地铁车辆段“造地养铁”一体化开发模式研究

从地铁车辆段用地的组成和特点出发,针对不同部分的开发手段归纳出地铁车辆段“造地养铁”的一体化开发的趋势,同时结合目前地铁车辆段开发中存在的现实问题,研究地铁车辆段用地一体化开发策略,寻求未来地铁车辆段一体化开发的新思路。

中国铁路的诞生

鸦片战争前后,有关铁路、火车的知识开始由一些洋教士传入中国.但中国人在当时只是以好奇的眼光来看待大洋彼岸传过来的东西,清王朝妄自尊大,闭关自守,把外国传入的先进技术一概斥之为“夷人之术”、“奇技淫巧”而拒之于门外.但在当时,以中国为“中心”的观念在一些开眼看世界的中国人心目中已发生动摇。

Dry sliding wear behavior of rheocast hypereutectic Al-Si alloys with different Fe contents

The effect of iron content on wear behavior of hypereutectic Al?17Si?2Cu?1Ni alloy produced by rheocasting process was investigated. The dry sliding wear tests were carried out with a pin-on-disk wear tester. The results show that the wear rate of the rheocast alloy is lower than that of the alloy produced by conventional casting process under the same applied load. The fine particle-likeδ-Al4(Fe,Mn)Si2 and polygonalα-Al15(Fe,Mn)3Si2 phases help to improve the wear resistance of rheocast alloys. As the volume fraction of fine Fe-bearing compounds increases, the wear rate of the rheocast alloy decreases. Moreover, the wear rate of rheocast alloy increases with the increase of applied load from 50 to 200 N. For the rheocast alloy with 3% Fe, oxidation wear is the main mechanism at low applied load (50 N). At higher applied loads, a combination of delamination and oxidation wear is the dominant wear mechanism.

Effect of casting vacuum on thermodynamic and corrosion properties of Fe-based glassy alloy

The effect of casting vacuum on thermodynamic and corrosion properties of Fe61Co7Zr8Mo5W2B17 in shape of cylinder of 3 mm in diameter and ribbon of 20?40μm in thickness and 2?3 mm in width were investigated with X-ray diffraction (XRD), differential scanning calorimetry (DSC), dilatometer (DIL), scanning electron microscopy (SEM) and electrochemical station. It is found that high casting vacuum can improve the glass forming ability (GFA), the contraction degree during heating, and the pitting resistance of the glassy alloy, which can be ascribed to the fact that the dissolution of tungsten in the melt is improved under the high casting vacuum.

Recovery of Fe,V,and Ti in modified Ti-bearing blast furnace slag

A two-stage oxidation—alkali leaching—acid leaching method was proposed to recovery Fe,V,and Ti in modified Ti-bearing blast furnace slag.The optimal experiment conditions of iron extraction were one-stage oxidation time 40 s and holding time 8 min.The recovery rate of iron was 89.93%.The optimum experiment conditions of vanadium extraction were total oxidation time of 126 s,NaOH concentration of 4.0 mol/L,leaching temperature of 95℃,leaching time of 90 min,and the number of cycle was 4.The leaching rate of vanadium was 92.13%.The optimal experiment conditions of titanium extraction were HCl concentration of 4.5 mol/L,leaching temperature of 75℃,and leaching time of 90 min.The TiO_(2)content of synthetic rutile was 98.61%.

Oxidation and roasting characteristics of artificial magnetite pellets

Compared with natural magnetite concentrate, artificial magnetite with more lattice defects and higher activity tends to be oxidized. And the artificial magnetite pellet at the temperature of 400℃ has the oxidation degree approaching to natural magnetite concentrate pellet fired at 1000℃. Besides, two kinds of pellets displayed quite different roasting characteristics. When preheated at the same temperature for the same period of time, natural magnetite concentrate pellet and artificial magnetite concentrate pellet need to be roasted at the temperature of 1100℃ and 1250℃, respectively, for 25 min to reach the compressive strength of 3000 N per pellet. When roasted at the same temperature of 1200℃, natural magnetite pellet and artificial magnetite pellet need to be roasted for 15 min and 30 min, respectively, to reach the compressive strength over 3000 N per pellet. It can be seen from the test that artificial magnetite pellet has a faster oxidation, resulting in the high porosity in the produced pellet, and it requires a roasting process at higher temperature for a longer time to reach the desired compressive strength for industrial production.

Microstructure and properties of high silicon aluminum alloy with 2% Fe prepared by rheo-casting

The morphology changes of both Fe-containing intermetallic compounds and the primary Si phase of Al-20Si-2Fe- 2Cu-0.4Mg-1.0Ni-0.5Mn （mass fraction, %） alloy produced by semi-solid rheo-diecasting were studied. The semi-solid slurry of high silicon aluminum alloy was prepared by direct ultrasonic vibration （DUV） which was imposed on the alloy near the liquidus temperature for about 2 rain. Then, standard test samples of 6.4 mm in diameter were formed by semi-solid rheo-diecasting. The results show that the DUV treatment suppresses the formation of needle-like ,β-Al5（Fe,Mn）Si phase, and the Fe-containing intermetallic compounds exist in the form of fine Al4（Fe, Mn）Si2 particles. Additionally, the primary Si grows up as fine and round particles with uniform distribution in α（Al） matrix of this alloy under DUV treatment. The tensile strengths of the samples at the room temperature and 573 K are 230 MPa and 145 MPa, respectively. The coefficient of thermal expansion （CTE） between 25 ℃ and 300 ℃ is 16.052 8×10^-6 ℃^-1, and the wear rate is 1.55%. The hardness of this alloy with 2% Fe reaches HB146.3. It is discovered that modified morphology and uniform distribution of the Fe-containing intermetallic compounds and the primary Si phase are the main reasons for reducing the CTE and increasing the wear resistance of this alloy.

Ecologically Inspired Water Network Optimization of Steel Manufacture Using Constructed Wetlands as a Wastewater Treatment Process

Traditional optimization models often lack a systems-level perspective at conception, which limits their effectiveness. Expanding system boundaries allow scientists and engineers to model complex interactions more accurately, leading to higher efficiency and profitability in industrial systems. Ecological systems have evolved for billions of years under conditions of material and energy shortage, and ecologists have defined analysis tools and metrics for identifying important principles. These principles may provide the framework to circumvent the limitations of traditional optimization techniques. More specifically, by recruiting functional roles that are often found in ecological systems, but are absent in industrial systems, industries can better mimic how natural systems organize themselves. The objective of this analysis is to traditionally optimize a manufacturing process by comparing the model with ecological and resource-based performance metrics in order to redesign the model with the addition of important functional roles that are found throughout nature. Industry partners provided data for this analysis, which involved building a water network for an existing steel manufacturing facility in China. The results of the traditional optimization model indicate a 23%, 29%, and 20% decline in freshwater consumption, wastewater discharge, and total annual cost, respectively. However, our ecologically inspired optimization model provides an additional 21% and 25% decline in freshwater consumption and total annual cost, respectively. Furthermore, no water is discharged. These results suggest that this unconventional approach to optimization could provide an effective technique not used by existing algorithms to solve the challenging problem of pursuing more sustainable industrial systems.

Mobility of Arsenic and Heavy Metals in a Sandy-Loam Textured and Carbonated Soil

The continued effect of the pyrite-tailing oxidation on the mobility of arsenic, lead, zinc, cadmium, and copper was studied in a carbonated soil under natural conditions, with the experimental plot preserved with a layer of tailing covering the soil during three years. The experimental area is located in Southern Spain and was affected by a pyrite-mine spill. The climate in the area is typically Mediterranean, which determines the rate of soil alteration and element mobility. The intense alteration processes that occurred in the soil during three years caused important changes in its morphology and a strong degradation of the main soil properties. In this period, lead concentrated in the first 5 mm of the soil, with concentrations higher than 1500 mg kg?1, mainly associated to the neoformation of plumbojarosite. Arsenic was partially leached from the first 5 mm and mainly concentrated between 5–10 mm in the soil, with maximum values of 1239 mg kg-1; the retention of arsenates was related to the neoformation of iron hydroxysulfates (jarosite, schwertmannite) and oxyhydroxides (goethite, ferrihydrite), both with a variable degree of crystallinity. The mobility of Zn, Cd, and Cu was highly affected by pH, producing a stronger leaching in depth; their retention was related to the forms of precipitated aluminium and, in the case of Cu, also to the neoformation of hydroxysulfate.

Influences of copper on solidification structure and hardening behavior of high chromium cast irons

The influences of copper on microstructure and the hardening behavior of high chromium cast irons subjected to sub-critical treatment were investigated. The results show that the microstructure of the as-cast high chromium cast irons consists of retained austenite, martensite and M1C3 type eutectic carbide. When copper is added into high chromium cast irons, austenite and carbide contents are increased. The increased addition of copper content from 0% to 1.84% leads to the increase of austenite and carbide from 15.9% and 20. 0% to 61.0% and 35.5% , respectively. In the process of sub-critical treatment, the retained austenite in the matrix can be precipitated into secondary carbides and then transforms into martensite in cooling process, which causes the secondary hardening of the alloy under sub-critical treatment. High chromium cast irons containing copper in sub-critical treatment appear the second hardening curve peak due to the precipitation of copper from supersaturated matrix.

Dynamic Performance Test and Estimation of Reinforcement Effect on a Workshop after Column-Cut Supported by Joist

The reinforcement effect of a reconstruction scheme for a steel factory building was investigated using finite element method and dynamic performance test. The workshop concerned is a portal frame structure with four spans and two slope roofs, of which ten columns need cutting for expanding span. The design and reconstruction project of column-cut supported by joist were introduced, which includes column reinforcement, connection rebuilding between brackets and crane beams, and the changing of rigid joint into hinge joint. The construction scheme was put forward in the light of the characteristics of the reinforcement and reconstruction. Spot test of dynamic performance on the workshop and comparison with theoretical analysis results show that the column-cut supported by joist design is effective and the reconstruction project is successful.

Structural Retrofitting of Old Illyria Hote

Illyria hotel （formerly Bozhur） was built during the sixties in the heart of the actual Kosovo＇s capital Prishtina, according to former old Yugoslav standards in a Modernist architectural style. It represents a massive structural system with brick walls up to 54 cm thick and ＂avramenko＂ type reinforced concrete floors. The investor＇s aim was to add another two floors on the top of the existing ones and to build two level underground parking floors, a health spa centre, whilst at the vicinity of the existing building （the northern side） to erect a new 17 story-high brand new hotel and administration building. The retrofitting of the structure as well as construction of the new structure has been done in full accordance with the new structural Eurocodes＇ recommendations. 3D FEM （finite element method） modeling was used for the analysis and design, using ETABS v 9.5 nonlinear and ARSAP 2010 （Autodesk Robot Structural Analysis Professional 2010）. Response spectrum design according to EC 8,3.2.2.4 has been used for seismic analysis and design with a reference peak ground acceleration on type A ground Of AgR = 0.25 g.

Development of Ferroelectric RAM （FRAM） for Mass Production

we have developed ferroelectric capacitor fabrication technique to realize low-voltage and high-density ferroelectric random access memory （FRAM）. High temperature deposited IrOxtop electrode reveals high crystalline quality which drastically reduces the degradation of ferroelectric film by preventing hydrogen diffusion into ferroelectric film. This improvement enables us to commercialize highly-reliable 1T 1C FRAM with memory density of 4 Mb or larger.

钢铁工业能耗高的原因与节能对策

钢铁工业是我国主要耗能部门.粉碎“四人帮”后,我国钢铁战线广大职工在节能方面做了不少工作,平均每吨钢能耗由一九七六年3.1吨标准煤降到一九七九年2.28吨标准煤.但是.与主要产钢国家比较,我国钢铁工业的能耗是很高的.一九七八年苏联平均每吨钢耗0.96吨标准煤.美国0.9吨,西德0.75吨,日本0.

先秦时期的生产力和土地制度

李学勤研究员最近在讲授先秦经济史时指出,越来越多的考古材料证明,过去我们对先秦时期生产力水平的估计是偏低的。拿金属工具来说,过去认为直到战国时期才开始用铁,近年来已经发现了春秋早期和中期的铁器和晚期的钢。用生铁和钢来铸造铁器,我国要比西方先进一千多年。铜器的起源就更早了。商代的青铜冶炼技术已经达到了相当高的水平。从考古发掘中,我们还发现了不少东周的青铜农具。在江、浙、皖一带发现的青铜农具多出于废料坑,更说明象这样的工具当时已不稀罕了。