经颅交流电刺激(transcranial Alternating Current Stimulation,tACS)是一种通过在头皮施加微弱电流的非侵入性电刺激技术,已有研究证实经颅交流电刺激会对大脑的全局属性产生影响.本文使用脑电相位同步方法构建了刺激组和对照组刺激...经颅交流电刺激(transcranial Alternating Current Stimulation,tACS)是一种通过在头皮施加微弱电流的非侵入性电刺激技术,已有研究证实经颅交流电刺激会对大脑的全局属性产生影响.本文使用脑电相位同步方法构建了刺激组和对照组刺激前、后静息态脑网络,并计算聚类系数、平均度、特征路径长度3种网络参数,来研究大脑各区域间的相关性.分析发现3种网络参数中,只有刺激组的特征路径长度在刺激后有明显下降,而对照组没有出现这种现象.特征路径长度的大小代表了大脑各区域间信息传递速度的快慢,说明经颅交流电刺激可以增强大脑各区域间的关联性,加快各区域的信息传递速度.展开更多
Near infrared spectroscopy(NIRS)is based on molecular overtone and combination vibrations.It is difficult to assign specific features under complicated system.So it is necessary to find the relevance between NIRS and ...Near infrared spectroscopy(NIRS)is based on molecular overtone and combination vibrations.It is difficult to assign specific features under complicated system.So it is necessary to find the relevance between NIRS and target compound.For this purpose,the chondroitin sulfate(CS)ethanol precipitation process was selected as the research model,and 90 samples of 5 different batches were collected and the content of CS was determined by modifed carbazole method.The relevance between NIRS and CS was studied throughout optical pathlength,pretreat ment methods and variables selection methods.In conclusion,the first derivative with Savitzky--Golay(SG)smoothing was selected as the best pretreatment,and the best spectral region was selected using interval partial least squares(iPLS)method under 1 mm optical cell.A multivariate cali-bration model was established using PLS algorithm for determining the content of CS,and the root mean square error of prediction(RMSEP)is 3.934gL-1.This method will have great potential in process analytical technology in the future.展开更多
This paper presents a "cluster" based search scheme in peer-to-peer network. The idea is based on the fact that data distribution in an information society has structured feature. We designed an algorithm to...This paper presents a "cluster" based search scheme in peer-to-peer network. The idea is based on the fact that data distribution in an information society has structured feature. We designed an algorithm to cluster peers that have similar interests. When receiving a query request, a peer will preferentially forward it to another peer which belongs to the same cluster and shares more similar interests. By this way search efficiency will be remarkably improved and at the same time good resilience against peer failure (the ability to withstand peer failure) is reserved.展开更多
文摘经颅交流电刺激(transcranial Alternating Current Stimulation,tACS)是一种通过在头皮施加微弱电流的非侵入性电刺激技术,已有研究证实经颅交流电刺激会对大脑的全局属性产生影响.本文使用脑电相位同步方法构建了刺激组和对照组刺激前、后静息态脑网络,并计算聚类系数、平均度、特征路径长度3种网络参数,来研究大脑各区域间的相关性.分析发现3种网络参数中,只有刺激组的特征路径长度在刺激后有明显下降,而对照组没有出现这种现象.特征路径长度的大小代表了大脑各区域间信息传递速度的快慢,说明经颅交流电刺激可以增强大脑各区域间的关联性,加快各区域的信息传递速度.
基金the Chinese National Level College Student Innovation Project (No.1110422080)the 863 program (Hi-tech research and development program of China)under contract NO.2012AA021505the National Training Programs of Innovation and Entrepreneurship for Undergraduates (No.201210422079).
文摘Near infrared spectroscopy(NIRS)is based on molecular overtone and combination vibrations.It is difficult to assign specific features under complicated system.So it is necessary to find the relevance between NIRS and target compound.For this purpose,the chondroitin sulfate(CS)ethanol precipitation process was selected as the research model,and 90 samples of 5 different batches were collected and the content of CS was determined by modifed carbazole method.The relevance between NIRS and CS was studied throughout optical pathlength,pretreat ment methods and variables selection methods.In conclusion,the first derivative with Savitzky--Golay(SG)smoothing was selected as the best pretreatment,and the best spectral region was selected using interval partial least squares(iPLS)method under 1 mm optical cell.A multivariate cali-bration model was established using PLS algorithm for determining the content of CS,and the root mean square error of prediction(RMSEP)is 3.934gL-1.This method will have great potential in process analytical technology in the future.
文摘This paper presents a "cluster" based search scheme in peer-to-peer network. The idea is based on the fact that data distribution in an information society has structured feature. We designed an algorithm to cluster peers that have similar interests. When receiving a query request, a peer will preferentially forward it to another peer which belongs to the same cluster and shares more similar interests. By this way search efficiency will be remarkably improved and at the same time good resilience against peer failure (the ability to withstand peer failure) is reserved.
