电感储能型脉冲电源是目前电磁发射技术的研究热点,提升装置储能密度对于推动电感储能型脉冲电源的应用和研究具有重要意义。本文介绍了一种适用于电感储能型脉冲电源的名为meat grinder with SECT的新电路,并对该电路进行了详细的原理...电感储能型脉冲电源是目前电磁发射技术的研究热点,提升装置储能密度对于推动电感储能型脉冲电源的应用和研究具有重要意义。本文介绍了一种适用于电感储能型脉冲电源的名为meat grinder with SECT的新电路,并对该电路进行了详细的原理分析,指出该电路兼具电流关断能力强和拓扑结构简单的优点。通过仿真将meat grinder with SECT和STRETCH meat grinder、STRETCH meat grinder with ICCOS这两种主流电路进行了性能比较,发现meat grinder with SECT电路在保持电气性能不变的同时,成本最低,体积最小。基于meat grinder with SECT电路,本文研制了50k J电感储能型脉冲电源并进行了试验测试,测试结果达到了预期目标。展开更多
Seventeen species, one subspecies and one variety of Dioscorea sect. Stenophora Uline were investi-gated for their phylogenetic relationships based on a sequence analysis of chloroplast matK and rbcL genes and trnL-F ...Seventeen species, one subspecies and one variety of Dioscorea sect. Stenophora Uline were investi-gated for their phylogenetic relationships based on a sequence analysis of chloroplast matK and rbcL genes and trnL-F intergenic spacer by maximum parsimony and maximum likelihood methods. The results showed that: (a) sect. Stenophora was a strongly supported monophyletic group; (b) D. rockii, D. membranacea, D. banzhuana, and D. simulans formed a moderately supported monophyletic group, and D. prazeri was weakly supported to be sister to this group; (c) D. althaeoides and D. nipponica ssp. nipponica formed a moderately supported clade, and D. nipponica ssp. rosthornii was not a member of this clade; (d) D. zingiberensis and D. sinoparviflora showed a moderate to strong sister relationship; and (e) D. collettii var. hypoglauca and D. collettii var. collettii were sister to each other, but with only weak support.展开更多
In this paper Clematis sect. Aspidanthera s.l. is revised. Seventy_ two species and 15 varieties are recognized. They are keyed, described, and in most cases illustrated, and are classified into six subsections. Of th...In this paper Clematis sect. Aspidanthera s.l. is revised. Seventy_ two species and 15 varieties are recognized. They are keyed, described, and in most cases illustrated, and are classified into six subsections. Of them, on e series, five species, and two varieties are described as new, and two new rank s are proposed. Brief taxonomic history and geographical distribution of the sec tion are given, the evolutionary trends of several important morphological characters observed are e numerated, and the relationships of its subsections are discussed. As a resul t, subsect. Dioicae, which shows striking resemblance in both habit an d floral structure to sect. Clematis subsect. Clematis, is regar ded as t he primitive group, while subsect. Insidiosae, bearing pistillate flower wit h erect sepals and no staminodes, is regarded as the advanced group within the s ection.展开更多
Vicia amirensis has pollen grain with swollen mesocipium, terete style, abaxially sproution stylar hairs and globes stigma, differing from other five species, V. amoena, V. Japonica, V. pseudo-orbus, V. ramulifloua, V...Vicia amirensis has pollen grain with swollen mesocipium, terete style, abaxially sproution stylar hairs and globes stigma, differing from other five species, V. amoena, V. Japonica, V. pseudo-orbus, V. ramulifloua, V. unijuga and V. venosa, in sect. Vicilla of Kupicha’s System. This result further support taxonomic treatment V. amurensis proposed by Endo and Ohash. The chromosome numbers of 64 pop ulations and karyotypes of 15 populations for sect. Vicilla and sect. Amurense were observed. V. amurensis and V. pseudo-orbus have similar karyotype features such as the same karyotype symmetry, comparable chromosome size and the same type of Sat-chromosomes, and therefore V. amurensis in sect. Amurense is assumed to be closely related to V. Japonica in sect. Vicilla. The primary study of nuclear DNA amount was carried out on nine populations of six taxa in sect. Vicilla and geographic distribution of different ploidy cytotypes. karyotype, nuclear DNA amount in sect. Vicilla and geographic distribution of different ploidy cytotypes.展开更多
Nigeria was listed as a part of terrorist states by United States of America as a result of Islamic group (Boko Haram Sect) attacks and other activities in the nation. It has also been discovered that the group emplo...Nigeria was listed as a part of terrorist states by United States of America as a result of Islamic group (Boko Haram Sect) attacks and other activities in the nation. It has also been discovered that the group employs “steganographic” schemes as a secure means for transmitting their hidden information to each other via Internet and social networks. The group has killed thousands of people since their increased insurgency in July, 2009. These challenges have affected the nation’s foreign policies, political and social economic developments. This research addresses the challenges by employing forensic technique using blind steganalysis approach to detect the presence of the hidden messages in images. Image Quality Metric is employed for extracting the features, and logistic regression is trained as the classifier to predict the stego-images. We show the effectiveness of the method by conducting test and analysis with 319 images varying in size and style. The result shows that the performance of the method is better than other steganalysis methods.展开更多
Dryopteris sect.Diclisodon is a small section of ferns with about 12 species mainly distributed in East Asia.Here,we carried out morphological and phylogenetic analyses of this section.A new species from southwest Chi...Dryopteris sect.Diclisodon is a small section of ferns with about 12 species mainly distributed in East Asia.Here,we carried out morphological and phylogenetic analyses of this section.A new species from southwest China,D.gaoligongensis,is described and illustrated.Dryopteris gaoligongensis resembles D.indonesiana and D.sparsa,but differs by having a creeping rhizome and large 4-pinnate fronds.We also show that D.glabrior Ching&Z.Y.Liu is a distinct species;however,because it is a later homonym of D.glabrior Copel.,it should be renamed D.renchangiana.We conclude that a species previously known as D.nitidula,also an illegitimate homonym,should be recognized with a new name,D.sinonepalensis.We resolve the phylogenetic position of D.yoroii as sister to other sampled species of D.sect Diclisodon.Our phylogenetic analyses confirm the distinctiveness of D.gaoligongensis,D.renchangiana,and D.sinonepalensis.A key to species of D.sect Diclisodon in China is provided.展开更多
In the northwest of Shandong Province during Late Qing Dynasty,the struggle for survival among the villagers became social norm due to the fragility of the natural ecology,which was not only an important cause of loca...In the northwest of Shandong Province during Late Qing Dynasty,the struggle for survival among the villagers became social norm due to the fragility of the natural ecology,which was not only an important cause of local social unrest,but also complicated social relations.The potential anti-government tendencies of folk secret sects made them the targets of Qing government’s crackdown.In order to seek survival and development,the folk secret sects in northwest Shandong turned their eyes to Christian churches for political protect that was North China Mission of the American Board of Commissioners for Foreign Missions.With the help of secret sects,missionaries of the North China Mission gained a foothold in northwest Shandong.But they were not willing to provide political protect for secret sects.They only used the social ties of secret sects to wedge themselves into the rural society of northwest Shandong,hoping to establish Christian mission stations and develop Christian communities,not to integrate with secret sects.展开更多
文摘电感储能型脉冲电源是目前电磁发射技术的研究热点,提升装置储能密度对于推动电感储能型脉冲电源的应用和研究具有重要意义。本文介绍了一种适用于电感储能型脉冲电源的名为meat grinder with SECT的新电路,并对该电路进行了详细的原理分析,指出该电路兼具电流关断能力强和拓扑结构简单的优点。通过仿真将meat grinder with SECT和STRETCH meat grinder、STRETCH meat grinder with ICCOS这两种主流电路进行了性能比较,发现meat grinder with SECT电路在保持电气性能不变的同时,成本最低,体积最小。基于meat grinder with SECT电路,本文研制了50k J电感储能型脉冲电源并进行了试验测试,测试结果达到了预期目标。
文摘Seventeen species, one subspecies and one variety of Dioscorea sect. Stenophora Uline were investi-gated for their phylogenetic relationships based on a sequence analysis of chloroplast matK and rbcL genes and trnL-F intergenic spacer by maximum parsimony and maximum likelihood methods. The results showed that: (a) sect. Stenophora was a strongly supported monophyletic group; (b) D. rockii, D. membranacea, D. banzhuana, and D. simulans formed a moderately supported monophyletic group, and D. prazeri was weakly supported to be sister to this group; (c) D. althaeoides and D. nipponica ssp. nipponica formed a moderately supported clade, and D. nipponica ssp. rosthornii was not a member of this clade; (d) D. zingiberensis and D. sinoparviflora showed a moderate to strong sister relationship; and (e) D. collettii var. hypoglauca and D. collettii var. collettii were sister to each other, but with only weak support.
文摘In this paper Clematis sect. Aspidanthera s.l. is revised. Seventy_ two species and 15 varieties are recognized. They are keyed, described, and in most cases illustrated, and are classified into six subsections. Of them, on e series, five species, and two varieties are described as new, and two new rank s are proposed. Brief taxonomic history and geographical distribution of the sec tion are given, the evolutionary trends of several important morphological characters observed are e numerated, and the relationships of its subsections are discussed. As a resul t, subsect. Dioicae, which shows striking resemblance in both habit an d floral structure to sect. Clematis subsect. Clematis, is regar ded as t he primitive group, while subsect. Insidiosae, bearing pistillate flower wit h erect sepals and no staminodes, is regarded as the advanced group within the s ection.
文摘Vicia amirensis has pollen grain with swollen mesocipium, terete style, abaxially sproution stylar hairs and globes stigma, differing from other five species, V. amoena, V. Japonica, V. pseudo-orbus, V. ramulifloua, V. unijuga and V. venosa, in sect. Vicilla of Kupicha’s System. This result further support taxonomic treatment V. amurensis proposed by Endo and Ohash. The chromosome numbers of 64 pop ulations and karyotypes of 15 populations for sect. Vicilla and sect. Amurense were observed. V. amurensis and V. pseudo-orbus have similar karyotype features such as the same karyotype symmetry, comparable chromosome size and the same type of Sat-chromosomes, and therefore V. amurensis in sect. Amurense is assumed to be closely related to V. Japonica in sect. Vicilla. The primary study of nuclear DNA amount was carried out on nine populations of six taxa in sect. Vicilla and geographic distribution of different ploidy cytotypes. karyotype, nuclear DNA amount in sect. Vicilla and geographic distribution of different ploidy cytotypes.
文摘Nigeria was listed as a part of terrorist states by United States of America as a result of Islamic group (Boko Haram Sect) attacks and other activities in the nation. It has also been discovered that the group employs “steganographic” schemes as a secure means for transmitting their hidden information to each other via Internet and social networks. The group has killed thousands of people since their increased insurgency in July, 2009. These challenges have affected the nation’s foreign policies, political and social economic developments. This research addresses the challenges by employing forensic technique using blind steganalysis approach to detect the presence of the hidden messages in images. Image Quality Metric is employed for extracting the features, and logistic regression is trained as the classifier to predict the stego-images. We show the effectiveness of the method by conducting test and analysis with 319 images varying in size and style. The result shows that the performance of the method is better than other steganalysis methods.
基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB31000000)the National Natural Science Foundation of China(31970232)the Technological leading talent project of Yunnan(2017HA014)。
文摘Dryopteris sect.Diclisodon is a small section of ferns with about 12 species mainly distributed in East Asia.Here,we carried out morphological and phylogenetic analyses of this section.A new species from southwest China,D.gaoligongensis,is described and illustrated.Dryopteris gaoligongensis resembles D.indonesiana and D.sparsa,but differs by having a creeping rhizome and large 4-pinnate fronds.We also show that D.glabrior Ching&Z.Y.Liu is a distinct species;however,because it is a later homonym of D.glabrior Copel.,it should be renamed D.renchangiana.We conclude that a species previously known as D.nitidula,also an illegitimate homonym,should be recognized with a new name,D.sinonepalensis.We resolve the phylogenetic position of D.yoroii as sister to other sampled species of D.sect Diclisodon.Our phylogenetic analyses confirm the distinctiveness of D.gaoligongensis,D.renchangiana,and D.sinonepalensis.A key to species of D.sect Diclisodon in China is provided.
文摘In the northwest of Shandong Province during Late Qing Dynasty,the struggle for survival among the villagers became social norm due to the fragility of the natural ecology,which was not only an important cause of local social unrest,but also complicated social relations.The potential anti-government tendencies of folk secret sects made them the targets of Qing government’s crackdown.In order to seek survival and development,the folk secret sects in northwest Shandong turned their eyes to Christian churches for political protect that was North China Mission of the American Board of Commissioners for Foreign Missions.With the help of secret sects,missionaries of the North China Mission gained a foothold in northwest Shandong.But they were not willing to provide political protect for secret sects.They only used the social ties of secret sects to wedge themselves into the rural society of northwest Shandong,hoping to establish Christian mission stations and develop Christian communities,not to integrate with secret sects.
