Cymbal hydrophones have small volume and high sensitivity, but their reception is not stable enough, and their reception is in too narrow a frequency band. In order to overcome these inadequacies, the structure of the...Cymbal hydrophones have small volume and high sensitivity, but their reception is not stable enough, and their reception is in too narrow a frequency band. In order to overcome these inadequacies, the structure of the cymbal hydrophone was improved. The single ceramic piezoelectric element was replaced with a double one, the radius of the ceramic piezoelectric element was reduced, and a parallel circuit was added. A static analysis of this new structure was developed, and then simulations were made of both the traditional and new hydrophone structure using finite element software. Tests were then conducted in a tank. The results showed that the improved hydrophone has reception in a wider frequency band, reception performance is stable within this frequency band, and sensitivity is still high.展开更多
To reduce the time required to complete the regeneration process of erasure codes, we propose a Tree-structured Parallel Regeneration (TPR) scheme for multiple data losses in distributed storage systems. Under the sch...To reduce the time required to complete the regeneration process of erasure codes, we propose a Tree-structured Parallel Regeneration (TPR) scheme for multiple data losses in distributed storage systems. Under the scheme, two algorithms are proposed for the construction of multiple regeneration trees, namely the edge-disjoint algorithm and edge-sharing algorithm. The edge-disjoint algorithm constructs multiple independent trees, and is simple and appropriate for environments where newcomers and their providers are distributed over a large area and have few intersections. The edge-sharing algorithm constructs multiple trees that compete to utilize the bandwidth, and make a better utilization of the bandwidth, although it needs to measure the available band-width and deal with the bandwidth changes; it is therefore difficult to implement in practical systems. The parallel regeneration for multiple data losses of TPR primarily includes two optimizations: firstly, transferring the data through the bandwidth optimized-paths in a pipe-line manner; secondly, executing data regeneration over multiple trees in parallel. To evaluate the proposal, we implement an event-based simulator and make a detailed comparison with some popular regeneration methods. The quantitative comparison results show that the use of TPR employing either the edge-disjoint algorithm or edge-sharing algorithm reduces the regeneration time significantly.展开更多
The rational design of polymer acceptors with strong and broad absorption is critical to improve photovoltaic performance.In this work,a new polymer acceptor PY9-T based on heptacyclic benzotriazole(Y9-C16)as a buildi...The rational design of polymer acceptors with strong and broad absorption is critical to improve photovoltaic performance.In this work,a new polymer acceptor PY9-T based on heptacyclic benzotriazole(Y9-C16)as a building block and thiophene unit as the linking unit was synthesized,which exhibited a low bandgap(1.37 eV)and a high extinction coefficient of the neat film(1.44×10^(5) cm^(−1)).When PY9-T was blended with the wide bandgap polymer donor PBDB-T,the all-polymer solar cells(APSCs)showed a high power conversion efficiency(PCE)of 10.45%with both high open circuit voltage of 0.881 V and short-circuit current density of 19.82 mA/cm^(2).In addition,APSCs based on PY9-T show good thermal stability,as evidenced by slight changes morphologies when annealed at 100℃.These results suggest that Y9-C16 provides a new building block to develop efficient and stable polymer acceptors.展开更多
This paper presents a new Transmitted Reference (TR) Ultra-WideBand (UWB) receiver based on Spatial Diversity (SD), which employs Multi-Antenna Technology (MAT) to improve the performance of TR-UWB receiver. According...This paper presents a new Transmitted Reference (TR) Ultra-WideBand (UWB) receiver based on Spatial Diversity (SD), which employs Multi-Antenna Technology (MAT) to improve the performance of TR-UWB receiver. According to the amplitude of correlator output of every antenna branch, this paper analyzed the performances of the proposed TR-UWB receiver employing three different kinds of combination strategies, i.e., Maximum Ratio Combination (MRC), Equal Gain Combination (EGC), and Selective Combination (SC), which are different from conventional ones, and theoretically proved that the performance of EGC is better than MRC. Simulation results verify that when EGC is adopted and BER=10-3, increasing three antennas provides Signal to Noise Ratio (SNR) gain of about 3 dB in CM4 channel and SNR gain of about 2 dB in CM2 channel.展开更多
Baseband ASIP designs for handsets are discussed based on the author's R&D backgrounds. Algorithms for 4G, 3G, and WLAN are analyzed and selected for implementation based on the trade off of cost and performan...Baseband ASIP designs for handsets are discussed based on the author's R&D backgrounds. Algorithms for 4G, 3G, and WLAN are analyzed and selected for implementation based on the trade off of cost and performance with power consumption in mind. A SDR ASIP baseband system architecture is proposed for 4G and 3G mobile handsets. Function partitions for heterogeneous symbol processors are introduced to get higher performance over cost. Three structures for DFE, FFE, and Matrix symbol ASIP are proposed. The concept of bit parallel processor is introduced. Challenges of baseband processors for UDN of 5G were briefly introduced. Conclusions on ASIP architecture and system design are given for different baseband processors on different products.展开更多
Objective： To observe the clinical effects of electroacupuncture （EA） at Jiaji （Ex-B 2） points plus herbal medicine for herpes zoster （HZ）. Methods： Sixty-two cases were randomly divided into a treatment group...Objective： To observe the clinical effects of electroacupuncture （EA） at Jiaji （Ex-B 2） points plus herbal medicine for herpes zoster （HZ）. Methods： Sixty-two cases were randomly divided into a treatment group and a control group. The treatment group was treated with EA at Jiaji （Ex-B 2） points plus herbal medicine based upon the pattern differentiation. The control group was treated with oral administration of Aciclovir tablets for resisting virus, and Mecobalamin tablets for nourishing the nerves and Aciclovir cream for skin rash. The therapeutic effects were compared between the two groups, after two-week treatment Results： After 7 d of the treatment, the therapeutic effect was remarkably better in the treatment group than that in the control group （P〈0.01）. After two-week treatment, the therapeutic effects were still different between the two groups （P〈0.05）. Conclusion： The therapeutic effect of EA at Jiaji （Ex-B 2） points plus herbal medicine for HZ is better than that of Western medications in resisting virus and nourishing nerves.展开更多
Objective： Conventional fixation of syndesmotic injuries with screws remains problematic. A novel fibrewire device （Tightrope） has suggested advantages. However, small case series have reported high soft tissue com...Objective： Conventional fixation of syndesmotic injuries with screws remains problematic. A novel fibrewire device （Tightrope） has suggested advantages. However, small case series have reported high soft tissue complication rates. The purpose of our study was to quantify complication rates and further procedures in patients treated with Tightropes. A secondary objective was to determine incidence of complications and further procedures in those treated with syndesmotic screws over the same period. Methods： All patients undergoing syndesmotic fixa- tion for ankle fracture between May 2008 and October 2009 were retrospectively reviewed. Incidence of complications, secondary procedures, maintenance of syndesmotic reduc- tion and time spent on non-weight bearing were recorded. Family doctors were contacted for those treated with Tight- ropes to check for any complications managed elsewhere. Results： Thirty-five patients required syndesmoticfixation, in which 12 were treated with Tightropes. They were followed up in clinic for a mean of 12.4 weeks. Family doctors were contacted at mean 14.6 months after treatment to determine any complications suffered. There were no complications attributable to method of fixation. In this series, 12 patients underwent 13 procedures and no patient had recurrent diastasis at discharge; 23 patients treated with screw fixation underwent 45 procedures （19 were screw removals）. There was 1 case ofsyndesmotic diastasis. Screw removal resulted in 2 minor complications. Conclusion： Tightrope fixation provideds effective syndesmotic fixation that is maintained at discharge. We do not experience soft tissue complications reported elsewhere.展开更多
Objective:To observe the efficacy of needling the Xi-Cleft points of yang meridians plus topical surrounding needling and pregabalin in treating postherpetic neuralgia(PHN)affecting the head and face and its influence...Objective:To observe the efficacy of needling the Xi-Cleft points of yang meridians plus topical surrounding needling and pregabalin in treating postherpetic neuralgia(PHN)affecting the head and face and its influence on quality of life(QOL).Methods:Eighty patients with PHN affecting the head and face were randomized into an acupuncture-medication group and a Western medication group by their visiting sequence,with 40 cases in each group.The Western medication group took pregabalin capsules orally,75 mg each time,twice a day.The dosage could increase to 150 mg each time and twice a day within 1 week based on the efficacy and tolerance.The treatment lasted for 5 weeks.The acupuncture-medication group was given additional surrounding needling at the herpes zoster on the head and face,and Xi-Cleft points of yang meridians were chosen according to the affected area for acupuncture,once every other day,for 5 weeks in total.Results:Prior to treatment,there were no significant differences in the visual analog scale(VAS)and QOL scores between the two groups(both P>O,05).After treatment,VAS and QOL scores dropped significantly in both groups(all P<0.01),and were significantly lower in the acupuncture-medication group than in the Western medication group(both P<0.01).The total effective rate was 67.5%in the Western medication group,versus 92.5%in the acupuncture-medication group,and the b etwee n-group difference was statistically significant(P<0.05).Conclusion:Based on oral administration of pregabalin,needling the Xi-Cleft points of yang meridians and topical surrounding needling can reduce PHN,notably improve patients'QOL,and produce more significant efficacy than oral administration of pregabalin alone。展开更多
文摘Cymbal hydrophones have small volume and high sensitivity, but their reception is not stable enough, and their reception is in too narrow a frequency band. In order to overcome these inadequacies, the structure of the cymbal hydrophone was improved. The single ceramic piezoelectric element was replaced with a double one, the radius of the ceramic piezoelectric element was reduced, and a parallel circuit was added. A static analysis of this new structure was developed, and then simulations were made of both the traditional and new hydrophone structure using finite element software. Tests were then conducted in a tank. The results showed that the improved hydrophone has reception in a wider frequency band, reception performance is stable within this frequency band, and sensitivity is still high.
基金supported by the National Grand Fundamental Research of China (973 Program) under Grant No. 2011CB302601the National High Technology Research and Development of China (863 Program) under GrantNo. 2013AA01A213+2 种基金the National Natural Science Foundation of China under Grant No. 60873215the Natural Science Foundation for Distinguished Young Scholars of Hunan Province under Grant No. S2010J5050Specialized Research Fund for the Doctoral Program of Higher Education under Grant No. 20124307110015
文摘To reduce the time required to complete the regeneration process of erasure codes, we propose a Tree-structured Parallel Regeneration (TPR) scheme for multiple data losses in distributed storage systems. Under the scheme, two algorithms are proposed for the construction of multiple regeneration trees, namely the edge-disjoint algorithm and edge-sharing algorithm. The edge-disjoint algorithm constructs multiple independent trees, and is simple and appropriate for environments where newcomers and their providers are distributed over a large area and have few intersections. The edge-sharing algorithm constructs multiple trees that compete to utilize the bandwidth, and make a better utilization of the bandwidth, although it needs to measure the available band-width and deal with the bandwidth changes; it is therefore difficult to implement in practical systems. The parallel regeneration for multiple data losses of TPR primarily includes two optimizations: firstly, transferring the data through the bandwidth optimized-paths in a pipe-line manner; secondly, executing data regeneration over multiple trees in parallel. To evaluate the proposal, we implement an event-based simulator and make a detailed comparison with some popular regeneration methods. The quantitative comparison results show that the use of TPR employing either the edge-disjoint algorithm or edge-sharing algorithm reduces the regeneration time significantly.
基金Project(21875286)supported by the National Natural Science Foundation of China。
文摘The rational design of polymer acceptors with strong and broad absorption is critical to improve photovoltaic performance.In this work,a new polymer acceptor PY9-T based on heptacyclic benzotriazole(Y9-C16)as a building block and thiophene unit as the linking unit was synthesized,which exhibited a low bandgap(1.37 eV)and a high extinction coefficient of the neat film(1.44×10^(5) cm^(−1)).When PY9-T was blended with the wide bandgap polymer donor PBDB-T,the all-polymer solar cells(APSCs)showed a high power conversion efficiency(PCE)of 10.45%with both high open circuit voltage of 0.881 V and short-circuit current density of 19.82 mA/cm^(2).In addition,APSCs based on PY9-T show good thermal stability,as evidenced by slight changes morphologies when annealed at 100℃.These results suggest that Y9-C16 provides a new building block to develop efficient and stable polymer acceptors.
文摘This paper presents a new Transmitted Reference (TR) Ultra-WideBand (UWB) receiver based on Spatial Diversity (SD), which employs Multi-Antenna Technology (MAT) to improve the performance of TR-UWB receiver. According to the amplitude of correlator output of every antenna branch, this paper analyzed the performances of the proposed TR-UWB receiver employing three different kinds of combination strategies, i.e., Maximum Ratio Combination (MRC), Equal Gain Combination (EGC), and Selective Combination (SC), which are different from conventional ones, and theoretically proved that the performance of EGC is better than MRC. Simulation results verify that when EGC is adopted and BER=10-3, increasing three antennas provides Signal to Noise Ratio (SNR) gain of about 3 dB in CM4 channel and SNR gain of about 2 dB in CM2 channel.
基金supported by the National HighTech Research and Development Program of China (863 Program) 2014AA01A705.
文摘Baseband ASIP designs for handsets are discussed based on the author's R&D backgrounds. Algorithms for 4G, 3G, and WLAN are analyzed and selected for implementation based on the trade off of cost and performance with power consumption in mind. A SDR ASIP baseband system architecture is proposed for 4G and 3G mobile handsets. Function partitions for heterogeneous symbol processors are introduced to get higher performance over cost. Three structures for DFE, FFE, and Matrix symbol ASIP are proposed. The concept of bit parallel processor is introduced. Challenges of baseband processors for UDN of 5G were briefly introduced. Conclusions on ASIP architecture and system design are given for different baseband processors on different products.
文摘Objective： To observe the clinical effects of electroacupuncture （EA） at Jiaji （Ex-B 2） points plus herbal medicine for herpes zoster （HZ）. Methods： Sixty-two cases were randomly divided into a treatment group and a control group. The treatment group was treated with EA at Jiaji （Ex-B 2） points plus herbal medicine based upon the pattern differentiation. The control group was treated with oral administration of Aciclovir tablets for resisting virus, and Mecobalamin tablets for nourishing the nerves and Aciclovir cream for skin rash. The therapeutic effects were compared between the two groups, after two-week treatment Results： After 7 d of the treatment, the therapeutic effect was remarkably better in the treatment group than that in the control group （P〈0.01）. After two-week treatment, the therapeutic effects were still different between the two groups （P〈0.05）. Conclusion： The therapeutic effect of EA at Jiaji （Ex-B 2） points plus herbal medicine for HZ is better than that of Western medications in resisting virus and nourishing nerves.
文摘Objective： Conventional fixation of syndesmotic injuries with screws remains problematic. A novel fibrewire device （Tightrope） has suggested advantages. However, small case series have reported high soft tissue complication rates. The purpose of our study was to quantify complication rates and further procedures in patients treated with Tightropes. A secondary objective was to determine incidence of complications and further procedures in those treated with syndesmotic screws over the same period. Methods： All patients undergoing syndesmotic fixa- tion for ankle fracture between May 2008 and October 2009 were retrospectively reviewed. Incidence of complications, secondary procedures, maintenance of syndesmotic reduc- tion and time spent on non-weight bearing were recorded. Family doctors were contacted for those treated with Tight- ropes to check for any complications managed elsewhere. Results： Thirty-five patients required syndesmoticfixation, in which 12 were treated with Tightropes. They were followed up in clinic for a mean of 12.4 weeks. Family doctors were contacted at mean 14.6 months after treatment to determine any complications suffered. There were no complications attributable to method of fixation. In this series, 12 patients underwent 13 procedures and no patient had recurrent diastasis at discharge; 23 patients treated with screw fixation underwent 45 procedures （19 were screw removals）. There was 1 case ofsyndesmotic diastasis. Screw removal resulted in 2 minor complications. Conclusion： Tightrope fixation provideds effective syndesmotic fixation that is maintained at discharge. We do not experience soft tissue complications reported elsewhere.
文摘Objective:To observe the efficacy of needling the Xi-Cleft points of yang meridians plus topical surrounding needling and pregabalin in treating postherpetic neuralgia(PHN)affecting the head and face and its influence on quality of life(QOL).Methods:Eighty patients with PHN affecting the head and face were randomized into an acupuncture-medication group and a Western medication group by their visiting sequence,with 40 cases in each group.The Western medication group took pregabalin capsules orally,75 mg each time,twice a day.The dosage could increase to 150 mg each time and twice a day within 1 week based on the efficacy and tolerance.The treatment lasted for 5 weeks.The acupuncture-medication group was given additional surrounding needling at the herpes zoster on the head and face,and Xi-Cleft points of yang meridians were chosen according to the affected area for acupuncture,once every other day,for 5 weeks in total.Results:Prior to treatment,there were no significant differences in the visual analog scale(VAS)and QOL scores between the two groups(both P>O,05).After treatment,VAS and QOL scores dropped significantly in both groups(all P<0.01),and were significantly lower in the acupuncture-medication group than in the Western medication group(both P<0.01).The total effective rate was 67.5%in the Western medication group,versus 92.5%in the acupuncture-medication group,and the b etwee n-group difference was statistically significant(P<0.05).Conclusion:Based on oral administration of pregabalin,needling the Xi-Cleft points of yang meridians and topical surrounding needling can reduce PHN,notably improve patients'QOL,and produce more significant efficacy than oral administration of pregabalin alone。
