浅析CDMA20001xEV-DO小区数据业务负荷及优化扩容思路

文章从CDMA20001xEV—DO与CDMA20001×的数据业务实现入手,通过对EV—DO小区数据业务三个相关指标的分析,找出判定EV—DO小区数据业务重负荷的依据,对负荷较重的小区提出了优化扩容原则和思路。     

High-performance and broadband photodetection of bicrystalline(GaN)1-x(ZnO)x solid solution nanowires via crystal defect engineering

Crystal defect engineering is widely used as an effective approach to regulate the optical and opto-electronic properties of semiconductor nanostructures.However,photogenerated electron-hole pair recombination centers caused by structural defects usually lead to the reduction of optoelectronic perfor-mance.In this work,a high-performance photodetector based on(GaN)1-x(ZnO)x solid solution nanowire with bicrystal structure is fabricated and it shows excellent photoresponse to ultraviolet and visible light.The highest responsivity of the photodetector is as high as 60,86 and 43 A/W under the irradiation of 365 nm,532 nm and 650 nm,respectively.The corresponding response time is as fast as 170,320 and 160 ms.Such wide spectral responses can be attributed to various intermediate energy levels induced by the introduction of various structural defects and dopants in the solid solution nanowire.Moreover,the peculiar bicrystal boundary along the axial direction of the nanowire provides two parallel and fast trans-mission channels for photo-generated carriers,reducing the recombination of photo-generated carriers.Our findings provide a valued example using crystal defect engineering to broaden the photoresponse range and improve the photodetector performance and thus can be extended to other material systems for various optoelectronic applications.     

Properties of Auger electrons following excitation of polarized atoms by polarized electrons

In non-relativistic approximation, the most general expression for differential cross sections describing the properties of Auger-electron emission induced in the excitation of polarized atoms by polarized electrons is obtained for the first time. The ways of the application of the general expressions suitable for the specific experimental conditions are outlined by deriving the expressions for the asymmetry parameters and the magnetic dichroism of the angular distribution of the Auger electrons as well as of the angular correlations between the scattered and Auger electrons.     

Sequencing analysis of a 40·2 kb fragment of yeast chromosome X reveals 19 open reading frames including URA2 (5′ end), TRK1, PBS2, SPT10, GCD14, RPE1, PHO86, NCA3, ASF1, CCT7, GZF3, two tRNA genes,three remnant delta elements and a Ty4 transposon

The complete sequence of a 40 247 bp DNA segment located on the left arm of chromosome X of Saccharomyces cerevisiae has been determined and analysed. The sequence encodes the 5′ coding region of the URA2 gene and 18 open reading frames of at least 100 amino acids. Ten of these correspond to known genes, whereas eight correspond to new genes. In addition, the sequence contains a tRNA-Ala gene, a tRNA-Asp gene, a Ty4 transposable element and three delta elements. The sequence has been deposited in the EMBL databank under Accession Numbers: Z49405, Z49404, Z49403, Z49402, Z49401, Z49400, Z49399, Z49398, Z49397, Z49396, Z49394, Z49392, Z49391, Z49390, Z49389, Z49387, Z49386, Z49385.     

新型多重富集低NOx煤粉燃烧器的研究

对多重富集低 NOx 煤粉燃烧器的结构及特点进行了分析 ,初步阐述了这种燃烧器的低负荷稳燃和低 NOx 排放原理 ,并进行了一系列冷态模化实验 ,研究了燃烧器结构和气流等因素对这种燃烧器性能 ,即浓淡风比、阻力系数的影响 .实验结果表明 ,档块间开度对燃烧器阻力损失影响显著 ,开度增加可使燃烧器阻力损失降低 ,浓淡风比减小 ,但双档块开度过多 ,会使加粉时煤粉气流的浓淡分离效果变差 ;浓淡风比受燃烧器浓淡侧阻力平衡决定 ,为此 ,必须在浓侧设置阻力调节器 ,满足阻力特性和风量平衡的多重要求 ,根据实验结果得到了优化的燃烧器结构 .     

Microstructure evolution and degradation mechanisms of reactor internal steel irradiated with heavy ions

Structure evolution and degradation mechanisms during irradiation of 18Cr-10Ni-Ti steel (material of VVER-1000 reactor internals are investigated). Using accelerator irradiations with Cr³⁺ and Ar⁺ ions allowed studying effects of dose rate, different initial structure state and implanted ions on features of structure evolution and main mechanisms of degradation including low temperature swelling and embrittlement of the 18Cr-10Ni-Ti steel. It is shown that differences in dose rate at most irradiation temperatures mainly exert their influence on the duration of the swelling transient regime. Calculations of possible transmutation products during irradiation of this steel in a VVER-1000 spectrum were performed. It is shown that gaseous atoms (He and H), which are generated simultaneously with radiation defects, stabilize the elements of radiation microstructure and influence the swelling. The nature of deformation under different temperatures of irradiation and of mechanical testing is investigated. It is shown that the temperature sensitivity of swelling behaviour in the investigated steel, with different initial structures can be connected with the dynamic behaviour of point defect sinks.     

Current status of kinematically complete studies of basic fragmentation processes in atomic systems

Recent developments on kinematically complete experiments on basic atomic fragmentation processes are reviewed. Comparisons between theoretical and experimental fully differential cross sections for single ionization of light atoms by charged particle impact are analyzed. Furthermore, a method developed very recently, four-particle Dalitz plots, is discussed in context of double ionization. The extraordinary power of these plots is their capability to provide a comprehensive picture of the momentum exchange between all four final-state particles in a single spectrum.     

cdma 1x EV-DO与cdma 1x共用室内分布系统的测试与分析

通过对EV-DO试验网开通后的测量分析,探讨cdma 1x EV-DO网络对cdma现网直放站及室内分布系统的影响及处理方式,为今后3G网络的平滑升级提供借鉴.     

(Bi_(1/2)Na_(1/2))TiO_3BaTiO_3系无铅压电陶瓷工艺的研究

详细探讨了在制备(Bi1/2Na1/2)TiO3 BaTiO3(abbr.BNBT)系无铅压电陶瓷的过程中,合成条件Ty和烧结温度Ts对材料压电介电性能的影响,确定了较好的制备BNBT系压电陶瓷的工艺条件,并且系统地研究了(1-x)·(Bi1/2Na1/2)TiO3 xBaTiO3(x=0 02、0 04、0 06、0 08、0 10)的性能。XRD结构分析发现系统的相界在x=0 06,此时d33等压电介电性能参数达到最佳值。     

Nano-to-macroporous TiO2 (anatase) by cold sintering process

Cold Sintering Process (CSP) was applied on commercial nanopowders to produce nanostructured TiO₂ anatase with nano-to-macro porosity. Nanoporous TiO₂ based materials were obtained by applying CSP at 150 °C and pressures up to 500 MPa on three TiO₂ nanopowders with different specific surface area (s.s.a. = 50, 90 and 370 m²/g), using water as transient aqueous environment. Although TiO₂ is insoluble in water, a density of 68% and s.s.a. = 117 m²/g were achieved from the powder with the highest specific surface area. A post annealing process at 500 °C increased the density up to 73% with a s.s.a. = 59 m²/g, and the crystallites dimensions passed from 110 Å in the powder to 130 Å in CSP material and 172 Å after post annealing. Finally, macroporosity was produced by using thermoplastic polymer beads as sacrificial templates within TiO₂ nanopowder during CSP, followed by a debonding at 500 °C.