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71.
1 Engineering science and technology have become a major drive for China's economic and social development
In the hall of the Chinese Academy of Engineering (CAE), there is a couplet collectively created by members of the CAE, which describes the engineering technology developments in both ancient and modem China. The first line describes Chinese achievements of engineering technologies in ancient times, which reads: Tracing back the five-thousand- year Chinese history, countless engineering achievements shine through the course, including the Four Great Inventions of ancient China, the Nine Chapters on the Mathematical Art, Exploitation of the Works of Nature, Shennong' s researches and trying of hundreds of herbs, building arch bridges, excavating canals, clearing oozes and constructing dams, and building the Great Wall, extraordinary and unparalleled feats indeed! 相似文献
In the hall of the Chinese Academy of Engineering (CAE), there is a couplet collectively created by members of the CAE, which describes the engineering technology developments in both ancient and modem China. The first line describes Chinese achievements of engineering technologies in ancient times, which reads: Tracing back the five-thousand- year Chinese history, countless engineering achievements shine through the course, including the Four Great Inventions of ancient China, the Nine Chapters on the Mathematical Art, Exploitation of the Works of Nature, Shennong' s researches and trying of hundreds of herbs, building arch bridges, excavating canals, clearing oozes and constructing dams, and building the Great Wall, extraordinary and unparalleled feats indeed! 相似文献
72.
This paper proves a new regularity criterion ω: = rotu∈L1(0,T;B·0∞,∞) for the 3D generalized MHD system with fractional diffusion terms(-Δ)αu with α 〉9/8 and zero magnetic diffusivity. Here u is the fluid velocity,ω is the vorticity and B·0∞,∞is the homogeneous Besov space. 相似文献
73.
A finite reaction rate model is presented as a closure of large eddy simulation (LES) to numerically study an open premixed methane/air swirling flame. The resultant model is firstly validated by comparing with reported data and then employed to investigate the effect of swirling intensity on flow field, flame characteristics and combustion instability of the swirling flame. Three differ- ent swirl numbers are considered. The LES results show that as swirling intensity increases, the vortex entrainment and micro-mixing are enhanced, leading to more lean equivalent ratios at flame front; consequently, higher swirling number causes lower flame temperatures and slower CO oxidization; for all simulated swirl numbers, flame fronts are completely located out of the recirculation zones and anchored at the inner surface of the annular swirling steams; swirl number has a crucial effect on swirling flame extension toward radial and tangential dimensions and then significantly affects streamwise flame length, which is a great influencing factor on combustion instability; vortex-induced disturbance on flame in streamwise plays a critical role in combustion instability. 相似文献
74.
Computational diffusion kinetics and its applications in study and design of rare metallic materials
Computational diffusion kinetics(CDK),with a spirit of and being coupled with the computational thermodynamics(CT,or called as the CALPHAD technique),plays increasingly important role in the alloy design/optimization and microstructure control during the processing of advanced metallic materials.This paper is to highlight recent progress of CDK in research with great focus on novel Ti and Zr alloys,which was largely performed in the authors’group.It ends with one representative example of the applications of CDK,coupled with CT,quantitative phase field,and three-dimensional(3D)statistical calculation,in designing the heattreatment schedule for the dual phase(αβ)Ti–6Al–4V alloys. 相似文献
75.
A proteinaceous binding media for the polychrome terracotta army of Emperor Qin Shihuang has been identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS).Methods for the preparation of the model samples and the elimination of interferences have been evaluated,as well as ageing processes.A method involving the complexation of EDTA in combination with dialysis was used to eliminate any interference in the polychrome layers taken from the historical samples.The model samples were aged by being buried in loess to replicate the ageing process of the historical samples as closely as possible.The optimum conditions for the extraction and subsequent enzymatic hydrolysis of the extracted protein were investigated.Under the optimized conditions,the‘‘peptide mass fingerprints’’of the proteinaceous binding media from the historical and model samples were determined by MALDITOF-MS.The results revealed that animal glue was used as the binding media for the polychrome layers of Emperor Qin Shihuang’s terracotta army.It also shows that animal glue used as binding media has a long history in China. 相似文献
76.
S. Naddaf Dezfuli Zhigang Huan J.M.C. Mol M.A. Lee flang Jiang Chang Jie Zhou 《自然科学进展(英文版)》2014,24(5):531-538
The human body is a buffered environment where p H is effectively maintained. HEPES is a biological buffer often used to mimic the buffering activity of the body in in vitro studies on the degradation behavior of magnesium. However, the influence of HEPES on the degradation behavior of magnesium in the DMEM pseudo-physiological solution has not yet been determined. The research aimed at elucidating the degradation mechanisms of magnesium in DMEM with and without HEPES. The morphologies and compositions of surface layers formed during in vitro degradation tests for 15–3600 s were characterized. The effect of HEPES on the electrochemical behavior and corrosion tendency was determined by performing electrochemical tests. HEPES indeed retained the local p H, leading to intense intergranular/interparticle corrosion of magnesium made from powder and an increased degradation rate. This was attributed to an interconnected network of cracks formed at the original powder particle boundaries and grain boundaries in the surface layer, which provided pathways for the corrosive medium to interact continuously with the internal surfaces and promoted further dissolution. Surface analysis revealed significantly reduced amounts of precipitated calcium phosphates due to the buffering activity of HEPES so that magnesium became less well protected in the buffered environment. 相似文献
77.
Synthesis and optical properties of turquoise- and green-colored brownmillerite- type Ba2In2-x-yMnxAlyO5+x codoped with manganese and aluminum 下载免费PDF全文
Peng Jiang Wen-hui Yang Yun-cheng Zhou Jian-lei Kuang Yong Li Ting Xiao 《矿物冶金与材料学报》2016,23(11):1346-1351
Brownmillerite-type oxides Ba2In2-x-yMnxAlyO5+x (0 ≤ x ≤ 0.6, 0 ≤ y ≤ 0.5) were prepared at 1300°C through solid-state reaction. X-ray diffraction (XRD) analysis showed that the structure symmetry evolved from orthorhombic to cubic with increasing Mn and Al contents. When y was greater than 0.3, peaks associated with small amounts of BaAl2O4 and Ba2InAlO5 impurities were observed in the XRD patterns. When substituted with a small amount of Mn (x ≤ 0.3), the Ba2In2-x-yMnxAlyO5+x samples exhibited an intense turquoise color. The color changed to green and dark-green with increasing Mn concentration. UV–vis absorbance spectra revealed that the color changed only slightly upon Al doping. The valence state of Mn ions in Ba2In2-x-yMnxAlyO5+x was confirmed to be +5 on the basis of X-ray photoelectron spectroscopic analysis. According to this analysis, the intense turquoise color of the Ba2In2-x-yMnxAlyO5+x samples is rooted in the existence of Mn5+; thus, the introduction of Al does not affect the optical properties of the compounds. 相似文献
78.
Wenxing Cao Jiancheng Shu Jiaming Chen Zihan Li Songshan Zhou Shushu Liao Mengjun Chen Yong Yang 《矿物冶金与材料学报》2024,(3):531-538
Iron-rich electrolytic manganese residue (IREMR) is an industrial waste produced during the processing of electrolytic metal manganese,and it contains certain amounts of Fe and Mn resources and other heavy metals.In this study,the slurry electrolysis technique was used to recover high-purity Fe powder from IREMR.The effects of IREMR and H2SO4 mass ratio,current density,reaction temperature,and electrolytic time on the leaching and current efficiencies of Fe were studied.Acc... 相似文献
79.
Daixiang Wei Wei Wang Longjin Jiang Zhidong Chang Hualei Zhou Bin Dong Dekun Gao Minghui Zhang Chaofan Wu 《矿物冶金与材料学报》2024,(2):315-322
Lithium recovery from spent lithium-ion batteries(LIBs) have attracted extensive attention due to the skyrocketing price of lithium. The medium-temperature carbon reduction roasting was proposed to preferential selective extraction of lithium from spent LiCoO2(LCO) cathodes to overcome the incomplete recovery and loss of lithium during the recycling process. The LCO layered structure was destroyed and lithium was completely converted into water-soluble Li2CO3 und... 相似文献
80.
Chunlin Chen Tuping Zhou Jiayun Zhang Shoukun Wei Xingxiang Lu Meng Bai Jinhong Jiang 《矿物冶金与材料学报》1999,6(3):187-192
The so-called Goto's model was modified by introducing a parameter of the oxygen efficiency from industrial trials, as well as the selected and newly re-assessed thermodynamic data. The application of the model to copper converters in Guixi Smelter has been carried out by the combination of thermodynamic calculations with the mass and heat balance using the plant data obtained in industrial trials for many heats. For the slag-making stage, good agreements have been reached between the calculated and measured temperature, blowing time as well as the contents for main elements in the matte and the slag. Relatively large deviations for contents of Zn and Pb in the slag may be caused by the complex chemical composition of the real molten slag, which may result in a large difference of γzn. and γPb,adopted with their real values. It is noted that the model can simulate the slag-making stage of copper converting process in industrial Pierce-Smith converters well. 相似文献