摩托车出口全纸质包装的设计

摩托车的包装已不局限于木箱、纸箱、铁包装、胶合板箱、密度板箱、蜂窝板箱和全纸质包装等包装材料,其中蜂窝板箱和纸箱是全球包装的发展趋势,由于该材料能回收再利用,符合环保要求,出口不受任何条件限制,因此得到了广泛地推广和使用。     

明挖顺作法深基坑加固设计与施工控制技术

为确保紧邻北京地铁和平里北街站东北风道北侧和平里七区6#楼的安全,提出了明挖顺作法施工的东北风道深基坑加固施工方案。通过运用典型的类比分析法对沉降分析,结合实际施工沉降量测数据,证明了施工方案的可行性和优越性。     

便携式铁路信号记录分析系统的设计

系统由底层记录部分和可视化分析平台2部分组成，其功能主要是记录轨道信号、检验机车信号的分析结论，并在分析平台上对记录数据进行可视化处理。底层采用ARM＋DSP的双CPU方案，分析平台运行在Windows环境下。详述了系统的整体功能及其软硬件设计，重点介绍了底层记录部分的硬件实现。     

续建工程新旧结构物衔接处理方法

由于各种原因,个别公路项目可能会出现中途停建的情况,续建时如何处理好新旧工程衔接问题,对项目的质量保证、营运安全十分重要。该文介绍了某公路项目在续建时对新旧结构物衔接处理的有关做法和经验,同时对旧桥缺陷处理方面也有一定参考价值。     

Heading control for turret-moored vessel in level ice based on Kalman filter with thrust allocation

This paper mainly focuses on the heading control of a position-moored vessel operating under level ice regime. A dynamic ice simulator interconnecting the vessel motions with the ice dynamics is used for the design of the heading control system. The strategy is to ensure that the vessel is kept at an appropriate position within the safe limits. Using a heading controller based on a Kalman filter, the desired control force is computed to counteract the environmental disturbances. A thrust allocation method is developed to go with the heading controller. To keep the ice forces to a reasonable level, the moored vessel should be aligned with the ice drift direction and small angles up to 15° in changes on heading against the ice flow could be possible. Therefore, heading control of a moored vessel exposed to level ice with drift angle 0° and 15° is simulated since the dynamic positioning system needs to resist ice yaw moments and lateral ice forces on the hull. The simulation indicates that the proposed control strategy performs satisfactorily for a moored vessel in level ice.     

Are there bubbles in the shipping freight market?

ABSTRACT

This paper addresses the reconsideration of price bubbles specific to the shipping freight market based on the method of the Generalized Supremum Augmented Dickey–Fuller (GSADF). This approach offers the opportunity to recognize multiple bubbles and set their corresponding original and final dates. Empirical results reveal that four bubbles existed in the shipping freight market between October 1988 and February 2018 in which freight deviated from fundamental values. Strong demand (especially in China), the supply capacity, crude oil prices and U.S. dollar fluctuations are potential explanations for the first three bubbles. The global financial crisis that burst in 2008 is the major factor results in the last bubble. Hence, we must distinguish the potential reasons of bubbles in different periods and take measures such as promoting economic multipolarization, strengthening the bargaining power of China, building an effective information transfer system, employing financial derivatives and accelerating the consolidation of the shipping industry to alleviate the negative influences on global seaborne trade.     

带吊舱水下机器人运动建模与仿真(英文)

To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle’s (AUV) motion controller, a six-degree of freedom (6-DOF) dynamic model for AUV controlled by thruster and fins with appendages is examined. Based on the dynamic model, a simulation system for the AUV’s motion is established. The different kinds of typical motions are simulated to analyze the motion performance and the maneuverability of the AUV. In order to evaluate the influences of appendages on the motion performance of the AUV, simulations of the AUV with and without appendages are performed and compared. The results demonstrate the AUV has good maneuverability with and without appendages.     

钢箱梁开启桥施工过程有限元分析

以海河开启桥为工程背景,建立施工全过程的空间数值分析模型,探讨了钢箱梁开启桥的力学性能特点,分析了其应力水平及其分布特点,为海河钢箱梁开启桥安装施工提供了技术参考.该桥的分析方法可供同类桥梁施工参考.     

车轮动态弯矩非正交误差的修正

针对车轮弯曲疲劳试验机由于传感器安装误差使得弯矩检测的非正交误差,难以达到国标规定的动态加载精度要求的问题,分析了非正交误差对弯矩检测精度的影响,建立了非正交误差修正模型,直接利用弯矩实测值经相关运算确定修正参数,并给出了该修正法的评价模型.理论分析和试验结果表明:该修正方法有效;采用该修正法,弯矩检测误差由4.6％降低到1％以下,提高了车轮动态加载精度,满足了本试验机弯矩加载精度要求.     

一种双组分锌盐表调剂的研究

开发一种双组分锌盐液体表调剂.通过配套磷化后的膜重和微观形貌考察了 PA-Z的表调能力,以及水质、PA-Z(A)和PA-Z(B)用量对表调能力的影响,表调槽液寿命.结果表明,PA-Z表调能力强;水质(电导率8～320 μs/cm)对表调能力影响小;PA-Z(A)用量1.25～2.5 g/L,PA-Z(B)剂用量1.2～...