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951.
952.
BT项目实施模式分析 总被引:1,自引:0,他引:1
根据实践中出现的各种BT项目管理模式,归纳出了具有代表性的“施工二次招标型BT模式,直接施工型BT模式,施工同体型BT模式,带资承包型BT模式”四种BT项目管理模式,并根据现行法律法规对其适用性和实施中应注意的问题进行了论述。 相似文献
953.
通过具体工程实践,在吸收现有滑模工艺技术的基础上,对平台扭转、中心垂直度控制等关键工艺进行创新,为提高工程质量提供技术保证,达到了创省级优质工程的效果。 相似文献
954.
应用水文过河缆道测验在传统水文测验中是一种行之有效的测验手段。本文主要结合黄河水文近年来开展的水文测报水平升级活动和现代化建设过程中取得的成功经验,分析说明水文过河缆道建设施工过程中的质量控制措施和方法。 相似文献
955.
956.
CAMC-IP是韩国AXT公司开发的二轴运动控制电路,详细介绍CAMC-IP的主要功能、特点及其内部结构,简要介绍以CAMC-IP为核心的基于PCI总线运动控制卡的设计. 相似文献
957.
In this paper, we present design features, implementation, and validation of a satellite simulator subsystem for the Korea Multi‐Purpose Satellite‐2 (KOMPSAT‐2). The satellite simulator subsystem is implemented on a personal computer to minimize costs and trouble on embedding onboard flight software into the simulator. An object‐oriented design methodology is employed to maximize software reusability. Also, instead of a high‐cost commercial database, XML is used for the manipulation of spacecraft characteristics data, telecommand, telemetry, and simulation data. The KOMPSAT‐2 satellite simulator subsystem is validated by various simulations for autonomous onboard launch and early orbit phase operations, anomaly operation, and science fine mode operation. It is also officially verified by successfully passing various tests such as the satellite simulator subsystem test, mission control element system integration test, interface test, site installation test, and acceptance test. 相似文献
958.
KS Min AR Khan MK Kwon YJ Jung Z Yun Y Kiso 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(8):909-915
The performance of a laboratory‐scale anaerobic acidogenic fermenter fed with a mixture of blended kitchen food‐waste and primary sludge from a sewage treatment plant was investigated for the production of volatile fatty acids (VFA). The operating variables for acidogenic fermentation were kitchen food‐waste content (10 and 25 wt %), hydraulic retention time (HRT: 1, 3 and 5 days), temperature (ambient: 18 ± 2 °C, and mesophilic: 35 ± 2 °C) and pH (varied from 5.2 to 6.7). The experimental results indicated that effluent VFA concentrations and VFA production rates were higher at ambient temperature than at mesophilic conditions. The net amount of VFA with 10 wt % food‐waste increased up to 920 mg dm?3 with an increase of HRT, but contrasting results (a decrease of 2610 mg dm?3) were found due to the conversion of VFA into biogas in the case of 25 wt % food‐waste, which increased significantly at HRT of 3–5 days. In terms of biogas composition (CO2 and CH4), the organic matter was converted into CO2 through the oxidative pathway by facultative species at low temperature while mesophilic temperature and optimum pH (6.3–7.8) played a pivotal role in increasing rate of conversion of VFA into biogas by methanogenesis. Rates of VFA production and their conversion are dependent on the food‐waste content in the mixture. Yet, the higher concentration of food‐waste (25% compared with 10%) did not produce VFA proportionally due to the increased rate of conversion of VFA into gaseous products. The maximum VFA production rate (0.318 g VFAproduced g?1 VSfed day?1) was achieved in the 10 wt % food‐waste at ambient temperature and at a 5‐day HRT. Copyright © 2005 Society of Chemical Industry 相似文献
959.
Yong Ma Yong‐zhen Peng Xiao‐lian Wang Shu‐ying Wang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(10):1118-1124
The laboratory scale anaerobic–anoxic–aerobic (A2O) process fed with synthetic brewage wastewater was designed to investigate the effects of changing feed C/P ratio on the performance of biological nutrient removal (BNR) processes. In the experiment, the influent chemical oxygen demand (COD) concentration was kept at approximately 300 mg L?1 while the total phosphorus concentration was varied to obtain the desired C/P ratio. Results showed that when the C/P ratio was lower than 32, phosphorus removal efficiency increased as C/P ratio increased linearly, while when the C/P ratio was higher than 32, the P removal efficiency was maintained at 90–98%, and effluent P concentration was lower than 0.5 mg L?1. However, regardless of the C/P ratio, excellent COD removal (90% or higher) and good total nitrogen removal (75–84%) were maintained throughout the experiments. It was also found that very good linear correlation was obtained between COD uptake per unit P released in the anaerobic zone and C/P ratio. In addition, the P content in the wasted activated sludge increased with the decrease in the C/P ratio. Based on the results, it was recommended that the wastewater C/P ratio and its effects be incorporated into BNR design and operational procedures, appropriate C/P ratios were used to achieve the effluent treatment goals. Copyright © 2005 Society of Chemical Industry 相似文献
960.
Mamata Mukhopadhyay Sameer V Dalvi 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(4):445-454
A supercritical antisolvent (SAS) process is employed for production of solid nanoparticles from atomized droplets of dilute solution in a flowing supercritical carbon dioxide (SC CO2) stream by attaining extremely high, very rapid, and uniform supersaturation. This is facilitated by a two‐way mass transfer of CO2 and solvent, to and from the droplet respectively, rendering rapid reduction in equilibrium solubility of the solid solute in the ternary solution. The present work analyses the degree of supersaturation and nucleation kinetics in a single droplet of cholesterol solution in acetone during its flight in a flowing SC CO2 stream. Both temperature and composition are assumed to be uniform within the droplet, and their variations with time are calculated by balancing the heat and mass transfer fluxes to and from the droplet. The equilibrium solubility of cholesterol with CO2 dissolution has been predicted as being directly proportional to the Partial Molar Volume Fraction (PMVF) of acetone in the binary (CO2–acetone) system. The degree of supersaturation has been simulated up to the time required to attain almost zero cholesterol solubility in the droplet for evaluating the rate of nucleation and the size of the stable critical nuclei formed. The effects of process parameters have been analysed in the pressure range of 7.1–35.0 MPa, temperature range of 313–333 K, SC CO2 flow rate of 0.1136–1.136 mol s?1, the ratio of the volumetric flow rates of CO2‐to‐solution in the range of 100–1000, and the initial mole fraction of cholesterol in acetone solution in the range of 0.0025–0.010. The results confirm an extremely high and rapid increase in degree of supersaturation, very high nucleation rates and stable critical nucleus diameter of the order of a nanometre. Copyright © 2005 Society of Chemical Industry 相似文献