粉体含能材料生产与储运中的静电安全及防护

分析了静电产生的原因,阐述了粉体含能材料生产中的静电起电现象、静电的危害、静电安全性评估标准以及建立在此标准基础上的静电放电危险的评价办法,提出了粉体含能材料在生产、运输中所需要采取的静电防护措施。     

荷能束辐照致使Cu/Ag表面偏析的研究

本文研究了金属(Cu)/金属(Ag衬底)系统的荷能束辐照引起的表面偏析现象。观察到Cu在多晶Ag衬底上溅射淀积过程中,Ag原子在Cu膜表面的偏析,且淀积Cu原子能量越大,Ag原子偏析程度越大,即观察到了淀积Cu原子10~(-1)～1eV量级的平均能量差异对膜层表面偏析行为的影响。对溅射淀积所得膜层进行keV量级的离子束辐照,Ag原子的表面偏析程度更甚。     

Design and control of a planar bipedal robot ERNIE with parallel knee compliance

This paper presents the development of the planar bipedal robot ERNIE as well as numerical and experimental studies of the influence of parallel knee joint compliance on the energetic efficiency of walking in ERNIE. ERNIE has 5 links—a torso, two femurs and two tibias—and is configured to walk on a treadmill so that it can walk indefinitely in a confined space. Springs can be attached across the knee joints in parallel with the knee actuators. The hybrid zero dynamics framework serves as the basis for control of ERNIE’s walking. In the investigation of the effects of compliance on the energetic efficiency of walking, four cases were studied: one without springs and three with springs of different stiffnesses and preloads. It was found that for low-speed walking, the addition of soft springs may be used to increase energetic efficiency, while stiffer springs decrease the energetic efficiency. For high-speed walking, the addition of either soft or stiff springs increases the energetic efficiency of walking, while stiffer springs improve the energetic efficiency more than do softer springs. Electronic Supplementary Material  The online version of this article () contains supplementary material, which is available to authorized users.

起爆索的概念及其特性

本文采用了新的导爆索芯药,得到了一种具有起爆特性的索,称之为起爆索。它能够被常规的电点火头、非电导爆管或延期体点火,并很快形成爆轰输出,对工业炸药实现引爆,因而具备工程雷管的功能。经过对起爆索爆速、殉爆距离、点火感度、起爆能力、轴向威力等的测定,反映出爆速与芯药线密度有关,其殉爆距离是普通导爆索的4倍多,对常规的电、非电导爆管和延期体点火方式则有较好的感度响应,爆速接近5 000 m/s时能够对粉状炸药、乳化炸药或水胶炸药实施引爆,而起爆索的轴向威力只达到2 mm厚铅板炸孔的合格水平。     

含能共晶技术研究进展

含能共晶技术在分子水平上可实现具有不同性能的含能化合物(如高能分子与低感度分子)之间的非共价键作用,并赋予含能化合物新的性能。同时,含能共晶技术在不改变原有含能化合物分子结构的前提下,可提高其稳定性,降低其感度。目前,高能量低感度含能化合物已成为研究热点之一。着重介绍了含能共晶技术的国内外研究现状,并主要从基础研究、研究进展、发展动态分析与理论计算等几个方面进行总结,最后对含能共晶技术研究存在的问题进行了分析。     

含能共晶技术研究进展

含能共晶技术在分子水平上可实现具有不同性能的含能化合物(如高能分子与低感度分子)之间的非共价键作用,并赋予含能化合物新的性能.同时,含能共晶技术在不改变原有含能化合物分子结构的前提下,可提高其稳定性,降低其感度.目前,高能量低感度含能化合物已成为研究热点之一.着重介绍了含能共晶技术的国内外研究现状,并主要从基础研究、研究进展、发展动态分析与理论计算等几个方面进行总结,最后对含能共晶技术研究存在的问题进行了分析.     

Enhanced energetic reasoning-based lower bounds for the resource constrained project scheduling problem

We present new and effective lower bounds for the resource constrained project scheduling problem. This problem is widely known to be notoriously difficult to solve due to the lack of lower bounds that are both tight and fast. In this paper, we propose several new lower bounds that are based on the concept of energetic reasoning. A major contribution of this work is to investigate several enhanced new feasibility tests that prove useful for deriving new lower bounds that consistently outperform the classical energetic reasoning-based lower bound. In particular, we present the results of a comprehensive computational study, carried out on 1560 benchmark instances, that provides strong evidence that a deceptively simple dual feasible function-based lower bound is highly competitive with a state-of-the-art lower bound while being extremely fast. Furthermore, we found that an effective shaving procedure enables to derive an excellent lower bound that often outperforms the best bound from the literature while being significantly simpler.     

Formation mechanism of nano-diamond films from energetic species: From experiment to theory

In this paper, a particular class of nano-diamond films deposited by energetic species is described. Deposition is carried out using the direct-current glow-discharge (DC GD) deposition technique from a methane/hydrogen mixture. In this method, film growth occurs from energetic species being accelerated and incorporated into the film surface. The growth of the nano-diamond film occurs on top of a preferentially oriented graphitic precursor with its basal planes perpendicular to the substrate surface. The nano-diamond films consist of an agglomerate of diamond particles with particle sizes in the 3-5 nm range with amorphous grain boundaries. The hydrogen concentration in the graphitic precursor is only a few percent; however, it increases to ∼15-20 at.% in the nano-diamond film.From a microscopic perspective nano-diamond film and growth from energetic species is explained as a sub-surface process in terms of a four-step cyclic process. The DC GD-deposited nano-diamond films were comprehensively explored by a number of complementary techniques. The hydrogen content and its role in nano-diamond film formation were assessed. The experimental methods used in our studies comprise near-edge X-ray adsorption fine structure (NEXAFS) to prove the short-range coordination of the carbon films and indirectly their phase composition. The surface and grain boundary phase composition were investigated by a combination of electron energy loss spectroscopy (EELS) measured as a function of incident electron energy and hydrogen etching experiments. By transmission electron microscopy (TEM), the micro-structural evolution and their visualization were achieved. The density evolution of the films was determined by X-ray reflectivity (XRR). The hydrogen content and its distribution in the films were studied by secondary ion microscopy spectroscopy (SIMS) and elastic recoil detection (ERD). The hydrogen bonding was investigated by high-resolution electron energy loss spectroscopy (HREELS).Most likely, hydrogen is bonded within the amorphous grain boundaries and saturates the nano-diamond particles. The surface of the films is amorphous in nature.     

Thermal and Spectroscopic Analyses of Caustic Side Solvent Extraction Solvent Contacted with 16 Molar and 8 Molar Nitric Acid

Abstract

Thermal and spectroscopic analyses were performed on multiple layers formed when Caustic Side Solvent Extraction (CSSX) solvent was contacted with 16 M or 8 M nitric acid. A rapid (i.e., minutes to hours) chemical reaction occurs between the solvent and 16 M or 8 M nitric acid as evidenced by color changes and the detection of nitro groups in the infrared spectrum of the aged samples. Thermal analysis revealed that decomposition of the resulting mixture does not meet the definition of explosive or deflagrating material.     

The physical demands upon (Dutch) fire-fighters in relation to the maximum acceptable energetic workload

The aim of this study was to assess the tasks and activities that make physical demands on Dutch fire-fighters and to compare them with a guideline related to the development of excessive fatigue. The occupational physical demands on Dutch fire-fighters were assessed by conducting a task analysis during 85 24-h shifts. While workplace observations on the duration and frequency of physical tasks and activities were recorded, the heart rate was measured. This was then used to calculate the heart rate reserve percentage (%HRR) for predefined working periods, tasks and activities during 24-h shifts. The findings indicate that actual fire-fighting during 24-h shifts is characterised by a low frequency of incidents, a short ‘turn-out’ time, short tasks, and activities with a moderate to occasionally high energetic workload. Two tasks which sometimes occur in actual fire-fighting exceeded the guideline on energetic workload. The conclusion was that, though the number of incidents and the occupational demands are low during 24-h shifts, the peak loads for these two tasks are energetically high and could lead to excessive fatigue. Consequently, attention may need to be paid to health surveillance for persons exposed to such energetic peak loads, the development of physical and medical selection procedures, training, and workplace adjustments.