产学研合作是培养文秘人才的基本途径

结合三门峡职业技术学院的实际情况，介绍了如何通过产学研合作培养适合不同用人单位需要的的文秘人才的经验。     

420nm thick CH_3NH_3PbI_(3-x)Br_x capping layers for efficient TiO_2 nanorod array perovskite solar cells

The rutile TiO_2 nanorod arrays with 240 nm in length, 30 nm in diameter, and 420 μm~(-2) in areal density were prepared by the hydrothermal method to replace the typical 200-300 nm thick mesoporous TiO_2 thin films in perovskite solar cells. The CH_3NH_3PbI_3-xBrx capping layers with different thicknesses were obtained on the TiO_2 nanorod arrays using different concentration PbI_2·DMSO complex precursor solutions in DMF and the photovoltaic performances of the corresponding solar cells were compared. The perovskite solar cells based on 240 nm long TiO_2 nanorod arrays and 420 nm thick CH_3NH_3PbI_(3-x)Br_x capping layers showed the best photoelectric conversion efficiency(PCE) of 15.56%and the average PCE of 14.93 ± 0.63% at the relative humidity of 50%-54% under the illumination of simulated AM 1.5 sunlight(100 mW·cm~(-2)).     

无线自组织网络可靠组播MAC协议

为了在无线自组织网络的MAC层中更好地提供可靠组播,在尽量少修改IEEE 802.11协议的原则下提出了一个可靠组播MAC协议RMMP(reliable multicast MAC protocol).首先由源节点组播RRTS(reliable RTS)帧,各接收节点依次回复RCTS(reliable CTS)帧;源节点在收到所有RCTS后,组播N个RDATA(reliable DATA)帧,各接收节点收到第N个要求回复的RDATA帧后依次回复RACK(reliable ACK)帧,然后源节点重传丢失帧.RMMP协议提高了MAC层组播可靠性.最后运用NS-2仿真软件对该协议进行验证,结果表明,RMMP在包投递率、吞吐量性能上都有很大的提高,实现了MAC层可靠组播,其代价是平均端到端时延略大.