SECOO石化聚丙烯装置紧急停车系统的设计

介绍HIMA公司H51q紧急停车系统在SECOO石化聚丙烯装置中的应用。与目前主流可编程安全系统相比,H51q是第三代经TUV认证的PES系统,采用四重化冗余自诊断结构,具有双CPU单元,4个同时工作的微处理器,与DeltaV系统采用Modbus协议进行串行通信,系统之间则利用工业级交换机Hirschmann构成安全以太网进行数据传输,从而确保安全系统长时间、高效率运行。详细说明了聚丙烯装置H51q与Deltav的系统结构配置和联锁系统操作界面设计,并以烷基铝配置和卸料装置为例说明联锁逻辑具体实现过程。读者可对H51q与DeifaV系统的联合设计和FAT测试过程有清晰的理解。     

Fast Fourier Transform simulation techniques for Coulomb gases

An improved approach to updating the electric field in simulations of Coulomb gases using the local lattice technique introduced by Maggs and Rossetto [A.C. Maggs, V. Rossetto, Phys. Rev. Lett. 88 (2002) 196402] is described and tested. Using the Fast Fourier Transform (FFT) an independent configuration of electric fields subject to Gauss' law constraint can be generated in a single update step. This FFT based method is shown to outperform previous approaches to updating the electric field in the simulation of a basic test problem in electrostatics of strongly correlated systems.     

Modular visions: Referents, context and strategies for database open media works

The processes of constructing meaning in digital database environments entail a paradigm shift from previous models of audio-visual communication. Media emerging from the Electro-mechanical era (film/TV/video) present fixed spatio-temporal linearity and material conditions which objectify and render passive viewer and process. The problematic aspects of cinematic communication were addressed by Latin American filmmakers of the q7x862113q0/xxlarge8220.gif" alt="ldquo" align="MIDDLE" BORDER="0">Third Cinemaq7x862113q0/xxlarge8221.gif" alt="rdquo" align="MIDDLE" BORDER="0"> movement. Their concerns and approach presaged and assisted an understanding of the radical redefinition of audio-visual communication possible with digital databases. The conceptual and aesthetic aspirations of q7x862113q0/xxlarge8220.gif" alt="ldquo" align="MIDDLE" BORDER="0">Third Cinemaq7x862113q0/xxlarge8221.gif" alt="rdquo" align="MIDDLE" BORDER="0"> artists such as Julio Garcia Espinosa and Fernando Solanas were ultimately contradictory to linear media and find their fitting medium in digital modular construction. The materiality of database expression lacks an intrinsic temporal or spatial state and permits a more dynamic and multidirectional set of power relationships between author/s, piece, viewer/s. Other important referents for contextualising database art are modern art practitioners that rejected linear representational space and fractured the centrality of authorship. The author's own work, q7x862113q0/xxlarge8220.gif" alt="ldquo" align="MIDDLE" BORDER="0">...two, three, many Guevaras,q7x862113q0/xxlarge8221.gif" alt="rdquo" align="MIDDLE" BORDER="0"> an exploratory database environment, embraces the redefinition of process as artistic expression, the empowerment of interacting generative forces, and serves to illustrate the revolutionary potential of the new media.     

Caste-dependent reactions to soldier defensive secretion and chiral alarm/recruitment pheromone inNasutitermes princeps

The soldier frontal gland secretion ofNasutitermes princeps induces strong short-range caste-specific alarm and attraction in both soldiers and workers. Soldiers are excited and patrol the surroundings of the source. The secretion per se does not induce ejection of additional secretion. Large workers of the second stage or older are massively attracted when tested in homogeneous groups. They focus their activities much more accurately than the soldiers around the source. The workers' reaction is less intense in the presence of soldiers. Large and small workers of stage 1 scarcely react at all to the secretion, whether tested in homogeneous or mixed groups. These results suggest the following complementary roles of soldiers and workers in defense. The first line of defense is provided by soldiers, which immobilize and incapacitate mobile enemies with their sticky secretion. Defense then is completed by older large workers as they eliminate the source of disturbance. The absence of reaction of young workers, small or large, confirms previous reports on age polyethism inNasutitermes observed in other contexts: young workers tend to stay in the nest. Alarm reactions are elicited by a source of (+)-q4j9525251l018xh/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-pinene, the major monoterpene in the secretion, while its enantiomer, almost absent from the secretion, induces a much weaker reaction.     

Yellow and red luminescence in Mg-implanted GaN epitaxial films

X-ray diffraction (XRD), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and photoluminescence (PL) were applied to study yellow and red luminescence properties of as-grown and Mg-implanted n-type wurtzite GaN films grown on sapphire substrates by metal-organic chemical vapor deposition. The influence of different Mg-implanted fluences on yellow and red luminescence was studied. The as-grown GaN thin films exhibited intense broad yellow emission which reduces drastically after Mg ion implantation. A red luminescence band at approximately 750 nm appears when the Mg implantation fluence is low (10¹³ cm⁻²) whereas a yellow luminescence band suddenly increases at a Mg-implanted fluence of 10¹⁶ cm⁻². The possible reasons of these phenomena are discussed.     

Kinetics of precipitation of U4O9 from hyperstoichiometric UO2+x

For safe and reliable operation of fission reactors in space, the phase diagrams and reaction kinetics of systems used as nuclear fuels, such as U-O, U-N, U-C, are required. Diffraction allows identification of phases and their weight fractions as a function of temperature in situ, with a time resolution of the order of minutes. In this paper, we will provide results from a neutron diffraction experiment studying the U-O system. Using the neutron diffractometer HIPPO, the decomposition of UO_2+x into UO₂ and U₄O₉ as a function of temperature was investigated in situ. From the diffraction data, the participating phases could be identified as UO_2+x, UO₂ and U₄O_8.94 and no stoichiometric U₄O₉ was found. Results of the experiment were used to improve existing thermodynamic models. The presented techniques (i.e., neutron diffraction and thermodynamic modeling) are also applicable to the other systems mentioned above.     

High-pressure high-temperature (HPHT) synthesis and magnetism of MSr2Y1.5Ce0.5Cu2O10 compounds with M = Ru, Mn, and Cr

We report synthesis and magnetization of MSr₂Y_1.5Ce_0.5Cu₂O₁₀ (M/Y-1222) compounds with M = Ru, Mn and Cr by HPHT. They are synthesized at high-pressure of 6 GPa in optimized temperatures of up to 1450 °C, for Ru, Mn and 1550 °C in the case of Cr based Y/1222, for a time duration of three hours for all the samples. All the samples crystallized with tetragonal structure in I4/mmm space group. Few minor impurities are also seen in the case of Mn,Cr/Y-1222 samples. DC magnetic susceptibility measurements exhibited ferromagnetic like transition for all the three compounds at low temperatures. At 5 K, the magnetization M(H) experiments showed clear ferromagnetic like hysteresis loops for Ru and Mn samples with sizeable returning moment (M_r) and coercive field (H_c). In the case of Cr/Y-1222 system though, ferromagnetism is visible below around 45 K in susceptibility measurements, the characteristic M_r and H_c are not seen. To the best of our knowledge the Mn,Cr/Y-1222 phases are synthesized for the first time and the quality of our earlier reported Ru/Y-1222 is improved.     

Dissipation of Gross-Pitaevskii Turbulence Coupled with Thermal Excitations

Microscopic dissipation mechanism of quantized vortices in quantum fluid is studied numerically by solving the Gross-Pitaevskii equation coupled with the Bogoliubov-de-Gennes equation for thermal excitations. At low temperatures, dissipation works at smaller scales than the vortex core size, which supports the self-similar cascade process of quantized vortices at large scales and the Kolmogorov energy spectrum of quantum turbulence. On the other hand, this dissipation spreads to larger scales at high temperatures, and directly affects the vortex dynamics. This effect of dissipation at high temperatures is qualitatively similar to the mutual friction in superfluid ⁴He.     

Liquid-metal-ion source development for space propulsion at ARC

The Austrian Research Centers have a long history of developing indium Liquid-Metal-Ion Source (LMIS) for space applications including spacecraft charging compensators, SIMS and propulsion. Specifically the application as a thruster requires long-term operation as well as high-current operation which is very challenging. Recently, we demonstrated the operation of a cluster of single LMIS at an average current of 100 μA each for more than 4800 h and developed models for tip erosion and droplet deposition suggesting that such a LMIS can operate up to 20,000 h or more. In order to drastically increase the current, a porous multi-tip source that allows operation up to several mA was developed. Our paper will highlight the problem areas and challenges from our LMIS development focusing on space propulsion applications.     

Field enhancement factor and field emission from a hemi-ellipsoidal metallic needle

We present an exact solution for the electrostatic field between a metallic hemi-ellipsoidal needle on a plate (as a cathode) and a flat anode. The basic idea is to replace the cathode by a linearly charged thread in a uniform electric field and to use a set of “image” charges to reproduce the anode. We calculate the field enhancement factor on the needle surface and ponderomotive force acting on the needle. Using the Fowler–Nordheim theory we obtain an exact analytical formula for the total current.