无卤印制电路的光谱分析和热分析

本文简要介绍了无卤板材和常规PCB的测试结果，并将不同制造商的无卤基材与常规FR-4基材作比较。     

中国重汽国内首创重卡板材激光拼焊技术

中国重汽卡车公司在HOWO重卡研发生产中，将世界先进的轿车车身板材激光拼焊技术应用于重卡车宽板材开发上。首创国内重型车车身板材激光拼焊技术。     

不厚此薄彼—谈音箱的板材

几年前曾为《高保真音响》写过“音箱丛谈”等文章,这些年来杂志社不断赠刊,有机会读到不少精彩佳文。因为忙,对杂志愧无贡献。最近潘志强主编来邮件,“不知能否拔冗为本刊写一些稿件？”。如果决定写,写什么内容？器材评述介绍的文章已不少;理论性太强的文章,也不适合在本刊发表。音响、音箱、扬声器……同火箭、卫星、飞机、汽车相比,自是小菜一碟。但即使是小菜一碟。亦可色味香俱全,环保科学、不可缺少。对酒当歌,闲可涉及文学艺术、音乐作曲。深可问人生儿何、去日苦多。老子言“治大国若烹小鲜”,那治音箱、治扬声器更是烹小鲜。我正在写《实用音箱手册》一书,希望是—本系统、严谨的书。是否可抽出一部分,另行组合、重行排列,让它趣味化？虽不能妙笔生花,引人如胜,却也不致味同嚼腊,无从下咽。我的同乡清代诗人阮元有一首《吴兴杂咏》：交流四水抱城斜,散作千溪通万家。深处种菱浅种稻,不深不浅种荷花。东抄西抄,抄来“不深不浅”之意,遂将系列短文,借名为《荷花集》。     

电路板制造覆铜板板材等级

1.FR-4A1级覆铜板 此级主要应用于军工,通讯,电脑,数字电路,工业仪器仪表,汽车电路等电子产品。该系列产品之质量完全达到世界一流水平。     

Process designing for laser forming of circular sheet metal

Laser forming is a new type of flexible manufacturing process that has become viable for the shaping of metallic components. Process designing of laser forming involves finding a set of process parameters, including laser power, laser scanning paths, and scanning speed, given a prescribed shape. To date, research has focused on process designing for rectangular plates, and only a few studies are presented for axis-symmetric geometries like circular plates. In the present study, process designing for axis-symmetric geometries-with focus on class of shapes-is handled using a formerly proposed distance-based approach. A prescribed shape is achieved for geometries such as quarter-circular and half-circular ring plates. Experimental results verify the applicability of the proposed method for a class of shapes.     

中强度激光辐照金属板材的变域动态温度分析

本文推出了金属板材受激光辐照后的变域速度 ,给出了板材发生边界物质液化脱离收缩 (内部不变 )时剩余板材内的温度分布方程及其边界条件 ,通过数值模拟 ,给出了不同时间、不同位置的温度分布图 ,分析了此种动态温度分布的形成机制。     

导模法生长超大尺寸蓝宝石板材的研究

采用自主设计制造的导模炉,通过热场模拟辅助设计出理想的模具表面温度分布,采用两段加热的方式控制晶体的应力和气泡缺陷,选择合适的提拉速率控制气泡层的分布,成功生长了高质量超大尺寸蓝宝石单晶板材,蓝宝石板材可利用尺寸690 mm×300 mm×12 mm.摇摆曲线半高宽为0.0163°,说明晶体具有良好的结晶质量.5 mm厚度样品的透过光谱测试表明,透过率与用其它晶体生长方法的晶体相同.     

激光辐照金属板材的温升和升温率

从光子与声子相互作用机制出发,导出金属材料的能量吸收速度;解热传导方程,求出激光辐照下金属板材料的温度分布;讨论了激光辐照时间、材料性质等对金属板材温升和升温率的影响。     

Analysis of the effect of blocking mass at corner interface of two plates at arbitrary angles on transmission of plane bending waves

Vibration energy transmission at corner interface of two infinite plates rigidly jointed at arbitrary angles was studied by wave approach so as to investigate the effect of blocking mass used for reducing plane bending wave transmission.Two local coordinate sys- tems were introduced and six new non-dimensional coefficients implying corresponding ratio governing characteristic impedances of plates or blocking mass were introduced to simplify for- mulations of transmission and reflection coefficients.Five samples were tested in experiment. Discussions were carried out based on the comparison between prediction and experiment in terms of insertion loss.It is concluded that blocking mass at corner interface acts like a"low- pass filter",effective for vibration attenuation above certain frequency.The value of TL and IL in"attenuation band"depends mainly on mass per unit length and band width of"attenuation band"on mass moment of inertia per unit length of the blocking mass.     

意大利新型隔声卷材和隔振板材

意大利艾索格玛公司（ＩＳＯＬＧＯＭＭＡ）在中国的独家代理上海得善贸易有限公司,于２０００年９月２２日在上海召开了新型隔声卷材和隔振板材介绍会．意大利工程师讲解了该种材料的性能、规格、用途、特点等． 新型隔声卷材和隔振板材的基料是被打碎的废橡胶轮胎,添加软木、树脂、乳液聚脂化合物等,制成Ｒ型和Ｓ型毡状卷材以及Ｍ型和ＭＡＶ型权状材,广泛应用于建筑物、工业、道路、铁路等领域的隔声、隔振． Ｒ型隔声卷材可以铺放在结构层地面上,不需要钉子和胶水粘结,它可降低噪声２４－２６ｄＢ．Ｓ型隔声卷材可简单地铺装于地面…