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Search Results: 1 - 10 of 280731 matches for " 李俊钰 "
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印记基因Igf2r和RB-1在代谢综合征不孕患者子宫内膜表达水平的研究
Expression of Imprinted Genes Igf2r and RB-1 in the Endometrium of Infertile Women with Metabolic Syndrome
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,,
Advances in Clinical Medicine (ACM) , 2012, DOI: 10.12677/ACM.2012.24006
Abstract:

目的:研究印记基因Igf2rRB-1在代谢综合征(MS)不孕患者子宫内膜的表达。方法:选择20117月至201112月因不孕症来我院生殖中心就诊的MS患者11例作为实验组,代谢正常女性15例作为对照组,收集分泌期的子宫内膜组织,采用实时定量聚合酶链反应方法(RT-PCR)测定子宫内膜组织Igf2rRB-1的表达水平。结果Igf2rRB-1MS患者和代谢正常妇女子宫内膜中均有表达,与正常女性相比较,MS患者子宫内膜Igf2r

北京周边城市大气污染物对其空气质量的影响
The Impact of Ambient Cities’ Atmospheric Pollutants on Air Quality of Beijing Surrounding Cities
 [PDF]

刘世, 涂斌, 林佳, 于华明
Open Journal of Nature Science (OJNS) , 2016, DOI: 10.12677/OJNS.2016.43034
Abstract:
由于城市空气污染物具有区域扩散性,基于单个城市的空气质量研究具有较大的局限性,所以要从区域角度分析不同城市之间空气质量的内在联系。本文利用相关性分析的方法重点分析了北京地区与石家庄地区相同大气污染物(PM2.5, PM10, CO, NO2, SO2)月平均浓度之间的相关关系,发现两地的CO月平均浓度之间有较强的相关性,SO2月平均浓度之间的相关关系次之,PM2.5月平均浓度之间相关关系最弱。通过对两地区相同污染物之间月平均浓度的相关性分析,进一步阐述了北京周边地区大气污染物扩散迁移对北京地区空气质量的影响,为北京及其周边城市区域大气污染的控制和环境保护政策的制定提供有利建议。
With the regional diffusivity of urban air pollutants, the research of air quality based on single city has great limitation, so it is necessary to analyze the internal relationships of the air quality in different cities from the regional point of view. This paper uses correlation analysis method to mainly analyze the relationships among the same atmospheric pollutants (PM2.5, PM10, CO, NO2, SO2) of their monthly average concentrations between Beijing and Shijiazhuang, which has found that the monthly average concentration of CO has a strong correlation between the two cities; the monthly average concentration of SO2 takes the second place and that of PM2.5 is the weakest. The further elaboration, according to the analysis of the monthly mean concentrations' correlations of the same pollutants between the two regions, tells the effects on the air quality in Beijing caused by the air pollutants diffused from Beijing surrounding areas, which provides favorable proposals for air pollution control and the establishment of environmental protection policy for Beijing and its surrounding areas.
从传播途径优化控制市区铁路噪声
翟国庆,争光,,张邦
环境科学 , 2008,
Abstract: 为控制市区铁路噪声污染,在对铁路噪声影响初步调查基础上,以杭州市区浙赣铁路沿线某拟建小区为例,结合小区规划、环境景观和配套工程设计,从传播途径上提出设置人工土坡、声屏障、绿化等多种降噪措施,合理组合形成若干典型降噪方案,应用Cadna/A软件对各方案的降噪效果做了模拟预测和比选.结果表明,不同方案对预测点的降噪效果最大相差19.4dB,方案二降噪效果最佳,但若只考虑铁路噪声影响,则以方案一为佳.研究成果可为今后市区铁路沿线住宅等建筑的规划及其噪声控制提供参考.
离体条件下雷公藤不定根生长与营养成分消耗动态研究
琰?,琪?,涛?
西北农林科技大学学报(自然科学版) , 2010,
Abstract: 【目的】研究悬浮培养条件下雷公藤不定根营养成分的消耗动态与不定根生长之间的关系,为雷公藤组织培养生产次生代谢产物中培养基的改良及无机元素的及时补充提供参考。【方法】以nt为基本培养基,将雷公藤不定根悬浮培养,每隔5~10d对培养基中碳源、氮源、磷酸盐、钾盐、钙盐、镁盐等营养物质的消耗动态及不定根增长量进行测定。【结果】雷公藤不定根对碳、氮、磷酸盐以及钾、钙、镁等营养物质的消耗并不是均匀的。蔗糖、氮、磷酸盐和钾盐在培养后期几乎被耗尽,其中氮的消耗速率最快,在不定根生长进入对数期以前,氮元素已经开始大量消耗,进入对数生长期后,培养基中的氮源90%被消耗。蔗糖、磷酸盐、钾盐和钙盐的消耗表现为先快后慢,早期吸收迅速,而在快速生长期其消耗速度减慢。细胞停滞生长以后,蔗糖、氮、磷酸盐和钾盐仍有大量消耗。nt培养基中碳、氮、磷、钾在培养的前期已经不能满足不定根生长的需要。雷公藤不定根培养过程中对钙和镁的消耗相对较少,培养结束后培养基中还有48.3%的钙离子和34.2%的镁离子存在。【结论】nt培养基中,碳源、氮源、磷酸盐和钾盐不足是影响雷公藤不定根生长的主要因素。
沼渣施用对土壤线虫群落结构的影响
Effects of biogas residue application on soil nematode community structure

,,孙钦平,刘本生,,吉进
- , 2017,
Abstract: 为了解沼渣施用对土壤生物环境的影响,以土壤线虫为指示工具,通过盆栽试验对比沼渣(BR)、有机肥(OR)、化肥(CF)和不施肥(CK)4个处理下土壤线虫群落结构,评估不同施肥对土壤健康的影响,结果表明:沼渣可极大地刺激r-策略线虫的增长,使得线虫总数高出其他处理。各处理共获得线虫22个属,以食细菌线虫的种类和比例最高,然而不同处理食细菌线虫功能群的组成差异较大,沼渣处理几乎全部为cp值为1的小杆科线虫,有机处理cp1和cp2线虫比例相当,化肥和对照处理则主要是cp2的线虫。植食性线虫在沼渣处理中受到了明显的抑制。利用线虫群落评价不同施肥后的土壤状况,发现施用沼渣的土壤最优,食物网呈结构化,土壤养分富集;而化肥和不施肥对照土壤则表现出一定胁迫的状态。
To identify the effects of biogas residue application on the soil environment,we carried out a pot experiment of four treatments.Which were BR (biogas residue),OR (organic fertilizer),CF (chemical fertilizer) and CK (unfertilized) was conducted.The structure of soil nematode community was analyzed to evaluate the effect of the different fertilizer applications on soil health.Nematodes were classified into four trophic groups:bacterivores,fungivores,plant parasites and omnivore-predators.Nematode ecological indices were used to evaluate soil quality and food webs.These included a maturity index for nematodes with cp2-5 (MI2-5),enrichment index (EI),structure index (SI) and basal index (BI),which were calculated using the online NINJA program.The ratio of fungivores to bacterivores (FB),and the ratio of omnivore-predators to plant parasites (OPPP) were also calculated.The Shannon index (H') and genus dominance (D) were also computed to describe nematode diversity.The results showed biogas residue stimulated populations of enrichment opportunists.The number of nematode found in this treatment was higher than in other treatments.A total of 22 genera were recorded,and bacterivores were dominant in all treatments.However,the composition of bacterivores differed among treatments.Most nematodes observed in BR were cp1 guilds (Rhabditidae),while the proportion of cp1 and cp2 nematodes were approximately equal in OR.In both CF and CK soils,cp2 guilds were the most dominant bacterivores.The relative abundance of omnivore-predators was significantly higher in OR treatments compared with other treatments (P<0.05).Biogas residue application suppressed plant feeders,compared with OR,CF and CK treatments.The maturity index for nematodes with cp2-5 (MI2-5),basal index and fauna analysis consistently showed that adding biogas residue to soil formed the healthiest soil environment compared with other treatments,with a structured soil food web and enriched soil condition.Chemical fertilizer and unfertilized treatments presented stressed soil conditions.The FB index indicated all treatments were bacteria-based decomposition.The OPPP index suggested a stronger control of predatory nematodes on herbivorous nematodes in BR soils compared with
小五台山森林落叶层对天然青杨种群更新方式的影响
霄峰, 胥晓, 王碧霞, 黄尤优, 王志峰,
植物生态学报 植物生态学报 , 2012, DOI: 10.3724/SP.J.1258.2012.00109
Abstract: ?通过野外样方调查和室内种子萌发实验两种方法,对河北小五台山天然青杨(Populuscathayana)种群的更新方式进行了研究,以揭示落叶层的化感作用和机械阻挡作用对青杨种子萌发的干扰机理。结果显示:1)种群样方中的幼苗都为无性繁殖的克隆分株,种子繁殖的幼苗年自然存活率为0%;2)落叶层对种子幼苗的存活率有显著影响。50mg·mL–1浓度的落叶水浸液可使青杨种子发芽率降低41%,使主根长度减少95%,100mg·mL–1浓度的落叶水浸液则完全抑制种子萌发;单层和多层落叶对种子萌发产生的影响差异不显著,都能完全阻碍种子的根系正常生长,导致幼苗脱水干枯死亡。结果表明,在高海拔山区的青杨天然林中,由于不断积累的落叶层通过化感作用和机械阻挡作用严重影响种子的萌发、定根以及正常生长,从而导致种子更新的途径受阻,而只能通过无性繁殖来完成正常的种群更新。
铝胁迫对青杨雌雄幼苗生理生态特征的影响
,胥晓,**,杨鹏,王碧霞,王志峰,霄峰,
应用生态学报 , 2012,
Abstract: 以青杨雌雄幼苗为对象,研究铝胁迫(al3+浓度为216mg·kg-1)下其生理生态特征及光合作用的差异.结果表明:铝胁迫下,青杨幼苗的丙二醛和可溶性蛋白含量显著增加(p<0.001),且雄株的丙二醛显著低于雌株,而可溶性蛋白显著高于雌株;雄株过氧化物酶活性显著增加、超氧化物歧化酶活性显著降低,而雌株无显著变化;雌雄幼苗的光合速率显著降低(p=0.001),雌株的蒸腾速率显著下降(p=0.007)、瞬时水分利用效率显著增加,而雄株均无显著变化;雌株幼苗的叶绿素a含量、总叶绿素含量和叶绿素a/b值显著降低,而雄株的叶绿素a/b值显著高于雌株;雌株的比叶面积显著降低、雄株的比叶面积显著增加,而叶和茎的干物质量无显著变化.与雌株相比,青杨雄株的可溶性蛋白含量、抗氧化酶活性、叶绿素含量和光合速率较高,其抗逆性更强.
中国北方地区植被覆盖度遥感估算及其变化分析
,贾坤,魏香琴,姚云军,,牟丽秋
国土资源遥感 , 2015, DOI: 10.6046/gtzyyg.2015.02.18
Abstract: 为了分析中国北方地区2000年之后植被覆盖度的时空分布及其变化,利用MODIS光谱反射率数据计算归一化植被指数,采用像元二分模型对中国北方地区2000—2012年植被覆盖度进行定量估算,分析研究区13a间植被覆盖度的时空变化特征。研究结果表明:植被覆盖度年内变化特征体现在最大植被覆盖度一般出现在7和8月份,与中国北方地区植被的生长季相一致;整个中国北方地区年最大植被覆盖度呈现缓慢增长的趋势,其增长速率为每年0.2%;年最大植被覆盖度变化的空间分布具有较大差异,其中东北、华北和黄土高原等三北防护林工程建设区的年最大植被覆盖度有较明显的增长。
尕海湿地生态系统土壤有机碳储量和碳密度分布
马维伟,王辉**,黄蓉,,李德
应用生态学报 , 2014,
Abstract: 2011年7月,研究了甘南尕海典型湿地(草本泥炭地、沼泽湿地、高山湿地和亚高山草甸)土壤剖面有机碳分布及其储量.结果表明:4种典型湿地土壤容重平均在0.22~1.29g·cm-3;草本泥炭地土壤有机碳含量明显高于其他类型,其平均值(286.80g·kg-1)约为沼泽湿地、高山湿地和亚高山草甸的2.91、4.99和7.13倍.各类湿地土壤平均有机碳密度为草本泥炭地>亚高山草甸>沼泽湿地>高山湿地,以0~10cm剖面的密度最大;各类湿地土壤剖面的有机碳密度与有机碳含量的变化趋势基本一致,均随土壤深度的增加呈现波动性变化;草本泥炭地、沼泽湿地、高山湿地和亚高山草甸的土壤有机碳均存在0~10和20~40cm两个明显储碳层;其0~60cm深度的土壤有机碳储量分别为369.46、278.83、276.16和292.23t·hm-2.尕海湿地4种类型湿地0~60cm土壤的总有机碳储量约为9.50×106t.
基于ADPSS的电力系统和牵引供电系统机电-电磁暂态混合仿真
徐家,王晓茹,王天,宏强
电网技术 , 2014, DOI: 10.13335/j.1000-3673.pst.2014.07.031
Abstract: 目前在牵引供电系统对电力系统的影响研究中,大多只单一对牵引供电系统建立详细仿真模型,而电力系统侧则是采用简化后的电路代替,缺乏一种实际电力系统与牵引供电系统的联合仿真模型,对电力系统-牵引供电系统的相互作用与影响认识不足。文中在牵引供电系统电磁仿真模型的基础上,基于电力系统全数字仿真装置(advanceddigitalpowersystemsimulator,ADPSS)搭建出了牵引供电系统与实际电网系统的机电-电磁暂态混合仿真模型,并将混合仿真计算结果与典型值相比较,验证了混合仿真的正确性,并研究分析了牵引供电系统负荷特性、牵引供电系统对电力系统的影响。
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