Welding process developments and future trends

The many welding processes now in use have developed over a period of 100 years in stages that can now be identified. No fundamentally new processes have appeared since 1970 but development has concentrated on quality and performance in production. A new period which will see the coming of the intelligent welding system now seems imminent. Greater use can be expected of the continuous electrode arc processes and newer specialised processes which are suitable for automated operation.     

高层斜交网格结构体系的性能研究

为研究钢管混凝土柱的轴向恢复力模型,设计制作了8个钢管混凝土柱试件并对其进行轴向往复加载,分析其受力机理和恢复力特性。基于试验结果,选用退化三线型模型,建立了钢管混凝土柱无量纲骨架曲线模型,并提出其轴拉与轴压方向的峰值承载力和位移的计算方法。鉴于钢管混凝土试件在轴拉与轴压方向受力机理的差异,对滞回曲线的正负向选用不同的滞回规则,建立了相应的卸载刚度函数。据此提出了钢管混凝土柱的轴向恢复力模型,并与试验滞回曲线进行对比,验证了恢复力模型的合理性,所建立的恢复力模型可为斜交网格结构体系的弹塑性分析提供依据。     

Current developments and trends in Dislocation Dynamics

Recent developments and applications of Dislocation Dynamics (DD) methodology are discussed in the context of their relevance to the Dynamics of Metals program at LLNL and parallel efforts elsewhere. The paper begins with a discussion of existing and developing linkages between DD and atomistic simulations (see the companion paper by Moriarty et al. in this issue). We then continue with an overview of the recent methodological developments leading to a discussion of connections between DD simulations and continuum meso-scale modeling and experiment (see the companion article by Becker et al. in this issue). The section finishes with a brief summary of issues that need to be resolved in the near future for the DD approach to deliver on its promise. This revised version was published online in June 2006 with corrections to the Cover Date.     

Current developments and trends on structural durability

Basic approaches for assessment of Structural Durability are outlined in principle. Some of their limits in actual application fields and new solutions are shown. Multiaxial Fatigue remains as to be treated very carefully. The superposition of damaging processes known as “Very High Cycle Fatigue” and “Corrosion Fatigue” might be a key for assessment of components at very high load cycles.     

Electron paramagnetic resonance: recent developments and trends

Major recent advances:High-field multi-frequency EPR improves our knowledge of magnetic materials, conductive polymers, and spin systems with large zero-field splittings. High-field electron nuclear double resonance provides better access to subtle details of the electronic structure of materials. Materials structure on length scales between 1.5 and 8 nm can now be characterized more precisely.     

新型高效红色磷光OLED器件

使用R-4B新型红色磷光染料作为掺杂剂,制作了结构为ITO/MoO3(10)/NPB(40)/TCTA(10)/CBP∶R-4B(x)/BCP(10)/Alq3(40)/LiF/Al的红色磷光器件,结合TCTA和BCP(电子和空穴阻挡材料),通过调节R-4B的掺杂比例,对器件的发光性能和发光机理进行了研究。结果表明,掺杂比例为6%时,得到光效和颜色稳定性较好的器件。在电压为4V时,电流密度为0.045mA/cm2,亮度为3.57cd/m2,最大电流效率为19.48cd/A;在电压分别为5、10和15V时,色坐标分别为(0.60,0.35)、(0.64,0.34)、(0.64,0.35)。分析认为,一方面,R-4B的发光机理主要有主体材料CBP对R-4B的能量传递及载流子直接注入R-4B形成激子;另一方面,TCTA和BCP的作用为对发光层内载流子、激子的阻挡及使空穴、电子更有效注入发光层。     

Sensor technology advances and future trends

Recent advances of sensor technologies have been powered by high-speed and low-cost electronic circuits, novel signal processing methods, and advanced manufacturing technologies. The synergetic interaction of new developments in these fields provides promising technical solutions increasing the quality, reliability, and economic efficiency of technical products. With selected examples, we will give an overview about the significant developments of methods, structures, manufacturing technologies, and signal processing characterizing today's sensors and sensor systems. Predominantly observed development trends in the future are discussed.     

Green nanotechnology of trends in future energy

It is well known that current fossil fuel usage is unsustainable and associated with greenhouse gas production. The amount of the world's primary energy supply provided by renewable energy technologies is required urgently. Therefore, the relevant technologies such as hydrogen fuel, solar cell, biotechnology based on nanotechnology and the relevant patents for exploiting the future energy for the friendly environment are reviewed. At the same time, it is pointed out that the significantly feasible world's eco-energy for the foreseeable future should not only be realized, but also methods for using the current energy and their by-products more efficiently should be found correspondingly to ensure the minimal environmental impact.     

Biomicrofluidics: Recent trends and future challenges

Biomicrofluidics is an active area of research at present, exploring the synergy of microfluidics with cellular and molecular biology, biotechnology, and biomedical engineering. The present article outlines the recent advancements in these areas, including the development of novel lab-on-a-chip based applications. Particular emphasis is given on the microfluidics-based handling of DNA, cells, and proteins, as well as fundamental microfluidic considerations for design of biomedical microdevices. Future directions of research on these topics are also discussed.     

Laser accelerator developments for future high-energy accelerators

Laser-driven accelerators will be realized as the next generation particle accelerators in the near future. Their development has been accelerated by success of high-energy gain electron acceleration by means of a laser wakefield excited via interaction of intense ultrashort laser pulses with underdense plasmas. On the basis of achievements of laser wakefield acceleration (LWFA) experiments, a design of LWFA for the second-generation study is considered from the point of view of application to high-energy accelerators, such as future linear colliders.     

New developments in magnetic separation

High extraction magnetic filters combine high gradient features of the Frantz Ferrofilter^R, high intensity concepts of the Jones separators, and principles of modern magnet design derived from high energy physics research. Evolution of high extraction magnetic filters used commercially by all major kaolin producers is reviewed and new trends in equipment are highlighted.     

New developments in insulin delivery

A vigorous research effort has been undertaken worldwide to replace injectable insulin by a more comfortable and painless delivery method. Several routes have been explored for their suitability with respect to insulin degradation in the human body. Considerable progress has been made in achieving the common goal for a convenient and equally effective insulin delivery. This article reviews the different routes available for insulin administration and the many successful developments that have been made in recent years for improving that particular route for a much better insulin delivery.