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Search Results: 1 - 10 of 323552 matches for " 王亚品 "
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基于 mean-shift 聚类的高鲁棒性白细胞五分类识别算法
A robust classification method for five types of leukocytes in peripheral blood based on mean-shift clustering

李小舜,曹益平,
- , 2018, DOI: 10.7507/1001-5515.201609067
Abstract: 本文提出了一种新型的基于 mean-shift 聚类算法的人体外周血中白细胞五分类算法,其核心思想是用一种近似人眼的可视化模式对白细胞纹理进行提取。首先利用 mean-shift 聚类算法从白细胞灰度图像中提取一些模式点,然后用其作为区域生长算法的种子点进行区域生长,得到一系列能够在某种程度上可视化地反映纹理的区域块。最后从这些区域块中提取一组参数向量作为白细胞的纹理特征。综合该向量和白细胞形态学特征,用人工神经网络(ANN)成功地完成了对白细胞的五分类识别。用了 1 310 个白细胞图像进行测试,得到中性粒细胞、嗜酸性粒细胞、嗜碱性粒细胞、淋巴细胞、单核细胞的正确识别率分别为 95.4%、93.8%、100%、93.1%、92.4%,证明了该算法的可行性和鲁棒性。
A new leukocyte classification method for recognition of five types of human peripheral blood smear based on mean-shift clustering is proposed. The key idea of the proposed method is to extract the texture features of leukocytes in a visual manner which can benefit from human eyes. Firstly, some feature points are extracted in a gray leukocyte image by mean-shift. Secondly, these feature points are used as seeds of the region growing to expand feature regions which can express texture in visual mode to a certain extent. Finally, a parameter vector of these regions is extracted as the texture feature. Combing the vector with the geometric features of the leukocyte, the five typical classes of leukocytes can be recognized successfully using artificial neural network (ANN). A total number of 1 310 leukocyte images have been tested and the accurate rate of recognition for neutrophil, eosinophil, basophil, lymphocyte and monocyte are 95.4%, 93.8%, 100%, 93.1% and 92.4%, respectively, which shows the feasibility and high robustness of the proposed method.
金银花规范化种植中噻虫嗪安全使用标准的研究
,李勇,董杰,张金良,,丁万隆
中国中药杂志 , 2015,
Abstract: 建立了噻虫嗪在金银花中的残留分析方法,并研究了其在金银花中的消解动态和最终残留量,以及对其安全使用标准进行讨论。采用甲醇超声提取、二氯甲烷液液分配及SPE柱净化后,通过HPLC-UV检测分析。结果表明不同添加浓度下噻虫嗪回收率为84.91%~94.44%,RSD为1.7%~5.0%,满足农药残留检测要求。田间试验采用推荐剂量(90g·hm-2)和高剂量(135g·hm-2)进行处理,2年实验结果表明,农药噻虫嗪在金银花上施用后7d可消解90%以上,半衰期为1.54~1.66d。农药噻虫嗪在金银花中的消解速度较快,噻虫嗪在金银花中的最高残留限量推荐值为0.1mg·kg-1,金银花规范化种植中建议每年施用25%噻虫嗪水分散粒剂剂量在90~135g·hm-2,喷施3次以下,最后一次施药和收获时间的安全间隔期可推荐为14d。
玉米淀粉分支酶基因启动子的克隆与功能分析
柴晓杰,,丕武,张宇,
生物技术通报 , 2006,
Abstract: 以玉米品种“吉糯1号”的基因组DNA为模板,通过PCR扩增得到玉米淀粉分支酶基因的启动子序列,克隆到pMD18-TVector上,经测序,该启动子大小为934bp。与已报道的序列比较仅有14个核苷酸发生改变,同源性为98.5%。用该启动子取代植物表达载体pBI121的35S启动子,与GUS基因编码区连接,构建成融合质粒pSBE-GUS。经农杆菌介导法转化烟草,获得了转基因植株。GUS活性检测结果表明,由该启动子序列引导的GUS基因能在种子中表达,而在其他组织中表达微弱或未表达,证实该启动子具有种子特异性表达的功能。
基于电导率的地沟油快速定性与半定量分析
飞艳,于修烛,吕曼曼,,韩凌霜
食品科学 , 2011,
Abstract: ?以食用油和地沟油为试材,建立基于电导率的地沟油定性与半定量检测方法。探讨油脂种类、温度、振荡时间、水油比对测定结果的影响,确定检测条件,并测定各类地沟油和食用油的萃取水相电导率,并建立食用油与处理后地沟油掺杂定量模型并对模型进行验证。结果表明检测条件为在室温条件下水油比4:1(ml/g)、振荡混合30s、静置分层10min,在此条件下,测得毛地沟油水相电导率为30.15~130.80μs/cm,处理后地沟油水相电导率为22.37~44.61μs/cm,食用油水相电导率为3.18~9.18μs/cm;测定食用油水相电导率大于10μs/cm,可以初步断定其掺伪;模型可实现半定量分析。
我国泥鳅微卫星遗传多样性初步分析
丁海燕?,朱明?,彭冲?,林根妹?,汤志宏?,梅?,杨官
水产学报 , 2015, DOI: 10.11964/jfc.20150409813
Abstract: 为有效管理和合理利用我国的泥鳅资源,用6个微卫星标记分析了安徽(ah)、甘肃(gs)、广东(gd)、广西(gx)、黑龙江(hlj)、江苏(js)和重庆(cq)7个泥鳅群体的遗传多样性。6个微卫星摘自泥鳅微卫星连锁图谱,不存在连锁不平衡,在hlj群体中处于哈代-温伯格平衡,适用遗传多样性分析。结果发现,6个微卫星共检测到69个等位基因,每位点7~16个,有效等位基因数(ne)3.0~5.5个,观察杂合度为0.202~0.408,期望杂合度为0.673~0.820,揭示的多样性信息含量(pic)在0.643~0.796。研究表明,7个泥鳅群体遗传多样性丰富。群体间遗传分化系数(fst)达到0.499,49.9%的变异可归于群体间差异,而fis在0.167~0.421,表明泥鳅群体存在较明显的近交或斑块化分布。聚类分析显示ah、gd、hlj和js聚成一个分支,而cq、gs和gx聚为另一个分支。研究表明我国泥鳅呈现东西向梯度分布并在南北向可能存在扰动。
西瓜钾素吸收特征及钾肥施用优化机制
,,吴萍,陆海燕,周世,董彩霞,任丽轩
南京农业大学学报 , 2018, DOI: 10.7685/jnau.201702028
Abstract: [目的]钾肥管理是西瓜生产的关键因素,对提高经济效益和维持生态环境可持续性具有重要意义,本文旨在研究西瓜的钾素吸收特征及钾肥优化施用的机制。[方法]采用田间试验方法,研究钾肥不同施用水平下西瓜各生育期的干物质量、钾素吸收量、钾素吸收速率以及西瓜的产量与品质。[结果]西瓜对钾素的吸收量与西瓜干物质量、产量和品质存在正相关关系。西瓜在不同生育期对钾肥水平的反应不同,幼苗期对钾肥最敏感,基肥施用量为90 kg?hm-2 K2O时,西瓜根、茎、叶中的钾含量最高,施用量高于180 kg?hm-2 K2O时,西瓜叶中的钾含量低于对照;在膨果期,钾肥追肥量为180 kg?hm-2时西瓜钾素吸收速率最大,该时期的钾素吸收量占全生育期吸收量的67.9%;在成熟期,450 kg?hm-2 K2O水平下西瓜叶片中钾含量最高,600 kg?hm-2 K2O水平下果实皮和瓤中的钾含量最高。钾肥施用量为300 kg?hm-2时,西瓜干物质积累量最大,钾素总吸收量最高,此时西瓜产量最高,且可溶性糖含量最高。[结论]西瓜钾肥施用的最佳方案为基肥施用90 kg?hm-2,坐果期追肥180 kg?hm-2,基肥和追肥的比例为1∶2。
[Objectives]Potassium fertilizer management is the key factor of watermelon production. It is significant on the improvement of agricultural economic efficiency and the development of sustainable ecological environment. [Methods]Field experiment was carried out to investigate dry matter,potassium absorption and absorbing rate,as well as the yield and quality on different levels of potassium fertilizer management on watermelon. [Results]Dry matter,yield and quality of watermelon were positively relative with potassium absorption. Watermelon growth responded to potassium fertilizer on each growing period. Dry matter and potassium content was sensitive to potassium fertilization at seedling stage. Potassium content in root,stem and leaf was the highest at 90 kg?hm-2 K2O fertilization. They were lower in leaf in more than 180 kg?hm-2 K2O treatments than that in control. In fruit expanding period,the potassium absorption rate was the highest at 180 kg?hm-2 K2O level fertilization. The potassium absorption in this period was 67.9% in the plant growing period. In mature period,potassium content in leaf was the highest at 450 kg?hm-2 K2O level fertilization. The potassium content was the highest in both rind and flesh at 600 kg?hm-2 K2O level fertilization. Biomass of watermelon was the highest on 300 kg?hm-2 K2O among all levels of potassium fertilization,as well as potassium absorption,yield and soluble sugar content. [Conclusions]The character of watermelon potassium absorption was that the least absorption in seedling period and the fastest potassium absorption rate in fruit expanding period. Therefore,the optimum management of potassium fertilizer was 90 kg?hm-2 K2O basic fertilizer and 180 kg?hm-2 K2O top fertilizer in fruit forming period. The rate of basic fertilizer to top fertilizer of potassium management was 1:2
醋酸铅作为铅源合成CH3NH3PbBr3-xClx纳米晶体颗粒
Synthesis of Colloidal Perovskite CH3NH3PbBr3-xClx Nanocrystals with Lead Acetate

,,彭路梅,张迪,方艳艳,周晓文,林原,()
- , 2017, DOI: 10.3866/PKU.WHXB201705115
Abstract: 采用醋酸铅作为铅源,成功制备出CH3NH3PbBr3-xClx (MA = CH3NH3,0 ≤ x ≤ 3)发光纳米晶体颗粒。醋酸铅比卤化物铅盐,尤其是氯化铅,能更好地溶解在N'N-二甲基甲酰胺(DMF)溶剂中,解决了卤化物盐溶解度低的问题。在MAPbBr3-xClx中,不同比例的Br/Cl可以产生不同的光谱性质,荧光光谱(PL)可以从399 nm调控到527 nm。所有荧光光谱的半峰宽(FWHM)在20 nm左右,说明色谱比较纯。制备的MAPbBr3-xClx纳米晶体颗粒尺寸分布在~(11 ± 3)nm,可以很好地分散在甲苯中。其中,MAPbBr3纳米晶体颗粒的荧光量子产率(PLQY)高达73%,其平均荧光寿命为97.4 ns。
Lead acetate, which is highly soluble in dimethylformamide, was used to synthesize mixed halide perovskite CH3NH3PbBr3-xClx (MA = CH3NH3, 0 ≤ x ≤ 3) nanocrystals (NCs). This method provides an approach to address the low solubility of lead halides, especially lead chloride. Different Br/Cl ratios in MAPbBr3-xClx lead to various optical properties. The photoluminescence emission peak can be tuned from 399 to 527 nm. Their full-widths at half-maxima (FWHM) are about 20 nm. MAPbBr3-xClx NCs have an average diameter of ~(11 ± 3) nm and have uniform dispersion in toluene. The MAPbBr3 NCs have a long average recombination lifetime (τave = 97.4 ns) and a photoluminescence quantum yield (PLQY) of up to 73%
废弃食用油逆向供应链最优契约模型研究
Research on Optimized Contract Models of Waste Cooking Oil Reverse Supply Chain
 [PDF]

,, 陈嘉成
Management Science and Engineering (MSE) , 2015, DOI: 10.12677/MSE.2015.43009
Abstract: 本文基于第三方物流回收模式,建立两级废弃食用油供应链模型,包含一个生物柴油制造商和一个废弃食用油第三方回收商,利用博弈理论设计了两种供应链契约模型(非合作博弈与合作博弈),通过对两种供应链契约模型进行比较,得出合作博弈下回收数量和系统利润较高的结论。
Based on third party logistics collecting model, a two-level waste cooking oil reverse supply chain (RSC) model involving one biodiesel manufacturer and one third party logistics collector is devel-oped. Optimized supply chain contract models (non-cooperative game and cooperative game) are proposed by employing game theory. These two RSC contract models are comparatively studied. It is found that order quantity and total system profit are larger in cooperative game than in non- cooperative game.
确定地基土先期固结压力pc试验方法的对比研究
吴会东,
铁道工程学报 , 2007,
Abstract: ?研究目的:通过2种试验方法的对比和综合分析,提出用非标准固结试验方法测定先期固结压力的修正方法,提高了试验的生产效率,与铁路客运专线勘察设计工期要求相适应。研究方法:通过对标准和快速固结试验结果分析对比,确定次固结修正法和k值修正法的修正方法,对修正后的结果与标准试验结果进行了误差分析,根据数理统计学原理进行检验分析。研究结果:对比试验数据表明,12h快速固结试验经两种方法修正后,以95%置信度与标准固结试验所得结果无显著差异,试验工期由9d可缩短为5d。研究结论:对比试验研究提高了试验效率,缩短了试验工期,其结果已经纳人了《铁路工程土下试验规程》(tb10102-2004),并被铁路勘察设计系统应用于铁路客运专线工程的土工试验中,有效地缓解了地质勘察设计的工期压力。
朱砂叶螨乙酰胆碱酯酶基因的克隆与特征分析
冯晓姣,卜春,师光禄,,有年,彭博,李金玲,韩晶玉
应用与环境生物学报 , 2014, DOI: 10.3724/SP.J.1145.2014.01051
Abstract: 乙酰胆碱酯酶(ache)是有机磷和氨基甲酸酯类杀虫(螨)剂的主要作用靶标,为建立以朱砂叶螨(tetranychuscinnabarinus)ache为靶点的杀螨剂体外筛选体系,本研究拟克隆朱砂叶螨ache基因,并分析其特征.采用同源基因克隆及race技术克隆基因,通过荧光定量pcr分析其表达特征.结果获得朱砂叶螨ache的cdna序列长为2512bp,其中开放阅读框(orf)为2064bp,编码687个氨基酸,n端有信号肽,剪切位点在甲硫氨酸开始的第74-75个氨基酸残基之间,c端有糖酯锚定结构,genbank登录号为agi96546.1.序列分析显示朱砂叶螨与其他蜱螨目的ache有高度的同源性,特别与同属叶螨属的二斑叶螨(tetranychusurticae)ache的同源性最高,但氨基酸序列比较分析显示两者酶的催化特性可能存在区别.朱砂叶螨不同发育期ache的转录水平比较分析显示幼螨期的表达量最高,且从幼螨期开始表达量逐渐下降,成螨期最低.本研究表明朱砂叶螨与二斑叶螨的ace1有较高的同源性,但酶特性存在差异,朱砂叶螨不同发育时期ace1基因表达水平的不同可能与不同发育期螨的习性和代谢特性有关.图7参20
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