This paper proposes a zer o current and zero voltage switching (ZCZVS) PWM Boost full bridge (FB) conve rter. With series inductors, the leading switches can realize zero current swit ching (ZCS) in a wide load ra...This paper proposes a zer o current and zero voltage switching (ZCZVS) PWM Boost full bridge (FB) conve rter. With series inductors, the leading switches can realize zero current swit ching (ZCS) in a wide load range using the energy of the output capacitor. Ma king use of parasitic capacitors of the lagging switches and parallel auxiliary i nductance with the primary winding of the transformer, the lagging switches can realize zero voltage switching (ZVS) under any load. Compared with the ZCS PWM Boost FB converter, the new converter has no current duty cycle loss. Operat ional principle and parameter design are analyzed. Experimental results verify the effectiveness of the proposed converter.展开更多
Pathogen and characteristics,occurrence law,damage symptom of Paulownia fortunei witches broom disease were simply described,and the control method of the disease was summarized.
The spatial pattern of paulownia witches＇ broom was investigated using an Iwao＇s （m^＊-m） model in Shaanxi Province, China. Iwao＇s （m^＊-m） model revealed that spatial pattern of paulownia witches＇ broom exhib...The spatial pattern of paulownia witches＇ broom was investigated using an Iwao＇s （m^＊-m） model in Shaanxi Province, China. Iwao＇s （m^＊-m） model revealed that spatial pattern of paulownia witches＇ broom exhibited a uniform distribution in sample plots. In this model, characteristics of contagiousness coefficient （a） justified the probability of infection by virus-transmission vectors. For tree age less than six, susceptible individuals were aggregated as clusters in the plots and then mutually repelled over age. A preliminary survey of stand volume show that from age five to six, stand volumes of disease grade II showed excessive vegetative growth and returned to normal level between ages ten and 11. Loss rate of volume increment with disease grade II decreased, and then returned to raising trend both at grades III and IV. This phenomenon is possibly caused by an over-compensation effect and by environmental factors. The redundancy of growth hormones in branches, shoots, leaves, buds and roots increased the stem volume of entire trees.展开更多
This paper dealt with the SDS polyacrymide gel electrophoresis of proteins ahd analysis of the amino acids in the diseasedand healthy leaves with the same strain respectively, which were at the same side and height, o...This paper dealt with the SDS polyacrymide gel electrophoresis of proteins ahd analysis of the amino acids in the diseasedand healthy leaves with the same strain respectively, which were at the same side and height, of Paulownia catalpifolia, P. elongata, P. albiphloea and P. kauakamii respectively. The results indicated that the leaves of 4 species of Paulownia trees with witches' broom had one protein band, of which molecular weight was 12 kD, which did not appear in the healthy leaves free of phytoplasmas. Moreover, the protein quantity in the affected leaves was more than that in the healthy leaves free of phytoplasmas, At the same time, there was significant difference on the amino acids between the healthy and diseased leaves of P. catalpifolia and P. kawakamii. The amount of cystine in the affected leaves was higher than that in the healthy leaves, but the change of amount of phenylalanine in the affected and healthy leaves was contrary.These changes of proteins and amino acids in the leaves might be related to the witches' broom of the Parlounia trees.展开更多
[Objectives]The paper was to screen and identify the control effect of resistant rootstock on jujube witches broom disease.[Methods]The seeds or branches of disease-free plants were collected from wild jujube bushes i...[Objectives]The paper was to screen and identify the control effect of resistant rootstock on jujube witches broom disease.[Methods]The seeds or branches of disease-free plants were collected from wild jujube bushes infected by witches broom disease,and 5434 seedlings were obtained by sowing or cutting.The virus was inoculated by grafting diseased bark.After 6 years of preliminary screening,40 plants with resistance to jujube witches broom disease were obtained.Taking these resistant plants as the rootstocks,the susceptible variety‘long red jujube’was grafted at a height of 40 cm.When the plants grew to appropriate thickness,diseased bark was grafted to‘long red jujube’and rootstock to transmit the virus.After 18 years of observation and judgment,4 rootstock strains with high resistance or immunity to jujube witches broom disease were finally determined,namely 90801,90803,90806 and 908011.The susceptible variety‘long red jujube’was grafted to 4 rootstocks and inoculated the virus through diseased bark grafting method.[Results]The resistant rootstock had obvious disease resistance effect.When the branches of 90801 and 90803 rootstocks were grafted to the trunk of diseased trees,the symptoms of jujube witches broom disease gradually alleviated till disappeared.[Conclusions]Using germplasm with high resistance or immunity to jujube witches broom disease as rootstock can effectively prevent the spread of jujube witches broom disease,and bridging the trunk of diseased trees with branches from resistant rootstock has certain therapeutic effect.展开更多
In 2021,the Shanting District Fruit Industry Service Center conducted an application test of a treatment for jujube witches broom disease using Changyun jujube.The results demonstrated that when diseased Changhong juj...In 2021,the Shanting District Fruit Industry Service Center conducted an application test of a treatment for jujube witches broom disease using Changyun jujube.The results demonstrated that when diseased Changhong jujube plants were grafted with Changyun jujube in the spring using bark or cleft grafting,the majority of the new shoots of Changyun jujube exhibited no symptoms of witches broom disease,while a few exhibited symptoms of the disease.With the growth of new shoots,the symptoms of witches broom disease gradually abated,returning to normal growth and development.Similarly,the symptoms of witches broom disease on the rootstock below the grafting mouth also gradually abated,returning to normal.The Changyun jujube rootstock was utilized as the intermediate rootstock to grafting the jujube cultivars Qiyuexian and Fucuimi.The two cultivars were subsequently affixed with branch bark from the witches broom disease.The two cultivars did not exhibit any symptoms of witches broom disease,thus providing an opportunity to investigate potential treatments for this disease in jujube.Finally,the cultivation techniques of the Changyun jujube were presented.展开更多
The American writer Nathaniel Hawthorne's The Scarlet Letter is about a forbidden love between a Reverend Dimmesdale and a married woman Hester Prynne. There have been numerous studies about it from different pers...The American writer Nathaniel Hawthorne's The Scarlet Letter is about a forbidden love between a Reverend Dimmesdale and a married woman Hester Prynne. There have been numerous studies about it from different perspectives since its publication in 1850. This paper aims to reveal how Hawthorne weaves witch's images and witchcraft's mysteries into his work The Scarlet Letter, and is relevant to the influence that these two mysterious elements have on this work.展开更多
Jujube witches＇ broom is a devastating disease of Ziziphusjujube that occurs in various jujube regions of China. Nucleic acid extracted from midribs of samples collected from three jujube varieties （＂Suanzao＂, ＂L...Jujube witches＇ broom is a devastating disease of Ziziphusjujube that occurs in various jujube regions of China. Nucleic acid extracted from midribs of samples collected from three jujube varieties （＂Suanzao＂, ＂Lajiaozao＂ and ＂Langzao＂） from symptomatic and asymptomatic shoots were tested by random amplified polymorphic DNA analyses. Using 13 different 10 and 11-bp random primers the amplification of jujube DNA was achieved from all the samples; AMI4 primer provided amplification of specific DNA fragments of about 400 bp, only from samples collected from symptomatic plants. No genetic variations in these varieties were identified using the other 11 arbitrary primers; only with primer AL07 it was possible to differentiate ＂Langzao＂ from the other two varieties tested. All the experiments were repeated 2 times and the results were consistent. Compared with PCR analyses with phytoplasma-specific primers, RAPD techniques resulted to be an alternative rapid and sensitive method for detecting jujube phytoplasmas presence in different jujube varieties.展开更多
The Irish-born British writer Clive Staples Lewis(1898-1963)is not only a literary critic with unique insights and a loy⁃al Christian missionary,but also a popular children’s writer.His The Lion,the Witch and the War...The Irish-born British writer Clive Staples Lewis(1898-1963)is not only a literary critic with unique insights and a loy⁃al Christian missionary,but also a popular children’s writer.His The Lion,the Witch and the Wardrobe is a world-famous chil⁃dren’s literature,which is deeply affected by the public.However,the academic researches and explorations on it are still in a state of youth.The dimensions of the domestic researches are single,and most scholars only pay attention to the religious connota⁃tion.Meanwhile,although the foreign studies have a wide range,there are few innovations in the studies.The thesis collates all kinds of literatures on Lewis and his The Lion,the Witch and the Wardrobe to summarize the current research status and provide new dimensions for later studies.展开更多
Stem segments from diseased Paulownia tomentosaXP, fortunei and leaves from healthy control were transformed with the expression vector p438PRSI via Agrobacterium tumefaciens. The p438PRSI vector contained shiva-1 gen...Stem segments from diseased Paulownia tomentosaXP, fortunei and leaves from healthy control were transformed with the expression vector p438PRSI via Agrobacterium tumefaciens. The p438PRSI vector contained shiva-1 gene, which encodes an antibacterial peptide under the control of a CaMV35S promoter. The regenerated plants from transformed explants were planted in a greenhouse and nursery. PCR and Southern blotting analysis showed that the shiva-1 gene was successfully integrated into the Paulownia genome. Transcription of the integrated shiva-1 gene was confirmed by RT-PCR. Bioassay in the green house and phytoplasma DNA-dot blotting demonstrated that resistance to Paulownia witch＇s broom disease （PWB） increased significantly in shiva-l-transgenic Paulownia. Further investigations indicated that higher Shiva- 1 expression correlated with fewer phytoplasma and less symptoms in diseased transgenic Paulownia. Together, our findings strongly suggest that breeding shiva-1-Paulownia is an effective strategy to control PWB disease.展开更多
Being too critical, outspoken or engaging in behavior deemed immoral can get you into big trouble in China. And it’s not the authori-ties we’re talking about here. The power of the people has found a new outlet to vent
During my summer holiday,I read some English books.One of them was The Wonderful Wizard of Oz.It is a fairy tale.Let me tell you多·成about it.The main character is a girl named Dorothy.One day,a tornado carried h...During my summer holiday,I read some English books.One of them was The Wonderful Wizard of Oz.It is a fairy tale.Let me tell you多·成about it.The main character is a girl named Dorothy.One day,a tornado carried her and her dog to the magical Land of Oz.There,she met a kind witch who told her to go to the Emerald City.On the way,she faced many diffi culties but also made new friends:the Scarecrow,the Tin Woodman,and the Lion.With their help,Dorothy defeated the Wicked Witch of the West.In the end,the Wizard of Oz told her how to go back home.展开更多
文摘This paper proposes a zer o current and zero voltage switching (ZCZVS) PWM Boost full bridge (FB) conve rter. With series inductors, the leading switches can realize zero current swit ching (ZCS) in a wide load range using the energy of the output capacitor. Ma king use of parasitic capacitors of the lagging switches and parallel auxiliary i nductance with the primary winding of the transformer, the lagging switches can realize zero voltage switching (ZVS) under any load. Compared with the ZCS PWM Boost FB converter, the new converter has no current duty cycle loss. Operat ional principle and parameter design are analyzed. Experimental results verify the effectiveness of the proposed converter.
文摘Pathogen and characteristics,occurrence law,damage symptom of Paulownia fortunei witches broom disease were simply described,and the control method of the disease was summarized.
文摘The spatial pattern of paulownia witches＇ broom was investigated using an Iwao＇s （m^＊-m） model in Shaanxi Province, China. Iwao＇s （m^＊-m） model revealed that spatial pattern of paulownia witches＇ broom exhibited a uniform distribution in sample plots. In this model, characteristics of contagiousness coefficient （a） justified the probability of infection by virus-transmission vectors. For tree age less than six, susceptible individuals were aggregated as clusters in the plots and then mutually repelled over age. A preliminary survey of stand volume show that from age five to six, stand volumes of disease grade II showed excessive vegetative growth and returned to normal level between ages ten and 11. Loss rate of volume increment with disease grade II decreased, and then returned to raising trend both at grades III and IV. This phenomenon is possibly caused by an over-compensation effect and by environmental factors. The redundancy of growth hormones in branches, shoots, leaves, buds and roots increased the stem volume of entire trees.
文摘This paper dealt with the SDS polyacrymide gel electrophoresis of proteins ahd analysis of the amino acids in the diseasedand healthy leaves with the same strain respectively, which were at the same side and height, of Paulownia catalpifolia, P. elongata, P. albiphloea and P. kauakamii respectively. The results indicated that the leaves of 4 species of Paulownia trees with witches' broom had one protein band, of which molecular weight was 12 kD, which did not appear in the healthy leaves free of phytoplasmas. Moreover, the protein quantity in the affected leaves was more than that in the healthy leaves free of phytoplasmas, At the same time, there was significant difference on the amino acids between the healthy and diseased leaves of P. catalpifolia and P. kawakamii. The amount of cystine in the affected leaves was higher than that in the healthy leaves, but the change of amount of phenylalanine in the affected and healthy leaves was contrary.These changes of proteins and amino acids in the leaves might be related to the witches' broom of the Parlounia trees.
基金Jujube Binzhou Comprehensive Test Station of China Agricultural Industry Research System(CARS30-ZZ-23).
文摘[Objectives]The paper was to screen and identify the control effect of resistant rootstock on jujube witches broom disease.[Methods]The seeds or branches of disease-free plants were collected from wild jujube bushes infected by witches broom disease,and 5434 seedlings were obtained by sowing or cutting.The virus was inoculated by grafting diseased bark.After 6 years of preliminary screening,40 plants with resistance to jujube witches broom disease were obtained.Taking these resistant plants as the rootstocks,the susceptible variety‘long red jujube’was grafted at a height of 40 cm.When the plants grew to appropriate thickness,diseased bark was grafted to‘long red jujube’and rootstock to transmit the virus.After 18 years of observation and judgment,4 rootstock strains with high resistance or immunity to jujube witches broom disease were finally determined,namely 90801,90803,90806 and 908011.The susceptible variety‘long red jujube’was grafted to 4 rootstocks and inoculated the virus through diseased bark grafting method.[Results]The resistant rootstock had obvious disease resistance effect.When the branches of 90801 and 90803 rootstocks were grafted to the trunk of diseased trees,the symptoms of jujube witches broom disease gradually alleviated till disappeared.[Conclusions]Using germplasm with high resistance or immunity to jujube witches broom disease as rootstock can effectively prevent the spread of jujube witches broom disease,and bridging the trunk of diseased trees with branches from resistant rootstock has certain therapeutic effect.
文摘In 2021,the Shanting District Fruit Industry Service Center conducted an application test of a treatment for jujube witches broom disease using Changyun jujube.The results demonstrated that when diseased Changhong jujube plants were grafted with Changyun jujube in the spring using bark or cleft grafting,the majority of the new shoots of Changyun jujube exhibited no symptoms of witches broom disease,while a few exhibited symptoms of the disease.With the growth of new shoots,the symptoms of witches broom disease gradually abated,returning to normal growth and development.Similarly,the symptoms of witches broom disease on the rootstock below the grafting mouth also gradually abated,returning to normal.The Changyun jujube rootstock was utilized as the intermediate rootstock to grafting the jujube cultivars Qiyuexian and Fucuimi.The two cultivars were subsequently affixed with branch bark from the witches broom disease.The two cultivars did not exhibit any symptoms of witches broom disease,thus providing an opportunity to investigate potential treatments for this disease in jujube.Finally,the cultivation techniques of the Changyun jujube were presented.
文摘The American writer Nathaniel Hawthorne's The Scarlet Letter is about a forbidden love between a Reverend Dimmesdale and a married woman Hester Prynne. There have been numerous studies about it from different perspectives since its publication in 1850. This paper aims to reveal how Hawthorne weaves witch's images and witchcraft's mysteries into his work The Scarlet Letter, and is relevant to the influence that these two mysterious elements have on this work.
文摘Jujube witches＇ broom is a devastating disease of Ziziphusjujube that occurs in various jujube regions of China. Nucleic acid extracted from midribs of samples collected from three jujube varieties （＂Suanzao＂, ＂Lajiaozao＂ and ＂Langzao＂） from symptomatic and asymptomatic shoots were tested by random amplified polymorphic DNA analyses. Using 13 different 10 and 11-bp random primers the amplification of jujube DNA was achieved from all the samples; AMI4 primer provided amplification of specific DNA fragments of about 400 bp, only from samples collected from symptomatic plants. No genetic variations in these varieties were identified using the other 11 arbitrary primers; only with primer AL07 it was possible to differentiate ＂Langzao＂ from the other two varieties tested. All the experiments were repeated 2 times and the results were consistent. Compared with PCR analyses with phytoplasma-specific primers, RAPD techniques resulted to be an alternative rapid and sensitive method for detecting jujube phytoplasmas presence in different jujube varieties.
文摘The Irish-born British writer Clive Staples Lewis(1898-1963)is not only a literary critic with unique insights and a loy⁃al Christian missionary,but also a popular children’s writer.His The Lion,the Witch and the Wardrobe is a world-famous chil⁃dren’s literature,which is deeply affected by the public.However,the academic researches and explorations on it are still in a state of youth.The dimensions of the domestic researches are single,and most scholars only pay attention to the religious connota⁃tion.Meanwhile,although the foreign studies have a wide range,there are few innovations in the studies.The thesis collates all kinds of literatures on Lewis and his The Lion,the Witch and the Wardrobe to summarize the current research status and provide new dimensions for later studies.
基金the National Natural Science Foundation of China，the President Foundation of the Chinese Academy of Sciences
文摘Stem segments from diseased Paulownia tomentosaXP, fortunei and leaves from healthy control were transformed with the expression vector p438PRSI via Agrobacterium tumefaciens. The p438PRSI vector contained shiva-1 gene, which encodes an antibacterial peptide under the control of a CaMV35S promoter. The regenerated plants from transformed explants were planted in a greenhouse and nursery. PCR and Southern blotting analysis showed that the shiva-1 gene was successfully integrated into the Paulownia genome. Transcription of the integrated shiva-1 gene was confirmed by RT-PCR. Bioassay in the green house and phytoplasma DNA-dot blotting demonstrated that resistance to Paulownia witch＇s broom disease （PWB） increased significantly in shiva-l-transgenic Paulownia. Further investigations indicated that higher Shiva- 1 expression correlated with fewer phytoplasma and less symptoms in diseased transgenic Paulownia. Together, our findings strongly suggest that breeding shiva-1-Paulownia is an effective strategy to control PWB disease.
文摘Being too critical, outspoken or engaging in behavior deemed immoral can get you into big trouble in China. And it’s not the authori-ties we’re talking about here. The power of the people has found a new outlet to vent
文摘During my summer holiday,I read some English books.One of them was The Wonderful Wizard of Oz.It is a fairy tale.Let me tell you多·成about it.The main character is a girl named Dorothy.One day,a tornado carried her and her dog to the magical Land of Oz.There,she met a kind witch who told her to go to the Emerald City.On the way,she faced many diffi culties but also made new friends:the Scarecrow,the Tin Woodman,and the Lion.With their help,Dorothy defeated the Wicked Witch of the West.In the end,the Wizard of Oz told her how to go back home.
