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Study on Joint Method of 3D Acoustic Emission Source Localization Simplex and Grid Search Scanning
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作者 Liu Wei-jian Wang Hao-nan +4 位作者 Xiao Yang Hou Meng-jie Dong Sen-sen Zhang Zhi-zeng Lu Gao-ming 《Applied Geophysics》 SCIE CSCD 2024年第3期456-467,617,共13页
Acoustic emission(AE)source localization is a fundamental element of rock fracture damage imaging.To improve the efficiency and accuracy of AE source localization,this paper proposes a joint method comprising a three-... Acoustic emission(AE)source localization is a fundamental element of rock fracture damage imaging.To improve the efficiency and accuracy of AE source localization,this paper proposes a joint method comprising a three-dimensional(3D)AE source localization simplex method and grid search scanning.Using the concept of the geometry of simplexes,tetrahedral iterations were first conducted to narrow down the suspected source region.This is followed by a process of meshing the region and node searching to scan for optimal solutions,until the source location is determined.The resulting algorithm was tested using the artificial excitation source localization and uniaxial compression tests,after which the localization results were compared with the simplex and exhaustive methods.The results revealed that the localization obtained using the proposed method is more stable and can be effectively avoided compared with the simplex localization method.Furthermore,compared with the global scanning method,the proposed method is more efficient,with an average time of 10%–20%of the global scanning localization algorithm.Thus,the proposed algorithm is of great significance for laboratory research focused on locating rupture damages sustained by large-sized rock masses or test blocks. 展开更多
关键词 acoustic emission simplex form grid search scan locating the epicenter
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'The Theory of Field-Effect Transistors XII.The Bipolar Drift and Diffusion Currents(1-2-MOS-Gates on Thin-Thick Pure-Impure Base)
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作者 揭斌斌 薩支唐 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第7期1227-1241,共15页
The previous report (XI) gave the electrochemical-potential theory of the Bipolar Field-Effect Transistors. This report (XII) gives the drift-diffusion theory. Both treat 1-gate and 2-gate, pure-base and impure-ba... The previous report (XI) gave the electrochemical-potential theory of the Bipolar Field-Effect Transistors. This report (XII) gives the drift-diffusion theory. Both treat 1-gate and 2-gate, pure-base and impure-base, and thin and thick base. Both utilize the surface and bulk potentials as the parametric variables to couple the voltage and current equations. In the present drift-diffusion theory, the very many current terms are identified by their mobility multiplier for the components of drift current,and the diffusivity multiplier for the components of the diffusion current. Complete analytical driftdiffusion equations are presented to give the DC current-voltage characteristics of four common MOS transistor structures. The drift current consists of four terms: 1-D (One-Dimensional) bulk charge drift term, 1-D carrier space-charge drift term,l-D Ex^2 (transverse electric field) drift term,2-D drift term. The diffusion current consists of three terms: 1-D bulk charge diffusion term,l-D carrier space-charge diffusion term,and 2-D diffusion term. The 1-D Ex^2 drift term was missed by all the existing transistor theories, and contributes significantly, as much as 25 % of the total current when the base layer is nearly pure. The 2-D terms come from longitudinal gradient of the longitudinal electric field,which scales as the square of the Debye to Channel length ratio, at 25nm channel length with nearly pure base, (LD/L)^2 = 10^6 but with impurity concentration of 10^18cm^-3 , (LD/L)^2 = 10^-2 . 展开更多
关键词 bipolar field-effect transistor theory surface potential drift and diffusion theory single-gate impure-base double-gate impure-base
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‘纯’和‘净’与紫砂
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作者 吴行其 《陶瓷科学与艺术》 CAS 2011年第12期53-53,共1页
紫砂在很大程度上是要寻求一种,不容许有丝毫瑕疵,如同人们对玉的品质要求一样。
关键词 紫砂壶 '纯’ '净’
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Bohr's Inequality on the Unit Ball B^n 被引量:2
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作者 王建飞 刘太顺 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2007年第2期159-165,共7页
Bohr's type inequalities are studied in this paper: if f is a holomorphic mapping from the unit ball B^n to B^n, f(0)=p, then we have sum from k=0 to∞|Dφ_P(P)[D^kf(0)(z^k)]|/k!||Dφ_P(P)||<1 for|z|<max{1/2+|... Bohr's type inequalities are studied in this paper: if f is a holomorphic mapping from the unit ball B^n to B^n, f(0)=p, then we have sum from k=0 to∞|Dφ_P(P)[D^kf(0)(z^k)]|/k!||Dφ_P(P)||<1 for|z|<max{1/2+|P|,(1-|p|)/2^(1/2)andφ_P∈Aut(B^n) such thatφ_(p)=0. As corollaries of the above estimate, we obtain some sharp Bohr's type modulus inequalities. In particular, when n=1 and |P|→1, then our theorem reduces to a classical result of Bohr. 展开更多
关键词 Bohr's inequality holomorphic mapping homogeneous expansions
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Expression of Kaposi's Sarcoma-associated Herpesvirus ORFK8.1 and Its Preliminary Diagnostic Application 被引量:6
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作者 Bi-shi FU Bao-lin LI +3 位作者 Xin-xing OUYANG Yan ZENG Fan-hong XU Lin-ding WANG 《Virologica Sinica》 SCIE CAS CSCD 2009年第3期202-208,共7页
The ORFK8.1 of Kaposi's sarcoma associated-herpesvirus (KSHV) was expressed in a prokaryotic expression system. The expression of recombinant E.coli containing pQE-80L-orf KS.1 was induced by isopropyl-b-D-thiogala... The ORFK8.1 of Kaposi's sarcoma associated-herpesvirus (KSHV) was expressed in a prokaryotic expression system. The expression of recombinant E.coli containing pQE-80L-orf KS.1 was induced by isopropyl-b-D-thiogalactopyranoside (IPTG). The fusion protein was purified by chromatyography. The expressed protein and its purified product were identified by sodium dodecyl sulfate-polyacrylamide gel eletrophoresis (SDS-PAGE). SDS-PAGE showed that a protein of 26 kDa was visualized as expected. A western blot assay was established to analyze the immunogenicity of purified recombinant ORFKS. 1 protein. The optimal condition of the recombinant ORFKS. 1 ELISA assay was confirmed: the concentration of antigen was 5 μg/mL, the dilution of serum was 1:200. We used the ELISA method to investigate the recombinant ORF KS. 1 protein's specificity, the data showed that the specificity of ORF KS.1 to detect KSHV was 100%. At the same time, 560 sera samples from Hubei province were detected by using ORFKS. 1 ELISA to investigate KSHV seroprevalence in this region. The KSHV seroprevalence in Hubei province is shown to be 6.80%. 展开更多
关键词 Kaposi's sarcoma-associated herpesvirus (KSHV) ORFKS. 1 Enzyme-linked immunosorbent assays (ELISA) SEROPREVALENCE
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The Effects of Natural Capital Protection on Pastoralist's Livelihood and Management Implication in the Source Region of the Yellow River, China 被引量:2
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作者 Fang Yi-ping 《Journal of Mountain Science》 SCIE CSCD 2013年第5期885-897,共13页
The interaction among different livelihood capitals is a key to generate a deeper understanding of the livelihood sustainability.In this paper,we use net income per capita(economic capital),meat and milk production pe... The interaction among different livelihood capitals is a key to generate a deeper understanding of the livelihood sustainability.In this paper,we use net income per capita(economic capital),meat and milk production per capita(physical capital),and areas of fenced pasture,livestock shelter,grassland rodent control and planted grassland(physical capital) as proxy indicators of livelihood promotion,livelihood provision,and livelihood protection respectively.By developing a correlation model between pastoralists' livelihood protection and improvement,we found that(1) there is a statistically significant correlation between the pastoralists' livelihood protection and promotion;(2) based on the maximum effect of pastoralists' livelihood promotion and provision,there is a benchmark in the effect of the intervention intensity of livelihood capital(grassland resource protection) on livelihood improvement;(3) on basis of two indicators,i.e.net income per capita and meat production per capita,the reasonable scales of fenced pasture,livestock shelter and planted grassland are less than 843,860 and 46 thousand hectares(hm2) per year respectively.With the marginal effect of livelihood protection,moderately decreased areas of fenced pasture and planted grassland,and increased area of livestock shelter is a critical to ensure pastoralist's livelihood sustainability. 展开更多
关键词 Regional sustainability Natural capitalprotection Pastoralist's livelihood Source Region ofthe Yellow River
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论李金发诗作“纯诗”品格
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作者 李金英 闫冰 《辽宁教育学院学报》 2001年第7期85-86,共2页
在中国早期象征派诗人中 ,李金发的创作成就是比较突出的。李金发深受法国象征主义诗歌和理论的影响 ,他的诗作表现出强烈的“纯诗”品格。具体表现为语言形式的沟通古今中西 ,打破日常语言后的“新奇怪丽”;思想情感上重视抽象思维和... 在中国早期象征派诗人中 ,李金发的创作成就是比较突出的。李金发深受法国象征主义诗歌和理论的影响 ,他的诗作表现出强烈的“纯诗”品格。具体表现为语言形式的沟通古今中西 ,打破日常语言后的“新奇怪丽”;思想情感上重视抽象思维和理性以及整体的象征。这种“纯诗”品格既表达了诗人对于纯粹艺术的追求 ,造就了不同寻常的艺术效果 。 展开更多
关键词 李金发 ''品格 语言表达方式
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慧琳《一切经音义》纯四等与A类的演变方向
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作者 计丽 杨军 《励耘语言学刊》 2020年第2期31-42,共12页
慧琳《一切经音义》(后简称《慧琳音义》)的纯四等与重纽A类合流已是定论,但两韵合流的演变方向诸家见解不一且鲜少得到系统论证.本文根据慧琳的反切结构分析得出《慧琳音义》的重纽仍为同一个韵的内部对立,A、B两类在没有解散的前提下,... 慧琳《一切经音义》(后简称《慧琳音义》)的纯四等与重纽A类合流已是定论,但两韵合流的演变方向诸家见解不一且鲜少得到系统论证.本文根据慧琳的反切结构分析得出《慧琳音义》的重纽仍为同一个韵的内部对立,A、B两类在没有解散的前提下,A类不可能并入四等,只能是纯四等产生与A类相同的-j-介音后并入了A类,《慧琳音义》中的纯四等不复存在. 展开更多
关键词 四等与A类 反切结构 重纽 演变方向
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Analysis of Zhang Xichun's Academic Thoughts of Using Shanzhuyu(Corni Fructus)
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作者 WANG Zhaohong ZHENG Aihua LIU Hongmei 《Chinese Medicine and Natural Products》 2021年第2期31-36,共6页
Zhang Xichun classifed the collapse syndrome into upper collapse,lower collapse and exterior col-lapse.Based on the therapeutic principle of tonifying the liver and astringing the liver to consolidate collapse,he used... Zhang Xichun classifed the collapse syndrome into upper collapse,lower collapse and exterior col-lapse.Based on the therapeutic principle of tonifying the liver and astringing the liver to consolidate collapse,he used drugs boldly to cure disease.The method of tonifying the liver and astringing sweating is applied to res-cue exterior collapse with Laifu Deoction(来复汤);the method of tonifying the liver and relieving asthma is applied to treat upper collapse with Shenzhe Zhenqi Decoction(参赭镇气汤);the method of restoring yang with emergent treatment is applied to rescue the lower collapse with Jijiu Huiyang Decoction(急救回阳汤).This will provide references for the prevention and treatment of critical diseases for later generations in practi-cing Chinese medicine. 展开更多
关键词 Records of Traditional Chinese and Westem Medicine in Combination(YI XUE ZHONG ZHONG CAN XI LU) Zhang Xichun Shanzhuyu(Corni Fructus) collapse syndrome shock
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Si purification by solidification of Al-Si melt with super gravity 被引量:14
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作者 李京伟 郭占成 +2 位作者 唐惠庆 王志 孙士瞳 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第4期958-963,共6页
The investigation on purification of metallurgical grade silicon by solidification of hypereutectic Al-Si melt with super gravity as an intensified separation way was carried out.The results indicate that the refined ... The investigation on purification of metallurgical grade silicon by solidification of hypereutectic Al-Si melt with super gravity as an intensified separation way was carried out.The results indicate that the refined silicon grains are successfully enriched at the bottom of the Al-Si alloy along the direction of super gravity.Then the refined silicon was collected by aqua regia leaching.The purity of the collected silicon is analyzed as 99.92%,which is obviously improved compared with the purity of the metallurgical grade silicon of 99.59%,proving the feasibility of this purification method.Furthermore,the mass fraction of B is reduced from 8.33×10-6 to 5.25×10-6 and that of P from 33.65×10-6 to13.50×10-6. 展开更多
关键词 super gravity metallurgical grade Si Al-Si melt SOLIDIFICATION PURIFICATION
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Optimization of Preparative Separation and Purification of Total Flavonoids from Radix Puerariae by Macroporous Resin Method 被引量:11
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作者 刘火安 王伯初 +3 位作者 戴传云 邵志勇 何从林 贾云 《Journal of Chinese Pharmaceutical Sciences》 CAS 2006年第2期121-126,共6页
Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separat... Aim To screen the optimum macroporous resin and conditions for the isolation and purification of flavonoids from Radix Puerariae. Methods The static and dynamic adsorption/desorption methods were used, and the separation and purification process was evaluated by measuring the concentration of total flavonoid in the fractions with UV spectrophotometer. Results The SP70 macroporous resin was the most effective compared with other macroporous resins. The optimum conditions were screened, which were 0.5 g· mL^- 1 corresponding to crude drug for concentration of extract, pH 5 - 6, and appended 60 times the volume of the resin bed (BV) with the adsorption speed 2 BV·h^-1, and the volume of aq. 70% (V/V) ethanol as eluant was 5 BV with desorption speed 2 BV·h^-1. By this method, the final contents of total flavonoids exceeded 80%. Conclusion The SP70 macroporous resin is the most effective one for large-scale isolation and purification of flavonoids from Radix Pueraria, which meets industrial needs. 展开更多
关键词 Radix Puerariae total flavonoids macroporous resin SEPARATION PURIFICATION
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Microstructure and texture of commercially pure titanium in cold deep drawing 被引量:6
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作者 张绪虎 唐斌 +3 位作者 张下陆 寇宏超 李金山 周廉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第3期496-502,共7页
The development of microstructure and texture during cold deep drawing of commercially pure titanium(CP-Ti) was investigated.Three parts,stretching region,drawing region and flange region,were sequentially formed in... The development of microstructure and texture during cold deep drawing of commercially pure titanium(CP-Ti) was investigated.Three parts,stretching region,drawing region and flange region,were sequentially formed in the deep drawing process of the hemispheric surface part,with reference to deformation modes and strain regimes.Results show that the plastic strain is accommodated by dislocation slip and deformation twinning in the whole deep drawing process.The texture of the CP-Ti sheet and its drawn part consists of rolling texture component and recrystallization texture component.The intensity and type of the initial texture varied during the drawing process are related to the production of deformation twinning and dislocation slip.Twinning weakens the initial texture by randomizing the orientations of crystals,especially for the recrystallization texture.The recrystallization texture in the drawing region disappears due to the significant forming of twinning.Furthermore,over drawing would result in the predominance of dislocation slip and the texture is strengthened. 展开更多
关键词 pure titanium deep drawing MICROSTRUCTURE TEXTURE
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Effect of electrical current on tribological property of Cu matrix composite reinforced by carbon nanotubes 被引量:9
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作者 许玮 胡锐 +1 位作者 李金山 傅恒志 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第10期2237-2241,共5页
Cu matrix composite reinforced with 10%(volume fraction) carbon nanotubes(CNTs/Cu) and pure Cu bulk were prepared by powder metallurgy techniques under the same consolidation processing condition.The effect of ele... Cu matrix composite reinforced with 10%(volume fraction) carbon nanotubes(CNTs/Cu) and pure Cu bulk were prepared by powder metallurgy techniques under the same consolidation processing condition.The effect of electrical current on tribological property of the materials was investigated by using a pin-on-disk friction and wear tester.The results show that the friction coefficient and wear rate of CNTs/Cu composite as well as those of pure Cu bulk increase with increasing the electrical current without exception,and the effect of electrical current is more obvious on tribological property of pure Cu bulk than on that of CNTs/Cu composite;the dominant wear mechanisms are arc erosion wear and plastic flow deformation,respectively;CNTs can improve tribological property of Cu matrix composites with electrical current. 展开更多
关键词 CNTs/Cu composite pure Cu bulk electrical current tribological property
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Purification of metallurgical grade silicon by electrorefining in molten salts 被引量:5
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作者 蔡靖 罗学涛 +4 位作者 卢成浩 Geir Martin HAARBERG Annabelle LAURENT Ole Edvard KONGSTEIN 王淑兰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第12期3103-3107,共5页
Electrochemical studies on silicon deposition were performed in molten salt electrolytes. Purification of metallurgical grade silicon by electrorefining was carried out in molten Si-chloride salts at temperatures from... Electrochemical studies on silicon deposition were performed in molten salt electrolytes. Purification of metallurgical grade silicon by electrorefining was carried out in molten Si-chloride salts at temperatures from 973 K to 1223 K. It was found that the use of a liquid alloy anode of silicon and copper was beneficial in molten CaCl2 with NaCl, CaO and dissolved Si. ICP-AES analysis results showed efficient removal of metal impurities, such as titanium, aluminum and iron, which are present in significant quantities in the feedstock. The contents of boron and phosphorus in the silicon after electrorefining were reduced from 36×10-6 and 25×10-6 to 4.6×10-6 and 2.8 ×10-6, respectively. The energy consumption of electrorefining was estimated to be about 9.3 kW?h/kg. 展开更多
关键词 ELECTROREFINING molten salt Si-Cu alloy SILICON PURIFICATION energy consumption
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Preparation and characterization of ZrO_2/TiO_2 composite photocatalytic film by micro-arc oxidation 被引量:7
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作者 罗强 蔡启舟 +4 位作者 李欣蔚 潘振华 李玉洁 陈喜娣 严青松 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第10期2945-2950,共6页
ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr(OH)4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope (... ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr(OH)4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and ultraviolet-visible (UV-Vis) spectrophotometer. The composite film shows a lamellar and porous structure which consists of anatase, futile and ZrO2 phases. The optical absorption edge of film is shifted to longer wavelength when ZrO2 is introduced to TiO2. Furthermore, the photocatalytic reaction rate constants of degradation of rhodamine B solution with ZrO2/TiO2 composite film and pure TiO2 film under ultraviolet irradiation are measured as 0.0442 and 0.0186 h 1, respectively. 展开更多
关键词 pure titanium micro-arc oxidation Zr(OH)4 colloidal particle ZrO2/TiO2 composite photocatalytic film
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Structure uniformity and limits of grain refinement of high purity aluminum during multi-directional forging process at room temperature 被引量:5
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作者 朱庆丰 李磊 +3 位作者 班春燕 赵志浩 左玉波 崔建忠 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第5期1301-1306,共6页
The effect of forging passes on the refinement of high purity aluminum during multi-forging was investigated. The attention was focused on the structure uniformity due to deformation uniformity and the grain refinemen... The effect of forging passes on the refinement of high purity aluminum during multi-forging was investigated. The attention was focused on the structure uniformity due to deformation uniformity and the grain refinement limitation with very high strains. The results show that the fine grain zone in the center of sample expands gradually with the increase of forging passes. When the forging passes reach 6, an X-shape fine grain zone is initially formed. With a further increase of the passes, this X-shape zone tends to spread the whole sample. Limitation in the structural refinement is observed with increasing strains during multi-forging process at the room temperature. The grains size in the center is refined to a certain size (110 μm as forging passes reach 12, and there is no further grain refinement in the center with increasing the forging passes to 24. However, the size of the coarse grains near the surface is continuously decreased with increasing the forging passes to 24. 展开更多
关键词 multi-directional forging high purity aluminum structure uniformity grain refinement
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Separation and Purification of Recombinant Hirudin Variant 3 from Bacillus subtilis 被引量:7
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作者 陈华友 齐向辉 +1 位作者 耿旭 徐庆刚 《Agricultural Science & Technology》 CAS 2009年第6期15-19,共5页
[ Objective] The research aimed to get the optimized separation and purification conditions of the hirudin produced from Bacillus subtilis DB403 (pUBH5). [Method] Through the systemic pretreatment, preliminary chrom... [ Objective] The research aimed to get the optimized separation and purification conditions of the hirudin produced from Bacillus subtilis DB403 (pUBH5). [Method] Through the systemic pretreatment, preliminary chromatography and fine chromatography. [Result]The optimized separation and purification conditions were that: Supernatant was treated by trichloroacetic acid, then by ultrafiltration desalt and anion exchange chromatography. Strong anion Q F. F. was better than weak anion DEAE F.F. The proper balanced solution was Tris-HCI ( pH 8.0). The proper conductivity was 6 ms/cm. The maximum applied sample was 240 ATU/ml to matrix of strong anion Q F. F. This optimized procedure was magnified in strong anion exchange HiPrep 16/10Q with the 90% recovery and 70.2% purity. The purification of gel filtration of Sephacryl S-100 to hirudin was not relative to flow rate within certain scope. The application size of sample was 10 ml. The purity checked by HPLC was 95.1%, and the recovery was 93%, and the band of SDS-PAGE was single. [ Conclusion] The research provided the reference of the further industrialization separation and purification of hiruin. 展开更多
关键词 HIRUDIN Bacillus subtilis Ion exchange Separation and purification
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A gradient nano/micro-structured surface layer on copper induced by severe plasticity roller burnishing 被引量:5
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作者 赵婧 夏伟 +1 位作者 李宁 李风雷 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第2期441-448,共8页
In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing (SPRB) and grain refinement mechanism, the microstructure characteristics and mat... In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing (SPRB) and grain refinement mechanism, the microstructure characteristics and material properties of sample at various depths from the topmost surface were investigated by SEM, TEM, XRD, OM etc. The experimental results show that the gradient nano/micro-structure was introduced into the surface layer of over 100μm in thickness. The remarkable increase in hardness near the topmost surface was mainly attributed to the reduced grain size. The equiaxed nano-sized grains were in random orientation and the most of their boundaries were low-angle grain boundaries (LAGBs). The coarse grains are refined into the few micro-sized grains by dislocation activities;deformation twinning was found to be the primary form for the formation of submicron grains;the formation of nanostructure was dominated by dislocation activities accompanied with rotation of grains in local region. 展开更多
关键词 BURNISHING pure copper gradient nano/micro-structure surface nanocrystallization
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Study on Purification and Properties of Antibacterial Substance from Antagonistic Bacteria P72 against Wheat Scab 被引量:12
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作者 裴韬 任大明 石皎 《Agricultural Science & Technology》 CAS 2008年第6期124-126,共3页
[Objective] The study aimed to explore the antibacterial activity and stability of antagonistic bacteria P72 against wheat scab.[Method] The Bacillus subtilis P72 was inoculated into fermentation media with the inocul... [Objective] The study aimed to explore the antibacterial activity and stability of antagonistic bacteria P72 against wheat scab.[Method] The Bacillus subtilis P72 was inoculated into fermentation media with the inoculation amount 5%,then cultured on shaking table at 28 ℃ for 48 h and centrifuged at 8 000 r/min for 10 min.The supernatant of fermentation broth was purified and then the genetic stability,thermal stability and pH stability were detected.[Result] By DEAE-52 ion exchange chromatography,the protein eluted by 0.5 mol/L NaCl solution possessed the strongest antagonistic ability against wheat scab pathogen.The SDS-PAGE electrophoresis showed that the molecular weight of the purified protein with antibacterial effect was 40 kD.By stability test,the antibacterial substance produced by P72 strain showed heritable antagonistic activity,high stability below 60 ℃,stability to acid and unstability to alkali.[Conclusion] The antagonistic bacteria P72 had strong antagonistic ability to wheat scab pathogen,stable antibacterial activity and thermal stability,so it would possess a wide development prospect. 展开更多
关键词 Wheat scab Antibacterial substance Isolation and purification
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Purification and Antimicrobial Activity of Antimicrobial Protein from Brown-spotted Grouper, Epinephelus fario 被引量:5
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作者 张英霞 邹瑗徽 +2 位作者 满初日嘎 周永灿 王世峰 《Zoological Research》 CAS CSCD 北大核心 2008年第6期627-632,共6页
Antimicrobial proteins and peptides had been found from a wide variety of organisms in the last few years These molecules have attracted much research interest because of their biochemical diversity, broad specificity... Antimicrobial proteins and peptides had been found from a wide variety of organisms in the last few years These molecules have attracted much research interest because of their biochemical diversity, broad specificity on anti-viral, anti-bacterial, anti-fungi, anti-protozoan parasites, anti-tumoural, and wound-healing effects. Antimicrobial proteins and peptides play key roles in innate immunity. They interact directly with bacteria and kill them. The brown-spotted grouper, Epinephelusfario, is an important marine fish cultured in southem China. Recently, bacteria and virus have caused high mortality in E. fario cultures, but its endogenous antimicrobial peptides and proteins have not been explored. An antimicrobial component was found from the skin homogenate of E. fario. After the skin homogenate was digested with trypsin, its antimicrobial activity was lost, which showed that the antimicrobial component is a protein. The antimicrobial protein (Efap) was purified from the skin homogenate of E. fario by successive ion-exchange and gel filtration chromatography. Efap was demonstrated to be single protein band by SDS-PAGE, with the apparent molecular weight of 41 kD. Efap exhibited antimicrobial activity both for the Gram-positive bacteria, Staphylococcus aureus, Micrococcus luteus and Bacillus subtilis, and for the Gram-negative bacteria, Vibrio alginolyticus, Vibrio parahaemolyticus, Vibrio fluvialis, Pasteurella multocida, Aeromonas hydrophila, Eschrrichiu coli, and Pseudomonas aeruginosa. Except A. hydrophila, P. aeruginosa, and E. coli (MIC〉20 mol/L), most of the tested Gram-negative bacteria were sensitive to Efap (MIC〈20 mol/L). Interestingly, Efap showed potent antimicrobial activity against Gram-positive bacteria S. aureus (MIC 5-10 mol/L) but comparatively weak antimicrobial activity against M. luteus and B. subtilis. The broad antimicrobial activities of Efap suggest that it contributes to the innate host defence of E. fario. 展开更多
关键词 Epinephelus fario Antimicrobial proteins and peptides PURIFICATION Gram-positive bacteria Gram-negative bacteria
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