检索结果-南通市图书馆

Simultaneous approach for simulation of a high-temperature gas-cooled reactor

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第7期12卷 567-574页

作者： Yang CHEN Jiang-hong YOU zhi-jiang SHAO ke-xin wang Ji-xin QIAN State key Laboratory of Industrial Control Technology Zhejiang University Hangzhou 310027 China

The simulation of a high-temperature gas-cooled reactor pebble-bed module(HTR-PM) plant is *** lumped parameter model has the form of a set differential algebraic equations(DAEs) that include stiff equations to model point neutron *** nested approach is the most common method to solve DAE,but this approach is very expensive and time-consuming due to inner *** paper deals with an alternative approach in which a simultaneous solution method is *** DAEs are discretized over a time horizon using collocation on finite elements,and Radau collocation points are *** resulting nonlinear algebraic equations can be solved by existing *** discrete algorithm is discussed in detail;both accuracy and stability issues are ***,the simulation results are presented to validate the efficiency and accuracy of the simultaneous approach that takes much less time than the nested one.

关键词： Differential algebraic equations(DAEs) High-temperature gas-cooled reactor(HTR) Simulation Simultaneous approach

Möbius Disjointness for Distal Flows in Short Intervals

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2022年第9期38卷 1512-1522页

作者： ke wang Data Science Institute Shandong UniversityJinan 250100P.R.China

We prove the M?bius disjointness conjecture in short intervals for a class of skew products on the 2-torus,which includes Furstenberg’s example of irregular flows.

关键词： M?bius disjointness exponential sums

A new sesquilignan from Selaginella sinensis (Desv.) Spring

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2007年第10期18卷 1224-1226页

作者： Yan zhi wang Hui Chen Xiao ke Zheng Wei Sheng Feng Henan College of Traditional Chinese Medicine Zhengzhou 450008 China

A new sesquilignan, namely sinensiol A, was isolated from the plant of Selaginella sinensis （Desv.） Spring. Its structure was identified on the basis of various spectroscopic data analysis.

关键词： Selaginella sinensis, Sinonsiol A Sesquilignan

An efficient method for the synthesis of dialkyl chlorophosphates from trialkyl phosphites using bis(trichloromethyl)carbonate

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2008年第8期19卷 904-906页

作者： Bo wang Chuan Ming Yu zhi Wei Chen Wei ke Su College of Pharmaceutical Sciences Zhejiang University of Technology Zhejiang Key Laboratory of Pharmaceutical Engineering Hangzhou 310014 China

A mild and simple method for the synthesis of dialkyl chlorophosphates is described, bis（trichloromethyl） carbonate （BTC） is used as the effective reagent for the conversion of dialkyl phosphites to their correspo... 详细信息

关键词： Bis(trichloromethyl) carbonate Dialkyl chlorophosphate Tdalkyl phosphite Synthesis

Effects of annealing temperature on microstructure and properties of tailor-rolled blank of medium-manganese steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2020年第8期27卷 933-939页

作者： Ying zhi Di-wen ke Xiang-hua Liu zhi-xin Feng State key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina School of Materials Science and Engineering Northeastern UniversityShenyang 110819LiaoningChina

The microstructure and mechanical properties of tailor-rolled blank (TRB) of medium-manganese steel during annealing were investigated. The annealing process of austenite-reverted transformation of the experimental steel was formulated. The effects of different morphologies on properties with different annealing temperatures in different thickness zones of TRB were analyzed. In the thin zone, the morphology is blocky, and in the thick zone, the morphology is lamellar. At the same annealing temperature, the tensile strength of the thick zone is lower than that of the thin zone, and the elongation and product of strength and elongation (PSE) of the thick zone are higher than those of the thin zone. With the increase in annealing temperature, the tensile strength increases, while the yield strength, the elongation and the PSE all decrease in the same thickness zone. Because the stability of lamellar austenite is higher than that of blocky austenite, the comprehensive mechanical properties in the thick zone are good. At the annealing temperature of 640 ℃, the experimental steel has the best comprehensive mechanical properties, and the maximum PSE is more than 40.0 GPa% in different thickness zones. Particularly, PSE is up to 45.6 GPa% in the thickness zone of 2.0 mm.

关键词： Tailor-rolled blank Medium-manganese steel Annealing temperature Austenite-reverted transformation Product of strength and elongation

Morphological analysis of Rhynchospio ***(Annelida:Spionidae)and comments on the phylogeny and reproduction of the family Spionidae

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 Oceanology and Limnology 2022年第3期40卷 1257-1276页

作者： zhi wang Ting XU Jian-Wen QIU Yinglu JI Zishan YU Caihuan ke State key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361102China Department of Ocean Science and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Hong Kong University of Science and TechnologyHong Kong 999077China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Department of Biology and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Hong Kong Baptist UniversityHong Kong 999077China North China Sea Marine Forecasting Center of State Oceanic Administration Qingdao 266061China College of Marine Life Sciences Ocean University of ChinaQingdao 266003China

The genus Rhynchospio has fronto-lateral horns on prostomium,paired branchiae from chaetiger 2 to near the posterior end,capillary notochaetae only,and more than two pairs of pygidial *** species are common in coastal soft bottom communities;nevertheless,many recorded Rhynchospio specimens around the world are currently *** we described a Rhynchospio species based on specimens collected from Qingdao,*** with the reported DNA sequences of four gene markers(16S rRNA,18S rRNA,28S rRNA,and Histone H3)and brief morphological description of specimens collected from Jinhae Bay,South Korea,previously reported as Rhynchospio ***,indicated that they are ***,specimens of *** from Qingdao are characterized by having neuropodial hooded hooks from chaetigers 14–17(vs.10–23 in ***)to near pygidial chaetigers,sperm from chaetiger 11 to 14(*** chaetiger 11 to 21–22 in ***),oocytes from chaetigers 16–17 to 26–39(*** 22–24 in ***),and 4–6(*** to 6 in ***)pygidial ***,Rhynchospio *** is most closely related to *** Hartman,1936 from California,USA with the interspecific distances of 20.02%(16S rRNA),4.50%(18S rRNA),8.44%(28S rRNA),2.74%(Histone H3),and 6.10%(concatenated sequences).Water flow across the dorsum created by ciliary beating of the branchiae and nototrochs,observed on live specimens,may help transport gametes from reproductive segments in anterior and middle parts to the posterior brooding *** trees based on concatenated sequences of four gene markers of 54 spioniform species in 25 genera revealed two clades,covering the two subfamilies Spioninae and Nerininae *** families(i.e.,Poecilochaetidae and Trochochaetidae)in the order Spionida were clustered within Spionidae,supporting a morphology-based proposal that these families bearing a pair of prehensile,grooved palps should be grouped within a

关键词： Annelida phylogeny taxonomy Yellow Sea

Application of transparent casting moulds prepared by additive manufacturing technology in hydraulic simulation

在线全文

学校读者我要写书评

暂无评论

China Foundry 2022年第4期19卷 299-306页

作者： Qian Feng Xing Ran ke-hui Hu Hao-yuan wang zhi-gang Lü State key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China AVIC Heavy Machinery Co. Ltd.Guiyang 550005China key Laboratory of Advanced Materials Processing Technology Ministry of EducationTsinghua UniversityBeijing 100084China

Hydraulic simulation is one of the critical methods to research the filling mechanism of molten metal in the casting ***,it only performs on test pieces with relatively simple structures due to the limitation of the preparation *** this study,the method of photocuring additive manufacturing was used to prepare the complex casting mould from transparent photosensitive *** pouring test was carried out under different centrifugal conditions,and the filling process of the gating system,support bars and other positions in the vertical direction was recorded and *** experimental results show that the internal liquid level and the filling process of the test piece prepared by this method can be observed *** angle between the liquid surface and the horizontal plane in the test piece gradually increases as the centrifugal rotational speed increases,which means the filling process is carried out from outside to inside at high rotational *** velocity of the fluid entering the runner increases with the increase of rotational speed,but the filling speeds is less affected by the centrifugal speed at other *** liquid flow is continuous and stable during the forward filling process,without splashing or interruption of liquid droplets.

关键词： additive manufacturing centrifugal casting investment casting hydraulic simulation transparent mould

Experimental study and cellular automaton simulation on solidification microstructure of Mg-Gd-Y-Zr alloy

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2021年第1期40卷 128-136页

作者： Xu-Yang wang Fei-Fan wang ke-Yan Wu Xian-Fei wang Lv Xiao Zhong-Quan Li zhi-Qiang Han School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China key Laboratory for Advanced Materials Processing Technology(Ministry of Education) Tsinghua UniversityBeijing 100084China Shanghai Spaceflight Precision Machinery Institute Shanghai 201600China

The solidification microstructure of Mg-Gd-YZr alloy was investigated via an experimental study and cellular automaton(CA)*** this study,stepshaped castings were produced,and the temperature variation inside the casting was recorded using thermocouples during the solidification *** effects of the cooling rate and Zr content on the grain size of the Mg-Gd-Y-Zr alloy were *** results showed that the grain size decreased with an increase in the cooling rate and Zr *** on the experimental data,a quantitative model for calculating the heterogeneous nucleation rate was developed,and the model parameters were *** evolution of the solidification microstructure was simulated using the CA method,where the quantitative nucleation model was used and a solute partition ceoefficient was introduced to deal with the solute trapping in front of the solid-liquid(S/L)*** simulation results of the grain size were in good agreement with the experimental *** simulation also showed that the fraction of the eutectics decreased with an increasing cooling rate in the range of 2.6-11.0℃·s^(-1),which was verified indirectly by the experimental data.

关键词： Solidification microstructure Mg-Gd-Y-Zr alloy Cooling rate Zr content Nucleation Cellular automaton

Effect of artificial tribological layer on sliding wear behavior of H13 steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2017年第9期24卷 943-949页

作者： Zhen Cao Shu-qi wang ke-zhi Huang Bo Zhang Guo-hong Wen Qiu-yang Zhang Lan wang School of Material Science and Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

An artificial tribological layer was formed on the worn surface during sliding,through supplying MoS_2,Fe_2O_3 or their equiponderant mixtures onto the sliding interface of H13/GCr15 *** effect of this tribological layer on the wear behavior of H13 steel was *** worn surfaces and subsurfaces of H13 steel were thoroughly characterized by using X-ray diffraction（XRD）,scanning electron microscopy（SEM）and energy dispersive spectrometry（EDS）;the wear mechanisms were *** research results demonstrated that tribological layer did not exist during sliding of H13 steel with no additive,but it formed with the addition of MoS_2,Fe_2O_3 or their equiponderant *** there was no tribological layer,the wear rate rapidly increased with an increase of the *** this case,adhesive and abrasive wear *** the additives were supplied,the artificial tribological layer was observed to be immediately formed and stably existed on worn *** tribological layer presented an obvious protective function from wear and ***,the wear rate and friction coefficient were significantly ***_2 as tribological layer seemed to present more obvious protective function than Fe_2O_*** supplying their mixture,the artificial tribological layer possessed not only the load-carrying capacity of Fe_2O_3,but also the lubricative capacity of MoS_*** two simultaneous capacities could improve the friction and wear properties of H13 steel further.

关键词： H13 steel Artificial tribological layer Wear behavior Wear mechanism