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Search Results: 1 - 10 of 435657 matches for " <br>刘运科 "
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钝体稳焰器尾涡控制研究
丁中涛?,
推进技术 , 1991,
Abstract: 采用流场显示技术观察研究了尾流中加设隔板后钝体尾流的流动稳定特性;在v形钝体后加设隔板,作为火焰稳定装置,测量了其流阻特性,并进行了火焰稳定性能试验.试验研究和讨论了这种简单尾涡控制技术的各种效果.
近64 a来哈密绿洲气候变化特征分析
Analysis on the Characteristics of Climate Change in Hami Oasis in Recent 64 Years
 [PDF]

,
Climate Change Research Letters (CCRL) , 2016, DOI: 10.12677/CCRL.2016.51009
Abstract:
利用哈密国家气象站1951~2014年气温和降水观测资料,运用线性回归、5a滑动平均等分析、Mann-Kendall突变分析等方法对哈密市64a来气温和降水的年际、季节变化及特征进行分析。分析结果表明:1)64a来哈密年平均气温总体呈现缓慢增加趋势,年均气温线性倾向率为0.12℃/10a,20世纪50年代至70年代气温逐渐降低,80~90年代气温维持在气候值,近14a气温明显升高。年内气温变化存在季节差异,冬、春两个季节气温呈上升趋势,夏、秋季的气温呈下降趋势,其中冬季气温对全年气温贡献最大。2)64a来哈密的年降水量呈增加趋势,年均降水量线性趋势率约为2.3mm/10a,50年代年降水量略有下降,60年代年降水量下降明显,70至80年代有所回升,在多年平均值附近,90年代以后降水开始增多,进入21世纪降水增加更加明显。四季降水均呈增加趋势,其中夏季对全年降水量贡献最大,其余各季增加幅度从大到小依次为春季、冬季、秋季。哈密在1987年发生显著性的增温突变,而降水为波动性的变化过程,未出现显著的突变年份。
Based on the observational data of temperature and precipitation from 1951 to 2014 from the na-tional weather station of Hami, the inter-annual and seasonal variation and characteristics of temperature and precipitation in recent 64 years of Hami city are analyzed by using the analysis methods of linear regression, 5-year sliding average, and Mann-Kendall test and wavelet analysis, etc. The analysis results show that: 1) In recent 64 years, the average temperature in Hami reveals a general trend of slow increase, and the linear tendency of the annual average temperature is 0.12?C/10 years. The temperature decreased gradually from 1950s to 1970s, and the temperature between 1980s and 1990s maintained at the climatic value, and the temperature increased ob-viously in recent 14 years. There were seasonal differences on variation of temperature within the year. The temperature in winter and spring showed an upward trend, while it showed an opposite tendency in summer and autumn, and winter air temperature contributed most to the whole year temperature. 2) In recent 64 years, the annual precipitation in Hami shows an increasing trend, and the liner tendency of the annual average precipitation is about 2.3 mm/10 years, and the annual precipitation in 1950s had a slight decrease, and it decreased obviously in 1960s and rose slightly from 1970s to 1980s maintaining around the average for previous years. The precipitation began to increase from 1990s and increased more obviously in the twenty-first century. The whole annual precipitation showed an increasing trend, and the annual precipitation in summer contributed most, and the increasing range of the rest seasons from large to small were spring, winter and autumn. In Hami, a significant change of temperature increase was demonstrated in 1987, whereas perception showed a trend of fluctuation, without any observation of sudden changes.
Biotransformation of Neomycin by Mutational Strain of Streptomyces fradiae Mutagenized with Neutron Radiation
费氏链霉菌中子辐射诱变菌株对新霉素的生物转化

MA Lin,DA W,LIU Yun,SHI Guan-Ying,YANG Qian,YANG Cong-Jun,YANG Ling-Yun,ZHANG Xin-Gang,TAO Ke,HOU Tai-Ping,<br>马林,达娃,,史冠莹,杨茜,杨从军,杨凌云,张新刚,,侯太平
微生物学通报 , 2010,
Abstract: A mutant of neomycin-producer Streptomyces fradiae was obtained from cultures mutagenized with neutron radiation. Utilizing the mutational strain which can not produce neomycin in normal culture, the biotransformation of neomycin was studied at different conversion conditions. The analysis results of fermentation broth by high performance liquid chromatography showed that the culture conditions such as the concentration of substrate, adding time of substrate, adding method of substrate, inoculation amount, the volume of medium, transformation time, carbon sources, nitrogen sources, pH of media and temperature had different influence on neomycin transformation. The transformation products of neomycin were isolated from a large scale fermentation broth by ion exchange chromatography and identified by thin layer chromatography. The antibacterial activity of four purified samples against Staphylococcus aureus, Erwinia carotovora and Pseudomonas solanacarum were tested by bioautographic analysis. All four samples showed obvious inhibitory activity against Staphylococcus aureus and Pseudomonas solanacarum, but only one sample had inhibitory effect against Erwinia carotovora.
Kinetics of Streptomyces fradiae HTP6 in the Batch Fermentation Process
费氏链霉菌HTP6分批发酵动力学

ZHANG Xin-Gang,SHI Guan-Ying,TAO Ke,TENG Yun,CUI Wen-Hu,LIU Yun,QUAN Xin,HOU Tai-Ping,<br>张新刚,史冠莹,,滕 云,崔文华, ,全 鑫,侯太平
微生物学通报 , 2009,
Abstract: 对费氏链霉菌HTP6产新霉素的分批发酵动力学进行了研究, 并建立了动力学模型。对数生长期最大比生长速率μm为0.0866 h-1, 产物合成期最大合成速率qp为1.1867×10-4 g/(mL×h)。对实验数据与模型模拟值进行拟合检验, 表现出很好的适用性, 实验平均相对偏差小于5%。表明该动力学模型对费氏链霉菌产新霉素的发酵生产具有实际意义。
Effects of thinning on fine root biomass and carbon storage of subalpine Picea asperata plantation in Western Sichuan Province, China
间伐对川西亚高山粗枝云杉人工林细根生物量及碳储量的影响

LIU Yun-Ke,FAN Chuan,LI Xian-Wei,LING Yin-Hua,ZHOU Yi-Gui,FENG Mao-Song,HUANG Cong-De,<br>,范川,李贤伟,凌银花,周义贵,冯茂松,黄从德
植物生态学报 , 2012,
Abstract: Aims Fine root carbon storage is an important part of forest ecosystem carbon pools. Our objective was to determine the effects of thinning on fine root biomass and carbon storage in a Picea asperata plantation in Western Sichuan Province, China. Methods We sampled fine roots of a 50 year-old P. asperata plantation thinned by different treatments in August 2010. We excavated soil blocks of 20 cm × 20 cm × 20 cm to sample intact fine root branches of at least the first five branch orders, dissected the intact root branches by order and measured the biomass and carbon storage of each order. Important findings Fine root biomass and carbon storage significantly increased with root order (p < 0.05). The first order roots had the smallest biomass and carbon storage, and the fifth order roots had the largest. Compared with the control, thinning the plantation had significant effects on fine roots biomass and carbon storage (p < 0.05), while the effects of fine roots biomass per plant varied. Thinning treatments of 10% and 20% were not significantly different from the control (p > 0.05). Thinning significantly affected the distribution of fine root biomass in the five root orders. As the thinning intensity increased, the ratio of biomass distribution in the first and second fine order increased. The first order had the largest increase. The ratio of biomass distribution in orders 3 to 5 decreased, and order 5 had the largest decrease. The 50% thinning significantly reduced the fine root biomass ratio in the lower soil layer (20–40 cm), but there was no significant difference compared with 20% and 30% (p > 0.05).
2-D crustal structures along Wuqing-Beijing-Chicheng deep seismic sounding profile
武清—北京—赤城二维地壳结构和构造

WANG Shuai-Jun,ZHANG Xian-Kang,ZHANG Cheng-Ke,WANG Fu-Yun,ZHAO Jin-Ren,ZHANG Jian-Shi,LIU Bao-Feng,PAN Su-Zhen,GAI Yu-Jie,<br>王帅军,张先康,张成,王夫,赵金仁,张建狮,宝峰,潘素珍,盖玉杰
地球物理学报 , 2007,
Abstract: In this paper the crustal velocity structure is obtained along Wuqing-BeijingChicheng profile,using wide angle reflection and refraction data.The results reveal strong vertical and lateral heterogeneities in the crust.The crust has layered features and its thickness gradually increases from 31.0 km in Wuqing to 40.0 km in Yanqing.The strong variation of topography of the crustal interfaces appears around the Beijing area,and the Moho deepens rapidly in the northwestern direction of Beijing area.Five shallow faults in the crust are inferred along this profile,based on the crustal velocity structures and the variations of the crustal interfaces.
CHANGES ON THE HISTOCHEMICAL LOCALIZATION IN THE DEVELOPMENT PROCESS OF PROEMBRYO OF KETELEERIA EVELYNANA MAST
云南油杉原胚发育过程中组织化学的变化

Liu Chengyun,<br>
植物科学学报 , 1989,
Abstract: A primary observation on the DNA, RNA, basic protein, acid protein and polysaccharide at the process of fertilization in the proembryo and early young embryo of Keteleeria evelyniana Mast has been made through histochemical methods. The following results are obtained:The DNA staining reaction was weaker by using Feulgen reation before and after fertilization within the egg nucleus. After formed proembryo and early young embryo, the content of DNA in the nuclei of the initials became normal. The RNA and acid protein contents are rich during the whole development, especially within the embryo initials. However, A-S staining of the basic protein was negative within the neocytoplasm, but the DNA, RNA, acid protein and polysaccharide were positive.
A dynamical diagnosis and analysis of typhoon Abby''s movement
Abby(8305)台风路径的动力诊断分析

Liu Kecheng,<br>
大气科学 , 1989,
Abstract: 根据G.J.Holland关于热带气旋运动的理论,对Abby台风路径作了诊断分析,揭示了台风在其路径的各个阶段的动力特征及其演变。
紫外线对杏鲍菇原生质体的诱变作用
刘海英,,范永山,,先拉
核农学报 , 2011,
Abstract: 对杏鲍菇(Pleurotuseryngii)菌株PL7的原生质体进行了紫外线诱变的研究。结果发现,用20W紫外灯(245nm),在垂直距灯管30cm处照射90s,PL7菌株的原生质体致死率达74%。获得再生菌株234株,其中20株与亲本菌株PL7有明显的拮抗反应,6个菌株菌落生长速度提高11.0%~17.8%,液体培养生物量提高19.3%~32.4%,Rep-PCR分析表现为新的基因型。通过出菇试验,6个菌株较PL7菌株长满培养料天数缩短3~6d,出现原基的时间提前5~8d,第一茬平均产量提高12.5%~40.6%,总生物学效率提高11.1%~32.4%。结果表明原生质体诱变是快速选育食用菌高产新菌株和改善品种性状的重要方法之一。
铽-环丙沙星稀土敏化荧光猝灭法测定叶酸
保生,王云,张彦青,
分析化学 , 2007,
Abstract: 在pH=5.0的醋酸-醋酸钠缓冲溶液中,铽(与环丙沙星反应形成1:2的稳定络合物,其最佳激发、发射波长分别为λex=330nm、λem=545nm。在该反应体系中加入适量叶酸溶液,铽(与环丙沙星络合物的激发、发射波长位置不变,但荧光强度下降。利用这一现象,建立了简单、快速、灵敏的测定叶酸的荧光分析方法。该方法保持了叶酸结构的完整性,叶酸浓度在22~880μg/L范围内符合线性关系;方法检出限为7.8μg/L。用于片剂及胶囊中叶酸含量的测定,结果满意。6次平行测定该方法回收率为93.7%~107.9%,相对标准偏差为0.38%~2.8%。
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