Effect of consecutive driving on accident risk: A comparison between passenger and freight train driving

This study combined driver-responsible accidents with on-board driving hours to examine the effect of consecutive driving on the accident risk of train operations. The data collected from the Taiwan Railway Administration for the period 1996–2006 was used to compute accident rates for varied accumulated driving hours for passenger and freight trains. The results showed that accident risk grew with increased consecutive driving hours for both passenger and freight trains, and doubled that of the first hour after four consecutive hours of driving. Additional accident risk was found for freight trains during the first hour due to required shunting in the marshalling yards where there are complex track layouts and semi-automatic traffic controls. Also, accident risk for train driving increased more quickly over consecutive driving hours than for automobile driving, and accumulated fatigue caused by high working pressure and monotony of the working environment are considered to be the part of the reason. To prevent human errors accidents, enhancing safety equipment, driver training programs, and establishing a sound auditing system are suggested and discussed.     

0.9μmASIC正向设计中的总体仿真及测试矢量产生

给出了在以VHDL为硬件描述语言的 0 9μmCMOS标准单元正向设计中 ,在存在用户定制单元及ROM宏单元情况下的总体仿真方法 ,讨论了测试矢量的产生及验证。     

Influence of precursor solution coating parameters on structural and dielectric properties of PZT thick films

Ferroelectric PZT(70/30) thick films were fabricated by the hybrid technique adding the sol-coating process to the normal screen-printing process to obtain a good densification. The screen-printing procedure was repeated four times to form PZT(70/30) thick films, and then PZT(30/70) precursor solution was spin-coated on the PZT thick films. All PZT thick films showed the typical XRD patterns of a perovskite polycrystalline structure. The thickness of all thick films was approximately 75–80 μm. The relative dielectric constant and dielectric loss of the PZT-6 thick film were 656 and 1.2%, respectively. The remanent polarization increased and coercive field decreased with increasing the number of sol coatings and the values of the PZT-6 thick films were 28.3 μC/cm² and 13.1 kV/cm, respectively. Leakage current density of PZT-6 thick films was 2.4 × 10⁻⁹ A/cm² at 100 kV/cm.     

XRD studies of electrochemically hydrided–dehydrided thin films of the alloy AZ31 and AZ31 with Ti

A magnetron sputtered thin films of the AZ31 alloy and AZ31 alloy with Ti capped with Pd were electrochemically hydrogenated and dehydrogenated in a 3 M KOH solution. A phase composition and structure of the films were studied by XRD. It has been determined that the behaviour of magnetron sputtered alloy AZ31 during electrochemical charging with hydrogen was alike that of pure Mg. The shift of the XRD peak Mg (0 0 0 2) to lower angles indicates that a hydrogen solid solution in the AZ31 alloy was formed along with MgH₂. When the AZ31 alloy with 18 at.% of Ti was electrochemically hydrogenated the whole film was transformed into hydride. The minor part of the hydride was in the nanocrystalline state with a structure of rutile and a major part of the hydride was in the amorphous state. After dehydrogenation only a part of the alloy recovered and the rest remained in the state of amorphous hydride. A positive shift of peak Pd (1 1 1) was observed in all of the XRD patterns for hydrogenated films. At least partially the shift should be associated with the compressive stresses in the top-cap layer of Pd, which arose due to the hydrogenation of the AZ31 alloy.     

Development of lipase inhibitors from various derivatives of monascus pigment produced by Monascus fermentation

Derivatives of monascus pigment having high lipase-inhibitory activities were developed and characterized. Various derivatives of monascus pigment were produced during Monascus fermentation with added l-, d-amino acids. From them, compounds having high inhibitory activities against a porcine pancreatic lipase were selected. Monascus pigments produced with aromatic and non-polar aliphatic l-, d-amino acids revealed strong inhibitory activities against the lipase. l-Trp and d-Tyr derivatives showed especially low IC₅₀ values of 61.2 and 103 μM, respectively. Further structure modifications of pigment derivatives were made with amino acid esters and dipeptides for enhanced inhibitory activity. l-Leu-OEt and l-Tyr-OEt derivatives made via further structure modifications showed high lipase-inhibitory activities with IC₅₀ values of 12.2 and 13.8 μM, respectively. The l-Leu-OEt derivative exhibited some specificity against porcine pancreatic lipase but not exhibit high activities against other digestive enzymes. Some compounds were developed from modification of monascus pigment followed by lipase-inhibitory activity tests.     

Full software analysis and impedance matching of radio frequencyCMOS integrated circuits

We present a systematic analysis technique of complementary metal-oxide-semiconductor (CMOS) radio-frequency (RF) integrated circuits (ICs). A full simulation program with integrated circuit emphasis (SPICE) simulation of the whole chip including the package and the die, with the parameters extracted from purely software analysis, has been performed. It is shown that the RF impedance matching without S-parameter based techniques is possible and the measured results agree well with our SPICE-only software based technique     

Dependence of thermo-mechanical and mechanical properties of novel fluorophosphate glass on various rare earth dopants

The dependence of thermo-mechanical, and mechanical properties on various rare earth dopants (RE) including Nd₂O₃, Er₂O₃, and Yb₂O₃ in 0.4MgF₂-0.4BaF₂-0.1Ba(PO₃)₂-0.1Al(PO₃)₃ glasses (MBBA system) is systematically investigated. MBBA system doped with RE dopants presented the potential application in the field of communication and high power layer system in the previous reports. In this work, it is found that the density of the doped glass increases with an increasing of RE concentration, which could be understood in terms of cationic field strength (CFS) effect. The Knoop hardness is found to decrease with the loading time and dopant concentration due to the indentation size effect (ISE) effect. The observed decrease of thermal expansion coefficient and the increase of glass transition temperature T _g with increasing dopant concentration are elucidated in terms of the increasing number of strong covalent bonds with increasing RE dopant concentration. Those results will be of paramount importance before designing optical devices.     

Design of holographic polymer‐dispersed liquid crystals based on solubility parameters

BACKGROUND: A slight change of polymer structure leads to a significantly different solubility parameter (SP), which is related to incompatibility and interface anchoring energy between a polymer and a liquid crystal (LC). RESULTS: Holographic gratings in polymer‐dispersed liquid crystals have been fabricated based on various urethane acrylate oligomer sizes and type of reactive diluent at two LC loadings. A large SP gap, using N‐vinylpyrrolidone as reactive diluent, gave much faster saturation of diffraction efficiency at higher level, but the grating failed to operate. On the contrary, films having a small SP gap, using 2‐ethylhexyl acrylate, operated under 20 V with a response time of about 10 ms, although their saturation of diffraction efficiency was relatively low. The results were interpreted in terms of morphology (determined using scanning electron microscopy), anchoring energy and resin elasticity. CONCLUSION: Low driving voltage and high diffraction efficiency are obtained by controlling the SP gap between LC and polymer. Copyright © 2007 Society of Chemical Industry     

儿童颅内外伤性动脉瘤的诊治

目的评价儿童颅内外伤性动脉瘤的诊断、介入治疗疗效和安全性。方法分析５例有明确头颅外伤史患儿颅内外伤性动脉瘤病例。经CT、MRI 检查，２例为外伤性蛛网膜下腔出血，２例分别表现为右枕部颅内出血及左颞部颅内出血，另１例为后颅凹少量出血伴天幕缘少量硬膜下出血，右侧侧脑室三角区少量出血。５例患儿经DSA全脑血管造影分别诊断为左颈内动脉C１段外伤性动脉瘤，右侧裂动脉分支外伤性动脉瘤，左大脑中动脉分支外伤性动脉瘤，右大脑后动脉远端外伤性动脉瘤，右小脑后下动脉外伤性动脉瘤。其中左颈内动脉C １ 段外伤性动脉瘤和右侧裂动脉分支外伤性动脉瘤经GDC栓塞术治疗，左大脑中动脉分支外伤性动脉瘤及右小脑后下动脉外伤性动脉瘤手术夹闭。另１例严密随访观察。结果２例外伤性颅内动脉瘤经GDC栓塞术及２例外伤性动脉瘤手术均获成功，未留任何后遗症；５例均能正常的学习和生活。结论儿童颅内外伤性动脉瘤虽属罕见，但GDC及手术治疗儿童颅内动脉瘤安全而有效，长期预后则有待于随访观察。