干涉型光纤水听器灵敏度校准方法研究

研究了利用贝塞尔函数比值来估算得到干涉型光纤水听器光相移的方法,而得到光纤水听器的相移灵敏度。对理论模型进行了模拟,并对一推挽式干涉型零差光纤水听器进行了实际校准。     

MgO/La2O3CO3复合材料对磷酸盐的吸附特征

采用水热法制备了MgO/La2 O2 CO3复合材料(ML).采用X射线衍射仪和扫描电子显微镜对其结构及表面形貌进行了表征,利用Zeta电位仪测定了其零点电位点,并探究了接触时间、初始磷酸盐浓度和初始pH对磷酸盐吸附效果的影响.结果 表明,ML呈现板块状堆叠而成的层状结构,零点电位点为4.52.准二级动力学模型和Fre...     

一体式膜-生物反应器经济曝气量的试验研究

增大曝气量一方面可提高膜面液体循环流速,从而减缓污泥在膜表面的沉积,降低膜污染形成速率;另一方面曝气量的增加也造成污泥粒径分布的变化,使混合液中细小污泥颗粒增多,从而导致膜孔堵塞,引起膜污染速率增加.一定污泥浓度下存在一个经济的曝气量,使得污泥絮体不大量在膜表面沉积,同时也不会产生更多的细小污泥粒子.实验考察了一体式膜-生物反应器在不同污泥浓度、不同曝气量下膜污染的发展趋势.实验结果:在污泥浓度为3,6,8和10g/L下的经济曝气量分别为36,72,84,120m3/(m2·h),经济曝气量随污泥浓度的增大而增加.     

西南桦木包装材料在热处理后的润湿性能研究

通过动态接触角测量、红外光谱分析、表面粗糙度测量、扫描电镜观察和偏相关分析,研究了西南桦木的润湿性能。结果表明,木材经180℃热处理4 h后,润湿性能下降:接触角由40°增至121°,羟基和羰基数量减少,粗糙度降低;处理时间与接触角显著相关;西南桦木用作包装材料,若采用热处理,可去除有害生物,还具备疏水功能。     

BM50型风扫磨机主齿轮失效分析

BM50型大力神风扫磨机在正常操作务件下主齿轮(材质为4340钢)出现早期失效，一齿断裂脱落，另有17齿开裂。采用化学成分分析、金相检验、扫描电镜观察以覆硬度测试方法，对断裂齿轮进行了失效分析，结果表明，失效齿轮属于疲劳断裂；引起断裂的直接原因是位于齿轮啮合面硬化层底部的堆积夹杂物，所用材料存在严重的冶金质量缺陷。     

2000年NIM铯冷原子喷泉时间频率基准装置研究的进展

本文报导了中国计量科学研究院(MM)研制新一代"激光冷却铯原子喷泉"国家时间频率基准装置的进展实现了从磁光阱(MOT)过渡到光学黏胶(OM)装载-冷却铯(Cs)原子,利用飞行时间(TOF)法记录到信噪比优于40的原子云荧光信号;原子经后冷却达到(10～20)μK;用光学黏胶从铯蒸气直接获得了冷原子云.并给出了对实验的讨论.     

谈影院票务的信息交换

长期以来,电影行业的基础信息统计汇总渠道不畅,无法及时得到电影行业的真实信息,影响到管理机构的科学决策.随着电影产业化的实施,电影行业的管理方式、产权结构、经营主体、经营情况以及观众等信息,会不断进行变化.如果不能及时地掌握这些信息的变化,将会出现决策落后于发展形势的局面.     

An efficient second‐order characteristic finite element method for non‐linear aerosol dynamic equations

In the paper we consider the non‐linear aerosol dynamic equation on time and particle size, which contains the advection process of condensation growth and the process of non‐linear coagulation. We develop an efficient second‐order characteristic finite element method for solving the problem. A high accurate characteristic method is proposed to treat the condensation advection while a second‐order extrapolation along the characteristics is proposed to approximate the non‐linear coagulation. The method has second‐order accuracy in time and the optimal‐order accuracy of finite element spaces in particle size, which improves the first‐order accuracy in time of the classical characteristic method. Numerical experiments show the efficient performance of our method for problems of log‐normal distribution aerosols in both the Euler coordinates and the logarithmic coordinates. Copyright © 2009 John Wiley & Sons, Ltd.     

Ultraviolet-visible and surface-enhanced Raman scattering spectroscopy studies on self-assembled films of ruthenium phthalocyanine on organic monolayer-modified silver substrates

A self-assembled film of ruthenium phthalocyanine (RuPc) fabricated on a silver substrate pre-modified with a monolayer of 4-mercaptopyridine (PySH) or 1,4-bis[2-(4-pyridyl)ethenyl]-benzene (BPENB) was studied by ultraviolet-visible (UV-Vis) and surface enhanced Raman scattering (SERS) spectroscopy. PySH or BPENB was used as a ligand to link RuPc since they not only modify the silver substrate, but also deliver a pyridyl group pointing out from the silver surface. Therefore, we can explore the relationship between the structure and orientation of metallophthalocyanine and the substrate modified by the two kinds of organic-monolayers with the different conjugates and molecular lengths. UV-Vis bands due to the organic-monolayer (PySH or BPENB) modified silver films shift to longer wavelengths and a new band arising from the metallophthlocyanine appears, suggesting the binding of RuPc to PySH/BPENB, as well as the interaction between the marcocycle of RuPc and the ring of PySH/BPENB. Vibrational bands arising from both the RuPc and PySH/BPENB moieties appear clearly in the SERS spectra of the RuPc-PySH/BPENB composite films, indicating that RuPc is successfully assembled on the top of PySH/BPENB film. The shifts and relative intensity changes of bands due to PySH or BPENB in the SERS spectra imply the binding of the metallophthalocyanine to the pyridyl group in the composite films. Furthermore, the comparison of the SERS spectra revealed that the orientations of PySH and BPENB in the two kinds of composite films are different; the BPENB moiety in the RuPc-BPENB composite film is more perpendicular to the silver surface compared with the PySH moiety in the RuPc-PySH composite film.