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991.
北本水电站是我国大唐集团在老挝境内以BOT方式开发建设的第一个大型水电项目。结合北本项目实际,对项目实施人力资源本土化的必要性、制约因素进行了研究分析。根据老挝以及项目实际情况,提出了具体措施和发展设想。 相似文献
992.
Antarctic scientific expedition has important strategic significance. It is an inevitable trend to apply robots to assist researchers during the Antarctic expedition. However, the robot manipula- tors at present have a series of problems and unable to meet the requirements of the Antarctic expe- dition. In this paper, a novel Antarctic modular robot manipulator is proposed, which has a compact structure with modular joints. The robot manipulator has high reliability, and quick assembling-and- disassembling ability. Through well wires arranging and thermal controlling, the manipulator can better adapt to the Antarctic environment. In addition, the work space of the manipulator is serious- ly analyzed, and a new hybrid position/force control method is adopted to make the manipulator per- form better. Simulation results validate the control method and show that the robot manipulator has a good performance to meet the requirements of Antarctic expedition. 相似文献
993.
在当前低碳经济背景下,对实现建筑装饰产业升级重要手段的集成化设计进行研究;从当下对建筑装饰产业的具体要求入手,对集成化开发所面临的具体问题以及解决方法进行了深入研究.最后以集成化实践应用加以印证,探讨了建筑装饰产业集成化开发的可行性. 相似文献
994.
对于一类具有人为故障率,修复率时间任意分布的可修复系统的数学模型,利用泛函理论将此系统转换为Banach空间下的第二型Volterra微分-积分方程,利用泛函分析初等方法得到系统解的存在唯一性证明,并同时得到系统解的形式。 相似文献
995.
996.
The thermal radiation properties of pyrolytic carbon (PyC) protective coatings for monocrystalline silicon furnace prepared by different processes were tested. The changes of normal emissivity of carbon materials caused by PyC protective coatings were discussed, and the influence of phase structure and surface appearance on the thermal radiation properties was investigated. The results show that the thermal radiation properties of PyC protective coatings with the wave band of 5 -25 I~m are better than C/C substrate, further, normal spectral emissivity of CVD PyC coating remains basically at 0. 85 - 0. 90, and the normal total emissivity can reach 0. 89, which shows high thermal radiation performance. For resin PyC coating and CVD PyC coating, the degree of graphitization are 44. 53% and 16. 28% respectively, and the R value of Raman spectrum are 0. g64 and 1. 384 respectively. Relatively disorder graphite structure of the latter causes various vibration modes, and the spectral emissivity is better, so the thermal radiation property of CVD PyC coating is excellent. A lot of spherical particles exists on the surface of the CVD PyC coating, and the more interface and spacing of particles reduce the number of particles per unit volume. Therefore, the scattering of thermal radiation is strongly strengthened, and the spectral emissivity is higher. 相似文献
997.
The reasons for bringing surface accuracy error in uhra-precision grinding ceramic ball joint were analyzed, and the influences wheel position error and shaft run-out error on the ball joint surface accuracy were discussed. Through establishing three-dimensional grinding model, the mathematical relationship between the position error and surface accuracy was derived, and the distance from any point on spherical surface to the ideal center was calculated when position error existed, and a precise surface shape was got, and theoretical support was provided to improve the surface accuracy during the grinding process. Using self-developed ultra- precision grinding machine to do the ceramic ball grinding experiment, the surface accuracy PV value of ceramic spherical joint is 4. 8 μm. 相似文献
998.
Abstract: The hot deformation behaviors of AI-Zn-Mg-Sc-Zr alloy were investigated in a temperature range of 340-500℃ and a strain rate range of 0.001-10 s 1 using uniaxial compression test on Gleeble-1500 thermal simulation machine. The results show that the flow stress increases with increasing strain and tends to be constant after a peak value. The flow stress increases with increasing strain rate and decreases with increasing deformation temperature. The phenomenon of dynamic recovery and dynamic recrystallization can be observed by microstructural evolutions. Based on the hyperbolic Arrhenius-type equation, the true stress-true strain data from the tests were employed to establish the constitutive equation considering the effect of the true strain on material constants (α, β, Q, n and A), which reveals the dependence of the flow stress on strain, strain rate and deformation temperature. The predicted stress-strain curves are in good agreement with experimental results, which confirms that the developed constitutive equations are suitable to research the hot deformation behaviors of Al-Zn-Mg-Sc-Zr alloy. 相似文献
999.
Bo Liu Shen-gen Zhang Jian-jun Tian De-an Pan Yang Liu Alex A. Volinsky 《北京科技大学学报(英文版)》2013,(10):941-946
Oily cold rolling mill (CRM) sludge contains lots of iron and alloying elements along with plenty of hazardous organic components, which makes it as an attractive secondary source and an environmental contaminant at the same time. The compound methods of "vacuum distillation + oxidizing roasting" and "vacuum distillation + hydrogen reduction" were employed for the recycle of oily cold rolling mill sludge. First, the sludge was dynamically vacuum distilled in a rotating furnace at 50 r/rain and 600℃ for 3 h, which removed almost hazardous organic components, obtaining 89.2wt% ferrous resultant. Then, high purity ferric oxide powders (99.2wt%) and reduced iron powders (98.9wt%) were obtained when the distillation residues were oxidized and reduced, respectively. The distillation oil can be used for fuel or chemical feedstock, and the distillation gases can be collected and reused as a fuel. 相似文献
1000.
在分析采区进风系统巷道火灾时风量变化原因的基础上,进行了采区进风系统相似模拟实验.结果表明:采区进风系统巷道发生火灾时,对主运顺槽和辅运顺槽之间的联络巷风量影响很大,尤以对靠近火灾点的联络巷风量影响最大,与火灾的发展、稳定燃烧和衰退过程相对应,巷道火灾对采区进风系统风量的影响也经历逐渐增大,达到最大和逐渐减小的过程. 相似文献