《振动与冲击》征稿简则

《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的振动、冲击和噪声方面的成果及经验的综合性学术刊物。     

密切协作 不断提升服务保障水平

2011年1月12日,第九次全国认证认可工作部际联席会议在京召开。来自国家发改委、科技部、工信部、公安部、环保部、住房和城乡建设部、交通运输部、铁道部、水利部、农业部、商务部、卫生部、海关总署、工商总局、广电总局、体育总局、国家林业     

《振动与冲击》征稿简则

<正>《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的振动、冲击和噪声方面的成果及经验的综合性学术刊物。本刊为国家科委中国科技论文统计源期刊、《中国核心期     

《安装工程创优策划与指导》等三本书审定会在北京召开

<正>本刊讯《安装工程创优策划与指导》、《机电工程常用规范理解与应用》、《超高层建筑机电工程施工技术与管理》三本书审定会于8月16日至18日在北京召开。中国安装协会副会长兼秘书长、审定委员会主任杨存成,审定委员会副主任李广远、王英俊、关洁、金卫东、张勤,审定委员耿鹏鹏、张来民、史均社、何伟斌、柏万林、田来、陈超、朱正、张国友、黄崇国、石玉成、毛俊琦、丁锐、胡新余、王晓峰、王清训、     

《振动与冲击》征稿简则

《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的振动、冲击和噪声方面的成果及经验的综合性学术刊物。本刊为国家科委中国科技论文统计源期刊、《中国核心期     

中国少数民族乐器介绍之八——西南地区少数民族乐器葫芦笙和巴乌

中国长期以来就是一个统一的多民族国家，少数民族人口有几千万。中国西南部的云贵高原和广西壮族自治区是少数民旗聚住最集中的地区，那里居住着苗、彝、壮、藏、布依、侗、瑶、白、佬、怒、佤、哈尼、傣、僳僳、拉祜、纳西、景颇、苦聪、独龙、     

举办过世博会的国家之最

曾经举办过世博会的国家有：英国、法国、美国、德国、比利时、加拿大、日本、澳大利亚、西班牙、意大利、韩国、葡萄牙等。     

综合性的高新技术标准——《机械振动、冲击与状态监测国家标准汇编》

机械振动与冲击是一项覆盖面很广的共性基础技术,它涉及到机械装备、仪器仪表、能源电力、船舶车辆、交通运输、航空航天、土木结构、冶金矿山、水利工程、道路桥梁、地质勘探、农林机械、电子电工、劳动保护、环境保护、公共安全、医药卫生等领域,几乎与国民经济的各个部门、社会生活的方方面面都有密切的关系。     

白酒产品质量如何？

日前,国家质检总局对白酒产品质量进行了国家监督抽查.共抽查了北京、天津、河北、内蒙古、辽宁、黑龙江、吉林、四川、贵州、湖北、湖南、安徽、河南、山东、江苏、浙江、陕西、福建、新疆、重庆等20个省、自治区、直辖市117家企业生产的117种产品,合格97种产品抽样合格率为82.9%.     

《振动与冲击》征稿简则

《振动与冲击》是中国振动工程学会、上海交通大学、上海市振动工程学会联合主办的反映和交流我国力学、航空、航天、造船、车辆、机械、土木建筑、水利、电力、矿山、化工、冶金、仪器仪表、海洋工程、轻工、环境保护等领域的振动、冲击和噪声方面的成果及经验的综合性学术刊物.     

Ultrasonic Sealing of Flexible Packaging Films – Principle and Characteristics of an Alternative Sealing Method

The closure process for packaging is a key process. It ensures the protective function of packaging and assures the packaged goods a long life. In this context, efficient and reliable sealing processes are essential for the production of sustainable packages. In this paper, several characteristics of the ultrasonic sealing process will be discussed and accompanied by experimental results. The introduction provides an insight into the ultrasonic sealing process, its heating mechanisms and the process steps. A comparison is made with conduction sealing. Furthermore, basic principles of heating and energy dissipation are related to the influences of the sealing parameters on the seam strength. The experimental studies were carried out on typical packaging films, such as polyamide‐polyethylene laminates. The seam strength in ultrasonic sealing is compared with that in conductive sealing. A lower seam strength was found for ultrasonic sealing in all the tested films. Furthermore, the sealing behaviour of the packaging films contaminated with different kinds of foods was analysed for both sealing methods. Although the ultrasonic sealing method has marginal advantages for bulk materials such as wheat flour, conduction sealing was shown to be better for other products. A comparison of the energy consumption during the ultrasonic and conduction sealing verified the advantages of ultrasonic sealing. In particular for thick packaging films, the amount of energy required for bonding is significantly lower than for conduction sealing. In summary, this paper provides a survey of the characteristics of the ultrasonic sealing method in packaging applications – its advantages and limitations. Copyright © 2011 John Wiley & Sons, Ltd.     

基于Ansys的不同截面密封圈密封性能仿真分析

目的对"凸"形、矩形和"Y"形截面密封圈的密封性能进行对比分析,为端面静密封形式的密封圈选型和结构设计提供参考。方法基于Ansys的大变形接触有限元分析,对3种不同截面密封圈进行应力和接触压力仿真分析,并对结果进行比较。结果 "凸"形截面密封圈在压缩过程中最大应力和最大接触压力变化均匀,最大接触压力面较宽;矩形截面密封圈最大应力变化均匀,最大接触压力在密封圈压缩量超过18%后呈现陡增现象;"Y"形截面密封圈最大应力和最大接触压力在密封圈压缩量超过18%后均呈现陡增现象,而且最大接触压力面狭窄。结论对于特定密封圈槽的端面静密封形式,"凸"形截面密封圈密封性能最优。     

基于插值与神经网络的包装薄膜热封参数分析

目的研究塑料薄膜热封工艺中热封参数之间的非线性关系,建立一种可用于自动包装机热封过程的数学模型。方法通过实验采集样本数据,并用附加动量法训练BP神经网络,建立热封参数之间的非线性数学模型,最后通过神经网络预测热封时间,并采用插值算法建立目标热封强度下热封温度和热封时间之间的多项式数学模型。结果通过插值算法与神经网络的结合运用,较为精确地描述了热封温度和热封时间之间的数学关系,插值函数实现了神经网络模型的简化,两者误差较小。结论通过文中方法确定了包装材料热封参数之间的非线性关系,将其用于热封包装设备,可提高设备的智能化程度。     

高寒环境下GIS密封圈材料的选用及存在问题

为满足使用要求,分析了影响气体绝缘开关(GIS)设备密封圈耐寒性能的关键因素,选择出了适合在高寒环境下使用的GIS设备密封圈材料;并对GIS设备密封圈在高寒环境下的喷霜和漏气原因进行了分析.结果表明:在高寒环境下,GIS设备密封圈材料可选用改性后的三元乙丙橡胶.密封圈中的活性剂、填充剂在橡胶中的溶解度随着温度的下降而减...     

气囊封口式封套野外封存应用验证

目的 验证气囊封口式封套在军事装备野外封存中的防护效果和勤务适应性,为军事装备野外封存防护探索解决方案。方法 基于高阻隔铝塑复合材料和气囊压力封口技术原理,依据军事装备野外驻训、战地部署的防护需求,设计气囊封口式封套,并选择8个典型气候环境区的部队,组织为期1年的野外实装封存试验。结果 气囊封口式封套材料容易破损,即使外观完好的封套,其封存效果也存在较大差异,有的防锈蚀效果很好,有的反而加速了装备锈蚀。结论 气囊封口式封套存在结构性缺陷,对封存场地要求较高,安装操作不便,容易受温差变化影响,不适合军事装备野外封存使用。     

高压容器双锥环密封性能的研究

针对高压容器双锥密封结构实际应用中泄漏事故,从高压容器双锥密封结构密封机理,关注双锥密封结构密封比压,提出了拐点压力和最小密封比压的概念。分析了操作工况主螺栓载荷计算、主螺栓预紧力计算,进而推导了双锥密封结构操作工况回弹量和密封比压公式,求出了双锥环与端盖支撑面刚产生、尚未产生径向间隙的拐点压力和此时的最小密封比压,并与有限元分析结果进行比较,两者结果相当一致,并建议GB150对最小密封比压进行校核。     

环氧灌封料低温开裂问题及对策研究进展

针对如何解决环氧树脂灌封料在低温下易产生开裂这一问题进行了探讨.简要分析了环氧树脂灌封料产生开裂的原因;着重从配方设计方面介绍了目前通过对环氧树脂、固化剂、增韧剂和填料的选择来提高环氧灌封料抗低温开裂性能的研究应用进展;同时,从产品结构设计、灌封工艺方面对如何改善环氧灌封料的抗低温开裂性能提出了一系列对策.     

Innovative focused ultrasound-based sealing method of flexible packaging films—Principles and characteristics

A key process to package goods is the closure procedure. It ensures the good protection against the environment and vice versa. Ultrasonic sealing presents the advantage of converting locally ultrasound into heat, which is optimal for temperature sensitive goods. The disadvantages remain, however, the equipment cost, the noise generation, and the process sensitivity to materials. It is necessary to develop a sealing process to decrease the acquisition cost of the sealing equipment and cover a wide range of polymer films. This paper focuses on a new sealing method based on high-intensity focused ultrasound. The principles and characteristics of this process are discussed and underpinned with experimental results. Both the acoustic and thermal effects of the sealing process are summarized. A study of the process parameter impact on the seam strength in static and dynamic operating is proposed. Low-density polyethylene films with a carrier layer of bi-oriented polypropylene and polyethylene terephthalate are used. A first test bench generates point-shaped seam. The heat generation is recorded with an infrared thermography system. A second test bench, a horizontal form fill and seal machine, produces longitudinal seams. The seam quality is controlled by tensile test and tightness test. A quick heating of the polymer films is found. Point seams and longitudinal seams are successfully generated. The seams behave similarly to the ones generated with ultrasonic sealing process. However, the sealing velocity is limited to 3 m/min. This work provides a summary of the characteristics and principles of the new sealing method in packaging applications.     

Heat-sealing integrity assessment through nondestructive evaluation techniques

Sealing is a critical step in different packaging industries. In heat sealing as one of the major types of sealing processes, two layers of materials (typically thermoplastics) are joined together through the application of heat and pressure load for a certain sealing time. Due to the capabilities of the heat-sealing process to seal different kinds and sizes of packages, it has a wide range of applications in many different industries such as the packaging of food and medical products. The quality and integrity of sealings produced by these techniques are crucial for the quality and safety of the contained materials. In this paper, different types and processes of sealing are discussed. Due to the variations in shape, size, and complexity of the sealing region, quality testing and inspection of these products is a challenging task. Nondestructive testing and evaluation (NDTE) techniques can be promising tools to overcome these challenges. Furthermore, a detailed study of various types of potential defects and their generation mechanism in heat sealing is presented. Then, various types of NDTE techniques that can be potentially used for the inspection of heat-sealing regions and their working principles, as well as their strength and weakness in sealing inspection, are debated. Finally, several cases of sealing inspection and relevant NDTE techniques that are developed as standard procedures are presented. The discussions in this study provide useful information for the selection and implementation of appropriate quality inspection and inline quality monitoring of sealing parts and processes.     

煤矿岩巷掘进爆破封孔材料研究

为解决煤矿岩巷掘进爆破施工作业中封孔工艺复杂、易冲孔以及掘进效率低等问题,设计了一种新型流体封孔材料与高效的封孔工艺。该封孔材料是由大理石粉、水与瓜尔胶三者按照70∶30∶0.15的质量比配制成的混合浆体,使用搅拌与泵送一体机,实现流体耦合封孔,并在顾北煤矿巷道掘进施工中得到应用。实验结果表明,该封孔材料具有黏度高、体系稳定和剪切变稀的流体特性,配合一体机使用,封孔工作效率提高304%,单循环进尺提高14.6%。封孔材料性能优良,封孔工艺简单,掘进效率与爆破效果得到明显提高。