摘要：【目的】对国标针织T恤衫新旧标准内容进行比对分析,梳理并归纳总结新旧标准的主要差异,探讨针织T恤衫的质量问题并提出相应的解决建议。【方法】通过逐条比对新旧标准的条款和分析近年来各地市场监管局对该产品的监督抽查结果,找出影响针织T恤衫产品的主要质量问题。【结果】新标准相对旧标准提高了内在质量和外观质量的要求,市场中的针织T恤衫在纤维成分含量、耐光色牢度和耐湿摩擦色牢度的检测结果上存在不合格的情况。【结论】为提高企业和检测机构对于标准的理解和产品质量的把控,需要相关企业积极适应新标准的要求,加大研发投入,提升产品设计和生产工艺水平。同时,相关监管部门需要加强对该产品的质量监督工作,不断提升针织T恤衫产品的质量水平。

摘要：A novel compact electromagnetic bandgap （EBG） structure constructed by etching two reverse split rings （RSRs） and inserting interleaving edge （IE） on the patch of conventional mushroom-like EBG （CML-EBG） is investigated. Simulated dispersion diagrams show that the proposed EBG structure presents a 13.6% size reduction in the center frequency of the bandgap. Two comparisons have been carried out for the analysis of the effect of the RSRs and IE configuration. Then, a sample of this novel EBG is fabricated and tested, further experimental data agree well with the simulated results. Thus, this EBG structure makes a good candidate to decrease mutual coupling in compact microstrip patch array.

摘要：基于非线性有限元数值模拟方法,考虑混凝土非线性力学特性,建立了包含竖向双层波纹管孔道的精细化数值有限元模型,分析了箱梁合龙段底板从开始加载至最终破坏的损伤发展过程.基于精细化数值模型分析结果,讨论了崩裂成因.研究表明,箱梁合龙段底板崩裂成因共有5种:孔肋间混凝土竖向受拉、波纹孔道下方混凝土冲切、孔肋顶部和底部混凝土横向开裂、波纹管与混凝土的剥离以及底板弯曲开裂和梗腋位置剪切开裂.根据5种崩裂成因出现的先后顺序,认为控制底板崩裂破坏形式为波纹管下方混凝土冲切破坏及孔肋间竖向受拉破坏.最后,提出了孔肋间受拉破坏承载能力设计公式和底板抗冲切承载能力设计公式.

摘要：针对非硅MEMS零件的装配瓶颈难题,提出一种面向非硅MEMS的桌面微装配系统模块化设计方法.论述了所提出桌面微装配系统的内涵、特点及其应用对象,并在此基础上提出了基于装配单元通用功能完整性和系统可重配置性的模块划分原则;利用相关性分析方法建立了综合相关矩阵并应用模糊聚类方法对其进行了操作,确定了模块划分定量计算流程,利用模糊评价方法对模块划分合理性进行了评价;以桌面微装配系统的自主式装配单元为实例进行了设计方法的验证,证明了模块化设计方法的有效性.

摘要：Based on rational behavior model of three layers, a tracking control system is designed for straight line tracking which is commonly used in underwater survey missions. An intelligent PID control law implemented as planning level during the control system using transverse deviation is came up with. Continuous tracking of path expressed by a point sequence can be realized by the law. Firstly, a path tracking control system based on rational behavior model of three layers is designed, mainly satisfying the needs of underactuated AUV. Since there is no need to perform spatially coupled maneuvers, the 3D path tracking control is decoupled into planar 2D path tracking and depth or height tracking separately. Secondly, planar path tracking controller is introduced. For the reason that more attention is paid to comparing with vertical position control, transverse deviation in analytical form is derived. According to the Lyapunov direct theory, control law is designed using discrete PID algorithm whose parameters obey adaptive fuzzy adjustment. Reference heading angle is given as an output of the guidance controller conducted by lateral deviation together with its derivative. For the purpose of improving control quality and facilitating parameter modifying, data normalize modules based on Sigmoid function are applied to input-output data manipulation. Lastly, a sequence of experiments was carried out successfully, including tests in Longfeng lake and at the yellow sea. In most challenging sea conditions, tracking errors of straight line are below 2 m in general. The results show that AUV is able to compensate the disturbance brought by sea current. The provided test results demonstrate that the designed guidance controller guarantees stably and accurately straight route tracking. Besides, the proposed control system is accessible for continuous comb-shaped path tracking in region searching.

摘要：我国某生活垃圾焚烧项目进口炉排炉为绝热炉墙设计,在运行过程中会出现结焦严重的问题。通过对焦块进行表征分析发现,其主要成分为钙黄长石,容易形成低温共融物。当炉膛温度过高时,焚烧产生的灰粒易软化、熔融,黏附在高温炉墙表面结成焦块。针对此问题,该项目对原焚烧炉侧墙进行模块化设计,使得各段炉墙之间封闭独立,并在局部高温区域将原绝热炉墙改造为风冷墙,以降低炉墙温度。改造后,炉墙结焦问题得到明显改善,增强了焚烧炉运行的安全稳定性,提高了锅炉热效率,节省运行成本,项目改造达到预期效果。

摘要：For identifying the tire/road friction coefficient accurately in real-time to meet the needs of automobile electronic control system and then improving the active safety performance of automobile, the road recognition method based on fuzzy control algorithm was studied in this paper. Adopt a 7-DOF vehicle dynamic model, wheel slip ratio 2 and longitudinal forces Fx as the input of fuzzy controller with fuzzy rules was proposed. The output is the weight coefficient of p-2 functional expression which is related to cl, c2 and c3 proposed by Burckhardt etc. By a simulation experiment of automobile brake on the condition of driving straight or veering on a single road and docking pavement, to some extent, indicates that this method is able to guarantee the real-time and accuracy of the road identification.

摘要：针对对置活塞轴向气缸结构的二冲程发动机,开展了对置活塞空间圆柱凸轮同步机构优化设计研究。为提高对置活塞发动机的性能,建立空间圆柱凸轮模型,对压力角、空间圆柱凸轮型线进行优化设计,进而得到发动机活塞的最佳运动位移曲线。利用发动机性能仿真软件GTpower,计算了不同活塞位移曲线下发动机的性能参数,分析活塞运动位移曲线对发动机性能参数的影响规律。计算结果表明:优化设计后的空间圆柱凸轮型线可以改进活塞运动位移的变化规律,进而提高发动机动力经济性能;随着活塞运动位移曲线的变化方向,发动机的性能先有所提升,而后开始下降,得出对置活塞发动机同步运动机构圆柱凸轮的优化设计方法。

摘要：Axial compression tests were conducted on AZ31 B magnesium and A6063 aluminum thin-walled square tubes with varied lengths and induced features at different compression rates. In compression, the magnesium tubes exhibited a "local buckling and fracture" mode, with three fracture patterns, i.e."horizontal","double-oblique", and "spiral" fractures. In general, the magnesium tube showed an inferior crashworthiness to the aluminum square tube. In addition, the effects of L/W ratio, strain rate and induced features on the crashworthiness of thin-walled square tubes were investigated. With an increase in the L/W ratio(L and W represent the tube length and width, respectively) from 1 to 4, the maximal force and global specific energy absorption decreased in a power-law trend for the magnesium tubes,while they remained approximately constant for the aluminum tubes. Furthermore, as the compression rate increased from 5×10-5 to 10 m/s, the primary crashworthiness parameters of the magnesium tubes increased in an approximately exponential manner,while for the aluminum tubes,they changed slightly. Finally,the involved induced features were proven to be not an effective method to improve the specific energy absorption of magnesium tubes, thus, more trigger types,locations,and sizes will be evaluated in future to improve the energy-absorption ability.

摘要：针对传热管的漩涡脱落诱发振动问题,在经典尾流振子模型的基础上,提出一种用于预测传热管涡致振动的改进尾流振子模型。计算结果与实验结果的对比显示,该模型能较好地模拟传热管涡致振动的重要特性。首先,通过研究发现,采用联合的位移耦合和加速度耦合模式,能较好地模拟柱体振动与漩涡脱落间的相互作用;其次,经典尾流振子模型中定义的经验参数为定常数,但通过分析发现,其经验参数应根据具体的结构参数来确定;最后,对改进的尾流振子模型所预测的结果与通过流固耦合数值模型计算得到的结果进行了对比分析,结果显示改进的尾流振子模型的结果与双向流固耦合模拟得到的结果吻合较好,说明尾流振子模型用于传热管的漩涡脱落诱发振动是可行的、合理的。