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11.
产业发展是解决农民就业的基本出路。我国目前的产业发展不能适应农民就业的需要:工业化和城镇化没有为农民创造足够的就业岗位;劳动密集型产业发展不够;中小企业发展不充分;农民的创业和就业环境不理想。促进产业发展,创造农民就业岗位的对策建议有:大力推进"以人为本"的新型工业化;重点发展吸纳农村富余劳动力多的劳动密集型产业;大力发展吸纳农村富余劳动力多的企业;为农民创业和就业创造良好的环境。  相似文献   
12.
Solidification of Fe-7.5%Mo-16.5%Si ternary quasiperitectic alloy is investigated by using differential scanning calorimetry (DSC) and drop tube containerless processing techniques.The primary phase is identified as R (Fe5Mo3Si2) and the quasiperitectic phases are τ1 (Fe5MoSi4) and Fe3Si.With the decrease of droplet diameter, the cooling rate and undercooling of the droplets in-crease rapidly.The experiment result indicates that the solidification microstructure is composed of remnant primary phase, qua-sip...  相似文献   
13.
针对规范中对大跨径桁架桥的双层主梁阻力系数在取值上的局限,提出一种主梁阻力系数计算方法,以施工阶段节段模型的风洞试验结果为基础,对双层桁架主梁进行模型简化后,使用CFD计算得出其三分力系数. 采用不同迎风面特征尺寸,桁架片数以及桁架间距,分析了迎风面特征尺寸对主梁的阻力系数的影响. 讨论了桁架间距以及片数不同对主梁的阻力系数的影响趋势. 结果表明:迎风面特征高度与特征宽度对主梁阻力系数影响的变化规律并不相同,对此提出以桁架纵高比为变量的双层桁架桥梁主梁的阻力系数拟合公式;当桁架间距较小时,桁架片数对主梁阻力系数无影响,但当桁架间距与桁架高度比值达到3 时,桁架片数的变化会对主梁的阻力系数产生较大的影响.  相似文献   
14.
1 Introduction For most of the industrial enterprises, the procurement of materials, components and parts is the first step of manufacturing Therefore, procurement management is very important for reducing total cost of supply chain, improving products quality, and shortening operation cycle Procurement management has been the most valuable part in supply chain management It is forecasted that the typical decision-makingissues of supply chain in future will focus on the field of procurement ma…  相似文献   
15.
1. INTRODUCTION Mobile ad hoc networks are wireless multi-hop networks where mobile nodes are self-organized, have highly dynamic topology, limited bandwidth and no support of fixed infrastructure[1]. These characteristics often cause ad hoc networks to be viewed as quite different from traditional networks. Routing a packet from a source to a destination in an ad hoc network is a challenging problem. The main source of the challenge comes from the fact that there are no base stations in …  相似文献   
16.
把罗伯特近(Howard Percy Robertson)对宇宙学的杰出贡献提给这次纪念讲演,对我来说是一个巨大荣誉,这感受,通过阅读罗伯特逊过去的优秀作品目录而进一步增强了。要评价罗伯特逊的工作,就必须了解其背景。爱因斯坦创立了广义相对论,它是现代的引力理论。在这理论中,引力和宇宙学都被几何化了。爱因斯坦本人想象了一个空间上封闭的、时间上独立的宇宙。弗里德曼(Alexander Friemann)找到了——或者说猜到了——爱因斯坦方程的一个非静止的宇宙解。哈勃(Edwin P.Hubble)关于遥远星系红移的发现,进一步证实了这样的观念,即宇宙通过其膨胀而进化。  相似文献   
17.
Interglacial or postglacial climates are all of charac-teristic of warmer conditions. However, if condition asso-ciated with the warm feature is wetter or drier than today,it would produce different impacts on natural environ-ments and human society. Quaternary studies found thatclimate with warm-dry or warm-wet conditions had oc-curred in China during the last 40—30 ka BP[1]. For ex-ample, it was warmer than the present during themid-Holocene (3—8 ka BP) and the late phases of MarineIsot…  相似文献   
18.
1 .INTRODUCTIONMultiple classifier fusion or combination has prov-enitself a powerful tool for achieving high classifi-cation accuracy with moderately discri minatingclassifiers .If only output class labels are availablethe voting fusion[1]is often used as a decisionlevelfusion. However ,the main drawback of the votingfusion is that all classifiers are considered equallyreliable and this maylead to a confident decisiontobe changed by a less reliable classifier . A possibleway of overcomin…  相似文献   
19.
In this paper, the spot welding technology of a new kind of 22MnMoB hot stamping quenched steel sheet was systematically studied by power frequency spot welder. Through a series of technology and test experiments, we have obtained the optimal spot welding technological parameter condition. According to the results, the relations among spot welding technological parameter, welding nugget, mechanical property and fracture mode were discussed. The effects of all the welding parameters such as welding current, welding time and electrode force on the quality of joint can be boiled down to one thing--the diameter of welding nugget. The experimental results showed that welding nugget diameter determines the mechanical property of spot welding joint and the relation between welding nugget diameter and the mechanical property of joint presents a kind of linear mathematic representation. There are two typical fracture models of 22MnMoB hot stamping quenched steel sheet, i.e., interracial fracture and nugget pullout. Other than mild steel or normal high strength steel, in the shearing tensile test, hot stamping quenched steel has a great tendency to fail in interfacial mode due to the effects of high strength matrix structure, welding soft zone and the porosity level of fusion zone.  相似文献   
20.
The magnetic properties of magnetosome magnetite are of interdisciplinary interest because magnetosomes are potential carriers of natural remanent magnetization and paleoenvironment, as well as novel nano-biomaterials in biotechnological and biomedical applications. We carried out magnetic and electron transmission microscopy analyses of fresh Magnetospirillum magneticum AMB-1 whole cells and isolated magnetosomes. Results revealed that AMB-1 synthesized single-domain magnetite magneto-somes, which are arra...  相似文献   
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