Flash Lamps as Ignition and Initiation Sources of the VS-2 Pyrotechnic Composition

In the present work it is found that the pyrotechnic composition VS-2 can be initiated with flash lamps IFC-500 and EVIS. VS-2 pyrotechnic composition contains 90% of mercury（Ⅱ） 5-hydrazinotetrazolate perchlorate and 10% of optically transparent copolymer of 2-methyl-5-vinyltetrazole and methacrylic acid （PVMT）. We have found that the flash lamps make it possible to initiate combustion of VS-2 composition with its transition to detonation both in cylindrical charges placed in brass caps of 5 mm diameter and 2 mm high， and film charges with 10 mm×80 mm in size and surface weights of 60 mg·cm^-2 and 90 mg·cm^-2， showing ignition delay times 10 μs and 3 μs， respectively. We also measured detonation velocities for VS-2 composition film charges， which were 4375-4505 m·s^-1 （of the charge being surface mass 60 mg·cm^-2） and 4221-4281 m·s^-1 （of the charge being surface mass 90 mg·cm^-2） and their blasting action on the aluminum plate. The depths of the normal shock wave imprints at the charge-barrier interface were 0.6-0.7 mm （for surface mass of the film charges 60 mg·cm^-2） and 1.2-1.3 mm （for surface mass of the film charges 90 mg·cm^-2）.     

滴施腐植酸肥和化肥对辣椒生产率的影响

正采用随机区组设计,在不添加腐植酸(单独施肥)和添加腐植酸(联合施肥)的条件下,以NPK推荐施肥量100%、80%和60%的3个施肥水平,研究了NPK滴灌对辣椒养分分配和生产率的影响。在较深的土层中,联合施肥能降低土壤速效N和K含量,提高土壤速效P含量。单独施肥的基础上联合施肥,辣椒产量提高了17%~27%。联合施肥的肥     

“至上”与“虚无”

<正>俄国画家马列维奇是"至上主义"抽象绘画流派的创始者,其绘画作品简约而纯粹,以最简单的形式——方块展现出艺术家丰富的感情世界,探索了形体、色彩与空间的关系。而同样善于运用几何形态的西班牙雕塑家奥泰萨的风格则显得冷静而克制,其雕塑作品通常看起来虚幻而抽象,没有强烈的情感表现,以高度理性化的手法展现出一种"虚无"的艺术境界。二人所专注的领域虽有不同,但他们的作品都在关注形式与其所在空间之间的复杂关系。     

基于新标准的俄罗斯釆金业职业风险评估

当前俄罗斯正在进行立法改革以实现治理体系现代化，其中改革的重点是国家管理体系中的劳动保护、工业安全和突发事件的应急处理。过去的立法体系侧重于对受伤员工提供健康补偿和医疗救护，而新的立法体系则以预防为主，以期通过建立完善的风险管理机制和运行规则，提高安全生产水平、普及安全文化教育，保障员工的生命安全。新标准强调企业必须进行职业风险评估，并将职业风险评估纳入企业工作管理体系。论文以采金业为例，选取伊尔库茨克州波戴波区金矿露天采场为研究案例，探讨了现代化职业风险评估的方法，明确了职业风险评估首先要进行危害鉴别，编制了风险源管理档案清单。采用实测员工风险因素的“记分法”和数学模拟“矩阵法”完成了伊尔库茨克州波戴波区金矿露天采场主要职业的风险评估。研究表明: 在钻井爆破作业场所，由碎石的喷射、粉尘的排放和噪声效应引起的危险为不可接受风险，通过实施安全生产制度（即遵守安全标准和技术要求、为工人提供防护装备）,可将高风险和不可接受风险化解为可接受风险；阐述了高风险职业，编制了风险手册，提出了改善工作条件的首要措施是消除影响爆破手和钻机操作员的有害因素，并为员工提供能更有效预防噪音和振动的个人防护用品。     

发呆,也是一种小美好

正白岩松说,没事儿的时候发发呆。我们疲于追逐成功的路上,发呆成了一种奢侈。是啊,回想一下,在我们每天仅有的24小时中,工作、交际以及各种琐事占据了大半,剩下的注意力又被手机等携带大量娱乐信息的产品夺走。我们每天生活的似乎都很"丰满",迈着急促的脚步穿梭于公司、学校、商场、电影院之间,甚至感觉时间不够用,经常熬夜到凌晨,因此,我们没有多余的时间去发呆,或者说,在这个充满娱乐信息的时代,我们不需要去孤独地发呆。     

SPEY项目——聚乳酸(PLA)短纤纱稳定环锭纺的工艺布局

介绍了Spun EcoYarn(SPEY)项目的研究现状。该项目旨在通过方法学分析与工艺分析,研究聚乳酸(PLA)短纤纱在家用或产业用纺织品领域的应用。工艺过程分析的目的是避免PLA在环锭纺过程中出现降解现象。目前,项目已成功制备出100%PLA环锭纱。当生产速度为23 m/min、纱线捻度为100 T/m时,可纺制25 tex的PLA纱,且纺纱工艺稳定、无断头。概述了采用PLA长丝进行环锭纺的试验结果,提出了稳定生产100%PLA环锭纱的优化工艺参数。     

Pulsed laser reshaping and fragmentation of upconversion nanoparticles-from hexagonal prisms to ID nanorods through“Medusa”-like structures

One dimensional(1D)nanostructures attract considerable attention,enabling a broad application owing to their unique properties.However,the precise mechanism of 1D morphology attainment remains a matter of debate.In this study,ultrafast picosecond(ps)laser-induced treatment on upconversion nanoparticles(UCNPs)is offered as a tool for 1 D-nanostructures formation.Fragmentation,reshaping through recrystallization process and bioadaptation of initially hydrophobic(β-Na_1.5Y_{1.5_}F₆:Yb³⁺,Tm³⁺/β-Na_1.5Y_{1.5_}F₆)core/shell nanoparticles by means of one-step laser treatment in water are demonstrated.“True”1D nanostructures through"Medusa^-like structures can be obtained,maintaining anti-Stokes luminescence functionalities.A matter of the one-dimensional UCNPs based on direction of energy migration processes is debated.The proposed laser treatment approach is suitable for fast UCNP surface modification and nano-to-nano transformation,that open unique opportunities to expand UCNP applications in industry and biomedicine.     

Influence of Nano-Materials on Mechanical and Permeation Characteristics of High Strength Concrete

Efforts have been made to evaluate the influences of the addition of nanoparticles on the strength,durability and mineralogical changes of high strength concrete (HSC).Therefore,mixes were prepared for conventional concrete mix (CCM) of M80 grade.Further,various mixes were prepared by replacing cementitious materials initially with 1% Nano-CaCO₃ (NC),2% NC,3% NC in the CCM,and then 1% NC and Nano-SiO₂ (NS) NS,2% NC and NS,3% NC and NS (NC and NS were in equal proportion) in...     

国际期刊干燥技术杂志的简史

正干燥是在大多数的工业领域中得到应用的最古老的单元操作。作为一种能源密集型的操作,其在全球范围内的研发受到了越来越多人的关注,这可以从数量众多的以干燥为主题的国际会议中得到佐证。但是作为一种将传质现象与材料科学结合起来的多学科交叉的独立领域方面的研发,才有大约40年的历史。大部分1980年之前的干燥技术文献的撰写语言不是英语,而是俄语、德语、法语、波兰语等。英文撰写的研发资料在80年代后才出现,这主要     

Contamination of potable roof-collected rainwater in Auckland, New Zealand

One-hundred and twenty-five domestic roof-collected rainwater supplies in four rural Auckland districts were investigated in a cross-sectional survey to determine water quality. Samples of cold faucet water were analysed for physico-chemical and microbiological determinands, including metals (zinc, copper and lead), bacterial indicator organisms--heterotrophic plate count (HPC), total coilforms (TC), faecal coliforms (FC), enterococci (ENT), bacterial pathogens including Salmonella spp., Legionella spp., Campylobacter spp., Aeromonas spp. and the protozoa, Cryptosporidium and Giardia. Twenty-two supplies (17.6%) exceeded one or more of the maximum acceptable values (MAV) or maximum guideline values for chemical determinands of the New Zealand Drinking Water Standards (NZDWS) and 70 (56.0%) supplies exceeded the microbiological criteria of < 1 FC/100 mL. Eighteen supplies (14.4%) exceeded the NZDWS MAV for lead of 0.01 mg/L and three (2.4%) exceeded that for copper, of 2 mg/L. Those supplies with lead or galvanised iron comprising part of the roof or collecting system were more likely to show lead contamination (p = 0.019) as were those supplies with a pH less than 7 (p = 0.013). The presence of the indicator organisms HPC, TC, FC and ENT were all significantly correlated with one another. Aeromonas spp. were identified in 20 (16.0%) supplies. There was a positive association between the presence of Aeromonas and the bacterial indicator organisms. Households reporting at least one member with gastrointestinal symptoms in the month prior to sampling, were more likely to have Aeromonas spp. identified in their water supply than those households without symptoms (odds ratio 3.22, 95% CI 1.15-9.01, p = 0.021). Salmonella typhimurium was detected in one of 115 (0.9%) supplies. Legionella spp. and Campylobacter spp. were not detected. There were 50 supplies sampled for protozoa (sampling criteria: > or = 30 FC or > or = 60 ENT). Cryptosporidium oocysts were detected in 2 (4%) of these. Giardia was not detected. This study demonstrates that roof-collected rainwater systems provide potable supplies of relatively poor physiochemical and microbiological quality in the Auckland area. Further research is required on Aeromonas spp. as potential indicators of both microbiological quality and health risk along with design and maintenance strategies to minimise contamination of potable roof-collected rainwater supplies.