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61.
磷酸盐激光玻璃非激活吸收系数测量研究   总被引:2,自引:2,他引:0  
介绍了高功率激光放大器系统中磷酸盐激光玻璃的静态透过率测量。在正常运行条件下,4片长按布儒斯特角放置的国产N31钕玻璃片对1.054um的激光波长平均静态透过率为94.5%,介质的损耗系数为0.294%cm-1,平均非激活吸收系数为0.146%cm-1。在此基础上对片状放大器的增益系数的测量结果进行了修正,获得了5.25%cm-1的小信号增益系数。  相似文献   
62.
The influence of oxygen transport rate on Rhodococcus erythropolis cultures has been studied in a stirred tank bioreactor under different transport and uptake conditions. Oxygen uptake rate has been measured by applying a modified dynamic method and a kinetic model is proposed, obtaining the kinetic parameter values: specific maintenance and yield coefficients. The volumetric mass transfer coefficients under inert conditions, kLa, and during the bioprocess, KLa, have been determined. The values obtained are different and a biological enhancement factor E, has been considered. These parameters have been predicted by the theoretical model and good agreement with experimental data under the conditions studied has been found. The oxygen limitation has been expressed by a modified dimensionless Damköhler number, Da, the relationship between transport and biological reaction rates. This number decreases with increasing stirrer speed; that is, when mass transport resistance decreases. The efficiency of oxygen utilization can be determined by a film effectiveness factor, η. The effectiveness factor was found to be a strong function of Damköhler number and decrease with increasing Da. Furthermore, oxygen concentration into culture depends on the mass transfer and consumption rates. The theoretical model proposed is able to reasonably predict the evolution of dissolved oxygen concentration with time of cultivation.  相似文献   
63.
二硫代磷酸硫化氧钼与硫,磷添加剂的复配特性研究   总被引:1,自引:0,他引:1  
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。  相似文献   
64.
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   总被引:9,自引:2,他引:7  
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。  相似文献   
65.
Thermal Radiative Properties of Xonotlite Insulation Material   总被引:1,自引:0,他引:1  
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…  相似文献   
66.
Abstract. A pth‐order random coefficient integer‐valued autoregressive [RCINAR(p)] model is proposed for count data. Stationarity and ergodicity properties are established. Maximum likelihood, conditional least squares, modified quasi‐likelihood and generalized method of moments are used to estimate the model parameters. Asymptotic properties of the estimators are derived. Simulation results on the comparison of the estimators are reported. The models are applied to two real data sets.  相似文献   
67.
Solubility of dimethyl-2,6-naphthalene dicarboxylate in acetic acid, N,N-dimethylfonnamide, N,N-dimethyl acetamide, dimethyl sulphoxide, and N-methyl-2-ketopyrrolidine were determined using a dynamic method. The measured systems were correlated by UNIFAC group contribution method. A new main group (aromatic ester, ACCOO) was defined to express the activity coefficients of the aromatic ester. New interaction parameters of the ACCOO group were expressed as the first-order function of temperature and were determined from the experimental data. The calculated results for the new interaction parameters were satisfactory. The measured systems were also correlated with the Wilson and 2-h models, and the results were compared with those of the UNIFAC model.  相似文献   
68.
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.  相似文献   
69.
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。  相似文献   
70.
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 Lp and ω. Water permeability coefficient, Lp and salt permeability coefficient, ω were estimated by taking account of active layer thickness of composite polymer gel. The Lp 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  相似文献   
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