随着科学技术的发展以及消费者需求的多样化,为适应不同场合的多种用途,插座产品的功能越来越丰富。带电源适配器(USB POWER SUPPLY)的插座产品,将交流和直流输出两种功能集于一体,满足了消费者同时给各类电子设备充电和大功率用电设备...随着科学技术的发展以及消费者需求的多样化,为适应不同场合的多种用途,插座产品的功能越来越丰富。带电源适配器(USB POWER SUPPLY)的插座产品,将交流和直流输出两种功能集于一体,满足了消费者同时给各类电子设备充电和大功率用电设备用电需求。但是,由于带电源适配器(USB POWER SUPPLY)插座的结构特殊性,国内外相关插座标准,对该类产品的温升试验方法尚未形成一致要求。本文通过对比分析国家标准GB/T 2099.1-2008(及其报批稿)、英国BS 1363-2:2016+A1:2018标准、现行IEC 60884-1:2002+A1:2006+A2:2013标准以及新版IEC FDIS 60884-3-1:2021标准草案,对带电源适配器(USB POWER SUPPLY)插座温升试验的不同要求;并依据不同方法对同一插座样品进行试验,归纳出不同试验方法对温升试验结果的影响。同时介绍分析即将发布的新版IEC 60884-3-1:2021标准的温升试验方法。展开更多
For direct sequence spread spectrum （DSSS） receivers, the capability of rejecting narrow-band interference can be significantly improved by a process of frequency-domain interference suppression （FDIS）. The key is...For direct sequence spread spectrum （DSSS） receivers, the capability of rejecting narrow-band interference can be significantly improved by a process of frequency-domain interference suppression （FDIS）. The key issue of this process is how to determine a threshold to eliminate interference in the frequency domain, which has been extensively studied. However, these previous methods are tedious or very complex. A simple and ef- ficient algorithm based on medians is proposed. The elimination threshold is only related to the median by a scale factor, which can be obtained by the numerical analysis. Simulation results show that the algorithm provides excellent narrow-band interfer- ence suppression while only slightly degrading the signal-to-noise ratio （SNR）. A one-pass algorithm using logarithmic segmentation is further derived to estimate medians with low computational complexity. Finally, the FDIS is implemented in a field programmable gate array （FPGA） of Xilinx. Experiments are carried out by connecting the FDIS FPGA to a DSSS receiver, and the results show that the receiver has an effective countermeasure for a 60 dB interference-to-signal ratio （ISR）.展开更多
Objective To evaluate the therapeutic effect and safety of time-oriented points opening of Linggui Bafa for Bell＇s palsy and provide a new idea for the clinical treatment of this problem. Methods Fifty-four cases inc...Objective To evaluate the therapeutic effect and safety of time-oriented points opening of Linggui Bafa for Bell＇s palsy and provide a new idea for the clinical treatment of this problem. Methods Fifty-four cases included in the study were randomized into two groups, and the treatment group was treated with the routine acupuncture combined with time-oriented points opening of Linggui Bafa. The control group was treated with the routine acupuncture only, Hegu （合谷 El 4）, Kunlun （昆仑 BL 60）, Jiache （颊车 ST 6）, Dicang （地仓 ST 4）, Xiaguan （下关 ST 7）, Cuanzhu （攒竹 BL 2）, Yangbai （附白 GB 14）, and Quanliao （颧髎 SI 18） were selected as the main points. The manipulation and time of retaining needles were as same as the treatment group. Both groups were treated once a day, 5 days made one session and 4 sessions were required in all. Modified Portmann＇s scale, Horse-Brackmann grading scale （H-B）, FDIP and FDIS were used to assess the therapeutic effect after the treatment. Results The curative and improvement rate in the treatment group was 80.8% （22/26）, and that in the control group was 66.7% （16/24）, with the statistically significant difference （P〈O.05）, the comparison of scores of Portmann＇s scale, H-B, FDIP and FDIS in the same group and between the two groups before and after the treatment also had statistically significant differences （all P〈0.05）. Conclusion The method of time-oriented points opening of Linggui Bafa for Bell＇s palsy is better than the routine acupuncture for Bell＇s palsy.展开更多
Foreign direct investments (or FDIs) have been employed since the early 1980s and they have become more and more immportant in Chinese economic development. However, the roles of FDIs are very different between region...Foreign direct investments (or FDIs) have been employed since the early 1980s and they have become more and more immportant in Chinese economic development. However, the roles of FDIs are very different between regions, partly due to the different locational preference of various source countries. Some facts show that FDIs from Hongkong - Macao indicate a strong locational preference. Therefore, this paper attempts to make an empirical research on the locational preference of Hongkong - Macao’s FDIs and their spatial diffusion under the support of statistical data with regrereion analysis. In this paper, three statistical models, including the special location model, the general location model and the spatial diffusion model, are created. The results show that this kind of analysis is successful. The major conclusions are as follows. (1) The optimum location for FDIs from Hongkong - Macao lies in the coastal area, especially Guangdong, Hainan, Jiangsu, Shandong, Fujian provinces. Besides, Hubei Province is also an important radon. (2) The FDIs from HongkongMacao in China have diffused gradually from the coastal provinces to the inland regions, the northem and the metropolis and from the locations that had attracted a large number of investments to their vicinities since the 1990s. (3) The special location factors, such as the herder effect, the unique social and kinship ties are the key factors determining the special locational distribution. (4) The general location and spatial diffusion of Hongkong - Macao’s FDIs are the results of interplay of several economic factors. They are the economic scale and advantage, the growth rate, the laier force and economic extrovert etc.展开更多
基金Supported by Program for New Century Excellent Talents in University(NCET-04-0283)the Funds for Creative Research Groups of China(60521003)+4 种基金Program for Changjiang Scholars and Innovative Research Team in University(IRT0421)the State Key Program of National Natural Science Foundation of China(60534010)and National Natural Science Foundation of China(60674021)the Funds of Ph.D.Program of Ministry of Education,China(20060145019)the 111 Project(B08015)
文摘随着科学技术的发展以及消费者需求的多样化,为适应不同场合的多种用途,插座产品的功能越来越丰富。带电源适配器(USB POWER SUPPLY)的插座产品,将交流和直流输出两种功能集于一体,满足了消费者同时给各类电子设备充电和大功率用电设备用电需求。但是,由于带电源适配器(USB POWER SUPPLY)插座的结构特殊性,国内外相关插座标准,对该类产品的温升试验方法尚未形成一致要求。本文通过对比分析国家标准GB/T 2099.1-2008(及其报批稿)、英国BS 1363-2:2016+A1:2018标准、现行IEC 60884-1:2002+A1:2006+A2:2013标准以及新版IEC FDIS 60884-3-1:2021标准草案,对带电源适配器(USB POWER SUPPLY)插座温升试验的不同要求;并依据不同方法对同一插座样品进行试验,归纳出不同试验方法对温升试验结果的影响。同时介绍分析即将发布的新版IEC 60884-3-1:2021标准的温升试验方法。
基金supported by the National Natural Science Foundation of China(60904090)
文摘For direct sequence spread spectrum （DSSS） receivers, the capability of rejecting narrow-band interference can be significantly improved by a process of frequency-domain interference suppression （FDIS）. The key issue of this process is how to determine a threshold to eliminate interference in the frequency domain, which has been extensively studied. However, these previous methods are tedious or very complex. A simple and ef- ficient algorithm based on medians is proposed. The elimination threshold is only related to the median by a scale factor, which can be obtained by the numerical analysis. Simulation results show that the algorithm provides excellent narrow-band interfer- ence suppression while only slightly degrading the signal-to-noise ratio （SNR）. A one-pass algorithm using logarithmic segmentation is further derived to estimate medians with low computational complexity. Finally, the FDIS is implemented in a field programmable gate array （FPGA） of Xilinx. Experiments are carried out by connecting the FDIS FPGA to a DSSS receiver, and the results show that the receiver has an effective countermeasure for a 60 dB interference-to-signal ratio （ISR）.
文摘Objective To evaluate the therapeutic effect and safety of time-oriented points opening of Linggui Bafa for Bell＇s palsy and provide a new idea for the clinical treatment of this problem. Methods Fifty-four cases included in the study were randomized into two groups, and the treatment group was treated with the routine acupuncture combined with time-oriented points opening of Linggui Bafa. The control group was treated with the routine acupuncture only, Hegu （合谷 El 4）, Kunlun （昆仑 BL 60）, Jiache （颊车 ST 6）, Dicang （地仓 ST 4）, Xiaguan （下关 ST 7）, Cuanzhu （攒竹 BL 2）, Yangbai （附白 GB 14）, and Quanliao （颧髎 SI 18） were selected as the main points. The manipulation and time of retaining needles were as same as the treatment group. Both groups were treated once a day, 5 days made one session and 4 sessions were required in all. Modified Portmann＇s scale, Horse-Brackmann grading scale （H-B）, FDIP and FDIS were used to assess the therapeutic effect after the treatment. Results The curative and improvement rate in the treatment group was 80.8% （22/26）, and that in the control group was 66.7% （16/24）, with the statistically significant difference （P〈O.05）, the comparison of scores of Portmann＇s scale, H-B, FDIP and FDIS in the same group and between the two groups before and after the treatment also had statistically significant differences （all P〈0.05）. Conclusion The method of time-oriented points opening of Linggui Bafa for Bell＇s palsy is better than the routine acupuncture for Bell＇s palsy.
文摘Foreign direct investments (or FDIs) have been employed since the early 1980s and they have become more and more immportant in Chinese economic development. However, the roles of FDIs are very different between regions, partly due to the different locational preference of various source countries. Some facts show that FDIs from Hongkong - Macao indicate a strong locational preference. Therefore, this paper attempts to make an empirical research on the locational preference of Hongkong - Macao’s FDIs and their spatial diffusion under the support of statistical data with regrereion analysis. In this paper, three statistical models, including the special location model, the general location model and the spatial diffusion model, are created. The results show that this kind of analysis is successful. The major conclusions are as follows. (1) The optimum location for FDIs from Hongkong - Macao lies in the coastal area, especially Guangdong, Hainan, Jiangsu, Shandong, Fujian provinces. Besides, Hubei Province is also an important radon. (2) The FDIs from HongkongMacao in China have diffused gradually from the coastal provinces to the inland regions, the northem and the metropolis and from the locations that had attracted a large number of investments to their vicinities since the 1990s. (3) The special location factors, such as the herder effect, the unique social and kinship ties are the key factors determining the special locational distribution. (4) The general location and spatial diffusion of Hongkong - Macao’s FDIs are the results of interplay of several economic factors. They are the economic scale and advantage, the growth rate, the laier force and economic extrovert etc.
