密度分布对原子核阻止同位旋效应的影响

利用同位旋相关的量子分子动力学（IQMD）模型,分析了中能重离子碰撞过程中相对论平均场和SkyrmeHartrere－Fork等核结构模型给出的核密度分布对原子核阻止的影响。研究表明,从费米能到的较大能量范围内,无论小质量体系还是大质量体系,原子核阻止对同位旋相关的核子－核子碰撞截面都非常灵敏,而不同模型给出的核密度分布对原子核阻止影响不大,说明原子核阻止作为提取同位旋相关核子－核子碰撞截面的灵敏探针是与原子核结构模型无关的。 Influence of densitydistributionwhichisgivenbyRMFandSkyrme－Hartrere－Fork etalnuclearstructuremodelonnuclearstoppinginheavy－ioncollisionsatintermediateenergiesarestudiedbyusingisospin－dependentquantummoleculardynamics(IQMD)model.ResearchshowsthatrangeformtheFermienergytothelargerenergyof 100 Mev/u, for bothsmallandlargemasssystem,nuclearstoppingisfoundtobestronglydependentonthenucleon－nucleoncrosssections,andweaklyondifferentdensitydistribution.ThisshowsthatnuclearstoppingcanbeusedasaprobetoextracttheinformationontheisospindependenceN－Ncrosssectionsandhasnorelationshipwithnuclearstructuremodels.     

Temperature-calibrated fiber-optic refractometer based on acompact FBG-SMS structure

A novel all-fiber temperature-calibrated refractometer based on a compact fiber Bragg grating(FBG) single-multi-single(SMS)structure is proposed and experimentally demonstrated.The sensor head is composed of a FBG combined with a SMS structure,in which the middle multimode fiber(MMF)section is etched by a time-controlled hydrofluoric.The transmission dip of SMS is extremely sensitive to ambient refractive index(RI)variation,whereas the upstream FBG provides the necessary temperature information for RI calibration.All aforementioned functions are performed via a compact FBG-SMS structure not longer than 25 mm.The proposed sensing device provides a linear RI sensitivity over water or waterbased solutions(RI values near 1.33 at optical wavelengths for most biological and many environmental applications),and has temperature-calibration capability.Hence,the said refractometer is a good candidate for sensing in chemical and biological applications.     

Analysis of the breakdown mechanism for an ultra high voltage high-side thin layer silicon-on-insulator p-channel lateral double-diffused metal\ben oxide semiconductor

This paper discusses the breakdown mechanism and proposes a new simulation and test method of breakdown voltage (BV) for an ultra-high-voltage (UHV) high-side thin layer silicon-on-insulator (SOI) p-channel low-density metal-oxide semiconductor (LDMOS). Compared with the conventional simulation method, the new one is more accordant with the actual conditions of a device that can be used in the high voltage circuit. The BV of the SOI p-channel LDMOS can be properly represented and the effect of reduced bulk field can be revealed by employing the new simulation method. Simulation results show that the off-state (on-state) BV of the SOI p-channel LDMOS can reach 741 (620) V in the 3-μm-thick buried oxide layer, 50-μm-length drift region, and at -400 V back-gate voltage, enabling the device to be used in a 400 V UHV integrated circuit.     

Analysis of the breakdown mechanism for an ultra high voltage high-side thin layer silicon-on-insulator p-channel low-density metal-oxide semiconductor

This paper discusses the breakdown mechanism and proposes a new simulation and test method of breakdown voltage(BV) for an ultra-high-voltage(UHV) high-side thin layer silicon-on-insulator(SOI) p-channel lateral double-diffused metal-oxide semiconductor(LDMOS).Compared with the conventional simulation method,the new one is more accordant with the actual conditions of a device that can be used in the high voltage circuit.The BV of the SOI p-channel LDMOS can be properly represented and the effect of reduced bulk field can be revealed by employing the new simulation method.Simulation results show that the off-state(on-state) BV of the SOI p-channel LDMOS can reach 741(620) V in the 3-μm-thick buried oxide layer,50-μm-length drift region,and at 400 V back-gate voltage,enabling the device to be used in a 400 V UHV integrated circuit.     

An improved novel joint channel estimation algorithm for the 112 Gbit/s PDM CO-OFDM system

In this paper, an improved novel joint channel estimation algorithm is proposed for the 112 Gbit/s PDM CO-OFDM system. This method combines the advantages of the intra-symbol frequency domain averaging (ISFA) method and the time domain averaging (TA) method, which can realize more accuracy channel estimation. Simulation results show that this proposal could promise a relatively stable performance even under a rapidly time varying environment. It significantly outperforms the ISFA method by 2.2 dB when the DGD equals 1000 ps, and has the advantages of 0.5 dB over ISFA in considering the laser linewidth and frequency offset.     

多角度偏振辐射计系统设计与实现

多角度和偏振遥感可解决传统遥感所不能解决的大气探测和目标识别等方面的问题。为实现气溶胶偏振信息的多角度探测,提出了一种新型的多角度偏振辐射计。该辐射计可以在多个角度上测量大气的偏振光谱信息,为大气光学和微物理特性的高精度反演提供重要的实测数据源。作为航天载荷的原理样机,多角度偏振辐射计的光机系统由多路并行望远光学模块组成,可在110°视场范围内,以0.5°间隔实现偏振信息的多角度探测;采集控制与数据传输系统由双控制核心和高速接口组成,大大提高了系统的并行处理能力和数据传输速度,可在高速运动的平台上实现多路偏振光谱信息的同步采集与实时传输,避免了由平台移动和信号的异步采集引入的误差。航飞试验结果表明,多角度偏振辐射计可实现气溶胶偏振信息的高精度探测。     

大尺寸弛豫铁电单晶PIMNT的坩埚下降法生长

PIMNT单晶是近年来最新发现的弛豫铁电晶体材料,该三元固溶体单晶具有比较理想的压电、铁电和介电性能,本文报道了大尺寸PIMNT单晶的熔体坩埚下降法生长的实验研究结果。采用固相合成钙钛矿相多晶料,采用垂直坩埚下降法成功生长出最大直径为3英寸的PIMNT单晶;从所生长单晶原胚的三方相区段切割加工出(001)取向晶片,就(001)晶片的介电、压电及铁电性能进行了测试表征,表明其材料性能能够满足相关超声换能器件制作的实用需求。本论文还着重讨论了PIMNT单晶生长所涉及的系列关键技术问题,如富铅熔体对铂金坩埚的侵蚀、晶体原胚的单晶性表征、晶体生长过程的组分偏析与单晶原胚的性能分布等。     

Highly ordered mesoporous Cr2O3 materials with enhanced performance for gas sensors and lithium ion batteries

Highly ordered mesoporous Cr(2)O(3) materials with high specific surface area and narrow pore size distribution were successfully prepared by a vacuum assisted impregnation method. Both 2-dimensional hexagonal and 3-dimensional cubic Cr(2)O(3) mesoporous replicas from SBA-15 and KIT-6 templates exhibit enhanced performance for gas sensors and lithium ion batteries, compared to the bulk Cr(2)O(3) counterpart.     

Reversible 3-Li storage reactions of amorphous phosphorus as high capacity and cycling-stable anodes for Li-ion batteries

An amorphous phosphorus/carbon nanocomposite demonstrates a reversible 3-Li storage capacity of 2355 mAh g(-1) with an excellent capacity retention of 90% over 100 cycles and a superior power capability with 62% of its capacity realizable at a very high rate of 8000 mA g(-1), possibly serving as a high capacity and high rate alternative anode for next-generation Li-ion batteries.