检索结果-南通市图书馆

An Analytical Solution for Wave Transformation Over Axi-Symmetric Topography

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2019年第6期33卷 694-703页

作者： CUONG San Sieu CHANG Jen-Yi TSAI Chia-Cheng CHOU wan-rong aInstitute of Oceanography National Taiwan UniversityTaipei 10617China Tainan University of Technology Tainan 71002China Department of Marine Environmental Engineering National Kaohsiung University of Science and TechnologyKaohsiung 81164China Department of Marine Environment and Engineering National Sun Yat-Sen UniversityKaohsiung 80424China Department of Hydraulic and Ocean Engineering National Cheng Kung UniversityTainan 701China

The present study considers wave scattering phenomena around a cylindrical island mounted on a general axisymmetric topography or a general submerged truncated axi-symmetric shoal based on the mild-slope equation. The method of separation of variables and Taylor series expansion are invoked to find the approximate solution to the variable water depth region which varies proportionally to an arbitrary power of radial distance. Validations against the solutions for the combined wave refraction and diffraction around a cylindrical island mounted on a paraboloidal shoal of Liu et al. in 2004 and the scattering and trapping of wave energy by a submerged truncated paraboloidal shoal of Lin and Liu in 2007 show excellent agreements as the power of radial distance being equal to two. For the solutions of wave refraction and diffraction around a cylindrical island mounted on a shoal with depth proportionally to an arbitrary power of radial distance, good agreements with Zhai et al.’s(2013) solutions are demonstrated. Since the robustness of the assumption of a general axi-symmetric geometry based on an arbitrary power variability of the radial distance, the present solution can be very conveniently employed to investigate the effects of bottom topography on wave scattering and trapping patterns.

关键词： general axi-symmetric topography mild-slope equation submerged truncated shoal wave refraction wave diffraction

Analysis of Oxides Formed on the Surface of the Alloy 690 in Hydrogenated Supercritical Water

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2016年第8期29卷 774-781页

作者： Jin Gao Fa-rong wan Guo-ping Cao Kumar Sridharan Todd Allen School of Materials Science and Engineering University of Science and Technology Beijing Department of Materials Science and Engineering University of Wisconsin-Madison

The oxides formed on the surface of the alloy 690 in hydrogenated supercritical water at 400℃ for 1000 h were investigated using scanning electron microscopy,transmission electron microscopy,scanning transmission electron microscopy and energy-dispersive X-ray *** oxides on me surface of the alloy 690 exhibited multi-layer structure：an outer layer consisted of granular crystallites（NiO and NiFe_2O_4） and a compact inner layer（spinel and Cr_2O_3）.Chemical analysis indicated that the outer layer was enriched in nickel but depleted in chromium,whereas the inner layer was enriched in chromium and iron but depleted in *** inner layer was also characterized as layered structure by Fe-rich spinel on top of continuous Cr_2O_3 ***,Cr_2O_3 nodules were readily observed at the oxides/alloy interface.

关键词： Alloy 690 Supercritical water Oxides Corrosion

Characteristics of the recirculation zone in a cylindrical confined space and its suppression by an annular orifice plate

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2023年第8期16卷 1391-1408页

作者： Yu Zhou wan-rong Ren Mengfan Quan Lei Jia Manning wang Yi wang State Key Laboratory of Green Building in Western China Xi'an University of Architecture and TechnologyXi'an 710055China School of Building Services Science and Engineering Xi’an University of Architecture and TechnologyNo.13 Yanta RD.Xi’an 710055China

The accumulation of pollutants in the recirculation zone can worsen *** is critical to reduce recirculation zones to improve the ventilation efficiency of ***,the variation rule of the recirculation zone in a cylindrical confined space(CCS)is unclear,and there are few solutions to suppress or eliminate the recirculation zone at *** this paper,an annular deflector orifice plate for suppressing the recirculation zone was developed based on the structural characteristics of the *** device is simple in structure and can be used *** experiments and numerical simulations,the variation rule of the recirculation zone length and the influence of structural parameters of the device on the vortex suppression were ***,empirical formulas for calculating the length of the recirculation zone in the CCS were *** addition,it was proved that placing the annular orifice plate inside the CCS effectively reduced the recirculation zone and improved the ventilation *** to the system without the annular orifice plate,the dimensionless length of the recirculation zone was decreased by 76.3%,and the time to completely discharge the pollutants from the CCS was decreased by 16.7%.Finally,parameters of the annular orifice plate that form the best vortex suppression effect were proposed:the porosity range was 40%–50%,uniform in shape with equal ring spacing,and placed more than one inlet diameter away from the *** results help guide the ventilation design of CCS.

关键词： cylindrical confined space recirculation zone vortex suppression orifice plate

Adaptive Radio Frequency Interference Mitigation for HF Surface Wave Radar

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

Wuhan University Journal of Natural Sciences 2005年第5期10卷 851-854页

作者： wan Xian-rong KE Heng-yu CHENG Feng School of Electronic Information Wuhan University Wuhan 430072 Hubei China

The paper analyses the characteristics of radio frequency interference （RFI） in HF surface wave radar （HFSWR） which adopts the linear frequency modulated interrupted continuous wave （FMICW）. RFI will influence all the range cells including all the positive frequency and negative frequency, and the negative frequency range cells contain only the interference information. Based on the above characteristics, we introduce and analyze a new adaptive interference mitigation beamforming algorithm using the negative frequency range cells samples to estimate the interference covariance matrix. Experimental results confirm that this general and robust algorithm can achieve effective RFI suppression using the data recorded by the HFSWR, located near Zhoushan in Zhejiang China.

关键词： HF surface wave radar array signal processing adaptive beamforming

Two-Dimensional Numerical Simulation of Flow Around Three-Stranded Rope

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2016年第4期15卷 627-636页

作者： wanG Xinxin wan rong HUANG Liuyi ZHAO Fenfang SUN Peng Laboratory of Fisheries Engineering Fisheries College Ocean University of China National Engineering Research Centre for Oceanic Fisheries Shanghai Ocean University

Three-stranded rope is widely used in fishing gear and mooring system. Results of numerical simulation are presented for flow around a three-stranded rope in uniform flow. The simulation was carried out to study the hydrodynamic characteristics of pressure and velocity fields of steady incompressible laminar and turbulent wakes behind a three-stranded rope. A three-cylinder configuration and single circular cylinder configuration are used to model the three-stranded rope in the two-dimensional simulation. The governing equations, Navier-Stokes equations, are solved by using two-dimensional finite volume method. The turbulence flow is simulated using Standard κ-ε model and Shear-Stress Transport κ-ω(SST) model. The drag of the three-cylinder model and single cylinder model is calculated for different Reynolds numbers by using control volume analysis method. The pressure coefficient is also calculated for the turbulent model and laminar model based on the control surface method. From the comparison of the drag coefficient and the pressure of the single cylinder and three-cylinder models, it is found that the drag coefficients of the three-cylinder model are generally 1.3–1.5 times those of the single circular cylinder for different Reynolds numbers. Comparing the numerical results with water tank test data, the results of the three-cylinder model are closer to the experiment results than the single cylinder model results.

关键词： cylinder turbulent Reynolds turbulence laminar circular hydrodynamic governing incompressible Navier

Axial intensity in a fiber-optic confocal microscope

在线全文

学校读者我要写书评

暂无评论

光学精密工程 2005年第5期13卷 608-612页

作者： LIU Yong CHEN Jia-bi REN Qiu-shi wanG Cheng LI wan-rong Optical and Electronic Information Engineering College University of Shanghai for Science ＆ Technology Shanghai 200093 China Institute for Laser Medicine ＆ Bio-photonics Shanghai Jiaotong University Shanghai 200030China

A fiber-optic confocal microscope has been analyzed by Fourier *** is found that the detected light intensity has three parts,each of which is depennted on the coupled lens,the detective lens,and the part comprised of the fiber and the *** simulated results show that the less the value of the parameter A is,which is dependent on the fiber and microprobe,the higher the axial resolution of the system is. For the case,as A→∞, the axial resolution is zero,which is corresponding to the conventional *** A≤1,the axial resolution changes slightly,and is close to the optimal value,which is corresponding to the perfect confocal *** the reflective loss takes place at the end of fiber,the contrast of axial intensity will *** that will help the design of endoscope with confocal microscope at cellular level.

关键词：光纤轴向分析亮度显微镜

Generation of cloned calves from different types of somatic cells

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2004年第5期47卷 470-476页

作者： GONG Guochun DAI Yunping ZHU Huabing wanG Haiping wanG Lili LI rong wan rong LIU Ying LI Ning State Key Laboratory for Agrobiotechnology China Agricultural UniversityBeijing 100094China Institute of Animal Science Chinese Academy of Agricultural ScienceBeijing 100094China

Six types of bovine somatic cell lines, including a granulosa cell line of Chinese red-breed yellow cattle (YGR), a granulosa cell line of Holstein cow (HGR), two skin fibroblast cell lines of two adult Holstein cows respectively (AFB1 and AFB2), a skin fibroblast cell line (FFB) and an oviduct epithelial cell line (FOV) of a Holstein fetus, were established. Somatic cell nu-clear transfer (SCNT) was carried out using these cells as nuclei donor, and a total of 12 healthy calves were cloned. The effects of different types of donor cells on developmental potential of bovine SCNT embryos were investigated. (i) There was no significant difference in development rates to the blastocyst stage for SCNT embryos from YGR and HGR (33.2% and 35.1%, respec-tively). Pregnancy rates of them were 33.3% and 30.2%, respectively; and birth rates were 16.7% and 11.6%, respectively. (ii) Development rates to the blastocyst stage for SCNT embryos from diffetent individuals (AFB1 and AFB2) differed significantly (27.9% and 39.4%, respectively, P <0.05). Pregnancy rates of them were 36.2% and 36.4%, respectively; and birth rates were 14.9 % and 27.3%, respectively. (iii) There was significant difference in development rates to the blastocyst stage for SCNT embryos from FFB and FOV of the same fetus (37.9% and 41.5%, respectively, P < 0.05). Pregnancy rates of them were 45.7% and 24.1%, respectively; and birth rates were 22.9 % and 10.3%, respectively. Finally, developmental potential of bovine SCNT embryos from all four types of somatic cells from Holstein cows (HGR, AFB, FFB and FOV) were compared. For in vitro development stage, development rates to the blastocyst stage for SCNT embryos from HGR, AFB, FFB and FOV were 35.1%A, 29.4%B, 37.9%A and 41.5%C, respectively (PABC<0.05); for in vivo development stage, pregnancy rates of them were 30.2%, 36.2%, 45.7% and 24.1%, respectively; and birth rates of them were 11.6%, 17.2%, 22.9% and 10.3% respec-tively.

关键词： nuclear transfer somatic cells bovine

Optimization of stratification scheme for a fishery-independent survey with multiple objectives

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2015年第12期34卷 154-169页

作者： XU Binduo REN Yiping CHEN Yong XUE Ying ZHANG Chongliang wan rong College of Fisheries Ocean University of China School of Marine Sciences University of Maine Laboratory for Marine Fisheries and Aquaculture Qingdao National Laboratory for Marine Science and Technology

Fishery-independent surveys are often used for collecting high quality biological and ecological data to support fisheries management. A careful optimization of fishery-independent survey design is necessary to improve the precision of survey estimates with cost-effective sampling efforts. We developed a simulation approach to evaluate and optimize the stratification scheme for a fishery-independent survey with multiple goals including estimation of abundance indices of individual species and species diversity indices. We compared the performances of the sampling designs with different stratification schemes for different goals over different months. Gains in precision of survey estimates from the stratification schemes were acquired compared to simple random sampling design for most indices. The stratification scheme with five strata performed the best. This study showed that the loss of precision of survey estimates due to the reduction of sampling efforts could be compensated by improved stratification schemes, which would reduce the cost and negative impacts of survey trawling on those species with low abundance in the fishery-independent survey. This study also suggests that optimization of a survey design differed with different survey objectives. A post-survey analysis can improve the stratification scheme of fishery-independent survey designs.

关键词： fishery-independent survey optimization stratified random sampling stratification scheme computer simulation

Effects of nitrogen fertilizer and chemical regulation on spring maize lodging characteristics, grain filling and yield formation under high planting density in Heilongjiang Province, China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2021年第2期20卷 511-526页

作者： LIU Xiao-ming GU wan-rong LI Cong-feng LI Jing WEI Shi College of Agronomy Northeast Agricultural UniversityHarbin 150030P.R.China Institute of Crop Sciences Chinese Academy of Agricultural SciencesBeijing 100081P.R.China

Now,lodging is a major constraint factor contributing to yield loss of maize (Zea mays L.) under high planting *** regulation and nitrogen fertilizer could effectively coordinate the relationship between stem lodging and maize yield,which significantly reduce lodging and improve the grain *** purpose of this study was to explore the effects of chemical regulation and different nitrogen application rates on lodging characteristics,grain filling and yield of maize under high *** this,we established a field study during 2017 and 2018 growing seasons,with three nitrogen levels of N100 (100 kg ha^(–1)),N200 (200 kg ha^(–1)) and N300 (300 kg ha^(–1)) at high planting density (90 000 plants ha^(–1)),and applied plant growth regulator (Yuhuangjin,the mixture of 3% DTA-6 and 27% ethephon) at the 7th *** results showed that chemical control increased the activities of phenylalanine ammonia-lyase (PAL),tyrosine ammonia-lyase (TAL),4-coumarate:Co A ligase (4CL),and cinnamyl alcohol dehydrogenase (CAD),and increased the lignin,cellulose and hemicellulose contents at the bottom of the 3rd internode,which significantly reduced the lodging *** lignin-related enzyme activities,lignin,cellulose and hemicellulose contents decreased with the increase of nitrogen fertilizer,which significantly increased the lodging *** 200 kg ha^(–1) nitrogen application and chemical control increased the number,diameter,angle,volume,and dry weight of brace *** 200 kg ha^(–1) nitrogen application and chemical control significantly increased the activities of ADP-glucose pyrophosphorylase (AGPase),soluble starch synthase (SSS) and starch branching enzyme(SBE),which promoted the starch accumulation in ***,improved the maximum grain filling rate (V_(max)) and mean grain filling rate (V_(m)),which promoted the grain filling process,significantly increased grain weight and grain number per ear,thus increased the final yield.

关键词： lodging resistance grain filling starch synthesis yield maize