2000m3低温丙烯球罐球壳板型式和材料的选择

大型球罐球壳板型式和材料的选择是设计的首要环节,从这两方面论述了设计时选择的过程。     

Preparation and application of polybenzoxazine adsorption resin

The synthesis and application of polybenzoxazine adsorption resin was studied. First, the precursor was synthesized by the solventless method. And then a kind of spherical and granular polybenzoxazine resin was obtained using reverse‐phase suspension polymerization technique in the process of solidification. Besides, the influence of dispersion medium, the volume ratio of precursor to medium, the solidification temperature, and the agitation speed were studied in detail in the process of polymerization. Second, the spherical shape of the polybenzoxazine resin was identified by scanning electronic microscope and the thermal stability of resin was measured by thermogravimetric analysis. Finally, the adsorption capacity of the spherical resin on pyridine was studied in cyclohexane systems. The correlation coefficient of Langmuir adsorption constant temperature line was bigger than 0.99, which indicated that the equilibrium sorption date was coincident with the Langmuir isotherm equation. And the saturated adsorptive capacity of dried resin achieved 222.2 mg g^?1. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

煤尘爆炸特征参数影响因素研究

采用20L球形爆炸装置研究了煤尘粒径、浓度、点火能量对煤尘爆炸最大压力、爆炸最大压力上升速率的影响。研究结果表明,在煤尘粒径一定的条件下,随着煤尘浓度的增大,爆炸最大压力及爆炸最大压力上升速率先增大后减小,煤尘浓度在400~480g/m3之间取得爆炸最大压力最大值0.94MPa、爆炸最大压力上升速率最大值28.79MPa/s;在煤尘浓度一定的条件下,爆炸最大压力不随煤尘粒径的减小而单调变化,爆炸最大压力上升速率随煤尘粒径的减小而逐渐增大;随着点火能量的增大,爆炸最大压力及爆炸最大压力上升速率明显增加。     

环面槽球笼式同步万向联轴器共轭曲面原理

采用共轭曲面原理对应用广泛的环面槽球笼同步万向联轴器,进行了分析;建立了球笼万向轴器实现同步运动时,各接触面的运动关系、曲面方程以及共轭运动关系,推导出了球笼万向联轴器瞬时同步的必要充分条件为两对啮合付的偏心值ε1T=ε1的结论.     

碳酸钴制备超细球形钴粉的工艺探讨

采用钢带式连续还原炉,以碳酸钴为原料,用氢气还原法制备钴粉。研究了还原温度和时间对钴粉粒度、碳氧含量等性能的影响。研究发现:升高温度或延长还原时间,钴粉的粒度增大,氧含量降低,而碳含量变化很小。在420～460℃下,还原2.5～3.0h,可制备Fsss为0.9μm,以面心立方结构为主的高纯钴粉。与传统方法相比,碳酸钴制备的钴粉呈球形或类球形,而非树枝状,是生产超细硬质合金的理想原料。     

锌粉颗粒形状对机械沉积无结晶镀层结构的影响

以球状锌粉和片状锌粉为原始锌粉借助于机械镀工艺制备了无结晶锌防护层，运用光学显微镜（OM）、扫描电子显微镜（SEM）观察了镀层的结构形貌；采用XRD技术分析了镀层的物相组成；采用贴滤纸法进行了镀层的孔隙率测试。研究结果表明，片状锌粉制备的镀层比球状锌粉制备的镀层表面要平滑、光亮。球状锌粉制备的镀层中锌粉颗粒呈紧密堆积，部分锌粉颗粒发生塑性变形；片状锌粉制备的镀层中的锌粉颗粒呈层片状叠加，镀层中锌粉颗粒没有发生明显塑性变形。两种形状锌粉制备的镀层均为锌基多相混合体系，镀层中没有固溶体、化合物等合金相产生，属于锌基复合镀层。锌粉颗粒形状对镀层中颗粒之间的结合机理没有显著影响，两种镀层中锌粉颗粒间均以机械咬合为主。     

表面包覆改善球形Ni（OH）2高温性能的研究

采用Yb／Co氢氧化物共沉淀包覆方法和Ca3（PO4）2与Co（OH）2分别沉淀分层包覆方法在球形Ni（OH）2的表面进行了均匀的包覆。前者利用COSO4，YbCl3和NaOH溶液进行共沉淀包覆，后者是先在球形Ni（OH）2的表面沉淀包覆Ca3（PO4）2，然后再沉淀包覆Co（OH）2。结果显示，两种包覆方法均能有效地提高球形Ni（OH）2的高温（60℃）性能。按照Yb／Co=0．75％：2％共沉淀包覆的试样制成AA型电池后，在60℃下1C放电的容量保持率达到常温下的90％。而2％Ca3（P04）2与2％Co（OH）2分层包覆后的球形Ni（OH）2制成AA型电池后，在60℃下1C放电的容量保持率达到常温下的81％。未包覆和仅用Co（OH）2包覆的球形Ni（OH）2制成的AA型电池，在60℃下1C放电的容量保持率分别只有46％和48％。通过循环伏安测试表明，利用表面包覆的方法可以增大正极材料Ni（OH）2在高温下的氧化电位、析氧电位和两者之间的电位差，从而提高了材料在高温下的电化学性能。     

双球面投影几何可量测全景模型的构建

针对全景影像难以提供空间度量的问题,提出一种基于双球面投影几何的可量测立体全景模型构建方法.该方法依据球面全景投影关系与多视几何原理,采用对应变换与本质变换求取旋转及平移参数,并推导出双球面核线约束;在此基础上,建立起双球面投影几何的立体全景模型,解决了球面全景的量测问题.实验结果表明,文中方法可使全景影像在真实呈现户外场景的同时,提供满足一定应用需求的量测分析功能.     

Labview在BP神经网络谐波监测中的实现

为了减少电力系统中谐波的危害,本文将神经网络理论应用于谐波监测,使用界面设计方便美观的Labview编程语言制作了一种谐波监测仪。文中构造了一个目前应用最为广泛的BP网络,给出了网络算法,形成了训练样本。并用基于Labview工作平台的G语言,编写了训练程序,将所形成的样本对网络进行了训练,然后对训练好的网络进行仿真实验。结果表明:所设计的神经网络可很好的监测谐波,并对谐波参数的显示设计了很好的人机界面。     

Analogy and duality of texture analysis by harmonics or indicators

According to the classic harmonic approach, an orientation density function (odf)f is expanded into its corresponding Fourier orthogonal series with respect to generalized spherical harmonics, and a pole density function (pdf) into its corresponding Fourier orthogonal series with respect to spherical harmonics. While pdfs are even (antipodally symmetric) functions, odfs are generally not. Therefore, the part of the odf which cannot be determined from normal diffraction pdfs can be mathematically represented as the odd portion of its series expansion. If the odff is given, the even part can be mathematically represented explicitly in terms off itself. Thus, it is possible to render maps ofharmonic orientation ghosts, and to evaluatevariants of mathematical standard odfs resulting in identical pdfs independent of pdf data. However, if only normal diffraction pdfs are known, the data-dependentvariation width of feasible odfs remained unaccessible, and within the harmonic approach a measure of confidence in a solution of the pdf-to-odf inversion problem does not exist.According to any discrete approach, an odff defined on some setG of orientations is expanded into its corresponding Fourier orthogonal series with respect to indicator functions of the elements of a partition ofG, and a pdf defined on the upper (lower) unit hemisphereS ₊ ^{3 3} into its corresponding Fourier orthogonal series with respect to indicator functions of the elements of a partition ofS ₊ ³ . The ambiguity of the pdf-to-odf inversion problem is discussed in terms of column-rank deficiency of the augmented projection matrix. The implication of the harmonic approach to split an odf into auniquely determined and anundetermined part does no longer seem to be reasonable. However, it is possible to numerically determine data-dependent confidence intervals for the Fourier coefficients with respect to the indicator functions which can be immediately interpreted as mean orientation densities within the elements of the partition ofG. Doing so for all Fourier coefficients in the finite series expansion, i.e. for all elements of the partition of the setG, eventually results in the data-dependent variation width of odfs feasible with respect to given pdf data, and to the partitions ofG andS ₊ ³ .Thus it is confirmed that the appearance of orientation ghosts, in particular correlations oftrue andghost orientation components, depends on the representation of an odf. It may be questioned whether in practical applications the implicit assumption of the harmonic method that the even part can be determined uniquely and free of error is generally a reasonable initial condition to develop ghost correction procedures.