箱形的

The interior sound pressure levels and exterior sound pressure levels of the complex box structure excited by an exterior point load are measured, and a good agreement between the theoretical results and the test results shows that the theoretical method and corresponding results are correct.

通过对几种具有理论解的结构辐射声场的分析，验证了本文理论的正确性，研究表明本文方法具有很高的精度；同时对复杂箱形结构进行了实验验证，在实验室条件下测量了复杂箱形结构在外部点载荷激励下的内、外部辐射声压级，与理论预估值比较表明，二者具有良好的一致性，进一步证实本文所建立的理论预估方法是有效的。

In the structural optimization, at First, the author analyses and contrasts characteristics and advantages of the mathematical programming method with optimality criterion method.

大型水压机横梁是关键的承载部件，一般采用薄壁箱形结构，这种大型薄壁箱形结构也广泛地应用在重型机械、造船、航空航天、核能电站、石油化工等领域。

In this dissertation, considering the influence of transverse shearing deflection and noncoincidence of torsion center and gravity center, the equilibrium formulas of variable-curvature box-girder with rectangular cross section were established. Based on deformation expression of arbitrary point on the girder and relationship between inner forces and displacement equations, considering noncoincidence of torsional center and gravity center, the governing differential equations for variable-curvature box-girders were generalized.

针对具有竖直对称轴的矩形断面变曲率箱梁，考虑了挠曲剪切应变和曲梁剪心和形心分离的影响，推导了变曲率箱梁的平衡方程；通过箱梁内任一点的位移方程和内力-位移关系，推导了考虑曲梁剪心和形心分离的变曲率箱梁的挠曲扭转控制微分方程。

All nutrition bee feed use: You can open the collection, feeding fermented box beam, box beam fed after soaking.

所有蜜蜂饲料的营养：您可以打开的收集，喂养发酵箱形梁，箱形梁浸泡后喂。

Both monotonic axial compressive and axially loaded cyclic tests have been carried out on the steel box brace used in New CCTV Building to investigate the effect of assembling welds including full penetration and partial penetration on the structural behavior of the brace.

为考察全熔透和部分熔透两种组装焊缝形式对箱形截面钢支撑受力性能的影响，本文对中央电视台新台址建设工程中的箱形截面支撑进行了单调受压、轴向反复拉压试验；同时，采用ABAQUS有限元软件实现了对部分熔透试件未熔透处的接触模拟和滞回性能模拟。

The cold-formed sheet is a groove-shaped structure that is composed of a crown plate and reinforced ribs connected with ends of the crown plate; the box beam is a box-shaped structure comprising an upper wing edge, a lower wing edge and two side webs that are connected in every two components.

由压型钢板、纤维增强塑料箱梁组成，压型钢板为由顶板和顶板端部的加强肋相连组成的槽形结构，箱梁为由上翼缘、下翼缘和两侧腹板两两相连组成的箱形结构，其结构如图所示。

Presenting the calculating method of the space displacement model of skewed box girder, whit main ideas of: dispersing the skewed box girder into some skewed beam segments and further dividing those segments into some plate pieces according to their forms; describing the displacement functions in the plane of plate piece by assuming that the space displacements of any point in the joint line between the plate pieces are described by using Hermite interpolation functions and that two displacements in the plane of plate piece are linear in the cross direction; Using Hermite interpolation functions to describe the bending the displacement of the unit length transverse frame cutting longitudinal from the skew box girder segment; Finally, describing the space displacements of a point in the plate pieces by two displacements in the plane of the plate and one bending displacement of plate.

提出了斜交箱形梁空间位移场的计算方法：将斜交箱形梁沿纵向离散为若干斜梁段单元，依据箱梁的构成进一步将斜梁段划分为若干板段子单元；各板段联结线上任意点的位移按Hermite函数插值，假定各板段的面内位移沿其宽度方向线性变化，以描述各板段面内位移；沿斜交箱梁段的纵向截取单位长度横截面框架，框架各杆件空间位移按Hermite函数插值，以描述各板段面外位移；板段内任意点的空间位移最终以2个面内位移和1个面外位移描述。

The paper describes how the local force of the main web is considered as the force caused by the Contact pressure among the trolley wheel, rail and top flange, and how the contact analysis model for the local force is built by means of both Hertz theory and finite element software ANSYS combined. Also, it analyzes the variation of the local stress under the different conditions and comes to a conclusion, and compares the results derived from the experimental formula with the result from ANSYS.

本论文的主要内容：将Hertz接触理论和有限元软件ANSYS结合起来，把主腹板的局部受力问题视为小车轮与轨道及轨道与上翼缘板之间发生接触行为作用下的受力问题，建立了小车轮压作用处偏轨箱形梁主腹板局部受力的接触分析模型，研究不同情况（小车轮压、箱形梁几何参数和轨道截面惯性矩）下局部应力的变化规律，得出相关结论；最后将经验公式解与ANSYS数值解进行对比分析论证。

But quite amount of cracks are found during the construction and operation in the PC box girder bridges, especially cracks in the anchorage zone and the inclined cracks in the box girder webs of the bridges, and some longitudinal cracks appear indeed in the deadweight phases,Moreover the variant Pre-stressed strand arrangements produce great influence for the inner inforce of the b

但目前在用预应力混凝土箱形梁的施工和运营过程中出现相当数量裂缝病害，尤其是箱梁锚固区裂缝、腹板斜裂缝，顶板纵向裂缝，有的甚至在未承受活载的自重阶段就出现裂缝，而不同的预应力布束方式对箱梁内力有很大的影响。

Using the software of ansys, this thesis compares and analyzes the seismic behavior of the joint of cold-formed rectangular tube-steel column and H-shaped beam and the joint of welding box column and H-shaped beam, in order to research the influence for the cold forming process of the cold-formed rectangular tube-steel column.

利用大型通用有限元分析软件，对冷弯矩形钢管柱与H型钢梁连接节点与焊接箱形钢管柱与H型钢梁连接节点的抗震性能进行对比分析，探讨出冷弯矩形钢管的特性对节点抗震性能的影响。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。