Synthesis and optical properties of polyacetylenes containing nonlinear optical chromophores

High molecular weight polyacetylenes bearing nonlinear chromophoric pendants poly[4-ethynyl-4′-(N,N-diethylamino)azobenzene-co-phenylacetylene]s [poly(EAAB-co-PA)s] were synthesized in moderate yields by [Rh(nbd)Cl]₂-Et₃N. The azo unit in the copolymers can be effectively controlled by the monomer feed ratio. Whereas the homopolymer of EAAB possessed low solubility, all the copolymers, however, dissolved readily in common organic solvents when the poly(EAAB) molar content was less than 41.7%. The structures and properties of the polymers were characterized and evaluated by UV, NMR, optical limiting, and nonlinear optical analyses. All the copolymers possessed high stereoregularity and thermal stability (≥300 °C). They can attenuate intense laser pulses, with solutions of high concentrations showing better performances. The third-order nonlinear susceptibility of the copolymers was as high as 4.62×10⁻¹¹ esu, which are two orders of magnitude larger than those of poly(PA), and larger than that of poly(N-carbazoylacetylene), and poly(1-naphthylacetylene).     

Influence of current density on oxygen transfer in an electroflotation cell

The objective of this work is to study the transfer of oxygen from gas to liquid phase in an electroflotation cell. The measurements were performed in a laboratory scale cell using insoluble electrodes, titanium coated with ruthenium oxide as anode and stainless steel as cathode. The volumetric mass transfer coefficient K _L a, was characterized for clean tap water as liquid phase for different values of current density (J). The global coefficient of mass transfer based on the liquid film, K _L , and the specific interfacial area, a, were characterized. A model which relates K _L a to current density was established. Different evaluation criteria of oxygen transfer in electroflotation process were determined and compared with other aeration process.     

废旧电池中有价金属回收利用探讨

随着中国经济的稳步发展和投资环境的不断优化,中国已成为电池的制造和消费大国,每年产生数亿只废旧电池。对废旧电池的回收利用已成为全社会关注的问题。介绍了废旧电池中有价金属的回收利用方法,着重介绍了锂离子二次电池正极材料有价金属的回收利用方法。指出,中国商品化的正极材料只有钴酸锂（LiCoO2）,这种正极材料钴含量高,且钴价值高,并且回收工艺可行,因此,从钴酸锂正极材料中回收钴等有价金属,对发展中国的循环经济具有重要意义。同时介绍了锂离子二次电池正极材料的研究现状。     

Frying Performance of No-<Emphasis Type="Italic">trans</Emphasis>, Low-Linolenic Acid Soybean Oils

Two extruded-expelled physically refined soybean oils with reduced contents of linolenic acid, ultra-low- linolenic acid (ULL, 1.5%) and low-linolenic acid (LL, 2.6%), and a extruded-expelled physically refined control oil (control, 5.3% linolenic acid) were evaluated by frying French fries in a commercial-like setting for 6 h day⁻¹ during 23 days. The oils became darker, increased in yellow color at the beginning, and became redder and less green throughout the process. Free fatty acids levels were not different among the oils until day 14, after which, ULL was different from the control for the remainder of frying. The conjugated dienoic acid values were greatest in the control. Generally, ULL and LL oils had lower percentages of polar compounds than did the control, providing a frying life 2 days longer than the control and ~30% increase in frying time. A trained sensory panel evaluated the French fries on days 2, 5, and 6. Buttery and potato flavors decreased, and rancid and painty flavors increased over frying time for all products. Rancid flavor was highest in the fries from the control oil. Overall, the ULL and LL oils performed better than did the control oil and ULL tended to perform better than the LL.     

废钴钼系催化剂中金属的全回收新工艺研究

开发了一种用于废Co/Mo/γ-Al2O3催化剂的金属全回收工艺.首先将催化剂在通空气的情况下进行氧化燃烧以除去碳和硫.焙烧后样品经浓氨水多次浸取,得到的溶液部分先用锌置换络合物中的少量钴,之后加硝酸回收MoO3;氨浸后的滤渣用硫酸溶解,加硫酸铵分离出氨明矾,以去掉大部分铝;所得少量浓缩液去掉铁等杂质之后,加过量氨使钴形成络合物,再用锌粉置换出金属钴粉.Mo、Al、Co的回收率分别大于90%、85%和90%.     

共沉淀法制备三元系铋基焦绿石型陶瓷粉体

采用改进的Mergen A．方案，用氧化锌、三氧化二铋、三氧化二锑为原料，氨水、草酸铵和碳酸铵分别为沉淀剂，盐酸为溶剂，用共沉淀法成功制备了亚微米级颗粒、高活性的铋基Bi1.5ZnSb1.5O7（BZS）焦绿石型介电陶瓷粉体。探讨了用不同的沉淀剂、在不同的烧结温度所得产物的形态。结果表明氨水做沉淀剂在570℃就可生成纯的焦绿石结构。与Mergen A方法相比成本大大降低，可以使瓷片组织的均匀性提高，电性能得到改善，电压梯度下降。     

The ageing Australian firefighter: an argument for age-based recruitment and fitness standards for urban fire services

Currently, there is no enforcement of physical standards within Australian fire services post-recruitment, possibly leading to inappropriate fitness and body composition. This study evaluated the impacts of ageing on physical standards of Australian firefighters. Seventy-three firefighters from three different 10-year age groups [25–34 years (n = 27), 35–44 years (n = 27), 45–54 years (n = 19)] volunteered for physical testing using dual-energy X-ray analysis and existing fitness tests used for recruitment by an Australian fire service. Older (45–54 years) participants demonstrated significantly poorer physical standards compared with younger participants including cardiovascular fitness (p < 0.05), strength (p = 0.001) and simulated operational power testing tasks (p < 0.001). Age-related body composition changes were also observed independent of body mass index. Minimum recruitment standards and fitness programs need to account for age-related declines in physical capabilities to ensure that the minimum standard is maintained regardless of age.

Practitioner Summary: Using dual-energy X-ray analysis and established fitness testing protocols, this study aimed to gain an appreciation of the current standards of body composition and fitness of Australian firefighters and the effects of ageing on their physical abilities post-recruitment. The study demonstrated a significant decline in physical standards due to age.     

Responses by amphisbaenianBlanus cinereus to chemicals from prey or potentially harmful ant species

We tested the ability of amphisbaenians (Blanus cinereus) to discriminate between odors of ant species selected as prey (Pheidole pallidula) and odors of potentially harmful ant species (Messor barbarus) that are avoided. Tongue-flick rate to swabs impregnated with ant odors, cologne, or deionized water differed among treatments, showing that amphisbaenians were able to discriminate ant species odors. Amphisbaenians showed an aggressive response and bit applicators bearing the odor of harmful ants, while the odor of prey ants did not elicit bites to swabs. The possible evolutionary advantage of identifying and avoiding harmful ants is discussed in relation to the fossoriality of amphisbaenians.     

On reactive routing protocols in ZigBee wireless sensor networks

ZigBee is the primary standard solution for wireless sensor networks, implementing the Ad hoc On‐Demand Distance Vector (AODV) protocol in the network layer and supported by the standard IEEE 802.15.4. This study is focused on mesh topologies and the critical problems encountered when AODV is executed in conjunction with the Carrier Sense Multiple Access with Collision Avoidance protocol. These problems are mainly related to the packet overhead required to carry out route creation. To perform preliminary experiments to be able to implement AODV in a real network, a new metric is proposed herein. This metric uses fuzzy logic to help in the decision‐making process. The objective of the fuzzy routine is to determine, during the route‐discovery process, the best node to forward request/reply packets, with the aim of reducing packet overhead and energy consumption. Moreover, minor changes are also added to the discovery procedure of AODV to improve the performance of the route‐creation process. This intelligent version of AODV has provided promising experimental results, greatly reducing the number of packets required, with the consequent energy saving while selecting the best nodes to be part of the routes.     

Amino-acids in humic,nitrohumic and nitrofuvic acids from coal

The humic acids, HA, extracted from a Spanish lignite and the nitrohumic acids, NHA, and nitrofulvic acids, NFA, extracted from the same lignite after its nitration, are hydrolysed with 6N HCI under reflux. The α-amino acids present in the hydrolysates are determined and thirteen α-amino acids are identified. The amounts of nitrogen in the amino-acids released by the hydrolysis increase according to the sequence: NFA > NHA > HA.