Grain-boundary de-segregation and intergranular cohesion in Si-Al-O-N ceramics

The influence of heat-treatment on high-temperature creep and sub-critical crack growth in hot-pressed Si-Al-O-N ceramics has been analyzed from microstructural evidence and determination of stress exponents and activation energies. The most significant change is the suppression of cavitation during creep and of the cavity-interlinkage mechanism for slow crack propagation. A creep mechanism of grain-boundary diffusion is characterized by stress exponent n=1 and unusually high activation energy >820 kJ mol^–1. The microstructural origin of the transformation in grain-boundary dominated properties is mainly the removal of triple-junction glassy residues within which cavities are nucleated. This is caused by grain-boundary diffusion of metallic impurities (Mg, Mn, Ca) into a surface silica oxidation layer, and consequent crystallization of the remaining glass components as . There is a continued improvement in grain-boundary cohesion and increased difficulty of grain-boundary diffusion following the stage at which triple-junction glass is removed. The resultant ceramics, in addition to superior mechanical behaviour, have an increased temperature for application due to a marked reduction in susceptibility to dissociation above 1400° C.     

Fatty acid composition of the sterol ester fraction of human adrenal cortex in Cushing's syndrome and after treatment with aminoglutethimide

The lipid that accumulated in the adrenal cortex of a patient who had been treated with aminoglutethimide has been compared with the lipid in normal human adrenal cortex and identified as esters of cholesterol with fatty acids. While the concentration of free cholesterol was normal, that of esterified cholesterol was three times greater than that in normal controls. Sterols were analyzed by gas chromatography and found to consist almost wholly of cholesterol. The fatty acid composition of the cholesterol esters in adrenal cortex from patients with abnormal steroid secretion rates was determined. An increased proportion of cholesteryl arachidonate (cholesteryl-3β-[allcis]-eicosa-5,8,11,14-tetraenoate) was found in adrenal cortex from patients with decreased steroid secretion rates and a decreased proportion in adrenal cortex from patients with steroid secretion rates raised sufficiently to cause Cushing's Syndrome. Publication no. 1429 of the Cancer Commission of Harvard University.     

羊毛染色新进展和机遇

综述了羊毛及其混纺织物的染色和印花中的最新研究成果和开发工作使用媒介染料和马来酸与三价铬离子形成的络合物对羊毛进行染色可降低六价铬离子对环境的污染而得色率高于重铬酸盐媒染法染色降低Cr系数会大幅度降低残余染液中铬离子的含量，而不降低羊毛染色的色牢度：有多种活性染料可供染羊毛使用，抗定型剂可抑制羊毛纤维中氨基酸的降解，系结合分析了染料、抗定型剂和羊毛损伤之间的关系，评价了羊毛喷墨印花的有关问题有39篇参考文献。     

The effect of various anti-setting systems in wool dyeing. Part 2: Sodium maleate based systems

Wool is subject to permanent setting reactions during dyeing at the boil. Sodium maleate additions to the dyebath exert an anti-setting effect, and in the case of wool piece-goods dyeing, the magnitude of anti-setting was evaluated using the crease angle method. To achieve anti-setting, the key reactions are the nucleophilic addition of the activated double bond in sodium maleate with wool thiolate anion groups and with free hydrosulphide anions generated by cysteine thiol decomposition. Optimum antisetting effects were achieved when wool fabric was treated with sodium maleate at pH 3. Fourier transform infrared reflectance spectroscopy was used to monitor chemical changes to the wool fibre. Compared to untreated wool, two new frequencies at 1354 and 865 cm⁻¹ were apparent; the highest intensity values for these bands were obtained for wool treated at pH 3, which indicates that wool, being positively charged in this acidic solution, adsorbed more sodium maleate, thus enhancing the chances for nucleophilic addition reactions.     

新西兰低影响雨水体系设计

低影响或是水环境敏感设计是现代景观设计实践的基础。概述了新西兰如何在设计和日常生活中推广及实施低影响设计,其具体的实施方法将引用新西兰奥克兰政府制定的《低影响设计手册》及《GD_O4指引文本》进行详细论述。在此会根据不同的水文情况和场地的大小,列举部分新西兰本地的设计项目,以及由中国与新西兰风景园林师共同合作的中国项目进行说明及阐述。     

Development of a company‐level dynamic cash flow forecasting model (DYCAFF)

Current methods of predicting cash flow have a number of significant weaknesses. At the project level, previous models are simple and incorporate only some of the variables affecting cash flow. On the company level, budgeting is performed on an overall basis (i.e. no account is taken of individual contracts). This is mainly due to the fact that a considerable amount of any year's turnover is contributed by contracts that have yet to be won (or even known of) at the time of the budget. This approach, in addition to being inaccurate, precludes the role of budgeting as a tool for strategy evaluation. This paper presents a dynamic cash flow forecasting model that would assist contractors to effectively plan and manage the cash flow of individual projects and at a company level. The advances made in the model can be represented by three of its main features. First, the development of a more accurate and complex cash flow calculation mechanism. Second, the development of an information system that will help the contractor enter the data necessary for this mechanism. Third, the development of a company‐level model that is based on individual projects, both known and unknown to the contractor at the time of the forecast.     

Friction and Wear Phenomena of Vegetable Oil–Based Lubricants with Additives at Severe Sliding Wear Conditions

The tribological responses of palm oil and soybean oil, combined with two commercial antiwear additives (zinc dialkyl dithiophosphate and boron compound), were investigated at a lubricant temperature of 100°C and under severe contact conditions in a reciprocating sliding contact. The friction coefficient of palm oil with zinc dialkyl dithiophosphate was closest to the commercial mineral engine oil, with a 2% difference. The soybean oil with zinc dialkyl dithiophosphate produced a 57% improvement in wear resistance compared to its pure oil state. The existence of boron nitride in vegetable oils was only responsive in reduction of wear rather than friction. The response of commercial antiwear additives with vegetable oils showed a potential for the future improvement in the performance of vegetable oils.