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71.
测试了减四线馏分油低温热容 ,并进行了热重 /微分热重 (TG/DTG)和差示扫描量热 (DSC)分析。在 80~ 373K温区 ,用高精度全自动绝热量热仪测定了热容值 ,用最小二乘法对实验测量值进行拟合 ,建立了热容随温度变化的多项式方程。从减四线馏分油的热容曲线 ,发现该样品从固相变为液相 ,存在着两个熔化峰 ,分别为 2 94 .17K和 331.5 7K ,后者为熔化主峰。以此为熔点 ,计算出熔化焓、熔化熵分别为 88.19J/g和0 .2 6 6 0J/ (K·g)。从TG/DTG分析曲线发现该油样在 5 73K开始失重 ,到 6 6 3K失重速度达到最大 ,可能是由于样品蒸发引起。从DSC分析曲线 ,发现样品除 333K附近出现熔化吸热峰外 ,在 5 73K到 873K范围还出现一系列吸热峰 ,可能与样品的蒸发和热分解有关。 相似文献
72.
73.
Ultraviolet (UV) disinfection is becoming increasingly popular as an alternative disinfection technology to chlorination in recent years. In this study, we investigated the photoreactivation of Escherichia coli following medium-pressure (MP) UV disinfection of synthetic water by a bench-scale collimated beam apparatus. The UV doses ranged from 1.6 -19.7 mWs/cm2 and photoreactivation was investigated for 6 hours under fluorescent light. In addition, chloramination was applied after UV disinfection to investigate its ability to control photoreactivation. It was found that photoreactivation occurred for all UV doses tested and the increase in bacteria numbers ranged from 0.04 to 1.35 log10. However, the degree of photoreactivation decreased with increased UV doses. Chloramination experiments revealed that the addition of 0.5 mg/l of monochloramine resulted in suppression of photoreactivation for 1 hour only. An increased monochloramine dose of 1 mg/l was found to prevent photoreactivation for the entire duration of the experiment. The results of this study have shown that photoreactivation occurs even after MP UV disinfection, although it is of a lesser extent at higher UV doses. This study has also established that secondary chloramination can effectively suppress and eliminate photoreactivation with a chloramine dose of 1 mg/l. 相似文献
74.
Jiacheng Tan Clapworthy G.J. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2003,91(3):383-388
In the context of using virtual environments (VEs) in Internet-based teleoperation, this paper addresses the issue of parameter acquisition for single-image-based modeling of VEs. By studying the properties of basic three-dimensional features such as point sets and edge corners, a parameter-searching method was developed that employs virtual objects as feature-matching templates. This approach is particularly valuable if the environment is subject to unpredictable change. 相似文献
75.
以较简单的电机控制线路,介绍了电器故障的检修方法,并以广钢金石分公司生产的实例分析了继电器接触控制系统和PLC自动控制系统电器故障的检修过程,说明电器故障的消除必须走了解过程、查找、排除三个步骤。 相似文献
76.
H.A. Barker Author Vitae A.H. Tan Author Vitae K.R. Godfrey Author Vitae 《Automatica》2003,39(1):127-133
Analysis of systems with direction-dependent dynamics is currently limited to cases in which the dynamics in the two directions of the output are first order; results for such systems have been published for both pseudo-random maximum-length binary (MLB) and inverse-repeat maximum-length binary (IR-MLB) inputs. These relatively limited analytical results make it useful to examine alternative ways of modelling such systems and in this paper, Wiener models are considered for this purpose. Methods for optimising the Wiener model parameters by matching the system and model cross-correlation functions, outputs, and discrete Fourier transforms of the outputs are considered, and the results are compared. These methods are also applied to a first-order direction-dependent system with a maximum-length ternary (MLT) input, for which no analytical results are currently available, and to a second-order system with an IR-MLB input. 相似文献
77.
谈金祝 《石油化工设备技术》1998,19(6):54-56
采用恒位移试验方法,在高温、高压、氢环境中用WOL试样测试了214Cr-1Mo钢及其焊接接头的应力腐蚀门限应力强度因子KIH。试验结果表明:采用恒位移试验方法测试高温、高压、氢环境中214Cr-1Mo钢及其焊接接头的KIH是可行的。 相似文献
78.
Films of electroactive polymers, such as polyaniline (PAN) in its emeraldine base form, and poly(3-alkylthiophene), poly(3-hexylthiophene) (P6TH), poly(3-octylthiophene) (P8TH), and poly(3-dodecylthiophene) (P12TH) can be readily functionalized via thermal or near ultraviolet-light-induced surface graft copolymerization with monomers of polyelectrolyte, polyampholyte and polymeric acids. The monomers used in the present work include dimethyl sulphate quaternized dimethylamino-ethylmethacrylate (DMAEM·C2H6SO4), 3-dimethyl(methacryloyloxyethyl)ammonium propane sulphonate (DMAPS), acrylic acid (AAc) and a sodium salt of styrene sulphonic acid (NaSS). The surface structures and compositions of the electroactive polymer films after functionalization via graft copolymerization were characterized by angle-resolved X-ray photoelectron spectroscopy. Graft copolymerization of poly(3-alkylthiophene) films, but not PAN films, with the hydrophilic monomers readily results in a stratified surface microstructure arising from the migration of the hydrophilic graft chains beneath a thin surface layer which is much richer in the substrate chains. On the other hand, graft copolymerization of PAN films with AAc and NaSS readily gives rise to a self-protonated (and thus conductive) surface structure. 相似文献
79.
本文用逐步选择因素组合法,对锥形件拉深临界压边力试验数据进行了处理,所得数学模型比一般逐步回归法具有更高的精度和可靠性,模型更为完善。 相似文献
80.
用流动微量量热法研究了十二烷基硫酸钠(SDDS)和十二碳羧酸钠(SL)在克拉玛依油田九区和乌尔禾区油砂上的吸附,简要地计论了吸附机理。所得实验结果表明,SL 在油砂上的吸附强度比 SDDS 的要大,在相当低的浓度下即可迟到饱和吸附。 相似文献