• 제목/요약/키워드: mixed-host structure

검색결과 20건 처리시간 0.025초

sI 천연 메탄하이드레이드의 존재 : 결정구조 변화의 분광학적 분석 (Preponderant Occurrence of sl natural methane hydrates: Spectroscopic analysis of crystalline structure transition)

  • 연순화;설지웅;이흔
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.387-390
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    • 2006
  • We report here that under strong attacksof external $CH_4$ guest molecules the sII and sH methane hydrates are structurally transformed to the crystalline me framework of sI, leading to favorable change of the lattice dimension of the host-guest networks. The High Power Decoupling $^{13}C$ NMR and Raman spectroscopies were used to identify structure transitions of the mixed $CH_4+C_2H_6$ hydrates (sIIl) and hydrocarbons (methylcyclohexane, isopentane) + $CH_4$ hydrates (sH). The resulting spectra indicate that most of the synthesized sII and sH hydrates were transformed to methane hydrate of sl under 110 bar and particularly the coexistence of sl with sII or sH appear according to the surrounding methane-rich gas conditions. The present findings might be expected to Provide rational evidences regarding the preponderant occurrence of naturally-occurring sI methane hydrates in marine sediments.

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Effect of Thermal Annealing on Nanoscale Thickness and Roughness Control of Gravure Printed Organic Light Emitting for OLED with PVK and $Ir(ppy)_3$

  • Lee, Hye-Mi;Kim, A-Ran;Kim, Dae-Kyoung;Cho, Sung-Min;Chae, Hee-Yeop
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.1511-1514
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    • 2009
  • Organic light emitting layer in OLED device was formed by gravure printing process in this work. Organic surface coated by gravure printing typically showed relatively bad uniformity. Thickness and roughness control was characterized by applying various mixed solvents in this work. Poly (N-vinyl carbazole) (PVK) and fact-tris(2-phenylpyridine)iridium($Ir(ppy)_3$) are host dopant system materials. PVK was used as a host and Ir(ppy)3 as green-emitting dopant. To luminance efficiency of the plasma treatment on etched ITO glass and then PEDOT:PSS spin coated. The device layer structure of OLED devices is as follow Glass/ITO/PEDOT:PSS/PVK+Ir(ppy)3-Active layer /LiF/Al. It was printed by gravure printing technology for polymer light emitting diode (PLED). To control the thickness multi-printing technique was applied. As the number of the printing was increased the thickness enhancement was increased. To control the roughness of organic layer film, thermal annealing process was applied. The annealing temperature was varied from room temperature, $40^{\circ}C$, $80^{\circ}C$, to $120^{\circ}C$.

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Luminescence of $Eu^{3+}$ and $Sm^{3+}$ Doped Potassium Tungstate Phosphors

  • Lee, Gwan-Hyoung;Kang, Shin-Hoo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1510-1513
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    • 2005
  • The luminescent properties of $Eu^{3+}$ and $Sm^{3+}$ doped potassium tungstate phosphor were investigated. The $K_{4-3x}(WO_4)_2:Eu_x$, $Sm_y$ phosphor was produced by firing the mixed precursors, followed by re-firing with a flux. The re-firing process provided the clean surface to the particles. The excitation spectra showed that the strong absorption in the region of ultra violet light occurred due to the high europium doping concentration. The incorporation of europium to potassium tungstate was easier, compared to other host materials. The excitation spectra could be controlled by the small addition of samarium. The increase of energy absorption around 405nm was assigned to the $Sm^{3+}$ ions. The comparison between real x-ray diffraction and simulated one revealed that the crystal structure of $K_{4-3x}(WO_4)_2:Eu_x,Sm_y$ phosphor is monoclinic with a space group, C2/c.

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DC Servo Motor의 최단시간 위치 제어 (A Study on Minimum Time Position Control of DC Servo-Motor)

  • 양주호
    • 수산해양기술연구
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    • 제28권1호
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    • pp.39-44
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    • 1992
  • Analog PID controllers have been designed to make good use of position control in industries. Recently, the importance of digital position control is emphasized for the requirements of controller which are not only to control the objects but to include various aspects such as easiness of design and implementation, simple exchange of control program and convenient communications of data between various controllers and a host computer. This study proposes a combined control method which is mixed the vaiable structure control (VSC) with the PI control for minimum time position control of DC servo motor by microcomputer. The results of test by this method show offset-free and minimum time optimal position control which is not affected by the disturbance and the system parameter variations. The validity of the proposed method comparing with the conventional PID control is proved by the response experiments.

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Luminescence of $Eu^{3+}$ and $Sm^{3+}$ Doped Potassium Tungstate Phosphor

  • Lee, Gwan-Hyoung;Kim, Tae-Hyung;Kang, Shin-Hoo
    • Journal of Information Display
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    • 제6권2호
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    • pp.25-29
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    • 2005
  • The luminescent properties of $Eu^{3+}$ and $Sm^{3+}$ doped potassium tungstate phosphor are investigated. The $K_{4-3x}(WO_4)_2:Eu^{3+}\;_x,Sm^{3+}\;_y$ phosphor is produced by firing the mixed precursors, followed by re-firing with a flux. The re-firing process results in the defect-free surface and uniform growth of the particles. The strong absorption in the region of ultra violet light is observed due to the 4f-4f electron transitions of the $Eu^{3+}$ and $Sm^{3+}$ ions. The doping concentration of europium into potassium tungstate is relatively high, compared to other host materials. It is revealed that the crystal structure is a monoclinic with space group, C2/c. This crystal structure facilitated the $Eu^{3+}$ ions to be located with the Eu-Eu distance larger than 5 ${\AA}$ so that concentration quenching does not occur even at high doping concentration. The excitation spectrum could be adjusted by the introduction of the samarium. A small amount of the $Sm^{3+}$ ions that acts as a sensitizer increases the energy absorption peak around 405 nm.

단일 호스트와 3색 도펀트를 이용한 고휘도 백색 유기발광다이오드 제작과 특성 평가 (Fabrication and Characterization of High Luminance WOLED Using Single Host and Three Color Dopants)

  • 김민영;이준호;장지근
    • 한국재료학회지
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    • 제26권3호
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    • pp.117-122
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    • 2016
  • White organic light-emitting diodes with a structure of indium-tin-oxide [ITO]/N,N-diphenyl-N,N-bis-[4-(phenylm-tolvlamino)-phenyl]-biphenyl-4,4-diamine [DNTPD]/[2,3-f:2, 2-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile [HATCN]/1,1-bis(di-4-poly-aminophenyl) cyclo -hexane [TAPC]/emission layers doped with three color dopants/4,7-diphenyl-1,10-phenanthroline [Bphen]/$Cs_2CO_3$/Al were fabricated and evaluated. In the emission layer [EML], N,N-dicarbazolyl-3,5-benzene [mCP] was used as a single host and bis(2-phenyl quinolinato)-acetylacetonate iridium(III) [Ir(pq)2acac]/fac-tris(2-phenylpyridinato) iridium(III) $[Ir(ppy)_3]$/iridium(III) bis[(4,6-di-fluoropheny)-pyridinato-N,C2] picolinate [FIrpic] were used as red/green/blue dopants, respectively. The fabricated devices were divided into five types (D1, D2, D3, D4, D5) according to the structure of the emission layer. The electroluminescence spectra showed three peak emissions at the wavelengths of blue (472~473 nm), green (495~500 nm), and red (589~595 nm). Among the fabricated devices, the device of D1 doped in a mixed fashion with a single emission layer showed the highest values of luminance and quantum efficiency at the given voltage. However, the emission color of D1 was not pure white but orange, with Commission Internationale de L'Eclairage [CIE] coordinates of (x = 0.41~0.45, y = 0.41) depending on the applied voltages. On the other hand, device D5, with a double emission layer of $mCP:[Ir(pq)_2acac(3%)+Ir(ppy)_3(0.5%)]$/mCP:[FIrpic(10%)], showed a nearly pure white color with CIE coordinates of (x = 0.34~0.35, y = 0.35~0.37) under applied voltage in the range of 6~10 V. The luminance and quantum efficiency of D5 were $17,160cd/m^2$ and 3.8% at 10 V, respectively.

라만 분광학과 분자모델링을 이용한 메탄 및 육불화황 혼합 가스 하이드레이트 성장 거동 연구 (Raman Spectroscopy and Molecular Modeling Study on the CH4 and SF6 Mixture Gas Hydrate Growth Behavior)

  • 임준혁;이주동;박성수;엄기헌;원용선
    • 청정기술
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    • 제19권4호
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    • pp.476-480
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    • 2013
  • 라만 분광학과 분자 모델링을 이용하여 메탄과 육불화황의 혼합 기체 가스 하이드레이트의 성장거동을 연구하였다. 라만 분광학 결과에 의하면 메탄을 객체 가스로 사용할 경우 메탄이 물 분자로 이루어지는 가스 하이드레이트 호스트 구조 내의 큰 동공을 채우고 차례로 작은 동공이 채워지게 되는데 반하여 육불화황을 혼합한 경우 육불화황과 메탄이 경쟁적으로 큰 동공을 채우고 이어 작은 동공에는 메탄만 채워지는 방식으로 전체 가스 하이드레이트 구조가 안정화됨을 관찰하였다. 분자 모델링에 의한 결합에너지 계산 결과 큰 동공의 경우 육불화황은 -26.9 kcal/mol, 메탄은 -24.2 kcal/mol의 결합에너지를 보여 육불화황이 채워지는 것이 약간 더 안정함을 알 수 있었고 작은 동공의 경우 육불화황은 1.2 kcal/mol, 메탄은 -22.0 kcal/mol로 큰 크기의 육불화황이 작은 동공에는 채워질 수 없음을 보여주었다. 이와 같은 접근법은 향후 다양한 객체 기체 가스 하이드레이트의 성장거동을 예측하는데 적용될 수 있을 것이다.

청송 주왕산지역 대전사 현무암의 암석화학적 연구 (Petrochemical study on the Daejeon-sa basalt in the Mt. Juwang area, Cheongsong)

  • 윤성효;이문원;고정선;김영라;안지영
    • 암석학회지
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    • 제9권2호
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    • pp.84-98
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    • 2000
  • 주왕산 화산암체의 최하부층에 해당하는 대전사 현무암층은 전체적으로 12매의 용암과 9매의 페페라이트가 교호하며, 각 용암과 페페라이트의 암층의 두께는 다양하다. 현무암류는 육안으로 반정이 관찰되지 않으며 기공이 없는 치밀한 현무암이지만, 한 단위의 용암층 내에서 상부에는 다공질의 현무암이 발견되기도 한다. 경하에서의 현무암류는 주된 반정 광물로 가상의 감람석을 가지며, 사장석과 단사휘석의 반정도 보인다. 석기는 주로 서브오피틱 조직을 보인다. 대전사 현무암류는 MgO 함량이 4.8∼7.6 wt.%, Al2O3 함량은 16∼18 wt.%, CaO 함량은 9.1∼10.9 wt.%, 그리고 FeOT 함량은 7.4∼8.7 wt.%의 조성을 보인다. TAS 성분도와 SiO2에 대한 K2O의 성분도 그리고, 알칼리지수에 대한 Al2O3의 관계도에서는 칼크-알칼리 현무암에 도시된다. MgO를 분화 지수로한 각 산화물의 변화 경향은 MgO가 감소함에 따라서 Al2O3와 CaO는 증가하며, FeOT 함량은 감소하고, 호정성 원소는 감소한다. 불호정성 원소 중에서 HFS 원소는 MORB값 비슷한 반면에, LIL 원소는 부화되어 있다. 특히 Ce, P, 및 Sm이 약간 부화되어 있으며, Nb는 뚜렷한 부이상을 보인다. 희토류 원소는 전체적으로 부화되어 있으며, HREE에 비해서 LREE가 부화되어 있다. 조구조 판별도에서는. 지판이 침강 섭입하는 지판경제부 영역의 칼크-알칼리 계열 현무암에 도시되고, 특히 Th/Yb에 대한 La/Yb의 상관도에서는 본 현무암류가 대륙연변호 칼크-알칼리 화산대 환경에서 생성되었음을 알 수 있다. 대전사 현무암류의 초생 마그마는 섭입에 따른 유체의 공급으로 쐐기형 상부맨틀을 구성하는 석류석 감람암이 약 15% 부분용융되어 생성된 현무암질 마그마에서 유래되었다. 이들 마그마는 분출되기 직전에 주로 감람석의 분별 정출작용과 지각 물질이 동화되면서 진화된 후, 분출하였다. 필요가 있다.이 높게 나타났다.들을 대상으로 규칙적인 식사의 중요성과 다양한 식품의 섭취를 홍보하는 영양교육 이 보건소를 통해 강화되어야 하리라고 보여진다.인들의 계절별 식품 섭취량에 있어 겨울철의 식품 섭취량이 다른 계절에 비해 유의하게 높았으며, 남자노인보다는 여자노인이 식품섭취에 계절에 의한 영향을 더욱 더 많이 받는 것으로 나타났다. 또한 장수 노인들은 가공식품보다는 계절마다 제철에 생산 되는 자연 식품의 섭취비율이 높았다. 전반적으로 장수노인들은 소식의 경향을 보였으며 이 와 같은 소식습관과 신선한 식물성 식품들의 일상 섭취가 건강한 장수에 영향을 미쳤을 가 능성도 있을 것으로 사료된다.며, 지방 조직내 지방축적에 영향을 미친다는 것을 말해 준다.에서 하는 부모교육과 반상회의 홍보자료에 반상회의 홍보자료에 반드시환경친화적 음식소비행동에 관한 교육이 포함되어야 한다. 조리사의 경우 정기교육과정에 환경친화적 음식소비행동에 관한 홍보를 함께 함으로써 외식이나 단체급식에서 발행하는 음식물 쓰레기의 양을 줄 일 수 있을 것이다.m its genes controlling host specificity to its population sturctures and dynamics, have begun to provide new insights into the potential mechanisms underlying race variation. In this review we aim to provide an overview on (a) the molecular basis of host specificity of M. grisea, (b) the population structure and dynamics of rice pathogens, and (c) the nature and mechanisms of genetic changes underpinning virulence variation

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간모세선충(Capillaria hepatica) 표피의 미세구조 (Ultrastructure of the Integument of Capillaria hepatica (syn. Calodium hepatica))

  • 김수진;민병훈;이행숙;이병욱;주경환
    • Applied Microscopy
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    • 제39권2호
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    • pp.167-173
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    • 2009
  • 간모세선충(Capillaria hepatica)은 설치류와 인간을 포함한 포유류의 간에 모세선충증(capillariasis)을 일으키는 기생선충이다. 성충은 모세관과 같이 대단히 가늘고 길며, 충체의 앞부분에는 stichosome (염주체) 및 bacillary band 등의 구조가 있다. 간모세선충은 설치류를 주숙주로 하며, 여러 지역에서 채집된 야생 설치류에 거의 100% 감염률이 보고되었다. 자연계에 존재하는 감염형 자충포장란은 물과 음식에 포함되어 포유류에 감염된다. 감염된 성충은 충란을 배출한 뒤 간 조직 내에서 사멸하고, 죽은 충체와 충란은 간 조직에서 숙주 면역반응을 유발시킨다. 본 연구에서는 집쥐로부터 충란을 수집하여 마우스에 감염형 자충포장란을 감염시키고. 감염 7주 후에 간 조직에 포함되어 있는 성충을 손상되지 않게 분리하였다. 분리된 간모세선충은 주사전자현미경과 투과전자현미경을 이용하여 충체 표피의 미세구조를 관찰하였다. 분리된 간모세선충은 길이가 약 99mm로 확인되었으며, 충체의 표피에는 cuticle, bacillary band 등의 구조물이 관찰되었다. Bacillary band에는 여러 형태의 pore가 분포하였고, pore는 cuticle을 가로질러 존재하며, cap material의 존재 유무에 따라 bacillary pore의 형태적 차이가 나타났다. 간모세선충은 간 조직내에서 성장하는 특성을 가지고 있으므로 손상되지 않도록 성충을 분리해 내기 어렵고, 이에 따라 충체 외부형태에 대한 연구가 용이하지 않았던 것으로 생각한다. 이러한 간모세선충의 성충을 손상없이 분리하고, 표피의 미세구조를 확인함으로써 아직까지 연구가 이루어지지 않은 간모세선충을 포함한 선충류의 형태에 관한 연구에 중요한 기초자료가 될 것으로 생각한다.

Brief Introduction of Research Progresses in Control and Biocontrol of Clubroot Disease in China

  • He, Yueqiu;Wu, Yixin;He, Pengfei;Li, Xinyu
    • 한국균학회소식:학술대회논문집
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    • 한국균학회 2015년도 춘계학술대회 및 임시총회
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    • pp.45-46
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    • 2015
  • Clubroot disease of crucifers has occurred since 1957. It has spread to the whole China, especially in the southwest and nourtheast where it causes 30-80% loss in some fields. The disease has being expanded in the recent years as seeds are imported and the floating seedling system practices. For its effective control, the Ministry of Agriculture of China set up a program in 2010 and a research team led by Dr. Yueqiu HE, Yunnan Agricultural University. The team includes 20 main reseachers of 11 universities and 5 institutions. After 5 years, the team has made a lot of progresses in disease occurrence regulation, resources collection, resistance identification and breeding, biological agent exploration, formulation, chemicals evaluation, and control strategy. About 1200 collections of local and commercial crucifers were identified in the field and by artificiall inoculation in the laboratories, 10 resistant cultivars were breeded including 7 Chinese cabbages and 3 cabbages. More than 800 antagostic strains were isolated including bacteria, stretomyces and fungi. Around 100 chemicals were evaluated in the field and greenhouse based on its control effect, among them, 6 showed high control effect, especially fluazinam and cyazofamid could control about 80% the disease. However, fluzinam has negative effect on soil microbes. Clubroot disease could not be controlled by bioagents and chemicals once when the pathogen Plasmodiophora brassicae infected its hosts and set up the parasitic relationship. We found the earlier the pathogent infected its host, the severer the disease was. Therefore, early control was the most effective. For Chinese cabbage, all controlling measures should be taken in the early 30 days because the new infection could not cause severe symptom after 30 days of seeding. For example, a biocontrol agent, Bacillus subtilis Strain XF-1 could control the disease 70%-85% averagely when it mixed with seedling substrate and was drenching 3 times after transplanting, i.e. immediately, 7 days, 14 days. XF-1 has been deeply researched in control mechanisms, its genome, and development and application of biocontrol formulate. It could produce antagonistic protein, enzyme, antibiotics and IAA, which promoted rhizogenesis and growth. Its The genome was sequenced by Illumina/Solexa Genome Analyzer to assembled into 20 scaffolds then the gaps between scaffolds were filled by long fragment PCR amplification to obtain complet genmone with 4,061,186 bp in size. The whole genome was found to have 43.8% GC, 108 tandem repeats with an average of 2.65 copies and 84 transposons. The CDSs were predicted as 3,853 in which 112 CDSs were predicted to secondary metabolite biosynthesis, transport and catabolism. Among those, five NRPS/PKS giant gene clusters being responsible for the biosynthesis of polyketide (pksABCDEFHJLMNRS in size 72.9 kb), surfactin(srfABCD, 26.148 kb, bacilysin(bacABCDE 5.903 kb), bacillibactin(dhbABCEF, 11.774 kb) and fengycin(ppsABCDE, 37.799 kb) have high homolgous to fuction confirmed biosynthesis gene in other strain. Moreover, there are many of key regulatory genes for secondary metabolites from XF-1, such as comABPQKX Z, degQ, sfp, yczE, degU, ycxABCD and ywfG. were also predicted. Therefore, XF-1 has potential of biosynthesis for secondary metabolites surfactin, fengycin, bacillibactin, bacilysin and Bacillaene. Thirty two compounds were detected from cell extracts of XF-1 by MALDI-TOF-MS, including one Macrolactin (m/z 441.06), two fusaricidin (m/z 850.493 and 968.515), one circulocin (m/z 852.509), nine surfactin (m/z 1044.656~1102.652), five iturin (m/z 1096.631~1150.57) and forty fengycin (m/z 1449.79~1543.805). The top three compositions types (contening 56.67% of total extract) are surfactin, iturin and fengycin, in which the most abundant is the surfactin type composition 30.37% of total extract and in second place is the fengycin with 23.28% content with rich diversity of chemical structure, and the smallest one is the iturin with 3.02% content. Moreover, the same main compositions were detected in Bacillus sp.355 which is also a good effects biocontol bacterial for controlling the clubroot of crucifer. Wherefore those compounds surfactin, iturin and fengycin maybe the main active compositions of XF-1 against P. brassicae. Twenty one fengycin type compounds were evaluate by LC-ESI-MS/MS with antifungal activities, including fengycin A $C_{16{\sim}C19}$, fengycin B $C_{14{\sim}C17}$, fengycin C $C_{15{\sim}C18}$, fengycin D $C_{15{\sim}C18}$ and fengycin S $C_{15{\sim}C18}$. Furthermore, one novel compound was identified as Dehydroxyfengycin $C_{17}$ according its MS, 1D and 2D NMR spectral data, which molecular weight is 1488.8480 Da and formula $C_{75}H_{116}N_{12}O_{19}$. The fengycin type compounds (FTCPs $250{\mu}g/mL$) were used to treat the resting spores of P. brassicae ($10^7/mL$) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm (A260) and at 280 nm (A280) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be lyzed by the FTCPs of XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol. In the five selected medium MOLP, PSA, LB, Landy and LD, the most suitable for growth of strain medium is MOLP, and the least for strains longevity is the Landy sucrose medium. However, the lipopeptide highest yield is in Landy sucrose medium. The lipopeptides in five medium were analyzed with HPLC, and the results showed that lipopeptides component were same, while their contents from B. subtilis XF-1 fermented in five medium were different. We found that it is the lipopeptides content but ingredients of XF-1 could be impacted by medium and lacking of nutrition seems promoting lipopeptides secretion from XF-1. The volatile components with inhibition fungal Cylindrocarpon spp. activity which were collect in sealed vesel were detected with metheds of HS-SPME-GC-MS in eight biocontrol Bacillus species and four positive mutant strains of XF-1 mutagenized with chemical mutagens, respectively. They have same main volatile components including pyrazine, aldehydes, oxazolidinone and sulfide which are composed of 91.62% in XF-1, in which, the most abundant is the pyrazine type composition with 47.03%, and in second place is the aldehydes with 23.84%, and the third place is oxazolidinone with 15.68%, and the smallest ones is the sulfide with 5.07%.

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