causes and sources, measure the annual sediment load, and monitor desilting campaigns in two small scale irrigation schemes in Ethiopia, Arata-Chufa(100 ha) and Ketar(430 ha), for three years(2016-2018). Sedimentation quantities were huge, where the annual river sediment influx ranged from 220 m3for the Arata-Chufa scheme to 1,741 m3for the Ketar scheme. On average 0.3 m3/m of sediment were removed from the main canal for Arata-Chufa costing 794 days of labor per year. In Ketar, sediment quantities were even greater: 1.1 m3/m was removed requiring 3,118days of labor per year. The sediment influx from the river source amounts to up to 95% for Arata-Chufa and moderately reaches 46% for Ketar, with the remainder of the sediment entering with overland erosion flows. Farmers reported increased sedimentation over time and difficulty paying operation and maintenance fees instead preferring to contribute labor for the desilting campaigns. Sedimentation management is fragile and mainly involves frequent desilting campaigns and unharmonized efforts to reduce overland sediment inflows. Factors contributing to sediment deposition include mild longitudinal bed slopes, the location of the intake, canal layout, and lack of canal banks for protection against surface water inflow in addition to sub-optimal canal operations. Excessive sedimentation is a major challenge resulting in underperformance of numerous irrigation schemes in SSA, and the stakeholders’ lack of awareness of the sources of sedimentation is an underlying factor aggravating sedimentation problems. It is concluded that investigating the sources, extent, and types of sedimentation entering a small-scale irrigation scheme is the basis for reducing maintenance costs and for effective man

关键词： Sediment sources Sediment management Irrigation performance Soil loss River sediment Erosion

Helmholtz equation and non-singular boundary elements applied to multi-disciplinary physical problems

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Communications in Theoretical Physics 2022年第8期74卷 18-34页

作者： evert Klaseboer Qiang Sun Institute of High Performance Computing 1 Fusionopolis WaySingapore 138632Singapore Australian Research Council Centre of Excellence for Nanoscale BioPhotonics School of ScienceRMIT UniversityMelbourneVIC 3001Australia

The famous scientist Hermann von Helmholtz was born 200 years *** complex physical wave phenomena in engineering can effectively be described using one or a set of equations named after him:the Helmholtz *** this has been known for a long time,from a theoretical point of view,the actual numerical implementation has often been hindered by divergence-free and/or curlfree *** is further a need for a numerical method that is accurate,reliable and takes into account radiation conditions at *** classical boundary element method satisfies the last condition,yet one has to deal with singularities in the *** review here how a recently developed singularity-free three-dimensional boundary element framework with superior accuracy can be used to tackle such problems only using one or a few Helmholtz equations with higher order(quadratic)elements which can tackle complex curved *** are given for acoustics(a Helmholtz resonator among others)and electromagnetic scattering.

关键词： acoustics Helmholtz cavity electromagnetics scattering boundary integral method

Cereal type and combined xylanase/glucanase supplementation influence the cecal microbiota composition in broilers

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Journal of Animal Science and Biotechnology 2022年第5期13卷 1531-1542页

作者： Dimitrios Kouzounis Jannigje G.Kers Natalia Soares Hauke Smidt Mirjam A.Kabel henk A.Schols Laboratory of Food Chemistry Wageningen University&Research6708 WG WageningenThe Netherlands Laboratory of Microbiology Wageningen University&Research6708 WE WageningenThe Netherlands Huvepharma NV 2600 BerchemBelgium

Dietary fiber-degrading enzyme supplementation in broilers aims at off-setting the anti-nutritive effect of non-starch polysaccharides and at promoting broiler ***,we demonstrated that xylanase/glucanase addition in wheat-based diet improved nutrient digestibility,arabinoxylan fermentability and broiler ***,maize arabinoxylan was found to be recalcitrant to xylanase *** findings suggested that enzyme-mediated improvement of nutrient digestion and carbohydrate fermentation depended on the cereal type present in the diet,and may have contributed to broiler ***,we aimed at further investigating the link between dietary enzymes and carbohydrate fermentation in broilers,by studying the impact of enzyme supplementation in cereal-based diets,to the microbial communities in the ileum and ceca of *** that purpose,96 one-day-old male broilers were randomly reared in two pens and received either wheat-based or maize-based starter and grower *** d 20,the broilers were randomly assigned to one out of four dietary *** broilers received for 8 d the wheat-based or maize-based finisher diet as such(Control treatments;WC,MC)or supplemented with a xylanase/glucanase combination(Enzyme treatments;WE,ME).At d 28,samples from the digestive tract were collected,and the ileal and cecal microbiota composition was determined by 16S ribosomal RNA gene amplicon sequencing.A similar phylogenetic(alpha)diversity was observed among the four treatments,both in the ileal and the cecal ***,a similar microbial composition in the ileum(beta diversity)was observed,with lactobacilli being the predominant community for all *** contrast,both cereal type and enzyme supplementation were found to influence cecal *** type of cereal(i.e.,wheat or maize)explained 47% of the total variation in microbial composition in the *** stratifying the analysis per cereal type revealed differences in microbio

关键词： Arabinoxylo-oligosaccharides Broiler gut microbiota Cereal non-starch polysaccharides Feed enzymes Fiber fermentation Prebiotics 16S rRNA

Breeding melon(Cucumis melo)with resistance to powdery mildew and downy mildew

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Horticultural Plant Journal 2022年第5期8卷 545-561页

作者： Lei Cui Lampros Siskos Chen Wang henk J.Schouten Richard G.FVisser Yuling Bai College of Agriculture Shanxi Agricultural UniversityTaiyuan030031China Plant Breeding Wageningen University&ResearchP.O.Box 3866700 AJWageningenthe Netherlands

Melon(Cucumis melo L.)production is often restricted by a plethora of pests and diseases,including powdery mildew and downy mildew caused respectively by the fungal species Podosphaera xanthii/Golovinomyces orontii and oomycete species Pseudoperonospora *** efforts have been directed on identification of resistant sources by screening(wild)melon *** the current review,we summarized such efforts from various publications of the last 50 plus *** to powdery mildew has been identified in 239 melon accessions and downy mildew resistance in 452 accessions of both *** and the wild relative species *** the resistance sources,*** *** accessions PMR 45,PMR 5,PMR 6,and WMR 29 as well as *** *** accessions PI 124111,PI 124112,and PI 414723 have been considered as the most valuable germplasm because multiple resistance genes have been identified from these accessions and are widely used in melon resistance *** genetic mapping in a number of resistant sources has enabled identification of 25 dominant genes,two recessive genes and seven QTLs conferring powdery mildew resistance,as well as eight dominant genes and 11 QTLs for downy mildew *** on the reported sequences of associated markers,we anchored physically(many of)these genes and QTLs to chromosomes of the melon ***92 *** addition to presenting a comprehensive overview on powdery mildew and downy mildew resistance in(wild)melon germplasm,we suggest strategies aiming at breeding melon with durable and broad-spectrum resistance to pathogens and pests.

关键词： Cucumis melo Melon Powdery mildew Downy mildew Resistance Breeding

基于Marchenko理论的成像域与数据域层间多次波消除方法对比

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地球物理学报 2022年第4期65卷 1416-1424页

作者：张乐乐邵婕郑忆康王一博 evert Slob 中国地质大学地球物理与空间信息学院地球内部多尺度成像湖北省重点实验室武汉430074 中国科学院地质与地球物理研究所北京100029 Delft University of Technology 2628 CN DelftThe Netherlands

Marchenko成像可以理解为一种基于Marchenko理论的成像域层间多次波消除方法.该方法利用Marchenko方程组将地表观测的地震数据准确的延拓到地下的成像点,得到震源位于地下成像点、检波点位于地表的上下行格林函数,进而采用多维反褶积获... 详细信息

Marchenko成像可以理解为一种基于Marchenko理论的成像域层间多次波消除方法.该方法利用Marchenko方程组将地表观测的地震数据准确的延拓到地下的成像点,得到震源位于地下成像点、检波点位于地表的上下行格林函数,进而采用多维反褶积获得该成像点不含多次波假象的像.基于Marchenko方程组所推导出的数据域多次波消除方法可以准确的预测并消除所有阶数的层间多次波.该方法不需要任何速度信息和匹配相减,避免了传统多次波消除方法对一次波造成的损害.基于数据域多次波消除之后的数据,可以获得地下结构不含多次波假象的像.本文对基于Marchenko理论的成像域及数据域层间多次波消除方法进行了对比分析,给出了详细的理论及数值模型试算结果,并对两种方法的优缺点进行了讨论.

关键词： Marchenko方程组层间多次波多次波消除多维反褶积

Nanoscale displacement of the image of an atomic source of radiation

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Chinese Optics Letters 2009年第2期7卷 149-151页

作者： henk F. Arnoldus Department of Physics and Astronomy Mississippi State University

Light emitted by an atomic source of radiation appears to travel along a straight line （ray） from the location of the source to the observer in the far field. However, when the energy flow pattern of the radiation is resolved with an accuracy better than an optical wavelength, it turns out that the field lines are usually curved. We consider electric dipole radiation, a prime example of which is the radiation emitted by an atom during an electronic transition, and we show that the field lines of energy flow are in general curves. Near the location of the dipole, the field lines exhibit a vortex structure, and in the far field they approach a straight line. The spatial extension of the vortex in the optical near field is of nanoscale dimension. Due to the rotation of the field lines near the source, the asymptotic limit of a field line is not exactly in the radially outward direction and as a consequence, the image in the far field is slightly shifted. This sub-wavelength displacement of the image of the source should be amenable to experimental observation with contemporary nanoscale-precision techniques.

关键词： Atoms Electric dipole moments Flow patterns Nanotechnology Vortex flow

The Biochemical Impact by Covalent Shielding of the Anionic Oxygen of the Phosphate Group in DNA and RNA as Methylated Phosphotriester Linkage on the Inhibition of DNA Duplication and on HIV-1 RNA Viral Infectivity Has Been Seriously Overlooked

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Journal of Biophysical Chemistry 2023年第2期14卷 59-66页

作者： henk M. Buck Kasteel Twikkelerf 94 Tilburg The Netherlands

With the help of model experiments, we are able to offer a detailed proposal for the inhibition of DNA duplication and no inhibition of RNA viral infectivity. As a backbone, we introduced methyl phosphotriester (MPTE). Duplex formation according to the traditional Watson and Crick base-pairing: [(MPTE)n−1 DNA] * DNA and [(MPTE)n−1 DNA] * RNA, where n = number of DNA and RNA bases. However, in the latter case, inhibition is obtained by reduction of the number of MPTE linkages, as is confirmed with model experiments and under biological conditions with micro (mi)RNA substrates. The latter results have recently been published. One or more single MPTEs are disseminated over different places of DNA without neighbour MPTEs (Prof. Wen-Yih Chen and his group, Taiwan).

关键词： Methylated Phosphotriester (MPTE) DNA Partially MPTE DNA Model Inhibition Experiments Micro (mi)RNA HIV-1 RNA Conformational Transition