Rare-earth free sensitizer in NaLuCrF4:Er upconversion material

Upconversion phosphors are known as a material system that can convert near-infrared light into visible/ultraviolet emissions by sequentially absorbing multiple photons. The studies on upconversion materials often use two rare earth (RE) ions as a sensitizer-activator pair. We investigated the influences on luminescence intensity depending on Cr-doping content (x) of hexagonal NaLu_0.98–xCr_xF₄Er_0.02 (x = 0–0.9) upconversion material by substituting Lu³⁺ ions with Cr³⁺in the absence of Gd³⁺. The change in upconversion luminescence intensity appears with saddle-like shape. We suggest that Cr³⁺ ions play the dual role as a constituent in host lattice and a sensitizer in the upconversion process. Optimal conditions for gaining the strongest upconversion emission correspond to x = 0.3–0.5, where there are effective energy transfers between Cr³⁺ and Er³⁺ ions and CrEr dimers. Apart from these values, the emission intensity decreases rapidly which can be ascribed to the absence of multiple-photon absorption for the case of low Cr³⁺ contents, and to the coupling between Cr³⁺ and/or Er³⁺ ions for the case of high Cr³⁺ contents. Magnetization and electron-spin-resonant measurements were performed to understand the correlation between the optical and magnetic properties.     

2014年下半年企业电子商务及网络营销发展状况分析

根据对我国境内31个省市区6000家企业法人单位进行的调查,给出了2014年下半年各企业电子商务在在线销售和在线采购两方面的使用情况,分析了企业在互联网营销推广方面的使用情况.     

Design of 25 Gbit/s half-rate CDR with 1:2 demultiplexer for 100 GbE optical interconnects

A 25 Gbit/s clock and data recovery(CDR) circuit with 1:2 demultiplexer for 100 Gbit/s Ethernet(100 Gb E) optical interconnects has been designed and fabricated in Taiwan Semiconductor Manufacture Company(TSMC) 65 nm complementary metal-oxide-semiconductor(CMOS) technology. A novel quadrature voltage-controlled-oscillator(QVCO) structure adopts two pairs of transconductance cell and inverters to acquire rail-to-rail output swing. A half-rate bang-bang phase detector adopts four flip-flops array to sample the 25 Gbit/s input data and align the data phase, so the 25 Gbit/s data are retimed and demultiplexed into two paths 12.5 Gbit/s output data. Experimental results show that the recovered clock exhibits a peak-to-peak jitter of 7.39 ps and the recovered data presents a peak-to-peak jitter of 7.56 ps, in response to 312-1 pseudorandom bit sequence(PRBS) input. For 1.2 V voltage supply, the CDR circuit consumes 92 m W(excluding output buffers).     

适应新常态,引领新常态,开创涂料行业新局面——2015年中国涂料、颜料行业工作年会在杭州隆重召开

草长莺飞的季节,春意盎然。3月26日,在素有"上有天堂下有苏杭"美誉之一的杭州,迎来了一年一度的涂料行业盛会——由中国涂料工业协会主办、为期两天的以"绿色环保,政策引导,共建未来"为主题的"2015年中国涂料、颜料行业工作年会"。有来自全国涂料、颜料、原材料及相关行业的约560名代表齐聚一堂,回眸2014,展望2015,共同探讨新常态下涂料行业产业升级、结构调整、节能减排,围绕涂料行业经济运行、涂料消费税、绿色建材政策、工业涂装VOC控制、水性工业涂料、全球涂料发展等热点进行探讨与交流。中国涂料工业协会会长孙莲英女士、国家工信部原材料司副司长潘爱华先生、国家税务总局领导、浙江省涂料行业协会理事长程磊楠先生、中国涂料工业协会秘书长杨渊德先生等领导嘉宾出席了会议。大会先后由中国涂料工业协会副秘书长刘丹、副秘书长刘杰,专家委员会主任桂泰江主持。     

Preparation of Silver Nanowires via a Rapid,Scalable and Green Pathway

Rapid synthesis of silver nanowires(Ag NWs) with high quality and a broad processing window is challenging because of the low selectivity of the formation of multiply twinned particles at the nucleation stage for subsequent Ag NWs growth.Herein we report a systematic study of the water-involved heterogeneous nucleation of Ag NWs with high rate(less than 20 min) in a simple and scalable preparation method.Using glycerol as a reducing agent and a solvent with a high boiling point,the reaction is rapidly heated to 210 ℃ in air to synthesize Ag NWs with a very high yield in gram level.It is noted that the addition of a small dose of water plays a key role for obtaining highly pure Ag NWs in high yield,and the optimal water/glycerol ratio is0.25%.After investigating a series of forming factors including reaction temperature and dose of catalysts,the formation kinetics and mechanism of the Ag NWs are proposed.Compared to other preparation methods,our strategy is simple and reproducible.These Ag NWs show a strong Raman enhancement effect for organic molecules on their surface.     

WIRELESS BODY-AREA NETWORKS

The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless person-     

影像导引肝脏恶性肿瘤多模态消融治疗技术专家共识

影像导引肝脏恶性肿瘤多模态消融治疗是以医学影像技术为导引，在冷冻消融与热消融交替转换过程中，通过对病灶区温度精准控制和消融过程定量规划，彻底破坏原位肿瘤细胞及其循环系统，同时最大程度释放活性肿瘤抗原，从而达到控制肝脏恶性肿瘤复发转移的目的。为规范肝脏恶性肿瘤多模态消融治疗技术操作，便于不同层级医院开展实施，确保医疗安全和临床疗效，中国抗癌协会肿瘤介入学专业委员会和上海市抗癌协会实体肿瘤聚焦诊疗专业委员会组织国内肿瘤治疗领域的多学科专家共同参与，认真讨论，最终达成本共识。