A Method of Analyzing the Parameter Sensitivity of Large Rotor Systems and Its Application

Based upon the eigenvalue sensitivity theory of non-self-adjoit system and the component mode synthesis method,a new technique is developed to analyze the eigenvalue sensitivity to variation of parameters of large rotor-bearing system. As an application, the influence of the journal bearing parameters on the stability of a large domestic turbine-generator set is analyzed and discussed.     

A Synchro-Solution Method for Generalized Eigenproblem and its Application in Parameter Sensitivity Analysis

A high efficient synchro-solution method for generalized eigenproblem has beenproposed ,it has also been demonstrated that how the method can be used in vibration parameter sen-sitivity analysis of the higher order non-self-adjoint vibration system such as rotor-journal bearing system.     

新疆各地州（市）相对资源承载力时空差异分析

为了多角度多维度地丰富相对资源承载力理论和应用的研究,考虑研究区的整体性、资源的开放性和动态性,在原有相对资源承载力模型的基础上,添加了天然湿地资源和林木资源对原模型进行改进,利用改进后的新模型对比分析了2004—2009年新疆各地州（市）的土地、水、经济、能源、天然湿地、林木相对资源承载力、相对综合承载力、承载状态及度的变化趋势。研究发现,从各地区各资源承载力纵向比较来看,总体呈上升趋势的有土地资源承载力和经济资源承载力,呈下降趋势的有水资源承载力和能源资源承载力,天然湿地资源承载力和林木资源承载力与其变化趋势相似,全区有增有减。全区相对综合承载力多数地区处于上升趋势。一直处于严重超载状态的地区有石河子市、伊犁地区,表明这些地区人口处于警戒状态,必须大力控制人口增长速度。虽然吐鲁番地区、哈密地区、克州、克拉玛依市、阿勒泰地区、巴州连续6年分别处于富余、非常富余状态,但这些地区的富余度和非常富余度均呈下降趋势,即人口的增长略高于承载力的增长,说明在经济发展的同时,也应注意控制这6个地区的人口数量,使之处于可持续发展状态。     

Intensity Comparative Analysis Based on Ideas Between Involute Gear and Double Involute Gear

Modeler and simulation modules in Ideas software are used to build the finite element models on involute gear and double involute gear with accurate tooth shape, and with the same design parameters and under the same loads, finite element contact analysis has been done. At last, the contact stress and bending stress on the two types gear transmission at the different meshing positions are solved out, and comparative analysis and study have been done. At the same time, that the ladder-shape tooth on the double involute gear how to influence contact stress and bending stress is emphatically analysed. All above offer the theoretical foundation that bring the double involute gear with ladder-shape tooth into the industry.     

Application and Test Analysis of Anti-float Anchor in Submerged Square

In this paper, based on the reconstruction project of the bar in Shekou, Shenzhen, under the action of circular loads, the ultimate bearing capacity and the stress along the anti-float anchor were tested and the change of the loading was analyzed in an in-situ test, which may be taken as reference for other similar projects with the same strata.     

草地螟产卵和取食寄主种类初报

通过2年多点广泛和系统的田间调查和观察,结合以往调查结果,确定了草地螟取食和产卵植物种类、方式,阐述了不同地区间、幼虫不同龄期时,草地螟对不同植物种类表现喜好度有差异;且观察到草地螟产卵寄主和取食寄主不完全一致,产卵部位和所占比率随环境温度和湿度不同而有所变化。以上结论进一步阐明了草地螟对寄主植物具有较强的选择性,而这种选择性是草地螟种群生存的需要。由此认为,草地螟是种植业上的重要害虫,调整种植作物种类是草地螟治理的有效措施,适时中耕除草可起到趋利避害作用。     

新型土坯墙体房屋抗震性能试验研究

提出了一种新型土坯墙房屋,对新型土坯墙房屋承重墙体的受力及抗震性能进行试验研究。设计三片新型土坯墙试件,研究土坯墙体在竖向荷载和反复水平荷载作用下的破坏过程、破坏形态、滞回曲线和骨架曲线特征以及墙体水平承载力和变形能力等,同时,研究新型构造措施对土坯墙抗震性能的作用。试验表明：新型土坯墙体的破坏模式与配筋混凝土小型空心砌块相似,土坯墙体具有良好的承载力和变形能力。新型构造措施对墙体整体抗震性能作用明显,其连接构造至关重要。与计算结果比较得出,在建筑抗震概念设计原则指导下,抗震设防7度区采用新型土坯墙建造二层房屋具有可行性。     

In situ off‐farm work in the transport industry among oil palm smallholders in Sabah: Negotiating the borders of licit and illegal activities

This paper examines the informal transport sector within the smallholder oil palm economies of Kinabatangan and Lahad Datu areas of eastern Sabah by looking at the metaphoric border that is constructed between licit and illegal activities that take place on roads. It describes the work of two groups of drivers, namely, those who are themselves smallholders who provide a crucial service to the community in getting their fresh fruit bunches to mills on time; and the piret (pirate) taxis who transport passengers including foreign nationals, some of whom are illegal workers. Many have been driving for some time, thereby challenging the notion about off‐farm work as providing a temporary safety net to smallholders. Drivers whose permits may be current may have used illegal means (such as meminggir – logging without licence), to accumulate the initial funds for acquiring their vehicles and necessary permits. Moreover, their clients are unconcerned about their ‘illegal’ status. Consequently, this paper maintains that there is no agreed‐upon norms about legality/illegality, and law enforcement being uneven, the zone in which drivers operate is a fluid one.     

Foundation pile test by self-balanced method of rock-socketed piles and friction piles in multilayer soil geological structure

结合检测工况对测试数据的影响,对自平衡“精确转换法”进行改进,提出摩擦桩位移协调转换法和嵌岩桩的荷载协调转换法,实际应用结果说明两种转换方法合理。所得测试结果表明湄公河大桥桩基承载力符合设计要求;分析湄公河大桥试桩的侧摩阻力和端承力分布,嵌岩桩和摩擦桩纵向承载均以侧阻力为主。     

Deflection and Stress Analysis of a Pavement Slab under Temperature Gradient and Axial Loading Coupling

It has been established that a pavement slab will curl up if a temperature gradient exists across the depth of a slab. A negative temperature gradient causes the slab edge to curl up while a positive temperature gradient curls up the slab center. Temperature stress in slabs is induced by self-weight and other slab constraints. At present in P. R. China, the total stress considered in cement concrete pavement design includes the load stress plus the temperature stress, and only transverse cracking from bottom to top is considered for concrete pavement. Slab responses under axial loads and temperature gradient coupling are not included. We modeled a single slab with a frictionless interface between the slab and foundation using the finite element method. Slab deflection and stress were calculated under axial loads at different slab positions and negative or positive temperature gradient coupling. The calculated results show that the different conditions of axial loads and temperature gradient coupling will change the maximum tension and cause various types of cracks in a slab.     

Theoretical and Experimental Analysis of Bending Behavior of Composite Beam with Notched Web

A new kind of steel-concrete composite beam with notched web is proposed, and the bend and shear behaviors of this composite beam are investigated. First of all, the constitution, bearing characteristics and merits of the steel-concrete composite beam with notched web are introduced; then, a group of formulas about the bending capacity, slip between the steel beam and the concrete flange, and the deflection are introduced; after that, the bending behavior, slip effect and bearing characteristic of the steel-concrete composite beam with notched web are studied on 4 specimens, which are tested by applying two concreted vertical loads on the top of concrete flange. And the finite element model is adopted to analyze the results of the 4 specimens; finally, the reliabilities of the formulas are verified by comparing the results of theoretical formulas, the results of tests and that of finite element analysis. Study shows that the bend behavior and shear behavior are fine, and the popularization of this new kind of composite beam which can be broadly used in building engineering will save the consumption of steel.     

西北牡丹品种瓣基色斑形态的初步研究

西北牡丹品种群是中国牡丹栽培品种中极富特色的品种群,所有品种的花瓣基部都有色斑。实地调查中发现,这些色斑在位置、大小、颜色、形状等方面存在丰富的变异,现结合文献资料,对这些变异进行整理分析。色斑的位置有基部和离基2种情况;颜色以棕红色、紫红色、棕色、黑紫色等紫黑色系居多;色斑的大小按其高度占花瓣的高度比例可分为特大型、大型、中型和小型4种;形状有卵形、椭圆形、圆形等10种。对色斑的描述可按照颜色、大小、形状的顺序。此外色斑透背与否及雄蕊瓣化瓣上的白色条纹等都有很大的变化,这些特点极大地提升了西北牡丹品种花朵的观赏性。     

Design and analysis of structural parameters for capillary oil film bearing

Structural parameters, such as the structure of recesses, the number of recesses, and throttle parameters, play decisive roles in determining the carrying capacity and rigidity of oil film bearings. These parameters are analyzed, and a state design is presented for a hydrostatic cavity and pat bearing, a hybrid bearing with an eccentric oil wedge, and ladder recesses. The mutual relationships between oil film bearing structural parameters and carrying capacity are calculated by combining numerical methods using MATLAB software programming. The results show that hybrid bearings with ladder recesses have superior carrying capacity compared to bearings with other structural forms.     

Comparisons of Methods for In-Plane Bearing Capacity Calculation of Two-Hinged Parabolic Steel Arch Under Full-Span and Half-Span Loads

The internal force would vary largely with different load ratio for steel arches under combined full-span with half-span loads. However, most relevant formulas on in-plane stability capacity of steel arches were obtained by studying the stability under a single load. Thus, it lacks full considerations of the applicability of bearing capacity formulas under a combined full-span load with half-span load. To overcome this shortcoming, the two-hinged parabolic steel arch was used to compare the results of bearing capacity of arches with different load ratios, rise-span ratios and sections calculated by several methods, The method proposed in the current Chinese design specification of steel arch structure and the finite element method based on the perfect arch and the consistent imperfect arch were included. The results showed that the method in the specification for designing a steel arch would be conservative with a large ratio of the full-span load to the total loads while unsafe with a large ratio of the half-span load to the total loads.     

Factors Affecting the Ultimate Bearing Capacity of Cold-Formed Steel Portal Frames

The FEM simulation analysis method was studied to identify the ultimate bearing capacity of cold-formed steel portal frames.In this study,the beam-spring system was used to simulate the performance of joints.The initial imperfection of frame components was considered.The deformation performance and failure features of portal frame structures under vertical loads also were studied.The analytic results of the FEM simulation analysis method are close to the values obtained by experimentation.The ultimate bearing capacity of portal frames were computed by changing parameters such as the web plate thickness,the flange width,the plate thickness of brackets,the portal frame roof inclination,and the column footing stiffness.The analytic results indicate that the ultimate bearing capacity may be improved when the parameters mentioned above are increased.     

Experimental Analysis of the Behavior of Steel Plate-masonry Composite Wall-beams

When steel plate-masonry composite structure used in the existing masonry structure with load bearing walls is removed for a large space, composite action should be considered between the beam and the supported masonry wall due to the arch effect formed in the supported wall. In order to investigate the working mechanism, failure mode, and load-carrying capacity, strain distribution in critical sections and mid-span defcection of this type of composite wall-beam, five steel plate-masonry wall-beams were tested under concentrated loads and analyzed, which considered variables of height-span-ratio of supported masonry wall, height-span-ratio of composite beam and thickness of steel plate. The results show that steel plate-masonry composite wall-beam starts failure from the masonry located at the line between loading point and supporting point; strain distribution of steel plate along section height meets the plane section assumption; the height-span-ratio of supported wall can directly influence the failure mode of masonry wall, buckling load corresponding to steel plate experiencing local buckling and ultimate load of tested specimens; the reasonable height of supported masonry wall is beneficial to the formation of composite action between supported masonry wall and composite beam, and the excessive high masonry wall will reduce the ultimate load of the tested specimen. Finally, the reasonable range for height-span-ratio of supported masonry wall was presented, and the proposed value representing the flexural stiffness of the steel plate-composite beam relative to the in-plane stiffness of the supported masonry wall was at least more than 79.     

Comparative Study on Plastic Hinges of Prestressed Concrete Frames Under Vertical or Horizontal Loads

In With one-storey, two-span prestressed frames, a comparative study is done between under vertical and horizontal loads. The studies include the pattern of the plastic hinges occurring and, the demanded and available rotational capability of the hinges in critical sections. The relative height of compression zone and prestressed degree are considered. The result indicates that there is much difference in the pattern of the plastic hinge occurring when each plastic hinge has enough rotational capability. The beams can finish a full redistribution of internal force under vertical loads, but not under horizontal loads. Moreover, as increasing of the relative height of compression zone, a stronger rotational capability of hinges will be demanded to finish a full redistribution under vertical loads when a weaker rotational capacity will be needed under horizontal loads.     

Galerkin Approximate Solutions of Displacement Including the Effect of Dead Loads for Two Kinds of Rectangular Plates

Based on the strain energy considering the effect of dead loads, the general form static equilibrium differential equations were formulated by means of the potential energy principle. The approximate solutions of live load or later load displacement including the effect of dead loads for the clamped rectangular plate and the simply supported rectangular plate were generated by the Galerkin method. These formulas are simple and clear, and their physical concepts are explicit. The correctness of these formulas was verified by the finite element method. The dead loads and other factors that influence the effect of dead loads are shown by these formulas. The effect of dead loads on the two different boundary condition rectangular plate were analyzed by these approximate solutions. The effect of dead loads improves the bending stiffness of plate and minimizes the displacement of live loads or later loads. The key physical factors governing the effects of dead loads on plates are the dead load, the ration of span to thickness and boundary condition etc. This effect of dead loads is not negligible, especial in thinner plates or plates with smaller stiffness, more attention should be paid to the effect of dead load in the calculation and analysis for plates.     

夏播大豆生育期结构和农艺性状的遗传参数研究

试验从339个大豆品种中选取生育期小于100d的103个品种进行生育期结构特性与农艺性状之间的遗传参数分析。结果表明：1）单株荚数与单株粒数、生育前期呈极显著正相关,与R1呈显著正相关;单株粒数与R7呈显著正相关;百粒重与全生育期呈极显著正相关。2）遗传力＞60%的农艺性状分别为结荚高度、株高、主茎节数、R1、百粒重、生育前期、荚长、生育后期、全生育期。3）相对遗传进度的大小依次为主茎分枝数、有效分枝始节、结荚高度、株高、单株粒数。4）遗传变异系数＞25%的为主茎分枝数、有效分枝始节、结荚高度、单株粒数、株高、单株荚数。     

Analysis of Internal Force Calculation of Beams with Finite Length Bearing Several Point Loads and on Soil Foundation

For making the theoretic results close to the fact,two methods used to calculate the internal force of beams with finite length bearing several point loads and on soil foundation were compared.These two methods were based on the Winkler's assumption and the half-space elastic foundation theory respectively.Through theoretic analysis,the difference between the two methods was found.And with the aid of FLAC~(3D) analysis,it was clear that the results deduced by the method based on the Winkler's assumption were more close to the fact.