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Search Results: 1 - 10 of 8014 matches for " YuCheng Dai "
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Progress report on the study of wood-decaying fungi in China
LiWei Zhou,YuCheng Dai
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5457-8
Abstract: This study addressed three important aims: (1) undermining the previously obtained raw data about wood-decaying fungi (WDF) distribution and continuously investigating permanent plots to address certain scientific questions in ecology, (2) resolving the higher-level phylogeny of WDF with the help of multiple loci, and (3) testing and estimating the medicinal values of species that are closely related to well-known medicinal species. More than 1200 species and 2469 strains of WDF in China were identified from 28908 specimens collected from a series of field investigations. Using these materials, studies in multiple disciplines, such as ecology, taxonomy and phylogeny, and medicine, have been performed. With respect to ecology, the diversity of wood-decaying polypores significantly differed among a boreal forest zone, a temperate and warm temperate forest zone, and a tropical and subtropical forest zone. For instance, from north to south, the number and proportion of brown-rot species and the proportion of species found on fallen trunks were both decreased. The ecological patterns of wood-decaying polypores on gymnosperm and angiosperm trees were also explored by a case study in Northeast China. Although the total species richness was similar between the two tree groups, several other characteristics were significantly different, such as community structure and richness in certain substrates. The taxonomy and phylogeny of wide samples were referred to and their phylogenetic positions were resolved or at least partially established. In particular, phylogenetic knowledge about four genera, Fomitiporia, Ganoderma, Inonotus and Perenniporia, which include medicinal species, was essential for further research to determine the medicinal values of these types of fungi. Among these medicinal species, we mainly focused on Inonotus obliquus for its medicinal purposes. Polyphenols, polysaccharides and lanostane-type triterpenoids, extracted from the sterile conk of this species, could dramatically decrease levels of free radicals, DPPH and hydroxyl radicals, respectively. The metabolic profiles (both production and composition) of cultured I. obliquus mycelia could be altered by co-culture with other medicinal species or by induction of S-nitrosylation and denitrosylation, which may enhance the antioxidant capacity of I. obliquus.
Rare and threathened polypores in the ecosystem of Changbaishan Nature Reserve of Northeastern China
长白山森林生态系统中的稀有和濒危多孔菌

DAI Yucheng,
戴玉成

应用生态学报 , 2003,
Abstract: In last 10 years, extensive field inventories were carried out to investigate Polypore species, the major wood-decaying fungi in the Changbaishan Nature Reserve of Northeastern China. The following 27 species were treated as rare or threathened species: Amylocystis lapponica (Romell) Singer, Anomoporia albolutescens (Romell) Pouzar, Anomoporia bombycina (Fr.) Pouzar, Anomoporia vesiculosa Y.C. Dai & Niemel?, Antrodia carbonica (Overh.) Ryvarden & Gilb., Antrodia crassa (P. Karst.) Ryvarden, Antrodiella citrinella Niemel? & Ryvarden, Diplomitoporus flavescens (Bres.) Dománski, Donkioporia expansa (Desm.) Kotl. & Pouzar, Gloephyllum carbonarium (Berk. & M. A. Curtis) Ryvarden, Haploporus odorus (Sommerf.) Bondartsev & Singer, Inonotopsis subiculosa (Peck) Parmasto, Nigroporus ussuriensis (Bondartsev & Ljub.) Y.C. Dai & Niemela, Oxyporus sinensis X. L. Zeng, Parmastomyces taxi(Bondartsev) Y.C. Dai & Niemela, Phellinidium sulphurascens(Pilat) Y.C. Dai, Phellinus vaninii Ljub., Polyporus vassilievae Thorn, Pycnoporellus fulgens (Fr.) Donk, Skeletocutis brevispora Niemela, Skeletocutis ochroalba Niemela, Skeletocutis perennis Ryvarden, Trechispora candidissima (Schwein.) Bondartsev & Singer, Wolfiporia dilatohypha Ryvarden & Gilb., Wolfiporia curvispora Y.C. Dai, Wrightoporia avellanea(Bres.) Pouzar and Wrightoporia lenta(Oveh. & J. Lowe) Pouzar. Polypores are richer in East Asia than in Europe and North America, not only because of destructive galciations and fewer hosts in the latters, but also because of the geography. NE Asia is a link between Europe and North America. Changbaishan Nature Reserve is very rich in polypores, and over 260 species were recorded in the reserve. Some rare species in North America and Europe, for instance, Anomoporia albolutescens, Antrodia crassa, Diplomitoporus flavescens, Inonotopsis subiculosa and Skeletocutis ochroalba etc. were found in Changbaishan Nature Reserve as well, and these species are in fact rare in the earth. Most of the 27 species occurred on fallen trunks or rotten wood in the reserve, but some of them grew on living trees. 18 species occurred on substrate of gymnosperms, and 9 species grew on wood of angiosperm. Among the 27 species, 7 species caused a brown rot, and 20 species produced a white rot. The morphology, substrate and ecology of each species were briefly discussed. The most important tool for polypore conservation is the conservation of their habitats, and it is necessary to study the ecology of the rare and threathened species of polypores in the Changbaishan Nature Reserve. Because most of polypores live on the substrate of fallen trunks and rotten wood, it is very important to keep such substrate in the ecosystem.
Study on the Mental Health of Impoverished College Students Education  [PDF]
Yucheng Fan
Creative Education (CE) , 2018, DOI: 10.4236/ce.2018.96064
Abstract: With economic and social development, the psychological health problems of poor college students present new characteristics and new situation. Psychological causes become more complex and malignant events happen frequently. To solve the adverse psychological conditions is urgently needed in the college students’ education work. Poor college students work, is to be about colleges and universities in the new period of cultivating qualified builders and reliable successors for the socialist basic task, according to a new problem, to explore the root causes, to find the effective method to solve the problem of poor college students mental health, and improve the pertinence and effectiveness of poor college students mental health work, to do a good job in people’s satisfactory education, train and bring up all-round development of socialist builders and successors.
Ecological function of wood-inhabiting fungi in forest ecosystem
木材腐朽菌在森林生态系统中的功能

WEI Yulian,DAI Yucheng,
魏玉莲
,戴玉成

应用生态学报 , 2004,
Abstract: Wood-inhabiting fungi are one of the most important parts of forest ecosystem,and play an important role in degrading the wood in forest ecosystem.The major species of these fungi include the groups of Aphyllophorales (Basidiomycota),Discomycetes (Ascomycota) and some imperfect fungi.They have the ability to degrade cellulose,hemicelluloses and lignin of wood.Three type of wood decaying have been found,i.e.,white rot,brown rot and soft rot.Many other organisms of forest ecosystem have symbiosis relationship with wood-decaying fungi.Wood-inhabiting fungi could offer the nutrition for many insects and birds,and spores of many wood-rotting species are spread by some insects.The high biodiversity of wood-decaying fungi is one of the important factors for the health of forest ecosystem.
A preliminary study on wood-inhabiting fungi on charred wood in Daxinganling forest areas
大兴安岭林区火烧迹地木腐菌主要类群的初步研究

YU Changjun,DAI Yucheng,WANG Zhengquan,
余长军
,戴玉成,王政权

应用生态学报 , 2004,
Abstract: Study on wood-inhabiting fungi is one of the active fields of mycology during past 30 years in China,and the study mostly focused on natural forest without fire disturbing.Forest fire changes forest ecology dramatically,and the fungi on charred wood are different from those in nature forests without fires.In this paper,we focused on the wood-inhabiting fungi growing on charred wood in Daxinganling forest areas.Seventeen species were reported:Antrodia sp.,Antrodia xantha,Ceriporiopsis mucida,Diplomitoporus lindbladii,Gloeophyllum carbonarium,Gloeophyllum sepiarium,Gloeoporus taxicola,Laurilia sulcata,Oligoporus sericeomollis,Phellinus igniarius,Postia caesia,Postia leucomallella,Postia tephroleuca,Schizopora flavipora,Skeletocutis ochroalba,Skeletocutis vulgaris,and Trichaptum fuscoviolaceum.Among them,eight species caused brown rot,and nine species caused white rot.Based on our field studies,eight species were pioneer fungi in charred wood,four species were common one,and three species were rare or threatened in the studied area.Setting up nature reserve should be the best way to protect the rare or threatened species of wood-inhabiting fungi.
Ways to produce and measure atto- and femtosecond soft X-ray pulses
YuCheng Ge
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0153-9
Abstract: The ways to produce and measure atto-and femtosecond soft X-ray pulses are reported. The laser phase relation of high-order harmonic generation (HHG) shows two different radiation energy distributions in time (or laser phase) domain. These energy-phase relations are helpful for realizing the dynamic processes of HHG. Two presented parameterized formulas can be used to calculate the durations of the energy distributions with a bandwidth of the pulse. These formulas are useful in calculating and simulating pulses transports and interactions with mediums. The time structures of atto-and femtosecond soft X-ray pulses can be directly measured with photoelectron spectrum transfer equations and the related laser phase determination methods without any previous pulse shape and the instantaneous frequency assumptions. These equations and methods can be used to evaluate and improve the technical parameters of the ultra-short X-ray sources. They have wide measurement ranges and high time resolutions, which may enable ultra-fast measurements to reach metrological precisions, and lead to a new tide of scientific researches in physics, chemistry, biochemistry, etc. The application of atto-and femtosecond X-rays as well as the theoretical and technical problems in measurements are briefly discussed.
Radiation properties of high-order harmonic generation for the measurements of femto- and attosecond X-ray pulses
YuCheng Ge
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0397-7
Abstract: Radiation properties of high-order harmonic generation (HHG) are calculated for atoms in a strong laser field. The laser-duration dependence and the carrier-envelope-phase (CEP) dependence of HHG radiation properties are presented. The CEP dependence of the pure single distribution pulse of HHG radiation properties shows interesting 180° periodic structures. The quantum enhancement of the laser-assisted photo-ionization by femtosecond (1 fs=10 15 s) and attosecond (1 as=10 18 s) X-ray pulses and the interference patterns of photo-electron energy spectra are theoretically investigated. Transfer equations are presented for pulse reconstructions. The theoretical root-mean-square time (energy) differences of attosecond pulse reconstructions with different durations are less than 2 as (0.8 eV). These methods may be developed as basic techniques to access ultra-fast measurements and molecular movie.
INTERSTERILITY GROUP T OF HETEROBASIDION INSULARE IDENTIFIED FROM CENTRAL AND EASTERN CHINA
华中和华南的岛生异担子菌T生物种的鉴定研究

Dai YuCheng,Wei YuLian,Cui BaoKai,Kari,KORHONEN,
戴玉成
,魏玉莲,崔宝凯,Kari,KORHONEN

菌物学报 , 2005,
Abstract: Specimens of Heterobasidion insulare sensu lato were collected from Pinus massoniana in Heng Mts. of Hunan Province (central China) and in Zijin Mts. of Jiangsu Province (eastern China). Pure cultures were isolated from 11 specimens and identified in mating tests by pairing them with homokaryotic tester strains of the T (Taiwan), N (North) and Y (Yunnan) intersterility groups of H. insulare. All the specimens proved to belong to the T group. This group seems to have a wide distribution in southeastern parts of China, and it occurs mostly as a saprotroph on Pinus marssoniana. Groups T and N are very similar in basidiocarp morphology while group Y shows a more differentiated morphology, in spite of the fact that the groups N and Y are very closely related, as concluded from interfertility tests and DNA studies.
Ways to Produce and Measure Atto- and Femtosecond Soft X-ray Pulses
Ways to produce and measure atto- and femtosecond soft X-ray pulses

GE YuCheng,
GE
,YuCheng

科学通报(英文版) , 2007,
Abstract: The ways to produce and measure atto-and femtosecond soft X-ray pulses are reported. The laser phase relation of high-order harmonic generation(HHG) shows two different radiation energy distribu-tions in time(or laser phase) domain. These energy-phase relations are helpful for realizing the dy-namic processes of HHG. Two presented parameterized formulas can be used to calculate the durations of the energy distributions with a bandwidth of the pulse. These formulas are useful in calculating and simulating pulses transports and interactions with mediums. The time structures of atto-and femto-second soft X-ray pulses can be directly measured with photoelectron spectrum transfer equations and the related laser phase determination methods without any previous pulse shape and the instantane-ous frequency assumptions. These equations and methods can be used to evaluate and improve the technical parameters of the ultra-short X-ray sources. They have wide measurement ranges and high time resolutions,which may enable ultra-fast measurements to reach metrological precisions,and lead to a new tide of scientific researches in physics,chemistry,biochemistry,etc. The application of atto-and femtosecond X-rays as well as the theoretical and technical problems in measurements are briefly discussed.
Use of photoelectron energy spectrum transfer equation for the measurement of a narrowband XUV pulse
YuCheng Ge,HaiPing He
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-011-4943-8
Abstract: To study the time evolution of a molecular state in an ultra-fast chemical reaction, the use of shorter pulses with higher photon energy and narrower bandwidth for both pump and probe is necessary. However, quick and precise measurement of their detailed time structures is a challenge. Over the last decade, great efforts have been made to measure an attosecond extreme ultraviolet (XUV) pulse. To date, several methods have been developed to measure the pulse duration and completely reconstruct it. The attosecond spectral phase interferometry for direct electric field reconstruction (SPIDER) and attosecond frequency-resolved optical gating (FROG) techniques are often used. However, these methods use state-of-the-art experimental set-ups and complicated data analysis procedures. To develop attosecond metrology for practical use (e.g. timing, measurement, evaluation, calibration, optimization, pumping, probing), we propose a quick and analytical method to precisely observe an attosecond XUV pulse with laser-assisted photo-ionization. The method is based on determining the laser-related phase of each streaked electron and using a transfer equation for one-step pulse reconstruction without any time-resolved measurements, iterative calculations, or data fitting procedures. Temporal errors of the pulse reconstruction are calculated from the XUV bandwidth. Because the transfer equation establishes a direct connection between the XUV pulse properties, the crucial laser parameters (peak intensity, phase, carrier envelope phase), the atomic ionization potential, and the measured photoelectron energy spectrum, we can use it to study any one of these properties from other known information and probe the dynamic processes of an ultra-fast reaction.
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