An analytical expression for the power coefficient of an ideal horizontal-axis wind turbine

The paper shows that an analytical evaluation of the power coefficient C_p for an ideal horizontal-axis wind turbine can be made via an expression giving the direct relationship of C_p and the axial induction factor a. The results obtained agree closely with those obtained numerically from the usual integral expression involving several variables.     

二硫代磷酸硫化氧钼与硫,磷添加剂的复配特性研究

研究了二烷基二硫代磷酸硫化氧钼（ＭｏＤＴＰ）摩擦改进剂及其与硫、磷、硫－磷型添加剂复合的抗磨减摩性能。试验表明，经过适当复配后，这类合活性元素的添加剂对ＭｏＤＴＰ的抗磨减摩性能均有增效作用，同一类型添加剂的活性愈高，增效作用愈显著。同时利用扫描电镜和Ｘ－射线能谱仪进行摩擦副表面膜的形貌照相及元素分析，对复合作用的机理进行了初步探讨。     

克拉2气田储层岩石的应力敏感性及其对生产动态的影响

克拉2气田是一个异常高压气藏，压力系数在2．0以上。在衰竭式开采条件下，其地层压力降幅可为普通气藏地层压力降幅的3倍以上，因此研究储层岩石应力敏感性及其对生产动态的影响意义重大。研究得出，岩石的应力敏感性特征主要有：岩石物性对应力的敏感性总体上不大，其中以孔隙度最小，渗透率次之，压缩系数最大；岩石物性随地层压力的下降而下降；在同一地层压降下．岩石物性下降幅度不是渗透率的连续函数，而是与渗透率分布范围有关，高渗透率范围，岩石物性下降幅度小，低渗透率范围，岩石物性下降幅度大。研究得出，克拉2气田岩石的应力敏感性对其生产动态的影响较小。     

Thermal Radiative Properties of Xonotlite Insulation Material

Introduction Xonotlite-type calcium silicate (6CaO?6SiO2?H2O) is synthesized porous insulation material by hydrothermal processing with quartz powder and limestone as the raw material (with CaO/ SiO2≈1:1). Compared with fire- retardant fibre, xonotlite has more excellent insulating performance, such as low thermal conductivity, environment friendly, high intension, and wide applying temperature range, which has been emphasized in recent years by many scholars and widely used in many indu…     

Simultaneous HPLC quantification of total cholesterol,tocopherols and β-carotene in Barrosã-PDO veal

A simple, rapid and sensitive procedure for the simultaneous determination of total cholesterol, tocopherols and β-carotene in meat is described. The method involves a direct saponification of the meat, a single n-hexane extraction and the analysis of the extracted compounds by normal-phase HPLC, using fluorescence (tocopherols) and UV–Vis photodiode array (cholesterol and β-carotene) detections in tandem. Rates of recovery of spiked meat samples were 93% for cholesterol, 83–86% for (α-, β- and -γ) tocopherols and 89% for β-carotene. Repeatabilities were high (CV < 6%) for all determined compounds, except for δ-tocopherol. This tocopherol, which is not usually present in meat, showed a much lower recovery percentage (73%) and repeatability (12.8%). This methodology was applied for the quantification of total cholesterol, tocopherols and β-carotene in three muscles (longissimus thoracis, longissimus lumborum and semitendinosus) of the Portuguese traditional Barrosã-PDO veal, obtained from autochthonous calves fed extensively during summer (with the least abundant green pastures) and slaughtered in early autumn (October). Barrosã-PDO veal showed median contents of total cholesterol (0.50–0.56 mg/g) and, depending on the analysed muscle, moderate to high contents of α-tocopherol (3.3–3.9 μg/g) and β-carotene (0.07–0.09 μg/g), suggesting an high sensorial and hygienic quality.     

Q195冷轧板材轧制困难原因分析

针对部分Q195冷轧板材存在轧制困难的现象，进行了现场检验与分析。带状组织、混晶现象严重导致变形强化系数偏高是造成轧制困难的主要原因。     

Water and salt permeability of reinforcement polymer‐gel composite membrane

The charged mosaic polymer membrane (CMM) without reinforcement and the composite charged mosaic polymer membrane (CCMM) with reinforcement were investigated in terms of salt and water transport (permeability). The composite charged mosaic polymer membrane (CCMM) with reinforcement showed a unique transport behavior such as preferential material transport L_p and ω. Water permeability coefficient, L_p and salt permeability coefficient, ω were estimated by taking account of active layer thickness of composite polymer gel. The L_p and ω values of CCMM with reinforcement were larger than those of CMM without reinforcement. On the other hand, the reflection coefficient of CCMM, σ, showed negative value, which suggested preferential material transport to solvent transport. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Water absorption properties of phosphate glass fiber‐reinforced poly‐ϵ‐caprolactone composites for craniofacial bone repair

The moisture uptake of polymers and composites has increasing significance where these materials are specified for invasive, long‐term medical applications. Here we analyze mass gain and the ensuing degradation mechanisms in phosphate glass fiber reinforced poly‐?‐caprolactone laminates. Specimens were manufactured using in situ polymerization of ?‐caprolactone around a bed of phosphate glass fibers. The latter were sized with 3‐aminopropyltriethoxysilane to control the rate of modulus degradation. Fiber content was the main variable in the study, and it was found that the moisture diffusion coefficient increased significantly with increasing fiber volume fraction. Diffusion, plasticization, and leaching of constituents appear to be the dominant aspects of the process over these short‐term tests. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

基于基尼系数的Web社区稳定性度量

Web社区是互联网中自组织程度较高的部分,它不是一个孤立系统,而是一个耗散系统,很多时候涨落无法耗散摔,导致社区运行不稳定.基尼系数可以用来衡量Web社区稳定性,通过基尼系数的简易计算公式计算社区内部成员积分或者其它参数,可以得出Web社区稳定性的度量.该度量对于研究和利用Web社区具有重要参考意义.     

土体中毛细水压力的研究

该文从毛细水产生负孔隙水压力概念入手 ,对较难确定的孔隙水压力系数以及较抽象的地下连续墙时效稳定分析等问题进行了定量计算 ,以期对工程实践有一定的指导作用