Li1+xMn2?yO4 spinels with various Li/Mn ratios were synthesized by a solid-state reaction. By X-ray diffraction analysis, Li2MnO3 was detected as a second phase with increasing the Li/Mn ratio; and the role of Li2MnO3...Li1+xMn2?yO4 spinels with various Li/Mn ratios were synthesized by a solid-state reaction. By X-ray diffraction analysis, Li2MnO3 was detected as a second phase with increasing the Li/Mn ratio; and the role of Li2MnO3 in Li1+xMn2-yO4 spinel was discussed. A slow scanning cyclic voltammetry(CV) at the rate of 0.1 mV/s was adopted to characterize the evolutions of 4 V and 5 V plateaus of Li1+xMn2-yO4 spinels. An additional Li+ insertion in 4 V region was observed in both Li-lack and Li-rich spinels at 3.95 V, which is different from the general Li+ insertion with weak Li-Li interaction and strong Li-Li interaction; and this plateau disappeared in the subsequent cycles. The 4.4 V/3.8 V plateaus correspondent to Li+ insertion and extraction of Li2MnO3 were discussed, and these plateaus have a high reversibility with cycling. The 5 V plateau was found only in the Li-rich samples, and this plateau has a tendency to emerge at higher voltage region with increasing Li/Mn ratio.展开更多
The investigation of fingerprint of Yubaizhi was performed by high-performance liquid chromatography （HPLC）. Chromatographic conditions were： the mobile phase was the mixture of acetonitrile-water （43：57, v/v）; ...The investigation of fingerprint of Yubaizhi was performed by high-performance liquid chromatography （HPLC）. Chromatographic conditions were： the mobile phase was the mixture of acetonitrile-water （43：57, v/v）; the flow rate was 1 mL/min; the column temperature was 40℃ ; the detection wavelength was 254 nm. The stability, precision and reproducibility were performed according to ＂Specification of Fingerprint of Injection of Chinese Traditional Medicine （temporarily）＂ regulated by State Food and Drug Administration（SFDA）. The HPLC fingerprints of Yubaizhi from various locations were well constant.展开更多
Compared with flat routing protocols, clustering is a fundamental performance improvement technique in wireless sensor networks, which can increase network scalability and lifetime. In this paper, we integrate the mul...Compared with flat routing protocols, clustering is a fundamental performance improvement technique in wireless sensor networks, which can increase network scalability and lifetime. In this paper, we integrate the multi-hop technique with a backoff-based clustering algorithm to organize sensors. By using an adaptive backoff strategy, the algorithm not only realizes load balance among sensor node, but also achieves fairly uniform cluster head distribution across the network. Simulation results also demonstrate our algorithm is more energy-efficient than classical ones. Our algorithm is also easily extended to generate a hierarchy of cluster heads to obtain better network management and energy-efficiency.展开更多
基金Project(2002CB211800) supported by the National Basic Research Program of China
文摘Li1+xMn2?yO4 spinels with various Li/Mn ratios were synthesized by a solid-state reaction. By X-ray diffraction analysis, Li2MnO3 was detected as a second phase with increasing the Li/Mn ratio; and the role of Li2MnO3 in Li1+xMn2-yO4 spinel was discussed. A slow scanning cyclic voltammetry(CV) at the rate of 0.1 mV/s was adopted to characterize the evolutions of 4 V and 5 V plateaus of Li1+xMn2-yO4 spinels. An additional Li+ insertion in 4 V region was observed in both Li-lack and Li-rich spinels at 3.95 V, which is different from the general Li+ insertion with weak Li-Li interaction and strong Li-Li interaction; and this plateau disappeared in the subsequent cycles. The 4.4 V/3.8 V plateaus correspondent to Li+ insertion and extraction of Li2MnO3 were discussed, and these plateaus have a high reversibility with cycling. The 5 V plateau was found only in the Li-rich samples, and this plateau has a tendency to emerge at higher voltage region with increasing Li/Mn ratio.
文摘The investigation of fingerprint of Yubaizhi was performed by high-performance liquid chromatography （HPLC）. Chromatographic conditions were： the mobile phase was the mixture of acetonitrile-water （43：57, v/v）; the flow rate was 1 mL/min; the column temperature was 40℃ ; the detection wavelength was 254 nm. The stability, precision and reproducibility were performed according to ＂Specification of Fingerprint of Injection of Chinese Traditional Medicine （temporarily）＂ regulated by State Food and Drug Administration（SFDA）. The HPLC fingerprints of Yubaizhi from various locations were well constant.
基金Supported by the National Natural Science Foundation of China under Grant No. 60872018,60721002,60875038the National Basic Research 973 Program of China under Grant No. 2007CB310607+2 种基金SRFDP Project under Grant No. 20070293001the Science and Technology Support Foundation of Jiangsu Province under Grant No. BE2009142 and BE2010180the Scientific Research Foundation of Graduate School of Nanjing University under Grant No. 2011CL07
文摘Compared with flat routing protocols, clustering is a fundamental performance improvement technique in wireless sensor networks, which can increase network scalability and lifetime. In this paper, we integrate the multi-hop technique with a backoff-based clustering algorithm to organize sensors. By using an adaptive backoff strategy, the algorithm not only realizes load balance among sensor node, but also achieves fairly uniform cluster head distribution across the network. Simulation results also demonstrate our algorithm is more energy-efficient than classical ones. Our algorithm is also easily extended to generate a hierarchy of cluster heads to obtain better network management and energy-efficiency.
