注塑模具超长细孔型芯的设计与制造

对于注塑模具来说,细孔特别是超长细孔的成型一直是业界的一个难题。文中以塑料光纤针座为例,提出了超长细孔型芯的设计与制作新方法,指出了传统制作方法的弊端,并对其新方法的效益和应用前景进行了描述。     

影响冲模寿命的因素及对策

对影响冲模寿命的因素进行分析，提出改进措施，实施后达到了预期效果。     

硬质合金刀具材料的新进展

目前硬质合金刀具已发展成完整的系列 ,成为刀具结构发展的主流。文中介绍了近几年来硬质合金刀具材料的新进展     

Truly Concomitant and Independently Expressed Short‐ and Long‐Term Plasticity in a Bi2O2Se‐Based Three‐Terminal Memristor

Concomitance of diverse synaptic plasticity across different timescales produces complex cognitive processes. To achieve comparable cognitive complexity in memristive neuromorphic systems, devices that are capable of emulating short‐term (STP) and long‐term plasticity (LTP) concomitantly are essential. In existing memristors, however, STP and LTP can only be induced selectively because of the inability to be decoupled using different loci and mechanisms. In this work, the first demonstration of truly concomitant STP and LTP is reported in a three‐terminal memristor that uses independent physical phenomena to represent each form of plasticity. The emerging layered material Bi₂O₂Se is used for memristors for the first time, opening up the prospects for ultrathin, high‐speed, and low‐power neuromorphic devices. The concerted action of STP and LTP allows full‐range modulation of the transient synaptic efficacy, from depression to facilitation, by stimulus frequency or intensity, providing a versatile device platform for neuromorphic function implementation. A heuristic recurrent neural circuitry model is developed to simulate the intricate “sleep–wake cycle autoregulation” process, in which the concomitance of STP and LTP is posited as a key factor in enabling this neural homeostasis. This work sheds new light on the development of generic memristor platforms for highly dynamic neuromorphic computing.     

Analysis of non-loading carrying fillet welds joint using SGBEM

Fatigue failure is probably the most common type of failure in welded construction. It is usually initiates at a stress concentration area within the structure. The fatigue behavior of non-load carrying cruciform fillet welded joint has been studied extensively using boundary element method. The symmetric boundary element method for multiple cracks problem is derived using Betti's reciprocal theorem in auxiliary fictitious state. High order element is proposed to solve the double integrals. The analysis demonstrates that symmetrical Galerkin boundary element method (SGBEM) can be used effectively for analyzing non-load carrying fillet welded cruciform joints containing any number of surface and embedded cracks. The stress intensity factor and the magnification factors M _k are analyzed. General formulation for this kind of fatigue life estimation is derived for engineering design purpose. The fatigue life estimate results are consistent with the code of practice and those of other researchers. This can provide a good method for engineering design under fatigue loading conditions.     

Torsion sensor based on two cascaded long period fiber gratings fabricated by CO2 laser pulse irradiation and HF etching technique respectively

A novel torsion sensor is proposed, which is composed of one long period fibre grating and one asymmetrically corrugated long period fibre grating based on the high-frequency CO₂ laser pulses technology and burning fibre coating and etching cladding technology, respectively. By combing the advantages of the two aforementioned elements, a sensitivity of 331.7 and 310.3 pm/(rad/m) towards clockwise and anticlockwise direction, respectively, is reached in the experiments.     

Tradeoff Analysis for RMS of Equipment Based Operation Availability and Life Cycle Cost

Reliability, maintainability, supportability (RMS) are the important performance indexes of equipment, which affect not only the availability, but also the life cycle cost (LCC) of the equipment. First discussed is the qualitative relation between reliability and LCC and the costs which may be used to enhance the reliability. Secondly, the factors that affect the maintainability are summarized, and if maintainability is advanced, the trend of the LCC is depicted. Thirdly, the qualitative relation between th...     

亭台楼阁类建筑的文学价值

亭台楼阁作为中国古代的传统建筑,其特殊的体式、功能及其与自然环境所构成的独特意境,成为历代文人登高临远的重要场所,形成了大量诗文,这些作品往往寄寓了游子怀乡、壮士悲歌、文士不遇等情感,许多名篇对后人产生了强大的精神感召力,成为中华民族精神文化遗产的一部分。     

风能、太阳能储能用铅蓄电池的开发前景

分析了风能、太阳能独立发电系统储能蓄电池的使用状况,探讨了储能蓄电池使用环境对蓄电池的要求,认为储能蓄电池开发和应用面临着很多困难,需从板栅合金、铅膏配方、固化、化成等各工序进行分析研究,力争有所突破。