Editorial - Asia Pacific Microwave Conference 2007 (APMC'07)

The Asia Pacific Microwave Conference was first convened in New Delhi in 1986 and then in Beijing in 1988. It was established to foster a close dialogue among engineers and academia in various applied electromagnetic disciplines inside and outside the Asia Pacific Region. It was also designed to serve as a conduit for channelling advanced technologies into the region, in particular, the developing countries. Starting from the fourth one held in 1992 in Sydney, APMC has been held annually throughout the major cities in the region. Thus after APMC'07 held in Bangkok in December 2007, the APMC series of annual conferences continues its successful run at scheduled dates and venues in the Asia Pacific region: APMC'08 in December 2008 in Hong Kong; APMC'09 in December 2009 in Singapore, APMC'10 in Yokohama, Japan; APMC'11 in Melbourne, Australia and APMC'12 in Taipei, Taiwan.     

AutoCAD与Word和Excel图文转换的效果处理

AutoCAD计算机辅助设计软件、Word字处理软件和Excel电子表格处理软件得到了极为广泛的应用，但Word本身能绘制图形的能力很有限，用于绘制标准的工程图则更难。而使用AutoCAD绘图时，要写入大量的文本和表格也十分不便，利用Word或Excel处理软件的特点写入文字或表格，然后插入到AutoCAD绘图文件中，会取得意想不到的效果。针对在AutoCAD与Word和Excel图文转换过程中存在的问题进行了深入探讨，从而完善了工程文件中不同软件的协同设计。     

The 55 mph limits and front-to-rear collisions involving autos and large trucks

The effects of the establishment of 55 mph limits on front-to-rear crashes involving automobiles and trucks were examined. Since the establishment of 55 mph limits resulted in a reduction in the difference between the reported average speed of automobiles and large trucks, it provided an opportunity to examine the effects of speed differences on the. frequency of crash involvement of these vehicles. Principal results of the study were as follows: In 1974, the year of the introduction of 55 mph speed limits, a substantial reduction in the number of front-to-rear crashes involving an automobile and tractor trailer on higher speed roads occurred in the states whose experience was examined. A substantial decline in the number of front-to-rear crashes involving an auto and single body truck on higher speed roads also occurred in 1974 in these states. The decline in the number of front-to-rear crashes involving an automobile and tractor trailer on higher speed roads was primarily the result of a major decline in the number of crashes in which an auto struck a tractor trailer in the rear. The number of crashes in which a tractor trailer struck an auto in the rear declined by a much smaller percentage. The decline in the number of front-to-rear crashes involving an automobile and single body truck on higher speed roads resulted from comparable decreases in the number of crashes in which an auto struck a single body truck in the rear and those in which a single body truck struck an auto in the rear. Prior to the establishment of 55 mph limits, tractor trailers struck automobiles in the rear in more than half of the front-to-rear crashes involving these vehicles on both higher and lower speed roads. Because the major decline in the number of crashes in which autos struck tractor trailers in the rear following the introduction of the new limits was not matched by as large a decline in the number of crashes in which tractor trailers struck autos in the rear, there was a significant increase in the proportion of front-to-rear crashes involving an automobile and tractor trailer in which the tractor trailer struck the automobile in the rear on higher speed roads. Prior to the establishment of 55 mph limits, single body trucks struck automobiles in the rear in more than half of the front-to-rear crashes involving these vehicles on both higher and lower speed roads. However, single body trucks struck autos in the rear in a lower proportion of their front-to-rear crashes with autos than did tractor trailers. The proportion of front-to-rear crashes involving an automobile and single body truck in which an auto was struck in the rear by a single body truck was not significantly affected by the establishment of 55 mph limits.     

Unconventional fractional quantum Hall effect in monolayer and bilayer graphene

The commensurability condition is applied to determine the hierarchy of fractional fillings of Landau levels in monolayer and in bilayer graphene. The filling rates for fractional quantum Hall effect (FQHE) in graphene are found in the first three Landau levels in one-to-one agreement with the experimental data. The presence of even denominator filling fractions in the hierarchy for FQHE in bilayer graphene is explained. Experimentally observed hierarchy of FQHE in the first and second Landau levels in monolayer graphene and in the zeroth Landau level in bilayer graphene is beyond the conventional composite fermion interpretation but fits to the presented nonlocal topology commensurability condition.     

Effect of Vortex Finder Diameter on Flow Field and Collection Efficiency of Cyclone Separators

In this study, aerocyclone separators, with five different vortex finder diameters are simulated using commercially available computational fluid dynamics code Fluent 6.3.26 to analyze flow field pattern and the collection efficiency. It is found that a decrease in vortex finder diameter results in an increase in pressure drop by 47.84% and an increase in the collection efficiency by 9.54%, whereas, the increase in vortex finder diameter leads to a reduction in pressure drop by 23.87% and a decrease in the collection efficiency by 7.70% as compared to the Stairmand high efficiency cyclone. It is also observed that a decrease in vortex finder diameter leads to about 33% increase in axial velocity and about 25% increase in tangential velocity, whereas, an increase in vortex finder diameter results in about 23% decrease in axial velocity and about 12% decrease in tangential velocity as compared to the Stairmand high efficiency cyclone.     

Bose-Einstein condensation and superfluidity of trapped polaritons in graphene and quantum wells embedded in a microcavity

The theory for spontaneous coherence of short-lived quasiparticles in two-dimensional excitonic systems is reviewed, in particular, quantum wells (QWs) and graphene layers (GLs) embedded in microcavities. Experiments with polaritons in an optical microcavity have already shown evidence of Bose-Einstein condensation (BEC) in the lowest quantum state in a harmonic trap. The theory of BEC and superfluidity of the microcavity excitonic polaritons in a harmonic potential trap is presented. Along the way, we determine a general method for defining the superfluid fraction in a two-dimensional trap, within the angular momentum representation. We discuss BEC of magnetoexcitonic polaritons (magnetopolaritons) in a QW and GL embedded in an optical microcavity in high magnetic field. It is shown that Rabi splitting in graphene is tunable by the external magnetic field B, while in a QW the Rabi splitting does not depend on the magnetic field in the strong B limit.     

Protein Corona: Impact of Lymph Versus Blood in a Complex In Vitro Environment

In biological environments, the surface of nanoparticles (NPs) are modified by protein corona (PC) that determines their biological behavior. Unfortunately, in vitro tests still give different PC than in vivo tests causing in vitro–in vivo discrepancy; hence, in vitro studies are not indicative for the NPs' behavior in vivo. Here is demonstrated that PC in vitro is strongly influenced by the type of extracellular fluid (ECF), blood or lymph, by their high and low flow conditions and transitions between ECFs, and a combination of these parameters. As a result, this in vitro study approaches fluidic and dynamic variations to which NPs are exposed in vivo: different ECF that NPs encounter first in different injection routes, different transitions in‐between ECFs during circulation, and simultaneous change in the exposed flow in these transitions. The most‐abundant proteins in PCs are found to be not the most abundant in ECFs, but those having high affinity for binding to the surface of NPs. Moreover, some proteins are differently abundant in PCs at different flows, which indicate force‐promoted binding, catch bonds. These results suggest that future in vitro studies should consider more complex incubation conditions to improve the in vitro–in vivo consistency necessary for translational research.     

生物质与生活垃圾共气化过程重金属的迁移转化规律

为了研究流化床生物质气化协同处置生活垃圾衍生燃料过程中重金属的迁移转化规律,在湖北某循环流化床气化炉耦合燃煤发电厂进行掺烧试验。研究表明重金属主要赋存于飞灰和炉渣中。空白工况下86.2%的Cr赋存于飞灰中,13.3%于炉渣中;75.5%的Pb在飞灰中,23.8%在炉渣中;79.5%的As迁移至飞灰中,11.7%在炉渣中。RDF工况下75.8%的Cr迁移至飞灰,20.7%迁移至炉渣;44.6%的Pb存在于飞灰中,52%存在于炉渣。协同处置后,重金属在飞灰和炉渣中的分配比例明显发生了变化,飞灰中重金属含量减少12.5%~31.3%,炉渣中重金属增加7.33%~20.1%,气化气的引入改变了炉内重金属的分配情况。协同处置可以有效处理生活垃圾,对固废中的热量进行资源化利用,且出炉物料中重金属含量均低于我国现行标准限值。     

北京城区和远郊区大气细颗粒PM_(2.5)元素特征对比分析

为了对比大气悬浮颗粒PM2.5及其所含元素在北京城区与远郊区的特征,在2007年不同季节和2008年北京奥运会期间进行了PM2.5的采样分析。结果表明:城区PM2.5和元素的浓度均高于郊区,元素浓度在城区与郊区具有不同的季节变化特征,春、冬季地壳元素浓度在城区与郊区都有所增加,在城区S元素和其它污染元素在秋、冬季最高,而郊区S元素浓度在夏季最高。污染元素的富集程度夏秋季高于春冬季,郊区高于城区,城、郊两地PM2.5中元素来源相似。雾霾天PM2.5及元素浓度在城区增加明显,奥运期间污染元素的质量分数较奥运前明显降低。     

碳标签制度下供应商参与碳减排的供应链决策研究

研究了碳标签制度下供应商参与碳减排的供应链决策问题。在考虑消费者低碳偏好情况下,探讨了3种减排模式：制造商和供应商均不投资碳减排（N模型）、仅制造商投资碳减排（M模型）、制造商和供应商均投资碳减排（SM模型）。结果表明,供应商参与碳减排投资后双方利润均多于仅制造商投资碳减排的模型,同时双方的碳排放量又少于仅制造商投资碳减排的模型,显然供应商参与碳减排促进了供应链整体经济效益和环境效益的提升。     

Effects of loading frequency and environment on delamination fatigue crack growth of CFRP

The delamination fatigue crack growth was investigated with two kinds of unidirectional CF/epoxy laminates. In the T300/3601 laminate, Mode I crack growths in air were cycle dependent, while it was time dependent in water, and the growth rate in water was lower than that in air. Mode II crack propagation rate either in air or in water was also constant with crack extension, and the crack growth was time-dependent. The crack propagation rate in water was faster than that in air, and it increased with prior-immersion period in water. In the M40J/2500 laminate either in air or in water, Mode I delamination fatigue crack growth was cycle-dependent, and the growth rate in water was lower than that in air. Mode II crack propagation rate either in air or in water was almost constant with crack extension, and the crack growth was cycle-dependent. The crack propagation rate in air was almost identical to that in water.     

爆破振动在混凝土与软土结构中传播差异性研究

研究内容是爆破振动在不同介质中的传播差异性。从理论角度对比研究了爆破振动在混凝土和软土中传播的主要特点及造成二者差异性的主要原因;指出混凝土介质中爆破振动速度主要分布在平面法线方向,软土介质中爆破振动速度主要分布在其平面上;并结合工程监测实践对分析结果作了进一步分析验证。本文结论对监测不同介质中的振动速度具有一定指导意义。     

The effect of additives on the properties and microstructures of Al2O3-C refractories

The effect of Al and Si additions on the properties and microstructure of Al₂O₃-C refractories has been studied. The results showed an increase in the strength and a decrease in porosity values with the increase in the Al content in the samples. The increase in firing temperature at a constant level of Al content had a deteriorating effect on the above mentioned properties. The oxidation resistance in the Al containing samples showed an improvement in the range of Al content studied in this work. Improvement in the oxidation resistance was also seen in the samples containing Si as additive. However, unlike the Al-case higher firing temperatures in the Si containing samples led to an increase in the strength and a decrease in the porosity values. The available thermodynamic data as well as x-ray diffraction (XRD) and scanning electron microscopy (SEM) were used in the interpretation of the experimental data.     

Research performance in key medical universities in China observed from the scientific productivity

Research activities in the life sciences during the past few years, have increased appreciably in China, both in regard to relative output of publications and in their impact on the international research community. The purpose of this study is to analyze and evaluate quantitatively the scientific productivity of key medical universities in China by using CBMdisc, MEDLINE and SCI databases. The results showed that Tongji Medical University ranks first in terms of paper output in Chinese and in English languages, while Beijing Medical University is placed second in output but is first in citation impact. Shanghai Medical University had the top annual paper output per scientist, with 2.53 papers in Chinese and 0.13 papers in English. The results also showed that the coverage of Chinese biomedical publications by western indexing services is very poor.     

The influence of low atmospheric pressure on carbon monoxide of n-heptane pool fires

Qualitative theoretical analysis about air pressure influence upon the gas concentration of a fire plume was given, different scale n-heptane pool fires were conducted in a small and a standard compartment room in Lhasa and Hefei, respectively. The experimental results show that, in Lhasa, the average mass burning rates in the small room and the standard room both decrease, burning time increases at about 53% in small room and 45% in standard room more than in Hefei. Whereas for maximum changes of CO concentration, in the small room, in Lhasa, CO concentrations reach about twice bigger peak values at larger increase rates than in Hefei. While in the standard room, in Lhasa and Hefei, there are no significant changes for CO concentration, which agrees well with the theoretical analysis results.     

An analysis of road traffic fatalities in Delhi, India

Road use patterns in Delhi, India are very different from those in cities in highly industrialized countries. In Delhi roads are also shared by unmotorized vehicles in large numbers. This study is an attempt to understand fatal crash patterns in Delhi in 1980 using police data. The results indicate that fatality patterns in Delhi are very different from those in highly industrialized countries. Pedestrians, two-wheeler riders and bus commuters comprise 80% of fatalities and motor-vehicle occupants a small minority. It appears that priorities for safety countermeasures in Delhi would have to be significantly different from those in more industrialized high-income countries. Some short-term and long-term measures are suggested in the paper.     

Microbial stability evaluation of cement-based waste forms at different waste to cement ratio

An evaluation of the effect of differences in chromium nitrate to cement ratio on the microbial stability of a chromium nitrate/cement waste form, as reflected in the leaching of chromium, calcium, magnesium and aluminum; was carried out in this study. An increase in the proportion of chromium in the waste form from 4.8 to 8.7% had no noticeable effect on microbial stability, with the total chromium leached essentially unchanged. Further increases in the proportion of chromium in the waste form from 8.7 to 10.7%, and from 10.7 to 15.9% resulted in a substantial decrease in microbial stability, with 3-fold and 1.3-fold increase in the total chromium leached, respectively, observed. For calcium, increases in the chromium proportion were accompanied with increases in the total calcium leached even though the increases were not in direct proportion to the increases in chromium proportion. For magnesium and aluminum, increases in the proportion of chromium within the range 4.8-10.7% were accompanied with increases in the total respective metals leached, with minor variation for each metal. On the whole, the maximum percentage chromium leached from the different waste forms was substantially lower than those of the other metals.     

Using the Vincenta code to analyse pressure increases in helium during the quench of a superconducting magnet

The Vincenta code is used to simulate the pressure increases in helium in case of a quench in the superconducting coils. We focus on two classes of coil in which helium is in direct contact with the conductor: coils consisting of cable-in-conduit conductors (as in ITER or JT-60SA), in which supercritical helium is forced through long channels; and bath-cooled coils, in which static helium is confined in short channels perpendicular to the conductor and opening into a bath (as in Tore Supra or Iseult). Various physical phenomena are responsible for the pressure increases in helium, which is subjected to strong heat flux in the conductor during a quench: at the local level, i.e. in the heated channels, the inertial forces that must be overcome to expel the fluid and the friction forces due to the induced velocity; at the global level, i.e. throughout the cryogenic system, the adiabatic compression of non-heated volumes hydraulically connected to the heated channels. Here we analyse the thermohydraulic behaviour of helium to highlight the dominant phenomena, according to the geometry of the helium flow paths. The results are applied to numerical simulation of the pressure rise in case of quench in a JT-60SA cable-in-conduit conductor (CICC) and in the bath-cooled Iseult coil.     

Rubber toughening of plastics

Mechanisms of fatigue damage in ABS and HIPS polymers were studied by monitoring changes in mechanical properties under sinusoidal and square wave loading at a frequency of 0.033 Hz. Both materials exhibited a large increase in hysteresis and a decrease in modulus. In ABS, these changes occurred to approximately the same extent in tension and compression, whereas in HIPS the changes in tensile properties were much more pronounced. From the shape of the hysteresis loops, and from volumetric measurements, it was concluded that crazing is the dominent fatigue damage mechanism in HIPS, whilst shear yielding is responsible for most of the damage observed in ABS. Large increases in hysteresis caused substantial rises in temperature despite the low frequency, and thus accelerated fatigue damage accumulation.