新型麝香DDHI中间体合成条件的优化

考察了麝香DDHI中间体2,6-二异丙基苯酚(简称262)合成中催化剂、反应温度、原料配比、助催化剂等因素,得出了最优工艺条件。     

Attachment security in very low birth weight infants.

34 infants of very low birth weight (VLBW) and a comparison group of 40 full-term infants were observed in the Strange Situation of M. D. Ainsworth et al (1978) at 14 and 19 mo and observed in the home at 14 mo of age, using E. Waters's (1995) Attachment Q-set. Results indicated that at 14 mo VLBW infants were more likely than the full-term infants to be insecurely attached when rated using the Q-set but not when using the Strange Situation. However, at 19 mo VLBW infants were also more likely than full-term infants to be insecurely attached in the Strange Situation assessment. There were no associations between the Q-set and Strange Situation measures of attachment security. These results are discussed in terms of the social-emotional development of VLBW infants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interfacial processes and the performance of cathode linings in aluminum smelters

Measurements of the rate at which aluminum carbide dissolves in aluminum smelting electrolytes show that the dependence on electrolyte acidity (or excess aluminum fluoride concentration) follows a similar trend to that for the carbide saturation solubility, indicating mass transfer control. However, since the electrolyte supply at the aluminum/cathode carbon interface is limited, preferential corrosive wear will occur in areas where there is maximum accumulation of sludge and subsequent back feeding. The rate of the carbide corrosion can be reduced by adding Ti(IV) in relatively small concentrations (about 100 ppm); this also causes wetting of the carbon by the electrolyte. With further increases in the Ti(TV) concentrations—typically to about 350 ppm—apparent wetting with the metal also occurs, but under such conditions an electronically conducting electrolyte/carbide layer exists between the carbon and the wetted metal. Because of the higher viscosity of the titanium-rich metal phase when metal wetting occurs, the thickness of the film increases significantly. This mitigates titanium diboride formation on the carbon surface when the electrolyte contains both titanium oxide and boron oxide.     

一种多参数钻井模型实时辩识方法

针对钻井生产过程随时间推移而逐渐变化的实际，提出了适于实时优化钻井的多参数钻井模型自适应跟踪算法。该方法不仅能对原来钻井模型进行实时修正辩识，而且利用计算机程序计算简便、控制精度较高。该方法是对两种递推算法的推广，特别适用于新探区建立钻井模型。文中有计算实例。     

Long-term soil accumulation of potentially toxic elements and selected organic pollutants through application of recycled phosphorus fertilizers for organic farming conditions

The pollutant input and the risk of contamination by long-term application of recycled P fertilizers (RPFs) in European agricultural soils were estimated by a mass balance approach. Calculations based on literature data were carried out for the potentially toxic elements (PTEs) Cd, Cr, Cu, Ni, Pb, Zn and for the persistent organic pollutants (POPs) PCBs, PAHs and polychlorinated dibenzo-dioxins and -furans. The PTE accumulation estimation during 200 years of fertilizer application, equivalent to 11 kg P ha^?1 year^?1, the mean P export via harvested products on European stockless organic farms, regarded soil background concentrations and proposed threshold concentrations. For PTEs, inputs were fertilizer application, atmospheric deposition and liming, output processes were leaching and crop harvest. The effect of varying site conditions was assessed by considering two precipitation excess (F) values and two soil pH values. For POPs, fertilizer application and the half-life time were considered. The PTE accumulation risk was low for most RPFs. For the analysed POPs no accumulation was found. The highest accumulation was found for all PTEs at pH 7 and F = 0.1 m year^?1, the lowest at pH 5 and F = 0.3 m year^?1. A high P concentration in fertilizers resulted in a low PTE flow per unit of P. Composts had the highest PTE accumulation risk due to lowest P contents. Struvite, meat and bone meal, digestate of catering waste, ash and biosolids would be better suited as P fertilizers. The use of fertilizers should be regulated based on their pollutant-to-nutrient ratio.     

Continuous Detonation Combustion of Hydrogen: Results of Wind Tunnel Experiments

Combustion tests of a ramjet model 1.05 m long and 0.31 m in diameter with an expanding annular combustor operating in the regime of detonation combustion of hydrogen are described. The tests are performed in a short-duration wind tunnel at free-stream Mach numbers of the incoming air flow from 5 to 8 and stagnation temperature of 290 K. Continuous detonation and longitudinally pulsating regimes of hydrogen combustion with characteristic frequencies of 1250 and 900 Hz, respectively, are observed. The maximum measured values of the fuel-based specific impulse and the thrust generated by the engine are 3600 s and 2200 N, respectively.     

以尺寸驱动为核心的参数化图形库管理系统的设计

本文介绍了以尺寸驱动为核心的参数化图形库管理系统ＸＴＬＩＢ的原理和结构。参数化图形库管理系统ＸＴＬＩＢ在工程设计中为用户提供了强大的零件库创建及管理功能，可以方便地完成零件的系列化设计和变型设计，使设计人员从繁琐的绘图中解脱出来，把精力投入到有创造性的设计中去。ＸＴＬＩＢ系统在实际的机械设计中得到了广泛的应用。